What it is
PEG-6 is a polyethylene glycol containing an average of about six ethylene oxide units, making it a water-soluble liquid. In formulas it acts as a humectant that helps retain moisture and as a solvent and co-solvent that keeps other ingredients dissolved and the texture uniform. In sunscreens it contributes to a smooth, even base and can help carry or stabilize other components.
Safety & warnings
PEG-6 is widely used and generally well tolerated on intact skin. Polyethylene glycols can in theory contain trace impurities such as 1,4-dioxane or residual ethylene oxide from manufacturing, so cosmetic-grade material is purified to limit these. It is not a known fragrance allergen and is not considered comedogenic at typical use levels.
Origin & sourcing
Synthetic; produced by the controlled polymerization of ethylene oxide to a defined average chain length.
Questions everyone asks
What does the number 6 mean in PEG-6?
It indicates the average number of repeating ethylene oxide units in the polymer chain, which influences whether the PEG is liquid or waxy.
Is PEG-6 a moisturizer?
It works as a humectant, meaning it helps attract and hold water in a formula, but it is used mainly as a solvent and texture aid rather than as a standalone moisturizer.