Benzalkonium chloride (BAC) is a quaternary ammonium compound widely used as a disinfectant, antiseptic, and preservative. It acts by disrupting microbial cell membranes, making it effective against bacteria, some fungi, and enveloped viruses, though less effective against non-enveloped viruses and bacterial spores.
Key points:
Uses: Found in surface disinfectants, hand sanitizers, antiseptic wipes, eye drops, nasal sprays, and cosmetics.
Mechanism: Cationic surfactant that binds to negatively charged microbial membranes, leading to leakage and cell death.
Safety: Generally considered safe at low concentrations (0.01–0.1%), but higher concentrations can cause skin, eye, and respiratory irritation.