(C₆H₅CH₃) A highly volatile and water-soluble benzene derivative that is highly toxic to most forms of life. Its estimated lifespan in the atmosphere--with respect to a photochemical reaction with hydroxyl radical---is 60 hours and this hydrocarbon is eventually oxidized to carbon dioxide. Toluene is used in a variety of industries including the manufacture of TNT, pharmaceuticals, rubbers, and other benzene derivatives, and is also a fuel additive and a paint solvent. Toluene also reaches the atmosphere from natural sources such as coal tar, mineral oils, and forest fires.