IEH Occupational Hygiene Tool
Singapore Permissible Exposure Level Lookup Tool
A practical reference tool for checking the Permissible Exposure Levels of toxic substances listed under Singapore’s Workplace Safety and Health (General Provisions) Regulations.
About this tool
Use this tool to quickly identify exposure limits for workplace chemical exposure assessment.
Permissible Exposure Levels are used by occupational hygienists, WSH professionals, employers and consultants to evaluate whether airborne exposure to toxic substances may exceed regulatory limits.
01
Search by substance
Look up a toxic substance by name, synonym or partial keyword, such as benzene, acetone, ammonia, chromium or respirable dust.
02
Check CAS number
Use the CAS number to verify whether the substance in an SDS or chemical inventory corresponds to a listed toxic substance.
03
Compare LT and ST PEL
Review both long-term and short-term exposure limits where available, then determine whether workplace monitoring or control review is required.
Important: This tool is intended as a quick reference. It should not replace professional occupational hygiene judgement, exposure monitoring strategy, regulatory review or competent interpretation of sampling results.
PEL Lookup Table
Search the table below by toxic substance name or CAS number. Values may be listed in ppm, mg/m³, fibre/cc or other applicable units depending on the substance.
| Toxic Substance | PEL (Long Term) ppm | PEL (Long Term) mg/m3 | PEL (Short Term) ppm | PEL (Short Term) mg/m3 | CAS Number |
|---|---|---|---|---|---|
| Acetaldehyde | NA | NA | 25 | 45 | 75-07-0 |
| Acetic acid | 10 | 25 | 15 | 37 | 64-19-7 |
| Acetic anhydride | 5 | 21 | NA | NA | 108-24-7 |
| Acetone | 750 | 1780 | 1000 | 2380 | 67-64-1 |
| Acetone cyanohydrin | NA | NA | 4.7 | 5 | 75-86-5 |
| Acetonitrile | 40 | 67 | 60 | 101 | 75-05-8 |
| Acetophenone | 10 | 49 | NA | NA | 98-86-2 |
| Acetylene tetrabromide | 1 | 14 | NA | NA | 79-27-6 |
| Acrolein | 0.1 | 0.23 | 0.3 | 0.69 | 107-02-8 |
| Acrylamide | NA | 0.03 | NA | NA | 79-06-1 |
| Acrylic acid | 2 | 5.9 | NA | NA | 79-10-7 |
| Acrylonitrile (Vinyl cyanide) | 2 | 4.3 | NA | NA | 107-13-1 |
| Adipic acid | NA | 5 | NA | NA | 124-04-9 |
| Adiponitrile | 2 | 8.8 | NA | NA | 111-69-3 |
| Aldrin | NA | 0.25 | NA | NA | 309-00-2 |
| Allyl alcohol | 2 | 4.8 | 4 | 9.5 | 107-18-6 |
| Allyl chloride | 1 | 3 | 2 | 6 | 107-05-1 |
| Allyl glycidyl ether (AGE) | 5 | 23 | 10 | 47 | 106-92-3 |
| Allyl propyl disulfide | 2 | 12 | 3 | 18 | 2179-59-1 |
| Aluminium Metal dust | NA | 10 | NA | NA | 7429-90-5 |
| Pyro powders, as Aluminium | NA | 5 | NA | NA | 7429-90-5 |
| Welding fumes, as Aluminium | NA | 5 | NA | NA | 7429-90-5 |
| Soluble salts, as Aluminium | NA | 2 | NA | NA | 7429-90-5 |
| Alkyls, as Aluminium | NA | 2 | NA | NA | |
| Aluminium oxide | NA | 10 | NA | NA | 1344-28-1 |
| 2-Aminopyridine | 0.5 | 1.9 | NA | NA | 504-29-0 |
| Amitrole | NA | 0.2 | NA | NA | 61-82-5 |
| Ammonia | 25 | 17 | 35 | 24 | 7664-41-7 |
| Ammonium chloride fume | NA | 10 | NA | 20 | 12125-02-9 |
| Ammonium perfluorooctanoate | NA | 0.01 | NA | NA | 3825-26-1 |
| Ammonium sulfamate | NA | 10 | NA | NA | 7773-06-0 |
| n-Amyl acetate | 100 | 532 | NA | NA | 628-63-7 |
| sec-Amyl acetate | 125 | 665 | NA | NA | 626-38-0 |
| Aniline | 2 | 7.6 | NA | NA | 62-53-3 |
| Anisidine | 0.1 | 0.5 | NA | NA | 104-94-9 |
| Antimony and compounds, as Sb | NA | 0.5 | NA | NA | 7440-36-0 |
| Antimony trioxide, as Sb | NA | 0.5 | NA | NA | 1309-64-4 |
| Arsenic, elemental and inorganic compounds, as As | NA | 0.01 | NA | NA | 7440-38-2 |
| Arsine | 0.05 | 0.16 | NA | NA | 7784-42-1 |
| Asbestos (all forms) | NA | 0.1 (fibre/cc) | NA | NA | 1332-21-4 |
| Asphalt (petroleum) fumes | NA | 5 | NA | NA | 8052-42-4 |
| Atrazine | NA | 5 | NA | NA | 1912-24-9 |
| Azinphos-methyl | NA | 0.2 | NA | NA | 86-50-0 |
| Barium, soluble compounds, as Ba | NA | 0.5 | NA | NA | 7440-39-3 |
| Barium sulfate | NA | 10 | NA | NA | 7727-43-7 |
| Benomyl | 0.84 | 10 | NA | NA | 17804-35-2 |
| Benzene | 1 | 3.18 | NA | NA | 71-43-2 |
| Benzoyl peroxide | NA | 5 | NA | NA | 94-36-0 |
| Benzyl chloride | 1 | 5.2 | NA | NA | 100-44-7 |
| Beryllium and compounds, as Be | NA | 0.002 | NA | NA | 7440-41-7 |
| Biphenyl | 0.2 | 1.3 | NA | NA | 92-52-4 |
| Bismuth telluride, Undoped | NA | 10 | NA | NA | 1304-82-1 |
| Bismuth telluride, Se-doped | NA | 5 | NA | NA | |
| Borates, tetra sodium salts, Anhydrous | NA | 1 | NA | NA | 1330-43-4 |
| Borates, tetra sodium salts,Decahydrate | NA | 5 | NA | NA | 1303-96-4 |
| Borates, tetra sodium salts,Pentahydrate | NA | 1 | NA | NA | 12179-04-3 |
| Boron oxide | NA | 10 | NA | NA | 1303-86-2 |
| Boron tribromide | NA | NA | 1 | 10 | 10294-33-4 |
| Boron trifluoride | NA | NA | 1 | 2.8 | 2/7/7637 |
| Bromacil | NA | 10 | NA | NA | 314-40-9 |
| Bromine | 0.1 | 0.66 | 0.2 | 1.3 | 7726-95-6 |
| Bromine pentafluoride | 0.1 | 0.72 | NA | NA | 7789-30-2 |
| Bromoform | 0.5 | 5.2 | NA | NA | 75-25-2 |
| 1,3-Butadiene | 2 | 4.4 | NA | NA | 106-99-0 |
| Butane | 800 | 1900 | NA | NA | 106-97-8 |
| n-Butanol | NA | NA | 50 | 152 | 71-36-3 |
| sec-Butanol | 100 | 303 | NA | NA | 78-92-2 |
| tert-Butanol | 100 | 303 | NA | NA | 75-65-0 |
| 2-Butoxyethanol (EGBE) | 25 | 121 | NA | NA | 111-76-2 |
| n-Butyl acetate | 150 | 713 | 200 | 950 | 123-86-4 |
| sec-Butyl acetate | 200 | 950 | NA | NA | 105-46-4 |
| tert-Butyl acetate | 200 | 950 | NA | NA | 540-88-5 |
| n-Butyl acrylate | 10 | 52 | NA | NA | 141-32-2 |
| n-Butylamine | NA | NA | 5 | 15 | 109-73-9 |
| tert-Butyl chromate, as CrO3 | NA | NA | NA | 0.1 | 1189-85-1 |
| n-Butyl glycidyl ether (BGE) | 25 | 133 | NA | 0.1 | 6/8/2426 |
| n-Butyl lactate | 5 | 30 | NA | NA | 138-22-7 |
| Butyl mercaptan (Butanethiol) | 0.5 | 1.8 | NA | NA | 109-79-5 |
| o-sec-Butylphenol | 5 | 31 | NA | NA | 89-72-5 |
| p-tert-Butyl toluene | 1 | 6.1 | NA | NA | 98-51-1 |
| Cadmium, Elemental | NA | 0.01 | NA | NA | 7440-43-9 |
| Cadmium, Compounds | NA | 0.002 | NA | NA | 7440-43-9 |
| Calcium carbonate (Limestone, Marble) | NA | 10 | NA | NA | 471-34-1 |
| Calcium chromate, as Cr | NA | 0.001 | NA | NA | 13765-19-0 |
| Calcium cyanamide | NA | 0.5 | NA | NA | 156-62-7 |
| Calcium cyanide | NA | NA | NA | 5 | 592-01-8 |
| Calcium hydroxide | NA | 5 | NA | NA | 1305-62-0 |
| Calcium oxide | NA | 2 | NA | NA | 1305-78-8 |
| Calcium silicate | NA | 10 | NA | NA | 1344-95-2 |
| Calcium sulfate | NA | 10 | NA | NA | 7778-18-9 |
| Camphor | 2 | 12 | 3 | 19 | 76-22-2 |
| Caprolactam, Dust | NA | 1 | NA | 3 | 105-60-2 |
| Caprolactam, Vapour | 5 | 23 | 10 | 46 | 105-60-2 |
| Captafol | NA | 0.1 | NA | NA | 1/6/2425 |
| Captan | NA | 5 | NA | NA | 133-06-2 |
| Carbaryl | NA | 5 | NA | NA | 63-25-2 |
| Carbofuran | NA | 0.1 | NA | NA | 1563-66-2 |
| Carbon black | NA | 3.5 | NA | NA | 1333-86-4 |
| Carbon dioxide | 5000 | 9000 | 30000 | 54000 | 124-38-9 |
| Carbon disulfide | 10 | 31 | NA | NA | 75-15-0 |
| Carbon monoxide | 25 | 29 | NA | NA | 630-08-0 |
| Carbon tetrabromide | 0.1 | 1.4 | 0.3 | 4.1 | 558-13-4 |
| Carbon tetrachloride, (Tetrachloromethane) | 5 | 31 | 10 | 63 | 56-23-5 |
| Carbonyl fluoride | 2 | 5.4 | 5 | 13 | 353-50-4 |
| Catechol (Pyrocatechol) | 5 | 23 | NA | NA | 120-80-9 |
| Cellulose | NA | 10 | NA | NA | 9004-34-6 |
| Cesium hydroxide | NA | 2 | NA | NA | 21351-79-1 |
| Chlordane | NA | 0.5 | NA | NA | 12789-03-6 |
| Chlorinated camphene (Toxaphene) | NA | 0.5 | NA | NA | 8001-35-2 |
| Chlorinated diphenyl oxide | NA | 0.5 | NA | NA | 6973-37-1 |
| Chlorine | 0.5 | 1.5 | 1 | 2.9 | 7782-50-5 |
| Chlorine dioxide | 0.1 | 0.28 | 0.3 | 0.83 | 10049-04-4 |
| Chlorine trifluoride | NA | NA | 0.1 | 0.38 | 7790-91-2 |
| Chloroacetaldehyde | NA | NA | 1 | 3.2 | 107-20-0 |
| Chloroacetone | NA | NA | 1 | 3.8 | 78-95-5 |
| 2-Chloroacetophenone (Phenacyl chloride) | 0.05 | 0.32 | NA | NA | 532-27-4 |
| Chloroacetyl chloride | 0.05 | 0.23 | 0.15 | 0.69 | 79-04-9 |
| Chlorobenzene (Monochlorobenzene) | 10 | 46 | NA | NA | 108-90-7 |
| o-Chlorobenzylidene malononitrile | NA | NA | 0.05 | 0.39 | 2698-41-1 |
| Chlorobromomethane, (Bromochloromethane) | 200 | 1060 | NA | NA | 74-97-5 |
| Chlorodifluoromethane | 1000 | 3540 | NA | NA | 75-45-6 |
| Chlorodiphenyl (42% chlorine) | NA | 1 | NA | NA | 53469-21-9 |
| Chlorodiphenyl (54% chlorine) | NA | 0.5 | NA | NA | 11097-69-1 |
| Chloroform (Trichloromethane) | 10 | 49 | NA | NA | 67-66-3 |
| bis (Chloromethyl) ether | 0.001 | 0.0047 | NA | NA | 542-88-1 |
| 1-Chloro-1-nitropropane | 2 | 10 | NA | NA | 600-25-9 |
| Chloropentafluoroethane | 1000 | 6320 | NA | NA | 76-15-3 |
| Chloropicrin (Trichloronitromethane) | 0.1 | 0.67 | NA | NA | 76-06-2 |
| β;-Chloroprene (2-Chloro-1,3-butadiene) | 10 | 36 | NA | NA | 126-99-8 |
| 2-Chloropropionic acid | 0.1 | 0.44 | NA | NA | 598-78-7 |
| o-Chlorostyrene | 50 | 283 | 75 | 425 | 2039-87-4 |
| o-Chlorotoluene | 50 | 259 | NA | NA | 95-49-8 |
| Chlorpyrifos | NA | 0.2 | NA | NA | 2921-88-2 |
| Chromium, Metal and Cr III compounds | NA | 0.5 | NA | NA | 7440-47-3 |
| Chromium, Water-soluble Cr VI compounds | NA | 0.05 | NA | NA | 7440-47-3 |
| Chromium, Insoluble Cr VI compounds | NA | 0.01 | NA | NA | 7440-47-3 |
| Chromyl chloride | 0.025 | 0.16 | NA | NA | 14977-61-8 |
| Clopidol | NA | 10 | NA | NA | 2971-90-6 |
| Coal, respirable dust | NA | 2 | NA | NA | |
| Coal tar pitch volatiles (Polycylic aromatic hydrocarbons), as benzene solubles | NA | 0.2 | NA | NA | 65996-93-2 |
| Cobalt, elemental and inorganic compounds, as Co | NA | 0.02 | NA | NA | 7440-48-4 |
| Cobalt carbonyl, as Co | NA | 0.1 | NA | NA | 10210-68-1 |
| Cobalt hydrocarbonyl, as Co | NA | 0.1 | NA | NA | 16842-03-8 |
| Copper Fume | NA | 0.2 | NA | NA | 7440-50-8 |
| Copper Dusts and mists | NA | 1 | NA | NA | 7440-50-8 |
| Cotton dust, raw | NA | 0.2 | NA | NA | |
| Cresol | 5 | 22 | NA | NA | 1319-77-3; 108-39-4; 95-48-7; 106-44-5 |
| Crotonaldehyde | 2 | 5.7 | NA | NA | 4170-30-3 |
| Crufomate | NA | 5 | NA | NA | 299-86-5 |
| Cumene | 50 | 246 | NA | NA | 98-82-8 |
| Cyanamide | NA | 2 | NA | NA | 420-04-2 |
| Cyanogen | 10 | 21 | NA | NA | 460-19-5 |
| Cyanogen chloride | NA | NA | 0.3 | 0.75 | 506-77-4 |
| Cyclohexane | 300 | 1030 | NA | NA | 110-82-7 |
| Cyclohexanol | 50 | 206 | NA | NA | 108-93-0 |
| Cyclohexanone | 25 | 100 | NA | NA | 108-94-1 |
| Cyclohexene | 300 | 1010 | NA | NA | 110-83-8 |
| Cyclohexylamine | 10 | 41 | NA | NA | 108-91-8 |
| Cyclonite | NA | 1.5 | NA | NA | 121-82-4 |
| Cyclopentadiene | 75 | 203 | NA | NA | 542-92-7 |
| Cyclopentane | 600 | 1720 | NA | NA | 287-92-3 |
| Cyhexatin (Tricyclo hexyltin) | NA | 5 | NA | NA | 13121-70-5 |
| DDT (Dichlorodiphenyltrichloroethane) | NA | 1 | NA | NA | 50-29-3 |
| Decaborane | 0.05 | 0.25 | 0.15 | 0.75 | 17702-41-9 |
| Demeton | 0.01 | 0.11 | NA | NA | 8065-48-3 |
| Diacetone alcohol, (4-Hydroxy-4-methyl-2-pentanone) | 50 | 238 | NA | NA | 123-42-2 |
| Diazinon | NA | 0.1 | NA | NA | 333-41-5 |
| Diazomethane | 0.2 | 0.34 | NA | NA | 334-88-3 |
| Diborane | 0.1 | 0.11 | NA | NA | 19287-45-7 |
| 2-N-Dibutylaminoethanol | 0.5 | 3.5 | NA | NA | 102-81-8 |
| Dibutyl phenyl phosphate | 0.3 | 3.5 | NA | NA | 2528-36-1 |
| Dibutyl phosphate | 1 | 8.6 | 2 | 17 | 107-66-4 |
| Dibutyl phthalate | NA | 5 | NA | NA | 84-74-2 |
| Dichloroacetylene | NA | NA | 0.1 | 0.39 | 7572-29-4 |
| o-Dichlorobenzene | 25 | 150 | 50 | 301 | 95-50-1 |
| p-Dichlorobenzene | 10 | 60 | NA | NA | 106-46-7 |
| 1,4-Dichloro-2-butene | 0.005 | 0.025 | NA | NA | 110-57-6 |
| Dichlorodifluoromethane | 1000 | 4950 | NA | NA | 75-71-8 |
| 1,3-Dichloro-5,5-dimethyl hydantoin | NA | 0.2 | NA | 0.4 | 118-52-5 |
| 1,1-Dichloroethane, (Ethylidene chloride) | 100 | 405 | NA | NA | 75-34-3 |
| 1,2-Dichloroethylene, (Acetylene dichloride) | 200 | 793 | NA | NA | 540-59-0; 156-60-5; 156-59-2 |
| Dichloroethyl ether | 5 | 29 | 10 | 58 | 111-44-4 |
| Dichlorofluoromethane | 10 | 42 | NA | NA | 75-43-4 |
| 1,1-Dichloro-1-nitroethane | 2 | 12 | NA | NA | 594-72-9 |
| 1,3-Dichloropropene | 1 | 4.5 | NA | NA | 542-75-6 |
| 2,2-Dichloropropionic acid | 1 | 5.8 | NA | NA | 75-99-0 |
| Dichlorotetrafluoroethane | 1000 | 6990 | NA | NA | 76-14-2 |
| Dichlorvos | 0.1 | 0.9 | NA | NA | 62-73-7 |
| Dicrotophos | NA | 0.25 | NA | NA | 141-66-2 |
| Dicyclopentadiene | 5 | 27 | NA | NA | 77-73-6 |
| Dicyclopentadienyl iron | NA | 10 | NA | NA | 102-54-5 |
| Dieldrin | NA | 0.25 | NA | NA | 60-57-1 |
| Diethanolamine | 0.46 | 2 | NA | NA | 111-42-2 |
| Diethylamine | 5 | 15 | 15 | 45 | 109-89-7 |
| 2-Diethylaminoethanol | 2 | 9.6 | NA | NA | 100-37-8 |
| Diethylene triamine | 1 | 4.2 | NA | NA | 111-40-0 |
| Diethyl ketone | 200 | 705 | NA | NA | 96-22-0 |
| Diethyl phthalate | NA | 5 | NA | NA | 84-66-2 |
| Difluorodibromomethane | 100 | 858 | NA | NA | 75-61-6 |
| Diglycidyl ether (DGE) | 0.1 | 0.53 | NA | NA | 5/7/2238 |
| Diisobutyl ketone (2,6-Dimethyl-4-heptanone) | 25 | 145 | NA | NA | 108-83-8 |
| Diisopropylamine | 5 | 21 | NA | NA | 108-18-9 |
| N,N-Dimethyl acetamide | 10 | 36 | NA | NA | 127-19-5 |
| Dimethylamine | 5 | 9.2 | 15 | 27.6 | 124-40-3 |
| Dimethylaniline , (N,N-Dimethylaniline) | 5 | 25 | 10 | 50 | 121-69-7 |
| Dimethylformamide | 10 | 30 | NA | NA | 68-12-2 |
| 1,1-Dimethylhydrazine | 0.5 | 1.2 | NA | NA | 57-14-7 |
| Dimethylphthalate | NA | 5 | NA | NA | 131-11-3 |
| Dimethyl sulfate | 0.1 | 0.52 | NA | NA | 77-78-1 |
| Dinitolmide (3,5-Dinitro-o-toluamide) | NA | 5 | NA | NA | 148-01-6 |
| Dinitrobenzene | 0.15 | 1 | NA | NA | 99-65-0 |
| Dinitro-o-cresol | NA | 0.2 | NA | NA | 1335-85-9 |
| Dinitrotoluene | NA | 0.15 | NA | NA | 602-01-7 |
| Dioxane | 25 | 90 | NA | NA | 123-91-1 |
| Dioxathion | NA | 0.2 | NA | NA | 78-34-2 |
| Diphenylamine | NA | 10 | NA | NA | 122-39-4 |
| Dipropylene glycol methyl ether | 100 | 606 | 150 | 909 | 13588-28-8; 34590-94-8; 13429-07-7; 20324-32-7; 55956-21-3 |
| Dipropyl ketone | 50 | 233 | NA | NA | 123-19-3 |
| Diquat, Total dust | NA | 0.5 | NA | NA | 2764-72-9 |
| Diquat, Respirable dust | NA | 0.1 | NA | NA | 2764-72-9 |
| Di-sec-octyl phthalate (Di (-2-ethylhexyl) phthalate) | NA | 5 | NA | 10 | 117-81-7 |
| Disulfiram | NA | 2 | NA | NA | 97-77-8 |
| Disulfoton | NA | 0.1 | NA | NA | 298-04-4 |
| 2,6-Di-tert-butyl-p-cresol | NA | 10 | NA | NA | 128-37-0 |
| Diuron | NA | 10 | NA | NA | 330-54-1 |
| Divinyl benzene | 10 | 53 | NA | NA | 1321-74-0 |
| Emery | NA | 10 | NA | NA | 12415-34-8 |
| Endosulfan | NA | 0.1 | NA | NA | 115-29-7 |
| Endrin | NA | 0.1 | NA | NA | 72-70-8 |
| Enflurane | 75 | 566 | NA | NA | 13838-16-9 |
| Epichlorohydrin (1-Chloro-2, 3-epoxypropane) | 2 | 7.6 | NA | NA | 106-89-8 |
| EPN | NA | 0.1 | NA | NA | 2104-64-5 |
| Ethanol (Ethyl alcohol) | 1000 | 1880 | NA | NA | 64-17-5 |
| Ethanolamine | 3 | 7.5 | 6 | 15 | 141-43-5 |
| Ethion | NA | 0.4 | NA | NA | 563-12-2 |
| 2-Ethoxyethanol (EGEE) | 5 | 18 | NA | NA | 110-80-5 |
| 2-Ethoxyethyl acetate (EGEEA) | 5 | 27 | NA | NA | 111-15-9 |
| Ethyl acetate | 400 | 1440 | NA | NA | 141-78-6 |
| Ethyl acrylate | 5 | 20 | 15 | 61 | 140-88-5 |
| Ethylamine | 5 | 9.2 | 15 | 27.6 | 75-04-7 |
| Ethyl amyl ketone (5-Methyl-3-heptanone) | 25 | 131 | NA | NA | 106-68-3 |
| Ethyl benzene | 100 | 434 | 125 | 543 | 100-41-4 |
| Ethyl bromide | 5 | 22 | NA | NA | 74-96-4 |
| Ethyl butyl ketone (3-Heptanone) | 50 | 234 | NA | NA | 106-35-4 |
| Ethyl chloride | 1000 | 2640 | NA | NA | 75-00-3 |
| Ethylene chlorohydrin | NA | NA | 1 | 3.3 | 107-07-3 |
| Ethylenediamine (1,2-Diaminoethane) | 10 | 25 | NA | NA | 107-15-3 |
| Ethylene dichloride (1,2-Dichloroethane) | 10 | 40 | NA | NA | 107-06-2 |
| Ethylene glycol | NA | NA | 50 | 127 | 107-21-1 |
| Ethylene glycol dinitrate | 0.05 | 0.31 | NA | NA | 628-96-6 |
| Ethylene oxide | 1 | 1.8 | NA | NA | 75-21-8 |
| Ethylenimine | 0.5 | 0.88 | NA | NA | 151-56-4 |
| Ethyl ether (Diethyl ether) | 400 | 1210 | 500 | 1520 | 60-29-7 |
| Ethyl formate | 100 | 303 | NA | NA | 109-94-4 |
| Ethylidene norbornene | NA | NA | 5 | 25 | 16219-75-3 |
| Ethyl mercaptan (Ethanethiol) | 0.5 | 1.3 | NA | NA | 75-08-1 |
| N-Ethylmorpholine | 5 | 24 | NA | NA | 100-74-3 |
| Ethyl silicate | 10 | 85 | NA | NA | 78-10-4 |
| Fenamiphos | NA | 0.1 | NA | NA | 22224-92-6 |
| Fensulfothion | NA | 0.1 | NA | NA | 115-90-2 |
| Fenthion | NA | 0.2 | NA | NA | 55-38-9 |
| Ferbam | NA | 10 | NA | NA | 14484-64-1 |
| Ferrovanadium dust | NA | 1 | NA | 3 | 12604-58-9 |
| Fibrous glass dust | NA | 10 | NA | NA | 65997-17-3 |
| Fluorides, as F | NA | 2.5 | NA | NA | |
| Fluorine | 1 | 1.6 | 2 | 3.1 | 7782-41-4 |
| Fonofos | NA | 0.1 | NA | NA | 944-22-9 |
| Formaldehyde | NA | NA | 0.3 | 0.37 | 50-00-0 |
| Formamide | 10 | 18 | NA | NA | 75-12-7 |
| Formic acid | 5 | 9.4 | 10 | 19 | 64-18-6 |
| Furfural | 2 | 7.9 | NA | NA | 98-01-1 |
| Furfuryl alcohol | 10 | 40 | 15 | 60 | 98-00-0 |
| Gasoline | 300 | 890 | 500 | 1480 | 86290-81-5 |
| Germanium tetrahydride | 0.2 | 0.63 | NA | NA | 7782-65-2 |
| Glutaraldehyde | NA | NA | 0.2 | 0.82 | 111-30-8 |
| Glycerin mist | NA | 10 | NA | NA | 56-81-5 |
| Glycidol (2,3-Epoxy-1-propanol) | 25 | 76 | NA | NA | 556-52-5 |
| Grain dust (oat, wheat, barley) | NA | 4 | NA | NA | |
| Graphite, respirable dust | NA | 2 | NA | NA | 7782-42-5 |
| Hafnium | NA | 0.5 | NA | NA | 7440-58-6 |
| Halothane | 50 | 404 | NA | NA | 151-67-7 |
| Heptachlor and Heptachlor epoxide | NA | 0.05 | NA | NA | 1024-57-3 |
| Heptane | 400 | 1640 | 500 | 2050 | 142-82-5 |
| Hexachlorobenzene | NA | 0.025 | NA | NA | 118-74-1 |
| Hexachlorobutadiene | 0.02 | 0.21 | NA | NA | 87-68-3 |
| Hexachlorocyclopentadiene | 0.01 | 0.11 | NA | NA | 77-47-4 |
| Hexachloroethane | 1 | 9.7 | NA | NA | 67-72-1 |
| Hexachloronaphthalene | NA | 0.2 | NA | NA | 58877-88-6 |
| Hexafluoroacetone | 0.1 | 0.68 | NA | NA | 684-16-2 |
| Hexamethylene diisocyanate | 0.005 | 0.034 | NA | NA | 822-06-0 |
| 1,6-Hexanediamine | 0.5 | 2.3 | NA | NA | 124-09-4 |
| Hexane (n-Hexane) | 50 | 176 | NA | NA | 110-54-3 |
| Other isomers | 500 | 1760 | 1000 | 3500 | 107-83-5; 96-14-0; 75-83-2; 73513-42-5; 79-29-8 |
| sec-Hexyl acetate | 50 | 295 | NA | NA | 108-84-9 |
| Hexylene glycol | NA | NA | 25 | 121 | 107-41-5 |
| Hydrazine | 0.1 | 0.13 | NA | NA | 302-01-2 |
| Hydrogenated terphenyls | 0.5 | 4.9 | NA | NA | 61788-32-7 |
| Hydrogen bromide | NA | NA | 3 | 9.9 | 10035-10-6 |
| Hydrogen chloride | NA | NA | 5 | 7.5 | 7647-01-0 |
| Hydrogen cyanide | NA | NA | 4.7 | 5 | 74-90-8 |
| Hydrogen fluoride | NA | NA | 3 | 2.6 | 7664-39-3 |
| Hydrogen peroxide | 1 | 1.4 | NA | NA | 7722-84-1 |
| Hydrogen selenide | 0.05 | 0.16 | NA | NA | 5/7/7783 |
| Hydrogen sulfide | 10 | 14 | 15 | 21 | 4/6/7783 |
| Hydroquinone (Dihydroxy benzene) | NA | 2 | NA | NA | 123-31-9 |
| 2-Hydroxypropyl acrylate | 0.5 | 2.8 | NA | NA | 999-61-1 |
| Indene | 10 | 48 | NA | NA | 95-13-6 |
| Indium and compounds, as In | NA | 0.1 | NA | NA | 7440-74-6 |
| Iodine | NA | NA | 0.1 | 1 | 7553-56-2 |
| Iodoform | 0.6 | 10 | NA | NA | 75-47-8 |
| Iron oxide dust and fume, as Fe | NA | 5 | NA | NA | 1309-37-1 |
| Iron pentacarbonyl, as Fe | 0.1 | 0.23 | 0.2 | 0.45 | 13463-40-6 |
| Iron salts, soluble, as Fe | NA | 1 | NA | NA | |
| Isoamyl acetate | 100 | 532 | NA | NA | 123-92-2 |
| Isoamyl alcohol | 100 | 361 | 125 | 452 | 123-51-3 |
| Isobutyl acetate | 150 | 713 | NA | NA | 110-19-0 |
| Isobutyl alcohol | 50 | 152 | NA | NA | 78-83-1 |
| Isooctyl alcohol | 50 | 266 | NA | NA | 26952-21-6 |
| Isophorone | NA | NA | 5 | 28 | 78-59-1 |
| Isophorone diisocyanate | 0.005 | 0.045 | NA | NA | 4098-71-9 |
| Isoproproxyethanol | 25 | 106 | NA | NA | 109-59-1 |
| Isopropyl acetate | 250 | 1040 | 310 | 1290 | 108-21-4 |
| Isopropyl alcohol | 400 | 983 | 500 | 1230 | 67-63-0 |
| Isopropylamine | 5 | 12 | 10 | 24 | 75-31-0 |
| N-Isopropylaniline | 2 | 11 | NA | NA | 768-52-5 |
| Isopropyl ether | 250 | 1040 | 310 | 1300 | 108-20-3 |
| Isopropyl glycidyl ether (IGE) | 50 | 238 | 75 | 356 | 4016-14-2 |
| Kaolin, respirable dust | NA | 2 | NA | NA | 1332-58-7 |
| Ketene | 0.5 | 0.86 | 1.5 | 2.6 | 463-51-4 |
| Lead, inorganic dusts and fumes, as Pb | NA | 0.15 | NA | NA | 7439-92-1 |
| Lead arsenate | NA | 0.15 | NA | NA | 7784-40-9 |
| Lead chromate, as Pb | NA | 0.05 | NA | NA | 7758-97-6 |
| Lead chromate, as Cr | NA | 0.012 | NA | NA | 7758-97-6 |
| Lindane | NA | 0.5 | NA | NA | 58-89-9 |
| Lithium hydride | NA | 0.025 | NA | NA | 319-84-6 |
| L.P.G. (Liquified petroleum gas) | 1000 | 1800 | NA | NA | 7580-67-8 |
| Magnesite | NA | 10 | NA | NA | 68476-85-7 |
| Magnesium oxide fume | NA | 10 | NA | NA | 546-93-0 |
| Malathion | NA | 10 | NA | NA | 1309-48-4 |
| Maleic anhydride | 0.25 | 1 | NA | NA | 121-75-5 |
| Manganese Dust and compounds | NA | 1 | NA | NA | 108-31-6 |
| Manganese Fume | NA | 1 | NA | 3 | 7439-96-5 |
| Manganese cyclopentadienyl tricarbonyl, as Mn | NA | 0.1 | NA | NA | 12079-65-1 |
| Mercury, Alkyl compounds | NA | 0.01 | NA | 0.03 | 7439-97-6 |
| Mercury, Aryl compounds | NA | 0.1 | NA | NA | 7439-97-6 |
| Mercury, Inorganic forms including metallic mercury | NA | 0.025 | NA | NA | 7439-97-6 |
| Mesityl oxide | 15 | 60 | 25 | 100 | 141-79-7 |
| Methacrylic acid | 20 | 70 | NA | NA | 79-41-4 |
| Methanol (Methyl alcohol) | 200 | 262 | 250 | 328 | 67-56-1 |
| Methomyl | NA | 2.5 | NA | NA | 16752-77-5 |
| Methoxychlor | NA | 10 | NA | NA | 72-43-5 |
| 2-Methyoxyethanol (EGME) | 5 | 16 | NA | NA | 109-86-4 |
| 2-Methoxyethyl acetate (Ethylene glycol methyl ethyl acetate, EGMEA) | 5 | 24 | NA | NA | 110-49-6 |
| 4-Methoxyphenol | NA | 5 | NA | NA | 150-76-5 |
| Methyl acetate | 200 | 606 | 250 | 757 | 79-20-9 |
| Methyl acetylene (Propyne) | 1000 | 1640 | NA | NA | 74-99-7 |
| Methyl acetylene-propadiene mixture (MAPP) | 1000 | 1640 | 1250 | 2050 | 59355-75-8 |
| Methyl acrylate | 10 | 35 | NA | NA | 96-33-3 |
| Methylacrylonitrile | 1 | 2.7 | NA | NA | 126-98-7 |
| Methylal (Dimethoxymethane) | 1000 | 3110 | NA | NA | 109-87-5 |
| Methylamine | 5 | 6.4 | 15 | 19 | 74-89-5 |
| Methyl n-amyl ketone (2-Heptanone) | 50 | 233 | NA | NA | 110-43-0 |
| N-Methyl aniline | 0.5 | 2.2 | NA | NA | 100-61-8 |
| Methyl bromide | 5 | 19 | NA | NA | 74-83-9 |
| Methyl-tert butyl ether | 40 | 144 | NA | NA | 1634-04-4 |
| Methyl n-butyl ketone (2-Hexanone) | 5 | 20 | NA | NA | 591-78-6 |
| Methyl chloride | 50 | 103 | 100 | 207 | 74-87-3 |
| Methyl 2-cyanoacrylate | 2 | 9.1 | 4 | 18 | 137-05-3 |
| Methylcyclohexane | 400 | 1610 | NA | NA | 108-87-2 |
| Methylcyclohexanol | 50 | 234 | NA | NA | 25639-42-3 |
| 0-Methylcyclohexanone | 50 | 229 | 75 | 344 | 583-60-8 |
| 2-Methylcyclopentadienyl manganese tricarbonyl, as Mn | NA | 0.2 | NA | NA | 12108-13-3 |
| Methyl demeton | NA | 0.5 | NA | NA | 8022-00-2 |
| Methylene bisphenyl isocyanate (MDI, Diphenyl methane diisocyanate) | 0.005 | 0.051 | NA | NA | 101-68-8 |
| Methylene chloride (Dichloromethane) | 50 | 174 | NA | NA | 75-09-2 |
| 4,4’-methylene bis (2-chloroaniline), [MOCA] | 0.01 | 0.11 | NA | NA | 101-14-4 |
| Methylene bis (4-cyclo-hexylisocyanate) | 0.005 | 0.054 | NA | NA | 5124-30-1 |
| 4,4’-Methylene dianiline | 0.1 | 0.81 | NA | NA | 101-77-9 |
| Methyl ethyl ketone (MEK, 2-Butanone) | 200 | 590 | 300 | 885 | 78-93-3 |
| Methyl ethyl ketone peroxide | NA | NA | 0.2 | 1.5 | 1338-23-4 |
| Methyl formate | 100 | 246 | 150 | 368 | 107-31-3 |
| Methyl hydrazine | NA | NA | 0.2 | 0.38 | 60-34-4 |
| Methyl iodide | 2 | 12 | NA | NA | 74-88-4 |
| Methyl isoamyl ketone | 50 | 234 | NA | NA | 110-12-3 |
| Methyl isobutyl carbinol (Methyl amyl alcohol) | 25 | 104 | 40 | 167 | 108-11-2 |
| Methyl isobutyl ketone (Hexone) | 50 | 205 | 75 | 307 | 108-10-1 |
| Methyl isocyanate | 0.02 | 0.047 | NA | NA | 624-83-9 |
| Methyl isopropyl ketone | 200 | 705 | NA | NA | 563-80-4 |
| Methyl mercaptan (Methanethiol) | 0.5 | 0.98 | NA | NA | 74-93-1 |
| Methyl methacrylate | 100 | 410 | NA | NA | 80-62-6 |
| Methyl parathion | NA | 0.2 | NA | NA | 298-00-0 |
| Methyl propyl ketone (2-Pentanone) | 200 | 705 | 250 | 881 | 107-87-9 |
| Methyl silicate | 1 | 6 | NA | NA | 681-84-5 |
| α;Methyl styrene | 50 | 242 | 100 | 483 | 98-83-9 |
| Metribuzin | NA | 5 | NA | NA | 21087-64-9 |
| Mevinphos (Phosdrin) | 0.01 | 0.092 | 0.03 | 0.27 | 7786-34-7 |
| Mica, respirable dust | NA | 3 | NA | NA | 12001-26-2 |
| Mineral wool fiber | NA | 10 | NA | NA | 65997-17-3 |
| Molybdenum, as Mo, Soluble compounds | NA | 5 | NA | NA | 7439-98-7 |
| Molybdenum, as Mo, Insoluble compounds | NA | 10 | NA | NA | 7439-98-7 |
| Monocrotophos | NA | 0.25 | NA | NA | 6923-22-4 |
| Morpholine | 20 | 71 | NA | NA | 110-91-8 |
| Naled (Dimethyl-1,2-dibromo-2,2 dichloroethyl phosphate) | NA | 3 | NA | NA | 300-76-5 |
| Naphtha | 300 | 1370 | NA | NA | |
| Naphthalene | 10 | 52 | 15 | 79 | 91-20-3 |
| Nickel, Metal | NA | 1 | NA | NA | 7440-02-0 |
| Nickel, Insoluble compounds, as Ni | NA | 1 | NA | NA | 7440-02-0 |
| Nickel, Soluble compounds, as Ni | NA | 0.1 | NA | NA | 7440-02-0 |
| Nickel carbonyl, as Ni | 0.05 | 0.12 | NA | NA | 13463-39-3 |
| Nickel sulfide, as Ni | NA | 1 | NA | NA | 12137-12-1 |
| Nicotine | NA | 0.5 | NA | NA | 54-11-5 |
| Nitrapyrin (2-Chloro-6-(trichloromethyl) pyridine) | NA | 10 | NA | 20 | 1929-82-4 |
| Nitric acid | 2 | 5.2 | 4 | 10 | 7697-37-2 |
| Nitric oxide | 25 | 31 | NA | NA | 10102-43-9 |
| p-Nitroaniline | NA | 3 | NA | NA | 100-01-6 |
| Nitrobenzene | 1 | 5 | NA | NA | 98-95-3 |
| p-Nitrochlorobenzene | 0.1 | 0.64 | NA | NA | 100-00-5 |
| Nitroethane | 100 | 307 | NA | NA | 79-24-3 |
| Nitrogen dioxide | 3 | 5.6 | 5 | 9.4 | 10102-44-0 |
| Nitrogen trifluoride | 10 | 29 | NA | NA | 7783-54-2 |
| Nitroglycerin (NG) | 0.05 | 0.46 | NA | NA | 55-63-0 |
| Nitromethane | 20 | 50 | NA | NA | 75-52-5 |
| 1-Nitropropane | 25 | 91 | NA | NA | 108-03-2 |
| 2-Nitropropane | 10 | 36 | NA | NA | 79-46-9 |
| Nitrotoluene | 2 | 11 | NA | NA | 88-72-2; 99-08-1; 99-99-0 |
| Nitrous oxide | 50 | 90 | NA | NA | 10024-97-2 |
| Nonane | 200 | 1050 | NA | NA | 111-84-2 |
| Nuisance particulates | NA | 10 | NA | NA | |
| Octachloronaphthalene | NA | 0.1 | NA | 0.3 | 2234-13-1 |
| Octane | 300 | 1400 | 375 | 1750 | 111-65-9 |
| Oil Mist, mineral | NA | 5 | NA | 10 | 8012-95-1 |
| Osmium tetroxide, as Os | 0.0002 | 0.0016 | 0.0006 | 0.0047 | 20816-12-0 |
| Oxalic acid | NA | 1 | NA | 2 | 144-62-7 |
| Oxygen difluoride | NA | NA | 0.05 | 0.11 | 7783-41-7 |
| Ozone | NA | NA | 0.1 | 0.2 | 10028-15-6 |
| Paraffin wax fume | NA | 2 | NA | NA | 8002-74-2 |
| Paraquat, Total dust | NA | 0.5 | NA | NA | 4685-14-7 |
| Paraquat, Respirable dust | NA | 0.1 | NA | NA | 4685-14-7 |
| Parathion | NA | 0.1 | NA | NA | 56-38-2 |
| Pentaborane | 0.005 | 0.013 | 0.015 | 0.039 | 19624-22-7 |
| Pentachloronaphthalene | NA | 0.5 | NA | NA | 1321-64-8 |
| Pentachloronitrobenzene | NA | 0.5 | NA | NA | 82-68-8 |
| Pentachlorophenol | NA | 0.5 | NA | NA | 87-86-5 |
| Pentaerythritol | NA | 10 | NA | NA | 115-77-5 |
| Pentane | 600 | 1770 | 750 | 2210 | 109-66-0; 78-78-4; 463-82-1 |
| Perchloroethylene (Tetrachloroethylene) | 25 | 170 | 100 | 685 | 127-18-4 |
| Perchloromethyl mercaptan | 0.1 | 0.76 | NA | NA | 594-42-3 |
| Perchloryl fluoride | 3 | 13 | 6 | 25 | 7616-94-6 |
| Perfluoroisobutylene | NA | NA | 0.01 | 0.082 | 382-21-8 |
| Perlite | NA | 10 | NA | NA | 93763-70-3 |
| Phenol | 5 | 19 | NA | NA | 108-95-2 |
| Phenothiazine | NA | 5 | NA | NA | 92-84-2 |
| Phenylenediamine | NA | 0.1 | NA | NA | 106-50-3 |
| Phenyl ether | 1 | 7 | 2 | 14 | 101-84-8 |
| Phenyl glycidyl ether (PGE) | 0.1 | 0.6 | NA | NA | 122-60-1 |
| Phenylhydrazine | 0.1 | 0.44 | NA | NA | 100-63-0 |
| Phenyl mercaptan | 0.5 | 2.3 | NA | NA | 108-98-5 |
| Phenylphosphine | NA | NA | 0.05 | 0.23 | 638-21-1 |
| Phorate | NA | 0.05 | NA | 0.2 | 298-02-2 |
| Phosgene | 0.1 | 0.4 | NA | NA | 75-44-5 |
| Phosphine | 0.3 | 0.42 | 1 | 1.4 | 7803-51-2 |
| Phosphoric acid | NA | 1 | NA | 3 | 7664-38-2 |
| Phosphorus | 0.02 | 0.1 | NA | NA | 12185-10-3 |
| Phosphorus oxychloride | 0.1 | 0.63 | NA | NA | 10025-87-3 |
| Phosphorus pentachloride | 0.1 | 0.85 | NA | NA | 10026-13-8 |
| Phosphorus pentasulfide | NA | 1 | NA | 3 | 1314-80-3 |
| Phosphorus trichloride | 0.2 | 1.1 | 0.5 | 2.8 | 2/12/7719 |
| Phthalic anhydride | 1 | 6.1 | NA | NA | 85-44-9 |
| m-Phthalodinitrile | NA | 5 | NA | NA | 626-17-5 |
| Picloram | NA | 10 | NA | NA | 1/2/1918 |
| Picric acid (2,4,6-Trinitrophenol) | NA | 0.1 | NA | NA | 88-89-1 |
| Pindone (2-Pivalyl-1,3-indandione) | NA | 0.1 | NA | NA | 83-26-1 |
| Piperazine dihydrochloride | NA | 5 | NA | NA | 142-64-3 |
| Platinum, Metal | NA | 1 | NA | NA | 4/6/7440 |
| Platinum, Soluble salts, as Pt | NA | 0.002 | NA | NA | 4/6/7440 |
| Portland cement | NA | 10 | NA | NA | 65997-15-1 |
| Potassium cyanide | NA | NA | NA | 5 | 151-50-8 |
| Potassium hydroxide | NA | NA | NA | 2 | 1310-58-3 |
| Propargyl alcohol | 1 | 2.3 | NA | NA | 107-19-7 |
| β-Propiolactone | 0.5 | 1.5 | NA | NA | 57-57-8 |
| Propionic acid | 10 | 30 | NA | NA | 79-09-4 |
| Propoxur | NA | 0.5 | NA | NA | 114-26-1 |
| n-Propyl acetate | 200 | 835 | 250 | 1040 | 109-60-4 |
| n-Propyl alcohol | 200 | 492 | 250 | 614 | 71-23-8 |
| Propylene dichloride, (1,2-Dichloropropane) | 75 | 347 | 110 | 508 | 78-87-5 |
| Propylene glycol dinitrate | 0.05 | 0.34 | NA | NA | 6423-43-4 |
| Propylene glycol monomethyl ether | 100 | 369 | 150 | 553 | 107-98-2 |
| Propylene imine | 2 | 4.7 | NA | NA | 75-55-8 |
| Propylene oxide (1,2-Epoxypropane) | 20 | 48 | NA | NA | 75-56-9 |
| n-Propyl nitrate | 25 | 107 | 40 | 172 | 627-13-4 |
| Pyrethrum | NA | 5 | NA | NA | 8003-34-7 |
| Pyridine | 5 | 16 | NA | NA | 110-86-1 |
| Quinone | 0.1 | 0.44 | NA | NA | 106-51-4 |
| Resorcinol | 10 | 45 | 20 | 90 | 108-46-3 |
| Rhodium, Metal | NA | 1 | NA | NA | 7440-16-6 |
| Rhodium, Insoluble compounds, as Rh | NA | 1 | NA | NA | 7440-16-6 |
| Rhodium, Soluble compounds, as Rh | NA | 0.01 | NA | NA | 7440-16-6 |
| Ronnel | NA | 10 | NA | NA | 299-84-3 |
| Rotenone | NA | 5 | NA | NA | 83-79-4 |
| Rouge | NA | 10 | NA | NA | 1309-37-1 |
| Selenium and compounds, as Se | NA | 0.2 | NA | NA | 7782-49-2 |
| Selenium hexafluoride | 0.05 | 0.16 | NA | NA | 7783-79-1 |
| Sesone | NA | 10 | NA | NA | 136-78-7 |
| Silica-Amorphous, Diatomaceous earth (uncalcined) | NA | 10 | NA | NA | 7631-86-9 |
| Silica-Amorphous, Precipitated silica | NA | 10 | NA | NA | 7631-86-9 |
| Silica, fume, respirable dust | NA | 2 | NA | NA | 7631-86-9 |
| Silica, fused, respirable dust | NA | 0.1 | NA | NA | 7631-86-9 |
| Silica gel | NA | 10 | NA | NA | 112926-00-8 |
| Silica-Crystalline, Cristobalite, respirable dust | NA | 0.05 | NA | NA | 14464-46-1 |
| Silica-Crystalline, Quartz, respirable dust | NA | 0.1 | NA | NA | 14808-60-7 |
| Silica-Crystalline, Tridymite, respirable dust | NA | 0.05 | NA | NA | 15468-32-3 |
| Silica-Crystalline, Tripoli, respirable dust | NA | 0.1 | NA | NA | 1317-95-9 |
| Silicon | NA | 10 | NA | NA | 7440-21-3 |
| Silicon carbide | NA | 10 | NA | NA | 409-21-2 |
| Silicon tetrahydride | 5 | 6.6 | NA | NA | 7803-62-5 |
| Silver, Metal | NA | 0.1 | NA | NA | 7440-22-4 |
| Silver, Soluble compounds, as Ag | NA | 0.01 | NA | NA | |
| Soapstone, Respirable dust | NA | 3 | NA | NA | 14807-96-6 |
| Soapstone, Total dust | NA | 6 | NA | NA | 14807-96-6 |
| Sodium azide as Hydrazoic acid | NA | NA | NA | 0.29 | 26628-22-8 |
| vapour | NA | NA | 0.11 | NA | 26628-22-8 |
| Sodium bisulfite | NA | 5 | NA | NA | 7631-90-5 |
| Sodium cyanide | NA | NA | NA | 5 | 143-33-9 |
| Sodium fluoroacetate | NA | 0.05 | NA | NA | 62-74-8 |
| Sodium hydroxide | NA | NA | NA | 2 | 1310-73-2 |
| Sodium metabisulfite | NA | 5 | NA | NA | 7681-57-4 |
| Starch | NA | 10 | NA | NA | 9005-25-8 |
| Stearates | NA | 10 | NA | NA | 57-11-4; 557-04-0; 557-05-1; 822-16-2 |
| Stibine | 0.1 | 0.51 | NA | NA | 7803-52-3 |
| Stoddard solvent | 100 | 525 | NA | NA | 8052-41-3 |
| Strontium chromate | NA | 0.0005 | NA | NA | 2/6/7789 |
| Strychnine | NA | 0.15 | NA | NA | 57-24-9 |
| Styrene, monomer (Phenylethylene, vinyl benzene) | 50 | 213 | 100 | 426 | 100-42-5 |
| Subtilisins | NA | NA | NA | 6.0E-5 | 1395-21-7; 9014-01-1 |
| Sucrose | NA | 10 | NA | NA | 57-50-1 |
| Sulfometuron methyl | NA | 5 | NA | NA | 74222-97-2 |
| Sulfotep | NA | 0.2 | NA | NA | 3689-24-5 |
| Sulfur dioxide | 2 | 5.2 | 5 | 13 | 5/9/7446 |
| Sulfur hexafluoride | 1000 | 5970 | NA | NA | 2551-62-4 |
| Sulfuric acid | NA | 1 | NA | 3 | 7664-93-9 |
| Sulfur monochloride | NA | NA | 1 | 5.5 | 10025-67-9 |
| Sulfur pentafluoride | NA | NA | 0.01 | 0.1 | 5714-22-7 |
| Sulfur tetrafluoride | NA | NA | 0.1 | 0.44 | 7783-60-0 |
| Sulfuryl fluoride | 5 | 21 | 10 | 42 | 2699-79-8 |
| Sulprofos | NA | 1 | NA | NA | 35400-43-2 |
| Talc | NA | 2 | NA | NA | 14807-96-6 |
| Tantalum, metal and oxide, as Ta | NA | 5 | NA | NA | 7440-25-7 |
| Tellurium and compounds, as Te | NA | 0.1 | NA | NA | 13494-80-9 |
| Tellurium hexafluoride | 0.02 | 0.1 | NA | NA | 7783-80-4 |
| Temephos | NA | 10 | NA | NA | 3383-96-8 |
| Terephthalic acid | NA | 10 | NA | NA | 100-21-0 |
| TEPP | 0.004 | 0.047 | NA | NA | 107-49-3 |
| Terphenyls | NA | NA | 0.53 | 5 | 26140-60-3; 92-06-8; 84-15-1; 92-94-4 |
| 1,1,1,2-Tetrachloro-2,2-difluoroethane | 500 | 4170 | NA | NA | 76-11-9 |
| 1,1,2,2-Tetrachloro-1,2-difluoroethane | 500 | 4170 | NA | NA | 76-12-0 |
| 1,1,2,2-Tetrachloroethane | 1 | 6.9 | NA | NA | 79-34-5 |
| Tetrachloronaphthalene | NA | 2 | NA | NA | 127-18-4 |
| Tetraethyl lead, as Pb | NA | 0.1 | NA | NA | 78-00-2 |
| Tetrahydrofuran | 200 | 590 | 250 | 737 | 109-99-9 |
| Tetramethyl lead, as Pb | NA | 0.15 | NA | NA | 75-74-1 |
| Tetramethyl succinonitrile | 0.5 | 2.8 | NA | NA | 3333-52-6 |
| Tetranitromethane | 0.005 | 0.04 | NA | NA | 509-14-8 |
| Tetrasodium pyrophosphate | NA | 5 | NA | NA | 7722-88-5 |
| Tetryl (2,4,6-Trinitrophenyl methylnitramine) | NA | 1.5 | NA | NA | 479-45-8 |
| Thallium, elemental and soluble compounds, as Ti | NA | 0.1 | NA | NA | 7440-28-0 |
| 4,4’-Thiobis (6-tert-butyl-m-cresol) | NA | 10 | NA | NA | 96-69-5 |
| Thioglycolic acid | 1 | 3.8 | NA | NA | 68-11-1 |
| Thioyl chloride | NA | NA | 1 | 4.9 | 7/9/7719 |
| Thiram | NA | 1 | NA | NA | 137-26-8 |
| Tin, Metal | NA | 2 | NA | NA | 7440-31-5 |
| Tin, Oxide inorganic compounds, as Sn | NA | 2 | NA | NA | |
| Tin, Organic compounds, as Sn | NA | 0.1 | NA | 0.2 | |
| Titanium dioxide | NA | 10 | NA | NA | 13463-67-7 |
| Toluene (Toluol) | 50 | 188 | NA | NA | 108-88-3 |
| Toluene-2,4-diisocyanate (TDI) | 0.005 | 0.036 | 0.02 | 0.14 | 584-84-9 |
| Toluidine | 2 | 8.8 | NA | NA | 108-44-1; 95-53-4; 106-49-0 |
| Tributyl phosphate | 0.2 | 2.2 | NA | NA | 126-73-8 |
| Trichloroacetic acid | 1 | 6.7 | NA | NA | 76-03-9 |
| 1,2,4-Trichlorobenzene | NA | NA | 5 | 37 | 120-82-1 |
| 1,1,1-Trichloroethane (Methyl chloroform) | 350 | 1910 | 450 | 2460 | 71-55-6 |
| 1,1,2-Trichloroethane | 10 | 55 | NA | NA | 79-00-5 |
| Trichloroethylene | 50 | 269 | 100 | 537 | 79-01-6 |
| Trichlorofluoromethane | NA | NA | 1000 | 5620 | 75-69-4 |
| Trichloronaphthalene | NA | 5 | NA | NA | 1321-65-9 |
| 1,2,3-Trichloropropane | 10 | 60 | NA | NA | 96-18-4 |
| 1,1,2-Trichloro-1,2,2-trifluoroethane | 1000 | 7670 | 1250 | 9590 | 76-13-1 |
| Triethanolamine | NA | 5 | NA | NA | 102-71-6 |
| Triethylamine | 1 | 4.1 | 5 | 20.7 | 121-44-8 |
| Trifluorobromomethane | 1000 | 6090 | NA | NA | 75-63-8 |
| Trimellitic anhydride | NA | NA | NA | 0.04 | 552-30-7 |
| Trimethylamine | 5 | 12 | 15 | 36 | 75-50-3 |
| Trimethyl benzene | 25 | 123 | NA | NA | 95-63-6; 526-73-8; 108-67-8; 25551-13-7 |
| Trimethyl phosphite | 2 | 10 | NA | NA | 121-45-9 |
| 2,4,6-Trinitrotoluene (TNT) | NA | 0.5 | NA | NA | 118-96-7 |
| Triorthocresyl phosphate | NA | 0.1 | NA | NA | 78-30-8 |
| Triphenyl amine | NA | 5 | NA | NA | 603-34-9 |
| Triphenyl phosphate | NA | 3 | NA | NA | 115-86-6 |
| Tungsten, as W, Insoluble compounds | NA | 5 | NA | 10 | 7440-33-7 |
| Tungsten, as W, Soluble compounds | NA | 1 | NA | 3 | 7440-33-7 |
| Turpentine | 100 | 566 | NA | NA | 8006-64-2 |
| Uranium, Soluble & Insoluble compounds, as U | NA | 0.2 | NA | 0.6 | 7440-61-1 |
| n-Valeraldehyde | 50 | 176 | NA | NA | 110-62-3 |
| Vanadium pentoxide Respirable dust or fume | NA | 0.05 | NA | NA | 1314-62-1 |
| Vegetable oil mists | NA | 10 | NA | NA | 68956-68-3 |
| Vinyl acetate | 10 | 35 | 15 | 53 | 108-05-4 |
| Vinyl bromide | 5 | 22 | NA | NA | 593-60-2 |
| Vinyl chloride (Chloroethylene) | 5 | 13 | NA | NA | 75-01-4 |
| 4-Vinyl cyclohexene | 0.1 | 0.4 | NA | NA | 100-40-3 |
| Vinyl cyclohexene dioxide | 10 | 57 | NA | NA | 106-87-6 |
| Vinylidene chloride (1,1-Dichloroethylene) | 5 | 20 | 20 | 79 | 75-35-4 |
| Vinyl toluene | 50 | 242 | 100 | 483 | 25013-15-4 |
| Warfarin | NA | 0.1 | NA | NA | 81-81-2 |
| Welding fumes | NA | 5 | NA | NA | |
| Wood dust, Hard wood | NA | 1 | NA | NA | |
| Wood dust, Soft wood | NA | 5 | NA | 10 | |
| Xylene | 100 | 434 | 150 | 651 | 1330-20-7; 95-47-6; 106-42-3; 108-38-3 |
| m-Xylene α;, α;1-diamine | NA | NA | NA | 0.1 | 1477-55-0 |
| Xylidine (dimethylaminobenzene) | 0.5 | 2.5 | NA | NA | 1300-73-8 |
| Yttrium metal and compounds, as Y | NA | 1 | NA | NA | 7440-65-5 |
| Zinc chloride fume | NA | 1 | NA | 2 | 7646-85-7 |
| Zinc chromates, as Cr | NA | 0.01 | NA | NA | 13530-65-9 |
| Zinc oxide, Fume | NA | 5 | NA | 10 | 1314-13-2 |
| Zinc oxide, Dust | NA | 10 | NA | NA | 1314-13-2 |
| Zirconium and compounds, as Zr | NA | 5 | NA | 10 | 7440-67-7 |
How to interpret PEL values
PEL values are exposure limits, not a complete risk assessment.
A substance may have a long-term PEL, a short-term PEL, both, or a limit expressed in a unit specific to that substance. Professional judgement is needed when interpreting exposure results.
Long-term PEL
A long-term PEL is normally used to evaluate average exposure over a full working shift. It is relevant for routine exposure monitoring, compliance assessment and evaluation of chronic exposure risk.
Short-term PEL
A short-term PEL is used to evaluate short-duration exposure peaks. It is especially important for irritants, acutely toxic substances or tasks with brief but high exposure potential.
Common use cases
- Reviewing SDS information against Singapore regulatory exposure limits.
- Planning occupational hygiene air monitoring programmes.
- Checking whether a chemical is listed as a toxic substance under the First Schedule.
- Supporting workplace health risk assessments and control reviews.
- Preparing for audits, inspections or workplace exposure investigations.
Limitations to note
- PEL values do not remove the need to control exposure as low as reasonably practicable.
- Mixture effects, skin absorption, sensitisation and task variability may require additional assessment.
- Sampling method, sampling duration, analytical method and detection limits must be selected carefully.
- Some substances may require specialist interpretation due to notation, unit, form or compound-specific listing.
- Regulatory sources should be checked for the latest official version before formal compliance decisions.
When to seek professional support
IEH can support exposure monitoring, interpretation and control recommendations.
If workers may be exposed to chemicals, dusts, fumes, vapours, gases or other airborne contaminants, a professional occupational hygiene assessment can help determine the actual exposure profile and appropriate control measures.
Exposure monitoring
Personal and area sampling for airborne contaminants, with appropriate sampling strategy, instruments and analytical methods.
Health risk assessment
Structured assessment of chemical hazards, exposure pathways, existing controls, worker groups and risk priorities.
Control recommendations
Practical recommendations covering substitution, engineering control, ventilation, administrative control and PPE programmes.
Need help interpreting exposure limits or planning monitoring?
IEH provides occupational hygiene consultancy, workplace exposure assessment, air monitoring and practical control recommendations for organisations across different industries.