Toluene, formerly known as toluol, is a colourless, 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.
Toluene is widely used as an industrial feedstock and as a solvent. Like other solvents, toluene is sometimes also used as an inhalant drug for its intoxicating properties; however, inhaling toluene has potential to cause severe neurological harm.Toluene is an important organic solvent.