Benzene is a colourless, liquid, flammable, aromatic hydrocarbon that is a component of petrol, or may result from incomplete combustion of fuels. Benzene, a natural component of crude oil, is emitted from a range of industrial and combustion sources. The major source of benzene is motor vehicles—both vehicle exhaust (contributing approximately 75% to 80% of emissions) and evaporative emissions (including evaporation losses from motor vehicles and evaporation losses during the handling, distribution and storage of petrol). Fuel quality standards imposing a benzene limit of 1% in petrol sold by 2006 should reduce benzene concentrations in the GMR.
