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^ <L 'i' rZ&&G-S TLVs Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1977 i t s f l e Cfi5o fit***" .^7 i Qi'/ui Ji r--\ Sf JyS k/../ hJ r Copyright 1977 by American Conference of Govern mental industrial Hygienists. The American Conference of Governmental Industrial Hygienists win welcome requests for permission to re publish or reprint these Threshold Limit Values. Re quests for such permission should be directed to the Secretary-Treasurer, P.0. Box 1937, Cincinnati, Ohio 45201. PRICE EACH V45..................................................................... $1.50 50-199................................................................. 1.25 2QC-9S9............................................................... 1.10 1000-4999.................................................................75 5000 or more.............................................................65 Docum&Ttction of the Threshold Limit Values for Sub stances in Wcrkroom Air.9 A separate companion piece to tr.e Chemical TLVs is issued by ACGIH under this title. This publication gives the pertinent scientific information and data with reference to literature sources that were used to base each limit. Each documentation also con;-:r.s a statement defining the type of response against wnich the limit is safeguarding the worker. For a belts' jpaerstanding of the TlVs it is essential that the Docu mentation be consulted when the TlVs are being used. Information concerning the availability of copies of the Documentation of the Threshold Limit Values for Substances in Workroom Air should be directed to the Secretary-Treasurer, ACGIH. ... JLXZUi TLVs Threshold Limit Values for Chemical Substances in Workroom Air Adopted by ACGIH for 1977 wiwi'im * ' 1 'w^i'iluwMrii U u f-fflrjfifwilfiih>iiiiit RSV 0011256 r nw' 1977 TLV AIRBORNE CONTAMINANTS COMMITTEE Hervey B. Elkins, Ph.D., Chairman Charles E. Adkins Hector P. Blejer, M.D. Paul E. Cap!an, P.E., M.P.H. Paul Gross, M.D. John W. Knauber. M.P.H. Jesse Liaberman, P.E. Trent R. Lewis, Ph.D. Keith R. Long, Ph.D. FrederickT. McDermott. Ph.D. Boyd A. Madsen Col. Walter W. Melvin, Jr.. M.D. Leonard D. Pagnotto, Secretary Meier Schneider, P.E., C.I.H. Herbert E.Stokinger, Ph.D. William D. Wagner Ralph C. Wands David H. Wegman, M.D. CONSULTANTS E. Mastromatteo, M.D. James F. Morgan Marshall Steinberg, Ph. D. Theodore R. Torkeison, Sc.D. Mitchell R. Zavon, M.D. Any comments or questions regarding these limits should be addressed to: Secretary-Treasurer American Conference of Governmental Industrial Hygienists P.0. Box 1937 Cincinnati OH 45201: (513) 825-0312 TABLE OF CONTENTS Chemical Substances Page Preface................................................................... Threshold Lrnit Values and Short Term Exposure Units................................................................ Radioactivity.......................................................... Mineral Dusts......................................................... Nuisance Particulates............................................. Notice of Intended Changes.................................... Appendices A. Occupational Carcinogens............................ B. Substances of Variable Composition............ C. Mixtures: Calculation of TLVs...................... D. Excursions Time-Weighted Average........................... Peak Concentrations................................ E. Nuisance Particuiates......................... F. Asphyxiants................................................. G. Conversion of Particle Count to Mass........... 2 9 31 32 33 34 36 43 45 50 51 52 52 53 Physical Agents Preface................................................................... Threshold Limit Values Heat Stress........................................................ Appendix G. Heat Stress........................................ Ionizing Radiation............................................... Lasers................................................................. Microwaves........................................................ Noise..... ............................................................ Impulsive or Impact Noise................................. Ultraviolet Radiation............................................ Notice of Intended Changes.................................... Notice of Intent: Establish TLV for Light....................................... Airborne Upper Sonic Acoustic Radiation............ Agents Proposed for Study...... ......................... 57 58 59 66 66 81 81 83 85 88 90 93 94 f k__ RSV 0011259 r PREFACE CHEMICAL CONTAMINANTS Threshold Irnit values refer to airborne concentra tions of substances and represent conditions under which it is believed that nearty all workers may be repea tedly exposed day after day without adverse effect. Be cause of wide variation in individual susceptibility, how ever. a small percentage of workers may experience discomfort from some substances at concentrations at or below the threshold limit; a smaller percentage may be affected more seriously by aggravation of a pre-exist ing condition or by development of an occupational ill ness. Tests are available (J. Occup. Med. 15: 564, 1973: Ann. N.Y. Acad. Sci., 151. Art. 2: 968, 1968) that may be used to detect those individuals hypersusceptible to a variety of industrial diemicals {respiratory irritants, he molytic chemicals, organic isocyanates, carbon disul fide). Three categories of Threshold Limit Values (TLVs) are specified herein, as follows: a) Threshold Limit Value-Time Weighted Average (TLV-TWA) -- the time-weighted average concentration V a normal 8*hour workday or 40-hour workweek, to nearly all workers may be repeatedly exposed, day r:=r day, without adverse effect. b) Threshold Limit Value-Short Term Exposure Limit (TLV-STEL) -- the maximal concentration to which workers can be exposed for a period up to 15 minutes continuously without suffering from 1) irritation. 2) chronic or irreversible tissue change, or 3) narcosis of sufficient degree to increase accident proneness, impair self-rescue, or materially reduce work efficiency, provid ed that no more than four excursions per day are permit ted. with at least 60 minutes between exposure periods, and' provided that the daily TLV-TWA also is net exceed ed. The STEL should be considered a maxima! allowable concentration, or absolute ceiling, not to be exceeded at any time during the 15-minute excursion period. STELs are based on one or more of the following criteria: (1) Adopted TLVs including those with a "C" or "ceiling" 2 limit. (2) TWA-TLV Excursion Factors fisted in Append* 0. (3) Pennsylvania Short-Term Limits for Exposure to Airborne Contaminants (Penna. Dept of Kith., Chapter 4, Art 432. Rev. Jan. 25.1968). (4) OSHA Occupation al Safety and Health Standards, Fed. Reg. VoJ. 36, No. 105, May 29.1971. The TWA-STEL should not be used as engineering design criterion or considered as an emergency exposure level (EEL). c) Threshold Limit Value-Ceiling (TLV-C) -- the con centration that should not be exceeded even instantan eously. For some substances, e.g., irritant gases, only one category, the TLV-Ceilmg. may be relevant. For other substances, either two or three categories may be rele vant, depending upon their physiologic action. It is im portant to observe that if any one of these three TLVs is exceeded, a potential hazard from that substance is pre sumed to exist. The TLV-TWA should be used as guides in the con trol of health hazards and should not be used as fine lines between safe and dangerous concentrations. Time-weighted averages permit excursions above the limit provided they are compensated by equivalent ex cursions below the limit during the workday. In some instances it may be permissible to calculate the average concentration for a workweek rather than for a workday. The degree of permissible excursion is related to the magnitude of the threshold limit value of a particular substance as given in Appendix D. The relationship be tween threshold limit and permissible excursion is a rule of thumb and in certain cases may not apply. The amount by which threshold limits may be exceeded for short periods without injury to health depends upon a number of factors such as the nature of the contamin ant. whether very high concentrations -- even for short periods -- produce acute poisoning, whether the effects are cumulative, the frequency with which high concen trations occur, and the duration of such periods. All-fac tors must be taken into consideration in arriving at a decision as to whether a hazardous condition exists. Threshold limits are based on the best available infor mation from industrial experience, from experimental human and animal studies, and. when possible, from a 3 RSV 0011260 '17'i combination of the three. The basis on which the values are established may differ from substance to substance; protection against impairment of health may be a guid ing factor for some, whereas reasonable freedom from irritation, narcosis, nuisance or other forms of stress may form the basis for others. The amount and nature ol the information available for establishing a TLV varies from substance to sub stance: consequently, the precision of the estimated TLV is also subject to variation and the latest Documentation should be consulted in order to assess the extent of the data available for a given substance. The committee holds to the opinion that limits based on physical irritation should be considered no less bind ing than those based on physical impairment. There is increasing evidence that physical irritation may initiate, promote or accelerate physical impairment through in teraction with other chemical or biologic agents. In spite of the fact that serious injury is not believed likely as a result of exposure to the threshold limit con centrations. the best practice is to maintain concentra tions of all atmospheric contaminants as low as is prac tical. These limits are intended for use in the practice of industrial hygiene and should be interpreted and applied snty by a person trained in this discipline. They are not intended for use. or for modification for use, (1) as a relative index of hazard or toxicity. (2) in the evaluation or control of community air pollution nuisances. (3) in estimating the toxic potential of continuous, uninterrupt ed exposures or other extended work pericds, (4) as proof or disproof of an existing disease or physical con dition, or (5) for adoption by countries whose working conditions differ from those in the United States of America and where substances and processes differ. Ceiling vs Time-Weighted Average Limits. Although the time-weighted average concentration provides the most satisfactory, practical way of monitoring airborne agents for compliance with the limits, there are certain substances for which it is inappropriate. In the latter group are substances which are predominantly fast act ing and whose threshold limit is more appropriately based on this particular response. Substances with this 4 type of response are best controlled by a ceiling "C" Unit that should not be exceeded. It is implicit 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 "C" limit, is not appropriate to the time-weighted limit; here, a sufficient number of samples are needed to permit a time-weighted average concentration throughout a com plete cycle of operations or throughout the work shift Whereas the ceiling limit places a definite boundary which concentrations should not be permitted to exceed, the time-weighted average limit requires an explicit limit to the excursions that are permissible above the listed values. The magnitude of these excursions may be pegged to the magnitude of the threshold limit by an appropriate factor shown to Appendix 0. It should be noted that the same factors are used by the Committee in ddermining the magnitude of the value of the STELs, or whether to include or exclude a substance for a "C" listing. "Skin" Notation. Listed substances followed by the -designation ''Skin" refer to the potential contribution to the overall exposure by the cutaneous route including mucous membranes and eye. either by airborne, or more particularly, by direct contact with the substance. Vehicles can alter skin absorption. This attention-calling designation is intended to suggest appropriate measures for the prevention of cutaneous absorption so that the threshold limit is not invalidated. Mixtures. Special consideration should be given also to the application of the TLVs in assessing the health hazards which may be associated with exposure to mix tures of two or more substances. A brief discussion of basic considerations involved in developing threshold limit values for mixtures, and methods for their develop ment. amplified by specific examples are given in Ap pendix C. Nuisance Particulates, in contrast to fibrogenic dusts which cause scar tissue to be formed in lungs when in haled 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. The 5 s- t RSV 0011261 nuisance dusts have also been called (biologically) "inert" dusts, but the tatter term is inappropriate to the extent that there is no dust which does not evoke some cellular response in the lung when inhaled in sufficient amount. However, the lung-tissue reaction caused by in halation of nuisance dusts has the following characteris tics: (1) The architecture of the air spaces remains in tact. (2) Collagen (scar tissue) is not formed to a significant extent. (3) The tissue reaction is potentially reversible. Excessive concentrations of nuisance dusts in the workroom air may seriously reduce visibility, may cause unpleasant deposits in the eyes, ears and nasal pas sages (Portland Cement dust), or cause injury to the skin or mucous membranes by chemical or mechanical action per se or by the rigorous skin cleansing proce dures necessary for their removal. A threshold limit of 10 mg/m3, or 30 mppcf, of total dust < 1% quartz is recommended for substances in these categories and for which no specific threshold limits have been assigned. This limit, for a normal work day, does not apply to brief exposures at higher concen trations. Neither does it apply to those substances which may cause physiologic impairment at lower concentra tions but for which a threshold limit has not yet been adopted. Some nuisance particulates are given in Appen dix . Simple Asphyxiants -- "Inert' Gases or Vapors. A number of gases and vapors, when present in high con centrations in air, act primarily as simple asphyxiants without other significant physiologic effects. A TLV may not be recommended for each simple asphyxiant be cause the limiting factor is the available oxygen. The minimal oxygen content should be 18 percent by volume under normal atmospheric pressure (equivalent to a par tial pressure, p02 of 135 mm Hg). Atmospheres deficient in 02 do not provide adequate warning and most simple asphyxiants are odorless. Several simple asphyxiants present an explosion hazard. Account shouid be taken of this factor in limiting the concentration of the asphyx iant. Specific examples are fisted in Appendix F. Physical Factors. It is recognized that such physical factors as heat, ultraviolet and ionizing radiation, humid- 6 )j7 rt iy, abnormal pressure (altitude) and the like may place added stress on the body so that the effects from expo sure at a threshold limit may be altered. Most of these stresses act adversely to increase the toxic response of a substance. Although most threshold limits have built-in safety factors to guard against adverse effects to moder ate deviations from normal environments, the safety fac tors of most substances are not of such a magnitude as to take care of gross deviations. For example, continu ous work at temperatures above 90*F. or overtime ex tending the workweek more than 25%. might be consid ered gross deviations. In such instances judgment must be exercised in the proper adjustments of the Threshold Limit Values. Biologic Limit Values (BLVs). Other means exist and may be necessary for monitoring worker exposure other than reliance on the Threshold Limit Values for industrial air, namely, the Biologic Limit Values. These values rep resent limiting amounts of substances (or their effects) to which the worker may be exposed without hazard to health or well-being as determined In his tissues and fluids or in his exhaled breath. The biologic measure ments on which the BLVs are based can furnish two kinds of information useful in the control of worker ex posure: (1) measure of the individual worker's over-all exposure: (2) measure of the worker's individual and characteristic response. Measurements of response fur nish a superior estimate of the physiologic status of the worker, and may be made of (a) changes in amount of some critical biochemical constituent, (b) changes in ac tivity of a critical enzyme, (c) changes in some physiolo gic function. Measurement of exposure may be made by (1) determining in blood, urine, hair, nails, in body tis sues and fluids, the amount of substance to which the worker was exposed: (2) determination of the amount of the metabolite(s) of the substance in tissues and fluids: (3) determination of the amount of the substance in the exhaled breath. The biologic limits may be used as an adjunct to the TLVs for air, or in place of them. The BLVs, and their associated procedures for determining compliance with them, should thus be regarded as an effective means of providing health surveillance of the worker. 7 L RSV 0011262 Unlisted Substances. Many substances present or handled in industrial processes do not appear on the TLV list. In a number of instances the material is rarely present as a particulate, vapor or other airborne con taminant, and a TIV is not necessary. In other cases sufficient information to warrant development of a TLV, even on a tentative basis, is not available to the Commit tee. Other substances, of low toxicity, could be included in Appendix E pertaining to nuisance particulates. This list (2s well as Appendbc F) is not meant to be aH inclu sive: the substances serve only as examples. In addition there are some substances of not incon siderable toxicity, which have been omitted primarily be cause onfy a limited number of workers (e.g., employ ees of a single plant) are known to have potential exposure to possibly harmful concentrations. "Notice of Intent." At the beginning of each year, proposed actions of the Committee for the forthcoming year are issued in the form of a "Notice of Intended Changes." This Notice provides not only an opportunity for comment, but solicits suggestions of substances to be added to the list. The suggestions should be accom panied by substantiating evidence. The list of Intended Changes follows the Adopted Values in the TLV booklet. Legal Status. By publication in the Federal Register (VoL 36. No. 105. May 29, 1971) the Threshold Limit Values for 1968 are now official federal standards for industrial air. Reprint Permission. This publication may be reprint ed provided that written permission is obtained from the Secretary-Treasurer of the Conference and that it be published in its entirety. 8 Substance Abate......................... Acetaldehyde.............. Acetic add.................. C Acetic anhydride.......... Acetone..................... Acetonitrile.,........ ....... Acetylene....... ;............ Acetylene dichloride, see 1,2-Oichloroethylene. Acetylene tetrabromide... Acrolein..................... Acrylamide -- Skin....... Aayionitrfle-- Skin...... Afdrin -- Skin............. Altyl alcohol -- Sion.... Allyl chloride................ Ally! gtycidyl ether (AGE) --Skin.......... Allyipropyi disulfide...... Alundum (A]20a) .......... 4-Aminodiphenyi -- Skin 2-Aminoethanol. see EthanoJamine........... 2-Aminopyridine.......... Ammonia.................... Ammonium chioride-fume.......... Ammonium sulfamate (Ammate)................ n-AmyJ acetate............ sec-Amyi acetate.......... Aniline -- Skin............ Anisidine (o-. p-isomers) -- Skin.... ' Antimony & Compounds (as Sb) ................... ANTU (o-Naphthyi thiourea)................. ADOPTED VALUES TWA ppm** mg/m3*4 _ 100 10 5 1,000 40 F 10 180 25 20 2,400 70 -- 200 790 1 14 O.t 0.25 -- 0.3 20 45 0.25 25 13 5 22 2 12 --E --. Alb 36 0.5 2 25 18 _ 10 __ 10 100 525 125 650 5 19 0.1 0.5 -- (0.5) _ 0.3 TENTATIVE VALUES STEL ppnt*> mg/m3*4 150 15 -- 1,250 60 -- 20 270 37 __ 3.000 105 250 1,000 1.25 17.5 0.3 0.75 __ 0.6 30 ss -- 0.75 4 10 26 10 44 3 18 __ 20 -- Alb 6 12 1.5 6 35 27 20 _ 20 150 790 150 610 __ __ llM 0.9 Capitaf lefts* refer to Appendices. Footnotes (a thru h) see Page 31. See Notices of Intended Changes. 9 RSV 0011263 ADOPTED VALUES TWA Substanceppm* mg/m*** Argon......................... F * Arsenic & compounds (as As)........ ........... Arsine........................ Astsslos (an forms)...... -- 0.05 -- Asphalt (petroleum) fumes...................... Azinphos methyl -- Skin -- -- Szygon (propoxur)....... -- Barium (soluble compounds)............. -- Benzene -- Skin.......... 10, A2 Benzidine production -- Skin.... -- p-Benzoquinone, see Ousione.................. 0.1 Benzoyl peroxide.......... -- 5enz(a)pyrene.............. -- Benzyl chloride............. Beryllium..................... 1 -- Biphenyl..................... Bismuth tefluride.......... 0.2 -- Bismuth telluride, Se-doped................. -- * Borates, tetra. sodium salts. Anhydrous ................ Oecahydrate............. -- -- Pentahydrate............ Boron oxide.................. Soron tribromide........... C Soron trifluoride........... -- -- 1 1 Bromine....................... Bromine pentafluoride.... 0.1 0.1 Bromochloromethane .... 200 Bromoform -- Skin..... 0.5 Butadiene (1. 3-butadiene)............ 1.000 Butane........................ - BOO Capital letters refer to Appendices. Footnotes (a thru hi see Page 31. "See Notice ot Intended Changes. 1977 Addition. -- (0.5) 0.2 Ala 5 0.2 0.5 0.5 30, A2 Alb 0.4 5 A2 5 0.002 1 10 5 1 5 1 10 10 3 0.7 0.7 I.OoO 5 2,200 1,400 10 TENTATIVE VALUES STEl ^ ppm*1 mglm* FF ---- ---- -- Ala -- 10 -- 0.6 -- 1.5 ---- ---- -- Alb 0.3 1.2 -- -- A2 ---- -- 0.025 -- -- 20 -- 10 -- -- -- -- 3 -- 0.3 0.3 250 -- 1.250 750 -- -- -- 20 30 -- 2 2 1.300 -- 2.750 1.610 Substanceppm* mg/m3* ADOPTED VALUES TWA ppm** mg/ro3** TENTATIVE VALUES Jfa Butanethid, see Butyl mercaptan............... 2-8utanone --.......... 2-Butoxy ethanol (Butyl CelJosofve) -- Skin.... n-Butyl acetate............. sec-Butyl acetate.......... tert-Butyl acetate.......... C n-Butyt alcohol -- Skin.. sec-Butyl alcohol.......... tert-Butyl alcohoi.......... C Butylamine -- Skin------ C tert-Butyl chromate (as CrOa) --SWn.......... n-Sutyl gfycidyl ether (B6E)..................... n-Butyl lactate............. Butyl mercaptan............ p-tert-Buty(toluene........ Cadmium, dust & salts (as Cd).................... C Cadmium oxide fume (as Cd)......................... Calcium carbonate......... Calcium arsenate (as As) Calcium cyanamide........ Calcium hydroxide......... Calcium oxide.............. Camphor, synthetic........ Caprolactam Dust........................ Vapor....................... * Captafol (DifoUtan*)-- Skin... Captan........................ Carbary! (Serins)........ Caibofuran (Furadan*).. Carbon blade............... Carbon dioxide............. Carbon disulfide -- Skin O.S 200 50 150 200 200 50 150 100 5 50 5 0-5 10 -- -- -- -- -- -- --- 2 -- 5 -- -- --- -- -- 5,000 20 Capital letters refer to Appendices. "See Notice of Intended Changes. 1977 Addition. 11 1.5 _ 590 300 240 T50 710 200 950 250 950 2S0 150 _ 450 _ 300 150 15 _ O.T _ 270 __ 25 _ 1.5 __ 60 20 0.05 _ 0.05 _ E_ 1_ 0.5 -b. 5_ (5) -- 12 3 1_ 20 10 0.1 5 5 0.1 3.5 9,000 60 -- _ -- 15.000 30 8as 720 950 1.190 1.190 __ 450 __ _ __ _ 120 0.15 _ 20 _ 1 _ -- 18 3 40 -- 15 10 7 18,000 90 I J RSV 001X264 (f ADOPTED VALUES TENTATIVE VALUES Substance TWA STEL ppm** mg/m3*' ppm** mg/ffi3*' Carbon monoxide......... Carbon tetradromide..... Carbon tetrachloride -- Skin.. Catechol (Pyrocatechol).. Cellulose (paper Tiber).... Cesium hydroxide......... Chiordene -- Skin........ Chlorinated campnene-- Skin..... Chtorinsted diphenyl oxide....................... Chlorate...................... Chlorine dioxide........... Chlorine trifluoride........ Chloroacetaldehyde....... a-Chloroacetophenone (Phenacyl chloride).... Chlorobenzene (McnocNorobenzene). o-Chiorobenrylidene malonoitrile-- Skin... Cntomeromomethane.... 2-Chioro-l.3-butadiene, see 0 Chloroprene..... thiorodifluorom ethane. Cnlcrodiphenyl (42% Chlorine) -- Skin...... Chlorodiphenyl (54% Chlorine) -- Skin...... 1-ChSoro. 2. 3-epoxy-propane (Ep;chlOfhydrin)........ 2-Ck;oroethanol (Ethylene chiarohydrin)........... Chlomethylene (Vinyl chloride)................. 50 0.1 10 5 -- -- -- __ __ 1 0.1 0.1 1 0.05 75 0.05 200 25 1,000 _ _ 5 1 A1C 55 400 1.4 0.3 65 25 20 -- E-- 2-- 0.5 -- 0.5 -- 0.5 -- 33 0.3 0.3 0.4 -- 3-- 0.3 -- 350 0.4 1,050 -- __ 250 90 35 3.500 1,250 1-- 0.5 -- 20 10 3 -- Ale 440 4.2 160 -- 20 2 1 1.5 9 0.9 ~ __ 1.300 135 4,3/5 -- 1 40 _ -- i ; i1 , 1 t Cajiti! letters refer to Aopendices. *1977 Addition. 12 Substvce ** GhionAvm (Tridforomethane).... bts-Qtawnethyl ether... 1-CMoro-l-nitro-propane Chioropicrifl................ 0-CWorcprene -- Skin.. CNorpyrifos (Dursban*)-- Skin... o-Chlonstyrene........... o-Chloratduene -- Skin. 2-CNoro- 6-(bidrioromethyl pytitfce (N-Serve*)... Chromses. certain insoWile forms........ Chromic add and Chrosates. (as Cr.)... Chromon. Sol. chromic, ch/omous salts (as Cr.)............ Clopidd(Coyden*)...... Coal ter pitch volatiles (See Particulate pofycjdic aromatic hyomcartions).......... ** Cobasmeial, dust and fume ...................... Copper tme................ Ouss 3 Mists.......... Coruncan (AljOa)......... Cotton ast. raw.......... Crag? hsbitide............ Cresoi. tl isorr.srs -- Skin....... CrotonaCehyde............ Cnrfomce*................. Cumer.e -- Skin.......... ADOPTED VALUES TWA ppm*' mg/m1*' (25) 0.001 20 0.1 25 50 50 (120) Ala 100 0.7 90 0.2 285 250 10 0.05A1a 0.05 0.5 -- 10 Ala _ (0.1) -- 0.2 --1 --E -- 0.2"' -- 10 5 22 26 --5 50 245 TENTATIVE VALUES STR ppm*' mg/m*** -- Ala ___ _ 35 135 0.6 75 430 75 375 20 Ala _ . 20 Ala --_ __ 2 __ E __ 0.6 __ 20 6 IS __ 20 75 365 m) Sees. 34. footnote -i thru h) see Page 31. "See tace of Intended Changes. 13 RSV 0011265 -- _______________ - ............... ...........- , Substance Cyanamide................... Cyanide, as CN -- Skin.. Cyanogen .................... Cyclohexane.;.............. Cydohexanol............... Cyclohexanone............. Cyclohexene................ Cydohexylamine -- Skin Cyclop entadiene............ 2. 4-0 (2. 4-0iphenoxy- acetic acid).............. OOT (Oichlorodiphenyl- trichloroethane)........ DOVP. See Dichlorvos ... Decaborane -- Skin...... Demeton -- Skin....... Diacetone alcohol (4-hydroxy-4-methyf2-pentanone)............ 1.2-Oiaminoethane, See Ethylenediamine........ Diazinon -- Skin.......... Oiazomethane.............. Oiborane....... ............. 1,2-Dibromoethane (Ethylene dibromide) -- Skin.................... Dibrom..................... 2-N-Dibutylaminoethanol -- Sian.................... Oibutyt phosphate........ Dibutyl phthalate.......... C Olchloracetylene.......... C o-Dichloroberaene........ p-Oichlorobenzene........ Oichlorobenzidine -- Skin........................ Dichlorodifluoromethane. ADOPTED VALUES TWA ppm mgym**' --2 --5 10 20 300 1,050 50 200 50 200 300 1,015 10 40 75 200 _ 10 TENTATIVE VALUES STR ppm-* mgVm3*' ---- ---- ---- 375 1,300 ---- ---- -- ---- 150 400 20____ _ 1-- 3 0.1 1 0.3 3 0.05 0.3 0.15 0.9 0.01 0.1 0.03 0.3 50 240 75 360 10 25 -- -- --* 0.1 -- 0.3 0.2 0.4 -- -- 0.1 0.1 -- -- 20 -- 2 1 -- 0.1 50 75 1.000 145 30 3-- 14 4 52 p-- 0.4 -- 300 -- 450 no A2 4,950 1,250 220 6 28 10 10 -- -- 675 A2 6,200 Capital letters refer lo Appendices. Footnotes (a fimi fi) see Page 31 *1977 Addition. 14 ADOPTED VALUES Substance TWA ppm" mg/m5*' 1.3-Ditf-oro-5, 5-dimetfiyt hydantoin.. -- 1.1-OicNoroethane...... 200 1, 2-Oicfdoroethane...... 50 1,2-DicWoroethyiene.... 200 DicNofoetfiyl ether -- Skin........................ S Dichioromelhane, see Methylene chloride.... 200 Dichloromonofluoro- methane.................. (1,000) C1.1-Dichloro-l* nitroethane............... 10 1,2-Oichloropropane, see Propylene dichloride................ 75 Diehlorotetrafluoro- ethane.................... 1,000 Dichiorvos (ODVP) -- Skin................... 0.1 Dicrotophos (Bidrtn-2) -- Skin........................ -- Dicyclopentadiene........ 5 Dicyclopentadienyl iron.. -- Dieldrm -- Skin........... -- Diethylamine................ 25 Oiethylaminoethanof -- Skin.................... . 10 Diethylene triamine -- Skin........................ 1 Oiethyl ether, see Ethyl ether....................... 400 Oiethyl phthalate.......... -- Difluorodibromomelhane. 100 C Org#ycidyi ether (DGc).... 0.5 Dihydroxybenzene, see HydroQuinone.......... -- Diisobutyl ketone......... 25 0.2 820 200 790 30 720 (4.200) 60 350 7.000 1 0.25 30 10 0.25 75 50 4 1.200 5 860 2.8 2 150 TENTATIVE VALUES STR ppm" mg/m** -- 0.4 250 1.025 75 300 250 1,000 10 60 250 900 -- -- 110 1.250 0.3 -- -- -- -- _ __ 500 -- 150 -- -- -- 525 8,750 3 -- -- 20 0.75 _ __ _ 1,500 10 1.290 -- 3 -- Capital letters refer to Appendices. *1977 Addition. **See Notice of Intended Ganges. i -X i- - --t RSV 0011266 c :/W Substance ADOPTED VALUES TWA ppm** mg/m3* Diisopropylamine -- Skin........................ 5 Dlmethoxymethane, see Methylal.................. 1,000 Dimetnyl acetamide -- Skin........................ TO Dimethyiamine............. 10 Dimethylaminobenzene, see Xyiidene............. 5 Cimethylanilme (N-OimeUiylanUine) -- Skin........................ 5 Dinethylbenzene, see Xylene..................... 100 Dimethyl-1, 2-di&romo-2-dichloroethyl phosphate, see Oibrom................... -- DLTethylformamkJe -- Skin........................ 10 2. 5-Dimethylheptanone, see Diisobutyl ketone.. 25 I, l-Dimethylhydrazine -- Skin................... 0.5 Oimethylphthatate......... -- C Otmethyl sulfate -- Skin........................ 0.1, A2 Dinitrobenzene fall isomers) -- Skin....... 0.15 Dinitro-o-cresol -- Skin . -- 3, 5-Oinftro-o-loluamide (Zcalene*)............... ___ Dinitrotoluene -- Skin ... -- Oioxane, tech, grade -- Skin........................ 50 Dioxathion (Oeinav*).... -- Diphenyl, see Biphenyl... 0.2 Diphenylamine............. -- 20 3.100 35 18 25 25 435 3 30 150 1 5 0.5, A2 1 0.2 5 1.5 160 0.2 1 10 TENTATIVE VALUES STEL ppm* mg/m3** 1,250 15 -- 10 3,875 50 -- 50 10 50 150 650 6 20 60 12 -- 10 -- __ 0.5 3 -- 0.5 10 --5 ---- 0.6 3 -- 20 Capital letters refer to Appendices. *1977 Addition. Footnotes (a thru h) see Page 31. 16 Substance Oiphenylrnethane diisocyanate, see Methylene bisphenyl isocyanate (MDI)....... Dipropytene glycol methyl ether -- Skin .. Diquat........................ Di-sec, octyl phthalate (Di-2-ethylhexylphthalate)................ Disulfuram.................. Disyston -- Skin.......... 2. 6-Ditert. butyl-p-cresol....... . ' Diuron........... ............ Dyfonate..................... Emery........................ Endosullan (Thiodan*) -- Skin................... Endrin Skin............. Epichlorhydrin -- Skin... EPN -- Skin................ 1, 2-Epoxypropane, see Propylene oxide........ 2.3-Epoxy-1-propanol, see GJycidol.............. Ethane........................ Ethanethiof, see Ethyl mercaptan............... Ethano famine............... Ethion (Niaiaie*) -- Skin 2-Ethoxyethanol -- Skin. 2-Ethoxyethyi acetate (Cellosolve acetate) -- Sun........................ Ethyt acetate................ Ethyl acrylate -- Skin .... Ethyl alcohol (Ethanol)... Ethylamtne................... ADOPTED VALUES TWA ppm*' mfl/tn3*' 0.02 0.2 too BOO -- o.s 5 --2 -- 0.1 - 10 -- 10 -- 0.1 --E __ 0.1 -- 0.1 5 20 -- 0.5 100 240 50 150 F-- 0.5 1 36 -- 0.4 100 370 100 400 25 1,000 10 540 1,400 100 1,900 18 TENTATIVE VALUES STEL ppm-' mg/m3* 0.02 0.2 150 900 --1 10 --5 -- 0.3 20 ---- ---- -- 20 _ 0.3 -- 0.3 10 40 -- 1.5 150 360 65 190 F-- 1.5 3 6 12 ---- 150 560 150 810 ---- ---- ---- ---- Footnotes (a thru h) see Page 31. '1977 Addition. 17 in P RSV 0011267 . . . " _____________________________________________________ L .________________ /- ADOPTED VALUES TWA Substanceppma) mg/m3** TENTATIVE VALUES STEL ppm** mg/mJ*' Ethyl sec-amyl ketone (4-Wethyl-3* heptanone)............... Ethyl benzene............... Ethyl bromide.............. Ethylbutyl ketone (3-Heptanone).......... Ethyf chloride............... Ethyl ether.................. Ethyl formate............... Ethyl mercaptan............ Ethyl silicate................ Ethylene...................... I Ethylene chlorohydrin -- Skin........................ Ethylene diamine.......... Ethylene dibromide, see 1,2-Dibromoethane... Ethylene dichloride, see 1.2-Oichloroethane... Ethyleneglycol. Particulate............... Vapor...................... Ethylene glycol dinitrate and/or Nitroglycerin -- Skin................... Ethylene glyccl monomethy! ether acetate {Methyl celtosolve acetate) -- Skin........................ Ethyfene oxide.............. Etfty'enimine -- Skin.... Ethyfcdene chloride, see 1.1-Dichtoroethane... : Elhyiidene nortornene... N-Ethyfmorphdine -- Skin........................ Fensulfothion (Dasanit).. Ferbam....................... 25 100 200 50 1,000 400 100 0.5 (100) f 1 10 20 50 _ 100 0.2* 25 50 0.5 200 5 20 -- -- 130 -- 435 125 890 250 230 2,600 1,200 300 1 (850) -- 3 25 75 1,250 500 150 -- --* F __ -- 145 30 200 75 10 260 125 120 40 90 75 1-- 320 250 25 -- 94 20 0.1 -- 10 -- -- 545 1,110 345 3.250 1,500 4S0 -- -- -- _ -- 220 300 20 325 180 135 -- 400 -- 94 -- 20 Capiei letters refer to Appendices. 18 ADOPTED VALUES TWA Substanceppm** mp/m1** Ferrovanadium dust...... fluoride (as F).............. fluorine ...................... Fluorotrichloromethane.. C Formaldehyde.............. Formamide.................. Formic add................. Furfural -- Skin............ Furfuryl alcohol -- Skin . Gasoline...................... Germanium tetrahydride. Glass, fibrous* or dust.. C Glutaraldehyde. activated or unactrvated.......... Glycerin mist............... Glycidot (2. 3-Epoxy- 1-propanol).............. Glycol monoethyl ether, see 2*Ethoxyethanoi... Graphite (Synthetic)...... Guthion*, see Azinphos-methyl....... Gypsum...................... Hafnium...................... Helium........................ Heptachlor -- Skin....... Heptane (n-Heptane)..... Hexachlorocydopenta- diene....................... Hexachloroethane -- Skin........................ Hexachloronaphthalene -- Skin................... Hexaduoroacetone........ Hexane (n-hexane)........ 2-Hexanone, see Methyl butyl ketone -- Skin .. Hexone (Methyl isobutyl ketone) -- Skin........ -- -- 1 1,000 2 20 5 5 5 -- 0.2 -- -- 50 100 -- -- -- F -- 400 0.01 1 0.1 100 25 100 1 2.5 2 5,600 3 30 9 20 20 B2 0.6 E (0.25) E 150 370 E 0.2 E 0.5 -- 0.5 1.600 0.11 10 0.2 0.7 360 100 410 TENTATIVE VALUES STEL ppm** mg/mJ** -- -- 2 1,250 -- 30 5 15 10 -- 0.6 -- 0.3 __ 4 7.000 -- 45 9 60 40 B2 1.8 E _ --E 75 225 150 560 ---- _ 0.6 -- 20 -- 1.5 F-- -- 1.5 500 2.000 0.03 0.33 3 30 0.6 0.3 2.1 125 450 40 150 125 510 Capital letters refer to Appendices. * 'See Notice of Intended Changes. 19 [ RSV 0011268 r /V Substance sec-Hexyl acetate.......... CHexyiene glycol............ * Hydrazine--Skin........ Hydrogen.................... Hydrogenated terphenyls Hydrogen bromide........ C Hydrogen chloride........ Hydrogen cyanide -- Skin........................ Hydrogen fluoride.......... Hydrogen peroxide....... Hydrogen seienide........ Hydrogen sulfide.......... Hydroquinone.............. Indene........................ Indium & Compounds (as In)..................... C Iodine......................... Iodoform..................... Iron oxide fume........... Iron pentacarbonyl........ Iron salts, soluble (as 9t)......................... Isoamyi acetate............ Isoamyl alccnol......... .. IscPutyl acetate........... isobutyl alcohol............ C isophorone................. Isophorone diisocyanate --Skin .. Isopropyl acetate.......... Isopropyl alcohol -- Skin IsopropySarmne............ Isopropyl ether............ Isopropyl giycidyl ether (IGE)....................... Kaolin......................... Ketene........................ ADOPTED VALUES TWA ppm-' mg/m**' 50 300 25 125 0.1 0.1 F 0.5 5 3 10 57 TENTATIVE VALUES STEL ppm-' mg/m**' _ __ ' __ F _-- __ _ __ 10 11 15 16 32 _ 1 1.4 2 2.8 0.05 0.2 _ _ 10 15 15 27 24 10 45 15 27 0.1 0.1 1 0.2 3 0.4 83 5 _ 0.01 0.05 _ 1_ 100 525 125 100 360 125 150 700 187 50 150 75 S 25 -- 0.3 0.6 10 2 655 450 875 225 -- 0.01 0.05 -- -- 250 950 310 1.185 400 980 500 1,225 5 12 10 24 250 1.050 310 1,320 50 240 75 360 __ -- 20 0.5 0.9 1.5 2.7 Capital letters refer to Appendices *1977 Afls&on. 20 Substance Lead, horg.. fumes & dusts (as Pb)............ Lead arsenate (as Pb).... Lead Chromate (as Cr)... Limestone.................... Lindane -- Skin............ Lithium hydride........... LP.G. (Liquified petroleum gas)......... Magnesite.................... Magnesium oxide fume.. Malathion -- Skin........ Maleic anhydride.......... C Manganese & Compounds (as Mn).. Manganese cyciopentadienyl tricarbonyi (as Mn) -- Skin........................ MarOle........................ Mercury (Alkyl compounds) -- Skin. As Hg...................... Mercury (All forms except alkyl) as Hg .... Mesityl oxide............... Methane................. .. Methanethiol. see Methyl mercaptan............... Methomyl (Lannate*) -- Skin........................ Methoxychlor............... 2-Methoxyethanol -- Skin (Methyl cellosolve)............... Methyl acetate.............. Methyl acetylene (propyne) ................ ADOPTED VALUES TWA ppm"* mg/m3*' -- 0.15 -- 0.15 -- 0.05, A2 -- -- 0.5 -- 0.025 1,000 -- -- -- 0.25 1,800 E 10 10 1 --5 -- 0.1 --E 0.001 -- 25 F 0.5 ---- 0.01 0.05 100 -- 1 2.5 10 25 200 1,000 80 610 1,650 TENTATIVE VALUES STEL ppm*' mg/ma" -- -- -- -- -- -- 1,250 -- -- -- -- -- 0.45 0.45 _ 20 1.5 -- 2.250 20 -- -- -- -- -- 0.3 -- 20 0.003 -- -- F -- -- -- 0.03 0.15 ---- -- -- -- 35 250 1.250 120 760 2,060 1977 Addition. Capital letters refer to Appendices. 21 RSV 0011269 r Substance Methyl acetylene-propadiene mixture (MAPP)........ Methyl acrylate -- Sidn .. Methyl acrylonitrile -- Skin........................ Methylaf (dimethoxymethane) .. Methyl alcohol (methanol) --Skin.... Methylamine................ Methyl amyl alcohol, see Methyl isobutyl carbinol................... Methyl 2-cyanoacrylate.. Methyl isoamyt ketone... Methyl n-amyl ketone (2-Heptanone).......... Methyl oromide -- Skin . Methyl butyl ketone, see 2-Hexanone.............. Methyl cellosolve -- Skin see2-Methoxyethanoi. Methyl cellosolve acetate -- Skin, see Ethylene glycol monomethyl ether acetate............. Methyl chloride............. Methyl chloroform........ Methyicydchexene....... Methylcyciohexanol....... o-Methycyclohexanone -- Skin................... Methytcydopentadienyl manganese tricarbonyl (as Mn) --Skin........ Methyl demeton -- Skin. ) Methylene bisphenyl isocyanate (MDI)....... ADOPTED VALUES TWA ppm*' mg/m**1 1.000 10 1 1.000 200 10 1.800 35 3 3.100 260 12 25 100 28 100 475 100 465 15 60 25 100 25 BO 25 120 100 210 350 1.900 400 1.600 50 235 50 230 0.1 0.2 -- 0.5 0.02 0.2 TENTATIVE VALUES STEL ppm*' mg/m311' 1,250 -- 2 1.250 250 -- 2.250 -- 6 3.875 325 -- 40 150 4 16 150 710 150 710 -- --- 40 ISO 35 120 35 150 125 260 450 2.375 500 2.000 75 350 75 345 0.3 0.6 -- 1.5 ---- CaprUI Jertars refers 10 ApoencicES. 22 Substance ADOPTED VALUES TWA ppm-' mg/m*** Methylene chloride (dichtoromethane)..... 200 4,4'*Methylene bis (2-cWoraniine) -- Skin........................ 0.02. A2 C Methylene bis (4-cydo- hexyiisocyanate)....... 0.01 Methyl ethyl ketone (MEK), see 2-Butanone.............. 200 C Methyl ethyl ketone peroxide........ ,........ 0.2 Methyl formate............. 100 Methyl iodide -- Skin.... 5 Methyl isobutyl carbinoi -- Skin................... 25 Methyl isobutyl ketone. see Hexone .............. 100 Methyl isocyanate -- Skin........................ 0.G2 Methyl mercaptan......... 0.5 Methyl methacrylate...... 100 Methyl parathion -- Skin -- Methyl propyl ketone. see 2-Pentanone....... 200 C Methyl silcate.............. 5 C<rMethyl styrene........ 100 Molybdenum (as Mo) Soluble compounds... -- Insoluble compounds. -- Monocrotophos (Azodrin*)............... -- Monomethyl aniline -- Skin........................ 2 C Monomethyl hydrazine -- SMn................... 0.2 Morphotine--Skin....... 20 Naphthalene................ 10 720 -- 0.11 590 1.5 250 28 100 410 0.05 1 410 0.2 700 30 4B0 5 10 0,25 9 0.35 70 50 TENTATIVE VALUES STEL ppm" mg/m*M 250 900 A2 -- ---- 250 740 ---- 150 375 10 56 40 150 125 510 ---- ---- 125 510 -- 0.6 250 875 ---- ---- -- 10 -- 20 -- -- 4 18 -- -- 30 105 15 75 Footnotes (a thru h) see Page 31. 1977 Addition. 23 rm- RSV 0011270 r ADOPTED VALUES TWA Substanceppm"* mg/m*** TENTATIVE . VALUES STEl. ppm-' mg/m*4> 0-Naphtfiylamine......... -- Neon.......................... F * Nickel carbonyl............. 0.05 Nickel metal.............. -- Nickel, soluble compounds (asNi).... Nicotine--SHn.......... -- Nitric acid.................... 2 Nitric oride.............. 25 p-Nitrcaniline -- Skin.... 1 Nitrobenzene -- Skin..... 1 p-Nitrochlorobenzene -- SHn........................ _ 4-Nitrodiphenyl............. -- Nitroethane................. 100 C Nitrogen dioxide.......... 5 Nitrogen trifluoride....... 10 Nitroglycerin* --Skin... 0.2 Nitrom ethane............... 100 i-Nitropropane............ 25 2-Nitropropane ............ 25 N*Nitrosodimetny!amine (dimetriylnitrosca/nine) -- Skin................... Nitrotoluene -- Skin...... 5 Nitrotricftloromethane, see Chloropicrin........ 0.1 Nonane....................... 200 Octachforonaphthaiene -- Skin................... _ Octane........................ 300 Oil mist....................... -- Osmium tetroxide (as Os)......................... 0.0002 Oxalic add.................. -- Oxygen difluoride......... 0.05 Ozone................. J...... 0.1 Paraffin wot fume........ -- Alb -- --F 0.35 -- 1-- 0.1 0.5 -- 54 3Q 35 62 52 1_ Alb -- 310 150 9-- 29 15 2-- 250 150 90 35 90 -- A2 30 10 0.7 1,050 0.3 250 0.1 1.450 5 375 -- O.C02 1 0.1 0.2 2 0.0006 -- 0.15 0.3 -- Alb -- -- -- 0.3 1.5 10 45 12 10 2 Alb 465 -- 45 -- 375 135 -- A2 60 2 1.300 0.3 1,800 10 0.006 2 0.3 0.6 6 Capital letters refer to Appendices footnotes U thru h) see Page 31. *1977 Addition. 24 ADOPTED VALUES TENTATIVE VALUES TWA STa Substanceppm*1 mg/m*u ' Paraquat--Skin.......... Partition -- Skin......... ppm" mp/m3** _ (0.5) 0.1 _ Particulate polycyclic aromatic hydrocarbons (PPAH) as benzene solubles... -- 0.2. Ala _ Pentaborane................ 0.005 0.01 0.015 Pentachloronaphtftalene . Pentachlorophenol -- Skin........................ Pentaeiythritol....,........ -- _ -- 0.5 -- 0.5 E __ Pentane...................... 600 1.800 750 2-Pentanone................ 200 700 250 Perchloroethyiene-- SHn........................ 100 670 150 Perchloromethyl mercaptan............... 0.1 0.8 -- Percftloryl fluoride........ 3 14 6 Petroleum distillates (naphtha)................ "83 _ 83 Phenol -- Skin............. 5 19 10 PhenotNazine -- Skin.... -- 5-- p>Phenyfene diamine -- SHn........................ -- 0.1 __ Phenyl ether (vapor)...... 1 72 Phenyl ether-Diphenyi mature (vapor)........ 1 72 Phenylethylene, see Styrene................... 100 420 125 Phenyl glyddyl ether (PGE)...................... 10 60 15 Pbenylhydrabne -- Skin. 5 22 10 Phenylpbosphine.......... 0.05 0.25 -- Phorate (Thimet) -- Skin........................ -- 0.05 -- Phosdnn (Mevinphos*) -- SHn................... 0.01 0.1 0.03 Phosgene (carbonyl chloride)................. 0.10 0.4 -- _ 0.3 Ala 0.03 1.5 1.5 20 2,250 875 1,000 -- 28 -- 38 10 __ 14 14 525 90 44 -- 0.15 0.3 Capital letters refer to Appendices. 'See Notice of Intended Changes. 25 C: V RSV 0011271 r Substance Phosphine................... Phosphoric add............ Phosphorus (yellow)..... Phosphorus pentachioride............ Phosphorus pentasulfide Phosphorus trichloride... ' Phthalic anhydride........ ' m-Phlhalodinitr3e......... Piclcram (Tordon*)...... Picric add -- Skin........ PwaJ*(2-PivaJyl-1,3indandione).............. Plaster of Paris............. Platinum (Soluble salts) as Pt....................... Poiychlorobiphenyls, see Chiorodphenyls........ Pclytstrafluoroethylene c "composition products.................. ; 3pussium hydroxide.... Propane...................... 0-Propiolactone............ Propargyl alcohol -- Skin........................ n-Propyi acetate............ Propyl alcohol -- Skin... n-Propyl nitrate........... Propylene.................... Propylene dichloride (1. 2-Oichloropropane).... Propylene glycol monomethyl ether.... Propylene imine -- Skin. Propylene oxide............ Propyne. see Methyl-acetylene....... Pyrethrum................... AOOPTFO VALUES TWA ppm" mg/m3*' 0.3 0.4 --1 0.1 TENTATIVE VALUES STEL ppm" mg/m3*' 11 _3 0.3 -- 1-- 3 -- 1-- 3 0.5 3-- -- 1 64 24 -- 5-- -- -- 10 _ 20 0.1 -- 0.3 -- 0.1 -- 0.3 E 20 0.002 -- -- F -- 1 200 200 25 F 75 100 2 100 1.000 -- B1 -- 2-- --F A2 -- 2 840 500 110 -- 3 250 250 40 F 350 115 360 150 5-- 240 150 1.650 1,250 5-- B1 -- -- A2 6 1.050 625 140 -- 525 450 -- 360 2.050 10 Capital letters refer to Appendices. *1977 Addition. 26 Substance ADOPTED VALUES TWA ppm" mg/m3*' Pyritine..................... 5 15 Quinone......-..... -..... RDX--Skin..... .......... Resordnd.................. 0.1 -- 10 0.4 1.5 45 Rhodium, Metal fume and dusts (as Rh)...... Soluble salts.......... . -- 0.1 -- 0.001 Ronnei........................ 10 Rosin core solder pyrolysis products (as formaldehyde).......... -- 0.1 Rotenone (commercial).. -- 5 Rouge ........................ -- E Rubber solvent............. 400 1.600 Sderium compounds (as Se)................ -...... Selenium hexafluoride. 0.2 as Se..................... 0.05 0.4 Sevin* {see Carbary!).... -- 5 Silane (seeStScon tetrahydride)............ Silicon........................ 0.5 -- 7 E Silicon carbide............. E SI con tetrahydride (Silane)................... 0.5 0.7 Silver, metal and soluble compounds, as Ag .... -- 0.01 C Sodium azide............... 0.1 0.3 SocSum fluoroacetate (1080) --Skin......... -- 0.05 C Sodium hydroxide........ -- 2 Starch ........................ -- E Stibine........................ 0.1 0.5 Stoddard solvent.......... 100 575 Strychnine.................. -- 0.15 Styrene, monomer (Phenylethyiene)....... 100 420 Sucrinaldehyde (see Glutaraldehyde)........ -- (0.25) Capital letters refer to Appercces. '1977 Addition. TENTATIVE VALUES STEL ppm" mg/m**1 10 30 0_.3 1 3 20 90 __ -- 0.3 0.003 " -- 0.3 -- 10 -- 20 -- ** 0.05 0.4 -- 10 ---- -- 20 -- 20 1 1.5 -- 0.03 ---- -- 0.15 ---- -- 20 0.3 1.5 150 720 -- 0.45 125 525 ---- I_______J. RSV 0011272 r Substance C Subtilisins (Proteolytic enzymes as 100% pure crystalline enzyme)................... Sucrose...................... Sulfur efioride.............. Sulfur hpcafluoride....... Sulfuric add................ Sulfur monochtoride...... Sulfur pentafluoride...... Sulfur tetrafluoride........ Sulfuryl fluoride............ Systox, see Oemeton*... 2. 4, 5*T..................... Tantalum..................... TEDP --Skin............... Teflon* decomposition products ................. Tellurium..................... Tellurium hexafluoride, as Te....................... TEPP -- Skin............... CTerphenyls.................. 1,1,1,2-Tetrachloro*2. 2-difluoroethane....... 1. 1. 2,2-Tetradiloro-l. 2-<Sfluorcethane....... 1.1.2. 2-Tetrachloroethane -- Skin................... Tetrachlorosthyiene, see Perchloroethylene...... Tetrachloromethane, see Carbon letradiforide... Tetrachioronaphthalene.. Tetraethyl lead (as Pb) -- SHn................... ADOPTED TENTATIVE VALUES_________ VALUES TWA STEL ppm" mg/m**' ppm" mg/m** 0.00006" --E 5 13 1.000 -- 6,000 1 16 0.025 0.25 0.1 0.4 5 20 0.01 0.1 -- 10 --5 -- 0.2 81 -- 0.1 _ __ 1,250 -- 3 0.075 0.3 10 0.03 -- -- -- _ -- 0.02 0.004 1 0.2 0.05 0.012 9-- 500 4.170 625 500 4.170 625 20 -- 7,500 -- 18 a 75 1 40 0.3 20 10 0.6 81 -- 0.15 -- 5,210 5.210 5 35 10 70 100 670 150 1.000 TO 65 20 130 -- 2-- 4 0.100** 0.3 Capital letters refer to Aopendces. Footnotes (a thru h) see Page 31. o)See Page 34. 28 Substanceppm" mgfm*** ADOPTED VALUES TENTATIVE VALUES TWA STEL ppm" mg/m** Tetrahydrofuran................ 200 590 250 700 Tetramethyt lead (as Pb) -- Sldn.................. . -- 0.150" mm* 0.45 Tetramethyt sucdnonrtnle -- Skin. 0.5 3 1.5 9 Tetranitromethane........... 1 8 Tetryl (2.4, 6-trinitrophenyl- metfiytnitramine)-- Skin.................................. 1.5 3.0 Thallium, soluble compounds (as Tl) -- Skin....................... 0.1 4,4*-Thiobis (6-tert. butyl-m-cresol)............. -- 10 -- , 20 Thiram*............................... 5 10 Tin. inorganic compounds, except SnH* and Sn02, (as Sn) Tin, organic compounds 2" 4 (as Sn) -- Skin........... -- 0.1 -- 0.2 Tin oxide............................. -- E-- 20 Titanium dioxide............... -- E-- 20 Toluene (toluol) -- Skin . 100 375 150 560 C Toluene-2,. 4-diisocyanate (TDI)... 0.02 0.14 -- -- o-To!uidine.......................... 5 22 10 44 Toxaphene, see Chlorinated camphene -- 0.5 -- 1.5 Tributyl phosphate........... 55 1,1,1-Trichloroethane, see Methyl chloroform 350 1,900 440 2,330 1.1,2-Trichloroethane -- Skin............................ Trichloroethylene............. 10 100 45 20 535 150 90 800 Trichloromethane, see Chloroform.............. (25) 020) -- -- Trichloronaphthalene..... -- 5-- 10 1.2.3-Trichloropropane 50 300 150 450 Capital letters refer to Appemfices. See Notice ot Intended Changes. 29 RSV 0011273 r m/i Substance 1.1.2-Trichloro 1. 2. 2-trifluoroethane....... Triethyiamine.............. Tricyclohexyltin hydroxide (Plictran*). Trifiuoromonobromo- methane................... Trimethyl benzene........ 2.4, 6-Trinitrophenol, see Picric acid.......... 2. 4,6-Trinitrophenylmethyfnitramine, see Telryl...................... Trinitrotoluene (TNT) -- Skin........................ Triorthocresyl phosphate Triphenyl phosphate...... Tungsten & compounds, as w Soluble................ Insoluble.............. Turpentine.................. Uranium (natural) soluble & insoluble compounds, as U...... Vanadium (VjOs), as V C Dust....................... Fume...................... Vinyl acetate................ Vinyl benzene, see Styrene.................... Vinyi bromide.............. * Vinyl chloride............... Vinyl cyanide, see Acrylonitrile.............. Vinyl cydohexene dioxide.................... Vinylidene chloride....... Vinyl toluene................ ADOPTED VALUES TWA ppm4' mg/m** 1,000 25 1,000 25 _ 7,600 100 5 6.100 120 0.1 1.5 _ (1-5) -- 0.1 --3 1 --5 100 560 -- 10 100 (250) (200) 20 10 10 100 0.2 0.5 0.05 30 420 (1.100) (510) 45 60 40 460 TENTATIVE VALUES STEL ppm*" mg/m,J 1.250 . 40 _ 1,200 35 9.500 150 10 7,625 180 0.3 3.0 _ __ -- 0.3 --6 3 -- 10 150 340 0.6 __ 1.5 ---- 20 60 150 630 ---- ---- 30 70 _ 20 80 150 720 *1977 Addition. 'See Notice of Intended Changes. 30 ADOPTED VALUES TWA Substanceppm** mg/m**1 Warfarin-................... Welding fumes (Total particulate)............... Wood dust (nonallergenic)......... Xylene (o-, m*. p-feomers) -- Skin.... *C m-Xylene a. a'-diamine. Xylidene -- Skin........... Yttrium...... ................ Zinc chloride fume........ * Zinc chromate (as Cr).... Zinc oxide fume........... Zinc stearate................ Zirconium compounds (as Zr).................... -- 0.1 -- 5. B3 --5 100 435 -- 0.1 S 25 --1 --1 -- 0.05, A2 --5 --E --5 TENTATIVE VALUES STEL ppm*' mg/m*** -- 0.3 -- B3 -- 10 150 655 --_ 10 50 __ 3 __ 2 ---- __ 10 -- 20 -- 10 *1976 Addition Capital letters refer to Appendices. a) Pans of vapor or gas per million parts of contaminated air by volume at 25aC and 760 mm. Hg. pressure. b) Approximate milligrams of substance per cubic meter of air. d) An atmospheric concentration of not more than 0.02 ppm. or personal protection may be necessary to avoid headache for intermittent exposure. e) <7/im in diameter. f) As sampled by method that does not collect vapor. g) According to analytically determined composition. h) For control of general room air. biologic monitoring is essential for personnel control. Radioactivity: For permissible concentrations of radioisotopes in air. see U.S. Department of Commerce. National Bureau of Standards Handbook 69."Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for 31 J ij j ij fi I j i 1 j i \ j t j i { I i RSV 0011274 Occupational Exposure," June 5,1969. Also, see U.S. Department of Commerce National Bureau of Standards. Handbook 59, "Permissible Dose from External Sources of Ionizing Radiation," September 24,1954, and adden dum of April 15,1958. A report. 8asic Radiation Protec tion Criteria, published by the National Committee on Radiation Protection, revises and modernizes the con cept of the NCRP standards of 1954, 1957 and 1958; obtainable as NCRP Rept. No. 39, P. 0. Box 30175, Washington, O.C. 20014. MINERAL DUSTS Substance SUJCA, SiQz Crystalline Quartz TLV in mppcf0: 300* % quartz + 10 TLV for respirable dust in mg/m3: 10 mg/rrr*'________ % Respirable quartz + 2 TLV for "total dust," respirable and nonrespirable: 30 mg/m3 % quartz + 3 Cristobalite............ Use one-half the value calculated from the count or mass formulae for quartz. Tridymite Use one-half the value calculated from formulae for quartz. Silica, fused Use quartz formulae. Tripoli Use respirable*" mass quartz for* mula *Amorphous................................................20 mppcf" "See Notice of Intended Changes. 32 SIUCATSS (< 7% quartz) Asbestos, all formst Graphite (natural) Mica Mineral wool fiber Perlite Portland Cement Soapstone Talc (nonasbestiform) Talc (fibrous), use Asbestos limit. Tremollte. see Asbestos. 5flbers/cc> 5/jn in length**; Ala 15 mppcf 20 mppcf 10 mg/m3 30 mppcf 30 mppcf 20 mppcf 20 mppcf COAL DUST 2 mg/m3 (respirabte dust fraction <5% quartz), if > 5% quartz, use respirable mass formula. NUISANCE PARTICULATES (see Appendix E) 30 mppcf or 10 mg/m3n of total dust < 1 % quartz, or, 5 mg/m3 respirable dust. Conversion factors: mppcf x 35.3 = Million particles per cubic meter particles per c.c. i) Millions of particles per cubic foot of air, based on impinger samples counted by light-field technics. j) The percentage of quartz in the formula is the amount determined from airborne samples, except in those instances in which other methods have been shown to be applicable. k) Both concentration and percent quartz for the appli cation of this limit are to be determined from the fraction passing a size-selector with the following characteristics: tA more stringent TLV (or oocidoEte may be required. I), n) See p. 34. 33 jrtm inaaTtiafriJ < RSV 0011275 r pH; Aerodynamic Diameter (^m) (wit density sphere) =; 2 2.5 3.5 5.0 10 % passing selector 90 75 50 25 0 l) containing <1% quartz; if quartz content > 1%, use formulas for quartz. m) lint-free dust as measured by the vertical-elutriator, cotton-dust sampler described in the Transactions of the National Conference on Cotton Oust, J. R. Lynch, Pff. 33, Way 2, 1970. n) As determined by the membrane filter method at 40O-45QX magnification {4 mm objective) phase con trast Rumination. o) Based on "high volume" sampling. p) "Respirable" dust as defined by the British Medical Research Council Criteria (1) and as sampled by a cevice producing equivalent results (2). (1) Hatch, T. E. and Gross, P., Pulmonary Deposi tion and Retention of inhaled Aerosols, p. 149. Academic Press, New York, New York, 19S4. :2) Interim Guide (or Respirable Mass Sampling, AIHA Aerosol Technology Committee, AHIA J. 31:2, 1970, p. 133. NOTICE OF INTENDED CHANGES (tor 1977) These substances, with Iheir corresponding values, comprise those for which either a limit has been pro posed for the first time, or for which a change in the "Adopted" listing 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, tf, after two years no evidence comes to Eight that ques tions the appropriateness of the values herein, the val ues will be reconsidered for the "Adopted" list. Docu mentation is available for each of these substances. 34 Substance Aliphatic schrent "140 Rash" t Aluminum metal and wide.... t Aluminum pyro powders....... t Aluminum welding fumes..... t Aluminum, soluble salts........ ? Aluminum a&yis (NQQ*........ 13-Amino 1,2.4-triazole........ t Antimony, soluble salts (as Sb).................................. Antimony Stiaode, handling & use (as a)....................... Antimony saodde production (asSb)._.......................... Arsenic trioode production (as As)-........................... Atra2ine. -........................ t Benomyl - ......... -........... t Bromaril..... ......................... Butyl acrytSe........................ C Cadmium Gride production (as Cd)..... ....................... Calcium hydroxide................ Calcium erode....................... Carbonyl fluoride.................. Chloroform............. ............. + Chloromethyi methyl ether.... Chromite ore processing (chroma), as Cr............. t cobait ms^, dust & fume (as Co).................................. t Cyclopentaie........................ Oichioronxnofluoromethane.. Dimethyl csrtamyl chloride... + Ethyl silicas.......................... *C Glutaraldshyde...................... + HexachloroCutadiene............ ppm mg/m3*' 25 150 -- 10 --5 --5 --2 --2 A2 -- --2 -- 0.5 -- 0.05, A2 -- 0.05, Ala -- 10 -- 10 -- 10 10 55 -- -- -- 5 10, A2 Alb 0.05, A2 5 2 15 50 Alb -- 0.05. Ala -- 0.05 300 850 500 2,100 A2 A2 10 85 0.2 0.8 A2 A2 Capital tetters refer xApoencics. *1977 Revision ar .Utibon. 'Not otherwise czssned. 35 1 `-9W ' RSV 0011276 r Substance ppm** m g/m3* Hexamethyl phosphoramide -- Skin.... vtLead chromate (as Cr).......... + Manganese fume (as Mn)..... Manganese tetroxide............. 4,4'-Methylene dianiline....... N. Methyi-2-pyrrolidone........ Nickel sulfide roasting (as Ni) Paraquat, respirable sizes..... t Phenyl-beta-naphthylamine... Phenyl mercaptan................. Phosgene................. ............ m-Phthalodinitrile................. C Propylene glycol dinitrate-Skin..................... Thioglycolic acid................... C 1, 2, 4-Trichlorobenzene....... Trimethyl phosphite.............. C 2, 4, b-Trinitrotoluene (TNT). Valeraldehyde....................... i Vinyl bromide....................... Vinyl chloride....................... t VM & P Naphtha................... A2 A2 -- 0.05, A2 --1 --1 -- A2 100 400 -- 1, Ala -- 0.1 A2 A2 0.5 2 0.1 0.4 --5 0.2 1 5 0.5 -- 50 5 Pending. Ale 300 2 5 40 2.6 0.5 175 22 -- 1,350 NOTICE OF INTENDED CHANGES MINERAL DUSTS Substance Silica, amorphous... Diatomaceous earth, natural ....*.......... TLV 5 mg/m3 Total dust (all sampled sizes)' 2 mg/m3 Respirable dust (< 5 /im) 1.5 mg/m3, Respirable dust Capital letters refer to Appendices. tl977 Addition. 36 APPENDIX A CARCINOGENS The Committee lists below those substances in in* dustriaf use that have proven carcinogenic in man, or have induced cancer in animals under appropriate exper imental conditions. Present fisting of those substances carcinogenic for man takes three forms: Those for which a TLV has been assigned (la), those for which environ* mental conditions have not been sufficiently defined to assign a TLV (1b), and (1c), those whose reassignment of a TLV is awaiting more definitive data, and hence should be treated as a 1b carcinogen. Ala. Homan Carcinogens. Substances, or substances associated with industrial processes, recognized to have carcinogenic or cocarcinogenic potential, with an assigned TLV: TLV Arsenic trioxide production As203, 0.05 mg/m3 as As S02i C 5.0 ppm Sb203, 0.5 mg/m3 (as Sb) Asbestos, all forms* 5 fibers/cc, >5 in length bis (Chloromethyl) ether 0.001 ppm Chromite ore processing (chromate). 0.05 mg/m3 (as Cr) Nickel sulfide roasting, fume & dust 1.0 mg/m3{as Ni) Particulate Pofycyclic Aromatic Hydrocarbons (PPAH) 0.2 mg/m3, as benzene solubles 1b. Human Carcinogens. Substances, or substances associated with industrial processes, recognized to 'Cigarette smoking can enhance the incidence of bronchogenic carcinoma from this and others at these subsances or pro cesses. 37 li i i MS % i. ! t ------ >. RSV 0011277 have carcinogenic potential without an assigned TLV: 4-Aminodiphenyl (p-Xenyfamine) Benzidine production beta-Naphthylamine 4-Nitrodiphenyl 1c. Human Carcinogens- Substances with recognized carcinogenic potential awaiting reassignment of TLV pending further data acquisition: Vinyl chloride For the substances in 1b, no exposure or contact by any route -- respiratory, skin or oral, as de tected by the most sensitive methods -- shall be permitted. "No exposure or contact" means hermitizing the process or operation by the best practicable engi neering methods. The worker should be property equipped to insure virtually no contact with the carcinogen. A2. industrial Substances Suspect of Carcinogenic Po tential lor MAN. Chemical substances or sub stances associated with industrial processes, which are suspect of inducing cancer, based on either (1) limited epidemiologic evidence, exclusive of clinical reports of single cases, or (2) demon* stration of rarcinogenesis in one or more animal species by appropriate methods. Antimony trioxide production* Benzene -- Skin Benz(a)pyrene Beryllium Cadmium oxide production Chloroform Chromates of lead and zinc (as CO 3, 3'-0ichlorobenzidine Oimethylcarbamyi chloride 0.05 mg/m3 10 ppm 2.0 ^g/m3 0.05 mg/m3 10 ppm 0.05 mg/m3 *CiQireZB smoking car enhance the mcider.ee of respiratory careen from this or others of these substances or processes. 38 1,1-Dimethyl hydrazine Dimethyl sulfate Epichlortiydrin Hexamethyl phosphoramide -- Skin Hydrazine 4,4'-Methyfene bis (2-chloroaniline) -- Skin 4,4'-Methyiene dianiline Monomethyl hydrazine Nitrosamines Propane sultone beta-Propiolactone Wnyl cyclohexene dioxide 0.5 ppm 1 ppm 5 ppm ------0.1 ppm 0.02 ppm ------. 0.2 ppm -------------10 ppm For the above, worker exposure by all routes should be carefully controlled to levels consistent with the animal and human experience data (see Documentation), including those substances with a listed TLV. A3. Guidelines for the Classification of Experimental ANIMAL Carcinogens. The following guidelines are offered in the present state of knowledge as an aid in classifying substances in the occupational envi ronment found to be carcinogenic in experimental animals. A need was felt by the Threshold Limits Committee for such a classification in order to take the first step in developing an appropriate TLV tor occupational exposure. Determination of Approximate Threshold of Re sponse Requirement. In order to determine in which category to classify an experimental carcin ogen for the purpose of assigning an industrial air limit (TLV), an approximate threshold of neoplastic response must be determined. Because of practi cal experimental difficulties, a precisely defined threshold cannot be attained. For the purposes of standard-setting, this is of little moment, as an ap propriate risk, or safety, factor cen be applied to the approximate threshold, the magnitude of which 39 RSV 0011278 i`Y is dependent on the degree of potency of the car* dnogenic response. To obtain the best 'practical' threshold of neoplas tic response, dosage decrements should be less than logarithmic. This becomes particularly Impor tant at levels greater than 10 ppm (or correspond ing mg/m3). Accordingly, after a range-finding de termination has been made by logarithmic decreases, two additional dosage levels are re quired within the levels of "effect" and "no effect" to approximate the true threshold of neoplastic re sponse. The second step should attempt to establish a me tabolic relationship between animal and man for the particular substance found carcinogenic in an imals. if the metabolic pathways are found compa rable, the substance should be classed highly sus pect as a carcinogen for man. If no such relation is found, the substance should remain listed as an experimental animal carcinogen until evidence to the contrary is found. Proposed Classification of Experimental Animal Carcinogens. Substances occurring in the occupa tional environment found carcinogenic ter animals may be grouped into three classes, those of high, intermediate and low potency. In evaluating the in cidence of animal cancers, significant incioence of cancer is defined as a neoplastic response which represents, in the judgment of the Committee, a significant excess of cancers above that occurring in negative controls. EXCEPTIONS: No substance is to be considered an occupational carcinogen of any practical signifi cance which reacts by the respiratory route at or above 1000 mg/m3 for the mouse, 2000 mg/m3 lor the rat; by the dermal route, at or above 1500 mg/kg for the mouse, 3000 mg/kg for the rat; by the gastrointestinal route at or above 500 mg/kg/d for a lifetime, equivalent to about 100 g T.D. for the rat. lOg T.D. for the mouse. 40 These dosage Imitations exclude such substances as dioxane and trichlorethyiene from consideration as carcinogens. Examples: Dioxane -- rats, hepatocellular and nasal tumors from 1015 mg/kg/d, oral Trichloroethylene -- female mice, tumors (30/98 @ 900 mg/kg/d), oral A3a. INDUSTRIAL SUBSTANCES OF HIGH CARCINO GENIC POTENCY IN EXPERIMENTAL ANIMALS 1. A substance to qualify as a carcinogen of high potency must fulfill one of the three following conditions in two animal species: la. Respiratory. Bicit cancer from (1) dosages below 1 mg/m3 (or equivalent ppm) via the respiratory tract in 6- 7-hour daily repeated inhalation exposures throughout lifetime; or (2) from a single intratracheally admin istered dose not exceeding 1 mg of parti culate. or liquid, per 100 ml or less of an imal minute respiratory volume; Examples: bis-Chloromethyi ether, malign ant tumors, rats. @ 0.47 mg/m3 (0.1 ppm) in 2 years; Hexamethyl phosphoramide, nasal squamous ceil carcino ma, rats, @ 0.05 ppm, in 13 months OR lb. Dermal. Bicit cancer within 20 weeks by skin-painting, twice weekly at 2 mg/kg body weight or less per application for a lotaf dose equal to or less than 1.5 mg. in a biologically inert vehicle; Examples: 7, 12-Dimethylbenz (a) anthra cene -- skin tumors @ 0.120.8 mg T.D. in four weeks 41 RSV 0011279 l mi 1^ I r ( Benz(a)pyrene, mice 12 /xg. 3X/wk for 18 mos. T.D. 2.6 mg, 90.9% skin tumors OR 1c. Gastrointestinal. Elicit cancer by daily in take via the gastrointestinal tract, within six months, with a six-month holding period, at a dosage below 1 mg/kg body weight per day; total dose, rat, 50 mg: mouse, 3.5 mg; Examples: 7, t2-Dimethylbenz(a)anthracene -- mammary tumors from 10 mg IX 3-Methylcholanthrene -- Tumors @ 3 sites from 8 mg in 89 weeks Benz(a)pyrene, mice. 3.9% leukemias, from 30 mg T.D. 198 days 2. Elicit cancer by all three routes in at least two animai species at dose levels prescribed for high or intermediate potency. i3b. INDUSTRIAL SUBSTANCES OF INTERMEDIATE CARCINOGENIC POTENCY IN EXPERIMENTAL AN IMALS To qualify as a carcinogen of intermediate potency, a substance should elicit cancer in two animal spe cies at cosages intermediate between those de scribed in A3a and A3c by two routes c: adminis tration. Example: Carbarnic acid Elhyl Ester Dermal, mammary turners, mice. 100%, 63 weeks, 500-1400 mg T.D. Gastrointestinal, various type tumors, mice 42 weeks, 320 mg T.D. Gastrointestinal, various type tumors, rats, 60 weeks, 110-930 mg T.D. 42 A3c. INDUSTRIAL SUBSTANCES OF LOW CARCINO GENIC POTENCY IN EXPERIMENTAL ANIMALS To qualify as a carcinogen of low potency, a sub stance should elicit cancer in one animal species by any one of three routes of administration at the following prescribed dosages and conditions: la. Respiratory. Elicit cancer from (1) dosages greater than 10 mg/m3 (or equivalent ppm) via the respiratory tract in 5- 7-hour, daily re peated inhalation exposures, for 12 months' exposure and 12 months' observation period; or (2) from intratracheally administered dos ages totaling more than 10 mg of particulate or liquid per 100 ml or more of animai minute respiratory volume; Examples: Beryl (beryllium aluminum silicate) malig. lung tumors, rats, @ 15 mg/m3 @ 17 months Benzidine, vat. tumors, rats, 10-20 mg/m3 @ > 13 mos. OR lb. Dermal. Elicit cancer by skin-painting of mice in twice weekly dosages of > 10 mg/kg body weight in a biologically inert vehicle for at least 75 weeks, i.e., a 1.5g T.D. Examples: Shale tar, mouse, 0.1 ml x 50 gT.D. 59/60 skin tumors Arsenic trioxide, man, dose un known, but estimated to be high lc. Gastrointestinal. Elicit cancer from daily oral dosages of 50 mg/kg/day or greater during the lifetime of the animai. APPENDIX B SUBSTANCES OF VARIABLE COMPOSITION Bl Polytetrafluoroethylene* decomposition products. Thermal decomposition of the fluorocarbon chain in `Trade Names: AJgoflon. Ftuon. Halon, Teflon. Tetran. 43 t L---------RSV 0011280 r. air leads to the formation of oxidized products con* taining carbon, fluorine and oxygen. Because these products decompose in part by hydrolysis in alkaline solution, they can be quantitatively determined in air as fluoride to provide an index of exposure. No TLV is recommended pending determination of the toxi city of the products, but air concentrations should be minimal. B2 Gasolinei The composition of gasoline varies greatly and thus a single TLV for all types of these materials is no longer applicable. In general, the aromatic hy drocarbon content will determine what TLV applies. Consequently the content of benzene, other aromat ics and additives should be determined to arrive at the appropriate TLV (Elkins, et al. A.I.H.A.J. 24:99, 1963); Bunion, ibid. 36, 338,1975).' 33 Welding Fumes--Total Paniculate (NOC)' TLV. 5 mgtnP Welding fumes cannot be classified simply. The com position and quantity of both are dependent on the alloy being welded and the process and electrodes used. Reli able analysis of fumes cannot be made without consider ing 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 atmo sphere such as argon. These arcs create relatively little fume, but 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 which generate considerable fume, and can produce carbon monoxide instead of ozone. Such fumes generally are composed of discreet particles of amorphous slags con taining iron, manganese, silicon and other metallic con stituents depending on the alloy system involved. Chro mium and nickel compounds are found in fumes when stainless steels are arc-welded. Some coated and fluxcored electrodes are formulated with fluorides and the *Not otherwise classified. 44 fumes associated with them can contain significantly more fluorides than oxides. Because of the above fac tors, arc-welding fumes frequently must be tested for individual constituents which are likely to be present to determine whether specific TLVs are exceeded. Conclu sions 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 MIXTURES C.1 THRESHOLD LIMIT VALUES FOR MIXTURES When two or more hazardous substances are pres ent, their combined effect, rather than that of either indi vidually, should be given primary consideration; 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. Ci ^ Ca TT+~T2 + exceeds unity, then the threshold limit of the mixture should be considered as being exceeded. Ci indicates die observed atmospheric concentration, and T1 the cor responding threshold limit (See Example 1A.a. and 1A.c.). Exceptions to the above rule may be made when there is a good reason to believe that the chief effects of die 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 compo nents of the mixture. In such cases the threshold limit ordinarily is exceeded only when at least one member of C C\ ( + or + etc.J itself has a value exceeding unity (See Example 1A.c.). 45 RSV 001128 X* Antagonistic action or potentiation may occur with some combinations of atmospheric contaminants. Such cases at present must be determined individually. Poten tiating or antagonistic agents are not necessarily harmful by themselves. Potentiating effects of exposure to such agents by routes other than that of inhalation is also possible, e.g. imbibed alcohol and inhaled narcotic (trichloroethylene). Potentiation is characteristically exhi bited 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 frequently be only feasible to attempt to evaluate the hazard by measurement of a single sub stance. In such cases, the threshold limit used for this substance should be reduced by a suitable factor, the magnitude of which will depend on the number, toxicity and relative quantity of the other contaminants ordinarily present. Examples of processes which are typically associated with two or more harmful atmospheric contaminants are welding, automobile repair, blasting, painting, lacquer ing, certain foundry operations, diesel exhauts, etc. CAA Examples of THRESHOLD UMIT VALUES FOR MIXTURES The following formulae apply only when the compo nents in a mixture have similar toxicologic effects; they should not be used for mixtures with widely differing reactivities, e.g. hydrogen cyanide & sulfur dioxide. In such case the formula for Independent Effects (lA.c.) should be used. lA.a. General case, where air is analyzed for each com ponent: a. Additive effects. (Note: It is essential that the atmosphere be analyzed both qualitatively and quantitatively for each component present, in order to evaluate compliance or noncom pliance with this calculated TLV.) Ci . Cj , Ca Ti *1 46 Example No. lA.a.: Air contains 5 ppm of carbontetrachloride (TLV * 10 ppm) 20 ppm of 1, 2-dichloroethane (TLV - 50 ppm) and 10 ppm of 1. 2-dibromoethane (TLV = 20 ppm) Atmospheric concentration of mix ture = 5 + 20 + 10 ** 35 ppm of mixture 5 20 10 25 + 20 + 25 10 50 20 50 1.4 Threshold Limit is exceeded. Furth ermore, the TLV of this mixture may be calculated by reducing the total fraction to 1.0; i.e. 35 TLV of mixture ^ = 25 ppm lA.b. Special case when the source of contaminant is a liquid mixture and the atmospheric composition is assumed to be simitar to that of the original mate rial; e.g. on a time-weighted average exposure basis, all of the liquid (solvent) mixture eventually evaporates. Additive effects (approximate solution) 1. The percent composition (by weight) of the liquid mixture is known, the TLVs of the constituents must be listed in mg/m3. (iVofe: In order to evaluate compliance with this TLV, field sampling instruments should be calibrated, in the laboratory, for response to this specific quantitative and qualitative airvapor mixture, and also to fractional concen trations of this mixture; e.g., 112 the TLV; 1 no the TLV; 2 x the TLV; 10 x the TLV; etc.) TLV of mixture = 1 TLV. TLV. TLVC 47 TLV. *TTT* ri < -i RSV 00X1282 i Example No. 1: Liquid contains (by weight) 50% heptane: TIV a 400 ppm or 1600 mg/m3 1 mg/m3 0.25 ppm 30% methylene chloride: TLV * 200 ppm or 720 mg/m3 1 mg/m3 * 0.28 ppm 20% perchioroethylene: TIV * 100 ppm or 670 mg/m3 1 mg/m3 s 0.15 ppm TLV of Mixture = ^ -d g 1600 + 720 + 67Q 1 0.00031 + 0.00042 + 0.00030 = o^=970m9/m3 of this mixture 50% or (970) (0.5) = 485 mg/m3 is heptane 30% or (970) <0.3) = 291 mg/m3 is methylene chloride 20% or (970) (0.2) * 194 mg/m3 is perchioroethylene These values can be converted to ppm as follows: heptane: 485 mg/m3 x 0.25 = 121 ppm methylene chloride: 291 mg/m3 x 0.28 = 81 ppm perchioroethylene: 194 mg/m3 x 0.15 = 29 ppm TLV of mixture = 121 + 81 + 29 = 231 ppm. or 970 mg/m3 lA.c. Independent effects. Air contains 0.15 mg/m3 of lead (TLV, 0.15) and 0.7 mg/m3 of sulfuric acid (TLV. 1). Threshold limit is not exceeded. IB. TLV for Mixtures of Mineral Dusts. For mixtures of biologically active mineral dusts the general formula for mixtures may be used. 48 For mixture containing 80% nortasbestiform talc and 20% quartz, the TLV for 100% of the mixture is given by: uv=nrLn:=9mppcf 20 + 2.7 TLV of norwsbestiform talc (pure) = 20 mppcf TLV of quartz (pure) = 300 300 = 2.7 mppcf 100 + 10 110 Essentially the same result will be obtained if the limit of the more (most) toxic component is used provided the effects are additive. In the above ex ample the Omit for 20% quartz is 10 mppcf. For another mixture of 25% quartz, 25% amor phous silica and 50% talc: 25% quartz -- TLV (pure) = 2.7 mppcf 25% amorphous silica -- TLV (pure) = mppcf 50% talc TLV (pure) = 20 mppcf 1 TLV 0.25 0.25 ^-=8 mppcf 2.7 20 20 The limit for 25% quartz approximates 9 mppcf. APPENDIX D PERMISSIBLE EXCURSIONS FOR TIME- WEIGHTED AVERAGE (TWA) LIMITS The Excursion TLV Factor in the Table automatically defines the magnitude of the permissible excursion above the limit for those substances not given a **C" designation: i.e., the TWA limits. Examples in the Table show that nitrobenzene, the TLV for which is 1 ppm, should never be allowed to exceed 3 ppm. Similarly, carbon tetrachloride, TLV = 10 ppm, should never be allowed to exceed 2D ppm. By contrast, those sub stances with a "C" designation are not subject to the excursion facor and must be kept si or below the TLV ceiling. 49 * RSV 0011283 I V2t XT. These limiting excursions are to be considered to provide a "rule-of-thumb" guidance for listed sub stances generally, and may not provide the most appro priate excursion for a particular substance e.g. the per missible excursion for CO is 400 ppm for 15 minutes. For appropriate excursions for 142 substances con sult Pa. Rules & Regs., Chap, 4, Art 432, and "Accept able Concentrations," ANSI, Substance Nitrobenzene Carbon tetrachloride Trimethyl benzene Acetone Boron trifluoride Butylamine TLV 1 10 25 1000 Cl C5 Excursion Factor 3 2 1.5 1.25 -- -- Max. Cone. Permitted for short time 3 20 40 1250 1 5 the question of interpretation of essentially "instanta neous" peaks arises. Although no general statement can be made covering ail occupational substances, the fol lowing guidelines should prove helpful, assuming peak excursions conform to time-weighted average TIV as stated above. The toxicologic importance of momentary peak con centrations depends on whether the substance is fast or slow acting. If slow acting, as for quartz, lead, or car bon monoxide, momentary-peaks are of no toxicologic concern provided, of course, they are not astronomic. On the other hand, fast-acting substances that rapidly produce disabling narcosis, e.g., H2S, or intolerable irri tation or asphyxiation, NHa, S02l C02, or initiate sensitiza tion -- the organic isocyanates, even `'instantaneous" peaks appreciably above the permissible excursion, should not be permitted, unless information exists to the contrary. Other more specific excursions will be devel oped in the future. EXCURSION FACTORS For all substances not bearing C notation 7LV>0-1 (ppm of mg/m3), TIV >1-10 TLV>10-100 TIV>10G-1000 Excursion Factor =3 *2 1.5 = 1.25 The number of times the excursion above the TIV is permitted is governed by conformity with the TimeWeighted Average TIV. INTERPRETATION OF MEASURED PEAK CONCENTRATIONS With increasing use of rapid, direct-reading analytical instruments for airborne contaminants in the work area, 50 APPENOIX E Some Nuisance Particulates** TLV. 30 mppcf or 10mg/m3 Alundum (Al203) Calcium carbonate Calcium silicate Cellulose (paper fiber) Portland Cement Corundum (AJ203) Emery Glass. fibrous* or dust Glycerin Mist Graphite (synthetic) Gypsum Vegetable oil miste (except castor, cashew nut, or similar irritant oils) Kaolin Limestone Magnesite Marble Mineral Wool Fiber Pentaerythritol Plaster of Paris Rouge Silicon Silicon Carbide Starch Sucrose Tin Oxide Titanium Dioxide Zinc Stearate Zinc oxide dust 51 ! H 1 E JL RSV 0011284 q) When toxic impurities are not present, e.g. quartz < r) <7fjn in diameter APPENDIX F Some Simple Asphyxiants*' Acetylene Argon 8utane Ethane Ethylene Helium Hydrogen Methane Neon Propane Propylene s) As defined on pg. 6. MrrcnuiA U Calculations for Conversion of Particle Count Concen tration (by Standard Light Field -- Midget Impinger Techniques), in mppcf, to Respirable Mass Concentra tion (by Respirable Sampler) in mg/m3 t 1. In 1967, Jacobsen and Tomb, t derived an empiri cal relationship of 5.6 mppcf to 1 milligram of respirable dust per cubic meter of air, based on 23 sets of samples, mostly coal dust. The follow ing calculation results in an equivalence of 8.37 mppcf to 1 mg/m3 of respirable dust. Thus, an approximate ratio of 6 mppcf to 1 mg/m3 of re spirable cfusl is suggested for conversion of TLVs from a count to a mass basis when the density and mass median diameter have not been deter mined. f'Relationahip Between Gfjvimevic Respirable Dust Concentration ano Midflei Imping/ Humber Concentntwi." by Murray Jacobson and T. F. Tome. AIHAJ. 28: Nov.-Oec. 1967. 52 2. Basic assumptions: a) Average density for silica containing dusts * 2.5 gms/cm3 (2500 mg/cm3). Pulmonary sig nificant dust densities may vary from 1.2 gm/cm3 for coal dust to 3.1 gms/cm3 for Portland Cement. Silica densities vary from 2.2 (amorphous) to 2.3 (cristobalrte and tridymrte) to 2.5 (alpha-quartz.) gms per cm3. b) The mass median diameter (mmd) of particles collected in midget impinger samplers and counted by the standard light field technique. and collected in a respirable sampler is ap proximately 1.5 pc/n or 1.5 x 10--* cm. This assumption is, of course, quite arbitrary since the mmd of all dust clouds is quite variable, depending on many independent parameters, such as source of dust, age of dust cloud, me teorological conditions, etc. 3. Calculation: a) vol. per particle: 4/3 rr r3; r = 0.75 x 10-* cm 4/3 (0.75 x 10-4)3 =s t.77 x I0"12cm3 b) wt. per particle = vol. x density 1.77 x J0_1acm3 x 2.5 x ID3 mg/cm3 4.425 x 10~ mg/particle c) 1 partide/ft-3 = 35.5 part./m3 (since 35.5 cu ft * 1 cu m.) 10* part./ft3 = mppcf 35.5 x 10* part./m3 wl. of 1 mppcf 35.5 x 10* part./m3 x 4.425 x 1Q-* mg/part. 1 mppcf m 0.157 mg/m3 or 6.37 mppcf 1 mg/m3 or approximately 6 mpeef f mg/m3. 4. Equivalent TLVs in mppcf and mg/m3 (respirable mass) for Mineral Dusts. 53 a. ;i RSV 0011285