Styrene (also vinyl benzene, ethenylbenzene, phenethylene, cinnamene, diarex HF 77, styrolene, styrol, styropol) is an organic compound. It is a colorless, oily, toxic, flammable organic liquid that occurs in plants, but is produced in industrial quantities from petroleum.

It is used to make plastics such as polystyrene, ABS, styrene-butadiene (SBS) rubber, styrene-butadiene latex and unsaturated polyesters. It evaporates easily and has a sweet smell. It often contains other chemicals that give it a sharp, unpleasant smell.

It dissolves in some liquids but doesn’t dissolve easily in water. Billions of pounds are produced each year to make products such as rubber, plastic, insulation, fiberglass, pipes, automobile parts, food containers, and carpet backing.

Most of these products contain styrene linked together in a long chain (polystyrene) as well as unlinked styrene. Low levels of styrene also occur naturally in a variety of foods such as fruits, vegetables, nuts, beverages, and meats.

Its molecular formula is C8H8, or structurally C6H5C2H3. It is synthesized by heating ethyl benzene (EB) with steam.