The name'glycereth- is used to describe a PEG (polyethylene glycol) ester of glycerol. The number after the name "glycereth-" indicates the average number of molecular units (-CH2-CH2-O-), e.g. glycereth-7, glycereth-12, glycereth-31, etc. The consistency (liquid to solid) and chemical-physical properties of the glycereth-derivative depend on the respective number of molecular units.
Glycereth-17 phosphate is used in cosmetic formulations as emulsifier (changes the interfacial tension of liquids such as water and oil so that they can be mixed together) and chelator.
The allergological relevance of the individual glycereth derivatives is not known.