Document gD81Qp5vLGZXKeDeLKp4m9VeQ

TLVs Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1972 w b* o b* BFG08838 Copyright 1972 by American Conference of Governmental Industrial Hygienists. The American Conference of Govern mental Industrial Hygienists will welcome requests for permission to republish or re print these Threshold Limit Values. Re quests for such permission should be directed to the Secretary-Treasurer, P.O. Box 1937, Cincinnati, Ohio 45201. PRICE EACH 1-49............................................................. 7H 50-200......................................................... 65f! Quantities over 200, prices upon request Documentation of the Threshold Limit Values for Substances in Workroom Air. A separate companion piece to the Airborne 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 contains a statement defining the type of response against which the limit is safeguarding the worker. For a better understanding of the TLVs it is essential that the Documentation 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 Chairman, TLV Committee. TLVs Threshold Limit Val ues for Substance in Workroom Air Adopted by ACGIH for 1972 t: 1027003 BFG08839 1972 TLV AIRBORNE CONTAMINANTS COMMITTEE Hector P. Blejer, M.D., D.I.H. Paul E. Caplan, P.E., M.P.H. William Durham, Ph.D. Hcrvcy B. Elkins, Ph.D. W.G. Frederick, Sc.D. Bernard Grabois, P.E. Paul Gross, M.D. John W. Knauber, M.P.H. Harold N. MacFarland, Ph.D. Frederick T. McDermott, P.E. E. Mastromatteo, M.D. Col. Walter W. Melvin, Jr., M.D. Ralph G. Smith, Ph.D. Mitchell R. Zavon, M.D. Herbert E. Stokinger, Ph.D., Chairman William D. Wagner, Recording Secretary LIAISON MEMBERS David A. Padden, Labor Union James F. Morgan, Industry Vernon K. Rowe, Industry Theodore R. Torkelson, Sc.D., Alternate 21027004 PREFACE AIRBORNE CONTAMINANTS Threshold limit values refer to airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect. Be cause of wide variation in individual suscep tibility, however, a small percentage of workers may experience discomfort from some substances at concentrations at or below the threshold limit, a smaller per centage may be affected more seriously by aggravation of a pre-existing condition or by development of an occupational illness. Simple tests are now available (J. Occup. Med. 9: 537, 1967; Ann. N.Y. Acad. Sci., 151, Art. 2: 968, 1968) that may be used to detect those individuals hypersusceptible to a variety of industrial chemicals (respira tory irritants, hemolytic chemicals, organic isocyanates, carbon disulfide). These tests may be used to screen out by appropriate job placement the hyperreactive worker and thus in effect improve this "coverage" of the TLVs. Threshold limit values refer to timeweighted concentrations for a 7 or 8-hour workday and 40-hour workweek. They should be used as guides in the control of health hazards and should not be used as fine lines between safe and dangerous con centrations. (Exceptions are the substances listed in Appendices B and F and those substances designated with a "C" or Ceiling value. Appendix D) Time-weighted averages permit excur sions above the limit provided they are 1027005 BFG08840 'T compensated by equivalent excursions below the limit during the workday. In some in stances 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 between 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 contaminant, whether very high concentrations -- even for short periods -- produce acute poison ing, whether the effects are cumulative, the frequency with which high concentrations occur, and the duration of such periods. All factors must be taken into consideration in arriving at decision as to whether a hazardous condition exists. Threshold limits are based on the best available information from industrial ex perience, from experimental human and animal studies, and, when possible, from a 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 guiding 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 of the information available for establishing a TLV varies from substance to substance; consequently, the 2id27006 precision of the estimated TLV is also sub ject to variation and the latest Documenta tion 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 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. In spite of the fact that serious injury is not believed likely as a result of exposure to the threshold limit concentrations, the best practice is to maintain concentrations of all atmospheric contaminants as low as is practical. These limits are intended for use in the practice of industrial hygiene and should be interpreted and applied only by a person trained in this discipline. They are not in tended for use, or for modification for use, (1) as a relative index of hazard or toxicity, (2) in the evaluation or air pollution nui sances, (3) in estimating the toxic potential of continuous, uninterrupted exposures, (4) as proof or disproof of an existing disease or physical condition, or (5) for adoption by countries whose working conditions differ from those in the United States of America and where substances and pro cesses differ. Ceiling vs Time-Weighted, Average Limits. Although the time-weighted average con centration provides the most satisfactory, 3 LmLZQ'XZ BFG08841 practical way. of monitoring airborne agents for compliance with the limits, there are certain substances for which it is inappro priate. In the latter group are substances which are predominantly fast acting and whose threshold limit is more appropriately based on this particular response. Sub stances with this type of response are best controlled by a ceiling "C" limit that should not be exceeded. It is implicit in these definitions that the; manner of sampling to determine compliance 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 complete 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 excur sions may be pegged to the magnitude of the threshold limit by an appropriate factor shown in Appendix D. It should be noted that the same factors are used by the Com mittee in making a judgment whether to in clude or exclude a substance for a "C" listing. "Skin" Notation. Listed substances fol lowed by the designation "Skin" refer to the potential contribution to the overall expo sure by the cutaneous route including mucuous membranes and eye, either by airborne, or more particularly, by direct contact with the substance. Vehicles can 2102^008 alter skin absorption. This attention-calling designation is intended to suggest appro priate measures for the prevention of cu taneous 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 mixtures of two or more substances. A brief discussion of basic considerations involved in develop ing threshold limit values for mixtures, and methods for their development, amplified by specific examples are given in Appendix C. Nuisance Particulates. 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. The nuisance dusts have also been called (biologically) "inert" dusts, but the latter term is inappro priate 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 inhalation of nuisance dusts has the following characteristics: 1) The archi tecture of the air spaces remains intact. 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 (iron oxide), may cause unpleasant deposits in the eyes, ears and nasal passages 5 ^ 1027009 BFG08842 T (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 procedures necessary for their removal. A threshold limit of 10mg/m3, or 30 mppcf, of total dust < 1 % quartz is recom mended for substances in these categories and for which no specific threshold limits have been assigned. This limit, for 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 concentra tions but for which a threshold limit has not yet been adopted. Some nuisance particu lates are given in Appendix E. 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 other significant phj-siologic effects. A TLV may not be recommended for each simple asphyxiant because the limiting factor is the available oxygen. The minimal oxygen con tent should be 18 percent by volume under normal atmospheric pressure (equivalent to a partial pressure, p02 of 135 mm Hg). Atmospheres deficient in Cfe do not provide adequate warning and most simple asphyx iants are odorless. Several simple asphyx iants present an explosion hazard. Account should be taken of this factor in limiting the concentration of the asphyxiant. Specific examples are listed in Appendix F. Physical Factors. It is recognized that such physical factors as heat, ultraviolet and ionizing radiation, humidity, abnormal 21027010 pressure (altitude) and the like may place added stress on the body so that the effects from exposure 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 moderate deviations from normal environments, the safety factors of most substances are not of such a magnitude as to take care of gross deviations. For ex ample, continuous work at temperatures above 90F or overtime extending the work week more than 25%, might be considered gross deviations. In such instances judgment must be exercised in the proper adjustments of the threshold limit values. "Notice of Intent." At the beginning of each year, proposed actions of the Com mittee for the forthcoming year are issued in the form of a "Notice of Intended Changes." This Notice provides not only an oppor tunity for comment, but solicits suggestions of substances to be added to the list. The suggestions should be accompanied by sub stantiating 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 are now official federal standards for industrial air. Reprint Permission. This publication may be reprinted provided that written permission is obtained from the SecretaryTreasurer of the Conference and that it be published in its entirety. -7, T T 0 Z .Z 0 T BFG08843 ' 'T - ADOPTED VALUES (In Alphabetic Order) Substance ppmo) Abate................................. * Acetaldehyde................... Acetic acid....................... * Acetic anhydride............ Acetone............................. Acetonitrile....................... 2-Acetylaminofluorene -- Skin............................... Acetylene.......................... Acetylene dichloride, see 1, 2-Dichloroethylene. Acetylene tetrabromide. Acrolein............................. Acrylamide -- Skin......... Acrylonitrile -- Skin.... Aldrin -- Skin.................. Allyl alcohol-- Skin.... Allvl chloride. . .... ! Allyl glycidyl ether (AGE)........................... (AI O )Allyl propyl disulfide___ Alundum 2 3 ............ 4-Aminodiphenyl--Skin. 2-Aminoethanol, see Ethanolamine.............. 2-Aminopyridine............. Ammonia.......................... Ammonium chloride, fume.............................. Ammonium sulfamate (Ammate)..................... -- (200) 10 (5) 1,000 40 -- F -- 1 0.1 -- 20 -- 2 1 (10) 2 -- -- -- 0.5 (50) -- -- , 3*> mg/M 10 (360) 25 (20) 2,400 70 A2 -- -- 14 0.25 0.3 45 0.25 3 5 (45) 12 E A14 -- 2 (35) 10 10 Capital letters refer to Appendices. Footnotes (a thru h) see Page 29. *1972 Addition. **See Xotice of Intended Changes 21027012 Substance 3b) ppm"1 mg/M n-Amyl acetate................ sec-Amyl acetate............ Aniline -- Skin................ Anisidine (0, p-isomers) -- Skin.......................... Antimony & compounds (as Sb)........................... ANTU (alpha naphthyl thiourea)....................... Argon................................. Arsenic & compounds (as As).......................... Arsine................................ Asphalt (petroleum) fumes............................. Azinphos methyl -- Skin. Barium (soluble compounds)................. C Benzene (benzol)--Skin. Benzidine -- Skin............ p-Benzoquinone, see Quinone......................... Benzoyl peroxide............ Benzyl chloride................ Beryllium......................... Biphenyl, see Diphenyl. Boron oxide...................... Boron tribromide............ C Boron trifluoride............. Bromine............................ Bromine pentafluoride.. Bromoform -- Skin........ Butadiene (1, 3- butadiene).................... 100 125 5 -- -- -- F -- 0.05 -- -- -- 25 -- -- -- 1 -- -- -- 1 1 0.1 0.1 0.5 1,000 Capital letters refer to Appendices. 525 650 19 0.5 0.5 0.3 -- 0.5 0.2 5 0.2 0.5 80 A16 -- 5 5 0.002 -- 10 10 3 0.7 0.7 5 2,200 N HO 3 q 9 BifO08844 'T Substance 36> ppmo) mg/M Butancthiol, see Butyl mercaptan.................... ---. 2-Butanone...................... 200 2-Butoxy ethanol (Butyl Ccllosolve) -- Skin... . 50 Butyl acetate (n-butyl acetate)......................... 150 sec-Butyl acetate............ 200 tert-Butyl acetate........... 200 Butyl alcohol................... 100 sec-Butyl alcohol............ 150 tert-Butyl alcohol........... 100 C Butylamine -- Skin........ 5 C tert-Butyl chromate (as CrOs) -- Skin............. -- n-Butyl glycidyl ether (BGE).......................... 50 Butyl mercaptan............ 0.5 p-tert-Butyltoluene........ 10 Cadmium (Metal dust and soluble salts)........ ___ C Cadmium oxide fume (as Cd)................................ __ Calcium carbonate.......... Calcium arsenate............ Calcium oxide.................. -- _ ___ Camphor (Synthetic) . . . CarbarvI (Sevin)........... Carbon black................... 2 -- __ Carbon dioxide................ 5,000 Carbon disulfide -- Skin. 20 Carbon monoxide............ 50 Carbon tetrachloride -- Skin............................... 10 Cellulose (paper fiber)... -- __ 590 240 710 950 950 300 450 300 15 0.1 270 1.5 60 0.2 0.1 E 1 5 12 5 3.5 9,000 60 55 65 E Capital letters refer to Appendices. 10 2102701-4 Substance Chlordane-- Skin........... Chlorinated camphene -- Skin............................... Chlorinated diphenyl oxide.............................. Chlorine............................ Chlorine dioxide.............. C Chlorine trifluoride........ C Chloroacetaldehyde........ a-Chloroacetophenone (phenacylchloride).... Chlorobenzene (monochlorobenzene).. o-Chlorobenzylidene malononitrile (OCBM) -- Skin.......................... Chlorobromomethane.. . 2-Chloro-l, 3-butadiene see Chloroprene.......... Chlorodiphenyl (42% Chlorine) -- Skin........ Chlorodiphenyl (54% Chlorine) -- Skin........ 1-Chloro, 2, 3- epoxypropane, see Epichlorhydrin............ 2-Chloroethanol, see Ethylene chlorohydrin. Chloroethylene, see Vinyl chloride.............. **C Chloroform (trichloromethane) -- 1 -Chloro-1 -nitropropane. Chloropicrin..................... ppmo) -- -- -- 1 0.1 0.1 1 0.05 75 0.05 200 -- -- -- -- -- -- (50) 20 0.1 3&) mg/M 0.5 0.5 0.5 3 0.3 0.4 3 0.3 350 0.4 1,050 1 0.5 (240) 100 0.7 N H* O Capital letters refer to Appendices. "See Notice of Intended Changes. 11 u\ Substance ppma) Chloroprene (2-chloro-l, 3-butadienc) -- Skin . . Chromic acid and chromates (as GYO3). . Chromium, sol. chromic, chromous salts as Cr. . ** Metal & insol. salts. . . Coal tar pitch volatiles (benzene soluble frac tion) anthracene, BaP, phenanthrene, acridine, chrysene, pyrene) Cobalt, metal fume & dust............................... Copper fume.................... Dusts and Mists___ Corundum (AI2O3).......... ** Cotton Dust (raw)......... Crag herbicide............... Cresol (all isomers) -- Skin............................... Crotonaldehyde............... Cumene -- Skin.............. Cyanide (as CN) --Skin. Cjmnogen......................... Cyclohexane.................... Cyclohexanol................... Cyclohexanone................ Cyclohexene.................... Cyclopentadiene.............. 2, 4-D................................ DDT................................. DDVP, see Dichlorvos. . Decaborane -- Skin........ Demeton -- Skin.......... 25 -- --Ala Ala -- -- -- -- -- -- 5 2 50 -- 10 300 50 50 300 75 -- -- -- 0.05 -- 3&) mg/M 90 0.1 0.5 (1.0) 0.2 0.1 0.1 1 E (1) 10 22 6 245 5 -- 1,050 200 200 1,015 200 10 1 -- 0.3 0.1 **See Notice of Intended Changes. 12 ~?j0^70\5 A Substance 3&) ppm*) mg/M Diacetone alcohol (4- hydroxy-4-methyl- 2-pcntanonc)................ 50 1, 2-Diaminoethane, see Ethylenediamine........ _ Diazinon -- Skin............. -- Diazomethane................. 0.2 Diborane.......................... 0.1 **C 1, 2-Dibromoethane (ethylene dibromide) -- Skin.......................... (25) Dibrom........................... -- * 2-N Dibutylaminoethanol -- Skin.......................... 2 Dibutyl phosphate.......... 1 Dibutylphthalate............ -- C Dichloracetylene............. 0.1 C o-Dichlorobenzene.......... 50 p-Dichlorobenzene.......... 75 ** Dichlorobenzidine -- Skin.............................. _ Dichlorodifluoromethane. 1,000 1, 3-Dichloro-5, 5dimethyl hydantoin... __ ** 1, 1-Dichloroethane........ (100) 1, 2-Dichloroethane........ 50 1, 2-Dichloroethvlene. .. 200 **C Dichloroethyl ether -- Skin............................... (15) Dichloromethane, see Methylene chloride... -- Dichloromonofluoro- methane........................ 1,000 240 . 0.1 0.4 0.1 (190) 3 14 5 5 0.4 300 450 A16 4,950 0.2 (400) 200 790 (90) -- 4,200 Capital letters refer to Appendices. *1972 Addition. **See Notice of Intended Changes. 13 juDsOGfSS T Substance - , 3*> ppma) mg/M C 1, 1-Dichloro-lnitroethane................... 1, 2-DichIoropropane, see Propylenedichloride... Dichlorotetrafluoroethane........................... Dichlorvos (DDVP) -- Skin............................... Dieldrin -- Skin............... Diethylamine................... Diethylamino ethanol -- Skin............................... * Diethylene triamine -- Skin............................. Diethylether, see Ethyl ether.............................. Difluorodibromo- methane........................ C Diglvcidyl ether (DGE). Dihydroxybenzene, see Hvdroquinone............. * Diisobutyl ketone........... Diisopropylamine -- Skin............................... Dimethoxymethane, see Methylal....................... Dimethyl acetamide -- Skin............................... Dimethylamine............... 4-Dimethylaminoazobenzene......................... Dimethylaminobenzene, see Xylidene................. 10 -- 1,000 -- -- 25 10 1 -- 100 0.5 -- (50) 5 -- 10 10 -- -- 60 -- 7,000 1 0.25 75 50 4 -- 860 2.8 -- (290) 20 -- 35 18 AJ -- Capital letters refer to Appendices. *1972 Addition. 14 21027016 Substance 3W ppmo) mg/M Dimethylaniline (Ndimethylaniline) -- Skin............................... Dimethylbenzene, see Xylene........................... Dimethyl 1, 2-dibromo2-dichloroethyl phosphate, see DiBrom... . Dimethylformamide -- Skin............................... 2, 6-Dimethylheptanone, see Diisobutyl ketone. 1, 1-Dimethylhydrazine -- Skin.......................... Dimethylphthalate......... ** Dimethylsulfate -- Skin. Dinitrobenzene (all isomers) -- Skin.......... Dinitro-o-cresol -- Skin. Dinitrotoluene -- Skin. . ** Dioxane (Diethylene dioxide) -- Skin........... Diphenyl........................... Diphenyl amine.............. Diphenylmethane diisocyanate (see Methylene bisphenyl isocyanate (MDI).... Dipropylene glycol methyl ether -- Skin. Di-sec, octyl phthalate (Di-2-ethylhexylphthalate)..................... Emery............................... 5 -- -- 10 -- 0.5 (1) -- -- -- 100 0.2 -- -- 100 -- -- 25 -- -- 30 -- 1 5 (5) 1 0.2 1.5 360 1 10 -- 600 5 E **See Notice of Intended Changes. 15 tio ttc n z BFG08847 Substance ppma) Endosulfan (Thiodan) -- Skin.......................... Endrin -- Skin................ -- -- Epichlorhydrin -- Skin.. EPN --Skin.................... 5 -- 1, 2-Epoxypropane, see Propylencoxide............ 2, 3-Epoxy-l-propanol, see Glycidol................. _ Ethane.............................. F Ethanethiol, see Ethylmercaptan.......... _ Ethanolamine.................. 3 '* 2-Ethoxyethanol--Skin. (200) 2-Ethoxyethylacetate (Cellosolve acetate) -- Skin.......................... 100 Ethyl acetate.................. 400 Ethjd acrylate -- Skin... 25 Ethyl alcohol (ethanol). . 1,000 Ethylamine...................... 10 Ethyl sec-amyl ketone (5- methyl-3-heptanone).. 25 Ethyl benzene.................. 100 Ethyl bromide................ 200 Ethjd butyl ketone (3- Heptanone).................. 50 Ethyl chloride................. 1,000 Ethyl ether...................... 400 Ethvl formate.................. 100 Ethjd mercaptan............ 0.5 Ethyl silicate................... 100 Ethvlene.......................... F Ethvlene chlorohydrin -- Skin............................... 5 3&) mg/M 0.1 0.1 19 0.5 -- _ 6 (740) 540 1,400 100 1,900 18 130 435 890 230 2,600 1,200 300 1 850 -- 16 "See Xotice of Intended Changes 16 210270 IS Substance ppm"' mg/M Ethylenediamine............. Ethylene di bromide, see 1, 2-Dibromoethane... Ethylene dichloride, see 1,2-Dichloroethane... C Ethylene glycol dinitrate and/or Nitroglycerin-- Skin............................... Ethylene glycol mono methyl ether acetate (Methyl cellosolve ace tate)-- Skin................ Ethylene imine -- Skin. Ethylene oxide................ Ethylidine chloride, see 1, 1-Dichloroethane... N-Ethylmorpholine -- Skin............................... Ferbam............................. Ferrovanadium dust.... Fluoride (as F)................ ** Fluorine............................ Fluorotrichloromethane. *C Formaldehyde.................. Formic acid...................... Furfural -- Skin............... ** Furfuryl alcohol.............. Gasoline............................ Glass, fibrous10 or dust... Glycerin mist.................. Glycidol (2, 3-Epoxy-lpropanol)...................... 10 -- -- 0.2d> 25 0.5 50 -- 20 -- -- -- (0.1) 1,000 2 5 5 (50) -- -- -- 50 25 -- -- -- 120 1 90 -- 94 10 1 2.5 (0.2) 5,600 3 9 20 (200) B2 E E 150 Capital letters refer to Appendices. Footnotes (a thru h) see Page 29. *1972 Addition. "See Notice of Intended Changes 17 21027019 BFG08848 T Substance ppma) mg/M Glycol monoethyl ether, see 2-Ethoxyethanol. . -- Graphite, (Synthetic)... -- Guthion, see Azinphos- methyl...................... -- Gypsum....................... -- Hafnium........................... -- Helium......................... F Heptachlor--Skin........... -- Heptane (n-heptane).... 500 Hexachloroethane -- Skin.......................... 1 Hexachloronaphthalene -- Skin.............................. -- Hexane (n-hexane)......... 500 2-Hexanone.......................... 100 Hexone (Methyl isobutyl ketone)............................. 100 sec-Hexyl acetate............ 50 Hydrazine--Skin............. 1 Hydrogen......................... F Hydrogen bromide.......... 3 C Hydrogen chloride.......... 5 Hydrogen cyanide -- Skin................................... 10 Hydrogen fluoride.......... 3 Hydrogen peroxide......... 1 Hydrogen selenide.......... 0.05 Hydrogen sulfide............ 10 Hydroquinone..................... -- Indene................................... 10 Indium and compounds, as In.................................. -- C Iodine................................... 0.1 Iron oxide fume.................. -- -- E -- E 0.5 -- 0.5 2,000 10 0.2 1,800 410 410 300 1.3 -- 10 7 11 2 1.4 0.2 15 2 45 0.1 1 10 Capital letters refer to Appendices. 18 21027020 Substance ppma) * Iron pentacarbonyl........ Iron salts, soluble, as Fe. Isoamyl acetate.............. Isoamyl alcohol............... Isobutyl acetate.............. Isobutyl alcohol.............. ** Isophorone....................... Isopropyl acetate............ Isopropyl alcohol............ Isopropylamine............... ** Isopropylether................. Isopropyl glycidyl ether (IGE)............................ Kaolin............................... Ketene.............................. ** Lead.................................. Lead arsenate.................. Limestone........................ Lindane............................. Lithium hydride.............. L.P.G. (Liquified petroleum gas)...................... Magnesite......................... Magnesium oxide fume.. Malathion -- Skin.......... Maleic anhydride............ C Manganese and compounds, as Mn............ Marble.............................. Mercury (Alkyl com- pounds) -- Skin.......... Mercury (All forms ex- cept alkyl).................... Mesityl oxide.................. 0.01 -- 100 100 150 100 -- 250 400 5 50 -- 0.5 -- -- -- -- 1,000 -- -- -- 0.25 -- -- 25 mg/M 0.08 1 525 360 700 300 -- 950 980 12 240 E 0.9 -- 0.15 E 0.5 0.025 1,800 E 10 10 1 5 E 0.01 0.05 100 Capital letters refer to Appendices. *1972 Addition. **See Notice of Intended Changes. 19 21027021 BFG08849 Substance ppmo) mg/M Methane............................ F Mcthanethiol, sec Methyl mercaptan..................... -- Methoxychlor................... -- 2-Methoxyethanol--Skin (Methyl cellosolve). . . 25 Methyl acetate................. 200 Methyl acetylene (pro- pyne)............................. 1,000 Methyl acetylene- propadiene mixture (MAPP)........................ 1,000 Methyl acrylate -- Skin . 10 Methylal (dimethoxy- methane)....................... 1,000 Methyl alcohol (metha- nol)................................. 200 Methylamine................... 10 Methyl amyl alcohol, see Methyl isobutyl carbi- nol.................................. -- Methyl 2-cyanoacrylate. 2 Methyl isoamyl ketone. . 100 Methyl (n-amyl) ketone (2-Heptanone)............. 100 Methyl bromide -- Skin. -- Methyl butyl ketone, see 2-Hexanone.................. Methyl cellosolve -- Skin see 2-Methoxyethanol. Methyl cellosolve acetate -- Skin, see Ethylene glycol monomethyl ether acetate................ -- Methyl chloride............... 100 -- -- 10 80 610 1,650 1,800 35 3,100 260 12 -- 8 475 465 -- 210 **See Notice of Intended Changes. 20 21027022 Substance Methyl chloroform......... Mcthylcyclohexane........ * Methylcyclohexanol.... * o-Methylcyclohexanone- -- Skin........................... Methylcyclopentadienyl manganese tricarbonyl (as Mn) -- Skin........... Methyl demeton -- Skin. Methyl ethyl ketone (MEK), see 2-Bu- tanone....................... Methyl formate............... Methyl iodide -- Skin. .. Methyl isobutyl carbinol -- Skin........................... Methyl isobutyl ketone, see Hexone................... Methyl isocyanate -- Skin............................... Methyl mercaptan.......... Methyl methacrylate___ Methyl parathion--Skin. Methyl propyl ketone. see 2-Pentanone........... Methyl silicate................. ! a Methyl styrene............. 1 Methylene bisphenyl iso- cyanate (MDI)............ Methylene chloride (di- chloromethane).......... Molybdenum (soluble compounds).. (insoluble compounds). 3t) ppma) mg/M 350 500 (100) 1,900 2,000 (470) (100) (460) 0.1 0.2 -- 0.5 ---- 100 250 5 28 25 100 ---- 0.02 0.5 100 -- 0.05 1 410 0.2 ---- 5 30 100 480 0.02 0.2 (500) (1,740) --5 -- 10 Capital letters refer to Appendices. **See Notice of Intended Changes. 21 1027023 BFG08850 T' *--i mi: Substance ppmo) mg/M Monomethyl aniline -- Skin............................... 2 C Monomethyl hydrazine -- Skin.......................... 0.2 Morpholine -- Skin........ 20 Naphtha (coal tar)......... 100 Naphthalene.................... 10 /3-Naphthylamine............ -- Neon................................. F Nickel carbonyl.............. 0.001 A Nickel, metal and soluble compounds (as Ni). . . _ Nicotine -- Skin.............. -- Nitric acid........................ 2 Nitric oxide...................... 25 p-Nitroaniline -- Skin. .. 1 Nitrobenzene -- Skin-- 1 p-Nitrochlorobenzene -- Skin............................... _ 4-Nitrodi phenyl.............. -- Nitroethane..................... 100 Nitrogen........................... F C Nitrogen dioxide............. 5 Nitrogen trifluoride........ 10 Nitroglycerin -- Skin-- 0.2 Nitromethane.................. 100 1-Nitropropane................ 25 2-Nitropropane................ 25 N-Ni trosodime thylamine (dimethylnitrosoamine) -- Skin.......................... Nitrotoluene -- Skin.... 5 Nitrotrichloromethane, see Chloropicrin........... __ Nitrous oxide................... F 9 0.35 70 400 50 A" -- 0.007 1 0.5 5 30 6 5 1 A10 310 -- 9 29 2 250 90 90 A2 30 __ -- Capital letters refer to Appendices. Footnotes (a thru h) see Page 29. 22 21027024; Substance ppm"* , 3 mg/M Octachloronaphthalene -- Skin.......................... -- Octane............................... 400 Oil mist, particulate.... -- Oil mist, vapor................ <B2 Osmium tetroxide........... -- Oxalic acid....................... -- Oxygen difluoride............ 0.05 Ozone................................ 0.1 Paraquat -- Skin............ -- Parathion -- Skin............ -- Pentaborane..................... 0.005 Pe n tac h1oronaphthalene -- Skin.......................... ---- Pentachlorophenol -- Skin.......................... -- Pentaerythritol................ -- Pentane............................. 500 2-Pentanone.................... 200 Perchloroethylene........... 100 Perchloromethyl mercaptan.................... 0.1 Perchloryl fluoride.......... 3 Petroleum Distillates (naphtha)..................... >B2 Phenol -- Skin................. 5 p-Phenylene diamine -- Skin............................... -- Phenyl ether (vapor) -- 1 Phenyl ether-Diphenyl mixture (vapor).......... 1 Phenylethylene, see Styrene......................... -- Phenyl glycidyl ether (PGE)........................... 10 Footnotes (a thru h) see Page 29. 0.1 1,900 5/) -- 0.002 1 0.1 0.2 0.5 0.1 0.01 0.5 0.5 E 1,500 700 670 0.8 14 -- 19 0.1 7 7 -- ** o 60 -4 0 f ?3 V: - 01 BFG08851 Substance ppma) mg/M Phcnylhydrazine-- Skin. Phcnothiazine -- Skin... Phosdrin (Mevinphos) -- Skin.......................... Phosgene (carbonyl chlo ride) .............................. Phosphine........................ Phosphoric acid.............. Phosphorus (yellow).... Phosphorus pentachloride................................ Phosphorus pentasulfide. Phosphorus trichloride. . Phthalic anhydride........ Picric acid -- Skin.......... Pival (2-PivaIyl-l, 3- indandione).................. Plaster of Paris............... Platinum (Soluble Salts) as Pt.............................. Polychlorobiphenyls, see Chlorodiphenyls.......... Polytetrafluoroethylene decomposition prod ucts ............................... Propane............................ /S Propiolactone............... Propargyl alcohol--Skin. n-Propyl acetate............. Propyl alcohol................. n-Propyl nitrate.............. Propylene dichloride (1, 2-Dichloropropane)... Propylene glycol mono methyl ether................ 5 -- 0.1 0.3 -- -- _ -- 0.5 2 -- _ -- _ F -- 1 200 200 25 75 100 22 5 0.1 0.4 0.4 1 0.1 1 1 3 12 0.1 0.1 E 0.002 __ Bl -- A* -- 840 500 110 350 360 *1972 Addition. 2102*7026 Substance ppma) Propylene imine -- Skin. Propylene oxide.............. Propyne, see Methyl- 2 100 acetylene...................... -- Pyrethrum....................... -- Pyridine............................ 5 Quinone............................ RDX--Skin................... 0.1 -- - Rhodium, Metal fume and dusts (as Rh).... -- Soluble salts............ -- Ronnel.............................. -- * Rosin Core Solder, pyrolysis products (as formaldehyde)............. -- Rotenone (commercial).. -- Rouge............................... -- Selenium compounds (as Se)................................. -- Selenium hexafluoride. .. 0.05 Silicon carbide................. -- Silver, metal and soluble compounds................... -- Sodium fluoroacetate (1080)--Skin.............. -- Sodium hydroxide.......... -- Starch............................... -- Stibine............................... 0.1 Stoddard solvent............ Strychnine........................ 200 -- Styrene (Monomer) (Phenyl ethylene).... 100 Sucrose.............................. -- Sulfur dioxide.................. 5 Sulfur hexafluoride......... 1,000 mg/M 5 240 -- 5 15 0.4 1.5 0.1 0.001 10 0.1 5 E 0.2 0.4 E 0.01 0.05 2 E 0.5 1,150 0.15 420 E 13 6,000 *1972 Addition. ?5 iz o iz a t BFG08852 Substance ppma) Sulfuric acid.................... -- Sulfur monochloride. . .. 1 Sulfur pcntafluoride....... 0.025 Sulfuryl fluoride.............. 5 Systox, see Demeton... -- 2, 4, 5 T........................... -- Tantalum........................ -- TEDP -- Skin................ -- Teflon decomposition products....................... -- Tellurium........................ -- Tellurium hexafluoride.. 0.02 TEPP --Skin.................. -- C Terphenyls...................... 1 1, I, 1, 2-Tetraehloro-2, 2 difluoroethane.......... 500 1, 1, 2, 2-Tetrachloro-l, 2-difluoroethane.......... 500 1, 1,2, 2-Tetrachloro- ethane -- Skin............. 5 Tetrachloroethylene, see Perchloroethylene.... -- Tetrachloromethane, see Carbon tetrachloride.. -- Tetrachloronaphthalene -- Skin......................... -- Tetraethyl lead (as Pb) -- Skin......................... -- Tetrahydrofuran............ 200 Tetramethyl lead (as Pb) -- Skin......................... -- Tetramethyl succinoni- trile -- Skin.................. 0.5 Tetranitromethane......... 1 . 3W mg/M 1 6 0.25 20 -- 10 5 0.2 B1 0.1 0.2 0.05 9 4,170 4,170 35 -- -- 2 0.100*> 590 0.150 3 8 Substance ppm* mg/M- Tetryl (2, 4, 6- trinitrophenyl- methylnitramine) -- Skin.............................. -- Thallium (soluble compounds)--Skin (as Tl). Thiram........................... -- -- Tin (inorganic com- pounds, except SnH4 and SnC>2) as Sn.......... -- Tin (organic compounds) -- Skin (as Sn)............ Tin oxide......................... Titanium dioxide............ ** Toluene (toluol).............. -- -- -- -- C Toluene-2, 4- diisocyanate................ 0.02 o-Toluidine...................... 5 Toxaphene, see Chlori- nated camphene.......... -- Tributyl phosphate........ -- 1, 1, 1-Trichloroethane, see Methyl chloroform. -- 1, 1, 2-Trichloroethane -- Skin.......................... 10 Trichloroethvlene........... 100 Trichloromethane, see Chloroform.................. -- Trichloronaphthalene -- Skin.............................. -- 1, 2,3-Trichloropropane. 50 1, 1, 2-Trichloro 1, 2, 2- trifluoroethane............ 1,000 Triethylamine.................. 25 1.5 0.1 5 2 0.1 E E -- 0.14 22 -- 5 -- 45 535 -- 5 300 7,600 100 Capital letters refer to Appendices. Footnotes (a thru h) see Page 29. 26 21027028 Capital letters refer to Appendices. 'See Notice of Intended Changes. 27 > ft 6z6zq tz BFG08853 T' Substance ppma> mg/M* ) Trifluoromonobromo- methane........................ 1,000 Trimethyl benzene.......... 25 2,4, 6-Trinitrophenol, see Picric acid.................... 2,4,6 -- Trinitrophenyl- -- methylnitramine, see Tetryl............................ Trinitrotoluene -- Skin.. -- Triorthocresyl phosphate..................... Triphenyl phosphate... . -- -- Tungsten & compounds, as W Soluble...................... Insoluble.................. Turpentine....................... Uranium (natural) sol -- 100 uble & insoluble com- pounds, as U................ Vanadium (V2O5), as V Dust............................... ' Fume............................. Vinyl acetate................... -- -- 10 Vinyl benzene, see Sty- rene............... ................ 1 Vinyl-bromide................. Vinyl chloride.................. -- 250 200 Vinylcyanide, see Acrylonitrile................ Vinyl toluene................... Warfarin........................... --- ' 100 -- ' Wood dust (nonallergenic)............ Xylene (xylol)................. -- 100 6,100 120 -- . 1.5 0.1 3 1 5 560 0.2 0.5 0.05 30 -- 1,100 770 480 0.1 5 435 Capital letters refer to Appendices. *1972 Addition. 21827030 Substance 3&) ppma) mg/M Xylidine -- Skin.............. Yttrium............................. Zinc chloride fume........ Zinc oxide fume............... Zirconium compounds (as Zr)........................... 5 -- -- -- -- 25 1 1 5 5 a) Parts of vapor or gas per million parts of contaminated air by volume at 25 C 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 protec tion may be necessary to avoid headache. e) < 5-7 (Am 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 concentra tions of radioisotopes in air, see U.S. De partment of Commerce, National Bureau of Standards Handbook 69, "Maximum Per missible Body Burdens and Maximum Per missible Concentrations of Radionuclides in Air and in Water for Occupational Expo sure," June 5, 1969. Also, see U.S. Depart ment of Commerce National Bureau of Standards, Handbook 59, "Permissible Dose from External Sources of Ionizing Radia tion," September 24, 1954, and addendum of April 15, 1958. A report, Basic Radiation Protection Criteria, published by the Na- 29 w 1027031 BFG08854 tional Committee on Radiation Protection, revises and modernizes the concept of the NCRP standards of 1954, 1957 and 1958; obtainable as NCRP Rept. No. 39, P.O. Box 4867, Washington, D.C. 20008. Substance MINERAL DUSTS m.p.p.e.f.') SILICA Cristobalite, Crystalline.......... Use one-half the value cal culated from the count or mass formulae for quartz. Amorphous, includ ing natural diatomaceous earth...................... 20 Quartz TLV in mppcf: 300j) % quartz + 10 TLV for respirable dust in mg/m3: 10 mg/m8t) % Respirable quartz + 2 TLV for "total dust," res pirable and nonrespirable: 30 mg/m3 % quartz + 3 Silica, fused Tridymite Use quartz formulae. Use one-half the value calculated from formulae for quartz. 2KJ27032 MINERAL DUSTS Substance m.p.p.c.f.0 SILICATES (< 1% quartz) **Asbestos, all types. Mica..................................... Perlite.................................. Portland Cement. . Soapstone........................... Talc (non-asbestiform)............................... Talc (fibrous) use asbestos limit___ Tremolite (see Talc, fibrous)............................ Graphite (natural). -- 20 30 30 20 20 -- -- 15 NUISANCE PARTICULATES (see Appendix E) 30 mp.p.p.c.f. or 10 mg/m3 of total dust <1% quartz 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 jbj which other methods have been sho^a to be applicable. ^ -------------- N> **See Notice of Intended Changes for Mineral <^1 Dusts. , 31 . BFG08855 k) Both concentration and percent quartz for the application of this limit are to be determined from the fraction pass ing a size-selector with the following characteristics: Aerodynamic Diameter (nm) (unit density sphere) <2 2.5 3.5 5.0 10 % passing selector 90 75 50 25 0 1) containing <1% quartz; if quartz con tent > 1%, use formulae for quartz. NOTICE OF INTENDED CHANGES (for 1972) These substances, with their correspond ing values, comprise those for which either a limit has been proposed 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. If, after two years no evidence comes to light that ques tions the appropriateness of the values herein, the values will be reconsidered for the "Adopted" list. Documentation is available for each of these substances. Substance ppma> mg/M Acetaldehyde...................... C Acetic anhydride............ Ammonia.............................. + Baygon................................. Bismuth telluride............ Bismuth telluride (Se- doped)............................... Butane.................................. + Caprolactam (2-Oxo- hexamethylenimine) Dust............................... Vapor........................ + Carbofuran -- Skin........ Chloroform (trichloromethane)........................... + bis-Chloromethyl ether.. + Chloromethyl ether........ 100 5 25 -- -- -- 500 -- 5 -- 25 -- -- 180 20 18 0.5 10 5 1,200 1 25 0.05 120 A16 A1* Capital letters refer to Appendices. +1972 Revision or Addition. 21027035 BFG08856 Substance + o-Chlorotoluene.............. + Cotton dust, raw............ + Cyclohexylamine............ 1, 2-Dibromoethane (ethylene dibromide)-- Skin.............................. 1, 1-Dichloroethane........ Dichloroethyl ether -- Skin............................... Diisobutyl ketone........... + Dimethyl sulfate -- Skin. + Dioxane -- Skin.............. Diquat.............................. + Disvston -- Skin............. 2-Ethoxyethanol -- Skin. Ethylene glycol, particu- late................................ Ethvlene glycol, vapor.. + Ethvlidene norbornene. . Fluorine............................ Furfuryl alcohol.............. Germanium tetrahydride (Germane).................... + Hexachlorocyclopenta- diene.............................. Hexafluoroacetone.......... Isophorone....................... Isopropyl ether................ Lead, inorganic com pounds fumes & dusts. + Manganese cyclopenta- dienyl tricarbonyl (as lln) -- Skin................. Methylacrylonitrile -- Skin.............................. 3&) ppma) b)mfl/M 50 -- -- 0.2m> 10 40 20 200 5 25 -- 50 -- -- 100 -- 100 0.2 1 5 0.2 0.01 0.1 10 250 145 820 30 150 A2 -- 0.5 0.1 370 10 260 0.6 2 20 0.6 0.1 0.7 55 1,050 0.15 0.1 3 +1972 Revision or Addition. 34 Substance Methyl bromide -- Skin. Methylcyclohexanol....... o-Methylcyclohexanone -- Skin.......................... + 4-4'-Methylene bis (2chloroaniline) -- Skin. +C Methylene bis (4-cyclohexylene isocyanate).. + Methylene chloride (Dichloromethane)___ +C Methylethyl ketone peroxide............................. Mineral wool fiber.......... Paraffin wax fume.......... C Phenylphosphine............ + Phorate (Thimet) -- Skin.............................. Silicon............................... + Silicon tetrahydride (Silane)......................... CSubtilisins (Proteolytic enzymes as 100% pure crystalline enzyme)... Sulfur tetrafluoride........ Toluene............................ + Zinc stearate.................... ppmo) 15 50 50 0.02 0.01 250 -- -- -- 0.05 -- -- 0.5 -- 0.1 100 -- 3 mg/M 60 235 230 A2 0.11 890 1 E 1 0.25 0.05 10 0.7 0.003 0.4 375 E a) Parts of vapor or gas per million parts of contaminated air by volume at 25 C and 760 mm. Hg. pressure. b) Approximate milligrams of particula per cubic meter of air. Capital letters refer to Appendices. +1972 Revision or Addition. 35 i BFG08857 Substance ppma> mg/M m) Lint free dust as measured by the verticalelutriator, cotton-dust sampler described in the Transactions of the National Con ference on Cotton Dust, J. R. Lynch, pg. 33, May 2, 1970. 36 21027038 NOTICE OF INTENDED CHANGES (Cont'd) MINERAL DUSTS Substance TLV Asbestos (All types)... 5 fibers/ml > 5m in length10 Au Coal dust (bituminous). 2mg/m3 (respirabledustp)frac tion < 5% quartz). If > 5% quartz use respirable mass formula. Perlite....................................................... 30mppcf +Silica flour........ Use respirable mass formula for quartz. "Tripoli. ............. Use respirable mass formula for quartz. n) As determined by the membrane filter method at 400-450 X magnification (4 mm objective) phase contrast illumi nation. Concentrations 5 fibers/ml but not to exceed 10, may be permitted for 15-minute periods each hour up to five times daily. p) "Respirable" dust as defined by the British Medical Research Council Cri teria (1) and as sampled by a device producing equivalent results (2). (1) Hatch, T. E. and Gross, P., Pul monary Deposition and Retention of Inhaled Aerosols, p. 149. Academic Press, New York, New York, 1964. (2) Interim Guide for Respirable Sampling, AIHA Aerosol Technology Committee, AHIA J. 81: 2, 19<4& p. 133. +1972 Revision or Addition. *0 <1 o 37 w iD I BFG08858 NOTICE OF INTENDED CHANGES (Cont'd) APPENDIX A Carcinogens The Committee lists below those sub stances in industrial use that have proven carcinogenic in man or have induced cancer in animals under experimental conditions. Present listing of those substances carcino genic for man takes two forms, those for which a TLV has been assigned (la), and those for which environmental conditions have not been sufficiently defined to assign a TLV (lb). la. Human Carcinogens -- Substances known to be occupational carcinogens with an assigned TLV: Asbestos, 5 fibers/cc > o^m in length; certain insoluble chromates, 0.1 mg/m3; Coal tar pitch volatiles, 200 ppb; Nickel carbonyl, 1 ppb. lb. Human Carcinogens -- Substances known to be occupational carcinogens without an assigned TLV: 4-Aminodiphenyl Benzidine & its salts bis-Chloromethyl ether Chloromethyl ether beta-Xaphthylamine 4-Xitrodiphenyl For the substances in lb, no exposure or contact by any route, respiratory, skin or oral, as detected by the most sensitive methods, shall be permitted. "No exposure contact" means hermitizing the process or operation by the best practicable engineering methods, and protecting the worker by 2102*7040 proper equipment that will insure virtually no contact or entry of the carcinogen by any route. 2. Experimental Carcinogens -- Industrial substances found to be of high potency in inducing tumors under experimental conditions in animals: 2-Acetylaminofluorene 3, 3'-Dichlorobenzidine 4-Dimethylaminoazobenzene Dimethyl sulfate Ethylenimine 4, 4'-Methylene bis (2-Chloroaniline) N-Nitrosodimethylamine beta-Propiolactone For the above, worker exposure by all routes should be reduced to a minimum in light of the warning of the potency of these substances to induce tumors in animals. "Reduced to a minimum" means extraordi nary care shall be taken both in manufacture and in handling so that worker exposure by all routes is kept to an irreducible minimum. APPENDIX B B1 Polytetrafluoroethylene* decomposition products. Thermal decomposition of the fluorocarbon chain in air leads to the formation of oxidized products contain ing 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 de termination of the toxicity of the prod ucts, but air concentrations should be minimal. . 39 21027041 M) .i BFG08859 B2 Gasoline and/or Petroleum Distillates. The composition of these materials varies greatly and thus a single TLV for all types of these materials is no longer applicable. In general, the aromatic hydrocarbon content will determine what TLV applies. Consequently the content of benzene, other aromatics and additives should be determined to arrive at the appropriate TLV (Elkins, et al. A.I.H.A.J. W. 99, 1963). *Trade Names: Algoflon, Fluon, Halon, Teflon, Tetran APPENDIX C B.l THRESHOLD LIMIT VALUES FOR MIXTURES When two or more hazardous substances are present, their combined effect, rather than that of either individually, 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, c. , _c2 , _a Tx Ta " T,, exceeds unity, then the threshold limit of the mixture should be considered as being ex ceeded. Ci indicates the observed atmo spheric concentration, and Tx the correspond ing threshold limit (See Example lA.a. and lA.c.). Exceptions to the above rule may be made when there is good reason to believe that the chief effects of the different harmful 2102fD42 suds lances are noi in mu omuiuc,___ 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 + or + etc.^ itself has a value exceeding unit (See Example 1A. c.). Antagonistic action or potentiation may occur with some combinations of atmo spheric contaminants. Such cases at present must be determined individually. Potenti ating or antagonistic agents are not neces sarily 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 charac teristically exhibited at high concentrations, less probably at low. When a given operation or process charac teristically 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 atmo spheric contaminants are welding, automo bile repair, blasting, painting, lacquering, 1027043 BFG08860 certain foundry operations, diesel exhausts, etc. (Example 2 in lA.a.). THRESHOLD LIMIT VALUES FOR MIXTURES EXAMPLES lA.a. General case, where air is analyzed for each component: a. Additive effects. (Note: It is essen tial that the atmosphere be analyzed both qualitatively and quantitatively for each component present, in order to evaluate compliance or noncompli ance with this calculated TLV.) Ch , C2 Ti ^ T2 + T3 + 1 Example No. 1: Air contains 5 ppm of car bon tetrachloride (TLV = 10 ppm) 20 ppm of ethylene dichloride (TLV = 50 ppm) and 10 ppm of ethylene dibromide (TLV = 25 ppm) Atmospheric concentration of mixture = 5 + 20 + 10 = 35 ppm of mixture 5 20 10 10 + 50 + 25 25 + 20 + 20 50 _ 6 Threshold Limit is ex ceeded. Furthermore, the TLV of this mixture may be calculated by reducing the total fraction to 1.0; i.e. TLV of mixture = = 27 ppm 1.0 2102W44 Example No. 2: Air contains 200 ppm of hexane (TLV = 500 ppm) 100 ppm of methylene chloride (TLV = 500 ppm) and 20 ppm of perchloroethylene (TLV = 100 ppm) Atmospheric concentration of mixture = 200 + 100 + 20 = 320 ppm of mixture 200 100 20 200 + 100+100 400 ,,,, 500+500+100 500 500 0-8 Threshold Limit is not exceeded. The TLV of this mixture = U.o = 400ppm lA.b. Special case when the source of con taminant is a liquid mixture and the atmospheric composition is assumed to be similar to that of the original material; e.g. on a time weighted average exposure basis, all of the liquid (solvent) mixture eventually evaporates. Additive effects (approximate solu tion) 1. The percent composition (by weight) of the liquid mixture is known, the TLVs of the con stituents must be listed in mg/m3. (Note: In order to evaluate compli ance with this TLV, field sampling instruments should be calibrated, in the laboratory, for response to this specific quantitative and qualitative 43 21027045 V BFG08861 air-vapor mixture, and also to frac tional concentrations of this mixture; e.g., 1/2 the TLV; 1/10 the TLV; 2 X the TLV; 10 X the TLV; etc.) TLV of mixture = 1 _l 1} l i TLVa ^ TLV,, ^ TLV,, ^ -n ' TLVn Example No. 1: Liquid solvent contains (by weight) 50% heptane (TLV = 2000 mg/m3) 30% methylene chloride (TLV = 1740 mg/m3) 20% perchlorethylene (TLV = 670 mg/m3) TLV of mixture = 0.5 0.3 0.2 2000 ^ 1740 + 670 1 _1 .00025 + .00017 + .0003 .00072 " 1390 mg/m3 Of this mixture: 50% or 695 mg/m3 is hep tane, 30% or 417 mg/m3 is methylene chloride and 20% or 278 mg/m3 is perchloroethylene These values can be converted to ppm as follows: 210Z7O46 heptane -- 2000 mg/m3 = 500 ppm 1 mg/m3 = 0.25 ppm 695 mg/m3 = 174 ppm methylene chloride -- 1740 mg/m3 = 500 ppm 1 mg/m3 = 0.287 ppm 417 mg/m3 =119 ppm perchloroethylene -- 670 mg/m3 = 100 ppm 1 mg/m3 = 0.15 ppm 278 mg/m3 = 42 ppm The TLV of this mixture = 174 + 119 + 42 = 335 ppm. lA.c. Independent effects. Air contains 0.15 mg/m3 of lead (TLV, 0.2) and 0.7 mg/m3 of sulfuric acid (TLV, 1). 0.15 0.20 0.75; 0.7 = 0.7 1 Threshold limit is not exceeded. lB.a. General Exact Solution for Mixtures of N Components With Additive Ef fects and Different Vapor Pressures. m CL+-CJ+... + -^=1(1) Tx+ T2 + + T,, L> (2) Ci + C2 + + C,, = T, (2.1) Cl Ca , rp T rp 1 * rp By the Law of Partial Pressures, 45 1027047 j ;: r i BF08862 (3) Cj = api, and by Raoult's Law, (4) pi = Fipi. Combine (3) and (4) to obtain (5) Ci = aFipi0. Combining (1), (2,1) and (5), we obtain (6) FiPi , F2P20 + + + F,,Pn Fipi F2P2 . Ti ^ T2 1 Fnp + -~TT and solving for T, (6.1) T= FlPl FsP2 + + F,,pn Fipi F2p| , Tx + T2 , F,,p,,0 or j=nFipi (6.2) T = 4-=-^ 1=n 2 FiPi Ti T -- Threshold Limit Value in ppm. C -- Vapor concentration in ppm. p --Vapor pressure of component in solution. P--Vapor pressure of pure com ponent. 21037048 F -- Mol fraction of component in solution. a -- A constant of proportionality. Subscripts 1, 2, ... n relate the above quantities to components 1, 2, ... n, respectively. Subscript i refers to an arbitrary component from 1 to n. Absence of subscript relates the quantity to the mixture. lB.b. Solution to be applied when there is a reservoir of the solvent mixture whose composition does not change appreciably by evaporation. Exact Arithmetic Solution of Specific Mixture Solvent Mol. Density TLV wt. p at 25 C Mol fraction in half-and- half solution by volume Trichloro ethylene (1) 131.4 1.46 g/ml 100 73mm Hg 0.527 Methyl- chloro form (2) 133.42 1.33 g/ml 350 125mm Hg 0.473 FiPi = (0.527) (73) = 38.2 F2P20 = (0.473) (125) = 59.2 38.2 + 59.2 38.2 59.2 100 + 350 (97.4) (350) 133.8 +59.2 (97.4) (350) 193.0 47 6P01Z01 BFG08863 TLV = 177 ppm (Note difference in TLV when account is taken of vapor pressure and mol fraction in comparison with the above sample where such account is not taken.) 2. A mixture of one part of (1) parathion (TLV, 0.1) and two parts of (2) EPN (TLV, 0.5). Cl | Cl Cm 0.1 + 0.5 ~ Cm C2 = 2Ci Cm = 3Ci Ci 2Ci = 3C, 0.1 + 0.5 Tm 7Ci = 3Ci 0.5 Tm Tm = = 0.21 mg/m3 1C. TLV for Mixtures of Mineral Dusts. For mixtures of biologically active mineral dusts the general formula for mixtures may be used. For a mixture containing 80% talc and 20% quartz, the TLV for 100% of the mixture is given by: TLV ' 0.8 [ 0-f - " "<*' 20 + 2.5 2X02^050 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 example the limit for 20% quartz is 10 mppcf. For another mixture of 25% quartz, 25% amorphous silica and 50% talc: TLV = _________ 1_________ 0.25 0.25 0.5 2.5 + 20 + 20 7.3 mppc^ The limit for 25% quartz approximates 8 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" designa tion; 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 tetra chloride, TLV 10 ppm, should never be allowed to exceed 20 ppm. By contrast, those substances with a "C" designation are not subject to the excursion factor and must be kept below the TLV. These limiting excursions are to be con sidered to provide a "rule-of-thumb" guid ance for listed substances generally, and may not provide the most appropriate excursion for a particular substance. Efforts are being made to develop such specific .49 21027051 il J P' BFG08864 excursions, when indicated to be significantly different from that recommended by the present excursion factors. Substance Excursion TLV Factor Max. Cone. Permitted for short time ppm ppm l3 Carbon tetrachloride 10 2 20 o-Dichlorobenzene 50 Acetone 1000 1.5 1.25 75 1250 Boron Trifluoride C 1 -- 1 Butylamine C 5 -- 5 Stvrene monomer C100 ____ 100 For all substances: Excursion TLV >0-1 (ppm or mg/m3). Factor =3 TLV >1-10 a " =2 TLV> 10-100 " = 1.5 TLV> 100-1000 " = 1.25 BASIS FOR ASSIGNING LIMITING "C" VALUES By definition in the Preface, a listed value bearing a "C" designation refers to a "ceiling" value that should not be exceeded; all values 2JLO&7052 should fluctuate below the listed value. This, in effect, makes the "C" designation a maximal allowable concentration (MAC). In general, the bases for assigning or not assigning a "C" value rest on whether excursions of concentration above a proposed limit for periods up to 15 minutes may result in a) intolerable irritation, b) chronic. or irreversible tissue change, or c) narcosis of sufficient degree to increase accident proneness, impair self-rescue or materially reduce work efficiency. APPENDIX E Some Nuisance Particulates11) Alundum (AI2O3) Calcium carbonate Cellulose (paper fiber) Portland Cement Corundum (AI2O3) Emery Glass, fibrousr) or dust Glycerin Mist Graphite (synthetic) Gypsum Vegetable oil mists (except castor, cashew nut, or similar irritant oils Kaolin Limestone Magnesite Marble Pentaerythritol Plaster of Paris Rouge Silicon Carbide Starch Sucrose Tin Oxide Titanium Dioxide q) When toxic impurities are not present e.g. quartz < 1% r) <5-7/im in diameter APPENDIX F Some Simple Asphyxiants -- "Inert" Ga and Vapors 51 BFG08865 Acetylene Argon Butane Ethane Ethylene Helium s) As defined Hydrogen Methane Neon Nitrogen Nitrous Oxide Propane i pg. 6. TLVs Threshold Limit Values of Physical Agents Adopted by ACGIH for 1972 21027054 BFG08S66 1972 TLV PHYSICAL AGENTS COMMITTEE Herbert H. Jones, NIOSH, Chairman Peter A. Breysse, University of Washington Gerald V. Coles, Uganda Ministry of Labour Irving H. Davis, Michigan Dept, of Health Dr. David A. Fraser, Univ. of North Carolina Lt. Col. Owen H. Kittilstad, USAF Dr. Ernest Mastromatteo, Ontario Dept, of Health William A. Palmisano, U.S. Army David H. Sliney, U.S. Army Dr. Robert N. Thompson, FAA Thomas K. Wilkinson, USPHS Eugene G. Wood, U.S. Dept, of Labor Ronald D. Dobbin, NIOSH Any comments or questions regarding these limits should be addressed to: Herbert H. Jones, Chairman Threshold Limits Committee for Physical Agents American Conference Governmental Indus trial Hygienists 1014 Broadway Cincinnati, Ohio 45202 21027Q56 PREFACE PHYSICAL AGENTS These threshold limit values refer to levels of physical agents and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect. Because of wide variations in individual susceptibility, expo sure of an occasional individual, at, or even below, the threshold limit may not prevent annoyance, aggravation of a pre-existing condition, or physiological damage. Threshold limit values refer to levels of exposure for an 8-hour workday for a 40-hour work week. Exceptions are those limits which are given a ceiling value (C). They should be used as guides in the control of health hazards and should not be used as fine lines between safe and dangerous levels of exposures. These threshold limits are based on the best available information from industrial experience, from experimental human and animal studies, and when possible, from a combination of the three. These limits are intended for use in the practice of industrial hygiene and should be interpreted and applied only by a person trained in this discipline. They are not intended for use, or for modification for use, (1) in the evaluation or control of the levels of physical agents in the community, (2) as proof or disproof of an existing physical disability, or (3) for adoption by countries whose working conditions differ from those in the United States of America. 55 21027057 BFG08867 These values are reviewed annually by the Committee on Threshold Limits for Physical Agents for revisions or additions, as further information becomes available. Ceiling Value -- There are some physical agents which produce physiological response from short intense exposure and whose threshold limit is more appropriately based on this particular response. Physical agents with this type of response are best controlled by a ceiling "C" limit which is a maxi mum level of exposure which should not be exceeded. Notice of Intent -- At the beginning of each year, proposed actions of the Com mittee for the forthcoming year are issued in the form of a "Notice of Intent." This notice provides not only an opportunity for comment, but solicits suggestions of phys ical agents to be added to the list. The suggestions should be accompanied by sub stantiating evidence. As Legislative Code -- The Conference recognizes that the Threshold Limit Values may be adopted in legislative codes and regulations. If so used, the intent of the concepts contained in the Preface should be maintained and provisions should be made to keep the list current. Reprint Permission -- This publication may be reprinted provided that written permission is obtained from the Se'cretaryTreasurer of the Conference/find .that this Preface be published in its [entirety along with the Threshold Limit Values. 56 210270581; NOISE These threshold limit values refer to sound pressure levels that represent conditions under which it is believed that nearly all workers may be repeatedly exposed with out adverse effect on their ability to hear and understand normal speech. The medical profession (1,2) has defined hearing impair ment as an average hearing threshold level in excess of 25 decibels (ANSI S3.6 1969) at 500, 1000, and 2000 Hz, and the limits which are given have been established to prevent a hearing loss in excess of this value. These values should be used as guides in the control of noise exposure and, due to individual susceptibility, should not be regarded as fine lines between safe and dangerous levels. Continuous or Intermittent The sound level shall be determined by a sound level meter, meeting the standards of the American National Standards Institute and operating on the A-weighting network with slow meter response. Duration of exposure shall not exceed that shown in Table I. 1. Guides for the Evaluation of Hearing Impairment. Transactions of the Ameri can Academy of Ophthalmology and Otolaryngology, (March-April, 1961). 2. Guides to the Evaluation of the Perma nent Impairment; Ear, Nose, Throat and Related Structures. Journal of the American Medical Association 197:489 (August 1961). 57 I j ! ' j . j : i 21027059 BFG08868