Behentrimonium chloride is a synthetic or plant-derived skin and hair care agent and emulsifier. https://www.paulaschoice.com/ingredient-dictionary/ingredient-behentrimonium-chloride.html?q=Behentrimonium%20Chloride&fdid=ingredients Behentrimonium chloride is an antistatic and hair conditioning agent; it is also an emulsifier.[6] It is a type of trimonium that causes cationic chains to attract anionic charges in the protein structure of skin and hair, creating a conditioning effect.[7] It tends not to dissolve in water, meaning it stays on the hair, making it popular in rinse-off conditioners.[8] Behentrimonium chloride is present in hundreds of personal care products, including conditioners, hair dyes, moisturizers, bath soaps, mousses, and other items.[9] https://puracy.com/blogs/ingredients/behentrimonium-chloride