Triethanolamine
Triethanolamine (TEA) is an alkaline organic compound used primarily as a pH adjuster in cosmetic formulations; a 1% solution has a pH of around 10. Its official CosIng functions include buffering, emulsifying, masking, and surfactant. It carries Cosmetic Restriction III/62, indicating regulated use conditions. While TEA itself is not considered a direct hazard, it can react with certain N-nitrogenating agents (e.g., preservatives containing "nitro" or "nitra" in their names) to potentially form carcinogenic nitrosamines.
TEA's primary role is to set and stabilize the pH of cosmetic formulations to the desired level. It also contributes minor emulsifying and surfactant properties. Properly formulated products containing TEA alone are generally considered safe for use.
When combined with N-nitrogenating agents (ingredients containing "nitro" or "nitra" in their names, such as 2-Bromo-2-Nitropropane-1,3-Diol or sodium nitrate), TEA can form carcinogenic nitrosamines; products containing both TEA and such agents are best avoided. TEA is highly alkaline (pH ~10 at 1% concentration).
