Stearalkonium Chloride is derived from stearic acid, a fatty acid found in plants and animals. It is used primarily in hair products (including rinses, conditioners, setting lotions and bleaches) to serve as an anti-static agent. It also has some preservative and surfactant properties. Stearalkonium Chloride is a “positively charged salt that attracts and binds proteins, which are negatively charged.” It is the only product (besides artificial fragrances, which rate an alarming 8) I will use with a rating as high as 4 . If I find a safer alternative that works, I will make the switch, you can be sure.