Document 3Na61kmonqk5MzzoyEgMo1y3y

Threshold Limit Values For 1967 RECOMMENDED AND INTENDED VALUES Adopted at the 29th Annual Meeting of the American Conference of Governmental Industrial Hygienists, Chicago, Illinois, May 1-2,1967. _-A Sf. 409972 0462 Copyright 1967, by American Conference of Governmental Industrial Hygienists. The American Conference of Governmental Industrial Hygienists will welcome requests for permission to republish or reprint these Threshold Limit Values. Requests for such permission should be directed to the Secretary-Treasurer, 1014 Broa'dway, Cincinnati, Ohio 45202. Price: 1 -- 49 Copies...................................50$ 50 - 999 Copies............................40$ 1000 or more Copies..................30$ The 2nd edition of the Documentation of Threshold Limit Values, rewritten and greatly enlarged to include the approximately 400 sub stances in the list, is available and may be pur chased from the Secretary-Treasurer. The Docu mentation should be consulted when using the Threshold Limit Values herein (Price -- $4.50 -- see order blank in back of this booklet). Reprinted by permission of The American Conference of Governmental Industrial Hygienists 409972 0463 THRESHOLD LIMIT VALUES FOR 1967 The Threshold Limit Values refer to air-bome concentrations of substances and represent con* ditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse effect. Because of wide variation in individual susceptibility, exposure of an occasional individual at or even below the threshold limit may not prevent discomfort, ag gravation of a pre-existing condition, or occupa tional illness. Clinical tests are becoming available that per mit detection of those individuals who will hyperreact upon exposure to certain industrial sub stances. Being predictive in character, they may be applied as screening tests in the preplacement job examination. Requests for further details of these tests should be directed to the Chairman of the Committee. Threshold limits should be used as guides in the control of health hazards and should not be regarded as fine lines between safe and dan gerous concentrations. Exceptions are the sub stances given in Appendix A and certain of the substances given a "C** listing. The values not given a **C" listing refer to time-weighted aver age concentrations for a conventional 7 or 8 hour workday. Time-weighted average concentrations permit excursions above the limit, provided they are compensated by equivalent excursions below the limit during the work day. The degree of permis sible excursion is pegged to the threshold limit value of the particular substance as given in table in Appendix C under "Test TLV Factor.** Hence, it is not considered appropriate to inter pret air concentration values as exceeding timeweighted average limits, if such values lie within the permissible excursions. (See section on Legislative Code.) The amount by which these concentrations 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 poisoning, whether the effects are cumula tive, the frequency with which high concentra tions occur, and the duration of such periods. 1 All must be taken into consideration in arriving Vi at a decision as to whether a hazardous situa- ^ tion exists. Enlightened industrial hygiene prac tice inclines toward controlling exposures below the limit rather than maintenance at the limit. Threshold limits are based on the bes: avail able information from industrial experience, 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; protec tion against impairment of health may be the guiding factor for some, whereas reasonable free dom from irritation, narcosis, nuisance or other forms of stress may dominate the basis for others. The Committee holds to the opinion that limits based on physical irritation should be considered no less binding than those based on physical impairment; growing bodies of evidence indicate that physical irritation may promote and accelerate physical impairment. These limits are intended for use in the field of industrial hygiene and should be interpreted and applied only by persons trained in this field. They are not intended for use, or for modifiestion for use, (1) as a relative index of toxicity, by making a ratio of two limits, (2) in the evalu ation or control of community air pollution or air pollution nuisances, (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 bv coun tries whose working conditions differ from those in the United States of America and where sub stances and processes differ. Documentation of Threshold Limit Values. A separate companion piece to the TLVs is is sued by ACGIH under this title. This publication gives the pertinent scientific information and da ta with reference to literature sources that were used to base each limit. Each documentation al so 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. Ceiling vs Time-Weighted Average Limits. Although the time-weighted average concentra- 2 409972 0465 tion provides the most satisfactory, practical way of monitoring air-bome agents for compli ance with the limits, there are certain substan ces for which it is inappropriate. In the latter group are substances which are predominantly fast acting and whose threshold limit is more appropriately based on this particular response. Substances with this type of response are best controlled by a ceiling "C" limit that should not be exceeded. It is implicit in these defini tions 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 "C1' limit, is not appropriate to the timeweighted limit: here, a sufficient number of sam ples 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 excursions may be peg ged to the magnitude of the threshold limit by an appropriate .factor shown in Appendix C. It should be noted that the same factors are used by the Committee in making a judgment whether to include or exclude a substance for a **C" listing. "Skin*1 Notation. Listed substances followed by the designation **SkinM refer to the potential contribution to the over-all exposure by the cu taneous route including mucous membranes and eye, either by air-bome, or more particularly, by direct contact with the substance. Vehicles can alter skin absorption. This attention-calling de signation is' intended to suggest appropriate measures for the prevention of cutaneous absorp tion so that the threshold limit is not invalidat ed. These values are reviewed annually by the Committee on Threshold Limits for revision or additions, as further information becomes avail able. Mixtures. Special consideration should be given also to the application of these values in assessing the health hazards which may be as- 3 4099720466 sociated with exposure to mixtures of two or more substances. A brief discussion of basic considerations involved in developing threshold limit values for mixtures, and methods for their development, amplified by specific examples are given in Appendix B. "Inert" or Nuisance Particulates. A number of dusts or particulates that occur in the working environment ordinarily produce no specific ef fects upon prolonged inhalation. Some insoluble substances are classed as inert (e.g. iron and steel dusts, cement, silicon carbide, titanium dioxide. cellulose); others may be solu ble (starch, soluble oils, calcium carbonate) but are of such a low order of activity that in con centrations ordinarily encountered do not cause physiologic impairment; still others may be rap idly eliminated or destroyed by the body (veg etable oils, glycerine, sucrose). In the case of the insoluble substances, there may be some ac cumulation in the respiratory passages. In the case of the soluble substances, this accumula tion will ordinarily be temporary but may inter fere to some extent with respiratory processes. Hence, it is desirable to control the concentra tions of such particulates in the air breathed by any individual, in keeping with good industrial hygiene practice. A threshold limit of 15mg/m^, or 50 mppcf, whichever is less, is recommended for substan ces in these categories and for which no specif ic threshold limits have been assigned. This limit, for a normal work day, does not apply to brief exposures at higher concentrations. Neither does it apply to those substances which may cause physiologic impairment at lower concen trations but for which a threshold limit has not yet been adopted. Some "inert" particulates are given in Appendix D. Simple Asphyxiants-"Inert" Gases or Vapors. A number of gases and vapors, when present in high concentrations in air, act primarily as sim ple asphyxiants without other significant phys iologic effects. A TLV may not be recommend ed for each simple asphyxiant because the limit ing factor is the available oxygen. The minimal oxygen content should be IS percent by volume 4 under normal atmospheric pressure (equivalent to a partial pressure, pO 2 of 135 mm Hg)l Atmos pheres deficient in O2 do not provide adequate warning and most simple asphyxiants are odor less. Several simple asphyxiants are listed in Appendix E. Some asphyxiants present an ex plosion hazard. Account should be taken of this factor in limiting the concentration of the asphyx iant. Physical Factors. It is recognized that such physical factors as heat, ultraviolet and ioniz ing radiation, humidity, abnormal pressure 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 of moderate deviations from normal en vironments, the safety factors of most substan ces are not of such a magnitude as to take care of gross deviations. For example, continuous work at temperatures above 90F or over-time, extending the work-week more than 50%, might be considered gross deviations. In such instan ces 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 Committee 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 substances to be added to the list. The suggestions should be accompanied by substantiating evidence. As Legislative Code. The Conference does not consider the Threshold Limit Values appro priate matter for adoption in legislative codes and regulations and recommends against such use. If, however, the list is 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 ob tained from the Secretary-Treasurer of the Con ference and that it be published in its entirety. 5 409972 0468 RECOMMENDED VALUES (In Alphabetical Order) Substance PPtv* * Acetaldehyde.................................................. 200 3S0 Acetic acid...................................................... 10 25 Acetic anhydride............................................ 5 20 Acetone............................................................ 1.000 2.400 Acetonitiile...................................................... 40 70 Acetylene dichloride, see 1,2 Oicloro- ethylene ........................................................ Acetylene tetratxomide.................................. I 14 Acrolein........................................................... 0.1 0.25 + Acrylamide-Skin................................. -- 0.3 Acrylonitrile-Skin............................................ 20 45 Aldrin-Skin ...................................................... - 0.25 Allyl alcohol-Skin........................................ 25 Ally! chloride................................................ 13 C Allyl glycidyl ether(AGE).......................... 10 45 Allyl propyl disulfide.................................. 2 12 2-Aminoethanot, see Ethanolamine_______ + 2-Aminopytidine...___ ...___ ............______... 0.5 2 Ammonia .......................................................... 50 35 Ammonium sulfamate (Animate)........ ........... - 15 n-Amyl acetate............... ....................... -....... 100 525 + sec-Amyl acetate........... ................................ 125 650 Aniline-Skin .................................................... 5 19 Anisidine (o, p-isomers)-$kin..'.____ _____________ - 0.5 Antimony & compounds (as Sb)....___ _____ - 0.5 ANTU (alpha naphthyl thiourea)__ ____ __ -- 0.3 Arsenic & Compounds (as As).... ......... -- 0.5 Arsine ..... ............... ........................................ 0.05 0.2 + Azinphos-methyl-Skin................... .............. -- 0.2 Barium (soluble compounds).__ ___________ C Benzene (benzol)-Skin.................................... - 0.5 25 80 Benzidine- Skin ............................................ -- A1 p-Benzoquinone, see Quinone...................... Benzoyl peroxide............... ........-------------- -- 5 Benzyl chloride.......... .... I5 Beryllium....,........... ................................... - 0.002 t Biphenyl, see Diphenyl..................... ....... Boron oxide__................ ................ -- 15 C Boron tiiftuoride ........................................... 13 Bromine............................................................ 0.1 0.7 + Bromoform-Skin............................................. 0.5 5 Butadiene (1,3-butadiene)............................ 1,000 2,200 * Ports of vapor or gos per million ports of contaminated ait by volume at 25 C ond 760 mm. Hg pressure. ** Approximate milligrams of particulate per cubic meter of olr. A Numbers, .See Appendix A + 1967 Addition t See Intended Values 6 409972 0469 Subitpnc* PPm* Mg/M* Butanethiol, see Butyl mercaptan ............. 2-Butanone........ _.......................................... 200 590 2-Butoxy ethanol (Butyl Cetlosolve)-Skin .. 50 240 + Butyl acetate (n-butylacetate)__ ___________ 150 710 + n-Butyl acetate .................................................. 150.710. + sec-Butyl acetate............................................... 200 950 + tert-Butyl acetate .............................................. 200.950. Butyl alcohol........................................................ 100 300 tert. Butyl alcohol ....................................... 100 300 C Butylamine-Skin............................................ 5 15 C tert Butyl chromate (as Cr03)-Skin........... - 0.1 n-Butyi glycidyl ether (BGE)....................... 50 270 Butyl mercaptan............................................. 10 35 p--tert Butyltoluene..................................... 10 60 + Cadmium (Metal dust and soluble salts)..... - 0.2 Cadmium oxide fume..._____ __ -................ -- 0.1 Calcium arsenate ..... - -1 Calcium oxide.____ ______________ -- --5 t Camphor.________________ -2 Carbaryl (Sevin) (R).-------------------------------- -5 + Carbon black.----------------------------- -- - 3.5 Carbon dioxide............................................... 5,000 9,000 Carbon disulfide-Skin................................... 20 60 + Carbon monoxide ______ ___ ____________ 50. 55. Carbon tetrachloride-Skin ......... 10 65 Chlordane-Skin......... .................................... - 0.5 Chlorinated camphene, -Skin............... ...... - 0.5 Chlorinated diphenyl oxide ...................... . - 0.5 + C Chlorine.----------------------------------------- .------- 1. 3. Chlorine dioxide .......................................... 0.1 0.3 C Chlorine trifluoride.... .................................. 0.1 0.4 C Chloroacetaldehyde.......................... 13 Chlorobenzene (monochlorobenzene) ......... 75 350 + O'Chlorobenzylidenemalononitrile (OCBM)M.... ..... ........................-............-.... - 0.05 0.4 Chlorobromomethane..................................... 200 1,050 2-Chtoro-l, 3 butadiene, see Chtoroprene .. Chlorodiphenyl (42% chlorine)-Skin........... -1 Chlorodiphenyl (54% chlorine)-Skin ........... - 0.5 1.Chloro, 2,3 epoxypropane, see Epichlorhydrin............................................. 2, Chloroethanol, see Ethylene chlorohydrin..... ........................................... Chloroethylene, see Vinyl chloride........... C Chloroform (trichloromethane).................... 50 240 l*Chloro-l-nitropropane ............................... 20 100 Chloropicrin................................................... 0.1 0.7 Chtoroprene (2-chloro-1,3-butadiene)-Skin 25 90 Chromic acid and chromates (as Cr03) ..... - 0.1 + Coal tar pitch volatiles (benzene soluble fraction) (anthracene, BaP, phenanthrene , acridine, chrysene, pyrene) -- 0.2. t Cobalt.............................. ............................. t See Intended Values 7 :sv . S 'X SubttanC* Coppet fume...................... Dusts and Mists.............. Cotton dust (taw).............. Ctag (R) hetbicide............ Ctesol (all isometsl-Skm . Ctotona tdehyde.................. Cumene-Skin .................... Cyanide (as CN)-Skin...... 0. 1. 1 15 .5 22 2 6. 50. 245. 5 Cyclohexane...................... Cyclohexanol.................... 300 1.050 50 200 Cyclohexanone.................. 50 200 Cyclohexene..................... Cyclopentadiene................ 2.4-0.................................. 300 1.015 75 200 10 OOT-Skin .......................... 1 DOVP-Skin........................ 1 Decabotane-Skin.............. Demeton (R)-Skin............... Diacetone alcohol (4-hydrox 4-methyl-2- 0.05 0.3 0.1 pentanone)........ 50 240 1,2 Diaminoethane, see Ethyl enediamine Diazomethane................................................ Oibotane.... ......... ..............-..............--.......... 0.2 0.4 0.1 0.1 1,2-Oibiomoethane (ethylene dibtomtde)- Skin.............................. ...... ... ..................... C o- Dichlotobenzene-------------------- ------------ 25 190 50 300 p-Dichlorobenzene......................................... 75 450 Oichlorodifluoromethane............. -............... l,3-Dichloro-5, 5-dimethyl hydantoin.......... 1.000 4.950 - o.; 1.1, -Dichloroethane..................................... 100 400 1,2-Dichlotoe thane...................................... 50 200 1,2-Dichlotoethylene................................... 200 790 C Dichlotoethyl ethei-Skin............................ ... 15 90 Dichloiomethane, see Methylenechloride .. Dichlotomonofluocomethane......................... l, 000 4.200 C 1,1-Dichloro-l-nitioethane........................... 10 60 1,2-Dichtoropropane, see Piopylenedi- dilotide......................................................... Dlchlorotettafluoroethane............................. Dieldrin-Skin ................................................. 1.000 7.000 -- o.: Diethylamine ................................................. 25 75 + Diethylamino ethanol-Skin........................... 10. 50. Oiethylethet, see Ethyl ethet..................... Oifluofodibtomomethane............................... 100 860 C Oiglycidyl ethet (OGE)................................. 0. 5 2. w*~. `^"L Dihydroxybenzene, see Hydtoquinone....... Diisobutyl ketone ......................................... 50 290 Dimethoxymethane, see Methylal............... Dimethyl acetamide-Skin ............................. 10 35 Dimethylamine............................................ . 10 IS Dimethylaminobenzene, see Xylidene....... OimethylanUine (N-dimethyianiline)-Skin .. 5 25 Dimethytbenzene, see Xylene..................... + 1967 Addition 409972 0471 Subttonc* ppm' Mg/MJ Dimethyl 1, 2-dibromo-2, 2-dichloioethyt phosphate, (Dibrom) (R)............ ............... -3 Oimethyltormamide-Skin.... -..... .................. 10 30 2,6 Dimethylheptanone, see Diisobutyl ketone........................................................... 1.1-Dimethylhydrazine-Skin........................ 0.5 1 Dimethylsulfate * Skin................................. Dinitrobenzene (all isomer$)-Skin............... 15 -1 Dinitio-o-cresol-$kin..................................... - 0.2 Dinitrotoluene-Skin....................................... -- 1.5 Oioxane (Diethylene dioxide)-Skin ...... 100 360 Oiphenylmethane diisocyanate (See Methylene bisphenyl isocyanate (MDI)..... Diptopylene glycol methyl ether-Skin......... 100 600 Di-sec, octyl phthalate (Di-2-ethylhexyl- phthalate...-.................................................. -5 Endrin-Skin................. .................. ................ -- 0.1 Epichtorhydrin-Skin....................... 5 19 EPN-Skin ............................ ...... ............ -.... 1.2-Epoxyptopane, see Ptopyleneoxide .... - 0. 5 2.3-Epoxy-l-propanol see Glycidol ........... Ethanethiol, see Ethylmeicaptan.... .......... Ethanotamine.... .................... 36 2 Ethoxyethanol-Skin ............ 200 740 2 Ethoxyethylacetate (Cellosolve acetate) -Skin ........ ..................................................-...... 100 540 Ethyl acetate........ ........... 400 1,400 Ethyl aciylate-Skin... ................ 25 100 Ethyl alcohol (ethanol).... .... ................ ...... 1,000 1,900 + Ethylamine.................................................. . 10. 18. + Ethyl sec-amyl ketone (5-methyl*3-heptan* one)........................................................_..... 25. 130. + Ethyl benzene ...... ICO. 435. Ethyl bromide.............................................. ... 200 890 + Ethyl butyl ketone (3-Heptanone)............... SO. 230. Ethyl chloride ...............................-.............. 1,000 2,600 Ethyl ether..................................................... 400 1,200 Ethyl formate................................................. 100 300 + C Ethyl mercaptan............................................ 10. 25. Ethyl silicate................................................. 100 850 Ethylene chlorohydi in-Skin........ ........... 5 16 Ethylenediamine ........................................... 10 25 Ethylene dibromide, see 1,2-Dibtomo- ethane........................................................... Ethylene dichloride, see 1,2-Oichtoro- ethane.............. ........................................... + C Ethylene glycol dinitiate-Skin..................... 0.2 1.2 Ethylene glycol monomethyl ether acetate, see Methyl cellosolve acetate................... + Ethylene imine-Skin ..................................... 0.5 1. Ethylene oxide............................................... 50 90 Ethylidine chloride, see 1,1-Dichloro- ethane........................................................... + N-Ethylmorpholine-Skin ............................... 20. 94. t See Intended Values 9 Swbatonc* ppm* Mg/M1* Fetbam .... .......................................... - Ferrovanadium dust....................................... --1 Fluoride (as F) ............................................. - 2.5 Fluorine ......................................................... 0.1 0.2 Fluorotrichloromethane................................. 1,000 5,600 C Formaldehyde................................................ 56 + Formic acid .................................................. 5. 9. Furfural-Skin .......................................................... 5 20 Futfuryl alcohol............................................. 50 200 Gasoline................................................................. - A6 Glycidol (2,3-Epoxy-l-propanol)................. 50 150 Glycol monoethyl ether, see 2-Ethoxy- ethanol ......................................................... Guthion, see Azinphosmethyl..................... Hafnium.......................................................... - 0.5 Heptachlor-Skin............................................. - 0.5 t Heptane (n-heptane> .................................... 500 2,000 Hexachloroethane-Skin ............. 1 10 Hexane (n-hexane)......................................... 500 1,800 2-Hexanone.......................... 100 410 Hexone ................................ .......................... 100 410 + sec-Hexyl acetate 50. 300. Hydrazine-Skin...... ........................................ 1 1.3 Hydrogen bromide......................................... 3 10 C Hydrogen chloride........................................ 57 Hydrogen cyanide-Skin........ ......................... 10 11 Hydrogen fluoride......................................... 32 Hydrogen peroxide, 90%............................... 1 1.4 Hydrogen selenide ....................................... 0.05 0.2 Hydrogen sulfide_____ ___ 10 15 Hydroquinone..... ..... --2 C Iodine............... ........................................... 0.1 1 + Iron oxide fume............................................ -- 10. Isoamyl alcohol.................................................... 100 360 + Isoamyl acetate................................................... 100.525. + isobuty! acetate................................................... 150. 700. Isophorone ............................................................ 25 140 + Isopropyl acetate..................................... 250. 950. Isopropyl alcohol........................................... 400 980 Isopcopy (amine............................ 5 12 Isopropylether ............................................... 500 2,100 Isopropyl glycidyl ether (IGE)..................... 50 240 Ketene............................................................. 0.5 0.9 Lead .......................... .................................... - 0.2 Lead arsenate............................................... - 0.15 Lindane-Skin ................................................. -- 0.5 Lithium hydride............................................. -- 0.025 L. P. G. (Liquified petroleum gas)............. 1,000 1,800 Magnesium oxide fume ................................. - 15 Malathion-Skin............................................... - 15 C Manganese .................................................... -5 Mercury-Skin................................................... -- 0.1 Mercury (organic compounds)-Skin ............. - 0.01 Mesityl oxide................................................. 25 100 15 + 1967 Addition 10 4099720473 Subtencv Methanethlol, see Methyl meicaptan ......... Methoxychlor .............................................. 2-Methoxyethanol, see Methyl cellosotve .. Methyl acetate..........................-.................. Methyl acetylene (propyne) ........................ Methyl acetylene-propadiene mixture (MAPP)........................................................ Methyl acrylate-Skin..................................... Methylal (dimethoxymethane)....................... Methyl alcohol (methanol) ........................... + Methylamine..... ..... ....................................... Methyl amyl alcohol, see Methyl iso- butyl carbinol.... .......................................... + Methyl (n-amyl) ketone (2-Heptanone) ....... C Methyl bromide-Skin......... .......................... Methyl butyl ketone, see 2-Hexanone...... 1. Methyl cellosolve-Skin..... .... ...................... Methyl cellosolve acetate-Skin.................. C Methyl chloride -................. -....................... Methyl chloroform................ ........... ............ Methylcyclohexane... ................................... Methylcyclohexanol..... ................................. o-Methylcyclohexanone-Skin........... ........... Methyl ethyl ketone (MEK)t see 2-Butan- one Methyl formate........ .................. ......... ......... + Methyl iodide Skin......... ........................... Methyl isobutyl carbinol-Skin ______ ___ Methyl isobutyl ketone, see Hexone ........ + Methyl isocyanate - Skin ............... -........... C Methyl mercaptan Methyl methacrylate.----__ ... Methyl propyl ketone, see 2-Pentanone..... C aMethy! styrene -.............. ............................ C Methylene bisphenyt isocyanate (MOI)....... Methylene chloride (dichloromethane) ....... Molybdenum (soluble compounds)............... (insoluble compounds) ........... Monomethyl aniline-Skin............................... C Monomethyl hydrazine*Skin..._________ __ Morpholine-Skin --_____________ _________ t Naphtha (coal tar)...................................... Napthalene --______ _______ ___ _________ P-Naphthylamine......................................... Nickel carbonyl......... ...........-...................... Nickel, metal and soluble compounds____ Nicotine-Skin................................................ Nitric acid______ ____ _______ ____ ______ p-Nitroaniline-Skin ....................................... Nitrobenzene-Skin......................................... p-Nitrochloro-benezene-Skin.... -............... . Nitroethane.................................................... C Nitrogen dioxide .... ...................................... Nitrogen trifluoride......... ............................. t See Intended Values ppm* - 15 200 610 1.000 1,650 1,000 10 1,000 200 10. 1.800 35 3,100 260 12. 100. 465. 20 80 25 80 25 120 100 210 350 1,900 500 2,000 100 470 100 460 100 250 5. 28. 25 100 0.02 0.05 10 20 100 410 100 48S 0.02 0.2 500 1, 740 --5 - 15 29 0.2 0.35 20 70 . 200 800 10 50 _ A2 .0.001 0.007 --1 -- 0.5 25 16 15 _1 100 310 59 10 29 Svhstonc* C Nitroglycerin-Skin----- ----- ----------------------Nitromethane ............ .................................... 1-Nitropropane............................................... 2-Nitropropane............................................... N-Nitiosodimethyl-amine (Oi-methylnitrosoamine)-Skin............ ......... .............. Nitiototuene-Skin........................................... Nitrotrichloromethane. see Chlotopictin .... t Octane............................................................. Oil mist (mineral) ......................................... Osmium tetroxide........................................... + Oxalic acid...................... .............................. Oxygen difluoride........ -........... ............. ...... Ozone..... ...................................... ............... Parathioa-Skin............................................... Pentaborane................................................... Pentachloronaphthalene-Skin..... ................. Pentachlorophenol-Skin............................... PentaneTM................ 2-Pentanone........ .................. Perchloroethylene......................................... Peichloiomethyl mercaptan ......................... Peichlocyl fluoride............................... ....... Petioleum Distillates (naphtha)_____ __ __ Phenol-Skin........... ....................... ................ p-Phenylene diamine-Skin......_________ + Phenyl ether (vapor)............... .................._ + Phenyl ethec-Biphenyl mixture (vapor)...... Phenylethylene, see Styrene.................... ... Phenyl glycidyl ethei (PGE)....... ............... Phenylhydrazine-Skin ........................ Phosdrin (Mevinphos) (R)-Skin ................... Phosgene (carbonyl chloride)..... .... ........... Phosphine....................................................... Phosphoric acid........... ................................. Phosphorus (yellow)..................................... Phosphorus pentachloride ........................... Phosphorus pentasuUide .... ........................ Phosphorus trichloride................. ............... Phthalic anhydride.__ ...___ Picric acid-Skin............................................. + Pival (2-Pivalyl-l,3-indandione) ............ Platinum (Soluble Salts)............................... Polytetiafluoioethylene decomposition products ...................................................... Propane ........ ................... ... ........... ...... ..... pPropiolactone............................................... n-Propyl acetate........................................... n-Propyl nitrate ............................................. Propylene dichlotide..................................... + Propylene imine - Skin................................ Propylene oxide............................................. Propyne, see Methylacetylene ................... Pyrettuum....................................................... + 1967 Addition ppm* Mg 0.2 100 25 25 2 250 90 90 - a3 5 30 500 2,350 -5 -- 0.0^ - jm 0.05 0.1 0.1 0.2 _ 01 0.005 0.01 - 0.5 -- 0.5 1,000 2,950 200 700 100 670 0.1 0.8 3 13.5 500 2,000 5 19 -- 0.1 1. 7. 1. 7. 50 5 0.1 0.3 -- -- -- 0.5 2 -- -- 310 22 0.1 0.4 0.4 1 0.1 1 1 3 12 0.1 0.1 0.002 -- 1,000 200 25 75 2. 100 A4 1,800 A9 840 110 350 5. 240 --5 12 409972 0475 Substonc* ppm* Mg/M1 Pyridine ......................................................... Quinone........................................................... + Rhodium, Metal fume and dusts ................. Soluble salts ............................................... Rotenone (commercial)................................. Selenium compounds (as Se)................... . + Selenium hexafluoride................................... Silver, metal and soluble compounds......... Sodium fluoroacetate (1080) -Skin.............. Sodium hydroxide........................................... Slibine ........................................................... t Stoddard solvent............. ............................. Strychnine......... ............................................. r c Styrene monomer (phenylethylene)....--------- Sulfur dioxide................................................. Sulfur hexafluoride .... Sulfuric acid................................................... Sulfur monochloride....................................... Sulfur pentafluoride....................................... Sutfuryl fluoride............................................. Systox, see Oemeton ................................... 2,4,ST ............... ......................................... Tantalum................................ ....................... TEOP-Skin..... ............................................. Teflon (R) decomposition products............. Tellurium ....................................................... + Tellurium hexafluoride................................. TEPP-Skin........ .......................................... 1.1.1.2- Tetrach loro-2,2-difluoroethane._ 1.1.2.2- Tetrachloro-l, 2-difluoroethane .... 1.1.2.2- Tetrachloroethane-Skin............. Tetiachloroethylene, see Perchloroethy- lene .............................................. -............... Tetrachloromethane, see Carbon tetra chloride........... ............................................. Tetraethyl lead (as Pb)- Skin..................... Tetrahydrofuran.............................................. + Tetiamethyl lead (TML) (as lead) Skin .... + Tetramethyl succinonitrile - Skin............... Tetranitromethane......................................... Tetryl (2,4,6-trinitrophenylmethylnifa mine) - Skin .... ............................................. Thallium (soluble compounds) - Skin......... Thiram...... ...................................................... Tin (inorganic cmpds, except oxide)......... Tin (organic cmpds) ..................................... Titanium dioxide................... Toluene (toluol) ........................................... c Toluene-2,4-diisocyanate ........................... o-Toluidine - Skin......................................... Toxaphene, see Chlorinated camphene..... 1,1,1-Tfichloroethane, see Methyl chloro form ............................................................... 5 15 0.1 0.4 -- 0.1 -- 0.001 -5 - 0.2 0.05 0.4 - 0.01 - 0.05 --2 0.1 0.5 500 2,900 - 0.15 100 420 5 13 1,000 6,000 -1 16 0.025 0.25 5 20 - 10 --5 - 0.2 -- A* -- 0.1 0.02 0.2 - 0.05 500 4,170 500 4,170 5 35 -- 200 -- 0.5 1 0.075 590 0.075 3. 8 -- 1.5 - 0.1 --5 -2 -- 0.1 -- 15 200 750 0.02 0.14 5 22 t Sec Intended Values 13 4099720476 ill Subttonc* + l, 1,2-Ttichloroethane Skin....................... Trichloroethylene ......................................... Trichloromethane, see Chlorofotm............. Trichloronaphthalene Skin......................... 1,2, 3-Trichloiopropane ............................... 1,1,2-Ttichloro 1,2.2*trifluoroethane....... Triethylamine................................................. Trifluoromonobromome thane.... .................... 2, 4,6-Thnittophenol see Picric acid......... 2.4,6-Tfinitrophenylmethylnitiamine, see Tetiyl ........................................................... Trinitrotoluene Skin................................... Ttiorthocresyl phosphate............................. Tciphenyl phosphate..................................... Turpentine ..................................................... t Uranium (soluble compounds) ..................... (insoluble compounds)................... C Vanadium (V 20 s dust)................................. (VzOs fume)................................. Vinyl benzene, see Styrene......................... C Vinyl chloride ................................. ,,........... Vinylcyanide, see Acrylonitrile................. Vinyl toluene................................................. Warfarin........................................................... + Xylene (xylol) _____ ------------------------Xylidine - Skin............................................... Yttrium.^.________ ...---------------- ---------- Zinc oxide fume............................................. Zirconium compounds (as Zr) ........... ...... ... 10. 100 _ sc 1.00' 2; l.oo: 45. 535 5 300 7.600 100 6.100 - 1.5 - 0.1 --3 103 560 - 0.05 - 0.25 -- 0.5 - 0.1 500 1,300 103 480 -- 0.1 103. 435. S 25 --1 --5 -5 Radioactivity: For permissible concentrations of radio isotopes in air, see U. S. Department of Commerce, National Bureau of Standards, Handbook 69, "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides ir. Air and in Water for Occupational Exposure,'* June S. 1959. 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. y + 1967 Addition 14 4099720477 RESPIRABLE DUSTS EVALUATED BY COUNT Subttonca m. p. p. e. I. SILICA Ctystalline Quartz, Threshold Limit calculated from the formula........................... 250 * *SiOz+ 5 Ciistobalite " " '* Amorphous, including natural diatomaceous earth........................... 20 + Tremotite........ .......... ....... .......---------------- 5 SILICATES (less than 1% crystalline silica) Asbestos .................................... 5 Mica .......................................-.......... 20 Soapstone .... ................................... 20 Talc .............................................. . 20 Portland Cement............................... 50 GRAPHITE (natural)........................... 15 "Inert" or Nuisance Particulates 50 (or 15 mg/m3 whichever is the see Appendix D smaller) Conversion factors mppcf x 35.3 = million particles per cubic meter = particles per c.c. * Millions of particles per cubic foot of oir, based on impinger samples counted by light-field technics. * The percentage of crystolline silica in the formula it the omeunl determined from air*bome samples, except in those instances in which ether methods have been shown to be applicable. IS ............. 1. .. .: ` " *;. NOTICE OF INTENDED CHANGES These substances, with their corresponding values, comprise those for which either a limit has been proposed for the first time, or for which a change in the "Recommended** listing has been proposed. In both cases, the proposed limits . should be considered trial limits that will remain in this listing for a period of at least two years. . During this time, the previously Recommended Limit will remain in effect. If, after two years no evidence comes to light that questions the appropriateness of the values herein, the values will be placed in the *'Recommended* * list. Docu mentation is available for each of these substan ces. Substance ppra* M3/M1 ++ Abate.-......__.......... -.......-............................ ++ Boton tribromide.............. ........-............. .... ++ Bromine pentafluoride.-............... ................ sec-Butyl alcohol..........................-........ ...... + Camphor.......... ......--........-........... .. ......._.... 1.0 0.1 150 2 15 -- -- 450 - \ **'' /t:''-.:'- a-Chloroacetophenone (phenacyI chloride).. Chromium, sol. chromic, chtomous salts, 0.05 0.3 '' V* : Metallic& insol. salts............................... Cobalt, Metal fume & dust..... -.......... ... .... ++ Cyanogen................. -...... ..............,.............. Dibutyl phosphate............................... .. ...... Dibutylphthalate________ ___-...... -........... ++C Diethylene triamine-Skin.................. -.......... Diiscpropylamine-Skin.... ..... -...................... Dimethylphthalate......-................................. Diphenyl.............-........... -___ _________ __ ++ Diphenyl amine...... -.............. -........... ........ + Ethyleneglycol dinitrate and/or Nitroglycerin-skin.... -............................... Fibrous glass................................................. Gasoline.....-......-............ ...................... . + Heptane.................................................. ........ Hexachloionaphthalene-Skin........ ................ 10 1. 10 5. 0.2 - F1F1 1. 0.1 20. 5. 1. 10 0.2* - 5. A 200 800 - 0.2 * Parts of vopor or gas per million ports of oir plus vapor by volume ot 2SC and 760 mm. Hg pressure. ** Approximate milligrams of particulate per cubic meter of oi r. * An atmospheric concentration of not more than 0.02 ppm, or personol protection may be + 1967 Revision ++ 1967 Additions 16 409972 0479 Subitonci + Indium and compounds, as In............ -..... -- ++ lion sails, soluble,as Fe.............. .............. Isobutyl alcohol............................................. Maleic anhydride .............. ..........-............ . ++C Methyl silicate...___________________ ____ Naphtha (coal tar).........-.... Nitric oxide........ -....................................... ... Octachloronaphthalene*Skin__ ___ + Octane........ Parquat-Skin__ ___ Phenyl glycidy! ether(PGE)____---_____ ++ Propargyl alcohol-Skin___ ____ _____ ..___ Propyl alcohol_________...........___ --____ ++ RDX-Skin______________________________ Ronnel___ __ __ _____________ ____ _____ ... + Stoddard solvent-__ _____ + Styrene. __________________ ___ ....___ C Terphenyls ____ __ _________ __________ Tetrachloronaphthalene-Skin.....__ Tributyl phosphate-.______ ++ Tungsten & compounds, as W Soluble________________________________ _ Insoluble___________ __________________ + Uranium, sol. & insol.compounds as U.... Zinc chloride (fume) ------------------------------ ppm* Mg/MJ - 0.1 --1 100. 300. 0.25 1. 5-- 100. 400. 25. 30. - 0.1 200 930 - 0.5 10. 62. 1-- 200. 510. - 1.5 -- 15. 200 -- 50 -- 1. 9.4 - 2. - 5. -1 -5 - 0.2 - 1. + 1967 Revision +-+ 1967 Additions 17 409972 0480 Appendix A Benzidine Because of high incidence of bladde; tumors in man, any exposure, including skin, is extremely hazardous. A (3-Nophhylamine. Because of the extremely high incidence of bladder tumors m workers handling Ihts compound and the in ability to control exposures.^-naphthylamine has been prohibited by the State o( Pennsylvania from manufacture, use and othei activities that involve human contact A'N-Nitrosodimethylomine Because of extremely high toxicity and presumed carcinogenic potential of this compound, con* tact by any route should not be permitted. A Polytetrofiuoroethylene* decomposition products* Thermal decomposition of the fluorocarbon chain tn air leads to the formation of oxidized products containing carbon,fluorme and oxygen. Because these products decompose in part by hydrolysis in alkaline solution, they can be quantita tively determined in air as fluoride to provide an index of exposure. No TLV is recommended pending determination of the toxicity of the products, but air concentrations should be minimal. Asp Propioioctone Because of high acute toxicity and demonstra ted skin tumor production in animals, contact by any route should be avoided. A4 Gasoline. The composition of gasoline varies greatly and thus a single TLV for all types of gasoline is no longer ap* plicable. In general, the aromatic hydrocarbon content will determine what TLV applies. Consequently the content of benzene, ether aromztics and additives should be determined to arrive at the appropriate TLV (Elkins, el ai. A.I.H.A.J. 24, 99, 1963). * Trade Names: Algoflon, Fluon, Halon, Teflon, Tetran Appendix B B. 1 THRESHOLD LIMIT VALUES FOR MIXTURES When two or more hazardous substances ate present, their combined effect, rather than that of either individually, should be given primary cpnsideration. In the absence of informa tion to the contrary, the effects of the different hazards should IS 409972 0481 be considered as additive. That is, if the sum of the following fractions. Ci C2 T t + T2 + Cn Tn exceeds unity, then the threshold limit of the mixture should be considered as being exceeded. Ci indicates the observed atmospheric concentration, and Ti the corresponding thres hold limit, (See Example lA.a.). Exceptions to the above rule may be made when there is good reason to believe that the chief effects of the different harmful substances are not in fact additive, but independent as when purely local effects on different organs of the body are produced by the various components of the mixture. In such cases the threshold limit ordinarily is exceeded only when at least one member of the series (Ct or_C2 etc.) itself Ti T2 has a value exceeding unity, (See Example lA.b.) Antagonistic action or potentiation may occur with some combinations of atmospheric contaminants. Such cases at present must be determined individually. Potentiating or an tagonistic 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 al cohol and inhaled narcotic (trichloroethylene). Potentiation is characteristically exhibited at high concentrations, less probably at low. When a given operation 0; process characteristically emits a number of harmful dusts, fumes, vapors or gases, it wilt frequently be only feasible to attempt to evaluate the hazard by measurement of a single substance. In such cases, the threshold limit used for this substance should be reduced by a suitable factor, the magnitude of which will depend on the number, toxicity and relative quantity of the other contami nants ordinarily present. Examples of processes which are typically associated with two or more harmful atmospheric contaminants are welding, automobile repair, blasting, painting, lacquering, certain foundiy operations, diesel exhausts, etc. (Example 2.) 19 THRESHOLD LIMIT VALUES FOR MIXTURES EXAMPLES 1A. Genet aI case, where air is analyzed for each component o. ADDITIVE EFFECTS Cl , C 2 . C 3 ^ , C M i Ti Ta T a Ts " Air contains S ppm of caibon tetrachloride (TLV, 10), 20 ppm of ethylene dichloride (TLV, SO) and 10 ppm of ethylene dibromide, (TLV, 2S). Threshold limit is exceeded. b. IHDEPEHDEHT EFFECTS Air contains 0.15 mg/ma of lead (TLV, 0.2) and 0.7 mg/m3 of sulfuric acid (TLV, 1). 0.15 0.20 0.75: JLZ_ = 0.7 Threshold limit is not exceeded. IB. Special case when source of contaminant is a mixture and atmospheric composition is assumed similar to that of original material, i. e. vapor pressure of each component is the same at the observed temperature. a. additive EFFECTS, approximate solution. 1. A mixture of equal parts (1) trichloro ethylene (TLV, 100), and (2) methyl chloroform (TLV, 350). C. C2 = Cm Solution applicable 100 350 Tm to "spot** solvent mixture usage. where all or neatly all, solvent evap orates. C1 = C 2 = -i- Cm Ci , Cl 100 350 JCj Tm 20 409972 0483 ,'r;;V: ': M 409972 0484 p = Vapot pressure of pure component F = Mol fraction of component tn 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. 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 Mol. wt. Oensity T pat Mol frac2SC tion in half-and half solo* tion by volume Trichloro ethylene (1) 131.4 1.46 g/ml 100 73mm Hg 0. 527 Methylchlotoform (2) 133.42 1.33 g/ml 350 125mm Hg 0.473 Fipi* = (0. S27) (73) = 38.2 F 2p 2 = (0. 473) <125) = 59.2 38.2 + 59.2 _ (97.4) (350) _ (97.4) (350) __ ~~ 38.2 , 59.2 ~~ 133.8 + 59.2" 100 + 350 193.0 T = 177 ppm (Note difference in T. L. V. when account is taken of vapor pressure and mol fraction in comparison with above example 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). 409972 0485 Cm = 3C t Cl 2C i __ 3C i 0.1 0.5 Tm 7Ci = 3Ci 0. S Tm Tm -- -- 0.21 mg/m 3 1C. T. L. V. for Mixtures of Mineral Ousts. For mixtures of biologically active mineral dusts the general formula for mixtures may be used. With the exception of asbestos, pure minerals are assigned TLV of 2. S, 20 or 50. For a mixture containing 80% talc and 20% quartz, the TLV for 100% of the mixture "C*1 is given by: TLV 1 0.8 . 0.2 20 1 2.5 8.4 mppcf 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 Aii JK5.- 7-3 "W** 2.5 1 20 + 20 The limit for 25% quartz approximates 8 mppcf. 409972 0486 Appendix C BASES FOR ASSIGNING LIMITING "C" VALUES By definition in the Preface, a listed value bear ing a *`C" designation refers to `ceiling' value that should not be exceeded; all values should fluctuate below the listed value. In general the bases for assigning or not assigning a "C" value cest on whether excursions of concentration above a proposed limit for periods up to IS 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. In order for the Committee to decide whether a sub stance is a candidate for a "C" listing, some guidelines must be formulated on the permissive fluctuation above the limit in terms of the seriousness of the response in the categories a, b, c, given above. For this the factors given in the table below have been used by the Committee. For both technical and practical reasons, the factors have been pegged to the concentration in an inverse manner. It will be noted that as the magnitude of the T. L. V. increases a correspondingly decreased range of fluctuation is permitted; not to decrease the factor for T. L. V. s of increasing magnitude would permit exposures to large absolute quantities, an undesirable condition, a condition that is minimized at low T. L. V. s. More over, larger factors at the lower T. L. V. s are con sistent with the difficulties in analyzing and con trolling trace quantities. T.l.V. RANGE ppm* or mc/mT Test T.L.V. Factor Examples 0 to 1 1 + to 10 3 Toluene diisocyanate-T. L. V., 0.02 ppm, if permitted to rise above 0.06 ppm may result it. sensitization in a single sub sequent exposure,' "C" listing recommended on category b. 2 Manganese -T.L.V., 5mg/m\ contains little or no safety factor. All values should fluct uate below 5mg/m5. "C" listing recommended on category b. i 4099720467 T.L.V. Test RANGE T.LV. ppm* er mi/mJ Factsr 10+ to 100 1.5 100+ to 1000 1.25 Eiimplct Methyl styrene-T. L. V. 100 if encountered at levels of 150 ppm will prove intense ly irritating, "C" listing recommended on category a. Methyl chloroform-T. l_ V. 350ppm, at 438 ppm for per iods not exceeding 15 min utes is not expected to re sult in untoward effects relating to category c. No "C" listing recommended. I * Whichever unit is applicable PERMISSIBLE EXCURSIONS FOR TIMEWEIGHTED AVERAGE (TWA) LIMITS As stated in the preface, the same factors may be used as guides for reasonable excursions above the limit for substan ces to which the time-weighted average applies. The timeweighted average implies that each excursion above the limit is compensated by a comparable excursion below the limit. Thus, a value of 6 -ppm HF is permissible for periods not ex ceeding 15 minutes, provided an equivalent decrease below the limit of 3 -ppm obtains. Appendix D Some "Inert" or Nuisance Particulates* Alundum (AI2O3) Calcium carbonate Limestone Magnesite Cellulose Portland Cement Corundum (AI2O3) Emery Glycerine Mist Marble Plaster of Paris Rouge Silicon Carbide Starch Graphite (synthetic) Gypsum Sucrose Tin Oxide Vegetable oil mists (except castor, cashew nut, or similar irritant oils) Titanium Dioxide When toxic impurities are not present. 25 4099720488 Appendix E Some Simple Asphyxiants - "Inert" Gases and Vapors. Acetylene Argon Ethane Ethylene Helium Hydrogen Methane Neon Nitrogen Nitrous Oxide EJ. Baier Hervey B. Elkins, Ph.D. W. W. Fredrick, Ph.D. Bernard Grabois, P.E. Paul Gross, M.D. Wayland J. Hayes, Jr., M.D. Harold N. MacFarland, Ph.D. Consultant Fredrick T. McDermott E. Mastromatteo, M.D. Walter W. Melvin, M.D. Ralph G. Smith, Ph. D. Mitchell R. Zavon, M.D. Herbert E. Stokinger, Ph.D., Chairman 26 409972 0489