"Mixed xylene" is a commercial mixture of three different chemical forms (isomers) of xylene. This mixture is a clear, colourless liquid with a characteristic aromatic odour. Xylene is a FLAMMABLE LIQUID AND VAPOUR. The liquid can accumulate static charge when flowing through a hose or when agitated and stirred. The vapour is heavier than air and may spread long distances making distant ignition and flashback possible. The liquid can float on water and may travel to distant locations and/or spread fire. Xylene can decompose at high temperatures to form toxic gases. Closed containers may rupture and explode in heat of fire. Xylene may cause lung injury but the effects may be delayed. Xylene is a central nervous system depressant. This means high vapour concentrations may cause headache, nausea, dizziness, drowsiness, confusion and incoordination. It can also cause skin irritation and is an aspiration hazard. Swallowing or vomiting of the liquid may result in aspiration into the lungs. This hazard, aspirating or drawing fluids into the lungs when a person vomits, is common among hydrocarbon solvents like xylene and other solvents derived from petroleum. Xylene is also a POSSIBLE REPRODUCTIVE HAZARD - it may cause fetotoxicity, based on animal information.

Commercial xylene is produced from petroleum and coal tar. The mixture of xylene isomers also occurs naturally in small quantities in petroleum stocks, coal tar and natural gas, and is formed during forest fires. Xylene is used as a solvent in paint, printing, rubber and leather industries; as a solvent for gums and resins, rubber, castor and linseed oils and dibenzylcellulose; as a constituent of paints, lacquers, varnishes, inks, dyes, adhesives and cleaning fluids; as a carrier in production of epoxy resins; as a degreaser and cleaning agent; as a constituent of motor and aviation fuels; in chemical synthesis; and in the manufacture of quartz crystal oscillators, perfumes and insect repellents.

There are three chemical forms (isomers) of xylene, ortho-xylene, meta-xylene and para-xylene. Commercial xylene, generally referred to as xylene (mixed isomers) or technical xylene, is a mixture of widely varying proportions of these three isomers (with m-xylene predominating), together with ethylbenzene (6-20%) and smaller amounts of toluene, trimethylbenzene, phenol, thiophene, pyridine and non-aromatic hydrocarbons. The information presented in this Chemical profile record is given for xylene (mixed isomers) where possible.

Xylene is also known as dimethylbenzene, methyltoluene, xylol, xylene (non-specific name).

Its CAS Registry Number is 1330-20-7. This number is assigned by the Chemical Abstracts Service (CAS) in the United States and is used as a unique identifier number world-wide.