Propylene glycol, also called propane-1,2-diol, is an organic compound with the chemical formula C3H8O2. It is a viscous colourless liquid which is nearly odourless 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. The compound is sometimes called α-propylene glycol to distinguish it from the isomer propane-1,3-diol (β-propylene glycol).