What it is
A polyethylene glycol ether of hydrogenated castor oil, a waxy solid or viscous liquid produced by ethoxylation.
What it does
Surfactant, emulsifier, and solubiliser that disperses oils into water-based formulas.
Why it’s a concern
Ethoxylation (reaction with ethylene oxide) can leave residues of 1,4-dioxane and ethylene oxide, both classified by the US EPA as probable human carcinogens. A 2018 investigation by New York State detected 1,4-dioxane in 80% of 220 consumer products sampled. Vacuum-stripping can reduce residues but it is not universally applied.
Also known as
PEG-40PEG-40 castor oil
CAS numbers
61788-85-0
Commonly found in
shampoofacial cleanserbubble bath
Safer alternatives
- non-ethoxylated surfactants (decyl glucoside, coco-glucoside)
- vegetable glycerin emulsifiers
Related chemical families
Sources
- NY DEC 1,4-Dioxane Report 2018
- US EPA IRIS: 1,4-Dioxane