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Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove
stain A stain is a discoloration that can be clearly distinguished from the surface, material, or medium it is found upon. They are caused by the chemical or physical interaction of two dissimilar materials. Accidental staining may make materials app ...
s in a process called bleaching. It often refers specifically, to a dilute solution of sodium hypochlorite, also called "liquid bleach". Many bleaches have broad spectrum
bactericidal A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their ...
properties, making them useful for disinfecting and sterilizing. They are used in
swimming pool sanitation Swimming pool sanitation is the process of ensuring healthy conditions in swimming pools. Proper sanitation is needed to maintain the visual clarity of water and to prevent the transmission of infectious waterborne diseases. Methods Two distinct ...
to control bacteria, viruses, and algae, and in many places where sterile conditions are required. They are also used in many industrial processes, notably in the
bleaching of wood pulp Bleaching of wood pulp is the chemical processing of wood pulp to lighten its color and whiten the pulp. The primary product of wood pulp is paper, for which whiteness (similar to, but distinct from brightness) is an important characteristic. These ...
. Bleaches also have other minor uses like removing mildew, killing weeds, and increasing the longevity of cut flowers. Bleaches work by reacting with many colored organic compounds, such as natural pigments, and turning them into colorless ones. While most bleaches are oxidizing agents (chemicals that can remove electrons from other molecules), some are reducing agents (that donate electrons). Chlorine, a powerful oxidizer, is the active agent in many household bleaches. Since pure chlorine is a toxic corrosive gas, these products usually contain
hypochlorite In chemistry, hypochlorite is an anion with the chemical formula ClO−. It combines with a number of cations to form hypochlorite salts. Common examples include sodium hypochlorite (household bleach) and calcium hypochlorite (a component of ble ...
, which releases chlorine. "Bleaching powder" usually means a formulation containing
calcium hypochlorite Calcium hypochlorite is an inorganic compound with formula Ca(OCl)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agent. Thi ...
. Oxidizing bleaching agents that do not contain chlorine are usually based on peroxides such as hydrogen peroxide, sodium percarbonate, and sodium perborate. These bleaches are called 'non-chlorine bleach,' ' oxygen bleach' or 'color-safe bleach.' Reducing bleaches have niche uses, such as
sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...
used to bleach wool, either as gas or from solutions of sodium dithionite; and sodium borohydride. Bleaches generally react with many other organic substances besides the intended colored pigments, so they can weaken or damage natural materials like fibers, cloth, and leather, and intentionally applied dyes such as the indigo of denim. For the same reason, ingestion of the products, breathing of the fumes, or contact with skin or eyes can cause health damage.


History

The earliest form of bleaching involved spreading fabrics and cloth out in a bleachfield to be whitened by the action of the sun and water. In the 17th century, there was a significant cloth bleaching industry in Western Europe, using alternating alkaline baths (generally lye) and acid baths (such as
lactic acid Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natur ...
from sour milk, and later diluted
sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...
). The whole process lasted up to six months. Chlorine-based bleaches, which shortened that process from months to hours, were invented in
Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...
in the late 18th century.
Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...
chemist Carl Wilhelm Scheele discovered chlorine in 1774, and in 1785
French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...
scientist Claude Berthollet recognized that it could be used to bleach fabrics. Berthollet also discovered sodium hypochlorite, which became the first commercial bleach, named ''Eau de Javel'' ("Javel water") after the borough of Javel, near Paris, where it was produced.
Scottish Scottish usually refers to something of, from, or related to Scotland, including: *Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland *Scottish English *Scottish national identity, the Scottish ide ...
chemist and industrialist Charles Tennant proposed in 1798 a solution of
calcium hypochlorite Calcium hypochlorite is an inorganic compound with formula Ca(OCl)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agent. Thi ...
as an alternative for Javel water, and patented bleaching powder (solid
calcium hypochlorite Calcium hypochlorite is an inorganic compound with formula Ca(OCl)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agent. Thi ...
) in 1799. Around 1820, French chemist
Antoine Germain Labarraque Antoine Germain Labarraque (28 March 1777 – 9 December 1850)Maurice Bouvet. Les grands pharmaciens: Labarraque (1777-1850)' (Revue d'histoire de la pharmacie, 1950, Volume 38, no. 128, pp. 97-107). was a French chemist and pharmacist, notable f ...
discovered the disinfecting and deodorizing ability of hypochlorites, and was instrumental in popularizing their use for such purpose.Scott, James, transl. (1828).
On the disinfecting properties of Labarraque's preparations of chlorine
' Published by S. Highley.
His work greatly improved medical practice, public health, and the sanitary conditions in hospitals,
slaughterhouse A slaughterhouse, also called abattoir (), is a facility where animals are slaughtered to provide food. Slaughterhouses supply meat, which then becomes the responsibility of a packaging facility. Slaughterhouses that produce meat that is no ...
s, and all industries dealing with animal products.Labarraque, Antoine-Germain
'' Nouvelle biographie générale'', volume 28 (1859), columns 323-324.
Louis Jacques Thénard Louis Jacques Thénard (4 May 177721 June 1857) was a French chemist. Life He was born in a farm cottage near Nogent-sur-Seine in the Champagne district the son of a farm worker. In the post-Revolution French educational system , most boys rec ...
first produced hydrogen peroxide in 1818 by reacting barium peroxide with nitric acid. Hydrogen peroxide was first used for bleaching in 1882, but did not become commercially important until after 1930. Sodium perborate as a laundry bleach has been used in Europe since the early twentieth century, and became popular in North America in the 1980s.


Mechanism of action


Whitening

Colors of natural organic materials typically arise from organic pigments, such as beta carotene. Chemical bleaches work in one of two ways: *An oxidizing bleach works by breaking the chemical bonds that make up the
chromophore A chromophore is the part of a molecule responsible for its color. The color that is seen by our eyes is the one not absorbed by the reflecting object within a certain wavelength spectrum of visible light. The chromophore is a region in the molec ...
. This changes the molecule into a different substance that either does not contain a chromophore, or contains a chromophore that does not absorb visible light. This is the mechanism of bleaches based on chlorine but also of oxygen-anions which react through initial nucleophilic attack. *A reducing bleach works by converting
double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...
s in the chromophore into
single bond In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons. That is, the atoms share one pair of electrons where the bond forms. Therefore, a single bond is a type of covalent bond. When shared, each of th ...
s. This eliminates the ability of the chromophore to absorb visible light. This is the mechanism of bleaches based on
sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...
. Sunlight acts as a bleach through a process leading to similar results: high energy photons of light, often in the violet or ultraviolet range, can disrupt the bonds in the chromophore, rendering the resulting substance colorless. Extended exposure often leads to massive discoloration usually reducing the colors to white and typically very faded blue.


Antimicrobial efficacy

The broad-spectrum effectiveness of most bleaches is due to their general chemical reactivity against organic compounds, rather than the selective inhibitory or toxic actions of
antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
s. They irreversibly denature or destroy many proteins, making them extremely versatile disinfectants. Hypochlorite bleaches in low concentration were also found to attack bacteria by interfering with heat shock proteins on their walls. According to 2013 Home Hygiene and Health report, using bleach, whether chlorine- or peroxide-based, significantly increases germicidal efficiency of laundry even at low temperatures (30-40 degrees Celsius), which makes it possible to eliminate viruses, bacteria and fungi from variety of clothing in home setting.


Types of bleaches

Most industrial and household bleaches belong to three broad classes: * Chlorine-based bleaches, whose active agent is chlorine, usually from the decomposition of some chlorine compound like
hypochlorite In chemistry, hypochlorite is an anion with the chemical formula ClO−. It combines with a number of cations to form hypochlorite salts. Common examples include sodium hypochlorite (household bleach) and calcium hypochlorite (a component of ble ...
or chloramine. * Peroxide-based bleaches, whose active agent is oxygen, almost always from the decomposition of a peroxide compound like hydrogen peroxide. * Sulfur dioxide based bleaches, whose active agent is
sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...
, possibly from the decomposition of some oxosulfur anion.


Chlorine-based bleaches

Chlorine-based bleaches are found in many household "bleach" products, as well as in specialized products for hospitals, public health, water chlorination, and industrial processes. The grade of chlorine-based bleaches is often expressed as percent active chlorine. One gram of a 100% active chlorine bleach has the same bleaching power as one gram of elemental chlorine. The most common chlorine-based bleaches are: * Sodium hypochlorite (), usually as a 3–6% solution in water, usually called "liquid bleach" or just "bleach". Historically called " Javel water" (french: eau de Javelle). It is used in many households to whiten laundry, disinfect hard surfaces in kitchens and bathrooms, treat water for drinking and keep swimming pools free of infectious agents. * Bleaching powder (formerly known as "chlorinated lime"), usually a mixture of
calcium hypochlorite Calcium hypochlorite is an inorganic compound with formula Ca(OCl)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agent. Thi ...
(),
calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed or slaked with water. It has m ...
(slaked lime, ), and calcium chloride () in variable amounts. Sold as a white powder or in tablets, is used in many of the same applications as sodium hypochlorite, but is more stable and contains more available chlorine. * Chlorine gas (). It is used as a disinfectant in water treatment, especially to make
drinking water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, ...
and in large public swimming pools. It was used extensively to bleach wood pulp, but this use has decreased significantly due to environmental concerns. * Chlorine dioxide (). This unstable gas is generated in situ or stored as dilute aqueous solutions. It finds large-scale applications for the
bleaching of wood pulp Bleaching of wood pulp is the chemical processing of wood pulp to lighten its color and whiten the pulp. The primary product of wood pulp is paper, for which whiteness (similar to, but distinct from brightness) is an important characteristic. These ...
, fats and oils, cellulose,
flour Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many culture ...
, textiles,
beeswax Beeswax (''cera alba'') is a natural wax produced by honey bees of the genus ''Apis''. The wax is formed into scales by eight wax-producing glands in the abdominal segments of worker bees, which discard it in or at the hive. The hive workers ...
, skin, and in a number of other industries. Other examples of chlorine-based bleaches, used mostly as disinfectants, are monochloramine,
halazone Halazone (4-(dichlorosulfamoyl)benzoic acid) is a chemical compound whose formula can be written as either or . It has been widely used to disinfect drinking water. Other names for this compound include ''p''-sulfondichloramidobenzoic acid, 4- ...
, and
sodium dichloroisocyanurate Sodium dichloroisocyanurate (INN: sodium troclosene, ''troclosenum natricum'' or NaDCC or SDIC) is a chemical compound widely used as a cleansing agent and disinfectant.. It is a colorless, water-soluble solid, produced as a result of reaction of ...
.


Peroxide-based bleaches

Peroxide-based bleaches are characterized by the peroxide chemical group, namely two oxygen atoms connected by a
single bond In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons. That is, the atoms share one pair of electrons where the bond forms. Therefore, a single bond is a type of covalent bond. When shared, each of th ...
, (–O–O–). This bond is easily broken, giving rise to very reactive oxygen species, which are the active agents of the bleach. The main products in this class are: * Hydrogen peroxide itself (). It is used, for example, to bleach wood pulp and hair or to prepare other bleaching agents like the perborates, percarbonates, peracids, etc. * Sodium percarbonate (), an adduct of hydrogen peroxide and
sodium carbonate Sodium carbonate, , (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield moderately alkaline solutions ...
("soda ash" or "washing soda", ). Dissolved in water, it yields a solution of the two products, that combines the degreasing action of the carbonate with the bleaching action of the peroxide. * Sodium perborate (). Dissolved in water it forms some hydrogen peroxide, but also the perborate anion () which can perform nucleophilic oxidation. * Peracetic (peroxoacetic) acid (). Generated in situ by some laundry detergents, and also marketed for use as industrial and agricultural disinfection and water treatment.V. Namboodiri and A. Garg (2017):
Evaluation of Combined Peracetic acid and UV treatment for Disinfection of Secondary Wastewater Effluent
. document EPA/600/R-17/172, National Risk Management Research Laboratory, U.S. Environmental Protection Agency,
*
Benzoyl peroxide Benzoyl peroxide is a chemical compound (specifically, an organic peroxide) with structural formula , often abbreviated as (BzO)2. In terms of its structure, the molecule can be described as two benzoyl (, Bz) groups connected by a peroxide () ...
(). It is used in topical medications for acne and to bleach
flour Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many culture ...
.(2004)
Benzoyl peroxide
FAO Publication FNP 52 Addendum 12.
* Ozone (). While not properly a peroxide, its mechanism of action is similar. It is used in the manufacture of paper products, especially
newsprint Newsprint is a low-cost, non-archival paper consisting mainly of wood pulp and most commonly used to print newspapers and other publications and advertising material. Invented in 1844 by Charles Fenerty of Nova Scotia, Canada, it usually has an ...
and white Kraft paper. * Potassium persulfate ( K2 S2O8) and other persulfate salts. It, alongside ammonium and sodium persulfate, are common in hair lightening products. * Permanganate salts such as Potassium permanganate (KMnO4). In the
food industry The food industry is a complex, global network of diverse businesses that supplies most of the food consumed by the world's population. The food industry today has become highly diversified, with manufacturing ranging from small, traditiona ...
, other oxidizing products like bromates are used as flour bleaching and
maturing agent A dough conditioner, flour treatment agent, improving agent or bread improver is any ingredient or chemical added to bread dough to strengthen its texture or otherwise improve it in some way. Dough conditioners may include enzymes, yeast nutrients ...
s.


Reducing bleaches

Sodium dithionite (also known as sodium hydrosulfite) is one of the most important reductive bleaching agents. It is a white crystalline powder with a weak
sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...
ous odor. It can be obtained by reacting sodium bisulfite with zinc :2 NaHSO3 + Zn → Na2S2O4 + Zn(OH)2 It is used as such in some industrial dyeing processes to eliminate excess dye, residual oxide, and unintended pigments and for bleaching wood pulp. Reaction of sodium dithionite with formaldehyde produces Rongalite, :Na2S2O4 + 2 CH2O + H2O → NaHOCH2SO3 + NaHOCH2SO2 which is used in bleaching wood pulp,
cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor p ...
, wool, leather and
clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay part ...
.


Photographic bleach

In Reversal processing, residual silver in the emulsion after the first development is reduced to a soluble silver salt using a chemical bleach, most commonly EDTA. A conventional fixer then dissolves the reduced silver but leaving the unexposed silver halide intact. This unexposed halide is then exposed to light or is chemically treated so that a second development produces a positive image. In colour and chromogenic film, this also generates a dye image in proportion to the silver. Photographic bleaches are also used in black-and-white photography to selectively reduce silver to reduce silver density in negatives or prints. In such cases the bleach composition is typically an acid solution of potassium dichromate.


Environmental impact

A Risk Assessment Report (RAR) conducted by the European Union on sodium hypochlorite conducted under Regulation EEC 793/93 concluded that this substance is safe for the environment in all its current, normal uses. This is due to its high reactivity and instability. The disappearance of hypochlorite is practically immediate in the natural aquatic environment, reaching in a short time concentration as low as 10−22 μg/L or less in all emission scenarios. In addition, it was found that while volatile chlorine species may be relevant in some indoor scenarios, they have a negligible impact in open environmental conditions. Further, the role of hypochlorite pollution is assumed as negligible in soils. Industrial bleaching agents can be sources of concern. For example, the use of elemental chlorine in the
bleaching of wood pulp Bleaching of wood pulp is the chemical processing of wood pulp to lighten its color and whiten the pulp. The primary product of wood pulp is paper, for which whiteness (similar to, but distinct from brightness) is an important characteristic. These ...
produces organochlorines and persistent organic pollutants, including
dioxin Dioxin may refer to: * 1,2-Dioxin or 1,4-Dioxin, two unsaturated heterocyclic 6-membered rings where two carbon atoms have been replaced by oxygen atoms, giving the molecular formula C4H4O2 *Dibenzo-1,4-dioxin, the parent compound also known as ...
s. According to an industry group, the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels. However, respiratory risk from chlorine and highly toxic chlorinated byproducts still exists. A European study conducted in 2008 indicated that sodium hypochlorite and organic chemicals (e.g.,
surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...
s, fragrances) contained in several household cleaning products can react to generate chlorinated volatile organic compounds (VOCs). These chlorinated compounds are emitted during cleaning applications, some of which are toxic and probable human carcinogens. The study showed that indoor air concentrations significantly increase (8–52 times for
chloroform Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to ...
and 1–1170 times for
carbon tetrachloride Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVAC ...
, respectively, above baseline quantities in the household) during the use of bleach-containing products. The increase in chlorinated volatile organic compound concentrations was the lowest for plain bleach and the highest for the products in the form of "thick liquid and gel." The significant increases observed in indoor air concentrations of several chlorinated VOCs (especially carbon tetrachloride and chloroform) indicate that the bleach use may be a source that could be important in terms of inhalation exposure to these compounds. While the authors suggested that using these cleaning products may significantly increase the cancer risk, this conclusion appears to be hypothetical: :* The highest level cited for a concentration of carbon tetrachloride (seemingly of highest concern) is 459 micrograms per cubic meter, translating to 0.073 ppm (part per million), or 73 ppb (part per billion). The OSHA-allowable time-weighted average concentration over an eight-hour period is 10 ppm, almost 140 times higher; :* The OSHA highest allowable peak concentration (5-minute exposure for five minutes in a 4-hour period) is 200 ppm, twice as high as the reported highest peak level (from the
headspace Headspace may refer to: *Headspace (company), an online healthcare company specializing in meditation *Headspace (organisation), an Australian non-profit organization for youth mental health *Headspace or ullage, the unfilled space in a container ...
of a bottle of a sample of bleach plus detergent).


Disinfection

Sodium hypochlorite solution, 3–6%, (common household bleach) is typically diluted for safe use when disinfecting surfaces and when used to treat drinking water. A weak solution of 2% household bleach in warm water is typical for sanitizing smooth surfaces prior to the brewing of beer or wine. US Government regulations (21 CFR 178 Subpart C) allow food processing equipment and food contact surfaces to be sanitized with solutions containing bleach, provided that the solution is allowed to drain adequately before contact with food, and that the solutions do not exceed 200 parts per million (ppm) available chlorine (for example, one tablespoon of typical household bleach containing 5.25% sodium hypochlorite, per gallon of water). A 1-in-47 dilution of household bleach with water (1 part bleach to 47 parts water) is effective against many
bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...
and some viruses in homes. Even "scientific-grade", commercially produced disinfection solutions such as Virocidin-X usually have sodium hypochlorite as their sole active ingredient, though they also contain surfactants (to prevent beading) and fragrances (to conceal the bleach smell). See Hypochlorous acid#Mode of disinfectant action, Hypochlorous acid for a discussion of the mechanism for disinfectant action. An oral rinse with a 0.05% dilute solution of household bleach is shown to treat gingivitis. Diluted sodium hypochlorite at a rate of 2000–1 (0.05% concentration) may represent an efficacious, safe and affordable antimicrobial agent in the prevention and treatment of periodontal disease.


Color safe bleach

Color safe bleach is a chemical that uses hydrogen peroxide as the active ingredient (to help remove stains) rather than sodium hypochlorite or chlorine. It also has chemicals in it that help brighten colors. Hydrogen peroxide is also used for sterilization purposes and water treatment, but its disinfectant capabilities may be limited due to the concentration in the colorsafe bleach solution as compared to other applications.


Health hazards

The safety of bleaches depends on the compounds present, and their concentration. Generally speaking, the ingestion of bleaches will cause damage to the esophagus and stomach, possibly leading to death. On contact with the skin or eyes, it causes irritation, drying, and potentially burns. Inhalation of bleach fumes can damage the lungs. Personal protective equipment should always be used when using bleach. Bleach should never be mixed with vinegar or other acids, as this will create highly toxic chlorine gas, which can cause severe burns internally and externally. Mixing bleach with ammonia similarly produces toxic chloramine gas, which can burn the lungs. Mixing bleach with hydrogen peroxide results in an exothermic chemical reaction that releases oxygen, and may cause the contents to splatter and cause skin and eye injury. Heating bleach and boiling it may produce chlorates, a strong oxidizer which may lead to a fire or explosion.


False claims as a cure

Miracle Mineral Supplement (MMS), also promoted as "Master Mineral Solution" or "Chlorine Dioxide Solution" or CDS, to evade restrictions by online retail platforms, is a bleach solution that has been fraudulently promoted as a cure-all since 2006. Its main active ingredient is sodium chlorite, which is "activated" with citric acid to form chlorine dioxide. In an attempt to evade health regulations, its inventor, former Scientologist, Jim Humble, formed the Genesis II Church of Health and Healing, a fake religion whose "sacrament" is MMS. During the COVID-19 pandemic advocates of MMS, such as QAnon proponent Jordan Sather and Mark Grenon, who are affiliated with the Genesis II Church, began to suggest this would treat COVID-19. Several sources interpreted remarks by U.S. President Trump, in a 23 April 2020 briefing, as promoting this claim, leading the Centers for Disease Control and Prevention, CDC, scientists, and bleach companies to re-state that bleach is harmful to humans and should not be ingested or injected. MSN News quoted Professor Rob Chilcott, a toxicology expert from the University of Hertfordshire, that there is no scientific evidence that injected bleach or disinfectants will affect viral particles, but that injecting bleach would "likely result in significant, irreversible harm and probably a very unpleasant death."


See also

* Calcium hypochlorite * Hydrogen peroxide * Milton sterilizing fluid * Tooth whitening * Washing soda


References


Further reading

* Bodkins, Dr. Bailey. ''Bleach''. Philadelphia: Virginia Printing Press, 1995. * Trotman, E. R. ''Textile Scouring and Bleaching''. London: Charles Griffin & Co., 1968. .


External links


"Bleach"
in the ''Encyclopædia Britannica''
Bleach (MSDS)
{{Authority control Bleaches, Disinfectants Dyes Household chemicals Laundry substances