Document omOQvB3Qg4jYVnqeV97jVxRoX

PPG Industries, Inc. One PPG Place Pittsburgh, Pennsylvania 15272 (412) 434-2801 James A. Barter, Ph.D. Manager, industrial Health, Hygiene and Toxicology Environmental Affairs Chemicals Group June 24, 1992 W. Caffey Norman, III Patton Boggs & Blow 2550 M Street, NW Washington, DC 20037 Thomas A. Robinson, Ph.D. Vulcan Chemicals One Metropiex Drive Birmingham, AL 35209 Jeanne Domoradzki, Ph.D. Dow Chemical USA 1803 Bldg. Midland, Ml 48674 Paul Dugard, Ph.D. ICI Americas, Inc. P.O. Box 751 Wilmington, DE 19897 William Hayes Dow Chemical USA 2020 Willard H Dow Center Midland, Ml 48674 James Knaack, Ph.D. Occidental Chemical Company P.O. Box 728 Niagara Falls, NY 14302 Peter Voytek, Ph.D. HSIA 1225 19th Street, NW Suite 300 Washington, DC 20036 Dear HSIA Health & Science Committee Members: At the June 19 HSIA H&S committee meeting, I agreed to obtain information on the recent American Congress of Governmental Industrial Hygienists (ACGIH) proposal for changes on exposure levels for perchloroethylene and trichloroethylene. A copy of the ACGIH report from their annual meeting taken from the June 10, 1992 issue of the BNA Occupational Safety & Health Reporter, is enclosed. Both of these materials are included in the Notice of Intended Changes (NIC) that came out of this meeting. The TLV Committee proposals are: Material Perchloroethylene Trichloroethylene TWA /ppm) Present /Proposed 50 25 50 50 STEL fppml Present/Proposed 200 100 200 100 Carcinogen ClassPresent /Proposed A3 A5 SL 036177 Page 2 June 24, 1992 As shown, the STELs for both materials and the TLV for perchloroethylene have been lowered. These actions were presumably taken as a result of ACGIH's review of information on these materials, although I do not know specifically what information caused the changes. The carcinogen classifications for these materials are based on the recently adopted ACGIH method (see page 80 of the enclosed report) and are roughly consistent with HSIA positions on the unlikely potential of these materials to cause carcinogenicity in humans. I believe that trichloroethylene is the first material to be placed in ACGIH's A5 classification (not suspected as a human carcinogen). This classification will probably cause a great deal of comment to ACGIH during the NIC comment period. Substances are now usually on the list of Notices of Intended Changes for 2 years before the changes are adopted by ACGIH. Dr. Doull, Chairman of the ACGIH TLV Committee, is out of the country until early July. I will contact him when he returns for details of how these decisions were reached. Sincerely, :dvr c: K. Daye R. Yuravage E. Kennah K. Lee SL 036178 52 Perhaps in response to these charges, Brooks said in his letter to OSHA that the state plan "desires and intends to provide federal OSHA with all information necessary to allow federal OSHA to properly monitor our program." He said the state "will continue to cooperate with federal OSHA to achieve the best possible workplace protection" for its workers, and "will continue to share ideas with federal OSHA toward a goal of improving worker protection across the nation." Brooks was defeated in the May Democratic primary election. Brooks' tenure will end in January 1992, when a new labor commissioner takes office (21 OSHR 1642,1643). Regulatory Policy METZENBAUM SCORES BUSH ADMINISTRATION ON MORATORIUM, CITES `CONSTITUTIONAL' ISSUE The Bush administration's regulatory moratorium "raises serious constitutional issues" and "may represent a con scious effort to subvert the will of Congress," Sen. Howard Metzenbaum (D-Ohio) said June 2. In a sharply worded speech on the floor of the Senate, Metzenbaum took President Bush to task for the moratori um, which began in January and has been extended through the end of August. "This deregulatory binge may be an effort to line the pockets of the president's business supporters," Metzenbaum said. "It may be an effort to salvage the president's reelection campaign in the face of a dwindling approval rating. But whatever the motivation, one thing is clear: the American people are paying the price." Metzenbaum, chairman of the Senate Labor and Human Resources Subcommittee on Labor, charged that the mora torium and accompanying regulatory review have delayed or weakened important health, safety, and environmental regulations. Metzenbaum said the pain and suffering caused by the moratorium are "very real." He further called on Bush and Vice President Dan Quayle--who is spearheading the regu latory freeze--to end "this dangerous charade." The Ohio Democrat made no specific proposals in his floor speech concerning a congressional response to the moratori um. A Metzenbaum aide told BNA that, while a lawsuit has been considered, there is little case law in that area on which to guide opponents of administration policy. At this point, no further action is planned, the aide said. Bring Issue To Light "He wanted to bring this issue to light because it hasn't received a lot of attention from people up here," the aide said, referring to Capitol Hill lawmakers. According to Metzenbaum, the freeze has affected pend ing rules across the regulatory spectrum. In the area of occupational health and safety, he cited studies by watchdog organizations Public Citizen and OMB Watch that estimated a 90-day freeze on pending regulations would result in 293 worker deaths and 1.3 million workplace injuries and illnesses. The administration has insisted that the moratorium would not affect regulations designed to protect workers or public health and safety. But administration critics, includ ing Metzenbaum, contend that has not been the case. Metzenbaum said Public Citizen and OMB Watch conclud ed that some 43 health, safety, and environmental rules have been delayed, three more have been issued in weakened form, and three others killed outright. OCCUPATIONAL SAFETY & HEALTH REPORTER The administration has delayed or weakened OSHA regu lations for hazards such as worker entry into confined spaces, environmental rules required under the Clean Air Act amendments of 1990, nutrition labeling requirements by the Pood and Drug Administration, and labeling standards for children's toys by the Consumer Product Safety Commis sion, according to Metzenbaum. "The president claims his regulatory moratorium will save billions of dollars," Metzenbaum said. "The administra tion has yet to substantiate that figure. What's clear, how ever, is that it doesn't include the cost of deregulation in human lives and in the health of American citizens." 'No Sense' `The president's moratorium makes no sense as a matter of policy," he added. "But it also raises serious constitution al issues." The Ohio Democrat said the moratorium seeks to block the execution and implementation of dozens of regulatory statutes enacted by Congress, which could be a violation of Article n of the Constitution. That article charges the president with ensuring that the laws are faithfully executed. "Even if few regulations are officially delayed, the diver sion of resources for the required review of all existing and proposed rules frustrates the will of Congress as expressed in countless laws," he asserted. Metzenbaum said that if Bush could delay regulations for seven months, then "what's to stop him from doing it for his entire term of office?" Formaldehyde ACGIH ADOPTS STRICT CEILING LIMIT, REJECTING INDUSTRY PUSH FOR LOOSER TLV BOSTON--The American Conference of Governmental Industrial Hygienists June 2 adopted a strict recommended ceiling limit concentration for formaldehyde, rejecting an industry push for a less stringent threshold limit value. The conference approved a new ceiling limit TLV of 0.3 parts formaldehyde per million parts air, a much stricter limit than the Occupational Safety and Health Administra tion's regulatory standard of 0.75 ppm as an eight-hour time-weighted average. TLVs are recommended workplace exposure limits for hundreds of hazardous substances set by the conference, a body of industrial hygienists affiliated with governmental organizations. The limits do not carry the force of regula tion, but they have served as a reference point for establish ing regulatory standards, particularly by federal OSHA. ACGIH adopted the formaldehyde TLV along with limits for a number of other substances during its annual member ship meeting at the American Industrial Hygiene Confer ence (see related article in this issue). The conference's decision comes a little more than a year after the Formaldehyde Institute, a trade group represent ing producers and users of formaldehyde, threatened to sue ACGIH over the strict limit (20 OSHR 1575). Formaldehyde formerly carried a TLV of 1 ppm as a time-weighted average. The institute contended that health effects stemming from formaldehyde exposure did not warrant such a reduction and that achieving the limit would have a severe economic impact on employers. Sara Schotland, a Washington, D C., attorney representing the Formaldehyde Institute, told BNA June 8 the institute 6-10-92 SL 036179 Copyright 1992 by The Bureau of National Affairs, Inc. 0095-3237/92/SO+.50 CURRENT REPORT 53 had not officially heard of the ACGIH decision and had no comment- controversial Move The controversy over ACGIH's move to lower the TLV for formaldehyde prompted the conference to delay action for a year. It had originally been scheduled to go to a vote of the full conference membership in May 1991. However, ACGIH agreed to let the formaldehyde industry continue to argue its case for a less strict limit and take up the matter again this year. According to Bill Wagner, ACGIH executive secretary, the new limit will be published in the conference's 1992-93 edition of TLVs, probably by the end of August. In addition to adopting the 0.3 ppm ceiling limit, ACGIH eliminated the old eight-hour time-weighted average and 2 ppm short-term limit. At the industrial hygiene conference, John Doull of the University of Kansas, chairman of the the conference's Chemical Substances TLV Committee, said the committee rejected the industry's argument and took issue particularly with the economic issue. "We agree that [cost] is a major issue, but the mandate of the TLV committee is not to consider economics or any other consideration other than health," Doull said. Dennis Paustenbach, an industrial hygienist who headed a task force to review formaldehyde literature for the indus try-backed Industrial Health Foundation, outlined the insti tute's case for a less stringent TLV before the industrial hygiene conference. Paustenbach said that, rather than adopt a ceiling limit, ACGIH should adopt a 0.3 ppm time-weighted average, a limit he contended would protect 90 percent of the exposed population from sensory irritation. Flawed Papers According to Paustenbach, compliance with a ceiling limit costs 10 times as much money as compliance with a time-weighted average. In addition, he said, a number of the pivotal papers on which the conference's TLV committee based its ceiling limit recommendation were flawed. Paustenbach said the committee did a good job in review ing the literature on formaldehyde within the panel's time constraints. "But we needed to take apart each study to see how strongly they could stand on their own," he added. After his task force finished its literature review, Paus tenbach said, it determined that only 17 of the 120 papers reviewed by ACGIH were useful for setting an occupational exposure limit. The task force found numerous problems with data contained in other papers, he added. The task force concluded the cancer risk at concentrations of 0.3 ppm is negligible, and that evidence of sensory irritation at concentrations below 0.3 ppm was uncertain, according to Paustenbach. Study subjects reported irritation with the same frequency whether they were exposed to formaldehyde at 0.3 ppm or to clean ambient air, he said. Chemicals ACGIH REVERSES ITS POSITION ON MBOCA, PROPOSES CHANGES TO OTHER THRESHOLD VALUES BOSTON--The American Conference of Governmental Industrial Hygienists June 2 reversed its proposal to classify t e chemical substance MBOCA as a known human carcino gen and instead recommended retaining the chemical's des ignation as a suspected cancer-causing agent. ACGIH will retain the proposed designation of 4.4'methyiene bis(2 chloroaniline) as an A2 suspected carcin^^ gen on its notice-of-intended change list for one year. TI^B conference's full membership will decide whether to adoj^^ the recommendation in 1993. The conference decided to take that action at its annual membership meeting held in conjunction with the American Industrial Hygiene Conference. ACGIH members acted on MBOCA and dozens of other substances for which they proposed or adopted threshold limit values or biological exposure indices. The complete TLV and BEI lists are published in the Full Text section of this issue. MBOCA has carried the A2 designation, along with a 0.01 parts per million threshold limit value with a skin notation, since the early 1970s. But based on new evidence concerning the substance's carcinogenicity, the conference's Chemical Substances TLV Committee recommended in 1990 to reclas sify MBOCA as a known carcinogen with no threshold limit value. The recommendation was based largely on an epidemiolo gic study by the National Institute for Occupational Safety and Health, according to John Doull, chairman of the ACGIH panel. Speaking at the industrial hygiene conference, Doull said the TLV committee met again in 1991 to review the matter and determined that the NIOSH data were inconclusive. Workers involved in the NIOSH study who contracted blad der cancer also had been exposed to other substances in addition to MBOCA, be said. George T. Bryan, representing the Polyurethane Manufac turers Association, told the industrial hygiene conference that current epidemiologic data do not support an A1 classics fication for MBOCA. Concerning the NIOSH study, BryaflJ said the workers may have come into contact with as many as 15 or 16 known or suspected carcinogens, including five other bladder carcinogens. Moreover, he said the workers involved had low-grade lesions and there was no evidence of recurring disease five years after removal of the lesions. That prompted Bryan to conclude "there is little evidence of a causal link between exposure to MBOCA and bladder cancer." The full conference membership will vote on whether to retain the current classification and TLV for MBOCA at the next membership meeting in May 1993 in New Orleans. In total, ACGIH proposed TLVs for 44 substances this year, including several chemicals which were held over from the 1991 notice-of-intended change list. Substances remain on the notice list for at least one year to allow for review of the proposed changes. Among those held over from the 1991 list are the follow ing: asbestos, benzene, cadmium and its compounds, epichlorohydrin, heptachlor and heptachlor epoxide, hydrazine, methyl hydrazine, nickel, nickel carbonyl, nickel sulfide, nitromethane, and triethanolimine. New Limits Proposed New limits were proposed for acetaldehyde, aceto phenone, acetic anhydride, adipic acid, adiponitrile, arsenic, arsenic trioxide production, benz(a]anthracene, benzyl ace tate, n-Butyl-acetate, tert-Butyi-alcohol, p-tert-Butyl- toluene, carbon tetrachloride, cobalt, p-Dichlorobenzene, and l,4-2-Dichloro-2-butene. Also, diethylamine, diquat, ethylamine, manganese, oil mist, perchloroethylene, rosin core solder, sodium perfluoroacetate, terephthalic acid, tetranitromethane, trichloro ethylene, triethanolamine, trimellitic anhydride, and vinyl acetate. SL 3(,lgg Occupational Safety & Health Reporter OO95-3237/92/S0+.SO 54 OCCUPATIONAL SAFETY & HEALTH REPORTER TLVs were adopted for some 22 substances, including a controversial ceiling limit for formaldehyde (see related article in this issue). The other substances are: benzo[b]fluoranthene, eaprolactum, carbon monoxide, catechol, o-Dichlorobenzene, 1-1-Dichloroethane, dimethylamine, dinitrotoluene, ethyl bromide, hexachloroethane, 1,6-Hexanediamine, kaolin, methylamine, perfluoroisobutylene, silica fume, silica fused, strontium chromate, tin, toluene, trimethylamine, and 4-Vinyl cyclohexene. ACGIH also adopted biologic exposure indices for chloro benzene and proposed BEls for 10 other substances. The conference also adopted TLVs for physical agents, including hand-arm vibration syndrome and heat stress. The annual reports of the TLV and BEI committees are published in the Full Text section of this issue. Synthetic Fibers MANVILLE SAYS STUDY ADDS TO EVIDENCE THAT FIBERGLASS IS NOT HUMAN CARCINOGEN BOSTON--The Manville Corp. June 2 unveiled prelimi nary results from a new study that the company says "strengthen the weight of scientific evidence" that fiber glass does not cause cancer in humans. Manville and other fiberglass products manufacturers are promoting the study as part of a campaign to sever the link between their products and cancer. The study was launched by the companies in 1989 in response to the International Agency for Research on Cancer's decision to designate fiberglass as a possible human carcinogen. The IARC designation, which ultimately led to fiberglass products carrying cancer-warning labels to inform workers and the public of potential hazards, was based on studies in which the fibers were surgically implanted into the bodies of rats. Industry officials contend that such studies do not accu rately reflect human exposure conditions. As a result, the industry undertook an inhalation study that exposed rats to two types of glass fibers representing 90 percent of fiber glass used in the United States, according to Manville officials. The study was managed and underwritten by the fiber glass industry trade group Thermal Insulation Manufactur ers Association Inc. Preliminary results were released at the American Industrial Hygiene Conference. A final report is expected in the fall. "These animal studies are significant because they strengthen the weight of the evidence for the safety of fiberglass," Thomas Hesterberg, one of the study's principal authors, said. Hesterberg is a senior toxicologist for a Manville subsidiary, Schuller International Inc. Hesterberg and other industry officials said the findings could provide the basis for an appeal to IARC to reconsider the carcinogen designation. In a letter to Schuller customers, Robert Anderson, the company's senior vice president for science and technology, said the results of the inhalation study and other studies "will provide the scientific and regulatory community with the necessary data to begin reassessing the potential risk associated with inhaling fiber glass." Mixed Reaction Reacting to the study, Sheldon Samuels of the Workplace Health Fund told BNA that the Manville study "is encourag ing, but not definitive. What we need is a thorough epi demiologic study, and that has not been done." Samuels noted that this study examined only two types of fiberglass and that other forms which mimic asbestos are carcinogenic to the degree that the fibers persist in the lung "We're hopeful that we have found a less risky substitute for asbestos, but this does not mean an automatic exoneration for fiberglass," he said. Bill Kojola, associate director for occupational health with the Laborers' Health & Safety Fund, agreed that the industry study should be regarded as a negative study in terms of carcinogenicity. "It doesn't provide any ammuni tion to argue that it is a carcinogen," Kojola told BNA. Kojola works on synthetic fiber issues for the fund, a joint labor-management project affiliated with the Laborers In ternational Union of North America. He said union health officials are more concerned at this point with the health effects of refractory ceramic fibers, which have produced tumors in animal inhalation studies. In describing the fiberglass study at the industrial hygiene conference, Hesterberg said rats were exposed to the two types of glass fibers over a two-year period at doses equiv alent to exposure levels of 30 fibers per cubic centimeter of air, 150 f/cc, and 240 f/cc. No lung fibrosis or mesothelio mas were observed and there was no statistically significant increase in lung tumors when compared with a control group of rats exposed to filtered air, he said. The only exposure-related finding in the study was the presence of cellular changes in the lungs that are thought to be reversible and which did not progress after six months of exposure, according to Hesterberg. The Schuller toxicologist said researchers used stateof-the-art technology for the study, developing fine glass fibers that approximate the size of airborne fibers in the workplace. The same technology was used in an earlier study involving refractory ceramic fibers and asbestos, both of which induced an elevation in lung tumors, according to Hesterberg. Industry Campaign As part of their campaign to reassess fiberglass, industry officials have presented their findings to the Occupational Safety and Health Administration and the Environmental Protection Agency. John Martonik, OSHA's deputy director of health stan dards programs, told BNA the agency is still reviewing the data and is not yet prepared to offer its interpretation of the study. OSHA requires fiberglass products to carry cancerwarning labels, having determined in May 1991 that several epidemiologic studies involving exposed workers were posi tive for carcinogenicity (21 OSHR 230). Such warnings are required under the agency's hazard communication stand ard, even if OSHA does not specifically regulate a substance as a carcinogen. OSHA also will propose an exposure limit for fiberglass as part of its air contaminants rulemaking for the construction, maritime, and agriculture industries, which is due to be published June 12. The agency is expected to propose a 1 f/cc exposure limit, according to sources. OSHA's labeling decision actually had little practical ef fect on the industry, since manufacturers already had decid ed to label their products for cancer hazards to take advan tage of safe harbor provisions in California's toxics law. Proposition 65. Prop 65 bases its list of cancer-causing substances on IARC designations. By labeling their products, manufactur ers are protected from liability for failure to warn users about potential hazards. 6-10-92 SL 36l8l Copyright 1992 by The Bureau of National Affairs. Inc. 0O95-3237/92/SO+.50 CURRENT REPORT 55 Methylene Chloride OSHA REOPENS RULEMAKING RECORD, SETS HEARINGS FOR SEPTEMBER, OCTOBER The rulemaking record for the Occupational Safety and Health Administration's proposed rule controlling exposure to methylene chloride was reopened by OSHA in a June 9 Federal Register notice (57 FR 24438). At the same time, the agency announced public hearings scheduled tor Sept. 16 in Washington, D.C., and Oct. 14 in San Francisco. OSHA said the proposed rule published in November 1991 raised a number of serious questions during the original five-month comment period that closed April 6. The agency said it would accept further comments on the proposal through Aug. 24. OSHA's notice reopening the comment period and estab lishing the hearing dates is published in the Full Text section of this issue. OSHA said it also expects to receive comments from the agency's Advisory Committee on Construction Safety and Health, which in May met for the first time since the proposal was published (21 OSHR 1694). The advisory com mittee formed a working group on methylene chloride, and OSHA said the panel expects to make formal recommenda tions at its next meeting in late July. In the hearing notice, OSHA restated and elicited testimo ny on a number of questions that were raised in the propos al. Among the issues addressed are the use of pharmaco kinetic data in estimating risk from methylene chloride exposure, interpretation of the epidemiologic data, engineer ing control technology and work practices in degreasing operations, and substitution of other products for methylene chloride. OSHA is proposing to reduce the permissible exposure limit for methylene chloride from 500 parts methylene chloride per million parts air to 25 ppm and establish an action level of 12.5 ppm, a short-term limit of 125 ppm, and other protective measures. The agency estimates the stand ard will cover 186,000 workers. The public hearings are scheduled to begin at 9:30 a.m. Sept. 16 in the auditorium, Frances Perkins Department of Labor Building, 200 Constitution Ave. N.W., Washington, D.C. 20210, and at 9:30 a.m. Oct. 14 in the Coit Room, Holiday Inn, Financial District, 750 Kearny St., San Francis co, Calif. 94108. Persons who wish to appear at the hearings must send quadruplicate notices of intention to appear, postmarked by Aug. 24, to Tom Hall, OSHA Division of Consumer Affairs, Docket H-71, Room N-3647, U.S. Department of Labor, 200 Constitution Ave. N.W., Washington, D.C., 20210; (202) 523-8615. Notices may be transmitted by facsimile machine to (202) 523-5986, provided the original and three copies are sent to the above address. For further information on the hearings, contact Hall. Testimony and documentary evidence must be submitted Jo OSHA's Division of Consumer Affairs and be postmarked '> Aug. 24 for the Washington, D.C., hearing and by Sept. 22 for the San Francisco hearing. rittcn comments on OSHA's proposed rule must be by Au8- 24 and sent in quadruplicate to the Officor' Docket H-71. Room N-2625, at the above 10 or (,,!"' f Labor address; (202) 523-7894. Comments of 523-S04R r Paes may 1x5 sent by facsimile machine to (202) For further information on the proposed rule, contact James Foster, Office of Public Affairs, Room N-3647, at above Department of Labor address; (202) 523-8151. Asbestos OSHA REMOVES NON-ASBESTIFORM MINERALS FROM STANDARDS, TO REGULATE AS PARTICULATES Non-asbestiform varieties of tremolite, anthophyllite, and actinolite are no longer regulated under the Occupational Safety and Health Administration's asbestos standards, but will be handled as particulates, OSHA said in a June 8 Federal Register announcement (57 FR 24310). OSHA said it took that action because subriantial evi dence is lacking to conclude that the non-asbestiform miner als pose the same type or magnitude of health threat as asbestos. OSHA's move is effective retroactively to May 29, the agency said. The agency will regulate the non-asbestiform minerals as particulates not otherwise regulated--part of its air contaminants standard in Table Z-l-A at 29 CFR 1910.1000 (Reference File, 31:8105). OSHA's notice establishing the final rule for nonasbestiform minerals is published in the Full Text section of this issue. The particulates standard carries a permissible exposure limit of 15 milligrams per cubic meter of air (total dust) and 5 mg/m1 (respirable dust). That is a less stringent exposure limit than the one contained in OSHA's asbestos standards, and the particulates standard does not require a number of other protective measures mandated by the comprehensive asbestos rules. Responding to OSHA's decision, John Moran, safety andhealth director for the Laborers National Health & Safety Fund, told BNA June 9 that his organization was "shocked" at the agency's move. Asked if labor organizations would challenge the decision, Moran said the Laborers were con sidering their options. Safety and health officers for the building and construc tion trades are scheduled to meet June 18, and the deregula tion of non-asbestiform minerals likely will be a topic for discussion, he said. The non-asbestiform minerals had been included in the 1986 revisions to OSHA's asbestos standards initially pro mulgated in 1972. But after a challenge by R.T. Vanderbilt Co., which mines and mills talc containing the minerals, OSHA stayed asbestos provisions concerning the nonasbestiform minerals. While it reviewed the matter, OSHA regulated the miner als under the less stringent 1972 asbestos regulations. OSHA's action removes the stay of the 1986 asbestos stan dards and places the minerals under the category of particulates. The Labor Department touted the action on nonasbestiform minerals as a major cost-savings to the econo my in a recent report to President Bush on its regulatory moratorium and review of pending rulemakings (22 OSHR 5). The department estimates the move would save $73.6 million annually and affect approximately 600,000 workers in the construction, paint, tile, and pottery industries. For further information, contact James F. Foster, Direc tor of Information and Consumer Affairs, Occupationa Safety and Health Administration, U.S. Department o Labor, Room N-3649, 200 Constitution Ave. N.W., Washing ton. D.C. 20210; (202) 523-8151. 6-10-92 SL 036182 Occupational Safety & Health Reporter 0095-3237/92/50-.50 77 Full Text AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HYGIENISTS' REPORT ON 1992-1993 PROPOSED AND CURRENT CHANGES TO TLV AND BEI LIST Annual Reports of the Committees on Threshold Limit Values and Biological Exposure Indices Chemical Substances TLV Commltteie Report to the ACGIH Membership for Approval at the Annual Membership Meeting; June 2,1992; Boston, Massachusetts Notice of Intended Changes for 1992-1993 - These substances, with their corresponding values, com prise those for which either a Emit has been proposed for the first time, for,which a change in the 'Adopted' listing has been proposed, or for which retention on the Notice of Intended Changes has been proposed. In all cases, the proposed limits should be considered trial limits that will remain in the listing for a period of at least one year. If after one year no evidence comes to light that questions the appropriateness of the values herein, the values will be reconsidered for the 'Adopted* list Documentation is available for each of these proposed sub stances and their values. Substance [CAS#] TWA_____________STEL ppm(a) mg/m3*0' ppm*1' mg/m3<b) [Acetaldehyde [75-07-0] C25/3 C 45>3 -- [Acetophenone [98-86-2] 10 49 -- fAcetic anhydride [108-24-7] 5 21 -- tAdipic add [124-04-9] -- 5-- tAdiponitrile [111 -69-3}--Skin 2 8.8 -- -- [Arsenic, elemental [7440-38-2], and inorganic compounds (except Arsine), as As 0.1 ,A1 -- --- [Arsenic trioxide Delete lisling; induded in fisting (or production Arsenic, elemental and inorganic compounds (except Arsine) Asbestos, alt forms [1332-21-4] -- 0.2t/cc.mA1 --- --- [Benz[a]anthracene [56-55-3] A2 A2 --- --- Benzene [71-43-2J-Slrin [Benzyl acetate [140-11-4] [n-Butyt acetate 0.1/1 10,A3 0.3/1 61/3 --- -- --- -- [123-86-4] [tert-Butyt alcohol 20 95 --- --- [75-65-0] 100 303 ---- Substance [CAS#] TWA STEL ppm*** mg/rti^' ppm*** mg/m3*0' tp-iert-Butyt toluene [98-51-1] 1 Cadmium [7440-43-9] and compounds, as Cd -- ' ' ' 6.1 -- -- 0.01/2, Total dust 0.002VA2 Re&pirabte fraction tCarbon tetrachloride [56-23-5]-SWn 5/3 31/3 10/3 63/3 [Cobalt, elemental [7440-48-4], and inorganic compounds, as Co -- 0.02/3 -- -- tp-Dichiorobenzene [108-48-7] 10/3 60/3 -- -- 11,4-Dichloro-2-bu1ene [764*41-OJ-Skin 0.005/2 0.025/2 -- -- tDiethytamine [109-69-7]-SUn 5 15 15 45 l.l-Dimethythydrazine [57-l4-7J-Skin tDiquat 0.01/2 0.025/2 -- -- 0.5, Total dust -- -- J231-36-7]-SWn -- 0.1, Respirable traction Epichlorohydrin [106-89-8]-SWn 0.1/2 0.38/2 -- -- tEthytamine [75-04-7] 5 9.2 15 27.6 Heptachlof and heplachior epoxide [76-44-8}-SWn - -- 0.05/2 -- -- Hexachlorobenzene [118-74-IJ-Skin -- 0.025/2 -- -- Hydrazine (302-01-2)-Skin 0.01/2 0.013/2 -- -- [Manganese, elemental [7439 96-5], and Inorganic compounds, as Mn -- 0.2 -- -- [4,4'-Methylene bis(2-chloroaniline) [101-14-4]-Skin 0.01/2 0.11/2 -- -- Methyl hydrazine [60-34-4]-Skin 0.01/2 0.019/2 -- -- Nickel, elemental [74404)2-0], insoluble and soluble compounds, as Ni -- 0.05/1 -- -- Nickel carbonyl Delete listing; induded in listing lor [13463-39-3], Nickel, elemental, insoluble and soluble as Ni compounds Nickel sulfide roasting. Delete listing; Induded in listing for fume A dust, as Ni Nickel, elemental, insoluble and soluble compounds 6-10-92 Occupational Safety & Health Reporter SL 036183 78 OCCUPATIONAL SAFETY & HEALTH REPORTER Substance [CAS#] TWA STEL PPm*4' mg/m3fb) ppm*4' mg/m3<b' Nitromethane [75-52-5] 20 fOil mist, mineral Severely refined Mildly refined, con taining benzene soluble polycyclic aromatic hydrocarbons t Perchloroethytene [127-18-4] 25,A3 50 5 0.2/1 170/3 -- ---- 100,A3 6B5.A3 tRosin core solder decomposition products, as resin acids-coiophony [8050-09-7] Sensitizer 1 Sodium perfluoroacetate [62-74-8]-SWn 0.05 tTerephthalic add [100-21-0] -- 10 tTetranitromethane [509-14-8] 0.005/2 0.04/2 tTrichloroethytene [79-01-6] 50/5 269/5 tTriethanoiamina [102-71-6] --5 tTrimellitic anhydride [552-30-7] C 0.04 tVinyl acetate [108-05-4J 10.A3 35/3 ---- ---- ---- 100/5 537/5 ---- 15,A3 53/3 t 1992-1993 Revision or Addition to the Notice Of Intended Changes. (a) Parts of vapor or gas pai million parts ot air by voljme at 2S*C and 760 tort. (b) Milligrams Of substance per cubic meter of air. (0 Fibers longer than S pm and with an aspect ratio equal to or greater than 3:1 as determined by the membrane tilter method at 40CM50X mag nification (4-mm objective) phase contrast illumination. G) This TLV is for the respirable fraction ol dust tor the substance listed. * The concentration ol respirable dust for the application ol this timit is to be determined from the traction passing a size-selector with the char acteristics defined in the *c* paragraphs of Appendix 0. A Refers to Appendix A, Carcinogens, in the TLV/BEI Booklet. C Denotes Ceiling Until Notice of Intended Change -- Appendix D Particle Size-Selective Sampling Criteria for Airborne Particulate Matter For chemical substances present in inhaled air as suspen sions of solid particles or droplets, the potential hazard depends on particle size as well as mass concentration be cause of 1) effects ot particle size on the deposition site within the respiratory tract and 2) the tendency for many occupational diseases to be associated with material deposited in particular regions ot the respiralory tract. The Chemical Substances TLV Committee has recom mended particle size-selective TLVs tor crystalline silica for many years in recognition ol the well-established association between silicosis and respirable mass concentrations. The Committee is now re-examining other chemical substances encountered in paniculate torm in occupational environments with the objective of defining 1) the size-fraction mosl closely associated for each substance with the health effecl of concern and 2) the mass concentration within that size fraction which should represent the TLV. The Particle Size-Selective TLVs (PSS-TLVs) will be ex pressed in three forms: a) Inhalable Particulate Mass TLVs (IPM-TLVs) for those materials that are haz ardous when deposited anywhere in the respiratory tract b) Thoracic Particulate Mass TLVs (TPM-TLVs) for those materials that are hazardous when deposited anywhere within the lung airways and the gas-exchange region. c) Respirable Paniculate Mass TLVs (RPM-TLVs) for those materials that are hazardous when deposited in the gas-exchange region. The three particulate mass fractions described above are defined in ouanfitafive farms in accordance with the following equations. ^ a) Inhalable Particulate Mass consists of those partides that are capfured according to the following collection efficiency regardless of sampler orientation with respect to wind direction: SKdJ-SOttxO+e"0-06^ for 0 < d * 100 pm where: Sl(d) - the collection efficiency for particles with aerodynamic diameter d in pm b) Thoracic Particulate Mass consists of those partides that are captured according to the following collection efficiency: ST(d)-SI(d)(1-F(x)J where: x = *n(d/n ln(2) r 11.64 pm I - 1.5 F(x)the cumulative probability function of a standardized normal variable, x c) Respirable Parliculale Mass consists ol those partides that are captured according to the following collection effidency: SR(d) - Sl(d) (I - F(x)] where F(x) has the same meaning as above with r 4.25 pm and I 1.5 Collection efficiencies representative of several sizes of partides in each of the respective mass fractions are shown in Tables I, II, and III. References 2 and 3 provide documentation for the respective algorithms representative of the three mass fractions. The most significant change in this proposal is the in crease in the median cut point for a respirable dust sampler from 3.5 pm to 4.0 pm; this is in accord with the proposed International Standards Organization/European Standardiza tion Committee (ISO/CEN) protocol*3* which has been recom mended to the European Economic Community. For some particle size distributions, the revised criterion is expected to register a larger dust concentration.*4' References 1. American Conference of Governmental Industrial Hygienists: Par ticle Size-Selective Sampling in the Workplace ACGIH.Cindnnatr, OH (1985). 2. Soderholm, S.C.: Proposed International Conventions for Particf Size-Selective Sampling Ann. Occup. Hyg. 33:301-320(1989). 6-10-92 Published by THE BUREAU OF NATIONAL AFFAIRS. INC.. Washington, DC. 20037 03618A Sh CURRENT REPORT 79 3. European Standardization Committee: Size Fraction Definitions for Measurement ot Airborne Partides in the Workplace. CEN/TC137/ WG3/N66 (E). draft version (1990). 4. Soderholm. S C.: Why Change ACGlITs Definition of Respirable Dust? Appl Occup. Env, Hyg. 6(4):248-250 (1991). Table I. Inhalabl# Particle Aerodynamic Diameter (pm) 0 1 2 5 10 20 30 40 50 100 Inhalable Particulate Mass (IPM) (%) 100 97 94 87 77 65 58 54.5 52.5 50 Table II. Thoracic Particle Aerodynamic Diameter (pm) 0 2 4 6 8 10 12 14 16 18 20 25 Thoracic Paniculate Mass (TPM) (%) 100 94 89 80.5 67 50 35 23 15 9.5 6 2 Table III. Respirable Particle Aerodynamic Diameter (pm) 0 1 2 3 4 5 6 7 8 10 Respirable Particulate Mass (RPM) (%) 100 97 91 74 50 30 17 9 5 1 Transfers to the Adopted List for 1992-1993 Substance (CAS #] ppm mg/m3 STEL ppm mg/m3 Benzo[b]fluoran1hene (20S-99-2) -- A2 ---- Caprolactam (105-60-2) Dust _i -- 3 Vapor 5 23 10 46 Substance (CAS 0] TWA STEL ppm mg/m* ppm mg'm1 Carbon monoxide (630-08-0) Cak-chol 1120-80 9}-Skin o-Dichlorobenzene [95-50-111 1,1 -Cichloroefhane (75-34-3) Dimethytamine (124-40-3) Dinitrotolueoe (25321-14-61-Skin Ethyl bromide [74-96-4]-Skin Formaldehyde (50-0041) Hexachloroethane (67-72-IJ-Skin 1,6-Hexanediamine (1244)9-4] Kaolin (1332-58-7] Methyiamine [74-89-5] 25 29 5 23 25 150 100 405 5 D.2 0.15.A2 5.A2 22/2 C 0.3/2 C 0.37.A2 1/2 9.7.A2 0.5 23 -- 2, Respirable dust 5 6.4 -- 50 15 _ _ _ -- 15 Perfluoioisobutylene (382-21-8) CO 01 C 0.082 Silica fume (amorphous) [69012-64-2] , _ 2, Respirable dust Silica fused (amorphous) (60676-86-0) _ 0.1,Respirable dust Strontium chromale [7789-06-2], as Cr 0.0005.A2 Tin, organic compounds as Sn-Skin _ 0.1 Toluene (1D8-88-3]-Skin 50 147 Trimethyiamine [75-50-3] 5 12 4-Vinyt cyclohexane (100-403] 01/2 0.4.A2 _ _ _ _ 15 _ _ -- 301 27.6 _ __ -- 19 _ _ 0.2 _ 36 _ Transfer to Adopted: Appendix A -- Carcinogens The Chemical Substances Threshold Limit Values (TLV) Committee has been aware of the increasing public concern over chemicals or industrial processes that cause or contribute to increased risk of cancer in workers. More sophisticated methods ot b:oassay, as well as the use of sophisticated mathematical models that extrapolate the leve!s ot risk among workers, have led to ditte' ing interpretations as to which chemi cals or processes should be categorized as human car cinogens and what the maximum exposure levels should be. The goal of the Committee has bc-en to synthesize the available information in a manner that will be useful lo practicing in dustrial hygienists, without overburdening them with needless details. The TLV Committee considers information from the follow ing kinds of studies to be indicators of a subslance's potential to be a carcinogen in humans: epidemiology studies, toxicology studies, and, lo a lesser extent, case histories. Scientific debate over the existence of biological thresholds for carcinogens is unlikely to be resolved in the immediate future. Because of the 6-10-92 Occupational Safety & Health Reporter SL 036185 -80 OCCUPATIONAL SAFETY & HEALTH REPORTER long latent period (or many carcinogens, and lor ethical reasons, it is often impossible to base timely risk-management decisions on results from human studies. In order to recognize the qualitative differences in research results, five categories of carcinogens are designated in this booklet A1--Confirmed Human Carcinogen: The agent is car cinogenic to humans based on the weight of evidence from epidemiologic studies of, or convincing clinical evidence in, exposed humans. A2--Suspected Human Carcinogen: The agent is car cinogenic in experimental animals at dose levels, by route(s) of administration, at site($), of histologic type(s), or by mecha nism^) that are considered relevant to worker exposure. Avail able epidemiologic studies are conflicting or insufficient to confirm an increased risk of cancer in exposed humans. A3--Animal Carcinogen: The agent is carcinogenic in experimental animals at a relatively high dose, by route(s) of administration, at site(s), of histologic type(s), or by mecha nism^) that are not considered relevant to worker exposure. Available epidemiologic studies do not confirm an increased risk of cancer in exposed humans. Available evidence sug gests that the agent is not likely to cause cancer in humans except under uncommon or unlikely routes or levels of ex posure. A4 -- Not Classifiable as a Carcinogen: There are inade quate data on which to classify the agent in terms of Its qprcinogenicity in humans and/or animals. A5 -- Not Suspected as a Human Carcinogen: The agent is not suspected to be a human carcinogen on the basis of properly conducted epidemiologic studies in humans. These studies have sufficiently long follow-up, reliable exposure his tories, sufficiently high dose, and adequate statistical power to conclude that exposure to the agent does not convey a sig nificant risk of cancer to humans. Evidence suggesting a lack of carcinogenicity in experimental animals will be considered if it is supported by other relevant data. Exposures to carcinogens must be kept to a minimum. Workers exposed to A1 carcinogens without a TLV should be properly equipped to eliminate to the fullest exlent possible all exposure to the carcinogen. For A1 carcinogens with a TLV and for A2 and A3 carcinogens, worker exposure by all routes should be carefully controlled to levels as low as reasonably achievable (ALARA) below the TLV. Refer to the Documenta tion of the Threshold Limit Values. Appendix A, 'Identification and Classification of Carcinogens,* for a more complete description and derivation of these designations. Chemical Substances and Other Issues Under Study Information, data especially, and comments are solicited to assist the Commitiee in its deliberations and in the possible development of draff documents Draft documentations are used by the Committee to decide what action, if any, to recom mend on a g;ven question. Chemical Substances Acetone Acelomethytchloride Aluminum aJkyts Antimony Anapulgite.'Palygofskite/ Sepiolite Bentonite Borax and boron compounds Bromine Bromochloromethane Bromodichloromethane Bromotorm 1,2.3,4-Butaneteiracarboxylic acid rvButyl alcohol sec-Butyl alcohol n-Butyt glyddyt ether (BGE) 2-l-Bu1yUzo-2-hydroxy-5- meityhexane Carbon disulfide ChbrodphenyU (42% &S4% chlorine) Chromium Copper lume CrislobalHe Cyanamide Cydohexytamirte Dialomaceous earth Dichlorocydopentadiene Dichtorodjphenyt sulfone 1.2- DicMoroethane 2,4-0 (2.4-Dichlorophenoxy acetic add) 1.3- Dichlorapropene Dtchlorvoa Dimethyl acetamide Oimethyttormamide Dimethyl disulfide Divinyt benzene Emery EPN 2-Ethoxyethanol (EGEE) 2-Ethoxyethyl acetate (EGEEA) Ethyl cNoride 2-Ethyt hexanoic add Fibrous glass dust (Man-made mineral fibers) Gallium arsenide Gasofine (unleaded) GlutaraUehyde Glyddol Glycol ethers Graphite fibers Hexachlorocydopentadiene Hydrogen bromide Isopropyl glyddyt ether Jet. petroleum, and diesel fuels Lead, inorganic Lead, organic compounds Malathion Man-made miners1 fibers Mercury 2-Methoxyelhanol (EGME) 2-Melhoxyelhyl acetate (EGME) Methyl acrylate Methyl alcohol Methyl bromide Methyl n-butyt ketone Methyl propyl ketone a-Mathyf styrene Methylene chloride Methylene diamine 4,4'-Melhylene dianfiine Methyl tart-butyl ether Mineral spirits Naled. Particulates Not Otherwise Classified (PNOC) Pentachlorophenol Pentane 2,4-Pentanedione Pertrte Persulfates Petroleum solvents Phenyl glyddyt ether Phosphates (including mining) Potash Propylene dichloride Styrene Sutfometuron-methyt Tantalum 1,t ,2,2-Tetrachloroethane Tetrahydrofuran Tetrakis (hydroxymethyl) phosphonium chloride Tetrakis (hydroxymethyl) phosphonium suKate Tetrasocfium pyrophosphate (Phosphates) Tobacco smoke Tridymile Triethylamine Tripropylene glycol Trona Uranium Vanadium Other Issues 1. Excursion Ljmii and Shon-Term Exposure Umit (STEL). 2. Reproductive effects. Committee activities for 1991-1992 Included: 1. Two stated plenary committee meetings: September 23-24, 1991, Cincinnati, OH; March 23-24,1992, Orlando. FL. 2. Commitlee'Subcommitlee meetings with interested parties for presentation of new/substantive data for: Asbestos, Ben zene, Cadmium and compounds, Epichlorohydrin, Formal dehyde, Mercury, 4,4'-Methylene bis(2-chloroani!ine), Nickel and compounds. Triethanolamine, Trimellitic anhydride, 4Vinylcyclohexene, Vinyl acetate. 3. New committee members: Gunter Oberdfirster. Ph D., Department of Biophysics, Environmental Health Sciences Center. University of Rochester; Roger P. Smith, Ph.D.. Department ot Pharmacology and Toxicology, Dartmouth Medical School. 4. Presentations by members of the Commitiee and ACGIH 6-10-92 Published by THE BUREAU OF NATIONAL AFFAIRS. INC.. Washington. O.C. 20037 03616 SL CURRENT REPORT 81 Stall on the history of TLV development; ACGIH policy lor the role ol TLVs; TLV documentation development process; and technical, scientific, and socioeconomic issues confront ing the Committee. Presentations made: Professional Devel opment Courses at the American Industrial Hygiene Con ference & Exposition and the Professional Conference on Industrial Hygiene; University of Cincinnati Medical Center, Institute ol Environmental Health. Biological Exposure Indices Report to the ACGIH Membership for Approval at the Annual Membership Meeting; June 2,1992; Boston, Massachusetts Biological Exposure Indices (BEIs) are reference values intended as guidelines for the evaluation of potential health hazards in the practice of industrial hygiene. BEIs represent the levels of determinants that are most likely to be observed in specimens collected from a healthy worker who has been exposed to chemicals to the same extent as a worker with inhalation exposure to the TLV. TLVs serve as a reference value. The determinant can be the chemical itself or its metab olite^), or a characteristic reversible biochemical change in duced by the chemical. The measurement can be made in exhaled air, urine, blood, or other biological specimens col lected from the exposed worker. Based on the determinant the specimen chosen, and the time of sampling, the measurement indicates either the intensity of a recent exposure, an average daily exposure, or a chronic cumulative exposure. BEIs do not indicate a sharp distinction between hazardous and nonhazardous exposures. Notice of Intent to Establish BEIs for 1992-1993 Airborne Chemical [CAS <) Determinant jAcetone [67-43-1] Acetone in urine Arsenic and soluble compounds including arsine [7784-42-1] Inorganic arsenic metabolites in urine Cadmium Cadmium in urine Sampling Time End of shift End of workweek Not critical Cadmium in blood Not critical Carbon monoxide [630-08-0] Carboxyhemoglobin End of shift in blood Carbon monoxide in End of shift end-exhated air 12-Ethoxyethanol (EGEE) [110-80-5] and t2-Ethoxyethyt acetate (EGEEA) [111-15-9] 2-Ethoxy acetic add In urine End ot shift at end ol workweek BEI Notation lOOmg/L B.Ns 50 pg/g B creatinine 5pg/g creatinine 5pg/L B B 3.5% of B.Ns hemoglobin 20 ppm B.Ns 100 mg/g creatinine Mercury Total inorganic mercury in urine Total inorganic mercury in blood Preshift End of shift at end ol workweek 35 pg'g creatinine 15p g/L B B Determinant Methyl isobutyl ketone (108-10-1) (MIBK) MIBK in urine Toluene [108-88-3] o-Cresol in urine Sampling Time End of shift End of shift Trichloroethylene f79-01-6| Trichloroethylene in blood 11992-1993 revision or addition. BEI Notation 2mg/L 1 mg/g Ns creatinine Sq Definition of Notations B Notation--The determinant is usually present in a significant amount in biological specimens collected from subjecls who have not been occupationally exposed. Such background levels are included in the BEI value. Ns Notation -- The determinant is nonspecific since it is observed after exposure to some other chemicals. These nonspecific tests are preferred because they are easy to use and usually offer a better correlation with exposure than specific tests. In such instances, a BEI for a specific, less quantitative biological determinant is recommended as a con firmatory test Sq Notation--The determinant is an indicator of exposure to the chemical, but the quantitative interpretation of the measure ment is ambiguous (semiquantitative). These determinants should be used as a screening test if a quantitative test is not practical or as a confirmatory test if the quantitative test is not specific and the origin of the determinant is in question. Transfers to the Adopted List for 1992-1993 Airborne Chemical [CAS #] Determinant Sampling Time Chlorobenzene [108-90-7] Total 4-chlorocatechol End ol shift in urine Total p^hlorophenol End of shift in urine BEI Notation 150 mg/g creatinine 25 mg/g creatinine Ns Ns Chemical Substances and Other Issues Under Study to Establish Biological Exposure Indices Chemical Substances Antimony Benzene 2-Butoxyethano! Cobalt Dichlorobenzene N,N-Dimethytacetamide (DMAC) Formaldehyde Lead 2-Methoxyethanol 2-Methoxyethyl acetate 4.4'-Methytene bis (2-chIoroaniline) [MOCA] Methylene chloride Nickel Perchloroethytene Polychlorinated biphenyls Synthetic pyrethrins Toluene, under study due to proposed adoption ol revised TLV (50 ppm; STEl defied). Vanadium Other Issues 1. Quality control. 2. Ettecl ol medicalion and illness on biological levels. 3. Control of biological measurement of exposures 1o mixtures by BEIs. 4. Biological moniloring strategy. 6-10-92 Occupational Safety & Health Reporter SL 036187 82 OCCUPATIONAL SAFETY & HEALTH REPORTER 5. Development ol BEI documentations tabled due to insuffi cient databases on: Acrylonitrile Alkylating agents Beiytlium Ethanol' 2,4-0 Herbicide Hydrazine Malathion Manganese PCB Propylene glyoot dinitrale Selenium *A BEI not reoommended because ol interference Item consumption of alcoholic beverages. Committee activities (or 1991-1992 Included: 1. Two stated plenary committee meetings: November 10-12, 1991, Key Biscayne, FL; March 19-21,1992, Orlando, FL 2. Procedures for the BEI Committee regarding revision of chemical substance TLVs: Notification of a proposed change in a chemical substance TLV for which a BEI exists, or is under study to establish a BEI, win initiate a BEI Committee review otthe proposed TLV and the placement of the existing BEI on the list ot 'Chemical Substances Under Study to Establish Biological Exposure Indices.* It the revised TLV (or which there is a BEI is transferred to the adopted list ol TLVs, the existing BEI will carry a notation indicating that the BEI is under review because of a change in the TLV and the BEI will remain so listed until the Committee completes its review and an action is recommended. 3. Committee membership: Gerald L. Kennedy, Jr., Haskell Laboratory, E.l. du Pont de Nemours & Co., Inc., retired as a consultant to the Committee: Joseph J. Saady, Ph.D., Medical College of Virginia Hospitals, Virginia Common wealth University, was appointed to the Committee; John Rosenberg, M.D., California Department of Health Services, was appointed Vice Chair of the Committee. 4. Revision and updating ot BEI documentations tor the 6th edition of the Documentation volume were completed and published. 5. Policy on establishing BEIs for monitoring of industrial chemi cals in exhaled air was reviewed and new procedures were published in Applied Occupational and Environmental Hygiene 6(9):B02-804, September 1991. 6. A description of pharmacokinetic models used in setting BEIs was incorporated in the 'Introduction* to the BEI Documentations, 6th edition, and will be published in Applied Occupational and Environmental Hygiene. Physical Agents TLV Committee Report to the ACGIH Membership lor Approval at the Annual Membership Meeting; June 2,1992; Boston, Massachusetts Notice of Intended Changes for 1992-1993 These physical agents, with their corresponding values, comprise those for which either a limit has been proposed tor the first time or for which a change in the "Adopted' listing has been proposed. In bolh cases, the proposed limits should be considered trial limits that will remain in the listing tor a period of at least one year, tf after one year no evidence comes to light that questions the appropriateness ot the values herein, the values will be reconsidered for the 'Adopted* list This notice provides not only an opportunity for comment but also solicits suggestions of physical agents to be added to the list. The suggestions should be accompanied by substantiating evi dence. t - 1992-1993 Revision or Addition. Introduction To The Physical Agents The following statement is to be added to the 'introduction* following 'Physical and Chemical Factors*: t Mutagenicity, Carcinogenicity, and Adverse Re productive Effects. The Physical Agents TLV Commit tee is examining the data related to mutagenicity, cancer, and adverse reproductive effects of physical agents. For example, it has been dearly demon strated that ionizing radiation is a cause of cancer in humans. Likewise, ultraviolet (UV) radiation shows mutagenic and carcinogenic effects in the skin. Heat stress, infrared energy, RF hyperthermia, and wholebody vibration have been assodated with adverse reproductive effects. More speculative is the scientific literature suggesting a connection between exposure to radiofrequency (RF), sub-RF energy, and/or magnetic fields with cancer. Neither an etiotogic role nor a risk analysis is established for these agents. The Physical Agents TLV Committee will continue to examine the bioeffects literature relating to cancer and adverse reproductive effects. Cold Stress Note 1 for Table 3. The first sentence is revised to read: t *1. Schedule applies to any 4-hour work period with moderate to heavy work activity, with warm-up periods ot 10 minutes in a warm location and with an extended break (e.g., lunch) at the end of the 4-hour work period in a warm location. For fight... (Step 5).* Ionizing Radiation The following statement is proposed as the replacement for the 1991-1992 TLV Booklet recommendation for Ionizing Radiation: t Ionizing Radiation Statement The Physical Agents TLV Committee accepts the occupa tional exposure guidance of the National Council on Radiation Protection and Measurements (NCRP) for ionizing radiation. For the purposes of this TLV, ionizing radiation indudes par ticulate and electromagnetic radiations having an energy ex ceeding 12,4 electron volts (eV) (i eV - 1.6 x 10~19 joule(J)], Animal and human studies have shown that exposure to ioniz ing radiation can result in carcinogenic, teratogenic, or mutagenic effects, as well as other sequelae. The scientific literature is summarized in critical reviews by the United Na tions Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). and the Biological Effects of Ionizing Radiation (BEIR) Committee ot the U.S. National Academy of Science. The NCRP has formulated occupational exposure guidance that.limits the risk of carcinogenesis and mutagenesis; further guidance is available regarding exposure of the pregnant woman to limit the in utero dose to the fetus. The TLV Commit tee also strongly recommends that all occupational exposure be minimized. 6-10-92 Published by THE BUREAU OF NATIONAL AFFAIRS, INC.. Washington. D C. 20037 SL 036188 CURRENT REPORT 83 The NCRP and the International Commission on Radiological Protection (ICRP) disseminate information and recommendations about radiation protection and related is sues, including the development of basic concepts. Their oc cupational exposure guidance is provided in NCRP Report No. 91 (Recommendations on limits for Exposure to Ionizing Radiation) and ICRP Report No. 60 ('The 1990 Recommenda tions of the ICRP"). Other ICRP and NCRP reports address specific areas of radiation protection and, collectively, provide an excellent basis for establishing a radiation control program. lasers A number of changes in the TLVs for lasers are recom mended for 1992, including a slight modification of the NIC from 1991. These changes introduce one new correction factor, Cc. which permits higher values for the TLVs at wavelengths between 1150 nm and 1400 nm. In addition, the TlVs at infrared wavelengths for pulsed lasers have been increased between 1400 nm and 2600 nm. The limiting apertures required for measuring laser radiation have also been revised, and a new statement on dealing with multiple-point laser sources has also been provided. The initial paragraph on page 100 of the 1991-1992 TLV/BEI Booklet remains. Revisions are proposed for the remaining text on page 100, for Table 1 on page 100, and for the first 10 lines on page 101 (up to 'Repetitively Pulsed Exposures'). Figure 1 on page 101 remains. t Limiting Apertures The TlVs expressed as radiant exposure or irradiance in this section may be averaged over an aperture of 1 mm, 3.5 mm, or 7 mm, depending upon the exposure condition as given in Table 1. t Extended Sources The TLVs for 'extended sources* are obtained through the use of a correction factor Ce provided at the bottom of Table 2 and are only applied at wavelengths in the retinal hazard region (400-1400 nm) for sources that subtend a linear angle greater than amin and less than Oma* 100 mrad. The angle amin is defined as: dmin - 1.5 mrad for t < 0.7 s, amin 2 t3'4 mrad for 0.7 s < t < 10 s, and own - 11 mrad for t > 10 s. Normally, a laser source is not an "extended source," and the TLVs in Table 2 can be applied directly without Ce. Any sources whose centers are separated by an angle greater than awn are treated as extended sources; examples would be some large laser diode arrays. t Correction Factors A. B, C (Ck Ce, Cc) The TLVt for ocular exposure in Table 2 are to be used as g'ven lor all wavelength ranges. The TLVs lor wavelengths between 700 nm and 1400 nm are to be increased by the factor Ca (to account tor reduced absorption of melanin) as given in Figure 1. For certain exposure times at wavelengths between 550 nm and 700 nm, a correction factor Ca (to account for reduced photochemical sensitivity for retinal injury) must be applied. The correction factor Cc is applied from 1150 to 1400 nm to account lor pre-retinal absorption of the ocular media. The TlVs tor skin exposure are given in Table 3. The TlVs are to be increased by a factor Ca as shown in Figure 1 for wavelengths between 700 nm and 1400 nm. To aid in the determination tor exposure durations requiring calculations of fractional powers, Figures 2 and 3 may be used. (Delete the current Table 1 (page 100) as this will no longer be needed and replace with a new Table 1 as given below,] fTABLE 1. Limiting Apertures Applicable to Laser TlVs (mm) ___________________________________ Spectral Reqion 180nm-400nm 180nm-400nm 400 nm - 1400 nm 400 nm-1400 nm 1400 nm- 0.1 mm 1400 nm-0.1 mm 0.1 mm-1.0 mm Duration 1 ns to 025 s 0.2S s to 30 ks 1 ns to 0.2S s 0.25 s to 30 ks 1 ns to 0.25 s 0.25 s to 30 ks 1 ns to 30 ks Eye____ Skin 1 mm 3.5 mm 7 mm 7mm 1 mm 3.5 mm 11 mm 3.5 mm 3.5 mm 3.5 mm 3.5 mm 3.5 mm 3.5 mm 11 mm t Insert the following correction factor Cc in Table 2 in the entries for 1R-A as follows: IR-A 1050 nm to 1400 nm 1050 nm to 1400 nm 700 nm to 1400 nm IR-BAC1.401 nm to 1.5 pm 1.401 pm to 1.5 pm 1.501 pm to 1 -8 pm 1.801 pm to 2.6 pm 1.801 pm to 2-6 pm 2.601 pm to I03pm 2.601 pm to 10s pm _______ 1,400 pm to 103 pm 10"* to 5 x 1(T 5 Cc x 10"* J/Cm* 5 x 10"* to 103 8 Cc (V Vt) J/cm1 103to3 x 104 320 Ca Cc pW/cm* 10"*to 10"3 0.1 J/cm* lO^tolO 0.56t'"jfcm* 10"* to 10 1.0 J/cm* 10"*to 10*3 0.1 J/cm* lO^tolO 0.56t1MJ/em* 10"* to 10-7 10 mJ/fcm*J/ttn* I0`7tol0 0.56t1rt J/Cm1 10 to 3 x 104 100mWm* Table 2 tTo the current footnote tor Table 2, which refers to correction factors Ca etc., add the following: Cc - 1.0 from 700 nm to 1150 nm; Cc - io0 018^-1150 nfT') for wavelengths greater than 1150 and less than 1200 nm; Cc - 8.0 from 1200 to 1400 nm. NOTE: For extended-source laser radiation (e.g., diffuse reflec tion viewing) at wavelengths between 400 nm and 1400 nm, the intrabeam viewing TLVs can be increased by the following correction factor Ce provided that the angular subtense of the source (measured at the viewer's eye) is greater than amin (e g., greater than 1.5 mrad for t < 0.7 s; amin - 2. t3'4 mrad for 0.7 s < t < 10 s, and amin - 11 mrad for t > 10 s). The value of Ce is equal to 1.0 for all angles a less than amin and is never less than 1.0. Ce - (cuomin) for amin < a < amax - 100 mrad Ce - 0*7(0mm * Qfflu) for a > Omxx - 100 mrad. for a expressed in mrad. The angle of 10C mrad may also be referred to as amu at which poini the TlVs may be expressed as a constant radiance and the last equation can be rewritten in terms of radiance L Itlv- 8.5 x 103 x (TLVp ttxxtt) J(an* sr) for t < 0.7 s Luv - (6.4 x 10s 1*) x (TLVp, muni J(cm* sr) for 0.7 s <t<10f Ltlv - (12 x 10*) x (TLVp, J(cm* * sr) (or expressed in W(crrr sr) as applicable) for t > 10 s The measurement aperture should be placed at a distance of 100 mm or greater from the source. Transfers to the Adopted List for 1992-1993 Hand-Arm (Segmental) Vibration Syndrome (HAVS) Paragraph 1 on page 86 of the 1991-1992 TLV/BEI Book let has been adopted: 6-10-92 Occupational Safety & Health Reporter SL 036189 84 The TLVs in Table 1 refer to component acceleration levels and durations ol exposure that represent condi tions under which it is believed that nearly all workers may be exposed repeatedly without progressing beyond Stage 1 of the Stockholm Workshop Classification Sys tem for Vibration-induced White Finger (VWF), also known as Raynaud's Phenomenon of Occupational Origin (Table 2). Since there is a paucity of doseresponse relationships for VWF. these recommenda tions have been derived from epidemiological data from forestry, mining, and metal working. These values should be used as guides in the control of hand-arm vibration - exposure; because of individual susceptibility, they should not be regarded as defining a boundary between safe and dangerous levels. Heat Stress Paragraph 2 on page 91 of the 1991-1992 TLV/BEI Book let has been adopted. Where there is a requirement for protection against other harmful substances in the work environment and additional personal protective clothing and equipment must be worn, a correction to the WBGT TLV values, as presented in Table 4, must be applied. Table 4 on page 98 has been adopted. TABLE IV. TLV WBGT Correction Factors In C for Clothing Clothing Type CIO Value* WBGT Correction Summer work uniform Cotton coveralls Winter work uniform Water barrier, permeable 0.6 1.0 1.4 12 0 -2 -4 -6 *Cto: Insulation value of clothing. One do unit 5.S5 kcat/m*/hr of heat exchange by radiation and convection for each C of tempera ture difference between the skin and adjusted dry bub temperature. Note: Deleted from Table 4 are trade names and Yuly encapsulat ing suit, gloves, boots, t hood,* induding its Cfo value of 12 and WBGT correction of -10. Lasers The footnotes to Table 2 on pages 103-104 of the 19911992 TLV/BEI Booklet were adopted: Ca - See Fig. 1: Ce - 1 for X - 4001o 549 nm; Ce - lO1'00^- sso,) for X - 550 to 700 nm; Ti- 10 s for X - 400 to 549 nm; Ti - 10 X 101OQZft "530,1 for X - 550 to 700 nm. Change Under Study: 1.536-1.544 pm, 1.0 ns to 1.0 ps, 1.0 J/cnr. Note: For extended-source laser radiation (e.g., diffuse reflection viewing) al wavelengths between 400 and 1400 nm. the intrabeam viewing TLVs can be increased by the following correction factor (C.F.) provided that the an gular subtense of the source (measured at the viewer's eye) is greater than omin (e g., greater than 3.5 mrad for t < 3.2 s. or greater than 11 mrad for t > 10 s) and less OCCUPATIONAL SAFETY & HEALTH REPORTER than 0.1 radian, i.e,, less than 100 mrad. Calculated correctionfactors should therefore never be less than 1 JO. C.F. - (a/3.5 mrad) for all exposure times less than 3.2 s C.F. - (a/1.11 mrad) lor exposure duration for 3.2 s iti10s C.E. - (a/11 mrad) for exposure duration > 10 s. However, fort > 10 s and less than IQ4 s, the radiance must not exceed 2.1 x Ce x 10* J/cmVsr to protect the retina against photochemical injury for 400 to700 nm. For wavelengths > 700 nm, only the third correction factor is applied. The extended source limits can also be expressed as values of integrated radiance Lp for exposure durations less than 3.2 s: TLV Lp * 1.04 X 10*/sr/C.F. (ELpt source) for 3.5 mrad sas 100 mrad TLV or EL Lp - 3.7 x 103 (ELpt source) a> 100 mrad sr) for No correction factor can be applied at UV wavelengths less than 400 nm or infrared wavelengths greater than 1400 nm. Physical Agents Understudy The Physical Agents TLV Committee has examined the current literature on the following agents and has not found sufficient data upon which to proposa a TLV. However, these agents will remain under study during the coming year to examine new evidence indicating the need and feasibility for establishing a proposed TLV. Comments and suggestions, accompanied by substantive documentation, are solicited and should be forwarded to the Executive Director, ACGIH. 1. Laser radiation with pulse durations less than 1 ns. 2. Vibration. Whole-body. 3. Pressure Variations. 4. Electromagnetic Pulses and Radiofrequency Radiation (RFR). Peak power limits. 5. Physical Agents as Carcinogens -- Known and Suspect. Committee activities for 1991-1992 Included: 1. Two stated Committee meetings: October 27-28,1991, Richland, WA; March 29-31,1992, Aberdeen, MD. 2. Revision and updating of Physical Agents documenta tions for ihe 6th edition of the Documentation volume were completed and published. 3. Committee participation and ACGIH cosponsorship of the Thirtieth Hanford Symposium, Richland, WA, on `Current Topics in Occupational Health.* 4. Joint meeting of the Physical Agents Committee with - the U.S. Army Environmental Hygiene Agency, Bio acoustics Division, Aberdeen Proving Grounds, MD. and international experts on noise-induced hearing loss. * 6-10-92 Published by THE BUREAU OF NATIONAL AFFAIRS, INC., Washington, D C. 20037 i SL 036190 iry