Hypochlorous acid becomes ineffective above pH 8.5, but chlorine dioxide retains some sanitizing power up to pH 10.0. Chlorine dioxide is a stronger oxidizer than other chlorine sanitizers and it is less likely to form chlorinated organic compounds. Chlorine dioxide is desirable whenever the organic load of the water is high. In addition, chlorine dioxide removes iron, manganese, odors, flavors, and colors from the water. Concentrations of chlorine dioxide can be easily measured by a test kit.
Chlorine dioxide is more expensive than chlorine gas or hypochlorites.
Chlorine dioxide decahydrate may be commercially prepared, but must be refrigerated because it decomposes at room temperature and can explode under certain conditions. Iodine Compounds Iodophors are a combination of iodine and a solubilizing agent that releases free iodine when diluted with water. Iodophors are fast-acting and effective against all bacteria. In diluted form, they are nonstaining, relatively nontoxic, nonirritating to skin, and stable. Iodophors are widely used in hand sanitizing solutions.