Wednesday, September 25, 2013


Any chemical entity with some destructive potential is viewed with fear by humans and Hydrogen Peroxide (H2O2) is no exception to it. This is a chemical which can kill most bugs at optimum concentrations and cause grievous injury to human beings if not handled carefully. No wonder it is declared as a hazardous material when it comes to handling, storage, transportation and use. As it is not a stable chemical, tending to decompose into water and nascent oxygen at higher temperatures with high oxidizing potential, its concentration for different applications will require careful calibration for getting optimum result. Though it is historically established as a powerful disinfectant from time immemorial, only recently its use without any harm for applications in ensuring bacterial and viral disinfection is being appreciated. Probably its dirt cheap price is responsible for it being overlooked by the chemical and pharmaceutical industry which always go for high vale business! If H2O2 has been fully exploited, many of those expensive chemicals used to fight infections would not have been there at all, saving billions of rupees for the public!   

The atmospheric ozone is responsible for generating H2O2 through interaction with water and the so ubiquitous rain water which falls on the earth is, in fact, a solution of H2O2 that has many beneficial effects to protect environment and vegetation. It is believed, supported by some scientific studies, that rain water is much superior to irrigation water for better plant growth because of the H2O2 content in it. Interestingly rain water that falls through highly polluted atmosphere containing many chemical substances contains much less H2O2 because of its reaction with such oxidizable pollutants. Probably the practice by some progressive farmers to spray dilute solution of H2O2 (1000-2000 ppm)  on their plants is for making up the depletion this chemical in the rain water due to environmental pollution. It is suggested that even for house hold gardening, use of water containing H2O2 may be beneficial for better plant growth.

The fear of H2O2 is some what misplaced because it is a harmless chemical at levels less than 10% and pharma grade H2O2 is even used for infusion for treatment of some health conditions. Besides food industry also uses this chemical in the processing of cheese, egg and whey products. Aseptic packing technology depends heavily on use of 35% H2O2 in the process for cold sterilization of the carton material before filling with HTST treated products like milk, juice and other liquid products. H2O2 is globally available in different concentrations and qualities. While 3% solution of pharma grade is commonly available, others like 6% beautician's grade, 35% technical grade, 35% food grade and 90% rocket grade are offered for specialized users. 

H2O2 is a naturally occurring biological substance in human body, generated and decomposed through many biological reactions, all controlled by the body under different conditions. Primarily H2O2 is produced in places within the body, viz, Lungs, Gut and the Thyroid. Some of the enzymes involved in the body like D-amino acid oxidase and acyl-CoA-Oxidase produce this chemical through reaction with certain amino acids and fatty acids. Plasma amine oxidase and xanthine oxidase systems also generate H2O2. Since high production and accumulation can be dangerous to the tissues, H2O2 is contained in specialized cells in the organelles like peroxisomes which also contain H2O2 decomposing enzymes like Catalase in abundance. 
Human immune system is designed to be activated in response to infection by bacteria, virus and other transgressors when large amounts of H2O2 is produced by the white cells which, in turn kill the invading vectors, neutralizing their adverse consequences. If H2O2 concentration becomes too high it can cause grievous damage to the cell DNA and other critical proteins which many believe is responsible for serious diseases like cancer, diabetes etc.

Since extensive use of H2O2 for sterilizing water at home instead of chlorine has come to stay and as chlorine is not considered a safe chemical for domestic use, it is a question of time before this consumer friendly humble chemical becomes a universally accepted sterilizer for water, environment and food materials. A combination of H2O2, sugar and water is also reported to be an excellent pesticide spray that can destroy most of the field insects and pests at least cost with no residue left behind unlike the present day cocktail of poisonous chemical pesticides. Ease of using dilute solutions of H2O2 through conventional bottles with drop dispensing spouts make its use more convenient and as H2O2 solutions are stable for long at refrigerated temperatures or in domestic freezers a small stock of the product can always be kept for use after dilution through drop dispensers as when needed. 

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