Benzene (C6H6) is an aromatic hydrocarbon that was used an industrial solvent and as an additive in fossil-based fuels. The complex hydrocarbon used on Earth called gasoline was made of such components as benzene, ethylene, and acetylene. In 2371, it was among the hydrocarbons Harry Kim detected in the rust later determined to originate from a 1936 Ford truck. (VOY: "The 37's") Yalosians required ten percent of a room's atmosphere to be benzene, as well as sixty percent nitrogen and thirty percent hydrogen fluoride. (DS9: "Improbable Cause")