What is "propylene glycol"

n. (context chemistry English) 1,2-propanediol, CH₃CH(OH)CH₂OH, a thick oily liquid, used as an antifreeze and in many industrial applications

n. a sweet colorless, viscous, hygroscopic liquid used as an antifreeze and in brake fluid and also as a humectant in cosmetics and personal care items although it can be absorbed through the skin with harmful effects [syn: propanediol]

Propylene glycol, also called propane-1,2-diol, is an organic compound with the chemical formula CHO. It is a viscous colorless liquid which is nearly odorless but possesses a faintly sweet taste. Chemically it is classed as a diol and is miscible with a broad range of solvents, including water, acetone, and chloroform.

It is produced on a large scale and is primarily used in the production of polymers but also sees use in food processing as the E-number E1520, and as a process fluid in low temperature heat exchange applications.

The compound is sometimes called α-propylene glycol to distinguish it from the isomer propane-1,3-diol (β-propylene glycol).