Benzalkonium Chloride is a disinfectant used for its spermicidal qualities. Like many over-the-counter spermicides, benzalkonium chloride (often referred to as ADBAC) affects the surface tension of liquids. This prevents sperm from moving freely, greatly reducing the chances of conception.

While benzalkonium chloride is a safe ingredient, it can cause adverse reactions in some users. It is commonly used in spermicidal creams, sometimes in conjunction with nonoxynol-9. In sexual lubricants, it is often used as a preservative rather than as a spermicide. ADBAC is also found in pharmaceuticals, cleaning agents and other household products