A chemical that is used widely by the chemical industry, and is also found in tobacco smoke, vehicle emissions, and gasoline fumes. Exposure to benzene may increase the risk of developing leukemia.

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. Exposure to this substance causes neurological symptoms and affects the bone marrow causing aplastic anemia, excessive bleeding and damage to the immune system. Benzene is a known human carcinogen and is linked to an increased risk of developing lymphatic and hematopoietic cancers, acute myelogenous leukemia, as well as chronic lymphocytic leukemia. (NCI05)

Toxic, volatile, flammable liquid hydrocarbon biproduct of coal distillation; structure consists of a closed hexagonal chain of six carbon atoms, each attached to a hydrogen atom and attached to each other by alternating single and double (resonating) bonds; in benzene derivatives, one or more of the hydrogen atoms are replaced by other atoms or radicals.