Hexane

Hexane is a simple aliphatic hydrocarbon with the chemical formula C6H14. It is a colorless, highly flammable liquid that occurs in various fractions of petroleum and other hydrocarbon streams. It is produced primarily during the refining of crude oil and processing of natural gas, and is often separated as part of light hydrocarbon fractions where it is sold as a solvent or chemical feedstock.

There are five structural isomers of hexane: n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, and 2,3-dimethylbutane. These isomers share the same molecular formula but differ in the arrangement of their carbon skeletons, which influences properties such as volatility and solvency.

Uses of hexane are largely solvent-related. It is employed in the extraction of edible oils from seeds and vegetables, in degreasing and cleaning metal parts, and as a component in various coatings, inks, adhesives, and rubber cements. It is also used as a nonpolar solvent in laboratory chromatography and as a component of some gasoline blends.

Safety and environmental considerations are important for hexane. It is flammable, and its vapors can form explosive mixtures with air. Chronic exposure, particularly to n-hexane, can cause nerve damage and other neurological effects; acute exposure can irritate the eyes, skin, and respiratory tract. Hexane is a volatile organic compound and contributes to air pollution; spills should be contained to minimize soil and water contamination. Workplace controls and proper ventilation reduce the risk of exposure.