Peg-20 (inci)

"PEG" is the acronym for the thermoplastic "polyethylene glycol". Polyethylene glycols (syn. to macrogol) are chemically inert, water-soluble and non-toxic polymers (macromolecule consisting of many low-molecular monomers - basic building blocks) of ethylene oxide (-CH2-CH2-O-)n-. Chemically, they are polyethers. The number 20 after "PEG-" (so-called code number) indicates the average number of ethylene oxide units, in this case 20 molecular units. The consistency of PEG derivatives becomes increasingly solid as the degree of polymerization increases. PEGs with an average molecular weight of up to 600 kg/mol are liquid, up to 1000 kg/mol waxy and from 4000 kg/mol solid, waxy.

PEG-20 is used in cosmetic formulations. The substance acts as moisturizer (is able to increase the water content of the skin) and as solvent (is able to dissolve or dilute substances without causing chemical reactions between the dissolved substance and the solvent).

1. Ammon HPT et al (2014) Hunnius Pharmaceutical Dictionary 11th Edition Walter de Gruyter Berlin-New York pp. 1437-1438