STEAROYL ETHYLTRIMONIUM METHOSULFATE is graded A (Safe) by Expert·ING, based on COSING regulatory data.

STEAROYL ETHYLTRIMONIUM METHOSULFATE

Safety grade: A

This is a synthetic conditioning agent derived from stearic acid (a fatty acid) that has been chemically modified to help blend ingredients together. It works like a bridge between water and oil-based components in formulas.

This ingredient helps mix and stabilize water and oil components in cosmetic formulations, preventing them from separating while also providing conditioning benefits to hair and skin.

Graded using: COSING.

Last verified: May 26, 2026