Description: Propylene glycol is a helper ingredient that improves the freeze-thaw stability of products. It’s also a solvent, humectant and to some extent a penetration enhancer. It has a bad reputation among natural cosmetics advocates but cosmetic scientists and toxicology experts do not agree. It can be a skin irritant used in high concentration, but in skincare formulations it’s used in very low concentrations (at our Organic Cleansing Foam it’s lees then 2%).