OSHA permissible exposure limits (PELs)
OSHA permissible exposure limits are legally enforceable airborne exposure limits for US workplaces, usually expressed as an 8-hour time-weighted average (TWA) in ppm or mg/m³. Many PELs date from 1971 and are less protective than NIOSH RELs or ACGIH TLVs, so compare all three on each chemical page.
108 chemicals in our database. Values are for the pure substance from public sources; check your supplier's SDS for your product.
See also: How to read exposure limits · What is a PEL?
| Chemical | CAS | OSHA PEL | Signal word |
|---|---|---|---|
| (+-)-2-Butanol | 78-92-2 | 150 ppm (450 mg/m³) | Warning |
| 1-Butanol | 71-36-3 | 100 ppm (300 mg/m³) | Danger |
| 1-Propanol | 71-23-8 | 200 ppm (500 mg/m³) | Danger |
| 1,1,1-Trichloroethane | 71-55-6 | 350 ppm (1900 mg/m³) | Warning |
| 1,2,4-Trimethylbenzene | 95-63-6 | none See Appendix G | Warning |
| 1,3-Butadiene | 106-99-0 | 1 ppm (2.21 mg/m³) | Danger |
| 2-Butoxyethanol | 111-76-2 | 50 ppm (240 mg/m³) | Danger |
| 2-Heptanone | 110-43-0 | 100 ppm (465 mg/m³) | Warning |
| 2-Pentanol | 6032-29-7 | TWA 100 ppm (360 mg/m3) See Appendix G | Warning |
| 2-Pentanone | 107-87-9 | 200 ppm (700 mg/m³) | Danger |
| 5-Methyl-2-hexanone | 110-12-3 | 100 ppm (475 mg/m³) | Warning |
| Acetic Acid | 64-19-7 | 10 ppm (25 mg/m³) | Danger |
| Acetone | 67-64-1 | 1000 ppm (2400 mg/m³) | Danger |
| Acetonitrile | 75-05-8 | 40 ppm (70 mg/m³) | Danger |
| Acetylene | 74-86-2 | none | Danger |
| Acrylamide | 79-06-1 | 0.3 mg/m³ | Danger |
| Acrylic Acid | 79-10-7 | none See Appendix G | Danger |
| Allyl Alcohol | 107-18-6 | 2 ppm (5 mg/m³) | Danger |
| Alpha-Methylstyrene | 98-83-9 | 100 ppm (480 mg/m³) | Warning |
| Ammonia | 7664-41-7 | 50 ppm (35 mg/m³) | Danger |
| Aniline | 62-53-3 | 5 ppm (19 mg/m³) | Danger |
| Anthracene | 120-12-7 | 0.2 mg/m³ as Coal tar pitch volatiles (benzene soluble fraction) | Danger |
| Arsenic | 7440-38-2 | 10 µg/m³ [5 µg/m³ Action Level] | Danger |
| Benzene | 71-43-2 | 1 ppm | Danger |
| Biphenyl | 92-52-4 | 0.2 ppm (1 mg/m³) | Warning |
| Borax (B4Na2O7.10H2O) | 1303-96-4 | none See Appendix G | Danger |
| Butane | 106-97-8 | none See Appendix G | Danger |
| Butyl Acetate | 123-86-4 | 150 ppm (710 mg/m³) | Warning |
| Cadmium | 7440-43-9 | 5 µg/m³ [2.5 µg/m³ Action Level] | Danger |
| Calcium Hydroxide | 1305-62-0 | 15 mg/m³ (total dust), 5 mg/m³ (respirable fraction) | Danger |
| Calcium Oxide | 1305-78-8 | 5 mg/m³ | Danger |
| Camphor | 76-22-2 | 2 mg/m³ | Danger |
| Carbon Dioxide | 124-38-9 | 5000 ppm (9000 mg/m³) | Warning |
| Carbon Monoxide | 630-08-0 | 50 ppm (55 mg/m³) | Danger |
| Chlorine | 7782-50-5 | 1 ppm (3 mg/m³) [Construction and Maritime Industries only] | Danger |
| Chloroform | 67-66-3 | 50 ppm (240 mg/m³) | Danger |
| Chromium Trioxide | 1333-82-0 | 0.005 [mg/m3], as Cr(VI) | Danger |
| Chrysene | 218-01-9 | 0.2 mg/m³ | Danger |
| Copper Sulfate | 7758-98-7 | 1.0 [mg/m3], as Cu | Warning |
| Cumene | 98-82-8 | 50 ppm (245 mg/m³) | Danger |
| Cyclohexane | 110-82-7 | 300 ppm (1050 mg/m³) | Danger |
| Cyclohexanol | 108-93-0 | 50 ppm (200 mg/m³) | Warning |
| Cyclohexanone | 108-94-1 | 50 ppm (200 mg/m³) | Warning |
| Diacetone Alcohol | 123-42-2 | 50 ppm (240 mg/m³) | Warning |
| Dichloromethane | 75-09-2 | 25 ppm [12.5 ppm Action Level] | Warning |
| Diethyl Ether | 60-29-7 | 400 ppm (1200 mg/m³) | Danger |
| Dimethylformamide | 68-12-2 | 10 ppm (30 mg/m³) | Danger |
| Diphenylmethane diisocyanate | 101-68-8 | 0.02 ppm (0.2 mg/m³) | Danger |
| Epichlorohydrin | 106-89-8 | 5 ppm (19 mg/m³) | Danger |
| Ethanol | 64-17-5 | 1000 ppm (1900 mg/m³) | Danger |
| Ethanolamine | 141-43-5 | 3 ppm (6 mg/m³) | Danger |
| Ethyl Acetate | 141-78-6 | 400 ppm (1400 mg/m³) | Danger |
| Ethyl ketone | 96-22-0 | none See Appendix G | Danger |
| Ethylbenzene | 100-41-4 | 100 ppm (435 mg/m³) | Danger |
| Ethylene Glycol | 107-21-1 | none See Appendix G | Warning |
| Ethylene Oxide | 75-21-8 | 1 ppm [0.5 ppm Action Level] | Danger |
| Formaldehyde | 50-00-0 | 0.75 ppm [0.5 ppm Action Level] | Danger |
| Furfuryl Alcohol | 98-00-0 | 50 ppm (200 mg/m³) | Danger |
| Glycerol | 56-81-5 | 15 mg/m³ (total dust), 5 mg/m³ (respirable) | — |
| Heptane | 142-82-5 | 500 ppm (2000 mg/m³) | Danger |
| Hexane | 110-54-3 | 500 ppm (1800 mg/m³) | Danger |
| Hydrochloric Acid | 7647-01-0 | 5 ppm (7 mg/m³) | Danger |
| Hydrofluoric Acid | 7664-39-3 | 3 ppm (2 mg/m³) | Danger |
| Hydrogen Peroxide | 7722-84-1 | 1 ppm (1.4 mg/m³) | Danger |
| Hydrogen Sulfide | 7783-06-4 | 20 ppm (C), 50 ppm (Peak) [10 min, once only, if no other measurable exposure occurs] | Danger |
| Isoamyl Alcohol | 123-51-3 | 100 ppm (360 mg/m³) | Danger |
| Isobutanol | 78-83-1 | 100 ppm (300 mg/m³) | Danger |
| Isophorone | 78-59-1 | 25 ppm (140 mg/m³) | Warning |
| Isopropanol | 67-63-0 | 400 ppm (980 mg/m³) | Danger |
| Lead | 7439-92-1 | 0.05 mg/m³ [0.03 mg/m³ Action Level] | Danger |
| M-Xylene | 108-38-3 | 100.0 [ppm] | Warning |
| Mercury | 7439-97-6 | 0.01 mg/m³ | Danger |
| Mesityl oxide | 141-79-7 | 25 ppm (100 mg/m³) | Warning |
| Mesitylene | 108-67-8 | none See Appendix G | Warning |
| Methanol | 67-56-1 | 200 ppm (260 mg/m³) | Danger |
| Methyl Ethyl Ketone | 78-93-3 | 200 ppm (590 mg/m³) | Danger |
| Methyl Isobutyl Ketone | 108-10-1 | 100 ppm (410 mg/m³) | Danger |
| Methyl Methacrylate | 80-62-6 | 100 ppm (410 mg/m³) | Danger |
| Naphthalene | 91-20-3 | 10 ppm (50 mg/m³) | Warning |
| Nitric Acid | 7697-37-2 | 2 ppm (5 mg/m³) | Danger |
| Nitrous Oxide | 10024-97-2 | none | Danger |
| O-Xylene | 95-47-6 | TWA 100 ppm (435 mg/m3) See Appendix G | Warning |
| Ozone | 10028-15-6 | 0.1 ppm (0.2 mg/m³) | Danger |
| P-Xylene | 106-42-3 | 100.0 [ppm] | Warning |
| Pentaerythritol | 115-77-5 | 15 mg/m³ (total dust), 5 mg/m³ (respirable fraction) | — |
| Phenanthrene | 85-01-8 | 0.2 mg/m³ as Coal tar pitch volatiles (benzene soluble fraction) | Warning |
| Phenol | 108-95-2 | 5 ppm (19mg/m³) | Danger |
| Phosphoric Acid | 7664-38-2 | 1 mg/m³ | Danger |
| Potassium Dichromate | 7778-50-9 | 0.005 [mg/m3], as Cr(VI) | Danger |
| Potassium Hydroxide | 1310-58-3 | none See Appendix G | Danger |
| Propane | 74-98-6 | 1000 ppm (1800 mg/m³) | Danger |
| Propargyl alcohol | 107-19-7 | 1 ppm | Danger |
| Propylene Oxide | 75-56-9 | 100 ppm (240 mg/m³) | Danger |
| Silver Nitrate | 7761-88-8 | 0.01 [mg/m3], as Ag | Danger |
| Sodium Cyanide | 143-33-9 | 5.0 [mg/m3], as CN | Danger |
| Sodium Hydroxide | 1310-73-2 | 2 mg/m³ | Danger |
| Sodium Pyrosulfite | 7681-57-4 | none See Appendix G | Danger |
| Styrene | 100-42-5 | 100 ppm | Danger |
| Sulfuric Acid | 7664-93-9 | 1 mg/m³ | Danger |
| tert-Butanol | 75-65-0 | 100 ppm (300 mg/m³) | Danger |
| Tetrachloroethylene | 127-18-4 | 100 ppm | Warning |
| Tetrahydrofuran | 109-99-9 | 200 ppm (590 mg/m³) | Danger |
| Titanium dioxide | 13463-67-7 | 15 mg/m³ (total dust) | Warning |
| Toluene | 108-88-3 | 200 ppm | Danger |
| Toluene 2,4-Diisocyanate | 584-84-9 | 0.02 ppm (0.14 mg/m³) | Danger |
| Trichloroethylene | 79-01-6 | 100 ppm | Danger |
| Vinyl Chloride | 75-01-4 | 1 ppm [0.5 ppm Action Level] | Danger |
| Zinc Oxide | 1314-13-2 | 5 mg/m³ | Warning |