Propylene Glycol (PG)

Propylene glycol, also called propane-1,2-diol, is a synthetic organic compound with the chemical formula C3H8O2. 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).