It is generally accepted that hair carries a negative electrical charge. Washing hair with shampoo-which primarily consists of anionic detergents (a category that also includes soap)-causes the hair to acquire an even greater negative charge; this generates static electricity, making the hair difficult to comb. When hair conditioner is applied, its primary active ingredients-cationic quaternary ammonium salts-adsorb onto the hair's surface, leaving behind a uniform monomolecular film. This imparts a range of benefits to the hair: increased softness, enhanced shine, improved manageability, and static control. Furthermore, it helps to repair, to a certain extent, damage caused by mechanical stress as well as chemical treatments such as perming and dyeing.
Most standard conditioners require rinsing after use; however, leave-in conditioners are typically formulated as sprays, gels, or hair oils. Deep-conditioning treatments (often referred to as "hot oil treatments" or "hair masks") require a processing time of 20 to 30 minutes after application, offering a significantly more intensive conditioning effect.