Home
gpo.gov
govinfo.gov

e-CFR Navigation Aids

Browse

Simple Search

Advanced Search

 — Boolean

 — Proximity

 

Search History

Search Tips

Corrections

Latest Updates

User Info

FAQs

Agency List

Incorporation By Reference

eCFR logo

Related Resources

Electronic Code of Federal Regulations

e-CFR data is current as of July 9, 2020

Title 29Subtitle BChapter XVIIPart 1926Subpart D → §1926.55


Title 29: Labor
PART 1926—SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION
Subpart D—Occupational Health and Environmental Controls


§1926.55   Gases, vapors, fumes, dusts, and mists.

(a) Employers must limit an employee's exposure to any substance listed in Table 1 or 2 of this section in accordance with the following:

(1) Substances with limits preceded by (C)—Ceiling Values. An employee's exposure, as determined from breathing-zone air samples, to any substance in Table 1 of this section with a permissible exposure limit preceded by (C) must at no time exceed the exposure limit specified for that substance. If instantaneous monitoring is not feasible, then the employer must assess the ceiling as a 15-minute time-weighted average exposure that the employer cannot exceed at any time during the working day.

(2) Other substances—8-hour Time Weighted Averages. An employee's exposure, as determined from breathing-zone air samples, to any substance in Table 1 or 2 of this section with a permissible exposure limit not preceded by (C) must not exceed the limit specified for that substance measured as an 8-hour time-weighted average in any work shift.

(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 §1926.1101 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.

Table 1 to §1926.55—Permissible Exposure Limits for Airborne Contaminants

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
Acrylamide79-06-10.3X
Acrylonitrile; see §1926.1145107-13-1
Aldrin309-00-20.25X
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)29191-52-40.5X
Antimony and compounds (as Sb)7440-36-00.5
ANTU (alpha Naphthylthiourea)86-88-40.3
Argon7440-37-1E
Arsenic, inorganic compounds (as As); see §1926.11187440-38-2
Arsenic, organic compounds (as As)7440-38-20.5
Arsine7784-42-10.050.2
Asbestos; see §1926.1101
Azinphos-methyl86-50-00.2X
Barium, soluble compounds (as Ba)7440-39-30.5
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 peroxide94-36-05
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 oxide1305-78-85
Calcium sulfate7778-18-9
Total dust   15
Respirable fraction   5
Camphor, synthetic76-22-22
Carbaryl (Sevin)63-25-25
Carbon black1333-86-43.5
Carbon dioxide124-38-950009000
Carbon disulfide75-15-02060X
Carbon monoxide630-08-05055
Carbon tetrachloride56-23-51065X
Cellulose9004-34-6
Total dust      
Respirable fraction      
Chlordane57-74-90.5X
Chlorinated camphene8001-35-20.5X
Chlorinated diphenyl oxide55720-99-50.5
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)53469-21-91X
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)67-66-3(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)7440-47-30.5
Chromium (III) compounds
(as Cr)7440-47-30.5
Chromium (VI) compounds; See 1926.1126o
Chromium metal and insol. salts (as Cr)7440-47-31
Chrysene; see Coal tar pitch volatiles
Coal tar pitch volatiles (benzene soluble fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene65996-93-20.2
Cobalt metal, dust, and fume (as Co)7440-48-40.1
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 Compound5X
Cyanogen460-19-510
Cyclohexane110-82-73001050
Cyclohexanol108-93-050200
Cyclohexanone108-94-150200
Cyclohexene110-83-83001015
Cyclonite121-82-41.5X
Cyclopentadiene542-92-775200
DDT, see Dichlorodiphenyltrichloroethane
DDVP, see Dichlorvos
2,4-D (Dichlorophenoxyacetic acid)94-75-710
Decaborane17702-41-90.050.3X
Demeton (Systox)8065-48-30.1X
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 phthalate84-74-25
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 hydantoin118-52-50.2
Dichlorodiphenyltrichloroethane (DDT)50-29-31X
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)62-73-71X
Dieldrin60-57-10.25X
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 phosphate300-76-53
Dimethylformamide68-12-21030X
2,6-Dimethyl-4-heptanone; see Diisobutyl ketone
1,1-Dimethylhydrazine57-14-70.51X
Dimethylphthalate131-11-35
Dimethyl 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)92-52-40.21
Diphenylamine122-39-410
Diphenylmethane diisocyanate; see Methylene bisphenyl isocyanate
Dipropylene glycol methyl ether34590-94-8100600X
Di-sec octyl phthalate (Di-(2-ethylhexyl) phthalate)117-81-75
Emery12415-34-8
Total dust      
Respirable fraction      
Endosulfan115-29-70.1X
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
Ethanolamine141-43-536
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 dust12604-58-91
Fibrous Glass
Total dust         
Respirable fraction      
Fluorides (as F)Varies with compound2.5
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
Gasoline8006-61-9   A3
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      
Hafnium7440-58-60.5
Helium7440-59-7E
Heptachlor76-44-80.5X
Heptane (n-Heptane)142-82-55002000
Hexachloroethane67-72-1110X
Hexachloronaphthalene1335-87-10.2X
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
Hydroquinone123-31-92
Indene95-13-61045
Indium and compounds (as In)7440-74-60.1
Iodine7553-56-2(C)0.1(C)1
Iron oxide fume1309-37-110
Iron salts (soluble) (as Fe)Varies with compound1
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      
Lindane58-89-90.5X
Lithium hydride7580-67-80.025
L.P.G. (Liquefied petroleum gas)68476-85-710001800
Magnesite546-93-0
Total dust      
Respirable fraction      
Magnesium oxide fume1309-48-4
Total particulate   15
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)7439-97-6   0.1X
Mercury (organo) alkyl compounds (as Hg)7439-97-60.01X
Mercury (vapor) (as Hg)7439-97-60.1X
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)7440-02-01
Nickel, soluble compounds (as Ni)7440-02-01
Nicotine54-11-50.5X
Nitric acid7697-37-225
Nitric oxide10102-43-92530
p-Nitroaniline100-01-616X
Nitrobenzene98-95-315X
p-Nitrochlorobenzene100-00-51X
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
Octachloronaphthalene2234-13-10.1X
Octane111-65-94001900
Oil mist, mineral8012-95-15
Osmium tetroxide (as Os)20816-12-00.002
Oxalic acid144-62-71
Oxygen difluoride7783-41-70.050.1
Ozone10028-15-60.10.2
Paraquat, respirable dust4685-14-7;0.5X
   1910-42-5;
   2074-50-2
Parathion56-38-20.1X
Particulates not otherwise regulated
Total dust organic and inorganic   15
PCB; see Chlorodiphenyl (42% and 54% chlorine)
Pentaborane19624-22-70.0050.01
Pentachloronaphthalene1321-64-80.5X
Pentachlorophenol87-86-50.5X
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 diamine106-50-30.1X
Phenyl ether, vapor101-84-817
Phenyl ether-biphenyl mixture, vapor   17
Phenylethylene; see Styrene
Phenyl glycidyl ether (PGE)122-60-11060
Phenylhydrazine100-63-0522X
Phosdrin (Mevinphos)7786-34-70.1X
Phosgene (Carbonyl chloride)75-44-50.10.4
Phosphine7803-51-20.30.4
Phosphoric acid7664-38-21
Phosphorus (yellow)7723-14-00.1
Phosphorus pentachloride10026-13-81
Phosphorus pentasulfide1314-80-31
Phosphorus trichloride7719-12-20.53
Phthalic anhydride85-44-9212
Picric acid88-89-10.1X
Pindone (2-Pivalyl-1,3-indandione)83-26-10.1
Plaster of Paris26499-65-0
Total dust      
Respirable fraction      
Platinum (as Pt)7440-06-4
Metal   
Soluble salts   0.002
Polytetrafluoroethylene decomposition products      A2
Portland cement65997-15-1
Total dust   15
Respirable fraction   5   
Propane74-98-6E
Propargyl alcohol107-19-71X
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
Pyrethrum8003-34-75
Pyridine110-86-1515
Quinone106-51-40.10.4
RDX; see Cyclonite
Rhodium (as Rh), metal fume and insoluble compounds7440-16-60.1
Rhodium (as Rh), soluble compounds7440-16-60.001
Ronnel299-84-310
Rotenone83-79-45
Rouge
Total dust      
Respirable fraction      
Selenium compounds (as Se)7782-49-20.2
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 1926.1153514808-60-7
Tripoli (as quartz); see 1926.115351317-95-9
Tridymite; 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 §1926.1101
Talc (containing no asbestos), respirable dust   14807-96-6(2)(2)(2)
Tremolite, asbestiform; see §1926.1101
Silicon carbide409-21-2
Total dust      
Respirable fraction      
Silver, metal and soluble compounds (as Ag)7440-22-40.01
Soapstone; see Silicates
Sodium fluoroacetate62-74-80.05X
Sodium hydroxide1310-73-22
Starch9005-25-8
Total dust      
Respirable fraction      
Stibine7803-52-30.10.5
Stoddard solvent8052-41-32001150
Strychnine57-24-90.15
Styrene100-42-5(C)100(C)420
Sucrose57-50-1
Total dust      
Respirable fraction      
Sulfur dioxide7446-09-5513
Sulfur hexafluoride2551-62-410006000
Sulfuric acid7664-93-91
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)93-76-510
Talc; see Silicates—
Tantalum, metal and oxide dust7440-25-75
TEDP (Sulfotep)3689-24-50.2X
Teflon decomposition products      A2
Tellurium and compounds (as Te)13494-80-90.1
Tellurium hexafluoride (as Te)7783-80-40.020.2
Temephos3383-96-8
Total dust      
Respirable fraction      
TEPP (Tetraethyl pyrophosphate)107-49-30.05X
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
Tetrachloronaphthalene1335-88-22X
Tetraethyl lead (as Pb)78-00-20.1X
Tetrahydrofuran109-99-9200590
Tetramethyl lead, (as Pb)75-74-10.15X
Tetramethyl succinonitrile3333-52-60.53X
Tetranitromethane509-14-818
Tetryl (2,4,6-Trinitrophenylmethylnitramine)479-45-81.5X
Thallium, soluble compounds (as Tl)7440-28-00.1X
Thiram137-26-85
Tin, inorganic compounds (except oxides) (as Sn)7440-31-52
Tin, organic compounds (as Sn)7440-31-50.1
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 phosphate126-73-85
1,1,1-Trichloroethane; see Methyl chloroform
1,1,2-Trichloroethane79-00-51045X
Trichloroethylene79-01-6100535
Trichloromethane; see Chloroform
Trichloronaphthalene1321-65-95X
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)118-96-71.5X
Triorthocresyl phosphate78-30-80.1
Triphenyl phosphate115-86-63
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
Warfarin81-81-20.1
Xylenes (o-, m-, p-isomers)1330-20-7100435
Xylidine1300-73-8525X
Yttrium7440-65-51
Zinc chloride fume7646-85-71
Zinc oxide fume1314-13-25
Zinc oxide1314-13-2
Total dust   15
Respirable fraction   5
Zirconium compounds (as Zr)7440-67-75

Table 2 to §1926.55—Mineral Dusts

Substancemppcf(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 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 to Tables 1 and 2 of this section:

1[Reserved]

2See Table 2 of this section.

3Use Asbestos Limit §1926.1101.

4[Reserved]

5See Table 2 of this section for the exposure limit for any operations or sectors where the exposure limit in §1926.1153 is stayed or is otherwise not in effect.

*An “X” designation in the “Skin Designation” column indicates that the substance is a dermal hazard.

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

bMilligrams 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]

dThe 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]

gFor sectors excluded from §1926.1128 the limit is 10 ppm TWA.

h-i[Reserved]

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

kThe 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]

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

nIf 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.

oIf 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.

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

qThis 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]

A2Polytetrafluoroethylene 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.

A3Gasoline 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.

[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; 81 FR 60273, Sept. 1, 2016; 82 FR 2750, Jan. 9, 2017; 84 FR 21576, May 14, 2019]

Need assistance?