Hydrogen peroxide is a chemical compound with the formula H
2 O
2 . In its pure form, it is pale blue, clear liquid, slightly more viscous than water. Hydrogen peroxide is the simplest peroxide (a compound with a single oxygen-oxygen bond). It is used as an oxidizer, bleach and antiseptic. Hydrogen peroxide concentrated, or "high test peroxide", is a reactive oxygen species and has been used as a propellant in a rocket. Its chemistry is dominated by its unstable peroxide bonding properties.
Hydrogen peroxide is unstable and slowly decomposes in the presence of a base or catalyst. Due to its instability, hydrogen peroxide is usually stored with a stabilizer in a weak acid solution. Hydrogen peroxide is found in biological systems including the human body. Enzymes that use or break down hydrogen peroxide are classified as peroxidase.
Video Hydrogen peroxide
Properties
Boiling point H
2 O > 2 has been extrapolated to 150.2 Ã, Â ° C, about 50 ° C higher than water. In practice, hydrogen peroxide will experience potentially explosive thermal decomposition if heated at this temperature. It can be safely distilled at lower temperatures under reduced pressure.
Aqueous solution
In aqueous solutions, hydrogen peroxide differs from pure material because of the hydrogen bonding effect between water and hydrogen peroxide molecules. Hydrogen peroxide and water form a eutectic mixture, indicating depression of freezing point; pure water has a melting point of 0 Â ° C and pure hydrogen peroxide -0.43 Â ° C. The boiling point of the same mixture is also depressed in relation to the mean of both boiling points (125.1 ° C). It occurs at 114 ° C. This boiling point is 14 ° C larger than pure water and 36.2 ° C. less than pure hydrogen peroxide.
Structure
Hydrogen peroxide ( H
2 O < br> 2 ) is a nonplanar molecule with (bent) C 2 symmetry. Although the O-O bond is a single bond, the molecule has a relatively high rotational barrier of 2460 cm -1 (29.45 kJ/mol); for comparison, the rotational barrier for ethane is 12.5 kJ/mol. The increased resistance is thought to result from the repulsion of a pair of adjacent oxygen atoms and produces hydrogen peroxide that exhibits atropisomerism.
Structure of gas molecules and crystals H
2 O 2 very different. This difference is associated with the effect of hydrogen bonding, which is not present in the gas state. Crystal H
2 O
2 is tetragonal with space group D 4
4 P 4 1 2 1 .
Comparison with analog
Hydrogen peroxide has some structural analogues with the binding arrangement (water is also shown for comparison). It has the highest (theoretical) boiling point of this series (X = O, N, S). Its melting point is also quite high, comparable to hydrazine and water, with only hydroxylamine crystallizing significantly more easily, indicating a very strong hydrogen bond. Diphosphane and hydrogen disulfide exhibit only weak hydrogen bonds and have little chemical resemblance to hydrogen peroxide. All these analogues are thermodynamically unstable. Structurally, all analogs adopt a similar oblique structure, due to repulsion between adjacent independent pairs.
Maps Hydrogen peroxide
Discovery
Alexander von Humboldt synthesized one of the first synthetic peroxides, barium peroxide, in 1799 as a by-product of his attempt to decipher the air.
Nineteen years later Louis Jacques ThÃÆ'Â © nard acknowledged that this compound could be used for the preparation of previously unknown compounds, which he described as oxidized water - later known as hydrogen peroxide. An improved version of this process uses hydrochloric acid, followed by addition of sulfuric acid to precipitate sulfate sulfate base. This process is used since the late 19th century until the mid-20th century.
ThÃÆ' Â © nard and Joseph Louis Gay-Lussac synthesized sodium peroxide in 1811. The effects of peroxide bleaching and its salts on natural dyes were known around that time, but initial efforts of peroxide production failed, and the first plant to produce hydrogen peroxide was built in 1873 in Berlin. The discovery of synthesis of hydrogen peroxide by electrolysis with sulfuric acid introduces a more efficient electrochemical method. It was first implemented into the industry in 1908 in WeiÃÆ'Ÿenstein, Carinthia, Austria. The anthraquinone process, still in use, was developed during the 1930s by the German chemical producer IG Farben in Ludwigshafen. The increase in demand and improvement in the synthesis method resulted in an annual increase in the production of hydrogen peroxide from 35,000 tons in 1950, to over 100,000 tons in 1960, to 300,000 tons in 1970; in 1998 reached 2.7 million tons.
The old pure hydrogen peroxide is believed to be unstable, because early attempts to separate it from water, which existed during synthesis, all failed. This instability is caused by impurity traces (metal-transition metals), which catalyze the decomposition of hydrogen peroxide. Pure hydrogen peroxide was first obtained in 1894 - nearly 80 years after its discovery - by Richard Wolffenstein, who made it with a vacuum distillation.
The determination of the molecular structure of hydrogen peroxide proved very difficult. In 1892 Italian physical chemistry Giacomo Carrara (1864-1925) determined the molecular mass by freezing depression, which confirmed that the molecular formula was H 2 O 2 . At least half a dozen hypothetical molecular structures seem consistent with available evidence. In 1934, the English mathematical physicist William Penney and the Scottish physicist Gordon Sutherland proposed a molecular structure for hydrogen peroxide which is very similar to the one currently accepted.
Production
Previously, hydrogen peroxide was prepared industrially by hydrolysis of ammonium peroxydisulfate, which was obtained by electrolysis of ammonium bisulfate solution ( NH
4 HSO
4 ) in sulfuric acid:
- ( NH
4 )
2 S
2 O
8 2 H
2 H 2 O
2 2 ( NH
4 ) HSO
4
Today, hydrogen peroxide is produced almost exclusively by the anthraquinone process, formalized in 1936 and patented in 1939. It begins with the reduction of anthraquinones (such as 2-ethylantrakuinone or 2-amyl derivatives) to the corresponding anthrahydroquinone, usually by hydrogenation of the catalyst palladium; anthrahydroquinone then undergoes autoxidation to regenerate the initial anthraquinone, with hydrogen peroxide as a by-product. Most commercial processes achieve oxidation by inflating compressed air through a solution of antiviral derivatives, in which oxygen in the air reacts with a labile hydrogen atom (from a hydroxy group), producing hydrogen peroxide and regenerating anthraquinones. Hydrogen peroxide is then extracted, and the anthraquinone derivatives are reduced back to dihydroxy (anthracene) compounds using hydrogen gas in the presence of a metal catalyst. The cycle then repeats itself.
The simplified overall equation for the process is simple:
- H
2 O
2 - > H
2 O > 2
Process economics is highly dependent on effective (expensive) quinone recycling and solvent extraction, and hydrogenation catalysts.
A process for producing hydrogen peroxide directly from the elements has been interesting for years. Direct synthesis is difficult to achieve, because the hydrogen reaction with oxygen thermodynamically supports water production. Systems for direct synthesis have been developed, most of which are based on dispersed metal catalysts. None of these have not reached a point where they can be used for industrial-scale synthesis.
Availability
Hydrogen peroxide is most commonly available as a solution in water. For consumers, it is usually available from pharmacies at concentrations of 3 and 6% by weight. Concentration is sometimes explained in terms of the volume of oxygen gas produced; a milliliter of volume 20 solution produces 20 milliliters of oxygen gas when it is completely decomposed. For laboratory use, a 30% weight solution is the most common. Commercial value from 70% to 98% is also available, but because of the potential solution of more than 68% hydrogen peroxide is converted entirely to vapor and oxygen (with steam temperatures increasing when concentrations rise above 68%) this value is potentially much more dangerous and requires special care in a dedicated storage area. Buyers should normally allow inspection by commercial manufacturers.
In 1994, world production H
2 O < span>
2 O
2 sold about 0.54 USD/kg , equivalent to 1.50 USD/kg (0.68 USD/lb) at "100% basis".
Hydrogen peroxide occurs in surface water, groundwater and in the atmosphere. It is formed on the illumination or natural catalytic action by a substance contained in water. Sea water contains 0.5 to 14 Âμg/L hydrogen peroxide, fresh water 1 to 30 Âμg/L and air of 0.1 to 1 part per billion.
Reaction
Decomposition
Hydrogen peroxide is thermodynamically unstable and decomposes to form water and oxygen with? H o of -98.2 kJ/mol and a S 70.5 J/(molÃ, Â · K):
- 2 H
2 O
2 -> 2 H
2 O O
2
Decomposition rates increase with increasing temperature, concentration, and pH, with cold, dilute, and acidic solutions that show the best stability. The decomposition is catalyzed by various compounds, including most transition metals and their compounds (eg manganese dioxide, silver, and platinum). Specific metal ions, such as Fe 2 or Ti 3 , may cause decomposition to take different paths, with free radicals such as (HOÃ, Â ·) and (HOOÃ, Â ·) being formed. Non-metallic catalysts include potassium iodide, which reacts very quickly and forms the basis of elephant toothpaste experiments. Hydrogen peroxide can also be biologically described by the catalase enzyme. The decomposition of hydrogen peroxide releases oxygen and heat; this can be dangerous, because spilling of high concentrations of hydrogen peroxide on flammable substances can cause direct fires.
Redox reaction
Hydrogen peroxide shows oxidation and reduces properties, depending on pH.
In an acid solution, H
2 O
2 is one of the most powerful oxidants known- stronger than chlorine, chlorine dioxide, and potassium permanganate. Also, through catalysis, H
2 O < span>
2 can be converted to hydroxyl radical (Â · OH), which is highly reactive.
In the acid solution Fe 2 oxidized to Fe 3 ( hydrogen peroxide acts as an oxidizing agent):
- 2 Fe 2
(aq) H
2 O
2 2 H (aq) -> 2 Fe 3 (aq) 2 H
2 O (l)
and sulfit ( SO 2 - 3 ) is oxidized to sulfate ( SO 2 -
4 ). However, the potassium permanganate is reduced to Mn 2 by acidic H
2 O < span>
2 . However, under alkaline conditions, some of these reactions reversed; for example, Mn 2
oxidized to Mn 4 MnO
2 ).
In a basic solution, hydrogen peroxide can reduce various inorganic ions. When acting as a reducing agent, oxygen gas is also produced. For example, hydrogen peroxide reduces sodium hypochlorite and potassium permanganate, which is a convenient method for preparing oxygen in the laboratory:
- NaOCl H
2 O
2 -> O < span>
2 NaCl H
2 O - 2 KMnO
4 3 H
2 O
2 -> 2 MnO 2 2 KOH 2 H 2 O 3 O sub style = "font-size: inherit; line-height: inherit; vertical-align: baseline"> 2
Organic reactions
Hydrogen peroxide is often used as an oxidizing agent. Illustrative is the oxidation of thioethers to sulfoxides:
- Ph -S-CH
3 H
2 O
2 -> Ph - S (O) -CH
3 < span> H
2 O
Alkaline hydrogen peroxide is used for epoxidation of the electron-deficient alkene such as acrylic acid derivatives, and for the oxidation of alkylboran to alcohol, the second step of hydroboration oxidation. It is also a major reactant in the Dakin oxidation process.
Precursors to other peroxide compounds
Hydrogen peroxide is a weak acid, forming hydroperoxide or peroxide salts with many metals.
It also converts the metal oxide to the corresponding peroxide. For example, after treatment with hydrogen peroxide, chromic acid ( CrO
3 H
2 SO
4 stable CrO ( O
2 < span>)
2 .
Such reactions are used industrially to produce peroxoanions. For example, the reaction with borax leads to sodium perborate, bleach used in laundry detergents:
- Na
2 B < span>
4 O
7 4 H
2 O
2 2 NaOH -> 2 Na
2 B
2 O
4 (OH)
4 H
2 O
H
2 O
< sub style = "inherit; vertical-align: baseline"> 2 change the carboxylic acid (RCO 2 H ) to peroxy acid (RC (O) O 2 H), which is used as an oxidizer. Hydrogen peroxide reacts with acetone to form acetone peroxide and with ozone to form trioxidane. Hydrogen peroxide forms a stable stir with urea (hydrogen peroxide - urea), sodium carbonate (sodium percarbonate) and other compounds. An acid-base adduct with triphenylphosphine oxide is a useful "carrier" for H
2 O
2 in several reactions.
Anion peroxide is a nucleophile that is stronger than hydroxide and replaces hydroxyl from oxyion for example. forming perborat and perkarbonat. Sodium perborate and sodium percarbonate are important consumer and industrial bleaching agents; they stabilize hydrogen peroxide and limit side reactions (eg reduction and decomposition of notes below). Anion peroxide forms a stir with urea, urea-hydrogen peroxide.
Hydrogen peroxide is an oxidizing agent and reducing agent. Oxidation of hydrogen peroxide by sodium hypochlorite produces a single oxygen. The net reaction of the iron ions with hydrogen peroxide is the iron and oxygen ions. This results through the oxidation of single electrons and hydroxyl radicals. It is used in several organic chemical oxidations, eg. in the Fenton reagent. Only the catalytic amount of iron ions is needed because the peroxide also oxidizes the iron ions to iron. The net reaction of hydrogen peroxide and permanganate or manganese dioxide is manganese ion; however, until the peroxide is depleted of some manganese ions in the reoxidation to make the reaction catalytic. This forms the basis for common monopropellant rockets.
Biological function
Hydrogen peroxide is formed in humans and animals as short-lived products in biochemical processes and is toxic to cells. This toxicity is caused by the oxidation of proteins, lipid membranes and DNA by the peroxide ions. A class of biological enzymes called SOD (superoxide dismutase) are developed in almost all living cells as important antioxidant agents. They promote superoxide disproportionation into oxygen and hydrogen peroxide, which are then rapidly broken down by the enzyme catalase into oxygen and water.
- The formation of hydrogen peroxide by superoxide dismutase (SOD)
Peroxisomes are organelles found in almost all eukaryotic cells. They are involved in the long-chain fatty acid catabolism, branched chain fatty acids, acid D -amino, polyamine, and plasmalogens biosynthesis, etherphospholipids that are essential for the normal functioning of the mammalian and lung brains. After oxidation, they produce hydrogen peroxide in the following process:
- FAD = flavin adenine dinucleotide
Katalase, enzym peroxisomal lainnya, menggunakan H 2 O 2 ini untuk mengoksidasi substrat lain, termasuk fenol, asam format, formaldehida, dan alkohol, melalui reaksi peroksidasi:
- , sehingga menghilangkan peroxide hydrogen beracun dalam process.
This reaction is important in liver and kidney cells, where peroxisomes neutralize the various toxic substances that enter the blood. Some human drinks of ethanol are oxidized to acetaldehyde in this way. In addition, when the excess H 2 O 2 accumulates in the cell, the catalase converts it into H 2 O through this reaction:
Another origin of hydrogen peroxide is the degradation of adenosine monophosphate which produces hypoxanthine. Hypoxanthin is then oxidatively catabolized first to xanthine and then to uric acid, and the reaction is catalyzed by the xanthine oxidase enzyme:
Degradation of guanosine monophosphate produces xanthine as an intermediate product which is then converted in the same way to uric acid with the formation of hydrogen peroxide.
Sea urchin eggs, shortly after fertilization by sperm, produce hydrogen peroxide. Then quickly separated into OHÃ, Â · radical. Radicals function as radical polymerization initiators, which surround an egg with a protective layer of polymer.
The bomber beetle has a device that allows it to shoot a corrosive bubble and stink to its enemies. The beetle produces and stores hydroquinone and hydrogen peroxide, in two separate reservoirs at the rear end of its stomach. When threatened, the beetle contracts a muscle that forces two reactants through a valved tube into a water-mixing chamber and a mixture of catalytic enzymes. When combined, the reactant undergoes a harsh exothermic chemical reaction, raising the temperature to near the boiling point of water. The boiling and foul-smelling liquid partially becomes gas (light evaporation) and is ejected through the outlet valve with a loud popping sound.
Hydrogen peroxide is the plant's signaling molecule against pathogens.
Hydrogen peroxide has a role as a signaling molecule in the regulation of various biological processes. This compound is a major factor involved in the theory of free-radical aging, based on how easily hydrogen peroxide can decompose into hydroxyl radicals and how superoxide radical byproducts from cell metabolism can react with ambient water to form hydrogen peroxide. These hydroxyl radicals in turn are readily reacting with and damaging vital cellular components, especially from mitochondria. At least one study also tried to link the production of hydrogen peroxide with cancer. These studies are often cited in false treatment claims.
The amount of hydrogen peroxide in biological systems can be tested using fluorimetric test.
Usage
Bleaching
About 60% of the world's hydrogen peroxide production is used for pulp and paper bleaching.
Detergent
The second major industrial application is the manufacture of sodium percarbonate and sodium perborate, which is used as a mild bleach in laundry detergents. Sodium percarbonate, which is an addition to sodium carbonate and hydrogen peroxide, is an active ingredient in products such as OxiClean and Tide washing detergents. When dissolved in water, it releases hydrogen peroxide and sodium carbonate:
- 2 Na 2 CO 3 Ã, Â · 3 H 2 O 2 -> 2 Na 2 CO 3 3 H 2 O 2
Production of organic compounds
It is used in the production of various organic peroxides with dibenzoyl peroxide into high volume samples. It is used in polymerization, as a flour bleach agent and as a treatment for acne. Peroxy acid, such as peracetic acid and meta-chloroperoxybenzoic acid are also produced using hydrogen peroxide. Hydrogen peroxide has been used to make organic peroxide based explosives, such as acetone peroxide.
Disinfectant
Hydrogen peroxide is used in certain wastewater treatment processes to remove organic impurities. In advanced oxidation processes, the Fenton reaction produces highly reactive hydroxyl radicals (Ã, Â · OH). It lowers organic compounds, including those that are usually strong, such as aromatic or halogenated compounds. It can also oxidize the sulfur-based compounds present in the waste; which is useful because it generally reduces their odor.
Hydrogen peroxide can be used for sterilization of various surfaces, including surgical instruments and can be used as vapor (VHP) for room sterilization. H 2 O 2 shows the broad spectrum of viral, bacterial, yeast, and bacterial spores. In general, greater activity was seen against Gram-positive bacteria than Gram-negative; however, the presence of other catalases or peroxidases in these organisms may increase tolerance in the presence of lower concentrations. Higher concentrations of H 2 O 2 (10 to 30%) and longer contact time are required for sporicidal activity.
Hydrogen peroxide is seen as a safe alternative to the environment with chlorine-based bleach, as it is degraded to form oxygen and water and is generally known to be safe as antimicrobial agents by the US Food and Drug Administration (FDA).
Historically hydrogen peroxide is used to disinfect wounds, in part because of their low cost and rapid availability compared to other antiseptics. It is now considered to inhibit healing and to induce scarring for destroying newly formed skin cells. Only very low concentrations of H 2 O 2 can induce healing, and only if not repeatedly applied. Surgical use may lead to the formation of gas embolism. Nonetheless, it is still used for wound care in many developing countries.
Dermal exposure to dilute the hydrogen peroxide solution causes bleaching or bleaching of the skin due to microemboli caused by oxygen bubbles in the capillaries.
Cosmetics app
Diluted H
2 O
2 (between 1.9% and 12%) mixed with ammonium hydroxide is used to whiten human hair. This chemical bleaching property lends its name to the phrase "blond peroxide". Hydrogen peroxide is also used for teeth whitening. It can be found in most whitening toothpaste. Hydrogen peroxide has shown positive results involving lightness and chroma shade tooth parameters. It works by oxidizing the color pigments to the enamel where the color of the teeth can indeed become lighter. Hydrogen peroxide can be mixed with baking soda and salt to make homemade toothpaste.
Hydrogen peroxide can be used to treat acne, although benzoyl peroxide is a more common treatment.
Use in alternative medicine
Alternative medicine practitioners have advocated the use of hydrogen peroxide for a variety of conditions, including emphysema, influenza, AIDS and cancer, although there is no evidence of effectiveness and in some cases can even be fatal.
This practice demands daily consumption of hydrogen peroxide, either orally or by injection and, in general, based on two precepts. First, that hydrogen peroxide is naturally produced by the body to fight infection; and secondly, that human pathogens (including cancer: See Warburg's hypothesis) are anaerobic and can not survive in an oxygen-rich environment. Intake or injection of hydrogen peroxide is believed to kill the disease by imitating the immune response in addition to increasing oxygen levels in the body. This makes it similar to other oxygen-based therapies, such as ozone therapy and hyperbaric oxygen therapy.
Both the effectiveness and safety of hydrogen peroxide therapy are scientifically questionable. Hydrogen peroxide is produced by the immune system but in a carefully controlled manner. A cell called a phagocytes swallows a pathogen and then uses hydrogen peroxide to destroy it. Peroxides are toxic to cells and pathogens and stored in special compartments, called phagosomes. Free hydrogen peroxide destroys any tissue it finds through oxidative stress; a process that has also been proposed as a cause of cancer. The claim that hydrogen peroxide therapy increases the oxygen cell level is not yet supported. The given quantity will be expected to provide very little additional oxygen compared to that available from normal respiration. It should also be noted that it is difficult to raise the level of oxygen around the cancer cells in the tumor, because the blood supply tends to be bad, a situation known as tumor hypoxia.
Large doses of hydrogen peroxide in concentrations of 3% can cause irritation and blisters to the mouth, throat, and abdomen and abdominal pain, vomiting, and diarrhea. Intravenous injection of hydrogen peroxide has been associated with 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, this therapy is not approved by the US FDA.
Propellant
High concentration H
2 O > 2 is called "high-test peroxide" (HTP). It can be used either as a monopropellant (not mixed with fuel) or as an oxidizing component of a bipropellant rocket. Use as a monopropellant takes advantage of the decomposition of 70-98% hydrogen peroxide concentration into vapor and oxygen. The propellant is pumped into the reaction chamber, where the catalyst, usually a silver or platinum screen, triggers decomposition, generating steam at more than 600 ° C (1,112 ° F), released through the nozzle, producing a boost. H
2 O
< subopport = "font-size: inherit; line-height: inherit; vertical-align: baseline"> 2 monopropellant generates maximum specific impulses ( I sp ) of 161 s (1.6 kNÃ, s/kg). Peroxide is the first large monopropellant to be adopted for use in rocket applications. Hydrazine eventually replaces the monopropellant thruster hydrogen-peroxide application primarily due to a 25% increase in vacuum-specific impulses. Hydrazine (toxic) and hydrogen peroxide (less toxic [ACGIH TLV 0.01 and 1 ppm respectively]) are the only two widely used monopropellan (other than cold gas) and are used for propulsion and power applications. Bell Rocket Belt, reaction control system for X-1, X-15, Centaur, Mercury, Joe Small, as well as turbo-pump gas generators for X-1, X-15, Jupiter, Redstone and Viking using hydrogen peroxide as monopropellant.
As a bipropellant, H
2 O < br> 2 decomposed to burn fuel as an oxidizer. Specific impulses as high as 350 s (3.5 kN Â · s/kg) can be achieved, depending on fuel. The peroxide used as an oxidizer gives slightly less than liquid oxygen, but is solid, can be stored, noncristogenic and can be more easily used to drive gas turbines to provide high pressure. using an efficient closed cycle . It can also be used for regenerative rocket engine cooling. Peroxides are used very successfully as oxidizers in Germany's World War II rocket motors (eg T-Stoff, containing oxyquinoline stabilizers, both for Walter HWK 109-500 Starthilfe RATO externally pumped monopropellant booster system, and for the series Walter HWK 109-509 series used for Me 163B), most commonly used with C-Stoff in self-accelerating hypergolic combinations, and for Black Knight and Black Arrow low-cost launchers.
In the 1940s and 1950s, the Hellmuth Walter KG turbine used hydrogen peroxide for use in submerged submarines; found too noisy and requires too much maintenance compared to diesel power systems. Some torpedoes use hydrogen peroxide as an oxidizer or propellant. Operator errors in the use of hydrogen-peroxide torpedoes are named as the probable cause of the sinking of HMS Sidon and the Russian submarine Kursk . SAAB Underwater Systems manufactures Torpedo 2000. This torpedo, used by the Swedish Navy, is powered by a piston engine driven by HTP as an oxidizer and kerosene for fuel in the bipropellant system.
Other uses
Hydrogen peroxide has a variety of domestic uses, especially as a cleaning agent and disinfectant.
- Glow sticks
Hydrogen peroxide reacts with certain esters, such as the phenyl oxalate ester (cyalume), to produce chemiluminescence; this application is most commonly encountered in the form of a light stick.
- Horticulture
Some horticultural and hydroponic users recommend the use of a weak hydrogen peroxide solution in the watering solution. Spontaneous decomposition releases oxygen which enhances root plant development and helps treat root rot (cellular root death from lack of oxygen) and various other pests.
- aerated fish
Laboratory tests conducted by fish culture in recent years have shown that ordinary household hydrogen peroxide can be used safely to provide oxygen for small fish. Hydrogen peroxide releases oxygen through decomposition when exposed to a catalyst such as manganese dioxide.
Security
Regulations vary, but low concentrations, such as 6%, are widely available and legal to be purchased for medical purposes. Most of the over-the-counter peroxide solutions are not suitable for consumption. Higher concentrations may be considered dangerous and are usually 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 reducing agent, high concentration H
2 O
2 will react violently.
High concentrations of hydrogen peroxide, usually above 40%, should be considered hazardous because the concrete hydrogen peroxide encounters the definition of DOT oxidators in accordance with US regulations, if released into the environment. The EPA Reportable Quantity (RQ) for hazardous waste D001 is 100 pounds (45 kg), or about 10 US gallons (38 L), of concentrated hydrogen peroxide.
Hydrogen peroxide should be stored in a cool, dry, well-ventilated area and away from combustible or flammable materials. These should be stored in containers comprising non-reactive materials such as stainless steels or glass (other materials including some aluminum plastics and alloys may also be suitable). Because it is quickly damaged when exposed to light, it should be stored in an opaque container, and pharmaceutical formulations usually come in brown bottles that block out the light.
Hydrogen peroxide, whether in pure or diluted form, may pose some risk, the main being that it forms an explosive mixture after contact with organic compounds. The highly concentrated hydrogen peroxide itself is unstable and can cause a boiling liquid boiling (BLEVE) blast from the remaining liquid. Distilling hydrogen peroxide at normal pressure is very dangerous. It is also corrosive, especially when concentrated, but even domestic strength solutions can cause irritation of the eyes, mucous membranes and skin. Soluble hydrogen peroxide solution is very dangerous, because abdominal decomposition releases large amounts of gas (10 times the volume of 3% solution), which causes internal bloating. Inhalation of more than 10% can cause severe lung irritation.
With a significant vapor pressure (1.2 kPa at 50 ° C), hydrogen-peroxide vapor is potentially dangerous. According to NIOSH AS, the hazardous limits for life and health (IDLH) are only 75 ppm. The US Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit of 1.0 ppm calculated as a weighted average of 8 hours (29 CFR 1910.1000, Table Z-1). Hydrogen peroxide has also been classified by the American Conference of Government Industrial Hygiene (ACGIH) as "known animal carcinogens, with unknown relevance to humans". For workplaces where there is a risk of exposure to hazardous concentrations of vapors, a continuous monitor for hydrogen peroxide should be used. Information on the dangers of hydrogen peroxide is available from OSHA and from ATSDR.
History incident
- On July 16, 1934, in Kummersdorf, Germany, a propellant tank containing an experimental monopropellant mixture consisting of hydrogen peroxide and ethanol exploded during the test, killing three people.
- During the Second World War, doctors in the German concentration camp experimented with the use of hydrogen peroxide injections in the murder of human subjects.
- Some people received minor injuries after a spill of hydrogen peroxide on a plane between US cities from Orlando and Memphis on October 28, 1998.
- Russian submarine K-141 Kursk is sailing for a rehearsal firing exercise in Pyotr Velikiy, a Kirov battlecruiser. On August 12, 2000 at 11:28 local time (07:28 UTC), there was an explosion while preparing to fire a torpedo. The only reliable report to date is that this is due to the failure and explosion of one of the Kursk-induced hydrogen peroxide torpedoes. It is believed that HTP, a form of high concentration hydrogen peroxide used as a propellant for torpedoes, seeps through its container, is damaged by rust or in a ground-loading procedure where an incident involving one torpedo accidentally touches the ground is not reported.. The ship was lost
Source of the article : Wikipedia
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