What it is
PEG-90 is a water-soluble polyether built from repeating ethylene oxide units, with 90 indicating a relatively long average chain. PEGs of this size are typically waxy solids and serve as humectants, solvents, and texture or viscosity modifiers rather than primary surfactants. In sunscreens and similar products it can help carry water-soluble ingredients, support stability, and adjust feel.
Safety & warnings
High-molecular-weight polyethylene glycols have a long history of safe cosmetic use and are non-comedogenic. As with all PEGs, responsible manufacturing controls trace 1,4-dioxane. It is not a fragrance allergen.
Origin & sourcing
Synthetic. It is made by polymerizing ethylene oxide to the target average chain length.
Questions everyone asks
What does the 90 in PEG-90 mean?
It refers to the average number of ethylene oxide units in the polymer chain, which makes it a higher-molecular-weight, waxier PEG.
What role does PEG-90 play in a formula?
It typically acts as a humectant, solvent, and texture or viscosity modifier rather than as a surfactant.