A Permissible Exposure Limit (PEL) is a Time Weighted Average (TWA) concentration that must not be exceeded during any 8-hour work shift of a 40-hour work week. A Short Term Exposure Limit (STEL) is measured over a 15-minute period. A "ceiling" concentration must not be exceeded during any part of the workday; if instantaneous monitoring is not feasible, the ceiling must be assessed as a 15-minute TWA exposure. The "skin" designation indicates the potential for dermal absorption; skin exposure should be prevented as necessary through the use of good work practices and gloves, goggles, and other appropriate equipment.
| Chemical Name | PEL (ppm) | PEL (mg/m3) | Comment |
| Acetaldehyde | 200 | 360 | |
| Acetic acid | 10 | 25 | |
| Acetone | 1000 | 2400 | |
| Acetonitrile | 40 | 70 | |
| STEL | 60 | 105 | |
| Acrolein | 0.1 | 0.25 | |
| STEL | 0.3 | 0.69 | |
| Acrylamide | 0.3 | skin | |
| Acrylonitrile | 2 | ||
| Ammonia (anhydrous) | 35 | 27 | |
| Ammonium hydroxide | 35 | 27 | |
| Aniline | 5 | 19 | skin |
| Arsine | 0.05 | 0.2 | |
| Benzene | 1 | 3.2 | |
| Boron trifluoride | 1 | 3 | ceiling |
| Bromine | 0.1 | ||
| Carbon disulfide | 4 | 12 | |
| STEL | 12 | 36 | skin |
| Carbon monoxide | 50 | 55 | |
| Carbon tetrachloride | 2 | 13 | |
| Chlorine | 1 | 3 | |
| Chloroform | 50 | 240 | ceiling |
| Chromium trioxide | 0.1 | ceiling | |
| Diazomethane | 0.2 | 0.4 | |
| Diborane | 0.1 | ||
| Dichloromethane | 500 | ||
| Diethyl ether | 400 | ||
| Dimethyl sulfate | 1 | 5 | skin |
| Dimethylformamide | 10 | 30 | skin |
| Dioxane | 100 | 360 | skin |
| Ethanol | 1000 | 1900 | |
| Ethyl acetate | 400 | 1400 | |
| Ethylene dibromide | 20 | 150 | |
| Ethylene oxide | 1 | 2 | |
| Fluorides (inorganic) | 2.5 | ||
| Fluorine | 0.1 | 0.2 | |
| Formaldehyde | 1 | 1.5 | |
| STEL | 2 | 2.5 | |
| Hexane | 500 | 1800 | |
| Hydrazine | 1 | 1.3 | skin |
| Hydrobromic acid | 3 | 10 | |
| Hydrochloric acid | 5 | 7 | ceiling |
| Hydrogen cyanide | 10 | 11 | skin |
| Hydrogen fluoride | 3 | ||
| Hydrofluoric acid | 3 | ||
| Hydrogen peroxide | 1 | 1.4 | |
| Hydrogen sulfide | 20 | 28 | ceiling |
| Iodine | 0.1 | 1 | ceiling |
| Lead | 0.05 | ||
| Mercury | 0.1 | ceiling | |
| Methanol | 200 | 260 | |
| Methyl ethyl ketone | 200 | 590 | |
| Methyl iodide | 5 | 28 | skin |
| Nickel carbonyl | 0.001 | 0.007 | |
| Nitric acid | 2 / 5 | ||
| Nitrogen dioxide | 5 / 9 - ceiling | ||
| Osmium tetroxide | 0.0002 | 0.002 | |
| Ozone | 0.1 | 0.2 | |
| Phenol | 5 | 19 | skin |
| Phosgene | 0.1 | 0.4 | |
| Phosphorus | 0.1 | ||
| Potassium hydroxide | 2 | ||
| Pyridine | 5 | 15 | |
| Silver | 0.01 | ||
| Sodium hydroxide | 2 | ||
| Sulfur dioxide | 5 | 13 | |
| Sulfuric acid | 1 | ||
| Tetrahydrofuran | 200 | 590 | |
| Toluene | 200 | 750 | |
| STEL | 150 | 560 | |
| Toluene diisocyanate | 0.02 | 0.14 | ceiling |
| Trimethyltin chloride | 0.1 | mg of tin |
