Which Chemicals Are in Gasoline?

Gasoline ingredients vary based on governmental regulations, but in general, gas contains about 150 chemicals. These chemicals serve a variety of purposes from improving engine performance to reducing pollution. BTEX compounds (benzene, toluene, ethylbenzene and xylene) in fuel gives it its characteristic odor and flammability. Methyl tertiary-butyl ether (MTBE) is an additive that helps reduce toxic fumes. Other chemicals commonly found in fuel include: naphthenes, olefins, oxygenators, and parafins.

More gas facts:

• Gasoline is produced by distilling crude oil, but because the resulting material cannot be used in engines (it's octane rating is too low) a variety of other chemicals or additives are included.
• Ethanol fuel is a type of gasoline that includes ethyl alcohol. Derived from corn, ethanol helps improve fuel efficiency and reduce environmental impact.


• Tetraethyl lead was a common and inexpensive gas additive that improved engine performance. Because of associated health and environmental concerns, however, leaded gasoline was banned in the US in 1996.