The scientific name of propylene glycol is "1,2-propanediol". Chemical formula CH3CHOHCH2OH. The molecular weight is 76.10. There is a chiral carbon atom in the molecule. The racemate is a viscous liquid that is easily hygroscopic and slightly spicy. The specific gravity is 1.036 (25/4°C), and the freezing point is -59°C. The boiling point is 188.2°C, 83.2°C (1,333 Pa). Chemicalbook is miscible in water, acetone, ethyl acetate and chloroform, and soluble in ether. It is soluble in many essential oils, but it is not miscible with petroleum ether, paraffin wax and grease. It is more stable to heat and light, and more stable at low temperatures. The boiling point of the L-body is 187～189℃, and the specific rotation [α]D20-15.0°. Propylene glycol can be oxidized into propionaldehyde, lactic acid, pyruvic acid and acetic acid at high temperature.

Propylene glycol can be used as a humectant, softener, solvent, etc. in cosmetics.