Table of exposure limits for chemical and biological substances Explanation of table headings Substance [CAS No.] TWA STEL simple asphyxiant

Transcription

1 Explanation of table headings Substance [CAS No.] Lists chemicals and other substances in alphabetical order. Numerals and prefixes, for example, 1,3-, tert-, o-, sec-, cis-, are disregarded in determining alphabetical order. In square brackets is the Chemical Abstracts Services (CAS) registry number. This is a unique identification number assigned specifically to that substance, and can be a convenient way to identify substances. WorkSafeBC reviews and updates this Table annually. If the exposure limit for a substance has been revised or newly adopted since January 1, 2003 this Table reports the change with the words "Revised (year)". Each year, newly included substances and amended substances are highlighted for a period of time. Recent deletions of substances from the Table are shown as strike through (e.g. Emery). Additional explanation about this table is available at G Annual revisions to exposure limits TWA This is the 8-hour time weighted average (TWA) limit, as defined in section 5.1 of the OHS Regulation. Units: Exposure limits are reported in ppm, mg/m 3, 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 metre (mg/m 3 ). See OHS Guideline G for a procedure to convert from one type of unit to the other. Fibrous substances, such as synthetic vitreous fibres (e.g., glass wool fibres) are reported in fibres per cubic centimetre (f/cc). This is equivalent to fibres per millilitre, or f/ml, which is another common term. Endnotes: Letters in parentheses indicate endnotes, which are explained at the end of the table. Substances which have an "L" endnote are subject to section 5.57 (Designated substances) of the OHS Regulation. For more information see OHS Guideline G5.57. STEL This is the short-term exposure limit or STEL, which is defined in section 5.1 of the OHS Regulation. Note that: "C" indicates a ceiling limit, which is defined in section 5.1 of the OHS Regulation. The units ppm and mg/m 3 are used as in the TWA column. In some cases, the term "simple asphyxiant" is used. This is a gas or vapour that can displace oxygen in the air, resulting in possible suffocation from lack of oxygen. Because simple asphyxiants do not have other significant toxic effects, an exposure limit is not applicable. The limiting factor is the available oxygen. See section 5.56 of the OHS Regulation (Oxygen deficiency). Notations The notations identify substances considered to be carcinogens, sensitizers and those with adverse reproductive effect under section 5.57 of the OHS Regulation. Section 5.57 deals with requirements for substitution and keeping exposure as low as reasonably achievable below the exposure limit. The notations column also indicates substances that contribute significantly to overall exposure by the skin route, in which case section 5.52 of the OHS Regulation applies. Note that: ACGIH notations A1 and A2 and IARC notations 1, 2A and indicate substances designated as carcinogens under section 5.57(1) of the OHS Regulation. The different categories used by the two organizations indicate different levels of certainty of carcinogenic effect, eg. from confirmed carcinogen to probable or possible. For more information see OHS Guideline G5.57. The letter "S" indicates that the substance is a sensitizer under section 5.57(1) of the OHS Regulation. For more information see OHS Guideline G5.57. The letter "R" means that the substance has an adverse reproductive effect under section 5.57(1) of the OHS Regulation. For more information see OHS Guideline G5.57. The term "Skin" identifies substances that contribute significantly to the overall exposure by the skin route. For more information see OHS Guideline G5.52. Page 1 of 18

2 Abate (See Temephos) Acetaldehyde [ ] C 25 ppm Acetamide [ ] Acetic acid [ ] 15 ppm Acetic anhydride [ ] 5 ppm Acetone [ ] ppm Acetone cyanohydrin [ ] C 1ppm Skin Acetonitrile [ ] 20 ppm Skin Acetophenone [ ] Acetylene [ ] Simple asphyxiant Acetylene tetrabromide (See 1,1,2,2 Tetrabromoethane) Acetylsalicylic acid (Aspirin) [ ] 5 mg/m 3 Acrolein [ ] C Skin Acrylamide, Inhalable [ ] Revised mg/m 3 (V) Skin; 2A Acrylic acid [ ] 2 ppm Skin; R Acrylonitrile [ ] 2 ppm Skin; Adipic acid [ ] 5 mg/m 3 Adiponitrile [ ] 2 ppm Skin Alachlor, Inhalable [ ] Revised mg/m 3 (V) S Aldrin, Inhalable [ ] Revised mg/m 3 (V) Skin Aliphatic hydrocarbon gases [C 1 -C 4 ] Revised 2004 Allyl alcohol [ ] 0.5 ppm Skin Allyl amine [ ] 2 ppm Allyl chloride [ ] 1 ppm 2 ppm Allyl glycidyl ether [ ] 1 ppm S Allyl propyl disulfide [ ] Revised ppm S Aluminum metal and insoluble compounds [ ], Respirable, Revised 10mg/m Aminodiphenyl [ ] (L) Skin; A1, 1 2-Aminopyridine [ ] 0.5 ppm Amitrole [ ] Revised mg/m 3 R Ammonia [ ] 25 ppm 35 ppm Ammonium chloride - Fume [ ] 10 mg/m 3 20 mg/m 3 Ammonium perfluorooctanoate [ ] 0.01 mg/m 3 Skin Ammonium sulfamate [ ] tert-amyl methyl ether (TAME) [ ] 20 ppm R Aniline [ ] 2 ppm Skin o-anisidine [ ] 0.5 mg/m 3 Skin; p-anisidine [ ] 0.5 mg/m 3 Skin Antimony and compounds, as Sb [ ] 0.5 mg/m 3 Antimony hydride (Stibine) [ ] Antimony trioxide - Production [ ] (L) A2; ANTU [ ] 0.3 mg/m 3 Argon [ ] Simple asphyxiant Arsenic and inorganic compounds, as As [ ] 0.01 mg/m 3 A1, 1 Arsine [ ] Revised ppm Asbestos - All forms [ ] 0.1 f/cc (F) A1, 1 Asphalt (Bitumen) fume, as benzene-soluble aerosol, Inhalable [ ] 0.5 mg/m 3 Page 2 of 18

3 Atrazine [ ] 5 mg/m 3 Azinphos-methyl, Inhalable [ ] 0.2 mg/m 3 (V) Skin; S Barium and soluble compounds, as Ba [ ] 0.5 mg/m 3 Barium sulfate [ ] Benomyl, Inhalable [ ] Revised mg/m 3 R, S Benz[a]anthracene [ ] Revised 2006 (L) A2, Benzene [ ] 0.5 ppm 2.5 ppm Skin; A1, 1 Benzidine [ ] (L) Skin; A1, 1 Benzidine based dyes 2A Benzo[b]fluoranthene [ ] (L) A2, Benzo[a]pyrene [ ] Revised 2006 (L) A2, 1 Benzotrichloride [ ] C Skin; A2, 2A Benzoyl chloride [ ] C 0.5 ppm 2A Benzoyl peroxide [ ] 5 mg/m 3 Benzyl acetate [ ] Benzyl chloride [ ] C 1 ppm 2A Beryllium and compounds, as Be, Inhalable [ ] Revised mg/m 3 Skin; S, A1, 1 Biphenyl [ ] 0.2 ppm Bis(2-dimethylaminoethyl) ether (DMAEE) [ ] 0.05 ppm 0.15 ppm Skin Bismuth telluride - Se-doped [ ] 5 mg/m 3 Bismuth telluride - Undoped [ ] Borate compounds, Inorganic, Inhalable [ ; ; ; 2 mg/m 3 6 mg/m ] Revised 2005 Boron oxide [ ] 10 mg/m 3 Boron tribromide [ ] C 1 ppm Boron trifluoride [ ] C 1 ppm Bromacil [ ] 10 mg/m 3 Bromine [ ] 0.2 ppm Bromine pentafluoride [ ] Bromochloromethane [ ] 200 ppm 2 Bromoform [ ] Revised ppm 1-Bromopropane [ ] Revised 2005 R 1,3-Butadiene [ ] 2 ppm A2, 1 n-butane [ ] 600 ppm 7 n-butanol [ ] 15 ppm C 30 ppm sec-butanol [ ] tert-butanol [ ] Butenes, All isomers [ ; ; ; ; ]; 2 including isobutene [ ] Revised Butoxyethanol (EGBE) [ ] Revised ppm 2-Butoxyethyl acetate [ ] Revised ppm n-butyl acetate [ ] 20 ppm sec-butyl acetate [ ] 200 ppm tert-butyl acetate [ ] 200 ppm n-butyl acrylate [ ] 2 ppm S n-butylamine [ ] C 5 ppm Skin Butylated hydroxytoluene (BHT), Inhalable, (2,6-Di-tert-butyl-p-cresol) [128-2 mg/m 3 (V) 37-0] tert-butyl chromate, as CrO3 [ ] C 0.1 mg/m 3 Skin n-butyl glycidyl ether (BGE) [ ] Revised ppm Skin; S; R n-butyl lactate [ ] 5 ppm n-butyl mercaptan [ ] 0.5 ppm R n-butyl methacrylate [ ] Page 3 of 18

4 o-sec-butylphenol [ ] 5 ppm Skin p-tert-butyltoluene [ ] 1 ppm Cadmium and compounds, as Cd [ ] 0.01 mg/m 3 A2, 1 Cadmium and compounds, Respirable, as Cd [ ] mg/m 3 A2, 1 Calcium arsenate, as As [ ] 0.01 mg/m 3 A1, 1 Calcium carbonate (incl. Limestone, Marble) [ ] 20 mg/m 3 Calcium chromate, as Cr [ ] mg/m 3 A2, 1 Calcium cyanamide [ ] 0.5 mg/m 3 Calcium hydroxide [ ] 5 mg/m 3 Calcium oxide [ ] 2 mg/m 3 Calcium silicate - Synthetic nonfibrous [ ] 10 mg/m 3 (E,N) Calcium sulfate, Inhalable [ ] 10 mg/m 3 Camphor - Synthetic [ ] 2 ppm 3 ppm Caprolactam, Dust [ ] 1 mg/m 3 3 mg/m 3 Captafol [ ] 0.1 mg/m 3 Skin; 2A; S Captan, Inhalable [ ] 5 mg/m 3 S Carbaryl, Inhalable [ ] Revised mg/m 3 (V) Skin; R Carbofuran, Inhalable [ ] Revised mg/m 3 (V) Carbon black [ ] 3.5 mg/m 3 Carbon dioxide [ ] 5000 ppm 15,000 ppm Carbon disulfide [ ] 4 ppm 12 ppm Skin Carbon monoxide [ ] 25 ppm R Carbon tetrabromide [ ] 0.3 ppm Carbon tetrachloride [ ] 2 ppm Skin; A2, Carbonyl fluoride [ ] 2 ppm 5 ppm Catechol [ ] 5 ppm Skin; Cellulose [ ] Cesium hydroxide [ ] 2 mg/m 3 Chlordane [ ] 0.5 mg/m 3 Skin; Chlorinated camphene [ ] 0.5 mg/m 3 1 mg/m 3 Skin; o-chlorinated diphenyl oxide [ ] 0.5 mg/m 3 Chlorine [ ] 0.5 ppm 1 ppm Chlorine dioxide [ ] 0.1ppm 0.3 ppm Chlorine trifluoride [ ] C Chloroacetaldehyde [ ] C 1 ppm Chloroacetic acid [ ] 0.3 ppm Chloroacetone [ ] C 1 ppm Skin 2-Chloroacetophenone [ ] 0.05 ppm S Chloroacetyl chloride [ ] 0.05 ppm 0.15 ppm Skin p-chloroaniline [ ] Chlorobenzene [ ] o-chlorobenzylidene malononitrile [ ] C 0.05 ppm Skin Chlorobromomethane (see Bromochloromethane) 1-Chloro-1,1-difluoroethane [ ] Chlorodifluoromethane [ ] 500 ppm 12 Chlorodiphenyl (42% chloride) [ ] 1 mg/m 3 Skin; 2A Chlorodiphenyl (54% chloride) [ ] 0.5 mg/m 3 Skin; 2A Chloroform [ ] 2 ppm ; R bis(chloromethyl) ether [ ] ppm A1, 1 Chloromethyl methyl ether [ ] (L) A2, 1 1-Chloro-1-nitropropane [ ] 2 ppm Page 4 of 18

5 Chloropentafluoroethane [ ] Chloropicrin [ ] 1-Chloro-2-propanol [ ] Revised ppm Skin; R 2-Chloro-1-propanol [ ] Revised ppm Skin; R beta-chloroprene [ ] Skin; ; R 2-Chloropropionic acid [ ] Skin; R o-chlorostyrene [ ] 75 ppm o-chlorotoluene [ ] 4-Chloro-o-Toluidine [ ] 2A Chlorotrifluoromethane [ ] Chlorpyrifos, Inhalable [ ] Revised mg/m 3 (V) Skin Chromite ore processing (Chromate), as Cr 0.05 mg/m 3 A1 Chromium - Metal [ ] 0.5 mg/m 3 Chromium (III) inorganic compounds, as Cr [ ] 0.5 mg/m 3 Chromium (VI) inorganic compounds - Insoluble, as Cr [ ] 0.01 mg/m 3 A1, 1 Chromium (VI) inorganic compounds - Water soluble, as Cr [ ] mg/m 3 C 0.1 mg/m 3 A1, 1 Chromyl chloride [ ] ppm Chrysene [ ] Revised 2006 (L) Clopidol [ ] Coal dust - Anthracite, Respirable 0.4 mg/m 3 Coal dust - Bituminous, Respirable 0.9 mg/m 3 Coal tar pitch volatiles, as benzene-soluble aerosol [ ] 0.2 mg/m 3 A1, 1 Cobalt and inorganic compounds, as Co [ ] 0.02 mg/m 3 Cobalt carbonyl, as Co [ ] 0.1 mg/m 3 Cobalt hydrocarbonyl, as Co [ ] 0.1 mg/m 3 Copper - Dusts and mists, as Cu [ ] 1 mg/m 3 Copper - Fume, as Cu [ ] 0.2 mg/m 3 Cotton dust - Raw 0.2 mg/m 3 (G) Coumaphos, Inhalable [ ] Revised mg/m 3 (V) Skin Cresol, all isomers [ ; ; ; ] 10 mg/m 3 Skin Crotonaldehyde [ ] C 0.3 ppm Skin Crufomate [ ] 5 mg/m 3 Cumene [ ] 25 ppm 75 ppm Cyanamide [ ] 2 mg/m 3 Cyanogen [ ] Cyanogen chloride [ ] C 0.3 ppm Cyclohexane [ ] Cyclohexanol [ ] Skin Cyclohexanone [ ] Revised ppm Skin Cyclohexene [ ] 300 ppm Cyclohexylamine [ ] Cyclonite [ ] 0.5 mg/m 3 Skin Cyclopentadiene [ ] 75 ppm Cyclopentane [ ] 600 ppm Cyhexatin [ ] 5 mg/m 3 2,4-D (2,4-Dichlorophenoxy-acetic acid) [ ] (see 2,4- Dichlorophenoxyacetic acid and its esters) DDT (Dichloro-diphenyltrichloroethane) [ ] 1 mg/m 3 Decaborane [ ] 0.05 ppm 0.15 ppm Skin Page 5 of 18

6 Demeton, Inhalable [ ] 0.05 mg/m 3 (V) Skin Demeton-S-methyl, Inhalable [ ] 0.05 mg/m 3 (V) Skin; S Diacetone alcohol [ ] 2,4-Diaminoanisole [ ] 2,4-Diaminotoluene [ ] Diazinon, Inhalable [ ] Revised mg/m 3 (V) Skin Diazomethane [ ] 0.2 ppm A2 Diborane [ ] 1,2-Dibromo-3-chloropropane [ ] 2-N-Dibutylaminoethanol [ ] 0.5 ppm Skin Dibutyl phenyl phosphate [ ] 0.3 ppm Skin Dibutyl phosphate, Inhalable [ ] Revised mg/m 3 (V) Skin Dibutyl phthalate [ ] 5 mg/m 3 R Dichloroacetic acid [ ] Revised ppm Skin; ; R Dichloroacetylene [ ] C o-dichlorobenzene [ ] 25 ppm p-dichlorobenzene [ ] 3,3'-Dichlorobenzidine [ ] (L) Skin; 1,4-Dichloro-2-butene [ ] ppm Skin; A2 2,2-Dichlorodiethyl sulfide (Mustard Gas) [ ] 1 Dichlorodifluoromethane [ ] 1,3-Dichloro-5,5-dimethyl hydantoin [ ] 0.2 mg/m mg/m 3 1,1-Dichloroethane [ ] 1,2-Dichloroethane (see ethylene dichloride) 1,2-Dichloroethylene, all isomers [ ; ; ] 200 ppm Dichloroethyl ether [ ] 5 ppm Skin Dichlorofluoromethane [ ] Dichloromethane [ ] 25 ppm 2,2'-Dichloro-n-methyldiethylamine (Nitrogen mustard) [ ] 2A 1,1-Dichloro-1-nitroethane [ ] 2 ppm 1,3-Dichloropropene [ ] 1 ppm Skin; 2,4-Dichlorophenoxyacetic acid and its esters [ ] Revised mg/m 3 20 mg/m 3 2,2-Dichloropropionic acid, Inhalable [ ] 5 mg/m 3 Dichlorotetrafluoroethane (Cryofluorane) [ ] Dichlorvos (DDVP), Inhalable [ ] 0.1 mg/m 3 (V) Skin; ; S Dicrotophos, Inhalable [ ] 0.05 mg/m 3 (V) Skin Dicyclohexylmethane-4,4'-diisocyanate [ ] (see Methylene bis (4- cyclohexyl-isocyanate)) Dicyclopentadiene [ ] 5 ppm Dicyclopentadienyl iron [ ] Dieldrin [ ] 0.25 mg/m 3 Skin Diesel fuel, as total hydrocarbons, Inhalable [ ; ; 100 mg/m 3 (V) Skin ; ; ] Diethanolamine, Inhalable [ ] Revised mg/m 3 (V) Skin Diethylamine [ ] 5 ppm 15 ppm Skin 2-Diethylaminoethanol [ ] 2 ppm Skin Diethylene triamine [ ] 1 ppm Skin; S Di(2-ethylhexyl)phthalate (DEHP) [ ] 5 mg/m 3 Page 6 of 18

7 Diethyl ketone [ ] 200 ppm 300 ppm Diethyl phthalate [ ] 5 mg/m 3 Diethyl sulfate [ ] 2A Difluorodibromomethane [ ] Diglycidyl ether (DGE) [ ] Revised ppm R Diisobutyl ketone [ ] 25 ppm Diisocyanates, not elsewhere specified, NOS ppm C 0.01ppm Diisopropylamine [ ] 5 ppm Skin 3,3'-Dimethoxybenzidine [ ] Dimethoxymethane [ ] 12 N,N-Dimethylacetamide [ ] Skin; R Dimethylamine [ ] 5 ppm 15 ppm Dimethylaniline [ ] 5 ppm Skin 3,3'-Dimethylbenzidine [ ] Dimethyl carbamoyl chloride [ ] Revised ppm Skin; A2, 2A Dimethyl disulfide [ ] Revised ppm Skin Dimethyl ether [ ] Dimethylethoxysilane [ ] 0.5 ppm 1.5 ppm Dimethylformamide [ ] Skin 1,1-Dimethylhydrazine [ ] 0.01 ppm Skin; 1,2-Dimethylhydrazine [ ] 2A Dimethyl phthalate [ ] 5 mg/m 3 Dimethyl sulfate [ ] C Skin; 2A Dimethyl sulfide [ ] Revised 2004 Dinitolmide [ ] (See 3,5-Dinitro-o-toluamide) Dinitrobenzene, all isomers [ ; ; ; ] 0.15 ppm Skin Dinitrol-o-cresol [ ] 0.2 mg/m 3 Skin 3,5-Dinitro-o-toluamide o toluamide [ ] Revised mg/m 3 Dinitrotoluene [ ] 0.2 mg/m 3 Skin; ; R n-dioctyl phthalate [ ] 5 mg/m 3 1,4-Dioxane [ ] 20 ppm Skin; Dioxathion, Inhalable [ ] 0.1 mg/m 3 (V) Skin 1,3-Dioxolane [ ] 20 ppm R Diphenylamine [ ] 10 mg/m 3 Dipropyl ketone [ ] Diproplyene glycol methyl ether [ ] 1 Skin Diquat, Inhalable [ ] 0.5 mg/m 3 Skin Diquat, Respirable [ ] 0.1 mg/m 3 Skin Disulfiram [ ] 2 mg/m 3 Disulfoton, Inhalable [ ] 0.05 mg/m 3 (V) Skin Diuron [ ] 10 mg/m 3 Divinyl benzene [ ] Dodecyl mercaptan [ ] Revised 2004 S Dyfonate, Inhalable [ ] Revised mg/m 3 (V) Skin Endosulfan, Inhalable [ ] Revised mg/m 3 (V) Skin Endrin [ ] 0.1 mg/m 3 Skin Enflurane [ ] 2 ppm Epichlorohydrin [ ] Skin; 2A; R EPN, Inhalable [ ] Revised mg/m 3 Skin Page 7 of 18

8 Ethane [ ] Revised 2004 See Aliphatic Hydrocarbon gases [C1-C4] Revised 2008 Ethanol [ ] Revised 2009 Ethanolamine [ ] 3 ppm 6 ppm Ethion, Inhalable [ ] Revised mg/m 3 Skin 2-Ethoxyethanol (EGEE) [ ] 5 ppm Skin; R 2-Ethoxyethyl acetate (EGEEA) [ ] 5 ppm Skin; R Ethyl acetate [ ] 1 Ethyl acrylate [ ] 5 ppm 15 ppm ; S Ethylamine [ ] 5 ppm 15 ppm Skin Ethyl amyl ketone [ ] Revised 2007 Ethyl benzene [ ] 125 ppm Ethyl bromide [ ] 5 ppm Skin Ethyl tert-butyl ether (ETBE) [ ] 5 ppm R Ethyl butyl ketone [ ] 75 ppm Ethyl chloride [ ] Skin Ethyl cyanoacrylate [ ] 0.2 ppm Ethyl methacrylate [ ] Ethylene [ ] Revised ppm Ethylene chlorohydrin [ ] C 1 ppm Skin Ethylenediamine [ ] Skin; S Ethylene dibromide [ ] 0.5 ppm Skin; 2A Ethylene dichloride (1,2-dichloroethane) [ ] 1 ppm 2 ppm Ethylene glycol - Aerosol [ ] C 100 mg/m 3 Ethylene glycol - Particulate [ ] 10 mg/m 3 20 mg/m 3 Ethylene glycol - Vapour [ ] C Ethylene glycol dinitrate (EGDN) [ ] 0.05 ppm Skin Ethylene oxide [ ] 1 ppm A2, 1; R Ethyleneimine [ ] 56 Revised ppm Skin; Ethyl ether [ ] 400 ppm 500 ppm Ethyl formate [ ] 2-Ethylhexanoic acid, Inhalable [ ] 5 mg/m 3 (V) R Ethylidene norbornene [ ] C 5 ppm Ethyl mercaptan [ ] 0.5 ppm N-Ethylmorpholine [ ] 5 ppm Skin Ethyl silicate [ ] Fenamiphos, Inhalable [ ] Revised mg/m 3 (V) Skin Fensulfothion, Inhalable [ ] Revised mg/m 3 (V) Skin Fenthion, Inhalable [ ] Revised mg/m 3 (V) Skin Ferbam, Inhalable [ ] Revised mg/m 3 Ferrovanadium dust [ ] 1 mg/m 3 3 mg/m 3 Flour dust, Inhalable 0.5 mg/m 3 S Fluorides (as F) 2.5 mg/m 3 Fluorine [ ] Fluroxene [ ] 2 ppm Fonofos (see Dyfonate) [ ] Formaldehyde [ ] 0.3 ppm C 1 ppm A2, 1; S Formamide [ ] Skin Formic acid [ ] 5 ppm Page 8 of 18

9 Furfural [ ] 2 ppm Skin Furfuryl alcohol [ ] 5 ppm Skin Gallium arsenide, Respirable [ ] Revised mg/m 3 1 Gasoline [ ] 300 ppm 500 ppm Germanium tetrahydride [ ] 0.2 ppm Glutaraldehyde, Activated & inactivated [ ] C 0.05 ppm S Glycerin - mist [ ] 10 mg/m 3 Glycerin - mist, Respirable [ ] 3 mg/m 3 Glycidol [ ] 2 ppm 2A Glyoxal, Inhalable [ ] 0.1 mg/m 3 (V) S Grain dust (oat, wheat, barley) 4 mg/m 3 (E) Graphite - All forms except graphite fibres, Respirable [ ] 2 mg/m 3 Gypsum [ ] 20 mg/m 3 Hafnium and compounds, as Hf [ ] 0.5 mg/m 3 Halothane [ ] 2 ppm R Helium [ ] Simple asphyxiant Heptachlor [ ] 0.05 mg/m 3 Skin; Heptachlor epoxide [ ] 0.05 mg/m 3 Skin Heptane (n-heptane) [ ] 400 ppm 500 ppm Hexachlorobenzene (HCB) [ ] mg/m 3 Skin; Hexachlorobutadiene [ ] 0.02 ppm Skin Hexachlorocyclopentadiene [ ] 0.01 ppm Hexachloroethane [ ] 1 ppm Skin; Hexachloronaphthalene [ ] 0.2 mg/m 3 Skin Hexafluoroacetone [ ] Skin; R Hexafluoropropylene [ ] Revised 2007 Hexahydrophthalic anhydride, all isomers, Inhalable [ ; ; C mg/m 3 S ] Revised 2004 (V) Hexamethyl phosphoramide [ ] Skin; Hexamethylene diisocyanate (HDI) [ ] ppm C 0.01 ppm S n-hexane [ ] 20 ppm Skin Hexane, other isomers 200 ppm 1,6-Hexanediamine [ ] 0.5 ppm 1-Hexene [ ] R sec-hexyl acetate [ ] Hexylene glycol [ ] C 25 ppm Hydrazine [ ] 0.01 ppm Skin; Hydrogen [ ] Simple asphyxiant Hydrogenated terphenyls - Nonirradiated [ ] 0.5 ppm Hydrogen bromide [ ] Revised 2004 C 2 ppm Hydrogen chloride [ ] Revised 2003 C 2 ppm Hydrogen cyanide, as CN [ ] C 4.7 ppm Skin Cyanide salts, as CN [ ; ; ] C 5 mg/m 3 Skin Hydrogen fluoride, as F [ ] C 2 ppm Hydrogen peroxide [ ] 1 ppm Hydrogen selenide [ ] 0.05 ppm Hydrogen sulfide [ ] C Hydroquinone [ ] Revised mg/m 3 S 2-Hydroxypropyl acrylate [ ] 0.5 ppm Skin; S Indene [ ] Revised ppm Page 9 of 18

10 Indium and compounds, as In [ ] 0.1 mg/m 3 Iodides, Inhalable Revised ppm (V) Iodine, Inhalable [ ] Revised ppm (V) Iodoform [ ] 0.6 ppm Iron oxide dust, as Fe [ ] 5 mg/m 3 Iron oxide fume, as Fe [ ] 5 mg/m 3 10 mg/m 3 Iron pentacarbonyl [ ] 0.01 ppm Iron salts - soluble, as Fe 1 mg/m 3 2 mg/m 3 Isoamyl alcohol [ ] 125 ppm Isobutanol [ ] Isobutyl acetate [ ] 1 Isobutyl nitrite, Inhalable [ ] C 1 ppm (V) Isooctyl alcohol [ ] Skin Isophorone [ ] C 5 ppm Isophorone diisocyanate [ ] ppm C 0.01 ppm S Isopropanol (Isopropyl alcohol) [ ] Revised ppm 400 ppm 2-Isopropoxyethanol [ ] 25 ppm Skin Isopropyl acetate [ ] Revised ppm Isopropylamine [ ] 5 ppm N-Isopropylaniline [ ] 2 ppm Skin Isopropyl ether [ ] 2 3 Isopropyl glycidyl ether (IGE) [ ] C Kaolin, Respirable [ ] 2 mg/m 3 (E) Kerosene [ ]/Jet fuels [ ], as total hydrocarbon vapour, 200 mg/m 3 (P) Skin Revised 2003 Ketene [ ] 0.5 ppm 1.5 ppm Lead - elemental and inorganic compounds, as Pb [ ] 0.05 mg/m 3 Elemental ; R/Other inorganic 2A, R Lead arsenate, as Pb 3 (AsO 4 ) 2 [ ] 0.15 mg/m 3 2A ; R Lead chromate, as Cr [ ] mg/m 3 A2; 2A; R Lead chromate, as Pb [ ] 0.05 mg/m 3 A2; 2A; R Lindane [ ] 0.5 mg/m 3 Skin Liquified petroleum gas (L.P.G.) [ ] 12 Lithium hydroxide [ ] C 1 mg/m 3 Lithium hydride [ ] mg/m 3 Magnesite [ ] Revised 2006 (See Particles Not Otherwise Classified (PNOC)) Magnesium oxide (fume), Inhalable [ ] Revised mg/m 3 Magnesium oxide, Respirable dust and fume, as Mg [ ] 3 mg/m 3 10 mg/m 3 Malathion, Inhalable [ ] Revised mg/m 3 (V) Skin Maleic anhydride [ ] S Manganese - Elemental & inorganic compounds, as Mn [ ] 0.2 mg/m 3 R Manganese cyclopentadienyl tricarbonyl, as Mn [ ] 0.1 mg/m 3 Skin Mercury - Alkyl compounds, as Hg [ ] 0.01 mg/m mg/m 3 Skin Mercury - Aryl compounds, as Hg [ ] 0.05 mg/m 3 C 0.1 mg/m 3 Skin Mercury - Elemental, as Hg [ ] mg/m 3 Skin; R Mercury - Inorganic compounds, as Hg [ ] mg/m 3 Skin; R Mercury Methyl, as Hg [ ] 0.01 mg/m mg/m 3 Skin Mesityl oxide [ ] 25 ppm Methacrylic acid [ ] 20 ppm Page 10 of 18

11 Methane [ ] Revised 2004 See Aliphatic Hydrocarbon gases [C1-C4] Revised 2008 Methanol [ ] 200 ppm 2 Skin Methomyl [ ] 2.5 mg/m 3 Methoxychlor [ ] 10 mg/m 3 2-Methoxyethanol (EGME) [ ] Revised 2006 Skin; R 2-Methoxyethyl acetate (EGMEA) [ ] Revised 2006 Skin; R Methoxyflurane [ ] 2 ppm 4-Methoxyphenol [ ] 5 mg/m 3 1-Methoxy-2-propanol (PGME) [ ] 75 ppm 2-Methoxy-1-propanol [ ] 20 ppm 40 ppm 1-Methoxypropyl-2-acetate [ ] 75 ppm 2-Methoxypropyl-1-acetate [ ] 20 ppm 40 ppm bis-(2-methoxypropyl) ether (DPGME) (see Dipropylene glycol methyl ether) [ ] Methyl acetate [ ] 200 ppm 2 Methyl acetylene [ ] Methyl acetylene-propadiene mixture (MAPP) [ ] 12 Methyl acrylate [ ] 2 ppm Skin; S Methylacrylonitrile [ ] 1 ppm Skin Methylal (see Dimethoxymethane) [ ] Methylamine [ ] 5 ppm 15 ppm Methyl n-amyl ketone [ ] N-Methyl aniline [ ] 0.5 ppm Skin Methyl bromide [ ] 1 ppm Skin Methyl tert-butyl ether (MTBE) [ ] R Methyl n-butyl ketone [ ] Revised ppm Skin; R Methyl chloride [ ] Skin; R Methyl chloroform o o [ ] 3 4 Methyl 2-cyanoacrylate [ ] 0.2 ppm Methylcyclohexane [ ] 400 ppm Methylcyclohexanol [ ] o-methylcyclohexanone [ ] 75 ppm Skin 2-Methylcyclopentadienyl manganese tricarbonyl, as Mn [ ] 0.2 mg/m 3 Skin Methyl demeton, Inhalable [ ] Revised mg/m 3 (V) Skin Methylene bisphenyl isocyanate (MDI) [ ] ppm C 0.01 ppm Skin; S 4,4'-Methylene bis(2-chloroaniline) (MBOCA; MOCA) [ ] 0.01 ppm Skin; A2, 1 Revised 2009 Methylene bis (4-cyclo-hexyl-isocyanate), [ ] ppm C 0.01 ppm Methylene chloride (See Dichloromethane) 4,4'-Methylene dianiline [ ] 0.01 ppm Skin; Methyl ethyl ketone (MEK) [ ] Methyl ethyl ketone peroxide (MEKP) [ ] C 0.2 ppm Methyl formate [ ] 1 Methyl hydrazine [ ] 0.01 ppm Skin Methyl iodide [ ] 2 ppm Skin Methyl isoamyl ketone [ ] Methyl isobutyl carbinol [ ] 25 ppm 40 ppm Skin Methyl isobutyl ketone [ ] 75 ppm Methyl isocyanate [ ] 0.02 ppm Skin; S Methyl isopropyl ketone [ ] 200 ppm Methyl mercaptan [ ] 0.5 ppm Page 11 of 18

12 Methyl methacrylate [ ] S 1-Methyl naphthalene [ ] Revised ppm Skin 2-Methyl naphthalene [ ] Revised ppm Skin Methyl parathion, Inhalable [ ] Revised mg/m 3 (V) Skin Methyl propyl ketone (2-pentanone) [ ] 1 2 Methyl silicate [ ] 1 ppm alpha-methyl styrene [ ] 75 ppm C Methyl vinyl ketone [ ] C 0.2 ppm Skin; S Metribuzin [ ] 5 mg/m 3 Mevinphos, Inhalable [ ] Revised mg/m 3 (V) Skin Mica, Respirable [ ] 3 mg/m 3 Molybdenum - Metal and insoluble compounds, Respirable [ ] 3 mg/m 3 Molybdenum - Metal and insoluble compounds, Inhalable [ ] 10 mg/m 3 Molybdenum - Soluble compounds, as Mo, Respirable [ ] 0.5 mg/m 3 Monochloroacetic acid [ ] See Chloroacetic acid Monocrotophos, Inhalable [ ] 0.05 mg/m 3 (V) Skin Morpholine [ ] 20 ppm Skin Naled, Inhalable [ ] 0.1 mg/m 3 (V) Skin; S Naphthalene [ ] 15 ppm Skin; 1,5-Naphthalene diisocyanate [ ] ppm C 0.01 ppm beta-naphthylamine [ ] (L) A1, 1 Natural gas [ ] Revised 2004 See Aliphatic Hydrocarbon gases [C1- C4] Revised 2008 Natural rubber latex, as Total proteins, Inhalable [ ] Revised 2004, mg/m 3 Skin; S 2008 Neon [ ] Simple asphyxiant Nickel - Insoluble inorganic compounds, as Ni [ ] 0.05 mg/m 3 A1, 1 Nickel - Elemental, Soluble inorganic compounds, as Ni [ ] 0.05 mg/m 3 A1, 1 Nickel carbonyl, as Ni [ ] ppm Nickel subsulfide, as Ni, Inhalable [ ] 0.1 mg/m 3 A1, 1 Nicotine [ ] 0.5 mg/m 3 Skin Nitrapyrin [ ] 20 mg/m 3 Nitric acid [ ] 2 ppm 4 ppm Nitric oxide [ ] 25 ppm p-nitroaniline [ ] 3 mg/m 3 Skin Nitrobenzene [ ] 1 ppm Skin; p-nitrochlorobenzene [ ] Skin 4-Nitrodiphenyl [ ] (L) Skin; A2 Nitroethane [ ] Nitrogen [ ] Simple asphyxiant Nitrogen dioxide [ ] C 1 ppm Nitrogen trifluoride [ ] Nitroglycerin (NG) [ ] 0.05 ppm Skin Nitromethane [ ] 20 ppm 1-Nitropropane [ ] 25 ppm Page 12 of 18

13 2-Nitropropane [ ] 5 ppm Nitropyrene, mono, di, tri, tetra, isomers [ ; ] n-nitrosodiethanolamine [ ] n-nitrosodiethylamine [ ] 2A n-nitrosodimethylamine [ ] (L) Skin; 2A n-nitrosomethylethylamine [ ] n-nitrosomorpholine [ ] n-nitrosopiperidine [ ] n-nitrosopyrrolidine [ ] Nitrotoluene, all isomers [ ; ; ] 2 ppm Skin 5-Nitro-o-toluidine, Inhalable [ ] Revised mg/m 3 Nitrous oxide [ ] 25 ppm R Nonane - All isomers [ ] 200 ppm Octachloronaphthalene [ ] 0.1 mg/m mg/m 3 Skin Octane, all isomers [ ] 300 ppm Oil mist - mineral, mildly refined 0.2 mg/m 3 1 Oil mist - mineral, severely refined 1 mg/m 3 Osmium tetroxide [ ] ppm ppm Oxalic acid [ ] 1 mg/m 3 2 mg/m 3 p,p'-oxybis(benzenesulfonyl hydrazide), Inhalable [ ] Revised mg/m 3 R Oxygen difluoride [ ] C 0.05 ppm Ozone - Heavy work [ ] 0.05 ppm Ozone - Moderate work [ ] 0.08 ppm Ozone - Light work [ ] Ozone - Light, mod., or heavy workload =/< 2 hrs [ ] 0.2 ppm Paraffin wax fume [ ] 2 mg/m 3 Paraquat, Respirable [ ] 0.1 mg/m 3 Paraquat [ ] 05mg/m Parathion, Inhalable [ ] Revised mg/m 3 (V) Skin Particles (Insoluble or Poorly Soluble) Not Otherwise Classified (PNOC) Pentaborane [ ] ppm ppm Pentachloronaphthalene [ ] 0.5 mg/m 3 Skin Pentachloronitrobenzene [ ] 0.5 mg/m 3 Pentachlorophenol [ ] 0.5 mg/m 3 Skin Pentaerythritol [ ] Pentane, all isomers [ ; ; ] 600 ppm Pentyl acetate, all isomers [ ; ; ; ; ; ] Perchloroethylene (See Tetrachloroethylene) Perchloromethyl mercaptan [ ] Perchloryl fluoride [ ] 3 ppm 6 ppm Perfluorobutyl ethylene [ ] Revised 2004 Perfluoroisobutylene [ ] C 0.01 ppm Perlite [ ] Revised 2006 (See Particles Not Otherwise Classified (PNOC)) Persulfates, as persulfate 0.1 mg/m 3 Phenol [ ] 5 ppm Skin Phenothiazine [ ] 5 mg/m 3 Skin N-Penyl-beta-naphthylamine [ ] Page 13 of 18

14 o-phenylenediamine [ ] 0.1 mg/m 3 m-phenylenediamine [ ] 0.1 mg/m 3 p-phenylenediamine [ ] 0.1 mg/m 3 S Phenyl ether - Vapour (Diphenyl ether) [ ] 1 ppm 2 ppm Phenyl glycidyl ether (PGE) [ ] Revised 2008 Skin; ; S; R Phenyl isocyanate [ ] ppm C 0.01 ppm Phenylhydrazine [ ] Skin Phenyl mercaptan [ ] C Phenylphosphine [ ] C 0.05 ppm R Phorate, Inhalable [ ] Revised mg/m 3 (V) Skin Phosgene [ ] Phosphine [ ] 0.3 ppm 1 ppm Phosphoric acid [ ] 1 mg/m 3 3 mg/m 3 Phosphorus (yellow) [ ] 0.1 mg/m 3 Phosphorus oxychloride [ ] Phosphorus pentachloride [ ] Phosphorus pentasulfide [ ] 1 mg/m 3 3 mg/m 3 Phosphorus trichloride [ ] 0.2 ppm 0.5 ppm Phthalic anhydride [ ] 1 ppm S m-phthalodinitrile [ ] 5 mg/m 3 Picloram [ ] Picric acid [ ] 0.1 mg/m 3 S Pindone [ ] 0.1 mg/m 3 Piperazine and its Salts, as Piperazine [ ] 0.3 mg/m 3 1 mg/m 3 S Piperidine [ ] 1 ppm Plaster of Paris [ ] 20 mg/m 3 Platinum - Metal [ ] 1 mg/m 3 Platinum - Soluble salts (as Pt) [ ] mg/m 3 S Polyvinyl chloride (PVC), Respirable [ ] Revised mg/m 3 Portland cement [ ] 10 mg/m 3 (E,N) Potassium hydroxide [ ] C 2 mg/m 3 Propane [ ] Revised 2004 See Aliphatic Hydrocarbon gases [C1-C4] Revised 2008 Propane sultone [ ] (L) n-propanol (n-propyl alcohol) [ ] Revised 2007 Propargyl alcohol [ ] 1 ppm Skin beta-propiolactone [ ] 0.5 ppm Propionaldehyde [ ] 20 ppm Propionic acid [ ] Propoxur [ ] 0.5 mg/m 3 n-propyl acetate [ ] 200 ppm 2 Propylene [ ] Revised ppm Propylene dichloride [ ] Revised ppm 1 S Propylene glycol dinitrate [ ] 0.05 ppm Skin Propylene oxide [ ] 2 ppm ; S Propyleneimine [ ] Revised ppm 0.4 ppm Skin n-propyl nitrate [ ] 25 ppm 40 ppm Pyrethrum [ ] 5 mg/m 3 S Pyridine [ ] Revised ppm Quinone [ ] Page 14 of 18

15 Resorcinol [ ] 20 ppm Rhodium, Metal and insoluble compounds as Rh [ ] 0.1 mg/m mg/m 3 Rhodium - Soluble compounds, as Rh [ ] mg/m mg/m 3 Ronnel, Inhalable [ ] Revised mg/m 3 (V) Rosin core solder thermal decomposition products (colophony) [ ] (L) S Rotenone (commercial) [ ] 5 mg/m 3 Rouge [ ] 10 mg/m 3 (E,N) Rubber solvent (Naphtha) [ ] Revised 2009 (H) Selenium and compounds, as Se [ ] 0.1 mg/m 3 Selenium hexafluoride [ ] 0.05 ppm Sesone [ ] Silica, Amorphous - Diatomaceous earth (uncalcined) Total [ ] 4 mg/m 3 Silica, Amorphous - Diatomaceous earth (uncalcined), Respirable [ mg/m 3 2] Silica, Amorphous - Fume Total [ ] 4 mg/m 3 Silica, Amorphous - Fume, Respirable [ ] 1.5 mg/m 3 Silica, Amorphous - Precipitated and gel, Total [ ] 4 mg/m 3 Silica, Amorphous - Precipitated and gel, Respirable [ ] 1.5 mg/m 3 Silica, Crystalline - alpha quartz [ ; ] and Cristobalite, mg/m 3 A2, 1 Respirable [ ] Revised 2006 Silicon [ ] Revised 2006 (See Particles Not Otherwise Classified (PNOC)) Silicon carbide Nonfibrous, Inhalable, [ ] Revised mg/m 3 (E) Silicon carbide, Nonfibrous, Respirable, [ ] Revised mg/m 3 (E) Silicon carbide, Fibrous (including whiskers) [ ] Revised f/cc (F) A2 Silicon tetrahydride (Silane) [ ] 0.5 ppm 1 ppm Silver and Compounds (as Ag) [ ] 0.01 mg/m mg/m 3 Soapstone 6 mg/m 3 (E) Soapstone, Respirable 3 mg/m 3 (E) Sodium azide (as Sodium azide) [ ] C 0.29 mg/m 3 Sodium azide (as Hydrazoic acid vapour) [ ] C 0.11 ppm Sodium bisulfite [ ] 5 mg/m 3 Sodium fluoroacetate [ ] 0.05 mg/m 3 Skin Sodium hydroxide [ ] C 2 mg/m 3 Sodium metabisulfite [ ] 5 mg/m 3 Starch [ ] Stearates 10 mg/m 3 (J) Stoddard solvent (mineral spirits) [ ] 290 mg/m mg/m 3 Strontium chromate, as Cr [ ] mg/m 3 A2 Strychnine [ ] 0.15 mg/m 3 Styrene - monomer [ ] 75 ppm Subtilisins, as crystalline active enzyme [ ; ] C S mg/m 3 Sucrose [ ] Sulfometuron methyl [ ] 5 mg/m 3 Sulfotepp (TEDP), Inhalable [ ] Revised mg/m 3 (V) Skin Sulfur dioxide [ ] Under review. See G ppm 5 ppm Sulfur hexafluoride [ ] Page 15 of 18

16 Sulfuric acid, Thoracic [ ] Revised mg/m 3 (M) A2, 1 Sulfur monochloride [ ] C 1ppm Sulfur pentafluoride [ ] C 0.01 ppm Sulfur tetrafluoride [ ] C Sulfuryl fluoride [ ] 5 ppm Sulprofos, Inhalable [ ] Revised mg/m 3 (V) Skin Synthetic Vitreous Fibres - Continuous filament glass fibres 1 f/cc (F) Synthetic Vitreous Fibres - Continuous filament glass fibres, Inhalable 5 mg/m 3 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) Synthetic Vitreous Fibres - Refractory ceramic fibres 0.2 f/cc (F) A2, 2,4,5-T (2,4,5-Trichlorophenoxyacetic acid) [ ] 10 mg/m 3 Talc - Containing no asbestos fibres, Respirable [ ] 2 mg/m 3 (E) Talc - Containing asbestos fibres [ ] 0.1 f/cc (K) A1, 1 Tantalum - Metal [ ] 5 mg/m 3 Tantalum oxide dusts, as Ta [ ] 5 mg/m 3 Tellurium and compounds (NOS), as Te, excluding hydrogen telluride 0.1 mg/m 3 [ ] Tellurium hexafluoride [ ] 0.02 ppm Temephos, Inhalable [ ] Revised mg/m 3 (V) Skin Terbufos, Inhalable [ ] 0.01 mg/m 3 (V) Skin Terepthalic acid [ ] Terphenyls [ ] C 5 mg/m Tetrabromoethane 1,1,2,2-Tetrabromoethane, Inhalable [ ] Revised 2006 (V) 1,1,1,2-Tetrachloro-2,2-difluoroethane [ ] Revised ,1,2,2-Tetrachloro-1,2-difluoroethane [ ] Revised ,1,2,2-Tetrachloroethane [ ] 1 ppm Skin Tetrachloroethylene (Perchloroethylene) [ ] 25 ppm 2A Tetrachloronaphthalene [ ] 2 mg/m 3 Tetraethyl lead, as Pb [ ] mg/m 3 Skin Tetraethyl pyrophosphate (TEPP), Inhalable [ ] Revised mg/m (V) Skin Tetrafluoroethylene [ ] 2 ppm Tetrahydrofuran [ ] Revised 2005 Skin Tetramethyl lead, as Pb [ ] mg/m 3 Skin Tetramethyl succinonitrile [ ] 0.5 ppm Skin Tetranitromethane [ ] ppm Tetrakis (hydroxymethyl) phosphonium chloride [ ] Revised mg/m 3 Tetrakis (hydroxymethyl) phosphonium sulfate [ ] Revised mg/m 3 S Tetryl [ ] 1.5 mg/m 3 S Thallium and soluble compounds, as Tl [ ] 0.1 mg/m 3 Skin 4,4' Thiobis (6-tert-butyl-m-cresol) [ ] (see Cresol, all isomers) Thioglycolic acid [ ] 1 ppm Skin Thionyl chloride [ ] C 1ppm Thiram, Inhalable [ ] Revised mg/m 3 (V) S Page 16 of 18

17 Tin - Metal [ ] 2 mg/m 3 Tin - Oxide and inorganic compounds, except tin hydride, as Sn [ ] 2 mg/m 3 Tin - Organic compounds, as Sn [ ] 0.1 mg/m mg/m 3 Skin Titanium dioxide [ ] Revised 2006 o-tolidine [ ] Skin; Toluene [ ] Revised 2007, ppm R Toluene-2,4-diisocyanate (2,4-TDI) [ ] ppm C 0.01 ppm ; S Toluene-2,6-diisocyanate (2,6-TDI) [ ] ppm C 0.01 ppm ; S o-toluidine [ ] Revised ppm Skin; 1 m-toluidine [ ] 2 ppm Skin p-toluidine [ ] 2 ppm Skin Tributyl phosphate [ ] 0.2 ppm Trichloroacetic acid [ ] 1 ppm 1,2,4-Trichlorobenzene [ ] C 5 ppm 1,1,2-Trichloroethane [ ] Skin Trichloroethylene [ ] Revised ppm A2, 2A Trichlorofluoromethane [ ] C Trichloronaphthalene [ ] 5 mg/m 3 Skin 1,2,3-Trichloropropane [ ] Skin; 2A 1,1,2-Trichloro-1,2,2-trifluoroethane [ ] 500 ppm 12 Trichlorphon, Inhalable [ ] Revised mg/m 3 Triethanolamine [ ] 5 mg/m 3 Triethylamine [ ] 1 ppm 3 ppm Skin Trifluorobromomethane [ ] 1,3,5-Triglycidyl-s-triazinetrione [ ] 0.05 mg/m 3 R; S Trimellitic anhydride, Inhalable [ ] Revised mg/m mg/m 3 Skin; S (V) Trimethylamine [ ] 5 ppm 15 ppm Trimethyl benzene (mixed isomers) [ ] 25 ppm Trimethyl hexamethylene diisocyanate [ ] ppm C 0.01 pm Trimethyl phosphite [ ] 2 ppm Tri-n-Butyltin compounds [ ] 0.05 mg/m 3 2,4,6-Trinitrotoluene (TNT) [ ] 0.1 mg/m 3 Skin Triorthocresyl phosphate [ ] 0.1 mg/m 3 Skin Triphenyl phosphate [ ] 3 mg/m 3 Tungsten - Metal and insoluble compounds [ ] 5 mg/m 3 10 mg/m 3 Tungsten - Soluble compounds, as W [ ] 1 mg/m 3 3 mg/m 3 Turpentine [ ] and selected monoterpenes [ ; ; 20 ppm S ] Revised 2003 Uranium (Natural) - Insoluble compounds, as U [ ] 0.2 mg/m mg/m 3 A1, 1 Uranium (Natural) - Soluble compounds, as U [ ] 0.05 mg/m 3 A1 n-valeraldehyde [ ] Vanadium pentoxide, Respirable dust and fume, as V2O5 [ ] C 0.05 mg/m 3 Vanadium pentoxide, as V, Inhalable [ ] Revised mg/m 3 Vegetable oil - Mist, except castor, cashew nut, or similar irritant oils [ mg/m ] Vegetable oil, Mist, Respirable, except castor, cashew nut, or similar 3 mg/m 3 irritating oil [ ] Vinyl acetate [ ] 15 ppm Vinyl bromide [ ] 0.5 ppm A2, 2A Page 17 of 18

18 Vinyl chloride [ ] 1 ppm A1, 1 4-Vinyl cyclohexene [ ] ; R Vinyl cyclohexene dioxide [ ] Skin; ; R Vinyl fluoride [ ] 1 ppm A2, 2A N-Vinyl-2-pyrrolidone [ ] Revised ppm Vinylidene chloride [ ] 1 ppm Vinylidene fluoride [ ] 500 ppm Vinyl toluene, all isomers [ ] 25 ppm 75 ppm VM & P Naphtha [ ] Revised 2009 (H) Warfarin [ ] 0.1 mg/m 3 Wood dust - Allergenic species 1 mg/m 3 1 Wood dust - Non-Allergenic Hardwood 1 mg/m 3 A1, 1 Wood dust - Non-Allergenic Softwood 2.5 mg/m 3 1 Xylene [ ] (o, m & p isomers) [ ; ; ] 1 m-xylene alpha,alpha'-diamine [ ] C 0.1 mg/m 3 Skin Xylidine - Mixed isomers, Inhalable [ ] 0.5 ppm (V) Skin Yttrium - Metal [ ] 1 mg/m 3 Yttrium and compounds, as Y [ ] 1 mg/m 3 Zinc chloride - Fume [ ] 1 mg/m 3 2 mg/m 3 Zinc chromates, as Cr [ ; ; ] 0.01 mg/m 3 A1 Zinc oxide, Respirable [ ] Revised mg/m 3 10 mg/m 3 Zinc stearate [ ] 20 mg/m 3 Zirconium [ ] and compounds, as Zr [ ] 5 mg/m 3 10 mg/m 3 Endnotes (E) - the value is for particulate matter containing no asbestos and less than 1% crystalline silica. (F) - the value for fibres longer than 5 microns, with an aspect ratio of equal than/greater than 3:1, as determined by the membrane filter method at 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, see OHS Guideline G (J) - does not include stearates of toxic metals. (K) - should not exceed 2 mg/m 3 respirable particulate. (L) - 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/m 3 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. (V) - vapour and inhalable aerosol. Page 18 of 18