Ppg-1-ceteth-20 (inci)

PPG is the acronym for "polypropylene glycol", the polymer of propylene glycol (1,2-propanediol), a dihydric alcohol. The number after "PPG" indicates the average number of propylene glycol molecular units, for "PPG-1" 1 propylene glycol molecular unit. "ceteth-5" denotes the polyoxyethylene ether of the cetyl alcohol containing on average 5 units "-CH2-CH2-O- " (see e.g. laurethe as polyoxyethylene ether of lauryl alcohol; steareth as polyoxyethylene ether of stearyl alcohol, etc.).
PPG-1-ceteth-5 is used in cosmetic formulations; the substance acts as emollient (makes the skin smooth and supple).