Beheneth-5

Beheneth-5 is a nonionic fatty alcohol ethoxylate used primarily as an emulsifier/surfactant in leave-on creams and cleansers, typically at low single-digit percentages. Nonionic surfactants of this type are generally well-tolerated, but they can still disrupt the stratum corneum and trigger stinging or dryness in highly reactive or eczematous skin, especially with frequent exposure or in cleanser formats. Based on its function and the known irritation potential of ethoxylated surfactants in compromised barriers, I score it as gentle but not inert. Safety Notes: Beheneth-5 (a C22 ethoxylated fatty alcohol) is most commonly used as a nonionic surfactant/solubilizer and co-emulsifier; in commercial leave-on creams/lotions and makeup its functional use level is often at the low end (~0.1–1%) to aid emulsification, slip, and stability. In consumer rinse-off cleansers and specialty high-surfactant systems (e.g., self-emulsifying cleansing oils/balms, makeup removers, and some hair/skin wash bases), higher levels are observed, with the upper end reaching ~5–8% where it functions as a primary emulsifier/solubilizer. There is no specific FDA/EU maximum concentration limit for Beheneth-5 in cosmetics; practical upper limits are usually set by sensory, irritation potential in rinse-off/leave-on context, and phase behavior.