|Preferred IUPAC name|
|Systematic IUPAC name|
|Other names |
Methylene glycol (diol forms in aqueous solution)
Formalin (aqueous solution)
3D model (JSmol)
|E number||E240 (preservatives)|
CompTox Dashboard (EPA)
|Molar mass||30.026 g·mol−1|
|Density||0.8153 g/cm3 (−20 °C)|
|Melting point||−92 °C (−134 °F; 181 K)|
|Boiling point||−19 °C (−2 °F; 254 K)|
|Vapor pressure||< 1 atm|
|Acidity (pKa)||13.27 (hydrate)|
|QP53AX19 ( WHO )|
|Safety data sheet||MSDS(Archived)|
|GHS Signal word||Danger|
|H301, H311, H331, H314, H317, H335, H341, H350, H370|
|P201, P280, P303+361+353, P304+340+310, P305+351+338, P308+310|
|NFPA 704 (fire diamond)|
|Flash point||64 °C (147 °F; 337 K)|
|430 °C (806 °F; 703 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|100 mg/kg (oral, rat)|
LC50 (median concentration)
|333 ppm (mouse, 2 h)|
815 ppm (rat, 30 min)
LCLo (lowest published)
|333 ppm (cat, 2 h)|
|NIOSH (US health exposure limits):|
|TWA 0.75 ppm ST 2 ppm (as formaldehyde and formalin)|
|Ca TWA 0.016 ppm C 0.1 ppm [15-minute]|
IDLH (Immediate danger)
|Ca [20 ppm]|
| Acetaldehyde |
| methanol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Formaldehyde (systematic name methanal) is a naturally occurring organic compound with the formula CH2O (H−CHO). It is the simplest of the aldehydes (R−CHO). The common name of this substance comes from its similarity and relation to formic acid.
Formaldehyde is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated at 8.7 million tons per year.It is mainly used in the production of industrial resins, e.g., for particle board and coatings.
In view of its widespread use, toxicity, and volatility, formaldehyde poses a significant danger to human health.In 2011, the US National Toxicology Program described formaldehyde as "known to be a human carcinogen".
Formaldehyde is more complicated than many simple carbon compounds in that it adopts several different forms. As a gas, formaldehyde is colorless and has a characteristic pungent, irritating odor. Upon condensation, the gas converts to various other forms of formaldehyde (with different chemical formulas) that are of more practical value. One derivative is the cyclic trimer metaformaldehyde (1,3,5-trioxane) with the formula (CH2O)3. There is also a linear polymer called paraformaldehyde. These compounds have similar chemical properties and are often used interchangeably.
When dissolved in water, formaldehyde also forms a hydrate, methanediol, with the formula H2C(OH)2. This compound also exists in equilibrium with various oligomers (short polymers), depending on the concentration and temperature. A saturated water solution, of about 40% formaldehyde by volume or 37% by mass, is called "100% formalin". A small amount of stabilizer, such as methanol, is usually added to suppress oxidation and polymerization. A typical commercial grade formalin may contain 10–12% methanol in addition to various metallic impurities. "Formaldehyde" was first used as a generic trademark in 1893 following a previous trade name, "formalin".
Processes in the upper atmosphere contribute up to 90% of the total formaldehyde in the environment. Formaldehyde is an intermediate in the oxidation (or combustion) of methane, as well as of other carbon compounds, e.g. in forest fires, automobile exhaust, and tobacco smoke. When produced in the atmosphere by the action of sunlight and oxygen on atmospheric methane and other hydrocarbons, it becomes part of smog. Formaldehyde has also been detected in outer space (see below).
Formaldehyde and its adducts are ubiquitous in living organisms. It is formed in the metabolism of endogenous amino acids[ which? ] and is found in the bloodstream of humans and other primates at concentrations of approximately 0.1 millimolar. Experiments in which animals are exposed to an atmosphere containing isotopically labeled formaldehyde have demonstrated that even in deliberately exposed animals, the majority of formaldehyde-DNA adducts found in non-respiratory tissues are derived from endogenously produced formaldehyde.
Formaldehyde does not accumulate in the environment, because it is broken down within a few hours by sunlight or by bacteria present in soil or water. Humans metabolize formaldehyde quickly, converting it to formic acid, so it does not accumulate in the body.
Formaldehyde appears to be a useful probe in astrochemistry due to prominence of the 110←111 and 211←212K-doublet transitions. It was the first polyatomic organic molecule detected in the interstellar medium.Since its initial detection in 1969, it has been observed in many regions of the galaxy. Because of the widespread interest in interstellar formaldehyde, it has been extensively studied, yielding new extragalactic sources. A proposed mechanism for the formation is the hydrogenation of CO ice:
HCN, HNC, H2CO, and dust have also been observed inside the comae of comets C/2012 F6 (Lemmon) and C/2012 S1 (ISON).
Formaldehyde was first reported in 1859 by the Russian chemist Aleksandr Butlerov (1828–86)and was conclusively identified in 1869 by August Wilhelm von Hofmann.
Formaldehyde is produced industrially by the catalytic oxidation of methanol. The most common catalysts are silver metal or a mixture of an iron and molybdenum or vanadium oxides. In the commonly used formox process, methanol and oxygen react at ca. 250–400 °C in presence of iron oxide in combination with molybdenum and/or vanadium to produce formaldehyde according to the chemical equation:
The silver-based catalyst usually operates at a higher temperature, about 650 °C. Two chemical reactions on it simultaneously produce formaldehyde: that shown above and the dehydrogenation reaction:
In principle, formaldehyde could be generated by oxidation of methane, but this route is not industrially viable because the methanol is more easily oxidized than methane.
Formaldehyde is a building block in the synthesis of many other compounds of specialised and industrial significance. It exhibits most of the chemical properties of other aldehydes but is more reactive.
Formaldehyde, unlike most aldehydes, oligomerizes spontaneously. The trimer is 1,3,5-trioxane, and the polymer is called paraformaldehyde. Many cyclic oligomers have been isolated. Similarly, formaldehyde hydrates to give the geminal diol methanediol, which condenses further to form oligomers HO(CH2O)nH. Monomeric CH2O is rarely encountered.
It is readily oxidized by atmospheric oxygen into formic acid. For this reason, commercial formaldehyde is typically contaminated with formic acid.
Formaldehyde is a good electrophile. With good nucleophiles such as thiols, amines, and even amides, no acid catalyst is required. The resulting hydroxymethyl derivatives typically react further. Thus amines give hexahydro-1,3,5-triazines. Similarly, when combined with hydrogen sulfide, it forms trithiane.
In the presence of acids, it participates in electrophilic aromatic substitution reactions with aromatic compounds resulting in hydroxymethylated derivatives:
When conducted in the presence of hydrogen chloride, the product is the chloromethyl compound, as described in the Blanc chloromethylation. If the arene is electron-rich, as in phenols, elaborate condensations ensue. With 4-substituted phenols one obtains calixarenes.Phenol results in polymers.
Cannizzaro reaction in the presence of basic catalysts to produce formic acid and methanol.
Formaldehyde is a common precursor to more complex compounds and materials. In approximate order of decreasing consumption, products generated from formaldehyde include urea formaldehyde resin, melamine resin, phenol formaldehyde resin, polyoxymethylene plastics, 1,4-butanediol, and methylene diphenyl diisocyanate. [ permanent dead link ]The textile industry uses formaldehyde-based resins as finishers to make fabrics crease-resistant. Formaldehyde-based materials are key to the manufacture of automobiles, and used to make components for the transmission, electrical system, engine block, door panels, axles and brake shoes. The value of sales of formaldehyde and derivative products was over $145 billion in 2003, about 1.2% of the gross domestic product (GDP) of the United States and Canada. Including indirect employment, over 4 million people work in the formaldehyde industry across approximately 11,900 plants in the U.S. and Canada.
When treated with phenol, urea, or melamine, formaldehyde produces, respectively, hard thermoset phenol formaldehyde resin, urea formaldehyde resin, and melamine resin. These polymers are common permanent adhesives used in plywood and carpeting. It is used as the wet-strength resin added to sanitary paper products such as (listed in increasing concentrations injected into the paper machine headstock chest) facial tissue, table napkins, and roll towels. They are also foamed to make insulation, or cast into moulded products. Production of formaldehyde resins accounts for more than half of formaldehyde consumption.
Formaldehyde is also a precursor to polyfunctional alcohols such as pentaerythritol, which is used to make paints and explosives. Other formaldehyde derivatives include methylene diphenyl diisocyanate, an important component in polyurethane paints and foams, and hexamine, which is used in phenol-formaldehyde resins as well as the explosive RDX.
Condensation with acetaldehyde affords pentaerythritol, a chemical necessary in synthesizing PETN, a high explosive.Condensation with phenols gives phenol-formaldehyde resins.
An aqueous solution of formaldehyde can be useful as a disinfectant as it kills most bacteria and fungi (including their spores). It is used to kill produced vaccines.Formaldehyde releasers are used as biocides in personal care products such as cosmetics. Although present at levels not normally considered harmful, they are known to cause allergic contact dermatitis in certain sensitised individuals.
Aquarists use formaldehyde as a treatment for the parasites Ichthyophthirius multifiliis and Cryptocaryon irritans .
Formaldehyde is also approved for use in the manufacture of animal feeds in the US. It is an antimicrobial agent used to maintain complete animal feeds or feed ingredients Salmonella negative for up to 21 days.
Formaldehyde preserves or fixes tissue or cells. The process involves cross-linking of primary amino groups. The European Union has banned the use of formaldehyde due to its carcinogenic properties as a biocide (including embalming) under the Biocidal Products Directive (98/8/EC). I of the Biocidal Products Directive for product-type 22 (embalming and taxidermist fluids) had been made as of September 2009 [update] .Countries with a strong tradition of embalming corpses, such as Ireland and other colder-weather countries, have raised concerns. Despite reports to the contrary, no decision on the inclusion of formaldehyde on Annex
Formaldehyde-based crosslinking is exploited in ChIP-on-chip or ChIP-sequencing genomics experiments, where DNA-binding proteins are cross-linked to their cognate binding sites on the chromosome and analyzed to determine what genes are regulated by the proteins. Formaldehyde is also used as a denaturing agent in RNA gel electrophoresis, preventing RNA from forming secondary structures. A solution of 4% formaldehyde fixes pathology tissue specimens at about one mm per hour at room temperature.
Formaldehyde and an 18 M (concentrated) sulfuric acid makes Marquis reagent—which can identify alkaloids and other compounds.
In photography, formaldehyde is used in low concentrations for process C-41 (color negative film) stabilizer in the final wash step,as well as in the process E-6 pre-bleach step, to make it unnecessary in the final wash.
Formaldehyde topical can be used as an antiperspirant to treat hyperhydrosis.
The safety of formaldehyde is very complicated. It occurs naturally and is "an essential intermediate in cellular metabolism in mammals and humans." ppm in air formaldehyde can irritate the eyes and mucous membranes, resulting in watery eyes. Formaldehyde inhaled at this concentration may cause headaches, a burning sensation in the throat, and difficulty breathing, and can trigger or aggravate asthma symptoms.It is not acutely toxic as ingestion of many milliliters is tolerated. The main concerns are associated with chronic (long term) exposure by inhalation. This may happen through three main sources: thermal or chemical decomposition of formaldehyde-based resins, emission from aqueous formaldehyde solutions (i.e. embalming fluids), and the production of formaldehyde resulting from the combustion of a variety of organic compounds (for example, exhaust gases). As formaldehyde resins are used in many construction materials it is one of the more common indoor air pollutants. At concentrations above 0.1
A 1988 Canadian study of houses with urea-formaldehyde foam insulation found that formaldehyde levels as low as 0.046 ppm were positively correlated with eye and nasal irritation.A 2009 review of studies has shown a strong association between exposure to formaldehyde and the development of childhood asthma. The primary exposure concern is for the workers in the industries producing or using formaldehyde.
The formaldehyde theory of carcinogenesis was proposed in 1978.In 1987 the U.S. EPA classified it as a probable human carcinogen, and after more studies the WHO International Agency for Research on Cancer (IARC) in 1995 also classified it as a probable human carcinogen. Further information and evaluation of all known data led the IARC to reclassify formaldehyde as a known human carcinogen associated with nasal sinus cancer and nasopharyngeal cancer. 2009 and 2010 studies have also shown a positive correlation between exposure to formaldehyde and the development of leukemia, particularly myeloid leukemia. Nasopharyngeal and sinonasal cancers are relatively rare, with a combined annual incidence in the United States of < 4,000 cases. About 30,000 cases of myeloid leukemia occur in the United States each year. There is some evidence that workplace exposure to inhaled chemicals such as formaldehyde can contribute to sinonasal cancers. Professionals exposed to formaldehyde in their occupation, such as funeral industry workers and embalmers, showed an increased risk of leukemia and brain cancer compared with the general population. Other factors are important in determining individual risk for the development of leukemia or nasopharyngeal cancer.
In the residential environment, formaldehyde exposure comes from a number of different routes; formaldehyde can off-gas from wood products, such as plywood or particle board, but it is produced by paints, varnishes, floor finishes, and cigarette smoking as well.In July 2016, the EPA released a prepublication version of its final rule on Formaldehyde Emission Standards for Composite Wood Products. These new rules impact manufacturers, importers, distributors, and retailers of products containing composite wood, including fiberboard, particleboard, and various laminated products, who must comply with more stringent record-keeping and labeling requirements.
The United States Environmental Protection Agency (EPA) allows no more than 0.016 ppm formaldehyde in the air in new buildings constructed for that agency. [ failed verification ] A U.S. Environmental Protection Agency study found a new home measured 0.076 ppm when brand new and 0.045 ppm after 30 days. The Federal Emergency Management Agency (FEMA) has also announced limits on the formaldehyde levels in trailers purchased by that agency. The EPA recommends the use of "exterior-grade" pressed-wood products with phenol instead of urea resin to limit formaldehyde exposure, since pressed-wood products containing formaldehyde resins are often a significant source of formaldehyde in homes.
For most people, irritation from formaldehyde is temporary and reversible, though formaldehyde can cause allergies and is part of the standard patch test series. In 2005–06, it was the seventh-most-prevalent allergen in patch tests (9.0%). [ citation needed ] and Japan. The eyes are most sensitive to formaldehyde exposure: The lowest level at which many people can begin to smell formaldehyde ranges between 0.05-1 ppm. The maximum concentration value at the workplace is 0.3 ppm. [ need quotation to verify ] In controlled chamber studies, individuals begin to sense eye irritation at about 0.5 ppm; 5 to 20 percent report eye irritation at 0.5 to 1 ppm; and greater certainty for sensory irritation occurred at 1 ppm and above. While some agencies have used a level as low as 0.1 ppm as a threshold for irritation, the expert panel found that a level of 0.3 ppm would protect against nearly all irritation. In fact, the expert panel found that a level of 1.0 ppm would avoid eye irritation—the most sensitive endpoint—in 75–95% of all people exposed.People with formaldehyde allergy are advised to avoid formaldehyde releasers as well (e.g., Quaternium-15, imidazolidinyl urea, and diazolidinyl urea). People who suffer allergic reactions to formaldehyde tend to display lesions on the skin in the areas that have had direct contact with the substance, such as the neck or thighs (often due to formaldehyde released from permanent press finished clothing) or dermatitis on the face (typically from cosmetics). Formaldehyde has been banned in cosmetics in both Sweden
Formaldehyde levels in building environments are affected by a number of factors. These include the potency of formaldehyde-emitting products present, the ratio of the surface area of emitting materials to volume of space, environmental factors, product age, interactions with other materials, and ventilation condition. Formaldehyde emits from a variety of construction materials, furnishings, and consumer products. The three products that emit the highest concentrations are medium density fiberboard, hardwood plywood, and particle board. Environmental factors such as temperature and relative humidity can elevate levels because formaldehyde has a high vapor pressure. Formaldehyde levels from building materials are the highest when a building first opens because materials would have less time to off-gas. Formaldehyde levels decrease over time as the sources suppress.
Formaldehyde levels in air can be sampled and tested in several ways, including impinger, treated sorbent, and passive monitors.The National Institute for Occupational Safety and Health (NIOSH) has measurement methods numbered 2016, 2541, 3500, and 3800.
Studies on the interactions between formaldehyde and proteins at the molecular level have been reported on the effects of the body's carrier protein, serum albumin. The binding of formaldehyde loosens the skeletal structure of albumin and causes exposure of aromatic ring amino acids in the internal hydrophobic region. Symptoms may affect personal awareness, making one feel tired or fatigued.[ citation needed ]
Formaldehyde inhalation has also shown to cause oxidative stress and inflammation in animals. Mice studied over an exposure to a high dose of formaldehyde (3ppm), showed increased NO−
3 levels in plasma. This result suggests that FA inhalation either decreased NO production or increased NO scavenging, which may be an anti-stress mechanism in the body. Formaldehyde inhalation changes the sensitivity of immune system, which influences oxidative stress.[ citation needed ]
In June 2011, the twelfth edition of the National Toxicology Program (NTP) Report on Carcinogens (RoC) changed the listing status of formaldehyde from "reasonably anticipated to be a human carcinogen" to "known to be a human carcinogen."Concurrently, a National Academy of Sciences (NAS) committee was convened and issued an independent review of the draft United States Environmental Protection Agency IRIS assessment of formaldehyde, providing a comprehensive health effects assessment and quantitative estimates of human risks of adverse effects.
Several web articles claim that formaldehyde has been banned from manufacture or import into the European Union (EU) under REACH (Registration, Evaluation, Authorization, and restriction of Chemical substances) legislation. That is a misconception, as Formaldehyde is not listed in the Annex I of Regulation (EC) No 689/2008 (export and import of dangerous chemicals regulation), nor on a priority list for risk assessment. However, formaldehyde is banned from use in certain applications (preservatives for liquid-cooling and processing systems, slimicides, metalworking-fluid preservatives, and antifouling products) under the Biocidal Products Directive.In the EU, the maximum allowed concentration of formaldehyde in finished products is 0.2%, and any product that exceeds 0.05% has to include a warning that the product contains formaldehyde.
In the United States, Congress passed a bill July 7, 2010 regarding the use of formaldehyde in hardwood plywood, particle board, and medium density fiberboard. The bill limited the allowable amount of formaldehyde emissions from these wood products to .09 ppm, and required companies to meet this standard by January 2013.The final Environmental Protection Agency rule specified maximum emissions of "0.05 ppm formaldehyde for hardwood plywood, 0.09 ppm formaldehyde for particleboard, 0.11 ppm formaldehyde for medium-density fiberboard, and 0.13 ppm formaldehyde for thin medium-density fiberboard."
Formaldehyde was declared a toxic substance by the 1999 Canadian Environmental Protection Act.
In the U.S. the Federal Emergency Management Agency (FEMA) provided travel trailers, recreational park trailers and manufactured homes starting in 2006 for habitation by residents of the U.S. Gulf Coast displaced by Hurricane Katrina and Hurricane Rita. Some of the people who moved into the FEMA trailers complained of breathing difficulties, nosebleeds, and persistent headaches. Formaldehyde-catalyzed resins were used in the production of these homes.
The United States Centers For Disease Control and Prevention (CDC) performed indoor air quality testing for formaldehydein some of the units. On February 14, 2008, the CDC announced that potentially hazardous levels of formaldehyde were found in many of the travel trailers and manufactured homes provided by the agency. The CDC's preliminary evaluation of a scientifically established random sample of 519 travel trailers and manufactured homes tested between December 21, 2007, and January 23, 2008 (2+ years after manufacture), showed average levels of formaldehyde in all units of about 0.077 parts per million (ppm). Long-term exposure to levels in this range can be linked to an increased risk of cancer and, at levels above this range, there can also be a risk of respiratory illness. These levels are higher than expected in indoor air, where levels are commonly in the range of 0.01–0.02 ppm, and are higher than the Agency for Toxic Substance Disease Registry (ATSDR, division of the CDC) Minimal Risk Level (MRL) of 0.008 ppm. Levels measured ranged from 0.003 ppm to 0.59 ppm.
FEMA, which requested the testing by the CDC, said it would work aggressively to relocate all residents of the temporary housing as soon as possible. Lawsuits were filed against FEMA trailer manufacturers as a result of the exposures.As of 2012, U.S. District Judge Kurt D. Engelhardt of New Orleans approved a $42.6 million class-action lawsuit settlement for the plaintiffs, who included roughly 55,000 residents of Louisiana, Mississippi, Alabama and Texas. The defendants included two dozen manufacturers who built mobile homes for the Federal Emergency Management Agency (FEMA), including Gulf Stream Coach Inc., Forest River Inc., Vanguard LLC and Monaco Coach Corp. A separate $5.1 million settlement dealt with claims against FEMA contractors including Shaw Environmental Inc., Bechtel Corp., Fluor Enterprises Inc. and CH2M Hill Constructors Inc., who were responsible for installing and maintaining the units.
Also in the U.S., problems arose in trailers again provided by FEMA to residents displaced by the Iowa floods of 2008. Several months after moving to the trailers, occupants reported violent coughing, headaches, as well as asthma, bronchitis, and other problems. Tests showed that in some trailers, levels of formaldehyde exceeded the limits recommended by the U.S. Environmental Protection Agency and American Lung Association.The associated publicity resulted in additional testing being planned to begin in November 2008.
Scandals have broken in both the 2005 Indonesia food scare and 2007 Vietnam food scare regarding the addition of formaldehyde to foods to extend shelf life. In 2011, after a four-year absence, Indonesian authorities found foods with formaldehyde being sold in markets in a number of regions across the country. kg of formaldehyde was confiscated. Foods known to be contaminated included noodles, salted fish, and tofu. Chicken and beer were also rumored to be contaminated. In some places, such as China, manufacturers still use formaldehyde illegally as a preservative in foods, which exposes people to formaldehyde ingestion. In humans, the ingestion of formaldehyde has been shown to cause vomiting, abdominal pain, dizziness, and in extreme cases can cause death. Testing for formaldehyde is by blood and/or urine by gas chromatography-mass spectrometry. Other methods include infrared detection, gas detector tubes, etc., of which high-performance liquid chromatography is the most sensitive. In the early 1900s, it was frequently added by US milk plants to milk bottles as a method of pasteurization due to the lack of knowledge and concern regarding formaldehyde's toxicity.In August 2011, at least at two Carrefour supermarkets, the Central Jakarta Livestock and Fishery Sub-Department found a sweet glutinous rice drink (cendol) contained 10 parts per million of formaldehyde. In 2014, the owner of two noodle factories in Bogor, Indonesia, was arrested for using formaldehyde in noodles. 50
In 2011 in Nakhon Ratchasima, Thailand, truckloads of rotten chicken were treated with formaldehyde for sale in which "a large network," including 11 slaughterhouses run by a criminal gang, were implicated.In 2012, 1 billion rupiah (almost US$100,000) of fish imported from Pakistan to Batam, Indonesia, were found laced with formaldehyde.
Formalin contamination of foods has been reported in Bangladesh, with stores and supermarkets selling fruits, fishes, and vegetables that have been treated with formalin to keep them fresh.However, in 2015, a Formalin Control Bill was passed in the Parliament of Bangladesh with a provision of life-term imprisonment as the maximum punishment and in addition 2,000,000 BDT as fine but not less than 500,000 BDT for importing, production or hoarding of formalin without license.
Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It has both medical and industrial uses. It may be applied to the affected area to treat psoriasis and seborrheic dermatitis (dandruff). It may be used in combination with ultraviolet light therapy. Industrially it is a railway tie preservative and used in the surfacing of roads.
Acetophenone is the organic compound with the formula C6H5C(O)CH3 (also represented by the pseudoelement symbols PhAc or BzMe). It is the simplest aromatic ketone. This colorless, viscous liquid is a precursor to useful resins and fragrances.
Acetaldehyde (systematic name ethanal) is an organic chemical compound with the formula CH3CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl). It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale in industry. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants. It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption. Pathways of exposure include air, water, land, or groundwater, as well as drink and smoke. Consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body.
Butanone, also known as methyl ethyl ketone (MEK), is an organic compound with the formula CH3C(O)CH2CH3. This colorless liquid ketone has a sharp, sweet odor reminiscent of butterscotch and acetone. It is produced industrially on a large scale, and also occurs in trace amounts in nature. It is soluble in water and is commonly used as an industrial solvent.
Styrene, also known as ethenylbenzene, vinylbenzene, and phenylethene, is an organic compound with the chemical formula C6H5CH=CH2. This derivative of benzene is a colorless oily liquid although aged samples can appear yellowish. The compound evaporates easily and has a sweet smell, although high concentrations have a less pleasant odor. Styrene is the precursor to polystyrene and several copolymers. Approximately 25 million tonnes of styrene were produced in 2010, increasing to around 35 million tonnes by 2018.
Tetrachloroethylene, also known under the systematic name tetrachloroethene, or perchloroethylene, and many other names (and abbreviations such as "perc" or "PERC", and "PCE"), is a chlorocarbon with the formula Cl2C=CCl2. It is a colorless liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid". It has a sweet odor detectable by most people at a concentration of 1 part per million (1 ppm). Worldwide production was about 1 million metric tons (980,000 long tons; 1,100,000 short tons) in 1985.
The chemical compound trichloroethylene is a halocarbon commonly used as an industrial solvent. It is a clear non-flammable liquid with a sweet smell. It should not be confused with the similar 1,1,1-trichloroethane, which is commonly known as chlorothene.
Cosmetology is the study and application of beauty treatment. Branches of specialty include hairstyling, skin care, cosmetics, manicures/pedicures, non-permanent hair removal such as waxing and sugaring, and permanent hair removal processes such as electrology and intense pulsed light (IPL).
Particle board – also known as particleboard, low-density fibreboard (LDF), and chipboard – is an engineered wood product manufactured from wood chips and a synthetic resin or other suitable binder, which is pressed and extruded. Particle board is often confused with oriented strand board, a different type of fiberboard that uses machined wood flakes and offers more strength.
1,4-Dioxane is a heterocyclic organic compound, classified as an ether. It is a colorless liquid with a faint sweet odor similar to that of diethyl ether. The compound is often called simply dioxane because the other dioxane isomers are rarely encountered.
Ethylbenzene is an organic compound with the formula C6H5CH2CH3. It is a highly flammable, colorless liquid with an odor similar to that of gasoline. This monocyclic aromatic hydrocarbon is important in the petrochemical industry as an intermediate in the production of styrene, the precursor to polystyrene, a common plastic material. In 2012, more than 99% of ethylbenzene produced was consumed in the production of styrene.
Urea-formaldehyde (UF), also known as urea-methanal, so named for its common synthesis pathway and overall structure, is a non-transparent thermosetting resin or polymer. It is produced from urea and formaldehyde. These resins are used in adhesives, finishes, particle board, medium-density fibreboard (MDF), and molded objects.
2-Butoxyethanol is an organic compound with the chemical formula BuOC2H4OH (Bu = CH3CH2CH2CH2). This colorless liquid has a sweet, ether-like odor, as it derives from the family of glycol ethers, and is a butyl ether of ethylene glycol. As a relatively nonvolatile, inexpensive solvent, it is used in many domestic and industrial products because of its properties as a surfactant. It is a known respiratory irritant and can be acutely toxic but animal studies did not find it to be mutagenic, and no studies suggest it is a human carcinogen. A study of 13 classroom air contaminants conducted in Portugal reported a statistically significant association with increased rates of nasal obstruction, the study also reported a positive association below the level of statistical significance with a higher risk of obese asthma and increased child BMI.
Embalming chemicals are a variety of preservatives, sanitising and disinfectant agents, and additives used in modern embalming to temporarily prevent decomposition and restore a natural appearance for viewing a body after death. A mixture of these chemicals is known as embalming fluid and is used to preserve bodies of deceased persons for both funeral purposes and in medical research in anatomical laboratories. The period for which a body is embalmed is dependent on time, expertise of the embalmer and factors regarding duration of stay and purpose.
Ethyl acrylate is an organic compound with the formula CH2CHCO2CH2CH3. It is the ethyl ester of acrylic acid. It is a colourless liquid with a characteristic acrid odor. It is mainly produced for paints, textiles, and non-woven fibers. It is also a reagent in the synthesis of various pharmaceutical intermediates.
Bis(chloromethyl) ether is an organic compound with the chemical formula (CH2Cl)2O. It is a colourless liquid with an unpleasant suffocating odour and it is one of the chloroalkyl ethers. Bis(chloromethyl) ether was once produced on a large scale, but was found to be highly carcinogenic and thus such production has been ceased.
Brazilian hair smoothing treatment is a semi-permanent hair smoothing method done by temporarily sealing a liquid keratin and a preservative solution into the hair with a hair iron. It is often confused for a hair straightener, it is not because it does not chemically alter the structure of the hair. The technique has many variations and is known by several other names and brands, including Brazilian Blowout, Breezilian straightening, Brazilian Keratin Treatment, BKT, and Keratin Cure. It is called Escova Progressiva in Brazil and Alisado brasileiro in Portugal. | The original formulation included formaldehyde H
2CO or methylene glycol H
2. The two products readily interconvert, and coexist in chemical equilibrium, when dissolved in water or body fluids. Since formaldehyde is a known health hazard, the compositions have been banned in several countries including Canada and the European Union. It is still performed in the United States, though there are regulations and have been controversies regarding the treatment.
A formaldehyde releaser, formaldehyde donor or formaldehyde-releasing preservative is a chemical compound that slowly releases formaldehyde.
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a ring with one hydrogen atom attached to each. As it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.
4,4'-Methylenedianiline (MDA) is an organic compound with the formula CH2(C6H4NH2)2. It is a colorless or white solid. It is produced on industrial scale as a precursor to polyurethanes.
Formaldehyde is used to inactivate bacterial products for toxoid vaccines, (these are vaccines that use an inactive bacterial toxin to produce immunity.) It is also used to kill unwanted viruses and bacteria that might contaminate the vaccine during production. Most formaldehyde is removed from the vaccine before it is packaged.
The emission standards will be 0.05 ppm formaldehyde for hardwood plywood, 0.09 ppm formaldehyde for particleboard, 0.11 ppm formaldehyde for medium-density fiberboard, and 0.13 ppm formaldehyde for thin medium-density fiberboard.
|Wikisource has the text of the 1911 Encyclopædia Britannica article Formalin .|