Document mqdj671ymagB3zeY9De1zDeR4

'.(( ofta 1910 Sunderland Place. N AY. Washington. D C. 20036 202-293-2980 Fax:202-293-2915 jrOTQQ^ Organization Resources Counselor^ Inc. June 13, 1989 Memorandum PLAINTIFF'S EXHIBIT AL-979 To: ORC Occupational Safety and Health Group ORC Western Occupational Safety and Health Group ORC Asbestos Task Force From: Rebecca L. Daiss Subject: NIOSH Studies on Asbestos Exposure Associated with Use of General and Negative-Pressure Glove Bag Removal Methods Attached is a copy a of slide presentation given at the National Asbestos Contractor's Symposium in March 1989, by Bruce Hollet of NIOSH's Engineering Control Technology Branch. Mr. Hollet's presentation was based on findings of an EPA sponsored NIOSH study on the effectiveness of two negative-pressure glove bag methods of controlling asbestos exposure during removal operations. The two types of glove bags examined, neither of which are widely used, were the Aero-pipe Capsule manufactured by Aerospace America, Inc., and a Custom Fabricated Glovebag designed to operate under negative pressure. Although Mr. Hollet presented the preliminary conclusions of the study at the symposium,*the actual study is not yet publicly available. According to Mr. Hollet, NIOSH is waiting for the results of TEM analysis of a number of samples and the report has not yet completed internal review at NIOSH. In the first half of the attached presentation describes an earlier EPA sponsored NIOSH effort to determine the effectiveness of glovebag methods in general. The second part outlines the preliminary findings of the negative-pressure study. In the earlier study, conducted in 1985, NIOSH surveyed asbestos removal projects in four schools in Cincinnati, Ohio. NIOSH issued four reports on the findings of the Cincinnati school surveys in the summer of 1987. General conclusions drawn from observation and analysis of those removal jobs were that glove bag6 alone are insufficient to control daily TWAs below the OSHA PEL under what NIOSH considers to be normal conditions i.e., infrequent glove bag use, limited experience, and inadequate training in the use of glove bags. Accordingly, NIOSH concluded 2- - that use of glove bags by well trained personnel who use glove ' bags regularly would likely result in better containment. However, based on the assumption that the level of training and 3 experience of workers observed in these studies is likely to be typical of workers involved in asbestos removal, NIOSH concluded that a second level of control, e.g. a negative-pressure enclosure, is needed to assure complete containment of asbestos fibers when glove bags are used. If you would like copies of the NIOSH survey reports, please call. According to Mr. Hoilet, the follow up study was conducted to investigate alternatives to the normal glove bag approach and determine if, as expected, negative-pressure glove bags provide better control of asbestos exposure. Preliminary PCM analysis results were favorable for the negative-pressure technology studied. However, NIOSH is awaiting TEM analysis of workers actual fiber exposure before making any definitive conclusions. For more information Mr. Hollet can be reached at (513) 841-4221. OSHA has recently given increased attention to the use of glove bags due to controversy within the Agency's compliance division over when the use of glove bags is permitted under the Asbestos Standard. Apparently, OSHA was considering eliminating the small job exemption, which allows use of glove bags for small jobs, and allowing the use of glove bags for all removal jobs. However, due to concern over NIOSH's findings in the earlier studies and disclosures regarding the most recent study> OSHA is apparently not going to take actions until the agency has reviewed the latest study and assessed the findings (OSHA has also been unable to obtain a copy of the complete study)., A more detailed explanation of. the controversy over regulatory requirements governing the use of glove bags versus negative-pressure enclosures, excerpted from Darrell Mattheis1 Health Standard Update, is attached. OSHA would welcome any sampling data ORC members have, on exposures during removals using glove bags. If you have information you are willing to provide, please send it to either my attention or Darrell's. RLD:lgs Attachments -3- ASBESTOS (exerpt from Health Standards Update) Asbestos continues to be an important issue for OSHA compliance. Presently, the big question is the definition of paragraph (e)(6). The question involves the requirement for negativepressure enclosures, the exception to the requirements of (e)(6) for small jobs, and the definition of a small job. Paragraph (e) is regulated areas, and (e)(6) is requirements for asbestos removal, demolition, and renovation operations. (e)(6)(i) requires that: "Wherever feasible, the employer shall establish negativepressure enclosures before commencing removal, demolition, and renovation operations." (e)(6)(iv). Exception, establishes the exception for small jobs. "For small-scale, short duration operations, such as pipe repair, valve replacement, installing electrical conduits, installing or removing drywall, roofing, and other general building maintenance or renovation, the employer is not required to comply with the requirements of paragraph (e)(6) of this section." Negative-Pressure Enclosures:- The question is, when is a negative-pressure enclosure required? OSHA solicitors have concluded, based on the standard, that a negative-pressure enclosure is required whenever the job is a removal, demolition or renovation, regardless of how small, and regardless of the * level of airborne asbestos fibers generated. OSHA field people are not as convinced, however, believing that if an employer can demonstrate that the levels of airborne asbestos generated are below the PEL, OSHA would lose in court if a citation were contested. In one case that is presently in court, the employer was removing asbestos insulation from 140 feet of pipe, treating it as a small job, using glove bags. OSHA came in, sampled for two hours, and found that the exposure for those two hours, was below the Action Level. OSHA cited the employer for not using a negative-pressure enclosure for a removal operation, regardless of what the level of exposure was. The issue here is the application of certain requirements in the standard based upon the presence of asbestos, regardless of the level of any exposure that might take place. If this approach is upheld in court, OSHA would not need to monitor, but simply to ascertain that asbestos was present and whether it was a large or small job. -4- " : .;.r u". / i The OSHA field people are now being told that if the primary : ij' reason for the job isvthe. removal-of.asbestos, it is to be- .j treated as- large-scale# and .a^negative-pressure enclosure is - fV .. required. A job is small scale only if-.the ;asbestos-removal is secondary to-the performance of the job.-.? - . .. ... Definition of a Small Job: OSHA has been writing citations for the use of glove bags for what are essentially removal operations. OSHA designed the small job exception for operations where asbestos removal or release is incidental to the performance of the job. OSHA views any operation where the removal of asbestos is the main purpose, as a large scale job requiring a negative-pressure enclosure. It generally makes no difference that the job could be done in a glove bag with exposure levels below the Action Level. Some employers have used multiple glove bags to sequentially remove asbestos containing insulation from pipes. OSHA considers this to be a violation of the standard. One standard that some in OSHA have used is that if a glove bag is longer than ten feet, it is no longer a small job. In some instances however, OSHA has allowed the small job designation to be used for what was in fact asbestos removal. In one case, where a large building was being renovated, there were one hundred rooms with an essentially identical pipe elbow with asbestos in the insulation. OSHA allowed the contractor to use glove bags on each of the elbows, class it as a small job, and not use negative-pressure enclosures. %/uu. y*r> ^ cc /iW 3co j/<"v <fc~ forty USPHS/CDC/ NIOSH / BPSE 2ajut K-t<uy I [\u~ CONTROL TECHNOLOGY ASSESSMENT OF ASBESTOS HFE LAGGING REMOVAL USING TWO NEGATIVE-AIR GLOVE BAG REMOVAL METHODS BY: BRUCE HOLLETT AND PHILLIP FROEHLICH NAC SY*ir*ci UM MABCH 311, 1989 Background: Many workers are exposed to asbestos: Construction workers - Demolition, Renovation, Sprinkler Fitters, Sheet Metal, Roofing, etc. Operations and Maintenance - Plumbing, HtftC, Electrical, House Keeping, etc. Building Occupants - Office Workers, clients, students, customers, public, etc. We proposed a pilot study in 1983 to assess need for research In the asbestos removal Industry. I nrrmv PILOT STUDY , 1984 PROTOCOL PEER REVIEW SPRING 1985 FOUR SCHOOL STUDY SUMMER 1985 WORKER PROTECTION * ENVIRONMENTAL PROTECTION CONTROL AX THE SOURCE THE BEST APPRQCH CONTAIN THE ASBESTOS BEFORE IT IS HFIFACT-n INTO THE ENVIRONMENT. .tt JOINT PROJECT WITH EBL -SUMMER OF 1985 EE& PROVIDED FUNDING FOR ANALYSIS NIOSH ADDED EYUIIATION OF CLEARANCE AND EVMIMION OF EFFICACY SOURCE CONTROLS FOR WORK AND ENVIRONMENT FIRST PRIORITY GLOVE BAGS WIDELY USED/OFTEN ALONE dove Bap were chosen as the first priority because they were widely used by the construction trades as well as by the O&M workers. They are often used as the only control measure. They seem to represent an economical source control te 'jtology. GLOVE BAG PHASE OBJECnVES EVALUATE WORKERS' EXPOSURE DURING GLOVE RAG- REMOVAL EVALUATE CLEARANCE SAMPLING METHODS EVALUATE THE EFFICACY OF THE GLOVE BAG REMOVAL METHODS EVALUATE WORKERS * By Personal Breathing Zone Fall Tkrm Seq. * Half day actWtj *> Morning and Afternoon * One Short Ifenn sample* on uch worker.- AM 4k. FM EVALUATE CLEARANCE SAMPLING METHODS * By comparing PCM 4k TEM- analysis both methoda. I will describe aggi wire* and, nomaggrvutee* * Replicate samples were-taken on polycarbonate 4k ceUnloso ester media for the- two* analysis EVALUATE THE EFFICACY OF THE GLOPE BAG MMOAi * By determialig if the post lertii are* lower by coBacting nnpho before* and. after-  . i. SAMPLING STRATEGY * OUTDOOR AMBIENT PRE-REMOVAL - 2 METHODS PERSONAL BREATHING ZONE TWA AND SHORT TERM AREA DURING REMOVAL . POST REMOVAL - 2 METHODS* * OUTDOORS AMBIENT *Paired 25 mm Cellulose Ester foil wrapped *Gut pumps si 3.5 1pm for the foil shift HIE ft POST REMOVAL -(First foe room is" sealed off) * Two eight hour sequential sampling periods >lst Non-Aggressive Thken in a d17 quiet room per EHV Blue Book guidance. > Aggressive Thkan in a dry room with blowers Blow down room with leaf blower - 3 pasies keep air moving with oscillating fons * Triplicate Replicate sampling 25 dt 37mm AREA DURING REMOVAL Duplicate Replicate sampling - 25 ft 37mm IBZ's 25mm cellulose esters In foil wrapped cowls HUE AND POST REMOVAL SAMPLING EQUIP1V IMNT FILTERS IN OPEN EU32> CASSETTES AND MOUNTED ON A 9 POSITION SAMPLING RING: 3 - 37mm cellulose ester 0.8 a 3 37mm pofrcsgfconatsi0.4a. wttlr a- 5.0 a ceDnlo-- ester baekap 3 - 25mm cellulose tster 0.8a SAMPLING PUMPS: 0 6 cassettes on a manifold, sack wltk 3.5 1pm orifices wttk Ugk powered GE and Gast Tarmrm pamps~ 3 cassettes on dnpont P4000 pumps THREE MEHODS SIDE BY SIDE IN TRIPLICATE. OTHER MONITORING AMBIENT, SHORT TERM, EAM's Ambient outside samples on paired 25mm cellulose ester filters with 2" foil wrapped*,cowls. a A 15 minute short term breathing zone sample on each worker, morning and. afternoon* EVM MEASURED RELATIVE LEVELS ONDf ` MONITORING' Morning and afternoon sequential breathing zone and replicate area samples collected at 2.5 to 3.5 1pm. FUt*TM moulted in open hwd canettes. Areas mounted on 4 position ring 2 - 37 mm Polycarbonate 0.4u *2-25 mm cellulose ester 0.8u in aluminum foil wrapped 2"cowls DUPONT P4000 SAMPLING PUMPS GLOVE RAG REMOVAL PROCESS PREEMPTION MIST LAGGING WITH' AGENT COVER PIPE LAGGING WITH POLY INSTALL RAGS OVER COVERING REMOVAL WORE INSIDE GLOVE RAG REMOVE POLY AND WET LAGGING REMOVE LAGGING & BRUSH CLEAN MOVE OR REPLACE GLOVE RAG WASH WELL AND TIE OFF RAG CLEANUP AND DISPOSE OF WASTE Preparation: First mist Hghtly to suppress dust. Cower lagsing In poly envelope then glovebags. -- SEE PHOTOS -- Remoral: Done inside sealed bags using long glares Cat poly envelope d lagging at Joints. USE CASE WET lagging and wash bag down OFTEN AND HEAVHY. Wtsh and Brash the pipe. Bottle or horse brashes -- SEE PHOTOS -- Moving/Remcrrlng Bag:VERY CRITICAL OPEN BAG TASK Wet the asbestos and wash bag thoronghly. Use HEBA racanin when collapsing bag - tie it off -- SEE PHOTOS -- Cleanup: Ongoing task ase HERV and wet mopping Double bag/label and dispose In approved fill. ' 'J 'V-. ' , ' r. VIDEO CONVENTIONAL GLOVE BAG METHOD STUDIED NIOSH CONTROL TECHNOLOGY ASSESSMENT A brief video presentation of the types of work activities and equipment associated with the asbestos removal methods studied. Also a illustration of the monitoring and site preparations for this control technology study. FINDINGS WORKING CONCENTRATIONS rBZ AND AREA MONITORING TWA EXPOSURE RANGES FOR FOUR WORKERS AT FOUR SITES 14 DtfS FIBERS/CUBIC CENTIMETER (f/cc) WORKER A, B, C, D I EACILITY i l,2y3t4 NK)SH 7400 METHOD (B RULES) Here you see a summery of the four workers' TWV exposures at ell four sites. Each vertical entry shows the ranee. Max and Min, and Mean for the specified worker and school. Note that nearly all of the Daily TWA's were above .1 f/cc and many were above JL f/cc The percentages are shown In the next slide. wrmw:wm- FINDINGS 7jTOSTF, DAHY TWA LEVELS: 37 / 51 (73%) ARE ABOVE 0.1 f/cc 30 / 51 (58%) ARE ABOVE 0.2 f/cc PREPARATION VS REMOVAL LEVELS: PREPARATION AMS 0.02 f/cc REMOVAL WORK AWGr 0.35 f/cc SHORT TERM LEVELS: HIGH> 9.3 f/c 16 / 69 (23%) ARE ABOVE 1.0 f/cc NIOSH 7400 METHOD (B BUIES) Daily T^A*S reflect a significant exposure potential above recommended control limits. Activity related exposure levels sheer that the removal exposures are aa order of magnitude higher than the preparation work exposures. Short Ten levels were peaked by the unplanned episode with a 9.0 f/cc. Also the 1.0 f/cc level was exceeded 23% of the time overall. FACILITY #1 DAILY TWA * NKDSH 7400 (B RULES)/TEM YAMAXE WORK DAY WORKER WORKER _ ES3C WORKER 1MD WORKER ~ 0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 PCM FIBERS ICC -TEM Asbestos Structure/CC Note: Day #1 afternoon B and C samples overloaded Note: Day one workers B and C samples were overloaded with particulate. Unable to count. The TEM : analysis ; wus done on the same Cellulose Ester 25 mm filter that the PCM Personal Beathing Zone analysis was. Due to limited support these are the c ly*'worker FHZ temples done by TEM. WORKER GLOVE BAG EXPOSURE OBSERVATION St CONCLUSION WORKERS WITH LIMITED TRAINING AND EXPERIENCE HAVE EXPOSURES ABOVE NIOSH RECOMMENDATIONS AND OSHA CRITERIA LEVELS. I GLOVE BAGS ALONE DO NOT SUFFICE IN CONTROLLING ! EXPOSURES UNDER THESE CONDITIONS. It is prudent to use respiratory protection during any glove bag operation due to potential leaks OSHA permits the use of high efficiency, air purifying respirators for asbestos; However, NIOSH recommends that type C positive pressure, supplied air respirators be used if levels exceed the REL. As a mtnimnm it is appropriate to seal off the air ducts and doorways to avoid contamination from an accidental release daring glove bag work. More extensive work should likely include the use of decontamination facilities and negative air. dove Bag Evaluation Status Negative Air Technology Two types of negative air glove enclosures have been studied. The AERO-PIPE CAPSULE manufactured by Aerospace America, Inc. and a Custom Fabricated Glovebag designed to operate under negative pres sure conditions. Preliminary PCM results would Indicate that both methods produced adequate control to meet the OSHA PEL and the NIOSH REL. However, TEM analysis of the post removal aggressive sampling have shown many thin fibers. We are awaiting TEM analysis of some of the working area samples to quantity the workers actual fiber exposure levels. VIDEO OF NEGATIVE-AIR GLOVE BAG METHOD STUDIED NIOSH CONTROL TECHNOLOGY ASSESSMENT A brief video presentation of the types of woik activities and equipment associated with the asbestos remora] methods studied. Also a illustration of the monitoring and site preparations for this control technology study. Negative Air Glovebag PCM Results BELOW LOD LOD FIBERS/OC BY NIOSH 7400 METHOD z 1/1,000 SAMPLE TYPE 33 Area A ^Ana B&C Area D AERO-PEPE CAPSULE/AEROSBACE AMERICA,INC. These resoHs are all below the LOD and therefore differences reflect the sample volume. The lower less than concentrations representing longer times for sample collection. Two short term samples of 20 minute duration were -taken in area D. The also were below the LOD around < 0.05 f/cc. We hare received preliminary results of our TIM on these persona] breathing zone samples. They indicate higher concentrations of asbestos that must be confirmed by a more complete analysis which Is pending. / The pre and post TEM analysis shows many fine fibers outside file PCM range. r ,{*; - 1 . Negative Air Glovebag PCM BELOW LOD ys TEM as/cc TOTAL FIBERS BY NIOSH 7400 METHOD vs TEM 0.1500.120 0.0900.050 0.030 0.000 - FEZ H_ 5 si 5 rfjl i l 5si i ! i iZa__E2. M ' " i TEM IA TEM OA RPR Tnfyrffi to-BAC-^ au 11 . *- l ... I - l ____ESI TEM EX SAMPLE LOCATION AND TYPE AERO-FTPE CAPSULE/AEROSB^E AMERICAJNC. PCM results an presented to the left of TEM for: Personal Breathing Zone (FBZ), Interior Area (IA), Outer Area (QA) and the HEPA Exhaust (EX). The PCM data represent tiro samples each. The TEM data Is from an nnetched half of one of the tiro 0B n MCE filter samples used for the PCM. Our laboratory had poor etching results. The other half from the remainder of the PCM hare Been submitted to the same laboratory which did the pre and post analysis to eliminate this TEM Interlaboratory variability factor. f Negative Air Glovebag PRE and POST TEM as/cc . Pre n*5 Amb n*!5 Fast n*5 SAMPLE LOCATION AND TYPE g^iA ES3 B&C ^Ambient ... AERO-PIPE CAPSULE / AEROSPACE AMERICA,INC. Fire pre mod post abatement samples were taken for six and a quarter hours using aggressive sampling in a poly enclosure at eight to ten liters per minute for a minimum sample volume of 3000 liters. Both the post sample sets are significantly higher than pre using a t-test on In(concentratlon) with p-values 0.0014 for area A and 0.0013 for area B/C The 15 outdoor ambients were at or below 0.0012 as/cc. As shown above all of the mean values for both area A (0.24 -0.78) and for area B/C (0.0130.074) well above this ambient level. PLOT OF STRUCTURES BY LENGTH AND DIAMETER . . - * * STRUCTURE LENGTH, MICROMETERS STRUCTURE DIAMETER, MICROMETERS AHERA TEM METHOD/ AERO-FIFE This slide shims the size distribution of asbestos structures from all fifteen outdoors ambient samples. The region outlined in the upper right quarter defines the ranges risible to PCM analysis1 for a 3:1 and 5:1 aspect ratio. Clearly there would not be a large number of PCM fibers on any one filter. The mean concentration for these samples was 0.0012 as/cc. ----- PCM METHOD 7400 . I CHRrSOIllE M a a I AMPHIBOlC B a a i ambiguous r C C 1 AMBIGUOUS c W W 1 NON ASBESTOS M i a \ 000 I M NNiI chrysotiic r CHRTSOIltC c. ... AMPHlBOlE.M . i-/ AM8ICU0US a. non asbestos r ,,* ooo xzx ,y v v I CHRTSOTilE B I AMPHlBOlE r I AMPHI801EC . IAMBICUOUSM- I NON ASBESTOS I Y r I NON AS8ES10SC i i,;,,. PLOT OF STRUCTURES BY LENGTH AND DIAMETER STRUCTURE LENGTH, MICROMETERS to 0 56 I 52 I 8- I O' 0 56 0 J2i!-------------------------------,------------------------------------:-----r------------r o 0t 0 052 01 0.52 'l.o 5-2 100 PRE AREA A STRUCTURE DIAMETER, MICROMETERS AHERA TEM METHOD/ AERO-PTFE This slide shows the size distribution of asbestos structures from all fire pre removal aggressive samples. The region outlined in the upper right quarter defines the ranges visible to PCM analysis for a 3:1 and 5:1 aspect ratio. Clearly there would not be a large number of PCM fibers on any one filter. The mean concentration for these samples was 0.26 as/cc. ------ PCMMCTHOO 7400 * I CHRYSOTIt u A A I AIMlOOtf o i ansicuous f C C I AMMCU0US C W 1 NON AS8CST0S M AA A i t CMTOotiir CMtYsomc r c ' 0 0 0 I ANRHIOOIE M. t AMIOUOUS 0. N N N I NON ASaCSTOS I NON AS8CST0S 1 PLOT OF STRUCTURES BY LENGTH AND DIAMETER STRUCTURE LENGTH, MICROMETERS STRUCTURE DIAMETER, MICROMETERS AHERA TEM METHOD/ AERO-HFE This slide shows the size distribution of asbestos structures from all fire post-remora] aggressive samples. The region outlined in the upper right quarter defines the ranges risible to PCM analysis for a 3:1 and 5:1 aspect ratio. Clearly there would not be a large number of PCM fibers on any one filter. The mean concentration for these samples was 0.78 as/cc. ------ PCM METH00 7400 . I CHRTSOTIIC M * a I AMPNIBOIC 8 6 8 1 AMBIGUOUS F C C I AMBICUOUS C W I NON ASBESTOS M i CHBvsonic.r i CHmomc c OOOI AMPNIBOIC M 0*1 AMBICUOUS 8 ' N n N I NON ASBESTOS r tty NON AS8CS10S C t CHRTSOTILE.B k-at u \ AMPNIBOIC f . o o O I AMPNIBOIC C .ri;! a'SSiA. EFFICACY CONCLUSIONS NEGATIVE AIR METHODS THIS UNIT MET THE OSHA PEL AND NIOSH REL FOR CONTROL OF WORKERS EXPOSURE TO ASBESTOS. FURTHER STUDY IS NEEDED TO DETERMINE THE SOURCE OF THE FINE ASBESTOS FIBERS SEEN IN TEM ANALYSIS. AERO-PIPE CAPSULE/AEROSPACE AMERIGAJNC. Negative Air Glovebag PCM Results TOTAL FIBERS/CC BY NIOSH 7400 -METHOD x 1/1,000 PBZ n-2 IA b-2 QA n-2 SAMPLE TYPE V//A B Rem C Prep 9 C Rem 6889 D Rem CUSTOM NEGATIVE-AIR BAG/ INTERSCIENCE RESEARCH These results are all below the OSHA PEL and NIOSH REL. TEM analysis hare shown there are asbestos ..-; structures present here although not as numerous as in the other study. It is noted that these PCM results would hare indicated higher feeds in this surrey. Each abatement environment well present a different relationship between the PCM results and the actual fiber distribution as shown by TEM. t Negative Air Glovebag PCM Results vs TEM as/cc PCM TOTAL FI IS tcc BY NK)SH 7400 METHOD x 1/1,000 FBZ n-2 to TEM IA n-2 to TEM QA n-2 to TEM SAMPLE TYPE E22 B Rem ES3 C Prep gg3 C Rem B3 D Rem CUSTOM NEGATIVE-AIR BAG/ INTERSCIENCE RESEARCH PCM results are presented to tlie left of TEM for: Personal Breathing Zone (FBZ), Interior Area (IA), Outer Area (QA). Area B samples were taken during remora] activity. Area C Prep samples were taken daring Preparation activity and C Rem were taken during removal activity in area C The PCM data represents two samples each. The TEM data is from an unetched half of one of the two 0.8um MCE filter samples used for the PCM. Since this TEM method may undercoant embedded fibers, the other half have been submitted to the same lab that performed etched pre and post TEM analysis. Negative Air Glovebag FRE and POST TEM as/cc AHERA TEM METHOD as/cc x 1/1,000 -------------------- . . ________ .0065 * Pre n5 .00058 Amb n*15 =L Post n5 SAMPLE LOCATION AND TYPE SSI C AND D ^3 Ambient n*i5' C GE] D CUSTOM NEGATIVE-AIR BAG/ INTERSCIENCE RESEARC Five pre and post abatement samples were taken for six and a quarter hours using aggressive sampling in a poly enclosure at eight to ten liters per minute for a minimum sample volume of 3000 liters. . ... - -.** Area D post samples are significantly lower than the pre. Using a t-test on ln(concentration) yield - p-values of 0.16 for area C and 0.0001 for area The 15 outdoor ambients were at or below 0.0011 as/cc. As shown above all of the mean values for both area C (0.010 - 0.0055) and area D (0.010 0.014) were slightly above ambient level. PLOT OF STRUCTURES BY LENGTH AND DIAMETER STRUCTURE LENGTH, MICROMETERS 10 J 5 b M il ia i o 0 56 .1 1?. (------- 0 01 0 0J2 0I 0 J2 to AMBIENT i2 10 0 STRUCTURE DIAMETER, MICROMETERS AHERA TEM METHOD/ CUSTOM GLOVEBAG This slide shows the size distribution of asbestos structures from all fifteen outdoors ambient samples. The region outlined in the upper right quarter defines the ranges risible to PCM analysis for a 3:1 and 5:1 aspect ratio. Clearly there would not be a large number of PCM fibers on any one Alter. The mean concentration for these samples was 0.0002 as/cc. ----- PCU UtlHOO 7400 . * I CHRrSOmC u .. * I AUPHlBOlC B a s i auuicuous r c c I AUQICU0US c w 1 NON AiBtSIOS U i CHRYsomc f m I CHRtSOTILC C 0 0 l AUPHlBOlC U m NN I I AUtMCUOUS g NON AS8CS10S f v V I NON ASBISIOS C I ClrS0lit 0 * x I AUPHlBOlC l O a l AUPtiiBOlC c t z I AUlllUHXIb U PLOT OF STRUCTURES BY LENGTH AND DIAMETER STRUCTURE LENGTH, MICROMETERS 10 0 S 6 -^1__/ i2 I ***** n* i8 i0 0 16 .1 o 0 01 0 0J2 0 I 0 12 0 - rj 2 IRE AREA C/D i0 0 STRUCTURE DIAMETER, MICROMETERS AHERA TEM METHOD/ CUSTOM GLOVEBAG This slide shorn the size distribution of asbestos structures from all fire pre-remoral aggressive samples. The region outlined In the upper right quarter defines the ranges visible to PCM analysis for a 3:1 and 5:1 aspect ratio. Cleariy there would not be a large number of PCM fibers on any one filter. The mean concentration for these samples was 0.01 as/cc.* -- a mcthoo 7oo i CHftYSomc u A A I AMPHIBOIE B 8 8 I AM0ICU0US r C C I AM8ICU0US C w I NON ASBESTOS M i CHRYSomt r i chrysotiic c 0 0 0 I AMPHIBOIE M I AMBIGUOUS B M N N 1 NON ASBESTOS f r t r I NON ASBESTOS C i cmysotiie b k x i amphiboie r OOOl AtPHIBOlE C till AMUICUOUS U V V V I NON ASBESI0S U i PLOT OF STRUCTURES BY LENGTH AND DIAMETER STRUCTURE LENGTH, MICROMETERS .J 0 j x " > 11i ii ; 0 ; 16 0 01 -0 0i2 0< . 0 S2 -to J 2 - ;0 0 POST AREA C STRUCTURE DIAMETER, MICROMETERS AHERA TEM METHOD/ CUSTOM GLOVEGAB This slide shows the size distribution of asbestos structures from all fire post-remoral aggressive samples. The region outlined In the upper right quarter defines the ranges risible to PCM analysis for a 3:1 and 5:1 aspect ratio. Cleaiij there would not be a large number of PCM flben on aqy one filter. The mean concentration for these samples was 0.0065 as/cc. ------ PCM METH00 7400 I CHRTSOTIIC u *a A 8 ( rI AMPHfBOLC B AMBIGUOUS C C t AM8ICU0US C W w 1 NON ASBESTOSM I CHBYSOTHE f l CHRYS01 HE C o000e1t AMPHIB0U AU8ICU0US u 8 NMN I NON ASBESTOS V t t I NON ASBESTOS f C A A i CHRrsotiu u XXX I AMPMtBOlt O O O I AMPHlOOlE C t z : I AMBIGUOUS U W V V I NON AS0LSIOS EFFICACY CONCLUSIONS NEGATIVE AIR METHODS THIS UNIT MET THE OSHA PEL AND NIOSH REL FOR 1 CONTROL OF WORKERS EXPOSURE TO ASBESTOS. FURTHER STUDY OF THIS CONTROL, UNDER VARIED WORK CONDITIONS, IS RECOMMENDED. CUSTOM NEGATIVE-AIRBAG/ INTERSCIENCE RESEARCH.