29 C.F.R. § 1926.55

Current through September 8, 2021
Section 1926.55 - Gases, vapors, fumes, dusts, and mists
(a) Exposure of employees to inhalation, ingestion, skin absorption, or contact with any material or substance at a concentration above those specified in the "Threshold Limit Values of Airborne Contaminants for 1970" of the American Conference of Governmental Industrial Hygienists, shall be avoided. See appendix A to this section.
(b) To achieve compliance with paragraph (a) of this section, administrative or engineering controls must first be implemented whenever feasible. When such controls are not feasible to achieve full compliance, protective equipment or other protective measures shall be used to keep the exposure of employees to air contaminants within the limits prescribed in this section. Any equipment and technical measures used for this purpose must first be approved for each particular use by a competent industrial hygienist or other technically qualified person. Whenever respirators are used, their use shall comply with §1926.103.
(c) Paragraphs (a) and (b) of this section do not apply to the exposure of employees to airborne asbestos, tremolite, anthophyllite, or actinolite dust. Whenever any employee is exposed to airborne asbestos, tremolite, anthophyllite, or actinolite dust, the requirements of §1910.1101 or §1926.58 of this title shall apply.
(d) Paragraphs (a) and (b) of this section do not apply to the exposure of employees to formaldehyde. Whenever any employee is exposed to formaldehyde, the requirements of §1910.1048 of this title shall apply.

APPENDIX A TO §1926.55-1970 AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HYGIENISTS' THRESHOLD LIMIT VALUES OF AIRBORNE CONTAMINANTS

THRESHOLD LIMIT VALUES OF AIRBORNE CONTAMINANTS FOR CONSTRUCTION

SubstanceCAS No.dppmamg/m3 bSkin Designation
Abate; see Temephos
Acetaldehyde75-07-0200360-
Acetic acid64-19-71025-
Acetic anhydride108-24-7520-
Acetone67-64-110002400-
Acetonitrile75-05-84070-
2-Acetylaminofluorine; see §1926.111453-96-3
Acetylene74-86-2E
Acetylene dichloride; see 1,2-Dichloroethylene
Acetylene tetrabromide79-27-6114-
Acrolein107-02-80.10.25-
Acrylamide79-06-1-0.3X
Acrylonitrile; see §1926.1145107-13-1
Aldrin309-00-2-0.25X
Allyl alcohol107-18-625X
Allyl chloride107-05-113-
Allyl glycidyl ether (AGE)106-92-3(C)10(C)45-
Allyl propyl disulfide2179-59-1212-
alpha-Alumina1344-28-1
Total dust--
Respirable fraction--
Alundum; see alpha-Alumina
4-Aminodiphenyl; see §1926.111192-67-1
2-Aminoethanol; see Ethanolamine
2-Aminopyridine504-29-00.52-
Ammonia7664-41-75035-
Ammonium sulfamate7773-06-0
Total dust-15-
Respirable fraction-5-
n-Amyl acetate628-63-7100525-
sec-Amyl acetate626-38-0125650-
Aniline and homologs62-53-3519X
Anisidine (o-, p-isomers)29191-52-4-0.5X
Antimony and compounds (as Sb)7440-36-0-0.5-
ANTU (alpha Naphthylthiourea)86-88-4-0.3-
Argon7440-37-1E
Arsenic, inorganic compounds (as As); see §1926.11187440-38-2---
Arsenic, organic compounds (as As)7440-38-2-0.5-
Arsine7784-42-10.050.2-
Asbestos; see 1926.58
Azinphos-methyl86-50-0-0.2X
Barium, soluble compounds (as Ba)7440-39-3-0.5-
Benzeneg; see §1926.112871-43-2
Benzidine; see §1926.111092-87-5
p-Benzoquinone; see Quinone
Benzo(a)pyrene; see Coal tar pitch volatiles
Benzoyl peroxide94-36-0-5-
Benzyl chloride100-44-715-
Beryllium and beryllium compounds (as Be); see 1926.1124(q)7440-41-70.002
Biphenyl; see Diphenyl
Bisphenol A; see Diglycidyl ether
Boron oxide1303-86-2
Total dust-15-
Boron tribromide10294-33-4110-
Boron trifluoride7637-07-2(C)1(C)3-
Bromine7726-95-60.10.7-
Bromine pentafluoride7789-30-20.10.7-
Bromoform75-25-20.55X
Butadiene (1,3-Butadiene); see 29 CFR 1910.1051 ; 29 CFR 1910.19(l) 106-99-0STEL 1 ppm/5 ppm-
Butanethiol; see Butyl mercaptan
2-Butanone (Methyl ethyl ketone)78-93-3200590-
2-Butoxyethanol111-76-250240X
n-Butyl-acetate123-86-4150710-
sec-Butyl acetate105-46-4200950-
tert-Butyl acetate540-88-5200950-
n-Butyl alcohol71-36-3100300-
sec-Butyl alcohol78-92-2150450-
tert-Butyl alcohol75-65-0100300-
Butylamine109-73-9(C)5(C)15X
tert-Butyl chromate (as CrO3); see 1926.1126n1189-85-1
n-Butyl glycidyl ether (BGE)2426-08-650270-
Butyl mercaptan109-79-50.51.5-
p-tert-Butyltoluene98-51-11060-
Cadmium (as Cd); see 1926.11277440-43-9
Calcium carbonate1317-65-3
Total dust--
Respirable fraction--
Calcium oxide1305-78-8-5-
Calcium sulfate7778-18-9
Total dust-15-
Respirable fraction-5-
Camphor, synthetic76-22-2-2-
Carbaryl (Sevin)63-25-2-5-
Carbon black1333-86-4-3.5-
Carbon dioxide124-38-950009000-
Carbon disulfide75-15-02060X
Carbon monoxide630-08-05055-
Carbon tetrachloride56-23-51065X
Cellulose9004-34-6
Total dust--
Respirable fraction--
Chlordane57-74-9-0.5X
Chlorinated camphene8001-35-2-0.5X
Chlorinated diphenyl oxide55720-99-5-0.5-
Chlorine7782-50-513-
Chlorine dioxide10049-04-40.10.3
Chlorine trifluoride7790-91-2(C)0.1(C)0.4-
Chloroacetaldehyde107-20-0(C)1(C)3-
a-Chloroacetophenone (Phenacyl chloride)532-27-40.050.3-
Chlorobenzene108-90-775350-
o-Chlorobenzylidene malononitrile2698-41-10.050.4-
Chlorobromomethane74-97-52001050-
2-Chloro-1,3-butadiene; see beta-Chloroprene
Chlorodiphenyl (42% Chlorine) (PCB)53469-21-9-1X
Chlorodiphenyl (54% Chlorine) (PCB)11097-69-1-0.5X
1-Chloro,2,3-epoxypropane; see Epichlorohydrin
2-Chloroethanol; see Ethylene chlorohydrin
Chloroethylene; see Vinyl chloride
Chloroform (Trichloromethane)67-66-3(C)50(C)240-
bis(Chloromethyl) ether; see §1926.1108542-88-1
Chloromethyl methyl ether; see §1926.1106107-30-2
1-Chloro-1-nitropropane600-25-920100-
Chloropicrin76-06-20.10.7-
beta-Chloroprene126-99-82590X
Chromium (II) compounds
(as Cr)7440-47-3-0.5-
Chromium (III) compounds
(as Cr)7440-47-3-0.5-
Chromium (VI) compounds; See 1926.1126o
Chromium metal and insol. salts (as Cr)7440-47-3-1-
Chrysene; see Coal tar pitch volatiles
Coal tar pitch volatiles (benzene soluble fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene65996-93-2-0.2-
Cobalt metal, dust, and fume (as Co)7440-48-4-0.1-
Coke oven emissions; see §1926.1129
Copper7440-50-8
Fume (as Cu)-0.1-
Dusts and mists (as Cu)-1-
Corundum; see Emery
Cotton dust (raw)-1
Crag herbicide (Sesone)136-78-7
Total dust--
Respirable fraction--
Cresol, all isomers1319-77-3522X
Crotonaldehyde123-73-9;26
4170-30-3
Cumene98-82-850245X
Cyanides (as CN)Varies with Compound-5X
Cyanogen460-19-510--
Cyclohexane110-82-73001050-
Cyclohexanol108-93-050200-
Cyclohexanone108-94-150200-
Cyclohexene110-83-83001015-
Cyclonite121-82-4-1.5X
Cyclopentadiene542-92-775200-
DDT, see Dichlorodiphenyltrichloroethane
DDVP, see Dichlorvos
2,4-D (Dichlorophenoxyacetic acid)94-75-7-10-
Decaborane17702-41-90.050.3X
Demeton (Systox)8065-48-3-0.1X
Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone)123-42-250240-
1,2-Diaminoethane; see Ethylenediamine
Diazomethane334-88-30.20.4-
Diborane19287-45-70.10.1-
1,2-Dibromo-3-chloropropane (DBCP); see §1926.114496-12-8-
1,2-Dibromoethane; see Ethylene dibromide
Dibutyl phosphate107-66-415-
Dibutyl phthalate84-74-2-5-
Dichloroacetylene7572-29-4(C)0.1(C)0.4-
o-Dichlorobenzene95-50-1(C)50(C)300-
p-Dichlorobenzene106-46-775450-
3,3'-Dichlorobenzidine; see §1926.110791-94-1
Dichlorodifluoromethane75-71-810004950-
1,3-Dichloro-5,5-dimethyl hydantoin118-52-5-0.2-
Dichlorodiphenyltrichloroethane (DDT)50-29-3-1X
1,1-Dichloroethane75-34-3100400-
1,2-Dichloroethane; see Ethylene dichloride
1,2-Dichloroethylene540-59-0200790-
Dichloroethyl ether111-44-4(C)15(C)90X
Dichloromethane; see Methylene chloride
Dichloromonofluoromethane75-43-410004200-
1,1-Dichloro-1-nitroethane594-72-9(C)10(C)60-
1,2-Dichloropropane; see Propylene dichloride
Dichlorotetrafluoroethane76-14-210007000-
Dichlorvos (DDVP)62-73-7-1X
Dieldrin60-57-1-0.25X
Diethylamine109-89-72575-
2-Diethylaminoethanol100-37-81050X
Diethylene triamine111-40-0(C)10(C)42X
Diethyl ether; see Ethyl ether
Difluorodibromomethane75-61-6100860-
Diglycidyl ether (DGE)2238-07-5(C)0.5(C)2.8-
Dihydroxybenzene; see Hydroquinone
Diisobutyl ketone108-83-850290-
Diisopropylamine108-18-9520X
4-Dimethylaminoazobenzene; see §1926.111560-11-7
Dimethoxymethane; see Methylal
Dimethyl acetamide127-19-51035X
Dimethylamine124-40-31018-
Dimethylaminobenzene; see Xylidine
Dimethylaniline (N,N-Dimethylaniline)121-69-7525X
Dimethylbenzene; see Xylene
Dimethyl-1,2-dibromo- 2,2-dichloroethyl phosphate300-76-5-3-
Dimethylformamide68-12-21030X
2,6-Dimethyl-4-heptanone; see Diisobutyl ketone
1,1-Dimethylhydrazine57-14-70.51X
Dimethylphthalate131-11-3-5-
Dimethyl sulfate77-78-315X
Dinitrobenzene (all isomers)1X
(ortho)528-29-0
(meta)99-65-0
(para)100-25-4
Dinitro-o-cresol534-52-1-0.2X
Dinitrotoluene25321-14-6-1.5X
Dioxane (Diethylene dioxide)123-91-1100360X
Diphenyl (Biphenyl)92-52-40.21-
Diphenylamine122-39-4-10-
Diphenylmethane diisocyanate; see Methylene bisphenyl isocyanate
Dipropylene glycol methyl ether34590-94-8100600X
Di-sec octyl phthalate (Di-(2-ethylhexyl) phthalate)117-81-7-5-
Emery12415-34-8
Total dust--
Respirable fraction--
Endosulfan115-29-7-0.1X
Endrin72-20-8-0.1X
Epichlorohydrin106-89-8519X
EPN2104-64-5-0.5X
1,2-Epoxypropane; see Propylene oxide
2,3-Epoxy-1-propanol; see Glycidol
Ethane74-84-0E
Ethanethiol; see Ethyl mercaptan
Ethanolamine141-43-536-
2-Ethoxyethanol (Cellosolve)110-80-5200740X
2-Ethoxyethyl acetate (Cellosolve acetate)111-15-9100540X
Ethyl acetate141-78-64001400-
Ethyl acrylate140-88-525100X
Ethyl alcohol (Ethanol)64-17-510001900-
Ethylamine75-04-71018-
Ethyl amyl ketone (5-Methyl-3-heptanone)541-85-525130-
Ethyl benzene100-41-4100435-
Ethyl bromide74-96-4200890-
Ethyl butyl ketone (3-Heptanone)106-35-450230-
Ethyl chloride75-00-310002600-
Ethyl ether60-29-74001200-
Ethyl formate109-94-4100300-
Ethyl mercaptan75-08-10.51-
Ethyl silicate78-10-4100850-
Ethylene74-85-1E
Ethylene chlorohydrin107-07-3516X
Ethylenediamine107-15-31025-
Ethylene dibromide106-93-4(C)25(C)190X
Ethylene dichloride (1,2-Dichloroethane)107-06-250200-
Ethylene glycol dinitrate628-96-6(C)0.2(C)1X
Ethylene glycol methyl acetate; see Methyl cellosolve acetate
Ethyleneimine; see §1926.1112151-56-4
Ethylene oxide; see §1926.114775-21-8
Ethylidene chloride; see 1,1-Dichloroethane
N-Ethylmorpholine100-74-32094X
Ferbam14484-64-1
Total dust-15-
Ferrovanadium dust12604-58-9-1-
Fibrous Glass
Total dust-
Respirable fraction--
Fluorides (as F)Varies with compound-2.5-
Fluorine7782-41-40.10.2-
Fluorotrichloromethane (Trichlorofluoromethane)75-69-410005600-
Formaldehyde; see §1926.114850-00-0
Formic acid64-18-659-
Furfural98-01-1520X
Furfuryl alcohol98-00-050200-
Gasoline8006-61-9A3-
Glycerin (mist)56-81-5
Total dust--
Respirable fraction--
Glycidol556-52-550150-
Glycol monoethyl ether; see 2-Ethoxyethanol
Graphite, natural, respirable dust7782-42-5(2)(2)(2)
Graphite, synthetic
Total dust--
Respirable fraction--
Guthion; see Azinphos methyl
Gypsum13397-24-5
Total dust--
Respirable fraction--
Hafnium7440-58-6-0.5-
Helium7440-59-7E
Heptachlor76-44-8-0.5X
Heptane (n-Heptane)142-82-55002000-
Hexachloroethane67-72-1110X
Hexachloronaphthalene1335-87-1-0.2X
n-Hexane110-54-35001800-
2-Hexanone (Methyl n-butyl ketone)591-78-6100410-
Hexone (Methyl isobutyl ketone)108-10-1100410-
sec-Hexyl acetate108-84-950300-
Hydrazine302-01-211.3X
Hydrogen1333-74-0E
Hydrogen bromide10035-10-6310-
Hydrogen chloride7647-01-0(C)5(C)7-
Hydrogen cyanide74-90-81011X
Hydrogen fluoride (as F)7664-39-332-
Hydrogen peroxide7722-84-111.4-
Hydrogen selenide (as Se)7783-07-50.05.02-
Hydrogen sulfide7783-06-41015-
Hydroquinone123-31-9-2-
Indene95-13-61045-
Indium and compounds (as In)7440-74-6-0.1-
Iodine7553-56-2(C)0.1(C)1-
Iron oxide fume1309-37-1-10-
Iron salts (soluble) (as Fe)Varies with compound-1-
Isoamyl acetate123-92-2100525-
Isoamyl alcohol (primary and secondary)123-51-3100360-
Isobutyl acetate110-19-0150700-
Isobutyl alcohol78-83-1100300-
Isophorone78-59-125140-
Isopropyl acetate108-21-4250950-
Isopropyl alcohol67-63-0400980-
Isopropylamine75-31-0512-
Isopropyl ether108-20-35002100-
Isopropyl glycidyl ether (IGE)4016-14-250240-
Kaolin1332-58-7
Total dust--
Respirable fraction--
Ketene463-51-40.50.9-
Lead, inorganic (as Pb); see 1926.627439-92-1
Limestone1317-65-3
Total dust--
Respirable fraction--
Lindane58-89-9-0.5X
Lithium hydride7580-67-8-0.025-
L.P.G. (Liquefied petroleum gas)68476-85-710001800
Magnesite546-93-0
Total dust--
Respirable fraction--
Magnesium oxide fume1309-48-4
Total particulate15--
Malathion121-75-5
Total dust-15X
Maleic anhydride108-31-60.25
Manganese compounds (as Mn)7439-96-5-(C)5-
Manganese fume (as Mn)7439-96-5-(C)5-
Marble1317-65-3
Total dust--
Respirable fraction--
Mercury (aryl and inorganic)(as Hg)7439-97-60.1X
Mercury (organo) alkyl compounds (as Hg)7439-97-6-0.01X
Mercury (vapor) (as Hg)7439-97-6-0.1X
Mesityl oxide141-79-725100-
Methane74-82-8E
Methanethiol; see Methyl mercaptan
Methoxychlor72-43-5
Total dust-15-
2-Methoxyethanol (Methyl cellosolve)109-86-42580X
2-Methoxyethyl acetate (Methyl cellosolve acetate)110-49-625120X
Methyl acetate79-20-9200610-
Methyl acetylene (Propyne)74-99-710001650-
Methyl acetylene-propadiene mixture (MAPP)10001800-
Methyl acrylate96-33-31035X
Methylal (Dimethoxy-methane)109-87-510003100-
Methyl alcohol67-56-1200260-
Methylamine74-89-51012-
Methyl amyl alcohol; see Methyl isobutyl carbinol
Methyl n-amyl ketone110-43-0100465-
Methyl 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
Methylene chloride; see §1910.1052
Methyl chloroform (1,1,1-Trichloroethane)71-55-63501900-
Methylcyclohexane108-87-25002000-
Methylcyclohexanol25639-42-3100470-
o-Methylcyclohexanone583-60-8100460X
Methylene chloride75-09-25001740-
Methylenedianiline (MDA)101-77-9
Methyl ethyl ketone (MEK); see 2-Butanone
Methyl formate107-31-3100250-
Methyl hydrazine (Monomethyl hydrazine)60-34-4(C)0.2(C)0.35X
Methyl iodide74-88-4528X
Methyl isoamyl ketone110-12-3100475-
Methyl isobutyl carbinol108-11-225100X
Methyl isobutyl ketone; see Hexone
Methyl isocyanate624-83-90.020.05X
Methyl mercaptan74-93-10.51-
Methyl methacrylate80-62-6100410-
Methyl propyl ketone; see 2-Pentanone
Methyl silicate681-84-5(C)5(C)30-
alpha-Methyl styrene98-83-9(C)100(C)480-
Methylene bisphenyl isocyanate (MDI)101-68-8(C)0.02(C)0.2-
Mica; see Silicates
Molybdenum (as Mo)7439-98-7
Soluble compounds-5-
Insoluble compounds
Total dust-15-
Monomethyl aniline100-61-829X
Monomethyl hydrazine; see Methyl hydrazine
Morpholine110-91-82070X
Naphtha (Coal tar)8030-30-6100400-
Naphthalene91-20-31050-
alpha-Naphthylamine; see §1926.1104134-32-7
beta-Naphthylamine; see §1926.110991-59-8-
Neon7440-01-9E
Nickel carbonyl (as Ni)13463-39-30.0010.007-
Nickel, metal and insoluble compounds (as Ni)7440-02-0-1-
Nickel, soluble compounds (as Ni)7440-02-0-1-
Nicotine54-11-5-0.5X
Nitric acid7697-37-225-
Nitric oxide10102-43-92530-
p-Nitroaniline100-01-616X
Nitrobenzene98-95-315X
p-Nitrochlorobenzene100-00-5-1X
4-Nitrodiphenyl; see §1926.110392-93-3
Nitroethane79-24-3100310-
Nitrogen7727-37-9E
Nitrogen dioxide10102-44-0(C)5(C)9-
Nitrogen trifluoride7783-54-21029-
Nitroglycerin55-63-0(C)0.2(C)2X
Nitromethane75-52-5100250-
1-Nitropropane108-03-22590-
2-Nitropropane79-46-92590-
N-Nitrosodimethylamine; see §1926.111662-79-9-
Nitrotoluene (all isomers)530X
o-isomer88-72-2;
m-isomer99-08-1;
p-isomer99-99-0
Nitrotrichloromethane; see Chloropicrin
Nitrous oxide10024-97-2E
Octachloronaphthalene2234-13-1-0.1X
Octane111-65-94001900-
Oil mist, mineral8012-95-1-5-
Osmium tetroxide (as Os)20816-12-0-0.002-
Oxalic acid144-62-7-1-
Oxygen difluoride7783-41-70.050.1-
Ozone10028-15-60.10.2-
Paraquat, respirable dust4685-14-7;-0.5X
1910-42-5;
2074-50-2
Parathion56-38-2-0.1X
Particulates not otherwise regulated
Total dust organic and inorganic-15-
PCB; see Chlorodiphenyl (42% and 54% chlorine)
Pentaborane19624-22-70.0050.01-
Pentachloronaphthalene1321-64-8-0.5X
Pentachlorophenol87-86-5-0.5X
Pentaerythritol115-77-5
Total dust--
Respirable fraction--
Pentane109-66-05001500-
2-Pentanone (Methyl propyl ketone)107-87-9200700-
Perchloroethylene (Tetrachloroethylene)127-18-4100670-
Perchloromethyl mercaptan594-42-30.10.8-
Perchloryl fluoride7616-94-6313.5-
Petroleum distillates (Naphtha)(Rubber Solvent)A3-
Phenol108-95-2519X
p-Phenylene diamine106-50-3-0.1X
Phenyl ether, vapor101-84-817-
Phenyl ether-biphenyl mixture, vapor17-
Phenylethylene; see Styrene
Phenyl glycidyl ether (PGE)122-60-11060-
Phenylhydrazine100-63-0522X
Phosdrin (Mevinphos)7786-34-7-0.1X
Phosgene (Carbonyl chloride)75-44-50.10.4-
Phosphine7803-51-20.30.4-
Phosphoric acid7664-38-2-1-
Phosphorus (yellow)7723-14-0-0.1-
Phosphorus pentachloride10026-13-8-1-
Phosphorus pentasulfide1314-80-3-1-
Phosphorus trichloride7719-12-20.53-
Phthalic anhydride85-44-9212-
Picric acid88-89-1-0.1X
Pindone (2-Pivalyl-1,3-indandione)83-26-1-0.1-
Plaster of Paris26499-65-0
Total dust--
Respirable fraction--
Platinum (as Pt)7440-06-4
Metal---
Soluble salts-0.002-
Polytetrafluoroethylene decomposition productsA2
Portland cement65997-15-1
Total dust-15-
Respirable fraction5-
Propane74-98-6E
Propargyl alcohol107-19-71-X
beta-Propriolactone; see §1926.111357-57-8
n-Propyl acetate109-60-4200840-
n-Propyl alcohol71-23-8200500-
n-Propyl nitrate627-13-425110-
Propylene dichloride78-87-575350-
Propylene imine75-55-825X
Propylene oxide75-56-9100240-
Propyne; see Methyl acetylene
Pyrethrum8003-34-7-5-
Pyridine110-86-1515-
Quinone106-51-40.10.4-
RDX; see Cyclonite
Rhodium (as Rh), metal fume and insoluble compounds7440-16-6-0.1-
Rhodium (as Rh), soluble compounds7440-16-6-0.001-
Ronnel299-84-3-10-
Rotenone83-79-4-5-
Rouge
Total dust--
Respirable fraction--
Selenium compounds (as Se)7782-49-2-0.2-
Selenium hexafluoride (as Se)7783-79-10.050.4-
Silica, 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 1926.115314464-46-1
Quartz; see 1926.1115 3514808-60-7
Tripoli (as quartz); see 1926.115351317-95-9
Trydimite; see 1926.115315468-32-3
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); use asbestos limit; see 1926.58
Talc (containing no asbestos), respirable dust 14807-96-6(2)(2)(2)
Tremolite, asbestiform; see 1926.58
Silicon carbide409-21-2
Total dust--
Respirable fraction--
Silver, metal and soluble compounds (as Ag)7440-22-4-0.01-
Soapstone; see Silicates
Sodium fluoroacetate62-74-8-0.05X
Sodium hydroxide1310-73-2-2-
Starch9005-25-8
Total dust--
Respirable fraction--
Stibine7803-52-30.10.5-
Stoddard solvent8052-41-32001150-
Strychnine57-24-9-0.15-
Styrene100-42-5(C)100(C)420-
Sucrose57-50-1
Total dust--
Respirable fraction--
Sulfur dioxide7446-09-5513-
Sulfur hexafluoride2551-62-410006000-
Sulfuric acid7664-93-9-1-
Sulfur monochloride10025-67-916-
Sulfur pentafluoride5714-22-70.0250.25-
Sulfuryl fluoride2699-79-8520-
Systox, see Demeton
2,4,5-T (2,4,5-trichlorophenoxyacetic acid)93-76-5-10-
Talc; see Silicates-
Tantalum, metal and oxide dust7440-25-7-5-
TEDP (Sulfotep)3689-24-5-0.2X
Teflon decomposition productsA2
Tellurium and compounds (as Te)13494-80-9-0.1-
Tellurium hexafluoride (as Te)7783-80-40.020.2-
Temephos3383-96-8
Total dust--
Respirable fraction--
TEPP (Tetraethyl pyrophosphate)107-49-3-0.05X
Terphenyls26140-60-3(C)1(C)9-
1,1,1,2-Tetrachloro-2,2-difluoroethane76-11-95004170-
1,1,2,2-Tetrachloro-1,2-difluoroethane76-12-05004170-
1,1,2,2-Tetrachloroethane79-34-5535X
Tetrachloroethylene; see Perchloroethylene
Tetrachloromethane; see Carbon tetrachloride
Tetrachloronaphthalene1335-88-2-2X
Tetraethyl lead (as Pb)78-00-2-0.1X
Tetrahydrofuran109-99-9200590-
Tetramethyl lead, (as Pb)75-74-1-0.15X
Tetramethyl succinonitrile3333-52-60.53X
Tetranitromethane509-14-818-
Tetryl (2,4,6-Trinitrophenylmethylnitramine)479-45-8-1.5X
Thallium, soluble compounds (as Tl)7440-28-0-0.1X
Thiram137-26-8-5-
Tin, inorganic compounds (except oxides) (as Sn)7440-31-5-2-
Tin, organic compounds (as Sn)7440-31-5-0.1-
Tin oxide (as Sn)21651-19-4---
Total dust--
Respirable fraction--
Titanium dioxide13463-67-7
Total dust--
Toluene108-88-3200750-
Toluene-2,4-diisocyanate (TDI)584-84-9(C)0.02(C)0.14-
o-Toluidine95-53-4522X
Toxaphene; see Chlorinated camphene
Tremolite; see Silicates
Tributyl phosphate126-73-8-5-
1,1,1-Trichloroethane; see Methyl chloroform
1,1,2-Trichloroethane79-00-51045X
Trichloroethylene79-01-6100535-
Trichloromethane; see Chloroform
Trichloronaphthalene1321-65-9-5X
1,2,3-Trichloropropane96-18-450300-
1,1,2-Trichloro-1,2,2-trifluoroethane76-13-110007600-
Triethylamine121-44-825100-
Trifluorobromomethane75-63-810006100-
Trimethyl benzene25551-13-725120-
2,4,6-Trinitrophenol; see Picric acid
2,4,6-Trinitrophenylmethylnitramine; see Tetryl
2,4,6-Trinitrotoluene (TNT)118-96-7-1.5X
Triorthocresyl phosphate78-30-8-0.1-
Triphenyl phosphate115-86-6-3-
Tungsten (as W)7440-33-7
Insoluble compounds-5-
Soluble compounds-1-
Turpentine8006-64-2100560-
Uranium (as U)7440-61-1
Soluble compounds-0.2-
Insoluble compounds-0.2-
Vanadium1314-62-1
Respirable dust (as V2 O5)-(C)0.5-
Fume (as V2 O5)-(C)0.1-
Vegetable oil mist
Total dust--
Respirable fraction--
Vinyl benzene; see Styrene
Vinyl chloride; see §1926.111775-01-4
Vinyl cyanide; see Acrylonitrile
Vinyl toluene25013-15-4100480-
Warfarin81-81-2-0.1-
Xylenes (o-, m-, p-isomers)1330-20-7100435-
Xylidine1300-73-8525X
Yttrium7440-65-5-1-
Zinc chloride fume7646-85-7-1-
Zinc oxide fume1314-13-2-5-
Zinc oxide1314-13-2
Total dust-15-
Respirable fraction-5-
Zirconium compounds (as Zr)7440-67-7-5

MINERAL DUSTS

Substancemppcf(j)
SILICA:
Crystalline 250(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 limit--
Graphite (natural)15
Inert or Nuisance Particulates:(m)50 (or 15 mg/m3 whichever is the smaller) of total dust <1% SiO2
[Inert or Nuisance Dusts includes all mineral, inorganic, and organic dusts as indicated by examples in TLV's appendix D]
Conversion factors
mppcf * 35.3 = million particles per cubic meter = particles per c.c.

Footnotes

1 [Reserved]

2 See Mineral Dusts Table.

3 Use Asbestos Limit §1926.58.

4 See 1926.58.

5 See Mineral Dusts table for the exposure limit for any operations or sectors where the exposure limit in §1926.1153 is stayed or is otherwise not in effect.

* The PELs are 8-hour TWAs unless otherwise noted; a (C) designation denotes a ceiling limit.

** As 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 §1926.1128 the limit is 10 ppm TWA.

h-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.

l [Reserved]

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

n If the exposure limit in §1926.1126 is stayed or is otherwise not in effect, the exposure limit is a ceiling of 0.1 mg/m3.

o If the exposure limit in §1926.1126 is stayed or is otherwise not in effect, the exposure limit is 0.1 mg/m3 (as CrO3) as an 8-hour TWA.

p This standard applies to any operations or sectors for which the respirable crystalline silica standard, 1926.1153, is stayed or otherwise is not in effect.

q This standard applies to any operations or sectors for which the beryllium standard, 1926.1124, is stayed or otherwise is not in effect.

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

A1 [Reserved]

A2 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.

A3 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 19.5% and be within the requirements addressing explosion in part 1926.

29 C.F.R. §1926.55

39 FR 22801, June 24, 1974, as amended at 51 FR 37007, Oct. 17, 1986; 52 FR 46312, Dec. 4, 1987; 58 FR 35089, June 30, 1993; 61 FR 9249, 9250, Mar. 7, 1996; 61 FR 56856, Nov. 4, 1996; 62 FR 1619, Jan. 10, 1997; 71 FR 10381, Feb. 28, 2006; 71 FR 36009, June 23, 2006; 81 FR 16875, Mar. 25, 2016; 81 FR 31168, May 18, 2016; 82 FR 2750, Mar. 10, 2017