PEG-40 (commonly PEG-40 hydrogenated castor oil or PEG-40 stearate) is a polyethylene glycol-derived nonionic surfactant used to emulsify, solubilize, and disperse oils and fragrances in cosmetic formulations. It functions as a formulation aid rather than a treatment active.
| Reported effect | How often | Notes |
|---|---|---|
Mild skin irritation | Uncommon | Can occur at higher concentrations or on compromised skin barriers. |
Allergic contact dermatitis | Rare | PEG compounds are infrequent sensitizers but documented in patch-test studies. |
Eye irritation | Uncommon | Possible with leave-on or cleansing products contacting the eyes. |
Concerns regarding 1,4-dioxane impurity | Rare | Trace byproduct from ethoxylation; minimized by purification and vacuum stripping in manufacturing. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.