Xylenes

**Definition:** A family of isomeric, colorless aromatic hydrocarbon liquids, that contain the general formula C6H4(CH3)2. They are produced by the destructive distillation of coal or by the catalytic reforming of petroleum naphthenic fractions. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

**Tree numbers:** - D02.455.426.559.389.948

**Synonyms:** - Dimethylbenzenes