Chlorine dioxide is a water-soluble gas, it does not ionize to form weak acids (as chlorine and bromine do) in aqueous
solutions. This allows chlorine dioxide to be effective over a wide pH range (4 – 10). For example, the pH dependent
speciation of chlorine produces hypochlorite ion and hypochlorous acid (HOCl). Hypochlorite is only 1/30 to 1/200
as effective as HOCl. Chlorine dioxide being a neutral species with rapid disinfection kinetics is 100% available for
disinfection in hard or soft water.