Title: Hydrogen peroxide
Content:  Practitioners of alternative medicine have advocated the use of hydrogen peroxide for various conditions, including emphysema, influenza, AIDS, and in particular cancer. There is no evidence of effectiveness and in some cases it has proved fatal. Both the effectiveness and safety of hydrogen peroxide therapy is scientifically questionable. Hydrogen peroxide is produced by the immune system, but in a carefully controlled manner. Cells called phagocytes engulf pathogens and then use hydrogen peroxide to destroy them. The peroxide is toxic to both the cell and the pathogen and so is kept within a special compartment, called a phagosome. Free hydrogen peroxide will damage any tissue it encounters via oxidative stress, a process that also has been proposed as a cause of cancer. Claims that hydrogen peroxide therapy increases cellular 
Title: Hydrogen peroxide
Content:  Hydrogen peroxide is a chemical compound with the formula. In its pure form, it is a very pale blue liquid, slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3–6% by weight) in water for consumer use, and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or "high-test peroxide", decomposes explosively when heated and has been used as a propellant in rocketry. Hydrogen peroxide is a reactive oxygen species and the simplest peroxide, a compound having an oxygen–oxygen single bond. It decomposes slowly when exposed to light, and rapidly in the presence of organic or reactive compounds. It is typically stored with a stabilizer in a weakly acidic solution in a dark bottle to block light. Hydrogen peroxide is found in biological systems including the human body. Enzymes that use or decompose hydrogen peroxide are classified as peroxidases.
Title: Hydrogen peroxide
Content:  converts it to H2O through this reaction: Another origin of hydrogen peroxide is the degradation of adenosine monophosphate which yields hypoxanthine. Hypoxanthine is then oxidatively catabolized first to xanthine and then to uric acid, and the reaction is catalyzed by the enzyme xanthine oxidase:  The degradation of guanosine monophosphate yields xanthine as an intermediate product which is then converted in the same way to uric acid with the formation of hydrogen peroxide. Eggs of sea urchin, shortly after fertilization by a sperm, produce hydrogen peroxide. It is then quickly dissociated to OH· radicals. The radicals serve as initiator of radical polymerization, which surrounds the eggs with a protective layer of polymer. The bombardier beetle has 
Title: Hydrogen peroxide
Content:  hazardous and require special care in dedicated storage areas. Buyers must typically allow inspection by commercial manufacturers. In 1994, world production of was around 1.9 million tonnes and grew to 2.2 million in 2006, most of which was at a concentration of 70% or less. In that year, bulk 30% sold for around 0.54 USD/kg, equivalent to US$1.50/kg (US$0.68/lb) on a "100% basis". Hydrogen peroxide occurs in surface water, groundwater and in the atmosphere. It forms upon illumination or natural catalytic action by substances contained in water. Sea water contains 0.5 to 14 μg/L of hydrogen peroxide, freshwater 1 to 30 μg/L and air 0.1 to 1 parts per billion.
Title: Hydrogen peroxide
Content: 2 + 2  →  + ; 2 H2O2 → O2 + 2 H2O Hydrogen peroxide is formed in humans and other animals as a short-lived product in biochemical processes and is toxic to cells. The toxicity is due to oxidation of proteins, membrane lipids and DNA by the peroxide ions. The class of biological enzymes called superoxide dismutase (SOD) is developed in nearly all living cells as an important antioxidant agent. They promote the disproportionation of superoxide into oxygen and hydrogen peroxide, which is then rapidly decomposed by the enzyme catalase to oxygen and water.  Peroxisomes are organelles found in virtually all eukaryotic cells. They are involved in the catabolism of very long chain fatty 
Title: Hydrogen peroxide
Content:  roles as a signalling molecule in the regulation of a wide variety of biological processes. The compound is a major factor implicated in the free-radical theory of aging, based on how readily hydrogen peroxide can decompose into a hydroxyl radical and how superoxide radical byproducts of cellular metabolism can react with ambient water to form hydrogen peroxide. These hydroxyl radicals in turn readily react with and damage vital cellular components, especially those of the mitochondria. At least one study has also tried to link hydrogen peroxide production to cancer. These studies have frequently been quoted in fraudulent treatment claims. The amount of hydrogen peroxide in biological systems can be assayed using a fluorometric assay.
Title: Hydrogen peroxide
Content:  Historically hydrogen peroxide was used for disinfecting wounds, partly because of its low cost and prompt availability compared to other antiseptics. Now it is thought to inhibit healing and to induce scarring, because it destroys newly formed skin cells. One study found that only very low concentrations (0.03% solution, this is a dilution of typical 3% Peroxide by 100 times) may induce healing, and only if not applied repeatedly. A 0.5% solution was found to impede healing. Surgical use can lead to gas embolism formation. Despite this, it is still used for wound treatment in many developing countries, and, in the United States, is prevalent as a major first aid antiseptic. Dermal exposure to dilute solutions of hydrogen peroxide causes whitening or bleaching of the skin due to microembolism caused by oxygen bubbles in the capillaries.
Title: Hydrogen peroxide
Content:  Small, but detectable, amounts of hydrogen peroxide can be formed by several methods. Small amounts are formed by electrolysis of dilute acid around the cathode where hydrogen evolves if oxygen is bubbled around it. It is also produced by exposing water to ultraviolet rays from a mercury lamp, or an electric arc while confining it in a UV transparent vessel (e.g. quartz). It is detectable in ice water after burning a hydrogen gas stream aimed towards it and is also detectable on floating ice. Rapidly cooling humid air blown through an approximately 2,000 °C spark gap results in detectable amounts. A commercially viable process to produce hydrogen peroxide directly from the environment has been of interest for many years. Efficient direct synthesis is difficult to achieve, as the reaction of hydrogen with oxygen thermodynamically favours production of water. Systems for direct synthesis have been developed, most of which employ finely dispersed metal catalysts similar to those used for hydrogenation of organic substrates. None of these has yet reached a point where they can be used for industrial-scale synthesis.
Title: Hydrogen peroxide
Content:  of oxygen have not been supported. The quantities administered would be expected to provide very little additional oxygen compared to that available from normal respiration. It is also difficult to raise the level of oxygen around cancer cells within a tumour, as the blood supply tends to be poor, a situation known as tumor hypoxia. Large oral doses of hydrogen peroxide at a 3% concentration may cause irritation and blistering to the mouth, throat, and abdomen as well as abdominal pain, vomiting, and diarrhea. Intravenous injection of hydrogen peroxide has been linked to several deaths. The American Cancer Society states that "there is no scientific evidence that hydrogen peroxide is a safe, effective, or useful cancer treatment." Furthermore, the therapy is not approved by the U.S. FDA.
Title: Hydrogen peroxide
Content:  pose several risks, the main one being that it forms explosive mixtures upon contact with organic compounds. Distillation of hydrogen peroxide at normal pressures is highly dangerous. It is also corrosive, especially when concentrated, but even domestic-strength solutions may cause irritation to the eyes, mucous membranes, and skin. Swallowing hydrogen peroxide solutions is particularly dangerous, as decomposition in the stomach releases large quantities of gas (ten times the volume of a 3% solution), leading to internal bloating. Inhaling over 10% can cause severe pulmonary irritation. With a significant vapour pressure (1.2 kPa at 50 °C), hydrogen-peroxide vapour is potentially hazardous. According to U.S. NIOSH, 

Question: where does hydrogen peroxide come from in the body?
Answer: nearly all living cells.