View all text of Subpart Z [§ 1915.1000 - § 1915.1501]

§ 1915.1000 - Air contaminants.

Wherever this section applies, an employee's exposure to any substance listed in Table Z—Shipyards of this section shall be limited in accordance with the requirements of the following paragraphs of this section.

(a)(1) Substances with limits preceded by “C”—Ceiling values. An employee's exposure to any substance in Table Z—Shipyards, the exposure limit of which is preceded by a “C,” shall at no time exceed the exposure limit given for that substance. If instantaneous monitoring is not feasible, then the ceiling shall be assessed as a 15-minute time weighted average exposure which shall not be exceeded at any time over a working day.

(2) Other Substances—8-hour Time Weighted Averages. An employee's exposure to any substance in Table Z—Shipyards, the exposure limit of which is not preceded by a “C,” shall not exceed the 8-hour Time Weighted Average given for that substance in any 8-hour work shift of a 40-hour work week.

(b)-(c) [Reserved]

(d) Computation formula. The computation formula which shall apply to employee exposure to more than one substance for which 8-hour time weighted averages are listed in subpart Z of 29 CFR part 1915 in order to determine whether an employee is exposed over the regulatory limit is as follows:

(1)(i) The cumulative exposure for an 8-hour work shift shall be computed as follows:

E = (Ca Ta + Cb Tb + ...Cn Tn) ÷ 8 Where: E is the equivalent exposure for the working shift. C is the concentration during any period of time T where the concentration remains constant. T is the duration in hours of the exposure at the concentration C. The value of E shall not exceed the 8-hour time weighted average specified in subpart Z of 29 CFR part 1915 for the material involved.

(ii) To illustrate the formula prescribed in paragraph (d)(1)(i) of this section, assume that Substance A has an 8-hour time weighted average limit of 100 ppm noted in Table Z—Shipyards. Assume that an employee is subject to the following exposure:

Two hours exposure at 150 ppm Two hours exposure at 75 ppm Four hours exposure at 50 ppm

Substituting this information in the formula, we have

(2 × 150 + 2 × 75 + 4 × 50) ÷ 8 = 81.25 ppm

Since 81.25 ppm is less than 100 ppm, the 8-hour time weighted average limit, the exposure is acceptable.

(2)(i) in case of a mixture of air contaminants an employer shall compute the equivalent exposure as follows:

Em = (C1 ÷ L1 + C2 ÷ L2) + ...(Cn ÷ Ln) Where: Em is the equivalent exposure for the mixture. C is the concentration of a particular contaminant. L is the exposure limit for that substance specified in subpart Z of 29 CFR part 1915. The value of Em shall not exceed unity (1).

(ii) To illustrate the formula prescribed in paragraph (d)(2)(i) of this section, consider the following exposures:

Substance Actual concentration of 8 hour exposure (ppm) 8 hr. TWA PEL (ppm) B5001000 C45200 D40200

Substituting in the formula, we have:

Em = 500 ÷ 1,000 + 45 ÷ 200 + 40 ÷ 200

Em = 0.500 + 0.225 + 0.200

Em = 0.925

Since Em is less than unity (1), the exposure combination is within acceptable limits.

Table Z—Shipyards

Substance CAS No. dppm a *mg/m 3 b *Skin Designation Abate; see Temephos Acetaldehyde75-07-0200360Acetic acid64-19-71025Acetic anhydride108-24-7520Acetone67-64-110002400Acetonitrile75-05-840702-Acetylaminofluorine; see § 1915.101453-96-3 Acetylene74-86-2E Acetylene dichloride; see 1,2-Dichloroethylene Acetylene tetrabromide79-27-6114Acrolein107-02-80.10.25Acrylamide79-06-10.3X Acrylonitrile; see § 1915.1045107-13-1 Aldrin309-00-20.25X Allyl alcohol107-18-625X Allyl chloride107-05-113Allyl glycidyl ether (AGE)106-92-3(C)10(C)45Allyl propyl disulfide2179-59-1212alpha-Alumina1344-28-1 Total dust15Respirable fraction5Aluminum, (as Al) Metal7429-90-5 Total dust15Respirable fraction5Alundum; see alpha-Alumina 4-Aminodiphenyl; see § 1915.101192-67-1 2-Aminoethanol; see Ethanolamine 2-Aminopyridine504-29-00.52Ammonia7664-41-75035Ammonium sulfamate7773-06-0 Total dust15Respirable fraction5n-Amyl acetate628-63-7100525sec-Amyl acetate626-38-0125650Aniline and homologs62-53-3519X Anisidine (o-, p-isomers)29191-52-40.5X Antimony and compounds (as Sb)7440-36-00.5ANTU (alpha Naphthylthiourea)86-88-40.3Argon7440-37-1E Arsenic, inorganic compounds (as As); see § 1915.10187440-38-2Arsenic, organic compounds (as As)7440-38-20.5Arsine7784-42-10.050.2Asbestos; see 1915.1001 Azinphos-methyl86-50-00.2X Barium, soluble compounds (as Ba)7440-39-30.5Barium sulfate7727-43-7 Total dust15Respirable fraction5Benomyl17804-35-2 Total dust15Respirable fraction5Benzene g; see § 1915.102871-43-2 Benzidine; see § 1915.101092-87-5 p-Benzoquinone; see Quinone Benzo(a)pyrene; see Coal tar pitch volatiles Benzoyl peroxide94-36-05Benzyl chloride100-44-715Beryllium and beryllium compounds (as Be); see 1915.1024 (q)7440-41-70.002 Biphenyl; see Diphenyl Bismuth telluride, Undoped1304-82-1 Total dust15Respirable fraction5Bisphenol A; see Diglycidyl ether Boron oxide1303-86-2 Total dust15Boron tribromide10294-33-4110Boron trifluoride7637-07-2(C)1(C)3Bromine7726-95-60.10.7Bromine pentafluoride7789-30-20.10.7Bromoform75-25-20.55X Butadiene (1,3-Butadiene); see 29 CFR 1910.1051; 29 CFR 1910.19(l)106-99-01
ppm/5
ppm
STEL
Butanethiol; see Butyl mercaptan 2-Butanone (Methyl ethyl ketone)78-93-32005902-Butoxyethanol111-76-250240X n-Butyl-acetate123-86-4150710sec-Butyl acetate105-46-4200950tert-Butyl acetate540-88-5200950n-Butyl alcohol71-36-3100300sec-Butyl alcohol78-92-2150450tert-Butyl alcohol75-65-0100300Butylamine109-73-9(C)5(C)15X tert-Butyl chromate (as CrO3); see 1915.1026 n1189-85-1 n-Butyl glycidyl ether (BGE)2426-08-650270Butyl mercaptan109-79-50.51.5p-tert-Butyltoluene98-51-11060Cadmium dust fume (as Cd); see 1915.10277440-43-9Calcium carbonate1317-65-3 Total dust15Respirable fraction5Calcium hydroxide1305-62-0Calcium hydroxide Total dust15Respirable fraction5Calcium oxide1305-78-85Calcium silicate1344-95-2 Total dust15Respirable fraction5Calcium sulfate7778-18-9 Total dust15Respirable fraction5Camphor, synthetic76-22-22Carbaryl (Sevin)63-25-25Carbon black1333-86-43.5Carbon dioxide124-38-950009000Carbon disulfide75-15-02060X Carbon monoxide630-08-05055Carbon tetrachloride56-23-51065X Cellulose9004-34-6 Total dust15Respirable fraction5Chlordane57-74-90.5X Chlorinated camphene8001-35-20.5X Chlorinated diphenyl oxide55720-99-50.5Chlorine7782-50-513Chlorine trifluoride7790-91-2(C)0.1(C)0.4Chloroacetaldehyde107-20-0(C)1(C)3a-Chloroacetophenone (Phenacyl chloride)532-27-40.050.3Chlorobenzene108-90-775350o-Chlorobenzylidene malononitrile2698-41-10.050.4Chlorobromomethane74-97-520010502-Chloro-1,3-butadiene; see beta-Chloroprene Chlorodiphenyl (42% Chlorine) (PCB)53469-21-91X Chlorodiphenyl (54% Chlorine) (PCB)11097-69-10.5X 1-Chloro,2,3-epoxypropane; see Epichlorohydrin 2-Chloroethanol; see Ethylene chlorohydrin Chloroethylene; see Vinyl chloride Chloroform (Trichloromethane)67-66-350240bis(Chloromethyl) ether; see § 1915.1008542-88-1 Chloromethyl methyl ether; see § 1915.1006107-30-2 1-Chloro-1-nitropropane600-25-920100Chloropicrin76-06-20.10.7 beta-Chloroprene126-99-82590X 2-Chloro-6-(trichloromethyl) pyridine1929-82-4 Total dust15Respirable fraction5Chromium (II) compounds (as Cr)7440-47-30.5Chromium (III) compounds (as Cr)7440-47-30.5Chromium (VI) compounds; see 1915.1026 oChromium metal and insol. salts (as Cr)7440-47-31Chrysene; see Coal tar pitch volatiles Clopidol2971-90-6 Total dust15Respirable fraction5Coal tar pitch volatiles (benzene soluble fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene65966-93-20.2Cobalt metal, dust, and fume (as Co)7440-48-40.1Copper7440-50-8 Fume (as Cu)0.1Dusts and mists (as Cu)1Corundum; see Emery Cotton dust (raw)1 Crag herbicide (Sesone)136-78-7 Total dust15Respirable fraction5Cresol, all isomers1319-77-3522X Crotonaldehyde123-73-9;26 4170-30-3 Cumene98-82-850245X Cyanides (as CN)Varies with Compound5Cyanogen460-19-510Cyclohexane110-82-73001050Cyclohexanol108-93-050200Cyclohexanone108-94-150200Cyclohexene110-83-83001015Cyclonite121-82-41.5X Cyclopentadiene542-92-7752002,4-D (Dichlorophenoxyacetic acid)94-75-710Decaborane17702-41-90.050.3X Demeton (Systox)8065-48-30.1X Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone)123-42-2502401,2-Diaminoethane; see Ethylenediamine Diazomethane334-88-30.20.4Diborane19287-45-70.10.11,2-Dibromo-3-chloropropane (CBCP); see § 1915.104496-12-81,2-Dibromoethane; see Ethylene dibromide Dibutyl phosphate107-66-415Dibutyl phthalate84-74-25Dichloroacetylene7572-29-4(C)0.1(C)0.4o-Dichlorobenzene95-50-1(C)50(C)300p-Dichlorobenzene106-46-7754503,3′-Dichlorobenzidine; see § 1915.100791-94-1 Dichlorodifluoromethane75-71-8100049501,3-Dichloro-5,5-dimethyl hydantoin118-52-50.2Dichlorodiphenyltrichloroethane (DDT)50-29-31X 1,1-Dichloroethane75-34-31004001,2-Dichloroethane; see Ethylene dichloride 1,2-Dichloroethylene540-59-0200790Dichloroethyl ether111-44-4(C)15(C)90X Dichloromethane; see Methylene chloride Dichloromonofluoromethane75-43-4100042001,1-Dichloro-1-nitroethane594-72-9(C)10(C)601,2-Dichloropropane; see Propylene dichloride Dichlorotetrafluoroethane76-14-210007000Dichlorvos (DDVP)62-73-71X Dicyclopentadienyl iron102-54-5 Total dust15Respirable fraction5Dieldrin60-57-10.25X Diethylamine109-89-725752-Diethylaminoethanol100-37-81050Diethylene triamine111-40-0(C)10(C)42X Diethyl ether; see Ethyl ether Difluorodibromomethane75-61-6100860Diglycidyl ether (DGE)2238-07-5(C)0.5(C)2.8Dihydroxybenzene; see Hydroquinone Diisobutyl ketone108-83-850290Diisopropylamine108-18-9520X 4-Dimethylaminoazobenzene; see § 1915.101560-11-7 Dimethoxymethane; see Methylal Dimethyl acetamide127-19-51035X Dimethylamine124-40-31018Dimethylaminobenzene; see Xylidine Dimethylaniline (N,N-Dimethylaniline)121-69-7525X Dimethylbenzene; see Xylene Dimethyl-1,2-dibromo- 2,2-dichloroethyl phosphate300-76-53Dimethylformamide68-12-21030X 2,6-Dimethyl-4-heptanone; see Diisobutyl ketone 1,1-Dimethylhydrazine57-14-70.51X Dimethylphthalate131-11-35Dimethyl sulfate77-78-315X Dinitrobenzene (all isomers)1X (ortho)528-29-0 (meta)99-65-0 (para)100-25-4 Dinitro-o-cresol534-52-10.2X Dinitrotoluene25321-14-61.5X Dioxane (Diethylene dioxide)123-91-1100360X Diphenyl (Biphenyl)92-52-40.21Diphenylamine122-39-410Diphenylmethane diisocyanate; see Methylene bisphenyl isocyanate Dipropylene glycol methyl ether34590-94-8100600X Di-sec octyl phthalate (Di-(2-ethylhexyl) phthalate)117-81-75Emery12415-34-8 Total dust15Respirable fraction5Endosulfan115-29-70.1X Endrin72-20-80.1X Epichlorohydrin106-89-8519X EPN2104-64-50.5X 1,2-Epoxypropane; see Propylene oxide 2,3-Epoxy-1-propanol; see Glycidol Ethane74-84-0E Ethanethiol; see Ethyl mercaptan Ethanolamine141-43-5362-Ethoxyethanol (Cellosolve)110-80-5200740X 2-Ethoxyethyl acetate (Cellosolve acetate)111-15-9100540X Ethyl acetate141-78-64001400Ethyl acrylate140-88-525100X Ethyl alcohol (Ethanol)64-17-510001900Ethylamine75-04-71018Ethyl amyl ketone (5-Methyl-3-heptanone)541-85-525130Ethyl benzene100-41-4100435Ethyl bromide74-96-4200890Ethyl butyl ketone (3-Heptanone)106-35-450230Ethyl chloride75-00-310002600Ethyl ether60-29-74001200Ethyl formate109-94-4100300Ethyl mercaptan75-08-10.51Ethyl silicate78-10-4100850Ethylene74-85-1E Ethylene chlorohydrin107-07-3516X Ethylenediamine107-15-31025Ethylene dibromide106-93-4(C)25(C)190X Ethylene dichloride (1,2-Dichloroethane)107-06-250200Ethylene glycol dinitrate628-96-6(C)0.2(C)1X Ethylene glycol methyl acetate; see Methyl cellosolve acetate Ethyleneimine; see § 1915.1012151-56-4 Ethylene oxide; see § 1915.104775-21-8 Ethylidene chloride; see 1,1-Dichloroethane N-Ethylmorpholine100-74-32094X Ferbam14484-64-1 Total dust15Ferrovanadium dust12604-58-91Fibrous Glass Total dust15Respirable fraction5Fluorides (as F)Varies with compound2.5Fluorine7782-41-40.10.2Fluorotrichloromethane (Trichlorofluoromethane)75-69-410005600Formaldehyde; see § 1915.104850-00-0 Formic acid64-18-659Furfural98-01-1520X Furfuryl alcohol98-00-050200Gasoline8006-61-9A 3Glycerin (mist)56-81-5 Total dust15Respirable fraction5Glycidol556-52-550150Glycol monoethyl ether; see 2-Ethoxyethanol Graphite, natural, respirable dust7782-42-5( 2)( 2)( 2) Graphite, synthetic Total dust15Respirable fraction5Guthion; see Azinphos methyl Gypsum13397-24-5 Total dust15Respirable fraction5Hafnium7440-58-60.5Helium7440-59-7E Heptachlor76-44-80.5X Heptane (n-Heptane)142-82-55002000Hexachloroethane67-72-1110X Hexachloronaphthalene1335-87-10.2X n-Hexane110-54-350018002-Hexanone (Methyl n-butyl ketone)591-78-6100410Hexone (Methyl isobutyl ketone)108-10-1100410sec-Hexyl acetate108-84-950300Hydrazine302-01-211.3X Hydrogen1333-74-0E Hydrogen bromide10035-10-6310Hydrogen chloride7647-01-0(C)5(C)7Hydrogen cyanide74-90-81011X Hydrogen fluoride (as F)7664-39-332Hydrogen peroxide7722-84-111.4Hydrogen selenide (as Se)7783-07-50.05 Hydrogen sulfide7783-06-41015Hydroquinone123-31-92Indene95-13-61045Indium and compounds (as In)7440-74-60.1Iodine7553-56-2(C)0.1(C)1Iron oxide fume1309-37-110Iron salts (soluble) (as Fe)Varies with compound1Isoamyl acetate123-92-2100525Isoamyl alcohol (primary and secondary)123-51-3100360Isobutyl acetate110-19-0150700Isobutyl alcohol78-83-1100300Isophorone78-59-125140Isopropyl acetate108-21-4250950Isopropyl alcohol67-63-0400980Isopropylamine75-31-0512Isopropyl ether108-20-35002100Isopropyl glycidyl ether (IGE)4016-14-250240Kaolin1332-58-7 Total dust15Respirable fraction5Ketene463-51-40.50.9Lead, inorganic (as Pb); see § 1915.10257439-92-1Limestone1317-65-3 Total dust15Respirable fraction5Lindane58-89-90.5X Lithium hydride7580-67-80.025L.P.G. (Liquefied petroleum gas)68476-85-710001800 Magnesite546-93-0 Total dust15Respirable fraction5Magnesium oxide fume1309-48-4 Total particulate15Malathion121-75-5 Total dust15X Maleic anhydride108-31-60.25 Manganese compounds (as Mn)7439-96-5(C)5Manganese fume (as Mn)7439-96-5(C)5Marble1317-65-3 Total dust15Respirable fraction5Mercury (aryl and inorganic)(as Hg)7439-97-60.1X Mercury (organo) alkyl compounds (as Hg)7439-97-60.01X Mercury (vapor) (as Hg)7439-97-60.1X Mesityl oxide141-79-725100Methane74-82-8E Methanethiol; see Methyl mercaptan Methoxychlor72-43-5 Total dust152-Methoxyethanol (Methyl cellosolve)109-86-42580X 2-Methoxyethyl acetate (Methyl cellosolve acetate)110-49-625120X Methyl acetate79-20-9200610Methyl acetylene (Propyne)74-99-710001650Methyl acetylene-propadiene mixture (MAPP)10001800Methyl acrylate96-33-31035X Methylal (Dimethoxy-methane)109-87-510003100Methyl alcohol67-56-1200260Methylamine74-89-51012Methyl amyl alcohol; see Methyl isobutyl carbinol Methyl n-amyl ketone110-43-0100465Methyl bromide74-83-9(C)20(C)80X Methyl butyl ketone; see 2-Hexanone Methyl cellosolve; see 2-Methoxyethanol Methyl cellosolve acetate; see 2-Methoxyethyl acetate Methyl chloride74-87-3100210Methyl chloroform (1,1,1-Trichloroethane)71-55-63501900Methylcyclohexane108-87-25002000Methylcyclohexanol25639-42-3100470o-Methylcyclohexanone583-60-8100460X Methylene chloride; see § 1910.1052 Methyl ethyl ketone (MEK); see 2-Butanone Methyl formate107-31-3100250Methyl hydrazine (Monomethyl hydrazine)60-34-4(C)0.2(C)0.35X Methyl iodide74-88-4528X Methyl isoamyl ketone110-12-3100475Methyl isobutyl carbinol108-11-225100X Methyl isobutyl ketone; see Hexone Methyl isocyanate624-83-90.020.05X Methyl mercaptan74-93-10.51Methyl methacrylate80-62-6100410100 Methyl propyl ketone; see 2-Pentanone Methyl silicate681-84-5530alpha-Methyl styrene98-83-9(C)100(C)480Methylene bisphenyl isocyanate (MDI)101-68-8(C)0.02(C)0.2Mica; see Silicates Mineral wool Total dust15Respirable dust5Molybdenum (as Mo)7439-98-7 Soluble compounds5Insoluble compounds Total dust15Monomethyl aniline100-61-829X Monomethyl hydrazine; see Methyl hydrazine Morpholine110-91-82070X Naphtha (Coal tar)8030-30-6100400Naphthalene91-20-31050alpha-Naphthylamine; see § 1915.1004134-32-7 beta-Naphthylamine; see § 1915.100991-59-8Neon7440-01-9Nickel carbonyl (as Ni)13463-39-30.0010.007Nickel, metal and insoluble compounds (as Ni)7440-02-01Nickel, soluble compounds (as Ni)7440-02-01Nicotine54-11-50.5X Nitric acid7697-37-225Nitric oxide10102-43-92530p-Nitroaniline100-01-616X Nitrobenzene98-95-315X p-Nitrochlorobenzene100-00-51X 4-Nitrodiphenyl; see § 1915.100392-93-3 Nitroethane79-24-3100310Nitrogen7727-37-9E Nitrogen dioxide10102-44-0(C)5(C)9Nitrogen trifluoride7783-54-21029Nitroglycerin55-63-0(C)0.2(C)2X Nitromethane75-52-51002501-Nitropropane108-03-225902-Nitropropane79-46-92590N-Nitrosodimethylamine; see § 1915.101662-79-9Nitrotoluene (all isomers)530X o-isomer88-72-2; m-isomer99-08-1; p-isomer99-99-0 Nitrotrichloromethane; see Chloropicrin Nitrous oxide10024-97-2E Octachloronaphthalene2234-13-10.1X Octane111-65-94001900Oil mist, mineral8012-95-15Osmium tetroxide (as Os)20816-12-00.002Oxalic acid144-62-71Oxygen difluoride7783-41-70.050.1Ozone10028-15-60.10.2Paraquat, respirable dust4685-14-7;0.5X 1910-42-5; 2074-50-2 Parathion56-38-20.1Particulates not otherwise regulated Total dust organic and inorganic15PCB; see Chlorodiphenyl (42% and 54% chlorine) Pentaborane19624-22-70.0050.01Pentachloronaphthalene1321-64-80.5X Pentachlorophenol87-86-50.5X Pentaerythritol115-77-5 Total dust15Respirable fraction5Pentane109-66-050015002-Pentanone (Methyl propyl ketone)107-87-9200700Perchloroethylene (Tetrachloroethylene)127-18-4100670Perchloromethyl mercaptan594-42-30.10.8Perchloryl fluoride7616-94-6313.5Perlite93763-70-3 Total dust15Respirable fraction5Petroleum distillates (Naphtha)(Rubber Solvent)A 3Phenol108-95-2519X p-Phenylene diamine106-50-30.1X Phenyl ether, vapor101-84-817Phenyl ether-biphenyl mixture, vapor17Phenylethylene; see Styrene Phenyl glycidyl ether (PGE)122-60-11060Phenylhydrazine100-63-0522X Phosdrin (Mevinphos)7786-34-70.1X Phosgene (Carbonyl chloride)75-44-50.10.4Phosphine7803-51-20.30.4Phosphoric acid7664-38-21Phosphorus (yellow)7723-14-00.1Phosphorus pentachloride10026-13-81Phosphorus pentasulfide1314-80-31Phosphorus trichloride7719-12-20.53Phthalic anhydride85-44-9212Picloram1918-02-1 Total dust15Respirable fraction5Picric acid88-89-10.1Piperazine dihydrochloride142-64-3X Pindone (2-Pivalyl-1,3-indandione)83-26-10.1Plaster of Paris26499-65-0 Total dust15Respirable fraction5Platinum (as Pt)7440-06-4 MetalSoluble salts0.002Polytetrafluoroethylene decomposition productsA 2Portland cement65997-15-1 Total dust1510 Respirable fraction5Propargyl alcohol107-19-71X beta-Propriolactone; see § 1915.101357-57-8 Propionic acid79-09-4n-Propyl acetate109-60-4200840n-Propyl alcohol71-23-8200500n-Propyl nitrate627-13-425110Propylene dichloride78-87-575350Propylene imine75-55-825X Propylene oxide75-56-9100240Propyne; see Methyl acetylene Pyrethrum8003-34-75Pyridine110-86-1515Quinone106-51-40.10.4RDX; see Cyclonite Rhodium (as Rh), metal fume and insoluble compounds7440-16-60.1Rhodium (as Rh), soluble compounds7440-16-60.001Ronnel299-84-310Rotenone83-79-45RougeTotal dust15Respirable fraction5Selenium compounds (as Se)7782-49-20.2Selenium hexafluoride (as Se)7783-79-10.050.4Silica, amorphous, precipitated and gel112926-00-8( 2)( 2)( 2) Silica, amorphous, diatomaceous earth, containing less than 1% crystalline silica61790-53-2( 2)( 2)( 2) Silica, crystalline, respirable dust Cristobalite; see 1915.105314464-46-1 Quartz; see 1915.1053 514808-60-7 Tripoli (as quartz); see 1915.1053 51317-95-9 Tridymite; see 1915.105315468-32-3 Silica, fused, respirable dust60676-86-0( 2)( 2)( 2) Silicates (less than 1% crystalline silica) Mica (respirable dust)12001-26-2( 2)( 2)( 2) Soapstone, total dust( 2)( 2)( 2) Soapstone, respirable dust( 2)( 2)( 2) Talc (containing asbestos)( 3)( 3)( 3) Talc (containing no asbestos), respirable dust14807-96-6( 2)( 2)( 2) Tremolite, asbestiform( 3)( 3)( 3) Silicon7440-21-3 Total dust15Respirable fraction5Silicon carbide409-21-2 Total dust15Respirable fraction5Silver, metal and soluble compounds (as Ag)7440-22-40.01Soapstone; see Silicates Sodium fluoroacetate62-74-80.05X Sodium hydroxide1310-73-22Starch9005-25-8 Total dust15Respirable fraction5Stibine7803-52-30.10.5Stoddard solvent8052-41-32001150Strychnine57-24-90.15Styrene100-42-510042050 Sucrose57-50-1 Total dust15Respirable fraction5Sulfur dioxide7446-09-5513Sulfur hexafluoride2551-62-410006000Sulfuric acid7664-93-91Sulfur monochloride10025-67-916Sulfur pentafluoride5714-22-70.0250.25Sulfuryl fluoride2699-79-8520Systox, see Demeton 2,4,5-T (2,4,5-trichlorophenoxyacetic acid)93-76-510Talc; see Silicates— Tantalum, metal and oxide dust7440-25-75TEDP (Sulfotep)3689-24-50.2X Teflon decomposition productsA2 Tellurium and compounds (as Te)13494-80-90.1Tellurium hexafluoride (as Te)7783-80-40.020.2Temephos3383-96-8 Total dust15Respirable fraction5TEPP (Tetraethyl pyrophosphate)107-49-30.05X Terphenyls26140-60-3(C)1(C)91,1,1,2-Tetrachloro-2,2-difluoroethane76-11-950041701,1,2,2-Tetrachloro-1,2-difluoroethane76-12-050041701,1,2,2-Tetrachloroethane79-34-5535X Tetrachloroethylene; see Perchloroethylene Tetrachloromethane; see Carbon tetrachloride Tetrachloronaphthalene1335-88-22X Tetraethyl lead (as Pb)78-00-20.1X Tetrahydrofuran109-99-9200590Tetramethyl lead, (as Pb)75-74-10.15X Tetramethyl succinonitrile3333-52-60.53X Tetranitromethane509-14-818Tetryl (2,4,6-Trinitrophenylmethylnitramine)479-45-81.5X Thallium, soluble compounds (as Tl)7440-28-00.1X 4,4′-Thiobis (6-tert, Butyl-m-cresol)96-69-5 Total dust15Respirable fraction5Thiram137-26-85Tin, inorganic compounds (except oxides) (as Sn)7440-31-52Tin, organic compounds (as Sn)7440-31-50.1Tin oxide (as Sn)21651-19-4Total dust15Respirable fraction5Titanium dioxide13463-67-7 Total dust15Toluene108-88-3200750100 Toluene-2,4-diisocyanate (TDI)584-84-9(C)0.02(C)0.14o-Toluidine95-53-4522X Toxaphene; see Chlorinated camphene Tremolite; see Silicates Tributyl phosphate126-73-851,1,1-Trichloroethane; see Methyl chloroform 1,1,2-Trichloroethane79-00-51045X Trichloroethylene79-01-6100535Trichloromethane; see Chloroform Trichloronaphthalene1321-65-95X 1,2,3-Trichloropropane96-18-4503001,1,2-Trichloro-1,2,2-trifluoroethane76-13-110007600Triethylamine121-44-825100Trifluorobromomethane75-63-810006100Trimethyl benzene25551-13-7251202,4,6-Trinitrophenyl; see Picric acid 2,4,6-Trinitrophenylmethylnitramine; see Tetryl 2,4,6-Trinitrotoluene (TNT)118-96-71.5X Triorthocresyl phosphate78-30-80.1Triphenyl phosphate115-86-63Tungsten (as W)7440-33-7 Insoluble compounds5Soluble compounds1Turpentine8006-64-2100560Uranium (as U)7440-61-1 Soluble compounds0.2Insoluble compounds0.2Vanadium1314-62-1 Respirable dust (as V2 O5)(C)0.5Fume (as V2 O5)(C)0.1Vegetable oil mist Total dust15Respirable fraction5Vinyl benzene; see Styrene Vinyl chloride; see § 1915.101775-01-4 Vinyl cyanide; see Acrylonitrile Vinyl toluene25013-15-4100480Warfarin81-81-20.1Xylenes (o-, m-, p-isomers)1330-20-7100435Xylidine1300-73-8525X Yttrium7440-65-51Zinc chloride fume7646-85-71Zinc oxide fume1314-13-25Zinc oxide1314-13-2 Total dust15Respirable fraction5Zinc stearate557-05-1 Total dust15Respirable fraction5Zirconium compounds (as Zr)7440-67-75

Mineral Dusts

Substance mppcf (j)SILICA: Crystalline250 (k)Quartz. Threshold Limit calculated from the formula (p)% SiO2 + 5 Cristobalite Amorphous, including natural diatomaceous earth20 SILICATES (less than 1% crystalline silica) Mica20 Portland cement50 Soapstone20 Talc (non-asbestiform)20 Talc (fibrous), use asbestos limitGraphite (natural)15 Inert or Nuisance Particulates: (m)50 (or 15 mg/m 3 whichever is the smaller) of total dust <1% SiO2Conversion factors mppcf × 35.3 = million particles per cubic meter = particles per c.c.

Footnotes to Table Z—Shipyards:

1 [Reserved]

2 See Mineral Dusts Table.

3 Use Asbestos Limit § 1915.1001.

4 See 1915.1001.

5 See Mineral Dusts table for the exposure limit for any operations or sectors where the exposure limit in § 1915.1053 is stayed or is otherwise not in effect.

* The PELs are 8-hour TWAs unless otherwise noted; a (C) designation denotes a ceiling limit. They are to be determined from breathing-zone air samples.

a Parts of vapor or gas per million parts of contaminated air by volume at 25 °C and 760 torr.

b Milligrams of substance per cubic meter of air. When entry is in this column only, the value is exact; when listed with a ppm entry, it is approximate.

c [Reserved]

d The CAS number is for information only. Enforcement is based on the substance name. For an entry covering more than one metal compound, measured as the metal, the CAS number for the metal is given—not CAS numbers for the individual compounds.

e-f [Reserved]

g For sectors excluded from § 1915.1028 the limit is 10 ppm TWA.

h Where OSHA has published a proposal for a substance but has not issued a final rule, the proposal is referenced and the existing limit is published.

i [Reserved]

j Millions of particles per cubic foot of air, based on impinger samples counted by light-field techniques.

k The percentage of crystalline silica in the formula is the amount determined from airborne samples, except in those instances in which other methods have been shown to be applicable.

m Covers all organic and inorganic particulates not otherwise regulated. Same as Particulates Not Otherwise Regulated.

n If the exposure limit in § 1915.1026 is stayed or is otherwise not in effect, the exposure limit is a ceiling of 0.1 mg/m 3.

o If the exposure limit in § 1915.1026 is stayed or is otherwise not in effect, the exposure limit is 0.1 mg/m 3 (as CrO3) as an 8-hour TWA.

p This standard applies to any operations or sectors for which the respirable crystalline silica standard, 1915.1053, is stayed or otherwise is not in effect.

q This standard applies to any operations or sectors for which the beryllium standard, 1915.1024, is stayed or otherwise is not in effect.

The 1970 TLV uses letter designations instead of a numerical value as follows:

A 1 [Reserved]

A 2 Polytetrafluoroethylene decomposition products. Because these products decompose in part by hydrolysis in alkaline solution, they can be quantitatively determined in air as fluoride to provide an index of exposure. No TLV is recommended pending determination of the toxicity of the products, but air concentrations should be minimal.

A 3 Gasoline and/or Petroleum Distillates. The composition of these materials varies greatly and thus a single TLV for all types of these materials is no longer applicable. The content of benzene, other aromatics and additives should be determined to arrive at the appropriate TLV.

E Simple asphyxiants. The limiting factor is the available oxygen which shall be at least 18% and be within the requirement addressing explosion in subpart B of part 1915.

[58 FR 35514, July 1, 1993, as amended at 61 FR 56856, Nov. 4, 1996; 62 FR 1619, Jan. 10, 1997; 67 FR 44545, July 3, 2002; 71 FR 10377, Feb. 28, 2006; 71 FR 36009, June 23, 2006; 76 FR 80740, Dec. 27, 2011; 81 FR 16874, Mar. 2 2016; 81 FR 31167, May 19, 2016; 81 FR 60273, Sept. 2, 2016; 82 FR 2744, Jan. 9, 2017]