Document n9aDm092w5kkV8eJxRdBk4kqz

HENDERSON, HANEMANN & MORRIS MIU* p. HCNOCnON CHARLf* HANKMANN J. MAMA OffAHAM JOIC^H A, ftClLLY, J*. aa*y j. aouoncAux KKVIN J. W(B KMIUC MCLANCON OAVC Mr. William B. Baggett, Jr. A Or(llONAk LAW COAAOAATIOH 900 LArAVtTTB ri**r HOUMA, LOUISIANA 70300 March 12, 1999 HOacnr HOUMA ISOM) a-zoi NKW OALIAM* (BOAI ai-1494 fACBIMIL* isoAj sst-ooao BAGGETT, MCCALL & BURGESS 3006 Country Club Road Post Office Drawer 7820 Lake Charles, LA 70606-7820 RECEIVED MAR 1 B1999 ># Re: Daniel J. and Elizabeth Elaine Ross v. Conoco, Inc., et al. Our File No, 0177.2738708 Dear Mr. Baggett: I am delivering herewith Minnesota Mining and Manufacturing Company's objections, comments, and response to the plaintiffs supplemental request for production of documents, together with copies ofthe documents. By copy of this letter, I am notifying all defense attorneys that they may obtain copies of the documents by requesting them from me. Sincerely, KJW/sb Enclosures F:\2738TCORRESVBAggettl7.doc cc: All Counsel of Record I ELIZABETH ELAINE ROSS, ET AL. VERSUS NO. 90-4837 * CONOCO, INC., ET AL. * 14TH JUDICIAL DISTRICT COURT PARISH OF CALCASIEU STATE OF LOUISIANA MINNESOTA MINING AND MANUFACTURING COMPANY'S OBJECTIONS, COMMENTS, AND RESPONSES TO PLAINTIFFS' SUPPLEMENTAL REQUEST FOR PRODUCTION OF DOCUMENTS Minnesota Mining and Manufacturing Company (3M) makes the following objections, comments, and responses to plaintiffs' supplemental request for production of documents: SJSNEBALgJWfiCJiPMS 3M makes the following general objections, which apply to all seven of the plaintiffs' 1 supplemental requests for production: Insofar as the plaintiffs' requests call for the production of documents that relate to any substance other than vinyl chloride, 3M objects because documents concerning any substance other than vinyl chloride are neither relevant nor reasonably calculated to lead to the discovery of admissible evidence. 3M objeci ts to the requests for production on grounds that they geek to extend the time period for discovery beyond the period set forth by the court in its order ofMarch 12, 1996. All of 3M's responses to the plaintiffs' requests for production are limited to the period 1973 through 1995 to conform with that order. t 3M makes the following general comments, which apply to all sixteen of the plaintiffs' supplemental requests for production: , I 3M makes this response to the plaintiffs' requests for production after a diligent search of its records This search is continuing. 3M reserves the right to supplement its response should it discover additional documents which may be responsive to the plaintiffs' request for production. i i 2. Certain of the documents produced herewith may be responsive to more than one of the plaintiffs' numbered requests. 3 3M has assigned production numbers to the documents which are being produced herewith The production numbers assigned by 3M and the individual numbered request or requests to which 3M believes them to be responsive are: 3M_Ppturotni gtn 3M 110285 - 3M 110291 3M 110293-3M 110317 3M 110320 -3M 110341 3M 110366-3M 110375 3M 110387-3M 110390 3M 110398 - 3M 110435 3M 010111-3M 010112 3M 010523 -3M 010526 3M 105130-3M 105132 3M 105169-3M 105175 3M 105183 -3M 105185 3M 105723-3M 105727 3M 107458 - 3M 107459 3M 107462 3M 107467 - 3M 107469 3M 109721 -3M 109732 3M 110436-3M 110457 3M 110469 -3M 110488 3M 110497 - 3M 110524 3M 110542-3M 110643 3M 110648-3M 110667 3M 110669 - 3M 110674 3M 1106^7-3M 110713 3M II0725-3M 110737 3M 110754-3M 110778 3M 110809 - 3M 110929 3M 111007 ~3M 111107 3M 110398 -3M 110435 3M 110930-3M 110966 No Responsive Documents &qpqtum w 1&2 3 4&5 6& 7 RESPONSES AND SPECIFIC OBJECTIONS 3M makes the following responses and/or specific objections to the plaintiffs' supplemental requests for production: REQUEST FOR PRODUCTION NO. 1; Please produce any notes, memorandum, correspondence, record, mifiutes of meetings, calendar entries, and any other documents with regards to the ISEA (Industrial Safety Equipment Association) and passive dosimeters for any employee and/or officers of 3M, including but not limited to. Bob Weber and James Kvickstad. RESPONSE TO REQUEST FOR PRODUCTION NO. I: See comment No. 3 above REQUEST FOR PRODUCTION NO. 2: Please produce any correspondence, telephone message slips, telephone conversation summaries, or any other documents with regards to the 1SEA (Industrial Safety Equipment Association) and passive dosimeters for any employee and/or officers of 3M, including but not limited to. Bob Weber and James Kvickstad. RESPONSE TO REQUEST FOR PRODUCTION NO, 2: See comment No. 3 above REQUEST FOR PRODUCTION NO, 3: Please produce any written or electronic record, including e-mail, which in any way concerns passive dosimeters and vinyl chloride and/or halogenated hydrocarbons and/or chlorinated hydrocarbons. * RESPONSE TO REQUEST FOR PRODUCTION NO. 3: For written or electronic records that pertain to passive dosimeters and vinyl chloride, please see the documents produced by 3M in its response to the plaintiffs' original request for production. Insofar as the request seeks written or electronic records that pertain to passive dosimeters and any other halogenated or chlorinated hydrocarbons, 3M objects to the request on grounds that it is too broad, vague and general to be susceptible of a categorical response, calls for information which is not admissible or reasonably calculated to lead to the discovery of the admissible evidence, and cannot be answered without imposing undue hardship and expense L upon Minnesota Mining and Manufacturing Company. Without waiving those objections, 3M responds to the request as follows: See comment to No. 3 above. REQUEST FOR PRODUCTION NO. 4: Please produce any notes, memorandum, correspondence, record, minutes of meetings, calendar entries, and any other documents with regards to the SEI (Safety Equipment Institute) and passive dosimeters. RESPONSE TO REQUEST FOR PRODUCTION NO. 4: See comment No. 3 above REQUEST FOR PRODUCTION NO. S: Please produce any correspondence, telephone message slips, telephone conversation summaries, or any other documents with regards to the SEI (Safety Equipment Institute) and passive dosimeters. RESPONSE TO REQUEST FOR PRODUCTION NO. S: See comment No. 3 above REQUEST FOR PRODUCTION NO, 6: Please produce any notes, memorandum, correspondence, record, minutes of meetings, calendar entries, and any other documents with regards to the ASTM Committee D22 on Sampling and Analysis of Atmospheres (including but not limited to Subcommittee designation D22.04 on Methods of Sampling and Analysis ofWork Place Atmospheres). RESPONSE TO REQUEST FOR PRODUCTION NO. 6: None. ' * REQUEST FOR PRODUCTION NO. 7: Please produce any correspondence, telephone message slips, telephone conversation summaries, or any other documents with regards to the ASTM Committee D22 on Sampling and Analysis of Atmospheres (including but not limited to Subcommittee designation 022.04 on i Methods of Sampling and Analysis of Work Place Atmospheres). RESPONSE TO REQUEST FOR PRODUCTION NO. 7; None. .... Kevin | Webb(^l 7857) Henderson, Hanemann & Morris A Professional Law Corporation 300 Lafayette Street Houma, LA 70360 Tel: (504) 868-2081 Attorneys for Minnesota Mining and Manufacturing Company i CERTIFICATE I HEREBY CERTIFY that a copy of the above and foregoing has this day been forwarded to all known counsel of record by placing same in the United States mail, postage prepaid and properly addressed. Houma, Louisiana, this I 3^-- day of jlQ Qa rAy . 1999. F:OT*N>IJXWUq. for Produce I t I I Internal Correspondence Occupational Health and Environmental Safety Division To: R.J. Haggerty - OH&ESD - 275-6W-01 From: R.A. Weber (7-4459) - OH&ESD - 260-3B-09 Subject: ISEA MEETING ON DIFFUSION MONITORS Date: February 14, 1995 BACKGROUND OSHA has requested ISEA to write a validation procedure for diffusion monitors. OSHA representative Bob Curtis indicated that OSHA wants employers to take a more proactive approach to workplace assessments. OSHA believes that if diffusion monitors could be officially validated, employers would more likely perform workplace assessments. Members of the ISEA Gas & Vapor Detection Committee are going to write a Diffusion Monitor Validation Protocol. The protocol will be forwarded to ANSI and ANSI will adopt it as a standard. SEI, a certification branch of ISEA will then use the ANSI standard for their certification process. MEETING HIGHLIGHTS On January 26 and 27, ISEA members, OSHA and other interested parties met to discuss the development of the standard. The following people were in attendance: Bill Emy (ISEA) Gus Manning (Assay Tech) Marshal Parker (Clayton) Katie Spear (MSA) Ralph Bums (Neotronics) Martin Harper (SKC) Rob Roberson (Sensidyne) Victor Elia (National Paper) Skip Elliott (Envirometrics) Alan Ilaid (Pro-Tech) Bob Curtis (OSHA) Rick Lee (OSHA) Warren Hendricks (OSHA) 110285 R.J. Haggerty Page Two February 14, 1995 The goals of the standard are to define performance criteria, develop testing requirements, define terminology and labeling, and finally allow manufacturers flexibility in defining the limits of their diffusion monitors. The committee attempted to define what types of diffusion monitors should be covered by the standard. There was much discussion if electrochemical sensors should be included. It was agreed that for the time being, these types of devices should be excluded because they have unique performance requirements. However, it was agreed that passive direct reading electrochemical air monitors would eventually be part of the standard. Therefore, this standard will not only impact our present line of diffusion monitors, it could also impact our sensor program. We discussed standards that were in existence today that could be used as the starting point for the ANSI document. The performance criteria (i.e., reverse diffusion, capacity, sampling rate etc...) outlined in the NIOSH and CEN documents are the same and the committee agreed that we should include them in our document. Although we agreed on the performance criteria, we did not agree with the test methods that NIOSH and CEN used to evaluate the performance criteria. SKC representative, Martin Harper, presented their modified NIOSH protocol. The SKC protocol included the same performance criteria, however, they modified some of the evaluation procedures. Martin indicated SKC has spent a lot of time and money to validate their monitors according to the NIOSH procedure and at this time, they are not willing to spend more time and money on validating their monitors to a new ANSI standard. I indicated that 3M has just developed their own validation protocol that is a hybrid between the NIOSH and CEN documents and that we will be presenting our views at the AIHC&E. I will be forwarding the protocol to committee members for review as a possible starting point for the ANSI standard. SUMMARY AND COMMENTS 3M 110286 One of the major reasons why the diffusion monitors market never reached its projected size is because OSHA never officially recognized diffusion monitors as a valid sampling device. With the new OSHA exposure assessment standard, OSHA 3M 110287 R.J. Haggerty Page Three February 14, 1995 officials are asking employers to better characterize their workplace by taking more samples on a routine basis. In fact. Bob Curtis indicated that OSHA will be citing more and more people for lack of sampling data. Bob also indicated that if OSHA expects employers to routinely monitor their workplace, they will need a simple, easy-to-use sampling device, like the diffusion monitor. OSHA commitment to this program is indicated by their newly approved protocol for evaluation of direct reading passive monitors (see insert). SEI is going to adopt this protocol as an interim standard for certification. The new ANSI standard that we are developing will then replace this interim standard. In my opinion, this ANSI standard plus the recognition and support by OSHA will help grow the diffusion monitor market not only here in the XJ.S., but also around the world. ' This is an exciting time and a great opportunity for diffusion monitors and I feel that we should take advantage of this opportunity. We need to continue our leadership position. Our next committee meeting will be in 2 to 3 months. RAW:llj/9 Attachment cc: R.A. Bernier - OH&ESD - 76-2E-02 D.C. Breckle - OH&ESD - 275-6W-01 A.R. Johnston - OH&ESD - 260-3B-09 R.E. King - OH&ESD - 260-3B-09 D.J. Larsen - OH&ESD - 260-3B-08 A.C. Murray - OH&ESD - 275-6W-01 J.B. Palazzotto - OH&ESD - 260-3B-08 K.E. Reed - OH&ESD - 260-3A-02 Y.T. Shih - OH&ESD - 260-3B-08 G.H. Smith - OH&ESD - 275-6W-01 L.G. Swope - OH&ESD - 275-6W-01 D.P. Wilmes - OH&ESD - 260-3A-07 _ 3H 110ZSS Internal Correspondence 3M Occupational Health and Environmental Safety Division To: R.J. Haggerty - OH&ESD - 275-6W-01 R.E. King - OH&ESD - 260-3B-09 From: R.A. Weber (7-4459) - OH&ESD - 260-3B-09 Subject: ISEA INSTRUMENT & GROUP MEETINGS Date: June 2, 1995 The ISEA Instrument group had two meetings during the AIHC. The first meeting involved the subcommittee working on the diffusion monitor protocol and the second was the entire instrument group. Review of Diffusion Monitor Subcommittee Meeting The following people were in attendance: Skip Elliott - Environmetrics, Gus Maiming - Assay Technology, Lawrence Locker - Advanced Chemical Sensors, Katie Spear - MSA, Bob Curtis - OSHA, Martin Harper - SKC, Stephen Zlocysti MSA (Auer). The group elected officers; Skip Elliott was elected chairman and I was elected vice-chairman. Stephen Zlocysti, chairman of the CEN committee working on the European diffusion monitor standard gave our group an update on their standard prEN838. This standard is now out for votes and he expected it to be a final standard by the end of the year. Since our last meeting in February, the group has been very active in writing the standard. We reviewed the draft document during this session and in general, we had some lively discussions. Some of the issues involved the following: 1. The types of devices that this standard should cover. Presently, we have settled on three classifications. 3M 110289 Page Two June 2, 1995 2. We discussed the evaluation criteria and we ended up with a consensus on what types of tests need to be conducted. Specifics on sample sizes and testing levels are still open for further discussion. We agreed that we will not include pressure in evaluation criteria and we also agreed that factorial designed experiments may be run as an option. 3. We agreed that the document should contain language or guidance on field evaluations. 4. The document will contain recommendations for manufacturers. This section will include information on quality control programs and labeling. 5. We decided that 25% accuracy would not be a requirement. Accuracies only need to be determined and started. Each member of the committee has specific sections to develop. Draft sections need to be submitted by the end of July. In August the document will be sent out for committee review. If committee finds this draft acceptable, we will then distribute to a field of experts for their comments. These comments will then be reviewed at our next committee meeting. We are scheduled to meet again during the National Safety Congress. Instrument Group Meeting The members of this group are mainly concerned about direct reading instruments. All of the major players in the business are participants in ISEA. Following is a list of items that the committee is actively involved with: ANSI Standard on Detector Tubes, ISA O2 Standard, NFPA306, CEN Instrument Standards, ANSI Z-l 17 Confined Space Standard, OSHA 1910.134 and writing an ANSI Diffusion Monitor Protocol. Although we presently do not have a product that fits into the direct reading sensor market, the meeting gave me an understanding of issues that our competition is dealing with. Page Three June 2, 1995 Summary I walked away from this meeting realizing that there is a maze of instrument and sensor standards that we need to better understand if we ever plan to enter this market. My major objectives in working with this ISEA committee is to assist in writing the ANSI Diffusion Monitor Protocol and to leam about the standards and issues of gas and vapor detection instruments. RAW:llj/45 cc: D.C. Breckle - OH&ESD - 275-6W-01 A.R. Johnston - OH&ESD - 260-3B-09 L.A. Koerschner - OH&ESD - 260-3B-10 D.J. Larsen - OH&ESD - 260-3B-08 A.C. Murray - OH&ESD - 275-6W-01 J.B. Palazzotto - OH&ESD - 260-3B-08 K.E. Reed - OH&ESD - 260-3A-02 Y.T. Shih - OH&ESD - 260-3B-08 L.G. Swope - OH&ESD - 275-6W-01 3M A i:\isea\pg\paasive.min Industrial Safety Equipment Association PRESENT Passive Dosimeter Manufacturers Meeting Thjisgday, ^^^^6^995, and S^giday, Jjmgary7T1995 Doubletree Hotel Salt Lake City, XJT Bob Weber Larry Locker Gus Manning Marshall Parker Skip Elliott William Emy Katie Spear Victor Elia Ralph Bums Bob Curtis Rick Cee Warren Hendricks Allan Aylward Ron Roberson Martin Harper 3M Company Advanced Chemical Sensors Company Assay Technology Clayton Environmental Environmetrics Products Industrial Safety Equipment Association Mine Safety Appliances Company NCASI Neotronics Occupational Safety and Health Administration Occupational Safety and Health Administration Occupational Safety and Health Administration Pro-Tek Sensidyne Inc. SKC 1. CALL TO ORDER The meeting was called to order at 9:10 a.m, . 2. INTRODUCTIONS AND ROLL CALL As the first order of business, each participant introduced himself and explain his interest in the standards development program for passive monitors. A common interest was expressed by the manufacturers in supporting and participating in the development of standard requirements for passive monitors. OSHA explained that through the establishment of a reliable validation method, they could more readily consider the use of passive monitors by OSHA field compliance officers in obtaining a broader range of exposure data, providing a better characterization of workplace exposure. Bill Emy gave a brief presentation on the ISEA. Bill explained that ISEA is the leading national association of personal protective equipment manufacturers and is organized into the following thirteen product group categories: Clean Room Eye and Face Protection Flammable Containers Emergency Eyewash and Shower Fall Protection Industrial First Aid Passive Dosimeter Manufacturers Meeting 3M 110293 i i:\iaea\pg\paasive.nun Industrial Warning Devices Head Protection Respiratory Protection Safety Wearing Apparel Instruments Hearing Protection Respiratory Protective Escape Devices The mission of the ISEA is to support its members in manufacturing and marketing the highest quality products to protect the safety and health of workers. ISEA does this by: acting as the industry voice promoting standardization of personal safety products representing the industry before government bodies providing timely information to members for use in making important business decisions promoting the proper use of PPE as essential to worker safety and health providing a forum for members to meet and discuss common industry-related issues Bill Eray explained that as an American National Standards Institute (ANSI) accredited standards developer, ISEA provides a forum for manufacturers to develop product performance standards through the ANSI program. Bill Emy reported that ANSI has given a verbal "green light" for ISEA to initiate a standards program for passive monitors. When initiated, ANSI which will announce the project in its "Standards Action" publication requesting public comment and interested parties who wish to be included on the review list. Bill Emy explained the requirements of participants and noted that this would be the last meeting as an open forum. All future meetings will be open to ISEA members and eligible participants only. ISEA will send a membership ballot to interested parties before March 1. Others industry experts may be invited to participate at the discretion of the Committee including non-manufacturers who have been identified as having significant knowledge and experience in the field of interest and who would significantly add value to the standards program. . Manufacturers who choose not to join the ISEA but wish to participate in the standards development program may do so on a per meeting basis and are charged a per meeting fee of $375.00 to help cover meeting expenses and administrative costs. In addition, non-ISEA member participants are required to share in project expenses incurred during the course of work, such as the purchase of technical documentation and the conducting of testing programs. Eligible non-member participants can vote on committee meeting issues but not on ISEA issues including the final approval of the standard for submission to ANSI. 3. PRODUCT CERTIFICATION Martin Harper reported on the recent establishment of an ASTM workplace atmosphere program, D2206, chaired by Richard Deanchick of Alcoa. NIOSH representatives Dave Barly and Gene Kennedy are participating. It was suggested that a possible joint venture program between ANSI and ASTM should be explored. Bill Emy was requested to contact ASTM and NIOSH to research the issue further and report back to the committee at the next meeting. Passive Dosimeter Manufacturers Meeting 3M 110294 2 i:\isea\pg\passive.min The attached news release, published in the SEI Update, was distributed to participants announcing the approval by the SEI Board of Directors to initiate a certification program for direct reading passive monitors. SEI will use an OSHA reviewed/ modified NIOSH protocol to conduct certification testing. When complete SEI would adopt the ANSI standard. Attached is the letter from OSHA to SEI regarding OSHAs review of the SEI protocol. Bob Curtis noted that OSHA expects to consider SEI-certified passive monitors for use by OSHA field officers by March 1. 4. PASSIVE MONITOR STANDARDS DEVELOPMENT PROGRAM The Group discussed the need for standardization. It was stated that standardization is required to provide product credibility by establishing a consistently reproducible test procedure to verify a product's performance as claimed by the manufacturer. The following goals of the standards program were identified: to facilitate the characterization of workplace exposures to provide accurate information to users to establish minimum performance based criteria to establish standardized test conditions and test methods for product evaluation to validate a manufacturer's claims to encourage innovation to encourage multiple suppliers/competition to standardize terminology and facilitate understanding The scope of the standard was discussed, including the consideration of electro chemical sensor technology. The Group noted the wide differences between the two technologies and the resulting differences in the appropriate evaluation methods that would need to be developed. The Group concluded that electro-chemical sensors will not be considered at this time but could be added later. Furthermore, the Group concluded that the following types of technology will be excluded from this project at this time: electro-chemical sensors direct reading short-term color tubes length of stain-pump required (active) * . .. As a result, the Group developed the following scope of technologies to be included under the ISEA passive monitor standards program: passive monitoring devices--no active pump required-diffusive sampler no user calibration required Type A-Direct Reading/Color Change (field analysis assay) Type B-Laboratory analysis The following suggested elements to include in the standard were identified: laboratory requirements/accreditation criteria for extrapolation to similar compounds manufacturer's statement of effective operating ranges accuracy limits versus validation manufacturers' claims Passive Dosimeter Manufacturers Meeting 3H 110295 3 i:\isea\pg\paaaive.min Q.A. program requirements manufacturers product use instructions/limitations--standardized presentation of information re-test requirements-changes to form, fit, or function specify compounds tested to tolerances on testing conditions (AT) test orientation test apparatus specifications-reference test methods in Appendix separate PEL and STEL tests The Group discussed the potential to include criteria for extrapolation of test data to similar compounds. It was suggested that a peer-review group could be established to evaluate and approve a manufacturer's request for extrapolation. The manufacturer would be required to submit justification and rationale. The peer-review group could be established as an ANSI standing committee or as a part of a certification program. It was discussed that an accuracy requirement of 25% is established by the NIOSH protocol. It was noted that the significance of accuracy depends greatly on the application and levels of exposure. It was recommended that that accuracy may be better driven by market forces rather than through mandated requirements. At this time, the Group determined that accuracy requirements may not be needed, but should be re-addressed at a later date. ; Requirements for Type B, laboratory analyzed monitors, were discussed. It was suggested that laboratory performance requirements should be included within the standard. Two different approaches were suggested: (1) Spell out specific laboratory requirements; or (2) require laboratory accreditation. The group determined that more discussion was needed on this issue. The Group identified the following suggested performance criteria to be included into the standard: analytical recovery reverse diffusion face velocity/wind effects factorial detection limit rate and capacity storage stability/shelflife temperature effects accuracy/precision The following "parked issues" were identified: ANSI versus ASTM/ANSI joint program list of standards reviewers/list of canvasses industry experts involvement of NIOSHZEPA/MSHA define a minimum performance level (box) or verify a manufacturer's claims statement of product limitations specific quality assurance requirements third-party certification extent of test apparatus specifications and reference methods Passive Dosimeter Manufacturers Meeting 3H 110296 4 i:\isea\pg\pasaivo.imn The following suggested format was developed: Section Number I II III IV V VI VII Heading Introduction Scope and Purpose Definitions of Terms Classification Technical Parameters Extrapolation Criteria Truth in Labeling The following action items were assigned: Section I-Gus Manning, Katie Spear, and Bob Curtis Section II-Skip Elliott, Rich Cee Section II-Skip Elliott, Martin Harper, Rich Cee Section IV-Martin Harper Section V-Gus Manning, Katie Spear Bill Erny was assigned to research ANSI requirements for the use of draft standards and inquire the level of interest of NIOSH/EPA. Martin Harper was assigned to inquire into the level of interest of the following user groups: Dupont Romm and Haas Chevron Exxon Shell - 5. OTHER BUSINESS Bob Weber expressed his interest in acting as Committee chairman. Committee members will be requested to vote on this issue at the next meeting. 6. NEXT MEETING , The next meeting was scheduled in accordance with the ISEA Instruments Group meeting in conjunction with the American Industrial Hygiene Conference and Exposition (AICHE) in Kansas City, Mo., on May 21. More specific details regarding the meeting place and time will be announced at a later date. 7. ADJOURNMENT There being no further business to come before the meeting, a motion to adjourn was adopted at 12:35 p.m. Manager of Product Groups Passive Dosimeter Manufacturers Meeting 3M 110297 6 i:\isea\pg\pms.min Industrial Safety Equipment Association MINUTES Passive Monitor Standards Committee of the Instruments Group Sunday, May 21,1995 Kansas City Marriott ISEA MEMBERS PRESENT Envirometrics Products Co. 3M Company Mine Safety Appliances OTHERS PRESENT Advanced Chemical Sensors Advanced Chemical Sensors Assay Technology AuergeseUschaft/Germany Clayton Environmental Dow Chemical Company OSHA/SLTC SKC Inc SKC Inc Webster, Chamberlain & Bean ISEA PRESIDING Skip Elliott Bob Weber Katie Spear Laurence D. Locker Hannah Johnson Gus Manning Stefan Zloczysti Marshall Parker Rolf M.A. Hahne Bob Curtis Martin Harper Lloyd Guild David Goch Bill Emy Skip Elliott, chairperson 1. CALL TO ORDER The meeting was called to order at 1:05 p.m. As first order of business, Bill Emy explained that ineligible ISEA members are permitted to participate in standards development projects on an invitational basis. The standards committee must approve by a simple majority their participation. If the ineligible ISEA member participant charges a consultation fee, the fee is charged as a Group expense and distributed evenly among Group members. Dave Goch explained committee procedures of the ISEA Product Groups. Meetings are conducted in accordance with the Robert's Rules of Order. 2. ELECTION OF COMMITTEE OFFICERS Nominations for Committee Chairman and Vice Chairman were requested. Skip Elliott, President of Envirometrics Products Company (EPC), was nominated as Chairman Passive Monitors Standards Committee 1 3M 110298 August 3,1996 i:\isea\pg\pms.min and Bob Weber of the 3M Company was nominated as Vice Chairman. The voting concluded with 6 affirm, 0 oppose, and 1 abstain for both positions. 3. REVIEW OF DRAFT 5/95 STANDARD As a result of the last meeting in Salt Lake, a draft standard for passive air sampling devices was developed. Copies of the first draft, dated 5/95, was distributed to meeting participants for review. The purpose of the standard was stated as setting performance parameters, minimum acceptance criteria, and manufacturer reporting requirements for diffusion type sampling devices used to determine concentrations of toxic gases and vapors in working environments. The Group set a completion deadline for a final draft for the beginning of the forth quarter of this year. The Group began a section by section review of the draft standard. Several parked issues were identified from the last meeting. The first being the establishment of a list of potential ANSI canvassees to include in the review and balloting in accordance with ANSI procedures. It was suggested that an educational campaign be initiated subsequent to canvassing to gain wide support for this new approach in validating passive devices. It was concluded that a "peer review group" should be developed conducted initially. All Committee members were requested to submit a list of peer reviewers to ISEA before the end of July. Additionally, Committee members were requested to review the preliminary list of ANSI canvassees included in the foreword of the draft standard and develop suggested revision for Committee consideration keeping in mind umbrella organizations. The group discussed the need for section 11, Rationale. It was stated that some explanation of why the standard was developed is needed to gain a broad range of understanding and acceptance from the industry. It was noted that this type of explanation is typically included in the foreword. Section 11.2, Goal and Objectives, was noted as duplication of sections 1.1 and 1.2, Purpose and Scope. Skip Elliott was assigned to combine section 11.2, into sections 1.1 and 1.2 for review at the next meeting. It was also requested to delete sections 11,1 and 11.2 and move Section 11.3 to the appendix. Gus Manning was assigned to draft a statement for item 3 under section 1.3 excluding continuous reading monitors from the scope of the standard. Also a definition for sorbent will be included in section 4. The Group was requested to review all definitions and submit any suggested changes to ISEA before the next meeting. The Level II classification was discussed. It was requested that Bill Emy check with ANSI regarding the merit of establishing an ANSI Standing Committee, chartered to evaluate and approve a manufacturer's claim for extrapolation of an analyte or a group of analytes, based on level I compliance of a similar analyte. Under this scenario, the manufacturer would be required to submit a disclosure including rationale for his request. If a third-party certification program is established for these devices, the third-party certification program would include a process to evaluate level II devices. It was suggested to include level II evaluation criteria in the appendix of the standard for guidance. Martin Harper was assigned to draft a section for Group review at the next meeting. Passive Monitors Standards Committee 2 3H 110299 August 3,1995 i:\isea\pg\pms.min The Group discussed section 5, Evaluation Program and Parameters. It was suggested that a factorial evaluation option be included an it was suggested that the European protocol be used, excluding the boundary conditions. Martin Harper was requested to draft language for Group review at the next meeting. Martin Harper was requested to draft shelf storage requirements. It was suggested that the European standard be used as a guide. Bob Weber was requested to draft field evaluation criteria for Group review at the next meeting. Gus Manning was requested to combine all reporting, marking and labeling requirements of section 6 and 10. It was suggested that the labeling of Type C monitors require that Type C monitors be submitted to an accredited laboratory for analysis and Type B monitors require a defined calibration protocol. In summary it was requested that all assignments be submitted to ISEA by July 31. 4. COMMITTEE ASSIGNMENTS Martin Harper reported on ASTM standards activity. The goal of the ASTM atmosphere monitoring committee is to develop an ISO standard and Dave Barley, chairman, has NIOSH funds to review the NIOSH protocol to use as a strawman. It was suggested that a joint effort could be pursued between ANSI and ASTM. However, the Group decided to continue with the ANSI program in a separate and parallel path to ASTM. Martin Harper was selected as the ISEA liaison ton ASTM. Martin and Skip Elliott were assigned to do a comparison between ANSI and ASTM standards. Stefan Zloczysti was introduced to meeting participants as the chairman of the European standards committee for atmosphere monitoring devices, CEN/TC-137. Stefan explained that their committee initially considered pursuing an ISO standards but decided not to, due to the length of time to complete such a program. Stefan announced that the CEN standard is currently out for ballot and is expected to be published by the end of this year. Their next meeting is scheduled for October in Brussels. Stefan stated he would send a copy when compete to the ISEA Rolf Hahne Safety Director of the DOW Chemical Company gave a user's perspective on the need for effective and reliable passive samplers and expressed a need for a standard protocol to validate them. Rolf stated he would inquire at the Chemical Manufacturers Association, CMA into interest in supporting the development of a validation standard. Martin Harper will act as the point of contact an report back at our next meeting. 5. NEW BUSINESS It was announced that SEI has issued its first passive air sampling badge certification to EPC. Bob Curtis of the OSHA Salt Lake Technical Center noted that OSHA has recognized the SEI certified badge for use by OSHA Compliance Officers through its Chemical Information File. 3M 110300 Passive Monitors Standards Committee 3 August 3,1995 i:\isea\pg\pms.min 6. NEXT MEETING ` The next meeting is scheduled for Sunday, November 5,1995 in conjunction with the National Safety Show, Dallas Texas. 7. ADJOURNMENT There being no further business to discuss, a motion to adjourn was accepted at 5 p.m. Respectfully submitted, William J. Emy Technical Director Attachment Passive Monitors Standards Committee 4 3M 110301 August 3,1995 i:\isea\pg\in.min Industrial Safety Equipment Association MINUTES Instruments Group Meeting Thursday, May 25,1995 Kansas City Marriott at Allis Plaza Kansas City, MO MEMBERS PRESENT Air Liquide America Biosystems IncL Envirometrics Products Co. Gas Tech Inc. 3M Company Mine Safety Appliances Neotronics Margarita Porto Robert Henderson Skip Elliott Bruce Holcom Bob Weber Ken Acer Ralph Burns MEMBERS ABSENT Scott Aviation A Perry OTHERS PRESENT Air Liquide America Bacharach Inc. RKI Instruments Inc. Webster, Chamberlain & Bean ISEA Emerson Todd Mark Coppler Bob Pellissier Art Herold BillEmy PRESIDING Robert Henderson, chairman 1. CALL TO ORDER The meeting was called to order at 9:00 a.m. As the first order of business, Chairman Henderson introduced three new Instruments Group members: Skip Elliott of Envirometrics, Margarita Porto ofAir Liquide America, and Bob Weber of 3M. Also, two potential members were introduced: Mark Coppler of Bacharach Inc. and Bob Pellissier of RKI Instruments Inc. 2. CONSIDERATION OF MINUTES OF NOVEMBER 12,1995 The meeting minutes of November 17,1995 were approved as presented. Instruments Group 1 May 25,1995 3M 110302 i:\isea\pg\in.mjjj ANSI/ISEA102-1990 " Bill Emy reported that ANSI/ISEA 102-1990, "American National Standard for Gas Detector Tube Units," is due for review in accordance with the 5-year review policy of the American National Standards Institute. Ken Acer was assigned to lead the revision effort Bill Emy was assigned to request an extension ofANSI. 4. DRAFT ISA/NEC UPDATE Mark Coppler, Chairman of ISA 1213, reported on the ISA Combustible Gas Committee. The Combustible Gas Standard, ANSI/ISA 1213 was reviewed in February and has been submitted to the program committee for review and approval as an American National Standard. The ISA "Recommended Practice" is up for review in 2 years. The committee has begun their initial review. An important new issue is the impact ofnew technologies. It was reported that the ISA standards for toxic gases (CO, NH3, Cl, Ox), are out for ballot approval. Comments will be considered at ISA's next meeting in June in Tucson, AZ. Bruce Holcom volunteered to act as ISA liaison to the Instruments Group. Bruce was requested to submit copies of the toxic gas standards to ISEA for circulation to members of the Instruments Group. It is expected they will be approved as final by the end of 1995. Chlorine was identified as a potential controversy due to a proposed protocol to produce concentrations of Chlorine to tight tolerances. . 5. NFPA306 Ken Acer reported that NFPA 306 is due for review by the end ofFall. Two important issues are the oxygen deficient requirement of 22% which conflicts with the 23.5% OSHA Confined Space requirement and calibration before and after use issue. It was suggested that the Group make a dear recommendation to the NFPA 306 Committee to establish consistent criteria. Bill Emy was requested to send out copies of306 to Group members for review and comment. 6. OTHER STANDARDS ACTIVITIES Mark Coppler reported that a draft ISA standard has been developed on generic performance criteria for toxic gas monitors. ISA 9207 would include requirements for monitors covered by ISA standards 9201 through 9206. The project was motivated by CEN TCI16/137 which has developed a similar document. 7. CEN STANDARDS It was discussed whether a published comparison exists between CEN and U.S. standards and whether the Instruments Group should take on such a project if none exists. Mark Coppler noted that a project has been undertaken by the ISA Bruce Holcom volunteered to report back to the Group on future ISA project activity. No Group action was determined at this time. Instruments Group 2 May 25,1995 3M 110303 i:\isea\pg\in.min 8. PASSIVE MONITORS SUBCOMMITTEE REPORT _ ' Bill Emy and Skip Elliott reported on recent activity of the passive monitors subcommittees (PMS). The PMS had their second meeting on Sunday afternoon. The objective of the PMS is to develop standard validation procedures for passive diffusive sampling devices and publish as an American National Standard. Skip Elliott has been elected as chairman and Bob Weber as Vice Chairman. The next meeting of the passive monitors subcommittee is tentatively scheduled in conjunction with the National Safety Show in Dallas which runs from November 6-8. A specific meeting date will be announced later. 9. CONFINED SPACE STANDARD, ANSI Z117 Bill Emy and Bob Henderson reported the results ofballoting Z117. It was explained that ISEA's comment regarding the definition of "entry" into a confined space was rejected. As a result, ISEA voted against the standard as written. ISEA requested that an entry be defined when "any part of the body" of an entrant breaks the plane of a confined space in accordance with OSHA regulations. The approved language defines an entry when any part of an entrant's face breaks the plane. Attached to these minutes is the Z117 Committee rationale for rejecting the ISEA suggestion which in part uses the 1994 NIOSH publication "Worker Deaths in Confined Spaces" as support documentation. The Group determined that no further official appeal action would be initiated at this time. However, Bill Emy was requested to contact ANSI to ensure our comments were received and recorded. 10. OSHA PROPOSED RESPIRATORY RULE, 29 CFR 1910.134 Bob Henderson reported that comments were submitted on behalf ofboth the ISEA Respiratory Protection and Instruments Groups. Specifically the Instruments Group raised concern over the fact that OSHA has removed a requirement for continuous CO monitoring on oil lubricated compressors. ISEA comments recommended the ANSI Z88.2-1990 requirements (see attached) that requires periodic sampling as directed by the program administrator. It was noted that ISEA has historically supported OSHA's adoption of Z88.2 in their regulations. Bill Emy reported that the OSHA public hearings are scheduled from June 6-20. ISEA is scheduled to present testimony on June 14. 11. AIHA GAS AND VAPOR DETECTION COMMITTEE It was reported that NIOSH is currently drafting standards on CO, H2S and Tritector monitor performance. Mary Woebkinberg ofNIOSH-Cindnnati is the project group leader. Bruce Holcom was assigned to contact NIOSH and collect specific information for Group distribution. A passive monitors round table is scheduled for Friday and is being chaired by Martin Harper of SKC Instruments. Ken Acer is attending and was requested to report the results of their discussion to the Group before the next meeting. A round table on "Emergent Technologies," chaired by Steve Day is scheduled for the Fall. Bob Henderson was requested to pass on the minutes as soon as they are available. Instruments Group 3 3H 110304 May 25,1995 i:\isea\pg\in.min 12. AIHA CONFINED SPACE COMMITTEE ,,' Bob Henderson reported on the meeting that transpired on Monday, May 21. The mai^ topic of discussion focused on performance characteristic and calibration requirements of sensors used in confined space applications. Bob was requested to pass along the official meeting minutes as they become available. It was suggested that the Instruments Group should put together a position paper on calibration frequency ofinstruments used in confined space applications. It was noted that the need for such information is paramount to end users. A cutoff date ofJune 15 was established for submittal of Group comments to ISEA. All comments will be circulated to Group members and a position paper will be developed. 13. NEW BUSINESS An overview ofoutside representation identified the following: Bruce Holcom Ken Acer Bob Henderson Bob Weber ISA, NIOSH NFPA306 AIHA Gas & Vapor Committee AIHA Respiratory Committee 14. NEXT MEETING The next meeting of the Instruments Group is scheduled in conjunction with the ISEA Mid-Year Meeting which is held from November 13-15 at the Ritz-Carlton Pentagon City, Arlington, Virginia. The specific meeting time, room location and agenda will be presented at a later date. 15. ADJOURNMENT There being no more business to discuss, the meeting was adjourned at 10:25 a.m. Respectfully submitted, Attachment William J. Emy Technical Director Instruments Group 4 May 25,1995 3M 110305 ANSI 288.2-1992 Table 4 - Periodic air sampling guidance for compression Type/sample Water vapor CO Condensed hydrocarbon C02 Odor Oil lubricated X X X X Non-oil lubricated X X Combustion engine powered X X X X X NOTES 1 When using air compressors, intake location shall be carefully selected and moni tored closely to ensure air supplied to the compressor is of adequate quality. 2 No frequency for periodic checks of air quality is specified, due to wide variation in equipment type, use and working environments, and operating experience. 3 Continuous monitoring of temperature and carbon monoxide are not required. 4 For non-oil lubricated compressors that operate at less than 35 psi, no sampling for water is required. 5 These requirements apply to systems designed for breathing air, other air-supply sys tems need to be evaluated on a case-by-case basis for the type and frequency of testing. 10.5.4.2 A compressor shall be constructed so as to avoid entry of contaminated air. For all air compressors, including portable types, the air intake location shall be carefully selected, and monitored closely to ensure continued quality of air supply to the compres sor. The system shall be equipped as neces sary with a suitable in-line air-purifying sor bent bed and filter to further assure breathing air quality. Maintenance and replacement/ refurbishment of compressor and associated air-purifying/filter media shall be performed periodically, by trained personnel following manufacturer's recommendations and instruc tions. 10.5.4.3 As part of acceptance testing, and prior to initial use, representative sampling of the compressor air output shall be performed to ensure that it complies with the require ments in 10.5.1 and 10.5.4. To ensure a con tinued high-quality air supply, and to account for any distribution system contaminant input, 18 a representative sample should be taken at distribution supply points. Samples should be collected on a periodic basis, as directed by the program administrator. Specific test rec ommendations are given in table 4. 10.5.4.4 The dew point of breathing air used with supplied air respirators should be lower than the lowest ambient temperature to which any regulator or control valve on the respira tor or air-supplied system will be exposed. 10.5.4.5 Breathing air couplings shall be incompatible with outlets for nonrespirable plant air or other gas systems to prevent inad vertent servicing of supplied-air respirators with nonrespirable gases. Breathing air out lets shall be labeled. 10.5.4.6 Breathing gas containers shall be marked in accordance with ANSI/CGA C-4-1990. Further details on sources of compressed air and its safe use will be found in CGA G-7-1988. 3H 110306 Industrial Safety Equipment Association Meeting Report Passive Dosimeter Manufacturers ATTENDING Skip Elliott Lloyd Kent Rena Kirkpatrick K Kirolos Mike Marselli Bob Curtis Ed Zimowski Dan Shipp Bill Eroy Envirometrics Products Co. Matheson Gas Products Assay Technology Gilian Environmental Corp. Sensidyne OSHA OSHA ISEA ISEA 1. PURPOSE This meeting was called to discuss the possible development of an ANSI standard for passive monitors for detection an measurement of hazardous contaminants. Mr. Elliott noted the product was developed to meet a need for a means of measuring and immediately determining the level of toxics. He noted that market enthusiasm is tempered by the need for some assurance of product performance. Third party validation of manufacturers claims will provide that assurance, he said, but such certification requires a uniform test protocol. A test protocol is in existence, developed by a NIOSH researcher. OSHA uses part of that protocol now. But there is a general preference for a voluntary standard, so manufacturers can have a role in its development and will be more likely to support it. ISEA staff described the association's structure and procedures for developing American National Standards. . 2. DISCUSSION Among the issues raised in discussion were the following: a. This standard would formalize a method for evaluating a new technology. b. Third-party testing can be used to validate a manufacturer's claims for a product, or to verify that a product meets a minimum level of performance. c. What should be the scope of the standard? Should it only cover directreading passive monitors or should it include sorbent monitors that have to be sent to a lab for processing? Should it include digital display monitors? 3H 110307 d. OSHA want3 to be able to use passive monitors, but needs assurance that they will work. e. ISEA staff explained that a standard could be a new ANSI standard, a new ANSI/ISEA standard, or a revision to the existing ISEA/ANSI gas detector tube standard. An interim protocol - ISEA or OSHA - could be used while the ANSI standard is being developed and reviewed. 3. DECISIONS AND NEXT STEPS The group will have to determine the scope of a proposed standard. They agreed to hold another meeting to develop these criteria. In preparation for this meeting, the participants will send the ISEA the names of other manufacturers. The ISEA will invite companies making on-site reading passive monitors, long-term detector tubes and sorbent monitors. They will not include electrochemical monitors at this point. Mr. Curtis offered the OSHA Technical Center in Salt Lake City as a site for this initial meeting, as well as a subsequent technical meeting. He and Mr. Eray will work out the details of the meeting. Mr. Elliott will draft the letter of invitation, to be mailed by ISEA to prospective participants. . I- cc: The Instruments Group Recorded by Daniel K. Shipp 3W "0308 iAiaea\pg\pms,min Industrial Safety Equipment Association MINUTES Passive Monitor Standards Committee of the instruments Group Sunday, Novembers, 1995 Stouffer Dallas Hotel Dallas, Texas MEMBERS PRESENT 3M Company Envirometrics Products Co. Mine Safety Appliances SKC Inc OTHERS PRESENT Assay Technology Webster, Chamberlain & Bean ISEA PRESIDING James Kvickstad Skip Elliott Katie Spear Martin Harper Gus Manning David Goch Bill Emy Skip Elliott, chairperson 1. CALL TO ORDER The meeting was called to order at 10:00 a.m. ; ... ur;- As the first order of business Chairman Elliott outlined the following three goals of the Committee meeting today: . Review and approve the draft standard for release to the informal peer review group; Approve the informal peer review group members; .. Consider and vote on the alternative section 6 on evaluation parameters submitted by Martin Harper. Martin Harper reported on ASTM Committee activity. Martin explained that Dave Bartley is the NIOSH representative to the ASTM D44 Committee on Air Sampling. Allen Ishe of Miles is the chairman of the D44 Committee. Richard Danchik of ALCOA is the chairman of the D44.02 subcommittee on workplace atmospheres. Martin has been maintaining communications with Dave Bartley who was assigned by the D44.02 Committee to update the NIOSH protocol. Passive Monitors Standards Committee 1 November 10,1996 3M 110309 i:\isea\pg\pms.min However, Dave has agreed to postpone revision of the fflOSH protocol until he has had a chance to look at the ISEA draft and will consider adopting the ISEA requirements as the NIOSH criteria. It was further explained that ASTM may adopt the ISEA/ANSI standard as an ASTM/ANSI standard. 2. CONSIDERATION OF MINUTES The minutes of May 21 were approved as presented. 3. REVIEW OF DRAFT 10/11/95 STANDARD The Group agreed to modify the title of the standard to more accurately describe the type of products included. The word TYPE was replaced with SAMPLERS AND MONITORS. The Group revised section 1, Purpose and Scope. Section 1.1 was replaced with the following: "This standard enables manufacturers and users of diffusive samplers and monitors to adopt a consistent approach to product evaluation." The revised language was developed to better explain the purpose of the standard. It was noted that the previously included background information was inappropriate and should be deleted. Section 1.3 was revised to delete a Type C device. It was decided to combine the Type A and Type B devices into Type A - On-site Reading Devices. The previous Type C devices were reclassified as Type B - Laboratory Analyzed Devices. It was noted that the separation of Type A and Type B was redundant and not needed to include all types of passive monitoring devices. Section 2 was modified to eliminate Level I and Level II compliance classifications. It was agreed that the reporting requirements required by the standard are sufficient to ensure that proper extrapolation criteria are followed since they require a manufacturer to disclose and provide rationale for exclusion of any test method due to extrapolation. The following was developed and included under section 2.1: "Compliance with this standard shall be established by a test report which details adherence to the test methods and evaluation parameters outlined in this standard. If it is known that a certain sampler or monitor is unaffected by a specific environmental influence, the relevant tests may be modified to examine only the factors likely to have an influence. The rationale for any modification to the test methods and evaluation parameters must be fully outlined in the test report." An alternate proposal for section 6 was presented by Martin Harper for consideration by the committee. Martin explained that the alternate section 6 was developed to promote international harmonization. Martin Harper explained that Passive Monitors Standards Committee 2 November 10,1995 3M 110310 i:\iaea\pg\pnj54nln complete harmonization is unfortunately not possible at*the present time since the European Standards specify accuracy limits and evaluation criteria. However, alternate section 6 was written so that products evaluated under the ANSI criteria could be included under the European and NIOSH criteria. After review and modification, the alternate section 6 was approved for adoption to replace the current section 6 with the following exceptions: the current section 6.1.6, Quality Control; section 6.1.9, Inter-reader variability; and section 6.1.10, Readout time were retained. Section 7 was removed since it is already included in the newly adopted section 6. Section 8 was re-titled "Quality Control Requirements" and renumbered as section 7. Section 8.2, "Reporting and Labeling Requirements" was made its own section 8. Martin Harper volunteered to review the reporting and labeling requirements section to ensure it coincides with the newly adopted section 6. The Group reviewed and made minor revisions to the definitions section to clarify and remove extraneous definitions that are not needed or used within the body of the text. The Group reviewed a proposed section on Field Test that was developed by Bob Weber of 3M. It was proposed that Bob's proposal replace the appendix. However, after review the Group concluded that the current language was dose to achieving the objective of describing generally the importance of field testing. It was noted that this standard should not and does not address field testing criteria. Gus Manning volunteered to review the appendix language on field evaluation and coordinate his revision with Bob Weber. Martin Harper suggested that Gus use the CEN section on field evaluation as reference. Skip Elliott was assigned to incorporate all approved changes into the draft standard within the next two weeks. Bill Emy was assigned to distribute the revised draft to Group members for review. ISEA will set up a conference call of the Passive Monitors Group for December 20 at 11:00 a.m. EST. The objective of the call is to discuss and resolve all concerns with the draft and to confirm approval of the draft for submission by the end of 1995 to the informal peer review group. The informal peer reviewers will be requested to return comment to the ISEA by the end of March. The Passive Monitors Group will meet at the AIHCE in Washington to review the comments and approve a final draft for submission to ANSI as an American National Standard. Martin Harper announced that a round table discussion is scheduled for the AIHCE, "Accuracy Considerations for Air Sampling and Analysis Methods". Passive Monitors Standards Committee 3 3M 110311 November 10,1995 i:\isea\pg\pma.min Attached is the round table abstract. Martin explained that a major topic of discussion will be the 1SEA draft diffusive sampler standard. It was agreed that the Group should include the feedback generated at the round table with the comments received by the peer reviewers. In conclusion it was agreed that a final draft standard is expected for completion for submittal to the ANSI canvass list by the spring of 1996 and that a final published document could be available by the fall of 1996. 4. CONSIDERATION OF THE INFORMAL PEER REVIEW GROUP The Group approved the following list of 10 peer reviewers that will be asked to review and comment on the ISEA draft: Dr. Gene Feigly, University of South Carolina Richard Brown, Health & Safety Laboratory Lee Montieth, University of Washington Mark Puskar, Abbott Laboratories Dave Bartley, NIOSH Dr. Stephan Zloczysti, CEN Rick Cee, OSHA Paul Michael, Rolf Hahne, Dow Chemical Company 5. NEXT MEETING The next meeting was tentatively scheduled for the third week in May in conjunction with the American Industrial Hygiene Conference which is being held in Washington D.C.. More specific information will be determined at a later date. 6. ADJOURNMENT .. There being no further business to discuss, a motion to adjourn was accepted at 4:25 p.m. Respectfully submitted, William J. Emy Technical Director Attachment Passive Monitors Standards Committee 4 November 10,1995 3M 110312 List of passive monitor peer review group 11-9-95 Dr. Gene Feigly University of South Camlina School of Public Health Dept, of Environmental Health Sciences Room 311 Columbia, SC 29208 Phone: (803)777-7739 Fax: (803) 777-3391 Lee Monteith, M.S. CJ.H. University of Washington Dept, of Environmental Health Seattle WA 98195-7234 Phone: (206) 543-3261 Dave Bartley NIOSH - Mail Stop R7 Robert A. Taft Laboratories 4676 Columbia Parkway Cincinnati OH 45226 Phone: (513)841-4277 Rick Cee OSHA- Salt Lake Technical Center 1781 S. 300 West Salt Lake City, UT 84165 Phone: (801)487-0073 * RolfHahne Dow Chemical Company 1803 Building Midland, MI 48674 Phone: (517)636-9065 Richard H. Brown Health & Safety Laboratory Broad Lane Sheffield S37HQ United Kingdom Mark Puskar, PhD Manager. Coip Industrial Hygiene Lab Abbott Laboratories 1401 Sheridan Rd, Dept 038A Chicago, EL 60064 Phone: 708)9374520 Dr. Stephan Zloczysti Auergesellschaft GMBH Thumannstr 1' D-12059 Berlin, GERMANY on P.O. Box 620 D-12006 Berlin, GERMANY Paul Michael Lab Director Monsanto Company 800 N. Lindbergy Blvd. Mail Stop U-4C St. Louis, MO 63167 Phone: (314)694-4838 Industrial Safety Equipment Association MINUTES Instruments Group Meeting Tuesday, November 14,1995 Ritz-Carlton Pentagon City Hotel Arlington, VA MEMBERS PRESENT Margarita Porto George Baker Robert Henderson Skip Elliott Ken Acer Jim Kvikstad (for Bob Weber) Ralph Burns MEMBERS ABSENT Bruce Holcom A1 Perry OTHERS PRESENT Pat Gleason Bruce Clash PRESIDING Air Liquide America Air Liquide America Biosystems Inc. Envirometrics Products Company Mine Safety Appliances Co. 3M Company Neotronics of North America Gas Tech Inc. Scott Aviation Safety Equipment Institute ISEA Robert Henderson, Chairman 1. CALL TO ORDER . The meeting was called to order at 9:00 a.m. 2. CONSIDERATION OF THE MINUTES The meeting minutes from May 25,1995, meeting were approved as presented. 3. GAS DETECTION TUBE UNITS - ANSI/ISEA102-1990 The ISEA would like to obtain an extension from ANSI for the standard to remain in effect beyond its five year lifetime. Bill Emy at ISEA was given the task offollowing up with ANSI on this issue. 4. REPORT ON PASSIVE MONITOR STANDARDS COMMITTEE Chairman Skip Elliott reported on the work being done by this committee, which held its first meeting in May at the American Industrial Hygiene Show in Kansas City. Skip explained that the objective of this standard is not to set performance criteria, but rather to set testing conditions and marking requirements for passive monitors. Martin Harper of SKC Inc. has looked into what Europe is doing. Skip noted that OSHA has been Instruments Group 3M 110314 1 November 14,1995 involved in this project since its inception and is keenly interested to see such a standard developed for passive monitors since it would provide more feasible alternatives in characterizing workplace exposures. Skip also stated that a joint ASTM/ANSI standard is being discussed. Skip reported that at the Dallas meeting, the committee approved a draft standard for circulation to an "advisory panel" including government officials, academia and industry professionals. The draft will be sent to the panel in January for their input and comment. The committee will meet next May at the AIHCE in Washington, D.C. and expects to begin ANSI canvassing shortly thereafter. 5. ISEA INSTRUMENT SPECIFICATION WRITING ACTIVITIES It was reported that in 1992, Underwriters Laboratories (UL) published a standard, UL 2034, for carbon monoxide (CO) detectors. The Consumer Product Safety Commission will conduct a public hearing on January 23-24,1996, to receive scientific, medical and other technical information about CO detectors and the voluntary standard for them. The subject of whether the ISEA should get involved in performance criteria for these detectors was discussed. It was felt that ISEA should have some input, but a plan for how to do so was not discussed. Ken Acer will be coordinating the ISEA action plan. 6. CONSENSUS ISEA CALIBRATION STATEMENT There was a discussion on what elements the ISEA calibration statement should contain: 1) Instruments should be maintained in accordance with manufacturers' specifications; 2) Instruments should be checked for accuracy before any day's use; and 3) Any detector with readings any amount lower or 10 percent higher should be adjusted before use. Two other suggestions were made: 1) If a portable instrument is assigned to one user who finds that it needs calibration less often, then calibration can be done based on the performance history of that instrument as it is known by that user; and 2) Calibration can be done less frequently on instruments that will be used exclusively in areas known to have a low probability of being hazardous. Discussion ensued on what to do with the statement once it is finalized. It was suggested that it be reviewed by the ISEA Quality Assurance Committee so that it would then become an official ISEA document. The idea that it then be incorporated into an editorial article in various publications was also discussed. Bob Henderson will circulate a statement to the Group members when it is drafted. 7. REVIEW OF NFPA 306 ACTIVITIES _ Ken Acer informed the Group that this standard is in the five year review process. The major issue for instruments manufacturers in this work practices in shipyards standard is oxygen high alarm set points. The first NFPA 306 meeting is in Arlington, VA, on December 12. Ken will continue to follow developments on this issue and will keep the Group informed. 8. DRAFT ISA/NEC UPDATES Bob said that he will have ISEA staff distribute the memo on this subject from Bruce Holcom. It was asked of Pat Gleason if SEI has an interest in certifying these Instruments Group 3M 110315 2 November 14,1995 products. Pat said she would check with Clayton labs and let Bob Henderson know the response. 9. ANSI Z-117 (CONFINED SPACES) UPDATE It was said that Barry Phillips of Racal Health and Safety is the official ISEA representative to this committee. He is working to determine where this issues stands at the moment. 10. OSHA1910.134 (RESPIRATORY PROTECTION) UPDATE This issue has some tangential interest for the Instruments Group. It is possible that the draft will be withdrawn and probably reissued as a proposed rule. ISEA is trying to get NIOSH and OSHA to coordinate their approach on respiratory protection. 11. REVIEW OF AIHA GAS AND VAPOR CONFINED SPACED COMMITTEE ACTIVITIES The Gas and Vapor Confined Space Committee round table for the 1996 AIHA conference will be centered on sensor performance and calibration issues. Bob Henderson will keep the Group informed of the Committee's activities. 12. SELECTION OF REPRESENTATIVES TO STANDARDS COMMITTEES Representatives to the various committees were selected: NFPA 306 Ken Acer AIHA Gas and Vapor Bob Henderson AIHA Confined Space Bob Henderson ISA Instruments Bruce Holcom 13. FUTURE ANSI/ISEA STANDARDS WRITING ACTIVITIES No items were discussed. 14. NEW OR UNFINISHED BUSINESS It was mentioned that OSHA will be looking at 1910.1000 permissible exposure limits soon. Skip Elliott volunteered to learn the status of OSHA's review and will talk to Bill Emy at ISEA to find out what The Jefferson Group is doing in this area. It was asked if instruments are induded in the comparison of international standards project that is underway by ISEA's International Trade Committee. Bob Henderson will talk with committee chairman Roger Gehrig about the project. Industrial Scientific Corporation was mentioned as a company that should be a member of the Instruments Group. Dave Wagner is the company's new product manager. ISEA staff will follow up with this prospect. AIM has verbally indicated that it will join the ISEA in the spring. Questions concerning the status of the Eye and Face Group's statistical survey were raised. There was a consensus that the Instruments Group would like a report on this project at the next meeting in order to see whether a similar survey would be feasible for instrument manufacturers. 3M 110316 Instruments Group 3 November 14,1995 15. NEXT MEETING DATE . The next meeting will occur during the AIHA show in Washington, D.C., during May 18-24. The exact date will be determined once the show meeting calendar is reviewed. Respectfully submitted, k-l&I Bruce R. Clash Public Affairs Director Instruments Group 3M 1103V7 4 November 14,1995 A-~ -Sa-tjV 503353*^ icamJaW. !**' fell &&*j C- * 75JL fe*4- f?^fc Cwt4i$ ..tu4Ad.ihu MtMd+uee. r JjLtej. LbrXte. 4'. Otfo ^g!V^g_ jM /t<LWv_ '. ^ _____ ._________ _ $V^>p felturtf' rMj>gou-lvi'rs K&~A fe.pVlWSrm V ^tU< \ tXt^J- ftluF'. gi-tw Otfb*/ Cn $tr- StuJun. AiA* M$ph . cLri~ti'k vl oMfuMJ/ ( -* -- Uf4l fj Jf.CM.'UtA J -- wjtjJ/e/fj~/r/.ari4iiZuos-Y^_______- i LlJT. ts\*sv*4ctd tjUvu/ ^ C ' 2.'-j !WVSAtkJh^r o4 huM. &- (1 gynA^^l^u AtuCZr/Aiflt .M'hisTiaM^jQ ^H^JLUk gL&Wl X-<S> . -- I \aSu^JLP <*i A*SvsjUtMfM&r*iz0 ' SgW Leuj'iS-- ftft r<mW .pfr_yi n&to -fcno^ Z7r.AKofZel.TT\2fSej oS^-i*3UDl- AyW Ci ura.U<g a ^kJ*J 77- PfeMU** ^ rt<n\ljr2/ A -^Rodt&iritAg^w' * ~tT?j?-7-amr"r. ---AA^3ttM -- tfaiiJWEfr -Pittekvii*/ I'citl CxojfUi-i MfrOn ^eUi-2 , *>f>iijh(r.^trr^lUL.l tin '* $f,H_________________ - /gj^* ?-CA*'l'**`- tM*jjM*% fa d6M#^ V fVc>Jy 1933 PranWW Qust Co.1 *v~ <*<*3R 3M A10320 i JWt extt4*l ^ }K - /JL -Ocwt "tew - su/ jvUt <rtrS*X e^'^iXaie ,4, ^ a n#t', _______________ ~ teon i___- MO// iuU,__ =$- Q&S*X*^*<4 r *C'e*v*-tj-p & Lg, M^C)- tL ~ t*e,4-9xZu Tlzf Ary |A Vim. |py 'febCk/'tti ' - r jejiLuj eMi 4c m-iy 6^ c. ^ Cmof^o-f pa-w 4lit fear 4.' A- k. Cyva-yfr^ ~^~ ^r Ge*J***. i<gCu. . OauI yvtvAtfie mfe. -------------------------------------'--.-- -------------------------------------.-- ______ V ** ~-Uv4 *ai ^Tk^-tXa 'luUs! tejU^fi'HTn J * __________ ^i tj Cujm.4- Ahm^a <w e.av<^**i ) r CO*VCfc/vtf^ g&JfriV dft4yii^lA/Wlg' /ut/* tXfrftAw) X. OrfLa-w- SVtw^ -j**A^ -tliliVi eUuyM. hlUiA*. 607tk*vv& ;,, W*4 ; if! 3M 110322 JX &> (MUrntt ( Ateiiit pi4n p ~ X-ffyS/^c yt-u -C AcrcAtfutA^ e* J&J-f 3t-<fF ~ tH^-orw X ty/f /ii*Ji**n*i l/i /7. ___ c^g^Zf. iHAim.UA (Uu^X? a muJ afgc. ~riM*jluXTLuA NKXH TCtrtv CA*i^ eUnUjk,- lrJu*2u /fab-`s&ljP / * f?fi&ai*r< [QSuu-JJ - WUtF&S'U'y *jj&rn**A&--****\ V*f*d- \*t'***~ O 1993 Franklin QUMI Co. PrifiWd in VSA :'- 3M 110323 Wa*' c "ISfc PiIAtoSX ( -ih %#"U'$\z<LzLf gl j*. -Ct~~ - tOfcUA/ _ftUk tVfl v ^T> Pwfi '-Mths* _?_mJ/Trt^fJ^U, a4m-r-k. Gf/4 L J^ ^ frfoi/VvvvtfcX_________________________________ '_______________________I - gL^ytot ~tVt -W'S iiHl235ti ''fcP.t P ~fmi/ -- &An*QjO-L-c*svi g3ii -- ~w uffc c -- eUni*/ i^vf- AxsiT hju&L.gap -Jk2kS -j^H/~Hml4p'Ghf^ t~,brm\ftutfa&%yfcz c. 1~frlt/U. U 4ou^i^~) -Mi /f^t- Utf- u/6li* ntA^uJjL& (bOjC-'llthU'*/ G -grp. bufltk j*#4 `k fegt ^3 - QuVw - tte AtAJ-*t*&- l/oti jW*Kfr i903FwMin(>istCo. PrtnMMUSA 3M 110324 3M 110325 Industrial Safety Equipment Association October 20,1995 TO THE PASSIVE MONITORS STANDARDS COMMITTEE: Draft standard and friendly peer review Attached is a revised agenda for November 5, the draft standard version 10.11.95 which incorporates all change as a result of our last meeting. Also a suggested alternative section 6, "Evaluation Parameters", has been submitted by Martin Harper and is attached separately for your review. Lastly, a list of friendly peer reviewers is included which needs to be approved at the November 5 meeting in Dallas. The main purpose of the Dallas meeting is to approve both a peer review group and a draft standard that we can submit to the peer review group to obtain important feedback from a user's perspective. Please review the enclosed materials dosely and be prepared to discuss them at the meeting in Dallas. If you are unable to attend the Dallas meeting, you my submit comments to me via FAX at (703)528-2148 or contact me directly at (703)525-1695. I look forward to seeing you all in a couple weeks and having a very productive session. Sincerely. __ Wmiam JJany Tedmiwn Director 3H 110326 1901 N. Moore Street, Suite 808, Arlington, VA 22209 Tel. (703) 525-1695 Fax (703) 528-2148 Meeting of the - PASSIVE MONITORS STANDARDS DEVELOPMENT COMMITTEE November 5,1995 9:00 a.m. to 5:00 p.m. Stouffer Dallas Hotel 2222 N. Stemmons Frwy Dallas, TX Revised - A Cl F N D A 1. Call to Order at 9:00 a.m. 2. Consideration of May 21,1995 meeting minutes 3. Committee Assignments: Group Input - Friendly Peer Review and ANSI Canvassees - Approve a peer review list - Review of all Definitions Skip Elliott - Rationale and History of Standard - Comparison Between ANSI and ASTM Standards - Update Draft Standard Gus Manning - Continuous Reading Monitors - Definition for Sorbent - Combine Reporting, Marking, and Labeling Requirements Bill Emy - ANSI Standing Committee for Level II Evaluation Martin Harper - Level II Evaluation Criteria (Appendix) - Factorial Evaluation Criteria - Rate/Capadty Criteria - Shelf life Requirements - Comparison between ANSI an ASTM Standards - Report of CMA Support for ANSI Standards Development Bob Weber - Field Evaluation Criteria 4. Review and approval of a draft for release to the review group 5. New Business 6. Next Meeting 7. Adjournment 3M 110327 List of passive monitor peer review group 10-20-95 Dr. Gene Feigly University of South Carolina School of Public Health, Dept, ofEnv. Health Sciences Room 311 Columbia, SC 29208 (803) 777-7739 F: (803)777-3391 Ron Roberson Sensidyne, INC. 16333 Bay Vista Drive Clearwater, FL 34620 (800)457-3444 F: (813)539-0550 Kim Chapman Eilian Environmental 2421 Bowland Parkway, unit 102 Virginia Beach, VA 23454 (804) 431-2260 F:(804)431-2255 Richard H. Brown Health & Safety Labcratory, UJC Lee Monteith, ACGIH University ofWashington Mark Puskar, PhD Manager, Corp Industrial Hygiene Lab Abbott Laboratories 1401 Sheridan Rd, Dept 038A Chicago, IL 60064 (708)937-4520 3H 110328 7035282148 ICSCfl F-696 T-158 P-001/003 NOU 06 '95 13;13 INDUSTRIAL SAFETY EQUIPMENT ASSOCIATION PLEASE DELIVER TO THE PERSON DESIGNATED FOR YOUR COMPANY. THANK YOUI Company Air Liquids America Corporation Biosystems Inc. Envirometrics Products Gas Tech Inc. 3M Company Mine Safety Appliances Mine Safety Appliances Neotronlcs NA SKC, Inc. Scott Aviation Webster, Chamberlain & Bean Representative Margarita Porto Robert Henderson Walter H. Elliott Bruce Holcom Robert A. Weber Kenneth Acer Wayde B. Miller Ralph Bums Martin Harper Al Perry David Goch Fax # 410-228-4251 203-344-1068 803-740-1721 510-794-8210 612-736-7344 412-776-3280 412-967-3056 404-967-1854 414-941-2184 716-683-5530 202-835-0243 To: Prom: Date: Re: ISEA Instruments Group Cristine Z. Fargo November 6, 1995 instruments Group Meeting, November 14, 1995 Attached please find a revised agenda for the upcoming instruments Group meeting, on Tuesday, November 14; 1995 at the Ritz-Carlton Pentagon City from 2:15 PM to 5:00 PM. If you have any questions, please feel free to contact me at 703-525-1695. tkUUAt JaAOO 9/18/95 3W 110329 7035282148 F-6S6 T-158 P-002/003 NOU 06 '95 13:13 INDUSTRIAL SAFETY EQUIPMENT ASSOCIATION 1901 North Moore Street, Suite 808 Arlington, Virginia 22209 Instruments Group Meeting Ritz-Carlton (Pentagon City) Hotel Arlington, Virginia Tuesday, November 14,1995 2:15 p.m. to 5:00 pan. 1- Meeting Called to Order by Chairman Henderson 2. Roll Call and Introductions 3. Approval of Minutes of May 25,1995 Meeting 4. Gas Detection Tube Units - ANSI/ISEA102-1990 ANSI 5 year review - Reaffirm or Revise? 5. Report on Passive Monitor Standards Committee - Skip Elliott 6. ISEA Instrument Specification Writing Activities 7. Consensus ISEA Calibration Statement - Bob Henderson 8. Review of NFPA 306 Activities - Km Acer 9. Draft ISA/NEC Updates - Bruce Holcom 10. ANSI Z-117 (confined spaces) Update 11. OSHA 1910.134 (respiratory protection) Update 1Z Review of AIHA Gas and Vapor and Confined Space Committee Activities - Bob Henderson 3M 110330 7035282148 F-696 T-158 P-003/003 HOU 06 '35 13:13 13. Selection of Representatives to Standards Committees NFFA306 AIHA Gas and Vapor AIHA Confined Space ISA Instruments 14. Future ANSI/1SEA Standards Writing Activities 15- New or Unfinished Business 16. Next Meeting Date 3M 110331 3M Company 3M OH & ES Division 3M Center Bldg 260-3B-09 St Paul, MN 55144-1000 Fax Cover Sheet DATE JULY 11,1995 TO: Bill Emy ISEA PHONE: 703-525-1695 FAX: 703-528-2148 FROM: Bob Weber 3M Company PHONE: 612-737-4459 FAX: 612-736-7344 RE: Appendix on Field Testing Number of pages including cover sheet: [3] Message Hi Bill; Enclosed you will find the draft appendix on field testing that should be included in the diffusion monitor validation protocol. I have some more to add, but because oftime constraints I haven't been able to complete, however I thought I should send what I have. I plan on completing sometime in August. I will forward the rest when later. Talk to you later. Bob Weber, CIH Senior Technical Service Representative 3M 110332 Appendix ? Field Test Introduction Laboratory validation of diffusion monitors defines the operating parameters of the device and accounts for many of the variables that may be encountered in the field; however, there may be factors in the workplace that will influence the performance of the diffusion monitor that cannot be anticipated in laboratory validation studies. For example such factors as intermittent and rapidly changing concentrations, or the presence of interference's. Therefore testing the diffusion monitor under actual field condtions is recommended. Several factors need consideration before conducting field evaluations. First, the true concentration is not known and therefore must be estimated with an independent method. However, the independent method is subject to errors just as the diffusion monitor. Therefore the difference between the two should not be interpreted as a bias. Second, the use of side-by-side sample collection must be carefully monitored. Sampling devices, either active or diffusive, placed on an individual's right and left lapels may give different results; although each may give an accurate yieasurement of the concentration to`which they were exposed. The differences in^sfde-Sy-side sampling can be attributed to the existence of concentration gradients in the sampling area. Concentration gradients may be due to the individual's location to the contaminant producing equipment or process, direction in which the individual is facing during exposure, and the type of work being performed. Third, the environmental factors in the field must be determined to insure that the diffusion monitor and independent method are being conducted within their operational ranges. Field Test Methods Evaluation of diffusion monitors in the field can be conducted by two different sampling techniques. The first technique, personal sampling, involves having individuals wear both the diffusion monitor and independent sampling device simultaneously. This technique is subject to errors outlined earlier. The second technique, field chamber sampling, involves exposing both sampling techniques to an atmosphere of homogenous analyte concentration and a face velocity sufficiently high enough to prevent diffusion monitor starvation. Workplace air is drawn into a chamber where a statisically significant number of sampling devices will simultaneously collect the contaminants. Field chamber sampling may not represent a typical worker exposure, however it does eliminate errors that are associated with personal side-by-side sampling. 3M 110333 Field Chamber Sampling Include technique, sample size, statistics and diagram of chamber. Personal Sampling Include technique, sample size, and statistics. Annex C (informative) Field tests - Paired comparisons Page 31 prEN 838:1995 C.1 Introduction Although thr diffuffivs uprak^ wil| hnim hrrn rlnTri'minnii, ill 1f1 BITy' nffnrT nf f*tv,*l,llliil~TiTnf Tt^*+ fwfnrt ~x rhpr.kwri in the lilhnrnTnry triTti there may be some factors existing in the workplace that will influence the performance of a diffusive sampler. Such factors may be rapidly changing concentrationa^or the presence of unanticipated interferences, or the presence of the analyte either as suspended matte sorbed onto suspended matter. Tests should therefore be conducted under conditions typical for Atrt*wv intended use of the diffusive sampler, to-determine the presence of any systematic difference between' the sampler results and those of an independent method. NOTE: In this context neither the diffusive sampler nor the independent method gives the "true* result, * as both are subject to error. The difference between individual paired results should not therefore be interpreted as a bias. i . A a . . / , . /)*.,/.. ---y. t-Q'l'f*- - C.2 Requirement C.2.1 Paired sample t-test 4m* ji"^' r Ca^-Ut ef- The mean value of [log x - log y] should not be significantly different from zero. If it is, it represents a systematic difference between the measurements made by the diffusive and independent methods for which an explanation should be sought. ... . C.2.2 Regression analysis The 95 % confidence limits of the values a and b (see C.4.2.2) should respectively- embrace zero and unity. If not, a deviation represents a systematic difference between the measurements made by the diffusive and independent methods for which an explanation should be sought. - NOTE: . Most computer programs for linear regression, analysis assume x is without error and slightly' underestimate b as a result. The correlation coefficient, r, ha* only qualitative value in this context. C.3 Materials See 6.1 and 6.2. C.4 Method of test . C.4.1 Procedure At an appropriate test site or sites, workers potentially exposed to the analyte should be selected, in order to cover as wide a concentration range as practicable, without deliberately exposing workers to concentrations at or around the limit value. For each selected worker, use one diffusive sampler and one sampler of an independent method (see 6.3; preferably that used to verify the calibration gas mixture in 6.4, provided it is suitable for personal monitoring), placing them in the breathing zone as close as practicable to each other, s that they sample from essentially the same atmosphere. At least 20 data- 3H 110335 prEN 838:1995 pairs are required for this test. Analyze the samplers and calculate the apparent exposure concentration for each sampler. For diffusiv samplers use the calculation in 7.5. C.4.2 Calculations C.4.2.1 General - V '' Compare the apparent exposure concentration measured by the diffusive sampler with that measured by the independent method. Any suitable statistical test may be used to determine any systematic difference between the two sets of results. Two possible tests are given in C.4.2.2 and C.4.2.3. C.4.2.2 Paired sample t-test Construct a table with the data-pair number (i) and the two estimates, x(i) and y(i), of the exposure concentration. In most practical situations, x and y will follow a log-normal distribution, so add columns for log x(i) and log y(i). Add a last column for Hog xti) - log yii)]. On the assumption that (log xf>) log y(i}] is normally'distributed, calculate the mean and standard deviation and test whether the mean is significantly different from zero by a t-test using 95 % confidence limits. C.4.2.3 Linear regression analysis On the assumption that there is a linear relationship between x and y, the relationship between the two sampling methods may be examined by linear regression analysis. It is convenient to use a computer program, and as in C.4.2.2, a logarithmic transformation is desirable in order to normalize the standard deviation of measurements made at different concentrations. The result of a linear regression analysis will normally be the values a and b of the equation: ' ' log y = a + b log x ... (C.1 ) together with standard errors of a and b, and a correlation coefficient, r. Annex D (informative) '. Field tests - Multiple comparisons 0.1 Introduction * Although the diffusive uptake rate will have been determined, and any effect of environmental factors checked in the laboratory tests, there may be some factors existing in the workplace that will influence the performance of a diffusive sampler. Such factors may be rapidly changing concentrations, or the presence of unanticipated interferences, or the presence of the analyte either as suspended matter or sorbed onto suspended matter. Tests should therefore be conducted under conditions typical of the intended use of the diffusive sampler, to determine the precision of replicate sampler results and those of an independent method under these conditions. D.2 Requirement ' The field precision of the diffusive sampler (see D.4.2.t) should not greatly exceed the precisi n determined under laboratory conditions (see 7.13). In deciding whether the field precision is acceptable, the determined value for the independent samplers (see D.4.2.2) needs to be taken into account. 3H 110336 3M Company 3M OH & ES Division 3M Center Bldg 260-3B-09 St Paul, MN 55144-1000 Fax Cover Sheet DATE AUGUST 28,1995 TO: Bill Emy ISEA PHONE: 703-525-1695 FAX: 703-528-2148 FROM: Bob Weber 3M Company PHONE: 612-737-4459 FAX: 612-736-7344 RE: Appendix on Field Testing Number of pages including cover sheet: [3] Message Hi Bill; . Enclosed is the updated draft for Field Evaluations with diffusion monitors. Talk to you later. a i> Bob Weber, CIH 3H 110337 Appendix ? Field Test Introduction Laboratory validation of diffusion monitors defines the operating parameters of the device and accounts for many of the variables that may be encountered in the field; however, there may be factors in the workplace that will influence the performance of the diffusion monitor that cannot be anticipated in laboratory validation studies. For example such factors as intermittent and rapidly changing concentrations, or the presence of interference's. Therefore testing the diffusion monitor under actual field conditions is recommended. Several factors need consideration before conducting field evaluations. First, the true concentration is not known and therefore must be estimated with an independent method. However, the independent method is subject to errors just as the diffusion monitor. Therefore the difference between the two should not be interpreted as a bias. Second, the use of side-by-side sample collection must be carefully monitored. Sampling devices, either active or diffusive, placed on an individual's right and left lapels may give different results; although each may give an accurate measurement of the concentration to which they were exposed. The differences in side-by-side sampling can be attributed to the existence of concentration gradients in the sampling area. Concentration gradients may be due to the individual's location to the contaminant producing equipment or process, direction in which the individual is facing during exposure, and the type of work being performed. Third, the environmental factors in the field must be determined to insure that the diffusion monitor and independent method are being conducted within their operational ranges. 3H 110338 Field Test Methods Evaluation of diffusion monitors in the field can be conducted by two different sampling techniques. The first technique, personal sampling, involves having individuals wear both the diffusion monitor and independent sampling device simultaneously. This technique is subject to errors outlined earlier. The second technique, field chamber sampling, involves exposing both sampling techniques to an atmosphere of homogenous analyte concentration and a face velocity sufficiently high enough to prevent diffusion monitor starvation. Workplace air is drawn into a chamber where a statistically significant number of sampling devices will simultaneously collect the contaminants. Field chamber sampling may not represent a typical worker exposure, however it does eliminate errors that are associated with personal side-by-side sampling. Field Chamber Sampling The field test chamber should be large enough to collect at least 5 sampling pairs simultaneously (one of the independent method and one diffusion monitor). The air flow into the chamber should be sufficient so that face velocity across the surface ofthe monitor is high enough to prevent starvation. The analyte concentrations in the workplace should be within the working range of both sampling devices. At least 20 sampling data pairs are needed for statistical comparison. Statistical analysis of data should be conducted to assess the difference between the sampling methods. Personal Sampling Chose a work site that has a wide range of analyte concentration, but has sufficient concentration in order to collect enough analyte to accurately measure in the laboratory. Each worker selected to participate in the study should wear a pair of sampling devices (one of the independent method and one diffusion monitor). Sampling pairs should be placed in the breathing zone of the worker and as close as practical to each other, if possible they should also be placed on the same lapel of the worker. At least 20 sampling data pairs are needed for statistical comparison. Statistical analysis of data should be conducted to assess the difference between the sampling methods. 3M 110339 Aug, 8. 1995 4:07PM 412 94 1 2184 No. 3066 P. 2/3 Quality Commitment TO: MEMBERS OF THE ISEA COMMITTEE ON PASSIVE MONITOR (DIFFUSIVE SAMPLER) STANDARDS 8 August 1995 During the month of July, I met with Dr Richard H. Brown of the Health & Safety Executive (U.K.), and Working Group 5 of CBN TC137. The subject of the meeting was the potential for trans Atlantic harmonization of diffusive sampler standards. The fallowing points came out of the discussion: 1. The CEN Committee TC137 is aware of the work of ISEA and is in favour of harmonization. 2. It was agreed that all protocols for the evaluation of diffusive samplers contained fairly minor variations of essentially the same tests to test the effects of a wellr cognized range of influences on the overall accuracy of the sampler. In view of this it should be possible for the experimental parts of two standards to become compatible. 3. The European protocol is incredibly flexible (more so than I had thought), which allows interpretations favourable to harmonization, such flexibility is demonstrated by: a) any test can be excluded based on published justifications, and, b) any test can be modified to exclude conditions that will not adversely affect the sampler (again, based on published justifications), 4. The European standard can be modified based on the results of future research (for instance, where tests are shown not to be adequate, or where poor test design becomes apparent), and a project to undertake such research has been submitted for European funding. /cont. SKC inc. 863 Valley View Road Eighty Four. PA 15330. USA Phone: 4-12-04-1-0704Fax: 442-94-I-136& tso oooa certified AIHa accreoiiect Lab 3M 110340 Aus. 8. 1995 4:07PM 412 94 1 2184 No. 3066 P. 3/3 page 2 of 2. 5. Third party certification or auditing is not required for compliance with the European standard. 6. The conditions used in the European standard are designed to be a minimum set of conditions that samplers ought to be able to pass. If an American evaluation happens to select those conditions then it will pass the European standard. If an American evaluation chooses a less stringent range of condition it may still pass the European protocol if a justification as per 3.b can be invoked. If not, it can still be used, but if there is a sampler that more closely passes the minimum conditions, that is the one that must be chosen. 7. The reasons for the accuracy and precision standards needed to pass the European standard 482 are not under current scrutiny and will not likely be relaxed (at 30% they are currently more relaxed than NIOSH) in the near future. I will be incorporating some of these comments into the parts of the draft standard for which I have responsibility. I hope it will be possible for all of them to be discussed further at the November meeting. This will be very timely since I will be presenting a paper at a meeting in London in December which will be titled "Moves towards standardization in the United States" at which I will be able to discuss these matters further with the CEN personnel. Best regards, and look forward to seeing you all again, Martin Harper, PhD Assistant Research Director, SXC Inc. Submitted to Skip Elliott (Chairman) for global distribution Copy to Bill Erny, ISEA David Bartley, NIOSH/ASTM 3M 110341 ANSI/ISEA 102-1990 for Gas Detector Tube Units Short Term Typefor Toxic Gases and m Vapors in Working Environments 3M 110366 American National Standards Institute 1430 Broadway Sew York. Sew York 10018 ANSMSEA 102-1990 American .. . . National Standard fAPProval 311 American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. ' . CAUTION NOTICE: This American National Standard may be revised or withdrawn - at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Published by . American National Standards Institute 1430 Broadway, New York, New York 10018 Copyright 1990 by American National Standards Institute All rights reserved. No part of this publication may be reproduced in my form, in an electronic retrieval system or otherwise, without prior written pet mission of the publisher. Printed in the United States of America ASC990A2 3M 110367 ANSI/ISEA102-1990 American National Standard for Gas Detector Tube Units - Short Term Type for Toxic Gases and Vapors in Working Environments Secretariat Industrial Safety Equipment Association Approved May 25,1990 American National Standards Institute, Inc 3H 110368 Foreword (This Foreword is not part of American National Standard ANSI/ISEA 102-1990.) This standard has been drafted to establish a-voluntary standard for gas detector tube units. The standard was developed from the National Institute for Occupational Safety and Health (NIOSH), originally titled 42 Code of Federal Regulation 84-1973. Its use was discontinued in recent years. The purpose of this standard is to provide a means of continual testing of gas detector tube units and components for accurate performance in working environments, by determining the concentrations of toxic gases and vapors. This standard was processed and approved for submittal to ANSI by the Canvass Method. The following organizations recognized as having an interest in the standardization of gas detector tube units were contacted prior to the approval of this standard. Inclusion in this list does not necessarily imply that the organization concurred with the submittal of the proposed standard to ANSI. AFL-CIO Alliance of American Insurers American Gas Association American Industrial Hygiene Association American Insurance Services Group, Inc American Iron and Steel Institute American Mining Congress ' American Petroleum Institute Bituminous Coal Operators Association Chemical Manufacturers Association Compressed Gas Association Edison Electric Institute Hazardous Material Research Center Industrial Health Foundation Industrial Safety Equipment Association - Instrument Society of America International Brotherhood of Electrical Workers International Chemical Workers Union Matheson Gas Products Mobil Oil Corporation National Fire Protection Association National Institute for Occupational Safety and Health National Safety Council ' Occupational Safety and Health Administration Oil, Chemical and Atomic Workers Union Sensidync, Inc United Auto Workers United Mine Workers United Steelworkers U. S, Department of Labor . ' Suggestions for the improvement of this standard will be welcome. They should be sent to the Industrial Safety Equipment Association, 1901 No. Moore Street, #501, Arlington, VA 22209. 3M 110369 Contents SECTION 1. Purpose 2. Referenced Standards 3. Definitions________ 4. Required Information 5. Construction and Performance Requirements.... 5.1 General___________________________ 5JZ Length-of-Stain Type Detector Tubes__ 53 Color-Comparison Type Detector Tubes.. 5.4 Calibration-------------------------------------- 6. Sampling Pumps 7. Quality Assurance7 7.1 Sampling Plan7 12 Acceptable Quality Level7 73 Inspection Levels7 Appendix Recommendation and Precaution concerning Gas Detector Tube Unit Use--------------------------- PAGE ,4 ,4 .4 ,5 7 3 m v-) \o vo 3M 110370 American National Standard for Gas Detector Tube Units - " Short Term Type for Toxic Gases and Vapors in Working Environments X. Purpose This standard sets forth the performance requirements for gas detector tube units and components, which are used to determine the concentrations of toxic gases and vapors in working environments. 2. Referenced Standards This standard is intended to be used with the following standards: MTL-STD-105E, 10 May 1989, Military Standard, Sampling Procedures and Tables for Inspection by Attributes1 MIL-STD-414,11 June 1957, Military Standard, Sampling Procedures and Tables for Inspection by Variables for Percent Defective1 3. Definitions batch. A quantity of material defined as lot or batch in MIL-STD-105D, 1989, and MIL-STD-414,1957. component Any gas detector tube, sampling pump, or other device that changes the nature of the contami nant so that it may be measured by the tube, and is designed to operate as a constituent of the tube unit in such a way that the entire unit meets the requirements of this standard. contaminant A specific chemical substance, usually a toxic gas or vapor, appearing in a workplace air environment cross-sensitive gas or vapor. A gas or vapor that produces a stain similar to that obtained from presence of the contaminant 1 Available from the Goventmem Printing Office, Washing ton, DC 20402. expiration date. The date until which tubes from the batch shall meet the requirements of this standard, if stored from time of manufacture according to the storage instructions. gas detector tube. A tube containing a chemically impregnated material which indicates the concentration of the contaminant or group of contaminants in the air by means of a chemically produced color change. Length-of-stain tubes indicate contaminant concentra tion by the length of stain formed. Color-comparison tubes indicate concentration by the color or intensity of the stain when compared to measurement standards. Group-type gas detector tube units are those designed and manufactured to measure more than one contami nant. independent tube reader. A person measuring the length of stain or comparing the color or intensity of stain in a tube unit, in accordance with the instructions furnished by the manufacturer, who is not aided by another person in reading the tube, has no knowledge of other reader results, and has no prior knowledge of the actual contaminant concentration other than from tube unit readings. interferent gas or vapor. Any gas or vapor that alters the expected stain length, color, or intensity for a given concentration of the contaminant. manufacturer. An individual, partnership, company, corporation, association, or other organization that designs, manufactures, or assembles, a gas detector tube unit. MIL-STD. A specific military standards document approved by the U.S. Department of Defense. operating range. The manufacturer's stated overall range of measurements for the contaminant. The operating range of the gas detector tube unit may exceed the test standard range. shall. The word shall denotes a mandatory' require ment. 4 3W should. The word should, denotes a recommendation. test standard. The contaminant concentration in air that is the current Adopted Value TLV published at the time of certification by the American Conference of Governmental Industrial Hygienists (ACGIH), for each contaminant for the purpose of defining the minimum concentration range to be measured by the tube. test standard range. 0.5 to 5 times the test standard concentration of the contaminant expressed in terms of parts per million (ppm) or percent by volume or other appropriate unit of measure. tube unit. A device for measuring or signaling the presence of one or more gaseous contaminants in the atmosphere of a working environment, which consists of a gas detector tube and a sampling pump, and which may also include a sample conditioning tube or pyrolyzer or any other components required for proper functioning of the gas detector tube, or any other device, such as an automatic stroke counter, which enhances the convenience or usability of the tube unit. The tube unit as defined herein consists only of components supplied by the same manufacturer. 4. Required Information 4.1 Each component or set of components shall include instructions stating the additional components with which it has been manufactured for use as a tube unit meeting the requirements of this standard. 4.2 Each sampling pump shall be accompanied by instructions that shall enable the user to verify by a simple field test the capability for accurate flow rate or proper time to fill the pump to full volume, and to verify the absence of leakage. Instructions shall also be provided for making simple corrective adjustments to the pump and for replacing minor parts. 4.3 Each box of gas detector tubes shall be labeled with the following minimum information: (1) Identification of the contaminant or contami nants for which the tubes were manufactured and designed to measure (2) Test standard range (3) The expiration date of the tubes (4) Manufacturer name, part number, and batch number (5) Storage instructions (6) Batch number of sample conditioning tube or applicable device, if included in box of gas detector tubes, and if different from gas detector tube batch number 4.4 If the operating range is stated on the label it shall be clearly differentiated from the test standard range. 4o Each box of gas detector tubes shall be accompa nied by the following information: (1) Instructions detailing the measuring procedure using the gas detector tubes, sampling pump, and any required components. (2) Instructions for obtaining contaminant concen tration values from tube readings. (3) The temperature, pressure, and humidity at which the tube has been calibrated, and methods for quantitatively correcting tube readings necessitated by use of the tubes at conditions of temperature, pressure, and humidity other than those at which the tube was calibrated. (4) Limitations of the tube unit in obtaining accurate concentration measurements, including a list of known interfered or cross-sensitive gases or vapors. (5) Basic chemical reactions involved in the operation of the tube, including the chemical composi tion of the reagent with which the contaminant reacts and the end products resulting from the chemical reactions, if known. Where such information is a trade secret, such information need not be set forth. (6) For length-of-stain type detector tubes only, each box of tubes shall be accompanied by a calibra tion chart or curve showing those concentrations of each contaminant that the tube measures which correspond to various stain lengths. Alternatively, the chart or curve or other calibration markings may appear directly on. or as part of, each tube. The calibration shall be based upon the method described in 5.4. (7) For color-comparison type detector tubes only, each box of tubes shall be accompanied by a color . chan showing those concentrations of each gas the tube measures, that correspond to various color changes of the indicating reagent section of the detector tube, and to the volumes of the air sampled. The calibration shall be based upon the method described in 5.4. (8) Each sampling pump, pyrolyzer. or other component not packaged inside a box of detector tubes must be identified by a serial number or other means of identification so that the date or batch number of manufacture, or both, may be ascertained. 5. Construction and Performance Require ments 5.1 General 5.1.1 The accuracy of gas detector tube units shall be such that measurements made by these units, when 3H 110372 5 AMERICAN NATIONAL STANDARD ANSI/ISEA 102-1990 used in accordance with the manufacturer's instruc tions, produce measurements of contaminant concen trations with 25 percent of the actual value at concentrations of 1,2, and 5 times the test standard of the contaminant, and within 35 percent of the actual value at a concentration of one-half the test standard. 5.1.2 Gas detector tubes shall continue to meet the performance requirements of this standard from the date of manufacture until the expiration date, if the tubes are stored according to the manufacturer's instructions during the elapsed time. 5-2 Length-of-Stain Type Detector Tubes 5-2.1 In addition to requirements stated in 5.1, length-of-stain type detector tubes shall produce either of the following; (1) A minimum length of stain such that the calibration point on the calibration chart or curve for a concentration equal to the test standard for the con taminant shall correspond to a stain length of 15 mm or greater (2) At a concentration equal to the test standard for the contaminant, produce a stain with such a clear and sharp end point that the following requirement is met: 4r 0.10 X where: s = The standard deviation of the tube readings obtained from three or more independent tube readers when reading an individual stained tube 1= Mean value of the tube readings 5.2.2 Channeling of airflow through the detector tube shall be minimized so that the maximum variation of stain length around the circumference of the tube at the interface between stained and unstained reagent shall be such that: a4-0J20 M where: Z.j = The concentration value indicated by the length of stain at the side of the tube where the stain is farthest extended along the tube's longitudinal axis. L, = The concentration value indicated by the length of stain at the side of the tube where the stain is least extended along the tube's longitudinal axis. M = The mean value between L, and I, 52223 Gas detector tubes should be assembled so that the zero point formed by the surface of the indicating material is perpendicular to the longitudinal axis of the tube. If this interface is not perpendicular. 6 the maximum variation shall not be greater chan 2 mm along the longitudinal axis of the tube. 53 Color-Comparison Type Detector Tubes. In addition to requirements stated in 5.1, color-compari son type detector tubes shall meet either of the following requirements: (1) Color chans and sampling volume combina tions shall be provided for concentrations of 0.03,1, 2, and 5 times the test standard. Additional color chans and sampling volume combinations shall be provided if necessary to meet the minimum perfor mance requirements of 5.1. (2) A sufficient number of color chans and sampling volume combinations shall be provided so that the following requirement is met when readings are obtained by interpolation between color compari son chans: ; 0.10 * x where: s = The standard deviation of the tube readings obtained from three or more independent tube readers when reading an individual stained tube T= Mean value of the tube readings 5.4 Calibration 5.4.1 Gas detector tubes from each batch of tubes shall be tested by the manufacturer for accuracy of contaminant concentration measurement, by using the tubes to sample known concentration of contaminants. 5.4.2 Correction factors for temperature, relative humidity, pressure, and other pertinent variables shall be applied to the tube readings before evaluating such readings for accuracy. 5.4.3 Routine calibration of each batch of tubes by the manufacturer shall be conducted at ambient room temperature in the range of 65-85 F (183-29-5C). Relative humidities shall be adjusted to approximately 50 percent, except for cases in which the presence of a substantial amount of water vapor would result in unstable contaminant concentrations, interfere with concentration monitoring systems, or otherwise cause a disturbance of test conditions. In such cases, a lower relative humidity may be used. 5.4.4 The manufacturer shall perform tube calibra tion tests on gas detector tubes from each batch of its tubes, at concentrations of 03.1,2, and 5 times the test standard for the contaminant To ensure acceptable performance over the full operating range, the manufacturer should perform adequate tube calibration tests on detector tubes from each batch of its tubes at suitable concentrations over the operating range. 3M 110373 5.4.5 Calibration concentrations shall be generated using one ot" the following methods; (1) A dynamic contaminant generation system, as by a gas saturating method (employing the vapor pressure of the substance), permeation tube devices, or other instruments or devices which generate gases at a steady, measurable rate (2) An analyzed gas mixture from a pressurized cylinder (3) A static concentration system prepared by injecting a known mass of liquid contaminant into a sealed container of known volume, and allowing time for evaporation and the equilibration of adsorption and desorption on container walls 5.4.6 Independent chemical or physical analysis shall be used to verify the test concentration of the gas generated, according to 5.4.5, except in the case when no independent method of acceptable accuracy has been developed. 5.4.7 The manufacturer shall periodically test gas detector tubes in the presence of interferent or cross sensitive gases to verify the stated interferent or cross sensitivity levels, and to determine what additional gases might also interfere or be cross-sensitive with detector tube readings, and to what degree such interferences or cross-sensitivities might occur. 6. Sampling Pumps 6.1 Sampling pumps for drawing the air to be sampled with detector tubes shall be free from leakage that can result in erroneously low tube readings, and shall be calibrated to sample at whatever flow rate or rates or time to fill the pump to full volume are deemed appropriate by the manufacturer, in order to assure accurate measurements. 62 Leakage shall not exceed 3 percent of the pump's single stroke volume per minute. This is tested by evacuating the pump and plugging the pump inlet with an unopened detector tube from the tube unit being tested. 63 Pumps shall be calibrated by the manufacturer to insure that they are capable of sampling accurately the stated volume at the stated flow rate. Subsequent to a check of proper flow rate and volume, the pump shall be capable of drawing 100 full-capacity strokes of air without deviating more than 10 percent from the calibration flow rate, and without deviating more than 5 percent from stated pump volume. 6.4 Flow control devices, if used, shall regulate the flow rate to within 10 percent of the rate stated by the manufacturer for each flow rate control device. American national standard ansi/isea 102-1990 62 To ensure that air samples do not backflow into detector tubes from the pump, the performance of the discharge check valve system shall be such that when 10 consecutive pump strokes are taken, the total volume of air drawn into the pump through its inlet, minus the total volume discharged through the pump inlet (or outlet if pump design mandates), shall be within 5 percent of 10 times the pump's volume capacity for a single stroke. 7. Quality Assurance 7.1 Sampling Plan. The sampling plan shall include a list of the characteristics to be measured, inspected, or tested. These characteristics shall be classified according to the potential effect of each nonconfor mance and grouped into the following classes; (1) Special. Tube reading accuracy. (2) Critical. A nonconformance that will make the gas detector tube unit completely inoperative or render it unusable for its intended purpose. (3) Major. A nonconformance other than critical, that is likely to result in failure, or reduce materially the usability of the gas detector tube unit in its in tended purpose. (4) Minor. A nonconformance that is not likely to reduce materially the usability of the gas detector tube unit for its intended purpose, or is a departure from established standards having little bearing on the effective use or operation of the gas detector tube unit. 72 Acceptable Quality Level. The acceptable quality level (AQL) for each special, critical, major or minor nonconformance, so classified by the manufac turer, shall be as follows: (1) Special. 6.5 percent. (2) Critical. 1.0 percent where tests are destruc tive. For non-destructive tests, see 63. (3) Major. 23 percent, (4) Minor. 4.0 percent. For critical characteristics and where tests are non destructive, each item manufactured shall be 100 percent inspected for nonconformances, and all nonconforming items shall be rejected. 73 Inspection Levels. Inspection level II as described in MIL-STD-414,1959, shall be used for special characteristics and destructive tests for critical characteristics, except when an equivalent inspection level is utilized. Inspection level II as described in MIL-STD-105D, 1989, or inspection level IV as described in MIL-STD-414.1959, shall be used for major and minor characteristics, except when an equivalent inspection level is utilized. 7 3M 110374 j y (This Appendix is not part of American National Standard ANSI/ISEA 102-1990. but is lA" information only.) . for Recommendation and Precaution concerning Gas Detector Tube Unit Use Since the indicating behavior of a detector tube depends not only on the stroke volume, but also on the qwtjon characteristic of the pump, it must be ensured that each detector tube is used only with the prescribed pump. Pump and tube and components are designed, manufactured, and calibrated together to form a gas detector tube unit User interchange ofpumps and tubes or components supplied by different manufacturers may provide erroneous and invalid measurements of toxic environments. Accordingly, such interchange is nor recommended. 8 3M UO375 Internal Correspondence __ . 3M Occupational Health and Environmental Safety Division To: R. J. Haggerty - OH&ESD - 275-6W-01 R.E. King - OH&ESD - 260-3B-09 From: R.A. Weber (7-4459) - OH&ESD - 260-3B-09 Subject: ISEA INSTRUMENT & GROUP MEETINGS Date: June 2, 1995 The ISEA Instrument group had two meetings during the AIHC. The first meeting involved the subcommittee working on the diffusion monitor protocol and the second was the entire instrument group. Review of Diffusion Monitor Subcommittee Meeting The following people were in attendance: Skip Elliott - Environmetrics, Gus Manning - Assay Technology, Lawrence Locker - Advanced Chemical Sensors, Katie Spear - MSA, Bob Curtis - OSHA, Martin Harper - SKC, Stephen Zlocysti MSA (Auer). The group elected officers; Skip Elliott was elected chairman and I was elected vice-chairman. Stephen Zlocysti, chairman of the CEN committee working on the European diffusion monitor standard gave our group an update on their standard prEN838. This standard is now out for votes and he expected it to be a final standard by the end of the year. Since our last meeting in February, the group has been very active in writing the standard. We reviewed the draft document during this session and in general, we had some lively discussions. Some of the issues involved the following: 1. The types of devices that this standard should cover. Presently, we have settled on three classifications. 3H 110387 Page Two June 2, 1995 2. We discussed the evaluation criteria and we ended up with a consensus on what types of tests need to be conducted. Specifics on sample sizes and testing levels are still open for further discussion. We agreed that we will not include pressure in evaluation criteria and we also agreed that factorial designed experiments may be run as an option. 3. We agreed that the document should contain language or guidance on field evaluations. 4. The document will contain recommendations for manufacturers. This section will include information on quality control programs and labeling. 5. We decided that 25% accuracy would not be a requirement. Accuracies only need to be determined and started. Each member of the committee has specific sections to develop. Draft sections need to be submitted by the end of July. In August the document will be sent out for committee review. If committee finds this draft acceptable, we will then distribute to a field of experts for their comments. These comments will then be reviewed at our next committee meeting. We are scheduled to meet again during the National Safety Congress. Instrument Group Meeting The members of this group are mainly concerned about direct reading instruments. All of the major players in the business are participants in ISEA. Following is a list of items that the committee is actively involved with: ANSI Standard on Detector Tubes, ISA 02 Standard, NFPA306, CEN Instrument Standards, ANSI Z-l 17 Confined Space Standard, OSHA 1910.134 and writing an ANSI Diffusion Monitor Protocol. Although we presently do not have a product that fits into the direct reading sensor market, the meeting gave me an understanding of issues that our competition is dealing with. 3M 110388 Page Three June 2, 1995 Summary I walked away from this meeting realizing that there is a maze of instrument and sensor standards that we need to better understand if we ever plan to enter this market. My major objectives in working with this ISEA committee is to assist in writing the ANSI Diffusion Monitor Protocol and to learn about the standards and issues of gas and vapor detection instruments. RAW:llj/45 cc: D.C. Breckle - OH&ESD - 275-6W-01 A.R. Johnston - OH&ESD - 260-3B-09 L.A. Koerschner - OH&ESD - 260-3B-10 D.J. Larsen - OH&ESD - 260-3B-08 A.C. Murray - OH&ESD - 275-6W-01 J.B. Palazzotto - OH&ESD - 260-3B-08 K.E. Reed - OH&ESD - 260-3A-02 Y.T. Shih - OH&ESD - 260-3B-08 L.G. Swope - OH&ESD - 275-6W-01 3M 110389 ^4" assay m technology The Technology Leader in, Personal Monitoring for Chemicals in the Workplace 1070 B. Meadow Circle Palo Alto, California 94303 FAX NUMBER : (415) 424-033$ / <*'3 J (415) 424-9944 V (800) 833-1258 mm; 12-14-95 T0: BOB WEBER" . ` COMPANY: 3M Co. FROM: GUS MANNING This Is page ONE of, ^ YOUR PAX NUMBER; uw.ni.nu REFERENCE: . SEE BELOW/ATTACHED Pages. If you do not receive all pages, please call 1*600-533-1258. Dear Bob... At our recent meeting of the Diffusive Sampler standard committee I was asked to work on the material you provided with respect to Field Testing. 1 agreed with every word you wrote and only sought to reduce the number of words and, perhaps, to sharpen the focus a little. Please review what I have done and provide some feedback either to myself or directly to Bill Erny at ISEA. - Best Regards... Gus Manning Field Testing While environmental factors affecting the accuracy of Diffusive Air Sampling Devices are described and studied in the Evaluation Program, factors which may affect accuracy in particular workplaces may be difficult to include in studies which can be reasonably conducted by device manufacturers or third party evaluators. Workplacespecific factors may include fluctuations in temperature, humidity* etc., beyond ranges studied, and, especially, the presence of substances which may overload the sampling device or interfere with the analysis of contaminants. The validation of Air Sampling Devices subject to such factors is generally believed to be accomplished by field testing. While field studies have the advantage of utilizing actual workplace conditions, they also have disadvantages, as follows. (1) Field conditions may not allow the analyst to present sufficient reference devices to uniform contaminant concentrations to establish statistically valid reference values tor comparison to the devices being tested. (2) Field conditions in a particular study may not reflect typical field conditions tor the workplace being studied. (3) Field conditions in a particular field study may not be applicable to other workplaces. In summary, field testing is recommended as a desirable supplement to the Standard which can determine the suitability of a generally validated Air Sampling Device for a specific workplace. Since field conditions existent in a particular workplace may not represent other workplaces, specific field testing requirements are not included in this standard which is developed for the general evaluation of devices. Further, field testing is not viewed as a replacement for the tests described under Evaluation Program. Ask about the u.Handbook for Chemical Exposure Monitoring and. Control" J10390 * May 2, 1995 VALIDATION OF DIFFUSION MONITORS SLIDE 1 (Title) Validation of Diffusion Monitors. R.A. Weber, and D.J. Larsen, 3M Occupational Health and Environmental Safety Division, 3M Center, Building 260-3B-09, St Paul 55144 SLIDE 2 (Picture) Difiusion monitors utilize the natural phenomena of difiusion to collect gases & vapors. Difiusion monitors have undergone extensive evaluations by the scientific community since their introduction in the late 1970's. Some of these evaluations have been comparison studies with reference sampling methods such as charcoal tubes and pumps while other evaluations have included the development of large validation protocols. Today I would like to talk about some of those protocols, plus I would like to present a newly developed 3M protocol that includes many aspects reviewed in other works. 3M has always conducted validation studies of their difiusion monitors, but with this new protocol we are standardizing our testing techniques. SLIDE 3 . A validation protocol specifies performance criteria that needs to evaluated. It should also include specific testing conditions, such as chamber exposure concentrations and sampling times. It may also reference sample sizes and the type of statistics that should be used to evaluate the critera. One goal of a protocol is to define the limitations of the sampling device. This is an important aspect that is sometime overlooked. For example, one type of diffusion monitor may not sample accurately for 8 hours at 2 times the PEL for benzene, however it may be very accurate at sampling the STEL for benzene. The protocol should find those performance limits and outline them so the user can understand the boundaries in which they operate. SLIDE 4 Most diffusion monitor validation studies agree on one thing that is the performance criteria that should be studied, such as, desorption efficiency, humidity, sampling rate, reverse diffusion, storage, face velocity, temperature, orientation and the relationship of concentration and time. 3H 110398 SLIDE 5 Since the introduction of diffusion monitors there have been numerous published and un published protocols. Manufacturers, laboratories, NIOSH, the European Community and now possibly the Industrial Safety Equipment Associate (ISEA) have all taken their turns in developing validation protocols. SLIDE 6 In the late 1970's 3M and DuPont were involved in the development of diffusion monitors, including setting of performance critera for evaluating accuracy. They realized that diffusion monitors like all other sampling devices do have limitations and they recognized that those limits needed to be investigated. Recently other manufacturers of diffusion monitors have also published information on methods. For example SKC has developed a bi-level validation approach, this technique evaluates performance of diffusion monitors for classes of compounds. SLIDE 7 Laboratories throughout the world have been involved in evaluating diffusion monitors since their introduction. Much of the evaluation work has been published in peer reviewed journals. Exxon, Abbot Laboratories and Goodyear have all conducted validation studies and while the studies were designed differently they looked at many of the same performance critera. In 1984 Brown et. al, at the Occupational Hygiene Laboratory published a paper titled "A Diffusive Sampler Evaluation Protocol." This work evaluated many of previously mentioned performance criteria, however instead of looking at each separately, factorial experiments were designed to look at the interaction of performance criteria. 3M 110399 1 SLIDE 8 In the late 1970's when diffusion monitors were introduced NIOSH took an active role in assisting in the development of guidelines for their evaluation. In 1987 NIOSH published a protocol intended as a guideline for manufactures and others to follow to evaluate diffusion monitors. This document has created allot of confusion in the industrial hygiene environment because some people have viewed this document as a standard instead of a guidance document. The protocol outlines many ofthe performance critera mentioned earlier, however NIOSH took the program one step further and recommended a complex 16 run factorial designed experiment. The protocol also included sample sizes for each experiment. In order to implement this protocol for a single chemical it would take in excess of 200 diffusion monitors. Because of the cost and complexity of the protocol it has never been fully accepted in the industrial hygiene community. SLIDE 9 The European Community for Standardization (CEN) has developed a protocol for diffusion monitors. The goal of the standard is a consistent procedure for manufactures and users to follow for evaluating diffusion monitors. Presently the protocol prEN 838 is in the draft stage. It addresses the same performance critera that has already been previously mentioned. SLIDE 10 At the request of OSHA the Industrial Safety Equipment Association (ISEA) and the Safety Equipment Institute (SEI) were asked to become involved in writing a ANSI sponsored validation protocol and developing a certification program for diffusion monitors. This process and program would be very similar to what has been developed and implemented with detector tubes. The program has just begun and a timetable for completion has not been established. 3H 110400 SLIDE 11 Consensus among manufactures and users is that diffusion monitors should undergo a laboratory evaluation prior to use in the field. Unfortunately to date a standardized evaluation program or validation protocol has never been agreed upon, therefore there many validation studies done over the years all have been designed differently. As a result there has been confusion about the performance of diffusion monitors. We believe the objectives of properly designed protocol are as follows: 1. Show the operating limits of the device 2. Evaluate desorption efficiency, reverse diffusion, storage, sampling rate, humidity, air velocity and the relationship between concentration and exposure time. 3. Can be utilized by others 4. Specify Testing Conditions 5. Results of validation are meaningful and they can be easily shared with the user, such as the industrial hygienist. While we wait for the ISEA/ANSI document to become a reality 3M has decided to implement their own standardized diffusion monitor protocol, in which the information can be easily passed along the end user. I would like to now review our protocol SLIDE 12 The first performance criteria to be evaluated in the validation study should be desorption efficiency. Recoveries will vary depending on the affinity of the analyte to the sorbent, solubility of the anlayte in the desorbing agent and the mass of analyte collected. The most wildly used solvent today is carbon disulfide, however alternative sorbents should be investigated if recoveries are below 75%. Possible alternatives are methylene chloride and acetonitrile. Some recent work by the OSHA Salt Lake City Laboratory has revealed that a mixture of CS2 and dimethylforamide (DMF) results in excellent recoveries with polar compounds. 3M 1 SLIDE 13 Our desorption efficiency study consists of analyzing three sets of four monitors at a mass levels that represent eight hour exposures at 0.1 EL, 0.5 EL and 1.0 EL. NOTE.EL refers to the exposure level, it could represent the TLV or PEL or another appropriate standard. Ifthe mean recoveries are greater than 75 % and the coefficient ofvariation is, <. 1 then the recovery solvent is acceptable. SLIDE 14 The following results were obtained by desorbing monitors with carbon disulfide. The data indicates for the mass levels between 0.1 to 1.0 EL for 8 hours - you could expect recoveries > 85%. Therefore the CS2 is an appropriate desorbing solvent for methylene chloride and toluene. SLIDE 15 Humidity will influence collection of gas & vapor contaminants with diffusion monitors because water will compete for active sites on the sorbent. This set of tests will investigate the relationship between relative humidity and capacity. Results can also be used to determine the sampling rate of the diffusion monitor. SLIDE 16 The test method utilizes 12 diffusion monitors. Monitors are exposed to 1 EL at a RH of 50%. 3 monitors are removed after 2 hours, 4 hours 6 hours and 8 hours.. Next the experiment is repeated at 80% RH. 3M 1104Q2 SLIDE 17 To interpret the results compare the derived sampling rates for the 50% RH and the 80% RH and 2 and 4 hour sampling times, this is referenced as cells 1,2,5, and 6, if results are statistically the same it shows that monitors can be used up to four hours. Next compare the 50% and 80% RH, 6 and 8 hour sampling rates, cells 3,4,7 and 8 with the previous calculated rates. If these are statistically the same it shows that the monitors can be used up to 1 EL for 8 hours. The table shows that the toluene sampling rate at 50% and 80% RH's for the 2 to 8 hour sampling times are the same, therefore the sampling rate then can be determined from cells 1 -8. SLIDE 18 The linear sampling rate of Toluene over these conditions can also be seen graphically by comparing the mass collected vs the sampling time. SLIDE 19 Reverse diffusion is defined as the loss of analyte that had been previously been adsorbed on the sorbent. Sorbents will have a finite capacity for gas & vapor analytes and this capacity may be reduced as environmental influences are introduced, such as other analytes or water vapor from high humidity. SLIDE 20 To evaluate reverse diffusion, 12 monitors were exposed to 2 EL for 30 minutes at 80% RH. After 30 minutes 6 monitors were removed and analyzed and the other 6 monitors are exposed to clean 80% RH air for an additional 450 minutes. The sampling rate means from each set are compared. Ideally reverse diffusion should be less than 10%. Losses >10% may indicate the need for a monitor with a back-up section or sampling times < 8 hours SLIDE 21 This graph shows that under experimental conditions the loss by reverse diffusion for both toluene and methylene chloride is <10%. 3M 110403 SLIDE 22 The next performance criteria that is evaluated is the relationship between concentration and sampling time. These experiments will define the uniformity of the sampling rate over a range of exposure times and exposure concentrations. This technique was outlined by Brown, et al in 1984 and as you will see it will provide a sampling performance matrix with respect to concentration and time. SLIDE 23 The two factorial design consists of nine separate experiments. This test can be performed in two steps. First, six diffusion monitors are exposed to conditions outlined in cells 1,3,7 and 9. Sampling rates from each experiment are determined. Cells 1,3,7 and 9 show the outer operating boundaries of the device. The accuracy of the sampling and analytical method can then be determined by using the sampling rate derived from the humidity experiments or from a previously published sampling rate. If accuracy's in cells 1,3,7 and 9 are not acceptable then accuracy's can be determined in the remaining cells. Exposure conditions outlined in the cells will have to vary from compound to compound, this is because as EL's get lower it becomes more difficult to generate test atmospheres and it becomes difficult to collect enough mass for analysis, therefore the accuracy determined in cells 1 and 3 may be greatly influenced by these conditions. SLIDE 24 The following is an example of this experiment. It shows the operating accuracy's of the an OVM for sampling toluene. The EL for this experiment was 100 ppm and a SR of 31.4 cc/min. was used as the reference to determine accuracy's. SLIDE 25 As noted earlier the sampling rate can be determined experimentally in the humidity studies However sampling rates can also be obtained theoretically by using the diffusion coefficients determined by the Hirsfelder equation and the empirical relationship defined by studying classes of compounds such as ketones, alcohols, aliphatics, esters, cellosolves, aromatics and halogens. 3M 110404 SLIDE 26 The following graph shows the sampling rate as a function of diffusion coefficient for 14 different halogenated compounds. The diffusion coefficient in cm2/ sec for methyl chloride is . 1102 and by using the regression line the theoretical sampling rate for methylene chloride 37.9 cc/min. The sampling rate obtained empirically by our latest humidity studies indicates a sampling rate of 37.4 SLIDE 27 Prolonged storage of diffusion monitors between exposure and analysis can potentially lead to errors. This experiment investigate loss of analyte after collection. Plus it also investigates room temperature storage vs refrigeration storage. SLIDE 28 Air velocity and orientation is also included in our validation program. The purpose of this experiment is to determine the minimum face velocity that is required and to evaluate the affects that orientation has on sampling rate. SLIDE 29 The final criteria in our validation protocol investigates the influence of temperature on the sampling rate. 3H ii405 SLIDE 30 Sampling gases & vapors with diffusion monitors offers many advantages over active sampling with a pump and sorbent tubes. The simplicity of monitors makes the task of characterizing the workplace environment much easier for the industrial hygienist. However the user ofthe monitor needs to understand the limits or operating boundaries of the device. All diffusion monitors operate based on Fick's law, but because of different geometry's and sorbents the operating boundaries will vary for each. In order for the user to compare monitors it is important that a standardized testing protocol be developed and utilized. The standardized technique must be practical and realistic to implement. The task of validating monitors for the hundreds of organic compounds is too great of a burden for manufacturers to undertake. Therefore private analytical laboratories may have to conduct their own validation studies. In 1992 Guild et al, proposed a bi-level validation. This approach involves validating a monitor to classes of compounds. The assumption in this technique is that if you can show the operational boundaries for the most demanding anlayte of a chemical class then you can assume the monitor will operate within the those same boundaries for less demanding analytes in that chemical class. In order to fully evaluate the performance of a diffusion monitor it also needs to undergo field evaluation. Environmental conditions cannot be fully duplicated in the laboratory. Therefore any type of diffusion monitor validation program should contain some guidance on how to evaluate in the field. 3M 110406 VALIDATION OF DIFFUSION MONITORS Presented at the 1995 American Industrial Hygiene Conference & Exposition SLIDE 1 (Title) Validation of Diffusion Monitors. R.A. Weber, and D.J. Larsen, 3M Occupational Health and Environmental Safety Division, 3M Center, Building 260-3B-09, St Paul 55144 SLIDE 2 (Picture) Diffusion monitors utilize the natural phenomena of diffusion to collect gases & vapors! Diffusion monitors have undergone extensive evaluations by the scientific community since their introduction in the late 1970's. Some of these evaluations have been comparison studies with reference sampling methods such as charcoal tubes and pumps while other evaluations have included the development of large validation protocols. Today I would like to talk about some of those protocols, plus I would like to present a newly developed 3M protocol that includes many aspects reviewed in other works. 3M has always conducted validation studies of their diffusion monitors, but with this new protocol we are standardizing our testing and reporting techniques. SLIDE 3 A validation protocol specifies performance criteria that needs to evaluated. It should also include specific testing conditions, such as chamber exposure concentrations and sampling times. It may also reference sample sizes and the type of statistics that should be used to evaluate the criteria. One goal of a protocol is to define the limitations of the sampling device. This is an important aspect that is sometime overlooked. For example, one type of diffusion monitor may not sample accurately for 8 hours at 2 times the PEL for benzene, however it may be very accurate at sampling the STEL for benzene. The protocol should find those performance limits and outline them so the user can understand the boundaries in which they operate. 3M 110407 SLIDE 4 Most diffusion monitor validation studies agree on one thing that is the performance criteria that should be studied, such as, desorption efficiency, humidity, sampling rate, reverse diffusion, storage, face velocity, temperature, orientation and the relationship of concentration and time. SLIDE 5 Since the introduction of diffusion monitors there have been numerous published and un published protocols. Manufacturers, laboratories, NIOSH, the European Community and now possibly the Industrial Safety Equipment Associate (ISEA) have all taken their turns in developing validation protocols. SLIDE 6 In the late 1970's 3M and DuPont were involved in the development of diffusion monitors, including setting of performance critera for evaluating accuracy. They realized that diffusion monitors like all other sampling devices do have limitations and they recognized that those limits needed to be investigated. Recently other manufacturers of diffusion monitors have also published information on methods. For example SKC has developed a bi-level validation approach, this technique evaluates performance of diffusion monitors for classes of compounds. SLIDE 7 Laboratories throughout the world have been involved in evaluating diffusion monitors since their introduction. Much of the evaluation work has been published in peer reviewed journals. Exxon, Abbot Laboratories and Goodyear have all conducted validation studies and while the studies were designed differently they looked at many of the same . performance critera. In 1984 Brown et. al, at the Occupational Hygiene Laboratory published a paper titled "A Diffusive Sampler Evaluation Protocol." This work evaluated many of previously mentioned performance criteria, however instead of looking at each separately, factorial experiments were designed to look at the interaction of performance criteria. 3M 110408 SLIDE 8 In the late 1970's when diffusion monitors were introduced NIOSH took an active role in assisting in the development of guidelines for their evaluation. In 1987 NIOSH published a protocol intended as a guideline for manufactures and others to follow to evaluate diffusion monitors. Although the intent of this document was purely guidance some people viewed it as a requirement or standard, thus creating confusion. The protocol outlines many of the performance critera mentioned earlier, however NIOSH took the program one step further and recommended a complex 16 run factorial designed experiment. The protocol also included sample sizes for each experiment. In order to implement this protocol for a single chemical it would take in excess of 200 diffusion monitors. The NIOSH Document established a good starting point for building a universal protocol but, because of the cost and complexity of the protocol it has never been fUlly accepted in the industrial hygiene community. SLIDE 9 The European Community for Standardization (CEN) has developed a protocol for diffusion monitors. The goal of the standard is a consistent procedure for manufactures and users to follow for evaluating diffusion monitors. Presently the protocol prEN 838 is in the draft stage. It addresses the same performance critera that has already been previously mentioned. SLIDE 10 At the request of OSHA the Industrial Safety Equipment Association (ISEA) and the Safety Equipment Institute (SEI) were asked to become involved in writing a ANSI sponsored validation protocol and developing a certification program for diffusion monitors. This process and program would be very similar to what has been developed and implemented with detector tubes. The program has just begun and a timetable for completion has not been established. 3M 1104Q9 SLIDE 11 Consensus among manufactures and users is that diffusion monitors should undergo a laboratory evaluation prior to use in the field. Unfortunately to date a standardized evaluation program or validation protocol has never been agreed upon, therefore there many validation studies done over the years all have been designed differently. As a result there has been confusion about the performance of diffusion monitors. We believe the objectives of properly designed protocol are as follows: 1. Show the operating limits of the device 2. Evaluate desorption efficiency, reverse diffusion, storage, sampling rate, humidity, air velocity and the relationship between concentration and exposure time. 3. Can be utilized by others 4. Specify Testing Conditions 5. Results of validation are meaningful and they can be easily shared with the user, such as the industrial hygienist. While we wait for the ISEA'ANSI document to become a reality 3M has decided to implement their own standardized diffusion monitor protocol, in which the information can be easily passed along the end user. I would like to now review our protocol SLIDE 12 The first performance criteria to be evaluated in the validation study should be desorption efficiency. Recoveries will vary depending on the affinity of the analyte to the sorbent, solubility of the anlayte in the desorbing agent and the mass of analyte collected. The most wildly used solvent today is carbon disulfide, however alternative solvents should be investigated if recoveries are below 75%. Possible alternatives are methylene chloride and acetonitrile. Some recent work by the OSHA Salt Lake City Laboratory has revealed that a mixture of CS2 and dimethylforamide (DMF) results in excellent recoveries with polar compounds. 3M 110410 SLIDE 13 Our desorption efficiency study consists of analyzing three sets of four monitors at mass levels that represent eight hour exposures at 0.1 EL, 0.5 EL and 1.0 EL. NOTE:EL refers to the exposure level, it could represent the TLV or PEL or another appropriate standard. If the mean recoveries are greater than 75 % and the coefficient of variation is, <. 1 then the recovery solvent is acceptable. SLIDE 14 The following results were obtained by desorbing monitors with carbon disulfide. The data indicates for the mass levels between 0.1 to 1,0 EL for 8 hours - you could expect recoveries > 85%. Therefore the CS2 is an appropriate desorbing solvent for methylene chloride and toluene. SLIDE 15 Humidity will influence collection of gas & vapor contaminants with diffusion monitors because water will compete for active sites on the sorbent. This set of tests will investigate the relationship between relative humidity and capacity. Results can also be used to determine the sampling rate of the diffusion monitor. SLIDE 16 The test method utilizes 12 diffusion monitors. Monitors are exposed to 1 EL at a RH of 50%. 3 monitors are removed after 2 hours, 4 hours 6 hours and 8 hours.. Next the experiment is repeated at 80% RH. 3M 110411 SLIDE 17 To interpret the results compare the derived sampling rates for the 50% RH and the 80% RH and 2 and 4 hour sampling times, this is referenced as cells 1,2,5, and 6, if results are statistically the same it shows that monitors can be used up to four hours. Next compare the 50% and 80% RH, 6 and 8 hour sampling rates, cells 3,4,7 and 8 with the previous calculated rates. If these are statistically the same it shows that the monitors can be used up to 1 EL for 8 hours. The table here shows that the toluene sampling rate at 50% and 80% RH's for the 2 to 8 hour sampling times are the same, therefore the sampling rate then can be determined from cells 1 -8. , SLIDE 18 The linear sampling rate of Toluene over these conditions can also be seen graphically by comparing the mass collected vs the sampling time. SLIDE 19 The humidity experiment was run with methylene chloride. Results indicate that the 2, 4 and 6 hour sampling rates are statistically the same. Represented in cells 1,2,3,5,6 and 7. The 8 hour sampling rates in cells 4 and 8 are statistically different. Conclusion form this experiment is that if you sample . 6 hours the accuracy will begin to be affected, especially at 80% RH. SLIDE 20 Reverse diffusion is defined as the loss of analyte that had been previously been adsorbed on the sorbent. Sorbents will have a finite capacity for gas & vapor analytes and this capacity may be reduced as environmental influences are introduced, such as other analytes or water vapor from high humidity. SLIDE 21 To evaluate reverse diffusion , 12 monitors were exposed to 2 EL for 30 minutes at 80% RH. After 30 minutes 6 monitors were removed and analyzed and the other 6 monitors are exposed to clean 80% RH air for an additional 450 minutes. The sampling rate means from each set are compared. Ideally reverse diffusion should be less than 10%. Losses >10% may indicate the need for a monitor with a back-up section or sampling times < 8 hours 3M 110412 SLIDE 22 This graph shows that under experimental conditions the loss by reverse diffusion for both toluene and methylene chloride is <10%. SLIDE 23 The next performance criteria that is evaluated is the relationship between concentration and sampling time. These experiments will define the uniformity ofthe sampling rate over a range of exposure times and exposure concentrations. This technique was outlined by Brown, et al in 1984 and as you will see it will provide a sampling performance matrix with respect to concentration and time. SLIDE 24 The two factorial design consists of nine separate experiments. This test can be performed in two steps. First, six diffusion monitors are exposed to conditions outlined in cells 1,3,7 and 9. Sampling rates from each experiment are determined. Cells 1,3,7 and 9 show the outer operating boundaries of the device. The accuracy of the sampling and analytical method can then be determined by using the sampling rate derived from the humidity experiments or from a previously published sampling rate. If accuracy's in cells 1,3,7 and 9 are not acceptable then accuracy's can be determined in the remaining cells. Exposure conditions outlined in the cells will have to vary from compound to compound, this is because as EL's get lower it becomes more difficult to generate test atmospheres and it becomes difficult to collect enough mass for analysis, therefore the accuracy determined in cells 1 and 3 may be greatly influenced by these conditions. SLIDE 25 The following is an example of this experiment. It shows the operating accuracy's of the an OVM for sampling toluene. The EL for this experiment was 100 ppm and a SR of 31.4 cc/min. was used as the reference to determine accuracy's. 3H 110413 SLIDE 26 The same experiment was run with methylene chloride. Results indicate a range of accuracy's. Note cell 3, the accuracy at 2.5 ppm for 8 hours was 26.6%. This result is larger then the others not because of performance of the device, but because of the difficulty in generating a 2.5 ppm test atmosphere. Also note cell 9, this test was run at 50 ppm for 8 hours. Earlier I indicated that sampling . 6 hours will influence accuracy and this experiment shows the degree of influence. SLIDE 27 As noted earlier the sampling rate can be determined experimentally in the humidity studies However sampling rates can also be obtained theoretically by using the diffusion coefficients determined by the Hirsfelder equation and the empirical relationship defined by studying classes of compounds such as ketones, alcohols, aliphatics, esters, cellosolves, aromatics and halogens. SLIDE 28 The following graph shows the sampling rate as a function of diffusion coefficient for 14 different halogenated compounds. The diffusion coefficient in cm2/ sec for methyl chloride is . 1102 and by using the regression line the theoretical sampling rate for methylene chloride 37.9 cc/min. The sampling rate obtained empirically by our latest humidity studies indicates a sampling rate of 37.4 SLIDE 29 Prolonged storage of diffusion monitors between exposure and analysis can potentially lead to errors. This experiment investigate loss of analyte after collection. Plus it also investigates room temperature storage vs refrigeration storage. SLIDE 30 Air velocity and orientation is also included in our validation program. The purpose of this experiment is to determine the minimum face velocity that is required and to evaluate the affects that orientation has on sampling rate. ' 3M 110414 SLIDE 31 The final criteria in our validation protocol investigates the influence of temperature on the sampling rate. SLIDE 32 Sampling gases & vapors with diffusion monitors offers many advantages over active sampling with a pump and sorbent tubes. The simplicity of monitors makes the task of characterizing the workplace environment much easier for the industrial hygienist. However the user of the monitor needs to understand the limits or operating boundaries of the device. All diffusion monitors operate based on Fick's law, but because ofdifferent geometry's and sorbents the operating boundaries will vary for each. In order for the user to compare monitors it is important that a standardized testing protocol be developed and utilized. The standardized technique must be practical and realistic to implement. The task of validating monitors for the hundreds of organic compounds is a great undertakeing, therefore private analytical laboratories and manufacturers may both have to conduct their own validation studies. In 1992 Guild et al, proposed a bi-level validation. This approach involves validating a monitor to classes of compounds. The assumption in this technique is that if you can show the operational boundaries for the most demanding anlayte of a chemical class then you can assume the monitor will operate within the those same boundaries for less demanding analytes in that chemical class. In order to fully evaluate the performance of a diffusion monitor it also needs to undergo field evaluation. Environmental conditions cannot be fully duplicated in the laboratory. Therefore any type of diffusion monitor validation program should contain some guidance on how to evaluate in the field. 3M 110415 l Validation of Diffusion Monitors R.A. Weber and D.J. Larsen 3M Occupational Health and Environmental Safety Division 3M 110416 * Goals of Validation Protocols Define performance criteria Specify testing conditions and sample size to evaluate performance criteria Define the limitations of the sampling device 3M 110417 Performance Criteria m Desorption Efficiency Humidity Sampling Rate Reverse Diffusion Storage Face Velocity Temperature and Orientation Relationship Between Concentration and Time g ltfllV Protocol Development Manufacturers Laboratories NIOSH European Community (CEN) ISEA 3M 110419 Manufacturers 3M and DuPont -Developed performance criteria and test conditions SKC developed bi-level validation technique Laboratories AlHA-Accredited Laboratories - Exxon - benzene - Abbott - ethylene oxide -Goodyear - vinyl chloride European Laboratories - Occupational Hygiene Lab London (1984) - Factorial experiments O IO NIOSH Late 1970s identified the need for a universal testing protocol - Specified performance criteria and experimental parameters -Sample size and simple statistics 1987 Protocol - Guidance document - Specified performance criteria -Sample size - > 200 diffusion monitors needed for a single gas and vapor analyte 3H 110422 CEN European Committee for Standardization Proposed Standard (prEN) "Workplace atmospheres - diffusive samplers for the determination of gases or vapors - Requirements and test methods" Outlines performance criteria Test methods specified 3M 11042 Industrial Salflety Equipment Association (ISEA) OSHA request for involvement in developing a protocol Safety Equipment Institute (SEI) certified 3M Validation Protocol (Objectives) Outline the operating limitations Evaluate performance criteria Specify testing conditions Laboratories and others should be able to implement Results can be easily shared and understood 3M 110425 Desorptidb Efficiency (Toluene & Methylene Chloride) Methylene Chloride Desorption Efficiency ~ Exposure Level Mean Mass Spiked Mean Recovery CV (%) 1.0 (EL) 0.5 (EL) 0.1 (EL) EL: ~25ppm ~ Exposure Level 1.59mg 0.795mg 0.159mg 0.902 0.901 0.877 Toluene Desorption Efficiency Mean Mass Spiked Mean Recovery 5.04 5.88 3.63 CV (%) 1.0 (EL) 0.5 (EL) 0.1 (EL) EL: -100pm 5.64mg 3.03mg 0.434mg 1.02 1.02 0.961 1.07 2.57 2.19 3M 110427 Humidity Relationship between humidity and capacity Water vapor competes for active sites on carbon sorbent Influence of water will vary depending on chemical properties M oo Desorptidh Efficiency (Test Method) 3 sets of four monitors Vapor spike mass levels (8 hours) -0.1 x EL - 0.5 x EL -1.0 x EL > 75% recovery with a CV <0.1 Note: EL equals an exposure level. It may represent a TLV or PEL or other appropriate standard. 3M 110429 Hufhidity (Toluene) Relative Humidity (%) 2 Hour Sample (SR) 4 Hour Sample (SR) 6 Hour Sample (SR) i2 3 50 30.8 1.1 31.0 1.5 29.7 1.4 56 7 80 30.4 1.1 30.8 2.3 29.4 1.0 8 Hour Sample (SR) 4 31.2 .3 8 29.7 1.4 SR = Sampling rate std. dev. x SR = 30.37 .2 (Based on cells 1-8) 3M 110430 Amount coll cted (mg) Toluene Hiltnidity Effects (1 EL, 50% & 80% RH) 50%RH a 80%RH Time (min) Concentration vs. Time (Toluene) Cone/ Time .1 EL 15 min. (accuracy) 1 23.8% 240 min. (accuracy) 2 480 min. (accuracy) 3 12.1% 1 EL 45 6 2 EL 8 6.8% 9 EL: ~1 OOppm Accuracy = 2 CV Bias Published SR =31.4cc/min. o'* CO 3H 110432 Temperature i Evaluate the influence of temperature on sampling rate 3M 110433 Desorption Efficiency I Methylene Chloride 100 11 11 11c<oo>cD 75 50 25 0.1 0.5 1.0 EL 1 EL: ~25ppm/8hrs eco con Toluene .100 75 a: 25 sO ^0 0.1 0.5 1.0 EL 1 EL: 100ppm/8hrs CO V/i/IIl/CJIU O^l/I f V * llliw (Methylene Chloride) Cone/ Time .1 EL 15 min. 240 min. (accuracy) (accuracy) 12 480 min. (accuracy) 3 26.6% 1 EL 45 6 2 EL 14.3% 7 8 7.7% 9 E L : ~25 ppm Accuracy = 2 CV Bias Published SR = 37.9 cc/min. 3H 110435 3M Occupational Health and Environmental Safety Division 3M Center St. Paul, Minnesota 55144-1 ooo 612/733 1110 December 18, 1989 . Milagros Diaz Parra Supervisor de Higiene Ocupacional Pequiven - Apartado 159 - Maracaibo, Venezuela - FAX 011-58-66-311053/100 RECEIVED MAR 0 9 1995 M.C. Fancy Dear Ms Diaz, In response to your Fax message to Doug Taylor, here are the responses. * 1. The appropriate monitor for vinyl Chloride Monomer is ~ the 3520. Since activated carbon has limited afinity for VCM, you should not use the 3500. I also recommend that you use the ratio of the weight of VCM analyte on the front and back sections of the 3520 as an internal check on the validity of the sample. If the amount of analyte found on the second sorbent wafer exceeds 50% of the material on the front sorbent wafer, then the sample is not valid. The ' details of this are covered in an 3520 Sampling Guide I am sending you. 2. I am sending you technical details of the 3720 monitor, and its validation studies in comparison to bisulfite impingers in the laboratory and field studies involving the 3720. The temperature correction coefficient for diffusional monitors comes from theoretical treatment of diffusion processes. These apply equaly to formaldehyde difusion, and the temperature correction factors found in the sampling guide for organic vapor monitors can be used. You will note that these correction factors are not very large, and are close to the value 1.0. The 3720 Formaldehyde Monitor can be used in a wide relative humidity range. We tested the product in RH ranges from 25% to 85%. This variation in RH has shown no variation in sampling rate. At extremely low RH's, we expect the collection efficiency vof the monitor to be affected if humidifying pad of the secondary body dries out, and the monitor sorbent cannot be humidified sufficiently during monitoring to allow the reaction of formaldehyde with the bisulfite salt in the 3M 010111 Page - 2 sorbent waf r. I would not expect this to be of concern in Venezuela. 3. - Sampling Rate Validation. I am sending you a copy of the Sampling Rate validation protocol. If there are compounds you wish to monitor which do not show up in the published tables with sampling rates, please consult us. By knowing the boiling point and molecular weight of the substances, we can compute the sampling rate using the Hirshfelder Equation and communicate this to you. Although this is only a semiempirical sampling rate, it is considered accurate to within +/" 5%. 4. You will need to send the Mercury Monitor back to our Monitor Analysis service for analysis. Please send monitors to: Monitor Analysis Service OH & ES Division Building 76-2W-02 St Paul, MN 55107 ' USA -' The 3600 Monitor analysis results goes back to you by 1st Class normal mail. Be sure to include your return address. I hope this answers all your questions. Sincerely, Paul Olson International Technical Manager 3M/Occupational Health and Environmental Safety Division cc: Doug Taylor - 220 - 3E - 04 Antonio Mata - 3M Venezuela 3M 010112 `f ` t ft ' Internal Correspond nee dc P.F.Guehler To: From: Subject: Date: E. D. HORNE L. W. ANDERS NIOSH RECOMMENDATION January 6, 1982 The attached NIOSH letter of October 9, 1979 is the only written recommendation: In the second paragraph, "NIOSH's immediate recommendation will be to- encourage use of the OVM #3500 for those compounds which have a complete set of data to verify among other properties, the capacity, recovery coefficient, and upper exposure limit at high humidity of the badge for the compound. These data may come from a variety of sources which include your laboratories as well as ours .... As new compounds qualify, the-use of the monitor will be expanded". We have done an extensive amount of documentation of sampling rate, capacity, recovery coefficient and upper exposure limits. This information was used to publish the new Sampling and Analysis Guide in May 1981. The technical documentation from the attached list of publications has all been summarized in the above Guides for easy reference. The accuracy and precision of the sampling rate is documented in publications 7, 9 and 11. The capacity for various organic contaminants is documented in publications 5, 10, 12, and 13. The determination of- recovery coefficient is documented in publication 2. The upper exposure limit at high relative humidity in publication 5, 6, 10, and 12. ' The above information provides a complete set of data for every compound in the new Sampling and Analysis Guides and therefore fulfills the NIOSH requirements to give immediate recommendation for encouraged use of the OVM #3500. L. W. Anders/ss Attachments 3H 010523 A NEW PERSONAL ORGANIC VAPOR MONITOR WITH IN-SITU SAMPLE ELUTION, D.W.Gosselink, D.L.Braun, H.E.Mullins, and S.T. Rodriguez, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 AIHA Conference, Los Angeles, May 1978 tion Submitted for publics- DETERMINATION OF DESORPTION EFFICIENCIES IN THE 3M 3500 ORGANIC VAPOR MONITOR, S.T.Rodriguez, D.W.Gosselink, and H.E.Mullins, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 '. AIHA Conference, Houston, May 1980 DIFFUSIONAL SAMPLING PRINCIPLES, THEORIES AND INDUSTRIAL APPLICATIONS, L.W.Anders, Occupational Health & Safety Products Division, 3M Company,' St. Paulr Minnesota 55144 AIHA Conference, Houston, May 198'0~ and Portland, May 1981 DIFFUSIONAL MONITORING: A NEW APPROACH TO PERSONAL SAMPLING, D.W.Gosselink, D.L.Braun, H.E.Mullins, S.T.Rodriguez, and F.W.Snowden, Chemical Hazards in the Workplace, Measurement, and Control, G. Choudbary, Ed. ACS Symposium Series 149, 1981 TECHNIQUE FOR DETERMINING CAPACITY OF DIFFUSIONAL SAMPLING DEVICES, L.W.Anders, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 - AIHA Conference, Portland, May 1981 publication To be submitted for 6. COMPARISON OF DIFFUSIONAL ORGANIC VAPOR MONITORS WITH CHARCOAL TUBES FOR SAMPLING LABORATORY CHALLENGES TO CONTAMINANT MIXTURE, L.W.Anders and H.E.Mullins, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 AIHA Conference, Portland, May 1981 To be submitted for publication 7. DOCUMENTATION OF SAMPLING RATES FOR THE 3M ORGANIC VAPOR MONITOR, L.W.Anders, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 ASTM Symposium,Boulder, August 1981 DIFFUSIONAL SAMPLING PRINCIPLES, THEORIES AND APPLICATION TO SAMPLING AMBIENT ATMOSPHERES FOR ENVIRONMENTAL CONTAMINANTS, L.W.Anders and R.M.Shor, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 EPA Symposium, Raleigh, May 1982 To be submitted for publication 3M 010524 9. DOCUMENTATION OF SAMPLING RATE ACCURACY AND PRECISION FOR DIFFUSTONAL DEVICES USED FOR PERSONAL AND ENVIRONMENTAL SAMPLING, L.W.Anders, R.M.Shor, and H.E.Mullins, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 ' EPA Symposium, Raleigh, May 1982 . To be submitted for publication 10. DIFFUSIONAL SAMPLING OF CHLORINATED ORGANIC CONTAMINANTS FROM KNOWN LABORATORY CHALLENGES, L.W.Anders and R.M.Shor, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 EPA Symposium, Raleigh, May 1982 . To be submitted for publication . 11. SAMPLING RATE VALIDATION PROTOCOL FOR ORGANIC VAPOR DIFFUSIONAL SAMPLERS, L.W.Anders and H.E.Mullins, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 AIHA Conference, Cincinnati, June 1982 To be submitted for publication 2. DIFFUSIONAL SAMPLING DEVICE PERFORMANCE WITH HIGHLY VOLATILE | COMPOUNDS, R.M.Shor and L.W.Anders, Occupational Health & Safety " Products Division, 3M Company, St. Paul, Minnesota 55144 AIHA Conference, Cincinnati, June 1982 To be submitted for publication 13. A DIFFUSIONAL ORGANIC VAPOR MONITOR WITH A SECONDARY ADSORBENT FOR MEASURING OVERLOAD WITH EXTENSION OF TOTAL SAMPLING CAPACITY, L.W.Anders, P.L.Sullivan, and H.E.Mullins, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 AIHA Conference, Cincinnati, June 1982 To be submitted for publication 14. SAMPLING RATE EVALUATION OF DIFFUSIONAL SAMPLERS AS A FUNCTION OF PATH LENGTH WITH TRANSIENT CHALLENGE CONCENTRATION, L..W.Anders and R.M.Shor, Occupational Health & Safety Products Division, 3M Company, St. Paul, Minnesota 55144 AIHA Conference, Cincinnati, June 1982 To ]be submitted for production 3M 010525  ** / department of health, education, and welfare PUBLIC HEALTH SERVICE ufo |,7r`r CENTER FOR QimCAmC CONTROL 0C1 national institute for occupational safety and health ROBERT A. TAFT LABORATORIES 4S7S COLUMBIA PARKWAY. CINCINNATI. OHIO 4SS2S t. 8V K-i.-.vu October 9, 1979 Mr. Einar D. Home Technical Director Occupational Health Safety Products Division/3M 230-B 3M Center . Sainc Paul, Minnesota 55101 Dear Einarr - On behalf of John Crable, Larry Doemeny, Chuck Geraci, Mary Lynn Woebkenberg and myself, I want to thank you and your co-workers for taking the time to meet with us on September 25. We found the exchange of information quite useful, as I hope you did. Because of our meeting, we are able to liberalize our recommendation on NIOSH's use of the Organic Vapor Monitor #3500. Due to the discrepancy over methylene chloride, our iauediate recommendation will be to encourage use of the OVM #3500 for those compounds which have a complete set of data to verify, among other properties, the capacity, recovery coefficient and the upper exposure limit at high humidity of the badge for the compound. These data may come from a variety of sources which include your laboratories as well as ours. In general, my recommendation will involve increased usage for compounds with moderate to low vapor pressures and moderate to low TLV's. Conversely, I will continue to take a conservative approach with high vapor pressure, high standard compounds/ As new compounds qualify, the use of the monitor will be expanded. For this reason, I am asking you co send qualification information to Dr. Charles Geraci and Ms. Mary Lynn Woebkenberg as it becomes available. PI ase keep in touch on this matter, as together we can do a great deal to promote the use of accurate and precise diffusion monitors in field industrial hygiene. Sincerely yours. *v Walter M. Haag ^***4 Director, Division of Physical Sciences and Engineering 3M 010526 WUETM - TECHNICAL BULLETIN ANOTHER STEP TOWARDS BETTER OCCUPATIONAL HEALTH AND SAFETY 3M Analytical Service does not analyze samples of compounds not appearinq on the Compound Guide. This policy may not have Keen clear in the past, therefore, as of January 1, I960 only compounds appearing on the NEW Compound Guide will be analyzed by 3M. 3M Analytical Service, through Tech Service, will continue to provide information, such as sampling rates or methods of calculating sampling rates for compounds not on the New Compounds Guide, but for which the OVM 3500 can be used. The list of compounds on tho New Compound Guide will be updated if new compounds are added. The following list of compounds is taken from the NEW Compound Guide. It is not an exhaustive list of compounds for which the OVM can be used, but it lists the only compounds that will be analyzed by 3M Analytical Service. TDB-l4-0VM-JAN 80 ginOccupational Health Safety Products Division 3M CENTER SAINT PAUt: MINNESOTA 93101 3M 105130 COMPOUNDS ANALYZED BY 3M ANALYTICAL SERVICE Ace cone * Acetonitrile Acrylonitrile Allyl Alcohol Allyl Chloride Amyl Acetate sec-Amyl Acetate iso-Amyl Alcohol sec-Amyl Alcohol Benzene Benzyl Chloride Bromoform Butadiene Butyl Acetate iso-Butyl Acetate sec-Butyl Acetate Cert-Butyl Acetate Butyl Alcohol iso-Butyl Alcohol sec-Butyl Alcohol tert-Butyl Alcohol Butyl Cello solve p-tert-Butyl Toluene Campho r Carbon Tetrachloride Cellosoive Cellosolve Acetate 1-Chloro-l-Nitropropane Cumene . Cyclohexane Cyclohexanol Cyclohexanone Cyclohexene Diacetone Alcohol Dibutyl Phthalate O-Dichlorobenzene P-Dichlorobenzene Diethyl Phthalate Diisobutyl Ketone (DiBK) Dimethyl Formamide (DMF) Dioxane Enflurane (2-Chloro-l,2trifluorethyl difluoromethyl ether) Epichlorohydrin Ethyl Acetate ' Ethyl Acrylate Ethyl Benzene Ethyl Bromide Ethyl Ether Ethylene Chlorohydrin Ethylene Dibromide Ethylene Dichloride (1,2-Dichloroethane) Freon 12: Dichlorodifluoro methane Freon 13: Chlorotrifluoromethane Freon 14: Tetrafluoromethane Freon 21: Dichloromonofluoromethane Freon 22-: Chlorodifluoromethane Freon 23: Trifluoromethane Freon 112: 1,1,2,2-Tetrachloro 1,2-Difluoroethane Freon 113: 1,1,2-Trichloro1,1,2-Trifluoroethane Freon 114: 1,2-Dichloro 1,1 2,2-Tetrafluoroethane Freon 115: 1-Chloro-l,1, 2,2,2-Pentafluoroethane Freon 116: Perfluoroethane Freon 12B2: Dibromodifluoromethane Freon 13B1: Trichloromonobromomethane Chlorobenzene Chlorobromomethane Chloroform Freon 11: Fluorotrichloromethane Furfural 3H 105131 COMPOUNDS ANALYZED BY 3M ANALYTICAL SERVICE (CONT'D) Ciycidoi ' Propyl Alcohol . ." HepCane Isopropyl Alcohol Hexane Isopropyl Ether Halothane (2-bromo-2Chloro-1,1,1-Trifluoroethane) Isophorone Mesityl Oxide Mesitylene Metliyl Ace Late Methyl Acrylate Methyl Butyl KeCone (MBK) Methyl Cellosolve Methyl Cellosolve Acetate Methyl Chloroform (1,1,1-Trichloroethane) Propylene Dichloride Stoddard Solvent Styrene 1.1.2.2- Tetrachloroethane Toluene 1.1.2- Tric hioroe thane Trichlorethylene Vinyl Chloride Vinyl Toluene Xylene Methyl Ethyl Ketone (MEK), Methyl Isobutyl Ketone (MIBK) Methyl Propyl Ketone Naphthalene Nitrobenzene n-Octane Pentane Perchlo^roethylene (Tetrachlorethylene) ^Phenyl Ether Propyl Acetate Isopropyl Acetate 3M 105132 Number: _____ __________________________ 3M Organic Vapor Monitor #3520 Product: ________________________________ Sampling For Butadiene Subject:________ __________________ I. INTRODUCTION . This technical data bulletin contains information to be used when sampling atmospheres for butadiene using the 3M Organic Vapor Monitor with back-up section #3520. Because of the low capacity, of the-charcoal sorbent for butadiene, use of the single sorbent Organic Vapor Monitor #3500 is not recorrmended. II. SAMPLING RATE 5.67 ug/ppm-hr 42.8 cc/min IH. CAPACITY The capacity of the charcoal sorbent for butadiene is highly dependent upon the relative humidity during the sampling period. The capacity of a single carbon wafer is: Relative humidity greater than 60% 40 micrograms Relative humidity 60% or less: 290 micrograms IV. MINIMUM DETECTABLE LEVEL The minimum reliable quantitative level is 4.0 micrograms. From Science, Simplicity. 3M Occupational Health and Safety Products Division Building 220-3E-04, 3M Center St. Paul, Minnesota 55144-1000 3M 105169 Litho in U.S.A. Axbulletin "uDZ7 a 3M Page 2 r V. RECOMMENDED SAMPLING TIMES Recommended sampling time is shown as a function of the ambient concentration of butadiene and the relative humidity during the exposure period in figures one through three. . The minimum sampling time is defined as the time required to collect 4.0 micrograms, the minimum reliable quantitation level. Although at concentrations above 3 ppm the sampling time required to _ reach 4 micrograms is less than 15 minutes, a 15 minute sampling time is the minimum recommended. This minimizes the errors inherent in short term sampling. The maximum sampling time is defined as the time required to exceed the capacity of the monitor. The capacity of the #3520 Organic Vapor Monitor is approximately three times that of the Single Wafer Monitor #3500. All sampling times are calculated for the #3520 monitor. A. Relative Humidty Greater Than 60% At an ambient relative humidity greater than 60%, the sampling time is shown as a function of butadiene concentration up to 10 ppm in figure one. At any given concentration, a sampling time in the shaded area of the graph will be within the operating limits of the monitor. At concentrations above 10 ppm (figure two) the maximum sampling time intersects the 15 minute recommended-minimum at 85 ppm. Due to the small difference between minimum and maximum sampling time at higher concentrations, sampling above 50 ppm is not recommended. 8. Relative Humidity of 60% or less The capacity of the Organic Vapor Monitor is greatly expanded at relative humidities of 60% or less. This is shown in figure three. At concentrations of less than 1 ppm, the minimum sampling time is the same as given in figure one. The maximum sampling time exceeds 100 hours. 3M 105170 ^TV--i_j-- AXbulletin "uDZ7 Page 3 C. Illustrative Example To determine sampling times, measure the relative humdity and estimate a possible range of concentrations based upon previous . sampling data. The lowest concentration will determine the minimum sampling time and the highest concentration will determine the maximum sampling time. Tor example, :onsider an exposure at 85% RH with an estimated concentration between 1 and 10 ppm. Using figure one, at one ppm the minimum sampling time is 0,75 hours. The maximum sampling time at 10 ppm is 3 hours. Thus, any exposure time between 45 minutes and 3 hours would be within the limits of the monitor for concentrations between 1 and 10 ppm at 85% RH. If there is no previous sampling data, it is suggested that sampling be conducted for 2, 4 and 6 hours. VI. ANALYTICAL PARAMETERS A. Desorbing Solvent: Methylene Chloride 3. Recovery Coefficient: It is recommended that the analyst run a "wording curve*' for each batch of analysis. Typical values would be 0.8 - 0.9. VII. MONITORING FOR BUTADIENE ANO ACRYLONITRILE Butadiene and acrylonitrile can be collected on the same monitor. The capacity of the monitor for acrylonitrile is not a limiting factor. The sampling parameters should be determined by butadiene. Both butadiene and acrylonitrile can be desorbed with methylene chloride. 3M 105171 CTTD Page 4 VIII. MONITORING BUTADIENE,- ACRYLONITRILE, AND STYRENE Use of the #3520 to sample for butadiene, acrylonitrile, and styrene simultaneously .is not recommended due to the low recovery of styrene when desorbed wth methylene chloride. When sampling for these three compounds, it is recommended that the - butadiene and acrylonitrile be collected on one #3520 Monitor and desorbed with methylene chloride, and the styrene be collected on a separate #3500 OVM and desorbed *ith carbon disulfide. ( ( 3M 105172 FIGURE ONE RECOMMENDED SAMPUNG TIME BUTADIENE COLLECTED ON #3520 AT RH > 60% SAMPLING TIME HOURS- 03 X in BUT8.DAT JAK 1/86 Legend MINIMUM X MAXIMUM FIGURE TWO RECOMMENDED SAMPLING TIME BUTADIENE COLLECTED ON #3520 AT RH > 60% SAMPLING TIME MINUTES- sJ BUT7 Legend MAXIMUM MINIMUM FIGURE THREE RECOMMENDED SAMPLING TIME BUTADIENE COLLECTED ON #3520 AT RH < 60% SAMPLING TIME HOURS- BUT9 .DAT JAK 1/86 insi Legend MINIMUM X MAXIMUM ^bulletin "uDZ7 a Number: 71 Product; 311 ORGANIC VAPOR MONITOPS Subject: SATFLING FOR tlETHYLENE CHLORIDE I. INTRODUCTION. -. Active carbon has been shown to have a poor affinity for methylene ~ chloride. This has resulted in strict limitations upon sampling times when using the 3M organic vapor monitors for sarrpling this compound. Recent experimental data suggests that an organic vapor monitor will sample methylene chloride satisfactorily when used within the sampling time guidelines and under steady state conditions. However, when the monitor is used in nonsteady state conditions, with varying concentrations of methylene chloride in the atmosphere, it is'possible to get desorption and subsequent sample loss when the ambient concentration of methylene chloride becomes zero. This sample loss could result in a sampling error, with the reported concentration less than the true ambient concentration. . II. SAMPLING RECOMMENDATIONS. Use of the 3M Organic Vapor Monitor #3500 is not recormiended for methylene chloride. Only the #3520 Organic Vapor Monitor with back-up section should be used for sampling methylene chloride. III. SAMPLING GUIDELINES. Maximum Sampling Time: 4 hours - Max. Qty. of Methylene Chloride on Top Wafer: 2000 micrograms If the quantity of methylene chloride on the back-up wafer exceeds 50% of the amount on the top wafer, the sample is invalid. If this occurs, the sampling should be repeated using a shorter sampling period. IV. ACCURACY. The capacity of the carbon wafers in the #3520 Organic Vapor Monitor for methylene chloride is strongly influenced by the presence of water vapor and competing organic vapors. This introduces an uncertainty into the results of analysis for methylene chloride. The accuracy of the #3520 Organic Vapor Monitor when used to sample methylene chloride can be as low as + 50% if high humidity or competing ^organic vapors are present. From Science, Simplicity. - Occupational Health and Safety Products Division/3M Building 230-B, 3M Center St. Paul. Minnesota 55144-1000 3M3M 105133 u a f^ipcx Lri A \BULLETIN DO Number: Product: Subject: 70 #3510 Organic Vapor Monitor Oatgaomd Selection List Changes Listed below are 14 compounds which have been eliminated from the #3510 Organic Vapor Monitor (with prepaid analysis) selection list. A recaimended sampling procedure is listed. COMPOUND RECOMMENDED SAMPLING PROCEDURE #3520 MAXIMUM SAMPLING TIME AT PEL (HOURS)- ACETONE #3520 OVM RH < 70% 2 RH > 70% 2 ACETONITRILE #3520 OVM 84 ALLYL CHLORIDE #3520 OVM 88 CHLOROBROMOMEIHANE See Tech Data Bulletin #71 DIMETHYL FORMAMIDE Solid Sorbent Tube (Silica Gel, 150 mg/75 mg) DICHLOROMETHANE (Methylene Chloride) See Tech Data Bulletin #71 ETHYL BROMIDE Solid Sorbent Tube (Coconut Shell Charcoal 100 mg/50 mg) ETHYL ETHER Solid Sorbent Tube (Coconut Shell Charcoal 100 mg/50 mg) ETHYELNE DIBRCMIDE #3500 OVM - Analyzed by ECD Gas Chrcmotography FREON 113 (1,1,2-Trichloro, 1,2,2-Trifluoroethane) NIOSH Method #S129 2nd Edition, Vol. 2 From Science, Simplicity. Occupational Health and Safety Products Division/3M Building 230-B. 3M Center St. Paul, Minnesota 55144-1000 3M 3M 105184 METHYL ACETATE PENTAINE ISOPROPYL ETHER 1,1,l-TRICHLOROETHANE (Methyl Chloroform) #3520 OVM #3520 OW #3520 OWi #3520 OW 22 - 1.5 1.5 33 .4 -4 For additional information, please contact OH&SP Technical Service at 1-800-243-4630. 3M 105185 . Operationally, passive dosimeters are ideally suited for monitoring rganic vapors in h spitsI perating rooms as they are compact, lightweight and do not require tubing or pumps. In this study, arc ntly developed passive diffusion sampler was used t collect 2-bromo-2-chl ro-1,1,1 -triflu roethane (Halothane) and 2-chloro-1, 1 .2 - trifluoroethyl difluor methyl ther (Enfluran ) in standard air mixtures over the rang of 0.2 - 10 ppm. Additionally, xposures to known c ncantrations war conducted for various lengths f tim . A side-by-side imparison of charcoal tubes (CT) end passiv dosim t r coll ction characteristics were made on known air ixtures and samples collected in operating rooms. Thb material adsorbed on charcoal from dosimeters and CT was desorbed with carbon disulfide and quantified using gas-liquid chromatography. The overall effici ncy of th dosimeters along with quality control data are presented. Evaluation of a passive dosimeter for collection of 2-bromo-2-chloro-1,1,1 -trifluoroethane and 2-chloroI,1,2-trifluoroethyl difluoromethyl ether in hospital operating rooms J. F. MAZUR. G. E. PODOLAK. G. G. ESPOSITO. D. S. RINEHART and R. E. GLENN US Army Environmental Hygiene Agency, Aberdeen Proving Ground, MD 21010 introduction It was almost a hundred years after the first use of an inhalation anesthetic in 1842 before anesthesiologists recognized the possible deleterious effects of occupational exposure to anesthetic gases. However, it has only been during the past decade that considerable effort has been Tccted toward the determination of trace concentrations I k anesthetic gases and vapors in the operating room mosphcrc, and the related potential hazards to chronically exposed personnel. In 1974, the American Society of Anesthesiologists Ad Hoc Committee on the Effects of Trace Anesthetics published a report on a national survey conducted on occupationally related diseases among dental and operating room personnel.1'**' At the time of this study, the number of operating room, dental, and veterinary personnel who were potentially exposed to anesthetic gases exceeded 200000 persons per year. T he results of this study, and others both human and animal, suggest that chronic exposure to anesthetic gases increases the risk of spontaneous abortion and congenital abnormalities in children of both female workers and wives of male workers. Chronically exposed personnel also showed increased incidence of hepatic and renal diseases. Other studies have indicated an increased risk of cancer and possible impairment of certain psychologic functions. Acute exposures to anesthetic gases have been shown to affect the central nervous system with resulting symptoms of headaches, nausea, fatigue, etc.'JI For reasons of both efficacy and safety, most of the anesthetic agents introduced prior to 1950 have been Ip opinions or assertions contained herein are the private views of authors and are not to be construed as reflecting the views of the artment of the Army or the Department of Defense. replaced. The flammable and explosive inhalation anesthetic agents such as diethyl ether and cyclopropane have- been replaced by noncxplosivc, nonflammable anesthetics such as halothane, enflurane, and methoxyflurane. Halothane and enflurane are currently the two most widely used halogenated anesthetic agents in US Army hospitals. They are generally used in conjunction with nitrous oxide and/or intravenously injected anesthetics. The US Army Environmental Hygiene Agency (USAEH A) is responsible for monitoring potential problem areas of occupational hazards and safety in US Army hospitals and clinics. Part of this surveillance program is concerned with operating room engineering controls and work practices affecting personnel exposure to waste anesthetic gases. Waste inhalation anesthetic gases are those gases and volatile liquids which arc inadvertently released into work areas either by faulty equipment or improper work practices. Scavenging systems designed to collect waste anesthetic gases and vapors from the breathing system at the point of discharge and disposing of them outside of the operating room are the primary means of controlling waste anesthetic gases. Sufficient ventilation rates within the operating room are necessary to dilute anesthetic agents that are not captured by the scavenging system. Failure to control properly one or more of the above-mentioned sources of waste anesthetic gases can result in potentially hazardous exposures to operating room personnel. Consequently, personal and general area monitoring of operating rooms are conducted by USAEHA to determine if a health hazard exists and to pinpoint sources of exposure, whether they be defective equipment, inadequate scavenging systems, poor ventilation, or improper administration of anesthetics. After identifying the cause Aiiink.ii Industrial llyp.'fnf Association JOURNAL Ceeyrgn< i960. American IndqstrieJ Hygiene AihcuIim (41) s/so 317 3M 105723 and extent of exposure, recommendations are made for improving work practices and engineering controls to meet the recommended levels for occupational exposure published by the National Institute Tor Occupational Safety ^d Health (NIOSH). Bit present, a safe level of exposure for waste anesthetic gas has not been established by NIOSH; instead, it recommends that exposures be suppressed to the greatest extent possible to minimize risk to operating room personnel. When used alone, NIOSH recommends occupational exposure to halothane and enflurane be controlled so that no worker is exposed at concentrations greater than 2 ppm. For halothane and enflurane their weights corresponding to 2 ppm would be 16.15 mg/cu m and 15.10 mg/cu m, respectively. These concentrations arc based on a 45-liter charcoal tube sample taken over a time period not exceeding I hour. When halogenated agents are used in combination with nitrous oxide, levels of approximately 0.5 ppm are achievable, provided the time weighted average of nitrous oxide is controlled at the recommended 25 ppm level. The NIOSH criteria document, "Occupational Exposure to Waste Anesthetic Gases and Vapors,"01 provides a comprehensive review of sampling methods, analytical procedures, and real-time monitors. Typical collection methods cited in the literature include those utilizing gas syringes,14*71 plastic sample bags,1*' and charcoal tubes.1'" These procedures make use of gas chromatography (GO) for the analysis of isolated samples. Additional analytical methods for anesthetic gases'"' based on GC, infrared troscopy (IR), and gas chromatography and mass trometry fGC-MS) have also been described in the literature. The lorenoted procedures have proved adequate for in-depth investigations and have been used extensively in research studies. For the purpose of routine personal monitoring however, these procedures have certain shortcomings. Some of the problems relate to equipment complexity, sample collection, and sample manipulation. because of ther unique working conditions that exist in operating rooms, it is essential that a personal sampler for monitoring worker occupational exposure meet certain performance criteria. Foremost, the collection of samples must not interfere with any of the various tasks performed by operating room personnel. In addition, areas designated as sterile zones must not be contaminated. Finally, the air sample should be proportional to a time-weighted average of anesthetic agent concentration. Traditionally, organic vapors have been collected and concentrated using the. charcoal tube (Cl*) technique. This method consists of pumping a known volume of air through a tube packed with charcoal for a definite period of time. Organic vap rs are adsorbed onto the charcoal and subsequently desorbed with an appropriate solvent. The desorbent is analyzed with a gas chromatograph. An alternative approach to sampling organic vapors is ^rough consideration of fundamental molecular diffusion ^Hmctry. Devices based on this principle have recently found their way into the industrial hygiene marketplace, and have been used selectively for the collection of certain organic vapors. With this type of sampler, volatile compounds enter the sampler by molecular diffusion such that the rate of sample collection is a function of the organic vapor concentration in air. Since the vapors enter the dosimeter by nonmechanical means, it requires neither calibration nor electrical power. The purpose of this investigation was to determine the suitability of the 3M Organic Vapor Monitor (OVM) for the collection, of halothane and enflurane in operating room environments. Side-by-side collection of known concentrations of halothane and enflurane were conducted with OVM and CTsamplers for comparison and correlation of test data. Variables studied were sampling time, sample concentration, and storage stability. In addition to the laboratory tests, samples were collected in operating rooms during administration of anesthesia to patients undergoing surgery. The effects of humidity and temperature on collection efficiency were not included in this study, since these parameters arc carefully regulated in operating rooms. experimental - passive dosimeter All passive dosimeter monitoring was conducted with the 3M Brand Model 3500Organic Vapor Monilor(OVM). 3M Company, St. Paul, MN, This unit consists of a round nylon body approximately 4.5 cm in diameter, weighing about 12 grams. A charcoal adsorbent pad is located inside the monitor, separated by spacers from a diffusion membrane. Contaminants enter the monitor by molecular diffusion and arc adsorbed onto the charcoal. At the conclusion of the sampling period, the diffusion membrane is removed, and a tight-fitting cap firmly snapped into place. The cap contains two ports which arc sealed by inserting the attached plugs. When the sample is ready for chromatographic analysis, the center port is opened and 1.5 ml. of carbon disulfide is introduced into the monitor via a glass syringe. The center port is rescaled, and the sample is allowed to desorb for 30 minutes. A GC sample is taken directly from the center port with a IO-/iL syringe. The OVM sampler and cover are shown in Figure I. The time-weighted worker exposure level is calculated using the following equations: mg/ m Corrected weight on badge (nanogranis) Sampling rale (cm /min) X Sampling time (min) ppm mg 22.4 L/mole '!*" K. 7o()-mni Mg m mwg/molc 273 K. P-mm Mg The sampling rates for halothane and enflurane are 25.1 cm'/min and 26.9 cm1/min, respectively. These sampling rates were calculated from diffusion coefficients corresponding to each compound. charcoal tuba monitor Charcoal tubes containing two sections of charcoal, 200/400 mg, were purchased from SKC Inc.. Eighty Four, PA. Samples were collected at two different sampling rates. 30 mL/min (Xccuhaler 808, Lcfco Engineering) and 500 3M 105725lit Am. Inti. Hyg Auoc. J (41) Miy. 1980 Apeizon L on 80-100 mesh Chromosorb W-HP; injection port temperature, 130 C; detector temperature, 300 C; initial column temperature, 120 C; final column temperature, 190 C; column temperature programming rate, 30/ min. mL/ min (Model P-4000A, E. 1. du Pont de Nemours & Co., gAkilmington, DE). Pump calibration was accomplished by ^^mccting a charcoal tube to a pump and mcasuringthe air tlow with a bubble meter. When the sample was ready for chromatographic analysis, the charcoal was poured from the glass sampling tube into a 10-mL vial and desorbed with 2 mL of carbon disulfide. gas chr matography Analysis of desorbent solutions was performed on a Hewlett-Packard Model 5820 gas chromatograph equipped with a flame ionisation detector and HP 18850A GC Terminal. The GC operating conditions were as follows: column, 17 ft. X l/g in. stainless steel packed with 30% test atmosphere Appropriate amounts of halothanc and enfluranc were injected into a 2-mL vial equipped with a septum and screw cap. The vial was transferred to a- 6920-liter static test chamber and positioned in front of a circulating fan. I he vial cap was removed and the chamber door closed immediately. After sealing the door, the circulating fan was turned on and 30 minutes were allowed to elapse to insure ~ complete mixing of the anesthetic agents with air. The OVM's were attached to a meter stick and inserted into the chamber through a side-access port. CT samples were collected at a port adjacent to the .OVM's. For some experiments having short sample collection times, successive tests were conducted using the same chamber concentration. ._ _ results and discussion -- OVM and CTuata for various concentrations of halothanc and enfluranc are presented in Table I.'Test atmospheres for Samples 1-3 contained only halothanc, whereas test Samples 4-8 were binary mixtures of both halothanc and enfluranc. The sampling rate for Samples 6 and 7 was 30 mL/min; the sampling rate for all other samples was 500 mL/min. In general, results from the OVM's were in good agreement with the theoretical values; whereas, results from the CTs showed a slight positive bias. Statistical treatment of the OVM data is presented in Table II. The values shown in Table 11 were derived from four replicates for each test. Since the GC analysis is an integral part of each test, the statistical data reflect the overall efficiency of both sample collection and analytical procedures. In general, the precision and accuracy were within acceptable limits over the tested concentration range. In sumtnary, a total of 44 OVM's were tested for halothane, and 25 OVM's for enflurane, at four concentration levels (0.5, 2, 5, and 10 ppm). An overall recovery of 100.6% and a Sample 1 2 3 4 5 6 7 8 TABLE I Halothane and Enflurane Laboratory Data Exposure Time Theoretical OVM. Hrs Cone., ppm Mean Observed Enflurane. ppm OVM* CT" Mean Observed Halothane. ppm OVM* CT" 4 S- 5.28 5.14 2 5 *- V. 5.34 5.40 4 2 - - 2.13 2.23 4 0.5 0.57 0.64 0.48 0.59 4 2 1.95 2.T3 2.27 2.30 2 2 1.65 2.47 2.06 2.22 1 2 2.01 2.11 1.95 2.11 4 10 9.17 11.49 9.51 10.30 AAverage of four OVM's. "Average of two CT's for Samples 6 and 7; all others average ot four CTs. Aim-tit .m Imluslii.il Hyi'irnr Assm.i.iliun KUIUNAt HO b/H<l 3M 105726 319 TABLE IV Field Data . > Sample 1 2 3 4 5 6 Halothane OVM ppm* CT ppm* IR ppm1' 3.42 1.87 0.40 -- -'** 3.43 2.04 0.56 -- -- 3.53 1.78 0.55 -- - Enflurane OVM ppm* CT ppm* -- -- 0.49 1.39 0.58 - -- 052 (N) (N) 'Average of four OVM's. "Average of two CT's. 1 Integration of chart reading. (N)Not taken so as to not interfere with operating room procedures. dosimeters come prcasscmbled. whereas CT dosimeters require on-site assembly of components. Most important, utilization of the OVM docs not interfere with personnel work routines nor present a contamination problem. Finally, the OVM becomes cost-effective when one takes into account equipment costs and personnel-time required lor the operation and maintenance of a charcoal tube sampling system. references 1. Cohen, E. N., B. W. Brown. D. L. Bruce. H. F. Cascorbi. W. Corbett. T. H. Jones and C. E. Whitcher: Occupational Disease Among Operating Room Personnel -- A National Study. Anesthesiolopy 4 7:321 (1974). 2. C hen, E. N.. B. W. Brown. D. L. Bruce, H. F. Cascorbi. W. Corbett, T. H. Jones and C. E. Whitcher: A Survey of Anesthetic Health Hazards Among Dentists. J. Amer. Dent. Assoc. 90:1291 (1975. 3. NIOSH: Criteria for a Recommended Standard Occupational Exposure to Waste Anesthetic Gases and Vapors. DHEW (NIOSH) Publication No. 77*140 (1977). 4. Panner, 8. J.. R. 8. Freeman. L. A. Roth-Moyo and W. Markowitch: Toxicity Following Methoxyflurane Anesthesia -- I. Clinical and Pathological Observations in Two Fatal Cases. JAMA 214:86 (1970). 5. Tobey. R. E. and. R. J. Clubb: Renal Function After Methoxyflurane and Halothane Anesthesia. JAMA. 233:649 (1973). , 6. Usubiaga, L.. J. A. Aidrete and V. Fiserova-Bergarova: Influence of Gas Flows and Operating Room Ventilation on the Daily Exposure of Anesthetists to Halothane. Anesth. Analg. (Cleveland). 51:968 (1972). 7. Strunin. L., J. M. Strunin and C. C. Mallios: Atmospheric Pollution With Halothane During Outpatient Dental -Anesthesia. Brit. Med. J. 41:459 (1973). 8. Nikki, P.. P. Pfaffl. K. Ahlman and R. Ralli: Chronic Exposure to Anesthetic Gases in the Operating Theatre and Recovery Room. Ann. Clin. Res. 4:266 (1972). 9. Gotell. P. and L. Sundell: Anesthetists' Exposure to Halothane. Lancet (Lett). 2:424 (1972). 10. Malmlund. H. O.: Determination of Oxygen, Carbon Dioxide. ' and Nitrous Oxide in Blood by Gas Chromatography. Scand. J. ` Clin. Lab. Invest. 28:471 (1971). 11. Finkelsori. M. J.: Gas-Solid Chromatographic Determination of Oxygen. Nitrogen. Carbon Dioxide. Ethylene, and Nitrous Oxide at Ambient Temperature. J. Assoc. OH. Anal. Chem. 56:1J 9 (1973). 12. Patzelova, V.: Gas Chromatographic Separation of Anesthetizing Gaseous Mixtures. Chromatographic. 4:174 (1971). 1 13. Wohlers. H. C., J. H. Suffet. W. S. Blakemore. D. Kenepp. L. L. Coriell and G. J. McGarrity: Gaseous Pollutant Evaluation of Hospital Clean Rooms. Am. Ind. Hyg. Assoc. J. 32:813 (1971). 14. Hanst. P. L.. A. A. Lefohn and B. W. Gay. Jr.: Detection of Atmospheric Pollutants at Pans-Per-Billion Levels by Infrared Spectroscopy. Appl. Spedrose. 27:188 (1973). 15. Lane. G. A.: The Measurement of Low Concentrations of Nitrous Oxide and Halothane by Infrared Spectroscopy. Brit. J. Anesthesia. 48:274 (1976). AWS Safety/Health research program fund drive The American Welding Society has launched a major fund drive to support a Welding Safety and Health Research Program with the overall objectives of: 1) demonstrating that the welding environment can be safe when responsible environmental precautions are followed and 2) meeting government requirements, that are technically and economically feasible. One long range research project wilt be concerned with the health effects of the welding environment on those who work with mild steel. Other research projects that are planned include a detailed chemical analysis of welding fume, a design for optimum ventilation systems, and short and long-term animal testing to predict health effects. Safety training materials wilPbe developed as part of this Research Program. All companies and organizations within the welding Mfustry, as well as all those with a vested concern for advancements in the fields of occupational safety and health, are being asked to financially support this Research Program to a reasonable degree -- consistent with the importance of welding within the individual company or organization Structure. To fund the projects now ready for implementation, a minimum of $500,000 is required per year for the next five to ten years. A brochure "Creating a Healthful Environment ... a Challenge to the Welding Industry" containing additional details on this Program, is available from Publications Services. American Welding Society. 2501 N.W. 7th Street. Miami. FL 33125. Telephone 305/642-7090. For additional information on this Program, contact Marvin Kennebeck. AWS Safety and Health Manager, at the American Welding Society. Ameucan Industrial Hy^toni* Association JOURNAL (41) S/SO 3M 105727 321 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Data for Cnftbon Te&ULcJtZo&idz____________ SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate Recovery Coefficient Upper Exposure Limit 3 26.5 cm /min.____________ 1.02 In CS?______________ 3000 ug (298 ppm~kouA&) COMPOUND PROPERTIES AND DATA Molecular Weight Published Diffusion Constant Density ` T.W.A. (TLV) - -1--5--3--.-8--2---------------- -----.------------0.0828 cm /4&c. - -______ 1.5942 [20C)____________ 10 ppm SPECIAL CONSIDERATIONS Sample Storage Precautions Humidity Effects The Upper Exposure Limit at % r.h. is Ceiling Level Monitoring Now_______ - . Uppm Expo-diuie. Limit Stightly Reduce. 298 ppm-hauAA Not Recommended CALCULATION PROCEDURE A = mass of analyte in micrograms 8 = sampling time in minutes Substitute A & B into equations below: mg _ 37.74 xA_________ 37.00 x A ma recovery coefficient xB ' - B ppm <4> 6.00 x A_______ __ recovery coefficient x B 5.88 x A B Footnotes: (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. (3) A minimum sampling time of 15 minutes is required. (4) ppm based on 25C. 760 mm Hg. R-3SQDS-4 3H 107458 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Data for ______ChtoHojotm SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate Recovery Coefficient Upper Exposure Limit (1> 0. 97 in CS? 3142 pq [ 340 ppm-howa) COMPOUND PROPERTIES AND DATA Molecular Weight Published Diffusion Constant Density . T.W.A. (TLV) 119.38_________________________ ' 0.0888 Cfli^Aec. 1.4984 \l5C) 10 ppm SPECIAL CONSIDERATIONS Sample Storage Precautions Humidity Effects The Upper Exposure Limit at _5_% R.H. is Ceiling Level Monitoring A/one UppgA ExpoAtute. Limit Stiaktln R&daazc 340 ppw-feotm Hot Recommzndzd CALCULATION PROCEDURE A = mass of analyte in micrograms 8 = sampling time in minutes Substitute A & B into equations below: mg 31.65 x A m3 recovery coefficient x B 32,63 x A B ppm 6.48 x A_________ recovery coefficient x B 6.68 x A B Footnotes: (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. (3) A minimum sampling time of 15 minutes is required. (4) ppm based on 25 *C. 760 mm Hg. R-3SQPS-5 3M 107459 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Oata for ______ MgXhyZ ChZoftofaoJun [111,1~TMA.chZ.OAV(iluLyiz) SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate -- Recovery Coefficient Upper Exposure Limit P> 28.0 cm^/min.____________ 1.02 In C$9______________ 4700 ug (1800 ppm-housu) COMPOUND PROPERTIES AND DATA Molecular Weight _, Published Diffusion Constant Density .- T.W.A. (TLV) 133.41____________________ 0.0794 cm^/Aec.__________ 1.3390 [20C)____________ 350 ppm________ SPECIAL CONSIDERATIONS' Sample Storage Precautions Humidity Effects The Upper Exposure Limit at % R.H. is Ceiling Level Monitoring Nont UppeA Expotusit Limit Stightly Rtduata Rtc.ormwd.zd CALCULATION PROCEDURE A = mass of analyte in micrograms B = sampling time in minutes Substitute A & B into equations below: mg 35.71 xA_________ 35,01 x A m3 recovery coefficient x B -B ppm W x A_________ recovery coefficient x B 6.42 xA `B Footnotes: . (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. (3) A minimum sampling time of 15 minutes is required. (4) ppm based on 25 C. 760 mm Hg. 9 3M 107462 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Data for ______ 1.1 r 2-Tju.cM.oaoethane___ SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate Recovery Coefficient Upper Exposure Limit 3 27.1 cm /min. 1.00 in CS?______ To Be Determined COMPOUND PROPERTIES AND DATA Molecular Weight . Published Diffusion Constant Density T.W.A. (TLV) 133.41 __________________________________________________________ 0.0792 cnZUec. - 1.4390 [20*0 10 ppm - "SPECIAL CONSIDERATIONS . Sample Storage Precautions Humidity Effects The Upper Exposure Limit at ~ % R.H. is Ceiling Level Monitoring^ Hone. UppeA. Expo&une Limit SLu}fitly Reduced Recommended CALCULATION PROCEDURE A = mass of analyte in micrograms B = sampling time in minutes Substitute A & B into equations below: HIS-- = ___ 36.90 x A , _ m3 recovery coefficient x B " 36.90 xA 'B m(4| _ 6.76 x A_________ _ pp ~ recovery coefficient x B ' 6.76 x A B . Footnotes: (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. (3) A minimum sampling time of 15 minutes is required. (4) ppm based on 25*C. 760mmHg. R-35QVS-14 3M 107487 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Data for _____ TtvLchZotiozthyZznz_____________________________ SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate Recovery Coefficient Upper Exposure Limit 28.0 on?/min, ________ 1.00 in CS?_______________ 20.3 mg ( 2250 ppm~houA&) COMPOUND PROPERTIES AND DATA Molecular Weight Published Diffusion Constant Density T.W.A. (TLV) -1--3--1-.-3--9------ it-------0.0875 cm /a&c., 1.462 120C) 100 ppm_______ SPECIAL CONSIDERATIONS Sample Storage Precautions Humidity Effects The Upper Exposure Limit at 85 % R.H. is Ceiling Level Monitoring None' UppeA. Expo&uste. Limit Reduced 1600 ppm-houu R&c.ome.nde.d CALCULATION PROCEDURE A = mass of analyte in micrograms 8 = sampling time in minutes Substitute A & B into equations below: mq 35.71 x A m1 ~ recovery coefficient x B " 35.71 x A B ppm W 6.65x A recovery coefficient x B " 6.65 X A B Footnotes: (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. (3) A minimum sampling time of 15 minutes is required. (4) ppm based on 25 "C. 760 mm Hg. R-36QVS-15 3M 107462 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Data for _______Vaju/Z ChZonZdz____________________________ SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate Recovery Coefficient Upper Exposure Limit I1* 40.7 cn?fmin. . 0.90~Zn C$>7___________ 168 yg (30 am-houu 1 COMPOUND PROPERTIES AND DATA Molecular Weight Published Diffusion Constant<2) Density ' T.W.A. (TLV) 62.50 Not.AvaZZabZz 1,0 ppm SPECIAL CONSIDERATIONS Sample Storage Precautions Humidity Effects Th Upper Exposure Limit at 90 % r.h. is Ceiling Level Monitoring <3> None UppeA. Expo^tt/te Limit Sub4tayvtLaZZu 5 ppm-kouJu ti.zdue.zd Not tizcommzndzd CALCULATION PROCEDURE A = mass of analyte in micrograms B = sampling time in minutes Substitute A & 8 into equations below: mg 24.59 x A , mJ recovery coefficient x B 2J.SL * A B ppm W 9.62 x A_________ recovery coefficient x 8 10.69 x A B Footnotes: . (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. . (3) A minimum sampling time of 15 minutes is required. (4) ppm based on 25 C. 760 mm Hg. ti-35QPS-16 3H 107469 FIELD VALIDATION OF 3M ORGANIC VAPOR MONITOR for VINYL CHLORIDE MONOMER G. WATTIES & R. HOFER,CIU THE GOODYEAR TIRE& RUBBER CO. 3M 109721 Vinyl Chloride Regulations PEL 1.0 ppm (2.6 mg/mA3) Ceiling 5.0 ppm (l3mg/mA3) * TLV 5.0 ppm -CTLV 20.0 ppm Confirmed Human Carcinogen (Al) :.-.-r :: :z=r.i .a. ns-: 2: exposure 12 vinyl rnlrnie ~:r.:-.ar, a .-rlrrless ras roar l.ruiries uccr. freezing, rauses rrr.cern for ".t r = a or jjfT:;.' rr workers who are involved v;izr on_s ::-.-~i:a. Ire ring 2 z booh employee arc wcrh glare rrv .3 r.a :e s .= a ry 0: ensure z.-.sr exprsur* re-5.1 r.a ::elcw -..-.e -1 ... - ; an:. rrr.c_ies \::r, ohe lav.-. Vinyl rulrride 1 re 7... r,r _ :r.s -razes :r.ar one "permissible exposure linio-?EL 1= leg-., a ceiling value of = ppn. American Conference of Irverr.-er.oa_ Infusorial Hygier.isos AC3TK- has a of.resf.old limit al-e - 71" :: leg- with a railing value rf Clpp-. -. -e. h a s ceer. :lass .riel 1" - i:r. firmed . t~-- : -r. ev-.ier. re :r:m ep _ ie-.. : 1 : 7 . : rouiies or a:-.s 3M 109722 3M 3520 Organic Vapor Monitor * Coconut Charcoal (New from 3M) 1 Front and backup sections 1 Passive Monitor (no pump needed) VCM Sampling Rate - 40,8 cc/min ' Analytical Recovery - 92% tipssp . r. * 8 'I."'/. :r. = :ra:r.;s ;h ioo7, ac::..ve " _ = Si -2 V r.as boch 7M : rie 3H 109723 Side by Side Sampling Samples collected at Chemical Plant - NIOSH 1007 vs 3M 3520 Sample time Full shift VCM concentration range 0.06 to 0.90ppm - '=*- = -cr.oorr ,n a field acmcschere. a senes or s. :r ss-c,es were ccllerced ac-che Treniral ?l=r.o. The arcns :rer :r c:;:r.u: rr.arccal screen luces as ,o I-1 2 =H i::~ and ;r. -he raw 3M 352: 2VM passive : ... . ao-ir accrrxiT.soely 3 heart, was used rcr rhe -z~z..r.z esc- sar.cle was also collected' , Several mm.os in one Znemsl ?l=r.r were chosen revering a vinvl r._ : r_ re ":c.r -- er range zrm .2= or . rOpptn 3H 109724 VCM Side by Side Sampling Results Sample Time (Min) 427 C.T. VoI(L) OVMVol(L) 21.3 17.4 C.T. ppm 0.78 OVIM ppm 0.87 : 1 430 21.8 17.5 051 0.40 ; i yi 438 425 21.9, 20.7 17.9 0.10 17.2 0.06 0.09 0.04 .*$ ` 441 21.8 18.0 0.00 0.00 Jl-li r~ I5 1.6 0.6 053 1.44 ji fi U,1 mi" \fr ."B ~r-- :;r :r.= scde-cy-scde ~ar.pl rr.g ir l.-.eriral ?l = r.c rr._;r_-= ~cr.rr.er sr.cw char boch rhe ser.siirvicv and :: ere :::::::: IMl sar.plrr.g redca c= rcc; auree-er-. me used ;r. me Xlm-: 1 : : - -ached when. i?.";c..r.r c. t .e;:--erne! cure .-.e c : =: cc rm . 7r.-_ ; sr.-re ;r. ".r.y. mlcr.re rcr.c~er re : mere d i : ; cc.-.e cr.a r:; a 1 cure ar.d rhe rcrer.ur 177-! ac = full = - y cr.e Ippr. , 1,1 PEL > 0 . Score ar.d ac 1 10 PEL or .ess : : are s/.rwr., alm.r w::r. me cl a.-,11 le.als have rc:i :: r r e 1 a : . : r. 'ha a.-.: " aar.clrr.u resale, mdreare a r : c a . c c ac Le . , 3H 109725 Advantages of 3M Field Test Chamber (FTC) " Homogeneous Sampling Atmosphere " Up to 10 Replicates Comparison of 2 Sampling Methods Controls Sampling Parameters | ijf;'- {m d lie-; Wi , _ ^ w ,v______ :y-sids sampling, a field "es: charder was ideal Plane co verify chac both media -ccor.u* OVM) had che idencical hcmccer.cus The field ease chamber, beside i bv 2>', :s. :c^C3r:ser. or _ ____ passive OVM can be made wich : was used ac 2 different; iccac; - ccncencracicr. varied. - j _l che field cesc chamber. 3H 109726 Here we see the field test chamber which is made of plexiglas. - Sampling ports for the charcoal tubes with pumps - up to 5 were used on each chamber. . - 5 QVM's in the chamber - all passive dosimeters were placed in parallel- direction. " Air was continuously pulled through the^chamber by a variable speed fan at a predetermined linear face velocity (ISO ft/min). The velocity was measured using a magnahelic monometer. Using the field test chamber,, both passive monitor OVM's and charcoal-tubes were exposed to identical atmospheric conditions. 3M 109727 I|- Results of FTC at 1.0 ppm and 0.05 ppm VCiVI ( C.T. vs OVM) Media CTeuytuI Tube Number of .Samples 8 Time (Min) Average VuI(L) Mean ppm 428 22.3 0.98 Sides- %U.SD 0.15 15.0 3M 3520 OVM 10 456 18.6 1.05 0.06 5.3- Charcoal Tube 3M 3520 OVM 9 302 31.7 0.058 0.007 12.8 . .f-i: 10 320 13.1 0.051 0.002 3.9 ------- rsl" St enc a- and wa ft R i*. ^ h, :r.e pen c: 0.058 s had a 3M 109728 Validation Requirements OVM vs NTOSH 1007 3 +/- 50% at 025 to 0.5 ppm 8 +/- 35% at 0.50 to 1.0 ppm 1 +/- 25% at 1.0 ppm and over C -- v, 3CC m0USU2ra - -33 sr. accuracy crmpa z 7 act ^ a s s "uan : 'ux- r cac _: aca cv*r 3M 109729 VCM Field Validation Conclusions "'At 1 ppm OVM is+7 % of NIOSH(10Q7) "At 0.06 ppm OVM is -12% ofNIOSH Analytical Recover 92% .......... 3M 109730 ft VCM AnaiyticaI Method a Gas chromatography/FID a Plot column (aluminum oxide/KCi) * Hydrogen carrier gas ' Electronic pressure programming ive.cped :c measure v;r.yl chloride -cnomer iaticn of "he passive 3M coconut QVM . lowinc: w B.rTi0 n n't t porous .aver seen tubular' column,- coated with e ar.d deactivated with potassium chloride \KC1) aration of light hydrocarbons. pressure prcgrammcng-EPP-better resolution, improver oeteotton limits, faster analysis. Initial `^tny.ene ml or ode used to desorb 0V>!. 3H 109732 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Data for Tetrachloroethylene*................... SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate Recovery Coefficient Upper Exposure Limit(1) 28.9 qr\3/min. 1.00.......................... 36r0_Mg_. (3060 ppn-hr) COMPOUND PROPERTIES AND DATA Molecular Weight Published Diffusion Constant<2) Density ' T.W.A. (TLV) 165^85___________________ None............. ......... 1.6226 (20C) 100 ppn (681 mg/foi ) SPECIAL CONSIDERATIONS Sample Storage Precautions Humidity Effects The Upper Exposure Limit at 85 % R.h. is Ceiling Level Monitoring t3) None ....... ............... _ Opck^effioeure limit S.Iigntly reduced, __ 36,CLMg (3060 ppn-hr) . ______ RporTrrn^rvWI_____________ ______ ____ CALCULATION PROCEDURE A = mass of analyte in micrograms B = sampling time in minutes Substitute A & B into equations below: mg 34.60 x A______________ 34.60 x A mJ recovery coefficient x B " B ppm 5.10 x A____ recovery coefficient x B 5.10 x A B Footnotes: . (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. (3) A minimum sampling time of 15 minutes is required. (4) ppm based on 25*C. 760 mm Hg. *Perchloroethylene 3M 110436 3M BRAND ORGANIC VAPOR MONITOR PRODUCT NO. 3500 Qualification Data for Epichlorohydrin* SAMPLING AND ANALYSIS INFORMATION Monitor Sampling Rate Recovery Coefficient Upper Exposure Limit 0) 3 29.8 cm /fam.__________ .94 28.8 Mg (4260 ppn-hrs) COMPOUND PROPERTIES AND DATA Molecular Weight Published Diffusion Constant Density T.W.A. (TLV) 92.53______________ None_______________ 1.1750 (25C) 5 ppn (20 mg/m ) SPECIAL CONSIDERATIONS Sample Storage Precautions Humidity Effects The Upper Exposure Limit at 85 % R.H. is Ceiling Level Monitoring None imit 28.8 Mg (4260 ppro-hrl Reoctnnended ______ CALCULATION PROCEDURE A = mass of analyte in micrograms B = sampling time in minutes Substitute A & B into equations below: mg _ 33.56 x A__________ 35.70 x A m3 recovery coefficient x B ~ B ppm <4> 8.87 xA__________ recovery coefficient x B 9.44 x A B Footnotes: (1) This number is the highest concentration of the compound actually measured by the 3M Lab. (2) Diffusion constants are provided for general interest. They are not required in the calculation procedure. (3) A minimum sampling time of 15 minutes is required. (4) ppmbasedon25C.760mmHg. *c3h5 O Cl 1 - Chloro-2,3 - epoxypropane 2 - Chloropropylene oxide gamna - chloropropylene oxide 3M 110437 FIGURE 2 IT w C o lle cte d 3M 11043S C o lle cte d FIGURE 3 Methylene Chloride Exposure Limit Organic Vapor Monitor #3500 i Wet Air FH @ 38.9% 10 50 FIGURE 4 Methylene Chloride Exposure Limit Organic Vapor Monitor #3500 Long Term Sampling With Diffusion Monitors Donald J. Larsen and Robert A. Weber OH&ESD, 3M Company INTRODUCTION Industrial hygiene is the science of recognizing, evaluating and controlling workplace hazards. Monitoring the environment is necessary to determine whether exposures are within safe guidelines or whether engineering controls or personal protective equipment are necessary. Monitoring for gases and vapors typically requires a battery operated pump with sorbent tubes or impingers. Monitors based on principles of diffusion have been shown to have comparable accuracy and have advantages over active sampling in many situations. The amount of a compound collected on a monitor based on the laws of diffusion can be described by the following formula: W = (DA/L)Ct where W is the weight collected, D is the diffusion coefficient, A is the cross-sectional area, L is the diffusion pathlength, C is the concentration and t is the sampling time. The DA/L term has the units of volume/time and can be treated as a sampling rate. The sampling rate for battery operated pumps can be varied from a few mL/min to a L/min. Sampling rates for diffusion monitors depend on the monitor geometry and the diffusion coefficient for the compound. The 3M Company manufactures diffusion monitors for Organic Vapors, Formaldehyde, Ethylene Oxide and Mercury. Typical sampling rates for the 3M organic vapor monitor range from 20 to 40 mL/min. The sorbent in the OVM is activated carbon which has a high surface area due to the microporous structure which is available for adsorption. Historically diffusion monitors have been validated for monitoring the working environment for full work shifts of 8 hours. We have also shown that our organic vapor monitors can be used to monitor sampling times of IS minutes to evaluate Short Term Exposure Limits (STELs). Recent concern with indoor air quality, environmental emissions and hazardous waste disposal gives rise to situations where monitoring for extended periods is desirable. Active sampling with battery operated pumps and sorbent tubes is difficult or impossible for many situations where extended sampling periods are required. 3M 110443 Many lab and field evaluations by 3M and others have been performed over the last 20 years to validate the use of diffusion monitors for work shift sampling. Studies comparing OVMs with charcoal tubes and validation of sampling rates have given most industrial hygienists the confidence to use diffusion monitors to evaluate 8 hour TWA sampling situations. REFERENCES 3M Organic Vapor Monitor Sampling Rate Validation Protocol Anders, L. W., and H. E. Mullins: Comparison of Diffusional Organic Vapor Monitors with Charcoal Tubes for Sampling Laboratory Challenges to Contaminant Mixtures Anders, L. W., H. E. Mullins and P. L. Sullivan: Organic Vapor Monitor with Backup Section When the capacity is poor and uptake rates depart from linearity as shown in the following graphs the 3520 monitor that has a backup section of charcoal can be used to extend sampling times. In 1990, 3M presented a paper at the ACS meeting in Boston to show that our organic vapor monitors are also valid for STEL sampling. Pieper, Richard M., Donald J. Larsen, and Patricia A. Ishaug: STEL Sampling Using Diffusional Monitors, American Chemical Society Meeting, Boston, MA, April, 1990. The following table shows a comparison of 1000 ppm acetone collected on charcoal tubes with monitors. The monitors and charcoal tubes indicate the same concentration. TIME (MIN) 7 1/2 15 15 22 1/2 STEL SAMPLING FOR ACETONE 3M 3520 ORGANIC VAPOR MONITOR MONITOR (PPM) CHARCOAL TUBE (PPM) 1085 4-/-68 (6.3%) 1134 47-59 (5.2%) 1092 +/-83 (7.6%) 1136 +/-60 (5.2%) 1057 +/-15 (1.4%) 1099 47-42 (3.9%) 1117 47-33 (2.9%) 1164 +/-11 (1.0%) 2 3M 1 Today we will present data to show that the OVM monitors can be used for extended sampling periods as well. A few previous references to the use of our monitors are shown below. They exposed the 3M 3500 monitors to very low concentrations (<50 ppb) for three weeks. They found the monitors acceptable but did not study the effects of reverse diffusion. REFERENCES Epstein, Paul S., et al: Experiences Using Passive Monitors to Measure Volatile Organic Compounds During Indoor and Ambient Air Quality Surveys, American Industrial Hygiene Conference, 1990. Cohen, Martin A., et al: The Validation of a Passive Sampler for Indoor and Outdoor Concentrations of Volatile Organic Compounds, J. Air Waste Manage. 40:993(1990). Validation of a diffusion monitor must address the following factors whether the sampling period is 8 hours, 15 minutes or 1 week: Recovery Analytical sensitivity Capacity (reverse diffusion) Linear uptake rate Orientation Temperature Face velocity Interferences Storage Recovery can vary with loading. This is especially true for oxygenated compounds which may have lower recoveries at very low loadings. For indoor air quality investigations the concentrations may be very low, so ldng sampling times may be necessary to accumulate enough for analysis. Epstein and Cohen found it necessary to use GC/MS/SIM to quantitatively analyze monitors at the low ppb levels even with long sampling times. Reverse diffusion (loss of previously adsorbed solvent during the sampling period) is the major concern which needs to be addressed for long term sampling. This manifests itself in a sampling rate which appears to be lower than predicted. These effects can be studied by using the 3520 monitor which has a backup section while exposing the monitor at levels which would not exceed the expected capacity for the primary layer. Effects due to orientation, temperature, face velocity, interferences and storage would be expected to be similar to that for workshift sampling and were not further tested in this study. 3 3M 110445 EXPERIMENTAL A source of compressed air is passed over heated water to provide a known humidity. We maintained a relative humidity of 30% at 23 C. Organic solvent is vaporized into the air stream to create a known concentration. For high concentrations we use a syringe pump to inject liquid onto a heated aluminum block. For the low concentrations in these studies we used a 3.7 mL septum capped vial having an appropriate sized hole (usually 1 mm diameter) in the septum. The challenge concentration is then passed through a Plexiglas chamber (5" x 5" x 21") containing the monitors which allows simultaneous sampling through sorbent tubes. The challenge concentration may also be monitored by portable infrared analyzer, flame ionization detector or gas chromatograph. A challenge air flow of 90 Lpm creates a face velocity of 19 feet per minute (fpm) and 140 Lpm creates a face velocity 29 fpm in our chamber. We generally recommend a minimum face velocity of 25 fpm to avoid starvation effects. We wished to evaluate our monitors for long exposure times to low concentrations of solvents to determine whether the published sampling rates in our Sampling and Analytical Guide would remain valid under these conditions. Laboratory tests were run using toluene, acetone, 1,1,1-trichloroethane, and methylene chloride. A field test evaluated exposure to a mixture of n-butanol and isopropanol. The compounds selected enabled us to test several classes of compounds having a range of affinity for the activated carbon sorbent. Toluene is held very well. Acetone and methylene chloride are held only weakly. This ability of the sorbent to hold the compound of interest leading to a linear uptake rate is one of the most critical parameters to measure. We used the 3520 monitors which have a backup section for our studies. The accuracy of a monitor for workplace evaluations is expressed as the following combination of the precision and bias: 2 X Coefficient of Variation + | Bias | <25%. Typical values for the CV are about 5 % and for the bias also about 5 % for a typical accuracy of 15% for workshift monitoring. 4 3H 110446 COMPOUND EXPOSURE CONC (PPM) AMOUNT TIME (DAYS) FOUND (MG) AMOUNT EXPECTED (MG) ACCURACY % Toluene 1,1,1-TCE 1,1,1-TCE Acetone 2 3/4 1 8 5 2.3 2.6 0.45 2.86 1.074 0.61 0.85 1.767 1.088 0.65 0.83 1.97 16.1 15.8 13.4 17.4 For our first experiment, we chose toluene. If anything could be expected to work, it would be toluene. Charcoal has a high affinity for toluene. The capacity on our monitor is >25 mg. Toluene can also be recovered from charcoal with carbon disulfide with 100% efficiency. After the 2 3/4 days at 2.3 ppm toluene, three of the monitors were exposed to clean air for 1, 2 or 3 days. No difference was seen in the amounts collected. This shows that back diffusion is not a problem under these conditions. Nothing was found on the backup section for the toluene and 1 day 1,1,1-trichloroethane experiments. For the 8 day 1,1,1-trichloroethane experiment nothing was found on the backup after 4 days and only 1 % after 8 days. For acetone, 16% was found on the backup, which is acceptable as our monitor allows up to 50%. For our 5th experiment, twenty-one monitors were exposed to methylene chloride at 1.9 ppm for 1 to 5 days. Three monitors were removed each day, separated and capped. A graph of the amount collected vs. time shows that the uptake rate remained linear throughout this exposure. The CV was 4.1% and the bias was +17.1% for an accuracy of 25.3%. Although this is somewhat higher than we usually see for 8 hour samples it is still very good for a compound which has low capacity. For occupational exposures we recommend a maximum of 4 hours sampling where concentrations are allowed to reach or exceed the proposed limit of 25 ppm. The other six monitors were removed from the exposure chamber after 24 hours and allowed to sit for 24 hours in the laboratory, then reexposed for 24 hours followed by 24 hours at 0 ppm and then another 24 hours in the chamber. These monitors had 72 hours of exposure and collected 95 % of the amount collected by the monitors with 72 hours of continuous exposure. Our 6th experiment was a field test in a 3M pilot plant where we measured the concentration of isopropanol and n-butanol over a 3 day time period. Monitors were exposed for 1, 2 and 3 days. Charcoal tube were taken on Day 1 and Day 3. The results shown in the following table indicate excellent agreement. 3M 110447 5 COMPOUND Isopropanol n-Butanol MONITOR PPM 0.55 +/- 0.07 0.18 +/-0.008 CHARCOAL TUBE PPM 0.48 +/-0.11 0.17 +/-0.03 CONCLUSIONS These experiments show that diffusion monitors can be used for extended sampling periods up to 1 week and still provide acceptable accuracy. When volatile compounds like acetone, isopropanol and methylene chloride are anticipated, it is essential to use the 3520 OVM which has a backup layer of sorbent. Future work will extend to even longer sampling periods, test at high relative humidity, test at low face velocities where starvation might be a concern and investigate other sorbents which might allow thermal desorption. 3M 110448 6 2 X Coefficient of Variation + | Bias | <25% 3M 110450 ALTERNATING EXPOSURE METHYLENE CHLORIDE Vft i 0 24 48 72 96 120 TIME (HOURS) LONG TERM LOW LEVEL EXPOSURES 3M 3520 ORGANIC VAPOR MONITOR COMPOUND EXPOSURE CONC (PPM) AMOUNT TIME (DAYS) FOUND (MG) AMOUNT EXPECTED (MG) Toluene 2 3/4 2.3 1.074 1.088 1,1,1-TCE 1 2.6 0.61 0.65 1,1,1-TCE 8 0.45 0.83 0.85 Acetone 5 2.86 1.767 1.97 COMPOUND Toluene 1,1,1-TCE 1,1,1-TCE Acetone CY (%) 7.4 4.8 5.5 3.6 BIAS (%) -1.3 -6.2 -2.4 -10.3 ACCURACY % 16.1 15.8 13.4 17.4 3M 110453 CO U1 41 ALTERNATING exposure METHYLENE CHLORIDE CO o U1 ill TIME (HOURS) 3M 3520 Methylate Chloride Uptake RaS 5 Days Exposure 2 ppm & 30% RH + Primary A Secondary Total 2.50 1 2.00 1.50 C3 1.00 0.50 3M 110456 0.00 0 24 48 72 HOURS 96 120 3M 3520 MethyldGe Chloride Uptake Raft 5 Days Exposure 2 ppm & 30% RH + Primary A Secondary O Total 3M 110457 Sheetl TOLUENE VALIDATION 1995 The exposure level (1EL) was 100 ppm. Using our published sampling rate of 31.4 +/- .6 cc/min, an 8 hr exposure at 1 EL = 5.68 mg, 0.5 EL = 2.84 mg and 0.1 EL = 0.57 mg. 1 Desorption Efficiency 1 1/2 mL CS2 used for desorption. GC/FID 30M x .25mm x ,25um D B5 or DBWax. Spike mg recovery ave rec std dev cv ave rec 5.636 5.842841 1.0367 1.019875 0.012286 1.204671 1.000117 5.636 5.676579 1.0072 5.636 5.739139 1.0183 5.636 5.733503 1.0173 3.0345 3.118859 1.0278 1.01965 0.026215 2.570962 3.0345 3.125535 1.03 3.0345 2.977148 0.9811 3.0345 3.15497 1.0397 0.434 0.407439 0.9368 0.960625 0.021069 2.192753 0.434 0.410911 0.9468 0.434 0.424756 0.9787 0.434 0.424886 0.979 Storage Spike with 2.601 mg (.5EL) plus 4 0 uL H20 stored at RT and 4 C. mg Recovery initial 2wks RT 2wks cold 3wks RT 3wks cold initial 2wks RT 2wks cold 3wks RT 3wks cold 2.658 2.541 2.704 2.627 2.684 1.021915 0.976932 1.0396 1.009996 1.031911 2.67 2.628 2.643 2.666 2.716 1.026528 1.010381 1.016148 1.02499 1.044214 2.558 2.676 2.68 2.742 2.747 0.983468 1.029604 1.030373 1.05421 1.056132 2.644 2.651 2.719 2.756 2.668 1.016532 1.019223 1.045367 1.059592 1.025759 average std dev cv 1.012111 1.009035 1.032872 1.037197 1.039504 0.019527 0.022798 0.012746 0.023663 0.013482 1.929361 2.259428 1.233991 2.281485 1.296918 Page 1 3M 110469 Sheetl Humidity Effect on Uptake Linearity Exposure to 94.8 ppm @ 50%RH time min mg mg coit SR ave SR std dev ave mg std dev cv(%) 120 1.387 1.363 31.71884 30.75074 1.120409 1.321 0.048134 3.644 120 1.291 1.268 29.52345 120 1.356 1.332 31.00992 242 2.801 2.752 31.76288 30.99555 1.509278 2.685 0.130761 4.869 242 2.58 2.535 29.25678 242 2.819 2.770 31.967 362 4.133 4.061 31.33134 29.69895 1.430686 3.849 0.185415 4.817 362 3.781 3.715 28.66291 362 3.839 3.772 29.10259 482 5.478 5.382 31.18869 31.24752 0.247277 5.392 0.04267 0.791 482 5.451 5.355 31.03497 482 5.536 5.439 31.51891 Ave SR 30.7 std dev 1.2 cv 3.9 Exposure to 93.9 ppm @80%RH time min mg mg corr SR ave SR std dev ave mg std dev cv 130 1.453 1.441197 30.96615 30.36941 1.08941 1.413 0.050702 130 1.366 1.354904 29.11201 130 1.456 1.444173 31.03008 250 2.934 2.910167 32.51509 30.78997 2.272368 2.756 0.203382 250 2.546 2.525319 28.21521 250 2.855 2.831809 31.6396 370 3.778 3.747311 28.28949 29.39521 0.995823 3.894 0.13191 370 4.036 4.003216 30.22138 370 3.963 3.930809 29.67476 490 5.359 5.315469 30.30069 29.6825 1.41681 5.207 0.248543 490 5.427 5.382917 30.68518 490 4.963 4.922686 28.06164 Ave SR 30.1 std dev 1.4 cv 4.7 3.587 7.380 3.388 4.773 Page 2 3M 110470 Sheetl Average Combined S R Combined Std Dev CV Bias Accuracy 30.4 1.3 4.3 -3.3 12.0 Exposure to 295 ppm (1111 mg/m3) @50%FtH in .25 X 1.75 in Al chamber at 30 scfh (FV=178 fpm) 339 13.277 13.01667 34.53892 426 16.106 15.7902 33.34161 657 23.953 23.48333 32.15163 657 25.384 24.88627 34.07243 721 27.401 26.86373 33.51503 721 27.748 27.20392 33.93946 Ave SR 33.6 std dev 0.8 CV 2.5 This expen ment shows linear uptake up to 12 hours at 300 ppm. Only a trace was found on the backup of one of the 12 hour samples showing that the capacity of the 3500 OVM is at least 27 mg. Rev rs Diffusion 31 min @204 ppm @fJ0%RH (A)+ 7 1/2 hrs @ 0 ppm(B] mg A mg Acorr mg B mg B corr SR A SR B 0.787 0.771569 0.777 0.761765 32.37527 31.96389 0.899 0.881373 0.81 0.794118 36.98267 33.32143 0.759 0.744118 0.766 0.75098 31.22341 31.51138 0.774 0.758824 0.759 0.744118 31.84048 31.22341 0.827 0.810784 0.787 0.771569 34.02077 32.37527 0.715 0.70098 0.801 0.785294 29.41336 32.95119 average 0.777941 stdev 0.062048 cv 7.975932 Difference equals -1.3 % after 7 0.767974 ave SR 0.019457 2.533541 12 hrs at 0 ppm. 32.43354 Page 3 3M 110471 Sheetl Concentration-Time Expose 477 min @ 186.4 ppm (2 EL) @ 50%RH mg mg corr sr ave sr std dev cv bias acc 10.555 10.34804 30.88335 32.00155 0.785679 2.455128 1.915767 6.826023 10.932 10.71765 31.98643 11.058 10.84118 32.3551 11.365 11.14216 33.25337 10.813 10.60098 31.63825 10.9 10.68627 31.8928 Expose 15 and 480 m n @ 11.2 ppm (.1 EL) (g>50%RH 0.0166 0.016275 25.70569 27.07356 1.347908 0.0178 0.017451 27.56393 0.0163 0.01598 25.24113 0.0175 0.017157 27.09937 0.0183 0.017941 28.3382 0.0184 0.018039 28.49306 0.609 0.597059 29.47057 29.42298 0.84738 0.6143 0.602255 29.72704 0.6344 0.621961 30.69972 0.5891 0.577549 28.50757 0.5878 0.576275 28.44466 0.6135 0.601471 29.68833 4.978687 2.879994 -13.7785 23.73583 -6.29623 12.05622 Exposure 15 min @ 96 ppm (2EL) @ 50% RH 0.36145 0.354363 31.9839 31.93729 1.524634 0.38584 0.378275 34.14211 0.33521 0.328637 29.66198 0.35031 0.343441 30.99814 0.37025 0.36299 32.76259 0.36248 0.355373 32.07504 4.773837 1.711127 11.2588 Page 4 3M 110472 Sheetl Face Velocity-Orientation mean std dev coef var 1.338 0.086 6.4 Using data from19-39!3 fpm. Excludes 3,10 and 14 fpm data. Mean corrected for rec of .97 = 1.380 Amount expected = 1.42 Bias= -2.8 Accuracy = SR = 30.50708 15.6 Data corrected to lOOppm for 12G min. mg mg corr av par/per std dev ave std dev fpm 1.435 1.435 1.330 0.131 1.316 0.101 1.372 1.372 1.183 1.183 1.388 1.388 1.302 0.088 1.307 1.307 1.212 1.212 1.208 1.381 1.289 0.080 1.308 0.085 1.088 1.243 1.087 1.242 1.255 1.434 1.327 0.103 1.153 1.318 1.075 1.229 1.252 1.192 1.131 0.094 1.166 0.074 1.238 1.179 1.074 1.023 1.27 1.210 1.200 0.034 1.221 1.163 1.29 1.229 1.119 1.079 1.157 0.090 1.211 0.086 28.8 19 9.7 14.2 Page 5 3M 110473 Sheetl 1.178 1.302 1.274 1.312 1.351 1.259 1.417 1.324 1.404 1.452 1.387 1.244 1.113 1.34 1.365 1.47 1.329 1.528 1.538 1.448 1.467 1.441 1.461 1.79177 1.80833 1.78772 1.74597 1.57744 1.80238 2.31486 2.36431 2.45103 2.53305 2.35019 2.35787 1.17468 1.30096 1.136 1.256 1.229 1.265 1.303 1.201 1.351 1.263 1.339 1.385 1.323 1.208 1.081 1.301 1.325 1.427 1.290 1.455 1.465 1.379 1.397 1.372 1.391 1.171 1.182 1.168 1.141 1.031 1.178 1.346 1.375 1.425 1.473 1.366 1.371 0.947 1.049 1.266 0.037 1.271 0.076 1.349 0.032 1.196 0.111 1.348 0.071 1.410 0.040 1.174 0.007137 1.117 0.076493 1.382 0.040075 1.403 0.060133 0.999 0.050946 1.310 0.067 24 1.272 0.117 59.5 1.410 0.040 399 1.145 0.05778 3 1.393 0.047195 340 w fan 0.985 0.057546 3 Page 6 3M 110474 Sheetl 1.24139 1.28218 1.10808 1.2177 1.62134 1.60883 1.74505 1.59486 1.67304 1.70339 1.001 1.034 0.894 0.982 1.329 1.319 1.430 1.307 1.371 1.396 Temperature Effects 0.970 0.070984 1.359 0.061718 1.358 0.045897 1.359 0.048648 340 w fan Toluene Temperature Effect Study October, 1995 Temp time 9C 9C 9C 9C 9C 9C 40 C 40 C 40 C 40 C 40 C 40 C RT (23 C) RT {23 C) RT {23 C) RT {23 C) RT (23 C) RT (23 C) Cone mg mg corr SR ave SR sd cv bias 240 130 3.911 3.911 33.26319 30.09223 1.890028 6.280783 -0.21353 240 130 3.502 3.502 29.78463 240 130 3.606 3.606 30.66915 240 130 3.408 3.408 28.98516 240 130 3.555 3.555 30.2354 240 130 3.247 3.247 27.61585 240 130 3.789 3.789 32.22557 31.46863 0.721836 2.293829 4.35064 240 130 3.743 3.743 31.83434 240 130 3.741 3.741 31.81733 240 130 3.685 3.685 31.34105 240 130 3.698 3.698 31.45162 240 130 3.544 3.544 30.14184 244 130 3.635 3.635 30.40898 30.15662 0.400726 1.328817 244 130 3.597 3.597 30.09109 244 130 3.591 3.591 30.0409 244 130 3.681 3.681 30.7938 244 130 3.541 3.541 29.62262 244 130 3.584 3.584 29.98234 Page 7 3M 110475 TOLUENE 95ppm50%RH-94ppm*80%RH + 50% RH A 80% RH time (min) 3M 110476 Face Velocity Toluene 100ppm2hrs Face Velocity (fpm) 3M 110477 Sheetl ISOPROPANOL VALIDATION 1995 ipa2.xis The exposure level (1EL) was 400 ppm. Using our published sampling rate of 39.4 cc/min, an 8 hr exposure at 1 EL = 18.59 mg, 0.5 EL = 9.30 mg and 0.1 EL = 1.86 mg. Desorption Efficiency 1 1/2 mL acetonitrile used for desorption. GC/FfD 30M x .25mm x ,25um D BWax. Spike mg recovery ave rec std dev cv ave rec 1.96 1.887 0.962755 0.968112 0.028442 2.937889 0.955834 1.96 1.857 0.947449 1.96 1.867 0.952551 1.96 1.979 1.009694 9.42 8.972 0.952442 0.941242 0.038572 4.098006 9.42 9.323 0.989703 9.42 8.489 0.901168 9.42 8.682 0.921656 18.84 17.958 0.953185 0.958148 0.044207 4.613841 18.84 19.257 1.022134 18.84 17.515 0.929671 18.84 17.476 0.927601 Storage Spike with 9.42 mg (.5EL) plus 40 uL H20 stored at RT and 4 C. mg Recovery initial 2wks RT 2wks cold 3wks RT 3wks cold initial 2wks RT 2wks cold 3wks RT 3wks cold 8.507 9.664 8.477 8.515 9.227 0.903079 1.025902 0.899894 0.903928 0.979512 9.387 9.643 8.558 8.844 8.487 0.996497 1.023673 0.908493 0.938854 0.900955 8.907 8.912 8.439 8.816 8.563 0.945541 0.946072 0.89586 0.935881 0.909023 8.645 9.143 8.172 8.35 8.318 0.917728 0.970594 0.867516 0.886412 0.883015 average std dev cv 0.940711 0.991561 0.892941 0.916269 0.918126 0.041149 0.039662 0.01775 0.025419 0.042343 4.374277 4.000006 1.987772 2.774236 4.611846 Page 1 3M 110478 Sheetl Humidity Effect on Uptake Linearity Exposure of 3M 3500 to 397 ppm( ave ir=400 & syr= 394.8) @ 50%RH time min mg mg coit SR ave SR std dev ave mg std dev cv(%) 124 4.251 4.428 36.59418 37.19677 2.09753 4.501 0.253814 5.639 124 4.12 4.292 35.46649 124 4.592 4.783 39.52964 227 8.243 8.586 38.76164 39.60806 0.803541 8.774 0.178 2.029 227 8.583 8.941 40.36044 227 8.443 8.795 39.70211 358 12.456 12.975 37.13969 38.48442 3.174661 13.445 1.109089 8.249 358 12.142 12.648 36.20344 358 14.123 14.711 42.11013 485 16.703 17.399 36.76168 36.16817 2.100785 17.118 0.994282 5.808 485 15.373 16.014 33.83448 485 17.224 17.942 37.90835 Ave SR 37.9 std dev 2.3 cv 6.1 bias -3.9 acc 16.2 Page 2 3M 110479 Sheetl Exposure of 3M 3520 to 397 ppm @ 50%RH time mg A mg B mg A cor mg B cor Total SR ave SR std dev ave mg std dev cv(%) 124 4.251 0 4.428 0 4.428125 36.59418 37.19677 2.09753 4.501 0.253814 5.639 124 4.12 0 4.292 0 4.291667 35.46649 124 4.592 0 4.783 0 4.783333 39.52964 227 8.243 0 8.586 0 8.586458 38.76164 39.60806 0.803541 8.774 0.178 2.029 227 8.583 0 8.941 0 8.940625 40.36044 227 8.443 0 8.795 0 8.794792 39.70211 358 12.456 0.0646 12.975 0.067292 13.12304 37.56344 38.79797 3.224315 13.554 1.126436 8.311 358 12.142 0.0259 12.648 0.026979 12.70727 36.37334 358 14.123 0.0529 14.711 0.055104 14.83269 42.45714 485 16.703 0.1756 17.399 0.182917 17.80138 37.61194 36.98728 2.119015 17.506 1.00291 5.729 485 15.373 0.1635 16.014 0.170313 16.38823 34.62615 485 17.224 0.1684 17.942 0.175417 18.32758 38.72374 Ave SR 38.1 std dev 2.2 cv 5.8 bias -3.2 acc 14.8 Page 3 3M 110480 Sheetl Exposure of 3M 3500 to 427 ppm {ave of ir=440 and pump = 414) @80%RH time min mg mg corr SR ave SR std dev ave mg std dev cv 120 4.422 4.60625 36.5715 38.84309 2.487127 4.892 0.313258 120 5.018 5.227083 41.50063 120 4.65 4.84375 38.45714 240 8.894 9.264583 36.77826 37.05945 0.36577 9.335 0.092139 240 8.93 9.302083 36.92713 240 9.062 9.439583 37.47297 360 12.776 13.30833 35.22068 34.81175 1.416484 13.154 0.535226 360 12.056 12.55833 33.23579 360 13.051 13.59479 35.97879 480 15.762 16.41875 32.58933 33.46598 1.967705 16.860 0.991345 480 17.276 17.99583 35.71965 480 15.52 16.16667 32.08897 Ave SR 36.0 37.95127 AveSR w/o6& 8hr 80% std dev 2.6 1.866078 Uptake deviation >5% @6&8hrs cv 7.3 4.917036 bias -8.5 -3.7 acc 23.1 13.5 6.403 0.987 4.069 5.880 Page 4 3M 110481 Sheetl Exposure of 3M 3520 to 427 ppm @ 80%RH time mg A mg B mg A cor mg B cor Total SR ave SR std dev ave mg std dev cv(%) 120 4.422 0 4.606 0 4.60625 36.5715 38.84309 2.487127 4.892 0.313258 6.403 120 5.018 0 5.227 0 5.227083 41.50063 120 4.65 0 4.844 0 4.84375 38.45714 240 8.894 0.014 9.265 0.014583 9.296667 36.90562 37.21714 0.341414 9.375 0.086003 0.917 240 8.93 0.026 9.302 0.027083 9.361667 37.16366 240 9.062 0.012 9.440 0.0125 9.467083 37.58214 360 12.776 0.192 13.308 0.2 13.74833 36.38514 35.88524 1.563047 13.559 0.590606 4.356 360 12.056 0.148 12.558 0.154167 12.8975 34.1334 360 13.051 0.191 13.595 0.198958 14.0325 37.13719 480 15.762 0.652 16.419 0.679167 17.91292 35.55507 37.03216 2.37948 18.657 1.1988 6.425 480 17.276 0.892 17.996 0.929167 20.04 39.77709 480 15.52 0.808 16.167 0.841667 18.01833 35.76431 Ave SR 37.2 std dev 2.0 cv 5.3 bias -5.5 acc 16.0 Ave Comb ned SR Combined Std Dev CV Bias Accuracy 3M 3500 37.0 37.89333 3M 3520 2.6 2.124904 7.0 5.607594 -6.2 -3.8 20.2 15.0 all points w/o nonlinear pts 37.7 2.1 5.6 -4.3 15.5 Non-linear difference >5% 8hr 80% 7.155172 6hr 80% 5.671387 Page 5 3H 110482 Sheetl Reverse Diffusion 30 min @2EL = 800 (ave ir=818 & syr= 772) ppm @80%RH (A)+ 7 1/2 hrs @ 0 ppm(B) mg A mg A coit mg B mg B coit mg back mg bk cor tot SR A SR B SR TOT 2.194 2.285417 2.19 2.28125 0.018 0.01875 2.3225 38.7399 38.66928 39.3685 2.17 2.260417 2.014 2.097917 0.011 0.011458 2.123125 38.31613 35.56161 35.98891 2.113 2.201042 2.067 2.153125 0.009 0.009375 2.17375 37.30967 36.49744 36,84705 2.106 2.19375 1.95 2.03125 0.01 0.010417 2.054167 37.18607 34.43155 34.82 2.16 2.25 2.093 2.180208 0.012 0.0125 2.207708 38.13956 36.95653 37.42268 2.133 2.221875 1.977 2.059375 0.012 0.0125 2.086875 37.66281 34.90829 35.37444 average 2.235417 stdev 0.035885 cv 1.605311 3M 3500 % Differenc 3M 3520 % Differenc -4.54334 -3.31314 2.133854 0.091227 4.275224 2.161354 37.89236 36.17078 36.63693 0.096714 4.474701 Page 6 3M 110483 Sheetl Concentration-Time Expose 15 min @(ir=775 pump=752.8) 764 ppm (2EL) <j% 50%RH mg mg coit sr ave sr stddev cv bias acc 1.183 1.232292 43.74549 41.16933 2.924306 7.103119 4.490674 18.69691 1.03 1.072917 38.08779 1.001 1.042708 37.01541 1.161 1.209375 42.93196 1.125 1.171875 41.60074 1.18 1.229167 43.63455 Expose 16 and 480 m n @ (ir=35 pump=53.2) 53.2 ppm (.1 EL) @5(}%RH 0.0815 0.084896 40.57506 40.12699 1.709023 4.259036 1.845153 0.0835 0.086979 41.57077 0.0814 0.084792 40.52527 0.0742 0.077292 36.94073 0.0833 0.086771 41.47119 0.0797 0.083021 39.67892 2.412 2.5125 40.02742 39.45489 1.275591 3.233038 0.13931 2.355 2.453125 39.0815 2.376 2.475 39.43 2.353 2.451042 39.04831 2.268 2.3625 37.63772 2.501 2.605208 41.50438 10.36322 6.605385 Page 7 3M 1104S4 Sheetl Exposure 480 min @ ir=791 pump=749.8)7`f0 ppm (2EL) @ 50%RH (3500) 30.67 31.94792 35.16535 33.67003 1.008734 2.99594 -14.5431 28.034 29.20208 32.14299 29.404 30.62917 33.71379 29.061 30.27188 33.32052 29.154 30.36875 33.42715 29.872 31.11667 34.25039 20.53495 Exposure 480 min @ 749.8 ppm (2EL) @ 5()%RH (3520) 30.67 2.13 31.94792 2.21875 36.82917 40.53819 28.034 2.148 29.20208 2.2375 34.12458 37.56123 29.404 2.56 30.62917 2.666667 36.49583 40.17128 29.061 1.801 30.27188 1.876042 34.39917 37.86346 29.154 2.353 30.36875 2.451042 35.76104 39.36249 29.872 2.029 31.11667 2.113542 35.76646 39.36845 39.14419 1.203505 3.074544 -0.64928 6.798365 Temperature Effects No specific data. Data for toluene, 1,1,1-trichloroethane , methylene chloride and hexane show that temperature effects are not s gnificant (<10%) in the range 10-40C. Face Velocity & Orientation Extensive tests with toluene, hexane and 1,1,1-trichloroethane have shown that the 3M organic vapor monitor is not affected by orientation and face velocity as long as a minimum face velocity of 25 fpm is maintained. Page 8 3M 110485 Isopropanol 397 ppm 50%RH - 427 ppm 80%RH + 50%RH A 80% RH time (min) 3Vt 1^0486 + total (3520) Isopropanol 397 ppm 50%RH A primary (3500) O secondary time (min) 3M 110487 total (3520) Isopropanol 427 ppm 80%RH A primary (3500) O secondary time (min) 3M 110488 Sheetl Methylene Chloride Validation 1995 _________ _________ The exposure level (1 EL) was 25 ppm. Using our published sampling rate of 37.9 cc/min, an 8 hr exposure at 1 EL = 1.58 mg, 0.5 EL = .791 mg and 0.1 EL ** 58 mg. i Desorption Efficiency 1 1/2 mL CS2 used for desorption. GC/FID 30M x .25 mm x .25 um DBWax. Spike mg recovery ave rec std dev cv Recovery 0.159 0.136 0.855346 0.877358 0.031863 3.631705 0.87 0.159 0.137 0.861635 0.159 0.138 0.867925 0.159 0.147 0.924528 0.795 0.669 0.841509 0.871069 0.020985 2.409144 0.795 0.693 0.871698 0.795 0.701 0.881761 0.795 0.707 0.889308 1.590 1.403 0.88239 0.860849 0.014699 1.707543 1.590 1.356 0.85283 1.590 1.364 0.857862 1.590 1.352 0.850314 Storage .795 mg p us 40 uL H20 stored at RT and 4 C initial 2wks RT 2wks cold rec Initial rec 2 wks rec 2wks cold 0.795 0.713 0.738 0.747 0.896855 0.928302 0.939623 0.795 0.73 0.775 0.784 0.918239 0.974843 0.986164 0.795 0.822 0.736 0.761 1.033962 0.925786 0.957233 0.795 0.721 0.747 0.768 0.906918 0.939623 0.966038 AVE stdev 0.94 0.94 0.96 0.06 0.02 0.02 3M 11M97 Sheetl 0.795 0.795 0.795 0.795 8wks RT 8wks cold 0.689 0.724 0.699 0.702 0.716 0.69 0.689 0.697 rec 8wks rec 8wks cold 0.866667 0.910692 0.879245 0.883019 0.900629 0.867925 0.866667 0.87673 AVE stdev 0.88 0.88 0.02 0.02 Humidity Effect on Uptake Linearity Methytene Chloride Exposure at 24 ppm, 80 % RH, 23.5 C, 29 fpm, DE=.87 time mg A mg B mg A corr mg B corr mg total mean stdev SR ave SR std dev CV(%) 120 0.33 0 0.379 0.000 0.379 0.369 0.016932 37.91578 36.88 1.692528 4.589072 120 0.304 0 0.349 0.000 0.349 34.92847 120 0.329 0 0.378 0.000 0.378 37.80088 242 0.569 0.032 0.654 0.037 0.735 0.744 0.008817 36.42877 36.89595 0.437027 1.184485 242 0.563 0.039 0.647 0.045 0.746 36.96432 242 0.571 0.038 0.656 0.044 0.752 37.29477 361 0.678 0.125 0.779 0.144 1.095 1.094 0.047835 36.39762 36.34669 1.589427 4.372962 361 0.733 0.118 0.843 0.136 1.141 37.91005 361 0.674 0.107 0.775 0.123 1.045 34.73242 480 0.668 0.218 0.768 0.251 1.319 1.337 0.03528 32.96375 33.40227 0.881643 2.639472 480 0.723 0.216 0.831 0.248 1.377 34.41718 480 0.694 0.204 0.798 0.234 1.314 32.82587 AVE SR stdev cv 35.9 1.9 36.7 1.2 Bias OSHA 5.2 5.3 15.7 3.3 -3.1 9.7 w/o 8hr 80% P^2 3M 110#B Sheetl Methylene Chloride Exposure at 24 ppm, 50 % RH, 22.5 C, 29 fpm, DE=.87 time mg A mg B mg A corr mg B corr mg total mean stdev SR ave SR std dev CV(%) 120 0.352 0 0.405 0.000 0.405 0.388 0.020891 40.44 38.76 2.088249 5.387868 120 0.343 0 0.394 0.000 0.394 39.41 120 0.317 0 0.364 0.000 0.364 36.42 240 0.673 0 0.774 0.000 0.774 0.747 0.035592 38.66 37.36 1.778865 4.761848 240 0.643 0.009 0.739 0.010 0.762 38.08 240 0.615 0 0.707 0.000 0.707 35.33 360 0.883 0.027 1.015 0.031 1.083 1.141 0.050318 36.09 38.01 1.676582 4.410572 360 0.966 0.026 1.110 0.030 1.176 39.19 360 0.946 0.03 1.087 0.034 1.163 38.76 480 1.294 0.054 1.487 0.062 1.624 1.578 0.043211 40.58 39.44 1.079842 2.737665 480 1.228 0.05 1.411 0.057 1.538 38.43 480 1.25 0.054 1.437 0.062 1.573 39.32 AVE SR stdev cv bias OSHA 38.4 1.7 4.3 1.3 10.0 Combined SR, etc. for 50% and 80%RH wit lout 80%RH 8hr data. 37.7 1.7 4.5 -0.6 9.5 P 3H 1 Sheetl R verse Diffusion mean std dev cv(%) %diff 30 min @ 52 ppm plus 3 1/2 hrs and 7 1/2 hrs @ 0 ppm @ 80%RH 0.19 0 0.208791 0 0.208791 0.204396 0.009299 4.549289 0.193 0 0.212088 0 0.212088 0.17 0 0.186813 0 0.186813 0.192 0 0.210989 0 0.210989 0.186 0 0.204396 0 0.204396 0.185 0 0.203297 0 0.203297 0.151 0.013 0.165934 0.014286 0.197363 0.194872 0.009062 4.650484 -4.6595 0.157 0.012 0.172527 0.013187 0.201538 0.142 0.011 0.156044 0.012088 0.182637 0.145 0.012 0.159341 0.013187 0.188352 0.146 0.013 0.16044 0.014286 0.191868 0.158 0.014 0.173626 0.015385 0.207473 0.089 0.034 0.097802 0.037363 0.18 0.184359 0.005001 2.712635 -9.80287 0.093 0.036 0.102198 0.03956 0.189231 0.084 0.035 0.092308 0.038462 0.176923 0.093 0.036 0.102198 0.03956 0.189231 0.091 0.035 0.1 0.038462 0.184615 0.088 0.037 0.096703 0.040659 0.186154 Pag 3M 111^)0 Sheetl Concentration-Time Exposure @ 52.1 ppm (2EL) and 50%RH time (min) mg mg corr SR ave SR sd cv bias acc 15 0.08498 0.102386 37.71615 38.26945 2.559761 6.688783 0.974812 14.35238 0.08193 0.098711 36.36249 0.08454 0.101855 37.52087 0.08037 0.096831 35.67013 0.08934 0.107639 39.65123 0.0962 0.115904 42.69586 Exposure (1>4 ppm (.1 EL) 50%RH ave sr std dev cv bias acc 493 0.23917 0.01132 0.288157 0.013639 0.318161 46.44708 45.24155 1.631583 3.606382 19.37084 26.58361 0.22199 0.01097 0.267458 0.013217 0.296535 43.28991 0.24709 0.01047 0.297699 0.012614 0.325451 47.51119 0.23749 0.01046 0.286133 0.012602 0.313858 45.81881 0.22612 0.01033 0.272434 0.012446 0.299814 43.76868 0.22989 0.0108 0.276976 0.013012 0.305602 44.61363 Exposure at 51 PPM (177.3 MG/M3)(2EL) @58%RH FOR 461 MIN DE=.87 461 2.215 0.186 2.545977 0.213793 3.016322 36.90354 36.87026 0.912462 2.474792 -2.717 7.666584 2.214 0.185 2.544828 0.212644 3.012644 36.85854 2.168 0.181 2.491954 0.208046 2.949655 36.0879 2.339 0.185 2.688506 0.212644 3.156322 38.61639 2.156 0.193 2.478181 0.221839 2.966207 36.2904 2.219 0.17 2.550575 0.195402 2.98046 36.46478 Pag 3H W501 Sheetl Exposure for 16 min at 9.1 ppm {.4EL) @50%RH 14:1 SPLIT DE = .97 amount co lected amount corrected SR 0.020863 0.021508 42.5259 0.019654 0.020262 40.06244 0.020362 0.020992 41.50567 0.02129 0.021948 43.39681 0.020045 0.020665 40.85871 0.019093 0.019683 38.91781 0.020843 AVE SR 41.2112 STD DEV 1.630679 CV 3.956884 bias 8.736675 ACCUR 16.65044 Orientation-Face Velocity Effects Extensive tests with toluene, hexane and 1,1,1-trichloroethane have shown tha the 3M organic vapor monitor is not affected by orientation and face velocity as long as a minimum face velocity of 25 fpm is maintained. T mperature Effects Exposed to 20 ppm for 243 min @RT mg mg corr SR ave SR ave mg 0.7816 0.898391 53.21656 52.71045 0.889847 0.795 0.913793 54.12892 0.7536 0.866207 51.31013 0.7631 0.877126 51.95695 0.7903 0.908391 53.80891 0.7614 0.875172 51.84121 6 3H Sheetl Exposed to 22.5 ppm for 243 min @40 C mg mg coit SR ave SR ave mg 0.9539 1.096437 57.73146 56.87508 0.960153 0.909 1.044828 55.01404 0.9567 1.099655 57.90092 0.9482 1.089885 57.38649 0.9328 1.072184 56.45446 0.9379 1.078046 56.76312 7.900969 Exposed to 21.1 ppm for 243 min @ 11.6 C mg mg corr SR ave SR ave mg %diff 0.8604 0.988966 55.52776 54.12623 0.913748 2.685964 0.8396 0.965057 54.18539 0.8225 0.945402 53.0818 0.8375 0.962644 54.04986 0.8263 0.94977 53.32704 0.8458 0.972184 54.58552 Pjk7 t Methylene Chloride Uptake Rate 24 ppm, 50% RH, 23 C, 29 fpm + Total A Primary O Secondary 2.00 I 1.50 a 1.00 0.50 - 0.00 0 60 120 180 240 300 360 420 480 time (min) 3H H()4 Methylene Chloride Uptake Rate 24 ppm, 80% RH, 23 C, 29 fpm + Total A Primary O Secondary 0 60 120 180 240 300 360 420 480 time (min) 3H nq|p? Sheetl 1,1,1-Trichloroethane Validation 1995 tce3.xls The exposure level (1 EL) is 350 ppm. Using our published sampling rate of 30.9 +/- .3 cc/min, an 8 hr exposure at 1 EL = 28.3 mg, 0.5 EL = 14.2 mg and 0.1 EL = 2.83 mg. Desorption Efficiency 1 1/2 mL CS2 used for desorption. GC/FID 30Mx.25mmx.25um DBS. Spike mg recovery ave rec std dev Recovery 28.1 27.769 0.988 0.988 0.003 1.00 2p.1 27.858 0.991 28.1 27.737 0.987 28.1 27.684 0.985 13.38 13.250 0.990 0.988 0.009 13.38 13.205 0.987 13.38 13.070 0.977 13.38 13.357 0.998 2.676 2.762 1.032 1.027 0.008 2.676 2.740 1.024 2.676 2.772 1.036 2.676 2.723 1.018 Storage Spike w 13.38 mg (0.5 EL) plus 4 0 uL H20 stored at RT and 4 C. mg Recovery initial 2wks RT 2wks cold 3wks RT 3wks cold initial 2wks RT 2wks cold 3wks RT 3wks cold 13.637 12.614 13.046 13.474 13.948 1.02 0.94 0.98 1.01 1.04 13.566 12.588 13.238 13.378 13.437 1.01 0.94 0.99 1.00 1.00 13.429 13.105 13.241 13.459 13.618 1.00 0.98 0.99 1.01 1.02 13.767 12.906 13.145 13.399 13.464 1.03 0.96 0.98 1.00 1.01 average std dev cv 1.02 0.96 0.98 1.00 1.02 0.01 0.02 0.01 0.00 0.02 1.04 1.93 0.70 0.34 1.72 Page 1 3M 110506 Sheetl -------------- 1-------------Humidity Effect on Uptake Linearity Exposure to 367 ppm @ 50%RH (3520 in G, 3500 in K) time min mg A mg B Acorr B corr mg tot 3520 SR Ave SR AVE MG std dev sr 3500 SR ave sr stdev sr 110 7.041 0 6.835922 0 6.835922 31.03336 31.43592 6.924595 0.374441 31.03336 31.43592 0.374441 110 7.209 0 6.999029 0 6.999029 31.77383 31.77383 110 7.147 0 6.938835 0 6.938835 31.50056 31.50056 235 15.24 0 14.79612 0 14.79612 31.44158 31.13349 14.65113 0.267323 31.44158 31.13349 0.267323 . 235 15.008 0 14.57087 0 14.57087 30.96294 30.96294 235 15.024 0 14.58641 0 14.58641 30.99595 30.99595 , 351 22.046 0.007 21.40388 0.006796 21.41883 30.47285 29.84447 20.97715 0.54421 30.45158 29.81205 0.553871 351 21.348 0.013 20.72621 0.012621 20.75398 29.52696 29.48745 351 21.355 0.012 20.73301 0.01165 20.75864 29.53359 29.49712 470 29.003 0.045 28.15825 0.043689 28.25437 30.0201 29.30503 27.58136 0.738922 29.91798 29.19761 0.74711 470 27.557 0.052 26.75437 0.050485 26.86544 28.54437 28.42636 470 28.354 0.045 27.52816 0.043689 27.62427 29.35063 29.2485 ave SR std dev cv 30.42973 1.02039 3.353268 30.39477 1.060039 3.487571 Page 2 3M 110507 leetl Exposure to 369 ppm @ 80%RH time min mg A mg B Acorr B COIT mg tot 3520 SR Ave SR ave mg stdev sr 3500 SR ave sr stdev sr 115 7.006 0 6.801942 0 6.801942 29.37644 29.7622 6.891262 1.256996 29.53653 29.92439 1.263846 115 7.433 0 7.216505 0 7.216505 31.16687 31.33672 115 6.855 0 6.65534 0 6.65534 28.74329 26.89993 230 13.822 0.122 13.41942 0.118447 13.68 29.54081 27.73361 12.84311 1.834187 29.13602 27.65132 1.609792 230 13.225 0.013 12.83981 0.012621 12.86757 27.78644 27.87758 230 12.306 0.016 11.94757 0.015534 11.98175 25.87358 25.94038 333 18.811 0.344 18.26311 0.333981 18.99786 28.33509 27.99027 18.76667 1.182293 27.38765 26.97902 1.06648 ' 333 19.081 0.418 18.52524 0.405825 19.41806 28.96181 27.78076 333 17.699 0.328 17.1835 0.318447 17.88408 26.67389 25.76865 1 469 23.765 1.391 23.07282 1.350485 26.04388 27.58017 27.26152 25.74298 0.312156 24.567 24.23069 0.448557 469 22.947 1.616 22.27864 1.568932 25.73029 27.24808 23.7214 469 23.607 1.187 22.91942 1.152427 25.45476 26.9563 24.40367 Ave SR std dev CV 28.1869 1.465519 5.199292 27.19636 28.18491 2.345778 1.765867 8.625339 6.26529 w8 hr w/o 8hr Mean of 5C)% & 80%RHSRs Std Dev CV Bias ' OSHA Accuracy 3M 3500 3M 3520 3M 3500 29.4 29.60071 28.8 1.76666 1.684456 2.41615 5.999315 5.690593 8.390701 -4.70004 -4.20482 -6.81048 16.69867 15.586 23.59188 w/o n-l pt all pts all pts Non-linear difference >5% 8hr 80% 10.90465 Page 3 3M 1105QS Sheetl Reverse Diffusion 30 min @6 94 ppm @ti0%RH (A)+ 7 1/2 hrs @ 0 ppm(B mg A mg B SR A SR B ave sr 3.518 3.243 30.96746 28.54675 3.827 3.497 33.68746 30.78261 3.528 3.325 31.05549 29.26856 3.421 3.444 30.11361 30.31607 3.385 3.407 29.79672 29.99037 3,774 3.528 33.22092 31.05549 average 3.5755 3.407333 stdev , 0.183509 0.107452 cv 5.132397 3.153542 %diff 4.703305 ave sr 31.47361 29.99331 30.73346 Concentration-Time Expose 48 3 min @37.8 ppm (.IE L) @ 50%R H mg mg coit SR ave SR std dev cv bias acc 3.209 3.209 32.41359 31.00284 0.74748 2.411006 0.33282 5.154831 3.022 3.022 30.52473 3.085 3.085 31.16109 3.028 3.028 30.58534 3.063 3.063 30.93887 3.009 3.009 30.39342 Expose 17 min @36.7 ppm (.1EL) @ 50%RH mg mg conr SR ave SR std dev cv bias acc 0.115 0.115 33.78106 32.89982 1.050946 3.194383 6.471908 12.86067 0.114 0.114 33.48732 0.113 0.113 33.19357 0.108 0.108 31.72483 0.107 0.107 31.43108 0.115 0.115 33.78106 Page 4 3M 110509 Sheetl 1 Expose 15 min @ 701 ppm (2EL) @ 50%RH mg mg coit SR ave SR stddev cv bias acc 1.862 1.862 32.45345 32.70327 1.147199 3.507903 5.835829 12.85164 1.944 1.944 33.88266 1.87 1.87 32.59289 1.886 1.886 32.87175 1.761 1.761 30.69309 1.935 1.935 33.72579 Expose 3500s to 480 min @695 ppm (2EL) (3>50%RH mg , mg corr SR ave SR std dev cv bias acc 51.663 51.663 28138207 29.32552 1.680546 5.73066 -5.09541 16.55672 50.727 50.727 27.86786 54.985 54.985 30.20707 49.892 49.892 27.40914 57.625 57.625 31.65741 55.39 55.39 30.42957 Expose 3520s to 480 min @695 ppm (2EL) <j3)50%RH mg A mg B tot mg cor SR ave SR std dev cv bias acc 51.663 0.836 53.5022 29.39247 30.35586 1.917036 6.315208 -1.76096 14.39138 50.727 0.57 51.981 28.55677 54.985 0.864 56.8858 31.25132 49.892 0.622 51.2604 28.16089 57.625 0.945 59.704 32.79955 55.39 1.278 58.2016 31.97418 Page 5 3M 110510 Temperature Effects 120 min exposures temp PPm mg ave mg % diff RT 238 5.508 5.4625 5.442 5.394 5.14 5.372 5.919 42 C i 237 5.448 5.393333 -1.26621 4.98 4.957 5.772 5.435 5.768 12 C 239 5.734 5.887 7.771167 5.92 5.821 5.884 5.915 6.048 Page 6 3M 110511 leetl Face Vel city-Orientation 1,1,1-Trichloroethane Face Veloc ty and Orientation Test (June-July, 1994) Using data from 14-400fpm Excludes 3 and 10 fpm Mean 2.152359 Std dev 0.172512 Coef Var 8.015002 Amt expec 2.225573 Bias -3.28969 Act 19.31969 Data Normalized to 120 min at 11 0 ppm mg mg coit av par/per stdev ave stdev fpm 2.15369 2.194 2.212 0.088988 2.226 0.105537 2.09523 2.134 2.26707 2.309 2.14874 2.189 2.24 0.139162 2.35343 2.397 2.0943 2.133 2.11722 2.025 2.131 0.128851 2.113 0.144662 2.1887 2.094 2.37792 2.275 2.02467 1.937 2.095 0.186392 2.1412 2.048 2.40501 2.3 2.37608 2.273 2.248 0.186401 2.177 0.201666 2.53035 2.42 2.14325 2.05 1.94741 1.863 2.105 0.227411 2.41886 2.314 2.23674 2.139 1.96915 2.111 2.149 0.033216 2.161 0.092121 2,01674 2.162 28 24 19 14 Page 7 3M 110512 2.02731 2.17388 1.92434 1.98042 1.95793 1.89261 1.94131 1.79496 1.81283 2.03437 1.99337 1.70338 1^80727 1.72088 1.81436 1.76545 2.76105 2.8937 2.7101 3.18293 2.9372 3.04077 3.00425 2.9362 3.33468 3.15633 3.12722 3.27171 3.37871 3.53563 3.05727 3.34085 3.48948 3.24541 3.86996 3.48862 3.54756 2.174 2.331 2.063 2.123 2.051 1.983 2.034 1.88 1.899 2.131 2.088 1.784 1.893 1.803 1.901 1.85 2.296 2.407 2.254 2.647 2.443 2.529 2.132 2.084 2.367 2.24 2.219 2.322 2.148 2.248 1.944 2.124 2.219 2.064 2.289 2.063 2.098 2.172 0.140364 2.023 0.035564 1.97 0.139715 1.922 0.153921 1.851 0.048983 2.429 0.145965 1.996 0.095571 1.887 0.109311 2.429 0.145965 2.227 0.10792 2.124 0.110493 2.169 0.135254 eetl 10 60 small 399 alum 221 alum 105 alum 302 alum Page 8 3M 110513 3.42883 3.86405 4.00981 2.16591 2.38476 2.17588 2.17778 2.43134 2.13983 1.71664 ' 1.4895 1.79993 1'.60569 1.79323 1.62921 2.5669 2.9666 2.63741 3.03423 2.77427 3.19705 3.02999 2.52125 2.79362 2.43123 2.70077 2.68732 3.26038 2.69148 2.89072 3.0294 3.01627 2.50654 3.55451 3.99627 3.73995 3.89665 2.028 2.167 2.371 2.072 2.281 2.081 2.083 2.326 2.047 2.118 1.838 2.22 1.981 2.212 2.01 1.822 2.105 1.872 2.153 1.969 2.269 1.938 1.612 1.787 1.555 1.727 1.719 2.085 1.721 1.849 1.937 1.929 1.603 2.08 2.338 2.188 2.28 1.779 0.162814 1.667 0.097136 1.885 0.184616 1.823 0.190681 2.202 0.129792 2.246 0.031215 2.148 0.121642 94 mod sm 2.063 0.148642 25 mod sm 2.032 0.173278 17 mod sm 1.723 0.134696 3 fan died 1.854 0.17125 3 2.224 0.087839 340 w fan Page 9 3M 110514 3.82977 3.79121 2.241 2.218 Page 10 3M 110515 + total 1,1,1 -Trichloroethane 367 ppm 50%RH A primary O secondary time (min) 3M 110516 + total 1,1,1 - mchloroethane 369 ppm 80%RH A primary O secondary time (min) 3M 110517 Face Velocity 1,1,1-Trichloroethane 110 ppm 2 hrs |JtpJ T*F1 T + 1 T + +T 1 i---------- 1---------- 1---------- 1---------- 1---------- 1---------- 1---------- 1---------- 1---------- 1______ i______ i i i i i i i 100 200 300 400 Face Velocity (fpm) 3M 110518 Sheetl RECOVER Y, STORAGE AND LONG TERM STORAGE NOVEMBER, 1995 ctcde3.xls EL CCI4 CHCI3 1,2-DCE SPIKE UG REC SPIKE UG REC SPIKE UG REC 0.1 47.7 62.3 1.30608 74.6 75.44 1.01126 62.8 65.58 1.044268 0.1 47.7 55.49 1.163312 74.6 73.04 0.979088 62.8 63.32 1.00828 0.1 47.7 60.06 1.259119 74.6 73.06 0.979357 62.8 64.71 1.030414 0.1 47.7 61.37 1.286583 74.6 77.37 1.037131 62.8 71.69 1.141561 0.5 238.5 262.72 1.101551 373 350.75 0.940349 314 305.38 0.972548 0.5 238.5 270.67 1.134885 373 358.68 0.961609 314 313.54 0.998535 0.5 238.5 264.53 1.10914 373 362.06 0.97067 314 311.71 0.992707 0.5 238.5 270.85 1.135639 373 364.64 0.977587 314 315.29 1.004108 1 477 528.75 1.108491 746 721.88 0.967668 628 621.91 0.990303 1 477 544.06 1.140587 746 730.25 0.978887 628 633.84 1.009299 1 477 526.63 1.104046 746 721.25 0.966823 628 619.57 0.986576 1 477 535.99 1.123669 746 732.84 0.982359 628 629.55 1.002468 2 954 1051.26 1.10195 1492 1433.58 0.960845 1256 1241.05 0.988097 2 954 1069.76 1.121342 1492 1439.27 0.964658 1256 1249.94 0.995175 2 954 1055.85 1.106761 1492 1431.91 0.959725 1256 1234.83 0.983145 2 954 1046.67 1.097138 1492 1420.15 0.951843 1256 1227.75 0.977508 AVE ALL SD CV 1.15 0.07 6.02 0.97 0.02 2.35 1.01 0.04 3.98 Me 1 3M 110519 Sheetl HUMIDITY EFFECT ON STORAGE @ .5EL Carbon Tetrachloride UG SPIKE IN IT DRY INIT WET 2WkS RT 2Wks CO 3Wks RT 3Wks CO 238.5 262.72 270.58 259.4 261.7 263.99 263.21 238.5 270.67 267.93 265.29 266.12 258.78 262.01 238.5 264.53 253.94 261.76 263.58 267.49 269.05 238.5 270.85 258.39 259.78 268.34 263.47 268.67 Carbon Tetrachloride Recovery INIT DRY INIT WET 2Wks RT 2Wks CO 3Wks RT 3Wks CO 1.10 1.13 1.09 1.10 1.11 1.10 1.13 1.12 1.11 1.12 1.09 1.10 1.11 1.06 1.10 1.11 1.12 1.13 1.14 1.08 1.09 1.13 1.10 1.13 AVE SD 1.12 1.10 1.10 1.11 1.10 1.11 0.02 0.03 0.01 0.01 0.02 0.02 Chloroform UG SPIKE INIT DRY INIT WET 2Wks RT 2Wks CO 3Wks RT 3Wks CO 373 350.75 367.53 348.53 345.93 341.16 346.08 373 358.68 357.14 354.65 347.02 338.22 344.35 373 362.06 344.54 348.29 355.92 356.54 350.52 373 364.64 349.44 351.65 353.68 348.26 356.19 Chloroform Recovery INIT DRY INIT WET 2Wks RT 2Wks CO 3Wks RT 3Wks CO 0.94 0.99 0.93 0.93 0.91 0.93 0.96 0.96 0.95 0.93 0.91 0.92 0.97 0.92 0.93 0.95 0.96 0.94 0.98 0.94 0.94 0.95 0.93 0.95 AVE SD 0.96 0.95 0.94 0.94 0.93 0.94 0.02 0.03 0.01 0.01 0.02 0.01 Pa I 3M 710520 Sheetl 1,2-Dichloroethane UG SPIKE IN1T DRY INIT WET 2Wks RT 2Wks CO 3Wks RT 3Wks CO 314 305.38 316.79 314.72 315.68 312.08 316.13 314 313.54 312.15 322.99 313.17 308.13 313.23 314 311.71 299.56 316.72 319.88 325.35 321.28 314 315.29 304.18 319.11 319.43 317.97 326.98 1,2-Dichloroethane Recovery INIT DRY INIT WET 2Wks RT 2Wks CO 3Wks RT 3Wks CO 0.97 1.01 1.00 1.01 0.99 1.01 1.00 0.99 1.03 1.00 0.98 1.00 0.99 0.95 1.01 1.02 1.04 1.02 1.00 0.97 1.02 1.02 1.01 1.04 AVE SD 0.99 0.98 1.01 1.01 1.01 1.02 0.01 0.02 0.01 0.01 0.02 0.02 Pag 10521 LONG TERM STORAGE @ 1EL Carbon Tetrachloride Initial Spike ug rec 477 523.61 1.097715 477 515.59 1.080901 477 523.04 1.09652 477 525.46 1.101593 All 511.93 1.073229 All 520.19 1.090545 ave 519.97 1.09 sd 5.228556 0.01 Chloroform Initial Spike ug rec 746 713.72 0.956729 746 695.79 0.932694 746 714.46 0.957721 746 721.01 0.966501 746 701.05 0.939745 746 712.29 0.954812 ave 709.72 0.95 sd 9.399472 0.01 Sheetl Pagi 3M 110522 1,2-Dichloroethane Initial Spike ug rec 628 619.13 0.985876 628 606.81 0.966258 628 621.57 0.989761 628 625.84 0.996561 628 611.53 0.973774 628 615.93 0.98078 ave 616.8017 0.98 sd 6.902656 0.01 Sheetl 3H 110523 Pai Fax Cover Sheet TorChristine Dalton Company:Industrial Hygiene Lab Fax:011 49 6371 868 788 From: Donald J. Larsen Phone: 612-737-4103 3M Occupational Health and Environmental Safety Division 3M Center Bldg. 260-3B-08 St. Paul, MN 55144 Fax: (612)737-3069 Number of pages including cover sheet: _1 Message: On September 28 we discussed your concerns about low recoveries for halogenated anesthetics. I ran some recoveries for Halothane, Ethrane and Forane at levels from 73 to 281 ug spiked on the monitors and found recoveries from 84 to 115 % as shown in the following table: Compound Halothane Ethrane Forane Spike (ug) 94 187 281 76 152 228 73 145 217 Recovery 1.15 1.01 1.05 0.93 0.84 0.86 0.93 0.84 0.86 Flease contact me if you continue to experience low recoveries. Best regards, Don Larsen, CtH 3M 110524 EVALUATION OF DIFFUSIVE SAMPLERS FOR MONITORING TOXIC GASES AND VAPOURS IN COALMINES Institute of Occupational Medicine Ltd, Edinburgh dc: R. Pieper 3M - INTERNAL CORRESPONDENCE To: From Subj J. Palazzotto D. Larsen OVM Validation by Institute of Occupational Medicine Ltd., Edinburgh Date: March 26, 1991 I reviewed the following report which compares the 3M 3500, Perkin-Elmer ATD 50, SKC 530, Draeger ORSA 5, MSA OVD, and PROTEK G-BB diffusion monitors. INSTITUTE OF OCCUPATIONAL MEDICINE LIMITED 8 Roxburgh Place Edinburgh EH8 9SU EVALUATION OF DIFFUSIVE SAMPLERS FOR MONITORING TOXIC GASES AND VAPOURS IN COALMINES by D. Mark, A. Robertson, H. Gibson, G. Borzucki, B. Cherrie, and W. M. Maclaren September, 1990 Diffusion monitors were evaluated for effects due to windspeed, orientation, vapor loading, fluctuating concentration, and airborne dust. Only the 3M 3500 gave acceptable results for all the tests. Windspeeds from 1-12 m/sec (197-2362 fpm) at orientations of 0 and 90 did not affect the 3M 3500 sampling rate. The 3M 3500 also exhibited low bias, low variability, and was unaffected by turbulence or airborne dust. The monitor did not show any significant loss when an initial 240 ppm 1,1,1trichloroethane spike for 10 minutes was followed by 470 minutes at 0 ppm. The Pro-Tek G-BB showed high variability and was very dependent on windspeed. The authors suggested that the diffusion barrier was not adequate to prevent these effects. The monitor worked so poorly in the initial tests that it was not tested further. The MSA OVD also showed high variability and bias in the windspeed and orientation tests. The Draeger ORSA 5 was effected significantly by high windspeeds and turbulence. 3Vt The Perkin-Elmer ATD 50 and SKC 530 sampling rates supplied by the manufacturer did not agree with the experimental rates. The PE ATD 50 showed a large consistent low bias and the SKC 530 a large high bias. The SKC 530 also showed some orientation effects on sampling rate and variability. This report concludes that the 3M 3500 was the only diffusion monitor which performed acceptably in all their tests. 3M 110544 Report No. TM/90/11 UDC 543.27:622.411.3 EVALUATION OF DIFFUSIVE SAMPLERS FOR MONITORING TOXIC GASES AND VAPOURS IN COALMINES by D Mark A Robertson H Gibson G Borzucki B Cherrie WM Maclaren September 1990 Price: 40 (UK) 45 (Overseas) 3ft A1Q545 Report No. TM/90/11 CEC CONTRACT 7260/04/028/08 INSTITUTE OF OCCUPATIONAL MEDICINE LIMITED EVALUATION OF DIFFUSIVE SAMPLERS FOR MONITORING TOXIC GASES AND VAPOURS IN COALMINES ' by D Mark, A Robertson, H Gibson, G Borzucki, B Cherrie, WM Maclaren FINAL REPORT ON CEC RESEARCH CONTRACT 7260/04/028/08 Duration of project: March 1986 to February 1989 Institute of Occupational Medicine Ltd 8 Roxburgh Place EDINBURGH EH8 9SU Tel: 031-667 5131 Telex: 9312100237=TD G Fax: 031-667 0136 September 1990 3H 110546 This report is one of a series of Technical Memoranda (TM) published by the Institute of Occupational Medicine Ltd. Current and earlier lists of these reports, and of other Institute publications, are available from the Librarian/Information Officer at the address overleaf. For further information about the Institute's facilities for research, service/consultancy and teaching, please contact the Librarian/Information Officer in the first instance. 3M 110547 CONTENTS SUMMARY Page No: 1. BACKGROUND 1 1.1 Introduction 1.2 Theoretical Considerations 1 2 1.2.1 1.2.2 Basic concepts Modifying influences to the simple theory 2 3 2. AIMS OF THE PROJECT AND PROJECT PLAN 7 3. THE DIFFUSIVE SAMPLERS 9 3.1 3.2 3.3 3.4 3.5 3.6 SKC 530 3M 3500 OVM MSA OVD DRACER ORSA 5 DUPONT PROTEC C-BB PERKIN ELMER ATD50 9 9 9 10 10 10 4. EXPERIMENTAL EQUIPMENT AND METHODS FOR LABORATORY EXPERIMENTS 11 4.1 Exposure 11 4.1.1 4.1.2 4.1.3 Exposure chamber Reference samplers Ceneral procedures 11 12 13 4.2 4.3 Analytical Procedures Experimental Protocoland Conditions 4.3.1 4.3.2 4.3.3 4.3.4 4.3.5 The effect of windspeedand orientation The effect of turbulent airflows The effect of vapour loading The effect of an initialvapour spike The effect of airborne dust 4.4 Methods of statistical analysis 4.4.1 4.4.2 4.4.3 Response variables analysed Weights used in theanalysis of variance Estimating residual mean squares 13 15 15 15 16 16 16 17 17 18 19 3M 110548 Page No: 5. RESULTS AND STATISTICAL ANALYSIS 21 5.1 Introduction 5.2 The Effect of Windspeed and Orientation 21 21 5.2.1 5.2.2 5.2.3 5.2.4 General Experiments with two sampler orientations evaluated in one run Experiments with two sampler types evaluated in each run Summary of findings from windspeed orientation runs ' 21 21 23 24 5.3 The effect of turbulent airflows 5.4 The effect of vapour loading 5.5 The effect of an initial vapour spike 5.6 The effect of airborne dust 25 26 26 27 6. UNDERGROUND INVESTIGATIONS 29 6.1 Introduction 6.2 Experimental Method 6.3 Statistical Methods 6.4 Results and Comments 29 29 30 30 7. DISCUSSION 33 8. CONCLUSIONS 37 ACKNOWLEDGEMENTS 39 REFERENCES 41 APPENDIX 43 FIGURES 49 TABLES 75 3H 110549 INSTITUTE OF OCCUPATIONAL MEDICINE Final Report on CEC Research Contract 7260/04/028/08 EVALUATION OF DIFFUSIVE SAMPLERS FOR MONITORING TOXIC GASES AND VAPOURS IN COALMINES by D Mark, A Robertson, H Gibson, G Borzucki, B Cherrie, WM Maclaren SUMMARY Diesel engines, resins and cleaning agents, which can all give off hazardous gases and vapours, are being used increasingly in British coalmines. With the increasing awareness of the potential risks to health associated with these materials it may, therefore, be necessary to monitor a wide range of gases and vapours in coalmines in the future. There are many procedures capable of sampling and analysing toxic gases and vapours in coalmines. Diffusive (or passive) samplers are particularly attractive because of their size and simplicity (no electrical pump is needed), ease of use and low cost. However, validation studies of these devices have not covered the relatively harsh environmental conditions encountered in coalmines and there is a dearth of information on their performances at high windspeeds, in turbulent air and in dusty atmospheres. The aim of this study was to investigate whether diffusive sampling offered a practical solution to sampling toxic gases and vapours in coalmines by studying the performances of a range of diffusive samplers under such conditions. A series of laboratory tests were, therefore, carried out in wind tunnels to determine the effects of windspeed, sampler orientation, turbulence, fluctuating vapour concentrations and dust on the performances of six commercially available diffusive samplers (SKC 530, 3M 3500, Drager ORSA 5, Dupont Protec G-BB, MSA OVD and Perkin Elmer ATD50). A limited underground field exercise was also undertaken to validate the laboratory work. The results of the research have clearly demonstrated that diffusive sampling could be used successfully to monitor toxic gases and vapours in the harsh environmental conditions which prevail in coalmines and that diffusive samplers are potentially flexible, simple and cheap tools for this purpose. 3M 110550 There are difficulties. In tests with only two vapours, just one sampler of the six tested (the 3M 3500) performed to its specification. (This device, we believe, is the most suitable for coalmine use). One did not perform as a static sampler in harsh conditions, two required recalibration and two were unsatisfactory. It is therefore essential that, before a diffusive sampler is used to measure any gas or vapour, independent validation data are obtained. 3H 110551 1 1. background 1.1 Introduction The sampling of gases in coalmines usually concerns methane and carbon monoxide, and well-proven methods are employed for this purpose. However, with the increasing use underground of diesel engines, resins, and cleaning agents which may produce hazardous gases or vapours, and the increasing awareness of their potential risks to health it may be necessary in the future to carry out regular monitoring of a wide range of gases and vapours. There are many techniques available for monitoring gases and vapours. Direct reading methods, which range from the simple colorimetric detector tubes to the complex electrical instruments can be used, but there are difficulties. Detector tubes, whilst cheap and easy to use, are subject to interferences from other gases, and have low precision. Electrical instruments can be selective, accurate, and precise, but are expensive to purchase particularly when large numbers of sampling sites are required. Stringent intrinsic safety requirements for the use of electrical instrumentation underground in coalmines is also a problem. Alternative methods of measuring gases and vapours in coalmines usually involve their collection in an absorptive medium which is returned to the central laboratory for analysis. For toxic organic vapours and gases sampling is commonly carried out by drawing a known volume of air through a small tube containing an adsorbent material (frequently charcoal) using a small battery-powered pump. Analysis is mainly by gas chromatography after chemical desorption. This procedure is commonly known as the NIOSH tube method (NIOSH, 1984). The method is precise, accurate and relatively inexpensive, but it does require the purchase and maintenance of intrinsicaily-safe pumps, and in practice only 10-20 samplers can be supervised by one investigator. Diffusive samplers (sometimes called passive samplers) appear to be an attractive alternative provided that their validity and reliability under mine conditions can be established. Diffusive samplers, like conventional pumped samplers, work on the principle that the gas to be monitored is absorbed in or adsorbed on a medium for laboratory analysis. Where they differ is the way in which the toxic gas arrives at the adsorbent surface. In diffusive samplers the airborne molecules of gas are transported to the surface in question by the action of molecular diffusion in the concentration gradient which exists in the surface and the atmosphere being sampled. There is therefore no need for a sampling pump, and consequently diffusive samplers are simpler and easier to carry and deploy in the workplace. However, they are more expensive to buy than the standard NIOSH tubes used with the pumps. Diffusive samplers are finding increasing applications in surface industries (e.g., oil, chemical, etc.,), and the performances of a number of different devices have been reported widely. Validation protocols have been proposed both in Britain (HSE, 1987) and in the USA (Cassinelli et al, 1987) to establish their performances. The test conditions specified in these protocols concentrate on their performance in little air movement because, when exposed to conditions of low windspeeds (<0.2 m/s), undersampling occurs due to the 3M 110552 2 depletion of the vapour concentration in front of the sampler. No account is taken of the more severe conditions found in coalmines. In particular there is a dearth of experimental information about how diffusive samplers perform in airflows where the velocities are high, the orientations are variable, the turbulence levels are high, and there are considerable quantities of airborne dust. The purpose of this project was to investigate the' performances of a range of diffusive samplers under such conditions. Experiments were carried out mainly in the laboratory where a range of mine environmental conditions were simulated in wind tunnels and exposure chambers. A field trial with the most promising diffusive samplers was conducted in one colliery location. 1.2 Theoretical Considerations . Although, as will be seen below, this project is not intended as a basic study of the physical processes governing the performances of diffusive samplers, a short review of the principles of operation of the various types of device will be a useful basis for interpreting the results of the experimental enquiry. Here therefore, a short review of the theoretical background is given. . 1.2.1 Basic concepts Diffusive samplers operate on the principle that, if a concentration gradient exists for a molecular species (e.g., a gaseous contaminant), then there will be a net flux of that species from regions of high to regions of low concentration. This well-known phenomenon! is described in classical kinetic theory by Fick's law, by which the flux is proportional to the concentration gradient and the constant of proportionality is known as the molecular diffusion coefficient. The latter is a fundamental property of the contaminant in question, also derivable from classical kinetic theory. There are two basic categories of diffusive sampler. The tube-type device first proposed by Palmes and Gunnison (1973) is shown schematically in Figure 1.1. Here the gradient which drives the molecular flux is set up along the length of a tube, one end of which is exposed to the contaminant of interest and the other end of which is maintained at a lower concentration due to the presence of an adsorbent surface. From Fick's law, the mass transfer rate to the sorbent (M) is M D A (dc/dx) 0) 3 where D is the molecular diffusion coefficient for the contaminant, A the cross-sectional area of the diffusion path, and dc/dx the gradient of the concentration (c) along the diffusion path (x-direction). For a diffusion path L and a perfect sorbent (so that c 0 at its surface), then this becomes M = D A (c/L) (2) For a sampler which has been exposed for a time t, then the time-averaged concentration of the contaminant in the air outside the sampler may be obtained from measurement of the mass collected. That is c = mL/DAt (3) where m is the mass of contaminant collected and we require to know the value of D. For tube-type diffusive samplers, theoretical values of D (based on kinetic theory) can provide accurate measurements of concentration. In the permeation-type devices proposed by Nelms et al (1977) and Bailey et al (1977), the concentration gradient is established by the placement of a membrane immediately in front of the-sorbent (as shown in Figure 1.2). Once again, transfer follows Fick's law, this time leading to c = K m/t (4) where K is the permeability coefficient for the membrane used, embodying both its dimensions (thickness and cross-sectional area) and the coefficient of molecular diffusion for the transfer of the contaminant across it. For practical diffusive samplers operating under this principle, K is usually determined experimentally for each sampler and for each contaminant. 1.2.2 Modifying influences to the simple theory Sorbent efficiency: The assumption of a perfect sorbent may not hold in practice. For example, it has been found that, for devices where organic vapours are adsorbed onto a carbon collecting medium, the sampling rate is dependent on the amount of gas already adsorbed. The concept of an adsorption isotherm has been introduced to describe this problem. The simplest is the linear isotherm, where the vapour pressure at the surface of the sorbent is directly proportional to the mass of sampled 3M 110554 4 contaminant. Underhill (1984) has shown that, under these conditions, the rate of uptake by a tube-type device like that described earlier takes the form dm/dt = (D A C / L) {1 - (m / k C) } (5) where k is a constant coefficient dependent on sampler properties. Equation (5) shows clearly the fall irr sampling rate as the contaminant builds up in the sorbent. Time-varying concentrations: The simple theory also assumes that the concentration of the contaminant outside the sampler is fixed. In practice, however, it would usually vary with time. The problem of varying concentrations was first addressed by Hearl and Manning (1980), whose main concern was the transient response of the sampler (where the contaminant concentration is fixed, but for a finite time which may be long or short). They showed that, although -Equation (1) holds well for long sampling periods, the contaminant is progressively undersampled for shorter sampling times. In addition to being a function of sampling time, the error is also a function of sampler geometry and dimensions. Typically, for a tube-type sampler of length 7 cm, the undersampling error involved in the collection of NO 2 is less than 1% for a sampling time of five hours, but rises to greater than 10% for a sampling time of 15 minutes. A similar problem occurs when the nature of the concentration variation takes the form of random fluctuations. Here, the sampling error is a function of the statistical properties of the fluctuating concentration. Bartley et al (1983) have examined theoretically the fluctuation-induced sampling error for a tube-type sampler containing a perfect sorbent. They referred to the 'pulsating* nature of fluctuating concentrations, and showed that the error increases with the degree of 'sharpness' of the pulses, although the error may be reduced if sampling takes place over longer periods. For shorter sampling periods, however, the error may be reduced by shortening the tube length (L). The nature of the errors deserves comment. In general, there is a tendency towards undersampling, corresponding to contaminant diffusing out of the sampler during intervals when the concentration gradient is unfavourable for collection. However, oversampling can occur when large pulses arrive near the end of the sampling period. Bartley (1983) examined the problem of weak sorbents together with fluctuating concentrations and showed that errors can arise due to a combination of the effects summarised above. His analysis showed that such errors can be significandy reduced by appropriate modifications to the sampler design, in particular the use of multiple sorbent stages. Such a system provides the added benefit that any saturation of the sorbent can be detected and - where necessary - the results obtained may be discarded. 3H 110555 5 Effects of an external wind: In the absence of any external air movement, the contaminant concentration is underestimated by a diffusive sampler as the source molecules in the immediate vicinity of the device are depleted by the flux to the sorbent. A finite air movement outside the sampler is therefore essential in order to replenish the 'pool* of contaminant on which the sampler depends for its operation. It has been estimated that a windspeed of a few cm/s would suffice for this purpose, needing to be higher for samplers of higher uptake rate. The effects of moving air at higher velocities are not well understood; neither are the effects of turbulent fluctuations in the wind velocity. It is recognised that any external wind effects sufficient in magnitude to induce air motions within the diffusion gap (e.g., the tube of a tube-type device) may well interfere with 'normal' sampler performance. However, it has been suggested that, for tube-type samplers, any such effects would be minimised by ensuring that the length-to-diameter ratio is less than about 3 (Coleman, 1983). Otherwise, the use of a wind shield might have the same desired effect. Effects of relative humidity: It has been suggested that humidity might effect the collecting properties, notably the adsorption capacity, of some sorbents (e.g., activated carbon, as reported by Werner, 1985). The mechanism is thought to involve competition between adsorption sites between contaminant and water molecules, but at present it is not well understood. Effects of other contaminants: The influence of competing gaseous species has already been alluded to (i.e., contaminant versus water molecules). A similar effect would occur if more than one gaseous contaminant is present (e.g., competing solvent vapours, as discussed by Gregory and Elia, 1983). In the underground mining application of diffusive samplers which is the subject of this report, a prominent airborne contaminant which might well influence sampler performance is airborne dust. At present, however, any effects of the presence of dust particles (e.g., on the surface of the sorbent) are not known. 3H 110556 6 3M 110557 7 2. AIMS OF PROJECT AND PROJECT PLAN The main aim of the project was to determine whether and under what conditions any of the currently, commercially-available (in Britain) diffusive samplers are suitable for monitoring toxic gases and vapours in coalmines. The following project plan was adopted 1. Select suitable types of commercially-available diffusive sampler. 2. Select suitable test vapours. 3. Identify environmental conditions specific to coalmines that are likely to effect the performance of diffusive samplers. / 4. Construct and commission exposure chambers. 5. Investigate the effect of high windspeeds and variable orientation on the performances of the diffusive samplers. 6. Decide, on the basis of these tests, whether any of the devices are entirely unsuitable for use underground and should be omitted from further testing. - 7. For the successful samplers investigate the effect on their performances of variable vapour loading, turbulent airflows, fluctuating vapour concentrations, airborne dust exposure. 8. Investigate the performances of the most suitable types of diffusive sampler in limited underground trials at selected colliery locations. 9. From the results of the above investigations make recommendations as to whether and under what conditions diffusive samplers may be used underground to monitor toxic gases and vapours. 3M 110558 V 1 i 9 3. THE DIFFUSIVE SAMPLERS Six commercially available diffusive samplers of different design were tested. The choice was influenced firstly by the requirement to evaluate the performance of currently available samplers, and secondly in order to form a rational basis for choosing diffusive samplers from future designs. Brief descriptions of the important features of each sampler are presented below. 3.1 SKC 530: Manufactured by SKC Inc.(USA) - Figure 3.1 This device consists of a reusable plastic badge, housing holding two adsorbent capsules behind two circular sampling windows of cross-sectional areas in the ratio 13:1. This enables two simultaneous samples to be taken at two different sampling rates (in proportion to the cross-sectional areas), and therefore it is possible to cover both high and low vapour concentrations with one device. The sampling windows are covered with porous plastic material to minimise external wind effects. The adsorbent capsules contain a fixed weight of activated charcoal sandwiched between discs of urethane and stainless steel gauze. 3.2 3M 3500 OVM: Manufactured by 3M Company (USA) - Figure 3.2 This unit consists of a round nylon body, approximately 45 mm diamter, containing a circular adsorbent pad based on charcoal, separated by spacers from a diffusion membrane - the distance between the membrane and adsorbent being the diffusion length. Contaminants reach the adsorbent by first permeating through the membrane wind shield before diffusing across the air gap. Another version of this design (3520 OVM), which has a second back-up adsorbent pad in series with the first, is available for demanding environments. 3.3 MSA OVD: Manufactured by Mine Safety Applicances Company (USA - Figure 3.3) This badge consists of a rectangular plastic case 12 mm by 72 mm in which are housed two activated carbon sampling strips and a separator. The case is sealed with a plastic top, which is perforated with five large rectangular holes behind which sits a paper windshield. Like the 3M device the first sampling strip is separated from the windshield with spacers, thus providing a diffusion path length. The second sampling strip provides a back-up for when the first strip becomes saturated. 3M 110560 10 3.4 Drager ORSA 5: Manufactured by Drager (West Germany) - Figure 3.4 The sampling section of this device consists of a glass tube 7.5 mm in diameter and 28 mm long, containing a fixed quantity of grains of activated charcoal held centrally within the tube by porous plugs at each end. The plugs form the diffusion path lengths over which the gas/vapour diffuses, from both ends simultaneously, to the adsorbent. The device can be used as a pumped tube sampler when higher sampling rates are required. When used in its diffusion mode the sampling section is mounted in a plastic holder which incorporates an attachment clip. 3.5 Dupont PROTEC G-BB: Manufactured by Dupont (USA) - Figure 3.5 This device comprises two identical, rectangular sections (12 mm by 75 mm) in series. Each section consists of an uptake control block (a plastic strip perforated with 281 holes: 1.1 mm diameter) held in intimate contact with an adsorbent strip based on activated charcoal. Vapour molecules diffuse along the tubes formed in the control block to give an uptake rate proportional to the ambient vapour concentration and a function of the length and cross-sectional area of the holes. The second section is- utilised only when the first becomes overloaded and the vapour molecules pass through the first section to repeat the process of diffusion and adsorption in the second strip. The uptake rate of the second strip is less than that of the first because of the extra distance the molecules must diffuse. In situations where vapour concentrations are low and/or short sampling times are involved the second adsorbent strip, together with the rear sealing cover, can be removed to form a 'sandwich' from the control blocks and the single adsorbent strip; vapour can now reach the adsorbent strip from two routes and the uptake rate is doubled. 3.6 Perkin Elmer ATD50: Manufactured by Perkin Elmer Ltd (UK) Figure 3.6 This device is a direct development of the original Palmes tube, consisting of a precision-made, stainless steel tube, 90 mm long and 5 mm internal diameter containing a carefully-weighed amount of Tenax GC (or similar) adsorbent material. At one end of the tube an aluminium sampling head is fitted, incorporating a semi-permeable silicon membrane and a stainless steel gauze. The distance between the surface of the adsorbent and the membrane defines the diffusion path length, which is carefully-controlled to be 15 mm. The combination of membrane and stainless steel gauze within the sampling head is designed to minimise external wind effects, and to inhibit the ingress of water vapour and particulate matter. These samplers have been developed specifically for analysis incorporating thermal desorption. 3M 110561 11 4. EXPERIMENTAL EQUIPMENT AND METHODS FOR LABORATORY EXPERIMENTS 4.1 Exposure 4.1.1 Exposure chamber One exposure chamber was used for the investigations. This comprised a wooden wind tunnel, shown schematically in Figure 4.1, 2.7 metres long and 0.35 metres square cross-section, which was used to examine the wind-dependent characteristics of the diffusive samplers. Air was drawn through the tunnel by a continuously variable-speed axial fan which produced airspeeds within the range 1 to 12 m/s. Velocity was measured using a hot-bead anemometer which had been previously calibrated using a pitot-static tube and micromanometer. Removable honeycomb sections 50 mm thick and 6 mm mesh size, positioned either side of the exposure area, were used to reduce the turbulent kinetic energy in the exposure area to a level such that turbulent intensities in the x-direction were around 3%. The vapour generator system (see Figure 4.2) was positioned at the tunnel intake and produced test vapour by evaporating droplets of the liquid in an air stream. Th system consisted of an evaporating/mixing manifold, a spinning disc rotated by an air-turbine, an air blower, and five vapour-dispersive pipes. Droplets with a nominal diameter of 25 /mi were produced by injecting the liquid onto the centre of the rotating disc from where it spread to the perimeter and disintegrated under the centrifugal force produced by the rotation. A constant liquid flowrate to the disc was maintained by either a constant head gravity feed arrangement or syringe pump. Air blown continuously into the manifold facilitated droplet evaporation and produced vigorous mixing before transporting the vapour out through the five dispersive pipes. Each pipe consisted of a 15 mm diameter copper tube, bent to form the shape shown in Figure 4.2, and perforated with a total of 24 4 mm diameter holes equidistantly spaced along the top and underside of the tube. The five pipes were positioned directly in front of the tunnel entrance so that the straight sections ran horizontally across the width of the tunnel entrance and were equally spaced in the vertical plane as can be seen in Figure 4.2. During operation this arrangement of pipes and emission holes produced a continuous vapour 'sheet' across the entrance which was drawn into the tunnel and distributed across the tunnel cross-sectional area (in the mixing length) before passing into the exposure area. A vapour concentration distribution, uniform to 10%, was invariably achieved across the wind tunnel using this vapour generation method. For the laboratory studies 1,1,1 trichloroethane (methyl chloroform) was used to generate test vapour clouds in the wind tunnel in concentrations ranging from 5 to 240 ppm. This solvent was chosen after a study of the chemicals used 3H 110562 12 underground in coalmines showed it to be the most widely used. benefit of being relatively non-toxic, and easy to handle. It also has the In the exposure area the diffusive samplers to be tested were mounted at six locations on a stainless steel frame as shown in Figure 4.3. At each location a NIOSH-type pumped-tube sampler and an inlet pipe to a flame ionisation detector (FID) were fixed close to the diffusive sampler under test. For some investigations isotropic turbulence in the air approaching the exposure area was generated by means of inserting square-mesh grids in the wind tunnel between the entry and the exposure area. By careful choice of bar width and distance between the grids and the samplers a range of turbulence conditions was obtained. For these runs the honeycomb sections were removed. For another set of investigations airborne dust clouds were produced by injecting test powders into the entry of the wind'tunnel (see Figure 4.1) by means of either a Wright dust feeder (Wright, 1954), or a turntable-venturi dust feeder, dependent upon the type of dust. 4.1.2 Reference samplers The main device chosen to give a measurement of the true vapour concentration and thus to serve as the reference sampler for the investigations was the SKC Sorbent Tube. This device, shown in Figure 4.4 and built in accordance with the NIOSH/OSHA-approved method for sampling vapours in the workplace (NIOSH, 1984), comprises a thin glass tube (6 mm diameter and 70 mm long) which contains a precisely-controlled quantity (150 mg) of coconut-base charcoal sorbent material separated into two sections: one for sample collection (100 mg); and the other for back-up to assure complete vapour collection (50 mg). For some experiments, especially those using high vapour concentrations and/or long sampling times larger identically-constructed tubes (8 mm diameter and 110 mm long) were used. These tubes each contained 400 and 200 /rg of charcoal in the front and rear sections respectively. Suction through the samplers, at a flowrate of approximately 80 ml/min was provided by a main vacuum pump via a multi-outlet manifold. Flowrate control was achieved by suitable restrictive orifices inserted into each sampling line. Flowrate measurement was carried out before and after exposure using a primary standard automatic bubble flowmeter (Dupont Buck Calibrator). Vapour concentrations were also monitored using a Flame Ionisation hydrocarbon analyser (Analysis Automation Ltd., Model 521). This was used to establish the initial levels of vapour concentration and to monitor those levels throughout the duration of exposure. Concentration levels from up to seven locations were monitored sequentially on a cycle controlled by a BBC microcomputer, which also logged the individual values and displayed the running means and standard deviations for each particular sampling location. Any departures from the required target concentration were thus quickly detected and rectified. 3H 110563 13 4.1.3 General procedures To ensure the quality control of the experiments two examples from each new batch of samplers were chosen and set aside to check for contamination. During this procedure two batches of Drager ORSA 5 samplers were found to be contaminated with the test solvent on delivery. At the end of the exposure period the test vapour was switched off first, the various samplers capped as quickly as possible, and stored in a refrigerator. A comprehensive labelling' and recording procedure was developed to ensure that the samplers were not mis-identified. 4.2 Analytical Procedures " The analytical procedures involved firstly the desorption of the captured solvent from the adsorbent material, and secondly the analysis of that solvent by gas chromatography. For analysis of the NIOSH pumped tubes and the diffusive samplers, apart from the Perkin Elmer ATD50, solvent desorption processes were employed. Slightly different procedures were adopted dependent upon the type of sampler involved. With the MSA OVD, the Dupont Protec, the Drager ORSA 5, and the SKC 530 diffusive samplers the charcoal adsortive strips were removed from their holders and placed in a 5 ml glass septum vial. 2 ml of carbon disulphide (Rathburn glass distilled, benzene-free), containing chloroform as an internal standard, were added to the charcoal using a precision gas-tight syringe. Samples were shaken for 30 minutes in a desorption shaker prior to analysis on the gas chromatograph. A similar procedure was adopted with the 3M 3500 diffusive sampler, except that desorption was carried out in the sampler body following removal of the permeable membrane. After desorption was complete (normally 30 minutes) the solution was transferred to a 5 ml septum vial ready for analysis. All analyses were carried out by gas chromatography using an Analytical-Instruments Model 93 gas chromatograph. It was operated under the following conditions:- Injector temperature Co 1umn Carrier gas Oven temperature Detector 200 C 2m x 4 mm glass tube packed with 1294 carbowax 1540 on 80/100 mesh Chromosorb W Nitrogen 55 C Flame ionisation held at 200 C. Adsorption peaks were recorded on a y-t chart recorder. Calibration standards were prepared by adding measured volumes of the test solvent Analar grade 1,1,1 3M 110564 14 trichloroethane, using a SGE microlitre plunger-in-needle syringe, to 2 ml of the carbon disulphide with chloroform as internal standard. Three calibration solutions were prepared for each run and the ratios of the peak heights from the 1,1,1 trichloroethane and the chloroform were measured and plotted against the known masses of 1,1,1 trichloroethane injected. Normally, linear relationships were found that went through the origin and the slopes of these lines represented the calibration constants to be used for each specific sampler. The Perkin Elmer ATD50 samplers were thermally desorbed using a Spantech GN Concentrator Mark IV in a stream of nitrogen at 250 C for five minutes and the sampled solvent was collected in a cold trap containing Tenax adsorbent material which was held at -30 C. The cold trap was then flash-heated to 250 C and flushed with nitrogen for 20 seconds,' to pass the desorbed solvent into the gas chromatograph via a pipe heated to 190 C. Once in the gas chromatograph analytical conditions and procedures were the same'as those described above, apart from the calibration. The calibration procedure in this case involved the volatilisation of known quantities of trichloroethane injected into an airstream of known flowrate. A measured portion of the resultant mixture was drawn at 20 ml/min through the Perkin Elmer samplers thereby giving a known mass of the trichloroethane in the device. The standards were analysed by thermal desorption and gas chromatography and the calibration constant calculated. Again three calibration points were evaluated for each different experimental condition. Desorption efficiencies for the various types of diffusive sampler were determined by injecting known quantities (0.5 ml) of 1,1,1 trichloroethane into a glass septum vial, containing the adsorbent material, using the microlitre syringe. Analysis of the adsorbed vapour was then determined by the above methods and the resultant masses of vapour compared to those injected. Desorption efficiencies very close to unity were obtained for all types of sampler, with values of 1.00 0.02. The masses (M) of 1,1,1 trichloroethane in the actual samples were calculated from the following equation M = PGp/E (6) where P is the ratio of peak heights 1,1,1 trichloroethane/chloroform, G is the calibration constant, p is the density of 1,1,1 trichloroethane, and E is the desorption efficiency. Calculation of the concentration was achieved from knowledge of the volume of air sampled. This was obtained by multiplying the uptake rate (Q), quoted by the manufacturers of the diffusive sampler, by the sampling period (t). C =PG p/ EQ t (7) To ensure quality control of the analytical procedures, blanks and calibration samples were run daily. Initially all analyses were carried out in duplicate, but after the usual 'teething problems' were resolved, agreement between the two samples was invariably within 3%. Consequently only one sample in six was analysed twice in later work. 3H i 15 4.3 Experimental Protocol and Conditions The experimental protocol was designed so that an initial comprehensive set of experiments on the effect of windspeed and orientation could screen out those samplers that were totally unsuitable. 4.3.1 The effect of windspeed and orientation Windspeeds in coalmines can vary from less than 0.5 m/s in poorly-ventilated headings to over 6 m/s on some coal faces, and in some main ventilation roadways. Furthermore extensive use is made underground of ventilation ducting for ventilating drivages, headings and other auxiliary ventilation purposes. To investigate whether a particular sampler was universally applicable to underground situations, therefore, experiments were planned, to cover a wide range of windspeeds namely 1, 3, 6 and 12 m/s and for two orientations of the sampler - facing the wind (0), and side-on to the wind (90). For each windspeed, six examples of a given type of diffusive sampler were tested simultaneously, three at 0, and three at 90. This was normally repeated once to give six samples for each windspeed-orientation combination. Generally each type of sampler was subjected to the above range of tests, but for the SKC 530 and the 3M 3500 samplers a further small set of experiments was carried out where three examples of each type were tested simultaneously with all either at 0, or all at 90 to the wind. . In the statistical analysis of the results (methods described below in Section 4.4) for the main set of runs the 'between-run' factors were sampler type (six types) and windspeed (four values), and the 'within-run' factor was orientation. For the shorter set of runs 'between-run' factors were orientation (0 and 90) and windspeed (four values), whilst the 'within-run* factor was sampler type. 4.3.2 The effect of turbulent airflows Airflows underground in coalmines are invariably turbulent with Reynolds numbers typically well in excess of 100,000. In a previous ECSC-funded project (Vincent et al, 1983) we demonstrated that turbulent airflows found underground could, to a limited extent, be simulated by the installation into the wind tunnel airflow of square-mesh grids (most of the turbulent structure being produced by the vertical legs of the powered supports). This work also confirmed that the flow behind these grids was stable and the intensity and length scale of the isotropic turbulence produced, could be safely predicted from the dimensions of the grids and the distance downwind from the grids. For this study four conditions were chosen to cover as wide a range of turbulent values as possible in the small wind tunnel. The conditions given in Table 4.1 included values (in the x-direction) of turbulent intensities in the range 0.06 to 0.20, and turbulent length scales in the range 0.3 to 10.0 cm. Experiments were carried out at a windspeed of 3 m/s, which for an empty wind tunnel gave a Reynolds number of 70,000. For each turbulence condition six examples of a given type of sampler were tested simultaneously; three at orientation 0, and 3M 110566 16 three at 90. With this experimental plan the within-run factor was orientation and the between-run factors were sampler type and turbulence condition. 4.3.3 The effect of vapour loading Vapour concentrations found underground are likely to be variable in both level and duration. It is important therefore, to ensure that samplers used to measure these vapours display results that are independent of adsorbed vapour load for the range of conditions likely to be found underground. A set of experiments was therefore carried out in which the samplers were exposed to a fixed vapour of 40 ppm for five sampling periods from 60 to 360 minutes; and to concentrations between 40 and 200 ppm for a fixed period of 60 minutes. A further shorter set of experiments was performed with just the SKC 530 and the 3M 3500 samplers which were exposed to a low concentration of 5 ppm for 180 minutes. (See Table 5.14 for experimental plan).. 4.3.4 The effect of fluctuating vapour concentrations When the project was first proposed it was thought that highly fluctuating vapour concentrations, where the amplitude of the pulse was large and the duration of the pulse short in comparison to the rate of diffusion, might be undersampled by diffusive samplers. However, subsequent theoretical and experimental work, mainly by Bartley et al (1983, 1987), has shown that providing that the exposure time is long (i.e., eight hour shift) and the appropriate choice of adsorbent material is made, then fluctuations in vapour concentration during the sampling period should have little effect on sampler performance. In the later work a performance test is proposed where the most severe challenge to the performance of diffusive samplers in fluctuating conditions is achieved by using single pulses at both the start and finish of the sampling period rather than a train of pulses as suggested in the earlier literature. A short series of runs was planned therefore in which a 'spike' of vapour of high concentration ('240 ppm) was injected into the wind tunnel for ten minutes at the start of the exposure run. The samplers were then either left in the wind tunnel at zero vapour concentration for a further 470 minutes (to simulate a start pulse), or immediately capped giving a total exposure time of ten minutes (simulating a finish pulse). General procedures for the wind tunnel, as described above, were carried out, and a windspeed of 3 m/s was employed. 4.3.5 The effect of airborne dust . One of the main environmental features found in underground coalmines is the relatively high concentrations of airborne dust. The effect of dust particles depositing on the adsorbent surface or the protective membrane of diffusive samplers has not been widely reported despite the possibility of some effect due to surface blockage. 3M 110567 17 The collection and retention of dust particles on a vertical surface depends upon both the inertial deposition (where for a given body size collection is a function of the particle aerodynamic diameter (dae) and the windspeed (U)), and the bounce or blow-off of particles from the exposed surfaces (where particle loss is a function of the particle geometric diameter (dg) and U). Consequently to cover the range of likely effects, two test dusts were chosen; (a) a near monodisperse fused alumina powder of mass median aerodynamic diameter (mm dae ) = 6 /on, and geometric standard deviation (<rg) = 1.3; and (b) a polydisperse powder of crushed coal of mm dae - 30 /tm, and <rg = 2.0. Thesewere dispersed into the wind tunnel airstream before vapour injection using a rotating table, compressed-air venturi dust feeder. Concentrations of around 20 mg/m3 for dust A and 300 mg/m3 for dust B wereachieved fortwo hours whilst a vapour concentration of 40 ppm was injected into the wind tunnel. 4.4 Methods of Statistical Analysis 4.4.1 Response variables analysed Each of the five series of runs described above was analysed separately, as were the two 'sub-series' of windspeed-orientation runs. Analyses of variance, in which the joint effects of all the experimental factors involved in a series of runs were considered together, were carried out only for the larger set of windspeed-orientation runs and the turbulence runs. For each of the other series of runs, statistical analysis was carried out for each sampler type separately. Of all the experimental factors being considered, only the effects of orientation were examined 'within-run'; comparisons of the effects of all other factors were subject to 'between-run' variation. The response variable analysed was the same in each of the five series. Consider first those runs involving six devices. Each of these yielded six values of the ratio R, where ^ _ Vapour concentration by diffusive sampler - Vapour concentration by pumped-tube sampler '' These could be split into two sets of three ratios by the 'within-run' factor, namely orientation. The variable used for analysis was the natural logarithm of the geometric mean of these triplets. For example, if devices at sampling positions 1, 2 and 3 were all placed at orientation 0, and those at sampling positions 4, 5 and 6 at orientation 90 , then a single run of this kind yielded two values of the response variate (Y) namely. Yo log R1 + log R2 + log R3 3 (9) 3M 110568 18 and Y 30 log R4 + log R5 + log R6 3 (10) in an obvious notation, ' Runs involving only three devices yielded only one value of the response variate, namely the logarithm of the geometric mean of the three values of R. The two analyses of variance, in which sampler type was incorporated as a factor, (strictly the analysis of the windspeed-orientation data should be referred to as an analysis of co-variance, since windspeed was treated as a continuous variable) were complicated by the fact that pairs of responses (Y0 and Ygo) from runs involving six devices were not statistically independent. These analyses were therefore carried out by deriving two further uncorrelated response variables S and D, defined as follows:- S 0.5 <Yq + Ygo) D 0.5 (Y0 - Ygo) (ID (12) Analysis of S yielded significance tests of the effects of 'between-run' factors averaged over sampler; analysis of D yielded tests of the average effect of orientation, and interactions between orientation and the 'between-run' factors. For those series of runs where the statistical analysis was performed separately for each sampler type, allowance for within-run correlation was not necessary, except in the case of the Perkin Elmer sampler in the vapour loading runs. 4.4.2 Weights used in analyses of variance In carrying out analyses of variance in which sampler-type was included as an experimental factor, it was necessary to make allowance for the fact that results from some types of diffusive sampler were more variable than others. Analyses were therefore carried out using the method of weighted least squares. Weights corresponding to each diffusive sampler, and specific to each series of runs, were chosen to be inversely proportional to the average within-run variance (see Table 5.1) each one calculated from the three ratios obtained in single runs at a given orientation. The sampler with the largest within-run variance was arbitrarily assigned a weight of unity. The assumption underlying this procedure is that the between-run variance of the responses Y0 and Ygo was proportional to the within-run variance of a single log ratio. This proportionality also held for the derived responses S and D; it is shown in the Appendix that the between-run variances of these variables were, respectively, i cr2 (1 + p) and i cr2 (1 - p), where a2 denotes the between-run variance of YQ and Ygo and p denotes the correlation coefficient between Y0 and Ygo. 3M 110569 19 4.4.3 Estimating residual mean squares to be used in the calculation of standard errors Only in the windspeed-orientation runs were there sufficient 'degrees of freedom for error' to provide a reliable estimate of the between-run variance of the response variables, Y0 and Ygo. In all other series of runs an estimate was derived, from within-run variability of single ratios, by applying a multiplying factor obtained from the analysis of windspeed-orientation data. In those runs where orientation was included as a within-run factor (other than the windspeed-orientation runs, e.g., turbulence and vapour loading runs), estimates of the residual mean squares to be used in the analyses of variance of S and D were obtained by assuming that the correlation between Y,, and Ygo was of the same magnitude as that estimated from the windspeed-orientation data. Details of the procedures outlined in Sections 4.4.1 - 4.4.3 are given in the Appendix. 3M 110570 21 5. RESULTS AND STATISTICAL ANALYSIS 5.1 Introduction Experiments were carried out to investigate the effect on the performances of diffusive samplers of five different 'hostile' environmental conditions. These were: wind velocity and orientation; turbulence; fluctuating concentrations; airborne dust exposure; and vapour loading. Combinations of these various conditions were not tested in this project. All concentrations as measured by the diffusive samplers were calculated using the uptake rates quoted by the manufacturers. Th conditions considered to be the most crucial to the successful use of diffusive samplers underground were high windspeeds and variable orientations. Consequently these were investigated first with a comprehensive experimental design using all the six types of diffusive sampler. The results were then used to screen out from further investigation some of those samplers whose performance was poor. 5.2 The Effect of Windspeed and Orientation 5.2.1 General This section contains the detailed account of the results and the statistical analysis, in Sections 5.2.2 and 5.2.3 followed by a summary of the important findings from the results. Some readers may wish, on first reading, to go straight to this summary presented in Section 5.2.4, consulting, if they wish, the data presented graphically in Figures 5.1 to 5.6. Furthermore, as explained in Section 4.3.1, two types of experiments were performed with the windspeed-orientation variables, one where two orientations of a single sampler type were evaluated in each run, and one where two sampler types were evaluated at the orientation in each run. For statistical reasons these are described separately. 5.2.2 Experiments with two sampler orientations evaluated in each run Results from 35 such runs are summarised in Table 5.1. Each entry in the table represents the geometric mean of three values of the ratio (R), of the vapour concentration measured by diffusive sampler divided by the vapour concentration measured by pumped-tube sampler, all obtained from single experimental runs at a specified windspeed and orientation. The respective geometric standard deviations are given in brackets. The individual values of R themselves are shown plotted against windspeed in Figure 5.1 to 5.6. Also shown are regression lines, fitted by the method of weighted least squares, from which the trends can be seen. On an initial qualitative assessment of the results, one may suggest that the samplers differ considerably from each other regarding their performances in conditions of trying windspeed and orientation. 3H 110572 22 Specifically, the results from the SKC 530 showed little effect of windspeed and orientation, but measured vapour concentrations were between 30 - 60% higher than those for the corresponding pumped-tube samplers. The 3M 3500 gave results close to those of the pumped-tubes, with no effects of windspeed or orientation. For the MSA OVD device values of the ratio R tended to increase with increasing windspeed, and were somewhat lower at orientation 90 than at orientation 0. Increasing trends in R with windspeed were also evident for the Drager ORSA 5 and the Dupont PROTEC samplers, whilst for the Perkin Elmer samplers, values of R were low at about 0.45, but with little sign of windspeed or orientation effects. The statistical significance of these effects was examined in an analysis of variance. To take account of the different amounts of random variation associated with each device, the method of weighted least squares was used. Weights associated with each device were taken to be inversely proportional to within-run variance, and are shown in Table 5.2. The resultant Analysis of Variance tables for S and D (see Section 4.4.1) are given in Tables 5.3 and 5.4 respectively. It is clear from these tables that the effects of windspeed and orientation must be considered jointly, and furthermore, are dependent upon the particular sampler. A summary of the fitted parameters obtained from the Analysis of Variance is shown in Table 5.5. The two parts of the table, labelled (i) and (ii), correspond to Tables 5.3 and 5.4 respectively, and show intercepts and slopes of regression lines upon windspeed by sampler type. It is important to note here that parts (i) and (ii) do not refer to regressions of Y0 and Yg(J (see Equations 9, lO) upon windspeed, but rather to regressions S and D (see Equations 11,12) respectively. The fitted parameters for the actual regression lines are obtained by adding and subtracting the estimates given in Table 5.5 and are given in Table 5.6. These are the lines plotted in Figures 5.1 to 5.6 . Table 5.5 may be interpreted by considering the results for each sampler separately. In general, the slope parameter under (ii) measures the difference between orientations in the linear trend of log R with windspeed, and a statistically significant result here indicates that the pairs of lines in Figure 5.1 to 5.6 are truly non-parallel. For two devices, the MSA OVD and the Drager ORSA 5, the effects of windspeed upon R depend upon the orientation of the sampler (see Figures 5.3 and 5.4). For the MSA the estimated average increase in R per unit increase in windspeed is 18% at orientation 0, and 8% at 90. For the Drager, corresponding figures are 7% and 20%. This dependence can be further demonstrated by showing that for the MSA, at 1 m/s the estimated R at 00 is 1.30 times that at 90 whilst at 12 m/s the factor is 3.42. Corresponding results for the Drager are 1.11 and 0.30. Considering now the Dupont PROTEC G-BB, there is no evidence of non-parallelism of the regression lines shown in Figure 5.5, but the statistically significant intercept in Table 5.5(H) suggests that there is an effect of orientation. At 6 m/s the magnitude of this effect is estimated to be a decrease by a factor of 0.69 in R when measured at 0 compared to that measured at 90. For the Dupont the effect of windspeed upon R is statistically significant at the 0.01 level, and represents an average increase of 15% per unit increase in windspeed. 3H 110S73 23 No effects of windspeed and/or orientation were found for the Perkin Elmer sampler, the only statistically significant regression parameter being the intercept in column (i). This suggests that the value of R for this device (about 0.46 on average) is genuinely below unity. For the SKC 530, there is no evidence to support either a differing effect of windspeed at the two orientations 0 and 90 (i.e., non parallelism) or an effect of orientation (i.e.,separate regression lines) upon log R. Also the effect of windspeed averaged over orientation is non-significant (t = 1.02, p > 0.3), suggesting no overall trend with windspeed. The 't' statistic for the intercept parameter given in Table 5.5(i) is 1.45, which again does not attain significance (0.15 < p < 0.2). However, a more appropriate test for elevated values of log R in this case is given by comparing the estimated log R at windspeed 6 m/s to zero. The appropriate value of log R is given by:- 0.250 + 6(0.0255) = 0.4030 (i.e., 1.5 in scale of R) which may be shown to have estimated standard of 0.1045 (t = 3.86, p < 0.002). At a windspeed in the centre of the chosen range 1 to 12 m/s, there is therefore strong evidence that the SKC 530 device has an elevated value of R. For the 3M 3500 the evidence suggests that R does not vary from unity for all windspeeds and orientations tested. Tests for the presence of curvilinearity in the trend of log R with windspeed were statistically non-significant, suggesting that the same model of linear regression used for the statistical analysis was adequate. The clearest evidence of curvilinearity is provided by the Drager device at orientation 90. Here the fitted line underestimates R at 1 m/s, and overestimates R at 6 m/s. 5.2.3 Experiments with two sampler types (SKC 530 and 3M 3500) evaluated in each run This small data set was produced when doubts were expressed over the validity of the initial results with the SKC 530 sampler when the clear bias in performance was first observed. It involves the use of two different types of sampler in the same run where both have the same orientation. For the statistical analysis it was more convenient to analyse data from these runs separately and those findings are presented below. The results from 11 such runs are given in Table 5.7, where geometric mean values of R together with the respective geometric standard deviations are presented as in Table 5.1. Individual values of R are plotted against windspeed in Figures 5.7 and 5.8. Also shown are the best fit lines by the method of least squares. Values of R for the SKC 530 are appreciably greater than unity (> 1.33) and, at orientation 90, were substantially higher at 12 m/sec. For the 3M 3500, R is close to unity for both orientations and all windspeeds. 3M 110574 24 Tables 5.8 and 5.9 show the analysis of variance for the SKC and 3M devices respectively. Estimated values of parameters (i.e., intercepts and slopes of regression lines of mean log R upon windspeed, by orientation) are shown in Table 5.10. Table 5.8 shows that there is an affect of windspeed upon log R for the SKC device, and that it depends on orientation. These affects are quantified in Table 5.10, (which assumes a linear relationship with windspeed). At orientation 0, the slight increasing trend in R with windspeed is not statistically significant but at orientation 90 it is significant. Both intercepts are statistically significantly greater than zero, at at least the 5% level, suggesting that the elevation of R at low windspeeds is a real effect. At orientation 0, there is no evidence that R for the 3M device departs from unity. However, at orientation 90, there is a significant increasing trend with windspeed (p < 0.05) but it is of very low magnitude (0.8% per unit increase in windspeed) and, therefore, unimportant. The results of this second set of windspeed-orientation runs agree with those in Section 5.1.1 for the 3M device. For the SKC however, there is now a statistically significant increase in the geometric mean value of R with windspeed, at orientation 90, probably because of the elevated values at 12 m/s. It can be observed in Figure 5.9 that for the SKC 530 a linear representation of the effects of windspeed may be an oversimplication. 5.2.4 Summary of findings from windspeed-orientation experiments 1. The SKC 530 consistently oversampled, normally by between 25 and 60% at windspeed up to 6 m/sec. At 90 to the wind, oversampling was considerably greater and the variability increased. .. 2. The 3M 3500 was essentially unaffected by variations in windspeed and orientation. The sampler displays very small bias and low variability, with individual values of R ranging from 0.94 to 1.33. 3. The MSA OVD was affected considerably by windspeed and orientation. It had both a large bias and high variability even at low windspeeds. Individual values ranged from 1.26 to 11.77. 4. The Drager ORSA 5 was affected considerably by windspeed and orientation, but at windspeeds up to 3 m/s the bias was not large and the variability relatively low (values of R in these conditions ranged from 0.78 to 1.22). At higher windspeeds the performance deteriorated progressively especially at orientation 90 where individual values of R up to 8.91 were observed. Despite these problems tests were continued. 5. The Dupont PROTEC G-BB was affected considerably by both windspeed and orientation. It had both large bias and variability even at low windspeeds. Individual values of R ranged from 1.09 to 12.80. 3W *10575 25 6. The Perkin Elmer ATD50 was unaffected by variations in windspeed and orientation. This sampler, however, despite displaying low variability had a large consistent bias with values of R ranging from 0.41 to 0.54. On the basis of these results the 3M 3500, SKC 530, Perkin Elmer ATD50 and the Drager ORSA 5 were investigated in all further tests. The effects turbulence and vapour loading were investigated for the MSA OVD. 5.3 The Effect of Turbulent Airflows Four different turbulence conditions were studied with experimental design very similar to that used in the windspeed-orientation runs. All runs were performed at a windspeed of 3 m/s with diffusive samplers orientated at 0 and 90 to the wind in each run. Tests were performed with the following 3M 3500, SKC 530, Drager ORSA 5, Perkin Elmer ATD50 and the MSA OVD. Twenty runs in all were carried out. Table 5.11 shows geometric means and standard deviations of three repeat values of R for each sampler obtained from single experimental runs for each specific turbulence condition. Data from the windspeed-orientation runs (Table 5.1) for the same windspeed of 3 m/s are included in the statistical analysis as a 'no-grid' control. These mean values of R are displayed in Figures 5.9 to 5.13 for each turbulence condition. From - these Figures it can be seen that, for the 3M 3500, SKC 530, and Perkin Elmer ATD50, there is little effect of turbulence upon performance. For the Drager ORSA 5, however, R is seen to increase between the 'no-grid' condition and all the four conditions in which turbulence grids were used. There is also a large increase in the random variation of the results for the Drager ORSA 5. The turbulence conditions caused no further deterioration in th performance of the MSA OVD. Tables 5.12 and 5.13 give the weighted analyses of variance of the derived variables S and D, (see Section 4.4.1). Weights were taken to be inversely proportional to within-run variance. The two degrees of freedom for error in each table were obtained from the windspeed-orientation results for the MSA OVD and the Drager ORSA 5 devices. However, these estimates of error were not used in significance tests. Instead appropriate estimates were obtained using within-run variance in conjunction with results from the windspeed-orientation runs. Details are given in the Appendix. The two Tables show that differences in R between types of sampler are real, and depend on orientation. However differences in R between turbulence conditions for each sampler tested were not statistically significant. This statement includes the Drager ORSA 5 sampler, where random variation in the results did not allow the differences apparent in the Table between turbulent conditions and the no grid control to reach significance. Due to the variability of the results, and the limited amount of data, no systematic relationship between the value of R and any function embodying the turbulent mixing caused by the grids was found. 3M 110576 26 5.4 The Effect of Vapour Loading The effects of vapour loading were investigated for five types of diffusive samples (SKC 530, 3M 3500, Drager ORSA 5, Perkin Elmer ATD50 and the MSA OVD). All samplers were positioned facing the wind, but with the Perkin Elmer ATD50, three samplers were positioned facing the wind and three side-on during each run. A total of 15 runs was carried out. Table 5.14 shows geometric means and standard deviations of three values of R, all obtained in single experimental runs, carried out under the specified experimental conditions. The results suggest that there is very little effect on R of varying vapour concentration, loading or time, with two exceptions, the high result for the SKC 530 at a concentration of 5 ppm, and the comparatively low result at 100 ppm for the MSA OVD. For statistical analysis, data from the windspeed-orientation runs for the same windspeed of 3 xn/s are included as one of the exposure conditions. This gave 23 runs in total. The complexity of the data structure was such that the results from each device were analysed separately. A one-way analysis of variance was carried out for each of the SKC 530, 3M 3500, MSA OVD and Drager ORSA 5. For this purpose runs of 60, 80 and 90 minutes were considered together as of 'short* duration, giving six experimental conditions to be compared in each analysis of variance. For the Perkin Elmer ATD50, two analyses of variance of variables S and D were carried out, since two orientations were examined in each run. Although an estimate of residual variability was available for the SKC 530, 3M 3500, MSA OVD and the Drager ORSA 5 devices (with low degrees of freedom), significance tests were performed using estimates of error obtained from the within-run variation, as in the analysis of the turbulence runs. Details are given in the Appendix. The analyses of variance are given in Table 5.15(a) and (b). There is evidence of differences in R between experimental conditions for the SKC 530. Comparisons of the geometric mean values of R showed that the significant variance ratio was due to the high result at the vapour concentration of 5 ppm; none of the ratios obtained at other conditions differed significantly. This low concentration of 5 ppm was unfortunately not evaluated for any of the other devices, and there was no evidence of a statistically significant vapour loading effect for the other conditions tested. The two analyses of variance carried out for the Perkin Elmer ATD50 showed no significant effect of vapour loading but a possible small effect, over all loadings, of orientation (0.1 < p < 0.25), mean values of R at 90 (0.45) being slightly lower than at 0 (0.48) - see Table 5.14. 5.5 The Effect of an Intitial Vapour Spike As explained in Section 4.3.4, the effect of continually fluctuating vapour concentrations during the exposure period had been demonstrated by other workers to be minimal. However, the degree of retention of vapour molecules sampled by the diffusive sampler, from a large initial spike of vapour, when it was followed 3k 27 by a period of zero exposure still remained open to the question. Eight runs were carried out therefore, to investigate the problem with four types of diffusive sampler, (SKC 530, 3M 3500, Perkin Elmer ATD50 and Drager ORSA 5). Table 5.16 shows geometric means and standard deviation of three repeat values of R obtained in single experimental runs carried out under the specified conditions. Data from five windspeed-orientation runs are also shown; these are included in the statistical analysis as 'steady-state* controls. It is clear from inspection that there are no statistically significant differences between values of R obtained under the three experimental conditions for the 3M 3500 and the Drager ORSA 5. A t-test of the difference between the average 'spike-run* result and the control for the SKC 530 was significant at the 1% level suggesting that the increase in R might be a real effect. For this test, an estimate of between-run variability, obtained from the observed within-run variability, was used. The observed decrease in R at run time 480 minutes for the Perkin Elmer ATD 50 was not statistically significant. 5.6 The Effect of Exposure to Airborne Dust A short series of runs was performed to investigate the effect of airborne dust on the performance of diffusive samplers. Three runs were carried out for each of two test dusts dispersed into the wind tunnel with nominal dust concentrations of 21 0.5 mg/m3 for the fine, monodisperse aloxite dust and 87 13 mg/m3 for the polydisperse coal dust (see Section 4.3.5 for details of particle size). Four types of diffusive sampler were evaluated (SKC 530, 3M 3500, Drager ORSA 5 and Perkin Elmer ATD50) at a constant windspeed of 3 m/s, and orientation 0 , for a constant exposure period of 120 mins for dust A and 360 mins for dust B. Table 5.17 gives geometric means and standard deviations of sets of three values of R for each type of diffusive sampler, and these are also displayed in Figure 5.11. By inspection there is clearly no difference in R between the two types of dust for both the 3M 3500 and the Perkin Elmer ATD50. For the SKC 530, a small difference in R (mean values 1.42 and 1.34) was observed, but a t-test showed that this difference failed to reach significance (0.2 < p < 0.3). For the Drager ORSA 5 there was also a small difference in the mean values of R for the two types of dust (1.05 and 0.97), but in this case it was significant (p < 0.01). (Here, as before, the estimated standard errors used in the V tests were obtained from within-run variance in conjunction with results from the windspeed-orientation runs). Unfortunately for this data set it was not possible to include rigorously the 'no-dust' results from Table 5.1 because no runs were performed in that series at a windspeed of 2 m/s. Nevertheless it is instructive to compare on an informal basis the results presented here with those at 3 m/s in Table 5.1. It can be seen that for all four types of sampler there is little effect on the values of R by the presence of airborne dust. 3H 11057S 29 6. UNDERGROUND INVESTIGATIONS 6.1 Introduction It is essential in any sampler investigation to include a field trials phase in the work programme to support the conclusions drawn from the laboratory studies. The work presented here described a limited trial carried out underground to monitor toluene vapour released during the joining of a steel-cord conveyor belt. As the use of organic solvent is not centrally monitored, suitable sites where 1,1,1 trichloroethane was being used in sufficient quantities were difficult to find. British Coal approval procedure for the joining of steel-cord belts specify that monitoring of vapour should take place during the operations. 6.2 Experimental Method The colliery chosen is situated in the northern part of the Nottinghamshire coalfield. The investigations took place in the return roadway cross-cut just downwind of a main belt transfer point. The coalface was ventilated homotropally and consequently the return roadway was used to convey the coal away from the coalface. A sketch of the site is given in Figure 6.1. The work being monitored concerned the extension of the main steel-cord conveyor belt by the addition of 50 m of new belting. This process involved two joining (or splicing) operations in which the ends to be joined were prepared by stripping away (with sharp knives) the rubber from the stranded steel cords, which were cut according to a special pattern. Once free from rubber, the cords were then cleaned with toluene, painted with cable primer and coated with rubber cement. The two ends were then placed together on thin rubber sheeting, the gaps filled with rubber strip, a second rubber sheet placed on top, and the joint cured by heating between copper plattens for approximately two hours. Monitoring was carried out during cleaning and cementing since most of the toluene would be released during this period. The instrumentation comprised four sampling sets (shown in Figure 6.2) centred around Casella type AFC123 intrinsically-safe sampling pumps. Each pump provided the suction for between 2 - 4 pumped-tube reference samplers, and also carried (on a special bracket) one example of each of the four types of diffusive samplers: SKC 530, 3M 3500, Drager ORSA 5 and Perkin Elmer ATD50. The four pumps were sited on a platform positioned across the conveyor structure some 3 m downwind of the joining area, and at the same height as the belt ends, as shown in Figure 6.1. For each pump the relative positions of each type of diffusive sampler was varied in an attempt to minimise bias due to vapour concentration gradients. High capacity (SKC Sorbent) pumped tubes were used as reference samplers, the flowrates through which were checked at the start and end of the sampling period using a calibrated rotameter. The diffusive samplers were equipped with protective sealing caps which were removed at the start of the 3M 110580 30 sampling period (when the pumps were switched on) and replaced as quickly as possible at the end. All the samplers, both pumped-tube and diffusive were positioned with their entries facing into the wind (orientation 0). The mean windspeed in the centre portion of the roadway (close to the conveyor belt) was 2 m/s, giving a Reynold's number for the bulk flow in the roadway of approximately 500,000. The entire process took place over the Easter weekend (1989) so that coal production would not be affected. The belt jointing process lasted two hours. This meant, therefore, that airborne dust levels would be very low. Owing to logistic problems the vapour released from only one of the two joints was monitored. However, a second sample was obtained by simulating the cleaning process using an equivalent quantity of toluene. Analysis of the various samples for toluene was carried out in the main lOM laboratory using same procedures described in Section 4.2 except that Analar grade toluene was used for calibration. In the light of the laboratory studies, the uptake rates used to calculate the mass of vapour collected by each sampler for toluene were determined by exposure in the wind tunnel at a windspeed of 1 m/s. These are given in Table 6.1 and are discussed later. 6.3 Statistical Methods The data formed as a three-way cross classification, with classifying factors, run number (two runs), sampling station (four stations) and sampler type (five types four diffusives and a pumped tube). There was one observation in each 'cell' of the classification, which gave 40 observations in total. An analysis of variance was carried out on the dog-transformed data, run number and sampling station being regarded as random factors. Differences between samplers were tested by an 'F' test, using the 'interaction' terms between samplers and runs as residual (see Table 6.2). Individual contrasts between samplers were tested using one quarter of the 'interaction' term as an estimate of the variance of the contrast. 6.4 Results and Comments The results obtained with the various samplers are given in Table 6.2. Mean values of vapour concentration (in ppm) are presented for the pumped-tube samplers and the four types of diffusive sampler at each sampling station. From the pumped-tube data it can be seen that, although there is a 2:1 difference in overall vapour levels between the two runs, the concentration profiles are identical, there being a slight increase from the side to the centre of the roadway. This means that it is valid to assess the two runs as repeats under esentially unchanged conditions. 3M 110581 31 All four types of diffusive sampler gave results that were higher than those for the pumped-tube samplers, with both the SKC 530 and the Perkin Elmer ATD50 having mean values of R of 1.15, and the 3M 3500 and the Drager ORSA 5 values of 1.11 and 1.05 respectively. The analysis of variance (carried out on logged data) is shown in Table 6.3. Since the four sampling stations and the two repeat runs were both treated as random samples from hypothetical populations of stations and runs respectively, consideration of expected mean squares showed that there was no immediate 'F' test of significance of differences between samplers. However, the analysis suggested that it was reasonable to assume that average differences between samplers were not dependent upon sampler position (i.e., that the *SxP* effect is zero. An 'F' test for sampler differences was then available using the mean square value for 'SxR' in the analysis of variance table. This suggested that the differences between the five types of sampler were too great to be attributable to chance (p-'-O.l). It may be shown that the estimated standard error of the difference between any pair of mean values (on the log scale) is 0.0416. A t-test (4 degrees of freedom) showed that the observed biases of 1.14 and 1.15 for the SKC and Perkin-Elmer devices respectively relative to the pumped tube were statistically significant at the 0.05 level. The bias for the 3M device (1.11) was not quite statistically significant (0.05 < p < 0.1). All other differences between pairs of samplers were not statistically significant. The results of the field exercise are fully compatible with the earlier laboratory trials. If the manufacturer's uptake rates (Table 6.1) had been used the results from the Perkin Elmer ATD 50 would have been very substantially lower than the pumped NIOSH tube method and those from the SKC 530 substantially higher. As the ventilation in the roadway was 2 m/s the performance of the Drager ORSA 5 was much as expected from the laboratory trials. The reasons for the apparent oversampling by all the diffusive samplers are difficult to ascertain. Small systematic errors in the determination of the uptake rates, analytical procedures and the pumped sampler flow rates could all have contributed. It is also possible to make some observations concerning the occupational hygiene aspects of the process. The British Coal Acceptance specifies that solvent vapours shall be kept to acceptable levels during use. Measurements taken during the cleaning and cementing processes (run 1) with vapour samplers positioned some 3 m downwind gave average levels of toluene of 28.0 ppm. The operational exposure limit (OEL) for toluene is 100 ppm for an eight hour working shift. A level of 28 ppm for two hours represents a full-shift exposure of 7 ppm - well below the OEL. Whilst these levels are low, one observation deserves mention. During the cleaning and cementing process two teams of two men were involved simultaneously on each end of the joint. Obviously one team would be exposed not only to vapour generated by their own actions but also that generated by the team upwind. Concentration of effort on to one end of the belt at a time would overcome this potential problem. 3M 110582 3M 110583 33 7. DISCUSSION The main message from the results of this project is that only one sampler - the 3M 3500 - performed according to its specification under the conditions tested in the laboratory and the field. The Perkin Elmer ATD50 and the SKC 530 should only be used if the uptake rates for the specific chemicals sampled have been determined experimentally. The manufacturer's quoted uptake rates were substantially different from those determined in the laboratory. The Drager ORSA 5 can only be used effectively in those locations in coalmines where windspeeds and turbulence levels are low. As other more suitable devices are available we would not recommend the ORSA 5 for coalmine use. Both the MSA OVD and the Dupont Protec G-BB gave results with too large a variability and dependence upon windspeed to be of use in most workplaces. For diffusive samplers to be of use generally, the uptake rates for each chemical quoted by the manufacturer must be applicable in practice. Of the four usable devices the quoted uptake rates for two did not hold even in relatively low windspeeds (Table 7.1). At-windspeeds of only 1 m/s both 1,1,1 trichloroethane and toluene were sampled by SKC 530 at a rate substantially higher (ca 40%) than quoted by the manufacturer whereas the Perkin Elmer ATD 50 sampled at around half the quoted rate. This means that results obtained with the SKC 530 or the Perkin Elmer ATD50 in atmospheres containing vapours of 1,1,1 trichloroethane or toluene, or perhaps other vapours, would be significantly in error if the manufacturers uptake rates were used. This particular problem with the use of diffusive samplers is very worrying and needs to be resolved. Consequently, the manufacturers and suppliers of those devices where the quoted uptake rates produce values of R appreciably different from unity were informed. Various explanations were discussed and diffusion barriers and membranes appear to be critical factors. A central library of validated uptake rates, that are updated frequently and readily accessible, would help the user overcome problems with uptake rates published by manufacturers. The Health and Safety Executive in Britain has just released this information in its EH40 database (HSE 1990). In the laboratory tests to investigate how aerodynamic parameters (windspeed-orientation, turbulence) affect performance, an appreciable degree of variability was found. For use in coalmines and other locations where windspeeds could be high (e.g., in the ambient atmosphere) it is essential that the performance of a diffusive sampler is independent of windspeed effects but most designers of diffusive samplers only take account of the effect of concentration depletion at very low windspeeds (< 20 cm/s). From consideration of the mechanisms involved however, it can be shown that in the absence of any diffusional resistance between the external vapour concentration and the internal adsorber then the mass transfer 3M 110584 34 equation will apply and the diffusional mass flux (M) produced will be dependent upon external windspeed, i.e., M = k AC (13) where k is the convective mass transfer coefficient (which is velocity dependent), and A is the cross-sectional area of the adsorber. The developers of the first viable diffusive sampler Palmes and Gunnison, 1973) appreciated this problem and chose to introduce an internal diffusional resistance that controlled the sampling rate. This they achieved by placing the adsorber at the closed end of a cylindrical sampling tube whose length to diameter ratio (L/d), which provides diffusion resistance, is large. This is the principle of the design of the Perkin Elmer ATD50, which has a diffusion length of 15 mm and internal diameter of 5 mm, and we have shown that its performance is independent of windspeed from 1 to 12 m/s. This sampler, described by Brown et al (1981), also incorporates a stainless steel gauze and silicon membrane at the sampler entry to assist in minimising the effects of external winds. The membrane is also employed to minimise the ingress of aerosol particles, which it achieves successfully, although as discussed above, the uptake rate of the device is considerably yet consistently reduced by its presence. Some loss of trichloroethane was observed in the studies of the effect of spikes of concentration. The adsorbent used in the study was Tenax and the problem of sample loss may be somewhat reduced if a different adsorbing medium, e.g. Chromosorb 102, were selected. A range of porous polymer adsorbents is suitable for use in the ATD50 samplers and care must be taken to ensure that the adsorbent/analyte combination is compatible This principle is also employed (in a modified form) in the design of the Dupont PROTEC G-BB. This sampler uses a diffusion barrier, placed over the adsorber, that has 281 cylindrical holes, each with L/d greater than 3. The designers (Lautenberger et al, 1980) predicted that this will be sufficient to prevent the adverse effects of external winds. Our results however, as shown in Table 5.1, do not support this prediction. It performed poorly with high variability displayed even at a windspeed of 1 m/s. This finding is in direct conflict with Lautenberger's results. To confirm that this effect was indeed due to aerodynamic processes a short series of supplementary experiments was carried out with various membranes, including those from the 3M 3500 and MSA samplers and cellulose ester filters, placed over the multihole diffusion barrier. The ratio R was determined for windspeeds of 1, 6, 12 m/s, and orientation 0, using experimental procedures as described above. The results depended on which membrane(s) were used but an appreciable improvement in performance was seen, with both the mean value and the variability of R being reduced at all windspeeds with all membranes and membrane combinations tested. There was no systematic attempt to identify the best membrane or test a range of membrane types. Nevertheless this limited study suggests aerodynamic processes caused the poor performance and development work on a suitable membrane windshield might improve performance to an acceptable level. 3M 110585 35 The Drager ORSA 5 sampler again uses a cylindrical tube to house adsorbent material, but in this case both ends of the tube are open and the adsorber is held in place by two cellulose acetate porous plugs. Pannwitz (1986), when describing the sampler, stated that the plugs were designed to control the sampling rate by providing a resistive barrier to diffusion. He presented results that showed very little effect on performance for windspeeds up to 2.5 m/s. Whilst our results show reasonable performance up to 3 m/s, at higher windspeeds R increased strongly with windspeed, especially when the sampler is oriented at 90 to the wind. In this orientation the axis of the tube itself is in line with the direction of the airflow. The tube can then be considered as a bluff body with positive pressure at the front end and negative pressure in the wake formed at the rear end. Because the tube is open at both ends, it is suggested that convection takes place down the tube and vapour no longer reaches the adsorber solely by diffusion. Obviously with this mechanism, the convected contribution to the adsorbed vapour increases as the windspeed increases and progressive oversampling occurs. A similar effect could possibly explain the high values of R for this sampler when subjected to turbulent airflow conditions. The results in Table 5.11 show a substantial increase in both the mean values and the variability of R. Penetration of the cellulose acetate foam diffusion barrier by turbulent eddies, carrying vapour molecules, could be a possible mechanism here. One simple method to minimise the convection of vapour through the tube to the adsorber may be to cap one end of the tube but a lower sampling rate would result. There were some quality control problems with this sampler as the first batch of samplers supplied was contaminated during manufacture or supply by 1,1,1 trichloroethane. This device is, of course, primarily intended as a personal sampler and these effects may be much less when they are worn as such because of the protection offered by the wearer's body. A short laboratory investigation could readily be carried out to ascertain whether harsh conditions would pose problems if the ORSA 5 were used, as intended, as a personal sampler. The remaining three types of sampler are all 'badge-type' with diffusion barriers supposedly defining the sampling rates of vapour molecules collected by adsorbent material of relatively large surface area. We believe that the poor performance of the MSA OVD sampler could be associated with the design of its diffusion barrier. In this sampler, a paper windshield rests on top of the charcoal cloth adsorber - and is held in place by a plastic cover (see Figure 3.3). On inspection of the sampler we found that the windshield was not held tightly by the cover plate and flapped in the wind, thus possibly allowing leakage of vapour molecules to occur at the edges of the wind shield. This leakage would probably not occur at the low windspeeds at which the performance of diffusive samplers are normally evaluated, but should be solvable with some further development on the design of the wind shield. The performance of the 3M 3500 sampler was unaffected by all the environmental conditions tested, but it is suggested that care must be taken to avoid gross contamination due to the accidental splashing of solvent onto the membrane. Areas where solvent spraying is carried out may not be suitable. Care also must be taken to avoid accidental physical damage to the membrane whose large surface area could be particularly vulnerable underground. The inclusion of some form of 3M 110586 36 wire mesh or plastic shield would protect the sampler. The SKC sampler was also largely unaffected by the environmental conditions tested although it should be remembered that the quoted uptake rates appear high. As a badge sampler, it too is quite liable to splashing and it would be subject to the same restrictions in use as the 3M 3500. 3M 110587 37 8. CONCLUSIONS The results of the research have clearly demonstrated that diffusive sampling could be used successfully to monitor toxic gases and vapours in the harsh environmental conditions which prevail in coalmines and that diffusive samplers are potentially flexible, simple and cheap tools for this purpose. There are difficulties. In tests with only two vapours, just one sampler of the six tested (the 3M 3500) performed to its specification. (This device, we believe, is the most suitable for coalmine use). One did not perform asa static sampler in harsh conditions, two required recalibration and two were totally unsatisfactory. Table 8.1 summarises the performances of the six samplers tested. Itis therefore essential that, before a diffusive sampler is used to measure any gas or vapour, independent validation data are obtained. 3H 11Q58S 39 ACKNOWLEDGEMENTS The authors wish to thank the Commission of European Communities and British Coal Corporation for their financial support of the work described in this report. We would also like to thank the Colliery Manager and his staff for the generous assistance given during the underground trial. Finally, our thanks are also due to the many colleagues at the Institute of Occupational Medicine who assisted in the work, and those staff at British Coal's Headquarters' Technical Department who made the arrangements for the underground trial. 3H 110590 41 REFERENCES Bailey A, Hollingdale-Smith PA. (1977). A personal diffusion sampler for evaluating time-weighted exposure to organic gases and vapours. Annals of Occupational Hygiene; 20: 345-356. Bartley DL. (1983). Passive monitoring of fluctuating concentrations using weak sorbents. American Industrial Hygiene Association Journal; 44: 879-885. Bartley DL, Doemeny LJ, Taylor DG. (1983). Diffusive monitoring of fluctuating concentrations. American Industrial Hygiene Association Journal; 44 : 241-247. Bartley DL, Deye GJ, Woebkenberg ML. (1987). Diffusive monitor test: performance under transient conditions. Applied Industrial Hygiene; 2: 119-122. Brown RH, Charlton J, Saunders KJ. (1981). The development of an improved diffusive sampler. American Industrial Hygiene Association Journal; 42: 865-869. Cassinelli ME, Hull RD, Crable JV, Teass AW. (1987). Protocol for the evaluation of passive monitors. In: Berlin A, Brown RH, Saunders KJ, eds. Diffusive sampling: an alternative approach to workplace air monitoring. Proceedings of an international symposium held, in Luxembourg, 22-26 September 1986. London: Royal Society of Chemistry: 190-202. Coleman SR. (1983). A tube diffusion dosimeter for sulphur dioxide. American Industrial Hygiene Association Journal; 44 : 631-637. Gregory ED, Elia VJ. (1983). Sample retentivity properties of passive organic vapour samplers and charcoal tubes under various conditions of sample loading, relative humidity, zero exposure level periods and a competetive solvent. American Industrial Hygiene Association Journal; 44: 88-96. Health and Safety Executive. (1987). Protocol for assessing the performance of a diffusive sampler. London: Health and Safety Executive - Occupational Medicine and Hygiene Laboratory (MDHS 27). . Health and Safety Executive (1990). EH40 Workplace air and biological monitoring database. London: Health and Safety Executive. Hearl FJ, Manning MP. (1980). Transient response of diffusion dosimeters. America! Industrial Hygiene Association Journal; 41: 778-783. Lautenberger WJ, Kring EV, Morello JA. (1980). A new personal badge monitor for organic vapours. American Industrial Hygiene Association Journal; 41: 737-747. Nelms LH, Reiszner KD, West PW. (1977). Personal vinyl chloride monitoring device with permeation technique for sampling. Analytical Chemistry; 49: 994-998. 3M 110592 42 National Institute for Occupational Safety and Health. (1984). NIOSH Manual of Analytical Methods, 3rd ed. Cincinnati (OH): US Department of Health and Human Services (DHHS (NIOSH) Publication No.84-100). Palmes ED, Gunnison AF. (1973). Personal monitoring device for gaseous contaminants. American Industrial Hygiene Association Journal; 34: 78-81. Pannwitz KH. (1986). Influence of air currents on the sampling of organic solvent vapours with diffusive samplers. In: Berlin A, Brown RH, Saunders KJ, eds. Diffusive sampling: an alternative approach to workplace air monitoring. Proceedings of an international symposium held in Luxembourg, 22-26 September 1986. London: Royal Society of Chemistry: 157-160. Underhill DW. (1984). Efficiency of passive sampling by adsorbents. American Industrial Hygiene Association Journal; 45: 306-310. Werner MD. (1985). The effects of relative humidity on the vapour phase adsorption of trichloroethylene by activated carbon. American Industrial Hygiene Association Journal; 46: 585-590. ' Wright BM. (1950). A new dust feed mechanism. Journal of Scientific Instruments; 27: 12-15. Vincent JH, Mark D, Gibson H, Botham RA, Emmett PC, Witherspoon WA, Aitken RJ, Jones CO, Miller- B. (1983). Measurement of inhalable dust in wind conditions pertaining to mines. Final Report on CEC Contract 7256-21/029/08. Edinburgh: Institute of Occupational Medicine. (IOM Report TM/83/7). 3Vt 110593 * ,t 43 APPENDIX 1 Statistical Methods A1 *1 Introduction This Appendix contains a broad description of methods used in the analysis of the five series of experimental runs. Sections A1.2 to A1.6 give details for each series. Analyses of variance, in which the type of diffusive sampler under consideration was included as an experimental factor, were carried out on data from only two of the five series - the larger set of 'windspeed orientation' runs and 'turbulence' runs* In these two series the method of weighted least squares was used, to allow for the fact that each device had associated with it different degrees of between-run random variation. In fact, the need for a weighted analysis was inferred from the observed differences between samplers in within-run variation rather than between-run. This was because direct measures of between-run variation, although available for each sampler except the SKC 530 in these two series, could only be based on small numbers of repeat measurements. The fundamental assumption was therefore made, that for each device, the between-run variance of log R meaned over three determinations within run (see Section 4.4.1 of the main Report), was proportional to the within-run variance of a single determination of log R. The proportionality factor was assumed to be the same for each sampler, and in each series of experimental runs. Under this assumption, weights used in analyses of variance were set to be inversely proportional to average within-run variances of log R for each sampler. Tests of significance for the larger set of windspeed orientation runs did utilise a 'pooled' measure of between-run variation, obtained from the analysis of variance (see Tables 5.3 and 5.4). This quantity gave an estimate of between-run variance for the device with the greatest within-run variability (which had been arbitrarily assigned a weight of unity). However, for turbulence runs, no such measure was available, and an estimate was obtained from within-run variation, assuming proportionality. The multiplying factor was obtained from windspeed orientation data. Data from all other series of runs (i.e., the smaller set of windspeed orientation runs, vapour loading runs, 'spike' runs, and dust runs) were analysed separately, by sampler type, and weighting was not used. Measures of between-run variability were obtained from within-run variability, using the proportionality factor derived from windspeed orientation data, exactly as in the case of turbulence data. 3M 110594 44 A1.2 Windspeed-orientation: Large Series of Runs The 35 runs provided 70 estimates of within-run variability. These are summarised by sampler type in Table 5.2 of the main report. The most variable sampler was the Dupont, which was assigned an arbitrary weight of unity. The weights for the other devices are also shown in the Table. These weights were assumed to be inversely proportional to the between-run variances associated with the quantities Y0 Ygo, introduced in Section 4 of the Report. They also apply to the derived variables S and D, since: Variance (S) = Variance ((Y0 + Ygo)/2) = (Variance (Y,,) + 2 Covariance (Y0j Ygo) + Variance (Ygo))/4 - i <r2 (1 + P) where <r2 denotes the between-run variance of Y0 and Ygo (for the Dupont, in this case) and p denotes the correlation coefficient between Y0 and Ygo. Similarly, Variance (D) - $ tr2 (1 - p) In the analysis of other series of runs, it was necessary to use an estimate of p. This was obtained from the residual mean squares from the analyses of variance of S and D (MS(S) and MS(D), say) as follows: MS(S) estimates a2 (1 + p) MS(D) estimates $ <r2 (1 - p) Hence, MS(S) + MS(D) estimates o'2 MS(S) - MS(D) estimates p a2 ' Substituting the results from Tables 5.3 and 5.4 gives estimated <r2 = 0.1293 + 0.0337 = 0.1630, estimated p a2 = 0.0956, and therefore, estimated p = 0.5865 The factor relating average 'within-run' variability to 'between-run' variability was also used in later analyses. From Table 5.2, the within-run variance of the 3M 110595 45 Dupont is 0.09335, and hence the multiplier by which the between-run variance is obtained from the within-run variance is 0.1630/0.09335 = 1.7461 A1.3 Turbulence Runs The average within-run variances, by sampler type, are shown in Table Al.l. (Data from windspeed-orientation runs for windspeed 3 m/s are also included, as a 'no turbulence* control). The most variable sampler is the Drager, and this device was arbitrarily assigned a weight of unity in the analysis of variance. As estimate of between-run variability is given by (1.7461) (0.1786) = 0.3119 and this quantity was assumed to have 23 degrees of freedom, for the purposes of significance tests (see Tables 5.3 and 5.4). Asstuning a within-run correlation of 0.5865, the estimated residual mean squares appropriate to the analysis of variance of S and D are, respectively, } 0.3119 (1 + 0.5865) = 0.2474 i 0.3119 (1 - 0.5865) = 0.0645 A1.4 Vapour Loading Runs Table A1.2 shows the average within-run variances, by sampler type, together with the estimated between-run variances obtained by applying the factor 1.7461. These estimates were used in significance tests (see footnote to Table 5.15(a). In runs involving the Perkin-Elmer device, orientation was included as a within-run factor, and the appropriate residual mean squares for the analysis of derived responses S and D were i 0.007325 (1 + 0.5865) = 0.005811, and i 0.007325 (1 - 0.5865) = 0.001515, respectively. These were assumed to have 20 degrees of freedom, i.e., the number of triplets of ratios multiplied by two degrees of freedom from each triplet. 3M 110596 46 At .5 'Spike' Runs The average within-run variance of log R for the SKC device was 0.000303, and multiplication by the factor 1.7461 gave an estimate of 0.000328 for the between--run variance of the mean of three determinations of log R. The estimated standard error of the comparison between 'spike' runs and steady concentration control runs was therefore given by Square root (0.000528 (1 + J)) = 0.0282 In the t-test using this quantity, six degrees of freedom were assumed - two from each triplet of ratios obtained from each run. A1.6 Dust Runs Significance tests were carried out only for the SKC and Drager devices. The average within-run variances of log R were 0.000585 and 0,000041 respectively. Estimated between-run variances of the mean of three such log ratios were therefore 0.001021 and 0.000072, and estimated standard errors of differences in such means between dust types were 0.0452 and 0.012 for the two devices. In t-tests, four degrees of freedom were assumed for the standard errors of differences. ' 3M 110597 47 Table Al.l Turbulence data (two orientations examined in each of 20 runs. Seven additional runs included from windspeed-orientation data) Average variances of log ratio (diffusive * pump), within run and at a constant orientation, by diffusive sampler type, with weighting factor used in analysis of variance. Sampler SKC 530 3M 3500 MSA Drager Perkin Elmer No. of triplets of ratios 10 10 12 12 10 Average 'within triplet'variance 0.00484 0.00155 0.02401 0.17857 0.00520 Weight 37 115 7 1 34 Table A1.2 Concentration-time data Average variances of log ratio (diffusive pump), taken over sets of three ratios obtained from single runs on specific samplers at constant orientation Sampler type SKC 530 3M 3500 MSA Drager Perkin Elmer No.of triplets Average 'within of ratios triplet' variance 7 0.00843 8 0.00463 6 0.03686 6 0.00488 10 0.00420 Estimated between- run variance of means of three 1oe ratios 0.0147 0.0081 0.0644 0.0085 0.0073 3M 110598 4- > concentration "c . Cross-sectional area A 49 concentration i' V V.N N'x * *. -I V.V>! r. v '"j Adsorbent material L- Figure 1.1 Schematic diagram of tube-type diffusive sampler m Adsorbent material Figure 1.2 Schematic diagram of permeation-type diffusive sampler 3M 110599 50 *____Vltu Oi Diffusion Figure 3.1 The SKC 530 Diffusive Sampler 3M 110600 This compact design containing a single charcoal sorbent provides an economical way to obtain accurate and reliable exposure readings. Analysis of the single sorbent saves on laboratory costs. In addition, the elimination of sorbent transfer or handling improves accuracy. Figure 3.2 The 3M 3500 Organic Vapour Monitor 3M 110601 52 PHYSICAL PARAMETERS OF MSA OVD SAMPLER DIFFUSER FIRST STRIP DIFFUSER BACKUP STRIP BOTTOM OF HOUSING Figure 3.3 The MSA Organic Vapour Dosimeter (OVD) 3M 110602 53 i.i Fig. 3 Design of sampling tube Rg. 3 1.1 Writing surface 1.2 Adsorption layer, consisting of approx. 400 mg of coconut shell carbon (grain size 0.4...0.8 mm) 1.3 Diffusion sections (acetate cellulose) Figure 3.4 The Drager ORSA5 Diffusive Sampler 3M JW603 54 Figure 3.5 The Dupont PROTEC G-BB Diffusive Sampler 3M 110604 55 Dirtuilon Mmbrn `O* Ring ' '0' Ring Figure 3.6 The Perkin Elmer ATD50 Diffusive Sampler 3M 110605 Figure 4.2 Vapour Generation System EXPOSURE AREA Figure 4.1 Exposure Chamber 3M 110606 i ) 57 Figure 4.3 Arrangement for holding Diffusive and Puinped-tubc Samplers in Exposure Chamber 3M 110607 59 Figure 5.1 Windspeed-orientation results for SKC 530 3M 110609 60 SAMPLER : 3M 3500 10 KEY : *-- ORIENTATION O' 9 ORIENTATION 90* 8 7 Figure 5.2 Windspeed-orientation results for 3M 3500 3M 110610 61 --f WIND SPEED (m sec"') Figure 5.3 Windspeed-orientation results for MSA OVD 3M 110611 62 SAMPLER : KEY: DRAGER ORIENTATION O' ORIENTATION 90* * * 13 S 12 WIND SPEED (m see") Figure 5.4 Windspeed-orientation results for Drager ORSA5 3M 110612 63 t Figure 5.5 Windspeed-orientation results for Dupont PROTEC G-BB 3M 110613 64 Ai 10 9 8 7 SAMPLER = PERKIN-ELMER KEY ORIENTATION O' * ORIENTATION 90' 4i RATIO Figure 5.6 Windpeed-orientation results for Perkin Elmer ATD50 3M 110614 TI 10 91 81 7 ! 6\ S 4 3 1: BOTH SAMPLERS AT ORIENTATION 0` KEY * * SKC 530 - 3M 3500 * V- * 1 X * : 0-5 # 4 12 WINO SPEED (m ste*1] Figure 5.7 Windspeed results for SKC 530 and 3M 3500 exposed together - orientation 0 AA0615 3 66 RATIO N BOTH SAMPLERS AT ORIENTATION 90' 10 KEY = - SKC 530 9 * 3M 3500 8 7 ,1 1 - *- 0-5 - 1 *i-------------------- r 69 -i------------------------- > 12 WIND SPEED lm sec"'; Figure 5.8 Windspeed results for SKC 530 and 3M 3500 exposed together - orientation 90 3H 110616 1 67 * /N 5 4 3 as * # 1' SAMPLER * SKC 530 KEY : * - ORIENTATION 0* * - ORIENTATION 90* t * 0-5 ,------------- i 7*5 50 DISTANCE FROM GRID (cm| 0-5 4-0 GRID BAR WIDTH (cm) ,1 100 4-0 ------------------- 1 250 4-0 I NO GRID Figure 5,9 Turbulence results - SKC 530 3M 110617 SAMPLER ! 3M 3500 KEY = * ORIENTATION 0* ORIENTATION 90* * x 5* * t* i------------------------1 7-5 50 DISTANCE FROM grid (cm) 0-5 4-0 GRID BAR WIDTH {em| T-- 100 4-0 1 250 NO GRID 4-0 Figure 5.10 Turbulence results - 3M 3500 3H '10618 69 a S 4' 3 SAMPLER : MSA KEY : * ORIENTATION 0* * ORIENTATION 90* 0-5 ' 1------------....... i 7-5 SO DISTANCE FROM GRID (cml 0-s 4-0 GRID BAR WIDTH (cm) 1 100 4-0 \_/ 2S0 NO GRID 40 t Figure 5.11 Turbulence results - MSA OVD 3H 110619 * SAMPLER : ORAGER KEY : * ORIENTATION 0* * * ORIENTATION 90* t * # 7-5 SO DISTANCE FROM GRID (cm| 0-5 40 GRID BAR WIDTH (cm) 100 4-0 * ** i 250 NO GRIO 40 Figure 5.12 Turbulence results - Drager ORSA5 3H 110620 71 * sampler = perkin-elmer KEY * * ORIENTATION 0* * ORIENTATION 90* ATIO s> tt 1 7-5 so DISTANCE FROM GRID (cm) 0-5 4-0 GRID BAR WIDTH (cm) ? 100 4-0 o N r A i NO GRID 40 Figure 5.13 Turbulence results - Perkin Elmer ATD50 3M 110621 72 ____TWO MEN SPLICING TABLE -- BELT CORDS .----- TWO MEN SAMPLING STATION Figure 6.1 Schematic plan of test site for underground trials 3M 110622 73 3M 110623 74 \. ! \ \ \ Draeger ORSA5 sampler Figure 7.1 Proposed airflow pattern over Drager ORSA5 when at orientation 90 3M 110624 m Table 5.1 Effects of windspeed and orientation - Geometric mean of three ratios (diffusive t pump) of measured vapour concentration, with geometric standard deviation In brackets, by type of sampler, windspeed and orientation. Results from runs repeated under unchanged conditions are shown on successive lines. Type of Diffusive Sampler 1 Of 900 SKC 530 3 m 3500 t . 34 0. 13) 1 . 04 (1..06) 1. 41 (1.13) 0. 99 (1.04) MSA OVD 1 ..69 (1 .26) 1. 60 (1.25) Or a ge r 0 .93 (1 .02) 0. 92 (1.06) Dupont Perkin Elmer t .20 (1 .02) 3 .67 (1 .08) 0 .47 d .04) 0 .47 (t .07) 1. 18 0.06) 1. 13 (1.03) 0. 46 (1.05) 0. 44 (Ml) 3 0o Windspeed (m/s) Orientation 90 o 6 90 1. 26 (1. 01) 1 , 01 (1 ,08) 1.32 (1. 06) 0.99 (1. 05) 2,.42 (1..40) .2 .31 (1 .06) 0 .98 d .04) 0 .85 (1 . 10) 4 .99 (2 .06) 2 .91 (1 .70) 0 .47 (1 .06) 1.34 (1..06) 1 .46 (1 .07) 1.03 (1 .03) 1.19 (1 .04) 2.86 (1 .34) 2.11 (1 .24) 0.41 (1 .18) 1. 61 (1.29) 1.,26 O.08) 1..00 (1 .02) 6..12 0.06) 3 .76 0.45) 1 .06 (1-01) l .12 (1.05) 2 .24 0.26) 7 .97 0.48) 0 .48 (1.02) 0 .46 0.04) 1. 46 o. 22) 1. 21 O .00) 0. 97 0 .01) 2. 55 O .15) 1. 94 0 .14) 1. 65 O .05) 1. 40 0 03) 2, 82 0 .04) 4..26 0 43) 0,,46 0 .04) 0, 42 0 .04) 12 0o 1. 63 (1..04) 1. 09 O .03) 9,.85 0 .20) l..67 (1 04) 1 .83 o 15) 9 .73 0 .15) 0 .47 0 .04) 900 l. 87 0. 39) 1..10 0 .01) 3,.13 0 .26) 6 .92 (1 .25) 5,.58 0 .20) 6..51 0 .03) 0 .46 0 .04) 3M 110625 Table 5.2 76 Windspeed-orientation data (two orientations examined in each of 35 runs). Average within-run variability, expressed as the variance of the logarithm of the ratio, diffusive -r pump, and the geometric standard deviation of the log ratio (GSD), by sampler type, with the weighting factor used in analyses of variance. Type of Diffusive Sampler SKC 530 3M 3500 MSA OVD Drager Dupont Perkin Elmer Variance 0.03105 0.00209 0.04122 0.01119 0.09335 0.00504 GSD 1.193 1.047 1.225 1.112 1.357 1.074 Weight 3 45 2 8 1 18 41 3H 110626 Table 5.3 77 Windspeed-orientation data (two orientations examined in each of 35 runs). Weighted analysis of variance of derived variable S*. Source of Variation df ' MS P value Type of diffusive sampler (T) 5 19.384 PCO.001 + Windspeed (W) 1 5.400 P<0.001 +WxT 5 2.630 0.05<P<0.01 Residual 23 0.129 Total 34 3.484 * This variable is discussed in Section 4.1 of the Report. It is defined as follows: S = one half of the mean of three log ratios (diffusive result + pump result) at orientation 0, plus one half of the mean of three log ratios (diffusive result -r pump result) at orientation 90. Table 5.4 Windspeed-orientation data (two orientations examined in each of 35 runs), Weighted analysis of variance of derived variable D*. Source of Variation df MS P value Orientation (0) 1 0.022 P>0.1 + Type of diffusive sampler (T) x O 5 1.056 P<0.001 + Windspeed (W) x O 1 0.580 P<0.001 +WxTxO 5 0.593 PcO.OOl Residual 23 0.036 Total 35 0.275 * This variable is discussed in Section 4.1 of the Report. It is defined as follows: D = one half of the mean of three log ratios (diffusive result + pump result) at orientation 0, minus one half of the mean of three log ratios (diffusive result -r pump result) at orientation 90. 3M 110627 Table 5.5 Windspeed-orientation data (two orientations examined in each of 35 runs). Estimated slopes and intercepts (estimated standard errors in brackets) of regression lines relating windspeed to the derived variables S and Dt. Type of Diffusive Sampler i SKC 530 3M 3500 MSA OVD Drage r Dupont Perkin Elmer Intercept (i) - S Slope 0.250 (0.172) 0.0255 (0.0250) 0.013 (0.043) ' 0.0087 (0.0064) 0.341 (0.184) 0.1204 (0.0294)*** -0.363 (0.087)*** 0.1245 (0.0119)*** 0.485 (0.220)* 0.1402 (0.0380)** -0.796 (0.056)*** 0.0022 (0.0091) Intercept (ii) - D Slope 0.0011 (0.0879) 0.0273 (0.0221) 0.0881 (0.0939) 0.1077 (0.0446)* 0.2581 (0.1125)* 0.0363 (0.0286) -0.0035 (0.0128) -0.0024 (0.0033) 0.0442 (0.0150)** -0.0592 (0.0061)*** -0.0116 (0.0194) -0.0013 (0.0046) t See footnotes to Tables 5.3 and 5.4. * PC0.05; ** PC0.01; **P<0.001. M Table 5.6 Windspeed-orientation data (two orientations examined in each of 35 runs). Estimated slopes and intercepts (estimated standard errors in brackets) of regression lines relating windspeed to the mean of three log ratios (diffusive result * pump result), by orientation and sampler type. Type of Diffusive Sampler SKC 3M MSA Drager Dupont Perkin Elmer Intercept Orientation 00 (e.s.e.) 900 Parameter Slope Orientation 00 (e.s.e.) 900 0.251 0.040 0.429* -0.255* 0.743** -0.760*** 0.249 -0.014 0.253 -0.471*** 0.227 -0.832*** (0.193) (0.048) (0.207) (0.098) (0.247) (0.063) 0.0220 0.0290 (0.0281) 0.0063 0.0111 (0.0072) 0.1646*** 0.0762* (0.0330) 0.0653*** 0.1837*** (0.0134) 0.1286** 0.1518** (0.0427) 0.0009 0.0035 (0.0102) * PC0.05; **P<0.01; ***P<0.001. (T> ro \D Table 5.7 Effects of windspeed and orientation runs (SKC 530 and 3M 3500 only, used together in each of 11 runs). Geometric mean of three ratios (diffusive - pump) of measured vapour orientation, with geometric standard deviation in brackets, by type of sampler, windspeed and orientation, Results from runs repealed under unchanged conditions are shown on successive lines. Oriental ion 1 'f SKC 530 3M 3500 0* 1.40 0.03) 1 .01 (1.04) 1.37 (1.01) 0.98 (1.04) 1.50 (1.04) 1 .00 (1.06) 90 0 1,51 (1.15) 1 .01 (1.04) SKC 530 W1ndspeed (m/s) 3 ------------------------------------------- 1----------Type of diffusive sampler 6 3M 3500 SKC 530 3M 3500 1.33 (1.09) 1.01 (1.04) 1.45 (1. 06) 0.99 (1.08) 1.50 (1.05) 1.05 (1.03) 1.57 (1 . 10) 1.03 (1.01) 12 SKC 530 3M 3500 1 .56 (1.06) ' 1 .03 (1.03) 2.25 (1.34) 3.19 (1.14) 1.10 (1.05) 1.11 (1.05) o> o Table 5.8 81 Windspeed-orientation data - SKC device. Analysis of variance of the within-run mean of three log ratios (diffusive result pump result). Source of Variation Windspeed (W) + Orientation (0) +Wx0 Residual Total df MS P value 1 0.355 0.001<P<0.005 1 0.087 0.05<P<0.1 1 0.127 0,025<P<0.05 7 0.016 10 0.068 Table 5.9 Windspeed-orientation data - 3M 3500 device, Analysis of variance of the within-run mean of three log ratios (diffusive result + pump result). Source of Variation Windspeed (W) + Orientation (0) +Wx0 Residual Total df MS P value 1 0.00881 PcO.OOl 1 0.00435 0.005<P<0.01 1 0.00151 0.005<P<0.1 7 0^00028 10 0.00166 3M U0631 Table 5.10 Windspeed-orientation data (SKC 530 and 3M 3500 only, used together in each of 11 runs). Estimated slopes and intercepts (estimated standard errors in brackets) of regression lines relating windspeed to the mean of three log ratios (diffusive result * pump result), by orientation and sampler type. Diffusive Sampler SKC 3M Intercept Orientation Of Slope Intercept 900 Slope 0.3352 (0.0739)** -0.0064 (0.0097) 0.0075 (0.0131) 0.0020 (0.0017) 0.2522 (0.1032)* 0.0061 (0.0135) 0.0580 (0.0126)** 0.0075 (0.0024)* * PC0.05; ** PC0.01. 3M 110632 m Table 5.11 t(feet3 of Turbulence - Geometric mean of three ratios (diffusive + pump) of measuied vapour concentration, with geometric standard deviation in brackets, by type of sampler, turbulence condition, and orientntion. fiesulis from runs repeated under unchanged conditions are shown on successive lines. Tv[y. f,C IlifTusn e Sampler 7 ,5 0.5 0 9(1 60 1.0 0 distance (cm) Grid bar width (cm) Orientation 90 (1 100 1.0 90 250 1.0 .1 it)0 So grid, (data from - raJs[>?&i/orienUkt ion nuts - u'inds|>e'xl = .J m/s] Orient alien 0 90 Mii; 1.20 It. 131 1. M 11.13) (is 1.01 (5.031 1.00 (1.05) MS.', 2.01 (1,0<l I t. 50 < J.H) firager 2. 39 (i .(10) l. 32 (1.09) Perkin i-lmer 0.5(1 (1.03) 0.19 I1.06) 1.11 (1.05) 1.31 (1.051 0.99 (1.01) 0.99 (1.03) 1.61 (1.27) 1.32 (1.12) 2.12 (1.26) 2.19 11.25) 0.52 (1.091 0.19 (1.03) 1.29 (1.061 1.31 (1.02) 0.99 (1.021 0.97 (1.02) 2.09 (1.251 1.31 n .05) 1.99 (1.19) 1.11 (1.10) 0.5t (1.09) 0.17 (1.011 1.31 1 1.07] i .27 11.05! 0.99 (1.011 0. HH (1.(13 i 1.79 (i.091 1. 10 < i .07) 2.22 (2.01) 2.83 (2.66i 0.19 (1.03) 0.16 (1.02i 1.26 (1.011 1.32 (!.061 1.01 11.09) 0.99 (1.051 ' 2. 12 (1.101 1.31 (1.061 2.31 (1.06) t .16 (1.071 0.98 i1.011 1.03 ( 1.03) 0.95 11. Ull 1.19 (1.01) 0.17 (t .061 0.11 (1.181 3M 110633 Table 5.12 84 Turbulence data. Weighted analysis of variance of derived variable S. Source of variation df MS Variance ratio* P value! Type of diffusive sampler (T) 4 28.8157 116.47 PCO.001 + Turbulence condition (0) 4 0.0473 0.19 P>0.1 +Tx0 16 0.0950 0.38 P>0.1 Residual 2 0.0008 Total 26 4.4990 See footnote to Table 5.3. * Obtained by dividing the MS column by 0.2474. t Degrees of freedom of residual = 23. Table 5.13 Turbulence data. Weighted analysis of variance of derived variable D. Source of variation Variance df MS ratio* P valuet Orientation (0) 1 + Type of diffusive sampler (T) x 0 4 + Turbulence condition (C) x 0 4 +TxCx0 16 Residua1 2 Total 27 0.2319 0.3563 0.0150 0.0475 0.0129 3.1111 3.60 5.53 0.05<P<0.1 0.001<P<0.005 0.23 P>0.1 0.74 P>0.1 See footnote to Table 5.4. * Obtained by dividing the MS column by 0.0644. t Degrees of freedom of residual = 23. 3M 110634 Table 5.14 Effects of vapour concentration, loading and sampling time. Geometric means of three ratios (diffusive * pump) of measured vapour concentration, with geometric standard deviations in brackets, by experimental conditions and sampler type. Results from repeat runs under unchanged conditions appear on successive lines. Vapour Concent ration (mg/m3) . Time (min) 5 180 40 60 80 90 180 360 100 60 200 60 Diffusive sampler SKC 3M MSA Drager Perkin Elmer Or ient ation 0 Of 00 ' 00 00 90 2.87 (1.10) 1.33 (1.09)* 1.35 (1.17) 1.26 (1.01)* 1.26 (1.08) 1.40 (1.09) 1.34 (1.06) 1.03 (1.08) 1.01 (1.08)* 1.01 (1.04)* 0.96 (1.13) 0.94 0.93 0.94 0.98 (1.04) (1.02) (1.05) (1.06) 2.42 (1.40 ) 2.31 (1.06) 2.12 (1.14)* 2.13 (1.26)* 1.69 (1.13) 2.14 (1.14) 0.98 (1.04)* 0.85 (1.10)* 0.88 (1.07) 0.90 (1.05) 0.93 (1.05) 0.93 (1.10) 0.47 (1.06)* 0.47 (1.02) 0.45 (1.01) 0.52 (1.03) 0.49 (1.03) 0.41 (1.18) 0.44 (1.04) 0.44 (1.05) 0.50 (1.02) 0.47 (1.05) Data from windspeed-orientation runs. 86 Table 5.15(a) Concentration-time data. Analyses of variance of the mean of three log ratios (diffusive result * pump result), for four samplers. Diffusive Sampler Source of Variation df MS VR* P value SKC Experimental Conditions 4 0.1300 8.84 PCO.OOI Residual 2 0.0012 Total 6 0.0871 3M Experimental Conditions 4 0.0022 0.27 P>0.1 Residua1 3 0.0005 Total 7 0.0015 MSA Experimental Conditions 4 0.0189 0.29 P>0.1 Residual 1 0.0011 Total 5 0.0153 Drager Experimental Conditions Residual Total 4 0.0004 0.05 P>0.1 1 0.0102 5 0.0024 * The residual mean squares used to obtain the variance ratios in the above Tables are, respectively: 0.0147, 0.0081, 0.0644 and 0.0085, assumed to have 14, 16, 12 and 12 degrees of freedom. < . 3M 110636 87 r Table 5.15(b) Concentration-time data - Perkin Elmer device. (i) Analysis of variance of derived variable S**. Source of variation df MS Variance ratiot P value Experimental Conditions 4 0.0038 0.65 P>0.25 t The residual mean square used to obtain the variance ratio is 0.0058, with 20 degrees of freedom. ** See footnote to Table 5.3. (ii) Analysis of variance of derived variable Dtt. Source of variation df MS Variance ratio P value Orientation (0) Experimental conditions x O Total 1 0.004351 2.88 0.KPC0.25 4 0.000510 0.34 P>0.25 5 0.001278 The residual mean square used to obtain the variance ratio is 0.0015, with 20 degrees of freedom, tt See footnote to Table 5.4. 3M 110637 Table 5.16 Effects of fluctuating vapour concentrations. Geometric means of three ratios (diffusive t pump) of measured vapour concentration, with geometric standard deviations in brackets, by experimental condition and sampler type. Results from runs repeated under unchanged conditions are shown on successive lines (Drager device only). j Di f fusive Sampler SKC 530 3M 3500 Drage r Perkin Elmer 1 1 1 10 1 1 1i t 00 | 11 11.45 (1.02) | (1.02) | Run time (min) l 1 1 l 480 Or Ientation 900 | 00 1 1 l 1.44 (1.01) 1 1 0.96 (1.00) t | l | | 1 1 Steady Concentration 1 1 (Data from wlndspeed1 orientation runs; 1 windspeed - 3m sec-1) 1 900 , OrientatIon 00 | 900 1' l l1 1 1.26 (1.01) | 1l 1 1.01 (1.08) [ 1.12 (1.04) 1.11 (1.02) 1.03 (1.03) 1.19 (1.04) 0.48 (1.05) 0.38 (1.05) 0.41 (1.18) oo 3M 110638 1 Table 5.17 Effects of Dust Exposure. Geometric means of three ratios* (diffusive * pump) of measured vapour concentration, with geometric standard deviations in brackets, by experimental condition and sampler type. Dust Type Dust Concent rat ion Aloxite Pulverised Fue 1 Low High SKC 530 D1ffusive Sampler 3M 3500 Drager Perkin Elmer* 1.42 (1.03) 1.34 (1.00) 0.98 (1.02) 0.98 (1.02) 1.05 (1.00) 0.97 (1.00) 0.45 (1.07) 0.46 (1.03) * Six results were obtained for the Perkin Elmer within each run. m 03 0* CO to Table 6.1 90 Uptake rates for toluene. Sampler SKC 530 3M 3500 Drager Orsa 5 Perkin Elmer ATD 50 Uptake rate (ml/min)* Manufacturers Experimentally determined 9.05 12.82 31.4 33.0 6.06 6.69 0.635 0.317 * Expressed as an equivalent air sampling flow rate for a pumped sampler. 3W 110640 ft H f Table 6.2 91 Field trial. Single measurements of vapour concentrations (ppm) for diffusive samplers; means of 2, 3 or 4 measurements for pumped tubes. Run Sampler 1 Pumped Tube Perkin Elmer 3M 3500 Drager SKC 530 2 Pumped Tube Perkin Elmer 3M 3500 Drager SKC 530 1 24.4 31.9 28.1 28.6 28.9 49.8 60.5 62.2 52.4 50.4 Sampling Station 23 26.0 31.7 29.4 28.6 31.9 59.4 62.9 66.1 67.2 69.8 30.5 32.3 29.7 31.3 33.5 66.1 76.6 80.2 65.9 77.0 4 34.5 34.9 32.4 34.0 37.6 71.2 81.8 82.0 70.4 88.9 Table 6.3 Field Trial. Analysis of variance of the Natural Logarithm of measured vapour concentration (ppm). Source of variation Variance df MS* . rat io P value Sampler (S) Position (P) Run (R) S xP S xR PxR S xPxR Total 4 0.0276 4.00 P=0.1 3 0.1458 1 6.0598 12 0.0041 1.47 P-0.25 4 0.0069 3 0.0161 12 0.0028 - 39 * *F' test of S uses the MS for S x R as denominator. 'F* test of S x P uses the MS for S x P x R as denominator. 3H 110841 92 Table 7.1 Ratio of uptake rates for diffusive samplers for 1,1,1 trichloroethane and toluene. Type of Sampler Rat io of Uptake Rates 1,1,1 t rich1o roe t hane* Experimental/Manufacturers toluene SKC 530 3M 3500 Drager Orsa 5 Perkin Elmer ATD 50 1.41 1.01 0.92 0.46 1.42 1.05 1.11 0.50 * This ratio was based on the average ratio of diffusive to pumped concentrations at 1 m/sec, quoted in Section 5. 3H 110642 cu oo\ fx CO I * Tabic 8*l Summary of conclusions from work. Type or Diffusive Sampler SKC 5:to 3M 3500 MSA OVD Drager Orsa 5 Dupont Protec 0-DR Perkin E1 me r ATI) 50 Validity of Manufacturer1 a Uptake Rate 1,1,1 TCE gives results with bias +40X OK 1,1,1 TCE gives results with bias +60X 1,1,1 TCE gives results with bias -8X Results too variable to assess 1,1,1 TEC gives results with bias -44X Effect of Hindspeed/ Orientation Effect of Turbulent Airflows Effect of Vapour Loading Effect of Initial 'Spike' Effect of Airborne Dust Underground Trial Toluene Not statistically significant Not statistically significant Results very variable affected by both wind k orientation Affected by both wind k orientation at high wtndspeeds ' , Results very variable affected by both wind k orientation Not statistically significant Not statistically significant Not statistically significant Not statistically significant No effect Not at most statistically cone's tested significant Not statistically significant Consistent results small bias Not Not statistically statistically significant significant Not statistically significant Consistent results small bias Not statistically significant DROPPED FROM FURTHER EVALUATION Introduces bias and random variation into results Not Not statistically statistically significant signifioiint Small unimportant effects Consistent results small bias DROPPED FROM FURTHER EVAUMTICN Not statistically significant Not statistically signifi cant Some loss of vapour (different adsorbent may be better) Not statistically signi fican t. Consistent results small bias Potentially Suitable for Coalmine Use Yes Yes No No No Yes 1 3M 3520 OVM DUPONT HCFC123 EXPOSURE 39 PPM DRY + PRIMARY/TOT Sheetl HEXACHLOROETHANE RECOVERY .5EU amt spike,ug amt rec rec avg rec 62.2 52.89 0.850322 62.2 54.97 0.883762 62.2 50.39 0.810129 62.2 48.74 0.783601 0.83 std dev 0.04 1EL amt spike,ug 124.4 124.4 124.4 124.4 amt rec 101.55 108.89 105.87 104.4 rec 0.816318 6.875322 0.851045 0.839228 avg rec 0.85 std dev 0.02 Page 1 3M 110649 3M OCCUPATIONAL HEALTH & ENVIRONMENTAL SAFETY DIVISION MONITOR BULLETIN X November, 1990 Listed in the following table are the theoretical calculated sampling rates (SR) for halothane, enflurane and isoflurane (Forane). Also listed are recoveries (REC) using carbon disulfide for desorption, limits of detection (LOD) for our analysis lab procedure using a flame ionization detector (FID) and retention times (RT) using our lab procedure. Our capillary column gas chromatography procedure involves simultaneous analysis on two columns (30m X .25mm I.D. X .25 urn film thickness J&W DB WAX and DBS) with a temperature program of 3 min @ 40C - 10C/min - 30 min 180c. SR REC RT (DB5) RT (DBWAX) Halothane 30.0 .97 4.68 Isoflurane 28.3 .75 2.55 4.47 Enflurane 28.3 .81 2.59 - LOD (UG) 10.8 10.4 10.8 A minimum sampling time of approximately 90 min is required to obtain 10 ug at an air concentration of 0.5 ppm. Lower LODs have been obtained with an electron capture detector (ECD) using isooctane for desorption and chromatography on a 30 m X .53 mm I.D. X 5 urn film thickness J&W DB1 megabore column at 100C isothermal. The recovery for halothane was 0.11. Contamination peaks from the OVM blank interfered with the isoflurane and enflurane peaks. 3M 110650 Methylene Chloride Passive Dosimeter Field Validation in a Single Component Atmosphere The current Method used for collecting Methylene Chloride (MeC12) samples is an active method which requires a Low Flow Sampling Pump and a 600 mg Medium Charcoal Tube. An alternative method, passive dosimeters, was evaluated for collecting MeC12 samples. The passive dosimeter method has many benefits compared to the active method: the dosimeters can be used rapidly without requiring the pre calibration of pumps, there will be less paper work with a passive dosimeter because pump calibration records will not be necessary, there will be less equipment required to collect samples, the procedure will be less cumbersome for the employee who's exposure is being evaluated because they will not be required to wear a pump with a hose and there will not be the possibility of a lost sample due to pump failure. However, before the passive dosimeters could replace the active method their use needed to be validated. The MeC12 Passive Dosimeter Field Validation Study was completed in January of 1995, Four passive dosimeter models and a new sorbent material from SKC were compared to the current active method, Medium Charcoal Tube. Ten individual field validations were performed, five for PEL validation and five for STEL validation. The Field Validations were performed under various temperatures, pressures and relative humidities as shown in Table 1. All Field validations were performed in CAPD Building R5/R6 were there was only one chemical component, MeC12, present at significant amounts. The four models of passive dosimeters evaluated were; SKC series 575, 3M model #3520 and Assay Technology model 541 and 546. All passive dosimeters evaluated performed acceptably, however, the new sorbent material was inferior to the current active method. A summary of the results of the field validations is given in Appendix A. Since all the models of passive dosimeters evaluated performed well, the recommendation of which model to use will be based on special characteristics of each style of dosimeter, ease of use and cost per dosimeter. Each style of dosimeter had some special characteristics. The 3M Badge has two sections which work in a similar way as the backup section in tubes, if greater than 50% of the total mass collected is on the secondary section the sample is considered invalid. This feature would be useful in high concentration areas, however, it was not needed during this series of field validations. The Assay Technology dosimeters offered a choice between a high sampling dosimeter and a high capacity dosimeter. This option is useful for STEL sampling because the high sampling rate model assures the collection of a quantifiable amount of MeC12 and for PEL sampling with the high capacity model which samples at a lower rate to avoid saturating the dosimeter. These dosimeters may also be re-usable when a new carbon wafer is placed in the dosimeter housing. The SKC series dosimeter was by far the easiest to desorb and analyze because of its single collection pad and internal desorption. The recommended shelf life of all dosimeters is given in Table 2. The cost per monitor is given in Table 3. The SKC dosimeter is the least expensive, however, there is the possibility that Assay Technology will sell us the individual carbon wafer that can be placed in the re-usable housing of the dosimeter. This option is sure to be significantly less than the cost of the complete badge. The SKC Series 575 is currently the recommended dosimeter of CIHL because of its ease of use and analysis and because of its reduced cost. This recommendation may change depending on the cost of the Assay Technology replacement carbon wafer. 3W Methylene Chloride Passive Dosimeter Field Validation Table 1. Environmental Conditions During Field Validation. Atmospheric Average Field Validation Date Pressure Temperature (mm HG) (Celsius) PEL 9/26/94 746 14.3 PEL 10/3/94 752 17.7 PEL 10/17/94 750 20.4 PEL 10/31/94 748 19.4 PEL 11/7/94 759 21.2 Average Relative Humidity (%) 60.7 54.1 58 37.6 23 Water Concentration (mg/m3) 7120 8190 9990 6040 4180 STEL STEL STEL STEL STEL 10/27/94 11/2/94 12/5/94 12/14/94 1/10/95 757 756 752 748 748 21.1 31.2 19.9 218 23.2 22.1 19.2 315 15.8 13.6 4010 6320 5390 3050 2790 Table 2. Recommended ShelfLife of Passive Dosimeters. Recomended Dosimeter Shelf Life Assay Technology Model 541/546 3M Model #3520 SKC Series 575 12 months 18 months 21 months Table 3. Cost for a single monitor. Monitor Assay Technology Model 541/546 3M Model #3520 SKC Series 575 Medium Charcoal Tube (a) Cost/Monitor $13.50 $16.26 $10.80 $6.14* * Includes cost of pump and calibration. (a)Thia value was determined baaed on the following assumptions and costs: Cost ofPump per sample: Cost ofGilibralor per sample Cost ofWages per sample Cost of600 mg Charcoal Tube ($425 Cost ofPump)/{(2 samples per week) x (52 weeks per year) x (5 year life ofPump)} " SO.82 per sample ($1000 Cost ofGilibrator)/{(50 samples per week) x (52 weeks per year) x (5 year life ofGilibralor)} = $0.08 per sample ($30,000 Salary x 1.33 for fringe) * S39,900/year ( $39,900 per year)/ {(2000 hra per year) x (60 min per hour) "33.3 cents per minute x 10 min per sample * $3.33 per sample S1.91 Total Cost per Sample = (Cost ofPump + Cost ofGilibralor + Cost ofWages + Cost ofTube) - (SO.82 + $0.08 $3.33 + $1.91) - $6.14 3M 110652 T^O/O e-tJ -3^7 Off +-SS February 2, 1995 Martin Harper Gus Manning Bob Weber SKC Assay Technology 3M cc: Mark Puskar Elisabel Puskar Jim Murphy Abbott Laboratories: CIHL Abbott Laboratories: CAPD Abbott Laboratories: CHS FIELD VALIDATION OF PASSIVE DOSIMETERS FOR THE DETERMINATION OF EMPLOYEE EXPOSURES TO METHYLENE CHLORIDE IN PHARMACEUTICAL PRODUCTION FACILITIES The Methylene Chloride Field Validation Study was completed in January of 1995, Enclosed for your review are the individual results of the ten field validations. Included with the results are the procedures followed to desorb the samples, a list of abbreviations, some of the calculations used to determine the results and a summary sheet for all ten validations showing the bias and accuracy of the various media as they compare to the Medium Charcoal Tube method. This information is being given to allow you the opportunity to interpret the raw data and submit suggested discussion topics and conclusions. We would also like your opinion on the possibility of performing one or two more field validations for the STEL portion of the study because of multiple results at the 100 ppm level. We look forward to your comments. If you are going to attend the Laboratory Accreditation Committee Meeting on February 12 please bring this information as Mark will attend and would like to discuss the results. If you have any questions or comments pleases feel free to contact Mark Puskar or myself Sincerely, CX Cktv^vQ Kem A. Charron Industrial Hygiene Chemist Corporate Industrial Hygiene Laboratory Abbott Laboratories D-038A 1401 Sheridan Road North Chicago, 1L 60064 Phone: (708) 938-6680 Fax: (708) 937-6293 . ~ 3M 110653 Methylene Chloride Passive Dosimeter Field Validation Summary Sample Type Medium Charcoal Tuba Assay Passive Monitor Carbon Molecular Slava Tuba SKC Passive Monitor 3M Passtva Monitor Date Mean (ppm) Cv(%) Bias(%) Accuracy Mean (ppm) Cv(%) Bias(%) Accuracy Mean (ppm) Cv(%) Bias{%) Accuracy Mean (ppm) Cv{%) Bias(%) Accuracy Mean (ppm) Cv(%) Bias{%) Accuracy ret 10/17/94 0.9 14.4 0 26.8 PEL 11/7/94 3.1 5.75 0 11.5 1.0 8.74 11.1 28 6 3.4 14.1 968 37.9 1.0 15.2 11.1 41.5 3.5 12 12.9 36.9 1,0 863 11.1 2&a 4.1 3.59 32.3 39.4 0.8 8.14 -11.1 27.4 3.0 2.69 -3.23 B.61 PEL 10/3/94 pa 9/26/94 PEL 10/31/94 Footed Bias= Pooled Accuracy9 i 14.6 26.9 62.7 1.1 0 2.20 1.37 0 2.74 26 0 5.20 0.00 10.1 13.5 1.76 -8.76 12.3 27.5 1.63 -4.64 8.10 590 2.51 -5.90 109 6.06 19.6 16.5 16.2 11.5 43.9 28.1 1.91 -2.77 6.59 69.7 9.93 11.2 31.0 9.89 32.0 14.8 3.03 000 6.1 28.0 3.17 -3.11 9.45 65.7 3.2 4.8 11.2 10.3 190 13.8 2.64 -6.76 12.0 26.5 3.12 -8.30 14.5 566 4.01 -9.73 17.7 7.83 16.1 STEL 12/5/94 14.4 9.96 0 199 sTa 1/10/95 96.2 3.32 0 664 14.6 4.87 1.39 11.1 106 4.4 12.27 21.1 13.6 6.2 -5.56 99.4 4.3 3.33 sTa 11/2/94 STEL 12/14/94 STa 10/27/94 Pooled Bias Pooled Accuracy 101 113 357 31.4 0 62.8 20.5 0 41.0 531 0 10.6 000 26.2 106 25.9 4.95 56.8 107 11.3 -5.31 27.9 394 5 57 10.36 21.5 6.86 27.7 92.1 26.1 -8.81 104 24.4 -7.96 357 6.54 000 6.41 Bias = ((Amount Found-Amount KncwnJ/Amount Known) * 100. Amount Known=Reterence Method, Medium Charcoal Tube Accuracy (2(CV)+|Bias|] 22.0 11.9 65.0 56.8 13.1 33.7 15.8 5.66 9.72 21.0 114 6.63 18.5 32.2 103 19.4 1.98 40.8 116 13.1 265 28.9 413 6.05 15.7 27.8 9.71 30.1 14.1 4.16 -2.08 10.4 87.6 6.66 -8.94 22.3 103 26.1 1.98 54.2 859 941 -24.0 42.8 345 6.17 -3.36 157 8.07 29 1 CO 0 01 in 41 Page 1 Methylen Chloride Passive Dosimeter Field Validation DESORPTION OF SAMPLING MATERIALS Medium Charcoal Tube (MCT) 600 m Desorption Efficiency: 100 % Desorption solution: Caibon Disulfide (CS2) with 5% Methanol (MeOH) Desorption procedure: Add 2 mL of CS2iMeOH to the front and back section of tube in seperate vials, immediatly reseal vial. Vortex mix the solution and place on counter for 30 minutes. After 30 min an aliquot is removed from the vial and placed in an autosampler vial for analysis. SKC Anasorb Carbon Molecular Sieve (CMS! 150/75mg Desorption Efficiency: 97.6 +/- 4.22% (n = 46) Desorption solution: Caibon Disulfide (CS2) Desorption procedure: Add 2 mL of CS2 to the front and back section of tube in seperate chilled vials. Mechanically agitae the vials for 30 minutes. An aliquot is removed from the vials and placed in an autosampler vial for analysis. SKC Passive Sampler 575 Series Desorption Efficiency: 96.0+/-4.3% Sampling Rate: Desorption solution: Caibon Disulfide (CS2) 14.5 mL/min Desorption procedure: Add 2 mL of CS2 to each monitor through the center port, immediatly reseal port. The monitors are agitaed for 30 minutes. An aliquot is removed from the monitor and placed in an autosampler vial for analysis. Assay Technologies Personal Monitoring System Model 541 and 546 Desorption Efficiency: Sampling Rate: Desorption solution: 92.0 % Monitor 541= 7.57 mL/min Caibon Disulfide (CS2) Monitor 546= 1.89 mL/min Desorption procedure: Use forcepts, quickly remove the sample wafer from the plastic cavity, break the wafer into two pieces and place into a 7ml glass vial with an inert closure. Quickly add 1.0 mL of CS2 to each vial. Agitate the vial continuously for 1 hr. An aliquot is removed from the 7 ml vial and placed in an autosampler vial for analysis. 3M Organic Vapor Monitors #3520 with Back-up Section Desorption Efficiency: 90 % Sampling Rate: Desorption solution: Carbon Disulfide (CS2) 37.9 mL/min Desorption procedure: Add 1.5 mL of CS2 to each monitor through the center port, immediatly reseal port. The monitors are occasionally agitaed for 30 minutes. An aliquot is removed from the monitor and placed in an autosampler vial for analysis. 3M 110655 Sheet13 Methylene Chloride Passive Dosimeter Field Validation Abreviations used on Results Sheets MCT= CMS= SKC* ASSAY33 3M= Medium Charcoal Tube, 600 mg total weight SKC Anasorb Carbon Molecular Sieve, 225 mg total weight SKC Passive Sampler 575 Series Assay Technologies Personal Monitoring System Model 541 and 546 3M Organic Vapor Monitor #3520 with Back-up Section _______________ Calculations used for determining results_____________ Equation 1 Concentration in ppm= (Total mcg)x(24.45)/(M.W. of MeCI2)x(Total Air Volume in L) Equation 2 Total meg for 3M Organic Vapor Monitors^ (Wp+(2.2xWs)) Wp= meg of MeCI2 on Primary Section. Ws meg of MeCI2 on Secondary Section. SKC and Assay Monitor results were corrected for Pressure and Temperature by multiplying the Concentration by a PT correction factor. The correction factor was determined using Equation 3. The 3M results were corrected according to the Table given in the ''3M Organic Vapor Monit r #3500/3520 Analysis Guide". Equation 3 1.5 PT= (Ta/Ts) (Ps/Pa) Ta= Temperature in Kelvin at sampling area Ts= Standard Temperature(298 Kelvin) Pa= Pressure in mm Hg at sampling area Ps= Standard Pressure(760 mm Hg) Page 1 3H 110656 Sfteetf Results for Methylene Chloride Passive Dosimeter Field Validation (Run # 1, PEL # 1, 9-26-94). Active Samples Pump ID 10374 10377 1037S 10376 10372 10378 10389 10379 10380 10426 10427 1042B 10429 10430 Sample ID T-MCT-A 1-MCT-B 1-MCT-C 1-MCT-O 1-MCT-E 1-MCT.F 1-MCT-BLANK 1-CMS-A 1-CMS-B 1-CMS-C 1-CMS-D 1-CMS-E 1-CMS-F 1-CMS-BLANK Pre-Cal (mL/min) 101.3 100.6 97.36 101.5 97.03 100.S 101.2 99.84 97.01 97.67 100.9 98.61 100.7 103.2 Post-Cal (mL/min) 100.95 101.1 97.72 100.1 94.84 100.9 101.2 102.6 99.91 98.71 101S 99.9 100.9 104.6 Avg (mL/min) 101.13 100.85 97.64 100.80 96.94 100.70 101.20 101.22 98.46 98.14 101 AO 99.26 100.80 103.90 Sample Time(min) 480 480 480 480 490 480 480 480 480 480 480 480 480 480 Total Vol(L) 48.54 4B.41 46.82 48.38 46.05 48.34 48.58 48.59 47.26 47.11 48.67 47.64 48.38 49.87 Desorption Efficiency 1 1 1 1 1 1 1 0.976 0.976 0.976 0.976 0.976 0.976 0.976 Analyzed amount (mcgJ2mL) Front Back Total 4891 0 4891 4838 0 4838 4649 0 4649 4852 11.4 4863 4668 0 4568 4976 0 4976 11.675 0 12 2436 2245 4795 3809 624 4642 3681 698 4487 4047 649 4611 3812 691 4614 4113 614 4843 7.4 0 B Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL Concentration (PPm) 29.0 29.8 28.6 28.9 28.6 29.6 0.1 28.4 27.7 27.4 28.6 27.9 28.8 0.0 MCT Average Conc.= 28.9 Std. Dev.* 0.40 C.V.* 1.37% CMS Average Cone.* 28.1 Std. Dev.* 0.54 C.V.= 1.91% Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample ID 1-001 1-002 1-003 1-004 1-005 1-006 1-BLANK T0061(Blk) T0062 T0053 T0054 T0Q55 T0057 T0058 VK 03760C VK03563C VK 03579C(Stk) VK03616C VK03652C VK03728C VK03769C Sampling Rate(mUmin) 14.5 14.5 14.5 14.5 14.5 14.5 14.5 7.67 7.57 7.57 7.57 7.57 7.57 7.57 37.9 37.9 37.9 37.9 37.9 37.9 37.9 Sampling Time 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 Total Vol(L) 6.96 6.96 6.96 6.96 6.96 6.96 6.96 3.63 3.63 3.63 3.63 3.63 3.63 3.63 18.19 18.19 18.19 18.19 18.19 18.19 18.19 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 0.96 610 [a] 635 0.96 611 [a] 636 0.96 621 [a] 647 0.96 622 [a] 648 0.96 639 [>1 666 0.96 662 [a] 690 0.96 0 ra] 0 0.92 0 [a] 0 0.92 604 [a] 657 0.92 610 [a] 663 0.92 612 Ea] 665 0.92 617 [a] 671 0.92 633 [a] 688 0.92 620 [a] 674 0.9 1714 108 2168 0.9 1724 97.4 2154 0.9 0 0 0 0.9 1884 76.8 2281 0.9 1717 99.5 2151 0.9 1778 123 2276 0.9 1733 81.1 2124 Desorption Corrected Volume (mL) Tout [b] 2mL 2m L 635 636 2mL 2mL 647 648 2mL 2mL 666 690 2mL 0 ImL 0 ImL ImL 328 332 ImL ImL 333 335 ImL ImL 344 337 1.5 mL 1626 1.6 mL 1615 1.5 mL 0 1.6 mL 1711 1.5 mL 1613 1.5 mL 1707 1.5 mL 1593 Concentration (ppm) 26.3 26.3 26.8 26.8 27.6 28.5 0.0 0.0 26.0 26.3 26.3 26.6 27.3 26.7 26.7 25.6 0.0 27.1 2S.S 27.0 2S.2 T/P Corrected Cone, (ppm) 27.2 27.3 27.7 27.8 28.5 29.6 0.0 0 27.0 27.2 27.3 27.5 28.3 27.7 26.2 26.1 0.0 27.6 26.0 27.6 25.7 SKC Average Cone.* 28.0 Std. Dev.* 0.89 C.V.* 3.17% 1 ASSAY Average Cone.* 27.5 Std. Dev.= 0.45 C.V.* 1.63% 3M Average Cone.* 26.5 Std. Dev.= 0.83 C.V.= 3.12% [a] There is only one section to these samples. [b] Corrected for desorption volume differences. Temperatures 14.3 degrees Celsius Pressures 74s mm Hg_________ Page 1 3H 1 Sheet3 Results for Methylene Chloride Passive Dosimeter Field Validation (Run # 2, PEL #2,10-3-94). Active Samples ID 10374 10377 1037S 10376 10372 10378 10389 10427 10426 10428 10430 10429 10380 10379 ID 2-MCT,A 2-MCT-B 2-MCT-C 2-MCT-D 2-MCT-E 2-MCT-F 2-MCT-BLANK 2-CMS-A 2-CMS-B 2-CMS-C 2-CMS-D 2-CMS-E 2-CMS-F 2-CMS-BLANK Pre-Cal (mL/min) 19.72 19.81 20.61 20.12 20.47 19.B6 19.93 19.94 19.67 20.03 20.08 20.44 20.17 20.74 Post-Cal (mUmin) 20.56 19.98 20.57 20.45 20.59 20.11 19.92 20 19.56 20.56 20.06 20.56 20.04 20.67 Avg (mL/min) 20.14 19.90 20.59 20.29 20.63 19.99 19.93 19.97 19.62 20.30 20.07 20.60 20.11 20.71 Sample Tlme(mln) 480 480 480 480 4B0 480 480 480 4B0 480 480 480 480 480 Total Vol (L) 9.67 9.55 9.B8 9.74 9.86 9.69 9.66 9.69 942 9.74 9.63 9.84 9.65 9.94 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 1 500.9 0 501 1 492.6 0 493 1 501.2 0 501 1 605.1 0 606 1 512 0 612 1 487 0 487 10 0 0 0.976 670 0 686 0.976 0.976 696.7 489 4.1 0 616 601 0.976 473 7.B 493 0.976 458 0 469 0.976 638 0 661 0.976 0 0 0 Desorption Volume (mL) 2mL 2mL 2mL 2m L 2mL 2mL 2mL 2mL 2m L 2mL 2mL ImL 2mL 2mL Concentration (ppm) 14.9 14.8 14.6 14.9 15.0 14.6 0.0 20.6 18.8 14.8 14.7 13.7 16.4 0.0 MCT Average Conc.= 14.8 Std. Dev.a 0.16 G.V.= 1.10% CMS Average Cone.= 16.5 Std. Dev.a 2.68 C.V.= 16.2% Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample ID 2-001 2-002 2-003 2-004 2-005 2-006 2-BLANK UIOIO(Blank) UIOOI U1002 U1003 U1005 111 006 U1009 VK03S66C VK03448C VK03817C VK03649C VK03514C VK 03B43C VK03897C Sampling Rate( mL/min) 14.5 14.5 14.5 14.5 14.5 14.6 14.6 1.89 1.89 1.89 1.89 1.89 1.89 1.89 37.9 37.9 37.9 37.9 37.9 37.9 37.9 Sampling Time 480 480 4B0 480 480 480 480 480 480 480 480 480 480 480 480 480 4B0 480 480 480 480 Total Vol (L) 6.96 6.96 6.96 6.96 6.96 6.96 6.96 0.91 0.91 0.91 0.91 0.91 0.91 0.91 18.19 1B.19 18.19 18.19 18.19 18.19 18.19 Desorption Analyzed amount {mcg/lmQ Efficiency Front Back Total 0.96 342 [a] 356 0.96 0.96 0.96 0.96 0.96 0.96 349 333 32B 326 323 0 W [a] [a] [a] Ial fa] 364 347 342 340 336 0 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.9 0 77 74.8 77.4 77.5 77.1 74.6 1013 la] [a] fa] fa] [a] fa] -M 21.7 0 84 81 84 84 84 81 1179 0.9 960 20.3 1116 0.9 968.6 24.9 1137 0.9 1023 25.5 1199 0.9 973 23.8 1139 0.9 977 24.6 1146 0.9 0 0 0 Desorption Volume (mL) 2m L 2mL 2m L 2mL 2mL 2mL 2m L ImL ImL ImL ImL ImL ImL ImL 1.6 mL 1.5 mL 1.5 mL 1.5 mL 1.6 mL 1.5 mL 1.5 mL Corrected Total lb] 356 364 347 342 340 336 0 0 42 41 42 42 42 40 884 837 853 899 854 859 0 Concentration TIP Corrected 1 1 (ppm) Cone, (ppm) 14.7 15.0 14.3 14.1 14.0 13.9 0.0 16.1 15.4 14.7 14.6 14.4 14.3 0.0 SKC Average Conc.= 14.8 Std. Dev.s 0.45 C.V.s 3.03% 0.0 13.3 12.9 13.3 13.4 13.3 12.8 0 13.5 13.3 13.7 13.7 13.7 13.2 ! ASSAY Average Conc.s 13.5 Std. Dev.= 0.24 C.V.= 1.78% 14.0 13.2 13.5 145 13.5 13.6 0.0 14.1 13.4 13.6 14.4 13.7 13.7 0.0 3M Average Conc.= 13.8 Std. Dev.= 0.36 C.V.= 2.64% [a] There is only one section to these samples. [b] Corrected for desorption volume differences. Temperature^ 17.7 degrees Celsius _____________ Pressure^ 7S2 mm Hg__________ 3M 110658 Page 1 Sheets Results for Methylene Chloride Passive Dosimeter Field Validation (Run U 2, PEL #2,10-3-94). Active Samples ID 10374 10377 10376 10376 10372 10378 10389 10427 10426 10428 10430 10429 103B0 10379 Sample ID 2-MCT-A 244CT-B 2-MCT-C 2-MCT-D f -fc 2-MCT-F 2-MCT-BLANK 2-CMS-A 2-CMS-B 2-CMS-C 2-CHS-O 2-CMS-E 2-CMS-F 2-CMS-BLANK Pre- Cal (mL/min) 19.72 19.81 20.61 20.12 2047 19.88 19.93 19.94 19.67 20.03 20.0B 20.44 20.17 20.74 Post-Cal (mL/min) 20.66 19.98 20.57 20.45 20.59 20.11 19.92 20 19.66 20.66 20.06 20.55 20.04 20.67 Avg (mL/min) 20.14 19.90 20.59 20.29 20.63 19.99 19.93 19.97 19.62 20.30 20.07 20.50 20.11 20.71 Sample Timefmin) 480 480 480 480 4B0 480 480 480 480 480 480 480 480 480 Total Vol (L) 9.67 9.55 9.88 9,74 9.86 9.69 9.56 9.59 9.42 9.74 9.63 9.84 9.65 9.94 Desorption Efficiency 1 1 1 1 1 1 1 0.976 0.976 0.976 0.976 0.976 0.976 0.976 Analyzed amount (mcg/2mL) Total 500.9 0 501 492.5 0 493 501.2 0 501 505.1 0 505 512 0 612 487 0 487 00 0 670 0 686 596.7 489 4.1 0 616 601 473 7.B 493 45B 0 469 53B 0 661 00 0 Desorption Volume ImU 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2m L 2mL 2mL Concentration I ppm) 14.9 14.8 14.6 14.9 15.0 14.6 0.0 20.6 1B.8 14.0 14.7 13.7 16.4 0.0 MCT Average Conc.= 14.8 C.Vs 1 IQ*/, CMS Average Cone.* 16.5 Std. Dev.= 2.68 C.v.= 16.2% Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample ID 2-001 2-002 2-003 2-004 2-006 2-006 2-BLANK tmiO(Blank) UIO0I U1002 U1003 U1005 U1008 U1009 VK 03866C VK0344BC VK03817C VK03649C VK03514C VK03843C VK03897C Sampling Ratef mL/min) 14.5 14.5 14.5 14.5 14.5 14.5 14.5 1.89 1.89 1.89 1.89 1,89 1.89 1.89 37.9 37.9 37.9 37.9 37.9 37.9 375 Sampling Time 480 480 480 480 4B0 480 480 480 4B0 480 480 480 480 480 480 480 480 480 480 480 480 Total Vol (L) 6.96 6.96 6.96 6.96 6.96 6.96 6.96 0.91 0.91 0.91 0.91 0.91 0.91 0.91 18.19 18.19 18.19 18.19 18.19 18.19 18.19 Desorption Analyzed amount (mcg/lmL) Efficiency Front Back Total 0.96 0.96 342 349 [a] [a] 356 364 0.96 0.96 333 328 M [a] 347 342 0.96 326 [a] 340 0.96 323 W 336 0.96 0 fa) 0 0.92 0 la] 0 0.92 0.92 77 74.8 [a] W 84 81 0.92 77.4 [a] 84 0.92 0.92 0.92 0.9 77.5 77.1 74.6 1013 la] M M 21.7 84 84 81 1179 0.9 960 20.3 1116 0.9 968.6 24.9 1137 0.9 1023 25.5 1199 0.9 973 23.8 1139 0.9 977 24.6 1146 0.9 0 0 0 Desorption Volume (mL) 2mL 2mL 2m L 2mL 2mL 2mL 2mL ImL ImL ImL ImL ImL ImL ImL 1.6 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL Corrected Total [b] 358 364 347 342 340 336 0 0 42 41 42 42 42 40 884 837 853 899 854 859 0 Concentration T/P Corrected (ppm) 14.7 16.1 15.0 14.3 14.1 14.0 13.9 154 14.7 14.5 14.4 14.3 . 0.0 0.0 0.0 13.3 12.9 13.3 13.4 13.3 12.8 0 13.6 13.3 13.7 13.7 13.7 13.2 14.0 13.2 13.5 14.2 13.5 13.6 14.1 13.4 13.6 14.4 13.7 13.7 0.0 0.0 1 1 SKC Average Cone,= 14.8 Std. Dev.= 0.45 C.V.= 3.0314 1 ASSAY Average Conc.= 13.5 Std. Dev.= 0.24 C.V.= 1.78% 3M Average Conc.= 13.8 Std. Dev.e 0.36 C.V.= 2.6414 [a] There is only one section to these samples. [b] Corrected for desorption volume differences. Temperatures 17.7 degrees Celsius _____________ Pressures 762 mm Hg__________ 110659 Page 1 Sheel4 Results for Methylene Chloride Passive Dosimeter Field Validation (Run #3, PEL #3,10-17-94}. Active Samples Pump ID 10374 10377 10375 10376 10372 10378 10389 10426 10430 10429 10428 10380 10427 10379 Sample ID 3-MCT^A 3-MCT-B 3-MCT-C 3-MCT-D 3-MCT-E 3-MCT-F 3-MCT-BLANK 3-CMS-A 3-CMS-B 3-CMS-C 3-CMS-D 3-CMS-H 3-CMS-F 3-C MS-BLANK Pre-Cal (mUmin) 20.62 20 20.67 20.47 20.79 20.27 19.9 19.56 20.36 20.29 20.88 19.89 20.9 20.66 Post-Cai Avg {mUmin) (mUmin) 19.95 2029 19.72 19.86 2042 20.55 20.4 20.44 20.37 20.58 20.2 B 20.28 19.62 19.76 1825 18.91 20.44 20.40 20.03 20.16 20.96 20.93 19.66 19.78 20.87 20.89 20.52 20.59 Sample Timefmin) 480 480 480 480 4B0 480 480 480 4B0 480 480 480 480 480 Total Vol(L) 9.74 9.53 9.86 9.81 9.88 9.73 9.48 9.07 9.79 9.68 10.05 9.49 10.02 9.88 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 1 37.6 0 38 1 31.4 0 31 1 28.3 0 28 1 26.8 0 27 1 26.6 1 28.9 1 2.78 0 0 0 27 29 3 0.976 33.8 0 35 0.976 0.976 41.2 30 0 0 42 31 0.976 30 0 31 0.976 0.976 0.976 27.3 32.8 5.78 0 0 0 2B 34 6 Desorption Volume (mL) 2mL 2mL 2mL 2m L 2mL 2mL 2mL 2mL ImL 2mL 2mL 2mL 2mL 2mL Concentration (ppm) 1.1 0.9 0.8 0.8 0.8 02 0.1 1.1 1.2 0.9 0.9 0.8 1.0 0.2 MCT Average Conc.= 0.9 Std. Dev.= 0.13 C.V.s 14.4% CMS Average Conc.s 1.0 Std. Dev.s 0.15 C.V.= 16.2% Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample ID 34)01 3-002 3-003 3-004 3-005 34)06 3-BLANK U1044(Biank) UI045 U1046 U1047 U104B U1049 U1060 VK04157C VK03670C VK0410BC VK04043C VK03948C VK03954C VK03844CBLK Sampling Rate(mUmin) 14.6 14.5 14.5 14.5 14.5 14.5 14.5 1.89 1.89 1.89 1.89 1.89 1.89 1.69 37.9 37.9 37.9 37.9 37.9 37.9 37.9 Sampling Time 480 480 4B0 480 480 480 4B0 480 480 4B0 480 480 480 480 480 480 480 480 480 4B0 480 Total Vol(L) 6.96 6.96 6.96 6.96 6.96 6.96 6.96 0.91 0.91 0.91 0.91 0.91 0.91 0.91 18.19 18.19 18.19 18.19 18.19 18.19 18.19 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 0.96 0.96 0.96 0.96 0.96 0.96 0.96 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.9 26.1 22.6 23.6 21.2 22.3 20.4 6.26 0 5.2 5.97 6.26 6.3 6.2 6.35 68.3 [a] [a] [a] la] [a] [a] - fa] la] [a] fa] fa] [a] [a] [a] 0 27 24 25 22 23 21 5 0 6 6 6 7 7 6 76 0.9 63 0 70 0.9 612 0 68 0.9 56.9 0 63 0.9 54.8 0 61 0.9 67.7 0 0.9 8.72 0 64 10 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL ImL ImL ImL ImL ImL ImL ImL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.6 mL 1.5 mL Corrected Total [b] 27 24 25 22 23 21 5 0 3 3 3 3 3 3 57 63 51 47 46 4B 7 Concentration T/P Corrected (ppm) Cone, (ppm) 1.1 1.1 1.0 1.0 1.0 1.0 0.9 0.9 1.0 1.0 0.9 0.9 0.2 02 0.0 0.0 0.9 0.9 1.0 1.0 0.9 0.9 1.1 1.1 1.1 1.1 0.9 0.9 0.9 0.9 0.8 0.8 0.B 0.8 0.8 0.8 0.7 0.7 0.8 0.8 0.1 0.1 SKC Average Conc.s 1.0 Std. Dev.= 0.09 C.V.s 8.83% l ASSAY Average Conc.s 1.0' Std. Dev.s 0.09 C.V.s B.74% 3M Average Conc.s 0.8 Std. Dev.= 0.07 C.V.= 8.14% [a] There ts only one section to these samples. [b] Corrected for desorption volume differences. Temperatures 20A degrees Celsius Pressures 7SO mm Hg_________ 3M 110660 Page 1 Sheets CO (T> cn Result* for Methylene Chloride Passive Dosimeter Field Validation (Run #4 STEL # 1,10-27-94). Active Samples Pump ID 10374 10377 10376 10376 10372 10378 10331 10426 10430 10429 10428 103B0 ' 10427 10379 Sample ID 4-MCT-A 4-MCT-B 4-MCT-C 4-MCT-O 4-MCT-E 4-MCT-F 4-MCT-BLANK 4-CMS-A 4-CMS-8 4-CMS-C 4-CMS-D 4-CMS-E 4-CMS-F 4-CMS-BLANK Pre- Cal (mUmin) 100.6 101 101.7 100.1 101.3 99.71 100.5 99.49 101.3 99.31 101.9 101.1 100.8 100.3 Post-Cal (mUmirO 101.1 100.9 101.1 101.3 101A 99.91 100.6 97.11 101.7 99.46 102.2 101.8 100.8 100 Avg (mUmtn) 100.85 100.95 101A0 100.70 101.35 99.81 100.55 98.30 101.60 99.39 102.05 101.45 100.80 100.16 Sample Time(min) 16 15 15 15 16 15 16 15 15 IS 16 15 15 15 Total Vol (L> 1.51 1.51 1.52 1.51 1.62 1.50 1.51 1.47 1.62 1.49 1.53 1.52 1.51 1.50 Desorption Efficiency 1 1 1 1 1 1 1 0.976 0.976 0.976 0.976 0.976 0.976 0.976 Analyzed amount (mcg/2mL) Front Back Total 1940 0 1940 2004 0 2004 1801 0 1801 1945 0 1945 1762 0 1762 1810 0 1810 00 0 1810 0 1855 2014 0 2064 1674 0 1716 1871 0 1917 1702 0 1744 1901 0 1948 00 0 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2ml. 2mL 2mL 2mL 2mL 2mL 2mL Concentration (ppm) 369.1 380.9 340.8 370.7 333.6 348.0 0.0 362.0 390.1 331.2 360.5 329.3 370.8 0.0 MCT Average Conc.= 357 Std. Dev.= 19.0 C.V.= 5.31*4 CMS Average Conc.= 357 Std. Dev.= 23.4 C.V.= 6.64*4 Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample ID 4-001 4-002 4-003 4-004 4-005 4-006 4-BLANK T0141(Blank) T0144 T0145 T0146 T0147 T0148 T0149 VK 03788C VK03663C VK03692C VK 0371SC VK03653C VK03769C VK03754C BLK Sampling RatefmUmin) 14.6 14.5 14.5 14.5 14.5 14.5 14.5 7.57 7.57 7.67 7.57 7.57 7.57 7.57 37.9 37.9 37.9 37.9 37.9 37.9 37.9 Sampling Time 15 15 15 15 IS 15 15 15 15 15 15 15 16 15 15 15 15 15 16 16 15 Total Vol (L) 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.67 0.57 0.57 0.57 0.67 0.57 0.57 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 0.96 321 M 334 0.96 277 [a] 289 0.96 305 la) 31B 0.96 303 [a] 316 0.96 279 [a] 291 0.96 282 [a] 294 0.96 0 (a) 0 0.92 0 [a] 0 0.92 289 [a] 314 0.92 292 [a] 317 0.92 301 la] 327 0.92 271 [a] 295 0.92 258 [a] 280 0.92 277 M 301 0.9 870 0 967 0.9 869 0 966 0.9 813 0 903 0.9 753 0 B37 0.9 790 0 878 0.9 768 0 853 0.3 0 0 0 Desorption Volume (mL) 2mL 2m L 2mL 2mL 2mL 2m L 2mL ImL ImL ImL ImL ImL ImL ImL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.6 mL 1.5 mL Corrected Total fb] 334 289 318 316 291 294 0 0 157 159 164 147 140 161 725 724 678 628 658 640 0 Concentration (ppm) 442.5 381.9 420.5 417.7 384.6 388.8 0.0 0.0 398.2 402.3 414.7 373.4 365.6 381.6 367.1 366.7 343.0 317.7 333.3 324.1 0.0 T/P Corrected Cone, (ppm) 449.7 388.0 427.3 424.5 390.8 395.0 0.0 0 404.6 408.8 421,4 379.4 361.2 387.8 370.8 370.3 346.6 320.9 336.7 327.3 0.0 SKC Average Conc.= 413 Std. Dev.= 25.0 C.V,= 6.05% 1 ASSAY Average Conc.e 394 Std. Dev.* 22.0 C.V.a 6.57% 3M Average Conc.= 345 Std. Dev.= 21.3 C.V.= 6.17% [a] There is only one section to these samples. [b] Corrected for desorption volume differences. Temperature^ 21.1 degrees Celsius _____________ Pressure= 757 mm Hg_________ Page 1 Sheets Results for Methylene Chloride Passive Dosimeter Field Validation (Run # 5, PEL #4,10-31-94). Active Samples Pump rc* i1n0v3i7A4 10377 10375 10376 10372 10378 10391 10426 10427 10429 10428 10430 103B0 10379 Sample IP c5-MuCrrT.-A 5-MCT-8 5-MCT-C 5-MCT-D 5-MCT-E 6-MCT-F S-MCT-BLANK 6-CMS-A 6-CMS-fl 5-CMS-C 5-CMS-D 5-CMS-E 6-CMS-F 6-CMS-BLANK Pre-Cal (mLfmin) m19.83i 19.76 20.33 20.5 20.33 20.14 20.62 19.78 20.26 20.11 20.2 19.93 20.64 20.17 Post-Cal (mLfmin) 19.49 20.87 19.97 20.88 19.63 20.23 20.43 19.16 20.33 20.48 21.85 20.19 20.72 20.39 Avg (mLfmin) m19i.-6g6 20.32 20.15 20.69 19.98 20.19 20.53 1947 20.29 20.30 21.03 20.01 20.68 20.28 Sample Total Time(min)_____ Vol (L) 480 ~ ' " 944 480 9.75 480 9.67 480 9.93 480 9.69 480 9.69 480 9.86 480 9.35 480 9.74 480 9.74 480 10.09 480 9.60 480 9.93 480 9.73 Desorption Analyzed amount (mcg/2mL) Efficiency 1' Front .2IT12--5 Back 0- Total ______ 2125 1 2050 0 2050 1 2102 0 2102 1 2160 0 2160 1 2143 0 2143 1 2071 0 2071 11 0 1 0.976 2179 0 2233 0.976 2496 0 2567 0.976 2160 0 2213 0.976 2245 0 2300 0.976 2623 0 2688 0.976 2105 0 2167 0.976 1 0 1 Desorption Volume ImL) ' ' 2mL 2m L 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2m L 2mL 2mL 2mL Concentration (ppm) _. _ 64.3 60.5 62.6 62.6 64.3 61.6 0.0 68.8 75.6 66.4 65.6 80.5 62.5 0.0 MCT Average Conc.= 62.7 Std. Dev.= 1.63 C.V.= 2.60% CMS Average Conc.= 69.7 Std. Dev.= 6.92 C.V.s 9.93% Passive Dosimeters Sample Type Sample ID SKC 6-001 SKC SKC SKC SKC SKC SKC 6-002 6-003 6-004 S-005 6-006 6-BLANK ASSAY U1004{Blank) ASSAY UI006 ASSAY U1011 ASSAY U1018 ASSAY ASSAY ASSAY U1019 U1041 U1043 3M VK 03941C 3M VK 03904C 3M VK03992C 3M VK 03963C 3M VK 03718C 3M VK 03970C 3M VK 03598C BL Sampling Rate{ mLfmin) 14.5 14.5 14.5 14.6 14.5 14.5 14.6 1.89 1.89 1.89 1.89 1.89 1.89 1.89 37.9 37.9 37.9 37.9 37.9 37.9 37.9 Sampling Time 480 480 4B0 480 480 480 4B0 480 480 480 480 480 480 480 4B0 480 480 480 4B0 480 480 Total Vol (L) 6.96 6.96 6.96 6.96 6.96 6.96 6.96 0.91 0.91 0.91 0.91 051 0.91 0.91 18.19 1B.19 1B.19 18.19 18.19 18.19 18.19 Desorption Efficiency 0.96 0.96 0.96 0.96 0.96 0.96 0.96 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.9 0.9 0.9 0.9 0.9 0.9 0.9 Analyzed amount (mcgf2mL) Front Back Total 1539 1610 1433 1668 1515 1471 1 W 1603 [a] 1573 (a) 1493 [a] 1633 la] 1678 fa] 1532 fa] 1 0 331 333 353 335 342 332 3628 [a] 0 fa] 360 [a] 362 fa] 3B4 [a] 364 fa] 372 fa] 361 248 4637 3740 268 4811 3506 332 4707 3466 248 4457 3519 325 4704 3905 282 502B 0 00 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL ImL ImL ImL ImL ImL ImL ImL 1.5 mL 1.5 mL 1.5 mL 1.6 mL 1.5 mL 1.5 mL 1.5 mL Corrected Concentration TIP Corrected Total fb] (ppm) Cone, (ppm) 1603 66.3 67.1 1573 1493 1633 1578 65.1 61.7 67.6 65.3 65.9 62.5 68.4 66.1 1532 1 63.4 0.0 64.2 0.0 0 0.0 0.0 180 57.1 181 57.4 57.8 58.1 192 60.9 61.6 182 57.8 186 59.0 180 57.3 58.5 59.7 68.0 3478 55.0 55.6 3608 3630 57.1 55.9 57.7 56.4 3343 62.9 53.4 3528 3771 0 55.8 59.7 0.0 56.4 60.3 0.0 SKC Average Conc,= E5.7 Std. Dev.= 2.10 C.V.= 3.20% | ASSAY Average Cone.9: 59.0 Std. Dev.= 1.48 C.V.s 2.51% 3M Average Conc.= 56.6 Std. Dev.= 2.27 C.V.= 4.01% [a] There is only one section to these samples. [b] Corrected for desorption volume differences. Temperatures 19.4 degrees Celsius Pressures 748 mm Hg_________ 3M 110662 Pago 1 Sheet7 Results for Methylene Chloride Passive Dosimeter Field Validation (Run #6 STEL # 2,11-2-94). Active Samples Pump ID 10374 10377 10375 10376 10372 10378 10391 10379 10380 10426 10427 10428 10429 10430 Sample ID 6-MCT-A 6-MCT-B 6-MCT-C 6-MCT-O 6-MCT-E 6-MCT-F 6-MCT-BLANK 6-CMS-A 6-CMS-B 6-CMS-C 6-CMS-D 6-CMS-E 6-CMS-F 6-CMS-BLANK Pre-Cal (mL/mln) 100.8 100.5 100.1 101.S 99.97 100.2 100.9 100.1 100.2 100.1 101.2 100 101.4 99.74 Post-Cal (mL/min) 100.9 101 99.62 100.96 99.16 99.62 100.8 100.5 100.4 99.55 100.9 99.52 101.1 99.73 Avg (mLfmin) 100.85 100.76 99.85 101.23 99.67 99.91 100.B5 100.30 100.30 99.83 101.05 99.76 101.26 99.74 Sample Timefmin) 15 IS 15 15 16 16 15 16 IS 16 IS 15 15 15 Total Vol (L) 1.51 1.61 1.50 1.52 149 1.50 1.51 1.60 1.50 1.50 1.62 1.60 1.62 1.60 Desorption Analyzed amount (mcgflmL) Efficiency Front Back Total 1 609 0 609 1 347 0 347 1 493 0 493 1 456 0 456 1 809 0 809 1 440 0 440 1 3.3 0 3 0.976 602 0 614 0.976 336 0 344 0.976 468 0 469 0.976 406 0 416 0.976 710 0 727 0.976 409 0 419 0.976 8.08 0 8 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2m L 2mL 2mL 2mL 2mL 2mL 2mL Concentration (ppm) 116.9 66.1 94.7 86.4 165.9 84.5 0.6 98.4 65.9 90.2 79.0 139.9 79.4 1.6 MCT Average Conc.= 100.6 Std. Dev.s 31.56 C.V.= 31.4V. CMS Average Conc.s 92.1 Std. Dev.- 25.89 C.V.= 28.1% Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample ID 6-001 6-002 64)03 6-004 6-005 6-006 6-BLANK T-BIk T0069 T0060 T0098 T0099 T0100 T0142 VK03544C VK 0364SC VK03625C VK03673C VK03674C VK03716C VK 03474C BLK Sampling Rate(mUmin) 14.5 14.5 14.5 14.5 14.5 14.5 14.5 7.67 7.67 7.57 7.67 7.67 7.57 7.67 37.9 37.9 37.9 37.9 37.9 37.9 37.9 Sampling Time 15 15 15 15 15 15 16 15 16 15 15 16 15 16 15 15 15 15 16 15 15 Total Vol (L) 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.57 0.57 0.67 0.57 0.57 0.57 0.57 Desorption Analyzed amount (mcgl2mL) Efficiency Front Back ToUl 0.96 71.2 [a] 74 0.96 0.96 0.96 0.96 0.96 0.96 94.9 94.4 61.2 62.6 79.3 0 H [a] [a] Ca] ta] [a] 99 98 64 65 83 0 0.92 0 [a] 0 0.92 0.92 92.4 110 fa] [a] 100 120 0.92 0.92 0.92 67.1 B1.9 76.5 [a] [a] [a] 62 89 83 0.92 28.7 ta] 31 0.9 360 0 389 0.9 223 0 248 0.9 232 0 25B 0.9 297 0 330 0.9 175 0 194 0.9 205 0 228 0.9 0 0 0 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL ImL ImL ImL ImL ImL ImL 2mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.6 mL 1.5 mL 1.5 mL Corrected Total [b] 74 99 98 64 65 83 0 0 50 60 31 45 42 31 292 186 193 248 146 171 0 Concentration T/P Corrected (PPm) Cone, (ppm) 98.2 95.0 130.8 130.1 126.6 125.9 84.4 61.6 86.3 109.3 0.0 83.5 105.8 0.0 0.0 0.0 127.3 161.6 123.2 146.6 78.7 76.1 112.8 1054 79.1 109.2 102.0 76.3 147.7 146.2 94.1 93.2 97.9 96.9 125.3 124.1 73.8 73.1 86.5 85.6 0.0 0.0 SKC Average Conc.s 103.1 Std. Dev.= 19.95 C.V.= 19.4% 1 ASSAY Average Conc.s 105.6 Std. Dev.= 27.37 C.V.s 26.9% 3M Average Conc.= 103.2 Std. Dev.= 26.98 C.V.s 26.1% [a] There is only one section to these samples. |b) Corrected for desorption volume differences. Temperatures 3t .2 degrees Celsius ____________ Pressures 756 mm Hg_________ 99011 Page 1 Sheets Results for Methylene Chloride Passive Dosimeter Field Validation (Run # 7, PEL # 5,11-07-94). Active Sample* Pump ID 10374 10377 10376 10376 10372 10378 10391 10380 10426 10427 10428 10429 10430 10379 Sample ID 7-MCT-A 7-MCT-B 7-MCT-C 7-MCT-D 7-MCT-E 7-MCT-F 7-MCT-BLANK 7-CMS-A 7-CMS-B 7-CMS-C 7-CMS-D 7-CMS-E 7-CMS-f 7-CMS-BLANK Pre- Cal (mUmin) 19.77 20.34 19.88 20.16 20.31 20.05 20.33 20.73 19.7 19.83 20.7 20.03 20.27 19.96 Post-Cal (mUmin) 20.46 20.74 19.14 19.82 16.35 19.81 20.12 20.92 17.63 20.14 20.5 20.59 20.42 19.72 Avg (mUmin) 20.12 20.64 19.61 19.99 18.33 19.93 20.23 20.83 18.67 19.99 20.60 20.31 20.35 19.84 Sample Time(min) 480 480 480 480 4B0 480 480 480 480 480 480 480 480 480 Total Vol (L) 9.66 9.86 9.36 9.69 8.80 9.57 9.71 10.00 8.96 9.69 9.89 9.75 9.77 9.52 Desorption Analyzed amount (mcg/2mL] Efficiency Front Back Total 1 110 0 110 1 10B 0 108 1 94.7 0 95 1 105 0 106 1 B8.3 0 88 1 110 0 10 0 110 0 0.976 0.976 102 129 0 0 105 132 0.976 111 0 114 0.976 112 0 115 0.976 111 0 114 0.976 111 0 114 0.976 3.23 0 3 Desorption Volume (mL) 2m L 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2m L 2mL Concentration (ppm) 3.3 3.2 2.9 3.2 2.9 3.3 0.0 3.0 4.2 3.4 3.3 3.4 3.4 0.1 MCT Average Cone.= 3.1 Std.Dev.s 0.18 C.V.= 5.75% CMS Average Conc.= 3.6 Sid. Dev.s 0.41 C.V.= 12.0% Passive Dosimeters Sample Type Sample ID SKC SKC SKC 7-001 7-002 7-003 SKC SKC SKC SKC 7-004 7-005 7-006 7-BLANK ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY U1031 (Blank) UI032 U1033 U1034 U1035 U1036 U1037 3M VK 03567C 3M VK03570C 3M VK03834C 3M VK038S3C 3M VK 03862C 3M VK03864C 3M VK 03526C BLK Sampling RatefmUmin) 14.5 14.5 14.5 14.6 14.5 14.5 14.5 1.89 1.89 1.89 1.89 1.89 1.89 1.89 37.9 37.9 37.9 37.9 37.9 37.9 37.9 Sampling Time 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 Total Vol (L) 6.96 6.96 6.96 6.96 6.96 6.96 6.96 0.91 0.91 0.91 0.91 0.91 0.91 0.91 18.19 18.19 18.19 18.19 18.19 18.19 18.19 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 0.96 0.96 0.96 0.96 0.96 0.96 0.96 89.8 88.7 95.7 96.5 90.8 94.7 0 [a] [a] [a] [a] [a] [a] [a] 94 92 100 101 95 99 0 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0 22.7 16.6 15.7 21.1 19.7 20.8 [a] [a] [a] ta] [a] [a] [a] 0 25 18 17 23 21 23 0.9 228 0 253 0.9 233 0 259 0.9 221 0 246 0.9 220 0 244 0.9 233 0 259 0.9 233 0 259 0.9 5.67 0 6 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL ImL ImL ImL ImL ImL ImL ImL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL Corrected Total [bj 94 92 100 101 95 99 0 0 12 9 9 11 11 11 190 194 184 183 194 194 5 Concentration (ppm) 3.9 3.8 4.1 4.2 3.9 4.1 0.0 0.0 3.9 2.9 2.7 3.6 3.4 3.6 3.0 3.1 2.9 2.9 3.1 3.1 0.1 TIP Corrected Cone, (ppm) 3.9 3.9 4.2 4.2 4.0 4.2 0.0 0.0 4.0 2.9 2.8 3.7 3.5 3.7 3.0 3.1 2.9 2.9 3.1 3.1 0.1 SKC Average Conc.= 4.1 Std. Dev.= 0.15 C.V.= 3.59% ASSAY | Average Conc.= 3.4 Std. Dev.= 0;48 C.V.= 14.1% 3M Average Conc.= 3.0 Std. Dev.s 0.08 C.V.= 2.69% [a] There is only one section to these samples. [b] Corrected for desorption volume differences. Temperature- 21.2 degrees Celsius ____________ Pressures 759 mm Hg__________ W901L hp Page 1 Results for Methylene Chloride Passive Dosimeter Field Validation (Run # 8, STEL # 3,12-5-94). Active Samples Pump ID 10374 10375 10376 10377 1037S 10379 3260 10391 10429 1042S* 10426 10360 10389 10430 * Sample ID Pre-Cal (mUmln) Post-Cal (mUmln) 8-MCT-A 102.1 100.6 8-MCT-8 102.1 100.3 8-MCT-C 103.2 1014 B-MCT-D 98.71 98.73 8-MCT-E 104.1 103.5 8-MCT-F 8-MCT-BLANK 101.1 98.47 99.19 99.4 8-CMS-A 98.6 98.16 8-CMS-8 B-CMS-C* 8-CUS-D 8-CMS-E 8-CMS-F 97.S 9B.6 100.5 1014 98.3 95.95 102.5 100.1 101 97.13 B-CMS-8LANK 99.17 96.72 This pump faulted out during the run. Avg (mUmln) 101.30 101.20 102.30 98.72 103.80 100.15 98.94 98.38 96.73 100.55 100.30 101.20 97.72 97.95 Sample Time(mln) 16 15 15 15 IS 16 15 IS 15 16 15 IS IS IS Total Vol <L) 1.S2 1.62 1.53 1.48 1.S6 1.60 1.48 1.48 145 1.51 1.50 1.62 147 147 Desorptlo Analyzed amount (mcg/2mL) Efficiency Front Back Total 1 79.3 0 79 1 75 0 76 1 69.2 0 69 1 87.3 0 87 1 74.2 0 74 1 70.5 10 0 0 71 0 0.976 0.976 75.7 63.9 0 0 78 66 0.976 0.976 0.976 9.69 73.6 68.6 0 0 0 10 75 70 0.976 0.976 61.4 0 0 0 63 0 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2m L 2m L 2mL 2mL 2m L 2m L 2ml. 2mL 2mL Concentration (PPm) 15.0 14.2 13.0 17.0 13.7 13.5 0.0 15.1 13,0 1.9 14.4 13.3 12.4 0.0 MCT Average Conc.= 144 Std. Dev.= 1.44 C.V.= 9.96% CMS Average Conc.= 13.6 Std. Dev.= 1.12 C.V.= 8.2% Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample ID 8-001 8-002 8-003 8-004 8-005 8-006 8-BLANK T0047(BJank) T0091 T0092 T0093 T0095 TOO96 T0097 VK03504C VK 03669C VK03572C VK03697C VK03840C VK04003C VK03533C BLK Sampling RatefmUmln) 14.5 14.5 14.6 14.6 14.5 14.5 14.5 7.57 7.57 7.67 7.67 7.67 7.67 7.S7 37.9 37.9 37.9 37.9 37.9 37,9 37.9 Sampling Time 15 16 15 16 16 16 16 16 IS IS 15 16 16 15 16 16 16 IS IS 16 15 Total Vol (L) 0.2176 02175 0.2175 0.2176 0.2175 0.2175 0.2176 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.67 0.67 0.67 0.57 0.S7 0.57 0.57 Desorption Efficiency 0.96 0.96 0.96 0.96 0.96 0.96 0.96 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.9 0.9 0.9 0.9 0.9 0.9 0.9 Analyzed amount (mcg)2mL) Front Back Total 12.2 11.2 [a] 13 12 11.4 11.3 10.2 11.3 0 0 11.1 10.6 10.7 10 9.7 10.3 35.2 [a] (a] (a] la] .. la] [a] [a] ll (a] la] [a] Ta] 0 12 12 11 12 0 0 12 12 12 11 11 11 39 34.1 0 38 32.8 0 36 32.9 0 37 31.7 0 35 31.7 0 36 0 00 Desorption Corrected Volume (mL) Total [b] 2m L 13 2mL 12 2mL 12 2mL 12 2mL 2mL 2mL 11 12 0 ImL ImL ImL 0 s 6 ImL 6 ImL 6 ImL ImL 6 6 1.5 mL 29 1.6 mL 2B 1.5 mL 27 1.6 mL 27 1.5 mL 26 1.6 mL 1.5 mL 26 0 Concentration (ppm) 16.8 15.4 16.7 16.6 14.1 15.6 0.0 0.0 15.3 14.6 14.7 13.8 13.4 14.2 14.9 144 13.8 13.9 134 13.4 0.0 TIP Corrected Cone, (ppm) 17.1 15.7 16.0 15.8 14.3 15.8 0.0 0.0 15.5 14.8 16.0 14.0 13.6 144 15.0 14.5 14.0 14.0 13.5 13.6 0.0 SKC Average Conc.= 15.8 Std. Dev.= 0.89 C.V.= 5.66% ASSAY , Average Conc.= 14.6 Std. Dev.= 0.71 C.V.= 4.87% 3M Average Conc.= 14.1 Std. Dev.s 0.59 C.V.= 4.16% [a] There Is only one section to these samples. [bj Corrected for desorption volume differences. Temperatures 19.9 degrees Celsius __________ Pressures 752 mm Hg_________ Page 1 Sheetl 0 Results for Methylene Chloride Passive Dosimeter Field Validation (Run # 9, STEL # 4,12-14-94). Active Samples Pump ID 10374 10375 10376 10377 1037B 10379 10380 10391 10426 10427 10428 10429 10430 10389 Sample ID 9-MCT-A 9-MCT-B 9-MCT-C 9-MCT-D 9-MCT-E 9-MCT-F 9-MCT-BLANK 9-CMS-A 9-CMS-B 9-CMS-C 9-CMS-D 9-CMS-E 9-CMS-F 9-CMS-BLANK Pre- Cal Post-Cal Avg (mUmln) (mUmln) (mUmin) 99.84 98.37 99.11 99.23 96.9 98.07 102.7 100.5 101.60 101.9 96.76 99.33 102.1 99.65 100.88 101.8 100.5 101.15 100.5 98.73 99.62 100.7 101.7 10120 100.7 100.8 99.02 100.4 101.2 97.88 100.55 101.00 98.46 101.7 100.1 100.9 99.9 101.30 100.00 99.15 96.85 98.00 Sample Tlme(min) 15 15 15 IS IS 15 IS 15 15 16 16 15 15 15 Total Vol (L) 1.49 1.47 1.52 1.49 1.51 1.52 1.49 1.62 1.51 1.52 1.48 1.62 1.50 1.47 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 1 618 0 618 1 460 0 460 1 65B 0 658 1 43B 0 433 1 775 0 776 1 692 0 592 10 0 0 0.976 0.976 607 374 0 0 622 383 0.976 0.976 609 467 0 0 624 478 0.976 0.976 0.976 724 423 0 0 0 0 742 433 0 Desorption Volume (mL) 2m L 2mL 2mL 2mL 2mL 2mL 2mL ' 2mL 2m L 2mL 2mL 2mL 2mL 2m L Concentration (ppm) 119.7 90.0 124.3 B4.6 147.4 112.3 0.0 117.9 73.1 118.8 93.3 140.5 B3.2 0.0 MCT Average Conc.= 113.1 Std. Dev.3 2320 C.V.= 20.52% CMS Average Cone.3 104.4 Std. Dev.3 25.46 C.V.= 24.4% Passive Dosimeters Sample Type SKC SKC SKC SKC SKC SKC SKC ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY ASSAY 3M 3M 3M 3M 3M 3M 3M Sample Sampling Sampling ID ate(mUml Tfme 9-001 14.5 15 9-002 14.6 15 9-003 14.5 IS 9-004 14.5 15 9-005 14.5 IS 9-006 14.6 15 9-BLANK 14.5 IS T0041 (Blank) 7.57 IS T0O42 7.57 15 T0044 7.57 15 T0045 T0O46 7.67 IS 7.57 IS T0048 7.57 15 T0050 7.57 15 VK 035B8C 37.9 IS VK03630C 37.9 15 VK03B39C 372 15 VK03956C 37.9 15 VK04070C 37.9 IS VK04119C 37.9 15 VK 03599C BLK 37.9 15 Total Vol (L) 02175 02175 02175 0.2175 0.2176 02175 0.2t75 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.57 0.57 0.57 0.57 0.57 0.57 0.57 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Totar 0.96 0.96 0.96 0.96 0.96 0.96 0.96 75.6 90.1 78.8 72.4 102.2 87.1 0 ta] la] (a) 1*1 (a] [a] [a] 79 94 82 76 106 91 0 0.92 0.92 0 87.1 1*1 [a) 0 95 0.92 73.9 [a) B0 0.92 0.92 72.8 87.6 [a] (a) 79 95 0.92 782 la) B5 0.92 65.2 t*l 71 0.9 196 0 218 0.9 191 0 212 0.9 214 0 238 0.9 200 0 222 0.9 184 0 204 0.9 237 0 263 0.9 0 0 0 Desorption Corrected Volume (mL) Total fb| 2mL 79 2m L 2mL 94 82 2mL 75 2m L 106 2mL 91 2mL 0 ImL 0 ImL 47 ImL 40 ImL ImL 40 48 ImL 43 ImL 35 1.6 mL 163 1.5 mL 159 1.5 mL 178 1.5 mL 167 1.5 mL 153 1.5 mL 1.6 mL 196 0 Concentration TIP Corrected (ppm) Cone, (ppm) 1042 104.3 1242 1242 108.6 106,7 99.8 99.8 140.9 140.9 120.1 120.1 0.0 0.0 0.0 120.0 0.0 120.0 101.8 101.8 100.3 100.3 120.7 120.7 107.7 107.8 83.8 89.9 82.7 82.7 80.6 80.6 90.3 90.3 84.4 84.4 77.6 77.6 100.0 100.0 0.0 0.0 [a] There Is only one section to these samples. |b] Corrected for desorption volume differences. Temperature3 21 .B degrees Celsius ___________ Pressure3 748 mm Hg_________ SKC Average Cone.3 116.3 Std. Dev.3 1522 C.V.3 13.09% ASSAY Average Conc.= 106.8 Std. Dev.3 12.03 C.V.= 11.3% 3M Average Cone.3 85.9 Std. Dev.3 8.09 C.V.s 9.41% Page 1 Sheelll OJ o cn xj Results for Methylene Chloride Passive Dosimeter Field Validation (Run #10, STEL # 5,1-10-95). Active Samples Pump ID 10374 10375 10376 10377 10378 10379 10380 10391 10426 10427 10428 10429 10430 10389 Sample ID 10-MCT-A 1044CT-B 10-MCT-C 10-MCT-D 10-MCT-E 10-MCT-F 10-MCT-BLANK 10-CHS-A 10-CMS-B 10-CMS-C 10-CHS-D 10-CMS-E 10-CMS-F 10-CMS-BLANK Pre-Cal (mUmln) 102.2 100.9 99.21 99.49 100.4 100.4 101.9 99.92 101.7 99.29 97.19 100.7 100.3 100.4 Post-Cai Avg (mUmln) (mUmln) 102.9 102.55 99.37 100.14 100.4 99.81 100.9 100.20 100.6 100.60 100 100.20 100.2 101.05 99.38 99.65 90.07 95.89 96.94 95.41 98.12 96.30 101.2 102.1 100.95 101.20 101.2 100.80 Sample Tlme(mln) 16 . 15 15 15 15 15 15 15 15 IS IS 15 15 15 Total Vol(L) 1.54 1.50 1.50 1.50 1.61 1.60 1.52 1.49 1.44 1.47 1.44 1.61 1.62 1.51 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 1 496 0 496 1 504 0 504 1 433 0 493 1 523 0 523 1 487 0 487 1 520 0 520 1 13.7 0 14 0.976 606 0 618 0.976 466 0 476 0.976 468 0 480 0.976 0.976 513 613 0 0 526 526 0.976 530 0 643 0.976 13.2 0 14 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2mL 2m L 2mL 2mL 2mL 2m L 2m L Concentration (PPm) 92.8 96.6 94.8 100.2 93.0 99.6 2.6 99.8 95.4 93.8 104.7 99.9 103.0 2.6 MCT Average Cone.? 96.2 Std. Dev.? 3.20 C.V.= 3.32% CMS Average Cone.? 99.4 Std. Dev.? 4.23 C.V.? 4.3% Passive Dosimeters Sample Sample Sampling Sampling Type ID RatefmUmln) Time SKC 10-001 14.6 15 SKC 10-002 14.5 IS SKC 10-003 14.5 15 SKC 10-004 14.6 16 SKC 10-005 14.5 16 SKC 104)06 14.5 16 SKC 10-BLANK 14.5 15 ASSAY ~V0O43(Blanlt) 7.57 15 ASSAY U1012 7.57 15 ASSAY U1013 7.57 16 ASSAY U1014 7.67 IS ASSAY U1017 7.57 15 ASSAY U102Q 7.67 IS ASSAY U1038 7.67 IS 3M VK 03767C 37.9 16 314 VK03884C 379 16 3M VK03905C 37.9 15 3M VK03936C 37.9 15 3M VK03972C 37.9 15 3M VK03991C 37.9 15 3M VK 035S4C BLK 37.9 15 Total Vol(L) 0.2175 0.2175 0.2175 02175 0.2175 0.2175 0.2175 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.57 0.57 0.57 0.67 0.57 0.57 0.57 Desorption Analyzed amount (mcg/2mL) Efficiency Front Back Total 0.96 0.96 0.96 0.96 0.96 0.96 0.96 93.3 78,3 84.3 82.6 77.4 83.1 0 [6] [a] [a] la) [a] M (a) 97 82 88 86 81 67 0 0.92 0.92 0.92 022 0.92 0.92 0.92 0.9 0 74.9 80.8 84.B 77.9 78.2 76.7 210 ta] [a] [a] la] Ea] [a] ta] _ 0 0 81 88 92 85 85 83 233 02 212 0 236 0.9 212 0 236 0.9 212 0 236 0.9 219 0 243 0.9 180 0.9 6.62 0 0 200 7 Desorption Volume (mL) 2mL 2mL 2mL 2mL 2mL 2mL 2m L ImL ImL ImL ImL ImL ImL ImL 1.6 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.5 mL 1.6 mL Corrected Total (b) 97 B2 88 86 81 87 0 0 41 44 46 42 43 42 176 177 177 177 183 150 6 Concentration TIP Corrected (ppm) Cone, (ppm) 128.6 127.8 107.9 107.2 116.2 115.5 113.9 113.1 106.7 106.0 114.6 0.0 113.8 0.0 0.0 0.0 103.2 102.5 111.3 110.6 116.8 107.3 116.1 106.6 107.7 107.0 105.7 106.0 88.6 88.6 89.6 89.5 89.5 89.5 89.5 89.5 92.4 92.4 75.9 75.9 2.8 2.8 [a] There Is only one section to these samples. [b] Corrected for desorption volume differences. Temperature? 23.1 degrees Celsius ____________ Pressure? 748 mm Hg_________ SKC Average Cone.? 113.9 Std. Dev.? 7.78 C.V.? 8.83% ASSAY Average Cone.? 108.0 Std. Dev.? 4.77 C.V.? 4.4% 3M Average Cone.? 87.6 Std. Dev.? 5.83 C.V.? 6.66% Page 1 FIELD VALIDATION OF PASSIVE DOSIMETERS FOR THE DETERMINATION OF EMPLOYEE EXPOSURES TO METHYLENE CHLORIDE ALONG WITH OTHER ORGANIC VAPORS IN HOSPITAL PRODUCTS PRODUCTION FACILITIES Proposed Validation Study: March 15, 1995 Kem Charron and Mark Puskar Corporate Industrial Hygiene Laboratory, Abbott Laboratories Introduction: To increase the ability of Abbott's industrial hygiene staff to collect data on employee exposures to multiple organic vapors in conjunction with Methylene Chloride (MeC12), the Corporate Industrial Hygiene Laboratory (CIHL) has committed itself to performing a "peer-review-quality" field validation of passive dosimeters for long-term (PEL) exposures to multiple components. The goal of this validation project will be to determine if a passive dosimeter can replace our current active method (600 mg Charcoal tube), for the determination of employee exposures to multiple organic vapors of which MeC12 is one of the components. The other organic solvents which may potentially be present are: acetone, chloroform, cyclohexanone, ethanol, ethyl acetate, Freon-113, heptane, methyl ethyl ketone, 2-propanol, toluene, 1,1,1-trichloroethane and trichloroethylene. Due to the complexity of this study, only area samples will be studied. No personal data will be collected. To enhance the strength of this study, manufacturers of passive dosimeters are requested to take part in this investigation. However, this is strictly optional and the study will be conducted with or without the manufacturers' participation. The proposed validation will include three types of passive dosimeters, each from a different manufacturer. The manufacturers/vendors include: Assay Technologies, 3M, and SKC. Each brand of monitor uses proprietary collection systems and a different methylene chloride extraction technique, however GC-FID analysis is similar to all the monitors. During the field validation exposures, air samples will be concurrently collected on 600 mg Charcoal tubes. Temperature, pressure, air velocity and humidity readings will be recorded at each sampling location. 3M 110669 Validation Study Design: Abbott's Hospital Products Division (HPD), in Laurinburg, NC has been selected as the location to validate the methods because of two reasons: (1) the first reason is its location. The HPD facility is located in North America. This will allow the field validation to be performed within the Continental United States. (2) recent data suggest that there are multiple organic solvents present with MeC12 concentrations over a wide range. This will allow the method to be tested over the full range of MeC12 concentrations expected in other locations of the corporation. Based on previous air monitoring results, 5 sampling locations in HPD's solvent sealing facility will be selected to test the full concentration range of MeC12 with multiple organic solvent concentrations for PEL monitoring. The approximate concentrations to be studied are: PEL: 8-hr TWA Samples Location Number Ideal Concentration in ppm MeCl 1 <10 2 10 3 25 4 50 5 >50 An exposure chamber has been built to expose an array of samples at each sampling location. Below is a list of the samples which will be collected at each of the 5 locations: 2 3M 110670 Samples to be Collected at Each Location Number of Samples 6 6 6 6 Type Assay Technologies: MeCl Monitor 3M: MeCl Monitor SKC: MeCl Monitor Charcoal Active Samples Frequency of Collection 8-hr 8-hr 8-hr 8-hr 1 Temperature 1 Humidity 1 Pressure 1 Air Velocity randomly randomly randomly randomly To accurately field validate MeCl monitors, two major problems must be overcome. The first problem is that a system must be developed where all monitors are turned on and off simultaneously. The second problem is that unique organic solvent concentrations may exist around different samples at the same location. If so, this must be understood, otherwise a false increased precision error would be added to all methods. These two effects will be limited with the exposure chamber designed and built. This exposure chamber was developed and built for an EtO EL study which was previously performed. [1,2]. The chamber features a two dimensional array stand for dosimeter exposure mounted inside a Plexiglas chamber. The height of the dosimeters can be adjusted so each active exposure area is on the same horizontal plane. The Plexiglas cover can be removed once the chamber is in the sampling area, so all the dosimeters can be exposed at once. Once sampling is completed and the hood is placed back over the sampling array and sealed down (dual Teflon gaskets), the inside can be purged with organic solvent free compressed air to remove residual solvent. This residual solvent and excess purge air vent through the one way values mounted on the top of the chamber. This design should allow equal exposure of all the dosimeters for the same sampling time. During each dosimeter exposure, six 600 mg Charcoal tubes will be sampled from six points circling the dosimeter array. Four of the sampling points are at each of the four comers of the dosimeter exposure horizontal plane. Point five is above the plane 4 inches and point 6 is below the plane 4 inches. These six charcoal tubes will be analyzed with the dosimeters and used to determine the actual concentration present and to determine if unique atmospheres may have existed at unique sampling location during the sample collection. 3 3M Collection Strategy: The following collection strategy will be followed at each location studied. 1. The Purged/MeCl Free Chamber will be opened in an organic solvent free area (< 0.1 ppm by GC-FID). Blanks will be opened and left in the organic solvent free area during the exposure to document that the area is free of organic solvents. 2. Monitors will be hung randomly across the two dimensional grid. The active sampling methods will be setup and connected to their pumps. 3. The chamber will be closed and MeCl-free air will be purged through the chamber during the chamber movement process from the clean area to the exposure area. 4. Once in the exposure area, the chamber will be opened and all the pumps will be started. Exposure time will be 480 minutes. 5. After exposure, the lid will be placed over the sampling grid and locked down. The purge air will be turned on and all sampling pumps will be turned off. The air flow rate will be sufficient to cause three complete air changes in the first 30 seconds. 6. The purge air will remain on until the chamber is successfully back in the organic solvent free area (<5 min.). The chamber will be opened and the samples will be removed. 7. All monitors will be Federal Expressed Over-night-air shipped to the CIHL. 8. All monitors will be stored in the CIHL according to manufacturer's instruction and analyzed within 2-week of collection. Calibration of Equipment: Gilian pumps will be used to collect the active samples. The Gilian pumps will be individually calibrated using a Gilibrator Primary Flow Calibrator. Analysis of Samples: All passive monitors will be extracted using the manufactures' instructions and will be analyzed using Hewlett Packard 5890 Series II GC-FID. Separation will be performed using a 100m PONA 0.2 mm ID column. Standards will be prepared in CS2 and laboratory MeCl QA/QC samples will be analyzed with each set of samples. The MeCl QA/QC samples and the 600 mg Charcoal tube samples will be desorbed as outlined in CIHL's MeCl Air Monitoring Method. 4 3Vt H0672 Data Interpretation and Report Generation: A full statistical analysis will be performed on the data generated from this study, and conclusions will be made regarding each of the methods. Depending on the results, Abbott may decide to publish this study as a peer-review article, as we did with the previous EtO Studies. [1-3] Role of HPD Facility: Assist in identifying locations for field validation. Role of the Manufacturer During the Validation Study: 1. Supply Abbott with 35 passive monitors along with all sampling/analysis instructions (5 sites x [6 samples + 1 blank] = 35). Advise Abbott's sampling staff on proper sampling, handling, preservation, and shipping procedures to assure that samples taken are not compromised. 2. Each manufacturer will be asked to comment on the study on three different occasions. This is strictly optional. By commenting or choosing not to comment, Abbott will not imply that the manufacturer agreed or disagreed with the study design, results or conclusions. These decisions will strictly be Abbott's. To expedite this study, comments must be received in writing within ten working days of receiving a request for comments. The First request for comment is upon receiving this document. Abbott is interested in receiving suggestions on enhancing and or adapting the proposed study design. 3. The second request for comments will be made after the raw data is collected and has been pooled. Each manufacturer, if interested, will be allowed to interpret all the raw data and submit suggested discussion topics and conclusions. The final request for comment will be made if Abbott decides to publish the study. An opportunity to comment on the manuscript will be given to each manufacturer prior to its submittal. Listed below are the current contacts for this study: Name Company Phone Number Kem Charron Martin Harper Gus Manning Bob Weber Abbott SKC Assay Technology 3M 708-938-6680 412-941-1369 415-424-9945 612-737-4459 5 3H 110673 References: 1. Puskar, M.A., Szopinski, F.G., and Hecker, L.H., "Development and Validation of a Protocol for Field Validation of Passive Dosimeters for Ethylene Oxide Excursion Limit Monitoring" Amer. Ind. Hyg. Assoc. J., 52(4):145-150 (1991). 2. Szopinski, F.G., Puskar, M.A., and Hecker, L.H. "Field Validation of Three Passive Dosimeters for Excursion Limit Monitoring of Ethylene Oxide" Amer. Ind. Hyg. Assoc. J., 52(4): 151-157 (1991). 3. Puskar, M.A. and Hecker, L.H., "Field Validation of Passive Dosimeters For the Determination of Employee Exposure to Ethylene Oxide in Hospital Product Sterilization Facilities." Amer. Ind. Hyg. Assoc. J., 50(1): 30-36 (1989). Comments and/or Questions should be directed to: Kem A. Charron Industrial Hygiene Chemist Abbott Laboratories, D-38A 1401 Sheridan Road North Chicago, IL 60064 708-938-6680 6 3Vt jiU uutupuuuiiui icauii unu Environmental Safety Division JKVl V^CULCl St. Paul. MN 55144-1000 612 733 1110 June 17, 1994 Mark Puskar Abbott Laboratories, D-038A Corporate Industrial Hygiene Lab 1401 Sheridan Rd. North Chicago, IL 60064 Dear Mark: We reviewed your proposed methylene chloride study and we would like to participate with our 3M 3520 Organic Vapor Monitor. However, it should be noted that our 3M 3520 Organic Vapor Monitor has limitations. The monitor has an approximate maximum capacity of 3000 micrograms at high relative humidities (i.e., > 60%). The capacity will increase as relative humidity drops. Based on a capacity of 3000 micrograms at a high humidity, the maximum concentration measurements are as follows: 15 minutes: 1518 ppm 240 minutes: 120 ppm 480 minutes: 60 ppm Based on this information, we recommend to our customers that sampling be limited to four hours when methylene chloride concentrations are unknown. However, if concentrations are expected to be at 50 ppm or below, the use of the 3520 monitor for eight hours is acceptable. The validation study that Abbott outlined calls for a sampling site that is greater than 50 ppm methylene chloride. If an 8 hour sample was collected at this location, it is feasible that the capacity of the monitor may be exceeded. This sampling site pushes the limitation of the monitor. However, all of the other sampling sites, including the sampling times, fall within the limitations of the 3M 3520 monitor. We would like to participate in the study, however, we want to caution you that our 3M 3520 monitor cannot be used in all situations, just like most other sampling devices. 3M a10697 Mark Puskar Page Two June 17, 1994 Please let me know when you would like the samples and other information. I look forward to working with you and Abbott. If you have any questions, please call me at 612-737-4459. Regards, Robert A. Weber, CIH Sr. Technical Service Representative 3M Occupational Health & Environmental Safety Division RAW:llj/123 be: A.R. Johnston - 260-3B-09 D.J. Larsen - 260-3B-08 J.B. Palazzotto - 260-3B-08 Y.T. Shih - 260-3B-08 G.H. Smith - 275-6W-01 L.G. Swope - 275-6W-01 3H 110698 pTJ ABBOTT June 15,1992 Abbott Laboratories North Chicago, Illinois 60064 Martin Harper Gus Manning Donald Larsen Linda Smith SKC Assay Technology 3M Gilian Environmental cc: Scott Fergon Larry Hecker Natalie Lisle Abbott Laboratories: CIHL Abbott Laboratories: CIHT Abbott Laboratories: CAPD FIELD VALIDATION OF PASSIVE DOSIMETERS FOR THE DETERMINATION OF EMPLOYEE EXPOSURES TO METHYLENE CHLORIDE IN PHARMACEUTICAL PRODUCTION FACILITIES Enclosed for your review and comments is a copy of the proposed protocol for field validation of passive dosimeters for methylene chloride. We hope to begin the preliminary laboratory work (Tedlar bag evaluations) this month and will be ready to receive your Quality Control monitors by mid to late-July. If all goes well, we will begin the actual field work by late August. If you have any questions or comments regarding the study please feel free to contact me. Sincerely, Mark A Puskar, Ph.D. Manager, Corporate Industrial Hygiene Laboratory Abbott Laboratories D-038A 1401 Sheridan Road North Chicago, IL 60064 (708) 937-4520 (708) 937-6293 3M 110699 FIELD VALIDATION OF PASSIVE DOSIMETERS FOR THE DETERMINATION OF EMPLOYEE EXPOSURES TO METHYLENE CHLORIDE IN PHARMACEUTICAL PRODUCTION FACILITIES Proposed Validation Study: June 15,1992 Mark Puskar and Scott Fergon Corporate Industrial Hygiene Laboratory, Abbott Laboratories Introduction: To increase the ability of Abbott's industrial hygiene staff to collect data on employee exposures to methylene chloride (MeCl), the Corporate Industrial Hygiene Laboratory (CIHL) has committed itself to performing a "peer-reviewquality" field validation of passive dosimeters, for both long-term (PEL) and short term STEL exposures to methylene chloride. The goal of this validation project will be to determine if a passive dosimeter can replace our current active method (600 mg Charcoal tube), for the determination of employee exposures to MeCl. Due to the complexity of this study, only area samples will be studied. No personal data will be collected. Due to the unfamiliarity of the CIHL with passive MeCl monitoring methods and to enhance the strength of this study, manufacturers of MeCl passive dosimeters are requested to take part in this investigation. However, this is strictly optional and the study will be conducted with or without the manufacturers' participation. The proposed validation will include four types of passive dosimeters, each from a different manufacturer. The manufacturers/vendors include: Assay Technologies, 3M, SKC, and Gilian. Each brand of monitor uses proprietary collection systems and a different methylene chloride extraction technique, however GC-FID analysis is similar to all the monitors. During the field validation exposures, air samples will be concurrently collected into Tedlar bags and will be analyzed onsite with a GCFID. Temperature, pressure, air velocity and humidity readings will be recorded at each sampling location. 3M 11Q700 Validation Study Design: Abbott's Chemical Manufacturing Facility (CAPD), in North Chicago, IL has been selected as the location to validate the methods because of two reasons: (1) the first reason is its location. CAPD is in the same location as the CIHL. This will allow the field validation to be performed near the labs location, reducing the need to ship equipment and lab personnel. (2) recent data suggest that a wide range of MeCl levels currently exist in CAPD. This will allow the methods to be tested over the full range of MeCl concentrations expected in the corporation. Using Tedlar air sampling bags and a Hewlett Packard Model 5890 Series II GCFID with a 1-mL sampling loop, 10 sampling locations in CAPD's pharmaceutical manufacturing facility will be selected to test the full range of EtO concentrations for both PEL and STEL monitoring. The approximate concentrations to be studied are: PEL: 8-hr TWA Samples Location Number Ideal Concentration in ppm MeCl 1 <10 2 10 3 25 4 50 5 >50 STEL: 15-min. TWA Samples Location Number Ideal Concentration in ppm MeCl 6 <25 7 50 8 125 9 300 3M 110701 2 10 >300 An exposure chamber has been built to expose an array of samples at each sampling location. Below is a list of the samples which will be collected at each of the 10 locations: Samples to be Collected at Each Location Frequency of Number of Samples Type Collection 6 Assay Technologies: MeCl Monitor 8-hr and 15-min. 6 Gilian: MeCl Monitor 8-hr and 15-min. 6 3M: MeCl Monitor 8-hr and 15-min. 6 SKC: MeCl Monitor 8-hr and 15-min. 6 Tedlar Sampling Bags 8-hr and 15-min. 6 Charcoal Active Samples 8-hr and 15-min. 6 Additional Adsorbent Samples (SKC) 8-hr and 15-min. 1 Temperature 1 Humidity 1 Pressure 1 Air Velocity continuous continuous continuous continuous To accurately field validate MeCl monitors, two major problems must be overcome. The first problem is that a system must be developed where all monitors are turned on and off simultaneously. The second problem is that unique MeCl concentrations may exist around different samples at the same location. If so, this must be understood, otherwise a false increased precision error would be added to all methods. These two effects will be limited with the exposure chamber designed and built. This exposure chamber was developed and built for an EtO EL study which was previously performed. [1,2] Pictures of the chamber are provided in the enclosed manuscripts. The chamber features a two dimensional array stand for dosimeter exposure mounted inside a Plexiglas chamber. The height of the dosimeters can be adjusted so each active exposure area is on the same horizontal plane. The Plexiglas cover can be removed once the chamber is in the sampling area, so all the dosimeters can be exposed at once. Once sampling is completed and the hood is placed back over the sampling array and sealed down (dual Teflon gaskets), the inside can be purged with MeCl free compressed air to remove residual MeCl. 3M 110702 3 This residual MeCl and excess purge air vent through the one way values mounted on the top of the chamber. This design should allow equal exposure of all the dosimeters for the same sampling time. During each dosimeter exposure, six Tedlar air sampling bags will be filled from six points circling the dosimeter array. Four of the sampling points are at each of the four corners of the dosimeter exposure horizontal plane. Point five is above the plane 4 inches and point 6 is below the plane 4 inches. These six bags will be analyzed immediately after sample collection (on site in triplicate) to determine the actual concentration present and to determine if unique atmospheres may have existed at unique sampling location during the sample collection. Two active sampling methods will also be collected at each location. The first active method will be 600 mg activated charcoal tubes (Abbott's current method for monitoring MeCl). The second method will be an adsorbent SKC recommends for monitoring MeCl. All preliminary studies necessary to document that the Tedlar air sampling bag method will be appropriate to estimate "actual-concentration-present" during the field validation will be performed following the protocol described in reference 1. These studies will include: validation of MeCl stability in Tedlar bags, validation of sampling process, and external verification of primary MeCl diffusion vial standard. Collection Strategy: The following collection strategy will be followed at each location studied. 1. The Purged/MeCl Free Chamber will be opened in an MeCl Free Area (<0.1 ppm by GC-FID). Blanks will be opened and left in the MeCl free area during the exposure to document that the area is MeCl free. 2. Monitors will be hung randomly across the two dimensional grid. The active sampling methods will be setup and connected to their pumps. 3. The chamber will be closed and MeCl-free air will be purged through the chamber during the chamber movement process from the clean area to the exposure area. 4. Once in the exposure area, the chamber will be opened and all the pumps will be started, including the six Tedlar bag pumps. Each Tedlar bag pump will draw air into a MeCl-free Tedlar bag. Exposure time will be either 15 or 480 minutes. \ 3M 110703 4 5. After exposure, the lid will be placed over the sampling grid and locked down. The purge air will be turned on and all sampling pumps will be turned off. The air flow rate will be sufficient to cause three complete air changes in the first 30 seconds. 6. The purge air will remain on until the chamber is successfully back in the MeCl Free Area (<5 min.). The chamber will be opened and the samples will be removed. 7. The six Tedlar bags will be analyzed immediately on site by GC-FID. After use, each Tedlar bag will be purged with MeCl free air. GC-FID verification will be performed prior to reuse. 8. All monitors will be Federal Expressed Over-night-air shipped to a secondary Abbott Location and then returned shipped to the CIHL to document any possible shipping effects. 9. All monitors will be stored in the CIHL according to manufacturer's instruction and analyzed within 1-week of collection. Calibration of Equipment: Gilian pumps will be used to collect the Tedlar Bag samples (0.021pm or 0.5 lpm). The GC-FID, used to analyze the Tedlar Bags, will be calibrated prior to and after each days sampling using a Dynacalibrator diffusion vial system. A middle standard will be analyzed every 10-15 injections. The active samples will be collected using Low-Flow Gilian pumps. Analysis of Samples: All passive monitors will be extracted using the manufactures' instructions and will be analyzed using Hewlett Packard 5890 Series II GC-FID. Separation will be performed using a 100m PONA 0.2 mm ID column. Standards will be prepared in CS2 and laboratory MeCl QA/QC samples will be analyzed with each set of samples. Data Interpretation and Report Generation: A full statistical analysis will be performed on the data generated from this study, and conclusions will be made regarding each of the methods. Depending on the results, Abbott may decide to publish this study as a peer-review article, as we did with the previous EtO Studies. [1-3] Role of the Manufacturer During the Validation Study: 1. Supply Abbott with 70 passive monitors along with all sampling/analysis instructions (10 sites x [6 samples + 1 blanks] = 70). Advise Abbott's sampling staff on proper sampling, handling, preservation, and shipping procedures to assure that sample taken are not compromised. 2. Each manufacturer will be asked to comment on the study on three different occasions. This is strictly optional. By commenting or choosing not to comment, Abbott will not imply that the manufacturer agreed or disagreed with the study design, results or conclusions. These decisions will strictly be Abbott's. To expedite this study, comments must be received in writing within ten working days of receiving a request for comments. The first request for comment is upon receiving this document. Abbott is interested in receiving suggestions on enhancing and or adapting the proposed study design. 3. The second request for comments will be made after the raw data is collected and has been pooled. Each manufacturer, if interested, will be allowed to interpret all the raw data and submit suggested discussion topics and conclusions. The final request for comment will be made if Abbott decides to publish the study. An opportunity to comment on the manuscript will be given to each manufacturer prior to its submittal. i Listed below are the current contacts for this study: Name Company Phone Number Mark Puskar Martin Harper Gus Manning Donald Larsen Linda Smith Abbott 708-937-4520 SKC 412-941-1369 Assay Technology 415-424-9945 3M 612-737-4103 Gilian Environmental 804-431-2260 References: 3H 110705 6 1. Puskar, M.A, Szopinski, F.G., and Hecker, L.H.. "Development and Validation of a Protocol for Field Validation of Passive Dosimeters for Ethvlene Oxide Excursion Limit Monitoring" Amer. Ind. Hyg. Assoc. J., 52(4):145-150 (1991). 2. Szopinski, F.G., Puskar, M.A., and Hecker, L.H. "Field Validation of Three Passive Dosimeters for Excursion Limit Monitoring of Ethvlene Oxide" Amer. Ind. Hyg. Assoc. J., 52(4):151-157 (1991). 3. Puskar, M.A. and Hecker, L.H., "Field Validation of Passive Dosimeters For the Determination of Employee Exposure to Ethylene Oxide in Hospital Product Sterlization Facilities." Amer. Ind. Hyg. Assoc. J., 50(1): 30-36 (1989). Comments and/or Questions should be directed to: Mark A Puskar, Ph.D. Manager, Corporate Industrial Hygiene Laboratory Abbott Laboratories, D-38A 1401 Sheridan Road North Chicago, IL 60064 708-937-4520 7 3H 110706 JUN 08 '94 10:32AM ABBOTT D836 SAFETY/ENV. HEALTH June 7,1994 Martin Harper Cm3 Manning Bob Weber SKC Assay Technology 3M cc: Mark Puskar Eiisabel Puskar Jim Murphy Abbott Laboratories: CIHL Abbott Laboratories: CAPD Abbott Laboratories: CHS P.2/8 FIELD VALIDATION OF PASSIVE DOSIMETERS FOR THE DETERMINATION OF EMPLOYEE EXPOSURES TO METHYLENE CHLORIDE IN PHARMACEUTICAL PRODUCTION FACILITIES Enclosed for your review is an updated protocol for the field validation of passive dosimeters for methylene chloride. This study was first proposed in 1992 and is now ready to be performed. The Corporate Industrial Hygiene Lab was supplied with methylene chloride spiked badges in 1992 which were analyzed to show that the Lab was capable of analyzing the dosimeters accurately. The Lab was successful in analyzing these spikes, however, since 1992 there have been some personnel changes. We feel that we are still capable of analyzing the samples accurately but are willing to analyze more blind spikes if you feel that it would be benificial. - The proposed start date for the field validation is July 15, 1994. We look forward to your participation in this study. If you have any questions or comments pleases feel free to contact Mark Puskar or myself. Sincerely, Kern A. Charron Industrial Hygiene Chemist Corporate Industrial Hygiene Laboratory Abbott Laboratories D-038A 1401 Sheridan Road North Chicago, H 0064 Phone: (708) 938-6680 Fax: (708)937-6293 3M 110707 JUN 00 '94 10:32AM ABBOTT D836 SAFETY/ENV. HEALTH P.3/0 FIELD VALIDATION OF PASSIVE DOSIMETERS FOR THE DETERMINATION OF EMPLOYEE EXPOSURES TO METHYLENE CHLORIDE IN PHARMACEUTICAL PRODUCTION FACILITIES Proposed Validation Study: July IS, 1994 Mark Puskar and Kem Charron Corporate Industrial Hygiene Laboratory, Abbott Laboratories Introduction: To increase the ability of Abbott's industrial hygiene staff to collect data on employee exposures to methylene chloride (MeCl), the Corporate Industrial Hygiene Laboratory (CIHL) has committed itself to performing a "peer-review-quality" field validation of passive dosimeters, for both long-term (PEL) and short-term STEL exposures to methylene chloride. The goal of this validation project will be to determine if a passive dosimeter can replace our current active method (600 mg Charcoal tube), for the determination of employee exposures to MeCl. Due to the complexity of this study, only area samples will be studied. No personal data will be collected. Due to the unfamiliarity of the CIHL with passive MeCl monitoring methods and to enhance the strength of this study, manufacturers of MeCl passive dosimeters are requested to take part In this Investigation. However, this is strictly optional and the study will be conducted with or without the manufacturers' participation. The proposed validation will include three types of passive dosimeters, each from a different manufacturer. The manufacturers/vendors include: Assay Technologies, 3M, and SKC. Each brand of monitor uses proprietary collection systems and a different methylene chloride extraction technique, however GC-FID analysis is similar to all the monitors. During the field validation exposures, air samples will be concurrently collected on 600 mg Charcoal tubes. Temperature, pressure, air velocity and humidity readings will be recorded at each sampling location. 3M 110708 JUN 08 '94 10:32AM ABBOTT D836 SAFETY/ENV. HEALTH P.4/8 Validation Study Design: Abbott's Chemical Manufacturing Facility (CAPD), in North Chicago, IL has been selected as the location to validate the methods because of two reasons: (1) the first reason is its location. CAPD is in the same location as the C1HL. This will allow the field validation to be performed near the labs location, reducing the need to ship equipment and lab personnel. (2) recent data suggest that a wide range of MeCl levels currently exist in CAPD. This will allow the methods to be tested over the foil range of MeCI concentrations expected in the corporation. Based on previous air monitoring results, 10 sampling locations in CAPD's pharmaceutical manufacturing facility will be selected to test the fUll range of MeCl concentrations for both PEL and STEL monitoring. The approximate concentrations to be studied are: PEL: 8-hr TWA Samples Location Number Ideal Concentration inppmMeQ 1 <10 2 10 3 25 4 50 5 >50 STEL: 15-min. TWA Samples Location Number 6 7 8 9 10 Ideal Concentration InppmMsCl <25 50 125 300 >300 2 3M 110709 JUN 08 '94 10:33AM ABBOTT D836 SAFETY/ENV. HEALTH P.5/8 An exposure chamber has been built to expose an array of samples at each sampling location. Below is a list of the samples which will be collected at each of the 10 locations: Samples to be Collected at Each Location Number of Samples 6 6 6 Im Assay Technologies: MeCl Monitor 3M: MeCl Monitor SKC; MeCl Monitor Frequency of Collection 8-hr and 15-min. 8-hr and 15-min. 8-hr and 15-min. 6 Charcoal Active Samples 8-hr and 15-min. 6 Additional Adsorbent Samples (SKC) 8-hr and 15-min. 1 Temperature 1 Humidity 1 Pressure 1 Air Velocity continuous continuous continuous continuous To accurately field validate MeCl monitors, two major problems must be overcome. The first problem is that a system must be developed where all monitors are turned on and off simultaneously. The second problem is that unique MeCl concentrations may exist around different samples at the same location. If so, this must be understood, otherwise a false increased precision error would be added to all methods. These two effects will be limited with the exposure chamber designed and built. This exposure chamber was developed and built for an EtO EL study which was previously performed. [1,2] The chamber features a two dimensional array stand for dosimeter exposure mounted inside a Plexiglas chamber. The height of the dosimeters can be adjusted so each active exposure area is on the same horizontal plane. The Plexiglas cover can be removed once the chamber is in the sampling area, so all the dosimeters can be exposed at once. Once sampling is completed and the hood is placed back over the sampling array and sealed down (dual Teflon gaskets), the inside can be purged with MeCl free compressed air to remove residual MeCl. This residual MeCl and excess purge air vent through the one way values mounted on the top of the chamber. This design should allow equal exposure of all the dosimeters for the same sampling time. During each dosimeter exposure, six 600 mg Charcoal tubes will be sampled from six points circling the dosimeter anay. Four of the sampling points are at each of the four comers of the dosimeter exposure horizontal plane. Point five is above the plane 3 3M 110710 JUN 00 '94 10:33AM ABBOTT D036 SAFETY/ENV. HEALTH P.6/8 4 inches and point 6 is below the plane 4 inches. These six charcoal tubes will be analyzed with the dosimeters and used to determine the actual concentration present and to determine if unique atmospheres may have existed at unique sampling location during the sample collection. Another active sampling method will also be used to monitor the MeCl concentration at each location. This method will be an adsorbent SKC recommends for monitoring MeCl. C<?Utton Strategy; The following collection strategy will be followed at each location studied. 1. The Purged/MeCl Free Chamber will be opened in an MeCl Free Area ( < 0.1 ppm by GC-FID). Blanks will be opened and left in the MeCl free area during the exposure to document that the area is MeCl free. 2. Monitors will be hung randomly across the two dimensional grid. The active sampling methods will be setup and connected to their pumps. 3. The chamber will be closed and MeCl-free air will be purged through the chamber during the chamber movement process from the clean area to the exposure area. 4. Once in the exposure area, the chamber will be opened and all the pumps will be started. Exposure time will be either 15 or 480 minutes. 5. After exposure, the lid will be placed over the sampling grid and locked down. The purge air will be turned on and all sampling pumps will be turned off. The air flow rate will be sufficient to cause three complete air changes in the first 30 seconds. 6. The purge air will remain on until the chamber is successfully back in the MeCl Free Area (<5 min.). The chamber will be opened and the samples will be removed. 7. All monitors will be Federal Expressed Over-night-air shipped to a secondary Abbott Location and then returned shipped to the C1HL to document any possible shipping effects. 8. All monitors will be stored in the CIHL according to manufacturer's instruction and analyzed within 1-week of collection. 4 3M 110711 JUN 08 '94 10:34At1 ABBOTT D836 SAFETY/ENV. HEALTH P.7/8 Calibration of Equipment: Gilian pumps will be used to collect the active samples. The Gilian pumps will be individually calibrated using a Gilibrator Primary Flow Calibrator. Analysis of Samples: All passive monitors will be extracted using the manufactures' instructions and will be analyzed using Hewlett Packard 5890 Series II GC-FID. Separation will be performed using a 100m PONA 0.2 mm ID column. Standards will be prepared in CS2 and laboratory MeCl QA/QC samples will be analyzed with each set of samples. The MeCl QA/QC samples and the 600 mg Charcoal tube samples will be desorbed as outlined in CIHL's MeCl Air Monitoring Method. The samples collected using the SKC adsorbent will be desorbed using the manufactures' instructions. Data Interpretation and Report Generation: A full statistical analysis will be performed on the data generated from this study, and conclusions will be made regarding each of the methods. Depending on the results, Abbott may decide to publish this study as a peer-review article, as we did with the previous EtO Studies. [1-3] Role of the Manufacturer During the Validation Study: 1. Supply Abbott with 70 passive monitors along with all sampling/analysU instructions (10 sites x [6 samples + 1 blank] *= 70). Advise Abbott's sampling staff on proper sampling, handling, preservation, and shipping procedures to assure that samples taken are not compromised. 2. Each manufacturer will be asked to comment on the study on three different occasions. This is strictly optional. By commenting or choosing not to comment, Abbott will not imply that the manufacturer agreed or disagreed with the study design, results or conclusions. These decisions will strictly be Abbott's. To expedite this study, comments must be received in writing within ten working days of receiving a request for comments. The first request for comment Is upon receiving this document. Abbott is interested in receiving suggestions on enhancing and or adapting the proposed study design. 3. The second request for comments will be made after the raw data is collected and has been pooled. Each manufacturer, if interested, will be allowed to Interpret all the raw data and submit suggested discussion topics and conclusions. The final request for comment will be made if Abbott decides to publish the study. An 5 3H 110712 JUN 00 '94 10:34AM ABBOTT D836 SAFETY/ENV. HEALTH P.8/0 opportunity to comment on the manuscript will be given to each manufacturer prior to its submittal. Listed below are the current contacts for this study: Name Company Phone Number Kem Charron Martin Harper Gus Manning Bob Weber Abbott SKC Assay Technology 3M 708-938-6680 412-941-1369 415-424-9945 612-737-4459 References: 1. Puskar, M. A., Szopinski, F.G., and Hecker, L.H., "Development and Validation of a Protocol for Field Validation of Passive Dosimeters for Ethvlene Oxide Excursion Limit Monitoring" Araer. Ind. Hyg. Assoc, J., 52(4):145-150 (1991). 2. Szopinski, F.G., Puskar, M.A., and Hecker, L.H. "Field Validation of Three Passive Dosimeters for Excursion Limit Monitoring of Ethvlene Oxide" Amer. Ind. Hyg. Assoc. J., 52(4);151-157 (1991). 3. Puskar, M.A. and Hecker, L.H., "Field Validation of Passive Dosimeters For the Determination of Employee Exposure to Ethvlene Oxide in Hospital Product Sterilization Facilities." Amer. Ind. Hyg. Assoc. J. 50(1): 30-36 (1989). Comments and/or Questions should be directed to: Mark A. Puskar, Ph.D. Manager, Corporate Industrial Hygiene Laboratory Abbott Laboratories, D-38A 1401 Sheridan Road North Chicago, IL 60064 708-937-4520 6 3H 110713 i Long term sampling with diffusion monitors By Donald J. Larsen and R bert A. Weber Donald Larsen and Robert Weber are a Certified Industrial Hygienists with 3M Occupational Health and Environmental Safety Division. Introduction Historically, diffusion monitors have been used to monitor the work environment for full work shifts of eight hours. Lab and field evaluations by 3M and others have been performed over the last 20 years to validate diffusion monitors for eight-hour and short term exposure limit (STEL) sampling. Recent concern with indoor air kuality, environmental emissions and azardous waste disposal gives rise to situations where monitoring for extended periods is desirable. Also, since concentrations in indoor air quality investigations may be very low, long sampling times may be necessary to accumulate enough mass for analysis. In long term diffusion sampling, the factor we were most interested in measuring was reverse diffusion. Reverse diffusion is the loss of previously adsorbed analyte during the sampling period. When this occurs, the sampling rate will be lower than predicted. Reverse diffusion effects can be studied by using a monitor that has a backup layer of sorbent and exposing the monitor to contamination levels that would not exceed the expected capacity of the primary layer. If the primary section on the monitor is not overloaded, any adsorbed material Ijpund on the backup section is due to reverse diffusion during sampling. In this report, we will outline results of five laboratory 3M Job Health Highlights Fall 1994 experiments conducted with the toluene alone. In addition, no following compounds: contaminant was found on the toluene monitor backup sections. 1,1,1-trichoIoroethane acetone methyl ethyl ketone (MEK) methylene chloride. Conclusion: If exposure occurred in the sampling period, followed by minimal or no exposure, no loss of contaminant occurred. These results indicate that reverse diffusion The compounds selected enabled us to test several classes of compounds that have a range of did not occur using 3M 3520 Organic Vapor Monitors under these conditions. boiling points and a range of affinities for activated carbon. Experiment 2 In each of the five lab studies, the mass of the collected analyte was measured and compared to the mass expected. The mass expected is derived from published sampling rates. A significant difference between the contaminant mass found and the mass expected would indicate contaminant loss and reverse diffusion. Six monitors were exposed to 0.45 ppm of 1,1,1-trichloroethane. After four days, two monitors were removed and two new monitors were started. Sampling continued for another four days. The two groups of monitors exposed for four days showed no contaminant on their backup sections. Less than 1% of the total mass collected was found on the backup sections of the monitors exposed for eight days. The average Experimental design amount of contaminant found was 0.83 mg compared to the amount To evaluate long term sampling expected of 0.86 mg. performance of the 3M 3520 Organic Vapor Monitor, known air concentrations of analytes were generated in a laboratory generator/dilution system. The challenge concentration was also monitored by a portable infrared Conclusion: This experiment indicates that the 3M 3520 Organic Vapor Monitor can be used for 1,1,1-trichloroethane monitoring at low concentrations for extended periods of time. analyzer. A relative humidity of 30% Experiment 3 and a temperature of 23C was maintained within the system. The challenge concentration was passed through a Plexiglas chamber (5" x 5" x 21") containing the monitors. A challenge air flow of 90 Lpm created a face velocity of 19 feet per minute (fpm). Six monitors were exposed to 2.86 ppm of acetone for five days. Based on the published sampling rate, the contaminant amount expected was 1.97 mg acetone. The mean acetone level was 1.77 mg with a standard deviation of .063 and a coefficient variation of 3.55. This translates to Experiment 1 an accuracy of 17%. We found Twelve monitors were exposed to 2.3 ppm of toluene. After 2.75 days, six of the monitors were removed and exposed to clean air for one, two or three days. The average amount found on the monitors given clean air exposure was the same as that 15% of the total mass collected on the backup section. Conclusion: This experiment indicates that the 3M 3520 Organic Vapor Monitor can be used to monitor acetone for extended periods of time. found on the monitors exposed to 3H 110725 Long term sampling, p-1 Experiment 4 Twelve monitors were exposed to a mixture of 0.17 ppm toluene and 0.03 ppm of methyl ethyl ketone (MEK). Six monitors were removed after two weeks, three more after three weeks and the last three after four weeks of exposure. The contaminant amounts found were very close to the amounts expected (see Table 1). No toluene or MEK was found on the monitor backup sections. Figure 1 shows that the uptake rate was linear throughout the 28-day experiment. Conclusion: This experiment demonstrates that the 3M 3520 Organic Vapor Monitor works accurately for long sampling periods. Table 1 Exposure of 3M 3520 Organic Vapor Monitors to a mixture of 0.17 ppm t luene and 0.03 ppm MEK for 28 days Toluene Amount Amount Hours Expected (pg) Found (pg) 365 438 4386.0% 500 618 615*4.7% 673 827 8153.6% MEK Amount Amount Hours Expected (pg) Found (>*3) 365 64 500 93 673 125 686.9% 100*3.9% 130*4.3% Experiment 5 Twenty-one monitors were involved in this experiment; some ' were exposed continuously and others intermittently to methylene chloride at 1.9 ppm for one to five days. Data from 15 monitors that were exposed continuously indicates the uptake rates remained linear throughout the exposure period. The remaining six monitors were exposed on a "day on/day off' basis to 1.9 ppm methylene chloride alternating with 0 ppm methylene chloride. The intermittently exposed monitors collected 95% of the amount on the monitors exposed continuously. Conclusion: The 3M 3520 Organic Vapor Monitor works accurately for long sampling periods as well as intermittent exposure. Conclusions These experiments demonstrate that the 3M 3520 Organic Vapor Monitor can be used for extended sampling periods of approximately one week to one month with accurate results. When monitoring volatile compounds like acetone or methylene chloride, it is critical that a monitor with a backup section be used to achieve accepted industry standards for accuracy. We can generalize our observations by recommending the use of a monitor with backup section for those compounds with boiling points below 60C and recommending the use of a monitor without a backup section for those compounds with boiling points above 90'C. For those compounds with boiling points between 60C and 90<'C, a monitor with backup would provide higher accuracy with less risk of loss. For more information on long term sampling, please call the 3M OH&ESD Technical Service Hotline at 1-800-243-4630. Further Reading Epstein, Paul S,, et at: Experiences Using Passive Monitors to Measure Volatile Organic Compounds During Indoor and Ambient Air Quality Surveys, American Industrial Hygiene Conference, 1990. Cohen. Martin A. et al: The Validation of a Passive Sampler for Indoor and Outdoor Concentrations of Volatile Organic Compounds, J. Air Waste Manage. 40:993(1990). Reprinted from 3M Job Health Highlights Volume 12, Number 2 Fall 1994 3M Occupational Health and Environmental Safety Division 3M Center Bldg. 275-6W-01 P.O. Box 33275 St. Paul, MN 55133-3275 3M Job Health Highlights Fall 1994 Figure I. Linear uptake rates ofMEK and toluene over 28 days demonstrate the long term sampling abilityy of the 3M 3520 Organic Vapor Monitor. 3M 110726 Long term sampling, p. 2 Internal Correspondence 3M Occupational Health and Environmental Safety Division To: C.E. Colton - OH&ESD - 260-3B-09 L.L. Janssen - OH&ESD - 260-3B-09 A.R. Johnston - OH&ESD - 260-3B-09 D.J. Larsen - OH&ESD - 260-3B-08 H.E. Mullins - OH&ESD - 260-3A-07 P.E. Olson - OH&ESD - 260-3B-09 J.B. Palazzotto - OH&ESD - 260-3B-08 Y.T. Shih - OH&ESD - 260-3B-08 From: R.A. Weber (7-4459) - OH&ESD - 260-3B-09 Subject: MONITOR ARTICLE ON LONG TERM SAMPLING Date: September 13, 1994 Don Larsen and I have been working on developing technical information that can support our diffusion monitors. If you have time, I would like you to review and comment on the enclosed article by September 26, 1994. At this time, the information will be sent out to customers on request, however, we are considering publishing if it is worthy. When you review, please do it with a critical eye. Thanks. RAW:llj/145 Attachment 3M 110727 t. J V\ j Long Term Sampling With Diffusion Monitors Donald J. Larsen and Robert A. Weber OH&ESD, 3M Company INTRODUCTION Historically diffusion monitors have been used for monitoring the working environment for full work shifts of 8 hours. Lab and field evaluations by 3M and others have been performed over the last 20 years to validate their use for 8 hour and STEL sampling.. Recent concern with indoor air quality, environmental emissions and hazardous waste disposal gives rise to situations where monitoring for extended periods is desirable. For indoor air quality investigations the concentrations may be very low, therefore long sampling times may be necessary to accumulate enough mass for analysis. Validation of a diffusion monitor must address the following factors - whether the sampling period is 8 hours , 15 minutes or several weeks: recovery, analytical sensitivity, capacity/reverse diffusion, linear uptake rate, orientation, temperature, face velocity, interference and storage. Validation of active sampling tubes like charcoal tubes must address these issues also. Reverse diffusion is the loss of previously adsorbed analyte during the sampling period. When this occurs with diffusion monitors the sampling rate will appear lower than predicted. Reverse diffusion effects can be studied by using a monitor that has a backup layer of sorbent and exposing the monitor to concentration levels that would not exceed the expected capacity of the primary layer. If the primary section on the monitor is not overloaded, any adsorbed material found on the backup section is due to reverse diffusion during sampling. In this study we evaluated the long term sampling performance of the 3M 3520 Organic Vapor Monitor. This report outlines results of five labortory experiments conducted with toluene, 1,1,1-trichloroethane, acetone, methyl ethyl ketone (MEK), and methylene chloride and a field test that evaluated the performance of the organic vapor monitors during exposure to a mixture of n-butanol and isopropanol. The compounds selected enabled us to test several classes of compounds that have a range of boiling points and a range of affinity for activated carbon. 3M 110728 EXPERIMENTAL DESIGN To evaluate the performance of the monitors the known air concentrations of analytes were generated in a laboratory generator/dilution system. The challenge concentration was also monitored by a portable infrared analyzer. A relative humidity of 30% and a temperature of 23 C. was maintained inside the system. The challenge concentration was passed through a Plexiglas chamber (5" x 5" x 21") containing the monitors. A challenge air flow of 90 Lpm created a face velocity of 19 feet per minute (fpm). In each of the five lab studies, the mass of the collected analyte was measured and compared to the mass expected. The mass expected is derived from our published sampling rates. A significant difference between the contaminant mass found and the mass expected would indicate contaminant loss and reverse diffusion. LABORATORY RESULTS Experiment 1 Twelve monitors were exposed to 2.3 ppm of toluene. After 2.75 days, six of the monitors were removed and analyzed. The remaining six monitors were exposed to 0 ppm toluene for 1, 2 or 3 days and analyzed. The average amount found on the monitors given additional exposure was the statistically the same as that of the monitors exposed to toluene alone (table 1). Based on a sampling rate of 31.4 cc/min. for toluene the predicted concentration on the monitors was 1.09 ppm whereas the average of the twelve monitors was 1.09 ppm +/- 0.064. These results indicate that reverse diffusion did not occur using the 3M 3520 Monitors under these conditions. TABLE 1 EXPOSURE TO 2.33 PPM TOLUENE FOR 2 3/4 DAYS PLUS 1, 2, OR 3 DAYS AT 0 PPM Set Exposure days at 2.75 ppm toluene 1 2.75 2 2.75 3 2.75 4 2.75 Exposure days at 0 ppm toluene 0 1 2 3 n Average Standard deviation 6 1.122 0.03 2 1.055 0.122 2 1.062 0.102 2 1.084 0.067 3M 110729 Experiment 2 Six monitors were initially placed in the chamber and exposed to 0.45 ppm of 1,1,1 trichlororethane. After 4 days, 2 were removed and 2 new monitors were started. Sampling continued for another four days. The two 4 day exposures showed nothing on the back-up section. Less than 1% of the total mass collected was found on the back-up of the monitors exposed for 8 days. The average amount found based on a sampling rate of 30.9 cc/min. was 0.83 mg compared to the amount expected which was 0.86 mg (table 2). This experiment indicates that the 3M 3520 can be used for 1,1,1-trichloroethane at low concentrations for extended periods of time. TABLE 2 EXPOSURE TO 0.45 PPM 1,1,1-TRICHLOROETHANE FOR 8 DAYS Exposure First 4 Days Last 4 Days All 8 Days mg Expected 0.45 0.41 0.86 mg Found A 0.394 0.445 0.393 0.384 0.890 0.842 0.772 0.817 mg Found B 0.000 0.000 0.000 0.000 0.005 0.005 0.004 0.005 mg Total 0.394 0.445 0.393 0.384 0.901 0.853 0.781 0.828 Average 0.830+/-0.044 8 day exposure (+/-5.3%) 3H 110730 Experiment 3 Six monitors were exposed to 2.86 ppm of acetone for 5 days. Based on the published sampling rate of 40. lcc/min. the amount expected over a five day period was 1.97 mg acetone. The mean acetone level was 1.77 mg with a standard deviation of .063 and a coefficient of variation of 3.55. This translates to an accuracy of 17.4%. For acetone, we found 15% of the total mass collected on the backup section (see table 3). If a single stage monitor had been used the amount on the back section would have been lost and this would have resulted in an accuracy of 40.9%. TABLE 3 EXPOSURE TO 2.86 PPM ACETONE FOR 5 DAYS ID mg A mg B mg Total 1 1.343 2 1.288 3 1.287 4 1.307 5 1.411 6 1.270 0.202 0.222 0.203 0.199 0.209 0.189 1.788 1.776 1.765 1.744 1.871 1.685 average mg: 1.767 standard deviation: 0.063 coefficient variation: 3.55% amount (mg) expected : 1.97 3N 110731 Experiment 4 Twelve monitors were exposed to a mixture of 0.17 PPM toluene and 0.03 PPM of methyl ethyl ketone. Six monitors were removed after 2 weeks, three more after 3 weeks and the last three after 4 weeks of exposure. The amount found was very close to the amount expected, (table 4). No toluene or MEK was found on the backup sections showing that reverse diffusion did not occur even after this extended sampling time. Figure 1 shows that the uptake rate was linear throughout the 28 day experiment. This experiment demonstrates that the 3M 3520 organic vapor monitor works accurately for long sampling periods. TABLE 4 28 DAY EXPOSURE TO MIXTURE OF 0.17 PPM TOLUENE AND 0.03 PPM MEK TOLUENE HOURS 356.3 500.2 673 AMT EXPECTED UG 438 618 827 AMT. FOUND UG 438+/-6.0% 615+/-4.7% 815+7-3.6% MEK HOURS 356.3 500.2 673 AMT EXPECTED UG 64 93 125 AMT FOUND UG 68 +/-6.9% 100 +/-3.9% 130 +7-4.3% FIGURE 1 TOLUENE & MEK EXPOSURE 3M OVM UPTAKE RATE + MEK .03 PPM A TOLUENE .17 PPM 3M 110732 Experiment 5 Twenty-one monitors were exposed continuously and intermittently to methylene chloride at 1.9 ppm for 1 to 5 days. Three monitors were removed each day and analyzed. Based on the 15 monitors exposed continuously over the five days, the uptake rate remained linear throughout this exposure. Analysis of the set indicated a coefficient of variation 5.3%, a bias of -3.2%, this translates to an accuracy of 13.8%. The remaining six monitors were exposed "day on day off' to the methylene chloride, for a total of 0 ppm methylene chloride for 48 hours and 1.9 ppm methlylene chloride for a total of 72 hours (table 5). This was done to simulate intermittent real life exposures. The intermittently exposed monitors collected 95% of the amount on the monitors exposed continuously. TABLE 5 METHYLENE CHLORIDE EXPOSURE AT 1.9 PPM FOR 5 DAYS ALTERNATING WITH 2 DAYS AT 0 PPM ( 72 hours at 1.9 ppm methylene chloride/ 4 days 0 ppm toluene) ID mg A mgB Total mg 1 0.558 0.185 0.964 2 0.542 0.211 1.006 3 0.569 0.180 0.965 4 0.557 0.172 0.936 5 0.570 0.199 1.007 6 0.539 0.195 0.968 FIELD TEST RESULTS Our field test was conducted at a 3M pilot plant. Monitoring was conducted for isopropanol and n-butanol from a coating operation over a 3 day time period. The coater operated intermittently. On day 1, it ran for 5 hours. On days 2 and 3 it ran for 12 hours. Monitors were exposed for 1, 2 and 3 days. We used this experiment as another measure of the effects of reverse diffusion. If the back up section contained significant concentrations and the monitors were not near their expected capacity, it would show that reverse diffusion was occurring. As a control we obtained charcoal tube samples on Day 1 and Day 3. Nine monitors were initially exposed to the n-butanol and isopropanol environment. Three monitors were removed each day and analyzed. The n-butanol results indicated nothing on the back section of any of the monitors. This shows that reverse diffusion of n-butyl alcohol did not occur. See table 6 for summary of n-butanol data. 3M 110733 TABLE 6 Time 1737 1737 1737 3255 3255 3255 4715 4715 4715 n-BUTANOL FIELD TEST mg ppm 0.025 0.027 0.025 0.164 0.172 0.163 0.053 0.052 0.056 0.182 0.180 0.194 0.077 0.076 0.076 0.184 0.180 0.181 Average of 3 0.166 0.185 0.182 The results of the isopropanol analysis were somewhat different. On day one we found 65 ug on the front and <1 ug on the back. On day two, 141 ug on the front and 6 ug on the back and on day 3,202 ug on the front and 10 ug on the back (see table 7). These results showed that reverse diffusion occurred with isopropanol although the effect was small, and that the use of a monitor with backup was able to provide accurate results. The average air concentration of isopropanol was 0.55 +/-0.07 ppm (+/-12.7%). 3M 110734 TABLE 7 Time mg A ISOPROPANOL FIELD TEST mg B Total mg ppm Ave of 3 1737 1737 1737 0.065 0.076 0.068 0.000 0.000 0.001 0.065 0.076 0.070 0.461 0.537 0.495 0.498 3255 3255 3255 0.155 0.149 0.144 0.003 0.004 0.004 0.162 0.157 0.153 0.611 0.593 0.577 0.594 4715 4715 4715 0.216 0.214 0.214 0.007 0.007 0.007 0.232 0.230 0.229 0.604 0.597 0.596 0.599 We compared the monitor results with charcoal tubes taken on Day 1 and Day 3 and can see excellent agreement (table 8). TABLE 8 Diffuison Monitor vs Charcoal Tube ComDound Isopropanol n-butanol Monitor ('own') 0.55 +/- 0.07 0.18+/-0.008 Charcoal Tube Tppm'l 0.48+/-0.11 0.17+/-0.03 3M 110735 CONCLUSIONS In summary, we can see that the accuracy's ranged from 10% to 17% which are well within the recommended 25%. These experiments show that diffusion monitors can be used for extended sampling periods of one week to one month and still provide acceptable accuracy. When volatile compounds like acetone and methylene chloride are anticipated, it is essential to use the 3M 3520 organic vapor monitor with a backup layer of sorbent to achieve accuracy of 25%. SUMMARY OF LONG TERM LOW CONCENTRATION EXPERIMENTS COMPOUND EXPOSURE TIME (DAYS) CONC (PPM) AMOUNT FOUND AMOUNT ACCURAC EXPECTED Y% Toluene 1,1,1-TCE Acetone Methylene Chloride Toluene/MEK Toluene/MEK Toluene/MEK 5 3/4 8 5 5 15 21 28 2.3 1.091 mg 1.088 mg 0.45 0.86 mg 0.83 mg 2.86 1.767 mg 1.97 mg 1.9 0.173/0.028 0.174/0.029 0.173/0.029 438.2/68.1 ug 614.9/99.8 ug 850.5/135.7 ug 438/64 ug 618/93 ug 827/125 ug 12.1 14.1 17.4 13.8 9.8/16.8 Comparison of boiling points vs. observations on reverse diffusion leads to the following general recommendation (table 9): the use of a monitor with backup section for those compounds with boiling points below 60 C and recommending the use of a monitor without a backup for those with boiling points above 90 C. For those compounds with boiling points between 60 and 90 C, a monitor with backup would provide higher accuracy with less risk of loss. 3M 110736 TABLE 9 BOILING POINT C N-BUTANOL TOLUENE ISOPROPANOL MEK 1,1,1 -TRICHLOROETHANE ACETONE METHYLENE CHLORIDE 118 111 82 80 75 56 40 REFERENCES 3M Organic Vapor Monitor Sampling Rate Validation Protocol Anders, L. W., andH. E. Mullins: Comparison ofDiffusional Organic Vapor Monitors with Charcoal Tubesfor Sampling Laboratory Challenges to Contaminant Mixtures Anders, L. W.,H. E. Mullins andP. L. Sullivan: Organic Vapor Monitor with Backup Section Pieper, RichardM., Donald J. Larsen, and Patricia A. Ishaug: STEL Sampling Using Diffusional Monitors, American Chemical Society Meeting, Boston, MA, April, 1990. Epstein, Paul S., et al: Experiences Using Passive Monitors to Measure Volatile Organic Compounds During Indoor and Ambient Air Quality Surveys, American Industrial Hygiene Conference, 1990. Cohen, Martin A., et al: The Validation ofa Passive Samplerfor Indoor and Outdoor Concentrations of Volatile Organic Compounds, J. Air Waste Manage. 40:993(1990). 3M 110737 ORGANIC VAPOR MONITOR WITH BACKUP SECTION #3520 L. w. Anders, H. E. Mullins, P. L. Sullivan Occupational Health & Safety Products Division 3M Company, Saint Paul, Minnesota Introduction The 3M Brand Organic Vapor Monitor #3520 with backup section is a diffusionally controlled sampling device designed to measure time-weighted-average concentration of potentially hazardous organic vapors in the environ ment. The sample is equipped with a backup section which collects contaminants when the capacity of the primary adsorbent has been exceeded. The monitor consists of two layers of adsorbent medium separated by a small space containing a placid air layer within the monitor. The amount of contaminant collected by the primary adsorbent layer is determined by sampling time and contaminant concentration in the environment. For a specific contaminant, the secondary adsorbent begins to collect contaminant by diffusion when the capacity of the primary adsorbent is exceeded for that particular contaminant. The capacity can be exceeded when sampling contaminant mixtures, contaminants at high concentrations, as well as contaminants for which activated carbon has a low capacity. By comparing the weight collected on each of the adsorbents (primary and secondary), the validity of the sample collected by the monitor can be determined. If the sample is determined to be valid, then the weight of contaminant on the primary and secondary adsorbent is used to calcu late the time-weighted-average concentration of the con taminant in the environment during the sampling period. Principle of the Method The 3M Brand Organic Vapor Monitor #3520 with the backup section is a personal sampler to be worn near the breathing zone of the worker. The sampler collects contaminants from the ambient atmosphere by diffusion onto the primary adsorbent where it is collected. The weight collection rate is a linear function of the exposure (product of the concentration and time). As the primary adsorbent collects contaminant, the collection rate will eventually deviate from the linear relationship. The adsorbent's capacity for the contaminant is defined as the weight adsorbed when the above deviation occurs. When the capacity of the primary adsorbent is reached with the 3520 Organic Vapor Monitor, the contaminant then diffuses to the secondary adsorbent in the backup section. Because of the geometric dimensions, the sampling rate of the con taminant onto the secondary adsorbent is 45% of the sampling rate onto the primary adsorbent. 3M 110754 2 Upon analysis of each adsorbent, the validity of the sample can be determined. Because the mass of activated carbon in the primary adsorbent is equivalent to the mass of activated carbon in the secondary adsorbent, the contaminant capacity on each should be equivalent. But in order to assure a valid sample under all sampling conditions, the ratio of the contaminant weight (W ) on the secondary adsorbent to the contaminant weight ) on the primary adsorbent must meet the following criteria. When sampling an environment containing multiple con taminants with the 3520 Organic Vapor Monitor, the above criteria can be used to determine the sample validity of each contaminant. Therefore, for those contaminants which fulfill the above criteria, the weight (W ) on the primary adsorbent and the weight (W ) on the secondary adsorbent can be used to accurately s determine the time-weighted-average concentration. The weight corrected for the blank of each contaminant on the primary and secondary adsorbent (W and W ) can be used to calculate the time-weighted-avirage cSncentration according to the following equation: 3W C (mg/m) = p. W" s K xt F K xt s W - corrected weight collected on the primary adsorbent Wg - corrected weight collected on the secondary adsorbent K - sampling rate of the contaminant onto the primary " adsorbent Kg - sampling rate of the contaminant onto the secondary adsorbent t - length of sampling period 3M 110755 3 The above equation C can be simplified to (mg/m ) = W p , + kws P the following: where, k -A constant determined by the ratio K /K . For all contaminants, this ratio has been determined to be a constant value of 2.2. * With this simplification, the time-weighted-average concentration of the contaminant in the environment can be calculated from the corrected weight collected by the primary and secondary adsorbent, the length of the sampling period and contaminant sampling rate onto the primary adsorbent. The geometric dimensions (area and length) of the primary diffusional chamber for the 3520 Organic Vapor Monitor with the backup section are the same as the dimensions of the diffusional chamber for the 3500 Organic Vapor Monitor. Therefore, the sampling rates (K ) for contaminants onto the primary adsorbent of the 35?0 Organic Vapor Monitor are the same as those tabu lated in the sampling and Analysis Guide for the 3500 Organic Vapor Monitor. As the diffusional capacity of the primary adsorbent is reached with the 3520 Organic Vapor Monitor and the secondary adsorbent starts to collect contaminant, it is merely an indication that for the primary adsorbent, the weight collection rate is no longer a linear function of the exposure. Although the diffusional capacity for the primary adsorbent may be reached during sampling, the adsorbent will continue to collect contam inant even though the weight collection rate deviates from the linear relationship. As will be shown later, the weight (W ) collected on the primary adsorbent even though in excess of the defined capacity can be combined with the weight (w ) collected on the secondary adsorbent to give an accurati determination of the time-weighted-average concentration in the sampled environment. These weights (W and W ) can be combined according to the above exPressioH as long as the ratio W /W complies with the above criteria. Therefore, the 320pOrganic Vapor with the backup section increases the effective sampling capacity by a factor of at least four over the 3500 Organic Vapor Monitor capacity. This allows the recommended sampling periods tabulated in the Sampling Guide for the 3500 Organic Vapor monitor to be increased by at least four times when sampling with the 3520 Organic Vapor Monitor. 4 To insure proper operation of the secondary section according to the given criteria, immediately separate the primary and secondary sections after sampling is terminated. Conclusion of sampling occurs when the white face of the monitor and the retaining ring are removed and the closure cap is snapped in place. Next, the primary and secondary sections are separated. The brown cap is snapped into place on the bottom of the primary section and the other closure cap is snapped on the secondary section. The two ports in the cap are firmly closed with the attached plugs. The improtance of these final steps should be emphasized since environmental sampling continues until the bottom brown cup and the closure are on with all ports closed. Documentation of Sampling Performance The 3M Brand Organic Vapor Monitor #3520 with the backup section is a diffusional sampling device which allows the industrial hygienist to determine sample validity. It is very valuable to assure sample validity when sampling an environment with a mixture of contaminants as well as con taminants at high concentrations. Besides assuring sample validity when sampling contaminants such as acetone, methylene chloride, vinyl chloride, etc. for which the activated carbon has a low capacity, the #3520 Organic Vapor Monitor also extends the effective sampling capacity and enables the recommended sampling periods to be increased. The following table is a list of eight commonly sampled contaminants which not only have high Permissible Exposure Level (PEL's) but also have limited capacity for activated carbon. From the table, it can be observed that the recommended sampling times can be extended in most instances to allow full work shift sampling. TABLE I 06HA PEL (ppm) Sanpling Primary fPate Adsorbent Micrograms \Capacity )^ ppn^hrs (nig) Recommended Sampling Period for 3520 OVM (hours) Concentration x PEL .lk . 5X IX 3X Acetone 1,000 5.71 3 8421 Ethyl acetate 400 7.45 10 8 885 Ethyl ether 400 6.68 .4 6 1 .6 .2 Methyl acetate 200 6.72 2 8 86 2 Methyl chloroform 350 10.09 12 8885 Methyl chloride 500 7.91 2 8421 Pentane 1,000 5.56 7 8 85 2 Vinyl chloride 1 6.22 .04 8 8 8 8 3M 110757 5 To document the incr ase in effective sampling capacity, a number of contaminants from the above table, were selected to be evaluated by sampling a laboratory chall nge of known con centration. In Figure 1, vinyl chloride was sampled at three concentrations (.39, 1.15 and 4.96 ppm) at a relative humidity of 60%. The double arrow between the primary and secondary curve indicates where the ratio W /W is equal to .50. Therefore, it is the point beyond which 5 tRe sample would be considered to be invalid. The response line of the 3520 was obtained from the combined weight (W ) of the weight (W ) on the primary adsorbent and the weight (W ) on the secoRdary adsorbent according to the following equation. Wc W + 2.2 W PS It can be observed that the response of the 3520 as measured by the combined weight (W ) is linear beyond the point of the double arrow and alsocthat the sampling time all concentrations can be in excess of eight hours. at FIGURE 1 VI KYI CHUK1DC xe-.an Collect*: ms; In Figure 2, acetone was sampled from known challenges of 63 and 470 ppm. At the lower concentration it can be observed that a valid sample was collected through the entire 12 hour sampling period while at the higher concentration after six hours of sampling the sample was invalid. Although, it should be pointed out that after eight hours, the response of the 3520 OVM as measured by the combined weight (W ) deviated only slightly from the expected linear response. 3Vt A A758 FIGURE 2 Acetone 6 In Figure 3, methylene chloride was sampled from known challenges of 58 and 482 ppm at a relative humidity of 85%. Again, the double arrow indicates the point beyond which an invalid sample would be collected as determined by the above criteria of weight ratio. As expected the response of the 3520 OVM as measured by the combined weight (W ) gives the expected linear relationship between weight anS the sampling time at known constant challenges. FIGUR.3 3 netnvlenc CftlorlO* *51 i fetfrylene CMorlde SSI 3M 110759 In Figure 4, methyl acetate was sampled from known challeng s of 27 and 24 8 ppm. From the results it can be observed that at both challenges a valid sample was collected through the eight hour sample periods. " FIGURE 4 Acetate *51 M itethvl Acetate . 151 AH In Figure 5, pentane and methyl ethyl ketone were sampled from challenges at concentrations of 135 and 200 ppm respectively. in both cases very little sample was collected by the secondary adsorbent during the sampling periods. FIGUkI: 5 Pentane 151 AH Hetnyi Ethyl Ketone 151 AH 3M 110760 8 As was pointed out earlier, the 3520 OVM is.also able to determin sample validity when sampling at very high concentrations. In Figure 6, MEK, toluene, ethyl acetate and propyl acetate were sampled from challenges where the known concentrations were very high. The double arrow again indicates the point beyond which the sample should be considered to be invalid. The response of the 3520 OVM as measured by the combined weight (W ) is linear even past the double arrow. c FIGURE 6 fettiyl Ethyl Ketone toluene Ethyl Acetate Prooyt Acetate 3M 110761 9 From the above results where the 3520 OVM sampled known challenges of a single contaminant, it has been shown that sample validity can be determined from a realistic criteria defined by the ratio of the weight collected on the secondary adsorbent to the weight collected on the primary adsorbent. It also has been shown that the effective capacity of the sampling device is greater than four times the capacity for a sampling devic containing only a single adsorbent. This increased effective capacity allows longer sampling periods when sampling contaminants with a low capacity on activated carbon. As was indicated above, the 3520 OVM is also very valuable to determine sample validity when sampling environments containing more than one contaminant. First the performance of the 3520 OVM was documented by sampling known charges of a two component mixture. In Figure 7, a mixture of methylene chloride and perchloroethylene at concentrations of 120 and 130 ppm respectively was sampled. As expected, the methylene chloride, for which the activated carbon has a low capacity, was collected on both the primary and secondary adsorbent. The perchloroethylere was collected only on the primary adsorbent of the 3520 OVM. The double arrow again indicates the point where the ratio is equal to .50. FIGUKK 7 sampling a MIXTURE OF ftmUNC CHLORIDE A RtRCHLOROETHYlENE Methylene Chloride Perchloroethylene Softino Tick mrt) s 3M 110762 10 In Figure 8, methylene chloride was sampled from a 464 ppm challenge for two hours. This was followed by a* challenge containing a zero concentration "of methylene chloride. It is evident that the primary adsorbent collected methylene chloride in excess of its capacity. Although the primary adsorbent lost methylene chloride during this period, the secondary adsorbent collected the appropriate amount from the primary adsorbent. The response of the 3520 as measured by the combined weight gave an accurate measure of the con centration sampled. FIGURE 8 Hetnylene Chloride In Figure 9, methylene chloride was again collected in excess of the capacity of the primary adsorbent. After the methylene chloride was sampled during the first two hours, a challenge of perchloroethylene was sampled for eight hours. During this period, the methylene chloride was displaced from the primary adsorbent. Again the response of the 3520 as measured by the combined weight gave an accurate measure of the concentration sampled for each of the contaminant. FIGURE 9 SCWCNT1AI W*UNG Of NClMYLCI* CHLOftlW. ON PtACHLWOtlHYU.Nl hethyler* Chloride Ptrchioroetiiylenc 3H 110763 1? A mixture of acetone and styrene is often found in many industrial environments. .In Figure IQ, these two contaminants were sampled from laboratory challenges "of 5970 and 873 ppm respectively. These were certainly very high concentrations, but valid samples were collected even in excess of the limit imposed by the validity criteria. It is interesting to point out that the secondary adsorbent collected more acetone than the primary adsorbent. This occurred because part of the capacity of the primary adsorbent was used by the adsorbed styrene. FIGURE 10 ACETONE SANPL1N6 A fllXTURE OF ACETONE A STYRENE STYRENE In Figure ll,instead of sampling acetone and styrene simul taneously from a mixture, the 3520 OVM was used to sequentially sample a known challenge of styrene for four hours then a known challenge of acetone for five hours. With styrene, the sample was valid because no contaminant was ever collected on the secondary adsorbent. For acetone, the sample would have been judged to be valid through seven hours of sampling by comparing the ration of W /W , but it is interesting that the 3520 OVM gave a linear response during the entire nine hour sampling period. 3M 110764 FIGURE II ACETOK MVlING A SEQUENTIAL EXPOSURE OF ACETONE > STYRENE STYRENE 12 Methyl ethyl ketone and toluene is another mixture often found in the industrial environment. in Figure 12, valid samples were collected through 12.5 hours when a known challenge of 208 and 247 ppm respectively FIGURE 12 SAMPLING A MIXTURE OF ICTHYl ETHYL KETONE A TOLUENE 3W A'0165 13 In Figure 13 the same mixture was sampled from a challenge with even higher concentrations of both methyl ethyl ketone and toluene. The response of the 3520 as measured by the combined weight (W ) is again linear even past where the weight ratio criteria has been exceed. When sampling the high concentration of this mixture, it can be observed that methyl ethyl ketone was displaced from the primary adsorbent by the toluene during latter portion of the sampling. This is evident by observing that the methyl ethyl ketone weight collected on the primary adsorbent decreases after one hour of sampling while the weight on the secondary continues to increase. Even though the displacement occurred, the combined weight as determined according to the above equation from the weight collected by the primary and secondary still gives the expected linear response as a function of sampling time. FIGURE 13 ifclhyl Ethyl Ketone SAMPLING * mixture of ItTKYl EIMYL KETOie TOLUENE Toluene 3M 110766 14 Figure 14 is another example of sequentially sampling a known challenge. Toluene was sampled for four hours with all the contaminant collected only on the primary adsorbent. Methyl ethyl ketone was sampled for the following four hours and all of the contaminant was collected on the primary adsorbent. During the next tour hours, the sampling devices were exposed to air with a zero challenge of each contaminant. It is evident that some methyl ethyl ketone was lost by the primary adsorbent during this period, but with the secondary adsorbent present, the 3520 response as measured by the combined weight accurately indicated the weight collected during the sampling of the known challenge. FIGURE 14 SMVUNG A SEQUENTIAL EXPOSURE OF KIHTL ETHYL KETOK A TOLUENE Ifethyi Etnyl Ketone Toluene In the next set of laboratory evaluations to document the performance of the 3520 OVM, challenges of three sets of con taminant mixtures were sampled. The mixtures consisted of a group of ketone, a group of esters and a group of halogenated compounds. In Figure 15, 16, and 17. the mixture consisted of acetone, methyl ketone and methyl isobutyl ketone. Three sets of challenges each with increased concentration of the contaminants were sampled. These ketones were selected because of the capacity ranqe activated carbon has for these contaminants. It should be indicated that sample validity can be judged for each contaminant independent of the response of the 3520 for the other contaminants present in the challenge being sampled. 3M 110767 FIGURE 15 Acetone SAMPUMS A MIXTURE OF THREE KETONES AT I5Z AH Itetnyl Ethyl retone 15 Hethy 1 Isobutyl Ketone tw) 3lljc: lUGDfl FIGURE If Acetone SJmiM A MIXTURE OF TlIRfZ a I'Hit AT til ra Methyl Ethyl Ketone Methyl Itobutyi Ketone FIGURE 17 Acetone ! SAreilNG A MIXTURE OF THREE KETONES AT SX AM Methyl Ethyl Ketone Methyl losOvtyl Ketone tnmliw ii'e tti'i' 3M 110768 1C The next mixture consisted of a group of esters again selected because of the capacity range the activated carbon has for these four contaminants. In Figure 18 < at the lowest challenge concentration, only methyl acetate was collected on the secondary adsorbent and the samples were valid for all contaminants for at least a nine hour sampling period. FIGURF 18 Mtnyl Acttate SArrifNC A K.IX7JK V FOUR tSTEfti Z">Z Ml Etnvl Acetate Frooyt Acetate tutyi Acetate 3M JfO?69 17 lr\ Figure 19, with the same esters at higher concentrations, the secondary adsorbent collected even butyl acetate after 12 hours of sampling. It is important to indicate again that the 3520 respons as measured by the linear response of the combined weight was excellent even past the point of the double arrows. FIGURE 19 nethyi Acetate MPPLIMG * mXTUW CF FQU* EilEHS *5t RH Ethyl Acetote Prooyl Acetate Butyl Acetate 3M 110770  1C In the above figure as well as in Figure 20, where the same contaminants are sampled even at higher concentration, the displacement of methyl acetate and ethyl- acetate from the primary adsorbent occurred during the latter part of the sampling period. But because of the secondary adsorbent, the combined weight gave the expected linear response even past the point where the samples were determined to be valid. FIGJiRF. 20 netiwl Acetate SMILING A illXTURC OF FOUR ESTERS CGI <"r Etnyl Acetate Proovi Acetate lutyl Acetate 3H 110771 In the next three figures, the 3520 sampled known chall nges of a mixture consisting of five halogenated hydrocarbons. In Figure 21# valid samples were collected for twelve hours for all of the contaminants except for methylene chloride. For methylene chloride, the sample was valid for a seven hour sampling period when judged by the weight ratio of the contaminant collected on the secondary and primary adsorbent FIGURK 21 Smpling a mxnrc of five MAUKEMtEU HYMOCWOMS AT 1S1 m Metftylenc Cnionde Qilorofoin 3M 110772 In Figure 22, the same contaminant mixture was sampled at somewhat higher challenge concentrations. Again, the con taminant with the lowest capacity,in this case methylene chloride, was displaced from the primary adsorbent during the latter portion of the sampling period. Even though dis placement occurred and sample validity according to the weight ratio criteria was exceeded past a four hour sampling period, it can be observed that all contaminants were sampled accurately for the entire 12 hour sampling period. FIGURE 22 SWUNG A ItlXTUftC Cf FIVt IIAlOUNATLO HYMOCARMNS AT IS! (W ncthylcn* cmor 10* Methyl Cmornfoin Carbon IctrornloriiM Percnloroethylent lt-j 1IMTO Vjwilrm lii. 'ini' 3M 110773 21 In Figure 23, at even higher concentrations, the weight ratio criteria for validity indicated that_ for four of the contam inants, the sampling could not be done for a 12 hour period. However, the response of the 3520 OVM as measured by the combined weight gave a linear response over the 12 hour sampling period for all contaminants except for methylene chloride. For methylene chloride, the combined weight deviates from a linear response after six hours of sampling. At this point even the secondary adsorbent is not able to properly sample methylene chloride due to the large amount of the other contaminants also being collected on the secondary adsorbent. It is again important to indicate that even though both the primary and secondary combined were not able to accurately measure the methylene chloride concentration, the sample is valid for the other contaminants even past an eight hour sampling period. FIGURE 23 Methylene Chlorine SMTUNC- * I'.UTWE OF FIVE liALPGEMTED KYCnPC/fiTONS AT tV. DM Methyl Chlcrofora CorDon Tetrachloride Perchloroethviine 3M 110774 22 The final challenge us d to evaluate the 3520 OVM preformance was mixture of contaminants selected from different hydro carbon families. In Figure 24, it can again be; observed that the 3520 response as measured by the combined weight was a linear function of the sampling time. When sampling this mixture, it can be observed that methyl ethyl ketone was dis placed from the primary adsorbent. Even with this displacement, the weight ratio criteria indicated a valid sample could be collected for a six hour sampling period and from the linear response of the combined weight a valid sample was actually collected for the entire 12 hour sampling period. FIGURE 24 Itetnvt Ethyl mar* itmiK. a mxruitt of FOUA HYMOCAJWMS twptan* Toluene praorl Acetate 3H 110775 23 * In conclusion, the above documentation of the sampling- performano of the 3520 Organic Vapor Monitor with the backup section demonstrates the accuracy and validity of the samples collected from known challenges. These challenges consisted of single contaminants for which the activated carbon has limited capacity as well as mixtures with numerous components. The 3520 OVM with the secondary adsorbent has been shown to have increased effective sampling capacity as well as the ability to determine sample validity long before the combined weight deviates from the expected linear response. This assures the industrial hygienist that accurate samples will be collected under any sampling condition when the weight ratio criteria is used to determine sample validity. R-3520TP Occupational Health and Sat ty Products Division/3M 220-7W 3M Center St. Paul. Minnesota 55144 TECHNICAL DATA BULLETIN 104 (replaces tech data bulletin #71) Sampling for Methylene Chloride Using the 3M 3520/3530 Organic Vapor Monitor March 23,1992 INTRODUCTION OSHA has proposed that the permissible exposure limit (PEL) for methylene chloride be changed from 500 ppm to 25 ppm with an action level of 12.5 ppm and a provision for a short term exposure limit (STEL) of 125 ppm. This Technical Data Bulletin describes sampling for methylene chloride using the 3520/3530 organic vapor monitor. SAMPLING PROCEDURE No special techniques are required. Follow the instructions for sampling found in either the monitor sampling guide or in the instructions accompanying the monitors. SAMPLING CRITERIA 1 The monitor must be exposed for at least 15 minutes and not longer than four hours. Monitoring times greater than four hours are not recommended. The quantity of methylene chloride on the back section of the monitor must not exceed 50% of the methylene chloride found on the front section of th monitor. If the quantity of methylene chloride on the back section of the monitor is greater than 50% of the methylene chloride found on the front section of the monitor, the monitor limitation for a specific situation may have been exceeded. Occupational Health and Envir nmental Safety Division 3M Center Bldg. 275-6W-01 St. Paul. MN 55144-1000 3M 3M 110777 In cases where complex mixtures, such as Stoddard solvent or petroleum distillates, are present at a relative humidity greater than 70%, the sampling time may need to be reduced. . ACCURACY The monitors are accurate to within +/- 25% when all sampling criteria are met. RANGE The minimum detectable amount of methylene chloride accurately measurable on the monitor in the 3M OH&ESD laboratory is 10 micrograms. MINIMUM CONCENTRATION MEASUREMENTS 15 minutes. 240 minutes, ..5.1 PPM 0.32 ppm The maximum amount of methylene chloride the monitor will collect is 3000 micrograms. MAXIMUM CONCENTRATION MEASUREMENTS 15 minutes. 240 minutes 1518 ppm 120 ppm Higher measurements may be possible, however the accuracy of measurements at very high levels may be less than + /- 25%. ' ANALYSIS Analysis of monitors exposed to methylene chloride is conducted following the procedures outlined in the 3M Analysis Guide. Carbon disulfide is used as the desorption solvent. The 3M OH&ESD laboratory recovery is listed as 90%. The experimentally validated sampling rate is 37.9 cc/min. 3M 110778 Occupational Health and Safety Products Division/3M 3M Center St. Paul, Minnesota 55144 612/733 1110 3M Dear Customer: Many industrial firms and government agencies from around the world have been conducting evaluations of the 3M Brand Organic Vapor Monitor It3500. The Occupational Health and Safety Products Division of 3M has made a concerted effort to collect and evaluate as much of this data as possible, for our information as well as that of our customer We are pleased to be able to share with you this collection of field and laboratory information. The data has been summarized for you. It is generally divided into two categories: field tests and laboratory tests. This new section of information can be added to your 3M Brand Organic Vapor Monitor It3500 3-ring notebook. Much of the data is submitted to 3M for anonymous publication. Many of these reports represent very thorough research on a specific organic vapor in a laboratory test. Other evaluations are in-depth field studies conducted under close supervision. In addition to the data summaries, two complete technical papers are enclosed for your reference file; (1) The "Comparison of 3M Organic Vapor Monitor Versus Charcoal Tubes" was submitted to 3M for our use as an anonymous publication. (2) The "Evaluation of a passive dosimeter for collection of 2-bromo-2-chloro-l,l,l-trifluoroethane and 2-chloro1,1,2-trifluoroethyl difluoromethyl ether in hospital operating rooms" by John Mazur et. al. was recently published in the May 1980 issue of the AIHA. 3M plans to be adding to this 3500 Organic Vapor Monitor notebook of information periodically with updates of new field and laboratory data as well as new Compound Sampling Rates. To insure receipt of this information, please be sure we have your correct address and spelling of your name. If you need to change the mailing address, please note the change on the enclosed blue and white reply card. 3M 110809 Page 2 If you wish to discuss any of the enclosed information in more detail, please feel free to contact your local 3M sales representative or Occupational Health and Safety Products Technical Service on our toll free number. You may reach the proper contact by calling 800-328-1300 (in Minnesota, 612-733-8029), and asking for Occupational Health and Safety Products Customer Service. Sincerely, Miriam I. Merino Market Coordinator Occupational Health & Safety Products Division/3M 220-7W 3M Center St. Paul, MN 55144 MIM:kms 9/1/80 3M 110810 3500 LABORATORY & FIELD TEST EVALUATIONS TABLE OF CONTENTS X, Laboratory Evaluations Compound(5) a. Toluene Evaluator Kttuzato University, Japan b. Toluene and Toluene mixture with iso 3ur.ar.ol Acetone/ and Perchloroethyler.e Technical Research Center of Finland c. Styrene/Acetone mixture Jutlandish institute of Technology, Denmark d. Vinyl Chloride Chemical Company (anonymous) Summary Four levels from 10-200 ppm were generated in a test chamcer and monitors exposed to these concentrations over varying time intervals. The Center ran controlled laboratory comparisons of the #3500 vs, standard charcoal tubes and low flow pumps. The compounds studied were Toluene, a mixture 0 Toluene and Iso Butyl Alcohol, Acetone, and Percnloroethylene. Chamber concentrations were checked by Micron IA infrared and by direct GC analysis. The Outlandish Institute of Technology in Denmark performed a laboratory comparison of a Styrene and Acetone mixture using #3500 OVM and SKC standard charcoal tabes. Low flow pumps were used for the SKC tubes and both systems were exposed for four hours. An airstream containing 0,61 pcm of vc was passed over the *3500 for fifteen minutes at two liters per minute. Relative Precision at 95% confidence level was 15% for the #3500 and 114% for the tube. e. Dichloromethane, I# 2 Dichloroethane. Tatrachloroethylene, Heptane , Enflurane 3M OH fi SP Division II. field Evaluations Compound(s) a. Complex Mixtures Ketones and Chlorinated Hydrocarbons Evaluator Chemical Company (anonymous) b. Benzene, Toluene Xylene in complex mixtures Oil Company (anonymous) c. Benzene, Toluene Chemical Company (anonymous) d. 1, 1, 2 Trichloroethylene e. Acetone 3M Industrial Hygiene Department Chemical Company (anonymous) . Benzene Steel Company (anonymous) III. Lab/F ieId _evaluation s Compound(s) a* Halothane Enflurane b. Methyl Methacrylate R-35LFT-A Evaluator U. S. Army Environmental Hygiene Agency Chemical Company (anonymous) Data show that the #3500 is gas tight. This data is valid in its conclusions only when the compound is stable. The data relates storage time to recovery coefficients (Desorption Efficiency). A study at an eastern U.S. university was carried out comparing the #3500, Miran IA, and Charcoal Tube (C.T.) to a known concentration in an exposure chamber. The #3500 correlated well with the tank concentration and had excellent coefficient of variance. A field ccmperison wee conducted between a 600 mg. charcoal tube and the *3500 in a complex mixture. Agreement ia good for all cases except acetone. Where it appears the *3500 samples are high. An explanation is given. A major oil company ran extensive side-by-aide comparative studies of standard charcoal tubes and the *3500. Thirty samples were taken for Benzene, Toluene, and Xylene. These compounds were present together in a complex mixture of hydrocarbons. A U.S. chemical company ran side-by-side personal exposures with the #3500 and standard charcoal tubes. Benzene and Toluene were both present in the air. Personal samples were run ir. a 3M plant. Samples were run for four hours and converted to tlv-TWA. Correlation was good between the two methods. Three separate methods of measuring acetone in a field area sample were used. The 600 mg. tubes were used in senes to be certain that loss through the tube was minimized. Comparability between methods is good. A u.S. Csapany ran side-ty-side area samples between tne #3500 and a standard charcoal tuba. The range of concentrations found were non" detectable to over 90 pcm, with an average of 7.89 crn. A high degree of correlation exists between t.ne 79 pairs of sample data. 3M 110811 Laboratory and field testing was performed on the subject gases. Field data vis taken in both unoccupied and occupied operating rooms. Kr.owr. cumtities of MMA were generated m a laboratory chamber. Lab precision zeat3 are shown, plus the side-b;-a;Je comparison of standard charcoal tube vs, t.-.e "3533 in personal field samples. Op rationally, passiv dosimeters are ideally suited for monitoring organic vapors in hospital operating rooms as they are compact, lightweight and do not require tubing or pumps. In this study, a recently developed passive diffusion sampler was us d to collect 2-bromo-2-chloro-1,1,1 -trifluoro thane (Halothane) and 2-chloro-1,1,2trifluoroethyl difluoromethyl ether (Enflurane) in standard air mixtures over the range of 0.2 - 10 ppm. Additionally, exposures to known concentrations were conducted for various lengths of time/ A side-by-side comparison of charcoal tubes (CT) and passive dosimeter collection characteristics were made on known air mixtuk s and samples collected in operating rooms. The material adsorbed on charcoal from dosimet rs and CT was desorbed with carbon disulfide and quantified using gas-liquid chromatography. The overall efficiency of the dosimeters along with quality control data are presented. Evaluation of a passive dosimeter for collection of 2-bromo-2-chloro-1 ,1 ,1 -trifluoroethane and 2-chloroI,1,2-trifluoroethyl difluoromethyl ether in hospital operating rooms J. F. MAZUR, G. E. PODOLAK, G. G. ESPOSITO. D. S. RINEHART and R. E. GLENN US Army Environmental Hygiene Agency, Aberdeen Proving Ground, MD 21010 introduction It was almost a hundred years after the first use of an inhalation anesthetic in 1842 before anesthesiologists recognized the possible deleterious effects of occupational exposure to anesthetic gases. However, it has only been during the past decade that considerable effort has been directed toward the determination of trace concentrations of anesthetic gases and vapors in the operating room atmosphere, and the related potential hazards to chronically exposed personnel. In 1974, the American Society of Anesthesiologists Ad Hoc Committee on the Effects of Trace Anesthetics published a report on a national survey conducted on occupationally related diseases among dental and operating room personnel.'1,21 At the time of this study, the number of operating room, dental, and veterinary personnel who were potentially exposed to anesthetic gases exceeded 200 000 persons per year. The results of this study, and others both human and animal, suggest that chronic exposure to anesthetic gases increases the risk of spontaneous abortion and congenital abnormalities in children of both female workers and wives of male workers. Chronically exposed personnel also showed increased incidence of hepatic and renal diseases. Other studies have indicated an increased risk of cancer and possible impairment of certain psychologic functions. Acute exposures to anesthetic gases have been shown to affect the central nervous system with resulting symptoms of headaches, nausea, fatigue, etc.'J> For reasons of both efficacy and safety, most of the anesthetic agents introduced prior to 1950 have been The opinions or assertions contained herein are the private views of the authors and are not to be construed as reflecting the views of the Department of the Army or the Department of Defense. replaced. The flammable and explosive inhalation anesthetic agents such as diethyl ether and cyclopropane have been replaced by nonexplosivc, nonflammable anesthetics such as halothane, enflurane, and methoxyfiurane. Halothane and enflurane are currently the two most widely used halogenated anesthetic agents in US Army hospitals. They are generally used in conjunction with nitrous oxide and/or intravenously injected anesthetics. The US Army Environmental Hygiene Agency (U SA E H A) is responsi ble for monitoring potential problem areas of occupational hazards and safety in US Army hospitals and clinics. Part of this surveillance program is concerned with operating room engineering controls and work practices affecting personnel exposure to waste anesthetic gases. Waste inhalation anesthetic gases are those gases and volatile liquids which are inadvertently released into work areas either by faulty equipment or improper work practices. Scavenging systems designed to collect waste anesthetic gases and vapors from the breathing system at the point of discharge and disposing of them outside of the operating room are the primary means of controlling waste anesthetic gases. Sufficient ventilation rates within the operating room are necessary to dilute anesthetic agents that are not captured by the scavenging system. Failure to control properly one or more of the above-mentioned sources of waste anesthetic gases can result in potentially hazardous exposures to operating room personnel. Consequently, personal and general area monitoring of operating rooms are conducted by USAEHA to determine if a health hazard exists and to pinpoint sources of exposure, whether they be defective equipment, inadequate scavenging systems, poor ventilation, or improper administration of anesthetics. After identifying the cause American Industrial Hygiene Association JOURNAL Copyright 1990. American Indultnal Hypiono A,rocunion m 5/80 3M 110812 317 and extent of exposure, recommendations are made for improving work practices and engineering controls to meet the recommended levels for occupational exposure published by the National Institute for Occupational Safety and Health (NIOSH). At present, a safe level of exposure for waste anesthetic gas has not been established by NIOSH; instead, it recommends that exposures be suppressed to the greatest extent possible to minimize risk to operating room personnel. When used alone, NIOSH recommends occupational exposure to halothane and enflurane be controlled so that no worker is exposed at concentrations greater than 2 ppm. For halothane and enflurane their weights corresponding to 2 ppm would be 16.15 mg/cu m and 15.10 mg/cu m, respectively. These concentrations arc based on a 45-liter charcoal tube sample taken over a time period not exceeding 1 hour. When halogenated agents are used in combination with nitrous oxide, levels of approximately 0.5 ppm are achievable, provided the time weighted average of nitrous oxide is controlled at the recommended 25 ppm level. The NIOSH criteria document, "Occupational Exposure to Waste Anesthetic Gases and Vapors,"*31 provides a comprehensive review of sampling methods, analytical procedures, and real-time monitors. Typical collection methods cited in the literature include those utilizing gas syringes,14 7' plastic sample bags,**' and charcoal tubes.'9' These procedures make use of gas chromatography (GC) for the analysis of isolated samples. Additional analytical methods for anesthetic gases'1*'13' based on GC, infrared spectroscopy (IR), and gas chromatography and mass spectrometry (GC-MS) have also been described in the literature. The forenoted procedures have proved adequate for in-depth investigations and have been used extensively in research studies. For the purpose of routine personal monitoring however, these procedures have certain shortcomings. Some of the problems relate to equipment complexity, sample collection, and sample manipulation. Because of the unique working conditions that exist in operating rooms, it is essential that a personal sampler for monitoring worker occupational exposure meet certain performance criteria. Foremost, the collection of samples must not interfere with any of the various tasks performed by operating room personnel. In addition, areas designated as sterile zones must not be contaminated. Finally, the air sample should be proportional to a time-weighted average of anesthetic agent concentration. Traditionally, organic vapors have been collected and concentrated using the charcoal tube (CT) technique. This method consists of pumping a known volume of air through a tube packed with charcoal for a definite period of time. Organic vapors are adsorbed onto the charcoal and subsequently desorbed with an appropriate solvent. The desorbent is analyzed with a gas chromatograph. An alternative approach to sampling organic vapors is through consideration of fundamental molecular diffusion dosimetry. Devices based on this principle have recently found their way into the industrial hygiene marketplace, and have been used selectively for the collection of certain organic vapors. With this type of sampler, volatile compounds enter the sampler by molecular diffusion such that the rate of sample collection is a function of the organic vapor concentration in air. Since the vapors enter the dosimeter by nonmechanical means, it requires neither calibration nor electrical power. The purpose of this investigation was to determine the suitability of the 3M Organic Vapor Monitor (OVM) for the collection of halothane and enflurane in operating room environments. Side-by-side collection of known concentrations of halothane and enflurane were conducted with OVM and CT samplers for comparison and correlation of test data. Variables studied were sampling time, sample concentration, and storage stability. In addition to the laboratory tests, samples were collected in operating rooms during administration of anesthesia to patients undergoing surgery. The effects of humidity and temperature on collection efficiency were not included in this study, since these parameters are carefully regulated in operating rooms. experimental passive dosimeter All passive dosimeter monitoring was conducted with the 3M Brand Model 3500Organic Vapor Monitor(OVM), 3M Company, St. Paul, MN. This unit consists of a round nylon body approximately 4.5 cm in diameter, weighing about 12 grams. A charcoal adsorbent pad is located inside the monitor, separated by spacers from a diffusion membrane. Contaminants enter the monitor by molcculardilTusion and are adsorbed onto the charcoal. At the conclusion of the sampling period, the diffusion membrane is removed, and a tight-fitting cap firmly snapped into place. The cap contains two ports which are sealed by inserting the attached plugs. When the sample is ready for chromatographic analysis, the center port is opened and 1.5 mL. of carbon disulfide is introduced into the monitor via a glass syringe. The center port is rescaled, and the sample is allowed to desorb for 30 minutes. A GC sample is taken directly from the center port with a 10-fiL syringe. The OVM sampler and cover are shown in Figure 1. The time-weighted worker exposure level is calculated using the following equations: mg/m' = Corrected weight on badge (nanograms) Sampling rate (cm /min) X Sampling time (min) mg ppm = "in 22.4 L/mole mwg/mole l~ K 27.1 K 760-mm Hg I'-mm Hg The sampling rates for halothane and enflurane are 25.1 cm3/ min and 26.9 cm3/min, respectively. These sampling rates were calculated from diffusion coefficients corresponding to each compound. charcoal tube monitor Charcoal tubes containing two sections of charcoal, 200/400 mg, were purchased from SKC Inc., Eighty Four, PA. Samples were collected at two different sampling rates, 30 mL/min (Accuhaler 808, Lefco Engineering) and 500 3M 11081331t Am. Ind. Hyg. Assoc. J. (41) May. 1980 Apeizon L on 80-100 mesh Chromosorb W-HP; injection port temperature, 130 C; detector temperature, 300 C; initial column temperature, 120 C; final column temperature, 190 C; column temperature programming rate, 30/min. test atmosphere Appropriate amounts of halothane and enflurane were injected into a 2-mL vial equipped with a septum and screw cap. The vial was transferred to a 6920-liter static test chamber and positioned in front of a circulating fan. The vial cap was removed and the chamber door closed immediately. After sealing the door, the circulating fan was turned on and 30 minutes were allowed to elapse to insure complete mixing of the anesthetic agents with air. The OVM's were attached to a meter stick and inserted into the chamber through a side-access port. CT samples were collected at a port adjacent to the OVM's. For some experiments having short sample collection times, successive tests were conducted using the same chamber concentration. mL/min (Mode! P-4000A, E. 1. du Pontde Nemours&Co,. Wilmington, DE). Pump calibration was accomplished by connecting a charcoal tube to a pump and measuring the air flow with a bubble meter. When the sample was ready for chromatographic analysis, the charcoal was poured from the glass sampling tube into a 10-mL vial and desorbed with 2 mL of carbon disulfide. gas chromatography Analysis of desorbent solutions was performed on a Hewlett-Packard Model 5830 gas chromatograph equipped with a flame ionization detector and HP 18850A GC Terminal. The GC operating conditions were as follows: column, 17 ft. X 1/8 in. stainless steel packed with 30% results and discussion OVM and CT data for various concentrations of halothane and enflurane are presented in Table I. Test atmospheres for Samples 1-3 contained only halothane, whereas test Samples 4-8 were binary mixtures of both halothane and enflurane. The sampling rate for Samples 6 and 7 was 30 mL/min; the sampling rate for all other samples was 500 mL/min. In general, results from the OVM's were in good agreement with the theoretical values; whereas, results from the CTs showed a slight positive bias. Statistical treatment of the OVM data is presented in Table II. The values shown in Tabic II were derived from four replicates for each test. Since the GC analysis is an integral part of each test, the statistical data reflect the overall efficiency of both sample collection and analytical procedures. In general, the precision and accuracy were within acceptable limits over the tested concentration range. In summary, a total of 44 OVM's were tested for halothane, and 25 OVM's for enflurane, at four concentration levels (0.5, 2, 5, and 10 ppm). An overall recovery of 100.6% and a Sample 1 2 3 4 5 6 7 8 TABLE I Halothane and Enflurane Laboratory Data Exposure Time OVM, Hrs Theoretical Cone., ppm Mean Observed Enflurane, ppm OVM* CT" Mean Observed Halothane, ppm OVM* CT" 45 5.28 5.14 25 -- 5.34 5.40 4 2 -- -- 2.13 2.23 4 0.5 0.57 0.64 0.48 0.59 4 2 1.95 2.13 2.27 2.30 2 2 1.65 2A7 2.06 2.22 1 2 2.01 2.11 1.95 2.11 4 30 9.17 11.49 9 51 10.30 ''Average of tour OVM's. "Average o( two CT s (or Samples 6 and 7; all others average of (our CT's. Aroonc.io ltultotn.il ItyiMi'tir AsMiOrfliOM lUIIIINAt (41) b/sn 3M 110814 319 i TABLE II Statistical Summary of OVM Results Halothane Enflurane Exposure Time Hrs 4 1 2 4 4 4 2 4 Theoretical Concentration ppm 0.5 2.0 2.0 2.0 2.0 5.0 5.0 10.0 Mean Recovery % 96.0 97.5 103.0 106.5 113.5 105.6 106.8 95.1 RSD % Mean . Recovery % 4.7 6.7 14.1 15.4 2.5 4.0 5.4 2.0 114.0 100.5 82.5 -- 97.5 -- -- 91.7 RSD % 31 10.1 1.7 0.8 -1.9 relative standard deviation (RSD) of 5.6% for halothane, and 96.5% recovery and an RSD of 3.5% for enflurane were observed. In order to determine the storage stability of halothane, two sets of four OVM's were exposed at the same time for I hour in the static test chamber; one set was analyzed within 24 hours, and the other set was stored at room temperature for 2 weeks before GC analysis was performed. No special precautions were taken; nor were the monitors stored in the foil envelopes. The test was repeated for halothane and enflurane (Sample 2) with the storage time extended to 3 weeks. Again, no special storage precautions were taken. As shown in Table III, there was no significant loss of analyte when OVM's were stored up to 3 weeks. It should be noted, however, that the results from Sample 2 were somewhat higher after storage. Since an actual increase during storage is not possible, this variance was attributed to the imprecision of the analytical procedure and not the fault of the sampling technique. Similar tests (Samples 3 and 4) were conducted on enflurane and halothane at concentrations near the detection limit of the method. Loss of analyte during storage was not observed. Table IV provides comparative field data of samples obtained during simulated and actual surgery. In tests 1-3, halothane and nitrous oxide were leaked into an unoccupied operating room equipped with a scavenging system; nitrous oxide was added at a rate equivalent to amounts commonly used with halothane. In order to achieve simultaneous and uniform sampling of the operating room atmosphere, OVM's and CTs were positioned on top of an IR analyzer located between the anesthetic gas source and the wall mounted exhaust register. A good correlation was observed between OVM, CT, and IR monitors. Of special significance is the excellent agreement among results obtained on Sample 1. Although an agreement between the OVM, CT. and IR results for Sample 2 is not quite as good, it should be noted that the OVM result falls between CT and IR. Samples 4, 5, and 6 represent multipoint collections of samples taken during surgery, the'anesthesia being used was nitrous oxide and enflurane. As not to interfere with any of the operating room practices, the sampling apparatus for Sample 4 was located along the wall furthest removed from the surgical team. Also, in keeping with previously conducted tests, OVM's and C'Ps were placed in close proximity to each other. The enflurane concentration level obtained with these samplers is shown in Table IV. Other OVM's (Sample 5) were placed on top of the anesthetic gas machine. As expected, this concentration was significantly higher than the level found in Sample 4 where enflurane had the opportunity to diffuse and become more dilute. The OVM for Sample 6 was attached to the collar of the anesthesiologist prior to surgery and removed in the recovery room after surgery. The overall exposure time was 2 hours and 5 minutes, and corresponding time-weighted average for enflurane was 0,58 ppm. conclusion The results presented in this study indicate the OVM to be a reliable, convenient method for collection of enflurane and halothane in operating room environments. Moreover, it offers several advantages over pump-type monitors. The OVM is small and compact and, because of its simplistic design, is not subject to malfunction. In addition, passive Sample 1 2 3 4 TABLE III OVM Storage Stability Halothane. ppm Enflurane. ppm Storage Time 2 wks 3 wks 2 wks 3 wks Before Storage 1.95 1.92 0.17 0.18 After Storage 1.83 2.09 0.16 0.15 Before Storage -- 1.66 0.19 0.19 After Storage 1.75 0.17 0.19 3M 110815320 Am. Ind. Hyg. Assoc. J. (41) May. 1980 Sample 1 2 3 4 5 6 TABLE IV Field Data Halothane OVM ppm' CT ppm" IR ppm1 3.42 1.87 0.40 -- 3.43 2.04 0.56 -- --- 3.53 1.78 0 55 -- - Enfiurane . OVM PpmA CT ppm" -- -- 0.49 1.39 0.58 -* -- -- 0.52 (N) (N) 'Average of four OVM's. "Average of two CT's. 'integration of chart reading (N)Not taken so as to not interfere with operating room procedures. dosimeters come preassembled, whereas CT dosimeters require on-site assembly of components. Most important, utilization of the OVM does not interfere with personnel work routines nor present a contamination problem. Finally, the OVM becomes cost-effective when one takes into account equipment costs and personnel time required for the operation and maintenance of a charcoal tube sampling system. references 1 Cohen, E. N.. B. W. Brown. O. L. Bruce, H. F. Cascorbi.W. Corbett, T. H, Jones and C. E. Whitcher: Occupational Disease Among Operating Room Personnel -- A National Study. Anesthesiology 41 ;321 (1974). 2.Cohen, E. N., B. W. Brown, D. L. Bruce, H. F. Cascorbi.W. Corbett, T. H. Jones and C. E. Whitcher: A Survey of Anesthetic Health Hazards Among Dentists. J. Amer. Dent. Assoc. 90:1291 (1975). 3. NIOSH: Criteria for a Recommended Standard Occupational Exposure to Waste Anesthetic Cases and Vapors, DHEW (NIOSH) Publication No. 77-140(1977). 4. Panner, B."J., R. B. Freeman, L. A. Roth-Moyo and W. Mark witch: Toxicity Following Methoxyflurane Anesthesia -- I. Clinical and Pathological Observations in Two Fatal Cases. JAMA 214:86 (1970). 5. Tobey, R. E. and R. J. Clubb: Renal Function After Methoxyflurane and Halothane Anesthesia. JAMA. 233:649 (1973). 6. Usubiaga, L., J. A. Aldrete and V. Fiserova-Bergarova: Influence of Gas Flows and Operating Room Ventilation on the Daily Exposure of Anesthetists to Halothane. Anesth. Analg. (Cleveland). 51:968 (1972). 7. Strunin, L., J. M. Strunin and C. C. Mallios: Atmospheric Pollution With Halothane During Outpatient Dental Anesthesia. Brit. Med. J. 41:459 (1973). 8. Nikki, P., P. Pfaffi, K. Ahlman and R, Ralli: Chronic Exposure to Anesthetic Gases in the Operating Theatre and Recovery Room. Ann. Clin. Res. 4:266 (1972). 9. Gotell, P. and L. Sundell: Anesthetists' Exposure to Halothane. Lancet (Lett). 2:424 (1972). 10. Malmlund. H. O.: Determination of Oxygen. Carbon Dioxide, and Nitrous Oxide in Blood by Gas Chromatography. Scand. J. Clin. Lab. Invest. 28:411 (1971). 11. Finkelson, M. J.: Gas-Solid Chromatographic Determination of Oxygen, Nitrogen, Carbon Dioxide, Ethylene, and Nitrous Oxide at Ambient Temperature. J. Assoc. Off. Anal. Chem. 56:119 (1973). 12. Patzelova, V.: Gas Chromatographic Separation of Anesthetizing Gaseous Mixtures. Chromatographic. 4:174 (1971). 1 3. Wohlers, H. C., J. H. Suffet, W. S. Blakemore. D. Kenepp, L. L. Coriell and G. J. McGarrity: Gaseous Pollutant Evaluation of Hospital Clean Rooms. Am. Ind. Hyg. Assoc. J. 32:813 (1971). 14. Hanst, P. L., A. A. Lefohn and B. W. Gay, Jr.: Detection of Atmospheric Pollutants at Parts-Per-Billion Levels by Infrared Spectroscopy. Appl. Spectrosc. 27:188 (1973). 15. Lane. G. A.: The Measurement of Low Concentrations of Nitrous Oxide and Halothane by Infrared Spectroscopy. Brit. J. Anesthesia. 48:274 (1976). AWS Safety/Health research program fund drive The American Welding Society has launched a major fund drive to support a Welding Safety and Health Research Program with the overall objectives of: 1) demonstrating that the welding environment can be safe when responsible environmental precautions are followed and 2) meeting government requirements, that are technically and economically feasible. One long range research project will be concerned with the health effects of the welding environment on those who work with mild steel. Other research projects that are planned include a detailed chemical analysis of welding fume, a design for optimum ventilation systems, and short and long-term animal testing to predict health effects. Safety training materials will be developed as part of this Research Program. All companies and organizations within the welding industry, as well as all those with a vested concern for advancements in the fields of occupational safety and health, are being asked to financially support this Research Program to a reasonable degree -- consistent with the importance of welding within the individual company or organization structure. To fund the projects now ready for implementation, a minimum of $500,000 is required per year for the next five to ten years. A brochure "Creating a Healthful Environment ... a Challenge to the Welding Industry" containing additional details on this Program, is available from Publications Services, American Welding Society, 2501 N.W. 7th Street. Miami, FL 33125. Telephone 305/642-7090. For additional information on this Program, contact Marvin Kennebeck, AWS Safety and Health Manager, at the American Welding Society. American Industrial Hygiene Association JOURNAL (41) 5/80 3H 110816 321 I. #3500 LABORATORY EVALUATION A. Toluene Dr. T. Takada of Kitazato University in Japan studies the response of the #3500 to varying time-concentration relationships of toluene. Four levels from 10-200 ppm were generated in a test chamber. Moni tors were exposed to these concentrations over varying time intervals. Temperature and humidity were kept constant at 24.3 C and 51%. Results show that the monitors can accurately predict varying con centration over time. A fifteen minute side-by-side exposure with charcoal tubes also shows excellent agreement. time and weight of Toluene collected in 3 M organic vapor monitor 3 Relation between exposure time and weight of Toluene collected in 3M organic vapor monitor in 3M organic vapor moni tor 5 Relation between concen tration in chamber and col lcctcd weight of Toluene in 3M organic vapor moni tor 02 7 Temporal change of Toluene concentration in chamber and T!\A concentration by 3M monitor 3M 110817 3 Mmonitor or charcoal lobe [p;*n] SI 8 Relation between Toluene concentration by 3 M monitor and by charcoal tube and the one in the chamber SE 2 Monitor and chamber concentration and collection rate of Toluene vapor exposure i monitor ' chamber I collection time , cone. Ippml : cone. Cppmj j Cnte%j 0 --0 13 0 :00--1 15 o :00--2 15 ` 3 00--3 15 4 00--4 15 5 00--3 13 6 00--G 15 1 00--7 15 S 00--S 15 0 __-1 20 n 20--4 00 4 00--0 00 G 00--8 00 0 --4 00 4 00--s 00 0 --5 00 ' 78.8 S4. 5 90, 1 43. 2 32. G 23. G 47, T 4S. 7 51.7 70.7 50.9 21.6 43.7 59.1 33. G 45, A i t 76.1 86.7 97.1 46.9 32.7 26.5 31.7 52.1 49.2 83.8 51.1 20.6 47.6 68.5 31. S 46. S , 103.5 ! 97.5 92.8 92.1 99.7 107.9 150,5 93.5 105.1 84.4 98.8 104. 9 91.8 86.3 103.7 96.8 SI 6 Schematic diagram of experimental apparatus - Scanning electron microscopte photograph uf white membrane f'o/. 1 .Vo. 2 19i>0 ?E3 Sen tin ir.g cit'dron micro^copic piioiofr;*;;:'. uf artivc adsorbent nu`d: n; 3M 110S1S II. #3500 LABORATORY EVALUATION B. Toluene and mixture of Toluene, isobutyl Alcohol, Acetone, and Perchloroethylene. The Technical Research Center of Finland ran controlled laboratory comparisons of the #3500 vs. standard charcoal tubes and calibrated, low flow pumps. The compounds studied were Toluene, a mixture of Toluene and Iso Butyl Alcohol, Acetone, and Perchloroethylene. Chamber concentrations were checked by Miran IA infrared and by direct GC analysis. Agreement with the reference methods are excellent except in the case where exposure time was less than the recommended fifteen minutes or deliberate overload conditions were chosen. In Over load conditions, the 3500 more closely estimated the concentration than the tube. TOLUENE TECH. RESEARCH CENTER OF FINLAND SAMPLE TIME - 4 hrs. RESULTS - PPM MIRAN, IA GC 3500 #1 #2 #3 #4 #5 #6 #7 #8 TUBE #1 TUBE #2 TEST #1 288 289 297 287 - - - 283 -- TEST # 2 89 86 86 87 87 85 88 88 87 89 85 85 3M 110819 TOLUENE TECH RESEARCH CENTER OF FINLAND RESULTS - PPM SHORT TERM SAMPLING Test #1 Test #2 Sample Time (min.) 20 15 Test #3 10 Miran, IA GC #3500 #1 #3500 #2 560 560 560 544 544 544 550 600 503 542 530 529 MIXTURE TEST TECHNICAL RESEARCH CENTER OF FINLAND MONITOR - 3M #3500 RESULTS - PPM SAMPLE TIME: TUBES 1 & 2 - 66 min. TUBES 3 & 4 - 30 min. #3500 - 220 min. Miran, IA G. C. Tube 1 Tube 2 Tube 3 Tube 4 #3500 1 2 3 4 5 6 Tube #3500 ISO BUTYL ALCOHOL 144 143 150 138 138 130 138 148 144 142 146 144 139 +8.2 144 + 3.5 TOLUENE 180 175 164 168 169 169 166 178 176 165 180 170 168 +2.4 173 + 6.4 3M 110820 ACETONE TECH RESEARCH CENTER OF FINLAND RESULTS - PPM Test #1 Sample time ( min.) 65 Miran,IA GC #1 GC #2 #3500 #1 #3500 #2 1070 1066 - 1043 1063 Tube #1 Tube #2 -- - * Deliberate Overload Condition Test #2* 240 1555 1538 1560 1338 1210 1018 1007 Test #3 240 385 380 - 373 400 377 . 400 PERCHLOROETHYLENE TECH RESEARCH CENTER OF FINLAND SAMPLE TIME - 4 hrs. RESULTS - PPM TEST #1 Miran,IA GC #1 GC #2 120 121 125 #3500 #1 #3500 #2 124 121 . Tube 122 TEST #2 42 40 42 41 42 - 3M 110821 I. #3500 LABORATORY EVALUATION C. Styrene and Acetone Mixture The Jutlandish Institute of Technology in Denmark performed a laboratory comparison of a Styrene and Acetone mixture using #3500 OVM and SKC standard charcoal tubes. Low flow, calibrated pumps were used for the SKC tubes and both systems were exposed for four hours. Two separate tests were conducted at different concentrations of the Acetone - Styrene mixture. Comparability of the two methods for the mixture is demonstrated. JUTLANDISH TECHNOLOGICAL INSTITUTE - DENMARK MONITOR - 3M #3500 PUMP & TUBE - SKC EXPOSURE TIME - 4 HRS. RESULTS - Mg/M3 TEST #1 TUBE #1 TUBE #2 MONITOR #1 MONITOR #2 Acetone Styrene 699 710 358 344 677 349 694 378 TEST #2 TUBE #3 MONITOR # 3 MONITOR #4 Acetone Styrene 198 187 125 120 192 124 ANALYTICAL UNCERTAINTY < + 5% RELATIVE 3H 110822 I. #3500 LABORATORY EVALUATION D. Vinyl Chloride A chemical company set up a lab trial to expose both #3500 and a standard charcoal tube to 0.61 ppm of VC. An airstream containing 0.61 ppm of VC was passed over the #3500 for fifteen minutes at two liters per minute. The same airstream was introduced into gas sampling bags and then pulled through the tube in ninety minutes with a low flow pump. Relative Precision at 95% confidence level was 15% for the #3500 and 114% for the tube. VINYL CHLORIDE EXPOSURE - 0.61 PPM RESULTS - PPM #3500 0.63 0.48 0.56 0.52 0.65 0.71 0.59 0.09 PUMP & TUBE 2.3 1.2 0.4 0.8 0.05 X 0.95 S 0.87 3M 110823 I. LABORATORY EVALUATION E. Stability of Samples using Dichloromethane, 1, 2 Dichloroethane, Tetrachloroethylene, Heptane. The following data shows that the #3500 is gas tight. The data relate storage time to recovery coefficients (Desorption Efficiency). This data are valid only when the compound is stable. Recovery Coefficients may drop due to decomposition, polymer ization, etc. over extended storage time. Methyl Ethyl Ketone is an example of decaying recoveries over time. Reliability of samples are not assured if the captured volatile compound can escape during storage. Storage Life Test Days Dichloromethane 1 2 3 4 5 1 3 10 14 31 1,2-Dichloroethane 1 2 3 4 5 1 3 10 14 31 Tetrachloroethylene 1 2 3 4 5 1 3 10 14 31 Heptane 11 2 81 3 132 4 237 Recovery - 2o~ .02 | .02 .93 T .06 J*91 .02 .90 x .01 .90 .01 .98 9? | .96 j .96 - .01 .03 .01 .02 .01 1.00 | 1.02 t 1.00 r 1.02 t 1.01 - .05 .01 .08 .02 .03 1.04 x .06 1.05 T .02 1.03 x .04 1.04 - .03 3H 110824 X. #3500 LABORATORY EVALUATION F. Enflurane A study at an eastern U.S. university was carried out comparing the #3500, Miran 1A and Charcoal Tube (C.T.) to a known concentration in an exposure chamber. The Miran sampled continuously with readings taken at fifteen minute intervals. Velocity scans were taken along with pressure and temperature to insure uniformity of exposure conditions. The #3500 correlated well with the tank concentration and had excellent coefficient of variance. The regression slope of #3500 versus tank concentration was 0.95. ENFLURANCE LABORATORY STUDY CORRELATION COEFFICIENTS LINEAR REGRESSION 3500 - Tank 3500 - C. T. 3500 ~ Miran 0.960 0.970 0.963 LINEAR REGRESSION (FIT THROUGH ZERO) 3500 - Tank 0.990 3500 - C. T. 0.993 3500 - Miran 0.990 COEFFICIENTS OF VARIATION TANK CONC. (PPM) 3500 MIRAN 5 0.08 0.10 10 0.06 0.07 20 0.16 0.03 C.T. 0.11 0.27 0.25 3H 110825 ENFLURANE LAB STUDY RESULTS " PPM TANK 5 10 20 3500 5.6 4.8 4.6 4.6 4.6 4.6 9.2 9.7 8.2 9.2 9.7 9.7 19.4 19.4 18.1 17.6 19.1 27.5 19.1 19.4 C.T. 5.2 5.2 4.6 4.6 5.0 5.0 10.4 10.4 8.5 8.5 8.9 8.9 19.7 19.7 19.3 19.3 20.9 20.9 19.2 19.2 MIRAN 4.4 4.4 4.2 4.2 4.2 4.2 8.8 8.8 7.8 7.8 8.0 8.0 15.9 15.9 15.3 15.3 15.9 15.9 15.9 15.9 3M 110826 II. FIELD EVALUATION A. Complex Mixtures A U.S. chemical company ran a field comparison between a 600 mg. charcoal tube and the #3500 in a complex mixture. Agreement is good for all cases except acetone, where it appears the #3500 samples are high. In fact, the #3500 is more closely estimating the true valve. In these conditions, it is believed that acetone is subject to displacement and is more readily swept from the tube. A diffusional system has no flow of air, only organic vapor, and suffers less from displacement losses. MIXTURES SAMPLE TIME: 6 hrs. RESULTS - PPM TUBE - 600 rag. #3500 Pump & Tube MIBK TOLUENE N-BUTYL ACETATE XYLENE MEK ACETONE METHYLENE CHLORIDE TRICHLOROETHYLENE PERCHLOROETHYLENE ACETONE METHYLENE CHLORIDE TRICHLOROETHYLENE PERCHLOROETHYENE ACETONE 8.5 16.5 2.3 0.4 ND 264 0.5 0.6 0.5 66.7 11.3 0.1 0.6 35.4 4.6 13.8 2.5 0.3 ND 115 0.3 0.4 0.3 45.2 9.2 0.1 0.4 17.0 3M 110827 II. FIELD EVALUATIONS B. Field Samples of Aromatics; Benzene, Toluene, Xylene in complex mixtures. A major oil company ran extensive side-by side comparative studies of standard charcoal tubes and the #3500. Thirty samples were taken for Benzene, Toluene and Xylene. These compounds were present together in a complex mixture of hydrocarbons. The #3500 showed good agreement with the means and deviations generated by the tube. The methods correlate well in this field sampling of mixtures. FIELD SAMPLES - AROMATICS NUMBER OF SAMPLES - 30 CHARCOAL TUBE (CT.) VS. #3500 RESULTS - PPM BENZENE - 3500 BENZENE - CT TOLUENE - 3500 TOLUENE - CT XYLENE - 3500 XYLENE - CT MEAN 0.396 0.334 0.508 0.463 0.397 0.367 STD. DEV 0.418 0.405 0.715 0.699 1.065 0.863 CORRELATION COEFFICIENTS Benzene - 0.894 Toluene - 0.935 Xylene - 0.966 3M 110828 II. FIELD EVALUATION C. Benzene-Toluene Mixture A U.S. chemical company ran side-by-side personal exposures with the #3500 and standard charcoal tubes. Benzene and Toluene were present at the same time in the air. For Benzene/ the correlation coefficient is 0.936 with linear regression of: C.T. = 0.823 (OVM) + 0.009 For Toluene, the correlation coefficient is 0.973 with linear regression of: C.T. = 1.02 (OVM) - 0.018 BENZENE - TOLUENE PERSONAL SAMPLES SAMPLE TIME: 8 hrs. RESULTS - PPM . BENZENE TOLUENE #3500 0.17 0.15 0.15 0.10 0.12 0.05 0.05 0.80 0.20 0.05 0.20 0.80 0.08 0.02 ND Pump & Tube 0.19 0.13 0.12 0-02 0.14 0.03 0.05 0.84 0.14 0.03 0.15 0.50 0.19' 0.02 ND #3500 0.15 0.10 0.18 0.13 ND ND ND 1.12 0.02 0.05 0.10 0.45 0.15 0.05 0.05 Pump & Tube 0.17 0.06 0.22 0.02 ND ND ND 1.18 0.02 0.04 0.10 0.26 0.24 0.02 ' 0.05 ND - Non Detected 3M 110S29 II. FIELD EVALUATION D. 1,1,2-Trichloroethylene 3M Company Industrial Hygiene ran comparison personal samples in a 3M plant. Samples were run for four hours and converted to TLV-TWA. Correlation was good between the two methods. 1,1,2 TRICHLOROETHYLENE 3M PLANT SAMPLE TIME: 4 hrs. RESULTS - PPM CORRELATION COEFFICIENT = 0.991 #3500 0.7 7.3 5.1 4.2 2.2 4.0 3.4 1.0 1.4 9.8 7.6 0.4 3.0 1.6 3.1 o 00 PUMP & TUBE 0.8 0.6 8.5 5.9 3.9 2.0 4.6 4.9 0.9 1.1 11.9 9.6 0.2 3.4 1.8 2.8 3H 110830 II. FIELD EVALUATION E. Acetone Three separate methods of measuring acetone in a field area sample were used. The 600 mg. tubes were used in series to be certain that loss through the tut>e was minimized. comparability between methods is good. ACETONE AREA SAMPLES Rh = 45% - 58% RESULTS - PPM METHOD #1 15 1 Bag Pump - 30 cc/min Sample time: 1-6 nrs. 182 18y 354 370 419 491 152 147 METHOD #2 2-600 mg tubes Pump - 40-60 cc/min Sample time: 3-6hrs. METHOD #3 #3500 Sample time: 3-6 hrs. 175 194 - 221 307 331 323 322 - 456 484 458 131 135 116 136 3M 110831 II. FIELD EVALUATION F. Benzene A steel company ran side-by-side area samples between the #3500 and a standard charcoal tube. The range of concentrations found were non-detectable to over 90 ppm, with an average of 7.89 ppm. A high degree of correlation exests between the 79 parts of sample data. BENZENE AREA SAMPLES CHARCOAL TUBE (C.T.) vs. #3500 NUMBER OF SAMPLES - 79 CONCENTRATION RANGE - 0-90 PPM AVG. CONCENTRATION - 7.89 PPM REGRESSION EQUATION #3500 = 1.063 (C.T.) + 0.091 r = 0.9988 r (Indoor) = 0.9980 r (Outdoor) = 0.9991 BENZENE PRESENT IN ATMOSPHERE CONTAINING TOLUENE AND XYLENE. 3M 110832 III. LABORATORY & FIELD EVALUATION A. Enflurane and Halothane The U.S. Army Environmental Hygiene Agency performed both laboratory and field testing on the subject gases. Field data was taken in both unoccupied and occupied operating rooms. The statistical data is for the lab trials and shows percent of theoretical measured by the monitor. Variability is measured by relative standard deviation. The complete study is published in the May 1980 AIHA Journal. HALOTHANE AND ENFLURANE LABORATORY DATA Sample Exposure Time OVM, Hrs Theoretical Cone., ppm Mean Observed Enflurance, ppm OVM* CT+ Mean Observed Halothane, ppm OVM* CT+ 14 5 5.28 5.14 22 5 -- -- 5.34 5.40 34 2 -- -- 2.13 2.23 44 0.5 0.57 0.64 0.48 0.59 54 2 1.95 2.13 2.27 2.30 62 2 1.65 2.47 2.06 2.22 71 2 2.01 2.11 1.95 2.11 8 4 10 9.17 11.49 9.51 10.30 Average of four OVM's +Average of two CT's for Samples 6 and 7; all others average of four CT's Charcoal Tube - SKC 200/400 mg Tube Sample Rates ~ 30 ml/min + 500 ml/min. 3H 110833 STATISTICAL SUMMARY OF OVM RESULTS Exposure Theoretical Time Concentration Hrs. ppm Halothane Mean Recovery RSD %% Enflurane Mean Recovery RSD %% 4 0.5 1 2.0 2 2.0 4 2.0 4 2.0 4 5.0 2 5.0 4 10.0 96.0 97.5 103.0 106.5 113.5 105.6 106.8 95.1 4.7 6.7 14.1 15.4 2.5 4.0 5.4 2.0 114.0 100.5 82.5 -- 97.5 -- -- 91.7 3.1 10.1 1.7 -- 0.8 -- -- 1.9 OVERALL RECOVERY HALOTHANE 100.6 9 RELATIVE iSTANDARD DEVIATION (RDS) 5.6 FIELD DATA ENFLURANE 96.5 3.5 Sample OVM ppm* Halothane CT ppm+ IR ppm** Enflurane OVM CT+ ppm* ppm+ * 1 3.42 3.43 3.53 2 1.87 2.04 1.78 -- -- 3 0.40 0.56 0.55 -- -- 4 -- -- -- 0.49 0.52 5 -- -- -- 1.39 # 6 " " -- " -- ** 0.58 # Average of four OVM's +Average of two CT's. Integration of chart reading #Not taken so as1 to not interfere with operating room procedures, Samples 1-3 & 4-5 - Area Samples Sample 6 - Personal Sample 3M 110834 III. LABORATORY AND FIELD EVALUATION B. Methyl Methacrylate A dynamic standards generator was used to produce known quan tities of MMA in a laboratory chamber. Percent relative error of the #3500 over concentrations of 8.3, 23.9, 48.3 and 92.8 PPM averaged 3.2% with a range of 0.4-4.8%. Lab precision tests are shown, plus the side-by-side comparison of standard charcoal tubes vs. the #3500 in personal field samples. LAB PRECISION TEST METHYL METHACRYLATE RESULTS - mg./hr. SAMPLE NUMBER - 6 EXPOSURE TIME - 8 HRS. THEORETICAL CONCENTRATION (PPM) 48.3 23.96 8.36 FIELD SAMPLES METHYL METHACRYLATE RESULTS - PPM #3500 (mg/hr) X = 0.3358 s = 0.0058 %CV = 1.73 X 0.1795 s = 0.0011 %CV = 0.63 X = 0.0573 s = 0.0005 %CV = 0.95% #3500 SO.6 57.0 187.8 6.0 2.3 4.8 35.5 3.8 2.5 2.3 5-1 3.1 PUMP & TUBE 88.1 61.6 146.5 5.50* 3.2 6.3 38.5 4.0 2.9 2.6 5.6 2.3 *Avg. of two samples 3H 110835 COMPARISON OF 3M'ORGANIC VAPOR MONITOR' VERSUS CHARCOAL TUBES In the Organic Vapor Monitor (OVM) only the contaminant is transported. The OVM consists of a charcoal disc of known area. A draft shield is a known distance above the disc. Between the draft shield and the disc, contaminant transport is by diffusion. The driving force is the difference between the contaminant concentration at the draft shield surface (the concentration one wishes to measure) and at the surface of the collection disc (which is essentially zero). The total amount of contaminant collected is proportional to the area of the disc, the driving force, the diffusion coefficient, and the duration of exposure, and inversely proportional to the distance between the draft shield and the disc [N = DA/L (Ce- 0) T]. Thus, since D, A, and L are constants, if one determines the amount collected (N) and the duration of exposure (t), the average concentration (Ce ) can be calculated. Of the seventy-nine (79) sets of paired samples, only two were personal samples. The remainder were general area samples. In all cases the opening to the charcoal tube was within approximately 1 to 2 inches of the draft shield of the OVM. All sample sets had a minimum sampling period of six hours. In some cases the total sampling period was split between two charcoal tubes, and a time-weighted average was determined. However, in the majority of the cases only one tube was used per sampling period. Although in these field tests the samples were analyzed for benzene, toluene and xylene, the subject report is only an analysis of the benzene results. This is mainly because benzene exposure measurement is more important presently than toluene and xylene. All results in this report refer to benzene measurements. Further reports will analyze the toluene and xylene data. Results For the 79 sample pairs, the benzene concentrations ranged from 0.00 ppm (or non-detectable) to slightly greater than 90 ppm. Based on the charcoal tube results (using charcoal tube as the independent variable), the sample distribution is listed in Table I. A list of all the individual sample results is contained in Table III at the end of the report. TABLE I Concentration Range No. of Samples Samples % of Total . Cumulative % ppm 1- 5 ppm 5-10 ppm 10-25 ppm 25 ppm 32 26 8 6 8 39.3 32.9 10.1 7.6 10.1 39.3 72.2 82.3 89.9 100.0 Average =7.89 ppm Std. Dev. = 15.99 ppm 3M 110836 The following linear regression equation of best fit was generated from the 79 samples pairs: OVM = 1.063 x Charcoal Tube + 0.091 The coefficient of correlation (r) for this data equals 0.9988. A r-value of 1.0 would represent a perfect correlation. Of the 79 sample pairs, 32 were taken indoors and 47 were taken outdoors. In order to see if there were any apparent differences in the two sampling circumstances, separate analyses were also performed on each set. The following regression equations were generated: INDOOR: OVM = 1.081 x Charcoal Tube + 0.043 r = 0.9980 n = 32 samples OUTDOOR: OVM = 1.058 x Charcoal Tube + 0.107 r = 0.9991 n = 47 samples In addition to the correlation field tests performed, a few precision tests on the OMV were conducted. Although 3M has conducted a great number of lab precision tests, few field tests have been conducted. A total of five sets of four OVM's were exposed. In each set two were analyzed by 3M and two by our lab. The results are listed in Table II. TABLE II Set 1 Set 2 Set 3 Set 4 Set 5 R-30.03 R-30.64 3M-30.71 3M-31.32 R- 1.03 R- 1.03 3M- 1.16 3M- 1.18 R- 0.64 R- 0.64 3M- 0.64 3M- 0.67 R- 2.47 R- 2.47 3M- 2.43 3M- 2.55 R- 0.14 R- 0.14 3M- 0.18 3M- 0.21 X=30.68 RSD=1.7* X= 1.10 RSD= 7.3* X= 0.65 RSD= 3.1* X= 2.48 X= 0.17 RSD= 2.0* RSD=17.6* Discussion of Results As can be seen from examining the results, there is excellent correlation between the two methods. The OVM's generally measure about 6$ higher than the charcoal tubes. In addition, since the Y-intercept is less than 0.1, even at very low concentrations, the ratio of OVM result to charcoal tube result remains consistent. The important point to consider is that neither method is necessarily correct, but that they are highly correctable. 3M 110837 The regression equations and correlation coefficients for the indoor and outdoor samples show there is essentially no difference between the two. Although the effort has not been made to prove this statistically, it appears to be the case. This demonstrates that in most indoor situations there is sufficient air movement to assure that diffusion within the OVM is the rate-limiting mode of transport. The samples that were collected in November have been temperature corrected. Although in general the OVM is fairly temperature independent (it varies directly with the square root of the ratio to standard temperature), the difference between the OVM's and charcoal tubes is temperature dependent to a greater degree. This is due to the charcoal tube results varying inversely with the ratio to standard temperature. The overall result is the difference varies with the three halves power of the temperature ratio [Difference (T/Ts) 3/2]# The temperatures on the sample days in November ranged from 15to 25C below standard temperature. At 0C the charcoal tube results are approximately high relative to the OVM results if left uncorrected. As seen in Table II the precision of our OVM's is very good. Typical charcoal tube relative standard deviations are approximately 10--15%. Most of the variation is due to varying pump performance, and the elimination of the pump from the sample collection process aids precision. In addition to benzene, toluene and xylene, other organic vapors (mostly heavier compounds) exist in the by-products area. The data show that the existence of mixed vapor systems does not significantly affect the performance of a diffusion device versus that of an active sampling device in the determination of benzene concentrations. The major advantage to the use of the OVM in the field is the absence of a sampling pump. Thus, pump mechanical problems no longer are a concern. In addition, pump calibration and maintenance time is minimized. Also, the OVM offers less physical hindrance to a worker than a pump and sampling train. 3M is currently making some packaging changes which should make the units easier to use in the field. Conclusions (1) An almost perfect correlation exists between the charcoal tube method and the OVM method for the determination of benzene concentrations in air. (2) The OVM method gives results approximately tube method. higher than the (3) There is sufficient air movement indoors to allow the OVM to function correctly. 3H 110838 Conclusions (Cont'd.) (4) Mixed vapor systems do not affect the OVM differently than charcoal tubes. (5) The OVM is at least as precise as the charcoal tube method. (6) The OVM is more reliable in the field than the charcoal tube/pump combination. Recommendations (1) The 3M Organic Vapor Monitor should be used for the determination of personal and area exposures to benzene. (2) Additional data for toluene and xylene should be analyzed in manner similar to that for benzene. 3M 110839 TABLE III IndividuaI Sample Results - Benzene Test Date Indoor or Outdoor Charcoal Building Tube (ppm) 3M OVM (ppm) 1 7 June Out 2 It Out 3 4 11 Out 11 In 5 II In 6 It In 7 II In 8 <1 Out 9 It Out 0.21 0.07 0.13 1.11 2.77 0.39 0.62 0.47 0.75 0.20 0.07 0.14 1.10 2.47 0.35 0.64 0.53 0.83 10 8 June In 11 11 It 12 II I 13 It 11 14 tl ll 15 it 11 0.21 0.81 0.28 2.64 0.91 0.30 0.42 1.21 0.41 2.85 0.95 0.49 16 9 June Out 1.81 1.93 17 II tt 0.84 0.91 18 11 M 7.98 8.82 19 II II 2.09 2.23 20 ll If 21.55 23.55 21 tl It 22.04 22.43 22 II It 75.42 81.93 23 It tt 29-13 33.09 24 14 June In 25 II tl 26 It If 0.60 0.42 0.55 0.56 0.50 0.56 27 20 June Out 10.02 9.60 28 it M 30.17 30.34 29 It It 90.73 94.05 30 ll it 13-22 15.79 *3 21 June In *3 If ;t 33 17 August In 34 it If 35 ll it 36 It it 37 ;t Out 38 IT If 39 ii tl 40 it II 41 M tl 2.12 1.73 0.14 0.45 1.46 1.23 5.81 0.18 0.03 3.64 1.57 2.57 1.94 0.22 0.59 2.17 1.26 6.78 0.23 0.00 4.61 2.04 . 3H 110840 Sample No^ 42 43 44 45 46 47 48 49 50 51 52 53 54 56 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 TABLE III Individual Sample Results - Benzene Test Date Indoor or Outdoor Charcoal Building Tube (ppm) 8 November II If If II If il If II In tl II It It It Out ft II 0.00 0.15 0.56 0.07 47.30 35.32 0.66 2.27 9.61 9 November If II It If If ft If It It In It II Out tt It If II If In 0.48 0.55 1.07 2.88 4.38 1.41 1.63 5.22 4.59 1.50 20 November It If ft ft It ft It It Out II II If . II It tt It It 6.78 7.62 2.81 2.91 1.99 1.87 2.88 3.68 22.10 21 November It II tl if II fi IT it It In tt If Out If tt II It II 11 8.75 15.80 40.60 0.78 38.30 1.58 7.20 0.48 0.87 0.44 Page 2 3M OVM (ppm) 0.00 0.00 0.52 0.00 49.71 42.06 0.61 2.72 11.08 0.50 0.57 1.22 3-58 5.28 1.59 1.71 6.00 4.84 1.45 7.49 8.76 2.79 2.81 1.91 1.07 1.86 3.75 22.20 8.80 17.80 42.20 0.89 41.30 2.00 7.63 0.40 0.90 0.74 ^Personal Samples Note: Samples #42 - 70 have been temperature corrected. 3M 110841 3M Occupational Health and Environmental Safety Division 3M Center St. Paul, Minnesota 55144-1000 612/733 1110 Mark Puskar Abbott Laboratories, D-38A 1401 Sheridan Rd North Chicago, IL 60064 Dear Mark: I want to apologize for the delay in responding to your methylene chloride study. We would like to participate in the study, however it should be noted that our 3M 3520 Organic Vapor Monitor has limitations. The monitor has a maximum capacity micrograms at high relative humidities (i.e., >60%). This capacity will increase as relative humidity drops. Based on a capacity of 3000 micrograms, the maximum concentration measurements are as follows: 15 minutes: 240 minutes: 480 minutes: 1518 ppm 120 ppm (' 6cT) ppm Based on this information we recommend that sampling be limited to four hours when methylene chloride concentrations are unknown. However, if concentrations are expected to be at the TLV (50 ppm) or below, the use of the 3520 monitor is acceptable. The validation study that Abbott outlined calls for a sampling site that is greater then 50 ppm methylene chloride. If an 8 hour sample was collected at this location, it is feasible that the capacity of the monitor may be exceeded. This sampling site pushes the limitation of the monitor. However, all of the other sampling sites, including the sampling times, fall within the limitations of the 3M 3520 monitor. We would like to participate in the study, however, we want to caution you that our 3M 3520 monitor cannot be used in all situations, just like most other sampling devices. QOO WorWwldo Sponsor '992 Olympic Games 3M 110842 Mark Puskar Page Two October 16, 1992 Per our discussion, we have spiked organic vapor monitors with methylene chloride. We have four sets with triplicates in each set. The methylene chloride concentrations are as follows: Set A: Set B: Set C: Set D: Set F: 1330 microgram 265 microgram 530 microgram 2650 micrograms Blanks If you have any questions, please feel free to give me a call at 612-737-4459. I look forward to working with you and Abbott in the future. Regards, Robert A. Weber, CIH Technical Service Representative 3M Occupational Health & Environmental Safety Division RAW:llj/54 Enclosure 3H 110843 3M Organic Vapor Monitor Summary of Technical Data Correlation With Methylene Chloride Acetone Methyl Acetate Pentane Charcoal Tubes ' Comparison of Diffusional Organic Vapor Monitors with Charcoal Tubes for Sampling Laboratory Challenges to Contaminant- Mixtures Laboratory Performance of Passive Personal Samplers for Waste Anesthetic Gas (Enflurane)oncentrations Field comparison of Charcoal Tubes and Passive Vapor Monitors with Mixed Organic Vapors ^ Sampling Variable Concentration Toluene Mixture (MEK/Hexane/Ethyl Benzene/1,1,2,2 Tetrachloroethane) Mixture (Toluene/MEK/TCE/Hexane/Ethyl Acetate) Sampling High Vapor Pressure Compounds Vinyl Chloride Pentane Dichloromethane Acetone Methyl Acetate 3M 110844 CORRELATION WITH CHARCOAL TUBES 3M 110845 METHYLENE CHLORIDE RH-85% VOLUME SAMPLED (liters) METHYLENE CHLORIDE RH-85% A 3M-0VM Charcoal Tubes 3M 110847 acetone RH-85% A 3M-0VM Charcoal Tubes 25% Accuracy 3H 110848 METHYL ACETATE RH-86% A 3M-0VM Charcoal Tubes 3M 110849 PENTANE RH-86% A 3M-0VM Charcoal Tabes <1 3M 110850 COMPARISON OP DIFFUSIONAL ORGANIC VAPOR MONITORS* WITH CHARCOAL TUBES FOR SAMPLING LABORATORY CHALLENGES TO CONTAMINANT MIXTURES. Anders, L. V. and Mullins, H.E., Occupational Health A Safety Products Division, 3M Company, St. Paul, Minnesota 55144. ABSTRACT Because most Industrial environments contain numerous oontamlnants, a laboratory evaluation compared performance of diffuslonal organic vapor monitors to charcoal tubes when sampling mixtures of known concentra tions. The challenges consisted of a binary mixture of toluene and methyl ethyl ketone and a tertiary mixture of benzene, toluene and xylene. Unleaded gasoline and unleaded gasoline containing various alcohols, e.g. ethanol, methanol and t-butyl alcohol were the complex mixtures used In the evaluation. The results of each sampling technique are correlated with the challenges of known concentrations. 3M 110851 COMPARISON OF DIFFUSIONAL ORGANIC VAPOR MONITORS VITH CHARCOAL TUBES FOR SAMPLING LABORATORY CHALLENGES TO CONTAMINANT MIXTURES. ANDERS, L.W. AND MULLINS, H.E. OCCUPATIONAL HEALTH & SAFETY PRODUCTS DIVISION, 3M COMPANY SAINT PAUL, MINNESOTA 55144. INTRODUCTION Diffusional sampling devices such as the 3M Organic Vapor Monitor (OVM) offer many advantages for measuring concentration levels of industrial contaminants because they are lightweight, require no power, pump or tubing and are not likely to impede the work activity of the user. Because these sampling devices could replace the conventional pump and charcoal tubes for sampling the industrial environment, this evaluation compared the precision and accuracy of the charcoal tubes to the 3M-0rganic Vapor Monitors. A selected set of simple and complex mixtures were used to generate air concentrations normally found in the industrial environment. This evaluation consisted entirely of sampling laboratory generated air concentrations of the contaminant mixtures. Evaluating the precision and accuracy of these two sampling techniques is in keeping with the NIOSH Standards Completion Program where the precision and accuracy of the charcoal tubes were validated by sampling known air concentrations of organic vapor contaminant from a laboratory generation system. 3M 110852 o PROCEDURE To evaluate and compare the sampling performance of charcoal tubes to the 3M Organic Vapor Monitors, known air concentrations were generated for simple and complex mixture in a laboratory generator-dilution system. This system as illustrated in Figure 1, consists of a calibrated dry air gas meter, a syringe device mechanism to deliver th liquid contaminant mixture to a heated manifold, and a device to hold eighteen (18) charcoal tubes or monitors. The air concentration can be determined by measuring the Initial and final weight of the syringe containing the liquid contaminant and measuring the total air volume during a sampling period of known time. The evaluation consisted of two parts; Part I - Comparison of Charcoal Tubes to 3M - Organic Vapor Monitor (OVM) when Sampling Contaminant Mixtures at Constant Concentrations, and Part II - Comparison of Charcoal Tubes to 3M - Organic Vapor Monitor (OVM) when Sampling Contaminant Mixtures at Variable Concentrations. In Part I, mixtures and desired concentrations used for the comparison are tabulated in Table I. In this part of the evaluation, three (3) charcoal tubes and three (3) 3M - Organic Vapor Monitors samples were collected at intervals of one (1), two (2), three (3), five (5), six (6) and seven (7) hours. For each mixture, the thirty six (36) samples (18 charcoal tubes and 18 - 3M Organic Vapor monitors) were collected during an eight hour sampling period. The time-weighted-average 3M 110353 concentration during the eight hour period was determined by measuring the total air volume and the weight of the liquid contaminant mixture delivered to the heated air manifold measuring the syringe/liquid contaminant weight at the beginning and at the end of the sampling period. Eighteen (18) samples could be collected simultaneously, therefore, the following sampling profile allowed the thirty six (36) samples to be collected in an eight hour period. The one hour samples were followed by the seven hour samples, the two hour samples followed by the six hour samples, and the three hour samples followed by the five hour samples. In order to compare the results with the known time-weighted-average concentration for the eight hour period as determined by mass balance of the air flow and liquid contaminant flow to the heated manifold, the results of the following data sets must be combined. The results of one hour samples combined with the seven hour samples, the two hour samples combined with the six hour samples and the three hour samples combined with the five hour samples. Although the results of the above sample sets had to be combined to compare them to the time-weighted-average concentration determined by mass balance of the laboratory generation system, a comparison of the charcoal tube results can be compared to the 3M - Organic Vapor Monitor results for each of sampling intervals. In Part II, the mixtures and desired concentrations sampled for the evaluation are tabulated in Table II. The evaluations in Part II are divided into exposure profile A where a contaminant mixture is sampled for one hour followed by sampling air with a zero concentration of the 3M 110854 contaminant mixture for one hour. ' This sequence was repeated four tlraea. In exposure profile B, a contaminant mixture is sampled for one hour, then air with a zero concentration of the contaminant mixture Is sampled for three hours. This sequence was repeated. In both profiles, the total sampling period was eight hours with the difference being in profile A,where the contaminant mixture concentration is sampled for four hours while in profile B, the contaminant mixture concentration is sampled for only two hours. In this part of the evaluation, the variable concentrations were sampled to evaluate if any sample loss occurs during the sampling period when the contaminant mixture concentration was zero. ANALYTICAL PROCEDURES After sample collection, the 3M-0rganic Vapor Monitor and the charcoal tubes were capped and stored at ambient temperatures. The recovery coefficients were determined for the 3M-0rganio Vapor Monitor according to the reoommended procedure. The recovery coefficient for the charcoal tubes were also determined by spiking the liquid mixture on a filter paper and allowing the charcoal to collect the organic vapors. After desorbing the samples with carbon disulfide, the analysis was performed using a Hewlett Packard (584QA) gas chromatograph equipped with a flame ionization detector. For the gasoline samples, the total integrated area was used to determine the sample weight. 3M 110855 For the charcoal tubes, the sampling rates were determined by calibration of critical orifices which ranged from 30-45 cubic centimeters per minute. For the 3M-0rganlc Vapor Monitor, the sampling rates for gasoline and naphtha were determined in separate experiments by measuring the weight collection rate from a challenge of known concentration. The sampling rates and recovery coefficients are tabulated in Table III. ' Results and Discussion PART I - COMPARISON OF CHARCOAL TUBES TO 3M - ORGANIC VAPOR MONITOR (OVM) WHEN SAMPLING CONTAMINANT MIXTURES AT CONSTANT CONCENTRATIONS. The results of sampling a toluene/methyl ethyl ketone mixture are summarized and tabulated in Table IV. For toluene, there is excellent correlation of the results of charcoal tube samples and the 3M Organic Vapor Monitor samples for each of the sampling intervals. The time-weighted-average concentrations as determined by the combined results of each sample set (18 samples) was 186 mg/ra^ measured by the 3M - Organic Vapor Monitor and 176 rag/m3 measured by the charcoal tubes. When compared to the concentration as determined by the mass balance of the generation system, these results are 97? and 92? of the concentration for 3M-0rganic Vapor Monitor and charcoal tubes respectively. For methyl ethyl ketone, the results of the charcoal tubes are very low and compare poorly with those of the 3M - Organic Vapor monitor. For the 3M - Organic Vapor Monitor, the time-weighted-average concentration 3M 110856 determined by the combined sample set (18) was 144 mg/m3, This is 1041 of the concentration determined by mass balance of the generation system. For the charcoal tubes, the time-weighted-average concentration determined by the combined sample set (18) was 50 mg/m3 or 361 of the concentration determined by mass balance of the generation system. These charcoal tubes were not overloaded, in fact, no methyl ethyl ketone was found in the back section of the charcoal tubes. In Table V, the results of sampling a benzene/toluene/xylene mixture are summarized and tabulated. For each of the contaminants in the mixture, there is excellent correlation of the charcoal tube with the 3M - Organic Vapor Monitor at all sampling intervals. The total time-weighted-average concentration determined by combining the eighteen (18) samples collected by each technique enables an assessment of the accuracy by comparison with the concentration determined by mass balance of generation system. For benzene, the results are 91) and 97) for the 3M - Organic Vapor Monitor and charcoal tubes respectively when comparing to the mass balance concentration. For toluene, the results are 90) and 95) and for xylene the results are 87) and 91) for the 3M Organic Vapor Monitor and charcoal tubes respectively for each data set. In Table VI, the results of sampling a complex mixture, VM & P Naphtha, are summarized and tabulated. There is excellent correlation of the charcoal tubes with the 3M - Organic Vapor Monitor at each of the sampling intervals. The accuracy is also excellent as determined by 3M 110857 comparing the time-weighted-average concentration with the concentration determined by the mass balance of the generation system. When combining all eighteen (18) samples collected by one technique, the accuracy is 95$ and 97$ for the 3M - Organic Vapor Monitor and charcoal tubes respectively. Unleaded gasoline was sampled at two concentrations, 42 mg/ra^ and 96 mg/m3. These results are summarized and tabulated in Tables VII and VIII. Again, the correlation of the two sampling techniques Is excellent. The accuracy as determined by comparing the time-weighted-average of the eighteen (18) samples collected by each technique and the concentration as determined by the mass balance of the generation system was at, the low concentration (42 mg/m3), 91$ and 95$ and, at the high concentration (96 mg/m3), 97$ and 101$ for the 3M - Organic Vapor Monitor and the charcoal tubes respectively in each of the evaluations. Unleaded gasoline blended with ethanol and unleaded gasoline blended with methanol and tert-butyl alcohol were also sampled as complex mixtures. The results are summarized and tabulated in Tables IX and X. Again, the correlation of the two sampling techniques is excellent. In gasoline/ethanol, the accuracy was 101$ and 103$ for the 3M - Organic Vapor monitor and the charcoal tubes. For the gasoline/methanol/TBA, the accuracy was 96$ and 103$ for the 3M - Organic Vapor Monitor and the charcoal tubes. The accuracy of each sampling technique is again compared to the concentration determined by the mass balance of the generation system. ' 3H 110858 Part II - COMPARISON OF CHARCOAL TUBES TO 3M - ORGANIC VAPOR MONITOR (OVM) WHEN SAMPLING CONTAMINANT MIXTURES AT VARIABLE CONCENTRATIONS. For this part of the evaulation, the variable concentrations were generated in two way3. The results are summarized and tabulated in Table XI for samples collected when sampling a high concentration of the contaminant mixture on one hour followed by sampling a zero concentration for three hours. This sequence was repeated so that the samples collected the high concentration for a two hour period. For the six simple and complex mixtures listed in Table II, it can be observed that the samplecollected with the charcoal tubes have xoellent correlation with those collected with the 3M - Organic Vapor Monitor with the exception of methyl ethyl ketone in the toluene/methyl k tone mixture. It can be noted that the charcoal tubes greatly under estimates the methyl ethyl ketone concentration. Besides the excellent correlation between the two sampling techniques, both techniques also have acceptable accuracy when comparing the concentration measured by the 3M - Organic Vapor Monitor and the charcoal tubes to the concentration determined from the mass balance of the generation system. In Table XII, the results are summarized and tabulated for samples collected when sampling a high concentration for one hour followed by sampling zero concentration for one hour and a repeat of this sequence four times. With the exception of the charcoal tube estimation of the methyl ethyl ketone concentration in the toluene/methyl ethyl ketone mixture, all the results tabulated in Table XII indciate again the 3M 110859 excellent correlation of the charcoal tubes results with the 3M Organic Vapor monitor results of measuring the concentration of the six simple and complex mixtures. Both techniques also have acceptable accuracy as determined by comparing the concentrations measured by the 3M - Organic Vapor Monitor and the charcoal tubes with the concentration determined by the mass balance of the generation system. Conolualona From these laboratory evaluations, the 3M - Organic Vapor Monitor was able to sample and determine the concentration of a representative set of simple and complex mixtures with excellent precision and accuracy. The charcoal tubes also measured the same mixtures with excellent precision and accuracy with the exception of methyl ethyl ketone in the toluene/methyl ethyl ketone mixture. 3M 110860 TABLE I - Simple and Complex Mixtures Generated for Part I of the Evaluation. Mixture Concentrations -- (m/m3.) . 1-1 Toluene/Methyl Ethyl Ketone 1-2 Benzene/Toluene/Xylene 1-3 Naphtfc (VM 4 P) 1-4 Gasoline (unleaded) 1-5 Gasoline (unleaded) 1-6 Gasoline/Ethanol 1-7 Gasoline/Methanol/TBA 147/147 3/15/22 204 49 123 123 123 (DDm) 50/50 1/5/5 50 10 25 25 25 TABLE II - Simple and Complex Mixtures Generated for Part II of the Evaluation. Mixture Concentration _________________ Imjt/mi)___ II-1 II-2 II-3 II-4 11-5 II-6 Toluene/Methyl Ethyl Ketone Benzene/Toluene/Xylene Naphtha (VM 4 P) Gasoline (unleaded) Gasoline (Ethanol) Gasoline/Methanol/TBA 147/147 30/150/220 204 1230 1230 1230 (DDm) 50/50 10/50/50 50 250 250 250 TABLE III - Sample Rates and Recovery Coeficients ComDOund _ ... Sampling Rate Res9verY Coefficient 3M-.0.VM ____________ 3M-QYM___ Charcoal Tube Benzene Xylene Toluene Methyl Ethyl Ketone Naphtha Gasoline 35.5 .6 27.3 + .5 31.4 .6 36.3 .9 33.2 .7 31.0 .6 1.02 1.07 1.05 1.00 1.04 1.05 1.02 .99 1.01 .86 .99 .99 3M 110861 ;E IV - Toluene/Methyl Ethyl Ketone Length of Sampling Period . UlR,.)... _____ 60 (0-60) 500 (60-560) Time-Weighted Average Concentration Sample Type Measured Concentration and (Wv Ifc*)____ Number of Saamlea_____ ..... TQlMftM___ Methvl Ethvl Ketone 3M-0VM (3) CT (3) 198 + 6 182 + 6 137 + 5 34 11 3M-0VM (3) CT (3) 186 +. 4 176 + 5 153 + 6 61 4 3M-0VM (6) CT (6) 187 (98#) 177 (92#) 151 (109 58 (42#) 120 (0-120) 440 (120-560) ^Time-Weighted^Arerage Concentration 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) 3M-0VM (6) CT (6) 202 + 6 162 14 140 6 30 + 3 182 + 2 182 + 5 140 + 4 53 + 4 166 (97#) 178 (93#) 140 (101#) 48 <35<) 180 (0-180) 380 (180-560) Time-WeightedAverage Concentration 3M-0VM (3) CT (3) 3M-OVM (3) CT (3) 3M-0VM (6) CT (6) 189 2 168 + 13 132 + 4 37 + 3 183 + 2 176 + 4 147 + 9 49 6 184 (96#) 173 (90#) 142 (102#) 45 (32#) Total Time-W ightedAverage Concentration Concentration from Mass Balance of Generation System 3M-0VM (18) CT (18) 186 (97#) 176 (92#) 192 (51/ppm) 144 (104#) 50 (36#) 139 (47 ppm) 3M 110862 ,lE V - Benzene/Toluene/Xylene Length of ^pling Period Imirul. . , 60 (0-60) 435 0-495) Sample Type and ___ . Number, of Samples , Measured Concentration (ma/mi) Benins---------------Taluene________ Xvlene __ 3M-0VM (3) CT (3) 12 + 1 12 + 1 53 1 63 11 53 + 1 62 x 10 3M-0VM (3) 3M-0VM (3) 5.0 .2 5.4 + 1 23 + 1 25 2 25 1 26 x 2 e-Weighted .verage Concentration SM-OVM (6) CT (6) 5.9 (961) 6.2 (102%) 27 (931) 30 (1031) 28 (931) 30 (loot) 125 ^p) 370 5-495) Ime-W ightedverage Concentration 3M-OVM (3) CT (3) 3M-OVM (3) CT (6) 3M-OVM (6) CT (6) 7.3 + .2 9.1 + 2 37 1 42 8 34 1 42 + 8 4.6 .3 4.7 + 1 22 +. 2 21 + 2 22 2 21 + 2 5.3 (871) 5.8 (951) 26 (901) 25 (901) 25 (831) 26 (871) 180 -180) 315 0-495) 3M-OVM (3) CT (3) 3M-OVM (3) CT (3) 6.7 + .1 7.2 1 4.6 .2 4-9 1 31 i 1 33 5 22 1 23 A 2 31 1 32 5 22 + 1 23 2 ne-Weightederage Concentration al le-Weightedarage Concentration ncentration from lance of ^^ion System 3M-OVM (6) CT (6) 3M-0VM (18) CT (18) 5.4 (891) 5.7 (931) 25 (861) 27 (931) 25 (831) 26 (911) 5.5 (911) 5.9 (971) 6.1 (1.9ppm) 26 (901) 28 (951) 29 (7.7 ppm) 26 (871) 27 (911) 30 (6.9 ppm) 3H 110863  jiJLE VI - Naphtha (VM & P) 236 mg/m3 (58 ppm) -- Length of Sampling Period (niin.,) Sample Type and ..... . Number of Samples_________ 60 (0-60) 3M-OVM (3) CT (3) 420 60- 480) 3M-0VM (3) CT (3) ine-Weighted Average Concentration 3M-OVM (6) CT (6) Measured Concentration (ma/mi) Naphtha 219 2 191 + 33 247 + 4 251 5 243 (103*) 243 (103#) 120 0-120) 0 :i20-480) 3M-0VM (3) CT (3) 3M-OVM (3) CT (3) 284 + 10 289 + 20 181 + 5 190 + 5 Time-WeightedAverage Concentration 3M-OVM (6) CT (6) 207 (88|) 214 (91*) 180 ,0-180) 300 180-4 80) rirae-WeightedAverage Concentration 3M-0VM (3) CT (3) 3M-OVM (3) CT (3) 3M-0VM (6) CT (6) 291 3 289 12 189 + 7 190 + 10 225 (95*) 244 (103*) 3tal ime-WeightedAverage Concentration Concentration from ^ass Balance of -j^^tion System 3M-0VM (18) CT (18) 225 (95*) 228 (97*) 236 (58 ppm) 3H 110864 rjjLE VII - Gasoline (Unleaded) (42 mg/m3) Length of sampling Period (min.) Sample Type and ... ..,NUfflbSE.9f Sarades 60 (0-60) 3M-0VM (3) CT (3) 375 C60-435) 3M-0VM (3) CT (3) [ne-Weighted Average Concentration 3M-0VM (6) CT (6) 120 iO-120) 315 435) 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) Time-WeightedAverage Concentration 3M-0VM (6) CT (6) 180 (0-180) 255 180-435) Ume-WelghtedAverage Concentration 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) 3M-0VM (6) CT (6) >tal (ime-Weightediverage Concentration oncentration from tass Balance of deration System 3M-0VM (18) CT (18) Measured Concentration _________________________________ _______________ _______ QaggUns (Vnlsafoti) ______________ 52 + 2 54 + 9 37 + 2 39 + 1 39 (93*) 41 (98*) 44 + 1 47 + 10 37 + 1 36 * 2 38 (91*) 30 (93*) 42 + 1 44 + 1 36 + 1 38 + 1 38 (91* 40 (95*) 38 (91*) 40 (95*) 42 (8.5 ppm) 3H 110865 jlSLE VIII - Gasoline (Unleaded) (96 ra/m^) Length of Sampling Period (min.) 60 (0-60) 420 (60-480) (lme-Weight d Average Concentration Sample Type and Number of Samples________ 3M-0VM (3) CT (3) 3M-OVM (3) CT (3) 3M-0VM (6) CT (6) 120 (0-120) 360 0-480) 3M-OVH (3) CT (3) 3M-OVM (3) CT (3) Time-WeightedAverage Concentration 3M-0VM (6) CT (6) 175 (0-175) 305 (175-480) Time-WeightedAverage Concentration 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) 3M-0VM (6) CT (6) total Time-WeightedAverage Concentration Concentration from Mass Balance of Generation System 3M-0VM (18) CT (18) Measured Concentration (mg/ml) Gasoline ............ . 93 7 87 3 92 3 95 5 92 (96%) 94 (98*) 93 + 3 95+7 91+4 96 + 4 91 (95*) 96 (100*) 93 + 1 99 * 3 96 + 5 103 3 92 (96* 102 (106*) 93 (97*) 97 (101*) 96 (19.5 ppm) 3H 110866 10LE IX - Gasoline (Ethanol) (125 mg/m3) Length of Sampling Period _ Sample Type and ........ Number of Samples_______ 60 (0-60) 3M-0VM (3) CT (3) 420 ;60-480) 3M-0VM (3) CT (3) ime-Weighted Average Concentration 3M-0VM (6) CT (6) 120 0-120) 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) o o CO Time-WeightedAverage Concentration 3M-0VM (6) CT (6) 180 0-180) 300 180-480) 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) Clme-WeightedWerage Concentration 3M-0VM (6) CT (6) Jtal Cirae-WeightedAverage Concentration Concentration from lass Balance of J tion System 3M-0VM (18) CT (18) Measured Concentration (nur/n>3.) Gasoline (Ethanol) ............... ....... 106 i 5 114 + 15 130 4 133 + 8 127 (102$) 131 (105$) 113 3 114 5 129 + 7 129 +. 16 125 (100$) 125 (100$) 113 5 116 2 134 3 139 jt 5 126 (101$) 130 (104$) 126 (101$) 129 (103$) 125 (25.4 ppm) 3M 110867 ABLE X - Gasoline (Methanol/TBA) Length of Sampling Period (min.) Sample Type and Number of SamDles 60 (0-60) 3M-0VM (3) CT (3) 420 (60-480) 3M-0VM (3) CT (3) ime-Weighted Average Concentration 3M-0VM (6) CT (6) Measured Concentration ________ ______ (mg/jA Gasoline (Methanol/TBA) 94 + 1 86 + 10 112 2 124 4 110 (97*) 119 (105*) 120 (0-120) ^360 A 480) 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) Time-VelghtedAverage Concentration 3M-0VM (6) CT (6) 102 + 3 101 2 108 + 5 119 1 107 (95*) 115 (102*) 180 (0-180) 300 120-480) Time-WeightedAverage Cone ntration 3M-0VM (3) CT (3) 3M-0VM (3) CT (3) 3M-0VM (6) CT (6) 102 4 . 103 6 116 2 122 4 111 (98*) 115 (102*) otal Time-WeightedAverage Concentration Concentration from Mass Balance of Generation System 3M-0VM (18) CT (18) 109 (96*) 116 (103*) 113 (22.9 ppm) 3M 110S68 XI - Variable Challenge Concentrations According to Profile A Concentration from Length of Mass Balance of >ijre Sampling Period Generation System ,?led (min.) (mg/m3) >-- 11' ,1 Toluene/ (thyl Ethyl itone 120 228 178 Sample Type and Number of Samples Toluene 3M-0VM (4) CT (4) Methvl Ethvl Ketone 3M-OVM (4) CT (4) .5 Benzene/ luene/ lene 120 Bsnzene 47 3M-0VM (4) CT (4) 222 .Tolnen? 3M-0VM (4) CT (4) 227 Xylene 3M-0VM (4) CT (4) 3 Naphtha 155 212 3M-0VM (9) CT (9) ^ Gasoline (unleaded) 120 1,000 3M-OVM (4) CT (9) 5 Gasoline/ Ethanol 120 1,011 3M-0VM (4) CT (4) 5 Gasoline/ Methanol/ TBA 120 1,011 3M-0VM (4) CT (4) Measured Concentration (mg/m3) 231 3 (101%) 217 + 10 (95*) 144 11 (81*) 48 + 1 (27*) . 45 1 (96*) 44 1 (94*) 207 6 (93*) 217 4 (98*) 222 7 (98*) 224 + 4 (99*) 214 + 5 (101*) 228 11 (108*) 957 38 (96*) 979 14 (98*) 1065 61 (105*) 1197 38 (118*) 981 48 (97*) 982 53 (97*) 3M 110S69 ja XII - Variable Challenge Concentrations According to Profile B iture ipled Length of Sampling Period (min.) Concentration from Mass Balance of Generation System (mg/m3) Sample Type and Number of Samples Toluene .1 Toluene/ 240 206 3M-0VM (4) thyl Ethyl CT (4) jtone 161 Methvl Ethvl Ketone 3M-0VM (4) CT (4) 'l Benzene/ toluene/ yiene 240 Benzene 47 3M-OVM (4) CT (4) 223 Toluene 3M-0VM (4) CT (4) 228 Xylene 3M-OVM (4) CT (4) [3 Naphtha 240 176 3M-0VM (4) CT (4) !*! Gasoline (unleaded) 240 906 3M-0VM (4) CT (4) *'5 Gasoline/ Ethanol 240 ^'6 Gasoline/ Methanol/ TBA ^----- -- --------- 240 897 3M-0VM (4) CT (4) 888 3M-0VM (4) CT (4) Measured Concentration (mg/m3) 226 + 3 (110$) 226 + 6 (110%) 155 10 (96$) 67 3 (42$) 46 3 (97$) 43 2 (92$) 211 15 (95$) 203 8 (95$) 227 30(100$) 209 9 (92$) 176 + 4 (100$) 183 13(103$) 807 32 (89$) 890 30 (98$) 933 32(104$) 1003 + 70 (112$) 830 41 (93$) 772 + 73 (87$) 3M 110870 Measured Concentration (m g/m ^) TOLUENE Test Number 3 m. METHYL ETHYL KETONE Measured Concentration (mg/m3) 290t 230-- 3M Organic Vapor Monitor A Charcoal Tubes ------ Known Concentration 170-- 110-^ *------------ * 50- 0-to o0-J0 l + 1 Test Number -f 3 Measured Concentration ( m g /m 3 ) BENZENE ioT 3M Organic Vapor Monitor A Charcoal Tubes Known Concentration 25% Accuracy I _L 4 ----------- 1----------- + 123 o 0ON0Jl Test Number Measured Concentration (mg/m ) 50 40-- TOLUENE 3M Organic Vapor Monitor A Charcoal Tubes ----- Known Concentration I30 20-7 10- -I----:------------ H CO 1 2 3 Test Number o 00 .usi Measured Concentration (mg/m3) 50-p 40 30-- 20'10-- 0- oo-uoji XYLENE 3M Organic Vapor Monitor Charcoal Tubes ----- Known Concentration T 25% Accuracy i 4 + 1 Test Number + 3 350-r NAPHTHA (VM & P) 3M Organic Vapor Monitor A Charcoal Tubes ----- Known Concentration o Measured Concentration (mg/m 300 l 25a20a15a- T 25% Accuracy l 100 - -1----------------- 1----------------- h u 12 3 ooo Test Number tn Measured Concentration (mg/m) 60r 50 30-- ----1 -I____ 1 GASOLINE (UNLEADED) - 42 mg/m *> 3M Organic Vapor Monitor A Charcoal Tubes -- Known Concentration ' I' 1 T 25% Accuracy i 20-- 10J------------ r--I--------------- 1------------------H 12 3 Test Number 0ss0ii Measured Concentration (mg/m 3 ) GASOLINE ( UNLEADED )-96 mg/m3 3M Organic Vapor Monitor Test Number 00v00j Measured Concentration (mg/m^) 190r 160 130" 100 GASOLINE (ETHANOL) - 125 mg/m3 3M Organic Vapor Monitor A Charcoal Tabes -------Known Concentration T- > 1. X, r1 T 25% X Accuracy 11 70-- 40-J------------------- 1------------------- 1------------------- h CO 12 3 o Test Number t0-fd>0 GASOLINE (METHANOL/TBA) Measured Concentration (mg/m3) 190j 160-- 130-10070-- T 3M Organic Vapor Monitor Charcoal Tubes ------- Known Concentration T ? 25% Accuracy 1 4<H----------------f 1 1 12 3 00 0o0 Test Number RESPONSE TO VARIABLE CONCENTRATION 1167- 1000- cofl 833 - N tae DDO- * ao 2 500-- fl e u 336* 167- SU Organic Vapor Monitor A Charcoal Tube* ------Known Concentration 25% Accuracy Limits Sampling Profile : 8 hours' If# 10 Toluene WFtr Benzene Toluene Xylene Naphtha Oaaoline Oaaoline/ Gasoline/ {Unleaded} Ethanol Methanol/ j 1_________ ^ 1I i IJ l TEA Mixture Sampled 00 00 j RESPONSE TO VARIABLE CONCENTRATION Mixture Sampled 3H 110882 Waste anesthetic gas exposures present a possible health hazard to selected health professionals (surgeons, jentists. nurses, veterinarians, etc ) Effective control of these exposures depends upon an anesthesiologist or Ihorse implemented scavenging system for the anesthesia environment together with a routine monitoring System for exposed personnel Personal charcoal tube samplers using battery powered pumps require trained personnel to obtain valid results and are not compatible with mobility and sterility requirements of operating rooms Continuous air monitors (/ e , infra-red analyzers) are expensive and complicated to use Alternatively, passive personal samplers developed to collect integrated time weighted average samples of gases in the worker breathing zone may be ideally suited for sampling the exposure in the operating room environment This study investigates the performance of passive personal samplers at concentrations of anesthetic gases in the range of those found in operating rooms (5-20 ppm) A unique quasi-dynamic system was employed to maintain stable gas concentrations. Results obtained using the passive personal samplers were compared to charcoal tube samples and infra-red analyzerreadings Data indicate that passive personal samplers are capable of determining concentrations of enflurane with .accuracies that range between i 24% to t70%. Laboratory performance of passive personal samplers for waste anesthetic gas (enflurane) concentrations LINDA COHEN JONAS.' CHARLES E. BILUNGS' and CONSOLACION LIUS" 'The Johns Hopkins University. School of Hygiene and Public Health, 615 N Wolfe Street. Baltimore. MD 21205, "Maryland Department of Health and Mental Hygiene, 201 W Preston Street. Baltimore. MO 21201 introduction It has been clearly shown"* that operating room and dental personnel are chronically exposed to varying concentrations of waste anesthetic gases. These gases, which include nitrous oxide with or without various volatile halogcnaicd anesthetic agents, exist (in the uncontrolled workplace) at concentrations up to 1000 ppm.*'* Investigators have attempted to quantify the health sequelae of such exposures through a number of animal and human studies. Most reports conclude that occupational exposure to waste anesthetic gases may result in an increased risk of miscarriage, congenital anomaly, cancer, renal and hepatic disease and other overt health effects, plus decrements in psychomqtor performance. Therefore, it has been concluded" '* that workplace levels of waste anesthetic gases shpuld be controlled and that monitoring of worker exposures should become an important facet of the hospital regimen. Monitoring waste anesthetic gas exposures may be done by several means. NIOSH recommends1'1 that samples be analyzed by infra-red spectrophotometry or by gas chromatographic analysis of charcoal lube samples collected using sampling pumps. The former method relies upon a trained professional using a complicated and expensive machine to make measurements. The latter method requires the use of cumbersome pumps to take samples and often requires an individual to monitor flow rates, sampling times and placement. A viable alternative to conventional methods of sampling is the use ol passive pctsonal samplers. Those samplers require no pumps and cannot break down, they arc inexpensive, lightweight and easv to use. 1 wo types of passive persutial samplers have been described, differing in the type of molecular principle which they employ. ' Permeation-type personal monitors"" are passive samplers with polymeric membranes. Gases and vapors arc absorbed in the membrane and permeate the membrane to he collected and stabilized in a medium such as charcoal. The transport of the gas in the sampler is represented mathematically by: C = vvk t p) where C ~ concentration, ppm, w = weight of contaminant. *tg. l = exposure time, hrs, and k ~ permeation constant. Permeation is limited by the diffusion through the membrane. The permeation constant is determined experimentally for the specific membrane used and the substance comprising the exposure. Use of a permeationtype passive sampler for monitoring vinyl chloride monomer has been described.*'" The other type of passive sampler'7 111 operates on the principle of diffusion through a stagnant gas layer. Diffusional samplers arc based upon movement of molecules through a draft-minimizing barrier to a collecting medium of large adsorptive capacity. Transport of a gas or vapor is based upon Hick's First l.aw of Diffusion: I - .rJj L (2) wKic J -- ii.wvt U.mvlcr tatc. moles sec. ........................... ' 3M 110883 DIFFUSIVE membrane I* - STAGNANT ' AIR LAVER MECHANICAL SUPPORT CASE COLLECTING ELEMENT A: CROSS SECTIONAL AREA. CM2 L: PATH LENGTH. CM Figure 1 - Typical diffusional sampler. I) = diffusion coefficient, cm"/sec, A = area of diffusional path, cm", C,-C,, concentration gradient, with C, being ambient concentration and C being concentration at the collector surface, and E = diffusional pathlength, cm. Because of the large adsorptive capacity of the collecting material, C,, for the collecting material can be assumed to be zero. This makes the mass transfer rate proportional to the ambient temperature. Multiplying both sides by time, we get: t X mass transfer = t X collection rate, or | total mass = IMCl.E (3) Due to the stagnant air layer in the sampler, transport is limited by Brownian motion. The driving force is therefore the concentration gradient difference between the ambient concentration C, and the collecting medium concentration C... Thus a stagnant air layer between the draft shield and the collecting element is essential to prevent disturbance of the molecular processes. A typical diffusional sampler is shown in Figure I. Dilfusional samplers which have been described differ mainly in diffusional geometry (A & l.), types of housings and matrix in which the charcoal is presented. The Abcor (iasbadgcIM is a large housing with replaceable charcoal elements, whereas the products made by 3M and DuPont are intended for single use. The 3M Organic Vapor Monitor is made for in-badge desorption with subsequent decanting o! the fluid into vials for analysis or for straight injection into a gas chromatograph. The DuPont Pro-tek,M allows for high-flow and low-flow sampling by providing two removable covers (increases A two limes when both covers are removed). I wo lactors have been identified11"' as having the greatest effect on diffusion rate. The first factor is air velocity, and this relates to the driving force in equation 2. C, . Equation 2 assumes that the ambient concentration is the same as (',. `I his would be true for a situation with adequate convection. But when convection is minimum. .*.. when V 0. ('. ` In this ease, where there is no convection. sonic of the resistance to transport picviousk desenhed ,i' *MO'l'l 41. (loll, t* * l H,,i residing in the internal stagnant air layer of the badge would be external to the badge, />., a stagnant air layer outside the badge. Thus, where there is little convection, resistance to transport increases, and the weight of the vapor collected by the badge is no longer related to the concentration of vapor in the area. It has been shown""' that at a face velocity below 15 ft / min, the dosimeter loses accuracy due to the increased convective resistance. Since ambient air velocities are usually a minimum of 50-75 ft min. this is rarely a problem. Temperature has also been identified as having a large effect on diffusion rale. The temperature dependance of the diffusion rate at ambient temperatures has been calculated'1"' to be less than 0.2' i C. Thus a temperature change from 25 C to 30 C should change the diffusion rate by less than lri. This study is intended to examine three commercially available passive personal samplers in terms of their use in monitoring laboratory concentrations of enfluranc. Enflurane was chosen for the study for several reasons. First, it is an anesthetic agent which is becoming widespread in hospital settings. It has a reputation lor fewer toxicological effects associated with its use and thus is expected to replace halothane as the most widely used halogenatcd anesthetic in this country. Secondly, there is a dearth of information about monitoring for enflurane using these types of samplers (let alone using these samplers for monitoring any substance). Easily, it is hoped that eventually field studies could he carried out in the operating rooms of a hospital to evaluate the field efficacy of using such a system for monitoring exposures. It would be quite helpful to have preliminary information concerning the functioning of these passive personal samplers in a controlled environment. apparatus and procedures A 379 liter (100 gallon) polypropy lenc cy luwli ical tank waadapted lor use as an exposure chamber. One-hall inch sampling ports were drilled in the side o) the lank to allow for continuous sampling ol the an with a MIK \N I 3 Poilablc lilli.i-ied (m* Aualv/ei and lomunciii vhutiu.il lube campling lu lumpcii'.ilc lot \uliimv .li.mci-- a- a icm!It ol ihaico.il luhi' s.impline, a >U lii. i Mvi.o I'.tr 1 3H 110884  XII CHAMBER INTO CHAMBER IN BELLOWS PUMP OUT Pivpjratinns l*> lest samplers wcic as lollops I wo samplers wcic clamped onto the wire suppoii and lowered into the duet, l.he blower was turned on I he heavy polypropylene lid was placed in the lank and sealed around the top with pliable weather stripping t he access to the diaphiagm (Mylar bag) was clamped and all other ports weie shut ofl, ease one port. A Gast pump was connected by a I to the chamber at this port and a manometer was connected to the other arm of the T. The vacuum pump was then turned on. The chamber was considered to be suitably sealed if the drop in the manometer (with 3 in. of vacuum and hose to the pump clamped) was less than 1/2 in./30 sec. Figure 2 - Equipment set-up. placed inside the chamber, with a Tygon tube acting as a vent to the outside air through the chamber's wall. To maintain adequate air velocities across the samplers, a quasi-dynamic air flow system was utilized."'1 This system consisted of a Dayton blower which was connected to a reducer and then to an eight-inch duct. Badges were hung in the center at a distance of two diameters down the duct from the inlet by means of a wire support. This dimension was chosen as an area of minimum turbulence and maximum flow stability. The entire system was placed within the chamber. Two one-eighth inch holes were drilled at right angles at a length down the duct equal to two diameters. Using an Alnor Type 8500 Thermo Anemometer, a traverse was jtaken to verify that velocities exceeded those required to minimize resistance to diffusional transport. A one-half inch hole was drilled in the lid of the chamber, through which a thermometer was inserted. Thus, the temperature of the inside of the chamber was recorded during the course of an experiment. MIRAN 1 -A A MIRAN I-A Portable Infra-red Gas Analyzer was utilized to monitor the concentration inside the chamber continuously. Operation and calibration of the analyzer were performed according to manufacturer's instructions. Comparison of the calibration curves for enfluranc performed prior to a series of experiments was made with manufacturer's (Foxboro/ Wilks) printed information. Prior to each experiment, the infra-red analyzer was allowed to warm up for approximately 10 minutes. The MIRAN was hooked up in scries with the chamber as depicted in Figure 2. The sample size calculated to give the appropriate chamber concentration was injected into the bellows pump, and the experiment was begun at that point. Thereafter, a sample was drawn through a charcoal tube the first fifteen minutes out of every hour for the six hours of the experiment (for sampler A) or for two hours during the third and fourth hours of the experiment (for samplers B and C). A DuPont low flow pump was used to draw samplers through SKC charcoal tubes. The pump was calibrated using a bubble meter and was run off house power via the battery charger. Sampler l1" a B i\e c 'j Amount Adsorbed ML" 1.89 .85 .26 .78 .36 79 .77 .62 .35 TABLE I Summary of Data' Tank Concentration ppm* MIRAN Concentration ppm" 20 16.5 10 9 2 5 4.7 20 158 10 8 2 5 43 20 16 4 10 92 5 39 Charcoal Tube Concentration ppm1 18.3 7.9 3.9 19 8 9.3 4.9 18 1 12.7 7.0 'Obtained by averaging raw data for each group of runs. "This represents the total amount of enflurane adsorbed by the sampler, obtained by comparing gas chromatographic analysis of the samples against a standard curve for enllurane ' Determined using the amount injected into the chamber, and adjusting for chamber volume. Determined by averaging fifteen minute interval readings of adsorbance at wavelength 8 7 comparing against a standard curve for enflurane. and 1 Determined as above for the sampler, only the pL of sample w is converted using sp gr, io mg and divided by the sample volumo to yield ppm 3M 110SS5 I*;* Jl'P, 3'm TABLE II Regression Analys e of All Combinations of Four Variables PPS Regression Correlation Intercept Slope A BADAD with TANKON BADAD with CHRCOL" BADAD with MIRAN' CHRCOL with TANKON" MIRAN with TANKON' MIRAN with CHRCOL1 B BADAO with TANKON BADAD with CHRCOL BADAD with MIRAN CHRCOL with TANKON MIRAN with TANKON MIRAN with CHRCOL C BADAD with TANKON BADAD with CHRCOL BADAD with MIRAN CHRCOL with TANKON MIRAN with TANKON MIRAN with CHRCOL 834 .806 846 .925 .996 934 .960 .970 963 994 .998 .996 .730 .830 748 .898 .993 .917 238 pL 085 pL 434 pL .177 ppm 1 08 ppm 3.58 ppm .024 /iL - .012 pL - 050 pL -.338 ppm .494 ppm .821 ppm .275 pL .079 pL .259 pL 4.48 ppm .422 ppm - 2.22 ppm 107 ill ppm 095 pL ppm .140 pL- ppm 998 ppm ppm .778 ppm'ppm .667 ppm/ppm .040 pL/ppm .040 pL/ppm .052 pL/ppm 1.00 ppm/ppm .764 ppm/ppm .758 ppm/ppm .026 pL/ppm .038 pL/ppm .033 pL/ppm .707 ppm/ppm .813 ppm/ppm .949 ppm/ppm 'Regression of badge-adsorbed sample on tank concentration (from amount injected into Chamber and volume of chamber). "Regression of badge-adsorbed sample on charcoal tube concentration. ' Regression of badge-adsorbed sample on MIRAN concentration. "Regression of ppm's using charcoal tubes on/tank concentration. 'Regression of MIRAN concentration on tank concentration. 'Regression of MIRAN concentration on charcoal tube concentration TABLE III Regression Analysis-Fit Through Zero PPS Regression Correlation Multiple R-Square' Slope A BADAD with TANKON BADAD with CHRCOL BADAD with MIRAN CHRCOL with TANKON MIRAN with TANKON MIRAN with CHRCOL B BADAD with TANKON BADAD with CHRCOL BADAD with MIRAN CHRCOL with TANKON MIRAN with TANKON MIRAN with CHRCOL C BADAD with TANKON BADAO with CHRCOL BADAO with MIRAN CHRCOL with TANKON MIRAN with TANKON MIRAN with CHRCOL .955 .950 .954 .983 998 981 .990 993 .990 .999 999 999 947 979 .952 .975 .998 982 .921 pL .093 pL 910 pL 965 ppm .997 ppm .963 ppm 981 pL 986 pL 981 pL 997 ppm .999 ppm 998 ppm 896 pL ' 958 pL .906 pL .951 ppm .997 ppm 964 ppm .092 pL/ppm .101 pL/ppm .108 pL/ppm .888 ppm/ppm .847 ppm/ppm .922 ppm/ppm .039 pL/ppm .039 pL/ppm .049 pL/ppm .979 ppm/ppm .795 ppm/ppm .810 ppm/ppm .044 pL/ppm .044 pL/ppm .053 pL/ppm 1 02 ppm/ppm .833 ppm/ppm .784 ppm/ppm 'Square of the regression (correlation). MIRAN-assesscd concentration in the chamber was termined by dividing the chart into fifteen-minute periods d obtaining the absorbance (at 8.7 nm) for each period, ^he average absorbance was taken as the sum of the fifteen- minute absorbances divided by 25. and the concentration "ms obtained from the calibration curve. Industrial Hygirnt Allocution JOURNAL (if) 7'81 After each run. weather stripping was removed from around the top of the chamber. The passive samplers were cither sealed in packages, or t he elements were transferred to vials. Charcoal tubes were capped. All samples were refrigerated until analysis was performed. 3M 110886 ,0' TABLE IV Calculated Diffusion Coefficients Sourca D. cm .'*ac PPS A PPS B PPS C M1 LAJ" X 129 076 144 076 056 076 'Calculated using reported sampling rates.'''1 Since Sam pling rale - DA/L. by dividing reported rata for enflurane of 26.1 cm'/min, by A/L x 60. obtain D. "Based on equation relating diffusion coefficient to molec ular weight'1'1 log D- 0.3927-0.7238 logW where log " log,,, 0 - Diffusion coefficient cm /sec, end MW - Molecular weight, g/mole. cnllurunc in the desorbing lluid i/.I cnilur.mel was calculated Iront standard curses. Ilcsoiptmn cllioencs ssax defined as the amount of enflurane reentered in desorbing fluid ilo ided b> the amount of enflurane to which the badge Has exposed Values greater than 1.0 indicated some discrepancy in ascertainment. results f or the purposes of this study, passive personal samplers were relabeled A, B and C. Table 1 summarizes the grouped data for all experiments. To facilitate data analysis, variable names were git on for the different sample concentrations: BADAD, for amount adsorbed on the sampler; TAN KON. for the calculated amount in the chamber, based on injection volume; MIRAN, for concentration determined using infra red analyzer; and CHRCOL, for concentration determined by charcoal tube samples. Table II shows the results of regression analysis on all data. In this table and subsequent tables of regression, "BADAD with TANKON" indicates the regression analysis of independent variable TANKON with dependent variable BADAD. Similarly, regression analysis was re-run in Table 111 utilizing a computer program that fit the line through the origin. gi chromatographic analysis Analysis on samples was performed at the Maryland department of Health and Mental Hygiene. Occupational jlcalth and Air Quality Laboratory, an American Industrial Hygiene Association accredited laboratory. Methods of Analysis were as recommended by NIOSH. Abcor samples were desorbed in three ml. of carbon disulfide, .AM samples were desorbed in two mL and one mL was used to desorb the DuPont samples and charcoal tubes. Samples were placed on a laboratory shaker for 30 minutes prior to analysis on a Varian 2443 gas chromatograph with auto sampler and FID detector. Chromatographic conditions were: 1/8 in.. 20 ft. stainless steel 10% FFAP on Chromosorb W, 60-80 mesh column Column temperature; 60 C injection temperature: 210 C Detector temperature: 230 C Carrier gas: N.-, 25 mL/min Hj: 25 mL/min Air. 300 mL/min to FID hsorption efficiency The desorption efficiency for each of the three passive Personal samplers was determined experimentally. Rampling elements were placed into scalable containers and IJuL. 2 pi, or 3 /iL of liquid enflurane was carefully added to "to charcoal. The samples were allowed to equilibrate for 24 tours. The samples were desorbed as usual (described thove). I he desorbed samples were analyzed for enflurane chroinatographically (sec above) and the amount of discussion reproducibility This study compared fourdifferent methods of assessing the levels of an anesthetic vapor in a test chamber. Any method can be used profitably if an understanding of the sensitivity, accuracy and precision of the methods exists. Since these tests involved a rather narrow range of exposure concentrations, sensitivity of each method may not be determined, but the reliability with which a method discerns accurately the concentration of gas to which it is exposed can be determined by repeated measurements of similar concentrations. From Table 1 it can be seen that tank concentration does not vary within each concentration level. This is a result of calculating the amount of enflurane needed to create a test atmosphere of the desired concentration, using the tank volume and specific gravity of the substance. The amount of enflurane was injected into the chamber at the beginning of an experiment. Any variation in tank concentration will not be disccrnable since there is no check on the amount actually delivered from the Hamilton syringe to the bellows pump nor the amount which vaporized immediately, nor the amount which was lost by adherence to walls of the chamber. If one assumes that the last two factors exert negligible effect on tank concentration, then any variation in tank concentration will be a function of the accuracy with which one can deliver an aliquot of volatile liquid using a 50 /iL Hamilton syringe which is then the primary standard. It is estimated, therefore, that this accuracy is 1 /iL or 0.48 ppm for this exposure chamber. Of the four methods, tank concentration is believed to have the least amount of error associated with it; this justifies its use as the primary Mandatd for concentration measurement in this study. 3M 110887 40 30 PPM 20 - 10 y x" * SLOPE 1.61 X . PROPOSED CURVE -L _L 6 10 20 TANK CONCENTRATION. PPM i^ure 3 - Badge versus tank concentration - Sampler A. Regression analysis was performed assuming a linear : jression model. It was believed that a linear model was ipropriate since response on charcoal is assumed to be ear below the loading capacity of the collecting element, nee the loading capacity of the badges is estimated to be ound 10-15 mg, and the badges only adsorbed at the most HfiLX 1.50 mg/ piL = 4.44 mg, the assumption appears to reasonable. Regression analysis showed high correlation with all iriables tested. MIRAN withTANKON shows the highest , rrelation in all three samplers, which indicates uniformly accuracy in all experiments using the MIRAN, when ^ mpared to the designated primary standard. Correlation dicates how much the dependent variables deviate from calculated regression line. Where BADAD was the pendent variable, sampler B consistently had the highest irrelations, followed by A and then C. The high ^relations were seen when BADAD was regressed on M'tV'W I ! 11 s . 1 :;i > icli.'vl ,i , '. .. Mi RAN cutiCL'ti'.i.iiit>ii 'incc '.vo Kn.!j.v p-i ~ "nr.- obtained lor one MIRAN daia point MIRAN wh1-, IANKON consistently shows highest coricLiiiun It was observed that in mans of the tegiessions thi intercept was non-/cro. Since all blanks were seen to he zero this can he attributable to random errois in methods loi determination of enflurane concentration. In table 111 regression analysis was repeated, hut the regression lines were fitted through zero. All cot relations were seen to increase, but sampler B still has the highest correlation when BADAD is regressed on TAN ICON (.990). w ith sampler A next highest (.955) and sampler C last (.947). it is difficult to see how much difference this makes in the arrangement of the data since all three correlations are very close to one. BADAD regressed on TANKON graphically for samplers A, B and C (figures not presented) show that the greatest deviation of the points from the line is in sampler C: in fact, it appears that the regression line for sampler C may be more appropriately curvilinear. Sampler B shows the best fit to the linear regression model with all points close to the regression line. diffusion coefficient In order to convert from weight of gas collected by the badge to ppm. it is necessary to know the diffusion coefficient of the gas in air. In this way: mg/ nr = _________ C.W. (D.E.XA/ L)(D)(S.T.) <> where G.W. = weight of gas collected by sampler, ng. D.E. = desorption efficiency, A/L = sampler geometry or ratio of cross sectional area to length, cm, D = diffusion coefficient, cm2/sec. and S.T. = sampling time. sec. o TANK CONCENTRATION. PPM Figure 4 Badge versus tank concentraiion Sampler B f|lln Iflduiliiil Hyfifrf Association JOURNAL H?) ?'8I 3M 110888 ,111 I Hr- >1 k .m he \h.iw n that '"l Ml .'2 4 I iiiiiIc . I K M W g mule 275'K 7(ili mm llji I* min H (SI tin. eimh was June al I atmosphere and at \im.iteh 25 (\ this becomes , 24 45 I. mole ppm * mg m * ^W^^ilY (6) | he diffusion coefficient, shown in equation 4 to be necessary to convert weight of gas on the badge to ppm, is provided for many solvents by the sampler manufacturers. I he constant D is not generally given; what is typically given the sampling rate, or DA/1,. However, if one knows the ^tripling rate of a sampler for benzene, for example, one can divide through by the published diffusion coefficient for bcn/cnc to obtain A/ L. the diffusional geometry of the sampler. This was done for all three samplers for the conditions of use. such that Aa i. = 7.34 cm, B.vi. - 5.90 cm nd ('a i = 7.67 cm. Using these values, and graphical representations of pi. adsorbed by badge versus tank concentration in ppm using slopes obtained by regression analysis (Table III), the diffusion coefficient was back calculated by the following method. For each badge, I pL could be found to coricspond to x ppm. Since pL can easily be converted to mg using data on specific gravity, substituting inlocquation 6, and then equation4 allowed for deduction of the diffusion coefficient as implied by each badge. Desorption efficiency of each badge was included in the calculation, with samplers A, B and C giving D.E.'s of .90, HI and 1.17 respectively. Analytical error is believed to have a large part in the anomalous results of D.E. for sampler The results of the above calculations are presented in Tabic IV. Included in this table is a diffusion coefficient calculated from a published sampling rate.'41 Another estimate of the diffusion coefficient for enfluranc is an equation in which log D is related to the log of the molecular weight. The average of all five values for D is .076 cm:/scc. 12 10 - * BADGE. PPM , /" / / // A _/ . PROPOSED CURVE figure 5 X 5 10 20 TANK CONCENTRATION PPM Badge versus tank concentration - Sampler C. 110 table V Coefficient! of Venation Tana Concentration ppm PPS A PPS B PPS C MIRAN Charcoal 5 09 08 24 10 10 28 06 30 07 20 34 16 23 03 C V . overall 30 12 35 08 11 27 25 23 'Calculated by taking (he sum oi the observed concentration divided by the tank concentration, taking the standard deviation of the sum and dividing by the mean. This appears to be the best approximation. It is further gratifying that the diffusion coefficients from PPS-B and M are the same, since the samplers were the same in both studies. Once the diffusion coefficient for enfluranc is obtained, it becomes a simple matter to convert pL enflurane collected by each badge to ppm. Graphical representations of badge concentration were made and are presented in Figures 3,4 and 5. These representations show that sampler A overestimates tank concentration by about 60%, while sampler B underestimates tank concentration by about 5%. Sampler C appears not to be a linear relationship at all when plotted as seen by the scatter of the points away from the best fit curve. coefficient of venation It has been written"''1 that "the relative variation of a normal distribution (such as randomly distributed errors occurring in industrial hygiene sampling and analytical procedures) is commonly described by the coefficient of variation (CV) . . . The CV is a useful index of dispersion in that limits computed from the true mean of a set of data plus or minus twice the CV will contain 95% of the data measurement." CV's were thus computed in order to gauge the accuracy ol the methods used to determine the concentration in the tank. In this case, accuracy k defined as "the difference between a measured concentration and the true concentration of the sample ... it includes both the random variation of the method about its own mean (commonh referred to as precision) and the difference between th< average result from the method and the true value (commonly referred to as the bias of the method)". CV's were calculated by taking the observed value dividing by the tank concentration (O/E), computing the standard deviation, and dividing by the mean. CV's wci determined over all data points within a method, and w itlim a tank concentration level. Table V presents a summari the calculated coefficients of variation for the three bad; tested and for the M1RAN and charcoal tuu * measurements. The lowest overall CV's were observed !> I the MIR AN and PPS-B, with CV's of 8% and C Irespectively. The charcoal tube coefficient of variation 23',.' overall; this is twice as high as the published O 3H 110889 1.H .'.I? H)t! Assoc l :!/) I ' I- ... u.'. i ' * :i '> n.s rcsu't u:*ih'. . 'i )*' 1'. I v i ".*n;c il , '.iS- not beer) culkthiMalivcIv U':<.! let ,:i. 'A *iit iM'S-A, a low CV was seen at tl.c itmcM ti.iion It seems the CV for PPS-A chjnges lroin.09 ppm to CV -- 14% at 20 ppm. The source of this ili> is unknown. PPS-C is most notably the least ,i.iie sampler tested, with an overall CV == .15%. docity and temperature affects .mi the velocity traverse taken in the exposure system, it is ,u i hat the boundary conditions of the transport equation met. /.<*., velocity of the duct at each point in the duct ,,eeds the 15 ft/min necessary to measure concentration. ;. no place in the duct did the velocity measure less than 70 ' min. A slight rise in temperature (< 6 C) was noted after a six1,>r experiment. The temperature rise was attributed to the .ntors on the Dayton blower plus the bellows pump. Some cat gain may have been due to radiant heat gain, as the vposure system was stationed near a window. The heat rise >t 5.6 C should have a negligible effect on the diffusion tperiments being performed, since (as discussed earlier) me would expect only about a 1% change in diffusion rate. Ihcrefore, the temperature rise noted in the experiments is Relieved to have a negligible effect on the performance of the dmplers. eonclusi ns and recommendations Three commercially available passive personal samplers rere examined experimentally in a controlled environment. They were compared against standard methods of sampling lor enflurane. Large differences in accuracy were discovered the samplers and two parameters (temperature, velocity) usociatcd with their use were examined and found to have Title operator error associated with their use. However, the tecuracy of the devices should be further evaluated in order *at their reliability for the assessment of occupational and Mvironmental exposures can be known in a variety of 'Pplications. This study has suggested possible non-linearity in the Performance of some passive personal samplers. It is hoped 'hat this work will be elaborated on in further experiments larger sample sizes and greater ranges of enflurane !ncentrations. Passive personal samplers hold great Promise for the future of industrial hygiene sampling and lnalysis, but only with extensive testing of the devices. references 1 Whitchor. C.E., E N Cohen and J R Trudel. ........... Exposure to Anesthetic Gases m the Operat i'y Retuti Anesthesiotogy-35(4) 348-353 (1971) 2. Linde, H and D. Bruce: Occupational Exposure of Anesthetists to Halothane. Nitrous Oxide and Radiation Anesthesiology 30 363-368 11969) 3 NIOSH: Criteria for a Recommended Standard Occupational Exposure to Waste Anesthetic Cases and Vapors HEW Publication No (NIOSH) 77-140 US Dept of Health, Education and Welfare, Public Health Service. Center for Disease Control. National Institute for Occupational Safety and Health. Cincinnati. Ohio (1977) 4. Cohen, E., D. Brown, et at.'. Occupational Disease among Operating Room Personnel: a National Study Anesthesi ology 41 321 -340 (1974). 5. Corbett, T,, R. Cornell, K. Lieding, at a/.: Incidence of Cancer among Michigan Nurse-Anesthetists. Anesthesi ology 38 260-263 (1973). 6. West, P-W. and K.O. Reiszner: Field Tests ol a PermeationType Personal Monitor lor Vinyl Chloride. Am. fnd. Hyg. Assoc. J. 39 645-650 (1978) 7. Bailey, P. and P. Hollingdale-Smith: A Personal Diffusion Sampler for Evaluating Time-Weighted Exposure to Organic Gases and Vapors. Ann. Occup. Hyg 20:345-356 (1977) 8. Bamberger. R.. G. Esposito, B. Jacobs, G. Podolakand J. Mazur: A New Personal Sampler for Organic Vapors. Am Ind. Hyg. Assoc. J. 39 701-708 (1978). 9. Campbell. J.E. and R.B. Konzen: The Development of a Passive Dosimeter (or Airborne Aniline Vapors. Am. Ind. Hyg. Assoc J. 41 180-184 (1980). 10. Gillespie. J.: A New Sampling Tool lor Monitoring Organic Vapor Exposures: Passive Sampling Equipment for Occupational Health Personnel. The Gasbadge'* Organic Vapor Dosimeter. Highlights -- Insur. Ind. Hyg Forum(1978) 11. Goaselink, O.W., O.L. Braun, H.E. Mullins and S.T. Rodriguez: A New Persona! Organic Vapor Monitor withinSitu Sample Elution. Occupational Health andSafety Product Division, 3M Company. 12. Tompkins. F. and R. Goldsmith: A New Personal Dosimeter for the Monitoring of Industrial Pollutants. Am Ind Hyg Assoc J 39 371-377(1977). 13. Calvo. O.J.. C.E. Billings, at a!.: Laboratory Analysis of Passive Personal Samplers lor Organic Vapors in the Presence of Adsorptively-Compehng Solvents Paper presented at 1 979 AIHC. Chicago. Ill 14. Mazur, J.F., G.E. Podolak, G.G. Esposito, D.S. Rinehart and R.F. Glenn: Evaluation of a Passive Dosimeter for Collection of 2-Bromo-2-chloro-1.1.1 -tnfluoroethane and 2 Chloro-1.1,2-tnfluoroethyl Difluoromethyl Ether in Hospital Operating Rooms Am Ind Hyg Assoc J. 41 317-321 (1980). 15 Jonas, L.A.: Personal communication 16 Leidel. N.A.. K.A. Busch and J.R. Lynch: Occupational Exposure Sampling Strategy Manual DHEW (NIOSH) Publication No 77-173. US Dept ol Health Education and Welfare, Public Health Services. Center for Disease Control. National Institute for Occupational Safety and Health. Cincinnati. OH (1977) ht*B Indtntfiii Hygienr A<.sooil>0n JOURNAL ttf) 181 3M 110890 in ^venty eight pairs of side-by- side charcoal tube and 3M Brand passive vapor monitor samples were taken in field and analyzed for 22 rganic chemicals including trichloroethylene, benzene, toluene. MEK. m-. p-. and Xylenes. isopropanol, and several C5 through C8 alkanes. Sixty-four pairs-were personal and fourteen pairs Hre area samples Linear regression analyses were performed for ten ch micals detected over a sufficiently targe (lnge of concentrations. Satisfactory correlation (r 0.90 and slopes not significantly different from 1.0) was |0und between monitors and tubes for n-hexane. methylcyclopentane, toluene. 2-methylpentane. 3-methylpgntane. n-heptane, n-pentane, and isopentane. Tube and monitor results differed for methylcyclohexane and ^octane. Paired t-tests were performed on the remainder of the chemicals, and no consistent significant differences (5% level) in the means were found. Field comparison of charcoal tubes and passive vapor monitors with mixed organic vapors JOHN L S HICKEY. Ph D.. P E and CAROLYN C BISHOP University ol North Carolina. Occupational Health Studies Group. School of Public Health. Chapel Hill. NC 27514 introduction Several brands of charcoal-adsorption passive vapor monimrs have been marketed recently. These monitors hold mueh attraction lor measuring workplace vapor exposures because they are lightweight, require no power, pump, or ^hing. and are not likely to interfere with workers' moveBnls. I lie operating principles of these monitors have been described, and their advantages and limitations have been compared to those of charcoal tube pump monitoring sys tems." " The performance of passive monitors has been evaluated lor vat ions chemicals under various conditions."' However, licld studies of the performance of passive mon itors in assaying mixed organic vapors are lacking, although an extensive field comparison of passive monitors and char coal tubes is planned.'" chemical analysis After exposure to the solvent vapors, the organic vapor monitors and charcoal tubes were capped and stored at -7r C until time ol analysis. Monitors were analyzed in accordance with the manufacturer's instructions.1'' using a Perkinl:liner gas chromatograph (Model Sigma I) equipped with a flame ionization detector. Concentration data were calcu lated with a Perkin-FImer Sigma It) data system. The desorption efficiency for each solvent was determined by our laboratory using the method recommended by the 3M Company.' ' Concentrations were calculated in accordance with manufacturer's instructions.""-`The diffusion factors or "umipliii); ran-\" (analagous to diffusion cocllicicntx) used arc listed in I able I lor each chemical. Charcoal tubes were desorbed in the standard manner and analyzed under the same procedures as the monitors. procedures Seventy-eight sets of simultaneous charcoal tube and 3M results Brand 03500 organic vapor monitor samples were collected I en of the chemicals were detected over a sufficiently wide and analyzed lor 22 organic chemicals as part ot a survey of range of concentrations in one or both plants to permit a lire manufacturing facilities. The chemicals, listed in Table I, linear regression analysis of passive monitor and charcoal were selected for analysis on the basis of their presence in lube sampling results. Slopes, intercepts, correlation coeffi materials used in tire manufacture. cients and 95'< confidence intervals for prediction ol indi Samples were collected during regular work shifts in tw o plants during two 2-day periods in July and August. 1979. vidual values' " are giv en in 1 able II. separately for the two surveys and for the combined data from both groups. Char Sixty-four sets were personal samples and 14 were area samples. coal tubes were (X) values and monitors were (Y) values; that is, charcoal tube sample results were considered to 1 he sampling periods varied from three to five hours. reflect "mu" concentrations, as a basis lor comparison. Charcoal tubes were usually changed during the sampling I he second column in Table II indicates the range ol ^riod to reduce the possibility of overloading: the monitors concentrations found in the samples. Columns J and 4 arc Kre not. Thus, with few exceptions, each pair of results the slope and Y-interecpt of the linear regression line, which consists of the concentration from a single monitor and the indicates how well the two methods agree. A slope of 1.0 and ime weighted average concentration from two charcoal at Y-intereept of zero indicate close overall agreement. I he tubes. correlation coefficient (column 5) reflects the degree ol < <q.v* xp'l I'Jftt * " llNt|.S|l.,|| m4.Avv.. I..}.,,. 3M 110891?$4 4m lr.<) Hyc Aisoc 1 ti?\ Ap'i 1981 TABLE I Chemicals Analyzed and Sampling Rates Chemical Sampling Rates (mL min)' isopentane n Penlane 2.2 Diitinthylliutane 3 Methylpentane 2 Melhylpenlane n Hexane Cyi.lopt'nlane Methylcyclopeniane n Heptane Cyclohexane Methylcyclohexane n-Octane 1,1.1 -Trichloroethane Methyl ethyl ketone isopropanol Benzene Trichloroethylene Toluene Ethylene dichloride p-Xylene m-Xylene o-Xylene 29 8 29 8 28 2 28 2 28 2 28 2 28 2 28 2 27 7 28 2 27 2 21 8 28 1 312 35 9 33 0 28 0 304 32 1 23 7 25 6 25.7 Reference U6. departure of data-pairs from the regression line. An r value of 1.00 indicates near perfect correlation, and lower r values indicate poorer correlation. The last two columns are the predicted 95% confidence limits of an individual passive moni tor sample, given some "true" concentration of X as indi cated by charcoal tube samples. The predictions were made for concentrations at the top of the data range observed. The other twelve chemicals were detected in compara tively few samples or mostly at low concentrations (less than I ppm), so no linear regression analyses were performed. Instead, the paired t-test'7' was used to determine if the monitor and tube sample means were statistically different at the 0.05 probability level, assuming normal distribution. No consistent difference in means was demonstrated except for n-octane. discussion The data in Table 11 show two trends. In Group No, I, for every chemical except n-heptanc the passive monitors show higher vapor concentrations than the charcoal tubes, as indicated by linear regression slopes greater than 1.0. In three cases (toluene, n-octanc and methylcyclohexane) the slopes were significantly different at the 95% confidence level from the ideal slope of 1.0. The observation of higher concentrations from passive monitors than from charcoal tubes is not unique. In one report.1101 acrylonitrile was moni tored with 18 Gasbadges,M and charcoal tubes side-by-side; the badges averaged 2.73 ppm and the tubes 2.14 ppm. a mean difference of 25 percent. The second trend was that Y-intercepts for nearly all chemicals in all groups were very close to zero (less than 1 ppm), and were in the main negative. Although a slight negative intercept is of little importance in monitoring sub stances with relatively large TLVs, it may indicate a detec American Industnal Hygiene Association JOURNAL tV)4'81 tion threshold or lack ol sensitiv ttv m the p.t-soe monitors at very low concentrations. Such a condition, il continued, should be considered in making decisions on the use ol passive monitors for detection ol substances with 11 Vs in the I ppm range or lower. Correlation coefficients (r) tor several of the substances were 0.94 or higher. T he 9,5 percent prediction limits on indiv iduul passive monitor sample concentrations are show n in Table II for given chemical concentrations. The predicted monitor concentrations are generally w ithin 25 percent ol the reference concentrations, in Group No. 2 and the com bined data, but vary widely in Group No. I because of the high slope values. This predictability would be much improved by use of the regression curve to "calibrate" the monitors. However, it is presumed that the curve w ill not be known a priori. If the slopes for any chemical had consist ently varied from 1.0 appreciably in both groups (as with n-octane and methylcyclohexane). an inaccurate ".sampling rate" for diffusion published by the passive monitor manu facturer might be responsible. For the statistical analysis, charcoal tube sampling results were presumed to reflect the true concentrations, and be subject to much less variation than the passive monitors. This is by no means a certainty. However, statistical analyses where both methods are subject to error arc rather compli cated'111 and the method used here is considered to be satis factory for this purpose."-' sources of error Several possible sources of errors in the results of this study are discussed below. 1. The "sampling rates" used with the monitors may be imprecise. These sampling rates are analagous to diffusion coefficients. Published sampling rates were used where available; the others were estimated on the basis of chemical similarity. Use of too low a sampling rate would increase the slope (b) of the regression line in inverse proportion to the sampling rate error, but would not affect the correlation coef ficient. This result was observed with methylcyelohexane. raising the possibility that the estimated "sampling rate" used (27.2 mL'min) was too low. Use of too high a sampling rate would tend to depress slopes in inverse proportion to the error. This type of systematic error could account for regression line slopes tending to be consistently greater than 1.0. 2. There may have been interference from unknown chemicals. Many small unidentified peaks were present in some of the chromatograms. Such inter ference would have affected tubes and monitors similarly. 3. On-site temperature and pressure departures from 298 C and 760 mm were not corrected. They were presumed to affect monitors and tubes equally except for the temperature correction*1'' to the sam pling rate (T K 298)' \ This could cause differences in monitor results ranging from -3 to +5 percent, as 3M 110892 295 a mIF TABLE II Comparison of Results of Simultaneous Sampling by Passive Monitors and Charcoal Tubes - Chemical Range of Data (ppm) Linear Regression Slope & Y-Intercept 95% C.L. (ppm) Correlation Coefficient (r) 95% Prediction Interval for Paisive Monitor Sample at True Concentration X Monitor Sample X (ppm) (ppm) Group No. 1 (30 sample pairs) n-Hexane 0-37 Methyicyclopentane 0-17 Toluene 0-18 n-Ociane 0-10 2-Methylpentane 0-18 3-Methylpentane 0-30 n-Heptane 0-7 Methylcyclohexane 07 n-Pentane 0-6 Isopentane 0-13 1,02 * 0 12 1.11 t 0 13 1 31 +0 12 1 41 + 0.15 110+015 1.13 + 0 16 0 94 + 0 13 1.33 0.30 1 23 0 47 1 12 0 68 0 50 0 72 -0 36 001 -0 50 -0 61 -0.31 -0 04 -0.01 092 0 96 0 96 0.97 0.96 0.94 C 94 0.94 086 0 73 0 54 40 20 20 10 20 30 10 10 10 10 33 8 to 46 6 18 3 to 24 6 23 2 to 28 6 12 0 to 16 2 17 7 to 25 5 27 0 to 39 5 7.3 to 10 9 9 7 to 16.9 7.9 to 17 9 3.4 to 20 9 Group No. 2 (48 sample pain) n-Hexane 0-27 Methyicyclopentane 0-20 Toluene 0-20 2-Methylpcntana 0-16* 3-Methylpentane 0-30 n-Heptane 0-25* Methylcyclohe..ane 0-20 n-Pentane 0-30* Isopentane 0-40" 0 91 0 10 0 99 0.11 0 97 0.10 0.92 + 0 07 0 91 0 05 1.09 + 0 13 1.39 + 0 13 0 93 0 07 1 06 0 03 -Oil -0 26 0 16 004 -002 0 56 0 15 -0.05 -0.17 094 0 94 0 97 0 97 0 98 093 0 96 097 0 99 25 17 9 to 27 6 20 16.1 to 22 9 20 16.6 to 22.4 20 16 2 to 20.6 30 24.6 to 30.0 25 22 2 to 31.0 20 24 3 to 31.0 30 24 1 to 31 3 40 40.4 to 44 2 Combined Date (78 sample pairs) n-Hexane 0-37 Methyicyclopentane 0-20 Toluene 0-20 2-Methylpentane 0-18 3-Methylpentane 0-30 n-Heptane 0-25 Methylcyclohexane 0-20 n-Pentane 0-30 Isopentane 0-40 0 97 + 0.07 1 03 + 0.08 1 09 0 08 0 99 + 0 07 1.01 0 06 1 07 0.10 1.38 Oil 0 92 0 07 1 06 + 008 -0 26 -0 38 006 *0 09 -0 15 0 53 -0 12 0 15 031 0.95 0 95 0 95 0 95 0 97 0 93 0 94 0 95 0 94 40 33.5 to 43.9 20 17 6 to 23 6 20 19 0 to 24 6 20 17 1 to 22 5 30 26 4 to 33 8 25 22.7 to 29.7 20 24.4 to 30.6 30 24 3 to 31.3 40 37 2 to 47 9 `Only 21 pairs ,'1 ppm. "Only 15 pairs >1 ppm the temperatures at sampling sites were judged to range from 5 C below to 10 C above 25 C. 4. Overloading of tubes and monitors could cause errors. Charcoal tubes sampled from 90 to 190 liters of air. averaging 130 tilers, at 1 L'min. Only two charcoal tubes showed concentrations over 100 ppm total organic vapors assayed (120 ppm and 150 ppm). These two tubes indicated 2K and 45 ppm total vapor respectively in their back charcoal sections. For other tubes, the total collected in the back section was less than 25 percent of that in the front section. Each monitor was exposed as long as both tubes in a set. Any significant overloading of monitors would result in regression line slopes substantially below 1.0. This did not occur. 5. The back section of a tube was analyzed whenever the chromatogram of the front section showed rather high peaks. In essence, the backs were analyzed if total organic vapors assayed exceeded about 50 ppm, which occurred in roughly half the samples. It is possible that a portion of vapors collected in the m tubes was missed in analyzing samples from areas with low v apor concentrations. This would tend to increase regression line slopes slightly and give substantiallv positive Y intercepts. The latter did not occur. 6. Tubes were analyzed 12 weeks after sampling, and monitors 17 weeks. All were kept at -7 C in the interim. This delay may have resulted in loss of collected vapors. One could speculate that migration of vapors to the back sections of charcoal tubes during storage might account for some loss in tubes whose back sections were not assayed. Losses in the monitors might be less as the vapors would have no alternate sink. Such migration would tend to increase regression line slopes slightly. It is the judgment of the authors that the potential errors did not significantly affect the results. significance of findings Since observed concentrations of substances were generally far below Tl.Vs and permissible exposure limits (PELs), no 3H 110893 Am fnd Hyg Assoc J(42} April, 1981 Li>ni.luMoiiM_.jh he .luu, h limn these data icgardmg correla tion ol monitors ami luhes at concentrations approaching 1I Vv without awummg lineality beyond the observed data. Howescr, since one ol the anticipated values ol the passive monitor is in routine monitoring, it is important to demon strate that they can reliably measure low exposures as well as high ones. The results ol this study indicate that the passive monitor reliable assaved low concentrations ol mixed vapors ol 20 ol the chemicals mentioned equally as well as charcoal tuhes, under the conditions encountered. C harcoal tube and passive monitor results dilfered signilicantly for methylcyclohexane and n-octane. The tendency toward negative Y-iniercepts( I able 11) may indicate a sub-ppm detection threshold in the monitors for some chemicals. More such comparative studies are needed to build a body of literature on which to establish the appli cations and limitations of the passive monitor. research support This research was supported by United Rubber Workers Union. Firestone Tire and Rubber Co., The General Tire and Rubber Co.. Goodyear Tire and Rubber Co., and Uniroyal, Inc. ref r ncea 1. Tompkins. F.C., Jr. and R.L. Goldsmith: A ew Personal Dosimeter for the Monitoring of Industrial Pollutants Am. Ind. Hyg Assoc. J. 38 371 (1977) 2 Bamberger, R.L.. G.G. Esposito, B.W. Jacobs, G.E. Podolak and J F Mazur A New Personal Sampler for Organic Vapors Ant Ind Hyg Assoc J 39 701 11978) 3 Woebkenbeig, M L.: Current NIOSH Research on Passive Dosimeters InPror o/the Symposium on the Development and Usage ol Personal Monitors tor Exposure and Health Effects Studies U S Environmental Protection Agencv. Research Triangle Park NC 2771 1 Publication EPA-600 9 79 032 (June. 1979) 4 Hirayama, T and M. Ikeda. Applicability of Activated Car bon Felt to the Dosimetry ol Solvent Vapor Mixture Am Ind Hyg Assoc J 40 1091 (1979) 5 3M Brand Organic Vapor Monitor Product Information and Usage Guide Occupational Health and Safety Products Div ision. 3M Commpany (undated) 6 Compound Guide for 3M P3500 Organic Vapor Monitor. 3M Company (Feburary, 1979) 7 Remington, R.D. and M.A. Schork: Statistics with Appli cations to the Biological and Health Sciences Prentice-Hall. Inc., Englewood Cliffs. NJ (1970) 8. Natrella, M.G.: Experimental Statistics National Bureau of Standards Handbook 91 (1963) 9. U.S. Environmental Protection Agency: Guidance tor Selecting TSP Episode Monitoring Methods. Research Tri angle Park. NC 27711. Publication No. EPA-450/4-79-007 (February. 1979). 10. Silverstein, L.G.: Validation of Abcor GASBADGE1'1 for Acrylonitrile and Improved Desorption Efficiency. Am. Ind. Hyg Assoc J 38 412 (1977) 11. Acton. F ,S.: Analysis of Straight-Line Data. John Wiley and Sons. Inc., New York. NY (1959) 1 12. Neter, J. and W. Wasserman: Applied Linear Statistical Models. Richard D. Irwin. Inc.. Homewood. IL (1974) 13 ACGIH: Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1979 Am Conf. of Governmental Industrial Hygienists. Cincinnati. OH 45201 (1979) Amrncin Industrial Hygirnr Association JOURNAL 14?) 4 III 3M 110894 267 SAMPLING VARIABLE CONCENTRATION 3M 110895 TOLUENE VARIABLE CONCENTRATION RH-80% TIME WEIGHTED AVERAGE CONCENTRATION (ppm) 3M-OVM Mass Balance 3M-OVM Charcoal Tube Mass Balance KM /f\f / < 'V ' ( l --------------- 24 68 SAMPLING TIME (hrs) 246 243 20 479 108 19 477 108 1805 178 -- ------ 1967 1958 179 3M 110896 SAMPLING A MIXTURE AT VARIOUS CHALLENGE CONCENTRATION 2 ad J 3M-0VM --------Mass Balance Teat #3 71 min 25% Accuracy ------- -V. C hallenge C o n c e n tra tio n (ppm ) Teat #2 266 min i I Teat #1 243 min O 00 ID Tolu ne MEK TCE H xane Ethyl Acetate SAMPLING HIGH VAPOR PRESSURE COMPOUNDS 3M 110898 IV-1 High Vapor Compounds Compound * Vinyl Chloride Butadiene Ethyl Ehter * Pentane Ethyl Bromide * Dichloromethane Al)yl Chloride * Acetone * Trans 1,2 Dichloroethylene 1,1 Dichloroethane * Cis 1,2 Dichloroethylene * Methyl Acetate * Chloroform Vapor Boiling Pressure Point (mm) ( C) -14 9]0 4 442 35 426 36 375 40 350 40 295 44 226 56 265 48 . 182 57 180 60 173 58 160 61 * Hexane Isopropyl Ether * Bromochloromehtane * Methyl hloroform 124 69 119 69 Il7 68 100 74 *Compounds sampled from various concentration to validate sampling rate and capacity values. PEL (ppm) 1 1000 400 1000 200 500 1 1000 50 100 50 200 50 500 500 200 . 350 3M 110899 Compound Vinyl Chloride Pentane Dichloromethane Acetone Methyl Acetate RH Cone. Page (%) (ppm) 60 .39 1.15 4.60 50 All 15 77 573 4030 85 127 50 All 59 129 764 85 All 58 482 50 All 87 644 1170 3770 85 141 545 50 23 75 200 488 85 20 200 IV- 3 4 5 IV-6 7 8 9 10 IV-11 IV-12 13 14 15 IV-16 17 18 IV-19 20 21 22 23 IV-2 4 25 IV-26 27 28 29 30 31 3M 110900 VINYL CHLORIDE 3H 110901 IV- 4 VINYL CHLORIDE RH - 60% 3H 110902 IV-5 VINYL CHLORIDE RH - 60% 3M 110903 PENTANE IV-6 3M 110904 PENTANE IV-7 W EIG HT (mg) 3M 110905 Iv-8 <> 3M 110906 PENTANE IV-9 3M 110907 PENTANE IV-10 W EIGHT (m i) EXPOSURE (min-mg/l) 3M 110908 IV-U PENTANE RH 86% EXPOSURE (min-mg/1) 3M 110909 IV-12 dichloromethane 3H 110910 IV-13 DICHLOROMETHANE 3H 110911 IV-14 DICHLOROMETHANE 3M 110912 IV-15 DICHLOROMETHANE 3M 110913 IV-16 3H 110914 DICHLOROMETHANE RH - 85% IV-17 3M 110915 IV-18 DICHLOROMETHANE EH -86% k i 3H 110916 ACETONE IV-19 3M 110917 ACETONE IV-20 3M 110918 ACETONE IV-21 1 3M 110919 ACETONE IV-2 2 3M 110920 ACETONE EXPOSUBE (jnin-mg/l) 3H 110921 ACETONE IV-24 W EIGHT (mg) 3M 110922 ACETONE RH - 85% IV-25 3H 110923 IV-26 METHYL ACETATE 3M 110924 METHYL ACETATE IV-27 3M 11092S lV-28 METHYL ACETATE 3M 110926 IV-29 METHYL ACETATE 3M 110927 METHYL ACETATE BH - 85% 3H 11092S METHYL ACETATE IV-3] W EIG HT (mg) 3M 110929 SEI Receives OSHA Support for Dosimeter Program he SHI Board of Directors, at their December 2,1994 Tmeeting, approved the initiation of a new program to certify direct reading passive monitors. 11115 program is a natural addition to the highly successful program for certifying gas detector tube units. SEI will use an OSHA approved Protocol for the Evaluation of Direct Reading Passive Monitors. Gayton Environmental Consultants will add this verification testing to their detector Golomski assurance manufactur the success in your program to certify gas detector tubes is particularily noteworthy current testing of gas tube units. Bill will conduct quality audits at participating ers' facilities. SEI will use the OSHA approved "Protocol" on an interim basis until the industry develops a consensus standard through the American National Standards Institute (ANSI)- The Industrial Safety Equipment Association (ISEA) is now forming a group to begin work on a standard for passive monitoring devices. Their next meeting is January 26-27 at the OSHA Salt Lake Technical Center. In a letter to Patricia A. Gleason, SEI President, officials from OSHA indicate they are pleased that SEI will provide third-party certification of passive monitoring devices, and state, "We also recognize the confidence manufacturers and government agencies, including NIOSH and MSHA, have demonstrated in SEI's ability to provide this service through their participation and comments regarding your existing programs. The success in your program to certify gas detector tubes is particularily noteworthy because it can be extended to cover what is needed for the certification of passive monitoring devices". This program will allow OSHA to include the device as an option for use by OSHA compliance officers. SEI expects OSHA to announce a similar recognition of SEI certified gas detector tubes. 3M 110930 \j S t>CPAj<TM-Vr OP L>DOK _ OCCUPATIONAL SAFETY * HjCALTH ADMINtATRATION Sill UW TnAutcil Cmi 17*1 South jre wot p.o. &m iSVtO S* UJtc Cj(v, LT til <41X10 December 16, 1994 FA.1- UMIA A.M ('! *>l Patricia A Gleason, President Safety Equipment Institute 1901 North Moore Street, Suite 80$ Arlington, VA 22209 Dear Ms. Gleason: Thank you for the opportunity to review the protocol you are considering for evaluating direct reading passive monitors, such as the ACTTM badges manufactured by Envirometrics Products Company. We are pleased that manufacturers of passive monitoring devices are considering funding the Safety Equipment Institute(SEI) to provide "third party; certification" of the effectiveness of these devices. As you know, OSHA strongly supported the ntied for this type of verification in its recent expansion ofthe personal protective equipment standard (Ijef. 2SCFR1910.132, April 26, 1994). We also recognize the confidence manufacturers and government agencies, including NIOSH and MSHA, have demonstrated in SEPs ability to provide this servictj through their participation and comments regarding your existing certification programs. The success in your program to certify detector tubes is particularly noteworthy because it can be extended to cover what is needed for the certification of passive monitoring devices. j i` Published field studies indicate a large variability in workplace exposures. Therefore, we want to encourage employers to obtain multiple samples for varying working conditions to obtain a more realistic characterization ofworkplace exposures. The availability of effective, inexpensive, and easy ', to use devices, such as passive monitors, provides a needed resource to employers to achieve this objective. Unfortunately, our evaluations of early passive monitors identified problems with some' of the devices on the market. The existence of a certification program to verify the claims of the manufacturers will greatly assist employers in identifying (hose devices which will be effective in monitoring their work sites. The program should also ijnprove the overall quality of these devices as manufacturers strive to meet a higher "industry standard". i i This brings us to the issue at hand. We recognize that the development of generic protocols for evaluating passive monitoring devices is being considered by both OSHA and ANSI. However, based on current knowledge, a successful evaluation of direct: reading passive monitors by your protocol (as modified) would allow us to include the device as an option for use by OSHA compliance officers. Also, recognizing our common goal of providing employers with a variety of effective tools for evaluating workplace hazards, please let us know if wfe can be of assistance in reviewing specific protocols for other types of sampling devices. i Robert A. Curtis, Director OSHA Health Response Team Field Instruments Team 3H 110931 DEC-23-94 FIU 12:41 P.02 Comments oa Evaluation Protocol for Direct Reading Passive Monitors Introduction ; The following comments are presented based on <^ur review ofthe draft protocol. These coiftmcnts are presented as elements for a "third party certification" ofa direct reading passive monitor and H should be understood that me manufacturer would perform a more thorough validation during development ofthe devices. The evaluation ofpassive devices should evaluate the manufacturer's claims ofaccuracy over the range of operating conditions for which the devices are supposed tojwork. These cooditiona normally include, but are not limited to, concentration, temperature, relative humidity, face vd city, exposure time, interferences, sample stability, analytical variability, and shelflife. Uijless otherwise stated, each exposure test will be conducted with 10 monitors for 3t4i$tical analysis, and will use standard exposure conditions of 25 degrees C, 50% relative humidity, 25 cm/s face velocity, and the appropriate OSHA PEL or ACGiH TLV concentration for the analyte being tested Ail teats are conducted using the manufacturer's specified operating parameters fo the monitor (e.g., exposure time, shelf life, etc.). Normally,'the two worst case extremes ofthe operating parameters and one or two intermediate values should be evaluated. Concentration and Exposure Time A concentration of0.1 times the appropriatePEL or TLV may be evaluated instead of 0.2S, as recommended in the draft NIOSH protcjcol, and the UK and European protocols. Normally, 2 times the appropriate PEL or TLV is used instead of 1.25. Testing at 0.75 times the exposure standard may be unnecessary. Expose the monitors fbr the specified period oftime described in the manufacturer's literature. Temperature and Relative Humidity j The two extremes and a midpoint of the ranges specified in the manufacturer's literature should be evaluated fbr both temperature and humidity. Pressure i Evaluate the adequacy ofthe manufacturer's instructions for reporting the results of monitoring at conditions other than 760 mm atmospheric pressure. Face Velocity The performance ofthe monitor should be evaluated in the air velocity range of 10 to 150 cm/s normally found in workplaces, as recommended by NIOSH, unless otherwise specified by the manufacturer's literature. 3H 110932 ( DEC-23-94 FR1 12:41 P.03 Interferes j i Adless whether the manufacturer has adequately Addressed potential positive and negative inlurferences based on the reaction chemistry used in the monitors. Where potential negative interferences have been documented in the literature, but have not been suifictently evaluated by the manufacturer, the user manual will instruct the user to conduct initial side-by-side sampling with alternative methods to assess the amount of interference occurring at the specific woric site, or the manual will explicitly state that the monitors can not be used in this type ofenvironment Where interferences have been identified by the ratanufacturer, expose monitors to the interferences at their PEL for the maximum sampling timeperiod. Verify that the manufacturer has documented and evaluated the extent ofknown interferences. } Shelf Life j 1! To verify shelf life, monitors will be stored per manufacturer's instructions (e.g. refrigerated ifrequired by the user manual) and tested at standard conditions (ie., 25 cm/s, 50% RH, PEL or TLV, and 25 Celsius) immediately prior to the expiration date if possible. Monitors may be given an initial certification based on an evaluation of manufacturer's tests ofmaximum shelflife. j iI ' Quality Control : Acceptable as proposed. : ' i. Monitor Orientation j j Expose monitors at orientations parallel and perpendicular to air flows for each type of Lodge design. j Reverse Diffusion lixpose 20 monitors to a 2X exposure limit for 0.5X the maximum specified sampling time and to 0% exposure limit for 0.5X the maximum specified sampling time. Use worst case temperature and humidity conditions. J Inter-reader Variability 3M 110933 I'pr direct reading dosimeters, inter-reader variability, either electronic or visual, must be assessed and incorporated into overall accuracy! ofthe system. An example protocol for testing visual precision may be found in the SE^ detector tube certification protocol. DEC-23-94 FRI 12:42 P.04 ( Readout Time , Evaluate the nwndraujn time atlowed between cessation ofsampling and measurement of exposure or specify that devices must be read out immediately. Evaluation of Qualitative Monitors ! .. i . ... A similar validation protocol to the quantitative monitors can be applied to qualitative monitors. Qualitative monitors are read visually by comparing the developed color to rofyrence color guides provided on the card (some monitors have one reference guide). Thp color guides typically represent the action level and the PEL fbr PEL-TWA cards (8 hours). The color on the STEL,or CEILING cards are based on the ACGIH STEL Of G$HA CEILING standards respectively. The intentity ofthe developed color in relation tc the color guide provides an indication ofthe exposure concentration. Field Ev.Juation j i Field evaluation ofpassive monitors in actual workplaces is encouraged. When possible, samples should be taken tide-by-tide with a reference method in industrial settings. Any shortcomings ofthe reference method should betaken into account when comparing the test method. The manufacturer should be encouraged to conduct the field test. The third pa.ny certifier should be capable ofreviewing thi manufacturer's field data for adequacy. Field testing can be conducted using criteria established in the NIOSH, Health and Safety Executive, CN or other protocol using should scientific principles and practices. ( 60:0t S6. e Nbf rOO-d iT-l 063-J 3H 110934 6Mc8cS2i MandardsiTesting Agencies hnp://www.safetyonline.net/SEINET.org/stardard. Standards/Testing Agencies The standards, testing agencies and auditors selected by SEI are: PRODUCT CATEGORY Disposable Coveralls Emergency Eyewash and Shower Equipment Eye & Face Protection Fire Service Life Safety Rope, Harness, and Hardware Gas Detector Tube Units SELECTED APPLICABLE STANDARD TESTING LABORATORY Professional Service ANSI/ISEA 101-1993 Industries, Inc. PTL Division ANSI Z358.1-1990 Professional Service Industries, Inc. PTL Division ANSI Z87.1-1989 Professional Service Industries, Inc. PTL Division NFPA 1983, 1995 Edition Professional Service Industries, Inc. PTL Division Clayton ANSI/ISEA 102-1990 Environmental Consultants, Inc. Gloves for Structural Fire Fighting NFPA 1973, 1993 Edition ETL Testing Laboratories, Inc. Headgear Used in Horse Sports and Horseback ASTM F-1163-95 Riding Helemts for Structural NFPA 1972, Fire Fighting 1972 Edition Liquid Splash-Protective Suits for Hazardous Chemical Emergencies NFPA 1992, 1994 Edition ETL Testing Laboratories, Inc. ETL Testing Laboratories, Inc. ETL Testing Laboratories, Inc. QUALITY ASSURANCE W.A. Golomski & Associates W.A. Golomski & Associates W.A. Golomski & Associates W.A. Golomski & Associates W.A. Golomski & Associates Quality Improvement Corporation W.A. Golomski & Associates W.A. Golomski & Associates W.A. Golomski & Associates 3M 110935 Standai'ds/Testing Agencies http://www.safetyonline.net/b hlNET.0rg/5tandarc ] Open-Circuit | Self-Contained | Breathing Appartus for ! Fire Fighters (SCBA) j *j1 ] Passive Dosimeters 1 Personal Alert Safety Systems (PASS) for Fire Fighters NFPA1981, . 1992 Edition Protocol for Evaluation of Direct Reading Passive Monitors NFPA 1982, 1993 Edition Prescription Safety Eyewear ANSI Z87.1-1989 Protective Clothing For Emergency Medical Operations NFPA 1999, 1992 Edition Protective Gloves For Emergency Medical Operations NFPA 1999, 1992 Edition Protective Clothing for NFPA 1976, Proximity Fire Fighting 1992 Edition Protective Clothing for NFPA 1971, Structural Fire Fighting 1991 Edition Protective Clothing and ; Equipment for Wildland NFPA 1977, j Fire Fighting (Helmets) 1993 Edition j Protective Clothing and ] Equipment for Wildland j Fire Fighting (Clothing) NFPA 1977, 1993 Edition j Protective Clothing and | Equipment for Wildland NFPA 1977, 1 Fire Fighting (Footwear) 1993 Edition | Protective Footwear for ] Structural Fire Fighting i" i ] Protective Headgear j Used in Bicycling NFPA 1974, 1992 Edition ASTM F 1447 - 94 j Protective Headwear I for Industrial Workers i Station\Work Uniforms | for Fire Fighters ANSI Z89.1-1986 NFPA 1975, 1994 Edition ETL Testing_ . Laboratories7lnc. Quality Improvement Corporation Clayton Environmental Consultants W.A. Golomski & Associates ETL Testing Laboratories, Inc. Professional Services Industries, Inc. PTL Division Quality Improvement Corporation W.A. Golomski & Associates ETL Testing Laboratories, Inc. W.A. Golomski & Associates ETL Testing Laboratories, Inc. ETL Testing Laboratories, Inc. ETL Testing Laboratories, Inc. Quality Improvement Corporation W.A. Golomski & Associates W.A. Golomski & Associates ETL Testing Laboratories, Inc. W.A. Golomski & Associates ETL Testing Laboratories, Inc. ARTECH Corporation ARTECH Corporation ARTECH Corporation ETL Testing Laboratories, Inc. ETL Testing Laboratories, Inc. W.A. Golomski & Associates Quality Improvement Corporation Quality Improvement Corporation Quality Improvement Corporation W.A. Golomski & Associates W.A. Golomski & Associates 3M 110936 2 of 3 4/1/97 10:3 http://www.safetyonhne.net/SEINET.org/standarc Support Function Protective Garments NFPA1993, For Hazardous Chemical 1994 Edition Operations Vapor-Protective Suits for Hazardous Chemical Emergencies NFPA 1991, 1994 Edition .. ETL Testing ; Laboratories,Tnc. W.A. Golomski & Associates ETL Testing Laboratories, Inc. W.A. Golomski & Associates If you require additional information or have questions about the SEI third-party certification programs for safety equipment, please do not hesitate to contact our Office703/525-3354. Introduction Board and Staff Certified Product List Suppliers Standards/Testing Agencies What's New Information Contact/Staff Request Form Information SEI Home sei headouarters@msn.com Copyright 1996 SafetvOnline. Inc. All rights reserved 3M 110937 3 of 3 4/1/97 10:34 SENSIDYNE MEMORANDUM TO: Distribution FROM: Ron Roberson DATE: August 1, 1995 SUBJ.: SEI Badge Certification Attached is some correspondence between Sensidyne and SEI concerning SEI's closed certification of Envirometrics Company's formaldehyde badge. I feel that SEI acted unfairly by not opening the certification opportunity to other companies. I have asked Sensidyne and Gastec not to participate in SEI's badge certification program, but to conduct our own program verifying with lab reports that the product meets the ANSI requirements. I have also asked Sensidyne and Gastec to carefully evaluate any benefit we receive from our current SEI certifications on our short term detector tubes. If you have questions or comments, please contact the writer at 1(800)451-9444. Sincerely yours, Ron Roberson Corporate Industrial Hygienist Copy: Kim Chapman, Gilian Environmental Gus Manning, Assay Technology Alan Levin, Air Scan Richard Wanek, GMD/Bacharach Bob Weber, 3M Ed Ligus, National Draeger Katie1 Spear, MSA Lloyd Kent, Matheson Gas 3M 110938 SENSIDYNE INC. Gas and Particulata Detection Systems 16333 3ay Vista Onve, Clearwater. Florida 34620 300-461-9444 / Florida 813-530-3602 TELEX 765223 / Fax 813-539-0630 June 1, 1995 Safety Equipment Institute 1901 North Moore Street Arlington, VA 22209 Attn: Patricia Gleason ear Ms. Gleason: As you are aware Sensidyne and Gastec have participated in SEl's detector tube certification program since ifs inception. Since the beginning cf our relationship with SEi, I have consistently been impressed with the degree of professionalism within SEI. SEI has historically operated in an unbiased fashion in dealing with both ISEA members and non members in the same program. Until recently 1 had never witnessed favoritism toward any singi company. SEl's detector tube certification program began with SEi contacting all th manufacturer's to solicit interest Following that a protocol was adopted, gases selected and a test schedule published. Every company that produced detector tubes for the U.S. market was given an equal opportunity to participate. No single company was given any chance to obtain an unfair market advantage under SEI's program. To this day that professional, non-biased practice is still demonstrated in SEI's detector tube program. Recently at the A1HC in Kansas City, Envirometrics Products Company was advertising an SEi-approved formaldehyde badge. I thought this to be false advertising since SEI's program was not yet started. However, upon checking at the SEi booth I was informed that Envirometrics had received certification in a special testing session they had requested. I was given a copy of SEI's May, 1995 newsletter that announced Envirametric's certification. I received my copy in the mail after my return from the AIHC. I have followed SEI's commitment to a badge program carefully. Sensidyne sent representatives to the ISEA badge meetings at the National Safety Congress in October, 1994 and Salt Lake City in January, 1995. I sent correspondence to SEI with questions following the December 1994 newsletter announcement of SEI's intention to start the program. Judith Bailey answered these questions with a letter dated 12/1/94. There should have been no question that Sensidyne and Gastec were interested in this program, yet we were not informed that testing had started. Bill Emy of ISEA estimated two years from January, 1995 for ISEA to complete the ISEA test protocol. We were not informed by SB that SB planned to start without that protocol. 3M 110939 SENSIDYNE INC. Gu and Pimquiaia Oi*enon Systems 16333 Say Vista Ortva. C.'aarwater. Florida 34620 300-451-94*4 / Florida 313-530-3602 TELEX 756223 / Fa* 813-539-0550 It is apparent that Envirometrics quietly pushed for a custom certification in order to obtain a market advantage on the other badge manufacturers. I am very disappointed that SEI supported this market advantage. It is clearly not within SEI's historical policy to provide a custom certification that was apparently not open to everyone. It is clearly not the actions of a responsible unbiased third party certifier to support one manufacturer at the expense of others. Please answer the following questions in writing so I can advise Sensidyne and Gastec on future dealings with SEI. 1) When did the passive monitor program begin? Was a test schedule announced? Why was Sensidyne not informed prior to testing? We advertise formaldehyde passive monitors. 2) Why was Envirometrics allowed to certify a product without soliciting other program participants? Is it SEI's policy to conduct custom certifications outside of published programs? 3) The following companies also advertise passive formaldehyde monitors. Which ones were informed of SEI's formaldehyde certification testing? a) Giiian Environmental ' b) Assay Technology c) Air Scan d) GMD e) 3M . 4) Why did SEI not follow the procedure set forth by the detector tube program? Why were the following steps omitted? a) Soliciting interested companies b) Publishing a test gas list c) Publishing a test schedule d) Informing manufacturers of certification opportunity 5) Why did SEI rush a custom certification for a single manufacturer? Did SEI intend to provide one company with a marketing advantage? Did SEI not realize the rush to certify in time for a major trade show promotion? 3M 110940 SENSIDYNE INC. Gas and Paniculata Detaction Systems 16333 Say Vista Onve, Clearwater. Florida 34620 800-431-9444 / Honda 813-S30-3602 TELEX 756223 / Fax 813-539-0550 I believe that SEI did not act responsibly in this initiation of a new program. I believe that all manufacturers should be given an equal opportunity to submit products if an unbiased third party certification truly exists. In my opinion SEI should do the following to rectify the situation. 1) Contact all companies that produce passive monitors and ask if they wish to participate in a certification program for formaldehyde monitors. Provide the test protocol to interested parties. 2) Produce a test schedule allowing all interested parties adequate time to submit products. 3) Inform all the manufacturers of the program schedule. 4) Put Envirometric's certification on "hold" to be released with the other participant's certifications. Please respond in writing as to SEI's planned actions to rectify this situation. Our continued support of SEI is pending SEI's response. Sincerely, >Si- , Ron Roberson Corporate Industrial Hygienist RR/tr copyiGilian Environmental Assay Technology Air Scan GMD 3M 3M 110941 m SEI Certifies 1st Passive Monitor OSHA he first certification for direct reading passive dosimeters was Recognizes SEI Jissued to the Envirometrics Products Company for their ACT Monitoring Card System For Formaldehyde. Verification ?sting was conducted by SHI contract lab, Clayton Environmental Certification onsultants, Inc. Envirometrics passed the SEI quality assurance adit which was conducted by William A. Golomski & Associates. A protocol, which underwent a thorough review by OSHA's rchnical staff in Salt Lake City, is being used as the basis for the new rogram. SEI plans to use this interim standard until a consensus zandard is published by ANSI. The Industrial Safety Equipment .ssociadon has formed a standards group to accomplish this task. SHA maintains a OChemical Information File containing substances encountered by compliance officers in their workplace audits. SEI certified Gas Detector Tubes and Passive Monitors will now Equestrian Safety be listed in this File as a recommended screening device Zantuuitdfrom paft I) ' Task Group Chair, Dru Malavase's suggestion, SEI is cosponsoring i poster that will reach thousands of equestrian riders. Among oth ers, another sponsor of the poster is the American Medical Eques- zrian Association. The poster includes a photo of Christopher Reeve iding his horse, Denver, and includes a quote, "In films I've played in invincible hero - but in real life, I wouldn't think of riding with- jut a helmet" The poster will be distributed nationwide. for OSHA compliance officers. This database is available to the public through the GPO and accessible via the Internet. This recognition by OSHA is a tremendous boost for companies with certified products to gain national exposure. Page 4 1901 N. Moore Street Arlington, VA 22209 Tel: 703/525-3354 Fax: 703/528-2143 inside... Quality, Standards, Testing - Focus at SEI Forum Global Issues in Quality Congressional Fire Services Institute Honors ETL ASSE & VPPPA Conferences to Feature SEI SEI - Your Symbol at Quality in Safety Equipment 3M 110942 SAFETY EQUIPMENT INSTITUTE 1901 North Moore Street Arlington, VA 22209 - 703/525-3354 703/528-2148 Fax June 6, 1995 Mr. Ron Roberson Sensidyne Inc. 16333 Bay Vista Drive Clearwater, FL 34620 Dear Ron: In response to your June 1, 1995 letter I would like to address your statements about SEI's continued professionalism in operating certification programs for safety and protective equipment. SEI's purpose continues to be to assist government agencies along with users and manufacturers of safety and protective equipment in meeting their mutual goals of protecting those who use safety and protective equipment on or of the job, in keeping with recognized standards and the current state of the art, and to recognize, for the convenience of users, those products which are certified to meet applicable standards. In all programs we attempt to provide a fair and equal opportunity to companies interested in participating in SEI certification programs. SEI is a non-profit organization with no interest in providing any company a market advantage. SEI's sole purpose is to test and certify products and to fill a void in the industry because of the lack of a government certification program for safety and protective equipment. We are proud of our accomplishments over the years and the tremendous growth and recognition of SEI's certification programs in general industry, the fire service and by consumers. In May of 1994 we had our first discussion with OSHA personnel about their interest in recognizing SEI certified gas detector tubes and passive monitors. The OSHA staff was already in the process of a review of a modification of the NIOSH protocol for passive monitors, which we thought could be used as the basis for an SEI certification program until a standard was published through ANSI. We were pleased at OSHA's interest and first publicized this exciting news on the cover of the August 1994 edition of SEI's participant newsletter, SET Update. To provide momentum to maintain OSHA's interest in recognizing SEI certified tubes and passive monitors, we decided to inform all SEI gas detector tube participants at a special meeting during the National Safety Congress on October, 25, 1994. With OSHA's level of interest being so strong, we invited two of the top OSHA Salt Lake City officials 3M 110943 to tell SEI participants first hand about their impending recognition of SEI certified products. At that meeting, a draft Interim Protocol for Direct Reading Passive Monitors was distributed to all attendees. Again it was emphasized that such a protocol would be reviewed by OSHA and be utilized by SEI until an ANSI standard was published. With the length of time it takes to develop a standard, utilizing an interim standard would address the short term need to support OSHA. The primary reason for holding the October 25 meeting was to announce the new SEI program, obtain input on the draft protocol and to gauge the level of interest of SEI participants. From our discussions and observations at the meeting, the first company that expressed interest in an immediate certification to the Interim Protocol was Environmetrics, Inc. A preliminary, open meeting was held the same day by the Industrial Safety Equipment Association (ISEA) to discuss the development of an ANSI standard. Those companies ISEA thought to be manufacturers of passive dosimeters were invited to attend the ISEA meeting. OSHA representatives attended that meeting as well to discuss their interests in development of a standard. We made certain all SEI participants were included in the invitation list. While the focus of the meeting was on development of an ISEA/ANSI standard for passive monitors, the new SEI program was discussed and the draft Interim Protocol was distributed. I understand their were five companies that attended that meeting and that Mike Marselli represented Sensidyne. Following the October meeting, Tom Augherton received a ietter from you inquiring about several issues, including audit costs for the passive monitor program. Judith Bailey responded with information available at the time. Over the next few months, OSHA continued their review of the Interim Protocol with SEI's insistence that it be generic so that it could be used for certifying similar passive monitors made by competing manufacturers. Input was also obtained from SEI's testing laboratory, Clayton Environmental Consultants and from a representative of 3M who was unable to attend the October meeting. This information was circulated to OSHA for review with the interim Protocol which received a final review from Robert Curtis and Rick Cee. On December 2,1995 the above information was presented to the SEI Board of Directors, who at that time approved the initiation of a program to certify passive monitors to the interim Protocol for the Evaluation of Direct Reading Passive Monitors. The intent is to utilize this standard until an ANSI standard is published. SEI announced this news on the front cover of the December 1995 issue of SEI Update. At this time SEI requested a fee schedule from Clayton and some time later we were notified by telephone that the fee structure was the same as the gas detector tube program. 2 3M 110944 A subsequent ISEA meeting was held at the OSHA Salt Lake Technical Center on January 26-27, 1995 to finalize a strategy for developing a consensus "standard through ANSI. At that meeting, the final OSHA reviewed interim protocol was distributed and attendees were informed of SEI initiating its certification program. Bob Curtis of OSHA notified attendees of their intent to recognize SEI certified passive monitors after March 1,1995. That meeting was well attended with eleven manufacturers present and Clayton Environmental Consultants was available for any questions about the SEI certification program. We received no indicator of interest from any manufacturer, except Environmetrics Inc. following any of these meetings. When Environmetrics applied for SEI certification, we initiated a certification process for their formaldehyde monitor. Publishing a test schedule for one company and one monitor seemed unnecessary. We sincerely believe there was a miscommunication with Sensidyne. Because of the unresolved cost issues surrounding your continued participation in the gas detector tube and our apparent misunderstanding of your company's dissatisfaction with fee structure, outlined in your February 3,1995 letter, we assumed that Sensidyne was not interested in pursuing another round of testing. We would have been pleased to include any interested company in the initial certification* I am certain that Environmetrics would have appreciated the cost reduction in testing fees. SEI's role in certifying the formaldehyde monitor assisted OSHA who was looking for products independently certified by a third party. With this program, SEI was trying to meet the needs of a government agency, and not any one manufacturer. We are making real progress in improving the management of the gas detector tube program. As always, we would like to accommodate any certification needs that you may have. If there are any passive monitors that you wish to have certified using the interim Protocol, please advise Tom Augherton, Judith Bailey or me. We can solicit other manufacturers to determine if they would like to participate. : In virtually all of SEI's other certification programs, participants submit products for certification at varying times. The unique nature of the gas detector tube program and passive dosimeter program allow for cost reductions through joint testing. Ron, we apologize for the miscommunication, and will make every effort to take that extra step in contacting all companies for future testing, even if there is no perceived interest. Patricia A. Gleason President J 3M 110945 SENSIOYNE INC. G and Particulate Detection Systems 18333 Say viati Orlva, Ciaarwitar. Florida 34820 300-451-94-44 / Florida 311-530-3602 TELEX 7582231 FAX 313-5380550 June 20,1995 Safety Equipment Institute 1901 North Moore Street Arlington, VA 22209 Attn: Patricia Gleason Dear Ms. Gleason: Thank you for your letter of 6/6/95 responding to my letter of 6/1/95. I have spent the last ten years developing a very good rapport with SE1, and my recent letters of complaint were difficult ones for me to write. I believe your conclusion of miscommunication is a valid one regarding the issue of the seemingly closed passive badge certification for Envirometrics. However, my opinion that SE1 acted unfairly is not changed, and I still believe that SEI should start the certification program over using SEi's protocol developed in the detector tube program. ` SEi's announcement of the intended badge certification program as stated in the December 1994 newsletter is just that It is an announcement that SEI intends to eventually have a program. There is no start date, no list of intended gases and no invitation for manufacturers to contact SEI for such information. It is simply an announcement that OSHA is interested. I received similar information from Tom Augherton in telephone conversations over the past two years. I was fully aware that SEI intended to certify badges in the future. I was never informed as to when testing would begin. Evidently no other company except Envirometrics was informed either. . My company attended the two meetings referenced in your letter. No start date was given at either meeting. The 10/25/95 meeting was simply to solicit interest from manufacturers. SEI gave no indication that the testing was actually about to start The Salt Lake City meeting of 1/26 and 1/27/95 was to initiate the writing of the ISEA/ANSI standard. There was no announcement that SEI would start a program prior to that standard's completion. I attended the Sait Lake City meeting personally and there were no SEI personnel present Bill Emy of ISEA announced that Marshall Parker of Clayton would represent SEI at that meeting. Mr. Parker stated that their lab fees would be similar to the detector tube lab 3M 110946 fees in any program that SEI would produce. But no start date nor.intended test gas was provided. Mr. Parker did not present a report He offered the lab fee information in direct response to my question. Bill Emy stated that 1SEA and SE1 were becoming separate entities, and that SEI has its own board of directors. He stated that he was not in a position to speak to SE1. He also stated that ISEA was not bound to use SEI as a certifier, but could use any certifier they choose to use. Bob Curtis of OSHA led the meeting, and he did not announce an SEI program. He did state that certification was not necessary for OSHA. If manufacturers could state that their product meets the ANSI standard requirements, and could provide the data, that was all that was necessary. If you believe that SEI's program was announced at that meeting, you have been misinformed. I also cannot believe that SEI thought Sensidyne/Gastec to be uninterested in a passive monitor program. I relayed our interest to Mr. Augherton in numerous phone calls. 1 wrote a letter to Judith Baiiey dated 9/30/94 with questions on the proposed program. Ms. Bailey answered some of the questions in a letter to me dated 12/1/94. My company spent nearly two thousand dollars to send me to the Salt Lake city meeting, and my name appeared in ISEA's meeting minutes. My letter of 2/3/95 regarding costs was written in an attempt to make both programs affordable to Gastec. How could SEI possibly conclude that we were not interested? All SEI had to do was ask. SEI was the party who knew that the testing was starting. We did not I have been involved in SEI's detector tube program since the initial "gathering interest" stage in 1984. SEI very skillfully handled the task of directing four strong competitors into one program. SEI acted as a "referee" and always made certain that the four companies were on a level playing field. There were many meetings and constant updates to manufacturers by telephone. A test schedule was published, and anyone who wanted to submit a product could do so. SEI's role as referee in this situation is very important to the manufacturers. In my opinion, if SEI no longer acts as referee, then SEI is no longer necessary. If clandestine certifications are allowed, the manufacturer might as well deal directly with the test lab and make his own claims. : You seem to be under the impression that SEI's name is an important issue with us. This is not necessarily true. SEI is still virtually unknown to the industrial hygienists. Our customers find out about SEI through our brochure. OSHA came to SEI as a result of a phone conversation I had with Rick Cee in June of 1991. At that time OSHA was conducting its own detector tube testing at the Salt Lake City lab. 1 told Rick about SEI's program in an attempt to reduce the duplication of effort I gave him SEI's contact information. Prior to that time OSHA had little or no interest in SEI. Rick seemed to be completely unaware or at least uninterested in SEI's program. OSHA was already Sensidyne's customer, and had been since the 1970's when we were still Bendix. OSHA did not start using detector tubes as a result of the SEI program. I see SEI's certification program for detector tubes as a benefit to the end user. I have this opinion because I worked as a field industrial hygienist for ten years. The management at Sensidyne and Gastec sees SEI's detector tube program as a cost of operation. We cannot point to any increased sales that can be attributed to SEI's program. We have remained in the tube program and planned to certify passive monitors, because as the SEI coordinator, I have 3M 110947 always advised Sensidyne and Gastec to participate as a service to end users. However, in light of recant developments with SEI, I am reconsidering this position.' Your letter of 6/6/95 does not address the direct questions I raised on the Envirometrics issue. It also does not address my proposed restart of the program under SEI's normal detector tube protocol. I have to assume that SEI has no intention of putting Envirometrics* formaldehyde certification on hold until others can be certified. If SEI does not intend to provide a level playing field, then 1 see no reason to pursue passive badge certification from SEI. I am not in a position to make the final decision of participation for either Sensidyne or Gastec. However, as the SEI coordinator, I will advise both companies to pursue their own manufacturers* claims for passive badges by dealing directly with the laboratory. Instead of an SEI certification we would simply state, "Meets the requirements of ANSI Standard XXXX, validation study available upon request" If this is good enough for OSHA, it should be good enough for anyone. As far as I know at this point, our detector tube certifications with SEI will remain unchanged. However, I believe there is a general lack of interest in this program among manufacturers, since we seem to be the lone participant submitting tubes for the new substances. If my proposed internal passive monitor program is accepted and successful, I will encourage a similar program in the future for our detector tubes. I believe such a program would be cost effective. Again, I do not make the final decision on our participation in your passive monitor program. If SEI does eventually issue a test schedule, please copy me. 1 sincerely hope that SEI endeavors to improve communications with manufacturers in the future. Sincerely, . Ron Roberson Corporate Industrial Hygienist 3M 110948 u. s. department of labor occupational safety a health ADMLNISTRaTION Sait Lalu Ttchnical Ctniir 17*1 South 300 Wot P.O. Bo* 63200 Salt Uko City, UT *4165-0200 December 16, 1994 TAX: 4VMI90 lUafidcM Patricia A Gleason, President Safety Equipment Institute 1901 North Moore Street, Suite 808 Arlington, VA 22209 Dear Ms. Gleason: Thank you for the opportunity to review the protocol you are considering for evaluating direct reading passive monitors, such as the ACTTM badges manufactured by Envirometrics Products Company. We are pleased that manufacturers of passive monitoring devices are considering funding the Safety Equipment Institute(SEI) to provide "third party certification" of the effectiveness of these devices. As you know, OSHA strongly supported the need for this type of verification in its recent expansion of the personal protective equipment standard (Ref. 29CFR1910.132, April 26,1994). We also recognize the confidence manufacturers and government agencies, including NIOSH and MSHA, have demonstrated in SEI's ability to provide this service through their participation and comments regarding your existing certification programs. The success in your program to certify detector tubes is particularly noteworthy because it can be extended to cover what is needed for the certification of passive monitoring devices. Published field studies indicate a large variability in workplace exposures. Therefore, we want to encourage employers to obtain multiple samples for varying working conditions to obtain a more . realistic characterization of workplace exposures. The availability of effective, inexpensive, and easy to use devices, such as passive monitors, provides a needed resource to employers to achieve this objective. Unfortunately, our evaluations of early passive monitors identified problems with some of the devices on the market. The existence of a certification program to verify the claims of the manufacturers will greatly assist employers in identifying those devices which will be effective in monitoring their work sites. The program should also improve the overall quality of these devices as manufacturers strive to meet a higher "industry standard". . This brings us to the issue at hand. We recognize that the development of generic protocols for evaluating passive monitoring devices is being considered by both OSHA and ANSI. However, based' on current knowledge, a successful evaluation of direct reading passive monitors by your protocol (as modified) would allow us to include the device as an option for use by OSHA compliance officers. Also, recognizing our common goal of providing employers with a variety of effective tools for evaluating workplace hazards, please let us know if we can be of assistance in reviewing specific protocols for other types of sampling devices. Robert A. Curtis, Director OSHA Health Response Team Rick Cee, Chief Field Instruments Team 3M 110949 Protocol for the Evaluation of Direct Reading Passive Monitors Introduction The evaluation of passive devices should evaluate the manufacturer's claims of precision and accuracy over the range of operating conditions for which the devices are supposed to work. These conditions normally include but are not limited to concentration, temperature, relative humidity, face velocity, monitor orientation, reverse diffusion, exposure time, interferences, sampler stability, analytical variability, and shelf life. Recommended evaluation criteria for direct reading passive dosimeters are listed below. In order to adequately evaluate the passive devices, the manufacturer must assure that the following exist: proper testing equipment and facilities; trained staff; written testing procedures; and calibration and quality control programs to perform the generation and testing of known concentrations in accordance with good industrial hygiene principles and practices. General The following are the elements for an evaluation of direct reading passive monitors, such as the ACTTM PEL-TWA and STEL monitoring cards (referred to only for example purposes). Unless otherwise stated, each exposure test should be conducted with 10 monitors for statistical analysis. Unless otherwise noted, standard exposure conditions apply to a temperature of 25 degrees Celsius, 50% relative humidity, 25 cm/s face velocity, specified exposure time of the monitor, and at the appropriate OSHA PEL or ACGIH TLV concentration for the analyte being tested. Concentration and Exposure Time Expose monitors to 0.5, 1.0 and 2.0 times the appropriate PEL or TLV and 1.0 time the OSHA ceiling or ACGIH STEL standard with 50% relative humidity at 25 degrees Celsius and a face velocity of 25 cm/s. PEL-TWA monitors are exposed for the maximum sampling time specified by the manufacturer. To determine whether any significant exposure exists in the workplace, a concentration of 0.1 times the appropriate PEL or TLV may be evaluated. Relative Humidity Expose monitors at the PEL or STEL concentration to 10 and 90 percent relative humidity at 25 degrees Celsius and 25 cm/s face velocity. For cards that have specified relative humidity ranges other than the typical 10 to 90 percent relative humidity, adjust the upper and lower humidity limits accordingly. 3H 110950 Temperature -- Expose monitors at the appropriate PEL or TLV concentration with 50% relative humidity at 10 and 40 degrees Celsius for either eight hours or the appropriate ceiling or STEL sampling time. If a monitor has a specified temperature range other than the typical 10 to 40 degrees Celsius, the upper and lower temperature limits will be substituted in place of the 10 and 40 degrees Celsius exposures. Pressure Evaluate the adequacy of manufacturer's instructions for utilizing the monitoring devices for comparison to PEL and TLV concentrations at varying pressures, particularly due to changes in altitude. Face Velocity To determine the effects of face velocity, expose monitors to 10 and 150 cm/s at the appropriate PEL or TLV concentrations with 50% relative humidity at 25 degrees Celsius. Interferences Assess whether the manufacturer has adequately adressed potential positive and negative interferences based on the reaction chemistry used in the monitors. Where potential negative interferences have been documented in the literature, but have not been sufficiently evaluated by the manufacturer, the user manual will instruct the user to conduct initial side-by-side sampling with alternative methods to assess the amount of interference occurring at the specific work site, or the manual will explicitly state that the monitors can not be used in this type of environment. Where interferences have been identified by the manufacturer, expose monitors to the interferences at their PEL for the maximum sampling time period. Document the extent of interferences observed. *' Shelf Life To verify shelf life, monitors will be stored per manufacturer's instructions (e.g. refrigerated if required by the user manual) and tested at standard conditions (i.e., 25 cm/s, 50% RH, PEL or TLV, and 25 Celsius) after the maximum stated shelf-life. Monitors may be given an initial certification based on an evaluation of manufacturer's tests of maximum shelf life. Quality Control Expose three different lots of monitors at standard concentration and exposure conditions to document the consistency between different manufactured lots. 3H 110951 Monitor Orientation Expose monitors at orientations parallel and perpendicular to air flows of 10 and 150 cm/s at lx PEL or TLV, 50%RH, and 25 Celsius. Reverse Diffusion Expose 20 monitors to a 2X exposure limit, 80% RH for 0.5X the maximum specified sampling time and to 0% exposure limit, 80% RH for 0.5X the maximum specified sampling time. .. Inter-reader Variability For direct reading dosimeters, inter-reader variability, either electronic or visual, must be assessed and incorporated into overall accuracy of the system. Evaluation of Qualitative Monitors A similar validation protocol to the quantitative monitors can be applied to qualitative monitors. Qualitative monitors are read visually by comparing the developed color to reference color guides provided on the card (some monitors have one reference guide). The color guides typically represent the action level and the PEL for PEL-TWA cards (8 hours). The color on the STEL or CEILING cards are based on the ACGIH STEL or OSHA CEILING standards respectively. The intensity of the developed color in relation to the color guide provides an indication ofthe exposure concentration. 3M 110952 PROPOSAL FOR AN INTEGRATED PROTOCOL ANALYTICAL RECOVERY 4 samplers spiked at each of 4 levels (0.1, 0.5, 1.0, 2.0 x LV) . 4 samplers spiked at 0.01 x LV (or method LOQ) . 4 samplers pre-humidified and spiked with 1.0 x LV. RATE AND CAPACITY Samplers exposed to 2 x LV for 1,2,4,6, and 8 hours for TWA sampling (four samplers for each time-period) , and to 1 x STEL for 15 minutes for STEL sampling (six samplers) . REVERSE DIFFUSION NIOSH or CEN test using six samplers in each part (total 12). STORAGE STABILITY Track storage as per OSHA sample tube validations, e.g. 16 samplers exposed, 4 analyzed immediately, 4 samplers after 7, 14, and 21 days. Repeat refrigerated if sampler fails, or as routine. WIND EFFECTS Face velocity and orientation effects evaluated one time only with one analyte. Pressure can be evaluated at this stage. TEMPERATURE EFFECTS Separate to avoid difficult experimental conditions (80% rh @ 40c), and correction factors confounding the factorial. Range can be chosen but stated clearly. Three experiments with 6 sampl rs each exposed to 2 x LV for 8 hours (ensures no reverse diffusion at high temps) at low, medium and high temperatures (18 samplers). FACTORIAL Should include concentration, exposure time, humidity, and interference (four samplers in each of 8 experiments). SHELF LIFE Repeat rate/capacity at expiration. ACCURACY & PRECISION To be discussed. 3H 110953 3M Occupational Health and Environmental Safety Division 3M Center St. Paul. MN 55144-1000 612 733 1110 November 10, 1994 Pat Gleason Safety Equipment Institute 1901 North Moore Street Arlington, VA 22209 Dear Ms. Gleason: It was a pleasure talking with you about validating/certifying diffusion monitors. We are very pleased that SEI has decided to pursue this issue and help in the development of an ANSI committee that will write a performance protocol for diffusion monitors. We are excited about the opportunity to work with SEI and ANSI on this program. I have reviewed the draft protocol that you sent. In general, it covers most of the important performance parameters and it will be a good guideline to build upon. My comments are as follows: Introduction . I realize that this draft document was written for direct reading passive sampling devices and that the accuracy of greater than 50% may be acceptable for such devices, however, we believe that the diffusion monitor has to be more accurate. The protocol for the diffusion monitor should address the traditional plus or minus 25% accuracy at a confidence level of 95%. The main purpose for developing a protocol is to show the health and safety professional that diffusion monitors are just as accurate as active sampling techniques. The protocol needs to convey to the user the limitations and operating range of the sampling device. Another area that needs to be addressed, is the need to certify for each compound verses a certification for an entire class of compounds. Reference to operating temperature should include some allowance for variability, such as 25C 3C. 3M 110954 Pat Gleason Page Two November 10, 1994 Concentrations and Exposure Time The main purpose of this experiment is to determine the sampling limitations of the diffusion monitor. It will evaluate the linear sampling rate and capacity of the device. We believe a factorial design with three concentration ranges such as 0.5 x EL, 1 x EL and 2 x EL vs. 30, 120 and 480 minute sampling times might give the user more information than the outlined experiment This design would give the user a range of operating concentrations and times instead of a single operating concentration and time. The manufacturer would have to state their operating conditions and the certification protocol would serve to verify these conditions. Relative Humidity This experiment did not contain any end-point to measure performance. The test protocol needs to have these targets established. The humidities of 10% and 90% are not realistic to most workplaces. We recommend using the humidities of 30% and 80%. Temperature Temperature will influence the sampling rate of the diffusion monitor. The manufacturer should show correction factors for temperature ranges. It has been our experience that these collections are very small and that if the experiment is not carefully controlled and designed, the sampling and analytical error would mask any deviation due to temperature changes. Pressure We believe that pressure will not influence the overall performance of the diffusion monitor, therefore a designed experiment is not necessary. Reverse Diffusion Reverse diffusion measures the ability of the sorbent to hold onto the analyte. Typically sampling device overloading is one of the most common errors made in 3M 110955 Pat Gleason Page Three November 10, 1994 use of either active or passive sampling devices and can significantly contribute to inaccurate air measurements. The outlined experiment does not include any statistically performance criteria. Sampling Rate, Analytical Recovery & Storage These performance parameters were absent and will have to be addressed in the protocol. I want to thank you for allowing 3M to comment on this first draft It is our opinion that the draft needs more work on addressing sample sizes and statistics, plus defining final performance criteria. However, we believe that you have touched on all the important performance parameters. We are drafting a similar document that consolidates the NIOSH and European protocols, plus draws on our own knowledge. We would be happy to share this document with you when it is completed. 3M would like to actively be involved with the entire development of this protocol so please keep us updated. I look forward to working with you and SEI on this program. Ifyou have any questions, please feel free to contact me at 612-737-4459. Best regards. Robert A. Weber, CIH Sr. Technical Service Representative 3M Occupational Health & Environmental Safety Division RAW:llj/172 7035282148 F-127 T-779 P-002 OCT 28 *94 12.1? October 24, 1994 Patricia A Gleason, President Safety Equipment Institute 1901 North Moore Street, Suite 808 Arlington, VA 22209 . Dear Ms. Gleason; Thank you for the opportunity to review the protocol you are considering for evaluating direct reading passive monitors, such as the ACTTM badges manufactured by Envirometrics Products Company. We are pleased that manufacturers of passive monitoring devices are considering funding the Safety Equipment Ihstitute(SEI) to provide "third party certification" of the effectiveness of these devices. As you know, OSHA strongly supported the need for this type of verification in its recent expansion of the personal protective equipment standard (Ref 29CFR1910.132, April 26,1994). We also recognize the confidence manufacturers and government agencies, including NIOSH and MSHA, have demonstrated in SETs ability to provide this service through their participation and comments regarding your existing certification programs. The success in your program to certify detector tubes is particularly noteworthy since it parallels what we envision is needed for the certification of passive monitoring devices. Recent literature and data from NIOSH field studies indicate that the variability in workplace exposure is often much greater than the variability in sampling. Therefore, we want to encourage employers to obtain multiple samples for varying working conditions to obtain a more realistic characterization of workplace exposures. The availability of effective, inexpensive, and easy to use devices, such as passive monitors, provides a needed resource to employers to achieve this objective. Unfortunately, our evaluations of early passive monitors identified problems with some of the devices on the market. The existence of a certification program to verify the claims ofthe manufacturers will greatly assist employers in identifying those devices which will be effective in monitoring their work sites. The program should also improve the overall quality ofthese devices as manufacturers strive to meet a higher "industry standard". This brings us to the issue at hand. We recognize that the development ofgeneric protocols for evaluating passive monitoring devices is being considered by both OSHA and NIOSH. However, based on current knowledge, a successful evaluation ofdirect reading passive monitors by your protocol (as modified) would allow us to include the device as an option for use by OSHA compliance officers. Also, recognizing our common goal of providing employers with a variety of effective tools for evaluating workplace hazards, please let us know ifwe can be of assistance in reviewing specific protocols for other types of sampling devices. Sincerely yours, Robert A. Curtis Director, OSHA Health Response Team 3M 110957 7035282148 F-127 T-779 P-003 OCT 28 '84 12: SEI Protocol for the Evaluation of Direct Reading Passive Monitors DRAFT - 10/24/94 Introduction The evaluation of passive devices should evaluate the manufacturer's claims of precision and accuracy over the range of operating conditions for which the devices are supposed to work. These conditions normally include but are not limited to concentration, temperature, relative humidity, face velocity, monitor orientation, reverse diffusion, exposure time, interferences, sampler stability, and shelf life. Recommended evaluation criteria for direct reading passive dosimeters are listed below. Traditionally, the goal of an acceptable moniioring method was to ensure an accuracy, to a 95% confidence level, of ndt less than plus or minus 25% at concentrations of contaminant at the occupational exposure limits (OSHA PIEL's, ACGIH TLV's). The NIOSH protocol for evaluating sampling and analytical procedures attempts to verify the achievement of this goal over a range of exposure conditions. However, devices which do not meet the NIOSH criteria can still provide equivalent or better worker protection under the following conditions: 1) The manufacturer expressly states the conditions under which the monitors do meet the validation criteria. For example, although draft NIOSH criteria for temperature effects require validation at 10, 25, and 40 degrees C, a large number of employee exposures occur in a much narrower temperature range, particularly in indoor operations. Therefore, if a device does not meet the accuracy criteria over a broad temperature range, the manufacturer may narrow the operating temperature range specified in its user manual to that range for which the criteria are met. 2) Methods with greater imprecision or inaccuracy may be acceptable if either 1) an adequate number of samples are collected by the user to characterize the distribution of employee exposures to the same level of statistical confidence that employee exposures comply with occupational standards, or 2) a positive error correction is made by the user to determine the potential upper level of exposure as long as the error corrections do not exceed the following values: - The inaccuracy at 0.5X, 1.0X, or 2.0X of the PEL or TLV does not exceed +/- 50% of the true concentration 95% of the time. - The inaccuracy at 0.1X the PEL or TLV does not exceed +/- 100% of the true concentration 95% of the time. - The inaccuracy at 1.0X the OSHA ceiling or ACGIH STEL does not exceed +/- 50% the true concentration 95% of the time. 3M 110958 7035202l4S F-127 T-779 P-004 OCT 20 *94 12:13 In order to adequately evaluate the passive devices, the manufacturer must assure that the following exist: proper testing equipment and facilities; trained staff; written testing procedures; and calibration and quality control programs to perform the generation and testing of known concentrations in accordance with good industrial hygiene principles and practices. General The following are the elements for an evaluation of direct reading passive monitors, such as the ACTTM PEL-TWA and STEL monitoring cards (referred to only for example purposes). Unless otherwise stated, each exposure test should be conducted with 10 monitors for statistical analysis. Unless otherwise noted, standard exposure conditions apply to a temperature of 25 degrees Celsius, 50% relative humidity, 25 cm/s face velocity, specified exposure time of the monitor, and at the appropriate OSHA PEL or ACGIH TLV concentration for the analyte being tested. Concentration and Exposure Time Expose monitors to 0.5,1.0 and 2.0 times the appropriate PEL or TLV and 1.0 time the OSHA ceiling or ACGIH STEL standard with 50% relative humidity at 25 degrees Celsius and a face velocity of 25 cm/s. FEL-TWA monitors are exposed for the maximum sampling time specified by the manufacturer. To determine whether any significant exposure exists in the workplace, a concentration of 0.1 times the appropriate PEL or TLV may be evaluated. Relative Humidity Expose monitors at the PEL or STEL concentration to 10 and 90 percent relative humidity at 25 degrees Celsius and 25 ettys face velocity. Fra: cards that have specified relative humidity ranges other than the typical 10 to 90 percent relative humidity, adjust the upper and lower humidity limits accordingly. Temperature Expose monitors at the appropriate PEL or TLV concentration with 50% relative humidity at 10 and 40 degrees Celsius for either eight hours or the appropriate ceiling or STEL sampling time. If a monitor has a specified temperature range other than the typical 10 to 40 degrees Celsius, the upper and lower temperature limits will be substituted in place of the 10 and 40 degrees Celsius exposures. Pressure Evaluate the adequacy of manufacturer's instructions for utilizing the monitoring devices for comparison to PEL and TLV concentrations at varying pressures, - particularly due to changes in altitude. 3M 110959 7035282148 F-127 T-779 P-005 OCT 28 >94 12 Face Velocity To determine the effects of face velocity, expose monitors to 10 and ISO cm/s at the appropriate PEL or TLV concentrations with 50% relative humidity at 25 degrees Celsius. Interferences Assess whether the manufacturer has adequately adressed potential positive and negative interferences based on the reaction chemistry used in the monitors. 'Where potential negative interferences have been documented in the literature, but have not been sufficiently evaluated by the manufacturer, the user manual will instruct the user to conduct initial side-by-side sampling with alternative methods to assess the amount of interference occurring at the specific work site, or the manual will explicitly state that the monitors can not be used in this type of environment. Where interferences have been identified by the manufacturer, expose monition to the interferences at their PEL for the maximum sampling time period. Document the extent of interferences observed. Shelf Life To verify shelf life, monitors will be stared per manufacturer's instructions (e.g. refrigerated if required by the user manual) and tested at standard conditions (Le., 25 cm/s, 50% RH, PEL or TLV, and 25 Celsius) after the maximum stated shelf-life. Monitors may be given an initial certification based on an evaluation of manufacturer's tests of maximum shelf life. Quality Control Expose three different lots of monitors at standard concentration and exposure conditions to document the consistency between different manufactured lots. Monitor Orientation Expose monitors at orientations parallel and perpendicular to air flows of 10 and 150 cm/s at lx PEL or TLV, 50%RH, and 25 Celsius. Reverse Diffusion Expose 20 monitors to a 2X exposure limit, 80% RH for 0.5X the maximum specified sampling time and to 0% exposure limit, 80% RH for 0JSX the maximum specified sampling time. 3M 110960 7035282148 F-127 T-77S P-006 OCT 28 *94 12:19 Inter-reader Variability For direct reading dosimeters, inter-reader variability, either electronic or visual, be assessed and incorporated into overall accuracy of the system. * Evaluation of Qualitative Monitors A similar validation protocol to the quantitative monitors can be applied to qualitative monitors. Qualitative monitors are read visually by comparing the developed color to reference color guides provided on the card (some monitors have one reference guide). The color guides typically represent the action level and the PEL for PEL-TWA cards (8 hours). The color on the STEL or CEILING cards are based on the ACGIH STEL or OSHA CEILING standards respectively. The intensity of the developed color in relation to the color guide provides an indication of the exposure concentration. 3H 110961 7035282143 F-127 T-779 P-002 OCT 28 '84 12:1? October 24, 1994 Patricia A Gleason, President Safety Equipment Institute 1901 North Moore Street, Suite 808 Arlington, VA 22209 Dear Ms. Gleason: Thank you for the opportunity to review the protocol you are considering for evaluating direct reading passive monitors, such as the ACTTM badges manufactured by Envirometiics Products Company. We are pleased that manufacturers of passive monitoring devices are considering funding the Safety Equipment Institute(SEI) to provide "third party certification" ofthe effectiveness of these devices. As you know, OSHA strongly supported the need for this type of verification in its recent expansion of the personal protective equipment standard (Rc 29CFR1910.132, April 26,1994). We also recognize the confidence manufacturers and government agencies, including NIOSH and MSHA, have demonstrated in SEPs ability to provide this service through their participation and comments regarding your existing certification programs. The success in your program to certify detector tubes is particularly noteworthy since it parallels what we envision is needed for the certification ofpassive monitoring devices. Recent literature and data from NIOSH field studies indicate that the variability in workplace exposure is often much greater than the variability in sampling. Therefore, we want to encourage employers to obtain multiple samples for varying working conditions to obtain a more realistic characterization of workplace exposures. The availability ofeffective, inexpensive, and easy to use devices, such as passive monitors, provides a needed resource to employers to achieve this objective. Unfortunately, our evaluations of early passive monitors identified problems with some ofthe devices on the market. The existence of a certification program to verify the claims ofthe manufacturers will greatly assist employers in identifying those devices which will be effective in monitoring their work sites. The program should also improve the overall quality ofthese devices as manufacturers strive to meet a higher "industry standard". This brings us to the issue at hand. We recognize that the development ofgeneric protocols for evaluating passive monitoring devices is being considered by both OSHA and NIOSH. However, based on current knowledge, a successful evaluation ofdirect reading passive monitors by your protocol (as modified) would allow us to include the device as an option for use by OSHA compliance officers. Also, recognizing our common goal ofproviding employers with a variety of effective tools for evaluating workplace hazards, please let us know ifwe can be of assistance in reviewing specific protocols for other types of sampling devices. Sincerely yours, Robert A Curtis Director, OSHA Health Response Team 3M 110962 7035282143 F-127 T-779 P-003 OCT 28 '94 12:17 SEI Protocol for the Evaluation of Direct Reading Passive Monitors DRAFT - 10/24/94 Introduction The evaluation of passive devices should evaluate the manufacturer's claims of precision and accuracy over the range of operating conditions for which the devices are supposed to work. These conditions normally include but arc not limited to concentration, temperature, relative humidity, face velocity, monitor orientation, reverse diffusion, exposure time, interferences, sampler stability, and shelf life. Recommended evaluation criteria for direct reading passive dosimeters axe listed below. Traditionally, the goal of an acceptable monitoring method was to ensure an accuracy, to a 95% confidence level, of not less than plus or minus 25% at concentrations of contaminant at the occupational exposure limits (OSHA PEL'S, ACGIH TLV's). The NIOSH protocol for evaluating sampling and analytical procedures attempts to verify the achievement of this goal over a range of exposure conditions. However, devices which do not meet the NIOSH criteria can still provide equivalent or better worker protection under the following conditions: 1) The manufacturer expressly states the conditions under which the monitors do meet the validation criteria. For example^ although draft NIOSH criteria for temperature effects require validation at 10^5, and 40 degrees C, a large number of employee exposures occur in a much narrower temperature range, particularly in indoor operations. Therefore, if a device docs not meet the accuracy criteria over a broad temperature range, the manufacturer may narrow the operating temperature range specified in its user manual to that range for which the criteria are met. ___ Methods with greater imprecision or inaccuracy may be acceptable if either 1) an adequate number of samples are collected by the user to characterize die distribution of employee exposures to the same level of statistical confidence that employee exposures comply with occupational standards, or 2) a positive error correction is made by the user to determine the potential upper level of exposure as long as the error corrections do not exceed the following values: fit'' at 0.5X, 1.0X, or 2TJX of PEL or TLV does not f the true concentrate of the time. inaccuracy at O.lXjhe PEL or TLV does not exo the true concentration95% of the time. The inaccuracy aO.QX/lhe OSHA ceiling or ACGIH STEL does not exceed +/- 50% tberftue concentration 95% of the time. _ fVo-Votl SfavLgcUy 3M 110963 7035282148 F-127 T-779 P-004 OCT 28 '94 12:18 A ' * #ku In order io adequately evaluate the passive devices, the manufacturer must assure that the following exist: proper testing equipment and facilities; trained staff; written testing procedures; and calibration and quality control programs to perform the generation and testing of known concentrations in accordance with good industrial hygiene principles and practices. General * 'Mi C4! r? The following are the-^ements for ann-ebaluarion of direct reading poassive monitors, such as the ACTrxJPg^TWA ancfSTEt)monitoring cards (referred to only for example purposes). Unless oihcrwise'stated, each exposure test should be conducted with 10 monitors for statistical analysis. Unless otherwise noted, standard exposure conditions apply to a temperature offfi degrees Celsius,relative huinidity,J25 cm/s face velocity, specified exposure time of the monitor, and at the appropriate or ACGIH TLV concentration for the analyte being tested. Concentration and Exposure Time - CKcV'"*^ c* -- --- dp- IU lV*/ J ^ JU.-v-<* . -- WVMA+ >X 'ti. jxA' 0 fAjdj. \/v\. Expose monitors to 0.5, 1.0 and 2.0 times the appropriate PEL or TLV and 1.0 time g the OSHA ceiling or ACGIH SJEI. .grandard with(^%)elative humidity ai$5jd^grees c Celsius and a face velocity of25 ctn/%) PEL-TWA monitors are exposed forTfie J/* ' , > maximum sampling time specified by the manufacturer. To determine whether any_ * -'rJL, ^ significant exposure exists in the workplace, a concentration qf3. $ times the yfSH&f ^ appropriate PEL or TLV may be evaluated. Relative Humidity * (b% ^ 2L+ Six O 2^* i tlx Expose monitors at the PEL or STEL concentration to(lUjft)d W^percgnLreiative 5,*<? S% humidity at 25 degrees Celsius and 25 cm/s face velocityr^Fwmards that have 1 r/-yspecified relative humidity ranges other than the typical 10 to 90 percent relative k: humidity, adjust the upper and lower humidity limits accordingly. + i M *4 Temperature 1(*tc. . / --/ -4-- ^ / f yj,' #1 t^Expose date PEL or TLV concentration with 50% relative ^uWwf' humidity^ 0 and 40 degre^ Celsius for either eight hours or the appropriate ceiling s# ^ar ", , or STEL aCV-- -Wrt(? fc 1*%J, + 40 degree monitor has a specified temperature range other than the ius, the upper and lower temperature limits will be .n " ******^ substimted-in-ppllaaecee--oofthe 10 and 40 degrees Celsius exposures. s\(M ke t ^ n ** i>&- - __j>fessure \ Evaluate the adequacy of manufacturer's instructions for utilizing the monitoring devices for'comparison to PEL and TLV concentrations at varying pressures. V' ^ 60 changes in altitude. W/y hlu*' 3M 110964 7035282143 F-127 T-779 P-005 OCT 28 *94 12:IS Face Velocity -Kir * Mi TSVl* ?0 To determine the effects of face velocity, expose monitors tojjQand 150 cm/rjtf-the appropriate PEL or TLV concentrations with 50% relative humidity at 25 degrees Celsius. Interferences - fo < ** / fat ^cro Assess whether the manufacturer has adequately adressed potential positive and negative interferences based on the reaction chemistry used in the monitors. Where potential negative interferences have been documented in the literature, but have not been sufficiently evaluated by the manufacturer, the user manual will instruct the user to conduct initial side-by-side sampling with alternative methods to assess the amount of interference occurring at the specific woric site, or the manual will explicitly state that the monitors can not be used in this type of environment Where interferences have been identified by the manufacturer, expose monitors to the interferences at their PEL for the maximum sampling time period. Document the extent of interferences observed. Shelf Life To verify shelf life, monitors will be stored per manufacturer's instructions (e.g. refrigerated if required by the user manual) and tested at standard conditions (i.e., 25 cm/s, 50% RH, PEL or TLV, and 25 Celsius) after the maximum stated shelf-life. Monitors may be given an initial certification based on an evaluation of manufacturer's tests of maximum shelf life. Quality Control Expose three different lots of monitors at standard concentration and exposure conditions to document the consistency between different manufactured lots. Monitor Orientation Expose monitors at orientations parallel and perpendicular to air flows of 10 and 150 cm/s at lx PEL or TLV, 50%RH, and 25 Celsius. Reverse Diffusion liters to a 2X exposure limit, 80% RH for 0.5X the maximum specified sampling time-and to 0% exposure limit, 80% RH for 0_5X the maximum specified 'time. e*>d -- No 7*+***-' 3 BL . 4 04014. 0(^0^ ftfai 'L ,/ , 'fc ^, 3M 110965 7035282148 F-127 T-779 P-006 OCT 28 '94 12:19 Inter-reader Variability For direct reading dosimeters, inter-reader variability, either electronic or visual, must be assessed and incorporated into overall accuracy of the system. Evaluation of Qualitative Monitors A cimilar validation protocol to the quantitative monitors can be applied to qualitative monitors. Qualitative monitors axe read visually by comparing the developed color to reference color guides provided on the card (some monitors have one reference guide). The color guides typically represent the action level and the PEL for PEL-TWA cards (8 hours). The color on the STEL or CEILING cards are based on the ACGIH STEL or OSHA CEILING standards respectively. The intensity of the developed color in relation to the color guide provides an indication of the exposure concentration. 'itu. 'jfa. Ate \}w&cf j1-7^1 (kt iM* n*ukM/ tf tflu, b)iti$[ ob^ a. Yluf t*-ru 3H 110966 TECHNIQUE FOR DETEMUIXKG CAPACITY Of DIPPU3I0EAL SAMPLING DEVICES And rs, L. W., Oooupetional Health A Safety Products Division, 3M Coapany, Saint Paul, Minnesota 551AV. AH-STHACT Mffusional sampling la a vary convanient technique for oaaauring the concentration of potentially hazardous or toxio gases and vapors in an environment. In this technique, as defined by Pick's Law of Diffusion, . the contaminant moleoules diffuse from the aablent atmosphere to the activated carbon adsorbent because of the concentration gradient between the aablent and tha adsorbent. The contaminant concentration . 'must be zero or hear zero at the adsorbent layer for the sampling rate to be function only of the ambient concentration. There is a limit to this criteria because the adsorbent has a finite capacity for a contaminant. During sampling, the weight of contaminant collected must not exceed the adsorbent's capacity and, therefore, the dlffusional sampling limits. The adsorbent's capacity for a contaminant in dlffusional sampling device can.be determined by spiking an exoess of the contaminant onto a set of monitors. During, an exposure of these monitors to a challenge with zero concentration of the contaminant, the amount of contaminant lost by the adsorbent as a function of time can be determined by the s quential removal and analysis of the monitor. The contaminant loss asymptotically approaches a limiting value, the adsorbent's capacity for the contaminant. For most common contaminants, the adsorbent's capacity can be expressed as a linear function of the contaminant's boiling point. 3M 111007 TECHNIQUE EON DETEMXNIM CAPACITT Of DIFFUSIONAL SAMPLING DEVICES Anders, L. V., Occupational Health A Safety Produota Division, 3M Company, Saint Paul, Minnesota 551*4 UffMWglffl Dirrusionsl saapllng is s vary staple technique for oollecting potentially hazardous or toxio gases and vapors from the ambient environment. For these devloea, the saapllng rate is controlled by diffusion and sample collection by absorption or chemical reaction. With a dlffusional devloe, the contaainant is sampled from the ambient atmosphere in the absence of air flow. This is in oontrast to the conventional charcoal tubes where the saapllng rate is determined by the air flow rate of a mechanical pump. With a dlffusional sampling device, the sampling rate la defined by Pick's Law where the weight collected is directly proportional to the concentration of the contaminant in the ambient atmosphere, the sampling time and a proportionality oonatant (DA/L) assuming C0 a o. W = (C-CQ) t L (1) Hy combining the unite f r the dlffusional coefflcl nt (cm2/min.) for the contaminant, the geometric area (cm2) and geometric length (cm) of the dlffusional ohamber, it can be observed that the proportionality constant haa unite of oublo centimeters per minute (ca^/min.). K * 1 L (2) Therefore, equation (1) can be simplified to the following: . W * K (C-C0) t (3) It is usually assumed that the concentration (CQ) at the adsorbent layer is zero or nearly zero. This is an important criteria and when it falls, dlffusional sampling is not easily defined by the above integrated form of Fiok*a Law. Not only is the concentration (C) in the ambient atmosphere an unknown, but the concentration (C0) at the adsorbent is also an unknown. Therefore, the adsorbent is responsible for effectively collecting the contaminant and maintaining a concentration (C0) equal to or nearly equal to zero. The adsorbent is able to maintain this requirement until its aapacity Is reached and then the dlffusional sampling limits have been exceeded. Pressure A technique has been developed to determine the capacity of the activated carbon In the 3H Organic Vapor Monitor. After spiking a set of monitors with an excess of a contaminant, they are exposed to an air 3H 111009 fiow with zero concentration of tha contaminant. At various time intervals monlt rs ara removed and analyzed. Tha amount of c ntamlnant on the monitor Is plotted as function of time. By this technique, Initially, the adsorbent contains more oontaainant than It can affectively collect and hold during the sampling process. The ampacity for the contaminant is determined from the limiting value which is asymptotically approached at infinite time. In a dlffusional sampling device, the adsorbent can effeotively oolleot and hold the contaminant as long as this capacity la not exceeded. . Results and Discussion -- A set of monitors were overloaded with 49.5 milligrams and with 20.5 milligrams of methyl ethyl ketone according to the. spiking prooedure outlined for determination of recovery ooeffiolents for the 3M Organic Vapor Monitors. These monitors were placed in a devloe with an air challenge containing zero concentration of methyl ethyl ketone. As shown in Figure 1, the amount of methyl ethyl ketone adsorbed strongly on the activated carbon asymptotically approaches a limiting value. These relationships oan be transformed into linear functions as shown in Figure 2 where the reciprocal of the weight loss (1/W0-W^) is plotted as a function of the reoiprooal of the time (1/t). It can be observed the data fits the following linear relationship . 1 b m1 Wo-Vi t (4) It can be observed that as the time (t) approaches Infinity, the value 3M 111010 It r.m be obs rved that as tha time (t) approaches Infinity, the value of the reciprocal of the tlaa approachea zero and = wc. Therefore, from the value of the Intercept (b), the oapaclty (We) can readily be determined by the following relationship - Wc W0 - JL b' (5) In Figure 1, it can be observed that both overload levels are asymptotically approaching the same limiting value. Prom the intercept values, the capacity of the adsorbent in the 3M Organic Vapor Monitor is determined'to be 12.4 milligrams for methyl ethyl ketone. Th activated carbon should have a unique capacity for every contaminant which la dependent on the heat of adsorption. In Figure 3, It. can be observed that for a group of ketones the activated oarbon has a different capacity for each. These relationships were transformed into linear functions along with numerous other contaminants. As depicted in Figure 4, the capacity can be plotted as a function of the contaminant boiling point. It can be observed that the activated carbon has approximately the same relationship between capaoity and boiling point for most contaminants except for the aliphatic compounds which have a relationship with somewhat greater oapaclty for the lower boiling point compounds. From Figure 5, the necessary aapacity required for sampling any contaminant with the 3H Organic Vapor Monitor can be determined. Assuming the contaminant concentration in the environment is at tha N 3H 111011 p rmissible expoaure level (PEL) and if an eight hour saapling period la desired, than tha eaount f o ntaalnant oollactad by tha 3H Organic Vapor Monitor oan readily ba determined from tha relationship plotted in Figure 5. For aany of the frequently aaepled oontaainanta, the required oapaoitiea idien saapling at the PEL for eight hours are plotted in Figure 6. As oan be observed In Figure 6, the activated carbon in the 3M Organic Vapor Monitor has sufficient oapaoitiea to sample eight hours at tha PEL for those aontaalnanta with boiling paints of 90c or greater. These account for 70S of the aost fr quently aaaplsd aontaalnanta. An additional 20% of the oontaainants have boiling points in the range froa 60C to 90C. For these contaminants, when sampling at concentration near the PEL, It la recommended that the seapllng period be shortened to a three to six hour period depending on the oonoentratlon. Tha final 10% of the aost frequently sampled oontaainants have boiling points below 60C and aust have tne length of the saapllng period aeleoted aooordlng to the contaminant concentration. m > 5< fble CO o id li ADSORBENT CAPAC^ OF MEK CAPACITY DETERMINATION 1 b +m 1 t 3M 111015 CAPACITY DETERMINATION b + m 4t t 00 w. 1 CAPACITY DETERMINATION 1 b + mi t CO Then 3M 111017 DETERMINATION OF ADSORBENT CAPACITY Time (hours] 3M 111018 Adsorbent Capacity (mg) ADSORBENT CAPACJp' AS A FUNCTION OF BOILING POINT OF CONTAMINANT Boiling Point (C) ADSORBENT CAPACITY AS A FUNCTION OF BOILING POINT OF CONTAMINANT 4 -+ H------h H 1 1 1 20 40 60 80 100 120 140 160 Boiling Point (C) MONITOR RETENTION OF PRELOADED TRICHLOROETHYLENE WHEN EXPOSED TO AIR AT 85% RH Exposure time (hrs) 3M 111022 SAMPLING PERCHLOROETHYLENE WITH MONITORS PRELOADED WITH TRICHLOROETHYLENE 85% ~RH Weight Collected (mg) Weight Collected (mg) SAMPLING PERCHLOROETHYLENE WITH MONITORS PRELOADED WITH TRICHLOROETHYLENE 85%-RH 3M 111024 SAMPLING PERCHLOROETHYLENE WITH MONITORS PRELOADED WITH TRICHLOROETHYLENE 85% - RH 3M 11102! W e ig h t (mg) DETERMINATION OF CAPACITY FOR ACETONE 3M 111026 W e ig h t (m g) ACETONE 3H 111027 ACETONE 3M 111021 ACETONE 3H 111029 ACETONE 3M 111030 DICHLOROMETHANE EXPOSURE (min-mg/l) 3H 111031 DICHLOROMETHANE 3M 111032 DICHLOROMETHANE 3H 111033 y DICHLOROMETHANE RH - 86% EXPOSURE (min-mg/l) DICHLOROMETHANE RH-85% 3M 111035 ACETONE RH - 86% 3H 111036 METHYLENE CHLORIDE RH-85K 3M 111037 METHYLENE CHLORIDE RH-85% 3M-OVM Charcoal Tabes 3H 111033 ACETONE RH-86% A 3M-0VM Charcoal Tubes WEIGHT COLLECTED mg) 3H 111039 PENTANE RH-85% A 3M-0VM . Charcoal Tabes VOLUME SAMPLED (liters) 3H 111040 Am. Ind. Hyg. Assoc. J. 46<Vi:52(i'531 (I4X5> Field Evaluation of Passive Organic Vapor Samplers STEVEN D S'iOCKTON.' and D.W UNDERHILL1' ''industrial Hygiene Services. L. S. Steel Corporation, POO Grant Street. Room "20. Pittsburgh. PA 15230: "Graduate School 01 Public Health. University oi Pittsburgh, Pittsburgh. PA 15261. sA 1 Five diffusion organic vapor monitors and charcoal tubes were exposed to industrial atmospheres containing benzene, toluene and xylene in .sets of six a piece in order to evaluate the relative performance of these devices under normal field conditions. The analytical results were . treated with two-way analysis of variance, and the least significant difference test was applied to the mean values to further refine the data. The results of this investigation showed that each sampler generally had a high precision. There was, however, a numerically significant difference between the types of samplers. This may be explained by examining the statistics and noting that there was very little variation around the mean values; thus, a small variation between samplers appeared numerically significant. Despite this significant numerical difference, from the pragmatic point of view, the samplers provided essentially equivalent results which allowed the industrial hygienist to determine what action was appropriate. Overall performance of ail the sampler types was very good. Each type of sampler could be used for industrial hygiene evaluations with confidence. . Introduction " The passive dtffusion-tvpe organic vapor monitor has become much more popular in recent years lor use in deter mining employee exposure to organic vapors. It is easy to use and. as compared to other sampling techniques, requires little attention in the Held. Once the diffusion cocllicicnt and badge parameters have been determined, organic vapor con centrations can be simply calculated. Since very little sot-un time is required, more employee exposure determinations are possible nm" sun ey thus allowing for an expanded sur veillance program. As the accuracy of the eharcoal tube method may be ailected by sampimg pump maintenance and calibration, eharcoal tube handling, spontaneous desorption of the oigamc vapor into the air stream and breakthrough, there are serious questions concerning its accuracy in determining airborne concentrations oi organic vapors. In an industrial 3M 111041 szs "I *V. 'Isioc I ;46l SeBtemoei 1985 Sampling Devices CT 3M DP MSA ND NMS TABLE I Benzene Results (ppm) Trial Number 1 Repetiti ns 1 23 4 5 6 ' 1.88 1.88 1.48 - 1.46 1.81 1.35 1.39 >.39 1.42 1.68 1.69 1.63 1.68 1.43 1.73 1.39 1.55 1.63 1.79 1.46 1.91 1.52 1.55 1.77 2.03 1.43 1.81 1.44 1.42 1.72 2.07 1.46 1.81 1.36 1.16 1.69 Key: CT -- Charcoal Tubes: 3M -- 3M Company: OP -- DuPont: MSA -- Mine Safety Appliances Company; NO -- National Draeger; NMS -- National Mine Service Company. Level Two-Way Analysis ot Variance Grand Mearr= 1.62 Grand Range = 1.16-2.07 Col. Mean Level- Row Mean Row Sid. Dev. 1 1.51 2 _ . 1.65 3 1.57 4 1.67 5 1.64 6 1.59 1 2 -3 4 53 1.38 1.45 1.32 1.42 1.46 1.69 0.15 0.02 0.06 0.06 0.18 0.05 Source O.F. Sum of Squares Mean Square F-Value ........... ^^Pnn$ ......... Error................ Total................ 5 5 25 35 1.2464 0.43922* 10' 0.27264 1.5630 0.2492S 0.87844 *103.10906 *10 ' 22.358 0.805 (uncontrolled) atmosphere, both the charcoal tube sampling method and the passive dilfusion sampling method may be aiTected by numerous environmental conditions resulting in inaccurate organic vapor determinations. These conditions include air temperature and humidity, multiple air contami nants and air movement. In reviewing the literature.'" it is apparent that numerous investigations have centered around comparison of a partic ular passive organic vapor sampler with charcoal tube eval uations of the same environment under laboratory condi tions. In some cases, such laboratory studies were followed by field evaluations. While laboratory conditions are neces sary for controlled comparisons, employee exposure moni toring under uncontrolled field conditions is the desired use: thus comparison under the normal environmental condi tions encountered by the industrial hygienist provides a pragmatic data set for performance evaluation. Further, a field test of alkavailable organic vapor sampling devices offers a unique comparison opportunity. This comparison fLpassive diffusion monitors and the charcoal tube sam- ^Pig method is to determine if the results given by any particular sampling device are statistically equivalent to the corresponding results from all the other devices subject to the same (uncontrolled) industrial environment. ' Am Ind. Hy< 4sjoc. 1 (A6) SuDiemoer 198b Method Passive diffusion organic samplers manufactured by five companies and charcoal tubes (SKC. Inc.) were used in this evaluation. The diffusion samplers were manufactured by 3.M Company (3M Organic Vapor Monitors), DuPont (DuPont Pro-tek G-BB Organic Vapor Badges), Mine Safety Appliances Company (MSA OVD Organic Vapor Dosimeter), National Mine Service Company (National Mine Service Company Gasbadge), and National Draeger (National Draeger Orsa 5). One of each type of sampler plus a charcoal tube were taken to be a set. One set of ~ samplers was placed on each side of an open mesh wire two foot cube (Figure I). In an industrial atmosphere known to contain vapor phase concentrations of benzene, toluene and xylene, the sampling system was suspended from one corner of the cube, thereby permitting free rotation around a diago nal axis. Free movement of the cube was not restricted in any fashion. Because of the arrangement of the samplers on each face of the sampling cube, each sampler was. at one or more locations on the cube, adjacent to each of the other types of samplers. Thirty-six samplers (six of each type sampler on six faces of the cube) were exposed to essentially the same atmosphere. This sampling procedure was repeated six times in different atmospheres resulting in six replicate sets of data Sampling Devices CT 3M OP MSA ND NMS , TABLE II Benzene Results (ppm) Trial Number 2 Repetitions 1 2 3 ' 4 5 6" T'2 i.70 1.50 i 38 1.94 1.43 1.23 1.26 1.38 1.38 1.25 1.22 1.63 1.54 1.64 1.67 1.63 1.32 1.36 1.30 1.33 1.30 1.27 1.27 1.56 1.13 1.56 1.27 0.99 0.99 1.44 1.51 1.73 1.47 1.60 1.57 Key: CT -- Charcoal Tubes: 3M -- 3M Company; DP -- DuPont; MSA -- Mine Safety Appliances Company; NO -- National Oraeger; NMS -- National Mine Service Company. Level Two-Way Analysis of Variance Grand Mean = 1.45 Grand Range = 0.99-1.94 Col. Mean Level Row Mean Row Std. Oev. 1 1.49 1 1.61 2 , 1.41 2 1.32 3 1.52 3 1.66 4 1.41 4 1.31 5 1.46 5 1.25 6 1.40 6 1.55 0.21 0.06 0.C9 0.03 0.26 0.11 Source D.F. Sum of Squares Mean Square F-Value Rows... ........ Columns ........ Error___ ........ Total___ ........ 5 5 25 35 0.94Q56 0.18811 0.77992* 10' 0.15598*10 1 0.61412 0.24565*10 1 1.6327 7.658 0.635 3M 111042 527 or thirty-six samples per sampler type with 216 total sam ples. The air temperature, barometric pressure, relative humidity and air flow rate were recorded at each location during the evaluation. Each sampler was handled in the manner specified by the manufacturer. A sequence of sampler "start times" was followed at the beginning and end of each sample period resulting in essentially the same expo sure times for all thirty-six samples on the sampler cube. All samples were analyzed by carbon disulfide desorption and gas chromatography. Each sample media was placed in a small vial to which the CS2 was added. Two to five millili ters of CSa were used for desorption in order to fully cover the media in the vials. The vials were shaken for 30 min, then analyzed on a Hewlett Packard 5840A Gas Chromatograph with an HP 7672A Automatic Sampler and an HP 5840A GC Terminal. An SP-I000 twenty-foot column at 130F was used. Injection temperature was 250 F, and the flame ionization detector temperature was 300 F, Evaluation of the automatic injection system indicates duplication of results for a standard solution with standard deviation of 0.05 (10 injection repetitions of standard solution). Sample results were calculated using manufacturers' instructions for calculations. Desorption efficiency was determined experimentally. Numerous investigators have Sampling Devices CT 3M OP MSA ND NMS TABLE III Benzene Results (ppm) Trial Number 3 Repetitions 1 23456 1.02 0.32 1.13 0.33 0.35 1.13 0.95 0.73 0.84 0.74 0.85 1.04 0.85 0 76 1.48 0.86 0.99 1.10 0.94 0.76 2.05 0.71 0.85 0.94 0 91 0.79 1.92 0.36 0.99 1.00 0.95 0.82 1.63 0.86 0.99 1.16 Key: CT -- Charcoal Tubes: 3M -- 3M Company; DP -- DuPont; MSA -- Mine Safety Appliances Company; NO -- National Draeger: NMS -- National Mine Service Company. Level Two-Way Analysis of Variance Grand Mean = 1.01 Grand Range - 0.71-2.05 Col. Mean Level Row Mean Row Sid. Dev. 1 0.96 1 0.94 2 0.86 2 0.78 3 1.01 3 1.54 4 1.04 4 0.61 5 1.08 5 0.92 6 1.10 6 1.06 0.06 0.04 0.48 0.07 0.08 0.08 Source D.F. Sum of Squares Mean Square F-Value Rows.............. Columns........ Error................ Total................ 5 5 25 35 2.3502 0.23550 1.0240 - 3.6097 0.47004 0.47100*10 ' 0.40960*10 ' 11.476 1.150 Sampling Devices TABLE IV Benzen Results (ppm) Trial Number 4 Repetitions 1 234 56 CT 3M _ DP MSA ND NMS 4.67 3.12 4.33 2.50 2.79 4.01 3.56 3.01 4.30 2.39 2.85 4.01 4.03 3.09 4.91 2.60 2.85 4.01 3.97 3.04 4.44 2.57 2.97 3.85 3.56 3.04 4.52 2.32 3.33 3.72 4.41 3.01 4.66 2.7 B 2.52 3.30 Key: CT -- Charcoal Tubes; 3M -- 3M Company; DP -- DuPont; MSA -- Mine Safety Appliances Company; ND -- National Draeger; NMS -- National Mine Service Company. Level Two-Way Analysis of Variance Grand Mean = 3.49 Grand Range = 2.39-4.91 Col. Mean Level . Row Mean Row Std. Dev. 1 3.57 1 4.03 2 3.35 2 3.05 3 3.58 3 4.53 4 3.47 4 2.53 5 3.42 5 2.90 5 3.55 6 3.90 0.45 0.04 0.23 0.16 0.23 0.13 Source Q.F. Sum of Squares Mean Square F-Value Rows ...,........ Columns ......... Error................ Total................ 5 5 25 35 18.026 0.25557 1.5160 19.797 3.6051 0.51113-10' 0.60640*10 ' 59.451 0.843 reviewed desorption of organic compounds from charcoal and reported their results in the literature.'2'*' The diffusion rates necessary for the calculations were supplied by the manufacturer (as diffusion rates or monitor constants). The data was analyzed using a computer program for two-way analysis of variance. The two hypotheses to be accepted or rejected by this analysis are: 1) Each type of organic vapor sampling device will, when subjected to the same industrial environment, provide a result that is not statistically different from other such devices; 2) Each type of organic vapor sampling device will pro vide precise measurements of organic vapors in the industrial environment. Such a result will also indi cate that the variation of results among each sampler type as a function of being on each side of the cube are not statistically different. The mean values for each sampling device on each sampling cube were ranked and further evaluated using the least sig nificant difference method of multiple comparisons. 3H 111043528 - Am Int) Hyk Assoc J tVbl Scptemoer `985 -- Sampling Devices CT 3M DP MSA ND NMS TABLE V Benzene Results (ppm) Trial Number 5 Repetitions 1 23 4 58 3.60 3.10 4.72 2.39 3.12 3.82 3.49 3.03 4.42 2.48 3.12 3.74 3.41 3.13 4.55 2.51 2.08 4.18 3.60 3.28 4.77 2.68 2.42 4.10 3.22 3.18 5.41 2.78 3.00 3.92 4.25 3.05 4.46. 2.58 2.77 4.07 Key: CT -- Charcoal Tubes: 3M -- 3M Company; DP -- DuPont; MSA -- Mine Safety Appliances Company; NO -- National Draeger; NMS -- National Mine Service Company. Level Two-Way Analysis of Variance Grand Mean = 3.46 Grand Range = 2.08-5.41 Col. Mean Level Row Mean Row Std. Dev. 1 3.46 1 3.60 2 3.38 2 3.13 3 3.31 3 4.72 4 3.48 4 2.57 5 3.59 5 2.75 6 3.53 6 3.97 0.35 0.09 0.24 0.14 0.42 0.17 Source O.F. Sum of Squares Mean Square F-Value ........ ^Hbmns......... Wtor................ Total................ 5 5 25 35 19.654 0.29745 2.1666 22.120 3.9207 0.59489*10 ' 0.36745*10 1 45.313 0.686 Discussion In 1970 White, et suggested that solvent vapors in the industrial atmosphere could be measured using charcoal tubes. This procedure was reviewed numerous times in the literature and ultimately accepted by the National Institute for Occupational Safety and Health (NIOSH) as the recom mended practice. This method for organic vapor sampling uses a low-flow sampling pump and an activated charcoal sampling tube. The charcoal tube is a glass tube containing two sections of 20/40 mesh activated charcoal with appro priate partitions. The front section of the tube usually con tains 100 mg of activated charcoal, and the back-up section, used for evaluation of breakthrough (saturation of the front section) and/ or migration of the sample, usually contains SO mg of activated charcoal. The sampling pump flow rate is calibrated to approximately 100 cubic centimeters per minute for optimum collection of many organic vapors. In the mid-I^Os, the use of diffusion monitors for organic vapor analysis became a viable approach to the evaluation of employee exposures to such vapors. Although these devices available in a variety of shapes and sizes, each uses the iroie basic approach to the collection of organic vapors. The use of such "badges'* has been hailed as great progress in simplifying the evaluation of employee exposures as these devices do not need individual flow calibrations, mainte nance or batteries essential to charcoal tube sampling. The benzene analysis results of this investigative compari son arc shown in Tables I through VI. For each table of - results, each device on each side of the sampling cube (noted as repetitions) was exposed to essentially the same atmos phere; thus, the results should be the same. Ideally, if all the samplers were identical, all the thirty-six sample results in each table would be the same result. The analysis of variance for each result on each sampling cube is noted below the corresponding table of results. The statistic for comparison is the calculated F value based on an a -0.05 level which is F(0.03.5.23) = 2.60. . The analysis of variance for all the benzene results tables shows the column's F-value is less than the statistic; thus, each type of sampling device provided results which did not exhibit a statistically significant difference for the repetitions of that device within each test. The hypothesis that each type of sampling device is precise is therefore accepted. This result also serves to validate the-use of t he sampling cube as a - device for multiple samples within an environment as a method for comparisons through simultaneous sampling repetition. This use of the sampling cube did not interfere with producing statistically similar responses from the sam- Sampling Devices CT 3M DP MSA ND NMS - TABLE VI - Benzene Results (ppm) Trial Number S Repetitions 1 234 5 6 5.04 4.19 6.08 3.34 3.96 5.32 4.86 3.92 4.57 3.19 3.51 4.97 5.01 4.17 6.29 3.39 3.62 5.67 4.67 4.78 4.70 3.68 3.85 5.45 5.34 4.12 6.14 3.46 3.85 5.10 5. :3 4.07 6.37 3.80 3.96 5.30 Key: CT -- Charcoal Tubes: 3M -- 3M Company; DP -- DuPont: MSA -- Mine Safety Appliances Company: ND -- National Draeger: NMS -- National Mine Service Company. Level Two-Way Analysis of Variance Grand Mean = 4.62 Grand Range = 3.19-6.37 Col. Mean Level Row Mean Row Std. Dev. 1 4.82 1 5.27 2 4.17 2 4.21 3 ' 4.69 3 5.69 4 4.52 4 3.48 5 4.75 5 3.79 6 4.78 6 5.30 0.56 0.30 0.90 0.23 0.19 0.25 Source D.F. Sum of Squares Mean Square F-Value Rows___ .... Columns. .... Error........ .... Total........ .... 5 5 25 35 25.165 1.8052 4.3020 31.272 5.0329 0.36104 0.17208 29.247 2.098 Am tna. Hyg Assoc J (AS) oeotemoer. 1985 3M 111044 529 Benzene Rank 1 2 3 4 S 6 LSD = 1 CT 1.38 DP 1.32 NMS 1.69 NO 1.46 3M 1.45 MSA 1.42 0.12 TABLE VII Rank of Mean Values (ppm) Test No. 2 34 t DP 1.66 ~\ DP 1.54 DP 4.53 CT 1.61 NMS 1.06 CT 4.03 NMS 1.55 CT 0.94 NMS 3.90 3M 1.32 ND 0.92 3M 3.05 MSA 1.31 ' MSA 0.81 ND 2.93 NO 1.25 3M 0.78 MSA 2.53 0.18 0.24 0.29 5 DP 4.72 NMS 3.97 CT 3.60 3M 3.13 ND 2.75 MSA 2.57 0.35 6 DP 5.69 NMS 5.30 CT 5.27 3M 4.21 NO 3.79 MSA 3.48 0.49 .Key: CT -- Charcoal Tubes: 3M -- 3M Company; DP -- DuPont: MSA -- Mine Safety Appliances Company; NO -- National Draeger; NMS -- National Mine Service Company. - _- - pling devices on various sides of the cube, either as a result of the sampling space size or as an obstruction or interferent in the sampling process, -- The analysis of variance evaluation for each of the Tables 1 through VI also shows the row mean values and the row standard deviation. These calculations and the mean square error values illustrate the generally very small variation around the mean values for each sampling device in each test. Thus, a small variation between the mean value results for each type of sampling device is likely to be statistically significant. Such a significant difference is evidenced by the generally large F values for the rows as listed in each analysis fot variance. When subjected to the same industrial environ ment. the hypothesis that each type of organic vapor sam pling device will provide a result that is not statistically different from other such devices is therefore rejected. Each type of sampling device tested will produce a statistically different result as compared to the other devices when exposed to the same industrial environment. Armitage'111 states "It wiil usually be important not to rely solely on the analysis of \ ariance table and its F test, but to examine the difference between groups more closely to see what patterns emerge". The method recommended for further analysis is calculation of the Least Significant Dif ference (LSD). This is shown inTable Vll forthe LSDatthe 5% level for the sampling devices' results in all six tests. With the LSD test, it is clear where the differences between the mean values for each test result-is significant. The values in Table VII indicate inconsistency in the ranked mean value for each type of sampling device; that is. for some benzene tests, the sampling devices rank in a particular order, while in other benzene tests, they rank in a completely different order. The current NIOSH standard method for evaluation of organic vapo^ concentrations is the use of charcoal tubes. If we concede this to be the "standard", then further analysis of ihe data in Table Vll can be accomplished by adding and ^ibtracting the LSD value from the charcoal tube mean value for each test. This procedure is illustrated in Table Vll with solid lines bracketing the sampling device results which are within LSD of the charcoal tube mean value. If inclu sion within the bracket is termed agreement (accuracy), then for the benzene analysis, the National Mine Service monitor is in agreement with the charcoal tube result 67% of the time, the DuPont monitor is in agreement 50% of the time, and the other monitors are in agreement less than 50% of the time. As previously noted, this investigation involved sampling device analysis for benzene, toluene and xylene. All the data can be subjected to the same statistical treatment as was the benzene data with the result presented m Table VM. Over all. the 3M monitor is in agreement with the charcoal tube result 50% of the time, the DuPont and Mine Safety Appliances monitors agree with the charcoal tube result 39% of the time, and the National Draeger and National Mine Service monitors agree with the charcoal tube result 33% of the time. - A pragmatic approach to the data is tc evaluate the aver age results of each sampling method with respect to criteria used tor industrial hygiene occupational exposures. The current Occupational Safety and Health Administration Permissible Exposure Limits (PEL) for exposures to ben zene. toluene and xylene are 10 ppm. 200 ppm and 100 ppm TABLE VIII Passive Organic Vapor Samplers' Results Agreement with Charcoal Tube Results % Agreement* Sampler Benzene Toluene Xylene Overall 3M 17 . 67 67 50 DP 50 67 0 39 * MSA 17 0 100 39 ND 17 17 50 33 NMS 67 0 33 33 'Percent of the sampling device results which are within plus or minus the Least Significant Difference (LDS) of the Charcoal Tube result for the same test. Key: 3M -- 3M Company; DP -- DuPont: MSA -- Mine Safety Appliance Company; NO -- Na tional Draeger; NMS -- National Mine Service Company. 3M 111045530 Am /nil ASSOC 1 (Jfil Seoiemoei 198b respectively. In each benzene, toluene and xylene test, the average results illustrate a relationship between an atmos pheric concentration of the contaminant and the OS HA PEL. The industrial hygienist must evaluate the results of tjM^mple with respect to the operation involved and related rl^Hal information to determine the extent of any potential health hazards. Using a sampling system that gives results which may vary from those given by another sampling sys tem by 20% or 2 ppm for benzene, or by 40 ppm and 20 ppm for toluene or xylene, respectively, should not significantly change the action to be talten by the industrial hygienist. If any sampling system indicates organic vapor concentrations in PEL ranges even with 20% variation in results, additional action is essential. Sampling results must be combined with operations data, medical data and other significant data to determine the course of action to be talten. Consistent and repetitious air monitoring should indicate patterns which can be used to protect the health of the employees. For a more specific relationship between charcoal tubes and a. particular diffusion organic vapor sampler, tests should be conducted with the organic compound of interest under conditions most like the actual sampling conditions to be encountered. In summary, the major source of variability is between types of samplers: therefore, the greatest reduction of variability would be achieved by consistent use of one sampler type. Acknowledgements We wish to thank the manufacturers of the sampling devices tuMkin this investigation for their contribution of materials i^^information. We also would like to thank those employees of U. S. Steel Corporation. Aluminum Company of America, and University of Pittsburgh for their valued consultation. These results were originally presented to the faculty of the Graduate School of Public Health. University of Pittsburgh in a Masters Essay. Although the research described in this article has been funded in part by the United States Environmental Protection Agency under Assistance Agreement #CR 806815, it has not been subjected to the Agency's required peer review and therefore does not neces sarily reflect the views of the Agency and no official endorsement should be inferred. References 1. Rose V.E. and J.L. Perkins: Passive Dosimetry-State of the Art Review. Am. Ind. Hyg. Assoc. J. 43:605 (1982). 2. Fracchla, M,, L. Pierce, R. Graul and R. Stanley: Desorption of Organic Solvents from Charcoal Collection Tubes. Am. Ind. Hyg. Assoc. J. 38:144 (1977). 3. Dommer, R.A., R.G. Melcher. Phase Equilibrium Method for Determination of Desorption Efficiencies. Am. Ind. Hyg. Assoc. J. 39:240 (1978). 4. Langvardt, P.W., and R.G. Melcher Simultaneous Determi nation of Polar and Non-Polar Solvents in Air Using a TwoPhase Desorption from Charcoal. Am. Ind. Hyg. Assoc. J. 40:1006 (1979). 5. Krafewski, J., J. Gromiec and M. Dobecki: Comparison of Methods for Determination of Desorption Efficiencies. Am. Ind. Hyg. Assoc. J. 47:531 (1980). 6. Evans, P.R. and S.W. Horstman: Desorption Efficiency Determination Methods for Styrene Using Charcoal Tubes and Passive Monitors. Am. Ind. Hyg. Assoc. J. 42:471 (1981). 7. Posner, J.C. and J.R. Okenfuss: Desorption of Organic Ana lytes from Activated Carbon I: Factors Affecting Process. Am. Ind. Hyg. Assoc. J. 42:643 (1981). 8. Posner. J.C.: Desorption of Organic Analytes from Acti vated Charcoal ll: Oealing with the Problems. Am. Ind. Hyg. Assoc. J. 42:647 (1981). 9. Rodriguez. S.T., D.W. Gosselink and H.E. Mullins: Determi nation of Desorption Efficiencies in the 3M 3500 Organic Vapor Monitor. Am. Ind. Hyg. Assoc. J. 43:569 (1982). 10. White, L.D., D.G. Taylor, P.A. Maner and R.E. Kupei: A Convenient Optimized Method for the Analysis of Selected Solvent Vapors in the Industrial Atmosphere. Am, Ind. Hyg. Assoc. J. 37:225 (1970). 11. Armitage, P.: Statistical Methods m Medical Researcn. John Wiley and Sons. New York (1971). 2 Noxemoer IVK4: Reused 22 April IVK5 - * Am Ina Hvk. Assoc J M6) Sepiemflei 1985 3H 111046 531 A two-phase study was conducted to assess the suitability of passive monitoring for the collection of airborne vapor degreasing solvents under laboratory and field conditions. The laboratory stage of the investigation involved the determination of collection fficiencies for methyl chloroform (MC| and trichloroethylene (TCE). A -1 6920 L static chamber was used to establish standard atmospheres of these solvents at various concentrations, Khich were then sampled using passive monitors: samples were subsequently analyzed by gas-liquid chromatogaphy. In the second part of the investigation, several MC and TCE vapor degreaser operations were monitored at US Army industrial plants. The purpose of the field study was to develop worker exposure profiles and to obtain a side-by-side comparison of the passive monitor with the traditional charcoal tube sampler. Presented are statistically reduced data and the performance characteristics of both collection techniques. _ Evaluation of passive monitors for assessing vapor degreaser emissions J.F, MAZUR. D.S. RINEHART, G.G. ESPOSITO and G.E. P000LAK US Army Environmental Hygiene Agency. Aberdeen Proving Ground. MO 21010 introduction Vapor degreasing is one of the most widely used of all metal cleaning techniques. It is suitable for cleaning all common industrial metals without the danger of etching or chemical attack. Furthermore, the process is relatively economical, and it is adaptable to parts in a wide range of si/es and shapes. This operation is used extensively by the metai t'abri) cation industry to remove soils before applying protective -lutings, electroplating, and before and after machining, lefjicieaning varies in quantity and complexity from small manual operations in which parts or tools are cleaned by solvent-dipping to mass production degreasing where large volumes of mciai parts are cleaned in units of great capacity having sophisticated engineering controls. Solvents most commonly used are methyl chloroform {I.I.I-tnchloroethanel. trichloroethylene, perchloroethylene. methylene chloride, and tnehlorotrifluoroethane. Of these, methyl chloroform (MC). and trichloroethane (TCE) are the most prominent. A solvent vapor degreaser consists of a tank or vat with a heat iource in the lower section to vaporize the solvent and a cool area in the upper section to condense the vapor. The parts to be cleaned are suspended in the vapor zone between the hot solvent and cool area. As the solvent condenses and Flows over the cool parts, it removes greases, oils, and other soils, and returns to the hot solvent. When the parts reach the temperature of the vapor, condensation stops and the pans become dry. The Army operates numerous vapor degreasers of various sizes at installations throughout the country. The majority of these units.were originally designed for use with TCE. however, almost all have been convened to methyl chloro form systems. If conducted properly, vapor degreasing "e opinions or assertions contained herein are the private views of the authors and are not to be construed as reflecting the views of the department of the Army or the Department of Defense, operations are safe and efficient. On the other hand, when standard operating procedures are not strictly observed o~r when obsolete or faulty equipment is used, solvent losses may occur which could easily cause worker exposures to reach hazardous levels. .NIOSH has estimated that workers exposed to MC and TCE in the United States alone number approximately 200 000 and 100 000 respectively.1121 The most common industrial use of these solvents is as degreasing agents. The present US Federal standard for an 3-hour time-weighted average exposure to MC is 350 ppm. The recommended standard takes into account central nor. ous system responve-. to acute exposures in man.''1'5' respiratory and cardiovascu lar effects in severai animal species associated with chronic exposures."* 71 and the absence of reported effects In man at concentrations below the recommended standard. The US Federal recommended standard for an S-hour time-weighted average exposure to TCE is currently 100 ppm: for 15 minute exposures. 150 ppm may not be exceeded. This TCE standard is supported by studies show ing the slight psychophysiologica! effects observed at ICO ppm.lS1 respiratory and prenarcosis effects at concentrations between 200 and 500 ppm.1*"111 and subject responses at 150-200 ppm.'9101 Fatalities have been reported*12'131 when workers were exposed to levels estimated to be between 1700 and 3300 ppm for 10 minutes. The NIOSH criteria documents for MC and TCE specify the charcoal tube method for the collection of breathing zone samples.11'1 This time-tested technique is capable of providing accurate and reliable results: however, it does not offer the convenience, compactness, and nonmechanical reliability of diffusion type passive monitors. Since the advent of the organic vapor passive monitor (OVPM), sev- Use of rrademarfced names does not imply endorsement by ibe US * Army, but is used only to assist in identification of a specific product. CdO*r<gnt T Ml cArt iptfunnal Ataocurm* 3M 111047 era! controlled laboratory studies on the performance of . these devices have been reported.114*1" In addition. Boeniger et al.aT) conducted a field comparison of two diffusion pas sive monitors with charcoal tubes under singular and multi exposure conditions. Our laboratory has conducted ^Wboratory and field studies'`31" to assess their applicability to various industrial hygiene related problems. None of the forementioned studies have dealt with the collec tion and analysis of MC and TCE in both field and con trolled environments. - This report presents the results of field and laboratory comparisons of the DuPont Pro-Tele (DPT) and 3M Organic Vapor Monitor(OVM) diffusion passive monitors with the charcoal tube for collecting V1C and TCE. The laboratory study consisted of the determination of collection efficiency, desorption efficiency, and storage stability of each device. Performance characteristics in the field were determined at several locations where MC and TCE were being used routinely. Two of these sites were selected ' because of previously reported high concentrations of vapors in the areas around the degreasing tanks. Both per-* sonal and stationary samples were collected; some monitors were intentionally subjected to high exposures for long peri ods of time in order to ascertain the capacity of theOVPM's. Comparative data for all three samplers are presented. experimental air sampling equipment Passive monitoring was conducted with the 3500 Organic ^por Monitor*. 3M Company. St. Paul. MN. and the ^mo-Tek* Organic Vapor Badge. .!. DuPont de Nemours 8l Co. (Inc.). Wilmington. DE. Both devices consist of an inert plastic body, diffuser, and charcoal collection dement. Contaminants enter the moni tor via molecular diffusion, traverse the air space between the monitor face and collection element, and are adsorbed on the charcoal collection pad. Aftersampling is terminated, the monitor is covered and then sealed in an aluminum foil bag provided by the manufacturer. The mass of the material collected on the charcoal is determined by gas chromatog raphy (GO subsequent to desorption with carbon disulfide. Both the OVM and DPT have design characteristics which offer distinct and unique advantages over each other. For example, the OVM is constructed so that the desorbing solvent can be added directly to the monitor body. Other monitors require that the charcoal collection element be transferred to a desorption vial prior to treatment with carbon disulfide. Additionally, most passive monitors havr-7'*' a fixed sampling rate which is predetermined by the diffu sion coefficient of the analyte and geometry of the monitor. The DPT. however, provides the capability of sampling at two different rates depending on whether one or both of its covers are removed during exposure. All the work described in this paper was conducted with only one of the covers removed. MC and TCE sampling rates provided by the manufacturers are 28.0 cc. min for both MC and TCE for the 3M OVM. 30.2 cc min MC and 32.6 cc/min TCE for the DuPont Pro-Tek (single cover sampling). The time-weighted worker exposure is calculated using the following equations; mg, m2 corrected weight on badge (nanograms) sampling rate (cmJ min) X sampling time (min) m" *gj wX 22,,.4 L mole X,, TJk Xw 760"-*m11 m Hg m. _ mwg, mole 273 3 X. P-mm Hg Charcoal tube collection was conducted with tubes (200, 400 mg) purchased from SKC Inc.. Eighty Four. Pa. Samples were collected at a nominal rate of 0.050 L min using Accuhaler808 plimps(MDA. Park Ridge, 1L) which were calibrated before and after field usage. Air sample volumes were determined by multiplying the air volume per stroke (determined in the laboratory) by the number of strokes indicated on the counter. gas chromatography Thecharcoal tubes and monitors were all analyzed using the same technique, i.e.. one and one-half mLs of carbon disul fide were added to the charcoal, samples were shaken with the CS>. and allowed to desorb for 30 minutes. Analvses :r carbon disulfide desorbent solutions were performed on a Hewlett-Packard VIodel 5S30 gas chromatograph equipne i with a flame ionization detector and H P ISS50A GC Termi nal. The GC operating conditions were as follows; column. 10 ft X I 8 inch stainless steel packed with 10 percent FFAP on SO-fOO mesh Chromosorb W-H P: injection port tempera ture. 250 3C: detector temperature, 250 : C; column temper ature. 110 C. laboratory testing Appropriate amounts of MC orTCE were introduced intoa 2-mL vial and sealed with a screw cap. The vial was trans- Loading Range ppfit-hr* 21-65 115-200 211 - 285 410 - 532 Overall TABLE I Methyl Chloroform Field. Data OVM SompJos Mean Recovery No,------ % Rel Std Dev % DPT Mean Recovery % Rel Std Oev % . 4. 7 *' 4 3 107 6 114.9 99.6 95 6 5.4 3.5 6.3 12.0 115 6 115.3 103.5 91 0 9.1 6.7 4.3 6.3 ta 106.7 9.3 108 7 11 4 3M 111048 Loading Range ppm-hrs TABLE II Trichloroethylene Field Data Samples N. OVM Mean Recovery % Std Oev % DPT Mean Recovery % Std Oev % 11-141 207 - 300 359 - 342 1161 -2090 3249 - 11 116 15 5 5 3 3 110 5 108. S 100.4 91.8 89.0 21.3 21 0 6.6 76 13.5 108.1 90.7 94 7 39 0 74.5 12.0 15.0 5.2 9.1 26 0 Overall 31 103.4 19.0 97.4 16.7 ferred to a 6920 liter static test chamber and positioned in front of a circulating fan. The vial cap was removed and the chamber door closed immediately. After sealing the door, the circulating fan was run for 30 minutes to vaporize the test sample and allow the chamber concentration to equilibrate. , The circulating fan remained on throughout the entire test ing period. The monitors were attached to a meter stick and introduced into the test atmosphere through a_side access" port of the chamber. CT samples were collected at a port adjacent to the passive monitors. Two or three successive CT samples were collected during each of the passive monitor exposures. Samples were generally analyzed within 24 hours after collection. ,' comparative field sampling .'An attempt was made to locate each sampler of a set in the ame environment without compromising the integrity of ny other sampler. Obviously, some variance in contami nant concentration is to be expected in the field even when samplers are in close proximity with each other. Most of the stationary sampling was performed by positioning 3 CT's. 2 OV M's. and 2 DPT's side-by-side in an alternating pattern 2 inches apart starting with a CT. To study possible "starva tion" effects induced by competitive sampling of monitors, some tests were conducted by randomly spacing 2 or 3 samplers 6 inches from adjacent samplers. Personal samples were collected by attaching a CT, DPT. and 0^ M to the collar or lapel of the worker being moni tored. All of the survey samples were kept at room tempera ture prior to chromatographic analysis which was per formed 1-3 weeks after sample collection. desorption efficiency Desorption efficiencies for MC and TCE were determined using the phase equilibrium technique. Known concentra tions of MC and TCE wereprepared in carbon disulfideand aliquots were added to each of the monitors. The carbon disulfide solutions were allowed to interact with the carbon for 30 minutes with occasional mixing. Desorption efficien cies were determined by comparing the GC analyses of standards before and after addition to the monitors, j' ^Bsults and discussion The first phase of the test program was to determine the efficiency of the passive monitors under controlled labora `1. tory conditions. All tests were conducted at room tempera ture in the6920 literchamber previously described: theoreti cal concentrations covered the ranges of approximately I 2 2 TLV for MC and 1/5 - 2 TLV for TCE. This study was initiated before the DPT badges became commercially available: consequently, fewer DPT badges were included in the laboratory phase of the investigation. Based on the anal ysis of 20 OVM badges and 6 DPT badges exposed to methyl chloroform, the coefficient of variation in the 160 - 8-U) ppm range was 0.045 for DPT and 0.047 for OVM. These vaiues correspond to a relative standard deviation of 15.7 and 16.5 ppm for DPT and OVM. respectively at 350 ppm (TLV for MC). In the trichloroethylene chamber study. 27 OVM and 10 DPT badges were exposed to concentrations of TCE in the range of 20 -200 ppm. The coefficient of variation in this range was 0.076 and 0.07" for the OV.M and DPT. respec tively. These v aiues correspond to a relative standard devo tion of7.6 ppm fortheOVM and 7.7 ppm for the DPT at 100 ppm (TLV for TCE). Based on the chamber study the mean percent recovery for methyl chloroform was found to be 93.3. 89.1. and 95.1 for the OVM. DPT. and CT, respec tively. For TCE the mean percent recovery equalled 9o.3 for OV.M. 93.6 for the DPT. and 95.4 for the CT. Since the purpose of the laboratory study was to determine empirical factors for correcting field survey samples, the given values were not corrected for desorption efficiencies which were found to be between 96 and 100 percent for all three devices. Tables I and 11 show thedata of all thesamples collected in the field and comprise both personal and stationary samples. These data are arranged in order of increasing sampler load ing expressed as ppm-hours. The loading ranges were caicu- Sample. Comparison TABLE III Statistical Data - Field Samples Slope TCE Personal (CT/ OVM) (CT/OPT) TCE Stationary (CT/OVM) (CT/OPT) MC Personal (CT/OVM) (CT/OPT) MC Stationary (CT/OVM) . (CT/OPT) " 1 08 1.00 1.06 0.99 1.07 0.99 0.90 0.98 Correlation Coefficient 0.98 0.98 0.98 0.9a 0.98 0.94. 0.89 0 94 3H 111049 Storage Time (Weeks) TABLE IV Storage Stability OVM Concentration (ppm) Within After Storage 24-Hours Time DPT Concentration (ppm) Within After Storage 24-Hours Time METHYL CHLOROFORM 2 2 3 3 - trichloroethylene" 2 3 45.2 285 0 45.2 285 0 85.9 45.S 299 0 44.3 284 0 39 3 253 253 82.0 820 249 243 82.0 84 2 la ted by multiplying the ppm concentration found on theCT times the hours sampled. For interpretive purposes, the OVM and DPT field results are reported relative to the CT results. All Held results were corrected using the mean per cent recoveries determined in the laboratory. Stationary sample results were obtained in each case by comparing the average of two (each type) passive monitors with the average concentration from three CT's. Field data for MC. Table I. includes 11 personal and 7 stationary samples. Samples were collected over time peri ods extending I -5 hours, at temperatures between 60 and 70 3 F and relative humidities of 35 and 45 percent. As can be en in Taole I. lower badge leadings resulted in higher overies. However, overthe rangetested. the overall mean ^coveries for both monitors were in good agreement with the charcoal tubes results and with each other. TCE Held data are presented in Table II. At the area monitored, the temperatures ranged from 65 -75 s F; relative humidity remained around .'0 percent. As shown in this Table, the relative mean recovery for the OVM and DPT passiva monitors was ; 03.4 and 97.4 percent, respectively. In some tests, badges were intentionally held at high TCE concentrations for long periods of time to promote high badge loadings (3249 - 11 116 ppm-hours). To preclude the overloading of charcoal tubes that were run concurrently with the badges, a series of three charcoal tubes were run consecutively with each badge exposure. As shown in Table II. good passive monitor recoveries were obtained with exposures up to 2040 ppm-hours: at the 3249 - 11 116 range, recoveries decreased significantly, an indication of overload ing. These results are in agreement with the manufacturers' upper exposure limits recommended for TCE. With the exception of the overloaded monitors: good correlations were obtained between the passive monitors and charcoal tubes. It can a\lso be noted that the recovery- ofTCE followed the same pattern as the case of MC: at the lower loadings higher recoveries were obtained: conversely, recoveries reased as the badge loadings increased. K his effect has been predicted by J. Martin from theoreti cal treatments of sorption phenomena and has been observed in experimental data. It is believed to be the result of a gradual decrease in available active sites for sorption, forc ing the organic molecules to move farther into the sorbent in order to be bound.'*" Table 111 presents the calculated slopes of regression lines and correlation coefficients of paired sample results for comparisons of CT and passive dosimeter field data. As indicated, the slopes and correlation coefficients are very close :o unity. - The results of storage stability tests are presented in Table IV 1`ortheOVM and DPT. The monitors wereexposed in the static chamber to MC and TCE. sealed in aluminum foil bags, and stored for up to 3 weeks at room temperature. 4 shown, no significant losses occurred when OV.M's and DPT's containing MC and TCE were stored for periods as long as three weeks. As. discussed above, passive monitor-recoveries for Held samples were calculated from results of charcoal tube:, sam ples concurrently. In essence, the CT results were taken as the "true value' of the concentration present. It must be recogm/ed that such comparisons can be somewhat mislead ing. Sampling errors of 7c'f and more have been documented for collecting TCE with CT's under controlled laboratory conditions.1'" Errors may be due to such factors as pump calibration errors and CT variations. When sampling Held atmospheres another potential source of error is introduced -- concentration gradients. These factors could account for large differences in concentration occasionally observed bet .veen the CT's and passive monitors. Although compari sons to the CT as the "true value" may not present passive monitor results in their true light, the CT sampling method remains the standard procedure for collecting time-weighted average concentrations ofTCE and MC and provides one means for evaluating the use of the monitors under field conditions. cc elusion As evidenced by the comparison data, both 3M and DuPon pa sive monitors appear to provide a viable means of collectin.. MC andXCE^l vapocdegreasing sites. When evaluated in he laboratory, both passive monitors were in good a' rment with the theoretical concentrations of both ana- 3M 111050 1> ces,in the field, the dsvices generally compared favorably with charcoal tubes and each oilier. In isolated cases where the passive monitors and CT*s disagreed, the source of error could not be positively defined. These discrepancies could ossibly be attributed to the inability to locate different Implers in the "same" atmosphere and or the combined imprecision of both sampling techniques. At concentration levels not exceeding VIC and TCE TLV's. both passive monitors can be used for 8 hour sam pling periods without being overloaded. If high concentra tions are expected, sequential sampling for shorter periods of time are recommended. references 1. Criteria far a Recommended Standard Occupational Expo sure to 1.1.1-Trich/oroethane (Methyl Chloroform). HEW Publication No. (NIOSH) 76-18* (1976). 2. Criteria for a Recommended Standard Occupational Expo sure to Trichloroethylene. HEW Publication No. (NIOSH) 73- 11025(1973). . 3. Salvini. M.. S. Binashci and M. Riva; Evaluation of the psychophysiological functions In humans exposed to the "Threshold Limit Value" of 1.1.1-trichloroethai'.e. J. Ind. Med. 25:286-92 (1971). 4-. Gamberale. F. and M. Hultengren: Methyl chloroform exposure -- If Psychoohysiological Function. Arebete Och. Halso. t:29-50(1972). 5. Stewart. R.D., H.H. Gay, A.W. Schaffer. D.S. Erley and V.K. Rowe: Experimental Human Exposure to Methylchloro- form Vapor Arch. Environ. Health. 19 407-72 (1969). Prendergast. J. A.. R.A. Jones. I__I. Jenkins and J. Siegel: Effects of Experimental Animals of Long-Term Inhalation of Trichloroethylene. Carbon Tetrachloride. 1.1.1-trichloro- ethane. Oichlorodifluoromeihane. and]. 1 -dichloroethylene. Toxicol. Appi Pharmacol. 70 270-39 (1 967). Quasi. J.F.. B.K.J. Leong. L.W. Rampy and P.J. Gehring: Toxicologic and Carcinogenic Evaluation of a Methylchloro- formil. 1.1 -Trich/oroethane) Formulation by Chronic Inhala tion m Rats--Interim Report After 2* Months. Midland. Mien . The Daw Chemical Conoany (1975*. . 8. Salvini. M.. S. Binashci and M. Riva: Evaluation of the Psychophysiological Function in Humans Exposed to Trichlo roethylene. 8r. J. Ind. Med. 28'293-95 (1971). 9. Stewart. R.D.. H.H. Gay. D.S. Erley. C.L. Hake and J.E. Peterson: Observations on the Concentration of the Trichlo roethylene in Blood and Expired Air Following Exposure of Humans. Am. Ind Hyg. Assoc. J. 23:167-70(1962). 10. Stewart. R.D., H.C. Dodd, H.H. Gay and D.S. Erley: Exper imental Human Exposure to Trichloroethylene. Arch. Environ. Health 20:64-71 (1970). 11. Stopps, G.J. and M. McLaughlin: Psychophysiological Testing of Human Subjects Exposed to Solvent Vapors. Am. . Ind. Hyg. Assoc. J. 25.43-50 (1967). 12. Kleinfeld. M. and I.R. Tabershaw: Trichloroethylene Tox icity -- Report of Five Fatal Cases. Arch. Ind. Hyg. Occup. Med. 10:134-41 (1954). 13. Longlev. E.O. and R. Jones: Acute Trichlorethylene Narco sis -- Accident Involving the use of Trichloroethylene in a Confined Space. Arch Environ. Health 7:249-52(1963). . 14. Bailey. A. and P.A. Hollingdale-Smith: A Personal Diffu sion Sampler for Evaluating Time Weighted Exposure to Organic Gases and Vapors. Annals Occup. Hyg. 20:345-56 (1977). 15. Tompkins. F.C, and R.L. Goldsmith:`A New Personal Dosimeter for the Monitoring of Industrial Pollutants. Am. Ind. Hyg. Assoc. J. 38:371 (1977). -- 16. Bamberger, R.L.. et. a/.: A New Personal Sampler for Organic Vapors. Am. Ind. Hyg. Assoc. J. 39:701 -08 (1978). 17. 8oeniger, M.F.. et a!.. A Field Comparison of Two Passiv Organic Vapor Monitors with Charcoal Tubes Under Singu/ar and Multiple Exposure Conditions. Am. Ind. Hyg. Assoc. - Mtg.. Chicago. ILU979). 13. Mazur. J.F., R.L. Bamberger. G.E. Pod lak and G.G. Esposito: Development and Evaluation of an Ammonia Dosimeter. Am. Ind. Hyg. Assoc. J. 39:749-753 (1978). 19. Mazur. J.F., G.E. Podolak, G.G. Esposito. D.S. Rinehart and R.E. Glenn: Evaluation of a Passive Dosimeter for Col lection of'2-Bromo-2'-chloro-1.1.1-tnfluoroethane and 2- Chloro-1,1,2-trifluoroethyl Difluoromethyl Ether in Hospital Operating Rooms. Am. Ind. Hyg. Assoc. J. (in press). 20. Martin. J., CPT: U.S. Air Force School of Aerospace Medi . cine. Brooks AF8. TX (private communication). 21 Reehner, L.R. and J. Sachdew: Collaborative Testing^)) Activated Charcoal Sampling Tubes for Seven Organic Sol vents. 0HEW (NIOSH). Conract No. HSM 99-72-98 (June. 1975). % 3M 111051 The use of passive organic vap r monitors has been suggested as an alternative to the use of charcoal tubes with a rtable pump as a method t assess a worker's exposure to organic compounds. This study simultaneously r mpares DuPont's. Abcor's. and 3M's passive monitors to the charcoal tube method. The study us d a \ ^fcll-characterized dynamic exposure system to closely duplicate actual environmental exposure conditions. The QRLent vapor generation system provid d accurate, stable, and reproducible atmospheres within the exposure chamber. This total system is recommended as a significant improvement over previously reported techniques. Temperature, relative humidity, barometric pressure and air velocity were monitored and held within a small range of variation. Desorption efficiencies were determined for each of the organic compounds on each of the sampling devices used. Statistical analysis determined monitor performance. All three manufacturer's monitors are demonstrated to be an acceptable alternative to the use of charcoal tubes. Several modifications are suggested concerning analysis of these devices. A problem in monitor performance is noted. A dynamic-flow chamber comparison of three passive organic vapor monitors with charcoal tubes under single and multiple solvent exposure conditions 0 3 vOELTE and F.W. WEIR . _ 'h* university of Texas Health Science Center, School of Public Health, P,0. Box 20186, Houston, Texas 77025 1 introduction : Occupational Safety and Health Administration has ccuircd mduMtry to monitor workers'exposures to various : came compounds and has established permissible levels to possible ill-effects to workers exposed to these ^Pmieals. These exposures are expressed as a time-weighted i .t.icc i I W A). a -en these limits were first established, the National 't :;:ie tor Occupational Safety and Health (N10SH) .'tr.mendod the collection of organic vapors on a charcoal iMng a calibrated pump. The charcoal in these tubes v.!' :hen analyzed using gas chromatography. This techv.oue has been extensively tested and reported in the litera ture. jnd has become the routine collection method for >rcame sapors.'1101 methods ot collection have been developed which '"* pusM\e organic vapor dosimeters. These monitors -.( require a mechanical pump, but rather use thediffuII principle as the driving force in sample collection. Wor' (lasbadge. 3M's 3500 organic monitor, with draft tucUlv and DuPont's Pro-Tek, without any shield, use -'u\ principle. IVcmous studies to evaluate these dosimeters have been ...... ` '*,n 'cope because of one-to-one comparisons of char- i. ahes to passive organic vapor monitors. The majority uiics have employed field monitoring*11-12' and have been of limited value because of many uncontrolled parame ters complicating interpretation. The few laboratory controlled studies have restricted themselves to the use of static'13'1-11 or quasi-dynamic' ,5) sys tems to expose these monitors. These exposure systems have several drawbacks which are minimized by the use of dynamic systems with larger exposure chambers and a flow through design which minimizes the "wall effects" found in many smaller static systems. A constant supply of organic vapors provides a stable concentration which is not reduced as the monitors collect the solvent. In static systems, this reduction can affect chamber concentration significantly at low concentrations. The study reported here compares the charcoal tube method to passive dosimeters of three major manufacturers: DuPont's Pro-Tek. Abcor's Gasbadge. and 3M's 3500 Organic Vapor Monitor; using a dynamic exposure system capable of generation of organic solvents over a wide range of concentrations. The resulting atmospheres are stable and reproducible. Other parameters known or suspected to interfere with these dosimeters, such as relative humidity, temperature, air velocity, and barometric pressure were monitored and remained within a small range of variation so as to minimize their effects. methods and procedures " on,:lus,0ns and suggestions incorporated in this paper are solely ** a the above authors. No pan of this paper was edited orrevised J <h* three c*rporat'"* which participated in this study. ,1 corBora,lons were given a copy of the completed manu asked to present their opinions, if any, to be included " ^ernments , exposure chamber Exposures were performed in a 0.25M3 Rochester type dynamic flow inhalation chamber constructed of plexiglass. Units of this design are used almost universally for inhala tion toxicology studies. Characteristics of these chambers, in terms of uniformity of air flow and contaminant concentra `' lu-.triji Hvgicnc Association JOURNAL Cocvriqm 1981, Am*rfCn lndur>ai Hygiene Aociiion 142} 12/81 3H 111052 S4S tion throughout, arc widely documented.'16'17' A vacuum system at the exhaust port created a negative pressure flow system. A Magnehelic gauge installed at this point measured the total flow rate in the chamber, which was controlled by a gate valve. The Magnehelic gauge was calibrated for flow using a 120 liter gas spirometer. A curve relating flow to gauge setting was prepared. This correlated significantly td the theoretical flows calculated for the various differential pressures. A chamber flow of 250 liters per minute (Lpm) was chosen and the corresponding value was set and moni tored using the Magnehelic gauge. The chamber's relative humidity and temperature were monitored with an Abbeon Certified Hygrometer and temperature indicator. A 2.5 cm (1 in) mesh wire was suspended 15.2 cm (6 in) below the top of the chamber and the badges were suspended at eight selected positions 5.1 cm (2 in) below this screen. Thus, all badges to be tested were located on a cross sectional plane approximately 10.2 cm (4 in) above the mid section of the chamber. Badges were placed a minimum of 15.2 cm (6 in) apart. In addition to the velocity of test atmosphere provided by the one change per mjnute (250 Lpm) flow through the chamber, air movement within the chamber, was augmented using two 20.3 cm (8 in) Tans, installed in the upper dome of the chamber. Air velocities at all badge positions were measured with a Kurtz air velocity meter and determined to be greater than 100" fpm at each position. A 30.5 cm (12 in) stainless steel needle was installed in the chamber and. when attached to a series A-2 Precision Sam pling gas syringe, was capable of sampling the atmosphere at positions adjacent to the badges being exposed. olvent generation system The solvent generation system employed the principle of a constant vaporconccntration at a constant temperature and pressure. The constants for vapor pressure calculations were obtained for the four solvents1181 and their saturated vapor concentrations were determined at 0C and 760 mm Hg. By knowing this, and setting the total exposure chamber flow at 250 Lpm. one may calculate the flow necessary for generat ing 10 and 100 parts per million (ppm). This system was similar to that employed to make the NIOSH Proficiency Analytical Testing Program samples.119' These flows were acheived using cylinders of purified nitrogen equipped with 2-stage regulators to reduce the pressure to a moderate level. The final flows were individually regulated with a blunt needle valve for each solvent and these flows were monitored by differential pressure manometers equipped with variable orifices and standard manometer fluid. The nitrogen was then directed into gas washing bottles containing each sol vent and the saturated vapor was directed into the intake port of the exposure chamber. The solvents in the gas wash ing bottles were maintained at a constant temperature with an ice-water bath at equilibrium. Figure I depicts the expo sure chamber-and solvent generation system. analytical conditions analytic determinations were performed on a Perkin er 3920 gas chromatograph equipped with a Supelco 3.05 m (10 ft) glass column, 2 mm ID, silane treated and packed with 10% FFAP on 80/130 mesh chromasorb W A^hmims The operating temperatures were set as fol lows: 160 0 C at the injection port, 220 0 C at the detector, and 100 C isothermal column operation. Chromatographic grade nitrogen was used as the carrier gas and the flow was set at 30 cc/min. A flame ionization detector was used. Maximum sensitivity of this detector was determined fol lowing the manufacturer's recommended steady state method. The settings determined were 16 pounds per square inch (psi) for the hydrogen and 60 psi for the zero air. Samples were introduced into the instrument in two ways. Liquid samples were injected following the method recom- mended by NIOSH.'1'6'10' A Glenco 10 jiL syringe is flushed with carbon disulfide several times and 3 /*L of carbon disulfide is drawn into the syringe. Then 0.2 pL of air is drawn into the syringe to be used as a marker. Finally, a 5 ^L aliquot of sample is drawn into the syringe and the plunger is retracted further to prevent evaporation at the end of the needle. Air standards and chamber samples were collected with a Precision Sampling Pressure-Lok Series A-2 1.0 mL syringe. Samples were collected with 30.5 cm (12 in) needles compat ible with this syringe. The plunger was slowly and com pletely withdrawn and the syringe flushed. This step was repeated, a sample taken, and the syringe valve was closed. The needle was removed and a 5.1 cm (2 in) needle attached. The valve was reopened, the volume was reduced to 1.0 mL. the valve was closed and the plunger was depressed to 0.2 mL. The needle was then inserted through the septum of the gas chromatograph, the valve was opened and the plunger was simultaneously depressed. All determinations were made using the peak height as a direct indication of peak area due to the high resolution and narrow width of the peaks. validation of chamber atmosphere stability Exposures were conducted to test the temporal stability of the exposure conditions. These exposures were monitored by discrete grab samples which were analyzed by gas chro matography. The variability of chamber concentration for each solvent at both low and high concentrations over six hour intervals was determined. Mean concentrations and standard deviations were determined and are presented in Table 1. Two preliminary studies were conducted to verify unifor mity of chamber concentrations and reconfirm that no sig nificant concentration gradients existed in the plane of exposure. Forone-of the solvents used in this study (trichlo roethylene), mean values were determined for 10 positions across a plane in the chamber, each position sampled 3 to 5 times. Relative results of these 10 values gave a mean of2650 ppm with a standard deviation of 2.9%. Using trichloroethy lene for a second series, four points (sampling each position 4 to 5 times) gave a mean value of 3400 ppm with a standard deviation of 0.5%. This degree of uniformity has been a common experience of this laboratory with these chambers in past studies. . 3H 111053us Am lad Hit- Assoc- J (A!) December. 1981 ' (42)12/81 Industrial H y m n * A llocution JOURNAL CO ui t<*4 CYLINDER OF PREPURIFIED NITROGEN WITH 2-STAGE REGULATOR EXPOSURE SYSTEM , ' I Figure 1 -- Exposure system. determination of desorption efficiencies Desorption efficiencies for the charcoal tubes and all three manufacturer's dosimeters followed the same basic steps outlined in NlOSH P and CAM 127(subject to the modifi cations by each manufacturer). Placing the charcoal or collection element in a septum. capped vial, the analyst injected the solvent(s) of interest onto the collection medium. The sample was allowed to stand overnight. The following day the appropriate amount of carbon disulfide solution was added, the sample gently agitated for 30 minutes and .an aliquot injected into a gas chromatograph. Standards and blanks were treated sim ilarly. Desorption efficiencies were determined using the equation: J . area sample -- area blank desorption efficiency = ------------- ------------------------ area standard All corrected sample values were divided by each of the standard values and these were averaged to give the most representative desorption efficiency for each solvent. Desorption of all solvents on all collection mediums was accomplished using a solution of 3% n-butanol in carbon disulfide. This is recommended by NlOSH and Abcor to improve the recovery of isopropanol.'21 All standards and samples were run a minimum of five times each and averaged to accurately reflect the actual value. Desorption efficiencies for the charcoal tubes were per formed first. A 100 mg sample of charcoal from thecharcoal tubes was placed into a 1.0 mL mini-vial and capped using Imierosep F-13S teflon lined septa, the solvent was then Injected into thecharcoal. The amount used was determined "to represent that present in a 10-liter sample at a concentra tion equal to the federal standard."111 Four samples and two blanks were prepared for each solvent and allowed to stand overnight. These samples were desorbed by injecting i .0 mL of the carbon disulfide solution into each sample. Duplicate standards were made for each solvent by injecting 10 times the amount used on the samples into 10 mL of car bon disulfide. The desorption efficiencies for each of the four solvents on the charcoal tubes were determined separately twice. A mix ture of these four solvents, in the same vdlume to volume proportions, was prepared and the amount used for the multiple solvent samples was equal to the sum of the volumes used for each of the previous single solvent samples. A statistical analysis of the desorption efficiencies deter mined by this method showed no difference between those determined one at a time.'61 Therefore, to conserve time and collection elements this later method was adopted for the rest of the determinations. Desorption efficiencies for Abcor were determined sim ilarly. The collection elements were placed in the vials pro vided by Abcor. These elements become overloaded at 15 mg ^f solvent so 13 uL of the solvent mix was used (11.4 mg) to hipare each sample. Private correspondence with Abcor ^ recommended using 3.0 mL of the CSj solution for desorp tion.1211 Standards were prepared by injecting 43.3 mL of mix (13 X 10/3) into 10 mL of CSj. Two standards and four samples were run. Desorption efficiencies for the DuPont badges were determined by placing the collection elements into 2.0 mL mini-vials. 26 pL of the solvent mix was used to prepare each sample. Three standards and four samples were run. 3 M recommends that the CS2 solution be placed into their badges and samples be withdrawn directly. This method was difficult to reproduce and the desorption efficiencies deter mined were much higher than 100% due to the large amount of air space within the badge. To determine the desorption efficiencies for the 3M badge, the collection element was removed and placed into a 2.0 mL mini-vial. 3M recom mends the amount of solvent used be determined by the amount of solvent present in a 7-liter sample at one-half the TLV. This was determined to be equivalent to 9.1 /iL of the solvent mixture. The lowest overload value reported was 8.5 mg for hexane and the total for the 9.1 pL was 7.9 mg. Standards were prepared by injecting 60.7 pL of the solvent mix into 10 mL CS2. A 1.5 mL aliquot of the CS2 solution was used to desorb the elements, as recommended by 3M.` Three standards and three samples were run. For all analyses, the attenuation was adjusted for each compound to provide for a reasonable peak height. The desorption efficiencies which were determined are presented in Table 11. exposure procedures This study consisted of sixteen exposures, each run included duplicate sampling using both charcoal tubes and each of the three brands of passive monitors. Eight positions were selected within the chamber at the cross-sectional plane described above. Constraints were imposed that badges should be separated from each other and the walls by 15.2 cmi6 in.) and air velocity should equal or exceed 0.508 m/ s (100 fpm). This specific velocity was recommended in NIOSH's protocol for the evaluation of Compound Hexana Isopropanol Trichloroethylene Toluene TABLE 1 Chamber Stability Concentration (ppm) 17.0 0.5 (n=27) 13.6 0.6 (r=19) 14.3 04(n=34) 13.9 0.7 (n=35) 91 2(n=35) 76 = 2(n=3S) 89 = 2(n=23) 102 -- 2 (n=23) ,, TABLE II Desorption Efficiencies for Various Organic Vapor Monitors Compound Charcoal Tube Passive Monitors DuPont Abcor 3M Hexane Isopropanol Trichloroethylene Toluene 1.02 0.98 1.03 1.01 1.02 0.71 0.96 0.94 1.01 0.93 1.02 1.01 0.96 0.85 0.95 0.96 3M 111055MS Am. Ind. Hyg 4tsoc. J (42} December 1981 TABLE Ml Summary of Statistical Analysis Comparing Charcoal Tub vs. Passive Monitors'* DuPont Intercept Estimated Standard Intercept (a) Deviation Slope Estimated Standard to* Slope (b) Deviation * r1 Corrected t,c Hexane Isopropanol Trichloroethylene Toluene -0.136 -0.1179 0.1168 0.0159 0.137 0.0902 0.0412 0.0405 -1.00 -1.31 2.84 0.39 1.0568 1.1292 0.9478 0.9610 0.0791 0.0584 0.0276 0.0262 0.72 2.21 . -1.89 -- 1.49 0.903 0.952 0.984 0.986 Abcor Hexane Isopropanol Trichloroethylene Toluene 3M -0.215 0.396 0.1474 0.0191 0.100 0.130 0.0520 0.0328 -2.14 3.05s 2.83d 0.58 1.1210 0.8429 0.9140 0.9644 00602 0.0848 0.0357 0.0208 2.01 -1.85 -2.41D -1.71 - " 0.953 0.852 0.975 0.992 - Hexane Isopropanol Trichloroethylene Toluene -0.1514 -0.0437 0.0560 -0.0096 0.0900 0.0613 0.0303 0.0293 -1.68 -0.71 1.85 -0.33 1.0772 1.0009 0.9318 0.9811 0.0527 0.0367 0.0191 0.0190 1.46 0.02 . -3.57s -0.99 ' 0.956 0.975 0.992 0.993 n 20 20 20 20 18 18 18 18 20 20 20 20 AData were analyzed using the model log y = a + trlog x _ a--0 b S.D. a C _ b~ 1 *' ~ S.D. b "Statistically significant at p < .05 ^Statistically significant at p < .01 ' e dosimeters.1'01 Manufacturers' criteria establishes a um velocity exposure well below the velocity used in this study.1221 At two of the locations in the chamber, charcoal tubes were placed in a vertical position and tubing was run to the outside of the chamber to a vacuum pump. Critical orifices were made, calibrated, and installed in these lines to accu rately control the sampling rates of the charcoal tubes at 0.194 and 0.286 Lpm. A single charcoal tube was used at each position for the single solvent low concentration expo sures. two for the single solvent high concentration (three for isopropanol), and four for the mixed exposures. These char coal tubes were changed at regular intervals to prevent over loading and loss of sample. To ensure complete collection, four charcoal tubes were joined in series to sample during each of the two spiked exposures. Placement of the passive monitors at the other six posi tions was randomly determined prior to the first exposure and then held constant for subsequent exposures. The ratio nale for this was based on the previously determined uni formity of solvent concentration across the plane of exposure. The first four exposures were low concentration (approx imately 10 ppm), and of six hours duration: each exposure utilizing one of the four solvents from this study. To deter mine the required flows of organic solvents to the chamber '-cessary to achieve the desired concentrations, a series of i^feis was prepared. A curve was established which rela^^concentration to peak height and the appropriate peak height representing a 10 ppm concentration was deter American Industrial Hygiene Association JOURNAL (42) 12/81 mined. Flows to the chamber were adjusted until the sample obtained duplicated this peak. The standards used for this series of exposures were made at 5, 10. and 15 ppm. These standards were prepared by injecting solvents into cali brated. sealed 20 L pyrex bottles. This container was fitted with a 30.5 cm (12 in) stainless steel needle. A 1.0 mL Series A-2 Precision gas sampling syringe was used to sample these standards. The second four exposures were high concentration (approximately 100 ppm), and of six hours duration: each exposure utilizing one of the four solvents from this study. The procedure was the same as above, using standards of 50 and 100 ppm. The third series consisted of six exposures. Each exposure was six hours in duration, with two solvents at the low concentration and two solvents at the high concentration. All six possible combinations were used. Flows were set using the volume which best reflected the above single sol vent exposures on the differential orifice manometers. Standards wpre made at 10 and 100 ppm for this series. Two final exposures were conducted to evaluate the effect of a short interval, high solvent concentration on a generally low background concentration exposure sequence since it was considered that the time of the spike might influence the apparent performance of the passive monitors relative to the performance of the charcoal tubes. These exposures involved subjecting the monitors for six hours to all four solvents at a low background level on which a spiked concentration was imposed for 36 minutes. The first of these exposures 3M 111056 MS involved spiking one hourafter the start of the run while the second exposure involved spiking just prior to the last hour of the run. Solvent concentrations for both the background jnd spike were established solely by consideration of total Monitor loading to preclude saturation. These concentra tions were in the range of 10 and 100 ppm. respectively. calculations Exposures were conducted in the four groups as mentioned in the exposure procedures section. The exposed charcoal tubes and monitors were removed immediately from the chamber after the six-hour exposure, sealed according to the appropriate manufacturer's instructions, and refrigerated at 2-4 C for up to two weeks prior to analysis. After each group of exposures had been completed, the samples were analyzed using the procedures previously described. Samples were analyzed three to five times each and averaged to reduce possible error. A series of standards was prepared in concentrations spanning the range of load ings for each monitor and analyzed each" day with the samples. _ "~ For each day of analysis, a curve relating chromato graphic peak height to concentration-of the standards was determined by linear regression with the restriction the line must pass through the origin. There were several reasons for this restriction. Theoretically, the curve should pass through this point and the higher the concentration of the standards the more accurately the standard could be made. Also, when I|ertain combinations of two solvents at high concentration and two at low concentration occurred, attenuation could not be adjusted to give a large peak for all four compounds because of dramatic shifting in the baseline. Peaks smaller in size but with a stable baseline were preferred. For smaller peaks, a small change in the v-intercept could cause a large change in the calculated value for the monitor. This limita tion was most pronounced for Abcor'sand 3M's monitors because of the lower loadings and larger amounts of carbon disulfide used to desorb the samples. Calculations to deter mine average exposures in ppm were carried out using the equations supplied by each manufacturer. TABLE IV Comparison of Results by Chamber Position Compound Charcoal Tube DuPont Monitor 4>2a n p Value" 6>3` n p Value" Hexane 6 10 .754 Isopropanol 4 10 .754 Trichloroethylene 4 10 .754 Toluene *v 6 10 .754 0 9 0.004 0 9 0.004 0 9 0.004 1 9 0.039 ANumber of exposures where the value at position 4 was greater than the value at position 2. 'Two-tailed sign test. ' Number of exposures where the value at position 6 was greater than the value at position 3. statistical analyses Separate comparison was made between the average of the charcoal tube values and each of the values from both of the passive monitors. Linear regression was used to compare the data. The model: log y = a+b log x was chosen, with y reflecting data from the charcoal tubes and x reflecting data from the passive monitors. As the concentration of a solvent increased the absolute variation also increased. By the use of logarithms, this phenomenon became more pronounced. Zero values were omitted for this analysis. The results of these calculations are shown in Table III. Separate compari sons were made between the average of the charcoal tube values and the higher value in each pair of values for the passive monitors and then repeated using the lower value of each pair. These sets of analyses gave results similar to the analysis encompassing all the data. Values for the charcoal tubes and DuPont's monitors were tested to determine if chamber position affected sampler performance. This determination was made using the sign test. The results of this arc presented in Table IV. results Table I shows the results of testing the stability of the solvent atmospheres generated for the exposure chamber. Temperature, relative humidity and barometric pressure were monitored for the sixteen exposures in this study. Mean values for these chamber parameters were: tempera ture 23.2 "C (with a standard deviation of 1.1 C). 46^ relative humidity (with a standard deviation of 7%), and 752 mm Hg barometric pressure (with a standard deviation of 3 mm Hg). The results of determining desorption efficiencies are presented in Table II. Comparison of individual passive monitor performance to charcoal tube performance is pre sented in Table III, Comparison of results by chamber posi tion are presented in Table IV. Data for the series of the sixteen exposures which were used in the statistical analysis of this paper can be found in Appendix '`A" of the unpub lished master's thesis.'21' discussion Chamber atmospheres were monitored for six hours for each solvent at both low and high concentrations to deter mine the temporal stability of the system. The results are presented in Table I. Absolute variability increased as the concentration increased while relative variability remained within 59c- Results of the preliminary studies on the planar uniformity of atmospheres are indicative of the performance of these chambers, the design of which has been used rou tinely in toxicology investigations for over 30 years. The results demonstrated by this investigation show the feasibil ity and desirability of generating organic solvent atmo spheres for exposure chambers by the system described in this study. Desorption efficiencies were determined for each solvent for each monitoring device and are presented in Table 11. Desorption efficiencies determined on charcoal tubes were 3M 111057850 Am Inn. Hyt. Assoc. J!42) December 1981 individually compared against those determined in a matrix and no significant difference was found. This finding had been reported earlier.'61 The desorption efficiencies for U the passive monitors were determined for all solts simultaneously, )esorption efficiencies for DuPont were run twice to confirm the low desorption efficiency determined for iso propanol. Seventy-one percent was determined each time and was accepted because of its reproducibility. Determination of desorption efficiencies for the 3 M moni tors was attempted twice using the 3M recommended method. Results were consistently above 100*^ recovery. No problems were experienced when the charcoal pads were removed from the badges and analyzed in 2 mL vials. In cases where there are solvents at both high and low concentrations* it is difficult to change attenuation on the gas chromatograph to give a large peak due to dramatic shifting in the baseline. This limitation was most pro nounced for Abcor's and 3 M's monitors due to the lower loadings and larger amounts of carbon disulfide used. Load ings. because of higher concentrations of other solvents, could not be increased without overloading the monitors. Since the peaks for some of the compounds were small, a change in the y-intercept could cause a large change in the value calculated for the monitor. Therefore, the standard curves were calculated with the restriction that the curve pass through the origin. Theoretically, the line should pass through this point. In addition, standards prepared at low vncentrations could not be made with as much accuracy as at higher concentrations. This made it difficult to fmine where the curve should pass at the lower end of these curves. Because of the problems encountered with solvents at these lower concentrations it is suggested that smaller amounts of carbon disulfide be used for desorption. The slight increase in desorption efficiency does not appear to outweigh the disadvantage of smaller peaks. - Difficulties were also encountered at lower concentrations with the quantification of isopropanoi due to a severe inter ference by carbon disulfide which made baseline determina tions difficult. If this problem is expected, analysis by a different chromatographic column, which will give better resolution, is recommended. Exposures within the chamber were all conducted with air velocities in excess of 0.508 m/s (100 fpm) as is recom mended by NIOSH, DuPont stated that for the testing of their Pro-Tek organic vapor monitors, their badges were more sensitive to inadequate face velocities than Abcor's or 3M's monitors.121' For this reason. DuPont's badges were placed at the two positions with the highest velocity. One position averaged 0.762 ml s (150 fpm) and the other posi tion averaged 0,635 m/s (125 fpm). No difference was expected since DuPont stated these monitors were cali brated to accurately measure between 0.169 mi s and 2.032 ^K35 to 400 fpm). After analysis of the first four expo- a noticable difference in values was observed. Posi tions of the DuPont monitors were recorded for the last 4mncan Industrial Hyfieno Association JOURNAL Wl 12/81 twelve exposures. Results by position were compared for charcoal tubes and the DuPont monitors. These results are presented in Table IV. It is clear that there is no significant difference in positions for the charcoal tubes while there is a significant difference in position demonstrated for the DuPont monitors. It appears that these monitors are sensi tive to differences in velocities of the surrounding air since all other variables were kept constant at both positions. These monitors, unlike Abcor's and 3M's monitors, do not have a draft shield. This could explain the difference in monitor performance. It is also possible that chamber concentration at these locations varied since they were not monitored during actual exposures. Data previously presented on uni formity of solvent concentration within the chamber mini mize this as a possible explanation. It should be emphasized that positions were not recorded for the Abcor and 3M monitors and therfore similar comparisons could not be made. Comparison of monitor performance to charcoal tube performance is the most widely recognized method for vali dation of passive monitors. Comparison was made usingthe model: log y = a+b log x where the v value was the average value for the charcoal tubes which was paired against each of the values calculated from the passive monitors for the same exposure. This series is summarized in Table III. Compari son was repeated using the average value for the charcoal tubes and the higher value in each pair for each organic monitor. Comparison was made substituting the lower values for the higher. Little difference was noted for these three series of analysis which demonstrated both organic vapor monitors and charcoal tubes would give a good representation of theexposure. Table III shows that all three brands of passive monitors should be considered an accept able alternative to the recognized charcoal tube method. All three companies' monitors had y-intercepts close to the origin. For the determination of higher concentrations closer to the TWA's of these compounds, the slope of the regression line becomes increasingly important. While all three companies' monitors have fairly good correlations with the results from the charcoal tubes. 3 M *s monitor gave the best slope in two out of four cases and showed the smallest variation every time as is demonstrated by examina tion of the standard deviation. 3M's monitor did not per form as well as DuPont's monitor for trichloroethylene and hexane. A poor correlation between charcoal tubes and Abcor's monitors pertaining to isopropanol could be due to problems with baseline determination discussed earlier. conclusions 1. Under conditions similar to those of this study, DuPont's. Abcor's. and 3M's passive organic vapor monitors are an acceptable alternate to the charcoal tube method for assessment of a worker's exposure to organic solvents, as is demonstrated by the good correlation between each monitor with the results obtained by the charcoal tubes. 2. Significant differences between monitor perfor mance were noted for DuPont's monitors. Sensitiv 3M 111058 ity to velocities surrounding the monitor is suspected as the reason. ' 3. _ When isopropanol is monitored at low concentra tions. especially in the presence of high concentra tions of other compounds, selection of chromatographic columns becomes important if one wishes to minimize interference by carbon disulfide. 4. Analysis of 3M's monitors is improved by removing the charcoal pad and placing it into a 2 ml septum capped vial. 5. Desorption efficiencies can be determined for sev eral solvents simultaneously with no significant dif ference over determination of each solvent individu ally. provided the charcoal device is not over-loaded with solvents. 6. The exposure system, including the organic solvent generation system described in this paper, is recom mended as a significant improvement over pre viously reported exposure techniques for the deter mination of monitor performance. It should be emphasized that this study was a laboratory controlled experiment which, while examining several important parameters, kept several other equally important parameters constant. The conclusions drawn in this paper should only be considered valid when the conditions of exposure have been met. This is the first of what should be a series of studies which need to be conducted to verify whether these conclusions can be extended to ^^onditions such as elevated relative humidity and extremes temperature. . references 1. NIOSH: Manual of Analytical Methods. 2nd Ed.: P and CAM 127, Organic Solvents in Air. OHEW (NIOSH) Publication No. 77-157. Cincinnati. OH (1977). 2. NIOSH: Manual of Analytical Methods. 2nd Ed.: Method S65, Isopropyl Alcohol. DHEW (NIOSH). Publication No. 77 157, Cincinnati, OH (1977). 3. NIOSH: Manual of Analytical Methods. 2nd Ed.: Method S90, Hexane. OHEW (NIOSH) Publication No. 77-157, Cincinnati. OH (1977). 4. NIOSH: Manual of Analytical Methods. 2nd Ed.: Method S336, Trichloroethylene. DHEW (NIOSH) Publication No. 77 157, Cincinnati. OH (1977). 5. NIOSH: Manual of Analytical Methods. 2nd Ed.: Method S343, Toluene. OHEW (NIOSH) Publication No. 77-157, Cincinnati. OH (1977). 6. White. L.D.. O.G. Taylor. P.A. Mauer and R.E. Kupel: A Convenient Optimized Method for the Analysis of Selected Solvent Vapors in the Industrial Atmosphere. Am. Ind. Hyg. Assoc. J. 31:225-232 (1970). 7. Mueller. P.X. and J.A. Miller: Determination of Airborne Organic Vapor Mixtures using Charcoal Tubes. Am. Ind. Hyg. Assoc. J. 40:380-386 (1979). 8. Saalwaechter. A.T.. C.S. McCammon. Jr.. C.P. Roper and K.S. Carlberg: Performance Testing of the NIOSH Char coal Tube Technique for the Determination of Air Concentra tions of Organic Vapors. Am. Ind. Hyg. Assoc. J. 38:476- 486(1977). 9. Larkin, R.L., J.V. Crable. L.R. Catlett and M.J. Seymour: Collaborative Testing of a Gas Chromatographic Charcoal Tube Method for Seven Organic Solvents. Am. Ind. Hyg. Assoc. J. 38:543-553 (1977). 10. Mindrup. R.F.: Determination of Organic Vapors in the Industrial Atmosphere. Bulletin 769A. Supelco. Inc. Bellefonte. PA (1977). 11. Boeniger. M.F., D.O. Zaebst. H.R. Ludwig, M.S. Crandall and P. Vongrongsemon: A Field Comparison of Two Passive Organic Vapor Monitors with Charcoal Tubes Under Singular and Multiple Exposure Conditions. Presented at the 19th Annual American Industrial Hygiene Conference Chicago (May. 1979). 12. Mazur. J.F.. G.E. Podolak, G.G. Esposito. D.S. Rinehart and R.E. Glenn: Evaluation of a Passive Oosimeter for Col lection of 2-bromo-2-chloro-1,1,1-trifluoroethane and 2- chlor - 1,1,2-trifluoroethyl difluoromethyl ether irV Hospital Operating Rooms. Presented at the 19th Annual American Industrial Hygiene Conference Chicago (May, 1979). 13. Tompkins, F.C.. Jr. and R.L. Goldsmith: A'New Personal Dosimeter for the Monitoring of Industrial Pollutants. Am. Ind. Hyg. Assoc. J. 38:371 -377 (1977). `` 14. Bamberger. R.L.. G.G. Esposito. B.W. Jacobs. G.E. Podolak and J.F. Mazur: A New Personal Sampler for Organic Vapors. Am. Ind. Hyg. Assoc. J. 39:701 -708 (1978). 15. Calvo. D.J.: Laboratory Performance of Passive Personal Samplers for Organic Vapors in the Presence of Adsorptively- Competing Solvents. Presented at the 19th Annual American industrial Hygiene Conference Chicago (May. 1979). 16. National Academy of Sciences: Principles and Procedures for Evaluating the Toxicity of Household Substances, pp. 61-69. Washington, D.C. (1977). 17. Silver. S.D.: Constant Flow Gassing Chambers: Principles Influencing Design and Operation. J. Lab. Clin. Med. 3/ :1153-1161 (1946). 18. Nelson. G.O.: Controlled Test Atmospheres Principles and ' Techniques, pp. 147, 217-219, Ann Arbor Science Publish ers. Ann Arbor (1971). 19. Hagmann, E.L.: Generation of Standard Reference Organic Solvent Samples by the Vapor Saturation Method. Presented at the 19th Annual American Industrial Hygiene Conference - Chicago (May, 1979). 20. NIOSH: Contract 210-78-0115. 21. Voeite. D.R.: A Dynamic-flow Chamber Comparison of Three Passive Organic Vapor Monitors with Charcoal Tubes under Single and Multiple Solvent Exposure Conditions. Unpublished Master's Thesis. The University of Texas School of Public Health. Houston. Texas (1980). 22. E.I. DuPont de Nemours and Company, Inc.: Technical Bulletin No. 1: Laboratory and Field Testing of the Organic Vapor G-AA Badge. Wilmington, Delaware (1979). 3H 111059 ssz Am Ind. Hyg Assoc. J (42) December. 1981 Am Ind Hyg Assoc. J 43(8) 605-621 (1982) The history of development and validation testing of passive dosimeters is reviewed. Theoretical consideration including possible limiting factors or interferences, are presented. Laboratory and field validation tests at critically reviewed and results ar presented for comparative purposes. Evaluation of available data indicates th; passive dosimetry, with some exceptions, is an acceptable method for monitoring gasses and vapors. Mo importantly, passive systems appear to be as reliable as the now accepted active sampling systems. Passive dosimetry -- state of the art review VERNON E. ROSE and JIMMY L PERKINS ' School of Public Health. University of Alabama m Birmingham. Birmingham. AL 35294 introduction Recognition. evaluation and control arc the cornerstone;* of the application of that mixture ol science and art know n as industrial hygiene. These three tasks, howcv er. are no longer the eminent domain of the industrial hygienist. In the past decade, a proliferation of training in the recognition of workplace hazards has been made widely available to workers and management alike. At the other end of the spccti um has been the training of indi\ iduals highly special ised in (he conirol of specific hazards, especially those in\ ol\ mg noise and toxic air contaminants. These dexclopments are w clcomed because they contribute significantly to the ultimate goal of protecting the health of workers by providing safer and more healthful workplaces. At the same time, professional industrial hygienists rec ognize that often the critical step in the process is not recog nition of toxicity , but evaluation of hazard which leads to the subsequent development of the most effective means of control where warranted. This key step of evaluation is the unique domain of the industrial hygienist, often supple mented by other members of the occupational hcaiih and safety team. Where evaluation requires the determination of w orkcr exposure to airborne toxic substances, the industrial hygienist has seen a rev olution in the development of sophis ticated techniques and equipment. The "organ-grinder" impinger sampler is a relic, having been replaced by constant flow, eight-hour battery-operated pumps, light enough to be carried by the worker. The liquid buhbler and impingcr have been replaced by the charcoal and chemical substrate sampling tube. The laboratory has come to the field in the form of the portable gas chromato graph and infrared monitor, albeit with a price rise directly proportional to the sophistication of the equipment. Even the once lowly, direct-reading detector tube has become legitimate with the establishment of government programs to certify accuracy and precision. But while most evaluation techniques were reaching the point w here the industrial hygiene staff required the addition of someone with a Ph.D. in electrical engineering, a new device has appeared which has the key of simplicity -- the Co0v"0h> 1982 Aw***n can Indu&lw1 Hyg*pnp Association jQURNAt (43} 8 82 personal passive dosimeter: personal, because it can he wo: by the worker in close proximity to the breathing /onv passive, because there is no pump to move the air over collector, which equates to fewer calibration and m.iinu nance problems. Some quarrel with the term dosimeter, wit purists preferring to call them collectors, monitors, o samplers. While many of the devices are collectors an require the application of subsequent analytical proced tire others prov ide for a more direct measurement of "c.xpo'-ur dose." Their basic appeal, however, is simplicity ol U'i Theoretically, elaborate calibration procedures are unnecesary. and all that is needed is a fairly reliable timepiece t measure exposure duration. There is some recognition the temperature and humidity may affect the observationtherefore, most manufacturers advise the user to report thev environmental conditions to the analytical laboratory pro cessing the dosimeter. Rather than vieu ing passive dosimeters as another wav t. replace the industrial hygienist, industrial hygieniMs mis recognize and appreciate the potential of the dosimeter' u helping to achieve the hygienists' goals. That potential 1 significant in that personal dosimeters, if properly ii-cd offer the opportunity to revolutionize the evaluation step The parallels with detector tubes, as well as with noise am ionizing radiation dosimeters, are obvious. Indeed, th parallel with radiation dosimeters, especially Him badge*, t striking. The opportunity to significantly expand the me.i surement of worker exposure to many toxic material' ca: provide a quantum leap in our ability to provide 'ale ar. healthful workplaces. With any sampling device, however There also must be the understanding that use ol such dev ice is only one part of the evaluation step. The concept' o proper selection of workers at risk: the understanding o limitations, interferences and similar factors, and ultimate! the proper interpretation of the results ate still, key ingr. dients in the evaluation step. 1 he possibility ol "tal'C ncg. live" decisions leading to erroneous assumptions ol sale: , or "false positive" conclusions leading ttv unwarranted expenditures of resources lor controls, 'till exists tegardlc'- of the measurement device used. ` A$*wrUMv' 3M 111060 6C With the rapid proliferation of passive dosimeters in the past several years, it is appropriate that industrial hygienists - evaluate the "state-of-the-an"and. as professionals, become involved with the proper application of these monitor- di evices. theori s of operation In that passive dosimeters by definition do not use an air mov ing dev ice to transport contaminated air to a collector, natural forces are relied upon to ensure that a representative amount of contaminant is "seen'* by the detector. To date, one of two principles has been applied in the design of dosimeters. The first, and most widely used, is the principle of diffusion of contaminant molecules through a stagnant gas (air) laser. The second principle involves the absorption in and subsequent pemwation of contaminant molecules through a membrane. Diffusional monitors rely on the movement ol contami nant molecules across a concentration gradient which for steady-state conditions, can be defined by Kick's first l aw of Diflusion 111 \\ = -IlA=dci d\ (1) where: Vi' = mass transfer rale, ng see. D = diffusion cuetficient. cm"' sec. A = cross sectional area of diflusion path. cm', and dc dv = the instantaneous rate of change in concentra tion over diffusion path, (ng cnv'jcm '. ^^honsidering the change in concentration (Ci -- C) over the total dillusion path length (Xi -- X,. = --I.), equation ( I) becomes. A w = n -- tCi - c.) (2) where. 1. = length ol the dillusion (static) path. cm. Ci = ambient concentration of contaminant, ng cm'. and Ci. = concentration of contaminant at collecting sur face. ng cm1. (I an effective collection medium is employ ed. the contam inant concentration at the surface of the collector (Cn) can be assumed to be zero, and multiply ing both sides of equation ( 2) by time, v iclds m = n --ten (3) where: M = total mass transferred, ng. and t = time that the badge is exposed to the contami nated air. sec. It is also interesting to note that the units of the product of md A. div ided by 1. are cm1 sec. w hich are the same units oeiated with active air-moving devices such as personal sampling pumps. 606 Rearranging equation (3) as follows: ' r Ml 1 DAt it becomes apparent that live lactorsalfect the measurement of theambient airconcentration ofa substancc(C i) 7 wu at the factors (l and A) arc physical parameters associated with the construction of the dosimeter, one ( M) is pros ided by measuring the total mass of contaminant collected bv the sampler, another is the duration (t) the sampler was exposed to the contaminated atmosphere, and the final factor ([>i i,, an individual property of each vapor or gas. It also iknown1" that the diflusion coefficient is directly propmtional to the absolute temperature (T) of the vapor, raised to three-halves power and inversely proportional to the atmo spheric pressure (P). Dosimeters that rely on the principle of pcrmcoiinn through a membrane are especially useful vv here the contam inant of concern is usually found mixed with other interim ing vapors or gases or when a liquid collecting medium is employed. The goal then becomes to identify a membrane material that is highly permeable to the contaminant ol interest and impermeable to most other components in the atmosphere, and or the collecting media. The determination of ambient concentrations of a con taminant using a permeation dev ice can be determined Iron, the formula: C = wk t (6) where: C = concentration of contaminant, ppm. vv = mass of contaminant collected, pa. k = permeation constant, ppm-hours pa. and t -- exposure time, hours. The permeation constant (k) is determined experimentally and is a function of the specific membrane maierial and contaminant ol interest. sources of measurement error The most obv ious sources of error for both ty pes of passive dosimeters are apparent from equations (4) and (6). Com mon to both badges are determinations of the mass of con taminant collected and the time of exposure of the dosimeter to the contaminated atmosphere. For the diffusional moni tor, accurate knowledge of the physical parameters asso ciated with badge construction (length and cross-sectional area) and the diffusion coefficient of the contaminant are important. There arc at least nine prediction methods for calculating the diffusion coefficient, and in one study com paring observed and expected values for more than 100 compounds it was not uncommon to have less than 50 percent of the calculated results within 5 percent of the observ ed.13' Montalv o has described a procedure tor limiting errors associated w ith computed diffusion coefficients. At Am Ind Hy( Assoc J (A3) JuCui: l9 3H 111061 least one manufacturer, the ? M Company, makes available its procedures for determining sampling rates (DA. L) for its badges.' " Its approach has been to experimentally determine the sampling rate for foe or six compounds in a chemical family to establish the relationship between the diffusion coefficient and the measured sampling rates. Sampling rates for other compounds are determined from the diffusion coefficients calculated by the Hirschfeldcr equation and the empirical relationships developed from the test compounds. The rationale for the selection of the Hirschfeldcr equation is not given, but in the study of the nine diffusion coefficient formulas, the author concluded that for higher molecular weight compounds the Hirschlelder. Biard and Spat/ equa tions were in closest agreement with determined values.131 Ku the permeation monitor, accurate determination o( the permeation coetticient lor each monitor is neccssarv for obtaining accurate results. Factors influencing permeation include: thickness and uniformity ol the membrane, affinitv ot the membrane lor the analyte, swelling or shrinkage of the niemhiane. and possible etching by corrosive chemicals. Considering temperature and pressure, and referring u equation (5) it can be shown that a temperature rise from 5 it 35 C would give a 16 percent increase in the diflusior coefficient, while a rise in barometric pressure Irom 710 tv 810 mm Hg would cause a 14 percent decrease. " However at the same time, the changes in temperature and pressure also arc affecting the concentration (mass v olume: actually density i.x the proper term but most authors use concentra tion) of the contaminant in that concentration is inversely proportional to the temperature and directly proportional tc the pressure. As a result, the total mass (M) collected by the dosimeter is only slightly affected by temperature ( Mai1' and is independent of the pressure."1 Consequently. w hile a i ambient temperatures, the diffusion coefficient will increase about 0 5 percent pcrC. and the total mass collected hy rlu sampler will increase less than 0,2 percent per (\ Therclorc a temperature change from 25 to 30 C. if uncot reeled, wi! introduce a measurement error of less than one percent while a change from 5 to 35 C, if uncorrceted. woulc introduce an error of about five percent. 1 he ptohlems associated with accurate determinations of The final source of error to consider is the velocity ol the the mass ol the contaminant collected arc similat to those involved with other collection devices such as charcoal or air external to the dosimeter: often this is referred to as lace velocity. In an early assessment of face velocity eflccts. espe silica gel tubes, or to those in which the collection of the cially the lack thereof. Tompkins and Goldsmith point ou; contaminant inv olves a chemical reaction with thccolleciion medium. I sing known amounts or concentrations of con that the important consideration is to contain all resistance tocontaminant transport within thestagnant air layer inside taminants to determine collection and or desorption effi the device."1 As Jonas el at. subsequently noted, the lace ciencies is as criiicaI a step lor passivc dosimeters as it is for velocity directly aflects the concentration gradient C ;--C> in other methods ol collection Saturation of the sorbent as equation (2). and Ci can no longer be assumed to he the well as the subsequent accuracy ol analy tical techniques are ambient concentration when the air external to the badge i* also part of the total error associated w ith the measurement. stagnant.'61 With zero or low face velocities, the length (I ) ol Another common concern in all types of environmental the diffusion pathway is effectively extended, and there i* I measurements is the potential lor interferences, cither posi tive or negativ e. I rum other contaminants in the sampled air. a decrease in the measured ambient concentration. In Tompkins' and Goldsmith's work with the GASBADCif'". As the evaluation ol passive dosimeters has matured, they determined experimentally that as long as lace veloci increased attention is being paid to possible interferences in multi-contaminant exposure situations, in both the labora ties were greater than 7.5 cm see (15 fpm) there was "no significant effect on dosimeter response:" however, experi tory and lield. In evaluating such interferences it should be mental results supporting this conclusion were not pre- recognized that there are several potential sites for such sented."1 High face velocities may also affect the concentra 1 interferences to appear, c.g.. cllects on adsorption or absorption efficiency ol the sampling medium, chemical tion gradient. Commercially available diffusion device* rely on either a large ratio of diffusion path length to delu i cautions of tw o or more contaminants prior to analysis, and sion tube diameter or a wind screen to limit error* Irom 1 the multitude of interferences associated with analysis of complex mixtures of gases and or vapors. These problems this condition. One of the most comprehensive tc*ts to document source* also arc lound in the more classical sampling and analyti of error has been conducted under contract lor the Nationa I cal methods. Accurate measurement of the time the sampling device is Institute for Occupational Safety and Health, and although concluded, it is not yet available as a public report The exposed, is essential to most industrial hygiene sampling study involved evaluation of the GASBADGF and 3M Organic Vapor Monitor'" (the DuPont badge not being 1 procedures. For both short-term and full-shift exposure measurements, errors less than one percent, i.e. 9 seconds in available at the time the study was initiated! via challenge with several organic vapors. The lactor* investigated were 15 minutes and 4.8 minutes over 8 hours, are not unreason precision, effects of storage, maximum and minimum level* a able goals. For the diftusion coefficient and possibly the permeation of quantification, face velocity eflect*. etleet* ol temperature and humiditv. off-gas*mg (related to storage!, exposure to constant, it w ould appear that three factors have the greatest mixtures, problems associated with applicable analytical eflect on variability . These taciorsare the twoalready identi methods, and adsorption ol the contaminant by the badge fied. temperature and pressure, and. less readily apparent, itself with subsequent leaching to the sensing surface. The the velocity of the air external to the badges. possibility of adsorption by the badge body, thu* giving i Ameiicar industm. A*soc>ai'On JOURNAl 1/3) 8 S? 3H 111062 s; higher results if the contaminant is subsequently released to the active medium, is of special concern in using passive concentrations. In this case the error in the instrument can be calculated or estimated. Charcoal tubes and critical ori dosimeters to measure very low ambient concentrations fices also have been used to measure "known" concentra such as might be found in air pollution studies. Such interest tions. If error in both the "known" concentration and the concern are evidenced by research on the subject being estimated concentration are considered, statistical tests used |sored bv the U S. Environmental Protection Agency to validate the experimental method become considerablv Vi "" Because of the lower concentrations involved with more complicated: hence, the error in measuring the "known" air pollution studies as opposed to w orkplace env ironments. concentration is usually assumed to be small and unimpor- the EPA also is concerned with the background or post manufacture contamination levels associated with the sens ing medium. Initially. the focus concerns organics and activ ated charcoal. In summary, although numerous factors may affect the lina! calculation ol concentration, only face velocity and the determination ol the diflusion coefficient are unique sources ol error for passive collectors. Therefore, if face velocities are sufficient to prevent "starvation"(probahly greater than 7.5 cm sec) and if diffusion coefficients have been accurately calculated or ex peri mentally determined, passive dosimeters should giv e results comparable to those obtained w ith tradiional active sampling systems. tant.191 Methods described above fordeterminint the "know n" concentration vary in their accuracy, a fact which should he considered when evaluating validation data for any sam pling and analytical method. When one is validating a method in the laboratory, there are two main considerations: the variation of the samples or data points about their mean, and the deviation of the sam ple mean from the true mean or"know^"concentration. The first consideration often is called precision and is probably the most important and reliable measure as it does not depend on the error in determining the "known"conccntration. Precision is estimated by determining the coefficient ol variation (CV) or relative standard deviation of the data set statistical considerations as follows: In evaluatingany new monitoring method, extensive laboraory and field testing is necessary. Interpretation of the CV = -^-X 100 (7) . esults of these tests requires the application of appropriate statistical techniques. The use of statistical techniques which ire meaningful and easily understood is important: conse where: s = Standard deviation of sample data set. and X = Mean of sample data set. quently. a discussion of the techniques used to evaluate ive dosimeters is appropriate. here are numerous statistical tests which can be applied oth field and laboratory validation data. The main diference between the two situations is the degree of certainty of the "true" concentration of the monitored environment, in the field, the true value is usually an estimate based on the esults of a standard sampling and analy tical method. In the ahoratory. experimental "know n"concentrations areev olved and are then used for comparison with thc'concentrations estimated from sampling and analytical methods. What is often not stated is that a certain amount of error also exists m the determination of laboratory-evolved "known" concentrations. These errors are often difficult to estimate. The "known"concentration is often calculated by weighing a syringe before and after an injection period (mass valance) or simply by injecting or allowing to diffuse a neaxured volume. It is assumed that the aliquot delivered vav v aporized or diffused into a test chamber of known size. Possible sources of error include adsorption to or leaks from .he test chamber, absorption and adsorption to articles placed in the chamber, degradation of the analyte by air oxidation or hydrolysis at high relative humidities, and error in measuring the injected contaminant. A backup monitor ing system may be used to ensure close proximity to the `known "concent i at i on. For example, an infia-red (1R) ana- y/cr or gas chromatograph may be used as a check on a ^inun" concentration Hn other instances an 1R analyzer or a direct reading instrument may be the only method fordetermining"known" Where samples arc taken at several concentrations, it is necessary to determine a pooled coefficient of variation which involves determination of number of levels tested.' ' It should be noted that determining the number of concen trations (or more appropriately, the number of statistical levels) is not always straightforward. For example, if 10 samples are taken at each of three concentrations, and if within each concentration five of the samples are collected over four hours while the other five are collected over eight hours, are there three levels or six levels? The important point to consider is whether the differentiation of a level is based upon an anticipated difference in the sample mean. Certainly if the investigator designs the experiment with different time levels, there is an anticipated effect of time on the mean. Unfortunately, when experiments are so designed, statistical analyses at the various levels usually are not performed. The second statistical consideration, the difference between the sample mean and the "known" value, is sometimes called accuracy, but the term bias is more appropriate. It is defined as: b=x_XoX)oo Xn |8) w here; X = mean of sample data set. and Xo = "known" value at level tested. If more than one level is sampled, it is necessary to determine the pooled bias of the data set.111' .01 Am Ind Hyi Ajjoc J (431 Aufuil 19S. 3M 111063 The bins for a given set of data can sometimes be cor rected. If the average bias (either the average of several samples at one level or the pooled bias for several levels) is large, one should note if the components of the bias value (either the indiv idual samples or the levels) are consistently negative or positive. If the bias is large and varies consis tently in one direction, the precision nevertheless may be quite small In this case a physical or chemical variable may be consistently affecting the method (a systematic as opposed to random error), causing the experimental values to con stant^ fall short or long of the "know^"concentration. This form of bias should be corrected. In addition to these statistical tests, others have been used to assess the validity of passive monitoring systems. Overall system accuracy"1' has been defined as (2 X CV) + absolute bias, express'd as a percent. Others'1'1 have used the percent age of the "known" concentration accounted for by the sample mean i two standard deviations as well as the term systematic error"31*1 which is equivalent to overall svstem accuracy. Relative standard deviation has also been used, and is defined as the equivalent of CV.'1'1 Additionally, some authors report only raw data while others report means without standard deviations or sample sizes, and various other combinations. While all of these statistical determina tions have utility, it seems important for comparative pur poses to consistently use those determinations which give the most information in the simplest form. Certainly , bias and precision meet these criteria. Discussion ot one other point seems necessary. NIOSH1101 has proposed as a guideline for their own internal purposes that sampling and analytical methods meet a minimum requirement of 25 percent accuracy, that is. the absolute total error of the method should be less than 25 percent in at least 95 percent of the sample population (assuming a nor mal distribution). NIOSH derives the maximum precision value for an unbiased method given the accuracy criteria stated. This value (12.8 percent) is the maximum precision value acceptable for an unbiased method. Although the 25 percent accuracy criterion has been critici7ed by some authors."6' it was adopted for NIOSH'sown internal use and is not meant as public policy. However. OSHA adopted the same criterion for the ben/cnc standard, w ithout a complete derivation or explanation. Consequently; this criterion has been criticized and alternatives have been proposed.'1" A second important point is that bias is also considered in the 25 percent criterion according to a somewhat complex statistical relationship,'10' but the overall sy stem accuracy as defined earlier"" is a fair approximation if the method has a true bias, i.e., its mean is statistically different from the "known concentration." A final point is that as the number of samples at a level increases, the standard deviation and CV should decrease These considerations are important when evaluating passive monitor validation data, especially in those cases where manufacturers have stated that they have met the 25 percent accuracy criterion. For field comparisons of conventional and passive moni tors. different statistical tests are necessary. If passive moni tor values, for example, arc plotted against charcoal tube American industoat H>$>ene Association JOURNAL fO 8 82 results (Y vs. X) and more than one concentration is sampled, one would expect an increase in X to cause an increase in Y. If the increase is linear, and the sample values lie on the regression line, the correlation coefficient (r) would have a value of one. If a change in X brings about an equal change in Y. then the slope would also have a value of one. If the individual values for the two devices arc indeed equiva lent. the line should intercept the origin. Each of these rela tionships is expected within reason. The difference of the slop from one. the correlation coefficient from one. and the intercept from zero can and should be tested. In order to perform the regression analysis described above we must assume that X (active sampling data) is not subject to error. Of course, we know and can calculate under laboratory conditions the error of active sampling systems There are at least three reasons why this error is often overlooked. First, it is assumed that consideration oi the error in X would only cause small difierences in regression analysis results. Second, in addition to laboratory demon strated error, a range of errors introduced by vary ing env i ronmental conditions must be considered. While difficult to assess, these errors may have a profound effect on X, and indeed the error in the X measurement may be as great or greater than that for Y. Finally, if the error in X is to be considered the statistical tests are complex. Such tests have been discussed for biological problems;'10' however, the the ories apparently have not been applied to sampling and analytical methods even though their appropriateness has been recognized."*" applications From a historical vantage, one of the earliest reports of a "passive" monitor for evaluation of airborne contaminants was patented by Gordon and Lowe in 1921}'*'' Their gas detector for carbon monoxide involved an "easily frangible vessel containing a solution of salts including palladium chloride, and a covering for said vessel of a light colored absorbent material." The principle involved breaking the vessel (a small ampule) and noting the subsequent color change of the solution as it reacted with the carbon monox ide on the light colored absorbent material. This type ol semiquantitative device was certainly a forerunner ol those that are available today, though it was undoubtedly aflectcd by air velocity as a stagnant air layer was not employed An extension of Gordon and Lowe's concepts in the late I960's provided the basis for Plantz el al. to develop a personal dosimeter for measuring hydrazine, unsymmetrical dimethylhvdra7ine and monomethylhydrazine.1'1' The reaction'of these compounds with a "colorimetric substance" (bindone) produced a purple color, the intensity of which was dependent on both concentration and duration of expo sure. Color standards then were used to estimate the concen tration as a function of the time the badge was exposed to the contaminated air; consequently, the method was only semtquantitative. In considering sources of error the authors noted that the purple color would also be produced by all volatile bases that were tested, including ammonia, aliphatic amines, aniline and cigarette smoke. 3M 111064 609 Of interest in this review. however. are quantitative devices based on the principle of either gas or sapor diffu sion or permeation through a stagnant air layer. The first such dev ice to be reported in the literature was described by fi^nes and Gunnison in 197?.1221 Theirdcvice employed the ^^^ciple of gas diffusion to determine airborne concentra tions of sulfur dioxide and will receive further consideration subsequently To gain the best overv iew of the \ a rious appli cations of these concepts, it is probably best to proceed by considering first the inorganic and then organic gases and v apors. inorganic gases and vapors ammonia In 1978. Ma/ur ct at. described the use of the Abcor G AS BADGE to sample employee exposure to ammonia (this device currently is not marketed).'*'' The investigators replaced the charcoal pad nor mails found in the G AS BADGE with an acid impregnated absorption pad. Of three acids tested, phosphoric was most successful in prov iding the best approximation of theoretical concentrations. They deter mined. howevei. that v olatile amines, specifically cyclohexy Iamine. could produce high readings, as high as 185 percent of the synthetic atmosphere. This led them to replace the glass fiber draft shield on the front of the GAS BADGE with a "charcoal impregnated glass fiber filter which had been pretreated with alcoholic KOH containing 0.1 percent surlactant " The charcoal served to adsorb amines as they dif fused into the dosimeter, while the KOH (aided by the wetting agent) eliminated irreversible ammonia adsorption the charcoal, which would have caused underestimation the ambient concentration. Additional laboratory exper iments demonstrated that storage time of up to 47 days, pi ior to analy sis. did not appear to adv ersely affect the results. More recently. DuPont has developed a commercially available system lor the measurement ol several airborne contaminants including ammonia. In 1981. Kring cl al. described Du Pont\ PRO-TE kT" >y stem for ammonia, nitro gen dioxide and sulfur dioxide sampling analy sis using a col orimetric readout instrument.1*4 1 he ammonia badge relies on molecular diffusion of ammonia and subsequent chemical reaction w ith a solution of 0.3 N boric acid a nd 0.03N sodium potassium tartarate (\ic). After exposure, the reagent pack is removed from the badge holder and analysis is initiated by pre-smg reagent "blisters" w hich arc adjacent to the absorb ing solution This action causes the release of a modified Nes-ler's reagent and the subsequent development of a c c red solution. For ammonia, ma ximum color intensity is dev eloped at 425 nanometers. The absorbance of the sample is then compared against a standard curve based on Beer's l aw After determination of the precision of the analy tical method and verification of the linear range of the color ehenustrv. laboratory testing was conduct 2 io establish the operational range as well precision and accuracy of the ov ci all meihod lsee Table I), The minumum and maximum xmns ol the sampling range were found to be 50 and 500 Fpm-hours. respectively For an eight-hour time weighted average. iVse values coriespond to oi.s-lourth and two and one-halftimes the current ACGl H Threshold limit Value of 25 parts per million.1'*1 In considering sources of error, environmental effects including temperature (10 to 40 C). relative humidity (10 to 80 percent). prcssure(730 to 790 mm Hg). and face velocity (2.5 to 125 cm sec) were included. Ol the environmental factors evaluated, temperature and the concentration of the contaminant were identified as being responsible lor 98 percent of the data variation. For ammo nia, a temperature correction factor of 0.6 percent per degree centigrade was suggested. Also investigated was the storage stability of both unexposed and exposed badges. Results indicated that refrigerated sioiagc is necessary to extend the shelf life of une.xposed badges. Once the badge is exposed to ammonia and before the reagents arc mixed, the badges can be stored for one (room temperature) to three (refrigerated ) weeks without losing any absorbed contaminant Once the reagents ate mixed and color formation is started, the badge should be read w ithin 90 minutes. Additional testing results conducted by DuPont are shown in Table l.,Jb' carbon monoxide Shorand Anders, of the 3M Company, have described the 3M "direct-read diflusional monitor" for evaluation of exposures to carbon monoxide.'2 ' The principle involves the reaction of the carbon monoxide and an unreported reagent(s) to give a visible color change from pink to tan Theoreticallv. "if any pink color is observable at the end ot the exposure period, then the exposure was less than the one time-weighted-average of 400 ppm-hours." They also state that noting the time to the endpoint allows for calculation ol the average concentration of carbon monoxide during the exposure period. The authors present summary results of laboratory evaluations using an infrared radiation dev ice to establish "known" concentrations (see Table I). chlorine Hardy et al. have described a personal chlorine monitor (REAL. Inc.) which employs the principle of permeation of the gaseous contaminant through a silicone membrane and into 10 mL of a fluorescein-bromide solution.'*'' Colorimet ric techniques then can be applied to determine the chlorine concentration. The authors report a detection limit of 0.013 ppm chlorine for an eight-hour exposure, with a "working range" of 0.1 to 2.0 ppm. They also suggest that for shorter time periods, concentrations of up to five ppm can be deter mined. Other observations included effects of temperature, humiditv. absorbent concent ration. pH and response time, with all laboratory results presented graphically. Moleculon Research Corporation has recently introduced a chlorine monitoring device which relies on plastic film impregnated with liquid reagents.'2*' Exposure of the badge to chlorine gas gives a visible, "blue-purple." color change. Optical transmission measurements, and comparison w ith a standard curve, can then provide quantitative exposures m ppm-hours The manufacturer's summary results indicating effects of temperature, humidity. w ind velocity and concen tration are reported as presenting an error at the 95 percent confidence level, which is "less than 15 percent. SlO A/r /ntf Hvt 4ss0 J (43* *vii 3H 111065 Chemical Ammonia Nitrogen Dioxide Sulfur Dioxide Hydrogen Sulfide Mercury CO TABLE I Inorganic Gases and Vapors Laboratory Results Dosimeter* Biei* Precisi n* Range" (ppm) Reference Notes DP DP GB GB OP DP MDA GB DP DP 05 05 -3.2 -3 2 -0.9 -4 9 -1 -08 7.4 6.9 9.3 21 7 7.5 8.7 4.1 13.8 58 7.5 20-50 20-48 6-62 4-11 4-11 4-1 1 6-9 4.6-5 3 4-11 4-11 24 26 23 r. r. 1 Hl 38 24 36 E(i 1 HI 38 24 GB 15 3 3M 05 9 3M 17 2 3M 0.3 4 7 1 6-2 2 0.03-0 3mg/m1 0.05-0.2mg/m` 50-1830 1 32 33 27 H K Kc. <; 'DP-DuPont Pro-Tek Colorimetric System Badges. 3M=3M Company Monitor. MDA=MDA Scientific. GB=Abcor GASBADGE "See text, equation (8) ' See text, equation (7) "Some values are rounded to nearest whole number ' Bias consistently negative ^Results derived from Table III of McCammon et al.,X!' "Results calculated from data provided in reference "This product is not currently marketed 'Bias could not be calculated from data given hydrogen sulfide In 1977. Tompkins and Goldsmith described the develop ment of the GASBADGE personal sampler.111 Although later work with this device focused on the collection of organics on an activated charcoal substrate, initial studies researched sampling of both organic and inorganic com pounds. (The GASBADGE for organic vapors is now mar keted bv National Mine Safetv Company, and those for inorganic vapors are not currentlv marketed.) Applications involving inorganic gases relied on collective elements ofan "appropriate substrate impregnated with a chemical medium specific for the contaminant of interest." Based on 60 obser vations, the authors' statistical summary is presented in Table I. Eighty percent of the measurements were within 25 percent of the "true" value. Challenge concentrations were established in a "well-mixed" environmental test chamber and were measured with an "independent wetchemistrv sampling train." Hardy and associates have described a permeation device (R E A L. Inc.) w hich relies on the permeation of H2S through a dimethyl silicone membrane and subsequent reaction w ith a solution of 0.2N sodium hydroxide and EDTA.130' The colored product (methvlene blue) is measured spectrophotometrically and compared with a calibration curve to determine ppm-hours. A knowledge of exposure time then allows for the determination of average exposure over the measurement period. The authors note that a critical step in American Industrial Hygiene Association JOURNAL MJJ 8 82 the development of such a device is the experimental deter mination of the permeation constant (see Equation 6). w hich involves calibration of each monitor by exposure to know n concentrations of the contaminant. The results of this labo ratory research demonstrated a detection limit of 0.01 ppm foran eight-hour exposure, with a working range ol 0.1 to 20 ppm and a linear response up to 200 ppm. The working range corresponds to one one-hundredth to two times the current eight-hour TLV of 10 ppm.'251 Evaluations ol envi ronmental effects indicated that neither temperature, over the range of--3 to 39 C. nor humidity, from 0 to 99 percent relative, caused any significant variations in response of the device. Further research demonstrated a good response to high concentrations in less than one minute, adequate sam ple stability up to 10 days if EDTA is used in the absorbing solution, and negative and positive interferences, respec tively. from chlorine gas and nitrogen dioxide. Precision and bias were not reported. a ,. Another approach forthe determination of gaseous hvdrogen sulfide has been reported by Gracdel and Franev.1311 Their research involved using a semiquantitative method without a stagnant airlayerand reiving on the discoloration of lead-stabilized polyvinvl chloride (PN C). The technique involves the diffusion of gas in a polvmer and, at high HjS levels, the detection rather than the measurement of toxic levels of H2S. Screening applications for low level exposures also are discussed. 3H 111066 sit mercury In 1977. McCammon and Woodfin of NIOSH reported the results of a laboratory evaluation of 3V1's mercury vapor monitor.<321 The monitor's operating principle ins olves molecula^^kffusion and deposition of mercury vapor on a gold The resulting ch. nge in electrical conductivity icros' the gold loil is related to the amount of mercury absorbed by the foil. Three other sampling methods, all of * hich m\ olved the active movement of air. also were inves tigated and include the LASL tandum sampling tube, the hopcalite tube, and the iodine impregnated charcoal tube. For the passive monitor, precision and accuracy, the effects of face velocity and temperature, and potential interferences were investigated. Concentrations of mercury vapor in an exposure chamber were monitored with an ultraviolet mer cury vapor meter, which in turn was calibrated by measure ments using the LAS1. method. To determine precision of the monitors, I 2 dev ices were exposed to a test atmosphere. Results from three measurements of the test atmosphere using the LASL method gave an "expected" concentration of 0.056 milligrams of mercury per cubic meter of air (mg m1). with a standard deviation (SD) of 0.002 mg m3 and a coefficient of variation (CV) of 0.037. Precision and bias calculated for the data given in Table III of McCammon ei ul.l3~ is summarized in Table I. A least squares regression analysis of the combined precision and accuracy results for the passive dosimeters versus the "known" concentrations gave a Y intercept of --0.004 mg m3 and a slope of 1.003. Tests for the effects of face velocities from 25 to 125 cm sec (50 to 250 Ipm) did not appear to have any adverse effect on p^^B'mancc. while variation of temperature experimentally cc^mrmcd its effect on both the diffusion constant and the concentration of the contaminant. The potential effects of changes in relative humidity were not discussed by the authors. The other area of investigation in this study inv olv ed potential interferences of chlorine, sulfur dioxide, and hydrogen sulfide. Concomitant and sequential exposure to mercury and chlorine, the latter at high levels (5.8 ppm), produced a negative bias, but a similar effect was observed with the UV meter and the LASL system. The authors suggested that the mercury and chlorine may have been reacting to form mercuric chloride which was not being measured by any of the systems. The interference effects of sulfur dioxide and hydrogen sulfide, although less thanchlorme, also were confirmed. In lQ80. McCammon and his NIOSH and OSHA co workers conducted further tests of the four previously desc'.bed mercury vapor sampling and analytical methods.'33' The design of this laboratory experiment involved inter comparison of four methods, and the findings suggested that the variability of the iodine charcoal tube method is signifi cantly different from that of the other three methods. It was observed that the other three methods, including the 3M passive dosimeter, exhibited eood precision ov er the concen tration range of 0 05 to 0.2 mg m3 as shown in Table 1. ^^fctcently SKC. Inc., introduced a gas monitoring badge t^wduccd by G M D. I nc.) w hich uses the principle of molec ular diffusion (vnthotii a stagnant air layer) to collect mer cury vapor.'341 The sampling media is referred to as "Hydrar Sorbent,"and "extensive"but unpublished field and labora tory testing are cited to show that "chlorine, moisture, etc., do not interfere" with measurements. HYDRAR is devel oped from a "manganese dioxide catalyst material similar to `Hopcalite.' " Quantitative determination is made by chemical desorption of the mercury and analysis with atomic absorption. nitrogen dioxide In 1976. Palmes et al. reported the results of their evaluation of a personal sampler for nitrogen dioxide (NOa).135' This work was an extension of their earlier pioneering efforts in developing a personal sampler, employing the principle of gas diffusion, for sulfur dioxide.'2*' In their design, the sam pling dev ice was a 1.3 cm (0.5 inches) acrylic tube. 7.1 cm (2.8 inches) long. At the "closed "end of the diffusion path (tube! were placed three stainless steel grids coated w ith triethanolaminc(TEA). TEA was selected because: 1) it captures NOj efficiently. 2) it provides a stable sampling surface, and 3) it yields a chemical complex with NO.> that is very stable over time. Subsequent analysis yielded a colored complex whose absorption was measured at 540 nanometers. Results were then compared against a standard curve which obeyed Beer's Law. The experimental evaluation of the NO-> sampler involved chamber measurements compared with "known" values determined by the volume of NOe introduced to the chamber or the weight loss of NO2 from a permeation tube. Although neither individual nor summary results were pre sented. graphical comparison of the data indicated a close agreement between the passive sampler results and theoreti cal concentrations. The effects of wind velocity and direction as well as stability over time also were considered. In deter mining wind effects, the uptake of water vapor, rather than NOa. was measured. The results indicated that there was an increase in average uptake with increased velocity and that the 45 degree incident angle gave the highest uptake (135 percent at 258 cm sec). Across all angles of exposure (0 to 180 degrees) the average uptake increased from 2 to 14 percent as the wind velocity increased from 50 to 258 cm sec (100 to 516 fpm). Stability studies indicated that the badges could be used for months both after preparation and before exposure as well as after exposure and before analysis. In the prev iously described studies w ith the GAS BADGE. Tompkinsand Goldsmith also monitored for nitrogen diox ide.1" Their summary results for 82 observations showed accuracies and precisions as summarized in Table I. Eightyfive percent of the observations were within 25 percent ot the "true" value. A commercial model of the Palmes passive sampler has been marketed by MDA Scientific. Inc., and additional laboratory testing demonstrated a linear collection effi ciency for any given dose. i.e.. concentration X time (see Table l).'36' The sampler exhibited a consistently negative bias as compared to concentration determinations using a continuous monitor and the NIOSH wet chemical method. As noted earlier, the DuPont PRO-TEK. system includes a badge for nitrogen dioxide. Laboratory test results ol this dev ice arc show n in Table I.'3'1 3M 111067 Am Ind H>f Assoc J (A3) AufuSt 19S7 sulfur dioxide As noted previously, pioneering work in 1973 on the design of a sampling device which relics solely on diffusion of gaseous contaminants through a stagnant air layer is attribJbied to Palmes and Gunnison.TM' Their initial studies involved experimental work on different tube lengths. The collecting medium was a complex of mercuric chloride and the final analysis involved colorimetric determination. The studies demonstrated that, except for very short diffusion paths (tube lengths), the diffusion monitor satisfactorily duplicated the results obtained by both wet chemical and conductrimetric measurements. Although this study did not go into the ramifications of environmental effects and inter ferences. it should be recognized as an important step in developing a new industrial hygiene technology. The last of the three inorganic gases looked at by Tompkinsand Goldsmith in their studies of thcGASBADGE was sulfur dioxide.111 Summary data for 23 observations on this gas are included in Table 1. One hundred percent of the observations were within 25 percent of the "true values. The results from DuPont's tests on their sulfur dioxide badge also are shown in Table l.<38> organic gases and vapors Most passive dosimeters designed to sample for organic gases and vapors use activated charcoal as the adsorbing medium. As we know from its extensive use in active sys tems. activated charcoal has an affinity for a wide range of organic compounds. Consequently, the discussion on the applications of passive dosimeters for the measurement of organic gases and vapors first will focus on desices using activated charcoal and then will turn to specific organics which rely on other collecting media. Chemical table ii Organic Gases and Vapors Laboratory Results Dosimeter*' Bias" Precisioitr Range"(ppm) Reference Notes Carbon Tetrachloride Toluene Formaldehyde Benzene Ethylene Oxide Hatothane Enflurane Acrylonitrile Hexane Vinyl Chloride Methyl Chloroform Trichloro* ethyiene OPA DPA NMS DP DPB NMS NMS 3M 3M 3M NMS NMS R 3M DPA NMS 3M DPA NMS 0.4 0.3 -1.7 1.5 3.3 -4 1 1.8 -1.4 3 -2.8 0 03 -1.2 -0.2 -5.9 -106 2.4 -3.9 -6.9 -0.5 4.4 5.25 . 1-7 6.3 4.7 1.7 17 3.2 7.4 4.8 8.7 2 3.7 , 4.7 45 2 7.6 7.7 1.9 3-18 57-228 12-47 0.24.2 3-24 08-5.4 13-13.5 300 0.5-20 0.5-20 0.7-19 10-37 1.5-14 160-840 160-840 15-65 20-200 20-200 15-67 10 E 45 13 rj 55 46 13 FJ 1 E.GJ 53 1 44 J 44 J 39 13 FJ 2 HJ 48 IJ 48 tlJ 12 48 IJ 48 E IJ 12 a3M = 3M Company Organic Vapor Monitor. DPA and DPB ~ DuPont PRO-TEK G-AA and G-BB Organic Vapor Badges. NMS = National Mine Safety GASBADGE. R = Real. Inc. MINIMONITOR. DP = DuPont PRO-TEK System Colorimetric Badges BSee text, equation (8) , cSee text, equation (7) nSome values are rounded to nearest whole number cSmall sample sire FKnowns were calculated using charcoal tubes with critical orifices. This could affect the bias measure ''Preliminary results MPermeation dosimeter 'Bias consistently negative JResults calculated from data provided in reference Amtncan Industrial Hygiene Association JOURNAL (43) B '82 3M 111068 613 rivaled charcoal devices - of March. 1982. there were lour manufacturers of passive -imeterx which rel> on diffusion and subsequent adsorp n on to activated charcoal. National Mine Service Com.nv^J.ASBADGE). 2M Company (Organic Vapor MoniD^^^Pont Company (PRO-TEK.. G-AA and G-BB ga^rc Vapor Air Monitoring Badge), and the Mine Safety r'pliance Company (Vaporgard Badge). In 1977. Tompkins and Goldsmith described the first mmercial passive dosimeter for monitoring organic pors.11' The GAS BA DGE relied on molecular diffusion of vapor into the badge and subsequent adsorption onto tivjted charcoal. The authors developed the theoretical rinciples ofthe badge's operation, and discussed sensitiv ity temperature and pressure, face velocity effects, and sponse time. Preliminary results showing the badge's sponse to benzene, ethyl acetate, methyl ethyl ketone, and yrene also were presented and were described as "verv couraging" (see Table II). In ihe same year. Silverstein reported results of laboratory ,d lield testing ofthe G ASBADG E for acrylonitrile. t!*' The suits ol the exposure of 22 badges to known concentra>ns m the laboratory are presented in Table II. The results dicate the acceptability of the GASBADGE for mcasureents of acrylonitrile over the range of 0.75 to 19 ppm. The ne of exposure in the laboratory was not given, however. -Id measurements did cover periods of up to seven hours, though temperature and relative humidity ranges were ported, data analysis to determine the effects of these inables was not presented Silverstein also looked at .^^tion elticiencies and determined that the best results '-^Hrcent) were obtained with four mL of two percent etone in carbon disulfide, I n 1978. Bamberger et a!, conducted a series of laboratory sts to evaluate the G ASBADG E Their approach mv olved e generation of known concentrations of solvents and ibsequent evaluation with charcoal tubes(active sampling) nd the passive dosimeter. To evaluate the applicability of ne dosimeter over a wide range ol compounds, the investiition included seven different organic compounds each .preventative of a different functional group Included in his study were: benzene (aromatic), n-butanol (alcohol), .-butyl acetate (ester), ixooctane (alkane), methyl chlororm (halogenated alkane), methyl isobutyl ketone(ketone), id trichloroethylene (halogenated alkene). The diffusion 'efficient ( D) used was that supplied by the badge manufac.rer. except in the case ol ixooctane which was reported as ng an unknown coefficient Computations involving iis .ompound relied on the coefficient for n-octane. A v ariety of experiments was conducted to look at a wide range of questions. Their findings corroborated dosimeter con sume similar to those ofactivesystems using charcoal tubes, i- g . minimum and maximum loadings are important, postimple contamination and loss can occur it the exposed bsorbent is not adequately sealed, percent recovery for tures is consistent with percent recoveries for single kounds. and differences in charcoal lots can give differYesults Other tests confirmed the need for some air 4 movement across the badge lace and the lack ol ellect ol temperature changes over a small range I I I ' C). I he results ol the simultaneous sampling with the badges and the char coal tubes indicated that the badges had a consistent nega tive bias. The authors suggested that, because the results were so reproducible, corrections lor adsorption dcsoi ption elticiencies less than 100 percent can he accomplished not as is dime for charcoal tube data In 1979, H irav a mu and I keda cv aluated t he applicat 'on 19 the GASBADGE tor monitoring exposures to mixed sol vents.1 Their research involved ditteieni preparations ol activated carbon "felt" in place ol the supplied collection medium and exposure to mixtures ol n-he.xane. cthy I acetate and toluene. Summary (graphical) data indicated that the amounts of contaminant absorbed by the dosimeter were proportional to both the vapor concentrations and time ol exposure. Halliday and Anderson reported on the use ol the G AS BA DGE in monitoring lor halothunc.''' Six ohserv ations indicated a range ol measurements Irom minus nine to plus ten percent ol the test atmospheres. Cnlortunatcly. the authors did not report their procedure lor determining the concentration of halothane in the test atmospheres. In 1981. Evans and Horstman reported evaluations ot desorption efficiencies ol charcoal tubes and the G ASB A DG E for stv rene,1 For iiquid dosing they found the dosimeter to be similar to the tube, while tor vapor dosing the badge was superior. The authors suggested that the differences m results mav, have been related to the use ol coconut shell carbon in the tubes and petroleum derived carbon in the badsje. Thev did not explain why this difference would altect one method of dosing and not the other. In 1980. Anders and Mullins of the 2M Company pre sented results comparing the 2 M passive monitor with char coal tubes in sampling for mixtures of organic compounds '' " The laboratory tests included a binary mixture of toluene and methyl ethyl ketone; a tertiary mixture of benzene, toluene and xylene: and complex mixtures ol unleaded and leaded gasoline containing various alcohols. Although the investigators cited "excellent" precision and accuracy tor the dilfusional monitor, sample sizes were small, and the com plicated studv design and lack of raw data preclude the determination of precision and bias statistics. Mazur and his co-workers'1" conducted side-by-side laboratory and field tests with charcoal tubes and 2M omanic vapor monitors to measure concentrations ol halothane (2-bromo-2-chloro-l. 1.1-trifluoroethane) and enflurane (2-chloro-l. 1,2-tnfluoroethyI difluoromethyl ether) The results ofthe laboratory studies are presented m Table 11 and support the authors' conclusions that the dosimeters are a reliable method for the collection of enflurane and halothane. In 1980. L.autenberger ei at. described DuPont's passive monitor for organic vapors.'11' Each charcoal strip in the PRO-TEK G-AA Organic Vapor Badge contains approxi mately 200 mg of coconut-based activated charcoal impreg nated in an inert polymer. A dual sampling rate of approxi- Am Ind 4ssac i {A3} Aunuit 198- 3M 111069 mutely 50 or 100 nil mm i\ determined by the removal of line or both ol the dosimeter's protective covers. One aspect ol their research inv nlvcd experimental determination of the diltiiMon eoellieient ol several gases and vapors. They reported that values calculated by I ugg'1' were within 10 percent of their experimental!} determined diffusion eoelli- cient values. Preliminary experimental results were used to discuss lace velocity clleets. ranee and sensitiv itv. maximum and minimum sampling times, vapor retention, storage sta bility. desorption efficiency. tmd overall budec efficiency. 1 he overall accuracy determinations were limited to four observations at each ol two concentrations ol carbon tetrachloride (see Fable II). However, the presentation of raw data, as well as an explanation of the statistical tests applied, is most usetul. I his same detail of information is also found in DuPont's validation reports lor toluene and ben/ene (see Table II). '' , In the ben/ene report. DuPont also describes its PRO-TEK G-BB badge. This badge has a backup section ol charcoal, which serves the same purpose as the second section in a charcoal tube. /.t\. to aid m determining il the sampler has been overloaded. I he 3M Company also markets an Organic \ apoi Monitor with a backup section.'1'' In studies ill the measurement of waste anesthetic gases with passive dosimeters. Jonas ei al. evaluated the CiASBADGE. 3M Organic Vapor Monitor and DuPont Pro-Tek in measuring enllurane. Bl l nfortunately. the badges were not identified in the presentation ol the results although interpretation of the reported sampler geometry would indi cate that A was the Du Pont badge. B was the 3.M badge, and C was the GASBADGE. The results of their laboratory studies indicated that badge 8 had the lowest coefficients of variation (CV was not calculated as described in this text) as compared to concentrations determined by infrared analy sis Badge A had a low CV I'D percent) at 5 ppm and a much higher \ alue l CV = 34 percent) at 20 ppm. The C badge had consistently high CV\ ranging from 23 to 30 percent. It should also be noted that the charcoal tube CV's ranged from I I to 27 percent, that desorption efficiencies for the badges ranged from 0.81 to 1.17. and that IR analyses of tank concentrations were constantly lower than expected. If badge B was the 3 M dev ice. the results of Jonas et al. support those reported by Ma/ur er a!.'141 Further testing of badges A and C seems necessary, however, to confirm their seemingly low precisions. Ma/ur and his coworkers conducted additional tests comparing the 3M and DuPont badges against charcoal tubes Methyl chloroform and trichloroethylene, two sol vents widely used in vapor degreasing operations, were sampled. In the laboratory phase of the study, the badges and charcoal tubes wereexposed tochamberconcentrations over the range of 160 to 840 ppm of methyl chloroform and from 20 to 200 ppm of trichloroethylene. Exposure times varied from two to six hours for methyl chloroform and I rom tour to six hours for trichloroethy lene. The laboratory work indicated that the percent recoveries of the various doses (concentration X time) were in good agreement except for one exposure of the 3M badge which involved a five hour Am-r-cjn `'Justrial Hygiene Association JOURNAL .'ajj a. a? exposure at 700 ppm. The authors noted that this exposu ol 3500 ppm-hours exceeded the upper expo-ure limit pr vided by the manufacturer. The overall mean recovery vali for each type of sampler was used to correct all suhseque Field data. In addition to the recovery measurements, tl laboratory phase ol this study also involved determinant of storage stability. The authors lound no significant loss, of methyl chloroform or trichloroethy lene from either bad; following storage of exposed badges for up to three week In 1978. West and Reis/ner reported on the field tests t the MINI.MONITOR" (REAL. Inc.) permeat ion person, monitor for vinyl chloride.'"1 This monitor was a modifie version of one previously described by Nelms ft al." " Th collecting medium was activated charcoal, but rather tha relying on molecular diffusion, the badge design involved polymeric membrane and the permeation of vinyl chloric through the membrane and adsorption onto the charcoa Initial laboratory calibration was used to determine th permeation constant ol the dev ice. I aboratory results ind cated good accuracies as summarized in Table II. During the same period that Tompkins and Goldsmith were describing the GASBADGE. Bailey and Hollingdulc Smith of Great Britain were presenting their ideas for . personal passive sampler for organic gases and vapors Their design involved the use of either one of two types t, membrane and subsequent adsorption onto activated char coal. They found two membranes to be satisfactory, one o thin silicone rubber which acted as a permeation barrier, am the second a porous polypropylene film which allowed to molecular diffusion of the gas and vapor. They conducts laboratory tests using carbon tetrachloride, styrene am dichlorodilluormcthane. Their test results do mix some ter minology. e.g.. permeation rates for both the permeation device and the diffusional device, but did provide an earlv demonstration of the feasibility of such a dev ice for monitor ing certain organics. The device, the Porton Dilliismr Sampler, seems to see its greatest use in Great Britain. acrylonitrile One of the newest applications of passive dosimetry involvethe use of a porous polymer ( Porapak N) as the collecting surface with subsequent thermal desorption and gas chro matographic analysis. Benson and Boyce have described such a device and its utility in sampling for acrylonitrile " Laboratory testing for acrylonitrile involved comparison oi the dosimeter values with concentrations measured on a g.ichromatograph. Initial experimentation indicated that the dosimeter can be used for aery lonitnle concentrations in the range of 4 ppm. but at concentrations of 2 ppm a 40 percem error is reported. * aniline In addition to activated charcoal, another widely used adsorbent medium is silica gel. To study the utility ol im material. Campbell and Konzen constructed passive dosim eters from glass culture tubes (1.05 cm inside diameter) with 40 60 mesh silica gel as the collecting surface.Laboratory testing involved exposure of the dosimeter to aniline, with exposure concentrations determined by gas chromato graphic analysis of ethanol gas scrubbers. Three dillerent 3H 111070 sis size (length) dosimeters were evaluatcd. w ith the best results phosgene obtained with the intermediate length tube( L = 3.0cm: A L -- 0 3 cmi. The authors present raw data and clearly described their statistical techniques. oxide ^^nlins and Anders ha\e recently described the 3M diffu sions i morn or for samp!ing ethy lene oxide in air.'53' In this badge the collecting surface is described as a "chemically impregnated charcoal surface, (where) a reaction occurs producing a stable compound with a \apor pressure sub Matherne et al. have recently described the CMD. Inc "passivedosimeter"which providesa semiquantitativc mea surement of phosgene exposure.15,1 The badge involves direct contact between the contaminated air and a chemi cally impregnated tape and therefore does not rely on a stagnant air layer. The treated paper stain intensity is reported to he logarithmically proportional to the phosgene dose overarangeof2tol00ppm-minutes. Forquantuat.ve measurements the badges can be read colorimetrically stantially lower than the parent compound." The authors present statistical!) summarized data describing the linearity and capacity of the monitor, the recovers of absorbed ethyl ene oxide, environmental effects, sample stability, and the effects of potential interferences. Precision and bias are presented in Table II. other methods Hill and Fraser have described the use of commercial detec tor tubes modified to act as passive dosimeters.In then research, common length-of-stain detector tubes were modi fied by cutting off the conical end of the tube and remov mg some of the indicator column material. This leaves an oni ice formaldehyde with a cross-sect tonal area equal to that of the inside ot tru Rodriguez </ al. have described another 3M diffusional tube and a path length determined by the distance from thi monitor for sampling formaldchv Jc.,S4' In this diffusional end of the tube, to the beginning of the indicator materia! monitor, the collecting surface is an "impregnated sorbent" One would expect, however, that as the sorbent matciinl which can then be desorbed in situ with water and the becomes exposed, i.e.. the length of stain increases, the concentration of formaldehyde determined col ori metrically. diffusion path length will also increase, thereby changing the Laboratory ev a I uat ion first tnv olv ed determination of recov sampling rate. Their evaluation of these devices involved ers coefficients, which at eight ppm-hours (19.5 micro separate laboratory exposures to toluene, ethanol and iso grams) were found to be 1.00 0 04 over six tests. The next propanol. The results of their w ork, although presented onlv step involved determination of the dosimeter's "sampling in graphical summarv. demonstrate the potential lor the use rate" ( DA l ) by exposing the dosimeters to "known" con of modified commercial detector tubes as passiv e dosimeter- centrations of formaldehvde as generated by a permeation tube The effect of relative humidity on the sampling rate was investigated, and evaluation of the data did not cate any statistically significant differences between the rates at 50 and 85 percent relative humidity The study protocol then involved simultaneous exposures of impingers (modified chromotropic acid method) and dosimeters The authors concluded that "the measured values by both methods lie within g: 25 percent of the expected response" and that "less variation is observed in the monitors than in the impingers." However, neither precision nor bias were reported. The authors also investigated effects of storage and determined that at elevated temperatures (38 C) losses up to II percent occurred after one week, however no signif icant loss was seen for samples stored at 23 C. The authors briefly discussed the potential for a negative interference from phenol and described the use of modified calibration curve' 'o address this problem. DuPont's PRO-TEK series of colorimetric Air Monitori'e Badges, includes a badge for formaldehyde. The collect.c.n principle involves a chromotropic acid-sulfuric acid reaction, laboratory ev aluation (42 samples/of the dev ice at seven exposure levels revealed results as shown in Table II l,v" Additional studies also were conducted on tempera ture and storaae effects The raw data and statistical analvsis procedures are presented field validation Relatively few studies have been published in which passive dosimeters have been compared side by side with charcoal tubes or other conventional sampling methods under actual field conditions For inorganic compounds only two stud ies. involving nitrogen dioxide'59' and chlorine.' have been identified. For organic compounds, eight stud ies'3 51 R"have inv olv ed field comparisons, with the number of compounds per study ranging from one to 22 In three of these studies, statistical analyses of data were no; presented and cannot be performed because of small sample size or insufficient presentation of data. Jones et conducted a field evaluation for NOj in a salt mine, which contained diesel equipment as the NO. source. At each of 16 different fixed area locations, two Palmes dosimeters and two TEA tubes with pumps were used to sample the atmosphere. The active sampling (pump i method gave a coefficient of variation (CV) of 8.7 percent while for passive tubes the CV was 5.8 percent. Regression a nalv sis (w here the active system was the X variable) of their data give's a correlation coefficient of 0.69. a slope of 0.59. and an intercept of 2.05 ppm fordata over the range of 3 7 to 5 5 ppm as sampled by the active method. This indicates thai the dosimeter gave consistently higher readings which is K nese1 has described a new passive dosimeter for formaJdehvds which is a modified vetsion of the Palmes tube, ^^whe pi esent time experimental data concerning this dev ice not a . ailablc reflected in the means for the two methods: 4.51 ppm lot passive and 4.14 ppm lor active sampling. The authors did not report wind velocities, but low velocities, as would be expected with area samples, should have caused passive $16 Am Ind Hy( Assoc Jt4Ji Ajiu"' 3M 111071 values to be low as compared to acme values; ibis was not the case. On the other hand, high face velocities could have led to the observed positive (passive versus active) bias. Hardy et al.'m reported the raw data results from a field evaluation of a permeation chlorine monitor (R EAL. Inc.). Thirteen comparisons were made in w hich the results from a battery operated pump and an impinger sampler were com* pared with the measurements from either two or three per meation samplers. To further evaluate their results, the investigators performed a regression analysis using their permeation sample means for each comparison as the dependent variable. The results are quite good with a corre lation coefficient of 0 95. a regression slope of 0.85. and an intercept of 0.15 over a range of 0.0,' to l.l ppm as detected by the impinger. It should be noted that with five impinger samples ol less than 0.1 ppm. the corresponding permeation dev ices detected considerably higher concentrations (0.16 to 0.4 ppm). Silverstcin<',`" reported field results for aery lonitrile moni toring using 18 paired samples of GASBADGE passive monitors and active systems (charcoal tubes and pumps) over a range of 0.8 to 5.8 ppm as determined by the active method. The differences in results using the active system as a reference ranged from --0.7 to 1.5 ppm. 1 he difference in mea ns. 2,18 for the passiv c v ersus 2.73 for the active system, was 25 percent. Further data were not presented. West and Rcts/net reported five sets of field results for viny I chloride sampled w it h permeation dosimeters (REAL, Inc.) and charcoal tubes.1*' Further interpretation of their results is presented in Table III. In each case data for the active system are the X values Four of the correlation coeff icient values are very near one, reflecting good correla tion. however, the slopes show quite a large degree of varia bility (0.69 to 1.31). indicating that badge values may fall either well below or above charcoal tube values. In those cases where the slopes were less than 1.0. very high humidi ties (67 to 91 percent) were reported by the authors. This factor may have interfered with permeation, although the authors reported that humidity had no effect in laboratory validations; hence the variation in slope remains unex plained. The authors noted that the overall field results showed that the badges had a slight positive bias. Hickey and Bishop exposed 78 pairs of side-by-side char coal tubes and 3N1 Organic Vapor Monitors to complex mixtures of organic chemicals in tire manufacturing opera tions,"1' Generally the sampling period ranged from three to TABLE III Regression Analysis of Vinyl Chloride Field Data11' N Range (ppm) r Slope Y-Intercept 7 002-1 0 99 1 19 B 0.08-1 B 0 99 0 69 12 0 02-6 3 10 1.31 39 005-1.8 0.82 0.81 24 1 48-16 7 0 96 1 08 0 03 0 05 0.01 0.11 0 43 American industrial Hygipnp Association JOURNAL (43) 8*82 five hours, and most observations consisted of one monito and the time weighted average concentration trom twi sequentially exposed charcoal tubes Sixty-four of the set were personal samples, while the remaining 14 were are. samples. The samples were collected in two separate plant' (30 sample pairs in one plant and 48 in the other) Ot the 21 organics potentially available for analysis, 10 were detected over a sufficiently w ide range of concentrations to allow to: appropriate statistical analysis by linear regression Tht results are interesting in that in the first plant, 9 of the !( organics measured by the dosimeters showed higher vupor concentrations as compared to the charcoal tubes, while ir the second plant only three substances had a regression slop, greater than one. The combined data for both plants did no indicate that the passive system was consistentlv bia-ec when compared to the active system. The authors did poin out that generally the Y-intercepts (Y = passive dosimete data) were slightly negativ e. a finding w hich may indicates lack of sensitivity on the part of the dosimeters at low concentrations. For the remaining 12 compounds, paired t-tests revealed no significant difference between the char coal lube and passive monitor means at the 95 percen: confidence level. The use of t-tests to analyse such data habeen questioned since the means of the two methods may be very similar but the components of paired values can be considerably different.1191 This condition can only be rev eaIce through regression analyses. In 1980. Mazur el al.,AA reported limited field data lor halothane and enflurane measurements using both 5M Organic Vapor Monitors (OVM) and an active system (charcoal tubes and pumps). For halothane three paired samples were reported. The mean concentration for the active system was 2.01 ppm while 1.9 ppm was reported lo' the OVM. a difference (relative to the active system) of five percent. Only one data pair was reported for enflurane: 04u ppm for the OVM and 0.52 ppm for the active system Obviously, more data are needed to draw conclusionregarding a comparison of the two methods for these agents A second study by Ma?ur el al.tAS' reported field compar isons of passive dosimeters and active systems (pumps and charcoal tubes) in sampling for trichloroethylene (TCE land methylchloroform (MC). Both DuPont PRO-TEK and 5M Organic Vapor Monitors were used for the passive systemPersonal samples included exposure of one each of all three monitors. Area sample results inv olved three av erage v alueone was the average of three charcoal tubes, and the other two, the average of two of each type of dosimeter For M C 11 personal and 7 area data points collected over time peri ods of 1 to 5 hours at 15 to 21 6C and 35 to 40 percent relative humidity were reported. For TCE. 22 personal and 7 area data points collected over periods of about I to 6 hours at 18 to 24 C and 30 percent relative humidity were reported 4 regression analysis in which the charcoal tubes were the independent variable was reported by the authors. I n each o; the following data sets the presented values involve TCE personal and stationary sampling followed by MC persona and stationary sampling. For the DuPont badge, regression 3H 111072 6; slopes of 1.0. 0 99. 0.99, and 0.98. and correlation coeffi cients of 0.98. 0 98.0.94, and 0.94 w ere obtained. For the 3M bodge, regression slopes of I OS. 1.06. 1.07. and 0,90, and correlation coefficients of 0.98. 0.98. 0.98. and 0.90 were de^rmined These values appear to be quite good: however, t^^pithors did not report if they tested the statistical signific^ffe of these values. They also did not report average of face velocities associated with stationary samples. E\ans ei al.'6"' of Great Britain reported field validation data for the Port on diffusion de\ ice vs hilc measuring methvi ethyl ketone. In this case the conventional sampler was a pump and a ca'sette fitted with a charcoal cloth similar to that used in the Porton device. A regression analysis per formed with their data showed good correlation (0.9) and good slope (0.9); however. the intercept value (4.69) indi cated that, at low concentrations, the "home-made" de\ice gase lower values than those determined with the conven tional monitor Concentrations reported for the convenlional device ranged from I I to 189 ppm. Be nson and Boyce1''1' field tested the Monsanto Poropak s' device in Great Britain. Conv entional samplers consisted of pumps and Poropak N poly mer tubes. Sixty-five pairs of .amples were obtained, and the range of acry lonitrile meaured by the tubes was 0.11 to 21.65 ppm. Regression analyis of their data indicates only fair correlation (0.63). a low lope (0 46). and a negative intercept ( -- 2.06). These values tppear to result Irom the apparent inability of the passive ;ev ice to accurately detect concentrations less than 0.5 ppm. Mso. comparisons between values over the lower half of .oncentrations sampled showed considerable scatter. e final field study to be discussed suggests perhaps the serious discrepancies resulting from use of charcoal passive dosimeters.16,1 This study was performed by NlOSH versonnel in conjunction with industry-wide studies of the Iry -cleaning, screen printing, and boat manufacturing indusries. and also included one viscose rayon and one cellothane plant Carbon disulfide, pcrchloroethy lene. toluene. Ttcthylisobuty 1 ketone (MIBK). styrene, and acetone were ampled using the 3M OYM, the GASBADGE. and active ystems with charcoal tubes. The presentation of the study Jesign is not clear, but it appears that area samples involved all three devices while personal samples involved charcoal tubes and only one of either passive dev ice. In that this study nvolves six compounds in 64 plants, the volume of data is ,uite large. In addition to regression analysis, paired t-tests nd W ileox signed rank tests were performed by the authors o determine equivalence of data sets. As noted earlier fn. u.-e of t-tests for determination of equivalence has Deer, questioned. Table IV shows the primary results of this study. Ascan be seen, the range of correlation coefficients (r) for most com pounds was quite large. Although 12 plants were sur eyed for toluene and MIBK. the data ere grouped vgether. and therefore ranges of the correlation coefficients ould not be determined For carbon disulfide, one plant s sur\eyed with the OVM and GASBADGE, and one was 4keyed with the GASBADGE only. Foi the ranges of r Tirted in Table IV. the upper values are quite acceptable, with the exception of carbon disulfide using the GAS BA DG E However, the correlation coefficient lor carbon disulfide using the OVM was 0.95. The correlation data can be summed up as being extremely variable. Table |V also reveals that concentration had an effect on the correlation coefficient for three of the compounds, though this was true for both monitors only when measuring acetone concentra tions Regression slopes were as variable as the correlation coefficients. The authors tested the slopes to see if they were significantly different from 7ero, and for acetone and carbon disulfide a difference could not be demonstrated for several of their data sets This indicated that there was no relation ship between the results obtained vv ith the activ e system and those obtained w ith the passive dosimeter. For other com pel unds, it would have been useful to test the difference ol the slope from one. which if not significantly different would indicate agreement of the two methods. In tests of equivalence of data sets, the authors noted that for all plant data combined, only toluene showed equality, and this for the charcoal tube-G ASBADGE (CT-GB) com parison. However, when results from individual plants are used, the comparison outcomes are quite variable. For pcrchloroethy lene. equality was reported for one of three CT-BG comparisons and for one of two CT-3M sets. For styrene, two of six CT-GB and no CT-3M comparisons showed equality For acetone, three of five CT-3M compari sons and one of six CT-GB data sets showed equality. In addition. GB-Ok \1 comparisons showed equality in 6 of I ' comparisons. It is obv ious that repeatability was not demon strated in this study. Whether the problem involves the dosimeters, investigative or laboratory techniques, and or env iron mental conditions cannot be determined. In t he only other field study of more than one plant. Hickey and Bishop'*1'also reported some problems with the consistency of observations These limited results clearly demonstrate the need for additional field studies of passive dosimeters as compared with standard monitoring techniques. discussion Passive dosimetry (monitoring) is a rapidly dev eloping tech nology as witnessed by the proliferation of devices and applications since Palmes and Gunnison introduced their concepts just under ten years ago.1"' The latest entry into the Field comes from the MSA Company and involves an adap tation of their length-of-stain direct reading tubes for inor ganic gases162' w hich incorporates the application of molecu lar diffusion and a chemically impregnated paper as the sampling medium Although research results are not availa ble. as a first approximation one might assume that these devices have precisions and biases similar to those of con ventional detector tubes. For any new technology to be accepted and used by prac ticing professionals, the development of a body of knowl edge demonstrating efficacy is necessary With env ironmental monitoring techniques, the determination of the efficacy usually starts in the laboratory and culminates in the field In the case of passive monitors, a body of knowledge based on laboratory testing is rapidly being developed- Of the vari- Am Imi Hvf j/4Ji Aucust 19T 3M 111073 TABLE IV Major Results of a Field Study for Organic Vapors'*1' Concentration Substance Comparison Overall r Range of r Dependency Perchloroethylene Styrene Acetone Toluene MIBK CS CT-GB CT-3M CT-GB CT-3M CT-GB CT-3M CT-GB CT-3M CT-GB CT-3M CT-GB CT-3M 0 62 0 86 0 82 0 76 0 38 0 45 0 80 0 91 0 88 0 79 0 30 0 95 0 62 -0 99 0 84-0 94 0 65-0,97 0 48-0 86 0 36 -0 86 0 25 0 83 NA NA NA NA 0 03 0 38 NA Yes Yes Yes Yes ahlcs that have been studied, three appear to uniquely a Meet a diffusion monitors accuracy in measurinj: airborne concen trations of gases or sapors. The most important factor appears to he determination of the contaminants'diffusion coefficient (ot the sampling rate when the dosimeter's geometry is also considered), the wind velocity at the dosimeter face, and the relative humidity of the sampled air. As discussed earliei. there are also a variety of potential sources ol error, such as interfering contaminants, sorbent capacity and problems associated with analytical determ i na tions. which arc common to both passive and active mea surement techniques. I aboratory determination of sampling rates! DA Dfora speedic monitor and a specific contaminant are important and are being provided by several dosimeter manufacturers lor an ever increasing number of compounds. Once an appropriate sampling rate has been determined, corrections lor field use. specifically for temperature variations, can be made The mam problem would inv olve situations where the env ironmental temperature fluctuated widely (more than 25 SC) and went unnoticed, a very unlikely condition. The research on effects ol lace velocities demonstrate that few problems should be encountered where dosimeters are worn by workers as personal monitoring dev ices. T heir use as area monitors should be carefully evaluated to ensure that stagnant atmospheres (velocities less than 7.5 cm seclarc not involved. High wind vclocities(at least what would normally be encountered in the workplace) or wind direction do not appear to have adverse effects on dosime ters with wind screens. Of greatest concern as a result of rev iew ing the literature on laboratory testing of passive dosimeters is not the results but rather the thoroughness of their presentation. As dem onstrated in Tables 1 and II. where statistical analyses arc presented by researchers, or where sufficient data are pre sented to allow the reader to determine bias and precision, the results arc very encouraging. Imlortunatcly the presentation of experimental design, as well as sufficient data and or statistical analyses, are often lacking. This is true for some indiv idual researchers as well as for several manufacturers c the dev ices, especially those for inorganic compounds If or, recommendation regarding laboratory testing is made, would be that those researchers inv olv ed in the evaluation c passive dosimeters in the laboratory take the time to repor the conditions of their experiments, especially equipmer used and procedures for determining "know n" concentra tions, and as much detail about their results as possible. I summarized data arc presented, the author should preser. the known concentration at each level, where levels ar determined by concentration and lime, the number of obser vat ions made with passive dosimeters, and the average valu and standard deviation of the results. Statistical analvseagain at each level tested, should involve determination c the coefficient ol variation (precision) and the bias a described in equations (7) and (S). respectivelv. Once th evaluations are made at the various test levels, the determi nation of a pooled precision and bias is appropriate I: addition to these measurements, researchers may aN choose to present an overall system accuracy. 1 o develop . better understanding of appropriate statistical technique and their application to passive dusimetrv. a review o l.autenbcrger ei at. is recommended.'11' For most active monitoring systems used in industry hygiene the random sampling error is usually assoctatec with the pump and is traditionally set at x 5 percent u lr many cases, especially lor the measurement of organs ' vapors, the analytical procedures and consequently thei associated errors are equivalent lor both passive and activ-. systems. Nevertheless, both systems have random error consequently, one should not expect perfect agreement o the results of comparisons obtained under field test condi tions. Another lactor complicating the evaluation ol ficlc results is the greatly increased possibility for the introduc tion of operator, or systematic, errors. Since active system* require mechanical pumps, the potential for operator erior would seem to be greater than for passive systems. Overall, it is apparent that existing field observationcomparing passive dosimeters with standard monitoring rftethods are highly varied. While some studies demonstrate good correlation and slope.'0''4'' others show only good correlation.1' or are extremely varied lor both categories "" Collectively, these references neither support nor refute th-. use of passive dosimeters. Certainly environmental lactor affect active systems as well as passive systems. In theory a case can be made that environmental factors (wind anc humidity ) affect passive systems to the greatest extent, w hi It temperature and pressure variations most greatly atks' active svstems. On the other hand one can also state that poor experimental quality control may affect such factors acontamination. time measurement error, and antilytica error. Of course, chemical interlerences may ufleci both systems. As with laboratory experimentation, recommendation regarding the field testing of passive dosimeters involve u pica for better reporting ol both tield conditions and result* of analysis. First, for both personal and area monitoring, the estimation and or measurement of face velocity is impot- Ampncar Asfutuwn JG'JRNAl (4J ? Z7 3M 111074 SI? tanl, Of equal importance is the reporting of airborne con.aminams other than the one(s) of interest and en\ ironmena! variables including temperature, pressure, and relative hurmditv along with information as to their variation over ihe period of observation. Again, if raw data cannot be tr^^ted. the reported results for each level tested (X value us^Brmined b_\ the standard method) should include the lumber of observations made with passive dosimeters, and heir associated mean and coefficient of variation. Statistical evaluations also should include a regression analysis of the data as outlined earlier. Undoubtedly. additional research is needed on the effect of not considering the error associated vith the supposedly, independent (X) variable. In summary, passive dosimeters show great promise as an mportant tool. The results presented in Tables 1 and II .ndicate that the precisions of the dosimeters are essentially equiv a lent to conv entional techniques and in mans cases the additional five percent error associated with mechanical umps makes passive dosimeter systems even more attracivc. This, coupled with their ease of use. lack of required taintenance, acceptance by workers due to light weight, and mnecessary calibration make passive dosimeters extremely dvantageous. Certainly they will not replace conventional nethods. as these have their place, especially for area sam'ling. The continued and growing use of passiv e dosimeters, owever. should generateadditional data documentingtheir eliability and eliminating doubts about their usefulness. cknowledgement he assistance of Dr. H. Kenneth Dillon. Head. Industrial I vxicnc Chemistry Section of Southern Research Institute. n^Bjcally review ing this paper is gratefully acknow ledged. eferences 1. Tompkins. F.C. and R.L. Goldsmith: A New Personal Dosimeter for Monitoring of Industrial Pollutants. Am. Ind Hyg Assoc J 30:371-377(1977). 2 West, P.W. and K.D. Reiszner: Field Tests of a Permeation- Type Personal Monitor for Vinyl Chloride Am Ind. Hyg. Assoc J. 39 645-650 (1 978). ' 3. Lugg. G.A.: Diffusion Coefficients of Some Organic and Other Vapors in Air. Anal. Chem. 40 1072-1077 (1968) 4. Montalvo. J.G.: Total Elemental Content Passive Personal Monitors. Am. Ind Hyg Assoc. J. 40 1046-1054(1979). 5 3M Company: Organic Vapor Monitor Sampling Rate Vali dation Protocol. St. Paul, MN 5. Jonas. L.C.. C.E. Billings, and C. Ulis: Laboratory Perfor mance of Passive Personal Samplers for Waste Anesthetic Gas (Enflurane) Concentrations. Am. Ind. Hyg Assoc. J 42 104-111 (1981). 7 Woebkenberg. M.L.: Current NIOSH Research on Passive Monitors. In Proceedings of the Symposium on the Develop ment and Usage of Personal Monitors for Exposure and Health Effect Studies, pp 27-33 Evironmental Protection Agency, EPA - 600/9-79-032 (1979). 8 Environmental Protection Agency: Laboratory Evaluation of Commercially Available Passive Organic Persona! Moni tors. Contract Number 68-02-2686 ) Hickey. J.L.S. and C.C. Bishop: Field Comparison of Char- ^^^oal Tubes and Passive Vapor Monitors with Mixed Organic ^^wapors Am. Ind Hyg Assoc. J. 42 264-267 (1981). 3 10. U S. Department of Health, Education, and Welfare: Doc umentation of NIOSH Validation Tests. NIOSH 77-185. Cincinnati (April. 1977). 11. Lautenberger. W.J.. E.V. Kring, J.A. Morello: A New Per sonal Badge Monitor for Organic Vapors. Am. Ind. Hyg Assoc. J. 41 737-747 (1980). 12. Bamberger, R.L.. G.G. Esposito. B.W. Jacobs. G-E. Pod lak and J.F. Mazur: A New Personal Sampler for Organic Vapors. Am Ind. Hyg Assoc. J. 39 701 -708 (1978) 13. National Mine Safety Company: GASBADGE Product Bulletin Chlorinated Solvents Performance Data. Oakdale. PA (1979) 14. National Mine Safety Company: GASBADGE Product Bulletin Aliphatic and Aromatic Performance Data. Oakdale. PA (1979) 15. Anonymous: Guide for Use of Terms in Reporting Data in Analytical Chemistry, Anal. Chem. 52.221 (1980). 16 Shotwell, H.P., J.C. Caporossi. R.W. MeCollom and J.F. Mellor: A Validation Procedure for Air Sampling Analysis Systems Am Ind Hyg Assoc. J. 40 737-742 (1979). 17. D'Agostino. R.B. and J.L. Gillespie: Comments on the OSHA Accuracy of Measurement Requirement for Monitor ing Employee Exposure to Benzene Am Ind. Hyg. Assoc J 39 510-513 (1978). 18 Carlson, F.D.. E. Sobel and G.S. Watson: Linear Relation ships Between Variables Affected by Errors Biometrics 22 252-267(1966). 19. Tuggle, R.M.: Incorrect Use of f-Tests. Am. Ind. Hyg. Assoc. J. 42 325-326 (1981). 20. Gordon. C.S. and J.T. Lowe: Carbon Monoxide Detector U S Patent 1.644.014(1927). 21. Plantz. C.A., P W. McConnaughey and C.C. Jenca: Colori metric Personal Dosimeter for Hydrazine Fuel Handlers Am. Ind Hyg Assoc J 29:162-164 (1968). 22. Palmes. E.D. and A.F. Gunnison: Personal Monitoring Devices for Gaseous Contaminants Am. Ind. Hyg Assoc. J 34 78-81 (1973). 23. Mazur. J.F., R.L. Bamberger and G.E. Podolak: Develop ment and Evaluation of an Ammonia Dosimeter. Am. Ind. Hyg. Assoc J. 39 749-753 (1978) 24 Kring. E.V.. W.J. Lautenberger, W.B. Baker, J.J. Douglas: A New Passive Colorimetric Air Monitoring Badge System for Ammonia, Sulfur Dioxide, and Nitrogen Dioxide Am. Ind. Hyg Assoc. J. 42:373-381 (1981). 25 ACGIH: Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1981. American Conference of Govern mental Industrial Hygienists. Cincinnati (1981). 26. DuPont: PRO-TEK Colorimetric Air Monitoring Badge Sys tem Laboratory Validation Report, Ammonia Badge. Type C-10 E.l. DuPont de Nemours and Company, Wilmington, DE (1981). 27. Shor. R.M. and L.W. Anders: Direct Read Carbon Monoxide Monitor Performance Under Possible Use Conditions. Pres entation at American Industrial Hygiene Conference. Portland. OR (May 25-29. 1981). 28. Hardy, J.K.. P.K. Dasgupta. K.D. Reiszner, and P.W. West: A Personal Chlorine Monitor Utilizing Permeation Sampling Env. Sci. Tech. 13 1090-1093(1979). 29. Moleculon Research Corp.: PROPLASTIC Chlorine Vapor Badge Information, Cambridge. MA. 30. Hardy, J.K., D.T. Strecker, C.P. Savariarand P.W. West: A Method for the Personal Monitoring of Hydrogen Sulfide Using Personal Sampling Am. Ind. Hyg Assoc. J. 42 283 286 (1981), 31. Graedel. T.E. and J.P. Franey: Gaseous Hydrigen Sulfide Determination by Discoloration of Lead-Stabilized PVC. Am Ind Hyg. Assoc J 47:947-953(1979). Am Ind Hyg Assoc J (43) August 1982 3M 111075 32 WcCammon, C S- and J.W. Woodfin: An Evaluation of Passive Monitor for Mercury Vapor Am. Ind. Hyg. Assoc. J. 38 378-386 11977) 33 McCammon. C.S.. S.L Edwards. R.D. Hull. W.J. Woodfin: A Comparison of Four Personal Sampling Methods for the Determination of Mercury Vapor Am. Ind. Hyg. Assoc. J. 41 528-531 (1980). 34 Cohen, H.J., R.K. Zahray. A.C- Misiaszekand H.J. Muranko: A New Passive Dosimeter for Mercury Presentation at American Industrial Hygiene Conference, Portland, OR (May 25 29 1981). 35 Palmes. E.D.. A.F. Gunnison, J. DiMattioand C.Tomczyk: Personal Sampler for Nitrogen Oioxide Am. Ind. Hyg. Assoc. J.37 570-577 (1976) 36 McMahon. R..T. Klinger. B. Ferber and G. Schnakenberg: New Technology for Persona/ Sampling of NO. and NO\ in the Workplace Presentation at American Chemical Society Exposition Symposium. Las Vegas. NV(August 25-28.1980). 37 OuPont: PROTEK Colorimetric Air Monitoring Badge Sys tem Laboratory Validation Report, Nitrogen Dioxide Badge, TvpeC-30 El DuPont de Nemours and Company. Wilmington. DE (1981) 38 DuPont: PRO-TEK Colorimetric Air Monitoring Badge Sys tem Laboratory Validation Report. Sulfur Dioxide Badge, TypeC-20 El DuPont de Nemours and Company. Wilmington, 0E (1981). 39 Silverstein. L.G.: Validation of Abcor GASBADGE for Acrylo nitrile and Improved Desorption Efficiency. Am Ind. Hyg. Assoc J. 38 412-413 (1977) 40. Hirayama. T. and M. Ikeda: Applicability of Activated Car bon Felt to the Dosimetry of Solvent Vapor Mixture. Am Ind. Hvg Assoc J 40 1091-1095(1979) 41 Halliday. M.M. and J. Anderson: Determination of Halothane n Operating Theatre Air by Using a Passive Organic Vapor Dosimeter The Analyst 105 289-292 (1980). 42 Evans. P.R, and S.W. Horstman: Desorption Efficiency Determination Methods for Styrene Using Charcoal Tubes and Passive Monitors Am Ind Hyg. Assoc J. 42 471 476 (1981) 43 Anders, L.W. and H.E. Mullins: Comparison of Diffusions! Organic Vapor Monitors with Charcoal Tubes for Sampling Laboratory Challenges to Contaminant Mixtures Presenta tion at American Industrial Hygiene Conference. Portland. OR (May 25-29. 1981) 44 Mazur. J.F.. G E. Podolak. G G Esposito, D.S. Rinehart and R.E. Glenn: Evaluation of a Passive Dosimeter for Col lection of 2-8romo-2-Chloro-1.1,1-Tnfluoroethane and 2Chloro-1,1.2-Trifluoroethvl Difluoromethyl Ether. Am. Ind. Hvg Assoc J 41 317-321 (1980) 45 OuPont: PRO-TEK Organic Vapor Air Monitoring Badges " Laboratory Validation Protocol for Diffusion-Type Air Moni toring Badges with Solid Solvents. E.l. DuPont de Nemours and Company. Wilmington. DE (1981). 46 DuPont: Laboratory and Field Validation Report for PRO-TEK G-8B Diffusion-Type Badges for Monitoring Benzene Vapors. E I DuPont de Nemoursand Company. Wilmington. DE(1981). 47. 3M C mpany; 33520 Organic Vapor Monitor with Backu Section. St. Paul. MN 48. Mazur, J.F., D.S. Rinehart, G.G. Esposito and G.E. Podolak Evaluation of Passive Dosimeters for Assessing Vapc Degreaser Emissions Am Ind. Hyg Assoc. J. 42 752 756(1981) 49. Nelms, L.H.. K.D. Reiszner and P.W. West: Personal Vin> Chloride Monitoring Device with Permeation Technique fc Sampling Anal Chem 49 994-998 (1977), 50. Bailey. A. and P.A. Hollingdale-Smith: A Personal Diffu sion Sampler for Evaluating Time Weighted Exposure tc Organic Gases and Vapors. Ann. Occup. Hyg 20 345 356(1977). 51. Benson, G.B. and G.E. Boyce: A Thermally-Desorbable Passive Dosimeter for Personal Monitoring of Acrylonitrile Ann. Occup Hyg 24 55-75(1981) 52. Campbell. J.E. and R.B. Konzen: The Development of Passive Dosimeter for Aniline Vapors. Am. Ind. Hyg Assoc J 41 180-184(1980). 53. Mullins. H.E. and L.W. Anders: A New Innovative Diffu siona!Monitor tor Sampling Ethylene Oxide in Air Presents tion at American Industrial Hygiene Conference. Portland OR (May 25-29. 1981). 54. Rodriguez, S.T., P.B. Olson and V.R. Lund: Colorimetric Analysis of Formaldehyde Collected on a Diffusional Moni tor. Presentation at American Industrial Hygiene Confer ence. Portland, OR (May 25-29. 1981). 55. DuPont: PRO-TEK Colorimetric Air Monitoring Badge Sys tem Laboratory Validation Report. Formaldehyde Badge. Ser ies II, Type C-60. E I. DuPont de Nemours and Company Wilmington. DE (1981). 56. Kriesel, R.S.: Formaldehyde Vapor Detection -- New Sam pling Technology. Presentation at American Industrial Hygiene Conference. Portland, Or (May 25-29. 1981), 57. Matherne. R.N., P.L. Lubsand E.J. Kerfoot: The Develop ment of a Passive Dosimeter for Immediate Assessment o< Phosgene Exposures. Am Ind. Hyg. Assoc. J. 42 681- 684(1981). 58. Hill. R.H. and D.A. Fraser. Passive Dosimetry Using Detec tor Tubes. Am. Ind. Hyg. Assoc. J. 41:721 -729 (1980). 59. Jones, W., E.D. Palmes. C.Tomczykand M. Mills n: Field Comparison of Two Methods for Determination of NO. Con centrations in Air. Am. Ind. Hyg. Assoc. J. 40 437- 438(1979). ' 60. Evans, M.. M. Molyneux, T. Sharp. A. Bailey and P. Hollingdale-Smith: The Practical Application of the Portor. Diffusion Sampler for the Measurement of Time Weighted Average Exposure to Volatile Organic Substances in Air ' Ann. Occup. Hyg. 20.357-363 (1977). 61. Zaebst. D.D.. M.F. Boenigerand J.R. Burg: Field Compari son of Two Passive Organic Vapor Sampling Devices to the Charcoal Tube. Presentation at American Industrial Hygiene Conference, Houston, TX (May 18-29. 1980). 62. McKee. E.S.. P.W. McConnaughey and I.M. Pritts: Colori metric Personal Dosimeters for Some Inorganic Contami nants. Mine Safety Appliances Co . Pittsburgh, PA. 29 December. 1981: Revised 8 February. 1982 Amencm industrial Hy(ifne Association JOURNAL (43! S V 3M 111076 62: Am Ind. Hyg Assoc. J 43(8) 569-574 (1982) A simple method for the determination of desorption fficiencies of organic compounds collected on the 3M 3500 Organic Vapor Monitor has been developed. The technique involves the introduction of the organic compound, in the liquid stat . onto a piece of filter paper placed between the elutriation cap and the diffusion plate of the organic vapor monitor. This is accomplished by direct injection of the organic compound through the center elutriation port of the monitor cap. The port is closed and the organic compound is given sufficient time to vaporize and consequently be adsorbed by the charcoal sorbent. The filter paper is removed and analyzed as a separate sample to assure complete transfer of the organic compound. All samples are desorbed by a suitable solvent and analyzed by gas chromatography. Desorption efficiencies for methyl chloroform, benzene, heptane, acetone, dioxane, isobutanol and ethyl acetate are determined. A comparison with results by the phase equilib rium method is made. Determination of desorption efficiencies in the 3M 3500 Organic Vapor Monitor S.T. RODRIGUEZ, M S., D W. GOSSELINK. Ph.D. and H.E. MULLINS Occupational Health & Safety Products Division. 3M Company, St. Paul, Minnesota 55144 introduction For a quantitative determination of the amount of contami nant collected on any sorbent, it is necessary to know how much of the adsorbate is eluted out. The ratio of the mea sured weight recovered by the desorbing solvent to the known weight of contaminant added to the adsorbent is defined as the desorption efficiency or recovery coefficient. One procedure for determining recovery coefficients from charcoal tubes involves direct injection of a known amount of the liquid compound into the activated charcoal using a microliter syringe.111 After overnight standing, the sample is eluted with an appropriate solvent and analyzed by gas chromatography Especially for polar compounds, the results from this method are often inconsistent.1'1 In addition, direct spiking of liquid does not correspond to actual field sam pling of vapor from the atmosphere. Liquid spiking may bea source of error, since the compound is localized in a small area of the sorbent rather than being uniformly distributed throughout the sorbent. In activated charcoal sorbent, the spaces, called pores, between the individual microcrystallites may be furtherclassified as: a) micropores, with effective radii of less than 18-20 Angstroms, comprising a minimum of 95% of the total surface area; b) mesopores. also called transitional pores, where capillary condensation takes place: with effective radii of roughly 20-1000 Angstroms which make up not more than 5% of the total surface area; and The ratio in which thedifferent classes of pores are present in a specific type of activated charcoal dictates its suitability for specific purposes. Microporous activated carbons are most effective for adsorption of small concentrations of gases and vapors. On the other hand, mesoporous carbons are better used to recover industrial solvent vapors. The pore size distribution determines the adsorption desorption pro cesses involved and also the resulting efficiencies. Micro pores may be suitable for efficient adsorption of vapors but consequent desorption from them is difficult since there may be no room for a displacing agent to enter.'4' Consider a model picture of the microcrystallites of acti vated charcoal.'31 During a vapor spike, schematically shown in Figure la, we can imagine the molecules first entering the macropores, then the mesopores and finally the micropores where some interactions with the walls tend to increase retention and decrease recovery by a solvent. However, a liquid spike would be concentrated in spots and tend to wet the walls of the mesopores. Imagine now that we have menisci as in Figure lb. which exhibit some surface tension. It has been verified experimentally that the vapor pressure of solvents in capillaries of a few microns radius are lowered 10-80 times more than what the Kelvin Equation predicts.'61 The Kelvin Equation relates the normal vapor pressure of a liquicTfassuming a fiat surface) to that observed over the curved surface of the liquid given its spherical surface radius. A decrease in vapor pressure makes it harder for the liquid to vaporize and occupy the micropores. The liquid would tend to stay in the mesopores where wall effects are small and the energy of adsorption is less. Consequent elution would then result in higher recoveries. c) macropores with effective radii of more than 1000 Angstroms which are too big to be filled by capillary condensation.'31 With these possible deficiencies of liquid spiking in mind, the vapor-state spiking technique for the 3M 3500 Organic Vapor Monitor was developed. American Industrial Hygiene Association JOURNAL Copyright 1982 Anierican Industrial Hygiene Association M3) 8/82 3M 111077 569 Figure ' a Concept of molecules m activated charcoal pores Figure 1b -- Menisci formation by molecules in activate cnar coal pores experimental gas chromatography A Hew iet!-f\ickard 5X4l)-\ gas eh". mutograph equipped .'.it" a I'aitte an detector arte n automatic sampler, M u,i' ^-ed The colur'" - wete 15', C'atbowa\ ion me'" Supdeoport, ' rti Mmniiul glass tb ; ! 4 n i 1' Curbouav 2n\1 on M) 11)0 mesh ('hr miosorh W . 2 : m 5 2 mm o a stainless steel 1 7 I 2 It * I ''.mi !0 h F>-2 ' 11() on >0 100 e'h Supdeoport. 5 0 m ^ 5 2mm->d 'tam-c" steel l 10 It ! X in i.O l',SP-IOOO on so 100 n'es.n C at^opack I X ;v 1 \2mmod stainless stee. it' It ! , anj (.hromos h |0|. loo 120 mesh. I) 4 ni n 4 O' o q glass , 5 tt c in, I s-i:,'p'cs /ed were son1.. 'ted m 1 ml glassetals sejetuun I.1,",- ed septum eu r ' procedure Foi the \ap >r stat spiking teehn _..e, Whatman -4 Idler paper. ! o err. .n d.ameter. was pltu/4 between the eltitriation cap and the dittusion plate tr each 1 \1 5500 Organic kapi'i Moni'.i" The elutrumon car- a ere snapped on and a known qttan: o; the organic so . ent utulet studv was tiicw'.-d sint, 'he paper through th_ .entei clutnation port I he pott was s osed and the system a as allowed to stand at room temperature to.r lb-24 hours ">etore elution to give suti.cien; tone tor total transfer o' 'ue organic compound Irom the lilter paper to the sorbent 570 Gaseous compounds, i.t\. ethyl chlonde. wete studies! b\ inserting a rub her septum into the center chit i .a: m p, -i .rd tmeenng the known quantity sit gas through th: sep'uf war. ;i gaslight svttnge In this ease, the iiltci p p - w..- : m. ntttesl I he s\ stem was allowed to 'land at ' o, r. t ,,::;\:.i:;.rr overntghi prior to dution \nother alternative lor gas spikes was to ,o` ,-t tae 'M 5500 Organic \ apor Monitor w tth a Ly Imdrm ev." slome equipped with art iniection port and a letior- :\5 -ep: .m. as in Figure 2 lo insure against leakage I'.;1 .trm* was wrapped around the glass at contact poiitm w ::*e mou toi I he know n amount s'l gas was then uaeste.l t'ni ougn the septum into the air above the momtoi \:tc 'Mnsl ue lisHti'. the diime. banter ttlrn and the but .c ' m hc'Cm o' the momini wem temovesl I he eii.tiuo on , . p w ' snapped into p'a. attsl noth pint' dosiC \ m .isut. u \ .;utue l I 5 m I ) ol cim ' w. .K " momts'r through the center port using an at.toma'.e dis penser I he pot t was resettled a tui t he s.i m p4 w a - a. i w ed to elutriate lot one-hall hour with occasional gculU agita tion \|tei decanting the dilate Irom the mop..:.-: .u'`'du" vials analysis bv gas chromatography w.i- ' "pud ,ir cadi sample I he tiltei papet ol eadt s.iu.p- -v i '-a- ratdv analysed Standards were prepared bv spiking an equo- a!cut amount of the organic compound into sealed ghi" v tai' containing I 5 ml ol the appropriate eluent using the 'time uueetioti 3H 111078 room temperature, decanted into glass vials, sealed, and analysed by gas chromatography. ivringe. The punctured seals were replaced bv new ones and the standards prepared were kept m the refrigerator at 5 C. Betore analysis, they were allowed to come to room temperature. A parallel experiment using the Phase Equilibrium method as run simultaneously.1,1 Working solutions of organic compound? diluted with the appropriate solvent were pre pared. The charcoal sorbent in some monitors was removed and 1 5 m i. of the working solution were added through the center port ot the elutriation cap These were used as the standard- An equal aliquot was added to another set of monitor' >nich still contained the charcoal sorbent. Both 'ets of monitors for each organic compound under investigation were allowed to elutriate for one-half hour at results and discussion The sampling rates of the 3M 3500 Organic Vapor Monitor for acetone, ben7ene, dioxane, ethyl acetate, ethyl chloride, heptane, isobutanol, methyl chloroform and methyl ethyl ketone are listed in Table I. The Threshold Limit Value Time-Weighted-Average(TLV-TW A) concentration for each compound was taken from the ACGIH handbook.18' The amount spiked was the number of milligrams expected in a monitor which samples a concentration of one-half TLV-TWA for four hours except when it was beyond the capacity of the monitor. For those cases. 75^ of the capacity was used. Considering bcn7ene with a sampling rate of 35.5 cc ' min and a TLV-TWA of 30 mg m3, we expect 0.1 mg adsorbed by the monitor at one-half TLV-TWA for four hours (mg = 35.5 cc min X 60 mitt hr X 4 hrs X 30 mg/ m3 X 1 2 X 1 m3 I06 cc). A comparison of desorption efficiencies obtained by the vapor-state spike and by the Phase Equilibrium method is shown in Table II. The results of five determinations per experiment are given with standard deviations. There is close agreement between the two methods except for the results of isobutanol and ethyl chloride. Both of these were eluted with methylene chloride while the rest were desorbed with carbon disulfide. Table III lists some physical constants for methylene chlo ride. isobutanol and ethyl chloride. When two atoms with different electronegativities are bonded together, the bond ing electrons spend a greater time near the atom of higher electronegativity, so that there is a net positive charge at the other atom and the molecule takes on a polar character. The dielectric constant and dipole moment are measures of polarity; the higher the value, the more polar is the com pound. The measured diffusion coefficients for methylene chloride and isobutanol are listed while that for ethyl chlo ride is,a theoretical value from the Hirschfelder Equation.18' TABLE I Compound Guide for Determination of Desorption Efficiencies in the 3M 3500 Organic Vapor Monitor Compound OVM Sampling Rate cc/min TLV-TWA"' PPM mg/m Spiked Amount* mg Acetone Benzene Dioxane Ethyl Acetate Ethyl Chloride Heptane Isobutanol Methyl Chloroform Methyl Ethyl Ketone 40 1 35 5 34 5 34.5 38.8 28 9 35.9 30.9 36.3 (1000) ' 10 (50) * 400 1000 , 400 50 350 200 (2400) 30 (ISO) 1400 2600 1600 150 1900 590 2,2 01 0.8 5.8 02 56 06 70 26 Amount sampled by the monitor at a concentration of 1 /2 TLV-TWA for four hours except when it is beyond the capacity of the monitor For those cases, the amount spiked, is 75% of the capacity. American inauiirial Hygiene Assoc.-alion JOURNAL ~3 3,32 3M 111079 The molecular radius of the compounds were predicted from atomic volumes."01 From our concept of the activated char coal surface with the different pore structures, we can imagine that with the presence of both methylene chloride and isobutanol in the Phase Equilibrium method, there results a competition between the two compounds as they travel into the pores. The greater mobility of the smaller molecule, in this case, methylene chloride, also results in faster diffusion tnto the micropores. Another contributing factor is the higher concentration of methylene chloride, present as the solvent, which allows for more collision and interaction with the surface than the isobutanol, permitting deep penetration into the finer pores. There exists, therefore, a higher concentration of isobutanol in the mesopores which have lower energies of adsorption. Upon decantation and analysis of the resulting solution, high isobutanol recoveries are obtained. Using vapor-state spiking, there is no competitor with isobutanol for the active sites on the charcoal surface, so the molecules are free to seek even the fine pores which have higher energies of adsorption. We have observed that a 30 minute interval was sufficient to transfer all the spiked isobutanol from the filter paper to the charcoal. For an experiment, several monitors were spiked with isobutanol and allowed to stand for0.5. 1.0. 4.0 and 24 hours prior to elution and analysis. Even at 30 minutes, no trace of isobutanol was found on the filter paper. Table IV shows that a longer adsorption time can cause lower recoveries for isobutanol. More molecules are adsorbed in the micropores, thus, desorption is difficult. Since analysis of samples does not immediately follow the field sampling, it is therefore recom mended that the method used for determination of desorp tion efficiencies be designed to duplicate actual use situa tions as closely as possible. The effect of time was also studied for the Phase Equili brium method using ethyl chloride. Aliquots of a prepared solution of ethyl chloride in methylene chloride were added to several organic vapor monitors and were analyzed at different time intervals, the results in Table V showachange in the adsorption desorption process w ithin 24 hours, giving an average desorption efficiency of 1.02 0.01. TABLE II Comparison of Desorption-Efficiencies Desorption Efficiencies Compound Vapor Spike Phase Equilibrium Acetone Benzene ioxane Ethyl Acetate Ethyl Chloride Heptane. Isobutanol Methyl Chloroform 0.93 0.03 0.99 0.01 0.92 = 0,03 0.98 = 0 03 0.81 0.03 1.04 O 03 0.90 C.02 1.02 0.02 0.94 0.01 0.99 + 0 01 0.88 0.02 0.98+0.01 1.01 0 01 1.03 0 01 1.04 0 01 1.02 0.01 These data also demonstrated that the 3M 3500 Organic Vapor Monitordoes not leak and that the monitor materials are inert both chemically and physically. The efficient seal of the organic vapor monitor was further verified by a test wherein monitors with the elutriation caps on were exposed to a chamber saturated with xylene vapors for two hours. A control sample without a cap was used and this collected about 59 mg of xylene while the capped ones only showed trace amounts. The results from an investigation of concentration effects on desorption efficiencies by both vapor-state spiking and Phase Equilibrium methods are summarized in Table VI. The concentrations chosen were all less than the suggested spiked amount of 2.6 mg MEK 1.5 mL carbon disulfide (see Table I). ~ The unpaired t statistical evaluation of the data showed no significant differences between the desorption efficiencies of concentration Levels II and 111 for both methods."1' At a confidence level of 95<?r. the test statistic t values for the vapor-state spiking method and for the Phase Equilibrium method were 0.24 and --0.89. respectively. Desorption effi ciency values at concentration Level I were significantly different from the pooled results of concentration Levels II and 111 for both methods. At low concentrations, the walls ot the pores in the sorbent strongly hold onto the molecules ot the compound and the eluent cannot completely sever all bonds formed, thus creating a case of irreversible adsorption A comparison between a vapor-state spike and a directly injected liquid spike onto the charcoal sorbent ot the 3M TABLE III Physical Constants"'111 Methylene Chloride Isobutanol Ethyl Chloride Molecular Formula Molecular Weight Boiling Point Dielectric Constant Dipole Moment Diffusion Coefficient Molecular Radius CHaC1a 84.94 39 75 C 1 0065 (gas) 9.08 (liq.) 1.60 debyes . 0.1037 crrr'/sec. 4 754 Z C-tHmO 74.12 108 C 15.8 (liq.) 1.64 debyes 0.0880 cmVsec. 5.637 X CjH-.C! 64.52 12.3 C 1 0132 (gas) 2.05 debyes 0 1134 cm2/sec. 4 856 X 3H 111080572 Am Ind Hyg Assoc J (A3) August 198C TABLE IV Effect of Time on Vapor State Spiking of Isobutanol Adsorption Time (hrs) Desorption Efficiency 0.5 1.0 40 240 0 97 0.99 0.98 091 TABLE V Effect of Time on Phase Equilibrium Method for Ethyl Chloride Adsorption Time (hrs) Desorption Efficiency 0.5 1.0 20 3.0 5.0 60 70 24 0 Average 1.02 1 01 1 01 1.03 1.01 1 02 1 02 1 01 1 02 x 0 01 .'500 Organic Vapor Monitor was made and the results are listed in Table VII. No difference in the desorption efficien cies ol MEK by both methods was seen when overnight adsorption was utilized (test statistic t was --0.973 at a = 0.05). The effect of different adsorption time intervals was studied. Results are given in Table VIII. It was noted that complete transfer of the compound from the filter paper to the sorbent was accomplished within 30 minutes prior to elution. No significant change was observed'esen after 24 hours adsorption time by the vapor-state spike method. On the other hand, a slight decrease in desorption efficiency was observed using the direct liquid spike method. summary The efficiency of elution recovery processes can be affected by many variables, including sample introduction, adsorpti on desorption time, chemical structures and concentration. M uch of the variability can be explained by differences in the mechanisms of filling and emptying the pores of specific shape and size. Since the filling of pores of the sorbent in the 3 M 3500 Organic Vapor Monitor in an actual field sampling of vapors from the atmosphere runs parallel to that in the vapor-state spiking method, more reliable desorption effi ciencies by this latter method is expected. Although it was shown that no differences were found between the vapor-state spiking method and the direct liquid spiking method for the determination of the MEK desorp tion efficiency, other factors like concentrations, the length of time of adsorption and chemical structure may make American Industrial Hygiene Association JOURNAL (43) 8/32 TABLE VI Effect of Concentration on Desorption Efficiency of MEK Concentration (pg/mL) Vapor-State Spiking Technique Phase Equilibrium Technique Level 1 80.54 0.70 0.69 0.69 0.68 0 70 Average. 0.69 = 0 01 0.94 0.87 0.92 0.86 085 0.89 0.04 Level II 805.4 0 90 0.89 0.90 Average. 0,90 0.01 0.91 0.95 0.93 0.93 0 02 Level III 1610.8 0.87 0.90 0.92 0.89 0 89 Average' 0.89 x 0 02 1.02 0.93 0 95 0.93 0 93 0.95 x 0 04 G.C. Column Temperature. Carrier Gas1 MEK Retention Time, 15% Carbowax 20M on 80/10O mesh Supelcoport. 1.8 m X 6.4 mm o.d. glass (6 ft. X 1/4 in ) Isothermal 60 C Helium 30.3 mL/min, 1 25 minutes TABLE VII Comparison of Desorption Efficiencies of MEK Vapor Spike Liquid Spike 0.92 092 089 0.91 0.92 Average. 0.91 0.01 Average: 0.91 092 0.92 0.92 0.92 0.92 x 0.004 TABLE VIII _ Effect of Time on Desorption Efficiency of MEK Desorption Efficiency Adsorption Time Vepor State Liquid (hrs) Spike Method Spike Method 0.5 1.0 4.0 24.0 0.91 0.90 0.92 0.90 094 092 0.91 0.91 3H 111021 573 greater differences. In our experiment, we used the suggested spiked amount for MEK representing an exposure of onehalf TLV-TW A for four hours. Measuring lower concentra tions in the field may produce 5-29% differences depending on whether the determination of the desorption efficiency of MEK is doen by the vapor-state spike or the Phase Equili brium techniques. The differences seem to be more pro nounced with polar compounds. The results of the two techniques agreed when less polar to nonpolar compounds were studied. The time of adsorption to achieve equilibrium of the adsorbed molecules with the structural atoms of the surface of the sorbent affects the vapor-state spiking method more than the Phase Equilibrium technique. The vapor-state spiking technique used to determine 3M published values is therefore recommended for the determi nation of desorption efficiencies using the 3M 3500 Organic Vapor Monitor. references 1.NIOSH Analytical Methods tor Set A. Standards Completion Program. National Technical Information Service, Springfield. VA (1975). 2. Burnett. R.D.: Evaluation of Charcoal Sampling Tubes. Am. Ind. Hyg. Assoc. J. 37:37-45 (1976). 3. Ponec, V.. Z. Knor and S. Corny: Adsorption on Solids, p. 578, CRC Press, Cleveland, OH (1974). 4. Hassler. J.W.: Activated Carbon, p. 247, Chemical PublishingXoL, Inc., New York, N.Y. (1963). 5. Adsorpti n Handb ok. Activated Carbon Division. Calgon Corp., Pittsburgh, PA. 6. Adamson. A.W.: Physical Chemistry of Surfaces. 2nd Ed. p. 59. Interscience Publishers. N.Y. (1967). 7. Oonner, R.A. and R.Q. Melcher: Phase Equilibrium Method for Determination of Desorption Efficiencies. Am. Ind. Hyg Assoc. J. 39:240-246 (1978). 8. Threshold Limit Values for Chemical Substances and Physi cal Agents in the Workroom Environment with Intended Changes for 1979. pp. 9-31. American Conference of Govern mental Industrial Hygienists, Cincinnati, OH (1979). 9. Chemical Engineers' Handbook. J.H. Perry, ed. Fourth Edi tion. Section 14-20. McGraw Hill Book Co., N.Y. (1963). 10. Le Bas: The Molecular Volume of Liquid Chemical Com pounds. Longmans, London (1915). 11. Ryan. T.A., Jr., B.L. Joiner and B.F. Ryan: MINITAB Stu dent Handbook, pp. 138-140. Duxbury Press, North Scituate. MA (1976). 12. The Merck Index. M. Windholz. ed. 9th Ed. Merck and Co Inc., Rahway. N.J. (1976). 13. Nelson. G.O.: Controlled Test Atmospheres. Ann Arbor Science Publishers Inc., Ann Arbor. Ml (1971). 21 January. 1982; Revised 8 February. 1982 574 Am Ind. Hyg. Assoc J (All 3M 111082 Determination of Desorption Efficiencies in the 3M 3500 Organic Vapor Monitor S. T. RODRIGUEZ, D. W. GOSSELINK, AND H. E. MULLINS Occupational Health & Safety Products Division 3M Company, Saint Paul, Minnesota 55101 A simple method for the determination of desorption efficiencies of organic compounds collected on the 3M 3500 Organic Vapor Monitor has been developed. The technique involves the intro duction of the organic compound, in the liquid state, onto a piece of filter paper placed between the elutriation cap and the diffusion plate of the organic vapor monitor. This is accomplished by direct injection of the organic compound through the center elutriation port of the monitor cap. The port is closed and the organic compound is given sufficient time to vaporize and consequently be adsorbed by the charcoal sorbent. The filter paper is removed and analyzed as a separate sample to assure complete transfer of the organic compound. All samples are desorbed by a suitable solvent and analyzed by gas chromatography. Desorption efficiencies for methyl chloroform, benzene, heptane, acetone, dioxane, isobutanol and ethyl acetate are determined. A comparison with results by the phase equilibrium method is made. ' 3H 111083 1 I. INTRODUCTION For a quantitative determination of the amount of contaminant collected on any sorbent, it is necessary to know how much of the adsorbate is eluted out. The ratio of the measured weight recovered by the desorbing solvent to the known weight of contam inant added to the adsorbent is defined as the desorption efficiency or recovery coefficient. One procedure for determining recovery coefficients from charcoal tubes involves direct injection of a known amount of the liquid compound into the activated charcoal using a microliter syringe.^" After overnight standing, the sample is eluted with an appropriate s~'vsnt and analyzed by gas chromatography. Especially for polar compounds, the results from this method are 2 often inconsistent. In addition, direct spiking of liquid does not correspond to actual field sampling of vapor from the atmosphere. Liquid spiking may be a source of error, since the compound is localized in a small area of the sorbent rather than being uniformly distributed throughout the sorbent. In activated charcoal sorbent, the spaces, called pores, between the individual microcrystallites may be further classified as: 3M 111084 2 2) micropores, with effective radii of less than 18-20 Angstroms, comprising a minimum of 95% of the total surface area; b) mesopores, also called transitional pores, where capillary condensation takes place; with effective radii of roughly 20-1000 Angstroms which make up not more than 5% of the total surface area; and c) macropores with effective radii of more than 1000 Angstroms which are too big to be filled by capillary condensation.^ The ratio in which the different classes of pores are present in a specific type of activated charcoal dictates its suitability for specific purposes. Microporous activated carbons are most effective for adsorption of small concentrations of gases and vapors. On the other hand, mesoporous carbons are better used to recover industrial solvent vapors. The pore size distribution determines the adsorption/desorption processes involved and also the resulting efficiencies. Micropores may be suitable for efficient adsorption of vapors but consequent desorption from them is difficult since there may be no room for a displacing agent to enter.^ Let us consider a model picture of the microcrystallites of activated charcoal.^ During a vapor spike, schematically shown in Figure la, we can imagine the molecules first entering the macropores, then the mesopores and finally the micropores where some interactions with the walls tend to increase retention and decrease recovery by a solvent. However, a liquid spike would be 3M 111085 3 concentrated in spots and tend to wet the walls of the mesopores. Imagine now that we have menisci as in Figure lb which exhibit some surface tension. It has been verified experimentally that the vapor pressure of solvents in capillaries of a few microns radius are lowered 10-80 times more than what the Kelvin Equation predicts.6 The Kelvin Equation relates the normal vapor pressure of a liquid (assuming a flat surface) to that observed over the curv d surface of the liquid given its spherical surface radius. A decrease in vapor pressure makes it harder for the liquid to vaporize and occupy the micropores. The liquid would tend to stay in the mesopores where wall effects are small and the energy of adsorption is less. Consequent elution would then result in higher recoveries. With these possible deficiencies of liquid spiking in mind, the vapor-state spiking technique for the 3M 3500 Organic Vapor Monitor was developed. .II. EXPERIMENTAL A. Gas Chromatography A Hewlett-Packard 5840A gas chromatograph equipped with a flame ionization detector and an automatic sampler. Model 7672A, was used. The columns were 15% Carbowax 20M on 80/100 mesh Supelcoport (6 ft. x 1/4 in. o.d. glass), 15% Carbowax 20M on 80/100 mesh Chromosorb W (7-1/2 ft. x 1/8 in. o.d. stainless steel), 10% SP-2100 on 80/100 mesh Supelcoport (10 ft. x 1/8 in. o.d. stainless steel), 0.1% SP-1000 on 80/100 mesh Carbopack C ( ft. x 1/8 in. o.d. stainl ss steel) and Chromosorb 101, 100/120 mesh (3 ft. x 1/4 in. o.d. glass). _ 3H 111086 4 Samples to be analyzed were contained in 1 ml glass vials sealed with Teflon-lined septum caps. B. Procedure For the vapor-state spiking technique, Whatman #4 filter paper, 1.6 cm in diameter, was placed between the elutriation cap and the diffusion plate in each 3M 3500 Organic Vapor Monitor. The elutriation caps were snapped on and a known quantity of the organic solvent under study was injected onto the paper through the center elutriation port. The port was closed and the system was allowed to stand at room temperature for 16-24 hours before elution to give sufficient time for total transfer of the organic compound from the filter paper to the sorbent. Gaseous compounds, i.e., ethyl chloride, were studied by inserting a rubber septum into the center elutriation port and injecting the known quantity of gas through the septum with a gastight syringe. In this case, the filter paper was eliminated. The system was allowed to stand at room temperature overnight prior to elution. Another alternative for gas spikes was to cover the 3M 3500 Organic Vapor Monitor with a cylindrical glass dome equipped with an injection port and a Teflon-lined septum, as in Figure 2. To insure against leakage, Parafili^'was wrapped around the glass at contact points with the monitor. The known amount of gas was then injected through the septum into the air above the monitor. After standing 16-24 hours, the dome, barrier film and the barrier film holder of the monitor were removed. The elutriation cap was 3M 111087 5 then snapped into place and both ports closed. A measured volume (1.5 ml) of eluent was added to each monitor through the center port using an automatic dispenser. The port was resealed and the sample was allowed to elutriate for 1/2 hour with occasional gentle agitation. After decanting the eluate from the monitor into glass vials, analysis by gas chromato graphy was performed on each sample. The filter paper of each sample was separately analyzed. Standards were prepared by spiking an equivalent amount of the organic compound into sealed glass vials containing 1.5 ml of the appropriate eluent using the same injection syringe. The punctured seals were replaced by new ones and the standards prepared were kept in the refrigerator at 5C. Before analysis, they were allowed to come to room temperature. A parallel experiment using the Phase Equilibrium method was .7 . run simultaneously. Working solutions of organic compounds diluted with the appropriate solvent were prepared. The charcoal sorbent in some monitors was removed and' 1.5 ml of the working solution were added through the center port of the elutriation cap. These were used as the standards. An equal aliquot was added to another set of monitors which still contained the charcoal sorbent. Both sets of monitors for each organic compound under investigation were allowed to elutriate for 1/2 hour at room temperature, decanted into glass vials, sealed, and analyzed by gas chromatography. 6 3M 111088 III. RESULTS AND DISCUSSION The sampling rates of the 3M 3500 Organic Vapor Monitor for acetone, benzene, dioxane, ethyl acetate, ethyl chloride, heptane, isobutanol, methyl chloroform and methyl ethyl ketone are listed in Table I. The Time-Weighted-Average concentration for each Q compound was taken from the ACGIH handbook. The amount spiked was the number of milligrams expected in a monitor which samples a concentration of 1/2 TWA for 4 hours except when it was beyond the capacity of the monitor. For those cases, 75% of the capacity was used. Considering benzene with a sampling rate of 33.0 cc/min 3 and a TWA of 30 mg/m , we expect 0.1 mg adsorbed by the monitor at 1/2 TWA for 4 hours (mg = 33.0 cc/min x 60 min/hr x 4 hrs x 30 mg/m^ x 1/2 x lm'VlO^ cc) . A comparison of desorption efficiencies obtained by the vapor-state spike and by the Phase Equilibrium method is shown in Table II. The results of five determinations per experiment are given with standard deviations. There is close agreement between the two methods except for the results of isobutanol and ethyl chloride. Both of these were eluted with methylene chloride while the rest were desorbed with carbon disulfide. Table III lists some physical constants for methylene chloride, isobutanol and ethyl chloride. When two atoms with different electronegativities are bonded together, the bonding electrons spend a greater time near the atom of higher electronegativity, so that there is a net positive charge at the other atom and the molecule takes on a polar character. The dielectric constant and dipole 3H 111089 7 moment are measures of polarity; the higher the value, the more polar is the compound. The measured diffusion coefficients for methylene chloride and isobutanol are listed while that for ethyl Q chloride is a theoretical value from the Hirschfelder Equation. The molecular radius of the compounds were predicted from atomic volumes.^ From our concept of the activated charcoal surface with the different pore structures, we can imagine that with the presence of both methylene chloride and isobutanol in the Phase Equilibria method, there results a competition between the two compounds as they travel into the pores. The greater mobility of the smaller molecule, in this case, methylene chloride, also results in faster diffusion into the micropores. Another contributing factor is the higher concentration of methylene chloride, present as the solvent, which allows for more collision and interaction with the surface than the isobutanol, permitting deep penetration into the finer pores. There exists, therefore, a higher concentration of isobutanol in the mesopores which have lower energies of adsorption. Upon decantation and analysis of the resulting solution, higher isobutanol recoveries are obtained. Using vapor-state spiking, there is no competitor with isobutanol for the active sites on the charcoal surface, so the molecules are free to seek even the fine pores which have higher en rgies of adsorption. 8 3M 111090 We have observed that a 30 minute interval was sufficient to transfer all the spiked isobutanol from the filter paper to the charcoal. For an experiment, several monitors were spiked with isobutanol and allowed to stand for 0.5, 1.0, 4.0 and 24 hours prior to elution and analysis. Even at 30 minutes, no trace of isobutanol was found on the filter paper. Table IV shows that a longer adsorption time can cause lower recoveries for isobutanol. More molecules are adsorbed in the micropores, thus, desorption is difficult. Since analysis of samples does not immediately follow the field sampling, it is therefore recommended that the method used for determination of desorption efficiencies be designed to duplicate actual use situations as closely as possible. The effect of time was also studied for the Phase Equilibria method using ethyl chloride. Aliquots of a prepared solution of ethyl chloride in methylene chloride were added to several organic vapor monitors and were analyzed at different time intervals. The results in Table V show no change in the adsorption/desorption process within 24 hours, giving an average desorption efficiency of 1.02 + 0.01. These data also demonstrated that the 3M 3500 Organic Vapor Monitor does not leak and that the monitor materials are inert both chemically and physically. The efficient seal of the organic vapor monitor was further verified by a test wherein monitors 3H 111091 9 with the elutriation caps on were exposed to a chamber saturated with xylene vapors for 2 hours. A control sample without a cap was used and this collected about 59 mg of xylene while the capped ones only showed trace amounts. The results from an investigation of concentration effects on desorption efficiencies by both vapor-state spiking and Phase Equilibria methods are summarized in Table VI. The concentrations chosen were all less than the suggested spiked amount of 2.2 mg MEK/1.5 ml carbon disulfide (see Table I). 12 The unpaired t statistical evaluation of the data showed no significant differences between the desorption efficiencies of concentration Levels II and III for both methods. At a confidence level of 95%, the test statistic t values for the vapor-state spiking method and for the Phase Equilibrium method were 0.24 and -0.89, respectively. Desorption efficiency values at concentration Level I were significantly different from the pooled results of concentration Levels II and III for both methods. At low con centrations, the walls of the pores in the sorbent strongly hold onto the molecules of the compound and the eluent cannot completely sever all bonds formed, thus creating a case of irreversible adsorption. A comparison between a vapor-state spike and a directly injected liquid spike onto the charcoal sorbent of the 3M 3500 Organic Vapor Monitor was made and the results are listed in Table VII. No difference in the desorption efficiencies of MEK by both methods was seen when overnight adsorption was utilized (test statistic t was -0.973 atoC = 0.05). The effect of 10 3H 111092 different adsorption time intervals was studied. Results are given in Table VIII. It was noted that complete transfer of the compound from the filter paper to the sorbent was accomplished within 30 minutes prior to elution. No significant change was observed even after 24 hours adsorption time by the vapor-state spike method. On the other hand, a slight decrease in desorption efficiency was observed using the direct liquid spike method. IV. SUMMARY The efficiency of elution recovery processes can be affected by many variables, including sample introduciton, adsorption/desorption time, chemical structures and concentration. Much of the variability can be explained by differences in the mechanisms of filling and emptying the pores of specific shape and size. Since the filling of pores of the sorbent in the 3M 3500 Organic Vapor Monitor in an actual field sampling of vapors from the atmosphere runs parallel to that in the vapor-state spiking method, we expect more reliable desorption efficiencies by this latter method. Although it was shown that no differences were found between the vapor-state spiking method and the direct liquid spiking method for the determination of the MEK desorption efficiency, other,factors like concentration, the length of time of adsorption and chemical structure may make greater differences. In our experiment, we used the suggested spiked amount for MEK representing an exposure of 1/2 TWA for 4 hours. Measuring lower concentrations in the field may produce 5-29% differences depending on whether the determination of the desorption efficiency of MEK is done by 3M 111093 the vapor-state spike or the Phase Equilibrium techniques. The differences seem to be more pronounced with polar compounds. The results of the two techniques agreed when less polar to non polar compounds were studied. The time of adsorption to achieve equilibrium of the adsorbed molecules with the structural atoms of the surface of the serbent affects the vapor-state spiking method more than the Phase Equilibrium technique. We use the vapor-state spiking technique to determine our published values and recommend it for the determination of desorption efficiencies using the 3M 3500 Organic Vapor Monitor. 3M 111094 12 V. REFERENCES 1. NIOSH Analytical Methods for Set A. Standards Completion Program. National Technical Information Service, Spring field, VA (1975). 2. Burnett, R. D.: Evaluation of Charcoal Sampling Tubes. Am. InJ. Hyg. Assoc. J. 32:37-45 (1976). 3. Ponec, V., Z. Knor and S. Cerny: Adsorption on Solids, p. 578, CRC Press, Cleveland, OH (1974). 4. Hassler, J. W.: Activated Carbon, p. 247, Chemical Publishing Co., Inc., New York, N. Y. (1963). 5. Adsorption Handbook. Activated Carbon Division. Calgon Corp., Pittsburgh, PA. 6. Adamson, A. W.: Physical Chemistry o^ Furfaces, 2nd Ed. p. 59 Interscience Publishers, N. Y. (1967). 7. Donner, R. A, and R. G. Melcher: Phase Equilibrium Method for Determination of Desorption Efficiencies. Am. Ind. Hyg. Assoc. J. 29;240~246 (1978). 8. Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1979. pp. 9-31. American Conference of Governmental Industrial Hygienists, Cincinnati, OH (1979). 9. Chemical Engineers* Handbook. J. H. Perry, ed. Fourth Edition, Section 14-20. McGraw Hill Book Co., N. Y. (1963). 3H 111095 13 10. Le Bas: The Mol cular Volume of Liquid Chemical Compounds Longmans, London (1915). 11. Handbook of Chemistry and Physics. R. C. Weast, ed. 58th Ed. CRC Press, Cleveland, OH (1977-1978). 12. Ryan, T. A. Jr., B. L. Joiner, and B. F. Ryan: MINITAB Student Handbook, pp. 138-140. Duxbury Press, North Scituate, MA (1976). 13. The Merck Index. M. Windholz, ed. 9th Ed. Merck and Co. Inc., Rahway, N. J. (1976). 14. Nelson, G. O.: Controlled Test Atmospheres. Ann Arbor Science Publishers Inc., Ann Arbor, MI (1971). 14 3M 111096 TABLE I COMPOUND GUIDE FOR DETERMINATION OF DESORPTION EFFICIENCIES IN THE 3M 3500 ORGANIC VAPOR MONITOR Compound OVM Sampling Rate cc/Min. O TWA 3 PPM mg/m" Spiked Amount mg Acetone Benzene Dioxane Ethyl Acetate Ethyl Chloride Heptane Isobutanol Methyl Chloroform Methyl Ethyl Ketone 35.4 33.0 33.6 29.4 40.1 27.7 31.2 28.0 31.2 (1000) 10 (50) 400 1000 400 50 350 200 (2400) 30 (180) 1400 2600 1600 150 1900 590 6.9 0.1 0.7 4.9 0.2 5.3 0-6 6.4 2.2 *Amount sampled by the monitor at a concentration of 1/2TWA for four hours except when it is beyond the capacity of the monitor. For those cases, the amount spiked is 75% of the capacity. 15 3H 111097 TABLE II COMPARISON OP DESORPTION EFFICIENCIES Compound Acetone Benzene Dioxane Ethyl Acetate Ethyl Chloride Heptane Isobutanol Methyl Chloroform Desorption Efficiencies Vapor Spike Phase Equilibrium 0.93 + 0.03 0.99 + 0.01 0.92 + 0.03 0.98 + 0.03 0.81 + 0.03 1.04 + 0.03 0.90 + 0.02 1.02 + 0.02 0.94 + 0.01 0.99 + 0.01 0.88 + 0.02 0.98 + 0.01 1.01 + 0.01 1.03 + 0.01 1.04 + 0.01 1.02 + 0.01 16 3M 111098 TABLE III PHYSICAL CONSTANTS13f14 Molecular Formula Molecular Weight Boiling Point Dielectric Constant Dipole Moment Diffusion Coefficient Molecular Radius Methylene Chloride ch2ci2 Isobutanol C4H10 Ethyl Chloride c2h5ci 84.94 74.12 39.75C 108C 1.0065 (gas) 9.08 (liq.) 15.8 (liq.) 1.60 debyes 2 0.10 37an /sec. 1.64 debyes 0.08 80cm3/sec. 4.754 A 5.637 A 64.52 12.3C 1.0132 (gas) 2.05debyes 0.113 4anVsec 4.856 A 3M 111099 17 TABLE IV EFFECT OF TIME ON VAPOR STATE SPIKING OF ISOBUTANOL in o Adsorption Time (hrs) 1.0 4.0 24.0 Desorption Efficiency 0.97 0.99 0.98 0.91 18 3M 111100 TABLE V EFFECT OF TIME ON PHASE EQUILIBRIUM METHOD FOR ETHYL CHLORIDE Adsorption Time (hrs) 0.5 1.0 2.0 3.0 5.0 6.0 7.0 24.0 Desorption Efficiency Average 1.02 1.01 1.01 1.03 1.01 1.02 1.02 1.01 1.02 + 0.01 3H 111101 19 TABLE VI EFFECT OF CONCENTRATION ON DESORPTION EFFICIENCY OF MEK Concentration (^y/ml) Level I 80.54 Vapor-State Spiking Technique Average: 0.70 0. 69 0.69 0.68 0.70 0.69 + 0.01 Level II 805.4 Average: 0.90 0.89 0.90 0.90 + 0.01 Level III 1610.8 Average: 0.87 0.90 0.92 0.89 0.89 0.89 + 0.02 Phase Equilibrium Technique 0.94 0-87 0-92 0-86 0.85 0.89 + 0.04 0.91 0.95 0.93 0.93 + 0.02 1.02 0.93 0.95 0.93 0.93 0.95 + 0.04 G.C. Column: 15% Carbowax 20M on 80/100 mesh Supelcoport 6 ft. x 1/4 in. o.d. glass Temperature: Isothermal 60C Carrier Gas: Helium 30.3 ml/min. MEK Retention Time: 1.25 minutes 3H 111102 20 TABLE VII COMPARISON OF DESORPTION EFFICIENCIES OF MEK Vapor Spike 0.92 0.92 0.89 0.91 0.92 Average: 0.91 + 0.01 Liquid Spike 0.91 0.92 0.92 0.92 0.92 Average: 0.92 + 0.004 3H 111103 21 TABLE VXIX EFFECT OF TIME ON DESORPTION EFFICIENCY OF MEK arption Time (Hrs) 0.5 1.0 4.0 24.0 Desorption Efficiency Vapor State Spike Method Liquid Spike Method 0.91 0.90 0.92 0.90 0.94 0.92 0.91 0.91 22 3M 111104 I I i f I I 1 I I 1 I I E I m FIGURE ib 24 3M 111106 FIGURE 2 25 3M 111107