Polypropylene Glycol Good Disolvente No known benefits Polypropylene Glycol description Also known by the acronym PPG, polypropylene glycol is a polymer, or large molecule, of propylene glycol. Like propylene glycol, it is used as a humectant and a delivery agent in cosmetics. Despite reports that it can be a skin sensitizer, researchers have found that it does not present a health risk for people when used in cosmetics. Related ingredients: Propylene Glycol