<P> Hydrogen peroxide is used in certain waste - water treatment processes to remove organic impurities . This is achieved by advanced oxidation processes, such as the Fenton reaction, which use it to generate highly reactive hydroxyl radicals (OH). These are able to destroy organic contaminates which are ordinarily difficult to remove, such as aromatic or halogenated compounds . It can also oxidize sulfur based compounds present in the waste; which is beneficial as it generally reduces their odour . </P> <P> Hydrogen peroxide can be used for the sterilization of various surfaces, including surgical tools and may be deployed as a vapour (VHP) for room sterilization . H O demonstrates broad - spectrum efficacy against viruses, bacteria, yeasts, and bacterial spores . In general, greater activity is seen against Gram - positive than Gram - negative bacteria; however, the presence of catalase or other peroxidases in these organisms can increase tolerance in the presence of lower concentrations . Higher concentrations of H O (10 to 30%) and longer contact times are required for sporicidal activity . </P> <P> Hydrogen peroxide is seen as an environmentally safe alternative to chlorine - based bleaches, as it degrades to form oxygen and water and it is generally recognized as safe as an antimicrobial agent by the U.S. Food and Drug Administration (FDA). </P> <P> Historically hydrogen peroxide was used for disinfecting wounds, partly because of its low cost and prompt availability compared to other antiseptics . It is now thought to slow healing and lead to scarring because it destroys newly formed skin cells . Only a very low concentration of H O can induce healing, and only if not repeatedly applied . Surgical use can lead to gas embolism formation . Despite this it is still used for wound treatment in many developing countries . </P>

Why hydrogen peroxide is used as bleaching agent