Triethanolamine
Also known as TEA, Trolamine, Triethylolamine
“CIR Expert Panel says: safe as used in cosmetics.”
Triethanolamine (TEA) is a tertiary amine used as a pH buffer and neutralizer in cosmetics. The CIR Expert Panel concluded TEA and TEA-containing ingredients are safe as used when formulated to be nonirritating, with a 5% limit in leave-on products and a prohibition on use with N-nitrosating agents. TEA itself does not directly form nitrosamines as a tertiary amine, but secondary-amine impurities (chiefly diethanolamine/DEA) in TEA raw materials can react with nitrosating agents to form N-nitrosodiethanolamine (NDELA), a recognized concern; CIR and EU Annex III entry 62 for trialkylamines/trialkolamines both address this via raw material purity and N-nitrosating agent exclusion conditions.
Effective pH buffer and neutralizer widely used to adjust formulation pH to skin-compatible range
Used to form TEA-soaps (anionic surfactants) via neutralization of fatty acids
Long safety history in cosmetics with well-characterized toxicology profile
- · Must not be used in formulations containing N-nitrosating agents (e.g., nitrites, nitrogen oxides) to prevent in-situ nitrosamine formation from DEA impurities
- · Potential for mild skin and eye irritation at elevated concentrations
Secondary-amine impurities (primarily diethanolamine/DEA) present as manufacturing byproducts in TEA raw materials can react with nitrosating agents to form N-nitrosodiethanolamine (NDELA), a potential carcinogen; TEA itself is a tertiary amine and does not directly nitrosate
EU Cosmetics Regulation Annex III entry 62 (trialkylamines/trialkolamines) restricts the class: max 2.5% in rinse-off finished products, raw material purity ≥99%, secondary amine impurity ≤0.5%, nitrosamine content ≤50 μg/kg
CIR Quick Reference Table (12/2017, revised 07/2018) — TRIETHANOLAMINE row: Finding=SQ, Citation=JACT 2(7):183-235, 1983; IJT 32(S1): 59-…
“Triethanolamine | SQ | safe for use in rinse-off products; but 5% in leave-on cosmetic products; and should not be used in products containing N-nitrosating agents | JACT 2(7):183-235, 1983; IJT 32(S1): 59-81, 2013”— QRT-122017revised072018.pdf, p. 135