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
| Substance | CAS No. d | ppm a | mg/m 3,b | Skin Designation |
|---|---|---|---|---|
| Abate; see Temephos | ||||
| Acetaldehyde | 75-07-0 | 200 | 360 | — |
| Acetic acid | 64-19-7 | 10 | 25 | — |
| Acetic anhydride | 108-24-7 | 5 | 20 | — |
| Acetone | 67-64-1 | 1000 | 2400 | — |
| Acetonitrile | 75-05-8 | 40 | 70 | — |
| 2-Acetylaminofluorine; see § 1926.1114 | 53-96-3 | |||
| Acetylene | 74-86-2 | E | ||
| Acetylene dichloride; see 1,2-Dichloroethylene | ||||
| Acetylene tetrabromide | 79-27-6 | 1 | 14 | — |
| Acrolein | 107-02-8 | 0.1 | 0.25 | — |
| Acrylamide | 79-06-1 | — | 0.3 | X |
| Acrylonitrile; see § 1926.1145 | 107-13-1 | |||
| Aldrin | 309-00-2 | — | 0.25 | X |
| Allyl alcohol | 107-18-6 | 2 | 5 | X |
| Allyl chloride | 107-05-1 | 1 | 3 | — |
| Allyl glycidyl ether (AGE) | 106-92-3 | (C)10 | (C)45 | — |
| Allyl propyl disulfide | 2179-59-1 | 2 | 12 | — |
| alpha-Alumina | 1344-28-1 | |||
| Total dust | — | — | ||
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| Respirable fraction | — | — | ||
| Alundum; see alpha-Alumina | ||||
| 4-Aminodiphenyl; see § 1926.1111 | 92-67-1 | |||
| 2-Aminoethanol; see Ethanolamine | ||||
| 2-Aminopyridine | 504-29-0 | 0.5 | 2 | — |
| Ammonia | 7664-41-7 | 50 | 35 | — |
| Ammonium sulfamate | 7773-06-0 | |||
| Total dust | — | 15 | — | |
| Respirable fraction | — | 5 | — | |
| n-Amyl acetate | 628-63-7 | 100 | 525 | — |
| sec-Amyl acetate | 626-38-0 | 125 | 650 | — |
| Aniline and homologs | 62-53-3 | 5 | 19 | X |
| Anisidine (o-, p-isomers) | 29191-52-4 | — | 0.5 | X |
| Antimony and compounds (as Sb) | 7440-36-0 | — | 0.5 | — |
| ANTU (alpha Naphthylthiourea) | 86-88-4 | — | 0.3 | — |
| Argon | 7440-37-1 | E | ||
| Arsenic, inorganic compounds (as As); see § 1926.1118 | 7440-38-2 | — | — | — |
| Arsenic, organic compounds (as As) | 7440-38-2 | — | 0.5 | — |
| Arsine | 7784-42-1 | 0.05 | 0.2 | — |
| Asbestos; see 1926.58 | ||||
| Azinphos-methyl | 86-50-0 | — | 0.2 | X |
| Barium, soluble compounds (as Ba) | 7440-39-3 | — | 0.5 | — |
| Benzene g; see § 1926.1128 | 71-43-2 | |||
| Benzidine; see § 1926.1110 | 92-87-5 | |||
| p-Benzoquinone; see Quinone | ||||
| Benzo(a)pyrene; see Coal tar pitch volatiles | ||||
| Benzoyl peroxide | 94-36-0 | — | 5 | — |
| Benzyl chloride | 100-44-7 | 1 | 5 | — |
| Beryllium and beryllium compounds (as Be) | 7440-41-7 | — | 0.002 | — |
| Biphenyl; see Diphenyl | ||||
| Bisphenol A; see Diglycidyl ether | ||||
| Boron oxide | 1303-86-2 | |||
| Total dust | — | 15 | — | |
| Boron tribromide | 10294-33-4 | 1 | 10 | — |
| Boron trifluoride | 7637-07-2 | (C)1 | (C)3 | — |
| Bromine | 7726-95-6 | 0.1 | 0.7 | — |
| Bromine pentafluoride | 7789-30-2 | 0.1 | 0.7 | — |
| Bromoform | 75-25-2 | 0.5 | 5 | X |
| Butadiene (1,3-Butadiene); see 29 CFR 1910.1051 ; 29 CFR 1910.19(l) | 106-99-0 | STEL 1 ppm/5 ppm | — | |
| Butanethiol; see Butyl mercaptan | ||||
| 2-Butanone (Methyl ethyl ketone) | 78-93-3 | 200 | 590 | — |
| 2-Butoxyethanol | 111-76-2 | 50 | 240 | X |
| n-Butyl-acetate | 123-86-4 | 150 | 710 | — |
| sec-Butyl acetate | 105-46-4 | 200 | 950 | — |
| tert-Butyl acetate | 540-88-5 | 200 | 950 | — |
| n-Butyl alcohol | 71-36-3 | 100 | 300 | — |
| sec-Butyl alcohol | 78-92-2 | 150 | 450 | — |
| tert-Butyl alcohol | 75-65-0 | 100 | 300 | — |
| Butylamine | 109-73-9 | (C)5 | (C)15 | X |
| tert-Butyl chromate (as CrO3); see 1926.1126 n | 1189-85-1 | |||
| n-Butyl glycidyl ether (BGE) | 2426-08-6 | 50 | 270 | — |
| Butyl mercaptan | 109-79-5 | 0.5 | 1.5 | — |
| p-tert-Butyltoluene | 98-51-1 | 10 | 60 | — |
| Cadmium (as Cd); see 1926.1127 | 7440-43-9 | |||
| Calcium carbonate | 1317-65-3 | |||
| Total dust | — | — | ||
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| Respirable fraction | — | — | ||
| Calcium oxide | 1305-78-8 | — | 5 | — |
| Calcium sulfate | 7778-18-9 | |||
| Total dust | — | 15 | — | |
| Respirable fraction | — | 5 | — | |
| Camphor, synthetic | 76-22-2 | — | 2 | — |
| Carbaryl (Sevin) | 63-25-2 | — | 5 | — |
| Carbon black | 1333-86-4 | — | 3.5 | — |
| Carbon dioxide | 124-38-9 | 5000 | 9000 | — |
| Carbon disulfide | 75-15-0 | 20 | 60 | X |
| Carbon monoxide | 630-08-0 | 50 | 55 | — |
| Carbon tetrachloride | 56-23-5 | 10 | 65 | X |
| Cellulose | 9004-34-6 | |||
| Total dust | — | — | ||
| Respirable fraction | — | — | ||
| Chlordane | 57-74-9 | — | 0.5 | X |
| Chlorinated camphene | 8001-35-2 | — | 0.5 | X |
| Chlorinated diphenyl oxide | 55720-99-5 | — | 0.5 | — |
| Chlorine | 7782-50-5 | 1 | 3 | — |
| Chlorine dioxide | 10049-04-4 | 0.1 | 0.3 | |
| Chlorine trifluoride | 7790-91-2 | (C)0.1 | (C)0.4 | — |
| Chloroacetaldehyde | 107-20-0 | (C)1 | (C)3 | — |
| a-Chloroacetophenone (Phenacyl chloride) | 532-27-4 | 0.05 | 0.3 | — |
| Chlorobenzene | 108-90-7 | 75 | 350 | — |
| o-Chlorobenzylidene malononitrile | 2698-41-1 | 0.05 | 0.4 | — |
| Chlorobromomethane | 74-97-5 | 200 | 1050 | — |
| 2-Chloro-1,3-butadiene; see beta-Chloroprene | ||||
| Chlorodiphenyl (42% Chlorine) (PCB) | 53469-21-9 | — | 1 | X |
| Chlorodiphenyl (54% Chlorine) (PCB) | 11097-69-1 | — | 0.5 | X |
| 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 § 1926.1108 | 542-88-1 | |||
| Chloromethyl methyl ether; see § 1926.1106 | 107-30-2 | |||
| 1-Chloro-1-nitropropane | 600-25-9 | 20 | 100 | — |
| Chloropicrin | 76-06-2 | 0.1 | 0.7 | — |
| beta-Chloroprene | 126-99-8 | 25 | 90 | X |
| Chromium (II) compounds | ||||
| (as Cr) | 7440-47-3 | — | 0.5 | — |
| Chromium (III) compounds | ||||
| (as Cr) | 7440-47-3 | — | 0.5 | — |
| Chromium (VI) compounds; See 1926.1126 o | ||||
| 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, pyrene | 65996-93-2 | — | 0.2 | — |
| Cobalt metal, dust, and fume (as Co) | 7440-48-4 | — | 0.1 | — |
| Coke oven emissions; see § 1926.1129 | ||||
| Copper | 7440-50-8 | |||
| Fume (as Cu) | — | 0.1 | — | |
| Dusts and mists (as Cu) | — | 1 | — | |
| Corundum; see Emery | ||||
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| Cotton dust (raw) | — | 1 | ||
| Crag herbicide (Sesone) | 136-78-7 | |||
| Total dust | — | — | ||
| Respirable fraction | — | — | ||
| Cresol, all isomers | 1319-77-3 | 5 | 22 | X |
| Crotonaldehyde | 123-73-9; | 2 | 6 | |
| 4170-30-3 | ||||
| Cumene | 98-82-8 | 50 | 245 | X |
| Cyanides (as CN) | Varies with Compound | — | 5 | X |
| Cyanogen | 460-19-5 | 10 | — | — |
| Cyclohexane | 110-82-7 | 300 | 1050 | — |
| Cyclohexanol | 108-93-0 | 50 | 200 | — |
| Cyclohexanone | 108-94-1 | 50 | 200 | — |
| Cyclohexene | 110-83-8 | 300 | 1015 | — |
| Cyclonite | 121-82-4 | — | 1.5 | X |
| Cyclopentadiene | 542-92-7 | 75 | 200 | — |
| DDT, see Dichlorodiphenyltrichloroethane | ||||
| DDVP, see Dichlorvos | ||||
| 2,4-D (Dichlorophenoxyacetic acid) | 94-75-7 | — | 10 | — |
| Decaborane | 17702-41-9 | 0.05 | 0.3 | X |
| Demeton (Systox) | 8065-48-3 | — | 0.1 | X |
| Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone) | 123-42-2 | 50 | 240 | — |
| 1,2-Diaminoethane; see Ethylenediamine | ||||
| Diazomethane | 334-88-3 | 0.2 | 0.4 | — |
| Diborane | 19287-45-7 | 0.1 | 0.1 | — |
| 1,2-Dibromo-3-chloropropane (DBCP); see § 1926.1144 | 96-12-8 | — | ||
| 1,2-Dibromoethane; see Ethylene dibromide | ||||
| Dibutyl phosphate | 107-66-4 | 1 | 5 | — |
| Dibutyl phthalate | 84-74-2 | — | 5 | — |
| Dichloroacetylene | 7572-29-4 | (C)0.1 | (C)0.4 | — |
| o-Dichlorobenzene | 95-50-1 | (C)50 | (C)300 | — |
| p-Dichlorobenzene | 106-46-7 | 75 | 450 | — |
| 3,3′-Dichlorobenzidine; see § 1926.1107 | 91-94-1 | |||
| Dichlorodifluoromethane | 75-71-8 | 1000 | 4950 | — |
| 1,3-Dichloro-5,5-dimethyl hydantoin | 118-52-5 | — | 0.2 | — |
| Dichlorodiphenyltrichloroethane (DDT) | 50-29-3 | — | 1 | X |
| 1,1-Dichloroethane | 75-34-3 | 100 | 400 | — |
| 1,2-Dichloroethane; see Ethylene dichloride | ||||
| 1,2-Dichloroethylene | 540-59-0 | 200 | 790 | — |
| Dichloroethyl ether | 111-44-4 | (C)15 | (C)90 | X |
| Dichloromethane; see Methylene chloride | ||||
| Dichloromonofluoromethane | 75-43-4 | 1000 | 4200 | — |
| 1,1-Dichloro-1-nitroethane | 594-72-9 | (C)10 | (C)60 | — |
| 1,2-Dichloropropane; see Propylene dichloride | ||||
| Dichlorotetrafluoroethane | 76-14-2 | 1000 | 7000 | — |
| Dichlorvos (DDVP) | 62-73-7 | — | 1 | X |
| Dieldrin | 60-57-1 | — | 0.25 | X |
| Diethylamine | 109-89-7 | 25 | 75 | — |
| 2-Diethylaminoethanol | 100-37-8 | 10 | 50 | X |
| Diethylene triamine | 111-40-0 | (C)10 | (C)42 | X |
| Diethyl ether; see Ethyl ether | ||||
| Difluorodibromomethane | 75-61-6 | 100 | 860 | — |
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| Diglycidyl ether (DGE) | 2238-07-5 | (C)0.5 | (C)2.8 | — |
| Dihydroxybenzene; see Hydroquinone | ||||
| Diisobutyl ketone | 108-83-8 | 50 | 290 | — |
| Diisopropylamine | 108-18-9 | 5 | 20 | X |
| 4-Dimethylaminoazobenzene; see § 1926.1115 | 60-11-7 | |||
| Dimethoxymethane; see Methylal | ||||
| Dimethyl acetamide | 127-19-5 | 10 | 35 | X |
| Dimethylamine | 124-40-3 | 10 | 18 | — |
| Dimethylaminobenzene; see Xylidine | ||||
| Dimethylaniline (N,N-Dimethylaniline) | 121-69-7 | 5 | 25 | X |
| Dimethylbenzene; see Xylene | ||||
| Dimethyl-1,2-dibromo- 2,2-dichloroethyl phosphate | 300-76-5 | — | 3 | — |
| Dimethylformamide | 68-12-2 | 10 | 30 | X |
| 2,6-Dimethyl-4-heptanone; see Diisobutyl ketone | ||||
| 1,1-Dimethylhydrazine | 57-14-7 | 0.5 | 1 | X |
| Dimethylphthalate | 131-11-3 | — | 5 | — |
| Dimethyl sulfate | 77-78-3 | 1 | 5 | X |
| Dinitrobenzene (all isomers) | 1 | X | ||
| (ortho) | 528-29-0 | |||
| (meta) | 99-65-0 | |||
| (para) | 100-25-4 | |||
| Dinitro-o-cresol | 534-52-1 | — | 0.2 | X |
| Dinitrotoluene | 25321-14-6 | — | 1.5 | X |
| Dioxane (Diethylene dioxide) | 123-91-1 | 100 | 360 | X |
| Diphenyl (Biphenyl) | 92-52-4 | 0.2 | 1 | — |
| Diphenylamine | 122-39-4 | — | 10 | — |
| Diphenylmethane diisocyanate; see Methylene bisphenyl isocyanate | ||||
| Dipropylene glycol methyl ether | 34590-94-8 | 100 | 600 | X |
| Di-sec octyl phthalate (Di-(2-ethylhexyl) phthalate) | 117-81-7 | — | 5 | — |
| Emery | 12415-34-8 | |||
| Total dust | — | — | ||
| Respirable fraction | — | — | ||
| Endosulfan | 115-29-7 | — | 0.1 | X |
| Endrin | 72-20-8 | — | 0.1 | X |
| Epichlorohydrin | 106-89-8 | 5 | 19 | X |
| EPN | 2104-64-5 | — | 0.5 | X |
| 1,2-Epoxypropane; see Propylene oxide | ||||
| 2,3-Epoxy-1-propanol; see Glycidol | ||||
| Ethane | 74-84-0 | E | ||
| Ethanethiol; see Ethyl mercaptan | ||||
| Ethanolamine | 141-43-5 | 3 | 6 | — |
| 2-Ethoxyethanol (Cellosolve) | 110-80-5 | 200 | 740 | X |
| 2-Ethoxyethyl acetate (Cellosolve acetate) | 111-15-9 | 100 | 540 | X |
| Ethyl acetate | 141-78-6 | 400 | 1400 | — |
| Ethyl acrylate | 140-88-5 | 25 | 100 | X |
| Ethyl alcohol (Ethanol) | 64-17-5 | 1000 | 1900 | — |
| Ethylamine | 75-04-7 | 10 | 18 | — |
| Ethyl amyl ketone (5-Methyl-3-heptanone) | 541-85-5 | 25 | 130 | — |
| Ethyl benzene | 100-41-4 | 100 | 435 | — |
| Ethyl bromide | 74-96-4 | 200 | 890 | — |
| Ethyl butyl ketone (3-Heptanone) | 106-35-4 | 50 | 230 | — |
| Ethyl chloride | 75-00-3 | 1000 | 2600 | — |
| Ethyl ether | 60-29-7 | 400 | 1200 | — |
| Ethyl formate | 109-94-4 | 100 | 300 | — |
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| Ethyl mercaptan | 75-08-1 | 0.5 | 1 | — |
| Ethyl silicate | 78-10-4 | 100 | 850 | — |
| Ethylene | 74-85-1 | E | ||
| Ethylene chlorohydrin | 107-07-3 | 5 | 16 | X |
| Ethylenediamine | 107-15-3 | 10 | 25 | — |
| Ethylene dibromide | 106-93-4 | (C)25 | (C)190 | X |
| Ethylene dichloride (1,2-Dichloroethane) | 107-06-2 | 50 | 200 | — |