What is "benzalkonium chloride"

n. (context organic chemistry English) A nitrogenous cationic surface-acting agent of the quaternary ammonium group, used as a biocide, as a cationic surfactant and as a phase transfer agent in the chemical industry.

Benzalkonium chloride, also known as BZK, BKC, BAC, alkyldimethylbenzylammonium chloride and ADBAC, is a type of cationic surfactant. It is an organic salt called a quaternary ammonium compound. It has three main categories of use: as a biocide, a cationic surfactant, and as a phase transfer agent. ADBACs are a mixture of alkylbenzyldimethylammonium chlorides, in which the alkyl group has various even-numbered alkyl chain lengths.