Toluene is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a CH3 group attached to a phenyl group. As such, its IUPAC systematic name is methylbenzene. It is an aromatic hydrocarbon.
As the solvent in some types of paint thinner, contact cement and model airplane glue, toluene is sometimes used as a recreational inhalant and has the potential of causing severe neurological harm.
Toluene occurs naturally at low levels in crude oil and is a byproduct in the production of gasoline by a catalytic reformer or ethylene cracker; It is also a byproduct of the production of coke from coal. Final separation and purification is done by any of the distillation or solvent extraction processes used for BTX aromatics (benzene, toluene, and xylene isomers).