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. 2018 Sep 20;60(5):419–542. doi: 10.1539/joh.ROEL2018

Table I-1.

Occupational exposure limits for chemical substances

Substance [CAS No.] OEL Skin
absorption		 Class of
carcino-genicity		 Class of sensitizing potential Reproductive Toxicants Year of proposal
ppm mg/m3 Airway Skin
Acetaldehyde [75-07-0] 50* 90* 2B '90
Acetic acid [64-19-7] 10 25 '78
Acetic anhydride [108-24-7] 5* 21* '90
Acetone [67-64-1] 200 470 '72
Acrylaldehyde [107-02-8] 0.1 0.23 '73
Acrylamide [79-06-1] — 0.1 S 2A 2 2 '04
Acrylonitrile [107-13-1] 2 4.3 S 2Aψ '88
Allyl alcohol [107-18-6] 1 2.4 S '78
2-Aminoethanol [141-43-5] 3 7.5 '65
Ammonia [7664-41-7] 25 17 '79
Aniline [62-53-3] 1 3.8 S 1 '88
o-Anisidine [90-04-0] 0.1 0.5 S 2B '96
p-Anisidine [104-94-9] 0.1 0.5 S '96
Antimony and compounds (as Sb except Stibine) [7440-36-0] — 0.1 ('13)
Arsenic and compounds (as As) [7440-38-2] (Table III-2) 1 1 '00
Arsine [7784-42-1] 0.01 0.032 '92
0.1* 0.32*
Atrazine [1912-24-9] 2 3 '15
Benomyl [17804-35-2] (Table I-2) '18
Benzene [71-43-2] (Table III-2) S 1 '97
Beryllium and compounds (as Be) [7440-41-7] — 0.002 1ψ 1 2 '63
Boron trifluoride [7637-07-2] 0.3 0.83 '79
Bromine [7726-95-6] 0.1 0.65 '64
Bromoform [75-25-2] 1 10.3 '97
1-Bromopropane [106-94-5] 0.5 2.5 2B 2 '12
2-Bromopropane [75-26-3] 1 5 S 1 '99
Buprofezin [69327-76-0] — 2 '90
Butane (all isomers) [106-97-8] 500 1,200 '88
1-Butanol [71-36-3] 50* 150* S '87
2-Butanol [78-92-2] 100 300 '87
Butyl acetate [123-86-4] 100 475 '94
t-Butyl alcohol [75-65-0] 50 150 '87
Butylamine [109-73-9] 5* 15* S ('94)
n-butyl-2,3-epoxy-propyl ether [2426-08-6] 0.25 1.3 2B 2 3 '16
Cadmium and compounds (as Cd) [7440-43-9] — 0.05 1ψ 1 '76
Calcium cyanide (as CN) [592-01-8] — 5* S '01
Carbaryl [63-25-2] — 5 S '89
Carbon dioxide [124-38-9] 5,000 9,000 '74
Carbon disulfide [75-15-0] 1 3.13 S 1# '15
Carbon monoxide [630-08-0] 50 57 1 '71
Carbon tetrachloride [56-23-5] 5 31 S 2B '91
Chlorine [7782-50-5] 0.5* 1.5* '99
Chlorobenzene [108-90-7] 10 46 '93
Chlorodifluoromethane [75-45-6] 1,000 3,500 2 '87
Chloroethane [75-00-3] 100 260 '93
Chloroform [67-66-3] 3 14.7 S 2B '05
Chloromethane [74-87-3] 50 100 2 '84
Chloromethyl methyl ether (technical grade) [107-30-2] — — 2A '92
Chloropicrin [76-06-2] 0.1 0.67 '68
Chromium and compounds (as Cr) [7440-47-3] 2 1 3 '89
Chromium Metal — 0.5
Chromium (III) compounds — 0.5
Chromium (VI) compounds — 0.05
Certain Chromium (VI) compounds — 0.01 1
Cobalt and compounds (without tungsten carbide) [7440-48-4] — 0.05 2B 1 1 '92
Cresol (all isomers) 5 22 S '86
Cyclohexane [110-82-7] 150 520 '70
Cyclohexanol [108-93-0] 25 102 '70
Cyclohexanone [108-94-1] 25 100 '70
Diazinon [333-41-5] — 0.1 S '89
Diborane [19287-45-7] 0.01 0.012 '96
Dibutyl phthalate [84-74-2] — 5 2 '96
o-Dichlorobenzene [95-50-1] 25 150 '94
p-Dichlorobenzene [106-46-7] 10 60 2B 3 '98
1,4-Dichloro-2-butene [764-41-0] 0.002 2B '15
3,3'-Dichloro-4,4'-diaminodiphenylmethane (MBOCA) [101-14-4] — 0.005 S 2Aψ '12
Dichlorodifluoromethane [75-71-8] 500 2,500 '87
1,1-Dichloroethane [75-34-3] 100 400 '93
1,2-Dichloroethane [107-06-2] 10 40 2B '84
2,2'-Dichloroethyl ether [111-44-4] 15 88 S '67
1,2-Dichloroethylene [540-59-0] 150 590 '70
Dichloromethane [75-09-2] 50 170 S 2A '99
100* 340*
1,2-Dichloropropane [78-87-5] 1 4.6 1 2 '13
2,2-Dichloro-1,1,1-trifluoroethane [306-83-2] 10 62 '00
Diethylamine [109-89-7] 10 30 '89
Di(2-ethylhexyl) phthalate [117-81-7] — 5 2B 1# '95
Diethyl phthalate [84-66-2] — 5 '95
N,N-Dimethyl acetamide [127-19-5] 10 36 S 2 '90
Dimethylamine [124-40-3] 2 3.7 3 '16
N,N-Dimethylaniline [121-69-7] 5 25 S '93
N,N-Dimethylformamide (DMF) [68-12-2] 10 30 S 2B 2 '74
Dimethyl sulfate [77-78-1] 0.1 0.52 S 2Aψ '80
1,2-Dinitrobenzene [528-29-0] 0.15 1 S '94
1,3-Dinitrobenzene [99-65-0] 0.15 1 S '94
1,4-Dinitrobenzene [100-25-4] 0.15 1 S '94
1,4-Dioxane [123-91-1] 1 3.6 S 2B '15
Diphenylmethane-4,4'-diiso-cyanate (MDI) [101-68-8] — 0.05 1 '93
Dusts (Table I-3 )
2,3-Epoxypropyl methacrylate (Glycidyl methacrylate, GMA) [106-91-2] (Table I-2) '18
Ethyl acetate [141-78-6] 200 720 '95
Ethylamine [75-04-7] 10 18 '79
Ethyl benzene [100-41-4] 50 217 2B 2 '01
Ethylenediamine [107-15-3] 10 25 S 2 2 '91
Ethylene glycol monobutyl ether [111-76-2] 20* 97* S 2 '17
Ethylene glycol monoethyl ether [110-80-5] 5 18 S 2 '85
Ethylene glycol monoethyl ether acetate [111-15-9] 5 27 S 2 '85
Ethylene glycol monomethyl ether [109-86-4] 0.1 0.31 S 1 '09
Ethylene glycol monomethyl ether acetate [110-49-6] 0.1 0.48 S 1 '09
Ethylene oxide [75-21-8] 1 1.8 1ψ 2 1 '90
Ethylenimine [151-56-4] (Table I-2) S 2B 3 '18
Ethyl ether [60-29-7] 400 1,200 ('97)
2-Ethy1-1-hexanol [104-76-7] 1 5.3 3† '16
Ethylidene norbrnene [16219-75-3] (Table I-2) 3 '18
Etofenprox [80844-07-1] — 3 '95
Fenitrothion [122-14-5] — 1 S '81
Fenobucarb [3766-81-2] — 5 S '89
Fenthion [55-38-9] — 0.2 S '89
Flutolanil [66332-96-5] — 10 '90
Formaldehyde [50-00-0] 0.1 0.12 2A 2 1 '07
0.2* 0.24*
Formic acid [64-18-6] 5 9.4 '78
Fthalide [27355-22-2] — 10 '90
Furfural [98-01-1] 2.5 9.8 S ('89)
Furfuryl alcohol [98-00-0] 5 20 '78
Gasoline [8006-61-9] 100b 300b 2B '85
Glutaraldehyde [111-30-8] 0.03* 1 1 '06
Heptane [142-82-5] 200 820 '88
Hexachlorobutadiene [87-68-3] 0.01 0.12 S '13
Hexane [110-54-3] 40 140 S '85
Hexane-1,6-diisocyanate (HDI) [822-06-0] 0.005 0.034 1 '95
Hydrazine (anhydrous) and Hydrazine hydrate [302-01-2/7803-57-8] 0.1 0.13 and 0.21 S 2B 1 '98
Hydrogen chloride [7647-01-0] 2* 3.0* '14
Hydrogen cyanide [74-90-8] 5 5.5 S '90
Hydrogen fluoride [7664-39-3] 3* 2.5* '00
Hydrogen selenide [7783-07-5] 0.05 0.17 '63
Hydrogen sulfide [7783-06-4] 5 7 '01
Indium and compounds [7440-74-6] (Table II-1 ) 2A '07
Iodine [7553-56-2] 0.1 1 2 '68
Isobutyl alcohol [78-83-1] 50 150 '87
Isopentyl alcohol [123-51-3] 100 360 '66
Isoprene [78-79-5] 3 8.4 2B '17
Isopropyl acetate [108-21-4] 100 '17
Isopropyl alcohol [67-63-0] 400* 980* '87
Isoprothiolane [50512-35-1] — 5 '93
Lead and compounds (as Pb except alkyl lead compounds) [7439-92-1] — 0.03 2B 1# '16
Lithium hydroxide [1310-65-2] — 1 '95
Malathion [121-75-5] — 10 S '89
Maleic anhydride [108-31-6] 0.1 0.4 2 2 ('15)
0.2* 0.8*
Manganese and compounds (as Mn except organic compounds) [7439-96-5] 0.2 2 '08
Man-made mineral fibers** '03
Ceramic fibers, Micro glass fibers — — 2B
Continuous filament glass fibers, 1 (fiber/ml)
Glass wool fibers, Rock wool fibers, Slag wool fibers
Mepronil [55814-41-0] — 5 '90
Mercury vapor [7439-97-6] — 0.025 2 '98
Methacrylic acid [79-41-4] 2 7.0 '12
Methanol [67-56-1] 200 260 S 2 '63
Methyl acetate [79-20-9] 200 610 '63
Methyl acrylate [96-33-3] 2 7 2 '04
Methylamine [74-89-5] 10 13 '79
Methyl bromide [74-83-9] 1 3.89 S '03
Methyl n-butyl ketone [591-78-6] 5 20 S '84
Methylcyclohexane [108-87-2] 400 1,600 '86
Methylcyclohexanol [25639-42-3] 50 230 '80
Methylcyclohexanone [1331-22-2] 50 230 S '87
Methyl methacrylate [80-62-6] 8.3 2 2 '12
4,4'-Methylenedianiline [101-77-9] — 0.4 S 2B '95
Methyl ethyl ketone [78-93-3] 200 590 '64
Methyl isobutyl ketone [108-10-1] 50 200 2B '84
N-Methyl-2-pyrrolidone [872-50-4] 1 4 S '02
Methyltetrahydrophthalic anhydride [11070-44-3] 0.007
0.015*		 0.05
0.1*		 1 '02
Nickel [7440-02-0] — 1 2 1 3 '11
Nickel carbonyl [13463-39-3] 0.001 0.007 '66
Nickel compounds (Total dusts) (as Ni) [7440-02-0], 2B 3 '11
Nickel compounds, soluble 0.01 '11
Nickel compounds, not soluble 0.1 '11
Nickel smelting dusts [7440-02-0] (Table III-2) 1 '11
Nitric acid [7697-37-2] 2 5.2 '82
p-Nitroaniline [100-01-6] — 3 S '95
Nitrobenzene [98-95-3] 1 5 S 2B ('88)
p-Nitrochlorobenzene [100-00-5] 0.1 0.64 S '89
Nitrogen dioxide [10102-44-0] (pending) '61
Nitroglycerin [55-63-0] 0.05* 0.46* S '86
Nitroglycol [628-96-6] 0.05 0.31 S '86
Nonane [111-84-2] 200 1,050 '89
Octane [111-65-9] 300 1,400 '89
Oil mist, mineral — 3 1ψ '77
Ozone [10028-15-6] 0.1 0.2 '63
Parathion [56-38-2] — 0.1 S ('80)
Pentachlorophenol [87-86-5] — 0.5 S 2 ('89)
Pentane [109-66-0] 300 880 '87
Pentyl acetate, All isomers [628-63-7; 123-92-2; 626-38-0; 620-11-1; 625-16-1; 624-41-9; 926-41-0] 50
100*		 266.3
532.5*		 '08
Perfluorooctanoic acid [335-67-1] 0.005c 2B† 1# '08
Phenol [108-95-2] 5 19 S 3 '78
m-Phenylenediamine [108-45-2] — 0.1 3 '99
o-Phenylenediamine [95-54-5] — 0.1 3 '99
p-Phenylenediamine [106-50-3] — 0.1 1 '97
Phosgene [75-44-5] 0.1 0.4 '69
Phosphine [7803-51-2] 0.3* 0.42* '98
Phosphoric acid [7664-38-2] — 1 ('90)
Phosphorus (yellow) [7723-14-0] — 0.1 ('88)
Phosphorus pentachloride [10026-13-8] 0.1 0.85 '89
Phosphorus trichloride [7719-12-2] 0.2 1.1 '89
Phthalic anhydride [85-44-9] 0.33* 2* 1 '98
o-Phthalodinitrile [91-15-6] 0.01 S '09
Picric acid — — 2 '14
Platinum, soluble salts (as Pt)[7440-06-4] — 0.001 1 1 '00
Polychlorobiphenyls — 0.01 S 1ψ 1 '06
Potassium cyanide (as CN) [151-50-8] — 5* S '01
Potassium hydroxide [1310-58-3] — 2* '78
Propyl acetate [109-60-4] 200 830 '70
Propyleneimine (2-Methylaziridine) 0.2 0.45 S 2B '17
Pyridaphenthion [119-12-0] — 0.2 S '89
Rhodium (Soluble compounds, as Rh) [7440-16-6] — 0.001 2 '07
Selenium and compounds (as Se, except SeH2 and SeF6) [7782-49-2] — 0.1 '00
Silane [7803-62-5] 100* 130* '93
Silver and compounds (as Ag) [7440-22-4] — 0.01 '91
Sodium cyanide (as CN) [143-33-9] — 5* S '01
Sodium hydroxide [1310-73-2] — 2* '78
Styrene [100-42-5] 20 85 S 2B 2 '99
Sulfur dioxide [7446-09-5] (pending) '61
Sulfuric acid [7664-93-9] — 1* '00
Sulfur monochloride [10025-67-9] 1* 5.5* '76
1,1,2,2-Tetrachloroethane [79-34-5] 1 6.9 S 2B '84
Tetrachloroethylene [127-18-4] (pending) S 2B 3 '72
Tetraethoxysilane [78-10-4] 10 85 '91
Tetraethyl lead (as Pb) [78-00-2] — 0.075 S '65
Tetrahydrofuran [109-99-9] 50 148 S '15
Tetramethoxysilane [681-84-5] 1 6 '91
Thiuram [137-26-8] 0.1 1 '08
Titanium dioxide (nanoparticle, as Ti) [13463-67-7] — 0.3 2B '13
Toluene [108-88-3] 50 188 S 1 ('13)
Toluene diisocyanates [26471-62-5] 0.005 0.035 2B 1 2 '92
0.02* 0.14*
Trichlorhon [52-68-6] 0.2 S '10
o-Toluidine [95-53-4] 1 4.4 S 1ψ '91
1,1,1-Trichloroethane [71-55-6] 200 1,100 '74
1,1,2-Trichloroethane [79-00-5] 10 55 S ('78)
Trichloroethylene [79-01-6] 25 135 1ψ 1 3 '15
Trichlorofluoromethane [75-69-4] 1,000* 5,600* '87
1,1,2-Trichloro-1,2,2-trifluoroethane [76-13-1] 500 3,800 '87
Tricyclazole [41814-78-2] — 3 '90
Trimellitic anhydride [552-30-7] 0.0005
0.004*		 1 S '15
1,2,3-Trimethylbenzene [526-73-8] 25 120 '84
1,2,4-Trimethylbenzene [95-63-6] 25 120 '84
1,3,5-Trimethylbenzene [108-67-8] 25 120 '84
Trinitrotoluene (all isomers) — 0.1 S '93
Turpentine 50 280 1 '91
Vanadium compounds 2
Ferrovanadium dust [12604-58-9] — 1 '68
Vanadium pentoxide [1314-62-1] — 0.05 2B '03
Vinyl chloride [75-01-4] (Table III-2) 1ψ '17
Xylene (all isomers and their mixture) 50 217 '01
Xylene for industrial use 2
Xylene (ortho-, meta-, para-xylene and their mixture) 3
Zinc oxide fume [1314-13-2] (pending) '69
1. ppm: parts of vapors and gases per million of substance in air by volume at 25°C and atmospheric pressure (760 torr, 1,013 hPa); OELs in ppm are converted to those in mg/m3, in which the values are rounded off with 2 significant digits.
2. ( ) in the year of proposal column indicates that revision was done in the year without change of the OEL value.
3. *: Occupational Exposure Limit-Ceiling; exposure concentration must be kept below this level.
**: Fibers longer than 5 μm and with an aspect ratio equal to or greater than 3:1 as determined by the membrane filter method at 400 × magnification phase contrast illumination.
ψ: Substance whose OEL is set based on non-caninogenic health effects; see III.
a: Exposure concentration should be kept below a detectable limit though OEL is set at 2.5 ppm provisionally.
b: OEL for gasoline is 300 mg/m3, and an average molecular weight is assumed to be 72.5 for conversion to ppm unit.
c: Not applicable to women of child bearing potential.
#: Precaution should be given for lower exposure than OEL-M or OEL-B. As for reproductive toxicity, it is generally known that there is a sensitive period, during pregnancy for example, and such effects of this substance have been identified.
†: Provisional.