Beheneth-20

Beheneth-20 is a nonionic ethoxylated fatty alcohol surfactant/emulsifier used in leave-on creams and cleansers, typically around ~0.5–5%, where it mainly improves texture and solubilization. Nonionic emulsifiers like this generally show low irritation in patch testing compared with anionic surfactants, but they can still contribute to barrier disruption or sting in eczema-prone or very compromised skin, especially in combination with other surfactants. Given that realistic use can produce mild, occasional reactivity in highly sensitive patients, I rate it as gentle rather than exceptionally gentle. Safety Notes: Beheneth-20 is used as a nonionic emulsifier/solubilizer and texture modifier, and in many leave-on lotions/serums it appears at low levels (~0.05–0.5%) as a secondary emulsifier or stabilizer alongside glyceryl stearate/cetearyl alcohol systems. In richer creams, cleansing balms, and high-structure emulsions it commonly runs ~1–4%, with the upper end (~6–8%) seen in some consumer-available anhydrous-to-emulsifying cleansers, thick rinse-off conditioners, and very heavy barrier creams where it functions as a primary emulsifier/viscosity builder; higher levels are generally constrained by waxy feel and potential irritation rather than a specific OTC regulatory cap.