Document aNxXjEjg1Rbgwb3kEdZyY3je

3 threshold Limit Values For 1966 r t recommended and tentative limits Adopted at the 28th Annual Meeting of the American C nference of Governmental industrial Hygienists, 'Pittsburgh, Pennsylvania, May 16- 17, 1966. EC- 2024 r ( < c Copyright i960, by American Conference of Governmental Industrial Hygienists. The American Conference of Governmental Industrial Hygienists will welcome requests for permission to republish or reprint these Thresh old Limit Values. Requests for such permission should be directed to the Secretary-Treasure1014 Broadway, Cincinnati, Ohio 45202. Single Copies -- 30 cents 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. THRESHOLD LIMIT VALUES FOR 1966 The Threshold Limit Values refer to air-borne -.oncentrations of substances and represent con rditions 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. Threshold limits should be used as guides in ^ - control of health hazards end should not be . garded as fine lines between safe and dan% rous 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 normal workday. 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- (Hve, the frequency with which high concentraions occur, and the duration of such periods. All must be taken into consideration in arriving 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 best avail able information from industrial experience, from / oerimental human and animal studies, and * ,en 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 \ ,'orms of stress may dominate the basis for others. The Committee holds to the opinion that EC- 2025 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. r 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 TLVs it is essential that the Documentation B consulted when the TLVs are being used. { Ceiling vs Time-Weighted Average Limits. Although the ume-weighted average concentra 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 should1 - 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 "C" limit, is not appropriate to the time- weighted 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. j 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-f 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 2 by the Committee in making a judgment whether to include or exclude a substance for a "C" listing. "Skin" Notation- Listed substances followed by the designation ''Skin" refer to the potential f ntribution to the over-all exposure by the cu' .neous 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. f Mixtures. Special consideration should be .n also to the application of these values in 4 ;$sing the health hazards which may be as 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 (ibstances are classed as inert (e.g. iron and eel 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 tSe insoluble substances, there may be some acI ulation in the respiratory passages. In the case of the soluble substances, this accumula tion will ordinarily be temporary but may interfere to some extent with respiratory processes. Hence, it is desirable to control the concentra tions of such particulates in the air breathed by / ny individual, in keeping with good industrial -ygi-ene practice, A threshold limit of 15mg/m , or SO mppcf, whichever is less, is recommended for substan- 3 EC- 2026 ces in these categories and for which no speci fic 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 conceft-f 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 limif ing factor is the available oxygen. The minima* oxygen content should be 18 percent by volung under normal atmospheric pressure (equivalent to a partial pressure, pO2, of 135 mm Hg). Atmos pheres deficient in Oz 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. 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 modifica tion 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 by coui^ tries whose working conditions differ from those ui the U.S. Physical Factors. It is recognized that such cphysical 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 trom exposure at a threshold Limit may be altered. Most of these stresses act 4 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-es are not of such a magnitude as to take care r f gross deviations. For example, continuous work at temperatures above 90F of 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. These values are reviewed annually by the Committee on Threshold Limits for revision or ditions, as further information becomes avail- "Notice of Intent*1 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 for a tentative limit. 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 obined from the Secretary-Treasurer of the Conlerence and that it be published in its entirety. ( 5 EC- 2027 Substance C o-DIchlorobenzene...................................... p-Oichloiobenzene..................................... Dichlotodifluoromethane............................. + l,3-Dichloro-5, 5-dimethyl hydantoin........ 1,1, -Dlchlotoethane.................................. 1.2-DiChloroethane........................... ........ 1.2-DichtOroethylene ............................... C Dichloroethyl ether-Skin............................. Dichloromethane, see Methylenechloride .. Oichloremonofluoromethane....................... C 1,1-Dichloro-l-nitroethane......................... 1.2-Dichloropropane, see Propylenedichloride.................................................... Dichlorotetrafluoroethane........................... Dieldtm-Skin ............................................. Diethylamine ............................ .... ............ Diethylether, see Ethyl ether.................... Difluoredibromomethane............................. C Diglycidyl ether (DGE).............................. Dihydroxybenzene, see Hydroquinone...... Diisobuty! ketone ...................................... Dimethoxymethane, see Methylal.............. Dimethyl acetamide-Skin ........................... + Dlmethylamine...................... ..................... Oimethylaminobenzene, seeXylidene...... Dimethylamiine (N-dimethylaniline)-Skin .. Dimethyl benzene, see Xylene............ ....... + Dimethyl 1.2-dibromo-2,2-dichlcroethyl phosphate, (Dibtom) (R)........................... + Dimethylfotmamide-Skin............................. 2,6 Dimethylheptanone, see Diisobutyl ketone...................................................... 1.1-Dimethylhydrazine-Skin....................... Dimethylsulfate Skin.............................. Dimtiobenzene (all isomers)-Skin............. Dinitro-o-cresol-Skin.................................. Olnitrotoluene-Skin.................................... Dioxane (Diethylene dioxide)-Skin ........... Dipiopylene glycol methyl ether-Skin ...... + Di-sec, octyl phthalate (Di-2-ethylhexylpnthalate ................................................. Endrln-Skm................................................ Epichlorhydrm-Skin................................... EPN-Skin .................................................. 1.2-Epoxyptopane, see Propyl eneoxide 2.3-Epoxy-I-propanol see Glycidol .......... Ethanethioi, see Ethylmercaptan ".......... Ethanolamine..................................... - - 2 Ethoxyethanol-Skin ................................ 2 Ethoxyethylacetate (Cellosolve acetate) -Skin .....................................................-.. Ethyl acetate............................................ Ethyl acrylate-Skin ................................... Ethyl alcohol (ethanol).............................. f Ethylamine ............................................... + 1966 Addition ppm* Mg/M1** Substance ppm* Mg/M1 50 300 75 450 ,000 4,950 - 0.2 100 400/* 50 200 \ 200 790 15 90 ,000 4, 200 10 60 ,000 7,000 -- 0.25 25 7if 100 8(3 0. 5 l 50 290 10 35 10 18 5 25 _3 10 30 0. 5 1 _ _ 100 100 S' if s'- 1 0.2 1.5 360 600 _5 - 0.1 (5 _ 11 V 36 200 740 100 540 { 400 1,400 K. 25 100 ,000 1,900 -- tC Ethylbenzene................. ........................... *_ Ethyl bremide............................................. Ethyl chloride ................................... ........ Ethyl ether................................................. Ethyl formate............................. ............... { ithyl mercaptan.......................................... 200 1,000 400 100 * 890 2,600 1,200 300 _ Ethyl silicate............................................ Ethylene chlorohydrln-Skin .................... Ethylenediamine................................... Ethylene dibromide, see 1,2-Dibromo- 100 850 5 16 10 25 ethane............................................ Ethylene dlchloride, see 1,2-Dichloro- ethane.................................................... C Ethylene glycol dinitrate-Skin.................... Ethylene glycol monomethyl ether acetate, 0.2 1.2 ^ , see Methyl cellosolve acetate................. tf tylene imine-Skin ............... ............. __ 2 nylene oxide................................... 1 ylidine chloride, see 1,1-Dichloro- 50 90 ' sthane............................ Ferbam.................................................... Ferrovanadium dust.............................. Fluoride (as F) ................................. Fluorine.................................................. Fluorotrichloromethane............................... C Formaldehyde................................ Freon 11, see Fluorotrichloromethane...... IS _ 1 2.5 0. 1 0.2 1,000 5,600 56 Freon 12, see Dichlorodifluoromethane... Freon 13B1, see Trifluotomonobromo- methane................................... Freon 21, See Dichloromonofluoro- s methane.......................... 1 reon 112, see l,l,2,2-Tetrachloro-l,2 difluoroethane .................. Freon 113, see 1,1,2-Trichloro, 1,2,2- trifluoroethane............................... Freon 114, see Dichlorotefrafluoro- ethane ........................... Furfural-Skin ........... .............................. Furfuryl alcohol.................................. Gasoline....................................... Glycidol (2,3-Epoxy-l-propanol)................ /'vcol monoethyl ether, see 2-Ethoxy- 5 20 50 200 A6 50 ISO 1 ;anol ........................................ f \-rhion, see Azinphosmethyl................ ' Hafnium.............................. Heotachlor-Skin...... Heptane (n-heptane) ........................ -i- Hexachloroethane-Skin............... , Hexane (n-hexane)................................... { -Hexanone.................................. V.iexone.................................... sec-Hexyl acetate........... Hydrazine-Skin........................................ Hydrogen bromide ....................... 0. 5 _ 0.5 500 2,000 1 10 500 1,800 100 410 100 410 50 295 1 1.3 3 10 T See Tentative Limits $9 EC- 2029 Substone* C Hydrogen chloride................................. Hydrogen cyanide-Skin.......................... Hydrogen fluoride ................................. Hydrogen peroxide, 90%......................... Hydrogen selenide.................................. + Hydrogen sulfide.................................... Hydroquinone......................................... C iodine ............................... .................... t Iron oxide fume ..................................... Isoamyl alcohol...................................... laophorone............................................. Isopropyl alcohol.................................... Isopropylamine.................. -................... Isopropylethet .................... -................. Isopropyl glycidyl ether (IGE)................. Ketene............ ......................................... Lead ..................... ................................ Lead arsenate......................................... Lindane-Skin .......................................... Lithium hydride............................. ......... + L. P. G, (Liquified petroleum gas)......... Magnesium oxide fume ............................ Malathion-Skin......................................... C Manganese ........................ ...................... Mercury-Skin.......................... ................. Mercury (organic compoundsl-Skin .......... Mesityl oxide.......................................... Methanethiol, see Methyl mercaptan ...... Methoxychlor ......... .................... ............ 2-Methoxyethanol, see Methyl cellosolve Methyl acetate .......................-................ Methyl acetylene (propyne) ..................... + Methyl acetylene-propadiene mixture (MAPP)................................................... Methyl acrylate-Skin................................ Methylai (dimethoxymethane).................... Methyl alcohol (methanol) ...................... Methyl amyl alcohol, see Methyl isotxrtyl carbinol.......................................... C Methyl bromide-Skin ..................... ........... Methyl butyl ketone, see 2-Hexanone....... Methyl cellosolve-Skin.............................. Methyl cellosolve acetate-Skin................. C Methyl chloride ......................................... Methyl chloroform ........ ............................ Methylcyelohexane ................................... Methylcyclohexanol.................................. o-Methyfcyclohexanone-Skin..................... Methyl ethyl ketone (MEK), see 2-Butanone.................................................. ........ Methyl formate.......................................... Methyl isobutyl carbinol-Skin ................... Methyl isobutyl ketone, see Hexone ........ +C Methyl mercaptan....................................... + 1966 Addition Rpm* Mw'M*** 5 10 3 1 0.05 10 -- 0.1 7 11 2 1.4 2 1 100 360 25 140 400 980 S 12 500 2,100 rSO 240 0.5 1,000 25 0:u25 1,800 15 15 5 0.1 0.01 100 15 200 610 1,000 1,650 { 1,000 10 1,000 200 1,800 35 3,100 260 ' 20 SO 25 80 25 120/ 100 21 q 350 1,900' 500 2,000 100 470 100 460 100 250 25 100 10 20 10 + Methyl methacrylate.................................. Methyl propyl ketone, see 2-Pentanone..... C aMethyl styrene.......................................... C Methylene bisphenyi isocyanate (MOI)...... 'tethylene chloride (dichloromethane) ....... t .lolybdenum (soluble compounds).............. (insoluble compounds) .......... Monomethyl aniline-Skln............................ + Morphollne-Skin................................... Naphtha (coal tar).............................. Naphtha (petroleum) ........................... + Naphthalene........................-.............. fi-Naphthylamine ................................. Nickel carbonyl.................................. + Nickel, metal and soluble compounds *<lcotine-$kin....................................... 4 ric acid tittoaniline-Skin robenzene-Skin .. Nitroethane................................................. Nitrogen dioxide........................................ Nitrogen trifluoride.................................... Nitroglycerin- + EGDN-Skin.,,.................... Nitromethane.......... ................................... 1-Nitropropane............................................ 2-Nitropropane........................................... N-NItrosodimethyl-amine (Di-methylnibosoaminel-Skin__________________ Nibotoluene-Skin............... ........................ Nftrotrichloromethane, see Chloropicrin .... ( Octane........................................................ )il mist (mineral) ........................ ............. Jsmium tettoxide........................................ Oxygen difluoride...................................... Ozone ........................................................ Parathion-Skin............................................ Pentaborane............................................... Pentachloronaphthalene-Skin..................... Pantachlorophenol-5kin............................. Pentane....................................................... 2-Pentanone............................................... Perchioroethyiene...................................... f 'chloromethyl mercaptan ........................ 1 rchloryl fluoride.................................... Phenol-Skin ................................... ............ p-Phenylene diamine-Skin ......................... Phenylethylene, see Styrene..................... Phenyl glycidyl ether (PGE)......-.............. c Phenylhydrazme-Skin................................ Phosdrin (Mevinphos) (R)-Skin .................. Phosgene (carbonyl chloride) ................... Phosphine..................................... ............. Phosphoric acid.......................................... ppm* MertM** 100 410 100 480 0.02 0.2 500 1, 740 --5 - 15 29 20 70 200 BOO 500 2,000 10 50 0.001 0.007 1 0.5 5 6 S 100 5 10 0.2 100 25 25 310 9 29 2 250 90 90 Aa 5 30 500 2,350 -5 * 0.002 0.05 0.1 0.1 0.2 e- 0.1 0.005i 0.01 - 0.5 - 0.5 1,000 2,950 200 700 100 670 0.1 0.8 3 13.5 5 19 0.1 50 310 5 22 -- 0.1 0.1 0.4 0.3 0.4 -1 t See Tentative Limits 11 EC- 2030 Svbsfence Phosphorus (yel low) ............................... Phosphorus pentachloride ..................... Phosphorus pentasulfide ....................... Phosphorus trichloride .......................... + Phthalic anhydride ............. ....... Picric acid-Skin........................................ Platinum (Soluble Salts) ...................... Polytetrafluoroethylene decomposition products .................................................. + Propane..................................................... Propyne, see Methylacetylene ............... pProoiolactone.......................................... n-Propyl acetate ....................................... n-Propyl nitrate ....................................... Propylene dichloride................................. t Propylene imine-Sktn ................................ Propylene oxide........................................ Pyrethrum ................................................. Pyridine ................................................... Quinone.................................................... Rotenone (commercial) ............................. + Selenium compounds (as Se) .................... + Silver, metal and soluble compounds ..... Sodium fluotoacetate (1080) Skin.......... Sodium hydroxide....................................... Stibine ...................................................... Stoddard solvent ....................................... Strychnine................................................. C Styrene monomer (phenylethylene) ........... Sulfur dioxide................................ . ..... Sulfur hexafluoride ........................... ........ Sulfuric acid............................................... Sulfur monochloride.................................. Sulfur pentafluonoe................................ Sul fury I fluoride........... T....... ... Systox, see Demeton .............................. 2. 4, ST .................................................. Tantalum ................................................. TEDP Skin.............................................. Teflon (R) decomposition products.......... Tellurium ................................................. TEPP Skin ......................................... i- 1,1,1.2-Tetrachloro-2, 2-difluoroethane .. 1.1.2.2-Tetrachioro-l, 2-difluoroethane .. 1.1.2.2-Tetrachloroethane-Skrn . ,. Tetrachloroethylene, see Perchloroethy- lene ........................................................ Tetrachloromethane, see carbon tetra chloride.................................................... Tetraethyl lead las Pb) - Skin . ... Tetrahydrofuran ................................. Tetramtromethane .................. Tetryl (2,4,6-tnnitrophenylmethylmba- mme) - Skin . . .............................. ppm* Mp'M5** - 0.1 *1 -1 0. 5 3 2 'if ~ O.Oud _ A* 1,000 1.800 __ A5 200 840 25 110 75 350 <100 5 l( 0. 1 (7.v -5 - 0.2 - 0.01 - 0. 05 -2 0. 1 0.5 500 2,900 - 0.15 100 420 5 13 1.000 - 1 6,000 1r 6 0.025 O.i^ 5 20 -- 10 -5 _ 0.2 - AJ - 0.1 - 0.05 417f500 4,170- 500 5 3?- - 0.075 200 590 / 1 8V _ 1.5 + 1966 Addition 12 Svbe twice ppm* Mg/MJ* Thallium (soluble compounds) - Skin ...... Thiram......................................................... Tin (inorganic cmpds,except nxide)........... Tin (organic cmpds) .................................. rTitanium dioxide........................................ Toluene (toluol) ........................................ v Toluene-2,4-diisocyanate ......................... o-Toluidine - Skin ................................... Toxaphene, see Chlorinated camphene 1,1,1-Trichloroethane, see Methyl chloro form .......................................................... Trichloroethylene ..................................... Triehloromethane, see Chloroform............ Triehloronaphthalene - Skin....................... 1,2,3-Triehloropropane ............................. J. 1,2-Trichloro 1, 2,2-tnfluoroethane ...... ( ethylamine.............................................. (' ifluoromonooromomethane....................... ,6-Trinitrophenoi see Picric acid....... 4,6-Trinltiophenylmethylnitramine, see Tetryl ............... ....................................... Trinitrotoluene - Skin................................. Triorthocresy! phosphate........................... Triphenyt phosphate................................... Turpentine .................................................. Uranium (soluble compounds) .................. (insoluble compounds).................. C Vanadium (VzOo dust).............................. (VzOs fume).............................. Vinyl benzene, see Styrene....................... C Vinyl chloride ......................................... Vinylcyanide, see Acrylonitrile................ / Vinyl toluene......................................... \ .farfarm....................................................... T Xylene (xylol) .......................................... Xylidine - Skin............................................ + Yttrium ...................................................... Zinc oxide fume.......................................... Zirconium compounds (as Zr) .................. - 0.1 -5 -2 - 0.1 - IS 200 7S0 0.02 0.14 5 22 100 535 50 1,000 25 1,000 5 300 7,600 100 6,100 - 1.5 - 0.1 -3 100 560 - 0.05 - 0.25 - 0,5 - 0.1 500 1.300 100 480 - 0.1 -5 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 rmissible Body Burdens and Maximum Permissible (ncentrations of Radionuclides in Air and in Water for Occupational Exposure, " June 5, 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. ^ arts of vapor or pas par million pqrts of air plus -- vapar by voluma at 25C and 760 mm. Hg prassure. ** Approximate milligrams of porttculate par cubic motar of air. A Numbara, See Appendix A T See Tentative Limits 13 C' RESPIRABLE DUSTS EVALUATED BY COUNT Swbttenca m. p, p. c. f. * SILICA Crystalline Quartz, Threshold Limit calculated from the formula......................... Cristoballte "" " Amorphous, including natural dlatomaeeous earth......................... 250 ** %SiOi + 5 20 r SILICATES (less than 1% crystalline silica) Asbestos........................................ 5 Mica............................................... 20 Soapstone...................................... 20 Tale............................................... 20 Portland Cement............................. 50 GRAPHITE (natural) ...................... is "Inert" or Nuisance Particulates 50 (or 15 mg/m a whichever is the see Appendix D smaller) ( ( Conversion factors mppcf x 35.3 = million particles pet cubic meter particles per c. c. ( ( * Millions of portide* per cubic foot of air, based on impinger sample* counted by light-field technics. ** The percentage of crystalline silica in the formula is the amount determined from air-borne samples, except in those instances in which other methods hove been shown to be applicable. C 14 TENTATIVE VALUES These substances, with their corresponding tentative limits, comprise those for which a limit has been assigned for the first time or for which a change in the `Recommended' listing has been made. In both cases, the assigned limits /" ould be considered trial values that will remain in the ten' .ive listing for a period of at least two years, during which time difinitive evidence and experience is sought. If accept able at the end of two years, these substances and values will be moved to the RECOMMENDED list Documentation foi tentative values are available for each of these substan ces. Substone# ( ttylamide - Skin ...................................... Aminopyridine.......................................... ( c-Amyl acetate........................................ nzinphos-methyl-Skin................................ Bromoform-Skin............... .......................... n-Butyl acetate .......................................... sec-Butyl acetate...................................... tert-Butyl acetate...................................... ++ sec-Butyl alcohol ...................................... Cadmium (Metal dust and soluble salts) .... Carbon black........ ..................................... Carbon monoxide........................................ ++ a-Chlotoacetophenone (phenacylchloride).. o-Chlorobenzylldene malonomtrile (OCBM) C Chlorine....... ............................................. A4, Chromium, sol. chromic, chromous salts, ( as Ct .................... .................................. Metallic & insol. salts............................ Coal tar pitch volatiles (benzene soluble fraction) (anthracene, BaP, phenanthrene, acridine, chrysene, pyrene)................... -H- Cobalt, Metal fume & dust........................ Crotonaldehyde ......................................... Cumene Skin ............................................ Cyclohexane............................................... Cyclohexene............................................... Oiazomethane..................................... ....... ( 2-Dibromo-ethane-Skin ........................... V .tbutyl phosphate.................... ................. + Dibutylphthalate ..................................... Diethylammo ethanol-Skin......................... ++ Diisopropylamme-Skin............................... ppm* M/M- -- 0.3 0.5 2 125 650 -- 0.2 0.5 5 150. 710. 200 950 200. 950. 150. 450. -- 0.2 - 3.5 50. 55. 0.05 0.3 .05 0.4 1. 3. 0.5 - 1. 0.2 - 0.1 2. 6. 50. 245. 300. 1,050. 300. 1,015. 0.2 0.4 25. 190. 1. 5. - 5. 10. 50. 5. 20. * Porta of vapor or ga* par million parts of air plus vapor by velum* at 2?C and 760 mm. Hg prssturs. C Approximate milligrams of particulate per Cubic motor of air. + 1966 Revision ++ 1966 Additions 15 EC- 2032 Subttonca Dimethylphthalate...................................... Diphenyl..................................................... Ethylamine....... ......................................... Ethyl sec-amyl ketone (S-methyl-3-heptanone).......................................................... Ethyl benzene ............................................ Ethyl butyl ketone (3-Heotanone).............. + C Ethylene glycol dinitrate &/or nitroglyeerinSkin ................................................. ... Ethylene imine-Skm ................................. c Ethyl mercaptan................................. ........ N-Ethyimorpholine-Skin............................. Fibrous glass............................................. Formic acid ............................................... ++ Gasoline_________ _____ _____________ sec-Hexyl acetate ++ Hexachloronaphthalene - Skin................... iron oxide fume ......................................... Isoamyl acetate.......................................... Isobutyl acetate......................................... H- Isobutyl alcohol......................................... lsoorooyl acetate....................................... + Maleic anhydride........................................ Methylamine............................................... Methyl (n-amyl) ketone (2-Heptanone) ...... Methyl iodide - Skin .................................. Methyl isocyanate - Skin ...................... Monomethyl hydraztne - Skin.................. Naphtha (coal tar).................................. Nitric oxide ........................................... Octachloronaphthalene Skin................ Oxalic acid............................................ Parquat - Skin ........................................ Phenyl ether (vapor).............................. Phenyl ether-Biphenyl mixture (vapor).... Phenyl glycidyl ether (PGE) ............... Rival (2-Pivalyl-l, 3-mdandione) ......... Propyl alcohol........................................ Propylene inline - Skin........................... Rhodium, Metal fume and dusts ...... Soluble salts ....................................... Ronnel..................................................... Selenium hexafluoride .................... Tellurium hexafluoride........................... Terphenyls.............................................. Tetrachloronaphthalene - Skin................. Tetramethyl lead (TML) (as lead) - Skin . Tetramethyl succmonitnle - Skin ......... Tiemolite .................. ........................... Tributyl phosphate ................................. 1,1,2-Trichloroethane - Skin ................. Xylene...................................................... ++ Zinc chloride.......................................... + 1966 Revision ++ 1966 Additions t For intermittent exposure only ppm1 25. 130. g100. 435. I 50. 230. 0.02f 0. If 0.5 u 10. 25. 20. 94. - 5. 5. 9. A 50. 300. -- 10-.j' 100. 525.1 150. 700. 100. 300. 250. 950. 0.25 1. 10. 12. 100. 465. 5. 28. 0.5 3. 5 mppcf- S. 10. 45. 100. 435. 1. 16 Appendix A A1 Benzidine Because of high incidence of bladder tumors in iiian, any exposure, including skin, is extremely hazardous, ( A2 P-Mophthylomine. Because of the extremely high incidence of bladder tumors in workers handling this compound and the inability to control exposures,^-naphthylamme has been pro hibited from manufacture, use and other activities that in volve human contact by the State of Pennsylvania. A'N-Nitrosodimethylamine Because of extremely high toxicity and presumed carcinogenic potential of this compound, con tact by any route should not be permitted. Polytetrafluoroethylene* decomposition products. C Thermal decomposition of the fluorocarbon chain in air leads to the formation of oxidized products containing carbon, fluor ine and oxygen. Because these products decompose by hydro lysis in alkaline solution, they can be quantitatively deter mined in air as riuoride to provide an index of exposure. No TLV is recommended pending determination of the toxicity of the products, but air concentrations should be minimal. Asf3 Propiolactene Because of high acute toxicity and demonstra ted skin tumor ptoduction in animals, contact by any route should be avoided. A8 Gasoline. The composition of gasoline vaties 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, other aromatics and additives should be determined to aitive at the appropriate TLV (Elkins, et al. A.l.H.A.J. 24, 99, 1963), Trade Names: Algoflon, Fluon, Halon, Teflon, Tetran Appendix B 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 die absence of informa tion to the contrary, the effects of the different hazards should 17 EC- 2033 be considered as additive.That is, if the Sum of the following fractions, Ci 4- C2-K ... Cn T i Te ~ exceeds unity, then the threshold limit of the mixture shot 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 mixtur^^- i such cases the threshold limit ordinarily is exceeded!! v when at least one member of the series (Ct ot_Cz etc.) ; T, Ta 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, lar probably at low. ^ When a given operation or process characteristically emits a number of harmful dusts, fumes, vapors or gases, it will frequently be only feasible to attempt to evaluate the hazard by measurement of a single 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 cont--'i- nants ordinarily present. I Examples of processes which are typically associated with two or more harmful atmospheric contaminants are welding, automobile repair, blasting, painting, lacquering, certain foundry operations, diesel exhausts, etc, (Example 2.) * 18 r c THRESHOLD LIMIT VALUES FOR MIXTURES EXAMPLES 1A. General case, where alt Is analyzed tor each component. s. ADDITIVE effects Cl + _Ci_ + _Cs_ + . , . c = 1 Ti Tz T T Air contains 5 ppm of carbon tetrachloride (TLV, 10), 20 ppm of ethylene dichlortde (TLV, SO) and 10 ppm of ethylene dibro mide, (TLV, 25). 5 + 20 is 50 10 IT 65 = 1.3 50 Threshold limit is exceeded. ( ( c b. INDEPENDENT EFFECTS Air contains 0.15 mg/ma of lead (TLV, 0.2) and 0.7 mg/m Jof sulfuric acid (TLV, 1). 0.15 = 0.20 0.75; 0,7 =s 0.7 I- 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 ot 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). Ci + Ca =st Cm 100 350 Tm Solution applicable to "spot" solvent mixture usage, where all ot nearly all, solvent evap orates. Ci = Ca -- _1_ Cm 2 Ci + Ci = 2C i 100 350 Tm 19 EC- 2034 7Ci t_2Cj_ = 2C i 700 700 Tm Tm = 700 x 2 = 155 ppm 9 IB. b. General Exact Solution for Mixtures of n Components With Additive Effects and Different Vapor Pressures. (1) Cl + C Z + . . . T CM = 1; Ti T 2 TN (2) Ct + Cz + a . T Cn = T; (2. _i_ + Cz + . . . + Ch = 1. TT T By the Law of Partial Pressures, (3) C i = ap i. And by Raoult*s Law, (4) pi = Ft pi". Combine (3) and (4) to obtain (5) C i = aF ip t. Combming(l), (2,1) and(S), we obtain (6) FlDl0 + F20 2 TT Fo^i = T Fipi + F202* + * . . + FnO.j Ti Tz Tn and solving for T, (6.1) T = F i o i* Fap.ll F ip i FzpzT i Tz i =n or 2 Fipi0 (6.2) T =1=1 i =n X i =1 Ftp t` Tt T = Threshold Limit Value in ppm. C = Vapor concentration m ppm. p = Vapor pressure of component in solution. f i V C c c p" = Vapor pressure of pure component. F = Mol fraction of component in solution. a = A constant of proportionality. Subscripts 1.2, ... n relate tbe 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. Density T pat Mol frac25C tlon in half-and half solu tion by volume Trichloroylene(l) 131.4 1.46g/mll00 73mm Hg 0. 527 Methylchloroform (2) 133.42 1.33 g/ml 350 125mm Hg 0.473 Fipf = (0. 527) (73) = 38.2 FzpZ" =(0.473) (125) = 59. 2 38.2 + 59.2 = (97.4) (350)= (97.4) (350) = 177 ( 38.2 + 59.2 100 350 133.8 + 59.2 193.0 T = 177 ppm (Note difference in T.L. V. when account is taken of vapor piessure and mol fraction in comparison with above example where such account is not taken). A mixture of one part of (1) parathion (TLV, 0,1) and two parts of (2) EPN (TLV, 0.5). 20 21 EC- 2035 Cl + Cl = Cm: Cl = lCl 0.1 0. 5 Tm Cm = 3Ci Ci -1- 2Ci 0.1 0, 5 7C 1 = 3C i 0.5 Tm Tm =1.5 =0.21 mg/m3 7 1C. T. L. V. for Mixture* of Mineral Duets. For mixtures of biologically active mineral dusts Die general formula for mixtures may be used. With the exception of asbestos, pure minerals are assigned TLV of 2.5, 20 or 50. For a mixture containing 80% talc and 20% quartz, the Tlv for 100% of the mixture "C" Is given by: t TLV = 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 = 0.25 + 0.25 + 0.5 ~ 7-3 "W'6* 2.5 20 20 The limit for 25% quartz approximates 8 mppcf. / V c 22 Appendix C BASES FOR ASSIGNING LIMITING "C" VALUES 8y definition in the Preface, a listed value bear- r,ng 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 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 aterially reduce work efficiency. In order for the Committee to decide whether a subC.ance is a candidate for a "C" listing, some idelines must be formulated on the permissive uctuation 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. MoreI ivet, 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 mf/mi c 0 to 1 c 1 + to 10 T**f T.LV. Fictor Eumplit 3 Toluene diisocyanate-T. L. V., 0.02 ppm, if permitted to rise above 0.06 ppm may result in sensitization in a single sub sequent exposure.! "C" listing recommended on category b. 2 Manganese -T.L.V., 5mg/m3, contains little or no safety factor. All values should fluct uate below 5mg/mJ. "C" listing recommended on category b. 23 EC- 2036 T.L.V. RANGE T.LV. ppm* or ttit/ftiJ Foctor 10+ to 100 1,5 100 +to 1000 1.25 Cumples Methyl stytene-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 grelating to category c. Nof "C" listing recommended^ * 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 timef weighted average implies that each excursion above the limiil 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 (AlzOs) Limestone Calcium carbonate Magnesite Cellulose Marble * ( Portland Cement Corundum (AI2O3) Plaster of Paris Rouge Emery Glycerine Mist Graphite (synthetic) Gypsum Silicon Carbide Starch Sucrose Tin Oxide c Vegetable oil mists Titanium Dioxide (except castor, cashew nut, or similar irritant oils) `When toxic impurities are not present. 24 Appendix E Some Simple Asphyxiants - "Inert" Gases and Vapors. r Acetylene Argon Ethane Ethylene Helium Hydrogen Methane Neon Nitrogen Nitrous Oxide f ( ( E. J. Baier Allan L.Coleman Hervey B. Elkins, Ph.D. W.G. Fredrick, Ph.D. Bernard Grabois, P.E. Paul Gross, M.D. Wr-'and J. Hayes, Jr. M.D. Harold N. MacFarland, Ph.D., Consultant E. Mastromatteo, M.D, Russel G.Scovill Ralph G. Smith, Ph.D. George w. Wright, M.D. Consultant Mitchell R. Zavon, M.D. Herbert E. Stokinger, Ph.D., Chairman ( 25 EC- 2037