Exposure limits are reported in ppm, mg/m3, or f/cc. In general, substances present in air as a vapour or gas are reported in parts per million (ppm). Substances present in air as an aerosol (dust, fume, mist) and mixtures such as diesel fuel are typically reported in milligrams per cubic meter (mg/m3). Fibrous substances, such as synthetic vitreous fibers (e.g., glass wool fibers) are reported in fibers per cubic centimeter (f/cc).

Notations column
The notations identify substances considered to be carcinogens, sensitizers and those with adverse reproductive effect. The notations column also indicates substances that contribute significantly to overall exposure by the skin route.

TWA column
This is the 8-hour time weighted average (TWA) limit, as defined in OHS Regulations.

STEL/Ceiling column
This is the short-term exposure limit or STEL, which is defined in the OHS Regulations.

Any missing compounds may be available – CDC NIOSH Pocket Guide.

Exposure Limits Chart

Substance [CAS No.] TWA STEL/Ceiling Notations
Abate (See Temephos)
Acetaldehyde [75-07-0] Revised 2014 C 25 ppm A2, 2B
Acetamide [60-35-5] 2B
Acetic acid [64-19-7] 10 ppm 15 ppm
Acetic anhydride [108-24-7] Revised 2011 1 ppm 3 ppm
Acetone [67-64-1] 250 ppm 500 ppm
Acetone cyanohydrin [75-86-5] C 1 ppm Skin
Acetonitrile [75-05-8] 20 ppm Skin
Acetophenone [98-86-2] 10 ppm
Acetylene [74-86-2] Simple asphyxiant
Acetylene tetrabromide (See 1,1,2,2 Tetrabromoethane)
Acetylsalicylic acid (Aspirin) [50-78-2] 5 mg/m3
Acrolein [107-02-8] C 0.1 ppm Skin
Acrylamide, Inhalable [79-06-1] Revised 2005 0.03 mg/m3 (V) Skin; 2A
Acrylic acid [79-10-7] 2 ppm Skin; R
Acrylonitrile [107-13-1] 2 ppm Skin; 2B
Adipic acid [124-04-9] 5 mg/m3
Adiponitrile [111-69-3] 2 ppm Skin
Alachlor, Inhalable [15972-60-8] Revised 2007 1.0 mg/m3(V) S
Aldrin, Inhalable [309-00-2] Revised 2007 0.05mg/m3(V) Skin
Aliphatic hydrocarbon gases [C1-C4] Revised 2004 1000 ppm
Allyl alcohol [107-18-6] 0.5 ppm Skin
Allyl amine [107-11-9] 2 ppm
Allyl bromide [106-95-6] (I)
Allyl chloride [107-05-1] Revised 2011 1 ppm 2 ppm Skin
Allyl glycidyl ether [106-92-3] 1 ppm S
Allyl propyl disulfide [2179-59-1] Revised 2006 0.5 ppm S
Aluminum metal and insoluble compounds [7429-90-5] , Respirable, Revised 2008 1.0 mg/m3
4-Aminodiphenyl [92-67-1] (L) Skin; A1, 1
2-Aminopyridine [504-29-0] 0.5 ppm
Amitrole [61-82-5] Revised 2006 0.2 mg/m3 R
Ammonia [7664-41-7] 25 ppm 35 ppm
Ammonium chloride – Fume [12125-02-9] 10 mg/m3 20 mg/m3
Ammonium perfluorooctanoate [3825-26-1] 0.01 mg/m3 Skin
Ammonium sulfamate [7773-06-0] 10 mg/m3(N)
tert-Amyl methyl ether (TAME) [994-05-8] 20 ppm R
Aniline [62-53-3] 2 ppm Skin
o-Anisidine [90-04-0] 0.5 mg/m3 Skin; 2B
p-Anisidine [104-94-9] 0.5 mg/m3 Skin
Antimony and compounds, as Sb [7440-36-0] 0.5 mg/m3
Antimony hydride (Stibine) [7803-52-3] 0.1 ppm
Antimony trioxide – Production [1309-64-4] (L) A2, 2B
ANTU [86-88-4] 0.3 mg/m3
Argon [7440-37-1] Simple asphyxiant
Arsenic and inorganic compounds, as As [7440-38-2] 0.01 mg/m3 A1, 1
Arsine [7784-42-1] Revised 2007 0.005 ppm
Asbestos – All forms [1332-21-4] 0.1 f/cc (F) A1, 1
Asphalt (Bitumen) fume, as benzene-soluble aerosol, Inhalable [8052-42-4] 0.5 mg/m3 (I)
Atrazine [1912-24-9] 5 mg/m3
Azinphos-methyl, Inhalable [86-50-0] 0.2 mg/m3(V) Skin; S
Barium and soluble compounds, as Ba [7440-39-3] 0.5 mg/m3
Barium sulfate [7727-43-7] 10 mg/m3(N)
Benomyl, Inhalable [17804-35-2] Revised 2008 1 mg/m3 R, S
Benz[a]anthracene [56-55-3] Revised 2006 (L) A2, 2B
Benzene [71-43-2] 0.5 ppm 2.5 ppm Skin; A1, 1
Benzidine [92-87-5] (L) Skin; A1, 1
Benzidine based dyes 2A
Benzo[b]fluoranthene [205-99-2] (L) A2, 2B
Benzo[a]pyrene [50-32-8] Revised 2006 (L) A2, 1
Benzotrichloride [98-07-7] C 0.1 ppm Skin; A2, 2A
Benzoyl chloride [98-88-4] C 0.5 ppm 2A
Benzoyl peroxide [94-36-0] 5 mg/m3
Benzyl acetate [140-11-4] 10 ppm
Benzyl chloride [100-44-7] C 1 ppm 2A
Beryllium and compounds, Inhalable, as Be [7440-41-7] Revised 2009; 2010; 2015 0.00005 mg/m3 Skin; S; A1, 1; (I)
Biphenyl [92-52-4] 0.2 ppm
Bis(2-dimethylaminoethyl) ether (DMAEE) [3033-62-3] 0.05 ppm 0.15 ppm Skin
Bismuth telluride – Se-doped [1304-82-1] 5 mg/m3
Bismuth telluride – Undoped [1304-82-1] 10 mg/m3(N)
Borate compounds, Inorganic, Inhalable [1303-96-4; 1330-43-4; 10043-35-3; 12179-04-3] Revised 2005 2 mg/m3 6 mg/m3
Boron oxide [1303-86-2] 10 mg/m3
Boron tribromide [10294-33-4] C 1 ppm
Boron trifluoride [7637-07-02] C 1 ppm
Bromacil [314-40-9] 10 mg/m3
Bromine [7726-95-6] 0.1 ppm 0.2 ppm
Bromine pentafluoride [7789-30-2] 0.1 ppm
Bromochloromethane [74-97-5] 200 ppm 250 ppm
Bromoform [75-25-2] Revised 2009 0.5 ppm
1-Bromopropane [106-94-5] Revised 2005 10 ppm R
1,3-Butadiene [106-99-0] 2 ppm A2, 1
n-Butane [106-97-8] 600 ppm 750 ppm
n-Butanol [71-36-3] 15 ppm C 30 ppm
sec-Butanol [78-92-2] 100 ppm
tert-Butanol [75-65-0] 100 ppm
Butenes, all isomers, including Isobutene [106-98-9; 107-01-7; 590-18-1; 624-64-6; 25167-67-3; 115-11-7] (I)
2-Butoxyethanol (EGBE) [111-76-2] Revised 2003 20 ppm
2-Butoxyethyl acetate [112-07-2] Revised 2003 20 ppm
n-Butyl acetate [123-86-4] 20 ppm
sec-Butyl acetate [105-46-4] 200 ppm
tert-Butyl acetate [540-88-5] 200 ppm
n-Butyl acrylate [141-32-2] 2 ppm S
n-Butylamine [109-73-9] C 5 ppm Skin
Butylated hydroxytoluene (BHT), Inhalable, (2,6-Di-tert-butyl-p-cresol) [128-37-0] 2 mg/m3(V)
tert-Butyl chromate, as CrO3 [1189-85-1] C 0.1 mg/m3 Skin
n-Butyl glycidyl ether (BGE) [2426-08-6] Revised 2005 3 ppm Skin; S; R
n-Butyl lactate [138-22-7] 5 ppm
n-Butyl mercaptan [109-79-5] 0.5 ppm R
n-Butyl methacrylate [97-88-1] 50 ppm
o-sec-Butylphenol [89-72-5] 5 ppm Skin
p-tert-Butyltoluene [98-51-1] 1 ppm
Cadmium and compounds, as Cd [7440-43-9] 0.01 mg/m3 A2, 1
Cadmium and compounds, Respirable, as Cd [7440-43-9] 0.002 mg/m3 A2, 1
Calcium arsenate, as As [7778-44-1] 0.01 mg/m3 A1, 1
Calcium carbonate (incl. Limestone, Marble) [1317-65-3] 10 mg/m3(N) 20 mg/m3
Calcium chromate, as Cr [13765-19-0] 0.001 mg/m3 A2, 1
Calcium cyanamide [156-62-7] 0.5 mg/m3
Calcium hydroxide [1305-62-0] 5 mg/m3
Calcium oxide [1305-78-8] 2 mg/m3
Calcium silicate – Synthetic nonfibrous [1344-95-2] 10 mg/m3(E,N)
Calcium sulfate, Inhalable [7778-18-9] 10 mg/m3
Camphor – Synthetic [76-22-2] 2 ppm 3 ppm
Caprolactam, Dust [105-60-2] 1 mg/m3 3 mg/m3
Captafol [2425-06-1] 0.1 mg/m3 Skin; 2A; S
Captan, Inhalable [133-06-2] 5 mg/m3 S
Carbaryl [63-25-2] Revised 2008; 2010 5 mg/m3 Skin; R
Carbofuran, Inhalable [1563-66-2] Revised 2004 0.1 mg/m3(V)
Carbon black, Inhalable [1333-86-4] Revised 2011 3 mg/m3 2B
Carbon dioxide [124-38-9] 5000 ppm 15,000 ppm
Carbon disulfide [75-15-0] 4 ppm 12 ppm Skin
Carbon monoxide [630-08-0] 25 ppm 100 ppm R
Carbon tetrabromide [558-13-4] 0.1 ppm 0.3 ppm
Carbon tetrachloride [56-23-5] 2 ppm Skin; A2, 2B
Carbonyl fluoride [353-50-4] 2 ppm 5 ppm
Carbonyl sulfide [463-58-1] Revised 2015 5 ppm
Catechol [120-80-9] 5 ppm Skin; 2B
Cellulose [9004-34-6] 10 mg/m3(N)
Cesium hydroxide [21351-79-1] 2 mg/m3
Chlordane [57-74-9] 0.5 mg/m3 Skin; 2B
Chlorinated camphene [8001-35-2] 0.5 mg/m3 1 mg/m3 Skin; 2B
o-Chlorinated diphenyl oxide [31242-93-0] 0.5 mg/m3
Chlorine [7782-50-5] 0.5 ppm 1 ppm
Chlorine dioxide [10049-04-4] 0.1ppm 0.3 ppm
Chlorine trifluoride [7790-91-2] C 0.1 ppm
Chloroacetaldehyde [107-20-0] C 1 ppm
Chloroacetic acid [79-11-8] 0.3 ppm
Chloroacetone [78-95-5] C 1 ppm Skin
2-Chloroacetophenone [532-27-4] 0.05 ppm S
Chloroacetyl chloride [79-04-9] 0.05 ppm 0.15 ppm Skin
p-Chloroaniline [106-47-8] 2B
Chlorobenzene [108-90-7] 10 ppm
o-Chlorobenzylidene malononitrile [2698-41-1] C 0.05 ppm Skin
Chlorobromomethane (see Bromochloromethane)
1-Chloro-1,1-difluoroethane [75-68-3] 1000 ppm
Chlorodifluoromethane [75-45-6] 500 ppm 1250 ppm
Chlorodiphenyl (42% chloride) [53469-21-9] 1 mg/m3 Skin; 2A
Chlorodiphenyl (54% chloride) [11097-69-1] 0.5 mg/m3 Skin; 2A
Chloroform [67-66-3] 2 ppm 2B; R
bis(Chloromethyl) ether [542-88-1] 0.001 ppm A1, 1
Chloromethyl methyl ether [107-30-2] (L) A2, 1
1-Chloro-1-nitropropane [600-25-9] 2 ppm
Chloropentafluoroethane [76-15-3] 1000 ppm
Chloropicrin [76-06-2] 0.1 ppm
1-Chloro-2-propanol [127-00-4] Revised 2008 1 ppm Skin; R
2-Chloro-1-propanol [78-89-7] Revised 2008 1 ppm Skin; R
beta-Chloroprene [126-99-8] 10 ppm Skin; 2B; R
2-Chloropropioni acid [598-78-7] 0.1 ppm Skin; R
o-Chlorostyrene [2039-87-4] 50 ppm 75 ppm
o-Chlorotoluene [95-49-8] 50 ppm
4-Chloro-o-Toluidine [95-69-2] 2A
Chlorotrifluoromethane [75-72-9] 1000 ppm
Chlorpyrifos, Inhalable [2921-88-2] Revised 2003 0.1 mg/m3(V) Skin
Chromite ore processing (Chromate), as Cr 0.05 mg/m3 A1
Chromium – Metal [7440-47-3] 0.5 mg/m3
Chromium (III) inorganic compounds, as Cr [7440-47-3] 0.5 mg/m3
Chromium (VI) inorganic compounds – Insoluble, as Cr [7440-47-3] 0.01 mg/m3 A1, 1
Chromium (VI) inorganic compounds – Water soluble, as Cr [7440-47-3] 0.025 mg/m3 C 0.1 mg/m3 A1, 1
Chromyl chloride [14977-61-8] 0.025 ppm
Chrysene [218-01-9] Revised 2006 (L) 2B
Citral, inhalable [5292-40-5] (I)
Clopidol [2971-90-6] 10 mg/m3(N)
Coal dust – Anthracite, Respirable 0.4 mg/m3
Coal dust – Bituminous, Respirable 0.9 mg/m3
Coal tar pitch volatiles, as benzene-soluble aerosol [65996-93-2] 0.2 mg/m3 A1, 1
Cobalt and inorganic compounds, as Co [7440-48-4] 0.02 mg/m3 2B
Cobalt carbonyl, as Co [10210-68-1] 0.1 mg/m3 2B
Cobalt hydrocarbonyl, as Co [16842-03-8] 0.1 mg/m3 2B
Copper – Dusts and mists, as Cu [7440-50-8] 1 mg/m3
Copper – Fume, as Cu [7440-50-8] 0.2 mg/m3
Cotton dust – Raw, Untreated, Thoracic, Revised 2011 0.1 mg/m3
Coumaphos, Inhalable [56-72-4] Revised 2006 0.05 mg/m3 (V) Skin
Cresol, all isomers [1319-77-3; 95-48-7; 108-39-4; 106-44-5] 10 mg/m3 Skin
Crotonaldehyde [4170-30-3] C 0.3 ppm Skin
Crufomate [299-86-5] 5 mg/m3
Cumene [98-82-8] 25 ppm 75 ppm 2B
Cyanamide [420-04-2] 2 mg/m3
Cyanogen [460-19-5] 10 ppm
Cyanogen bromide [506-68-3] (I)
Cyanogen chloride [506-77-4] C 0.3 ppm
Cyclohexane [110-82-7] 100 ppm
Cyclohexanol [108-93-0] 50 ppm Skin
Cyclohexanone [108-94-1] Revised 2003 20 ppm 50 ppm Skin
Cyclohexene [110-83-8] 300 ppm
Cyclohexylamine [108-91-8] 10 ppm
Cyclonite [121-82-4] 0.5 mg/m3 Skin
Cyclopentadiene [542-92-7] 75 ppm
Cyclopentane [287-92-3] 600 ppm
Cyhexatin [13121-70-5] 5 mg/m3
2,4-D (2,4-Dichlorophenoxy-acetic acid) [94-75-7] (see 2,4-Dichlorophenoxyacetic acid and its esters)
DDT (Dichloro-diphenyltrichloroethane) [50-29-3] 1 mg/m3 2B
Decaborane [17702-41-9] 0.05 ppm 0.15 ppm Skin
Demeton, Inhalable [8065-48-3] 0.05 mg/m3 (V) Skin
Demeton-S-methyl, Inhalable [919-86-8] 0.05 mg/m3 (V) Skin; S
Diacetone alcohol [123-42-2] 50 ppm
Diacetyl [431-03-8] Revised 2015 0.01 ppm 0.02 ppm
2,4-Diaminoanisole [615-05-4] 2B
2,4-Diaminotoluene [95-80-7] 2B
Diazinon, Inhalable [333-41-5] Revised 2003 0.01 mg/m3 (V) Skin
Diazomethane [334-88-3] 0.2 ppm A2
Diborane [19287-45-7] 0.1 ppm
1,2-Dibromo-3-chloropropane [96-12-8] 2B
2-N-Dibutylaminoethanol [102-81-8] 0.5 ppm Skin
Dibutyl phenyl phosphate [2528-36-1] 0.3 ppm Skin
Dibutyl phosphate [107-66-4] Revised 2009; 2010 1 ppm 2 ppm Skin
Dibutyl phthalate [84-74-2] 5 mg/m3 R
Dichloroacetic acid [79-43-6] Revised 2005 0.5 ppm Skin; 2B; R
Dichloroacetylene [7572-29-4] C 0.1 ppm
o-Dichlorobenzene [95-50-1] 25 ppm 50 ppm
p-Dichlorobenzene [106-46-7] 10 ppm 2B
3,3′-Dichlorobenzidine [91-94-1] (L) Skin; 2B
1,4-Dichloro-2-butene [764-41-0] 0.005 ppm Skin; A2
2,2-Dichlorodiethyl sulfide (Mustard Gas) [505-60-2] 1
Dichlorodifluoromethane [75-71-8] 1000 ppm
1,3-Dichloro-5,5-dimethyl hydantoin [118-52-5] 0.2 mg/m3 0.4 mg/m3
1,1-Dichloroethane [75-34-3] 100 ppm
1,2-Dichloroethane (see ethylene dichloride)
1,2-Dichloroethylene, all isomers [540-59-0; 156-59-2; 156-60-5] 200 ppm
Dichloroethyl ether [111-44-4] 5 ppm 10 ppm Skin
Dichlorofluoromethane [75-43-4] 10 ppm
Dichloromethane [75-09-2] 25 ppm 2B
2,2′-Dichloro-n-methyldiethylamine (Nitrogen mustard) [51-75-2] 2A
1,1-Dichloro-1-nitroethane [594-72-9] 2 ppm
1,3-Dichloropropene [542-75-6] 1 ppm Skin; 2B
2,4-Dichlorophenoxyacetic acid and its esters [94-75-7] Revised 2006 10 mg/m3 20 mg/m3 (I)
2,2-Dichloropropionic acid, Inhalable [75-99-0] 5 mg/m3
Dichlorotetrafluoroethane (Cryofluorane) [76-14-2] 1000 ppm
Dichlorvos (DDVP), Inhalable [62-73-7] 0.1 mg/m3(V) Skin; 2B; S
Dicrotophos, Inhalable [141-66-2] 0.05 mg/m3 (V) Skin
Dicyclohexylmethane-4,4′-diisocyanate [5124-30-1] (see Methylene bis (4-cyclohexyl-isocyanate))
Dicyclopentadiene [77-73-6] 5 ppm
Dicyclopentadienyl iron [102-54-5] 10 mg/m3(N)
Dieldrin [60-57-1] 0.25 mg/m3 Skin
Diesel fuel, as total hydrocarbons, Inhalable [68334-30-5; 68476-30-2; 68476-31-3; 68476-34-6; 77650-28-3] 100 mg/m3(V) Skin; (I)
Diethanolamine [111-42-2] Revised 2009; 2010 2 mg/m3 Skin; 2B
Diethylamine [109-89-7] 5 ppm 15 ppm Skin
2-Diethylaminoethanol [100-37-8] 2 ppm Skin
Diethylene triamine [111-40-0] 1 ppm Skin; S
Di(2-ethylhexyl)phthalate (DEHP) [117-81-7] 5 mg/m3 2B
Diethyl ketone [96-22-0] 200 ppm 300 ppm
Diethyl phthalate [84-66-2] 5 mg/m3
Diethyl sulfate [64-67-5] 2A
Diethylene glycol monobutyl ether [112-34-5] (I)
N,N-Diethylhydroxylamine [3710-84-7] (I)
Difluorodibromomethane [75-61-6] 100 ppm
Diglycidyl ether (DGE) [2238-07-5] Revised 2007 0.01 ppm R
Diisobutyl ketone [108-83-8] 25 ppm
Diisocyanates, not elsewhere specified, NOS 0.005 ppm C 0.01ppm
Diisopropylamine [108-18-9] 5 ppm Skin
3,3′-Dimethoxybenzidine [119-90-4] 2B
Dimethoxymethane [109-87-5] 1000 ppm 1250 ppm
N,N-Dimethylacetamide [127-19-5] 10 ppm Skin; R
Dimethylamine [124-40-3] 5 ppm 15 ppm
Dimethylaniline [121-69-7] 5 ppm 10 ppm Skin
3,3′-Dimethylbenzidine [119-93-7] 2B
Dimethyl carbamoyl chloride [79-44-7] Revised 2007 0.005 ppm Skin; A2, 2A
Dimethyl disulfide [624-92-0] Revised 2007 0.5 ppm Skin
Dimethyl ether [115-10-6] 1000 ppm
Dimethylethoxysilane [14857-34-2] 0.5 ppm 1.5 ppm
Dimethylformamide [68-12-2] 10 ppm Skin
1,1-Dimethylhydrazine [57-14-7] 0.01 ppm Skin; 2B
1,2-Dimethylhydrazine [540-73-8] 2A
Dimethyl phthalate [131-11-3] 5 mg/m3
Dimethyl sulfate [77-78-1] C 0.1 ppm Skin; 2A
Dimethyl sulfide [75-18-3] Revised 2004 10 ppm
Dinitolmide [148-01-6] (See 3,5-Dinitro-o-toluamide)
Dinitrobenzene, all isomers [528-29-0; 99-65-0; 100-25-4; 25154-54-5] 0.15 ppm Skin
Dinitrol-o-cresol [534-52-1] 0.2 mg/m3 Skin
3,5-Dinitro-o-toluamide [148-01-6] Revised 2007 1 mg/m3
Dinitrotoluene [25321-14-6] 0.2 mg/m3 Skin; 2B; (I); R
n-Dioctyl phthalate [117-84-0] 5 mg/m3
1,4-Dioxane [123-91-1] 20 ppm Skin; 2B
Dioxathion, Inhalable [78-34-2] 0.1 mg/m3(V) Skin
1,3-Dioxolane [646-06-0] 20 ppm R
Diphenylamine [122-39-4] 10 mg/m3
Dipropyl ketone [123-19-3] 50 ppm
Dipropylene glycol methyl ether [34590-94-8] 100 ppm 150 ppm Skin
Diquat, Inhalable [2764-72-9] 0.5 mg/m3 Skin
Diquat, Respirable [2764-72-9] 0.1 mg/m3 Skin
Disulfiram [97-77-8] 2 mg/m3
Disulfoton, Inhalable [298-04-4] 0.05 mg/m3 (V) Skin
Diuron [330-54-1] 10 mg/m3
Divinyl benzene [1321-74-0] 10 ppm
Dodecyl mercaptan [112-55-0] Revised 2004 0.1 ppm S
Dyfonate, Inhalable [944-22-9] Revised 2006 0.1 mg/m3(V) Skin
Endosulfan [115-29-7] Revised 2009; 2010 0.1 mg/m3 Skin
Endrin [72-20-8] 0.1 mg/m3 Skin
Enflurane [13838-16-9] 2 ppm
Epichlorohydrin [106-89-8] 0.1 ppm Skin; 2A; R
EPN, Inhalable [2104-64-5] Revised 2003 0.1 mg/m3 Skin
Ethane [74-84-0] Revised 2004 See Aliphatic Hydrocarbon gases [C1-C4] Revised 2008
Ethanol [64-17-5] Revised 2009 1000 ppm
Ethanolamine [141-43-5] 3 ppm 6 ppm
Ethion, Inhalable [563-12-2] Revised 2003 0.05 mg/m3 Skin
2-Ethoxyethanol (EGEE) [110-80-5] 5 ppm Skin; R
2-Ethoxyethyl acetate (EGEEA) [111-15-9] 5 ppm Skin; R
Ethyl acetate [141-78-6] 150 ppm
Ethyl acrylate [140-88-5] 5 ppm 15 ppm 2B; S
Ethylamine [75-04-7] 5 ppm 15 ppm Skin
Ethyl amyl ketone [541-85-5] Revised 2007 10 ppm
Ethyl benzene [100-41-4] Revised 2011 20 ppm 2B
Ethyl bromide [74-96-4] 5 ppm Skin
Ethyl tert-butyl ether (ETBE) [637-92-3] 5 ppm R
Ethyl butyl ketone [106-35-4] 50 ppm 75 ppm
Ethyl chloride [75-00-3] 100 ppm Skin
Ethyl cyanoacrylate [7085-85-0] 0.2 ppm
Ethyl methacrylate [97-63-2] 50 ppm
Ethylene [74-85-1] Revised 2005 200 ppm
Ethylene chlorohydrin [107-07-3] C 1 ppm Skin
Ethylenediamine [107-15-3] 10 ppm Skin; S
Ethylene dibromide [106-93-4] 0.5 ppm Skin; 2A
Ethylene dichloride (1,2-dichloroethane) [107-06-2] 1 ppm 2 ppm 2B
Ethylene glycol – Aerosol [107-21-1] C 100 mg/m3
Ethylene glycol – Particulate [107-21-1] 10 mg/m3 20 mg/m3
Ethylene glycol – Vapour [107-21-1] C 50 ppm
Ethylene glycol dinitrate (EGDN) [628-96-6] 0.05 ppm Skin
Ethylene oxide [75-21-8] 0.1 ppm 1 ppm A2, 1; R
Ethyleneimine [151-56-4] Revised 2009; 2010 0.5 ppm Skin; 2B
Ethyl ether [60-29-7] 400 ppm 500 ppm
Ethyl formate [109-94-4] Revised 2015 100 ppm
2-Ethylhexanoic acid, Inhalable [149-57-5] 5 mg/m3(V) R
Ethylidene norbornene [16219-75-3] C 5 ppm
Ethyl isocyanate [109-90-0] (I)
Ethyl mercaptan [75-08-1] 0.5 ppm
N-Ethylmorpholine [100-74-3] 5 ppm Skin
Ethyl silicate [78-10-4] 10 ppm
Fenamiphos, Inhalable [22224-92-6] Revised 2006 0.05 mg/m3 (V) Skin
Fensulfothion, Inhalable [115-90-2] Revised 2005 0.01 mg/m3 (V) Skin
Fenthion, Inhalable [55-38-9] Revised 2006 0.05 mg/m3 (V) Skin
Ferbam, Inhalable [14484-64-1] Revised 2009 5 mg/m3
Ferrovanadium dust [12604-58-9] 1 mg/m3 3 mg/m3
Flour dust, Inhalable 0.5 mg/m3 S
Fluorides (as F) 2.5 mg/m3
Fluorine [7782-41-4] 0.1 ppm
Fluroxene [406-90-6] 2 ppm
Fonofos (see Dyfonate) [944-22-9]
Formaldehyde [50-00-0] 0.3 ppm C 1 ppm A2, 1; S
Formamide [75-12-7] 10 ppm Skin
Formic acid [64-18-6] 5 ppm 10 ppm
Furfural [98-01-1] 2 ppm Skin
Furfuryl alcohol [98-00-0] 5 ppm 10 ppm Skin
Gallium arsenide, Respirable [1303-00-0] Revised 2005 0.0003 mg/m3 1
Gasoline [86290-81-5] 300 ppm 500 ppm 2B
Germanium tetrahydride [7782-65-2] 0.2 ppm
Glutaraldehyde, Activated & inactivated [111-30-8] C 0.05 ppm S
Glycerin – mist [56-81-5] 10 mg/m3
Glycerin – mist, Respirable [56-81-5] 3 mg/m3
Glycidol [556-52-5] 2 ppm 2A
Glyoxal, Inhalable [107-22-2] 0.1 mg/m3(V) S
Grain dust (oat, wheat, barley) 4 mg/m3(E)
Graphite – All forms except graphite fibres, Respirable [7782-42-5] 2 mg/m3
Gypsum [13397-24-5] 10 mg/m3(N) 20 mg/m3
Hafnium and compounds, as Hf [7440-58-6] 0.5 mg/m3
Halothane [151-67-7] 2 ppm R
Helium [7440-59-7] Simple asphyxiant
Heptachlor [76-44-8] 0.05 mg/m3 Skin; 2B
Heptachlor epoxide [1024-57-3] 0.05 mg/m3 Skin
Heptane (n-Heptane) [142-82-5] 400 ppm 500 ppm
Hexachlorobenzene (HCB) [118-74-1] 0.002 mg/m3 Skin; 2B
Hexachlorobutadiene [87-68-3] 0.02 ppm Skin
Hexachlorocyclopentadiene [77-47-4] 0.01 ppm
Hexachloroethane [67-72-1] 1 ppm Skin; 2B
Hexachloronaphthalene [1335-87-1] 0.2 mg/m3 Skin
Hexafluoroacetone [684-16-2] 0.1 ppm Skin; R
Hexafluoropropylene [116-15-4] Revised 2007 0.1 ppm
Hexahydrophthalic anhydride, all isomers, Inhalable [85-42-7; 13149-00-3; 14166-21-3] Revised 2004 C 0.005 mg/m3 (V) S
Hexamethyl phosphoramide [680-31-9] Skin; 2B
Hexamethylene diisocyanate (HDI) [822-06-0] 0.005 ppm C 0.01 ppm S
n-Hexane [110-54-3] 20 ppm Skin
Hexane, all isomers except n-Hexane 200 ppm
1,6-Hexanediamine [124-09-4] 0.5 ppm
1-Hexene [592-41-6] 50 ppm R
sec-Hexyl acetate [108-84-9] 50 ppm
Hexylene glycol [107-41-5] C 25 ppm
Hydrazine [302-01-2] 0.01 ppm Skin; 2B
Hydrogen [1333-74-0] Simple asphyxiant
Hydrogenated terphenyls – Nonirradiated [61788-32-7] 0.5 ppm
Hydrogen bromide [10035-10-6] Revised 2004 C 2 ppm
Hydrogen chloride [7647-01-0] Revised 2006 C 2 ppm
Hydrogen cyanide, as CN [74-90-8] C 4.7 ppm Skin
Cyanide salts, as CN [592-01-8; 151-50-8; 143-33-9] C 5 mg/m3 Skin
Hydrogen fluoride, as F [7664-39-3] C 2 ppm
Hydrogen peroxide [7722-84-1] 1 ppm
Hydrogen selenide [7783-07-5] 0.05 ppm
Hydrogen sulfide [7783-06-4] C 10 ppm
Hydroquinone [123-31-9] Revised 2008 1 mg/m3 S
2-Hydroxypropyl acrylate [999-61-1] 0.5 ppm Skin; S
Indene [95-13-6] Revised 2008; 2010 10 ppm
Indium and compounds, as In [7440-74-6] 0.1 mg/m3 2B; (I)
Iodides (I)
Iodine [7553-56-2] Revised 2008; 2010 C 0.1 ppm
Iodoform [75-47-8] 0.6 ppm
Iron oxide dust, as Fe [1309-37-1] 5 mg/m3
Iron oxide fume , as Fe [1309-37-1] 5 mg/m3 10 mg/m3
Iron pentacarbonyl [13463-40-6] 0.01 ppm
Iron salts – soluble, as Fe 1 mg/m3 2 mg/m3
Isoamyl alcohol [123-51-3] 100 ppm 125 ppm
Isobutanol [78-83-1] 50 ppm
Isobutyl acetate [110-19-0] 150 ppm
Isobutyl nitrite, Inhalable [542-56-3] C 1 ppm (V)
Isooctyl alcohol [26952-21-6] 50 ppm Skin
Isophorone [78-59-1] C 5 ppm
Isophorone diisocyanate [4098-71-9] 0.005 ppm C 0.01 ppm S
Isopropanol (Isopropyl alcohol) [67-63-0] Revised 2003 200 ppm 400 ppm
2-Isopropoxyethanol [109-59-1] 25 ppm Skin
Isopropyl acetate [108-21-4] Revised 2003 100 ppm 200 ppm
Isopropylamine [75-31-0] 5 ppm 10 ppm
N-Isopropylaniline [768-52-5] 2 ppm Skin
Isopropyl ether [108-20-3] 250 ppm 310 ppm
Isopropyl glycidyl ether (IGE) [4016-14-2] C 50 ppm
Kaolin, Respirable [1332-58-7] 2 mg/m3(E)
Kerosene [8008-20-6]/Jet fuels [64742-47-8], as total hydrocarbon vapour, Revised 2006 200 mg/m3(P) Skin
Ketene [463-51-4] 0.5 ppm 1.5 ppm
Lead – elemental and inorganic compounds, as Pb [7439-92-1] 0.05 mg/m3 Elemental 2B; R
Other inorganic 2A; R
Lead chromate, as Cr [7758-97-6] 0.012 mg/m3 A2, 1; R; (I)
Lead chromate, as Pb [7758-97-6] 0.05 mg/m3 A2, 1; R; (I)
Lindane [58-89-9] 0.5 mg/m3 Skin
Liquified petroleum gas (L.P.G.) [68476-85-7] 1000 ppm 1250 ppm
Lithium hydroxide [1310-65-2] C 1 mg/m3
Lithium hydride [7580-67-8] 0.025 mg/m3
Magnesite [546-93-0] Revised 2006 (See Particles Not Otherwise Classified (PNOC))
Magnesium oxide (fume), Inhalable [1309-48-4] Revised 2003 10 mg/m3
Magnesium oxide, Respirable dust and fume, as Mg [1309-48-4] 3 mg/m3 10 mg/m3
Malathion, Inhalable [121-75-5] Revised 2003 1 mg/m3(V) Skin
Maleic anhydride [108-31-6] 0.1 ppm S
Manganese – Elemental & inorganic compounds, as Mn [7439-96-5] 0.2 mg/m3 R
Manganese cyclopentadienyl tricarbonyl, as Mn [12079-65-1] 0.1 mg/m3 Skin
Mercury – Alkyl compounds, as Hg [7439-97-6] 0.01 mg/m3 0.03 mg/m3 Skin
Mercury – Aryl compounds, as Hg [7439-97-6] 0.05 mg/m3 C 0.1 mg/m3 Skin
Mercury – Elemental, as Hg [7439-97-6] 0.025 mg/m3 Skin; R
Mercury – Inorganic compounds, as Hg [7439-97-6] 0.025 mg/m3 Skin; R
Mercury – Methyl, as Hg [7439-97-6] 0.01 mg/m3 0.03 mg/m3 Skin; 2B
Mesityl oxide [141-79-7] 10 ppm 25 ppm
Methacrylic acid [79-41-4] 20 ppm
Methane [74-82-8] Revised 2004 See Aliphatic Hydrocarbon gases [C1-C4] Revised 2008
Methanol [67-56-1] 200 ppm 250 ppm Skin
Methomyl [16752-77-5] 2.5 mg/m3
Methoxychlor [72-43-5] 10 mg/m3
2-Methoxyethanol (EGME) [109-86-4] Revised 2006 0.1 ppm Skin; R
2-Methoxyethyl acetate (EGMEA) [110-49-6] Revised 2006 0.1 ppm Skin; R
Methoxyflurane [76-38-0] 2 ppm
4-Methoxyphenol [150-76-5] 5 mg/m3
1-Methoxy-2-propanol (PGME) [107-98-2] 50 ppm 75 ppm
2-Methoxy-1-propanol [1589-47-5] 20 ppm 40 ppm
1-Methoxypropyl-2-acetate [108-65-6] 50 ppm 75 ppm
2-Methoxypropyl-1-acetate [70657-70-4] 20 ppm 40 ppm
bis-(2-Methoxypropyl) ether (DPGME) (see Dipropylene glycol methyl ether) [34590-94-8]
Methyl acetate [79-20-9] 200 ppm 250 ppm
Methyl acetylene [74-99-7] 1000 ppm
Methyl acetylene-propadiene mixture (MAPP) [59355-75-8] 1000 ppm 1250 ppm
Methyl acrylate [96-33-3] 2 ppm Skin; S
Methylacrylonitrile [126-98-7] 1 ppm Skin
Methylal (see Dimethoxymethane) [109-87-5]
Methylamine [74-89-5] 5 ppm 15 ppm
Methyl n-amyl ketone [110-43-0] 50 ppm
N-Methyl aniline [100-61-8] 0.5 ppm Skin
Methyl bromide [74-83-9] 1 ppm Skin
Methyl tert-butyl ether (MTBE) [1634-04-4] 50 ppm R
Methyl n-butyl ketone [591-78-6] Revised 2008 5 ppm 10 ppm Skin; R
Methyl chloride [74-87-3] 50 ppm 100 ppm Skin; R
Methyl chloroform [71-55-6] 350 ppm 450 ppm
Methyl 2-cyanoacrylate [137-05-3] 0.2 ppm
Methylcyclohexane [108-87-2] 400 ppm
Methylcyclohexanol [25639-42-3] 50 ppm
o-Methylcyclohexanone [583-60-8] 50 ppm 75 ppm Skin
2-Methylcyclopentadienyl manganese tricarbonyl, as Mn [12108-13-3] 0.2 mg/m3 Skin
Methyl demeton, Inhalable [8022-00-2] Revised 2007 0.05 mg/m3 (V) Skin
Methylene bisphenyl isocyanate (MDI) [101-68-8] 0.005 ppm C 0.01 ppm Skin; S
4,4′-Methylene bis(2-chloroaniline) (MBOCA; MOCA) [101-14-4] Revised 2009 0.01 ppm Skin; A2, 1
Methylene bis (4-cyclo-hexyl-isocyanate), [5124-30-1] 0.005 ppm C 0.01 ppm
Methylene chloride (See Dichloromethane)
4,4′-Methylene dianiline [101-77-9] 0.01 ppm Skin; 2B
Methyl ethyl ketone (MEK) [78-93-3] 50 ppm 100 ppm
Methyl ethyl ketone peroxide (MEKP) [1338-23-4] C 0.2 ppm
Methyl formate [107-31-3] 100 ppm 150 ppm Skin
Methyl hydrazine [60-34-4] 0.01 ppm Skin
Methyl iodide [74-88-4] 2 ppm Skin
Methyl isoamyl ketone [110-12-3] 50 ppm
Methyl isobutyl carbinol [108-11-2] 25 ppm 40 ppm Skin
Methyl isobutyl ketone [108-10-1] Revised 2011 20 ppm 75 ppm 2B
Methyl isocyanate [624-83-9] 0.02 ppm Skin; S
Methyl isopropyl ketone [563-80-4] Revised 2011 20 ppm
Methyl mercaptan [74-93-1] 0.5 ppm
Methyl methacrylate [80-62-6] 50 ppm 100 ppm S
1-Methyl naphthalene [90-12-0] Revised 2007 0.5 ppm Skin
2-Methyl naphthalene [91-57-6] Revised 2007 0.5 ppm Skin
Methyl parathion [298-00-0] Revised 2009; 2010 0.2 mg/m3 Skin
Methyl propyl ketone (2-pentanone) [107-87-9] 150 ppm 250 ppm
Methyl silicate [681-84-5] 1 ppm
alpha-Methyl styrene [98-83-9] Revised 2015 10 ppm R; 2B
Methyl vinyl ketone [78-94-4] C 0.2 ppm Skin; S
Metribuzin [21087-64-9] 5 mg/m3
Mevinphos, Inhalable [7786-34-7] Revised 2003 0.01 mg/m3 (V) Skin
Mica, Respirable [12001-26-2] 3 mg/m3
Molybdenum – Metal and insoluble compounds, Respirable [7439-98-7] 3 mg/m3
Molybdenum – Metal and insoluble compounds, Inhalable [7439-98-7] 10 mg/m3
Molybdenum – Soluble compounds, as Mo, Respirable [7439-98-7] 0.5 mg/m3
Monochloroacetic acid [79-11-8] See Chloroacetic acid
Monocrotophos, Inhalable [6923-22-4] 0.05 mg/m3 (V) Skin
Morpholine [110-91-8] 20 ppm Skin
Naled, Inhalable [300-76-5] 0.1 mg/m3(V) Skin; S
Naphthalene [91-20-3] 10 ppm 15 ppm Skin; 2B
1,5-Naphthalene diisocyanate [3173-72-6] 0.005 ppm C 0.01 ppm
beta-Naphthylamine [91-59-8] (L) A1, 1
Natural gas [8006-14-2] Revised 2004 See Aliphatic Hydrocarbon gases [C1-C4] Revised 2008
Natural rubber latex, as total proteins, Inhalable [9006-04-6] Revised 2004; 2008; 2010 0.001 mg/m3 Skin; S
Neon [7440-01-9] Simple asphyxiant
Nickel – Insoluble inorganic compounds, as Ni [7440-02-0] 0.05 mg/m3 A1, 1; (I)
Nickel – Elemental, Soluble inorganic compounds, as Ni [7440-02-0] 0.05 mg/m3 A1, 1, 2B; (I)
Nickel carbonyl, as Ni [13463-39-3] 0.001 ppm 1; (I)
Nickel subsulfide, as Ni, Inhalable [12035-72-2] 0.1 mg/m3 A1, 1
Nicotine [54-11-5] 0.5 mg/m3 Skin
Nitrapyrin [1929-82-4] 10 mg/m3(N) 20 mg/m3
Nitric acid [7697-37-2] 2 ppm 4 ppm
Nitric oxide [10102-43-9] 25 ppm
p-Nitroaniline [100-01-6] 3 mg/m3 Skin
Nitrobenzene [98-95-3] 1 ppm Skin; 2B
p-Nitrochlorobenzene [100-00-5] 0.1 ppm Skin
4-Nitrodiphenyl [92-93-3] (L) Skin; A2
Nitroethane [79-24-3] 100 ppm
Nitrogen [7727-37-9] Simple asphyxiant
Nitrogen dioxide [10102-44-0] C 1 ppm
Nitrogen trifluoride [7783-54-2] 10 ppm
Nitroglycerin (NG) [55-63-0] 0.05 ppm Skin
Nitromethane [75-52-5] 20 ppm 2B
1-Nitropropane [108-03-2] 25 ppm
2-Nitropropane [79-46-9] 5 ppm 2B
Nitropyrene, mono, di, tri, tetra, isomers [5522-43-0; 57835-92-4] (I)
n-Nitrosodiethanolamine [1116-54-7] 2B
n-Nitrosodiethylamine [55-18-5] 2A
n-Nitrosodimethylamine [62-75-9] (L) Skin; 2A
n-Nitrosomethylethylamine [10595-95-6] 2B
n-Nitrosomorpholine [59-89-2] 2B
n-Nitrosopiperidine [100-75-4] 2B
n-Nitrosopyrrolidine [930-55-2] 2B
Nitrotoluene, all isomers [88-72-2; 99-08-1; 99-99-0] 2 ppm Skin; 2A; (I)
5-Nitro-o-toluidine, Inhalable [99-55-8] Revised 2007 1 mg/m3
Nitrous oxide [10024-97-2] 25 ppm R
Nonane [111-84-2] Revised 2015 200 ppm
Octachloronaphthalene [2234-13-1] 0.1 mg/m3 0.3 mg/m3 Skin
Octane, all isomers [111-65-9] 300 ppm
Oil mist – mineral, mildly refined 0.2 mg/m3 1
Oil mist – mineral, severely refined 1 mg/m3
Osmium tetroxide [20816-12-0] 0.0002 ppm 0.0006 ppm
Oxalic acid, anhydrous [144-62-7] Revised 2015 1 mg/m3 2 mg/m3
Oxalic acid, dihydrate [6153-56-6] (I)
p,p’-Oxybis(benzenesulfonyl hydrazide), Inhalable [80-51-3] Revised 2008 0.1 mg/m3 R
Oxygen difluoride [7783-41-7] C 0.05 ppm
Ozone – Heavy work [10028-15-6] 0.05 ppm
Ozone – Moderate work [10028-15-6] 0.08 ppm
Ozone – Light work [10028-15-6] 0.1 ppm
Ozone – Light, mod., or heavy workload =/< 2 hrs [10028-15-6] 0.2 ppm
Paraffin wax fume [8002-74-2] 2 mg/m3
Paraquat, Respirable [4685-14-7] 0.1 mg/m3
Paraquat [4685-14-7] 0.5 mg/m3
Parathion, Inhalable [56-38-2] Revised 2003 0.05 mg/m3 (V) Skin
Particles (Insoluble or Poorly Soluble) Not Otherwise Classified (PNOC) 10 mg/m3(N)
Pentaborane [19624-22-7] 0.005 ppm 0.015 ppm
Pentachloronaphthalene [1321-64-8] 0.5 mg/m3 Skin
Pentachloronitrobenzene [82-68-8] 0.5 mg/m3
Pentachlorophenol [87-86-5] 0.5 mg/m3 Skin; 2B
Pentaerythritol [115-77-5] 10 mg/m3(N)
Pentane, all isomers [78-78-4; 109-66-0; 463-82-1] 600 ppm
2,4-Pentanedione [123-54-6] (I)
Pentyl acetate, all isomers [628-63-7; 626-38-0; 123-92-2; 625-16-1; 624-41-9; 620-11-1] 50 ppm 100 ppm
Peracetic acid [79-21-0] (I)
Perchloroethylene (See Tetrachloroethylene)
Perchloromethyl mercaptan [594-42-3] 0.1 ppm
Perchloryl fluoride [7616-94-6] 3 ppm 6 ppm
Perfluorobutyl ethylene [19430-93-4] Revised 2004 100 ppm
Perfluoroisobutylene [382-21-8] C 0.01 ppm
Perlite [93763-70-3] Revised 2006 (See Particles Not Otherwise Classified (PNOC))
Persulfates, as persulfate 0.1 mg/m3
Phenol [108-95-2] 5 ppm Skin
Phenothiazine [92-84-2] 5 mg/m3 Skin
N-Penyl-beta-naphthylamine [135-88-6]
o-Phenylenediamine [95-54-5] 0.1 mg/m3
m-Phenylenediamine [108-45-2] 0.1 mg/m3
p-Phenylenediamine [106-50-3] 0.1 mg/m3 S
Phenyl ether – Vapour (Diphenyl ether) [101-84-8] 1 ppm 2 ppm
Phenyl glycidyl ether (PGE) [122-60-1] Revised 2008 0.1 ppm Skin; 2B; S; R
Phenyl isocyanate [103-71-9] 0.005 ppm C 0.01 ppm Skin; S
Phenylhydrazine [100-63-0] 0.1 ppm Skin
Phenyl mercaptan [108-98-5] C 0.1 ppm
Phenylphosphine [638-21-1] C 0.05 ppm R
Phorate, Inhalable [298-02-2] Revised 2005 0.05 mg/m3 (V) Skin
Phosgene [75-44-5] 0.1 ppm
Phosphine [7803-51-2] 0.3 ppm 1 ppm
Phosphoric acid [7664-38-2] 1 mg/m3 3 mg/m3
Phosphorus (yellow) [12185-10-3] 0.1 mg/m3
Phosphorus oxychloride [10025-87-3] 0.1 ppm
Phosphorus pentachloride [10026-13-8] 0.1 ppm
Phosphorus pentasulfide [1314-80-3] 1 mg/m3 3 mg/m3
Phosphorus trichloride [7719-12-2] 0.2 ppm 0.5 ppm
Phthalic anhydride [85-44-9] 1 ppm S
m-Phthalodinitrile [626-17-5] Revised 2009 5 mg/m3(V)
o-Phthalodinitrile [91-15-6] (I)
Picloram [1918-02-1] 10 mg/m3(N)
Picric acid [88-89-1] 0.1 mg/m3 S
Pindone [83-26-1] 0.1 mg/m3
Piperazine and its Salts, as Piperazine [110-85-0] 0.3 mg/m3 1 mg/m3 S
Piperidine [110-89-4] 1 ppm
Plaster of Paris [26499-65-0] 10 mg/m3(N) 20 mg/m3
Platinum – Metal [7440-06-4] 1 mg/m3
Platinum – Soluble salts (as Pt) [7440-06-4] 0.002 mg/m3 S
Polyvinyl chloride (PVC), Respirable [9002-86-2] Revised 2008 1 mg/m3
Portland cement, Respirable [65997-15-1] Revised 2015 1 mg/m3(E)
Potassium hydroxide [1310-58-3] C 2 mg/m3
Propane [74-98-6] Revised 2004 See Aliphatic Hydrocarbon gases [C1-C4] Revised 2008
Propane sultone [1120-71-4] (L) 2B
n-Propanol (n-Propyl alcohol) [71-23-8] Revised 2007 100 ppm
Propargyl alcohol [107-19-7] 1 ppm Skin
beta-Propiolactone [57-57-8] 0.5 ppm 2B
Propionaldehyde [123-38-6] 20 ppm
Propionic acid [79-09-4] 10 ppm
Propoxur [114-26-1] 0.5 mg/m3
n-Propyl acetate [109-60-4] 200 ppm 250 ppm
Propylene [115-07-1] Revised 2006 500 ppm
Propylene dichloride [78-87-5] Revised 2006 75 ppm 110 ppm S
Propylene glycol dinitrate [6423-43-4] 0.05 ppm Skin
Propylene oxide [75-56-9] 2 ppm 2B; S
Propyleneimine [75-55-8] Revised 2009; 2010 2 ppm 2B
n-Propyl nitrate [627-13-4] 25 ppm 40 ppm
Pyrethrum [8003-34-7] 5 mg/m3 S
Pyridine [110-86-1] Revised 2004 1 ppm
Quinone [106-51-4] 0.1 ppm
Resorcinol [108-46-3] 10 ppm 20 ppm
Rhodium, Metal and insoluble compounds as Rh [7440-16-6] 0.1 mg/m3 0.3 mg/m3
Rhodium – Soluble compounds, as Rh [7440-16-6] 0.001 mg/m3 0.003 mg/m3
Ronnel, Inhalable [299-84-3] Revised 2006 5 mg/m3(V)
Rosin core solder thermal decomposition products (colophony) [8050-09-7] (L) S
Rotenone (commercial) [83-79-4] 5 mg/m3
Rouge [1309-37-1] 10 mg/m3(E,N)
Rubber solvent (Naphtha) [8030-30-6] Revised 2009 (H)
Selenium and compounds, as Se [7782-49-2] 0.1 mg/m3
Selenium hexafluoride [7783-79-1] 0.05 ppm
Sesone [136-78-7] 10 mg/m3(N)
Silica, Amorphous – Diatomaceous earth (uncalcined) Total [61790-53-2] 4 mg/m3
Silica, Amorphous – Diatomaceous earth (uncalcined), Respirable [61790-53-2] 1.5 mg/m3
Silica, Amorphous – Fume Total [69012-64-2] 4 mg/m3
Silica, Amorphous – Fume, Respirable [69012-64-2] 1.5 mg/m3
Silica, Amorphous – Precipitated and gel, Total [112926-00-8] 4 mg/m3
Silica, Amorphous – Precipitated and gel, Respirable [112926-00-8] 1.5 mg/m3
Silica, Crystalline – alpha quartz [14808-60-7; 1317-95-9] and Cristobalite, Respirable [14464-46-1] Revised 2006 0.025 mg/m3 A2, 1
Silicon [7440-21-3] Revised 2006 (See Particles Not Otherwise Classified (PNOC))
Silicon carbide Nonfibrous, Inhalable, [409-21-2] Revised 2003 10 mg/m3(E)
Silicon carbide, Nonfibrous, Respirable, [409-21-2] Revised 2003 3 mg/m3(E)
Silicon carbide, Fibrous (including whiskers) [409-21-2] Revised 2003 0.1 f/cc (F) A2
Silicon tetrahydride (Silane) [7803-62-5] 0.5 ppm 1 ppm
Silver and Compounds (as Ag) [7440-22-4] 0.01 mg/m3 0.03 mg/m3
Soapstone (see Talc) Revised 2011
Sodium azide (as Sodium azide) [26628-22-8] C 0.29 mg/m3
Sodium azide (as Hydrazoic acid vapour) [26628-22-8] C 0.11 ppm
Sodium bisulfite [7631-90-5] 5 mg/m3
Sodium fluoroacetate [62-74-8] 0.05 mg/m3 Skin
Sodium hydroxide [1310-73-2] C 2 mg/m3
Sodium metabisulfite [7681-57-4] 5 mg/m3
Starch [9005-25-8] 10 mg/m3(N)
Stearates 10 mg/m3(J)
Stoddard solvent (mineral spirits) [8052-41-3] 290 mg/m3 580 mg/m3
Strontium chromate, as Cr [7789-06-2] 0.0005 mg/m3 A2
Strychnine [57-24-9] 0.15 mg/m3
Styrene – monomer [100-42-5] 50 ppm 75 ppm 2B
Subtilisins, as crystalline active enzyme [1395-21-7; 9014-01-1] C 0.00006 mg/m3 S
Sucrose [57-50-1] 10 mg/m3(N)
Sulfometuron methyl [74222-97-2] 5 mg/m3
Sulfotepp (TEDP), Inhalable [3689-24-5] Revised 2005 0.1 mg/m3(V) Skin
Sulfur dioxide [7446-09-5] 2 ppm 5 ppm
Sulfur hexafluoride [2551-62-4] 1000 ppm
Sulfuric acid, Thoracic [7664-93-9] Revised 2004 0.2 mg/m3(M) A2, 1
Sulfur monochloride [10025-67-9] C 1ppm
Sulfur pentafluoride [5714-22-7] C 0.01 ppm
Sulfur tetrafluoride [7783-60-0] C 0.1 ppm
Sulfuryl fluoride [2699-79-8] 5 ppm 10 ppm
Sulprofos [35400-43-2] Revised 2009; 2010 1 mg/m3 Skin
Synthetic Vitreous Fibres – Continuous filament glass fibres 1 f/cc (F)
Synthetic Vitreous Fibres – Continuous filament glass fibres, Inhalable 5 mg/m3
Synthetic Vitreous Fibres – Glass wool fibres 1 f/cc (F)
Synthetic Vitreous Fibres – Rock wool fibres 1 f/cc (F)
Synthetic Vitreous Fibres -Slag wool fibres 1 f/cc (F)
Synthetic Vitreous Fibres – Special purpose glass fibres 1 f/cc (F) 2B
Synthetic Vitreous Fibres – Refractory ceramic fibres 0.2 f/cc (F) A2, 2B
2,4,5-T (2,4,5-Trichlorophenoxyacetic acid) [93-76-5] 10 mg/m3
Talc – Containing no asbestos fibres, Respirable [14807-96-6] 2 mg/m3(E)
Talc – Containing asbestos fibres [14807-96-6] 0.1 f/cc (K) A1, 1
Tantalum – Metal [7440-25-7] 5 mg/m3
Tantalum oxide dusts, as Ta [1314-61-0] 5 mg/m3
Tellurium and compounds (NOS), as Te, excluding hydrogen telluride [13494-80-9] 0.1 mg/m3
Tellurium hexafluoride [7783-80-4] 0.02 ppm
Temephos, Inhalable [3383-96-8] Revised 2005 1 mg/m3(V) Skin
Terbufos, Inhalable [13071-79-9] 0.01 mg/m3 (V) Skin
Terepthalic acid [100-21-0] 10 mg/m3(N)
Terphenyls [26140-60-3] C 5 mg/m3
1,1,2,2-Tetrabromoethane, Inhalable [79-27-6] Revised 2006 0.1 ppm (V)
1,1,1,2-Tetrachloro-2,2-difluoroethane [76-11-9] Revised 2008; 2010 500 ppm
1,1,2,2-Tetrachloro-1,2-difluoroethane [76-12-0] Revised 2008; 2010 200 ppm
1,1,2,2-Tetrachloroethane [79-34-5] 1 ppm Skin; 2B
Tetrachloroethylene (Perchloroethylene) [127-18-4] 25 ppm 100 ppm 2A
Tetrachloronaphthalene [1335-88-2] 2 mg/m3
Tetraethyl lead, as Pb [78-00-2] 0.075 mg/m3 Skin
Tetraethyl pyrophosphate (TEPP), Inhalable [107-49-3] Revised 2007 0.01 mg/m (V) Skin
Tetrafluoroethylene [116-14-3] 2 ppm 2B
Tetrahydrofuran [109-99-9] Revised 2005 50 ppm 100 ppm Skin
Tetramethyl lead, as Pb [75-74-1] 0.075 mg/m3 Skin
Tetramethyl succinonitrile [3333-52-6] 0.5 ppm Skin
Tetranitromethane [509-14-8] 0.005 ppm 2B
Tetrakis (hydroxymethyl) phosphonium chloride [124-64-1] Revised 2005 2 mg/m3
Tetrakis (hydroxymethyl) phosphonium sulfate [55566-30-8] Revised 2005 2 mg/m3 S
Tetryl [479-45-8] 1.5 mg/m3 S
Thallium and soluble compounds, as Tl, Inhalable [7440-28-0] Revised 2011 0.02 mg/m3 Skin
4,4′-Thiobis (6-tert-butyl-m-cresol) Inhalable [96-69-5] Revised 2011 1 mg/m3 Skin
Thioglycolic acid [68-11-1] 1 ppm Skin
Thionyl chloride [7719-09-7] C 1ppm
Thiram [137-26-8] Revised 2008; 2010 1 mg/m3 S
Tin – Metal [7440-31-5] 2 mg/m3
Tin – Oxide and inorganic compounds, except tin hydride, as Sn [7440-31-6] 2 mg/m3
Tin – Organic compounds, as Sn [7440-31-6] 0.1 mg/m3 0.2 mg/m3 Skin
Titanium dioxide [13463-67-7] Revised 2006 10 mg/m3(N) 2B
o-Tolidine [119-93-7] Skin; 2B
Toluene [108-88-3] Revised 2007; 2008 20 ppm R
Toluene-2,4-diisocyanate (2,4-TDI) [584-84-9] 0.005 ppm C 0.01 ppm 2B; S
Toluene-2,6-diisocyanate (2,6-TDI) [91-08-7] 0.005 ppm C 0.01 ppm 2B; S
o-Toluidine [95-53-4] Revised 2009 2 ppm Skin; 1
m-Toluidine [108-44-1] 2 ppm Skin
p-Toluidine [106-49-0] 2 ppm Skin
Tributyl phosphate [126-73-8] 0.2 ppm
Trichloroacetic acid [76-03-9] 1 ppm 2B
1,2,4-Trichlorobenzene [120-82-1] C 5 ppm
1,1,2-Trichloroethane [79-00-5] 10 ppm Skin
Trichloroethylene [79-01-6] Revised 2007 10 ppm 25 ppm A2, 1
Trichlorofluoromethane [75-69-4] C 1000 ppm
Trichloronaphthalene [1321-65-9] 5 mg/m3 Skin
1,2,3-Trichloropropane [96-18-4] 10 ppm Skin; A2, 2A
1,1,2-Trichloro-1,2,2-trifluoroethane [76-13-1] 500 ppm 1250 ppm
Trichlorphon, Inhalable [52-68-6] Revised 2003 1 mg/m3
Triethanolamine [102-71-6] 5 mg/m3
Triethylamine [121-44-8] 1 ppm 3 ppm Skin
Trifluorobromomethane [75-63-8] 1000 ppm
1,3,5-Triglycidyl-s-triazinetrione [2451-62-9] 0.05 mg/m3 R; S
Trimellitic anhydride [552-30-7] Revised 2008; 2010 C 0.04 mg/m3 Skin; S
Trimethylamine [75-50-3] 5 ppm 15 ppm
Trimethyl benzene (mixed isomers) [25551-13-7] 25 ppm
Trimethyl hexamethylene diisocyanate [28679-16-5] 0.005 ppm C 0.01 ppm
Trimethyl phosphite [121-45-9] 2 ppm
Tri-n-Butyltin compounds [688-73-3] 0.05 mg/m3
2,4,6-Trinitrotoluene (TNT) [118-96-7] 0.1 mg/m3 Skin
Triorthocresyl phosphate [78-30-8] 0.1 mg/m3 Skin
Triphenyl phosphate [115-86-6] 3 mg/m3
Tungsten – Metal and insoluble compounds [7440-33-7] 5 mg/m3 10 mg/m3
Tungsten – Soluble compounds, as W [7440-33-7] 1 mg/m3 3 mg/m3
Turpentine [8006-64-2] and selected monoterpenes [80-56-8; 127-91-3; 13466-78-9] Revised 2003 20 ppm S
Uranium (Natural) – Insoluble compounds, as U [7440-61-1] 0.2 mg/m3 0.6 mg/m3 A1, 1; (I)
Uranium (Natural) – Soluble compounds, as U [7440-61-1] 0.05 mg/m3 A1, 1; (I)
n-Valeraldehyde [110-62-3] 50 ppm
Vanadium pentoxide, as V, Inhalable [1314-62-1] Revised 2015 0.05 mg/m3 2B
Vegetable oil – Mist, except castor, cashew nut, or similar irritant oils [8008-89-7] 10 mg/m3
Vegetable oil, Mist, Respirable, except castor, cashew nut, or similar irritating oil [8008-89-7] 3 mg/m3
Vinyl acetate [108-05-4] 10 ppm 15 ppm 2B
Vinyl bromide [593-60-2] 0.5 ppm A2, 2A
Vinyl chloride [75-01-4] 1 ppm A1, 1
4-Vinyl cyclohexene [100-40-3] 0.1 ppm 2B; R
Vinyl cyclohexene dioxide [106-87-6] 0.1 ppm Skin; 2B; R
Vinyl fluoride [75-02-5] 1 ppm A2, 2A
N-Vinyl-2-pyrrolidone [88-12-0] Revised 2003 0.05 ppm
Vinylidene chloride [75-35-4] 1 ppm
Vinylidene fluoride [75-38-7] 500 ppm
Vinyl toluene, all isomers [25013-15-4] 25 ppm 75 ppm
VM & P Naphtha [8032-32-4] Revised 2009 (H)
Warfarin [81-81-2] 0.1 mg/m3
Wood dust – Allergenic species 1 mg/m3 A1, A2, 1; (I)
Wood dust – Non-Allergenic Hardwood 1 mg/m3 A1, A2, 1; (I)
Wood dust – Non-Allergenic Softwood 2.5 mg/m3 1
Xylene [1330-20-7] (o, m & p isomers) [95-47-6; 108-38-3; 106-42-3] 100 ppm 150 ppm
m-Xylene alpha,alpha’-diamine [1477-55-0] C 0.1 mg/m3 Skin
Xylidine – Mixed isomers, Inhalable [1330-73-8] 0.5 ppm (V) Skin
Yttrium – Metal [7440-65-5] 1 mg/m3
Yttrium and compounds, as Y [7440-65-5] 1 mg/m3
Zinc chloride – Fume [7646-85-7] 1 mg/m3 2 mg/m3
Zinc chromates, as Cr [13530-65-9; 11103-86-9; 37300-23-5] 0.01 mg/m3 A1, 1; (I)
Zinc oxide, Respirable [1314-13-2] Revised 2003 2 mg/m3 10 mg/m3
Zinc stearate [557-05-1] 10 mg/m3(N) 20 mg/m3
Zirconium [7440-67-7] and compounds, as Zr [7440-67-7] 5 mg/m3 10 mg/m3

 

Endnotes

1, 2A and 2B indicate substances designated as carcinogens

(C) – Ceiling limit.
(E) – the value is for particulate matter containing no asbestos and less than 1% crystalline silica.
(F) – the value for fibers longer than 5 microns, with an aspect ratio of equal than/greater than 3:1, as determined by the membrane filter method at 400 – 450 times magnification (4 mm objective), using phase-contrast illumination.
(G) – as measured by the vertical elutriator, cotton-dust sampler, see TLV Documentation.
(H) – reciprocal calculation method based on OHS Guideline G5.48-12.
(I) – see Special Notes
(J) – does not include stearates of toxic metals.
(K) – should not exceed 2 mg/m3 respirable particulate.
(L) – No exposure limit. Exposure by all routes should be carefully controlled to levels as low as possible.
(M) – refers to sulfuric acid contained in strong inorganic acid mists.
(N) – the 8-hour TWA listed in the Table is for the total dust. The substance also has an 8-hour TWA of 3 mg/m3 for the respirable fraction.
(O) – sampled by method that does not collect vapour.
(P) – application restricted to conditions in which there are negligible aerosol exposures.
(R) – substance has an adverse reproductive effect.
(S) –  indicates that the substance is a sensitizer.
(V) – vapour and inhalable aerosol.

 

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