{Water treatment, contact lens solution, etc} Contact Lens Solution: "(Regard™) using a combination of sodium chlorite (NaClO2; used to disinfect mains water) and trace amounts (100 ppm) of hydrogen peroxide (Atkins 2004). The peroxide stabilises the inherently unstable chlorine dioxide (ClO2) generated, and the combination is said to be effective against Gram-positive and Gram-negative bacteria, fungi and yeasts. Decomposition products are sodium chloride, water and oxygen. When lenses are removed from solution, the residual sodium chlorite decomposes readily into sodium chloride and oxygen. " "It is a powerful oxidant that disrupts protein synthesis, making it an efficient antimicrobial. However, penetration of biofilms can be challenging and chlorine dioxide can take months to achieve microbial control, can corrode pipework and readily decomposes, particularly in hot water, though higher concentrations can be used in the hot water supply.130,133,134 Concentrations of 0.5 mg/l are effective against planktonic and sessile Legionella in hot water systems. However, The Drinking Water Inspectorate advises a maximum of 0.5 mg/l chlorine dioxide in drinking water "