Ethylbenzene is an organic compound with the formula C₆H₅CH₂CH₃. It is a highly flammable, colorless liquid with an odor similar to that of gasoline. This monocyclic aromatic hydrocarbon is important in the petrochemical industry as an intermediate in the production of styrene, the precursor to polystyrene, a common plastic material. In 2012, more than 99% of ethylbenzene produced was consumed in the production of styrene. Ethylbenzene is also used to make other chemicals, in fuel, and as a solvent in inks, rubber adhesives, varnishes, and paints. Ethylbenzene exposure can be determined by testing for the breakdown products in urine.