Anionic surfactants are the most widely used detergents in the cosmetology profession. They are inexpensive, simple to prepare, and excellent cleaners. They also rinse easily from the hair. A major disadvantage is that they can be harsh and irritating to the scalp Frequently, other surfactants and ingredients are added to reduce skin irritation. Cationic surfactants are rarely used in high concentrations in the cosmetology profession.
Many types are dangerous to the eyes but are safe and useful in low amounts.
Until recently, their positive charges prevented them from being mixed with negatively charged anionic surfactants. Newer types, however, eliminate this incompatibility.