Toluene is a colorless organic liquid solvent widely used in the paint, lacquer, and resin industries; as a thinner for inks, perfumes, and dyes; as a gasoline additive; and in the manufacture of a number of chemicals, explosives, dyes, and other organic compounds. It can be absorbed through the skin or via inhalation, with target sites of liver, kidney, and blood. Inhalation of airborne toluene is the main source of human exposure, and both occupational and inhalational abuse scenarios exist with the chemical. In the laboratory, toluene has been developmentally toxic by the inhalational route in the rat, mouse, and hamster, but was not in the rabbit under the conditions employed. In the human, chronic inhalation abuse of toluene during pregnancy have been associated with teratogenicity and other developmental toxicity in a number of case reports. Toluene is one of the smaller-sized human developmental toxicants. The structure of toluene contains no heteroatoms and therefore is incapable of hydrogen bonding.