Occupational Exposure Values - Compiled by ACGIH
(shown for reference only - verify latest values)
ACGIH Values - Benzene | C6H6
Threshold limit value (TLV): 0.5 ppm, 1.6 mg/m3 TWA; 2.5 ppm, 8 mg/m3 STEL
OSHA PELs - Benzene | C6H6
Permissible Exposure Limits: 1 ppm, 3 mg/m3 TWA; 5 ppm, 15 mg/m3 STEL
NIOSH RELs - Benzene | C6H6
Recommended Exposure Limit (REL): Not Available
Benzene is a clear, colorless, highly flammable and volatile, liquid aromatic hydrocarbon with a gasoline-like odor. Benzene is found in crude oils and as a by-product of oil-refining processes. In industry benzene is used as a solvent, as a chemical intermediate, and is used in the synthesis of numerous chemicals.
As benzene occurs naturally in crude petroleum at levels up to 4 g/l, human activities using petroleum lead to exposure. These activities include processing of petroleum products, coking of coal, production of toluene, xylene and other aromatic compounds, and use in industrial and consumer products, as a chemical intermediate and as a component of petrol (gasoline) and heating oils. The presence of benzene in petrol and as a widely used industrial solvent can result in significant occupational exposure and widespread emissions to the environment.
Benzene causes central nervous system damage acutely and is a known carcinogen.
Benzene is highly toxic and proper safeguards, including gas monitoring, are deemed critical to industrial health and safety programs.