Petrol, which is also known as gasoline, is a carbon-based fuel mixture that is composed of over 150 individual chemicals. The primary ingredient in petrol is processed crude oil, but some of its other chief constituents are benzene, toluene, ethyl benzene and xylene. Additionally, lubricants, anti-icing chemicals and anti-rusting compounds are also present in most petrol. Different petrol-producing companies produce different proprietary blends.
Ethanol and lead are two other important constituents of some petrol. Ethanol is an alcohol made from corn, which can be added to reduce the amount of pollution produced and increase the efficiency of engines. Until the early 1980s, lead was a common additive for petrol. Manufacturers incorporated the lead to reduce engine knock. However, as the health effects of lead became better understood, regulations were put into place that forced manufacturers to produce lead-free varieties.
It has been determined that inhaling gasoline is very harmful and potentially lethal to humans. The chronic exposure to low-doses of gasoline, such as by breathing polluted air or drinking polluted water, damages the lungs and nervous system. Additionally, while no evidence demonstrates that gasoline is a carcinogen, some of its constituents, such as benzene, are associated with an increased risk of leukemia.