Benzalkonium chloride

[Sonia]

C6H5CH2N(CH3)2(CnH2n 1)Cl or C9H13N(CnH2n 1)Cl
Various chemical formula
A type of cationic [surfactant]. It is an organic salt classified as a [quaternary] ammonium compound. It has three main categories of use: as a biocide, a cationic surfactant, and as a phase transfer agent. [Benzalkonium chloride] is commonly used as preservative in eye drops like Visine in extremely small quantity, antiseptics, cleaning agent like Lysol, etc.
Benzalkonium chloride is strong eye and human skin irritant, despite being present in many eye drops.