Document dQmmwoexBx41RwO97ewKV906B

STO!05375 POUCY STATEMENT ON THE USES OF TLVs AND BEls The Threshold Limit Values (TLV3) and Biological Exposure Indices (BEls) are developed as guidelines to assist in the con 1 1 1990-1991 trol ol health hazards. These recommendations or guidelines are intended for use in the practice of industrial hygiene, to be Inter preted and applied only by a person trained in this discipfine They I Threshold Limit Values are not developed tor use as legal standards, and the American Conference of Governmental Industrial Hygienists (ACGIH) does not advocate their use as such. However, it is recognized that in certain circumstances individuals or organizations may wish to for Chemical Substances make use of these recommendations or guidelines as a supple ment to their occupational safety and health program. The ACGIH will not oppose their use in this manner, if the use of TLVs and BEls in these instances win contribute to the overall improve in the ment in worker protection. However, the user must recognize the constraints and limitations subject to their proper use and bear the responsibility lor such use. * The introductions to the TLV/BEI booklet and the TLV/BEI Work Environment Documentation provide the philosophical and practical bases for the uses and limitations of the TLVs and BEls. To extend those uses of the TLVS and BEls to include other applications, such as use without the'judgment of an industrial hygienist, application to a different population, development of new exposure/recovery time models, or new effect endpoints, stretch the reliability and even viability of the data base for the TLV or BEI as evidenced by the individual documentations. It is not appropriate for individuals or organizations to impose on the TLVs or the BEls their concepts of what the TLVS or BEls should be or how they should be applied or to transfer regulatory standards requirements to the TLVs or BEls. .The Policy Statement on the Uses of TLVs/BEIs was approved by the Board of Directors of ACGIH on March 1, 1988. t vi Adopted by ACGIH with Intended Changes for 1990-91 Contents Introduction............................................................................ Adopted Threshold Limit Values.......................................... Notice of Intended Changes................................................ Appendix A -- Carcinogens................................................. Appendix B -- Substances of Variable Composition .... Appendix C -- Threshold Limit Values for Mixtures----Appendix O -- Particle Size-Selective Sampling Criteria for Airborne Particulate Matter ................. Chemical Substances and Other Issues Under Study ... Committee Members............................................................. 3 11 39 41 42 43 45 47 49 Special Note: The year of most recent adoption of a TLV, or change thereto, is listed in parentheses after the substance in the adopted list. 2 STOI 05876 INTRODUCTION TO THE | CHEMICAL SUBSTANCES Threshold Limit Values (TLVs) refer to airborne concentrations of substances and represent conditions under which it is believed that nearly ail workers may be repeatedly exposed day after day without adverse health effects. Because of wide variation in individual susceptibility, however, a small percentage ot workers may experience discomfort from some substances at concentra tions at or below the threshold limit; a smaller percentage may be affected more seriously by aggravation of a pre-existing condition or by development of an occupational illness. Smoking of tobacco is harmful for several reasons. Smoking may act to enhance the biological effects of chemicals encountered in the workplace and may reduce the body's defense mechanisms against toxic sub stances. Individuals may also be hypersusceptible or otherwise unusu ally responsive to some industrial chemicals because of genetic factors, age, personal habits (smoking, alcohol, or other drugs), medication, or previous exposures. Such workers may not be ade quately protected from adverse health effects from certain chemi cals at concentrations at or below the threshold limits. An occupational physician should evaluate the extent to which such workers require additional protection. TLVs are based on the best available information from indus trial experience, from experimental human and animal studies, and, I when possible from a combination of the three The basis on which 1 the values are established may differ from substance to substance: i protection against impairment of health may be a guiding factor I for some whereas reasonable freedom from irritation, narcosis, ! nuisance, or other forms of stress may form the basis for others. The amount and nature of the information available for I establishing a TLV varies from substance to substance; consequenti ly, the precision of the estimated TLV is also subject to variation and the latest TLV Documentation should be consulted in order to assess the extent of the data available for a given substance. These limits are intended for use In the practice of indus trial hygiene as guidelines or recommendations in the control j of potential health hazards and for no other use, e.g., In the evaluation or control of community air pollution nuisances; in estimating the toxic potential of continuous, uninterrupted ex posures or other extended work periods; ss proof or disproof of an existing disease or physical condition; or adoption by countries whose working conditions differ from those In the I United States of America and where substances and processes | differ. These limits are not fine lines between safe and dan gerous concentration nor are they a relative index of toxicity. 3 They should not be used by anyone untrained In the discipline of industrial hygiene. The TLVs, as issued by the American Conference of Govern mental Industrial Hygienists, are recommendations and should be used as guidelines for good practices. In spite of the fact that seri ous injury is not believed likely as a result of exposure to the threshold limit concentrations, the best practice is to maintain con centrations of ail atmospheric contaminants as low as is practical. The American Conference of Governmental Industrial Hygienists disclaims liability with respect to the use of TLVs. Notice at Intended Changes. At me beginning oi each year, proposed actions at the Chemical Substances TLV Committee for the forthcoming year are issued In the form of a "Notice of Intend ed Changes." This Notice provides an opportunity for comment and solicits suggestions o( substances to be added to the List. The sug gestions should be accompanied by substantiating evidence. The "Notice of Intended Changes" is presented after the Adopted Values in this section (and in the cither two sections) of the booklet. Values listed in parenthesis in the "Adopted" list are to be used during the period in which a proposed change for that Value is listed in the Notice of Intended Changes. Oeffrifdbna. Three categories of Threshold Limit Values (TLVs) are specified herein, as follows: a) Threshold Limit Vakje-rime-WbightedAverage (TLV-TWA)-- the time-weighted average concentration for a normal 8-hour work day and a 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. b) Threshold Limit Value-Short-Term Exposure Limit (TVfSTEL)--the concentration to which workers can be exposed con tinuously for a short period of time without suffering from 1) irrita tion, 2) chronic or irreversible tissue damage, or 3) narcosis of sufficient degree to increase the likelihood ol accidental injury, im pair self-rescue or materially reduce work efficiency, and provided that the daily TLV-TWA is not exceeded. It is not a separate independent exposure liml; rather, it supplements the time-weighted average (TWA) limit where there are recognized acute effects from a substance whose toxic effects are primarily of a chronic nalure. STELs are recommended only where toxic effects have been report ed from high short-term exposures in either humans or animals. A STEL is defined as a 15-minute TWA exposure which should not be exceeded at any time during a workday even if the 8-hour TWA is within the TLV-TWA. Exposures above the TLV-TWA up to the STEL should not be longer than 15 minutes and should not occur more than four times per day. There should be at least 60 minutes between successive exposures in this range. An averag ing period other than 15 minutes may be recommended when this is warranted by observed biological effects. c) Threshold Limit Value-Ceiling (TLV-C)--the concentration that should not be exceeded during any part of the working exposure. 4 In conventional industrial hygiene practice it instantaneous monitoring is not feasible, then the TLV-C can be assessed by sam pling over a 15-minute period except for those substances that may cause immediate irritation when exposures are short. For some substances, e.g., irritant gases, only one category, the TLV-Ceiling, may be relevant. For other substances, one or two categories may be relevant, depending upon their physiologic ac tion. It is important to observe that if any one of these types of TLVs is exceeded, a potential hazard from that substance is presumed to exist. The Chemical Substances TLV Committee holds to the opin ion that TLVs based on physical irritation should be considered no less binding than those based on physical impairment. There is increasing evidence that physical irritation may initiate; promote, or accelerate physical impairment through interaction with other chemical or biologic agents. Time-Weighted Average (TWA) vs Celling (C) Limits. TWAs permit excursions above the TLV provided they are compensated by equivalent excursions below the TLV-TWA during the workday. In some instances, it may be permissible to calculate the average concentration for a workweek rather than for a workday. The rela tionship between the TLV and permissible excursion is a rule of thumb and in certain cases may not apply. The amount by which the TLVs may be exceeded for short periods without injury to health depends upon a number of factors such as the nature of the con taminant, whether very high concentrations--even for short periods--produce acute poisoning, whether the effects are cumula tive, the frequency with which high concentrations occur, and the duration of such periods. All factors must be taken into considera tion in arriving at a decision as to whether a hazardous condition exists. Although (he TWA concentration provides the most satisfac tory, practical way of monitoring airborne agents for compliance with the TLVs, there are certain substances for which if is inappropri ate. in the latter group are substances which are predominantly fast acting and whose TLV is more appropriately based on this par ticular response. Substances wilh this type of response are best controlled by a ceiling limit that should not be exceeded. It is Im plicit in these definitions that the manner of sampling to determine noncompliance with the limits for each group must differ; a single, brief sample, that is applicable to a ceiling limit, is not appropriate to the TWA; here, a sufficient number of samples are needed to permit a TWA concentration throughout a complete cycle of oper ations or throughout the workshilt. Whereas the ceiling limit places a definite boundary that con centrations should not be permitted to exceed, the TWA requires an explicit limit to the excursions that are permissible above the listed TLVs. It should be noted that the same factors are used by the Chemical Substances TLV Committee in determining the magnitude of trie value of the STELs. or whether to include or exclude a substance tor a ceiling listing. ILSSOIOIS Excursion Limits. For the vast majority ol substances with a TLV-TWA, there is not enough toxicological data available to warrant a STEL. Nevertheless, excursions above the TLV-TWA should be controlled even where the 8-hour TLV-TWA is within recommend ed limits. Earlier editions ol the TLV list included such limits whose values depended on the TLV-TWAs of the substance in question. While no rigorous rationale was provided for these particular values, the basic concept was intuitive: in a well-ccntrollecl process exposure, excursions should be held within some reasonable Emits. Unfortunately, neither toxicology nor collective industrial hygiene experience provide a solid basis for quantifying what those limits should be. The approach here is that the maximum recommended excursion should be related to variability generally observed in actual industrial processes. In reviewing large numbers of industrial hygiene surveys conducted by the National Institute for Occupa tional Safety and Health, Leidei, Busch, and Crouse*'* found that short-term exposure measurements were generally lognormally dis tributed with geometric standard deviations mostly in the range of 15 to 25. While a complete discussion ol the theory and properties of the lognormal distribution is beyond the scope of this section, a brief description of some important terms is presented. The measure o( central tendency in a lognormal description is the antilog of the mean logarithm of the sample values. The distribution is skewed, and the geometric mean is always smaller than the arithmetic mean by an amount which depends on the geometric standard devia tion. In the lognormal distribution, the geometric standard devia tion (sd,) is the antilog of the standard deviation of the sample value logarithms and 6826% of all values lie between m^/Sd, and m, x sd,. If the short-term exposure values in a given situation have a geometric standard deviation of 2.0, 5% of all values will exceed 813 times the geometric mean. If a process displays a variability greater than this, it is not under good control and efforts should be made to restore control. This concept is the basis for the fol lowing excursion limit recommendations which apply to those TLV-TWAs that do not have STELs: Excursions in worker exposure levels may exceed 3 times the TW-TWA tor no more than a total ol 30 minutes during a work day. and under no circumstances should they exceed 5 times the TLV-TYA, provided that the TLV-TWA is not exceeded. The approach is a considerable simplification of the idea of the lognormal concentration distribution but is considered more con venient to use by the practicing industrial hygienist. If exposure ex cursions are maintained within the recommended limits, the geometric standard deviation of the concentration measurements will be near 20 and the goal of the recommendations will be accomplished. When the toxicological data for a specific substance are avail able to establish a STEL, this value takes precedence over the ex- 6 I cursion limit regardless of whether it is more or less stringent. I "Skin" Notation. Listed substances followed by the designa- ; tion "Skin" refer to the potential contribution to the orerall exposure i by the cutaneous route including mucous membranes and eye, i either by airborne or, more particularly, by direct contact with the I substance Vehicles can alter skin absorption. Little quantitative data are availabie describing absorption ot I vapors and gases through the skin. The rate oI absorption is a func1 tion ol the concentration to which the skin is exposed. Substances having a skin notation and a low TLV may present I a problem at high airborne concentrations, particularly if a signift' cant area of Ihe skin is exposed for a long period of time. Protec tion of the respiratory tract, while the rest of the body surface is exposed to a high concentration, may present such a situation. Biological monitoring should be considered to determine the relative contrfoution of dermal exposure to the total dose. This attentioncalling designation is intended to suggest appro priate measures tor the prevention of cutaneous absorption so that the TLV is not invalidated. Mixtures. Special consideration should be given also to the application of the TLVs in assessing the health hazards that may be associated with exposure to mixtures of two or more substances. A brief discussion of basic considerations involved in developing TLVs for mixtures and methods for their development, amplified by specific examples, are given in Appendix C. Respirable and Total Oust. For solid substances and liquified mists, TLVs are expressed in terms ot total dust, except where the term "respirable dust" is used. See Appendix 0, Particle SizeSelective Sampling Criteria for Airborne Particulate Matter, for the definition of respirable dust. Particulates Not Otherwise Classified (PNOC). In contrast to fibrogenic dusts which cause scar tissue to be formed in lungs when inhaled in excessive amounts, so-called "nuisance" dusts have a long history of little adverse effect on lungs and do not produce significant organic disease or toxic effect when exposures are kept under reasonable control. Such dusts have also been called (biologically) "inert" dusts, but the latter term is inappropriate to the extent that there is no dust which does not evoke some cellu lar response in the lung when inhaled in sufficient amount. However, the lung-tissue reaction caused by inhalation of PNOCs has the following characteristics: 1) the architecture of the air spaces remains intact; 2) collagen (scar tissue) is not formed to a signifi cant extent; and 3) the tissue reaction is potentially reversible. Excessive concentrations of PNOCs in the workroom air may seriously reduce visibility: may cause unpleasant deposits in the eyes, ears, and nasal passages (e.g., Portland cement dust); or cause injury to the skin or mucous membranes by chemical or mechanical action perse or by the rigorous skin cleansing proce dures necessary (or their removal. A TLV-TWA of 10 mg/m3 of total dust containing no asbestos and < 1% crystalline silica is recommended lor substances'm these 7 9 L 8 S 0 I 01S categories and for which no specific TLVs have been assigned. This limit, (or a normal workday, does not apply to brief exposures at higher concentrations. Neither does it apply to those substances which may cause physiologic impairment at lower concentrations but tor which a TLV has not yet been adopted. The separate nuisance dust appendix was deleted in favor of individual entries in the Adopted listing for those substances formerly carried in this appendix. Simple Asphyxiants -- "Inert" Gases or Vapors. A number of gases and vapors, when present in high concentrations in air, act primarily as simple asphyxiants without tfher significant physiologic effects. A TLV may not be recommended tor each simple asphyxiant because the limiting factor is the available oxygen. The minimal oxygen content should be 18% by volume under normal atmospheric pressure (equivalent to a partial pressure, pQ, of 135 torr). Atmospheres deficient in 02 do not provide adequate warn ing and most simple asphyxiants are odorless. Several simple asphyxiants present an explosion hazard. Account should be taken of this factor In limiting the concentration of the asphyxiant. The separate appendix, which contained examples ot some asphyxi ants, has been deleted. Those substances formerly carried in that appendix continue as alphabetical'entries in the Adopted listing. Physical Factors. It is recognized that such physical factors as heal, ultraviolet and ionizing radiation, humidity, abnormal pres sure (altitude), and the like may place added stress on the body so that the effects from exposure at a TLV may be altered. Most of these stresses act adversely to increase the toxic response of a substance. Although most TLVs have pulUn safety factors to guard against adverse effects to moderate deviations from normal environ ments, the safety factors of most substances are not of such a mag nitude as to take care of gross deviations. For example, continuous work at temperatures above 90F, or overtime extending the work week more than 2S%, might be considered gross deviations. In such instances, judgment must be exercised in the proper adjust ments of the TLVs. Unlisted Substances. Marry substances present or handled in industrial processes do not appear on the TLV list. In a number ot instances, the material is rarely present as a particulate, vapor, or other airborne contaminant, and a TLV is not necessary. In other cases, sufficient information to warrant development of a TLV, even on a tentative basis, is not available to the Chemical Substances TLV Committee. Other substances, of low toxicity, could be classi fied as Particulates Not Otherwise Classified. In addition, there are some substances of not inconsiderable toxicity that have been omitted primarily because only a limited num ber of workers (eg., employees of a single plant) are known to have potential exposure to possibly harmful concentrations. Unusual Work Schedules. Application of TLVs to workers on work schedules markedly different from the conventional 8-hour day, 40-hour week requires particular judgement in order to pro vide, for such workers, protection equal to that provided to workers on conventional workshifts. As tentative guidance, field hygienists are referred to the "Brief and Scala model" and the "OSHA model." both of which are described and explained at length in Patty.13 | The Brief and Scala model reduces the TLV proportionately j for both increased exposure time and reduced recovery (non | exposure) time, and it is the more conservative of the two models. | The OSHA model classifies air contaminants by type of toxic ef fect and recommends different adjustment procedures for the ex i posure limits (including zero adjustment) on that basis. | The two models are generally intended to apply to work sched ules longer than 8 hours/day or 40 hours/week. The models should not be used to justify very high exposures as "allowable" where the exposure periods are short (eg., exposure to 8 times the TLVTWA for one hour and zero exposure during the remainder of the shift). In this respect, the general limitations on TLV excursions and STELs should be applied to avoid inappropriate use of the models with very short exposure periods or shifts. Since adjusted TLVs do not have the benefit of historical use and long-time observation, medical supervision during initial use of adjusted TLVs is advised. In addition, the hygienist should avoid unnecessary exposure of workers even if a model shows such ex posures to be "allowable" and should not use models to justify higher-tharv-necessary exposures. Both the OSHA and the Brief and Scala models are easier to use than some of the more complex models based on phar macokinetic actions. However, hygienists thoroughly familiar with such models may find them more appropriate in specific instances. Use of such models usually requires knowledge of the biological half-life of each substance, and some models require additional data. Short workweeks can allow workers to have two full-time jobs, perhaps with similar exposures, and may result in overexposure even if neither job by itself entails overexposure. Hygienists should be alert to such situations. Conversion of TLVs in ppm to mg/m3. TLVs for gases and vapors are usually established in terms of parts per million of sub stance in air by volume (ppm). For convenience to the user, these TLVs are also listed here in terms of milligrams of substance per cubic meter of air (mg/m3). The conversion is based on 760 torr barometric pressure and 25"C (77F), giving a conversion equa tion of: TLV in mg/m3 = (TLV in ppm) (gram molecular weight of the substance) 24.45 Resulting values are rounded to two significant figures below 100 and to three significant figures above 100. This is not done to give any converted value a greater precision than that of the original TLV, but to avoid increasing or decreasing the TLV significantly merely by the conversion of units. 9 6L8S0IQ1S The above equation may be used to convert TO& to any degree of precision desired. When convening TLVs to mg/m3 units for other temperatures and pressures, the reference TLVs should be used as a starting point. These are the values expressed in ppm, ex cept for benomyi, caprolactam, and sodium azide, which are es tablished in terms ol mg/m1. Also, when converting values expressed as an element {eg., as Fe, as Ni), the molecular value ol the element should be used, not that of the entire compound. In making conversions lor substances with variable molecu lar weights, appropriate molecular weights have been estimated or assumed (see the TLV Documentation). Operational Guideline*. The ACGIH Board ol Directors has adopted operational guidelines tor the Chemical Substances TLV Committee. These guideines prescribe: charge, authority, policies, membership, organization, and operating procedures. The policies include the appeals procedures. Copies of the guidelines docu ment are available from the ACGIH Publications Office at a cost ol $5 per copy. The guidelines were also published in the March 1988 issue ol Applied Industrial Hygiene. These guidelines permit public input. Bateranees 1. Leidel. N.A.; Busch, KA; Crouse; W.E.: Exposure Measure ment, Action Level and Occupational Environmental variabili ty. DHEW (NIOSH) Pub. No. 78-131 (December 1975). 2. Paustenbach, DJ.: Occupational Exposure Limits, Pharmacoki netics, and Unusual Vtork Schedules. In: Party's Industrial Hygiene and lexicology, 2nd ed., Vol. 3A. The Work Environ ment. Chap. 8 pp. 111-277. LJ. Cralley and L.V. Cralley, Eds. John Wiley and Sons Inc., New York (1985). NOTE: In the interest of keeping this book as compact as possible the footnotes for the adopted values appear on the fold-out of the back cover. All pertinent footnotes relating to the materials in this booklet now appear on the fold-out of the back cover. Substance[CAS l] ppm** ADOPTED VALUES TWA STa ppnr* mg/m*' Acetaldehyde (7M7-q ti976). Acetic acid im-uti oarei . Acetic anhydride 100 180 10 25 (108-24-71 (1976)............ Acetone 167-64-1| (1962).... Acetonitrle rmmi |i976) .. Acetylene (7446-2) <i96i) ... C 5 C 21 750 1780 40 67 -- Acetylene dfchtoride. see 1.2-DichJoroeihvlene Acetylene tetrabromide (79-27-6) (1986)................. Acetytsafcylic add (Aspirin) (50-78-21 (I960)............... Acrolein (107-02-81 <1976)___ Aciytamide [7W6-i| -- 1 14 _5 0.1 0.23 Skin (1987)............... Acrylic add |79i07]-- -- 0.03.A2 Skin (1990)............... Acrylonitrile |to7-i3-i(-- 2 5.9 Skin 0964)................ "AWnn pcs-oo-2)--Skin (1966) Altyl alcohol |io7-ib-6I -- 2.A_2 4.3.A2 0.25 Skin (1976).............. AByl chloride 1107-C6-11119761 AByl glyddyt ether (AGE) 2 4.8 1 3.0 [106-92-31 (1976)............. Alfyl propyl disulfide 5 23 [2179-59-11 (1976).............. o-Alumina, see Aluminum oxide 2 12 Aluminum (7429-90-5). as Al _Metal dust nsas).......... _Pyro powders <1979)........ _Welding fumes (1979)___ 10 5 5 Soluble salts H979I . Alkyls (NOCm) (1979) .. ___ 2 2 Aluminum oxide 11344-26-11. as Al (1966)............. - 10W 150 IS _ 1000 60 0.3 - 4 2 to 3 _ -- 270 37 2380 101 0.69 - 95 6.0. 47 1A _ 088S0I01S Substance (CAS 1] ADOPTED VALUES TWA STEL ppm- mg/m*' ppnr' mg/m*1 4-Airtnodiphenyt [92-67*1] -- Skin (1972) .... -- A1 -- 2-Aminoethanol, see Etharolamine 2-Aminopyridine [504-2941 (1966)................ 0.5 2.0 -- 3-Amino-1.2.4-triable, see Amitrole Amitrole |6t-S2S) om .... -- 0.2 -- Ammonia (766mi-ti (is76).. 25 17 35 Ammonium chloride fume [12125-02-91 11970) ............ -- 10 -- Ammonium pedluorooctanoale [3825-26.1] (1968)........ -- 0.1 -- Ammonium sultamate [77730641 (1986) ...'........ -- 10 -- Amosite. see Asbestos n-Amyt aratats [628-63-7] <i7) sec-Amyl acetate 100 532 * -- [626360| (1987)................ 125 665 -- -Aniline [62-53-3] and homologues--Skin (1986) Anisidine |29i9i-52 -q (o-, p- 2 7.6 -- isomers)--Skin (1977) ... 0.1 0.50 -- Antimony [7440.360] and compounds, as Sb (i960) -- 0.5 -- Antimony tnoxide [1309-64-4] Handling and use. as Sb [1978]............................ _ 0.5 -- Production (i960)............ -- A2 -- ANTU |8688-| (1986).......... Argon [744iw7-i| (1981)........ -- 0.3 __: -- -- -- Arsenic (7440362] and soluble compounds, as As (1980).................... _ 0.2 -- Arsenic trioxide production [1327-53-31 (I960).............. Arsine (7784-42 1| (1977)___ -- A2 0.05 0.16 -- -- Asbestos Amosite I12172-735] (1960) 0.5 fiber/cc, A1 Chrysotiie [120013.5] irasci) 2 fibers/cc, A1 Croddolite itzm-264] (igacp 0.2 fiber/cc, A1 Ottver torms (i960)........ 2 fibers/cc, Af Asphalt (petroleum) fumes |8052 42 4| (1967).............. Atrazine |i9iz-24-9] (1983) ... _ -- 5-- 5-- -Arinphos-metfiyi [66-50-01 -- Skin (1966) .... -- 0.2 -- -- -- -- 24 20 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 12 Substance [CAS f( ADOPTED VALUES TWA STEL ppm*' mg/m*' ppm*' mg/m*' Banum 17440-363). soluble compounds, as Ba H977) -- 0.5 Barium sulfate 17727-437) (1986)............................... -- 10 Benomyl |i7804-35-2| (1986).. 0.84 10 ^-Benzene 171-4321 |i987) -- (10.A2) (32.A2) Benzidine (92-87-5)--Skin (1962)............................. -- A1 p-Benzoquinone. seeQuinone Benzoyl peroxide [94-36-01 11977)............................... -- 5 Benzopyrene 15032-8] 11975) -- A2 Benzyl chloride [10044-7] (1977) 1 5.2 Beryllium [744041-7] and compounds, as Be (1979) -- 0.002,A2 Biphenyl [92-52-4] (1987) .... 0.2 1.3 Bismuth teUurtde 1130442-1] (1966) ............ -- 10 Se-doped (1986).............. -- 5 Borates, telra. sodium salts |130396-4] Anhydrous (1977)............ -- 1 Oecahydrate (1977).......... -- 5 Pentahydrate (1977)........ -- 1 Boron oxide 11303462] (1966) -- 10 Boron tribiomide 110294-3341 (1966) ............ C 1 c 10 Boron trifiuorkte [7637-07-21 (1977).............. c 1 C 2.8 Bromacil |3i4-409| |i986) ... 1 11 Bromine [7726-954] (1976). .. 0.1 0.66 Bromine pentaftuoride 17789-30-2] (1986).............. 0.1 0.72 Bromochloromettiane. see Chlorobromomethane Bnomoform |7S-32]-- Skin (1977)..................... 0.5 5.2 1,3-Butadiene [1069901 (1986) 10.A2 22.A2 Butane [i06974| (i98i)........ 800 1900 Butanethiol. see Butyl mercaptan 2-Butanone. see Methyl ethyl ketone (MEK) 2-6utoxye!tianot (EGBE) 1111-762) --Skin (1967) ... 25 121 n-Butyi acetate |1234M (1975) 150 713 sec-Buty( acetate (1QWM (1987]................ 200 960 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0.3 -- " -- -- -- 200 -- -- -- -- " -- -- -- -- -- -- -- -- -- -- -- -- -- 2.0 -- -- -- -- -- 950 -- 13 188901OiS Substance [CAS 1] ADOPTED VALUES TWA STEL ppm" mg/m1" ppm*' rng/m1" tert-Sutyt acetate [54M65] (1907)................ 200 Butyl acrylate 1141-32-zi 0973) 10 n-Butyl alcohol (71363)-- Skin (1977)...................... C50 sec-Butyt alcohol (7B-9Z-2) (1990)................. IX tert-Butyl alcohol (75-65-01 (1976)................. IX Butylamine [109-73-9J-- Skin (1976)..................... C5 tert-Butyl chromate, as CrO, |1186861]-Skin (1977) .. -- n-Butyl giycidyl ether (BGE) (2426006) (1961)............. .. 25 rvButyl lactate (13622-7) 11977) -5 Butyl mercaptan (109-79-5) (1977)............... - .0.5 o-sec-Butylphenol (a9-72-5|-Skin (i960).... 5 p-tert-Butyltoluene (96-51-1) (1976)................. 10 $-"Cadmium (744643-9) dusts and salts, as Cd (1976) .. -- {Cadmium oxide 11306-19-01 Fume, as Cd (1974)....... -- Production (1983)........... -- Calcium carbonate 11317-66-31 (1966)............. -- Calcium cyanamide (15662-7) (1986) . ............. -- Calcium hydroxide [13066201 (1976)............. Calcium oxide (13057691 (i97B) -- -- tCalcium silicate |1344-95-2| (1974)............ -- Calcium sulfate (7776-18-91 (1906)............. Camphor, synthetic [75-22-21 (1976)................. 2 (Caprolactam |ios60-2| Dust (1974).................. -- Vapor (i974| ................ (4.3) Captafol (2425-061) -- Skin (1977).................... Captan (133-06-2) (1986)....... -- -- 950 52 C 152 303 303 C 15 C0.1 133 X 1.8 31 61 (0.05) (C 0.05) (0.05) 10"' 0.5 5 2 10< 10"' 12 (D (20) 0.1 5 14 -- -- -- -- IX -- -- -- -- ---- 20 -- -- -- -- -- -- -- -- -- 3 -- (8.6) -- -- -- -- -- -- 455 -- -- -- -- 121 -- -- -- -- -- -- -- -- -- 19 (3) (40) -- -- ADOPTED VALUES Substance TWA STEL [CAS fl ppm" mg/m**' ppm" mg/m1" _ _ _Carbaryl (63-2621 0986) ... Carbofuran |i563-2l (1977). 5 -- 0.1 -- Carbon black M333-9M <1966) _ 3.5 _ _ Carbon dioxide (124-30-9) (1906) -Carbon disulfide (76i60| -- Skin (1966).................... 5000 10 9000 31 30,OX -- 54.0X __ -Carbon monoxide [630-0661 (1976)............... 50 57 400 458 Carbon tetrabromide 1558-134) (1976)............... 0.1 1.4 0.3 4.1 Carbon tetrachloride (5623-5)-Skin (1966) . . . 5.A2 31.A2 -- -- Carbonyl chloride, see Phosgene Carbonyl fluoride 1353-504) (19811.............. Catechol [120809] (1977) ... 2 5.4 5 13 5 23 -- -- Cellulose (paper fiber) [9004-34-6] (1906)............. -- 10 -- -- Cesium hydroxide [21351-79-11 (1977) ........... _ 2-- _ ChJordane [57-74-91-- Skin (1980).................... 0.5 _ _ Chlorinated camphene [8001-3621 -- Skm (1976) . . -- 0.5 -- 1 SCMorinated diphenyl oxide |31242-9Sq (1990) ........... _ 0.5 Chlorine (7782-505| (i989> .. 0.5 1.5 Chlorine dioxide _ __ 1 2.9 {10049-04-41 (1976)........... 0.1 0.28 0.3 0.83 Chlorine Wluoride [7790-91-21 (1977)............. C 0.1 C 0.38 _ _ Clfioroacetaklehyde |107-2OC| (1977)............... C 1 C 3.2 -- -- Chioroacetone (76965)-- Skin (1989) .................. c 1 C 3.8 -- _ a-Chtoroacetophenone (532-27-4) (1977).............. 0.05 0.32 -- -- fChloroacetyi chloride (7604-91 (1900)................ (0.05) (0.23) -- -- tChtorobenzene (106907) (1950) (75) (345) -- -- o-Chlorobenzylidene maJononitrSe 1269641-11 --Skin (1983) .. C 0.05 C 0.39 _ _ Chlorobfomomethane (74-97-5) (1990)............. 200 1X0 -- -- 2-Chtoro-1.3-butacSene. see 5-CMoroprene .5 289S0 10iS Substance [CAS lt\ ADOPTED VALUES TWA STEL ppm*' mg/m**' ppm" mg/m1" Chtorodrfluofomethane J7S45-6) (1990)................. S'ChtoftxSphenyt (42% chlorine) [53469-21-91--Skin (19S0). . 1000 3540 1 _ <hlorodiphenyl (54% chlorine) (11037-89-11 -- Skil (1980).. 0.5 _ ___ 1-Chtoro-2,3-epoxy propane, see Epichlorohydrin 2-Chloroelhanol, see Ethylene chlorohydrin Chloroethytene, see Vinyl chloride WaHOTOfOrm [67-66-3] (1966) .. 10.A2 49.A2 *bis(Chloromethyl) ether p--ii (iai)................ 0.001. 0.0047. A1 A1 CNoromethyl methyl ether _ _(107-30-21 (1883)................ A2 A2 _1-Chloro-l-nitropropane 160025-91 (1*1)................ ' .2 10 _ _Ctioropentafluoroetiane 17015-31(1*1).............. 1000 6320 _ SChioropicrin (750021 d990i.. 0.1 0.67 -- -- ^-CNoroprene 11208981 -- Sirin (I960) . .. 10 36 __ O-Chtofostyrene PC3987-4I (197.............. 50 283 75 425 oChrotDluere |8o*oei (1990) 50 259 -- -- 2-Chloro-6-{tnchloroniethyl) pyridme, see Nitrapyrin CNotpytifos 1292188-21-- Skin (1990) ..................... -- 0.2 Chromite ore processing _ _ _(Chromate), as Cr (197 . 0.05.A1 Chromium (7WM7-31 Metal |i*i) ................... _ 0.5 _ Chromium (11) compounds, as Cr (ii)................... Chromium (110 compounds, 0.5 as Cr (iai)................... -..Chromium (VI) compounds, 0.5 as Cr -Water soluble ni>... 0.05 Certain water insoluble (i*D......................... 0.05.A1 _ Chromyl chloride _ --114977-6181 (1982) ............ 0.025 0.16 Chrysene 1218-01-91 (198D ... A2 A2 -- -- _ _Ctvysoble. see Asbestos ClopidOl [2971-90 (1990) . . . 10 -- 16 Substance [CAS #] ADOPTED VALUES TWA STEL ppm*1 mg/m1" ppm" mg/m1" Coal dust (1967)................. -- Coal tar pitch volatiles (6599693-21, as benzene solubles <ii).. -- Cobalt p440-48-41, as Co Metal dust & fume (1987) -- Cobalt carbonyl 1HB108611. as Co (198 . Cobalt hydrocarbonyl (18842-0381. as Co 11983) . --1 Copper [7440508) Fume (1977)................... Dusts & mists, as Cu (1986) -- -- Cotton dust, raw (1986).... Cresol [1319-77-31, all -- isomers--Skin (1977).... 5 Cristobalte, see Slica--Crystaine Crocidotite, see Asbestos Crotonaldetiyde [417030-3) (1967).............. SCruiomate |29S865l (1990).. 2 -- Cumene [964281--Skin ('987) 50 Cyaramide (42084-2) (i977> . -- Cyanides (isi-soa; 143-33-91, as CN--Skin (1977)....... -- Cyanogen (460-19-51 (1977) .. 10 Cyanogen chloride 150S-77-4) (i960)............... C 0.3 Cyclohexane |i1082-7] ii987) 300 Cyclohexanol iioe-93-o]-- Skin H977)..................... 50 Cyclohexanone (106-94-11-- Skin (1987)..................... 25 Cyclohexene |ii0838) (1977) Cyclohexylamine 300 (106-91-81 (1977)................ 10 SCydonite 1121-82-41-- Skin (1990)................... Cyclopentadiene 1542-92-71 (1987)................ 75 Cyclopentane 1287-92-3] 0987) Cyhexatin |1312i-to-s| 0986). 600 -- 2,4-0 (94-7671 (1985)............ ODT (Dichlorodiphenyl- trichkxoethane) [50-29-31 (1906) ................ 2* Respirable fraction 0.2.A1 0.05 0.1 0.1 0.2 1 0.2" 22 -- "*" "* -- -- -- -- -- 5.7 -- -- 5---- 246 -- -- 2---- 5---- 21 -- -- C 0.75 -- -- 1030 -- -- 206 100 -- -- 1010 -- -- 41 -- -- 1.5 203 -- -- 1720 -- -- 5---- 10 1 " C88S0IOiS . Substance [CAS J/| ADOPTED VALUES TWA STEL ppm"' mg/m3** ppm" mg/m1" 1 m 1? 1 Skin (1976)...................... 0.05 0.25 -Demeton 1806546-3] -- Skin 0906)...................... 0.01 0.11 Diacetone alcohol 112342-31 (1987).............. SO 238 1,2-Oiaminoethane, see Ethytenedumine Diatomaceous earth, see Slica --Amorphous -Diarinon |333~4i-Sj-- Skin 0966)...................... -- 0.1 Oia2omeihane (334-88-31 (1977) Dfcorane 1132574571 (1977) . 0.2 0.34 0.1 0.11 1.2-Oibromoethane, see Ethylene dibromide 2-N-Dibutylaminoethanol Ii02ai-8|--Skin (1986) ... 2 14 `Dibutyl phenyl phosphate 12528-78-71 -- Stt) (1990). . 0.3 3.5 Oixityt phosphate (107-66-41 (1976)................' i 8.6 Ofeutyl phthalate (84-74-21 (1987).................. -- 5 Oichloroacetylene (7572-2541 (1977).............. C 0.1 C 0.39 3o-. * S T Skin 0977)...................... C 50 0 301 p-Dichlorobenzene 110646-71 (1977).............. 75 451 3,3'-Oichforobenzidine [91-94-11 --Skin (1976)----- _ A2 Dichlorodilluoromethane (75-71-81 (1986).................. 1000 4950 1,3-0lchloro-5.5-dimethyl hydantoin |iis-52-5| (1976). -- 0.2 1.1-Didiloroethane 17534-31(19761 ................ 200 810 1.2-Oichloroethane, see Ethylene dchloride l.l-Oichloroethytene. see Vinyfdene chloride 1,2-D'tchloroeihylene (540-59-0] (1987)................ 200 793 Dichloroettiyt eiher [1114441--Skin (1976) ... 5 29 Dichlorofkioromethane (75-43-41 (1980).................. 10 42 Dichlorotnethane. see Methylene chloride 1.1-0ichloro-1-nitroethane 1594-72-91 (1986)............ 2 12 18 0.15 -- -- -- -- -- -- 2 -- -- -- 110 -- -- -- 250 -- 10 _ -- 0.75 -- -- -- -- -- -- _ 17 -- -- -- 681 -- -- 0.4 1010 -- 58 -- -- Sutwtance [CAS t\ ADOPTED VALUES TWA STEL ppm" mg/m3*1 ppm" mg/m3*' 1.2-DichloroorDpane, see Propylene dichloride uicnioropropene (542-75-61 -- Sign (1986) ... t 4.5 -- _ 2.2-Dichloropropionic acid (759901 (I960)................. Dichlorotetrafluoroethane 1 5.8 _ _ (76-14-21 (1986)................. 1000 6990 -- _ -Dichlorvos [62-7571 -- Skin ()986)...................... 0.1 0.90 -- __ Dicrotophcs [141-66.2]-- Skin (1977)..................... Dicyclopentadtene -- 0.25 -- _ (77-756] (1977)................. 5 27 -- _ Dicyclopentadienyl iron --(102-54-5] (1966)............... 10 -- __ -- ""Oieldrin [60-57-1]--Skin 11966) -- 0.25 Diethanolamine (11142 2] (1980)............... Diethytamine [109-69-7] o96i) 2-Diethylaminoethanol 3 13 -- -- 10 30 25 75 1100-37-8] -Skin (1977) ... 10 48 _ __ Diethylene triamine (111-40-01--Skin (1977) ... 1 4.2 -- -- Diethyl ether, see Ethyl ether Di(2-ethylhexyl)phthalate, see Of-sec-octyi phtfiaJate Dtetnyl ketone (96-22-ot u98i> 200 706 Diethyl phthalate [84-66-2] (1967)................. -- 5 Difluorodibromomethane -- _ ^ _ [7561-61 (1966)................. 100 858 -- _ Diglycidyi ether (DGE) (2238-07-51 (1981)............. 0.1 0.53 -- _ Dihydroxybenzene, see Hydroquinone OusoDutyl ketone 1108-83-8) (1977)............... Diisopropylamine 25 145 _ _ (108-18-91--Skin (1977) . . . Dimethoxymelhane. see MelhylaJ 5 21 ---- Dimethyl acetamide (127-1551-Skin |I986) ... 10 36 -- -- Dknethylamine 112440-31 (1977) 10 18 -- _ Dimethylaminobenzene. see Xylidene ^Dimethytanilne (N.N-DimethyUnJine) -- Skin (1976)............ ... Oimethylbenzene. see Xylene 5 25 10 50 19 *i88SGiGJLS . Substance [CAS fl ADOPTED VALUES TWA STEL ppm" mg/m3*' ppnr' mg/m3*' Dimethyl carbamoyl chlohde 179-44-7] (1978).................. A2 A2 -- Dimethyl-1.2-dibroiTO-2,2-<JicMoroetJiyl phosphate, see Naled -Dimethylformamide 16912-21--Skin (1966).... 10 30 -- 2.6-Dimelhyl-4-heptanone. see Oisobutyi ketone {1,1 -Dimethylhydrazine (57-14-71--Skin 11976) .... (0.5.A2) (1.2.A2) -- Dimelhylnitrosoam're. see N-Nitrasodmethytamme _Dimethylphthalate (131-11-3) (1986)................ 5_-- Dimethyl sulfate 177-76-11 -- Skin (1977) .... 0.1 .A2 0.52.A2 -- -- Dimtolmide 114601-6) (1976) . -- 5 -- -- -Dinitrobenzene (526-260. 96650 10925-4) (al isomers) -- Skin (1986) 0.15 1.0 _ Dinitro-o-cresol 1534-52-1) -- Skin (1966) . . 0.2 -- -- 3,5-Dinitro-o-toluamide. see Dinitolmide Dinitrotoluene 125321-146)-Skin (1986). . ... - 1.5 _ Oioxane 1123-91-1] --Skin (1986) ... 25 90 -- -- -Oioxathion (76342) -- Skin (1977)...................... _ 0.2 -- -- _Diphenyl, see Biphenyl Kphenylamine 1122-364) (1986) 10 _ -- Diptenyimeftane diisocyanate, see Methylene txspheny! isocyanate Oipropylene glycol methyl ether (345999481Skin (1976)...................... 100 606 150 909 Dipropyl ketone 1123-163) (1981)................ 50 233 -- - Diquat [85697] (1986).......... -- 0.5 -- "" Di-sec-octyl phthalate 1117-81-7) (1976)................ Disulfiram (97-776| |1986) .. Disulfoton I296044J (1986) .. _5 --2 -- 0.1 -- 10 -- ---- 2.6-Di-tert-butyl-p-cresol 11286761 (1987) .............. Diuron |339541) (1S77).......... _ 10 -- -- 10 -- - Divinyi benzene |1321-740| (1980) ............ Emery (1302-74-5) |i986) .. 10 53 -- -- 10' -- - 20 Substance[CAS J] ADOPTED VALUES TWA STEL ppm*' mg/m3*1 ppm" mg/m3*' Endosulfan (iis-as-zi-- _Skin (1988)...................... -- 0.1 -- Endrin [72 208)--Skin (1968) -- 01 -- ___ _Enflurane |i3836ie-9| (i98S). 75 566 _ Enzymes, see SubbTisins {EpicHorohydrin (109868)-Skin (1986) .. (2) (7-6) -- _ -EPN (2104645)--Skin (1986) -- 0.5 1.2-Epoxypropane, see Propylene oxide 2.3-poxy-1-propanol. see Glycidol Ethane (74-846) (i96ii.......... -- __ _ Ethanethiol, see Ethyl mercaptan Ethanol, see Ethyl alcohol Ethanolamine [141-43-Si (197B> 3 7.5 6 15 -Ethion IS6612-21--Skin (1977) -- 0.4 _ __ 2-Ethoxyethanol (EGEE) 1119895)-Skin (1964) ... 2-Ethoxyetiyl acetals (EGEEA) 5 18 -- _ ini-159)--Skin (1984) ... 5 27 -- -- Ethyl acetate (141-78-6) (1977) 400 1440 -- _ Ethyl acrylate |i4oa65] (1990) Ethyl alcohol (64-17-5) 11977). Ethylamine [750471 (1977) .. 5.A2 1000 10 20.A2 1880 18 15.A2 -- -- 61,A2 -- _ Ethyl amyl ketone 1541655) (1977)................ 25 131 -- -- Ethyl benzene |i094i-4| (1976) {Ethyl bromide [74964| (1976) Ethyl butyl ketone (106-35-4] (1987)................ Ethyl chloride (75093) (1986) Ethylene |7465i) (i98i) ... 100 (200) 50 1000 --*C| 434 (891) 234 2640 -- 125 (250) -- _ -- 543 (1110) _ _ _ Ethylene chbrohydrin 110767-3) -- Skin (1977) . . C 1 C 3.3 _ _ Ethylenediamine (107-15-31 (1977)................ 10 25 -- _ Ethylene dibromide [1059641 --Skin (1982) .. A2 A2 -- -- Ethylene dichloride (107-0921 (1986)................ to 40 -- _ Ethylene glycol 1107-21-ij \6por and mist (i98i) ... C 50 C 127 -- _ Ethylene glycol dinitrate (629996)-Skin (1965) .. 0.05 0.31 -- -- Ethylene glycol methyl ether acetate, see 2-Methoxyethyl acetate Ethylene oxide [75-21^1 (19S4) 1.A2 1.8,A2 -- 21 S88S0I01S Substance [CAS ADOPTED VALUES TWA STEL ppm" mg/m1" ppm" mg/m1" Ethyienimine |isi-5M) -- Skin (1377)...................... 0.5 0 88 Ethyl ether (60-29-71 <19TO) .. Ethyl formate |ios-9M] (i7) 400 1210 100 303 500 1520 ---- EthyUdene chloride, see 1.1-Dichtoroethane Ethytidene norbomene (1621975-31 (1977) ............ C 5 C 25 Etiyl mercaptan (ts-ob-ij (i98B| 0.5 1.3 -- -- N-EthytmorphoSne 1100-74-31 --Skin (1986) ... 5 24 _. Ethyl silicate 178-104] (1986). 10 85 -- -- -Fenamiphos (22224-32-61 -- Skin (1984)...................... 0.1 _ -Fensultathiofl 1115-902111977) -- 0.1 -- -- -Fenthion |S6389|--Skin (1983) -- 0.2 -- -- Fetbam |1448L64-1| (1988). .. -- 10 -- -- Ferrovanadlum dust 112604-58-9X1983) ............ - 1_ 3 Fibrous glass dust (i978)... - -- 10 -- -- -Fluorides, as F (1977)........ -- 2.5 -- -- Fluorine (7782-41-4) (1978) .. . .1 1.6 2 3.1 Fluorotrichtoromethane, see Trichbnofluoromethane -FonOfOS (944-22-91 -- Skin (1977)...................... -- 0.1 {Formaldehyde isoood (1985) (1.A2) (1.2.A2) (2.A2) (2.5,A2) Formamide [75-12-7] -- Skin (1988)...................... 10 18 _ _ {Formic add (64-18-6] (1967).. -Furfural (98-0i-i| -- Skin (1987) 5 9.4 (-) <-) 2 7.9 -- -- Furfuryl alcohol |98000| -- Skin (1982)...................... 10 40 15 60 Gasoline (8006-6191 (1982)... 300 890 500 1480 Germanium letrahytiride _[7782-65-2] (1966).............. 0.2 0.63 _ Glass, fibrous or dust, see Fbrous glass dust Glutaraldehyde |m-388| (19791 C 0.2 C 0.82 Glycerin misl |568i-5] (1981) -- 10'1* GtyCidOl 1556-52-5) (1967) .... 25 76 _ -- -- _ ~ -- Glycol monoethyl ether, see 2-Ethoxyethanol Grain dust (oat. wheat, barley) (1986).................. -- {Graphite (natural) [7782-42-5] (1987) ............ (2-5^', Respirable dust) {Graphite (synthetic) 1778242 5| (1971| ............ _ (10') _ _ Gypsum, see Calcium sulfate 22 AOOPTED VALUES Substance [CAS TWA STEL ppm" mg/m1" ppm" mg/m1*' Hafnium [74485661 (1986) . _ 0.5 Halothane [i5i 67-7) (isesy .. Helium [744859-7) nseii 50 404 _tc) {Heptachlor [7644-ai -- Skin (1986)...................... -- (0.5) Heptane [142-62-51 (n-Heptane) (1976).......... 400 1640 2-Heptanone, see Methyl n-arrryl ketone 3-Heptanone, see Ethyl butyl ketone Hexachtorobutadfene 187-68-3)-Skin (1982) .... 0.02,A2 0.21.A2 Hexachlorocyclopentadiene 177-47 4) (1986).................. 0.01 0.11 {Hexachloroethane 167-72-11 (1989).................. Hexachloronaphttialene (1) (9.7) 11335-87-1] --Skin (1986) . -- 0.2 Hexafluoroacetone (684-1621-- Skin (1966) .. 0.1 0.68 Hexamethytere diisocyanale 1822-0601 (1988)............... 0 005 0.034 Hexamethyl phosphoramide 168831-91-Skin (1978) .. . A2 A2 -Hexane (n-Hexane) 111854-31 (1982)................ 50 176 Other isomers (1962) ___ 500 1760 2-Hexanone, see Methyl n-bulyl ketone Hexone. see Methyl isobutyl ketone sec-Hexyt acetate ItOe-64.9! (1977).............. Hexylene glycol 58 295 110741-51 (1977)................ {Hydrazine [302-01-21 -- C 25 C 121 Skin (1977)...................... (0.1.A2) (0.13.A2) Hydrogen (1333-74-01 (i98i).. --(cp -- Hydrogenated terphenyts (37275-59-51 (1977) ............ 05 4.9 Hydrogen bromide (10036186] (1966)............ C 3 C99 Hydrogen chloride (7647-01-01 (1977) ............ Hydrogen cyanide C 5 C 7.5 (74-9881 --Skin (I960) . .. C 10 C 11 Hydrogen fluoride [7664383]. as F (1986) . .. C 3 C 2.6 _ -- -- -- 500 -- -- -- -- -- -- 1000 -- -- _ -- --. -- -- _ -- -- -- 2050 -- -- -- -- -- -- 3500 -- -- -- -- -- -- -- 23 988S0IulS Substance [CAS ifl ADOPTED VALUES TWA STEl ppm" mg/m3*' ppm*' 1 E Hydrogen peroxide |7722-84-1| (19861 .............. 1 1.4 -- Hydrogen selenide [7783-C7-5). as S (1977).. 0.05 0.16 -- Hydrogen sulfide [77B3-06-4] (1976).............. 10 14 15 Hydroquinone |i23-3i-9| (1967) -- 2_ 4-Hydroxy-4-methy1-2-pentanone. see Diacelone alcohol 2-Hydroxypropyl acrylate 199961-1) -- Sldn (199 .. Indene |95-i3-6] H9a7)........ 0.5 2.8 to 48 -- __ Indium 17440-74-6) 4 compounds, as In (19661. Iodine 17553-56-21 (1977) . .. Iodoform [7S-47-8| (1966) .. Iron oxide fume (Fe,Oj) (1309-37-11, 3S Fe (1966) .. -- C0.1 0.6 ' \ B2 0.1 C 1.0 10 " '5 _ _ _ -- Iron pentacarbonyl |13463406|. as Fe (1982) . 0.1 0.23 0.2 Iron salts, soluble, as Fe (1986).............................. -- 1_ Isoamyl acetate 1123-92-21 (1987)................ 100 532 -- Isoamyl alcohol (123-51-3J (1975)................ 100 361 125 lsobutyl acetate [110-194] (1990)................ 150 713 -- isobutyl alcohol I7S-83-IJ (1967) ................ 50 152 -- Isooctyl alconol 126952-21-61--Skin (1982) . Isophorone i78-59-i| (1977) 50 266 C 5 C 28 -- _ Isophorone diisocyanate (4098-71-91-- Skin (1988) . 0 005 0.045 -- isopropoxyethanol 1109-59-1) (1987)................ 25 106 -- Isopropyl acetate [108-21-41 (1976)................ 250 1040 310 Isopropyl alcohol 167-63-0) (1976) .............. 400 983 500 Isopropylamine (75-ai-oi (1976) 5 12 10 N-lsopropytaniline 1768-52-51 -- Skin (1986) . . . 2 11 _ Isopropyl ether [108-20-31 0976).............. 250 1040 310 -- -- 21 -- _ _ -- -- _ -- 0.45 -- -- 452 -- -- -- -- -- _ 1290 1230 24 _ 1300 24 Substance [CAS #J ADOPTED VALUES TWA STEL Ppm" mg/m3" ppttr' mg/m3" Isopropyl glycidyl ether (ISE) 1401614-2) (1976).............. Kaolin (1333-58-7) (1966) .... 50 238 -- 10* Ketene |463-5i-`| (1976) .... 0.5 0.86 -lead 17439-92-1). inorg. dusts S fumes, as Pb (1986) .. -- 0.15 Lead arsenate i7784-40-9|. as PbHAsO, (1985) ........ -- 0.15 JH.ead chromate [7758-97-6I, (as Cr) (t977|.................. -- (0.05.A2) Limestone, see Calcium carbonate Lindane 158-89-9)-- Skin (1966)..................... -- 0.5 Lithium hydride [758067-81 (1977).............. -- 0.025 L.P.G. (Liquified petroleum gas) 168476867) (1987).. Magnesite 1546-93-01 (1966) . 1000 -- 1800 10" Magnesium oxide fume [1309-48-41 |1977).............. -- 10 -Malathicn (121-75-5) -- Skin (1977)..................... -- 10 Maleic anhydride [108-31-61 [1977)................ 0.25 1.0 Manganese 17439-96 5). as Mn Dust 4 compounds (1988) Fume (1979)................... -- -- 5 1 Manganese cyclopentadienyl tricarbonyl 112079-6611, as Mn--Skin (1966) ___ Marble, see Calcium carbonate -- 0.1 Mercury [7439-97 6), as Hg--Skin Alkyt compounds |i9eoi . -- 0.01 All forms except alkyl Vapor (1982)................ -- 0.05 Aryl 6 inorganic compounds (1982) .. -- 0.1 Mesityl oxide 1141-79-7[ 119811 15 60 Melhacrylic acid 179-41-4)11981) ................ Methane [74-82-a| (i9aii . 20 70 _(0 -- Methanethicl, see Methyl mercaptan Methanol, see Methyl alcohol -Methomy! [16752.77-5] (1977) -- 2.5 75 356 ---- 1.5 2.6 ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- --3 ---- -- 0.03 ---- ---- 25 100 ---- ---- --- 25 L88S0 101s Substance [CAS #1 ADOPTED VALUES TWA STEL ppm" mg/m**' ppm" mg/m**1 Msthoxychlof [72-0-51 (1977) -- 10 2-Methoxyethanol (EGME) (i09-aw|--Skin (1984)... 5 16 2-Methoxyethyl acetate (EGMEA) [110-49-8] -- Stan (1964)...................... 5 24 4-Methcxyphenol llSO-re-51 (1982)................ -- 5 Methyl acetate (79-20-91 (1976) 200 606 Methy( acetylene [74-99-7) 11990)................ 1000 1640 Methyl acetylene-propadiene mixture (MAPP) (1978) \ . iood 1640 Methyl acrylate [98-33-3) -- Skin (1977)...................... 10 35 Methylacrylonitrile [1289871 --Skin (1988)... i 2.7 Methylal p 0867-5) (1987)... 1000 3110 Methyl alcohol (87-581) -- Skin (1976).................... 200 262 Methylamme P4-89-5) (1977) 10 13 Methyl amyl alcohol, see Methyl isobutyl carbinol Methyl n-amyl ketone 1110-4301 (1987)................ 50 233 -N-Methyl aniline [ioo-61-ai-- Skin (19881...................... OS 2.2 Methyl bromide (74-83-91 -- Skin 11966)...................... 5 19 Methyl n-butyl ketone [591-7861 --Skin 11981)... 5 20 Methyl chloride (74-87-3) -- Skin (i96i)...................... 50 103 -Methyl chlorotorm (71-55-6| (1976)................ 350 1910 Methyl 2-cyanoacrylate (137-05-31 (19761................ 2 9.1 Methylcyclohexane (108-87-21 (1987)................ 400 1610 Methyicyclohexanol (25639-42-31 (1987)............ 50 234 o-Methylcydohexanone 1583-68 61-Skin (1976). . . 50 229 2-Methylcyclopentadienyl manganese tncarbonyl (1210813-31. as Mn -- Skin (1986) .................... -- 0.2 -- -- 250 1250 -- 250 -- " 100 450 4 " 75 -- -- -- 757 2050 -- 328 207 2460 18 344 -- 26 Substance [CAS q ADOPTED VALUES TWA STEL ppm" mg/m**' ppur* mg/m**' -Methyl demeton 18022-00-21-Skin (196$) . Methylene bisphenyl 0.5 isocyanate (MOI) 1101-6881 11968)................ 0.005 0.051 Methylene chloride [75-09-2111988) ................ 4,4 '-Methylene 50.A2 174.A2 bis(2-chk>roaniline) |ioi-i4-4| --Skin (1974)... (0.02.A2) (0.22.A2) Methylene bis(4-cydo- hexylisocyanate) 15124-30-1] (1968).............. 0005 0.054 4.4'-Methylene diamline 1101-77-9) --Skin (1986). .. 0.1.A2 0.81 ,A2 -Methyl ethyl ketone (MEK) (7893-31 (1978)................ Methyl ethyl ketone 200 590 300 885 peroxide |i338-23-4| 11977) C 0.2 C 1.5 Methyl formate |107-31-3|(1976) .............. 100 246 150 368 5-Methyt-3-heptanone, see Ethyl amyl ketone (Methyl hydrazine (60-34-41 -Skin (1976).... (C0.2.A2)(C038.A2) Methyl iodide |74-884| -- Skin (1988) .................... Methyl isoamyl ketone 2.A2 12.A2 (11812-31 (1982)................ 50 234 Methyl isobutyl carbmol [108-11-21 -- Skin (19761... Methyl isobutyl ketone 25 104 40 167 (108181] (1981)................ Methyl Isocyanate 50 205 75 307 (624-83-91 -- Skin (1977). . . 0.02 0.047 Methyl isopropyl ketone 1563-884) (1981)................ Methyl mercaptan 200 705 (74-93- i| (1977)............ Methyl methacrylate 0.5 0.98 18862-61 (1987)................ 100 410 -Methyl paraihion |298080| -- Skin (1986) .. 0.2 Methyl propyl ketone |107-87-9| (1976).............. Methyl silicate 200 705 250 361 1681-84-51 11966).............. 16 888S0 101s Substance [CAS 1] ADOPTED VALUES TWA STEL ppm*' mg/m* ppm" mg/m1*' o-Metbyl styrene I95B39] (198)1................ SO Metribuzin [21067-64-9] (1984) -- -MevinpbOS [7786-34-71 -- Skin (1976)..................... Mica [12X1-26-2] (19861 ... Mineral wool fiber 11974) .. 0.01 -- -- Molybdenum [7439-98-71. as Mo Soluble compounds (1988) Insoluble compounds (1986)................. ' _ Monochlorobenzene. see Chlorobenzene Monocrotophos 1692322-4] (1977)....'.;:. -- {Morpholine iio-9t-a|-- Skin (1966)..................... -Naled 1300-76-5]--Skin (1966) 20 -- Naphthalene [9i-20-3| (1976). 10 p-Naphthyiamine 191-59-81(1972)................ Neon |7440-0i-9| (I98i|........ _ __;o Nickel [744002-0] {Metal (1966)................. _ {Insoluble compounds, as Mi 11974)........................... {Soluble compounds, as Ni (1976) ......................... _ {Nickel carbonyl [13463-39-31, as M [1977) . (0.05) {Nickel sulfide toasting, fume & dust as Ni (1978) _ Nicotine ]54-ii-5| -- Skin (1986)..................... Nitrapyrin [i929-82-4| 0982) . . -- Nitric acid 17697 37-2| (1976). 2 -Nitric oxide |10102-43-9| (1906) .. . . 25 -p-Nitroaniline |ioo-oi-S] -- Skin (1982) ................... _ -Nitrobenzene [96-95-3] -- Skin (1986)..................... 1 -p-Nitrochlorobenzene 1100005]--Skin (1988) . . 0.1 4-Nitrodiphenyl 192-93-31 (19761 ............................. _ 242 100 483 5-- -- 0.092 0.03 0.27 3,<i Respirable dust 10m -- -- 5 10 _ _ 0.25 71 3 52 A1 -- (1) (D (0.1) (0.12) (1.A1) 0.5 10 5.2 31 3 5 0.64 A1 (30) (107) ---- 15 79 ---- ---- _ --_ __ -- __ __ -- 20 4 10 _-- __ __ ---- ---- 28 ADOPTED VALUES TWA STH Substance [CAS f] ppm" mg/m*' ppm" mg/m**' Nitroethane [79-24-3] (19) . Nitrogen [7727-37-9) (1989) .. Nitrogen dioxide 100 1 307 -- -- _ -- |10102-44-0[ (1981)............ 3 5.6 5 9.4 Nitrogen trifluoride (778354-21 (1986).............. Nitroglycerin (NG) 1556301-Skin (1985) ... 10 0.05 29 0.46 -- -- -- _ {Nitromethane 175-52-5] (1986) (100) (250) -- -- 1-Nitropropane |105032| (1986)............... 25 91 -- -- 2-Nitropropane 179-48-9] (1987) ................ 10.A2 36,A2 -- -- N-Nitrosodimethylamine 162-7591 --Skin (1972] ... -Nitrotoluene [8572-2; 99-051; A2 -- 99-9901 -Skin (1902) .... 2 Nitrotrichloromethane, see Chtoropicrin Nitrous oxide (10024-97-2J (1989)............ 50 Nonane |ii 1^4-2] (1976).... 200 11 90 1050 -- -- " -- Nuisance particulates, see Particulates Not Otherwise Classified (PNOC) Octachloronaphthalene (2234-1311--Skin (1976) . . -- 0.1 -- Octane |in-659|0976).... 300 1400 375 Oil mist, mineral 0976). .. Osmium tetroxide -- S -- (2X1512 0], as Os (19761 . 0.0002 0.0016 0.0006 Oxalic acid (144 62-7] (i97si. -- 1-- Oxygen difluoride [778341-7] (1986).............. C 0.05 C 0.11 -- Ozone 110028-156] 11989) . . Paraffin wax fume C 0.1 C 0.20 -- 0.3 1750 10 0.0047 2 -- -- |8002-74-2| (1987J.............. Paraquat |4685-i4-7]. -- 2-- " respirable sizes (1978) . -- 0.1 -- -Parathion 156-38-2] -- Skin 0986)..................... -- 0.1 -- Particulate polycyclic aromatic hydrocarbons (PPAH). see Coal tar pitch volatiles -- -- Particulates Not Otherwise Classified (PNOC) (1986) Pentaborane [19624-22 7] (1976)............ 0 005 to 0.013 -- 0.015 -- 0.039 *68890 IQiS Substanee [CAS #1 ADOPTED VALUES TWA STEL ppm*' mg/m3*' ppm" mg/m3" PentachloronaphthaJene 11321-64-8] (1966].............. -- 0.5 -- -Pentachlorophenol 187-66-51 -- Skin 119861 - - -- 0.5 -- Pentaerythritol [115-77-51 (1986) .............. Pentane [109-66-ci 0976) ... -- 10 600 1770 -- 750 2-Pentanone, see Methyl propyl ketone Perchloroethylene 1127-18-4] {1984)................ 50 339 200 Perchloromethyl mercaptan (594-42-31 (1977).............. 0.1 0.76 -- Perchloryl fluoride [7616-94-6] (1976).............. 3 13 6 Precipitated silica, see Silica --Amorphous Perlite 193763-70-31 (1966) . . -- 1QM Petroleum distillates, see Gasoline: Stoddard solvent: VM&P naphtha Ptienacyi chloride, see a-Chloroacetophenone -Phenol |i06-95-2| -- Skin (1987)...................... 5 19 -- Phenothiazine [92-84-2]-- Skin 0986)...................... -- 5-- N-Phenyt-beta-naphthytamine [135-88-6] (1979)... A2 A2 -- Tp-Phenylenediamine [106-50-3]-(Skin) (1966).. -- 0.1 -- Phenyl ether [ioi-84-a]. vapor (1976).................... 1 Phenylefhylene. see Styrene, monomer 7 2 --Phenyl glycidyl ether (PGE) [122-60-1] (1962)................ 1 6.1 -- ^Phenylhydrazine [100-63-01 -- Skin (1985) ... (5.A2) (22.A2) (10,A2) Phenyl mercaptan [106-96-51 (1978)................ 0.5 2.3 -- Phenylphosphine [638-21-11 (1977)................ C 0.05 C 0.23 -- Phorate [296-02-21 -- Skin (1976)...................... -- 0.05 -- Phosdrin. see Mevinphos Phosgene |7544-5] (1978)... Phosphine |7803-51-21 (1976) 0.1 0.40 0.3 0.42 -- 1 Phosphoric acid 17664-38-21 (1976) ............ -- 1-- -- -- -- 2210 1370 -- 25 -- -- -- -- -- 14 -- (44.A2) -- -- 0.2 -- 1.4 3 30 Substance [CAS f] ADOPTED VALUES TWA STEL ppm" mg/m3*' ppm" mg/m3" Phosphorus (yellow) [7723-14-01 11988) ............ -- 0.1 Phosphorus oxychloride (10025-87-31 (1990)............ 0.1 0.63 Phosphorus pentachloride [10026-13-8] (1980)............ 0.1 085 Phosphorus penlasulfide 11314-80-31 (1976).............. _ 1 Phosphorus trichloride (7719-12-2) (1982) 0.2 1.1 Phthalic anhydride 185-44-91 (1987) ................ t 6.1 m-Phthalodinitrile 1626-17-5] 11977)................ SPicloram [i9i602-i| (19901.. 'Picric acid |88-a9-i| 11990) . Pindone (83-26-11 o 987].... --5 _ 10 _ 0.1 _ 0.1 Piperazine dihydrochloride 1142-64-3] (19821................ -- 5 2-Pivalyl-1.3-indandione, see Pindone Raster ol Paris, see Calcium sulfate Platinum ]7440-06-| Metal (i98i).................... Soluble salts, as Pt (i98ii _1 _ 0.002 Polychlorobiphenyls, see Chlorodlphenyts Polytetratluoroethylene decomposition products (1972)............................ Portland cement 165997-15-1) (1986)............ _ B1 _ 1(>.i Potassium hydroxide [1310-56-3| (1977).............. Propane (74-98-61 (i98i)___ -- C2 _M _ Propane sultone |I120-71-4| (1977).............. Propargyl alcohol A2 A2 1107-19-71 - Skin (1987) . .. 1 2.3 P-Propiolactone (57-57-ai (1987) .............................. Propionic acid [79-09-41 (19901 Propoxur [114-2611 (1987) .. 0.5.A2 10 _ 1.5.A2 30 0.5 n-Propyl acelate [109-60-41 11976) .............. 200 835 n-Propyl alcohol [7i-23-8| -- Skin ii976) ............ Propylene (115-07-11 (1976).. 200 _tdi 492 -- 31 0 6 8 9 C -- __ __ _3 0.5 2.8 _ __ _ __ -- _ __ _ __ _ _. _ _ _- __ _ --_ __ __ __ _ 250 1040 250 614 ---- lOiS Substance [CAS 4] ADOPTED VALUES TWA STEL ppm" mg/m1" ppm" mg/m1" Propylene dichloride [78-87-5] (1976) ................ -Propylene glycol dimtrate (6423-43-41 -Skm (1965). . Propylene glycol monomettiyl ether 1107-98-2] 11976)................ Propylene imine (75-55-81-- Skin (1983)..................... Propylene oxide [75-56-9! (1961) ................ n-Propyl nitrate [627-13-41 (1978)................ Propyne. see Methyl acelylene Pyretnrum 18003-34-7] (1981) Pyridine itio-86-i] (1987) ... Pyrocatechol, see Catechol Quartz, see Silica--Crystaline Quinone |1085M| 11987) ROX, see Cydonite Resorcinol M08483] (1976) . Rhodium (7440-16-6) Metal (1962|.................. Insoluble compounds, as Rh (1964).................. Soluble compounds, as Rh (1984).................. Ronnel (299-84-3] (1977) . . Rosin core solder pyrolysis products, as formaldehyde (1987)___ Rotenone (commercial) [83-79-4| (1967)................ Rouge (1986)...................... Rubber solvent (Naphtha) (1977) ............................. Selenium |7782-49-2| and compounds, as Se (19771 Selenium hexafluoride (7783-79-11, as Se (1979) Sesone [138787] nseei.... Silane, see Silicon tetrahydride Silica --Amorphous Diatomaceous earth (uncalcined) (61790-5821(19861. .. 75 0.05 100 2.A2 20 25 .5 0.1' 10 ^ ___ _ -- _ -- 400 __ 0.05 -- 347 0.34 389 4.7,A2 48 107 5 16 0.44 45 \1 1 0.01 10 0.1 5 10"' 1590 0.2 0.16 10 Iff" 110 _ 150 40 -- 20 _ _ _ -- _ -- _ _ -- 508 553 _ 172 _ -- 90 _ _ _ -- _ -- _ -- 32 Substance [CAS 4) ADOPTED VALUES TWA STEL ppm" mg/m1" ppm" mg/m1" Precipitated silica 111292800-8) (1987)........ Silica gel 10" - - [1129280881 (1967)........ 10" Silica--Crystaline Cristobalite 114464-4811 (1966)......... Quartz |14808687| (1966) t*Silica. fused [6067886-01 (t985|.......... Tridymrte |1546832-3| (1966)........................... Tripoli |1317 989| (1985) . 0.05.U Respirable dust -- O.I.i* Respirable dust _ 0.1.1 Respirable dust __ 0.05, Respirable dust -- 0.1." of contained Silicon [744821-3] (1986)___ Silicon carbide respirable quartz ID" - - I409-21-2I 11986)............... 10" - - Silicon tetrahydride 17803-62-5] (1983)............. Silver (744822-4) 5 6.6 Metal (i98i)................... Soluble compounds, 0.1 - - as Ag (i98i|................. Soapstone 0.01 Respirable dust (1985).. Total dust (i985i.......... 3i _ _ _ &! _ _ Sodium azide [2662822-81 (1977)............ C 0.11 C 0.29 - Sodium bisulfite |7631-985| (1980)............... 5- - Sodium 2,4-dichloro-phenoxyethyl sulfate, see Sesone Sodium fluoroacetate [62-74-81 -- Skin (1976) . Sodium hydroxide 0.05 - 0.15 |131873-2| (1977)............. Sodium metabisullite C2 - (7681-57-4) (1980)........... Starch |9005-258| (1986) . . Stearates"10988)............... _ 510 -- 10 - - Stibine 17803-52-31 (1966) ... Stoddard solvent 0.1 0.51 (8052-41-31 (1967)............. Strychnine (57-24-9) |i9S6).. -Styrene, monomer _100 525 0.15 (10842-51 -- Stal (1981) . 50 213 100 426 " I G8S0 I 01S Sobttanca (CAS 0] ADOPTED VALUES TWA sra ppm" mg/m*" ppm" mg/m**' Subtilisins (1396-21-71 (Proteolytic enzymes as 100% pure crystalline enzyme) (1977)................ Sucrose [57-50-11 (1986)___ Sulfotep 13689-24-51 -- Skin (1986)..................... Sulfur dioxide (7446-09-5) (1966)........... Sulfur hexafluoride |2S51-62-4| (1966).............. Sulfuric add [7664-93-9) (19).............. Sulfur monochloride 110025-67-9] 0986)............ Sulfur pentafluoride [571422-7) (1966)............. Sulfur tetrafluoride [7783-60-0) (1986) .......... Sulfuryl fluoride 12699-79-8] (1976).............. SulprofOS [3540043-21 (1964) Systox. see Demelon 2,4,5-T [93-76-51 (1986)........ Talc (containing no asbestos fibers) |i4807-966( (1963) . Talc (containing asbestos fibers) (1985) ................. Tantalum [74*0-25-7], metal and oxide [1314-61-01 dusts (i9e)................... TEDP. see Sulfotep Tellurium (i3494-eo-9| and compounds, as Te (1977) Tellurium hexatluoride (7783-80-4), as Te (1977) , . -TemephOS |3383-9M| (196S> -TEPP [107-49-31 -- Skin (1986).......................... Terphenyls [26i4O60-3| (i960) 1,1,1,2-Tetrachloro-2,2difluoroethane 176-11-91 (1986) .................. 1,l.2,2-Tetrachloro-l.2dilluoroethane 176-12-0] (1986) ................... -- C0.00006" 10 -- -- -- 0.2 2 5.2 5 13 1000 5970 13 C 1 C 5.5 C0.01 C 0.10 c or ` C 0.44 5 21 10 42 . -- -- 1 "" "7 10 -- 2. Respirable dust Use asbestos TLV-TWA.'"> -- 5-- -- 0.1 -- -- 0.02 0.10 -- -- 10 0.004 0.047 -- -- C 0.5 C 4.7 500 4170 500 4170 -- -- 34 Substance [CAS #] ADOPTED VALUES TWA 3TEL ppm" mg/m*" ppm" mg/m3* 1,1,2.2-Teitachtoroethane [79-345)--Skin (1986) . .. 1 6.9 Tetrachloroethytene, see Perchloroethylene Tetrachloromethane, see Carbon tetrachloride Telrachtoronaphthalene 11335-88-2) (1986)............ - 2 Telraethyi lead [78-oo-2|, as Pb--Skm (1986)........ Tetrahydrofuran 0.1" [109-99-91 (1976)............... Tetrametftyl lead )7S-74i|, 200 590 as Pb -- Skin (i986i___ Tetramethyl succinonitrile 0.19 [3333-52-61-Skin (1986). . 0.5 2.8 TetranitromeOiane 1509-148] (1977)............... 18 Tetrasodium pyrophosphate 17722-88-51 (I960)............. Tetryl |479456| (1986)........ Thallium pm-a-ai 5 -- 1.5 Soluble compounds, as Tl-Skin (1977) ... 0.1 4.4'-Thiobis(6-tert-butyl- m-cresoO 196-69-5) (1966) . Thiogfycofic acid 10 [68-11-11 --Skin (1976) ... Thionyl chloride 1 3.8 1771909-7) (1986)............. 'Thiram (137-28-8) (i990> ... Tin 17440-31-5) C 1 C 4.9 --1 Metal (1982)................. Oxide & inorganic compounds, except 2 SnH,, as Sn (1982)........ ^Organic compounds, as 2 Sn--Skin (1965)............ Titanium dioxide 0.1 (13463-67-7) (1986)........... o-Tofdine |ii993-7| -- 10 Skin (1982)..................... -Toluene (108-88-3) (1976) ... A2 A2 100 377 Toluene-2,4-disocyanate (TDI) |584849( (1983) -o-Toluidine (95-53-41 -- Skin (i984i..................... 0.005 0.036 2.A2 8.8,A2 250 _ -- 150 0.02 _ 737 _ _ (-1 565 0.14 _ K 268S0I01S Substance [CAS ADOPTED VALUES TWA ppm" STEL ppm" mg/m5*1 m-Toluidine (i08-44-i| -- Skin (1986)........................ 2 8.8 p-Toluidine (iOWS-01 -- Stan (1986)........................ 2.A2 8.8.A2 Toluol, see Toluene Toxaphene. see Chlorinated camphene Trtoutyl phosphate J126-73-8] {1936)................. 0.2 2.2 Trichloroacetic acid |76-03-91 (1980)................. 1 8.7 1.2,4-Trichlorobenzene 1120-82-1) (1978)................. C 5 C 37 1,1,1-Trichloroethane. see Methyl chloroform 1,1,2-Trichloroethane 179-00-5) --Skin (19861 . . 10 55 Trichloroethylene 179-01-6] (1904) ................. .50 269 Trichlorofluoromethane [75-69-4] (1982) ................. C 1000 C 5620 Trichloromethane. see Chloroform Trichloronaphthalene 11321-65-91 -- Skin 11986) ,. -- 5 Trichloronitromethane, see Chloropicrin 1,2,3-Trichloropropane I96-18-4) -- Skin (1987) ... 10 60 1.1,2-Tnchloro-1,2,2- tritluoroethane (76-13-11 (1976) ................. 1000 7670 Tricyclohexyltin hydroxide, see Cyhexatin Tridymite, see Silica--Crystaline Triethylamme (121-44-BJ (1983)................. 10 41 Trifiuorobromomethane (75-63-81 (1986) ................. 1000 6090 Trimellitic anhydride 1552-30-7) (19611................. 0.005 0.039 Tnmethylamine (75-50-3) (1983) ................. 10 24 Trimethyl benzene [25551-13-71 (1987)............. 25 123 Trimethyl phosphite [121-45-9] (1986) ............... 2 10 2.4.6-Trinitrophenol, see Picric acid 2.4.6-Trinitrophenylmettiytnitramine. see Tetryl -2,4,6-Trinitrotoluene (TNT) 1118-96-71--Skin (1986) .. -- 0.5 - - -- 200 -- -- 1250 15 -- -- 15 _ -- -- -- -- 1070 -- -- - 9590 62 -- -- 36 _ -- 36 I Substance [CAS fl ADOPTED VALUES TWA STEL ppm" mg/m5*' ppm** mg/m5** Triorthocresyl phosphate (78-30-8) - Skin (1986) .. . 0.1 Triphenyl amine (603-34-9] (I960).............................. _ 5__ _Triphenyl phosphate (115-86-6) 11986)................ 3 __ __ Tripoli, see Silica--Crystaline Tungsten 17440-33-7I, as W Insoluble compounds (1976) 5 to Soluble compounds (1976) . -- 1-- 3 Turpentine |800064-2| 11967) 100 556 -- -- Uranium (natural) |74406i-i] Soluble & insoluble compounds, as U (1978). 0.2 0.6 _n-Valeraldehyde |11M2-3| (19781 ................ 50 176 __ Vanadum. as V2Os(i3i4-62-i) Respirable dust & fume (1962)................. 0.05 Vegetable oil mists1*1 <i972) -- 10 -- -- Vinyl acetate |ioe-os-4| (1576) 10 35 20 70 Vinyl benzene, see Styrene Vinyl bromide 1593-60-21 (I960)................ 5,A2 22.A2 Vinyl chloride |75-0i-4| (1980) 5.A1 13.A1 -- -- Vinyl cyanide, see Acrylonitrile Vinyl cyctohexene dioxide 1106-87-61--Stan (1977).. . 10,A2 57,A2 Vinyiidene chloride [75-35-4] (1984) . . .. 5 20 20 79 Vinyl toluene |25O13-15-4|(1901) . . . SO 242 100 483 _ _VM & P Naphtha [BG32-32-4] (1987).............. 300 1370 Warfarin |8i-8i 2) (1987)____ -- 0.1 ---- Welding fumes (NOC`) (1977)................... , 5,B2 _ _ Wood dust (certain hard woods as beech & oak) (1981)................................... 1 Soft wood (i96ii.............. -- 5 -- 10 -Xylene (1330-20-7: 95-47 6; 106-38-3; 106-42-31 (0-. m-. p-isomers) (1975).............. 100 434 150 651 m-Xylene a,a '-diamine (1477-55-0) --Skin (1977) . . _ C 0.1 _ __ '6GCI01S Substance [CAS #| ADOPTED VALUES TWA STEL ppm*' ma/m** ppm** mp/m*' -Xylidine (mixed isomers) 11300-73-8) --Skin (1990) .. Yttrium 17045-S| metal & compounds, as Y (i9sei. Zinc chloride fume (7846-86-7) (1976).............. Zinc chromates (1353065-9; 1103-86-9. 37300-23-5f. as C7 (19881 .. Zinc oxide (I3i*-i32i Fume (1976).................... Dust (1978).................... Zirconium [744087-7] and compounds, as Zr (1976) 0.5,A2 2.5,A2 -1 -1 - 0.01 JA1 -5 - 10" -5 2 10 10 SPECIAL NOTICE On page 39, under "Notice of Intended Changes," the carcinogen designation for Benzene should read "A1" under both "ppm" and "mg/m . Please change the entry for Benzene to read fBanzdo* [71-43-2J -- Skin 0.1.A1 0.3,A1-------- 38 NOTICE OF INTENDED CHANGES (lor 1990-91) These substances, with their corresponding values, comprise those for which either a limit has been proposed for the first time, or for which a change in the "Adopted" isting has been proposed. In both cases, the proposed limits should be considered trial limits that will remain in the listing for a period of at least two years. If, after two years no evidence comes to light that questions the appropriateness of the values herein, the values will be recon sidered for the "Adopted" 1st. Documentation is available for each of these substances. Substancs TWA [CAS #] ppm"1 STEL ppm*1 mfl/m5*' /(Benzene [71-43-2]--Skin. 0.1.A4 0.3,Aj - - (Cadmium [7440-43-9] and compounds, as Cd . O.OI.A2. Total Oust 0.002.A2. Respirable fraction"1 Calcium chromate [13765-19-0], as Cr ... -- 0.001.A2 -- -- Calcium silicate (synthetic) 11344-95-21................. -- ID" -- (Caprolactam [105-60-2] Dust............................. -- 1-- 3 Vapor........................... 5 23 10 46 Chloroacetyf chloride [79-04-9]-Skin.......... 0.05 0.23 0.15 0.69 Chlorobenzene [108-90-7] 10 46 -- 2-Chloropropionic acid -- 1598-78-7]-Skin........ 0.1 0.44 1,1-Dimethylhydrazine [57-14-7]-Skin ........ 0.01.A2 0.025.A2 -- (Epichiorohydrin [106-89-8]--Skin ... 0.1,A2 0.38 A2 -- TEthyl bromide (74-96-41 -Skin .......... 5.A2 22.A2 -- -- Formaldehyde [50-00-0]. C 0.3.A2 C; 0.37,A2 -- Formic acid [64-18-6]___ 5 9.4 10 19 Graphite (all forms except graphite fibers) (7782-42-5].................. 2" Respirable dust tHeptachlor and heptachlor epoxide [76-44-8] -- Skin......................... -- 0.05.A2 -- 33ti68S0 t 01S Substance TWA ST& [CAS fl ppm" mg/m*' ppm" mg/m1*' tHexachloroethane [67-72-1]..................... 1.A2 9.7.A2 -- -- Hydrazine (302-01-2) -- Skin............................. 0.01.A2 Lead chromate (7758-97-6) as Pb............................ _ as Cr............................ -- 0.013.A2 0.05A2 0.012.A2 - _ -- - _ |4,4'-Methylene bis(2-chloroaniline) 1101-14-41 --Skin ........ Methyl hydrazine A1 A1 - -- [60-34-4]-Skin.......... 0.01.A2 0.019,A2 - - Morpholne [110-91-8)-- Skin............................. Nickel (7440-02-0] 20 71 - - Metal ........................... Insoluble compounds. - 0.05.A1 - - as Ni......................... - 0.05.A1 Soluble compounds. as Ni ........................ . -- 0.05, A1 - _ - -- Nickel carbonyl 113463-39-3), as M .. . Delete listing: nickel listing above applies. Nickel sulfide roasting. fume S dust, as NI ... - Delete listing: nickel listing above applies. tNitromethane [73-52-5] .. 20 50 - - Penlachloronitrobenzene 182-66-8)...................... - 0.5 - tPerfluoroisobutylene 1382-21-8) .................... C0.01 C 0.082 - - m-Phenylenediamine (108-45-2) .................. o-Phenyfenediamine 0.1 (95-54-5) ..................... p-Phenylenediamine - 0.1.A2 - - (106-50-3).................... Phenylhydrazine 0.1 - (100-63-0) --Skin........ 0.1Jk2 0.44,A2 - - Silica fume (amorphous) (69012-64-2)................ - 0.2," Respirable dust iw (Silica, fused (amorphous) [60676-86-0]................ Strontium chromate - 0.1, Resipirable dust 17789-06-21. as Cr .... - 0.001.A2 Tin, organic compounds. as Sn--Skin................. - (Triethanolamine [ 102-71-6J 0.5.A2 0.1 3.1.A2 - 0.2 40 ADOPTED APPENDICES APPENDIX A Carcinogens The Chemical Substances Threshold Limit Values Committee classifies certain substances found in the occupational environ ment as either confirmed or suspected human carcinogens. The present listing of substances that have been identified as car cinogens takes two forms: those lor which a TLV has been as signed and those tor which environmental and exposure conditions have not been sufficiently defined to assign a TLV. Where a TLV has been assigned, it does not necessarily imply the existence of a biological threshold; however, if exposures are controlled to this level, we would not expect to see a measur able increase in cancer incidence or mortality. The TLV Committee considers Information from the follow ing kinds of studies to be indicators of a substance's potential to be a carcinogen in humans: epidemiology studies, toxicology studies, and, to a lesser extent, case histories. Scientific debate over the existence of biological thresholds for carcinogens is un likely to be resolved in the near future. Because of the long la tent period for many carcinogens, and for 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, two categories of carcinogens are designated in this booklet: A1 --Confirmed Human Carcinogens. Substances, or sub stances associated with industrial processes, recog nized to have carcinogenic potential, and A2--Suspected Human Carcinogens. Chemical substances, or substances associated with industrial processes, which are suspect of inducing cancer, based on either limited epidemiological evidence or demonstration of carcinogenesis in one or more animal species by ap propriate methods. 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 extent possible all exposure to thB carcinogen. For A1 carcinogens with a TLV and for A2 car cinogens. worker exposure by all routes should be carefully con trolled to levels as low as reasonably achievable (ALARA) below the TLV. Please see the Documentation of the Threshold Limit " S68S0I01S Values, Appendix A, "Identification and Classification of Carcino gens," for a more complete description and derivation of these designations. APPENDIX B Substances of Variable Composition B1. Pofytetrafluonethytena* decomposition products. Thermal decom position of the fluorocarbon chain in air leads to the formation of oxidized products containing carbon, fluorine, and oxygen. Be cause these products decompose in part by hydrolysis in alka line solution, they can be quantitatively determined in air as fluoride (o provide an index of exposure. No TLV is recommended pending determination of the toxicity of the products, but air con centration should be minimal. (`Trade names: Aigoflon, Fluon, Teflon, Tetran) B2. Wotdlng Fumes-- Total Particulate (HOC)* TLV-1WA, 5 mg/m3 Welding fumes cannot be classified simply. The composi tion and quantity of both are dependent on the alloy being welded and the process and electrodes used. Reliabie analysis of fumes cannot be made without considering the nature of the welding process and system being examined; reactive metals and alloys such as aluminum and titanium are arc-welded in a protective, inert atmosphere such as argon. These arcs create relatively little fume, but they do create an intense radiation which can produce ozone. Similar processes are used to arc-weld steels, also creating a relatively low level of fumes. Ferrous alloys also are arc-welded in oxidizing environments that generate considerable fume and can produce carbon monoxide instead of ozone. Such fumes generally are composed o( discreet particles of amorphous slags containing iron, manganese, silicon, and other metallic consti tuents depending on the alloy system involved. Chromium and nickel compounds are found in fumes when stainless steels are arc-welded. Some coated and flux-cored electrodes are formu lated with fluorides and the fumes associated with them can con tain significantly more fluorides than oxides. Because of the above factors, arc-welding fumes frequently must be tested lor individual constituents that are likely to be present to determine whether specific TLVs are exceeded. Conclusions based on total fume concentration are generally adequate if no toxic elements are present in welding rod, metal, or metal coating and conditions are not conducive to the formation of toxic gases. Most welding, even with primitive ventilation, does not produce exposures inside the welding helmet above 5 mg/m3. That which does, should be controlled. APPENDIX C Threshold limit Values for Mixtures When two or more hazardous substances which act upon the same organ system are present, their combined effect, rather than that of either individually, should be given primary consider ation. In the absence of information to the contrary, the effects of the different hazards should be considered as additive. That is. If the sum of the following fractions, exceeds unity, then the threshold limit of the mixture should be considered as being exceeded. C, indicates the observed at mospheric concentration and T, the corresponding threshold limit (see Example A.1 and B.1J. Exceptions to the above rule may be made when there is a good reason to believe that the chief effects of the different harmful substances are not in fact additive, but independent as when purely local effects on different organs of the body are produced by the various components of the mixture In such cases the threshold limit ordinarily is exceeded only when at least one member of the series (C,/T, + or + C/Tj, etc.) itself has a value exceeding unity (see Example B.1). Synergistic action or potentiation may occur with some com binations of atmospheric contaminants. Such cases at present must be determined individualty. Potentiating or synergistic agents are not necessarily harmful by themselves. Potentiating effects of exposure to such agents by routes other than that of inhala tion are also possible, e.g.. imbibed alcohol and inhaled narcot ic (trichloroethylene). Potentiation is characteristically exhibited at high concentrations, less probably at low. When a given operation or process characteristically emits a number of harmful dusts, fumes, vapors or gases, it will fre quently be only feasible to attempt to evaluate the hazard by measurement of a single substance. In such cases, the threshold limit used for this substance should be reduced by a suitable fac tor, the magnitude of which wilt depend on the number, toxicity, and relative quantity of the other contaminants ordinarily present. Examples of processes that are typically associated with two or more harmful atmospheric contaminants are welding, automo bile repair, blasting, painting, lacquering, certain foundry opera tions, diesel exhausts, etc. Examples ol TLVs lor Mixtures A. Additive effects. The following formulae apply only when the com ponents in a mixture have similar toxicologic effects; they should not be used for mixtures with widely differing reactivities, e.g., "968S0101S hydrogen cyanide and sulfur dioxide. In such case, the formula for Independent Effects (B) should be used. 1. General case, where air is analyzed for each component, the TLV of mixture = C, C, C, " + -- + -- + ... -- I Tj Tj Note: It is essential that the atmosphere be analyzed both qualita tively and quantitatively for each component present in order to evaluate compliance or noncompliance with this calculated TLV. Example A.1: Air contains 400 ppm of acetone (TLV. 750 ppm), 150 ppm of sec-butyl acetate (TLV, 200 ppm) and 100 ppm of methyl ethel ketone (TLV, 200 ppm). Atmospheric concentration of mixture = 400 + 150 + 100 = 650 ppm of mixture. 400 150 750 + 200 J00 200 0.53 + 0.75 + 0.5 = 1.78 Threshold Limit is exceeded. 2. Special case when the source of contaminant is a liquid mix ture and the atmospheric composition is assumed to be simi lar to that of the original material, e.g., on a time-weighted average exposure basis, all of the liquid (solvent) mixture even tually evaporates. When the percent composition (by weight) of the liquid mixture is known, the TLVs of the constituents musi be listed in mg/m1. TLV of mixture = 1 f. f, f. | f. TLV. + TLV, + TLV. + ' " TLV. Note: In order to evaluate compliance with this TLV, field sam pling instruments should be calibrated, in the laboratory, for response to this specific quantitative and qualitative air-vapor mixture, and also to fractional concentrations of this mixture, e.g., 1/2 the TLV; 1/10 the TLV; 2 x the TLV; 10 x the TLV; etc.) Example A.2: Liquid contains (by weight): 50% heptane: TLV = 400 ppm or 1600 mg/mJ 1 mg/m1 -- 0 25 ppm 30% methyl chloroform: TLV = 350 ppm or 1900 mg/m' 1 mg/m1 = 0.18 ppm 20% perchloroethylene: TLV = 50 ppm or 335 mg/m1 1 mg/m1 = 0.15 ppm TLV of Mixture = ------------------- ----------------------- 0.5 ^3_ _02_ 1600 + 1900 + 335 44 0.00031 + 0.00016 + 0.0006 I = 935 mg/m1 0.00107 of (his mixture 50% or (935)(0.5) = 468 mg/m' is heptane 30% or (935X0.3) = 281 mg/m1 is methyl chloroform 20% or (935)(0.2) = 187 mg/m1 is perchloroethylene These values can be convened to ppm as follows: heptane: 468 mg/m' x 0.25 =117 ppm methyl chloroform: 281 mg/m-' x 0.18 = 51 ppm perchloroethylene: 187 mg/m1 x 0.15 ** 29 ppm TLV of mixture = 117 + 51+ 29 = 197 ppm, or 935 mg/m1 i. Independent nttetls. TLV for mixture = _i_ . _l . _El T, T, " T, I; etc. Example B.l: Air contains 0.15 mg/m' of lead (TLV, 0.15) and 0.7 mg/m1 of sulfuric acid (TLV, 1). 0.15 _ 0.15 ~ ' jL7_ I 0.7 Threshold limit is not exceeded. C. TL V for mixtures ot mineral dusts. For mixtures of biologically active mineral dusts, the general formula for mixtures given in A.2 may be used. 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 wel as mass concentration because of: 1) effects ot particle size on deposition site within the respiratory tract, and 2) the tendency lor many occupational diseases lo be associated with material deposited in particular regions of the respiratory tract. ACGIH has recommended particle size-selective TLVs for crys talline silica for many years in recognition of the well established association between silicosis and respirable mass concentrations. It now has embarked on a re-examination of other chemical sub stances encountered in particulate form in occupational environ- 45 L68SGIOiS merits with the abjective of defining: 1) the size-fraction most closely associated for each substance with the health effect of concern, and 2) the mass concentration within that size fraction which should represent the TLV. The Partide Size-Selective TT_Vs (PSS-TLVs) wil be expressed in three forms, e.g.. a. Inspirabte Particulate Mass TLVs (IPM-TLVs) for those materials that are hazardous 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 Particulate Mass TLVs (RPM-TLVs) for those mate rials that are hazardous when deposited in the gas-exchange region. The three particulate mass fractions described above are defined in quantitative terms as follows: a. Inspirable Particulate Mass consists of those particles that are captured according to the following collection efficiency regard less of sampler orientation with respect to wind direction: E = 50(1 + expl-0.06 dj) 10; for 0 <d,< 100 pm Collection characteristics for d.>100 pm are presently unknown. E is collection efficiency in percent and d, is aero dynamic diameter in pm.' b. Thoracic Particulate Mass consists of those particles that pene trate a separator whose size collection efficiency is described by a cumulative lognormal function with a median aerodynamic diameter of 10 pm 1.0 pm and with a geometric standard deviation of 1.5 (0.1). c. Respirable Particulate Mass consists of those particles that penetrate a separator whose size collection efficiency is described by a cumulative lognormal function with a median aerodynamic diameter of 3.5 pm 0.3 pm and with a geometric standard deviation of 1.5 (0.1). This incorporates and clari fies the previous ACGIH Respirable Dust Sampling Criteria. These definitions provide a range of acceptable performance for each type of size-selective sampler. Further information is availa ble on the background and performance criteria for these particle size-selective sampling recommendations.1'1 Mmnctt 1. Amwfca Confirmer <* GwarrrwiM Industrial Hygtanlsti: Particle Sue-Satectire Smptng in the Workplace. Pub. No. 0830. ACGIH. Cincinnati, OH (1984). ( : | 1 CHEMICAL SUBSTANCES AND OTHER ISSUES UNDER STUDY Information, data especially, and comments are solicited to assist the Committee in its deliberations and in the possible development of draft documents. Draft documentations are used by the Com mittee to decide what action, if any, to recommend on a given question. Chemical Substances Acetaldehyde Acetomethytchlonde Acetophenone Adipic acid Adlponitrile Aluminum alkyls Arsenic Bentonite Benzyl acetate Borax and boron compounds Bromine Bromine pentafluoride Bromochloromethane Bromodichloromethane Bromoform 1,2,3,4-Butanetetracarboxyllc acid n-Butyl acetate n-Butyl glycidyf ether (BGE) 2-t-Butylazo-2-hydroxy-5- methylhexane Carbon disulfide Carbon monoxide Chlorodiphenyfs (42% & 54% chlorine) Chromium Chrysene Cobalt Copper fume Cristobalrte Cyanamide Cyanides Diatomaceous earth Dichlorocyclopentadiene Dichlorodiphenyf sulfone 1,1 -Dichloroethane 1,2-Dichloroethane 2,4-D (2,4-Dichbrophenoxy acetic acid) 1,3-Oichtoropropene Dichioivos Diethytamine Dimethylamine Dimethyl acetamide Dimethyl formamide Dimethyl disulfide Dinitrotoiuene Emery EPN 2-Ethyl hexanoic acid Fibrous glass dust Gallium arsenide Gasoline (unleaded) Glutaraldehyde Glycol ethers Graphite fibers Hexachlorobenzene Hexachforocydopentadiene Hexamethylene diamine Hydrogen bromide Jet, petroleum, and diesel fuels Inorganic lead Kaolin Matathion Manganese Man-made mineral fibers Mercury 2-Methoxyethanol Methyl bromide Methylene chloride Methylene diamine 4,4'-Methylene diariHine 47 868S0I01S I Methyl tort-butyl ether Tantalum 1989-90 CHEMICAL SUBSTANCES TLV Mineral spirits Naled Terphenyls Terephthalic acid COMMITTEE Particulates Not Otherwise Classified (PNOC) Pentachlorophenol 2,4-Pentanedione Perchloroethytene Perlite Persullates Petroleum solvents ^ ,, Phosphate (including'mining) Potash Propylene dichloride Silane Silica, fumed (amorphous) Silica, fused (amorphous) Sulfur monochloride Sulfur tetraftuoride Sulfuryi fluoride 1,1,2,2-Tetrachloroethane TetraJas (hydroxymethyl) phosphonium chloride Tetrakis (hydroxymethyl) phosphonium sulfate Tetranitromethane Tetrasodium pyrophosphate Tobacco srnoto Toluene Trichloroethylene Tridymite Triethylamina Trimellrbc anhydride Trona Vinyl cyclohexene Uranium Ernest Mastromstteo, M.D., University of Toronto--Chair James R. Crawl, CIH, US Navy 0. Dwight Culver, M.D., University of Califomra-lrvine Janet Fekete, MS, Michigan Occupational Safety and Health Administration Stanley Haimes, M.Q, CIH, University of South Florida John L.S. Hickey, Ph.D., CIH, Retired William S. Lainhart, M.D.. Retired "Rent R. Lewis, Ph.D. Retired Jesse Lieberman, PE, CIH, Retired Robert F Phalen, Ph.D, University of Califomia-irvine, Air Sampling Procedures Liaison Ronald S. Ratney. Ph.D, CIH, Occupational Safety and Health Administration Meier Schneider, PE, CIH, Retired Raghubir Sharma, Ph.D. CIH, Utah Stale University Judith A. Sparer, CIH. Yale University Other Issues Robert Spirtas, Dr. PH, National Institutes of Health Vera F. Thomas, Ph D.. University of Miami, BE! Liaison 1. Excursion limit and Short-Term Exposure Limit (STEL). Elizabeth K. Weisburger, Ph.D, Retired, Corresponding Liaison 2. A working group has been formed to review classification sys tems for carcinogens that are used by other organiza Calvin Wilhite, Ph D., Slate of Caliiornia Margie E. Zalesak, CIH, Mine Safety and Health Administration tions/agencies. CONSULTANTS Gerald L Kennedy, Jr., Haskell Laboratory, E.l. du Pont de Nemours and Company, Inc. Georg Kimmerle, M.D., Bayer AG, German MAK Commission Liaison Richard A. Youngstrom, CIH, CSR IUE Local 201 48 *668S0I01S