Polyethylene Glycol

Polyethylene glycol (PEG), a related agent found in most skin cleansers, is a caustic used to dissolve grease and is the same substance found in oven cleaners and on green wood to prevent it cracking and shrinking. Propylene Glycol, Butylene Glycol, and Polyethylene Glycol (PEG) are used as humectants, solubilizers, stabilizers, and to help increase the absorption of a ingredients of a product into the skin.

PEG has the ability prevent a product from becoming liquid at higher temperatures, or from solidifying at lower temperatures. As a way of putting this property of PEG into perspective, antifreeze is pure propylene glycol, although the concentration of PEG in skincare products is much less, it is absorbed by the skin so it is better to err on the side of caution and avoid products containing polyethylene glycol (PEG)