Formaldehyde is a naturally occurring organic compound with the formula CH2O (H−CHO).
The pure compound is a pungent-smelling colorless gas that polymerises spontaneously into paraformaldehyde (refer to section Forms below), hence it is stored as an aqueous solution (formalin).
CAS Number:50-0-0
EC Number: 200-001-8
IUPAC Name: Methanal
Chemical Formula:CH2O
Other names: aldeideformica, BFV, CH2O, Chloditan, Chlodithan, Chlodithane, dormol, Durine, formaldehyde, formalin, methanal, Paraformaldehyde, 50-00-0, formol, Methylene oxide, Oxomethane, Paraform, Formic aldehyde, Oxymethylene, Methyl aldehyde, Fannoform, Formalith, Formaldehyde solution, Methaldehyde, Oxomethylene, Superlysoform, Formalina, Lysoform, Morbicid, Karsan, Formaldehyd, Formaline, 30525-89-4, Aldehyde formique, FYDE, Formaldehyde, gas, Formalin 40, Aldeide formica, Oplossingen, Dormol, Formalin-loesungen, Rcra waste number U122, oxomethyl, Aldehyd mravenci, CH2O, UN 2209 (formalin), Formaldehyde (gas), Formaline [German], NCI-C02799, Formalina [Italian], Oplossingen [Dutch], HCHO, Caswell No. 465, FORMYL GROUP, Fordor, UN 1198, Aldehyd mravenci [Czech], Aldeide formica [Italian], Aldehyde formique [French], Formalin-loesungen [German], Formaldehyd [Czech, Polish], CCRIS 315, NSC 298885, Formaldehyde [USP], HSDB 164, Aldehyde formique [ISO-French], BFV, Formaldehyde, solution, UNII-1HG84L3525, CHEBI:16842, AI3-26806, UN1198, UN2209, RCRA waste no. U122, EPA Pesticide Chemical Code 043001, methanone, DTXSID7020637, Formalin Solution, Formaldehyde, Para, Formaldehyde (USP), MFCD00003274, 1HG84L3525, NSC-298885, Formaldehyde, solution (37% to 50%), Formalde-Fresh Solution, Polyformaldehyde, DSSTox_CID_637, Formalin, Buffered, 10%, DSSTox_RID_82549, Paraformic aldehyde, DSSTox_GSID_47796, Formaldehyde, 37% by Weight, Formaldehyde, 40% by Volume, Paraformaldehyde, 90%, pure, Formaldehyd (CZECH, POLISH), Formalde-Fresh Solution, Buffered, Formalaz, Formaldehyde, solutions, flammable [UN1198] [Flammable liquid], MFCD00133991, Formaldehyde, solutions with not <25% formaldehyde [UN2209] [Corrosive], Buffer Solution, pH 4.00, Color-Coded Red, Formic aldehyde, formaidehyde, formaldeyde, formaldhyde, methanon, paraformaldehyd, paraformaldehye, Formadehyde, Formaldehye, Durine, paraformaidehyde, Formaldehyde, 37 wt% sol. in water, stab. with 5-15% methanol, Formaldehyde, ACS reagent, 37 wt% sol., stab. 10-15% methanol, para formaldehyde, paraform-aldehyde, Para-formaldehyde, Formalin solution, neutral buffered, 10%, histological tissue fixative, F-gen, Hyperband (TN), Formalin [JAN], EINECS 200-001-8, HCOH, Floguard 1015, Formalin (JP17), CARBON-MONOXIDE, Hercules 37M6-8, H2CO, WLN: VHH, Formaldehyde [BSI:ISO], Paraformaldehyde (JP17), ACMC-1AVX8, bmse000256, Epitope ID:116196, EC 200-001-8, Formaldehyde, 4% in PBS, Formaldehyde, methanol-free, CHEMBL1255, Formaldehyde solution, 10%, BIDD:ER0493, GTPL4196, AMY6741, Formaldehyde, as formalin solution, Formaldehyde, solutions, flammable, Tox21_111160, Tox21_302438, ANW-44009, FM 282, NSC298885, AKOS008967440, BufferPac™ Color-Coded Solutions, DB03843, Formaldehyde, 37% in aqueous solution, MCULE-1476806907, NA 9202, UN 1016, UN 2209, Formaldehyde solution 37 wt. % in H2O, NCGC00255116-01, BP-21234, E240, formaldehyde;formaldehyde [bsi:iso];methanal;formaldehyde (act. 37%);formalin;formaldehyde formaldehyde [bsi:iso] methanal formaldehyde (act. 37%) formalin, Formaldehyde (37per cent w/w aq. soln.), Formaldehyde solution, 37 wt. % in H2O, F0622, FT-0626522, FT-0689115, P0018, Y1318, Formaldehyde solution ACS 37 wt. % in H2O, C00067, D00017, D01494, A827922, Q161210, SR-01000944454, Formaldehyde, solutions with not <25% formaldehyde, SR-01000944454-1, Q27110014
Formaldehyde 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.
Formaldehyde 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".
-General Description-
Formaldehyde, also called formic aldehyde or methyl aldehyde, has extensive application. For instance, it is used as a tissue preservative or organic chemical reagent.
Thus, formaldehyde is very common to the chemical industry.
In fact, formaldehyde is an important chemical used widely by industry to manufacture building materials and numerous household products.
Formaldehyde is also a by-product of combustion and certain other natural processes.
Formaldehyde is present in substantial concentrations both indoors and outdoors.
Formaldehyde is well known as a preservative in medical laboratories, as an embalming fluid, and as a steriliser.
Its primary use is in the production of resins and as a chemical intermediate.
Urea–formaldehyde (uf) and phenol–formaldehyde (pf) resins are used in foam insulations, as adhesives in the production of particle board and plywood, and in the treating of textiles.
Sources of formaldehyde in the home include building materials, smoking, household products, and the use of unvented, fuel-burning appliances, like gas stoves or kerosene space heaters.
Formaldehyde, by itself or in combination with other chemicals, serves a number of purposes in manufactured products.
Formaldehyde itself is a colourless gas, but it is more commonly purchased and used in aqueous solution (called formalin solution), with a maximum concentration of 40%.
Formalin solutions often contain some amount of methanol as well.
Both formaldehyde gas and solutions have a characteristic pungent, unpleasant odour.
Formaldehyde is a colorless, flammable gas with a distinctive pungent odor.
Formaldehyde is the simplest aldehyde, which is a class of organic compounds with the carbonyl group bonded to at least one hydrogen atom.
Formaldehyde was described by August Wilhelm von Hoff mann (1818–1892) in 1867 after the Russian Aleksandr Butlerov (1828–1886) had inadvertently synthesized it in 1857.
Formaldehyde readily dissolves in water to produce a solution called formalin, which is commonly marketed as a 37% solution.
-Computed Properties-
Molecular Weight: 30.026
XLogP3-AA: 1.2
Hydrogen Bond Acceptor Count: 1
Exact Mass: 30.010564683
Monoisotopic Mass: 30.010564683
Topological Polar Surface Area: 17.1 Ų
Heavy Atom Count: 2
Complexity: 2
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes
-Chemical Properties-
Formaldehyde is an important chemical widely used by industry to manufacture building materials and numerous household products.
Formaldehyde is also a by-product of combustion and certain other natural processes.
Formaldehyde is present in substantial concentrations both indoors and outdoors.
Formaldehyde is well known as a preservative in medical laboratories, as an embalming fluid, and as a sterilizer.
Formaldehyde is primary use is in the production of resins and as a chemical intermediate.
Urea formaldehyde (uf) and phenol formaldehyde (pf) resins are used in foam insulations, as adhesives in the production of particle board and plywood, and in the treating of textiles.
Sources of formaldehyde in the home include building materials, smoking, household products, and the use of unvented, fuel-burning appliances, like gas stoves or kerosene space heaters.
Formaldehyde, by itself or in combination with other chemicals, serves a number of purposes in manufactured products.
It has been reported that the use and production of formaldehyde in 1998 was about 11.3 billion pounds and the international production crossed over 46 billion pounds in 2004.
-Physical properties-
Formaldehyde is a clear, colorless liquid with a pungent, suffocating odor. Burning taste.
Experimentally determined odor threshold concentrations of 1.0 ppmv and 0.50 ppmv were reported by Leonardos et al. (1969) and Nagata and Takeuchi (1990), respectively.
Also,formalin is an aqueous solution that is 37% formaldehyde by weight; inhibited solutions (added to prevent polymeri zation) usually contain 6 12% methyl alcohol.
Formaldehyde is used in the manufacture of plastics and resins by reaction with phenols,urea, and melamine. It is used as a preservative,a disinfectant, and as a chemical intermediate.
-Forms-
Formaldehyde is more complicated than many simple carbon compounds in that it adopts several diverse forms.
These compounds can often be used interchangeably and can be interconverted.
Molecular formaldehyde. A colorless gas with a characteristic pungent, irritating odor.
Formaldehyde is stable at about 150 °C, but polymerizes when condensed to a liquid.
1,3,5-Trioxane, with the formula (CH2O)3. It is a white solid that dissolves without degradation in organic solvents.
Formaldehyde is a trimer of molecular formaldehyde.
Paraformaldehyde, with the formula HO(CH2O)nH.
Formaldehyde is a white solid that is insoluble in most solvents.
Methanediol, with the formula CH2(OH)2.
Formaldehyde 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".
-Occurrence-
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.
Formaldehyde is formed in the metabolism of 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.
-History-
Formaldehyde is a by-product of combustion of organic compounds, metabolism, and other natural processes.
Formaldehyde results from wood combustion and elevated atmospheric concentrations can result from forest fires, as well as from urban pollution sources such as transportation.
Formaldehyde has been identified as a significant indoor air pollutant.
Building materials such as particleboard, plywood, and paneling are major sources of formaldehyde because they incorporate formaldehyde resins as bonding adhesives.
Other sources of formaldehyde in the home are carpets, upholstery, drapes, tobacco smoke, and indoor combustion products.
Formaldehyde may be emitted from building materials for several years after installation.
In the two decades of the 1960s and 1970s, a half million homes in the United States used urea formaldehyde foam insulation, but health complaints led to its elimination as an insulator in the early 1980s.
People react differently to formaldehyde exposure, but it is estimated that between 10% and 20% of the population will experience some reaction at concentrations as low as 0.2 parts per million.
Formaldehyde irritates the eyes, nose, and throats, producing coughing, sneezing, runny nose, and burning eyes.
More severe reactions result in insomnia, headaches, rashes, and breathing difficulties. Some states have established indoor air quality standards ranging from 0.05 to 0.5 ppm.
-Uses-
Formaldehyde is used as the preservative; disinfectant; antiseptic; in embalming solutions; in the manufacture of phenolic resins, artificial silk, cellulose esters, dyes, urea, thiourea, melamine res ins, organic chemicals, glass mirrors and explosives; used in improving fastness of dyes on fabrics; in tanning and preserving hides; in mordanting and waterproofing fabrics; as a germicide and fungicide for vegetables and other plants.
Destroying flies and other insects; in preserving and coagulating rubber latex; prevent mildewand spelt in wheat and rot in oats; used to ren der casein, albumin, and gelatin insoluble; in chemical analysis; as a tissue fixative; as a component of particle board and plywood; in the manufacture of pentaerythritol, hexamethylenetetramine and lkbutanediol; used in ceiling and wall insulation; in res ins used to wrinkle-proof fabrics; in photography for hardening gelatin plates and papers,
for toning gelatin-chloride papers and for chrome printing and developing; intermediate in drug manufacture; pesticide intermediate; in the production of urea, phenolic melamine and acetale resins; in textile products; as an astringent, disinfectant, and preservative in cosmetics, metal-working fluids, shampoos, etc.; antiperspirant in cosmetics; anticracking agent in dental plastics; in anhidrotics; chipboard production; in cleaning products, disinfectants and deodorizers, dry-cleaning materials, and glues; in mineral-wool production, paints and coatings, paper industry, phenolic resins and urea plastics; in adhesives and footwear, photographic paper and solutions, polishes, printing materials, tanning agents, wart remedies, embalming solutions, fertilizers, wood composites, and insulation.
Formaldehyde is used in the manufactureof phenolic resins, cellulose esters, artificialsilk, dyes, explosives, and organic chemicals.Other uses are as a germicide, fungicide, anddisinfectant; in tanning, adhesives, waterproofingfabrics, and for tonic and chromeprinting in photography; and for treating skindiseases in animals.
In vitro neutralizationof scorpion venom toxicity by formaldehydehas been reported (Venkateswarlu et al.1988).
Formaldehyde constitutes about 50% ofall aldehydes present in the air.
Formaldehyde is oneof the toxic effluent gases emitted fromburning wood and synthetic polymeric substancessuch as polyethylene, nylon 6, andpolyurethane foams.
Firefighters have a greaterrisk to its exposure.
Incapacitation fromthe toxic effluent gases is reported to occurmore rapidly from the combustion of syntheticpolymers than from that of naturalcellulose materials.
Formaldehyde is directly emitted into theair from vehicles.
It is released in traceamounts from pressed wood products suchas particleboard and plywood paneling, fromold “sick” buildings, and from cotton andcotton–polyester fabrics with selected crosslinkfinishes.
Formation of formaldehyde hasbeen observed in some frozen gadoid fishdue to enzymic decomposition of the additivetrimethylamine oxide (Rehbein 1985).
Its concentration can build up during frozenstorage of fish (Leblanc and Leblanc 1988;Reece 1985).
It occurs in the upper atmosphere,cloud, and fog; it also forms inphotochemical smog processes.
More than half of the commercial formaldehyde produced is used to manufacture phenolic,urea, and melamine formaldehyde resins.
Polyacetyl resins use another 5–10% of formaldehyde,and approximately 80% of formaldehyde goes into the resins and plastics industry.
Phenolic-formaldehyde resins were the first synthetic plastics to be produced.
The first plasticwas called Bakelite.
Formaldehyde has traditionally been used as a preservative in biology and medical laboratoriesand in embalming fluid.
Embalming fluids typically contain 5–15% formaldehyde, a significant percentage of alcohol, and other additives to perform certain functions, for example,bleaches and coloring to preserve skin color.
Formaldehyde has been used to preserve deadbodies since 1900 and has several qualities that make it the preferred preservative.
Foremostamong these is its low cost, but it also has several biochemical advantages: it kills germs andmicroorganisms, destroys decomposition enzymes, retards decomposition of proteins, andhardens body tissues.
Formaldehyde (methyl aldehyde, methylene oxide) is a ubiquitous compound found endogenously in the body and environment.
It is a colorless, flammable gas with a distinct, pungent odor and is most commonly available in aqueous solutions under the name formalin (37% formaldehyde in water).
Formaldehyde has been used as a disinfectant, an embalming agent, and in industry as a precursor in the fabrication of complex compounds.
Since scientific research has identified links between formaldehyde and adverse health effects, precautions and protections must be considered during use.
-Synthesis and industrial production-
Laboratory synthesis:
Formaldehyde was first reported in 1859 by the Russian chemist Aleksandr Butlerov (1828–86).
In his paper, Butlerov referred to formaldehyde as "dioxymethylen" (methylene dioxide) because his empirical formula for it was incorrect (C4H4O4).
It was conclusively identified by August Wilhelm von Hofmann, who first announced the production of formaldehyde by passing methanol vapor in air over hot platinum wire.
With modifications, Hoffmann's method remains the basis of the present day industrial route.
Solution routes to formaldehyde also entail oxidation of methanol or methyl iodide.
Industry:
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:
2 CH3OH + O2 → 2 CH2O + 2 H2O
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:
CH3OH → CH2O + H2In 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.