Hydrogen Peroxide
Hydrogen peroxide (H₂O₂) is a pale blue liquid that is chemically similar to water but contains an additional oxygen molecule. It is the simplest peroxide and is known for its strong oxidizing properties, which allow it to break down into water and oxygen, especially when heated or in the presence of certain metals. Historically discovered in 1818, the production of pure hydrogen peroxide evolved, leading to its use as a potent disinfectant and cleaning agent, replacing less safe alternatives like ethylene oxide. Commercially, hydrogen peroxide is available in varying concentrations, with higher concentrations being highly corrosive and potentially life-threatening upon inhalation or ingestion.
It has diverse applications, including in the textile, food production, and medical sectors, where it serves as a bactericide and fungicide. Despite its effectiveness, the use of hydrogen peroxide in alternative medicine has led to misconceptions about its safety and efficacy for treating various ailments. Health authorities have issued warnings against the consumption of concentrated hydrogen peroxide due to the serious health risks it poses, emphasizing the importance of using it responsibly and with proper knowledge.
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Hydrogen Peroxide
Hydrogen peroxide is similar in composition to water (H2O) with an additional oxygen molecule (H2O2). The usual form is liquid, though small amounts of gas can sometimes be found in the air. It is the simplest of all the peroxides and breaks down into water and oxygen upon heating as well as in the presence of salts from several metals (copper, chromium, iron, manganese, or nickel). When mixed with some compounds, most notably sodium perborate (NaBO2·H2O2·3H2O or NaBO3·4H2O), it creates mild oxidizing crystalline solids, a common component in laundry detergents and chlorine-free bleaches. Hydrogen peroxide storage containers can explode if exposed to heat or fire.
Because it is unstable, hydrogen peroxide deteriorates without stabilizers such as acetanilide or similar organic materials. When stabilized in a 60 percent hydrogen peroxide solution, it is colorless like water. Unlike water, it has a bitter taste.
Brief History
Discovered by Louis Jacque Thenard in 1818 through a process of reacting barium peroxide with nitric acid, the process was refined by the use of hydrochloric acid. He ultimately added sulphuric acid, which yielded a precipitate of barium sulfate as a by-product. The Thenard process was used until the middle of the 1900s. From there, the production changed dramatically.
The common belief was that pure hydrogen peroxide was too unstable because of failed attempts to separate it from water present during the synthesis process. It was discovered that the lack of success was due to the water’s impurities catalyzing the decomposition. The first time pure hydrogen peroxide was produced happened in 1894 by a vacuum distillation process discovered by Richard Wolffenstein. For several years, the formula remained in question. Before the end of the century, Petre Melikishvili and student L. Pizarjevski identified it as having two bonded oxygen molecules: both of which have one hydrogen molecule attached. The H2O2 molecules have a skew-chain structure as a result of intermolecular repulsion.
From the beginning, hydrogen peroxide was identified as a superior cleaning agent and disinfectant. It rapidly replaced ethylene oxide because of its safety and efficiency as a decontaminant. When used for its antiseptic properties on skin, it has a mildly irritating effect. Solutions of 3 to 5 percent are relatively safe for this purpose. Hydrogen peroxide has found applications as bleach for hair, with some products reaching a concentration of 10 percent. Concentrations of 8 percent and above can be corrosive and induce side effects similar to burns. Inhalation of the chemical at low concentrations is generally harmless in adults, but may have effects on children (due to the size of their lungs and body weight ratio). Inhalation of commercial grade hydrogen peroxide (30 percent and above) can be a life-threatening situation.
Hydrogen peroxide commercial applications are abundant; it is an important ingredient in producing rocket fuel, decontaminating spacecraft, bleaching textiles, producing foam rubber, and more. Because it has antiseptic properties as bactericide, fungicide, and sporicide, it has wide applications in food production, and the product has found a home in medical research and treatment. It is cheap and can be used in low concentrations (3 percent). Heating it makes it even more effective.
Overview
Commercial grade aqueous solutions of hydrogen peroxide contain 35, 50, 70, or 90 percent concentration. Inhalation of those products can be fatal. That being said, it has become a staple in manufacturing and even energy production since its first use as a propellant by the Germans, when they could synthesize relatively safe and stable 80-percent concentrations. Hellmuth Walter opened the first H2O2 combustion device business in 1935, and it soon moved into mass production to fuel submarines, planes, and missiles.
The chemical also plays a role in medical treatment and research. In 1990, Indian researchers isolated hydrogen peroxide produced in the thyroid, where it modulates iodination of tyrosine. More recently, studies have suggested that some types of cancer cells produce hydrogen peroxide and other types of cancer cells are killed when hydrogen peroxide is delivered to them.
Hydrogen peroxide research continues with a fairly good rate of success in most areas. However, it has also become something a cult cure-all to the lay public. A brief search of the internet and book stores demonstrates a plethora of myths about hydrogen peroxide’s curative power. What is called "food grade" is frequently used by alternative practitioners for ailments such as arthritis, allergies, diabetes, lupus, etc. Few, if any, of these anecdotal presentations are authored by researchers who have credentials that would give them authority to recommend ingestion of this also toxic agent.
In 2006 the Food and Drug Administration issued a warning: Do not consume high-strength hydrogen peroxide for medicinal use. They have been issuing warnings since 1989 to manufacturers of concentrated hydrogen peroxide to stop making medical claims and recommending the product for ingestion. The theory that ingestion and injection are harmless, releasing oxygen into the blood stream, is more myth than medicine. What has been demonstrated are collapse of vessels and deaths from IV administration, burning of the mucosa with gastrointestinal irritation, ulceration after swallowing, and neurologic damage.
Bibliography
Burdge, Julia R., and Raymond Chang. Chemistry. London: McGraw Hill, 2008. Print.
Food and Drug Administration. "FDA Warns Consumers Against Drinking High-Strength Hydrogen Peroxide for Medicinal Use." 27 July 2006. Web. 30 Dec. 2015. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108701.htm.
Gruber, Bryce. "A 3-cent Tooth Whitener and More Surprising Uses for Hydrogen Peroxide." TODAY.com. 30 Oct. 2014. Web. 30 Dec. 2015. http://www.today.com/style/surprising-beauty-uses-peroxide-1D80246758.
"Hydrogen Peroxide." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 30 Dec. 2015. http://www.britannica.com/science/hydrogen-peroxide.
"Hydrogen Peroxide." PubChem. National Institutes of Health. 12 June 2015. Web. 30 Dec. 2015. http://pubchem.ncbi.nlm.nih.gov/compound/hydrogen‗peroxide.
"Hydrogen Peroxide Poisoning." MedlinePlus, 2 Nov. 2023, medlineplus.gov/ency/article/002652.htm. Accessed 20 Nov. 2024.
"Hydrogen Peroxide: Uses, Side Effects, Interactions, Pictures, Warnings and Dosing." WebMD. WebMD, n.d. Web. 30 Dec. 2015. http://www.webmd.com/drugs/2/drug-76035/hydrogen-peroxide/details.
Morrison, Mark M., and Julian R. Roberts, Jr. "Oxidation-Reduction Chemistry of Hydrogen Peroxide in Aprotic and Aqueous Solutions." Inorganic Chemistry 18.7 (1979): 1971–73. Web. 30 Dec. 2015. http://pubs.acs.org/doi/abs/10.1021/ic50197a050.
Verma, S., et al. "Discovery of a Novel and Alternate Hydrogen Peroxide Generation Machinery in the Mammalian Thyroid Gland that Modulates Iodination of Tyrosine." Biochemical and Biophysical Research Communications 169.1 (1990): 1–7. Print.