Triethanolamine

A pH adjuster and emulsifier. Triethanolamine (TEA) functions primarily as a pH adjuster and emulsifying agent in cosmetic formulations. As a pH adjuster, it neutralizes acidic components, forming salts that can increase the viscosity and stability of emulsions. As an emulsifier, TEA reacts with free fatty acids (e.g., stearic acid) to form anionic soaps (e.g., triethanolamine stearate) in situ, which reduce interfacial tension between oil and water phases, stabilizing oil-in-water emulsions by forming a protective film around dispersed oil droplets.

The CIR Expert Panel considers Triethanolamine safe for use in cosmetics when formulated to be rinse-off or when formulated in leave-on products at concentrations ≤ 5%, provided that products containing TEA are not applied to the skin more frequently than once daily. It has the potential for irritation or sensitization, particularly at higher concentrations or if impurities are present, and can form nitrosamines if formulated with nitrosating agents.

Look for products with 0.1-5% (commonly used for pH adjustment or emulsification; CIR Expert Panel reviewed concentrations up to 10% in leave-on and 25% in rinse-off products). for clinical efficacy.