Table of exposure limits - updated may 25, 2007

Table of exposure limits for chemical and biological substances
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.
• If the exposure limit for a substance has been revised or newly adopted since January 1, 2003 this column reports the change with the words "Revised (year)".
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/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 metre (mg/m3). See OHS Guideline G5.48-4 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/m3 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 2B 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.
TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Acetylene tetrabromide (See 1,1,2,2 Tetrabromoethane) Acrylamide, Inhalable [79-06-1] Revised 2005 Alachlor, Inhalable [15972-60-8] Revised 2007 Aldrin, Inhalable [309-00-2] Revised 2007 Aliphatic hydrocarbon gases [C1-C4] Revised 2004 Allyl propyl disulfide [2179-59-1] Revised 2006 Aluminum - Alkyls, not otherwise specified - NOS, as Al [7429-90-5] Aluminum - Pyro powders, as Al [7429-90-5] Aluminum - Soluble salts, as Al [7429-90-5] Aluminum hydroxide [21645-51-2] (see Aluminum - Metal dust) Antimony and compounds, as Sb [7440-36-0] Antimony trioxide - Production [1309-64-4] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Arsenic and inorganic compounds, as As [7440-38-2] Asphalt (Bitumen) fume, as benzene-soluble aerosol, Inhalable [8052- 0.5 mg/m3 Barium and soluble compounds, as Ba [7440-39-3] Beryllium and compounds, as Be [7440-41-7] Bis(2-dimethylaminoethyl) ether (DMAEE) [3033-62-3] Borate compounds, Inorganic, Inhalable [1303-96-4; 1330-43-4; 10043- 2 mg/m3 35-3; 12179-04-3] Revised 2005Boron oxide [1303-86-2] 2-Butoxyethanol (EGBE) [111-76-2] Revised 2003 2-Butoxyethyl acetate [112-07-2] Revised 2003 Butylated hydroxytoluene (BHT), Inhalable, (2,6-Di-tert-butyl-p-cresol) 2 mg/m3 (V)[128-37-0]tert-Butyl chromate, as CrO3 [1189-85-1] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
n-Butyl glycidyl ether (BGE) [2426-08-6] Revised 2005 Cadmium and compounds, Respirable, as Cd [7440-43-9] Calcium carbonate (incl. Limestone, Marble) [1317-65-3] Calcium silicate - Synthetic nonfibrous [1344-95-2] Carbofuran, Inhalable [1563-66-2] Revised 2004 o-Chlorinated diphenyl oxide [31242-93-0] o-Chlorobenzylidene malononitrile [2698-41-1] Chlorobromomethane (see Bromochloromethane) TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Chlorodiphenyl (42% chloride) [53469-21-9] Chlorodiphenyl (54% chloride) [11097-69-1] Chlorpyrifos, Inhalable [2921-88-2] Revised 2003 Chromite ore processing (Chromate), as Cr Chromium (III) inorganic compounds, as Cr [7440-47-3] Chromium (VI) inorganic compounds - Insoluble, as Cr [7440-47-3] Chromium (VI) inorganic compounds - Water soluble, as Cr [7440-47- Coal tar pitch volatiles, as benzene-soluble aerosol [65996-93-2] Cobalt and inorganic compounds, as Co [7440-48-4] Copper - Dusts and mists, as Cu [7440-50-8] Coumaphos [56-72-4] Inhalable Revised 2006 Cresol, all isomers [1319-77-3; 95-48-7; 108-39-4; 106-44-5] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
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] Diazinon, Inhalable [333-41-5] Revised 2003 Dichloroacetic acid [79-43-6] Revised 2005 2,2-Dichlorodiethyl sulfide (Mustard Gas) [505-60-2] 1,3-Dichloro-5,5-dimethyl hydantoin [118-52-5] 1,2-Dichloroethane (see ethylene dichloride) 1,2-Dichloroethylene, all isomers [540-59-0; 156-59-2; 156-60-5] 2,2'-Dichloro-n-methyldiethylamine (Nitrogen mustard) [51-75-2] 2,4-Dichlorophenoxyacetic acid and its esters [94-75-7] Revised 2006 2,2-Dichloropropionic acid, Inhalable [75-99-0] Dichlorotetrafluoroethane (Cryofluorane) [76-14-2] Dicyclohexylmethane-4,4'-diisocyanate [5124-30-1] (see Methylene bis (4-cyclohexyl-isocyanate))Dicyclopentadiene [77-73-6] Diesel fuel, as total hydrocarbons [68334-30-5; 68476-30-2; 68476-31- 100 mg/m3 (V) 3; 68476-34-6; 77650-28-3]Diethanolamine [111-42-2] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Di(2-ethylhexyl)phthalate (DEHP) [117-81-7] Diglycidyl ether (DGE) [2238-07-5] Revised 2007 Diisocyanates, not elsewhere specified, NOS Dimethyl carbamoyl chloride [79-44-7] Revised 2007 Dimethyl disulfide [624-92-0] Revised 2007 Dinitolmide [148-01-6] (See 3,5-Dintro-o-toluamide) Dinitrobenzene, all isomers [528-29-0; 99-65-0; 100-25-4; 25154-54-5] 0.15 ppm 3,5-Dintro-o-toluamide [148-01-6] Revised 2007 Diproplyene glycol methyl ether [34590-94-8] Dodecyl mercaptan [112-55-0] Revised 2004 Dyfonate [944-22-9] Inhalable Revised 2006 TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Ethion, Inhalable [563-12-2] Revised 2003 Ethyl amyl ketone [541-85-5] Revised 2007 Ethylene dichloride (1,2-dichloroethane) [107-06-2] Ethylene glycol dinitrate (EGDN) [628-96-6] 2-Ethylhexanoic acid, Inhalable [149-57-5] Fenamiphos [22224-92-6] Inhalable Revised 2006 Fensulfothion, Inhalable [115-90-2] Revised 2005 Fenthion [55-38-9] Inhalable Revised 2006 TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Gallium arsenide, Respirable [1303-00-0] Revised 2005 Glutaraldehyde, Activated & inactivated [111-30-8] Graphite - All forms except graphite fibres, Respirable [7782-42-5] Hexafluoropropylene [116-15-4] Revised 2007 Hexahydrophthalic anhydride, all isomers, Inhalable [85-42-7; 13149- Hexamethylene diisocyanate (HDI) [822-06-0] Hydrogenated terphenyls - Nonirradiated [61788-32-7] Hydrogen bromide [10035-10-6] Revised 2004 Hydrogen chloride [7647-01-0] Revised 2003 Cyanide salts, as CN [592-01-8; 151-50-8; 143-33-9] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Isopropanol (Isopropyl alcohol) [67-63-0] Revised 2003 Isopropyl acetate [108-21-4] Revised 2003 Isopropyl glycidyl ether (IGE) [4016-14-2] Kerosene [8008-20-6]/Jet fuels [64742-47-8], as total hydrocarbon Lead - elemental and inorganic compounds, as Pb [7439-92-1] Liquified petroleum gas (L.P.G.) [68476-85-7] Magnesite [546-93-0] Revised 2006 (See Particles Not Otherwise Classified (PNOC)) Magnesium oxide (fume), Inhalable [1309-48-4] Revised 2003 Magnesium oxide, Respirable dust and fume, as Mg [1309-48-4] Malathion, Inhalable [121-75-5] Revised 2003 Manganese - Elemental & inorganic compounds, as Mn [7439-96-5] Manganese cyclopentadienyl tricarbonyl, as Mn [12079-65-1] Mercury - Alkyl compounds, as Hg [7439-97-6] Mercury - Aryl compounds, as Hg [7439-97-6] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Mercury - Inorganic compounds, as Hg [7439-97-6] 2-Methoxyethanol (EGME) [109-86-4] Revised 2006 2-Methoxyethyl acetate (EGMEA) [110-49-6] Revised 2006 bis-(2-Methoxypropyl) ether (DPGME) (see Dipropylene glycol methyl ether) [34590-94-8]Methyl acetate [79-20-9] Methyl acetylene-propadiene mixture (MAPP) [59355-75-8] Methylal (see Dimethoxymethane) [109-87-5] Methyl tert-butyl ether (MTBE) [1634-04-4] 2-Methylcyclopentadienyl manganese tricarbonyl, as Mn [12108-13-3] Methyl demeton, Inhalable [8022-00-2] Revised 2007 Methylene bisphenyl isocyanate (MDI) [101-68-8] 4,4'-Methylene bis(2-chloroaniline) (MBOCA; MOCA) [101-14-4] Methylene bis (4-cyclo-hexyl-isocyanate), [5124-30-1] Methyl ethyl ketone peroxide (MEKP) [1338-23-4] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
1-Methyl naphthalene [90-12-0] Revised 2007 2-Methyl naphthalene [91-57-6] Revised 2007 Methyl propyl ketone (2-pentanone) [107-87-9] Mevinphos, Inhalable [7786-34-7] Revised 2003 Molybdenum - Metal and insoluble compounds, Respirable [7439-98-7] 3 mg/m3Molybdenum - Metal and insoluble compounds, Inhalable [7439-98-7] Molybdenum - Soluble compounds, as Mo, Respirable [7439-98-7] Natural rubber latex, as Total proteins, Inhalable [9006-04-6] Revised 0.001 mg/m3 Nickel - Insoluble inorganic compounds, as Ni [7440-02-0] Nickel - Elemental, Soluble inorganic compounds, as Ni [7440-02-0] Nickel subsulfide, as Ni, Inhalable [12035-72-2] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Nitropyrene, mono, di, tri, tetra, isomers [5522-43-0; 57835-92-4] Nitrotoluene, all isomers [88-72-2; 99-08-1; 99-99-0] 5-Nitro-o-toluidine, Inhalable [99-55-8] Revised 2007 p,p'-Oxybis(benzenesulfonyl hydrazide), Inhalable [80-51-3] Ozone - Light, mod., or heavy workload =/< 2 hrs [10028-15-6] Parathion, Inhalable [56-38-2] Revised 2003 Particles (Insoluble or Poorly Soluble) Not Otherwise Classified Pentane, all isomers [78-78-4; 109-66-0; 463-82-1] Pentyl acetate, all isomers [628-63-7; 626-38-0; 123-92-2; 625-16-1; 624-41-9; 620-11-1]Perchloroethylene (See Tetrachloroethylene) Perfluorobutyl ethylene [19430-93-4] Revised 2004 Perlite [93763-70-3] Revised 2006 (See Particles Not Otherwise Classified (PNOC))Persulfates, as persulfate TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Phenyl ether - Vapour (Diphenyl ether) [101-84-8] Phorate, Inhalable [298-02-2] Revised 2005 Piperazine and its Salts, as Piperazine [110-85-0] Platinum - Soluble salts (as Pt) [7440-06-4] Polyvinyl chloride, Total dust [9002-86-2] n-Propanol (n-Propyl alcohol) [71-23-8] Revised 2007 Propylene dichloride [78-87-5] Revised 2006 Rhodium, Metal and insoluble compounds as Rh [7440-16-6] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Rhodium - Soluble compounds, as Rh [7440-16-6] Rosin core solder thermal decomposition products (colophony) [8050- Selenium and compounds, as Se [7782-49-2] Silica, Amorphous - Diatomaceous earth (uncalcined) Total [61790-53- 4 mg/m32]Silica, Amorphous - Diatomaceous earth (uncalcined), Respirable [61790-53-2]Silica, Amorphous - Fume Total [69012-64-2] Silica, Amorphous - Fume, Respirable [69012-64-2] Silica, Amorphous - Precipitated and gel, Total [112926-00-8] Silica, Amorphous - Precipitated and gel, Respirable [112926-00-8] Silica, Crystalline - alpha quartz [14808-60-7; 1317-95-9] and Cristobalite, Respirable [14464-46-1] Revised 2006 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 Silicon carbide, Fibrous (including whiskers) [409-21-2] Revised 2003 Silicon tetrahydride (Silane) [7803-62-5] Sodium azide (as Sodium azide) [26628-22-8] Sodium azide (as Hydrazoic acid vapour) [26628-22-8] Stoddard solvent (mineral spirits) [8052-41-3] Subtilisins, as crystalline active enzyme [1395-21-7; 9014-01-1] Sulfotep (TEDP), Inhalable [3689-24-5] Revised 2005 TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Sulfuric acid, Thoracic [7664-93-9] Revised 2004 Synthetic Vitreous Fibres - Continuous filament glass fibres Synthetic Vitreous Fibres - Continuous filament glass fibres, Inhalable Synthetic Vitreous Fibres - Glass wool fibres Synthetic Vitreous Fibres - Rock wool fibres Synthetic Vitreous Fibres -Slag wool fibres Synthetic Vitreous Fibres - Special purpose glass fibres Synthetic Vitreous Fibres - Refractory ceramic fibres 2,4,5-T (2,4,5-Trichlorophenoxyacetic acid) [93-76-5] Talc - Containing no asbestos fibres, Respirable [14807-96-6] Talc - Containing asbestos fibres [14807-96-6] Tellurium and compounds (NOS), as Te, excluding hydrogen telluride 0.1 mg/m3[13494-80-9]Tellurium hexafluoride [7783-80-4] Temephos, Inhalable [3383-96-8] Revised 2005 1,1,2,2-Tetrabromoethane [79-27-6] Inhalable Revised 2006 1,1,1,2-Tetrachloro-2,2-difluoroethane [76-11-9] 1,1,2,2-Tetrachloro-1,2-difluoroethane [76-12-0] Tetrachloroethylene (Perchloroethylene) [127-18-4] Tetraethyl pyrophosphate (TEPP), Inhalable [107-49-3] Revised 2007 Tetrakis (hydroxymethyl) phosphonium chloride [124-64-1] Revised Tetrakis (hydroxymethyl) phosphonium sulfate [55566-30-8] Revised Thallium and soluble compounds, as Tl [7440-28-0] 4,4' Thiobis (6-tert-butyl-m-cresol) [96-69-5] (see Cresol, all isomers) Tin - Oxide and inorganic compounds, except tin hydride, as Sn [7440- 2 mg/m331-6] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
Tin - Organic compounds, as Sn [7440-31-6] Titanium dioxide [13463-67-7] Revised 2006 Toluene-2,4-diisocyanate (2,4-TDI) [584-84-9] Toluene-2,6-diisocyanate (2,6-TDI) [91-08-7] 1,1,2-Trichloro-1,2,2-trifluoroethane [76-13-1] Trichlorphon, Inhalable [52-68-6] Revised 2003 1,3,5-Triglycidyl-s-triazinetrione [2451-62-9] Trimethyl benzene (mixed isomers) [25551-13-7] Trimethyl hexamethylene diisocyanate [28679-16-5] Tungsten - Metal and insoluble compounds [7440-33-7] Tungsten - Soluble compounds, as W [7440-33-7] Turpentine [8006-64-2] and selected monoterpenes [80-56-8; 127-91- 3; 13466-78-9] Revised 2003Uranium (Natural) - Insoluble compounds, as U [7440-61-1] Uranium (Natural) - Soluble compounds, as U [7440-61-1] Vanadium pentoxide, Respirable dust and fume, as V2O5 [1314-62-1] Vanadium pentoxide, Total dust, as V2O5 [1314-62-1] Vegetable oil - Mist, except castor, cashew nut, or similar irritant oils [8008-89-7]Vegetable oil, Mist, Respirable, except castor, cashew nut, or similar irritating oil [8008-89-7]Vinyl acetate [108-05-4] TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations Table of exposure limits for chemical and biological substances
Substance [CAS No.]
Notations
N-Vinyl-2-pyrrolidone [88-12-0] Revised 2003 VM & P Naphtha [8032-32-4] Revised 2006 Xylene [1330-20-7] (o, m & p isomers) [95-47-6; 108-38-3; 106-42-3] m-Xylene alpha,alpha'-diamine [1477-55-0] Xylidine - Mixed isomers, Inhalable [1330-73-8] Zinc chromates, as Cr [13530-65-9; 11103-86-9; 37300-23-5] Zinc oxide, Respirable [1314-13-2] Revised 2003 Zirconium [7440-67-7] and compounds, as Zr [7440-67-7] 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 400 - 450 times magnification (4 mm objective), using phase-contrast illumination.
(G) - as measured by the vertical elutriator, cotton-dust sampler, see TLV Documentation. (J) - does not include stearates of toxic metals.
(K) - should not exceed 2 mg/m3 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. Note: This OEL has been suspended. See OHS Guideline 5.48-11.
(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.
TWA column, bracketed letters e.g. "(L)" are end notes;STEL column C = Ceiling limit;Notations column R = Adverse reproductive effect; S = Sensitizer; A1, A2, 1, 2A, 2B = Carcinogen designations

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