This chemical profile record refers to common, commercial unleaded gasoline used for automotive purposes, unless otherwise specified.

Gasoline is a complex mixture of petroleum hydrocarbons. The composition of the hydrocarbons depends on factors such as the origin of the crude oil used for refining and refining conditions. In general, the hydrocarbon groups consist of chains containing 4 to 12 carbons, and are mostly paraffins (alkanes), isoparaffins (isoalkanes), cycloparaffins (cycloalkanes) and aromatics. n-Hexane (1.5-3.0%) and benzene (0.5-2.0%) are normally present.

In addition, trace or small amounts of additives and blending agents such as anti-knock compounds (MMT - methylcyclopentadienyl manganese tricarbonyl), anti-icing agents, anti-rust agents and metal deactivators can be found in gasoline.

The chemical and physical properties of gasoline are highly variable depending on the specific product. As well, the hazards of gasoline are affected by the proportion of individual components. For example, gasoline containing a significant proportion of n-hexane may have toxic effects attributable to n-hexane. For information on specific components in gasoline consult the manufacturer or the appropriate chemical profile record(s) where possible.