Behentrimonium Methosulfate is a conditioning emulsifier that is derived from rapeseed oil.
It is renowned for its superior detangling ability, without causing build-up on hair while being skin friendly. It helps to improve wet and dry comb ability.
It leaves hair feeling soft and silky. It is NOT a 'sulfate' and it is so gentle that it is recommended for use in baby products.
The Environmental Working Group (EWG's) Skin Deep is the world's largest personal care product safety guide. They rate ingredients according to their hazard score on a 0-10 scale from low to high hazard. For example, they give water a score of 0.
Accordingly they have rated Behentrimonium Methosulfate with a score of 1.