It is used to absorb extra water and maintain moisture in certain medicines, cosmetics, or food products. It is a solvent for food colors and flavors, and in the paint and plastics industries. Propylene glycol is also used to create artificial smoke or fog used in fire-fighting training and in theatrical productions.
Propylene glycol acts as a humectant at a low concentration level. It secures the water and takes it to the outer layer of your skin. Hence, the cosmetics products which have Propylene Glycol are good for skin hydration and to resolve your skin dryness and dull appearance.