Chlorites are also known as salts of chlorous acid. It is the theoretical anhydride of chlorous acid. Chlorine dioxide reacts rapidly with HO to form chlorous acid. First, the chlorous acid adds to the aldehyde. The free acid, chlorous acid, HClO, is only stable at low concentrations. Examples include chlorous acid, bromous acid, and iodous acid. Chlorous acid, bromous acid, and iodous acid are all unstable. Upon mixing the main active ingredient, chlorous acid is produced in equilibrium with chlorite anion.