Hypochlorous acid

Hypochlorous acid (HClO, CAS 7790-92-3) is a weak inorganic acid that exists only in dilute aqueous solution. It carries no assigned E-code for food use in the EU. It is sold under trade names including Comfosy, Dent Zia, Brio HOCl, and Briotech HOCl.

In water treatment, HClO acts as the active disinfecting species produced during chlorination, penetrating microbial cell walls more effectively than hypochlorite ion at equivalent concentrations. In food processing and personal care, it functions as a biocide and surface sanitiser, disrupting bacterial membranes and oxidising pathogens without leaving toxic residues at approved concentrations.

Hypochlorous acid is supplied as a dilute aqueous solution, typically in the range of 50 to 500 ppm active chlorine, as the pure acid cannot be isolated. Relevant compliance frameworks include REACH registration and, for food-contact or pharmaceutical applications, alignment with applicable national or EU biocidal product regulations under BPR 528/2012.