هیدروژن پراکسید یا آباکسیژنه (H۲O۲) یک اکسنده متداول است که به عنوان سفید کننده استفاده می شود. هیدروژن پراکسید سادهترین پراکسید است (پراکسیدها ترکیباتی هستند که دارای یک پیوند یگانه اکسیژن-اکسیژن هستند). آب اکسیژنه خالص H۲O۲ یک مایع ناروانی است که کمی آبی رنگ میباشد و با زحمت زیاد میتوان آنرا تهیه نمود. آب اکسیژنهای که در داروخانهها به اسم آب اکسیژنه رقیق فروخته میشود محلولی است از آب اکسیژنه در آب که در ۱۰۰ قسمت آن سه قسمت آب اکسیژنه است، مانند آب بیرنگ و بیبوست، مزه تلخی دارد و کمی اسیدی است. این مایع اکسید کننده یی قوی است.
تجزیه این ماده باعث ایجاد رادیکالهای OH میشود که بیش از چند ثانیه در دسترس نمیباشند و در این مدت با خاصیت شدید اکسیدکنندگی خود، مواد آلی و معدنی را اکسید میکند.
خصوصیات آب اکسیژنه[ویرایش]
به مرور آب اکسیژنه تجزیه و تبدیل به آب و اکسیژن میگردد. این عمل تجزیه در محیط بازی سریعتر و در محیط اسیدی کندتر از محیط خنثی صورت میگیرد. اگر مدت مدیدی آب اکسیژنه را انبار کنند، ممکن است کاملاً تجزیه و تبدیل به آب گردد. بر اثر گرد بعضی اجسام عمل تخریب آب اکسیژنه تسریع میگردد مانند گرد بیاکسید منگنز و گرد فلزات .
اگر بر روی محلول آب قدری از اجسام پایدار کننده مانند اسید فسفریک، اوره، اسید بنزوئیک و نظیر آنها بیفزایند، عمل تخریب بسیار کند میگردد. آب اکسیژنه اثر میکروب کشی و بوبری دارد چنانکه اگر یک تکه کالباس قرمز را درون ظرف محتوی آب اکسیژنه قرار دهیم پس از چند روز محتویات ظرف کاملاً بیبو است و بوی گندیده نمیدهد. آب اکسیژنه رنگها را نیز تخریب میکند بهمین دلیل تکه کالباس درون ظرف بعد از مدتی بیرنگ میشود.
موارد استعمال آب اکسیژنه[ویرایش]
لکه شراب قرمز، خون، قهوه و غیره را هم میتوان بوسیله آب اکسیژنه پاک نمود. محلول غلیظ H۲O۲ به عنوان یک اکسیدان برای سوخت موشکها نیز مورد استفاده قرار می گیرد. برخی از خمیر دندانها و سایر اجسامی که برای پاک کردن دندانها بکار میرود در موقع استعمال تولید آب اکسیژنه میکنند و اکسیژن این آب اکسیژنه دندان را سفید مینماید.
آب اکسیژنه در بیرنگ کردن شاخ، پشم گوسفند، پنبه، کتان، کنف، کاه، چوب، کاغذ، روغن، چربی، واکس، صابون، ابریشم، عاج، پر و غیره بکار میرود. رنگ بعضی لکههای صورت را هم آب اکسیژنه تخریب میکند. اگر موی سیاه را پس از شستن با کربنات سدیم ( تا چربی آن برطرف شود ) در محلول آب اکسیژنه بگذارند به رنگ روشن در میآید.اگر موی سیاه سر را با مخلوطی از ۱۰۰ گرم آب اکسیژنه ۳۰% و چهار قطره محلول ۲۵% آمونیاک تر نمایند و پس از ۱۰ تا ۲۰ دقیقه با آب خالص و سپس با محلول اسید استیکدار بشویند، بور مایل به قرمز میشود. وجود آمونیاک از این جهت لازم است که آب اکسیژنه در حضور قلیاییها سریعتر اکسیژن میدهد و در نتیجه موها تندتر بور میشوند. مصرف مکرر آب اکسیژنه برای مو مضر است زیرا که مو را شکننده مینماید. در جنگ جهانی دوم آب اکسیژنه ۸۵%برای اکسیداسیون سریع الکل در زیر دریاییها و موشکها مصرف میکردند.
کاربرد در پزشکی[ویرایش]
آب اکسیژنه در گذشته به دلیل خاصیت ضدعفونی کننده آن در پانسمان زخمهای عفونی استفاده میشد ولی امروزه به دلیل آسیبی که به بافتهای مجاور وارد میکند دیگر در پانسمان استفاده نمیشود و فقط گاه برای ضدعفونی لوازم یا سطوح استفاده میشود.از آنجایی که آب اکسیژنه بوبر است گاه در درمان زخمهای بدبو مورد استعمال قرار میگیرد. در قرصهای اریتزون ۳۶% آب اکسیژنه به ۶۴% اوره متصل است و چون این قرصها را در دهان بگذارند، اکسیژن میدهد. پس هم میکروبهای دهان را میکشد و هم دندانها را سفید مینماید.آب اکسیژن رقیق را برای قرقره کردن هم بکار میبرند.
کاربرد در بهداشت استخرها[ویرایش]
آب اکسیژنه برای حذف مواد آلی و معدنی که موجب فاسد شدن آب استخر میشوند بکار میرود. تزریق این عنصر قبل از دستگاه UV باعث ایجاد رادیکالهای OH میشود که بیش از چند ثانیه در دسترس نمیباشند و در این مدت با خاصیت شدید اکسید کنندگی خود، مواد باقیمانده آلی و معدنی را تجزیه میکند. بدین ترتیب نیاز به تعویض آب استخرها کاهش می یابد.
در صورتی که از آب اکسیژنه در آب استخرها استفاده شود دارای مزایا به شرح زیر است: ۱. آب اکسیژنه موجود در آب با دوز صحیح، برای شناگر غیر قابل تشخیص است. ۲. با آب بخوبی مخلوط میشود، غیر فرار است و تا زمان اکسید کردن مواد آلی در آب باقی میماند. ۳. خالص است و ایجاد املاح نمیکند. ۴. خورنده نیست و در نتیجه به تجهیزات و تاسیسات آسیب نمیرساند. ۵. ایجاد کف نمیکند، بی بو و بی طعم است. ۶. غیر سمی است ۷. ایجاد رسوب نکرده و در نتیجه آب کاملاً شفاف می ماند.
شناسایی آب اکسیژنه[ویرایش]
در یک لوله آزمایشی که قبلاً چند سانتیمتر مکعب محلول بیکرمات پتاسیم و قدری اسید سولفوریک رقیق ریختهایم آب اکسیژنه میافزاییم در نتیجه رنگ آبی تند که بعداً تبدیل به سبز میشود، ظاهر میگردد. بهمین طریق میتوان وجود آب اکسیژنه را در اریتزن ثابت نمود.
تهیه آب اکسیژن در صنعت با روش خود اکسایش[ویرایش]
در این فرایند یکی از مشتقات آتراکینون بر اثر واکنش با هیدروژن در مجاورت کاتالیزور پالادیوم به آنتراهیدروکینون تبدیل می شود. با عبور هوا از ماده اخیر، محلول پراکسید هیدروژن ۲۰ درصد وزنی بدست می آید.
رقیه قدیم خانی و دکتر لطفعلی سقط فروش، آزمایشگاه شیمی معدنی ۱، انتشارات پیام نور
Hydrogen peroxide is a chemical compound with the formula (H
Structure and properties
The boiling point of H
In aqueous solutions
In aqueous solutions hydrogen peroxide differs from the pure material due to the effects of hydrogen bonding between water and hydrogen peroxide molecules. Hydrogen peroxide and water form a eutectic mixture, exhibiting freezing-point depression; pure water has a melting point of 0°C and pure hydrogen peroxide of −0.43 °C, but a 50% (by volume) solution of the 2 freezes at -51°C. The boiling point of the same mixture is also depressed and occurs at 114°C, less than the average of the boiling points of pure water and hydrogen peroxide (125°C).
Hydrogen peroxide (H
The molecular structures of gaseous and crystalline H
Comparison with analogues
Hydrogen peroxide has a number of structural analogues of which hydrogen disulfide is perhaps the most closely related. It has the highest (theoretical) boiling point of all the analogues. Its melting point is also fairly high, being comparable to that of hydrazine, with only hydroxylamine crystallising significantly more readily. This indicates the presence of particularly strong hydrogen bonding. All of the analogues are thermodynamically unstable, particularly upon heating, with hydrazine and hydroxylamine being potentially explosive. Diphosphane is unique in being pyrophoric and is the most difficult of the analogues to synthesise. Structurally, the analogues all adopt similar skewed structures, due to repulsion between adjacent lone pairs.
Hydrogen peroxide was first described in 1818 by Louis Jacques Thénard, who produced it by treating barium peroxide with nitric acid. An improved version of this process used hydrochloric acid, followed by addition of sulfuric acid to precipitate the barium sulfate byproduct. Thénard's process was used from the end of the 19th century until the middle of the 20th century.
Pure hydrogen peroxide was long believed to be unstable as early attempts to separate it from the water, which is present during synthesis, all failed. However, this instability was due to traces of impurities (transition metals salts) which catalyze the decomposition of the hydrogen peroxide. Pure hydrogen peroxide was first obtained 80 years after its discovery by Richard Wolffenstein, who produced it via vacuum distillation. At the end of the 19th century, Petre Melikishvili and his pupil L. Pizarjevski showed that of the many proposed formulas of hydrogen peroxide, the correct one was H−O−O−H.
Previously, hydrogen peroxide has been prepared industrially by hydrolysis of the ammonium peroxydisulfate, which was itself obtained via the electrolysis of a solution of ammonium bisulfate (NH
Today, hydrogen peroxide is manufactured almost exclusively by the anthraquinone process, which was formalized in 1936 and patented in 1939. It begins with the reduction of an anthraquinone (such as 2-ethylanthraquinone or the 2-amyl derivative) to the corresponding anthrahydroquinone, typically via hydrogenation on a palladium catalyst; the anthrahydroquinone then undergoes to autoxidation to regenerate the starting anthraquinone, with hydrogen peroxide being produced as a by-product. Most commercial processes achieve oxidation by bubbling compressed air through a solution of the derivatized anthracene, whereby the oxygen present in the air reacts with the labile hydrogen atoms (of the hydroxy group), giving hydrogen peroxide and regenerating the anthraquinone. Hydrogen peroxide is then extracted and the anthraquinone derivative is reduced back to the dihydroxy (anthracene) compound using hydrogen gas in the presence of a metal catalyst. The cycle then repeats itself.
The simplified overall equation for the process is deceptively simple:
A process to produce hydrogen peroxide directly from the elements has been of interest for many years. Direct synthesis is difficult to achieve as, in terms of thermodynamics, the reaction of hydrogen with oxygen favours production of water. Systems for direct synthesis have been developed; most of which are based around finely dispersed metal catalysts. However none of these have yet reached a point where they can be used for industrial-scale synthesis.
Hydrogen peroxide is most commonly available as a solution in water. For consumers, it is usually available from pharmacies at 3 and 6 wt% concentrations. The concentrations are sometimes described in terms of the volume of oxygen gas generated; one milliliter of a 20-volume solution generates twenty milliliters of oxygen gas when completely decomposed. For laboratory use, 30 wt% solutions are most common. Commercial grades from 70% to 98% are also available, but due to the potential of solutions of >68% hydrogen peroxide to be converted entirely to steam and oxygen (with the temperature of the steam increasing as the concentration increases above 68%) these grades are potentially far more hazardous, and require special care in dedicated storage areas. Buyers must typically allow inspection by commercial manufacturers.
In 1994, world production of H
The rate of decomposition increases with rising temperature, concentration and pH. With cool, dilute, acidic solutions showing the best stability. Decomposition is catalysed by various compounds, including most transition metals and their compounds (e.g. manganese dioxide, silver, and platinum). Certain metal ions, such as Fe2+
Non-metallic catalysts include potassium iodide; which reacts particularly rapidly and forms the basis of the Elephant toothpaste experiment. Hydrogen peroxide can also be decomposed biologically by enzyme catalase.
The decomposition of hydrogen peroxide liberates oxygen and heat; this can be dangerous as spilling high concentrations of hydrogen peroxide on a flammable substance can cause an immediate fire.
Hydrogen peroxide exhibits oxidizing and reducing properties, depending on pH.
In acidic solutions, H
In acidic solutions Fe2+
and sulfite (SO2−
In basic solution, hydrogen peroxide can reduce a variety of inorganic ions. When it acts as a reducing agent, oxygen gas is also produced. For example hydrogen peroxide will reduce sodium hypochlorite and potassium permanganate, which is a convenient method for preparing oxygen in the laboratory.
Hydrogen peroxide is frequently used as an oxidizing agent in organic chemistry. One application is for the oxidation of thioethers to sulfoxides. For example, methyl phenyl sulfide can be readily oxidized in high yield to methyl phenyl sulfoxide:
Formation of peroxide compounds
For example, on addition to an aqueous solution of chromic acid (CrO
A study published in Nature found that hydrogen peroxide plays a role in the immune system. Scientists found that hydrogen peroxide inside of cells increased after tissues are damaged in zebra fish, which is thought to act as a signal to white blood cells to converge on the site and initiate the healing process. When the genes required to produce hydrogen peroxide were disabled, white blood cells did not accumulate at the site of damage. The experiments were conducted on fish; however, because fish are genetically similar to humans, the same process is speculated to occur in humans. The study in Nature suggested asthma sufferers have higher levels of hydrogen peroxide in their lungs than healthy people, which could explain why asthma sufferers have inappropriate levels of white blood cells in their lungs.
Hydrogen peroxide has important roles as a signaling 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.
Drinking water treatment
Hydrogen peroxide can be used for cleaning well water or other drinking water sources, by removing odors, organic materials that change the water taste, and the removal of H2S and Iron, while reducing trihalomethanes and haloacetic acids. Hydrogen peroxide can be used to increase or decrease the amount of ozone in drinking water.
Hydrogen peroxide is replacing prechlorination as a way to deal with odors entering wastewater treatment plants:
The processing of wastewater sludge (or biosolids) can cause the generation of hydrogen sulfide, a poisonous and odoriferous gas. Hydrogen sulfide can also damage equipment and concrete structures.
Sulfides are found throughout the environment as a result of both natural and industrial processes. Most sulfides found in nature were produced biologically (under anaerobic conditions) and occur as free hydrogen sulfide (H2S) – characterized by its rotten egg odor. Biogenic H2S is encountered in sour groundwaters, swamps and marshes, natural gas deposits, and sewage collection/treatment systems. Man-made sources of H2S typically occur as a result of natural materials containing sulfur (e.g., coal, gas and oil) being refined into industrial products. For a variety of reasons – aesthetics (odor control), health (toxicity), ecological (oxygen depletion in receiving waters), and economic (corrosion of equipment and infrastructure) – sulfide laden wastewater must be handled carefully and go through a remediation process before it can be released to the environment. Typical discharge limits for sulfide are < 1 mg/L.
Hydrogen peroxide is a strong oxidizer effective in controlling sulfide and organic-related odors in wastewater collection and treatment systems. It is typically applied to a wastewater system where there is a retention time of 30 minutes to 5 hours before hydrogen sulfide is released. Hydrogen peroxide oxidizes the hydrogen sulfide and promotes bio-oxidation of organic odors.
BOD and COD removal from wastewater
Hydrogen peroxide decomposes to oxygen and water, adding dissolved oxygen to the system, thereby negating some Biochemical Oxygen Demand (BOD). Typical sewage at its first stage has aerobic organisms quickly consuming the oxygen, then dying and decomposing, and anaerobic organisms usually bacteria, set in, creating a toxic environment through their anaerobic digestion. In order to "re-vitalize" the water, various methods of aeration are typically used.
Hydrogen peroxide has been used to reduce the BOD and COD of industrial waste-water for many years. While the cost of removing BOD/COD through chemical oxidation is typically greater than that through physical or biological means, there are nonetheless specific situations which justify its use. These include:
Supply of supplemental Dissolved Oxygen (DO) when biological treatment systems experience temporary overloads or equipment failure.
As indicated by these examples, hydrogen peroxide can be used as a stand-alone treatment or as an enhancement to existing physical or biological treatment processes, depending on the situation.
Nitrogen oxide (NOx) abatement
Nitrogen oxides are major pollutants in the atmosphere, being a precursor to acid rain, photochemical smog, and ozone accumulation. The oxides are mainly nitric oxide (NO) and nitrogen dioxide (NO2) both of which are corrosive and hazardous to health, typically created from the decomposition of organic materials, assisted by anaerobic organisms, or released during the combustion of fossil fuels.
With the use of catalytic converters on automobiles, the initial regulatory focus of controlling of mobile NOx emissions has reached the point where further restriction has become economically impractical. Consequently, the stationary sources of NOx emissions are now being subjected to more stringent standards in many areas of the U.S. Stationary sources include nitric acid manufacturing plants, manufacturers of nitrated materials such as fertilizer and explosives, and industrial manufacturers (metallurgical processors, glass manufacturers, cement kilns, power generators, etc.) where high processing temperatures are used.
Because of the environmental concerns posed by air pollution, much research time and money have been expended to develop methods for controlling NOx emissions. Several 'NOx scrubbing' processes have been developed, using H2O2 as part of the solution, where the nitrogen oxides are converted to nitrate, nitric acid or nitrogen.
Hydrogen peroxide is also used to eliminate nitrogen oxide development 'at the source', by reacting with HNO as it is formed, and eliminating its decomposition into NO or NO2.
Hydrogen peroxide is one of the most versatile, dependable and environmentally compatible oxidizing agents. The relative safety and simplicity of its use as an oxidizing agent has led to the development of a number of applications in refinery wastewater systems:
The strong oxidizing power of hydrogen peroxide makes it suitable for the destruction of a variety of pollutants. Optimization of conditions using hydrogen peroxide to destroy these pollutants can involve control of pH, temperature and reaction time. No additional additives are required.
Pollutants that are more difficult to oxidize require hydrogen peroxide to be activated with catalysts such as iron. Catalyzed oxidation can also be used to destroy easily oxidized pollutants more rapidly.
Under acid pH conditions, the addition of iron salts to a wastewater solution activates hydrogen peroxide to generate free radicals, which can attack a variety of organic compounds. Other metal salts and conditions can apply (e.g. in cyanide destruction, a copper catalyst can be used at a pH of 8.5 – 11.5).
Aeration for fish and plants
Some horticulturalists and users of hydroponics advocate the use of weak hydrogen peroxide solution in watering solutions. Its spontaneous decomposition releases oxygen that enhances a plant's root development and helps to treat root rot (cellular root death due to lack of oxygen) and a variety of other pests.
Laboratory tests conducted by fish culturists in recent years have demonstrated that common household hydrogen peroxide can be used safely to provide oxygen for small fish. The hydrogen peroxide releases oxygen by decomposition when it is exposed to catalysts such as manganese dioxide.
Bleaching wood pulp
Possible alternative to chlorine bleaches
Other bleaching applications are becoming more important as hydrogen peroxide is seen as an environmentally benign alternative to chlorine-based bleaches. However scientific studies have found hydrogen peroxide to be ineffective in certain cases, and generally instruct hospitals, medical institutions, and other locations where public health is monitored, to use chlorine-based bleaches for disinfection.
Mild bleaches in laundry detergents
Intermediate processes in the chemical industry
Hydrogen peroxide is also used in the production of epoxides, such as propylene oxide: Reaction with carboxylic acids produces a corresponding peroxy acid. Peracetic acid and meta-chloroperoxybenzoic acid (commonly abbreviated mCPBA) are prepared from acetic acid and meta-chlorobenzoic acid, respectively. The latter is commonly reacted with alkenes to give the corresponding epoxide.
In the PCB manufacturing process, hydrogen peroxide mixed with sulfuric acid was used as the microetch chemical for copper surface roughening preparation.
A combination of a powdered precious metal-based catalyst, hydrogen peroxide, methanol and water can produce superheated steam in one to two seconds, releasing only CO
Recently, there has been increased use of vaporized hydrogen peroxide in the validation and bio-decontamination of half-suit and glove-port isolators in pharmaceutical production.
Rapid oxidation for nuclear plant shutdown
Nuclear pressurized water reactors (PWRs) use hydrogen peroxide during the plant shutdown to force the oxidation and dissolution of activated corrosion products deposited on the fuel. The corrosion products are then removed with the cleanup systems before the reactor is disassembled.
Oil and gas exploration fossil analysis
Hydrogen peroxide is also used in the oil and gas exploration industry to oxidize rock matrix in preparation for micro-fossil analysis.
A method of producing propylene oxide from hydrogen peroxide has been developed. The process is claimed to be environmentally friendly, since the only significant byproduct is water. Two of these "HPPO" (hydrogen peroxide to propylene oxide) plants came onstream in 2008: One of them located in Belgium is a Solvay, Dow-BASF joint venture, and the other in Korea is an EvonikHeadwaters, SK Chemicals joint venture. A caprolactam application for hydrogen peroxide has been commercialized. Potential routes to phenol and epichlorohydrin utilizing hydrogen peroxide have been postulated.
Hydrogen peroxide is generally recognized as safe (GRAS) as an antimicrobial agent, an oxidizing agent and for other purposes by the U.S. FDA. For example, 35% hydrogen peroxide is used to prevent infection transmission in the hospital environment, and hydrogen peroxide vapor is registered with the US EPA as a sporicidal sterilant.
On the other hand many false claims have been made about the therapeutic properties of hydrogen peroxide, some even lethal, as discussed below.
Disinfectant for inanimate objects
Hydrogen peroxide has been used, in sufficient concentrations, to disinfect inanimate objects. As stated above scientific research concluded that chlorine based disinfectants are better used in hospital and other public institutions.
Hydrogen peroxide mixed with baking soda and salt is used as a toothpaste, but its use was shown to be no more effective than toothpaste.
Hydrogen peroxide and benzoyl peroxide are sometimes used to treat acne. This too has been challenged by the medical establishment, after research showed that hydrogen peroxide even at minute quantities is harmful to the healing process. A fundamental difference from benzoyl peroxide is that hydrogen peroxide is not lipid soluble. Benzoyl peroxide selectively concentrates in the follicles and sebaceous glands because of its lipophilic properties, but hydrogen peroxide is much less soluble in lipids and is a much smaller molecule. This allows it to penetrate at any point in the skin and enter damaged cells relatively easily, leading to the aforementioned harm to the healing process.
Commonly used as treatment for disinfecting wounds, there is a body of evidence, e.g. and many reports since, that the use of large volumes of hydrogen peroxide over substantial tissue areas can lead to a dangerous oxygen embolism (gas embolism). While judicious use on surface wounds can utilize the catalase-caused "fizzing" effect to assist debridement and cleaning of soil from the wound, clinicians are advised to consult the literature before using peroxide on wounds and tissue cavities. It has also been shown that hydrogen peroxide, even in dilute solutions and minute quantities can slow the healing process on wounds. Further, hydrogen peroxide applied to wounds can impede healing and lead to scarring because it destroys newly formed skin cells.
At one time, the most common household use of hydrogen peroxide was to disinfect wounds, but it is now thought to slow healing by affecting tissue growth through several possible factors. Only a very minute concentration of H2O2 can induce healing, and only if not repeatedly applied. Surgical use can lead to gas embolism formation.
Cure for cancer
Following the call by alternative medicine advisors for drinking diluted hydrogen peroxide, and using it in various ways such as in shampoo and as an additive to toothpaste, as a treatment to illness in general and cancer in particular, the American Cancer Society states that "there is no scientific evidence that hydrogen peroxide is a safe, effective or useful cancer treatment", and advises cancer patients to "remain in the care of qualified doctors who use proven methods of treatment and approved clinical trials of promising new treatments."
Inhalation, Oral administration and Injection
For treatment of various illnesses, another alternative medical procedure advocated by this group of medical doctors (now banned from publishing their material) is intravenous injection of hydrogen peroxide, which has been linked to several deaths. Also advocated by this group and its followers are oral administration of "dilute quantities" of H2O2, and inhalation of hydrogen peroxide at a concentration of about 1%. These practices have been challenged by the medical establishment as well.
It is used to whiten bones that are to be put on display.
Hydrogen peroxide is used with phenyl oxalate ester and an appropriate dye in glow sticks as an oxidizing agent. It reacts with the ester to form an unstable CO
Hydrogen peroxide can be combined with vinegar and table salt to form a substitute for industrial chemicals such as ferric chloride, ammonium persulfate, or hydrochloric acid as a hobbyist's printed circuit board etchant.
Hydrogen peroxide may be used in accelerated aging of alcoholic spirits. Some hobby distillers advocate adding small amounts of hydrogen peroxide to distilled spirits, on the theory that the oxygen released will accelerate the oxidation of compounds that occurs naturally when spirits are aged in somewhat permeable oak barrels. This has not been proven scientifically.
High concentration H
As a bipropellant H
In the 1940s and 1950s, the Walter turbine used hydrogen peroxide for use in submarines while submerged; it was found to be too noisy and require too much maintenance compared to diesel-electric power systems. Some torpedoes used hydrogen peroxide as oxidizer or propellant, but this was dangerous and has been discontinued by most navies. Hydrogen peroxide leaks were blamed for the sinkings of HMS Sidon and the Russian submarine Kursk. It was discovered, for example, by the Japanese Navy in torpedo trials, that the concentration of H
While rarely used now as a monopropellant for large engines, small hydrogen peroxide attitude control thrusters are still in use on some satellites.They are easy to throttle, and safer to fuel and handle before launch than hydrazine thrusters. However, hydrazine is more often used in spacecraft because of its higher specific impulse and lower rate of decomposition.
Hydrogen peroxide has been used for creating organic peroxide based explosives for improvised explosive devices, including the 7 July 2005 London bombings. These explosives tend to degrade quickly and hence are not used as commercial or military explosives.
Regulations vary, but low concentrations, such as 6%, are widely available and legal to buy for medical use. Most over-the-counter peroxide solutions are not suitable for ingestion. Higher concentrations may be considered hazardous and are typically accompanied by a Material Safety Data Sheet (MSDS). In high concentrations, hydrogen peroxide is an aggressive oxidizer and will corrode many materials, including human skin. In the presence of a reducing agent, high concentrations of H
High-concentration hydrogen peroxide streams, typically above 40%, should be considered hazardous due to concentrated hydrogen peroxide's meeting the definition of a DOT oxidizer according to U.S. regulations, if released into the environment. The EPA Reportable Quantity (RQ) for D001 hazardous wastes is 100 pounds (45 kg), or approximately 10 US gallons (38 L), of concentrated hydrogen peroxide.
Hydrogen peroxide should be stored in a cool, dry, well-ventilated area and away from any flammable or combustible substances. It should be stored in a container composed of non-reactive materials such as stainless steel or glass (other materials including some plastics and aluminium alloys may also be suitable). Because it breaks down quickly when exposed to light, it should be stored in an opaque container, and pharmaceutical formulations typically come in brown bottles that filter out light.
Hydrogen peroxide, either in pure or diluted form, can pose several risks, the main one being that it forms explosive mixtures upon contact with organic compounds. Highly concentrate hydrogen peroxide itself is unstable, and can then cause a boiling liquid expanding vapor explosion (BLEVE) of the remaining liquid. Distillation of hydrogen peroxide at normal pressures is thus highly dangerous. It is also corrosive especially when concentrated but even domestic-strength solutions can 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 (10 times the volume of a 3% solution) leading to internal bleeding. Inhaling over 10% can cause severe pulmonary irritation.
With a significant vapor pressure (1.2 kPa at 50 °C[CRC Handbook of Chemistry and Physics, 76th Ed, 1995–1996]), hydrogen peroxide vapor is potentially hazardous. According to the U.S. NIOSH Immediately dangerous to life and health limit (IDLH) is only 75 ppm. The U.S. Occupational Safety and Health Administration (OSHA) has established a permissible exposure limit of 1.0 ppm calculated as an eight hour time weighted average (29 CFR 1910.1000, Table Z-1) and hydrogen peroxide has also been classified by the American Conference of Governmental Industrial Hygienists (ACGIH) as a "known animal carcinogen, with unknown relevance on humans." Information on the hazards of hydrogen peroxide is available from OSHA and from the ATSDR.
Dubious health claims
Hydrogen peroxide therapy, a purported treatment where small, highly diluted amounts of food-grade hydrogen peroxide are taken orally or administered intravenously, is claimed to cure everything from acne to HIV and cancer. Several books on the topic advocate this therapy. This therapy is not approved by the U.S. FDA. 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". Deaths and serious injury have been reported after intravenous injection of hydrogen peroxide.