Formaldehyde (/fɔːrˈmældɪhaɪd/ⓘfor-MAL-di-hide, US also /fər-/ⓘfər-) (systematic namemethanal) is an organic compound with the chemical formulaCH2O and structure H−CHO, more precisely H2C=O. The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as aqueous solutions (formalin), which consists mainly of the hydrate CH2(OH)2. It is the simplest of the aldehydes (R−CHO). As a precursor to many other materials and chemical compounds, in 2006 the global production of formaldehyde was estimated at 12 million tons per year.[14] It is mainly used in the production of industrial resins, e.g., for particle board and coatings. Small amounts also occur naturally.
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.[citation needed]
Molecular formaldehyde. A colorless gas with a characteristic pungent, irritating odor. It is stable at about 150 °C, but it 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. It is a trimer of molecular formaldehyde.
Paraformaldehyde, with the formula HO(CH2O)nH. It is a white solid that is insoluble in most solvents.
Methanediol, with the formula CH2(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".[16]
Main forms of formaldehyde
Monomeric formaldehyde (subject of this article)
Trioxane is a stable cyclic trimer of formaldehyde.
Paraformaldehyde is a common form of formaldehyde for industrial applications.
Methanediol, the predominant species in dilute aqueous solutions of formaldehyde
Processes in the upper atmosphere contribute more than 80% of the total formaldehyde in the environment.[23] 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.
Formaldehyde and its adducts are ubiquitous in nature. Food may contain formaldehyde at levels 1–100 mg/kg.[24] Formaldehyde, formed in the metabolism of the amino acids serine and threonine, is found in the bloodstream of humans and other primates at concentrations of approximately 50 micromolar.[25] 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.[26]
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.[27][28] It nonetheless presents significant health concerns, as a contaminant.
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.[29] 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.[30] A proposed mechanism for the formation is the hydrogenation of CO ice:[31]
Formaldehyde was discovered in 1859 by the Russian chemist Aleksandr Butlerov (1828–1886) when he attempted to synthesize methanediol ("methylene glycol") from iodomethane and silver oxalate.[34] In his paper, Butlerov referred to formaldehyde as "dioxymethylen" (methylene dioxide) because his empirical formula for it was incorrect, as atomic weights were not precisely determined until the Karlsruhe Congress.
The compound was identified as an aldehyde by August Wilhelm von Hofmann, who first announced its production by passing methanol vapor in air over hot platinum wire.[35][36] With modifications, Hofmann's method remains the basis of the present day industrial route.
Solution routes to formaldehyde also entail oxidation of methanol or iodomethane.[37]
Industry
Formaldehyde is produced industrially by the catalytic oxidation of methanol. The most common catalysts are silver metal, iron(III) oxide,[38] iron molybdenum oxides (e.g. iron(III) molybdate) with a molybdenum-enriched surface,[39] or vanadiumoxides. In the commonly used formox process, methanol and oxygen react at c. 250–400 °C in presence of iron oxide in combination with molybdenum and/or vanadium to produce formaldehyde according to the chemical equation:[40]
2CH3OH + O2 → 2CH2O + 2H2O
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 + H2
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.[40]
Biochemistry
Formaldehyde is produced via several enzyme-catalyzed routes.[41] Living beings, including humans, produce formaldehyde as part of their metabolism. Formaldehyde is key to several bodily functions (e.g. epigenetics[25]), but its amount must also be tightly controlled to avoid self-poisoning.[42]
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.[44]
Polymerization and hydration
Monomeric CH2O is a gas and is rarely encountered in the laboratory. Aqueous formaldehyde, unlike some other small aldehydes (which need specific conditions to oligomerize through aldol condensation) oligomerizes spontaneously at a common state. The trimer 1,3,5-trioxane, (CH2O)3, is a typical oligomer. Many cyclic oligomers of other sizes have been isolated. Similarly, formaldehyde hydrates to give the geminal diol methanediol, which condenses further to form hydroxy-terminated oligomers HO(CH2O)nH. The polymer is called paraformaldehyde. The higher concentration of formaldehyde—the more equilibrium shifts towards polymerization. Diluting with water or increasing the solution temperature, as well as adding alcohols (such as methanol or ethanol) lowers that tendency.
Gaseous formaldehyde polymerizes at active sites on vessel walls, but the mechanism of the reaction is unknown.[45] Small amounts of hydrogen chloride, boron trifluoride, or stannic chloride present in gaseous formaldehyde provide the catalytic effect and make the polymerization rapid.[46]
Formaldehyde forms cross-links by first combining with a protein to form methylol, which loses a water molecule to form a Schiff base.[47] The Schiff base can then react with DNA or protein to create a cross-linked product.[47] This reaction is the basis for the most common process of chemical fixation.
Oxidation and reduction
Formaldehyde is readily oxidized by atmospheric oxygen into formic acid. For this reason, commercial formaldehyde is typically contaminated with formic acid. Formaldehyde can be hydrogenated into methanol.
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.[49] Phenol results in polymers.
Other reactions
Many amino acids react with formaldehyde.[41] Cysteine converts to thioproline.
When condensed with phenol, urea, or melamine, formaldehyde produces, respectively, hard thermoset phenol formaldehyde resin, urea formaldehyde resin, and melamine resin. These polymers are permanent adhesives used in plywood and carpeting. 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:[51]
Niche uses
Disinfectant and biocide
An aqueous solution of formaldehyde can be useful as a disinfectant as it kills most bacteria and fungi (including their spores). It is used as an additive in vaccine manufacturing to inactivate toxins and pathogens.[52]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.[53]
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.[56]
Tissue fixative and embalming agent
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 as a biocide (including embalming) under the Biocidal Products Directive (98/8/EC) due to its carcinogenic properties.[57][58] Countries with a strong tradition of embalming corpses, such as Ireland and other colder-weather countries, have raised concerns. Despite reports to the contrary,[59] no decision on the inclusion of formaldehyde on Annex I of the Biocidal Products Directive for product-type 22 (embalming and taxidermist fluids) had been made as of September 2009[update].[60]
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.
In photography, formaldehyde is used in low concentrations for the process C-41 (color negative film) stabilizer in the final wash step,[61] as well as in the process E-6 pre-bleach step, to make it unnecessary in the final wash. Due to improvements in dye coupler chemistry, more modern (2006 or later) E-6 and C-41 films do not need formaldehyde, as their dyes are already stable.
Safety
In view of its widespread use, toxicity, and volatility, formaldehyde poses a significant danger to human health.[62][63] In 2011, the US National Toxicology Program described formaldehyde as "known to be a human carcinogen".[64][65][66]
Concerns are associated with chronic (long-term) exposure by inhalation as may happen from thermal or chemical decomposition of formaldehyde-based resins 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.[67][68] At concentrations above 0.1 ppm in air, formaldehyde can irritate the eyes and mucous membranes.[69] Formaldehyde inhaled at this concentration may cause headaches, a burning sensation in the throat, and difficulty breathing, and can trigger or aggravate asthma symptoms.[70][71]
The CDC considers formaldehyde as a systemic poison. Formaldehyde poisoning can cause permanent changes in the nervous system's functions.[72]
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.[73]
A 2009 review of studies has shown a strong association between exposure to formaldehyde and the development of childhood asthma.[74]
A theory was proposed for the carcinogenesis of formaldehyde in 1978.[75] In 1987 the United States Environmental Protection Agency (EPA) classified it as a probable human carcinogen, and after more studies the WHOInternational 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[76] associated with nasal sinus cancer and nasopharyngeal cancer.[77] Studies in 2009 and 2010 have also shown a positive correlation between exposure to formaldehyde and the development of leukemia, particularly myeloid leukemia.[78][79] Nasopharyngeal and sinonasal cancers are relatively rare, with a combined annual incidence in the United States of < 4,000 cases.[80][81] About 30,000 cases of myeloid leukemia occur in the United States each year.[82][83] Some evidence suggests that workplace exposure to formaldehyde contributes to sinonasal cancers.[84] 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.[85] Other factors are important in determining individual risk for the development of leukemia or nasopharyngeal cancer.[84][86][87] In yeast, formaldehyde is found to perturb pathways for DNA repair and cell cycle.[88]
In the residential environment, formaldehyde exposure comes from a number of routes; formaldehyde can be emitted by treated wood products, such as plywood or particle board, but it is produced by paints, varnishes, floor finishes, and cigarette smoking as well.[89] In July 2016, the U.S. EPA released a prepublication version of its final rule on Formaldehyde Emission Standards for Composite Wood Products.[90] 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.[91]
The U.S. EPA allows no more than 0.016 ppm formaldehyde in the air in new buildings constructed for that agency.[92][failed verification] A U.S. EPA study found a new home measured 0.076 ppm when brand new and 0.045 ppm after 30 days.[93] The Federal Emergency Management Agency (FEMA) has also announced limits on the formaldehyde levels in trailers purchased by that agency.[94] 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.[77]
The eyes are most sensitive to formaldehyde exposure: The lowest level at which many people can begin to smell formaldehyde ranges between 0.05 and 1 ppm. The maximum concentration value at the workplace is 0.3 ppm.[95][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.[96]
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 conditions. 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.
In operating rooms, formaldehyde is produced as a byproduct of electrosurgery and is present in surgical smoke, exposing surgeons and healthcare workers to potentially unsafe concentrations.[97]
Formaldehyde levels in air can be sampled and tested in several ways, including impinger, treated sorbent, and passive monitors.[98] The National Institute for Occupational Safety and Health (NIOSH) has measurement methods numbered 2016, 2541, 3500, and 3800.[99]
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."[64][65][66] Concurrently, a National Academy of Sciences (NAS) committee was convened and issued an independent review of the draft U.S. EPA IRIS assessment of formaldehyde, providing a comprehensive health effects assessment and quantitative estimates of human risks of adverse effects.[100]
Acute irritation and allergic reaction
For most people, irritation from formaldehyde is temporary and reversible, although 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%).[101] People with formaldehyde allergy are advised to avoid formaldehyde releasers as well (e.g., Quaternium-15, imidazolidinyl urea, and diazolidinyl urea).[102] 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).[53] Formaldehyde has been banned in cosmetics in both Sweden[103] and Japan.[104]
Other routes
Formaldehyde occurs naturally, and is "an essential intermediate in cellular metabolism in mammals and humans."[40] According to the American Chemistry Council, "Formaldehyde is found in every living system—from plants to animals to humans. It metabolizes quickly in the body, breaks down rapidly, is not persistent and does not accumulate in the body."[105]
The twelfth edition of NTP Report on Carcinogens notes that "food and water contain measureable concentrations of formaldehyde, but the significance of ingestion as a source of formaldehyde exposure for the general population is questionable." Food formaldehyde generally occurs in a bound form and formaldehyde is unstable in an aqueous solution.[66]
In humans, ingestion of as little as 30 millilitres (1.0 US fl oz) of 37% formaldehyde solution can cause death. Other symptoms associated with ingesting such a solution include gastrointestinal damage (vomiting, abdominal pain), and systematic damage (dizziness).[72] 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.[106]
Regulation
Several web articles[like whom?] 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.[107][108] 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.[53]
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 0.09 ppm, and required companies to meet this standard by January 2013.[109] The final U.S. EPA 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."[110]
The FDA is proposing a ban on hair relaxers with formaldehyde due to cancer concerns.[112]
Contaminant in food
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.[113] In August 2011, at least at two Carrefour supermarkets, the Central Jakarta Livestock and Fishery Sub-Department found cendol containing 10 parts per million of formaldehyde.[114] In 2014, the owner of two noodle factories in Bogor, Indonesia, was arrested for using formaldehyde in noodles. 50 kg of formaldehyde was confiscated.[115] 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.[116] 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[117] regarding formaldehyde's toxicity.[118][119]
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.[120] In 2012, 1 billion rupiah (almost US$100,000) of fish imported from Pakistan to Batam, Indonesia, were found laced with formaldehyde.[121]
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.[122] 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 as well as a maximum fine of 2,000,000 BDT but not less than 500,000 BDT for importing, producing, or hoarding formalin without a license.[123]
^Spence, Robert; Wild, William (1935). "114. The vapour-pressure curve of formaldehyde, and some related data". Journal of the Chemical Society (Resumed): 506–509. doi:10.1039/jr9350000506.
^Humans, IARC Working Group on the Evaluation of Carcinogenic Risks to (2006). Summary of Data Reported and Evaluation. International Agency for Research on Cancer. Archived from the original on 2024-02-02. Retrieved 2023-03-06.
^"Chapter 5.8 Formaldehyde"(PDF). Air Quality Guidelines (2nd ed.). Copenhagen, Denmark: WHO Regional Office for Europe. 2001. Archived(PDF) from the original on 2023-02-18. Retrieved 2023-02-18.
^Zuckerman, B.; Buhl, D.; Palmer, P.; Snyder, L. E. (1970). "Observation of interstellar formaldehyde". Astrophys. J. 160: 485–506. Bibcode:1970ApJ...160..485Z. doi:10.1086/150449.
^See: A. W. Hofmann (14 October 1867) "Zur Kenntnis des Methylaldehyds" ([Contributions] to our knowledge of methylaldehyde), Monatsbericht der Königlich Preussischen Akademie der Wissenschaften zu Berlin (Monthly Report of the Royal Prussian Academy of Sciences in Berlin), vol. 8, pages 665–669. Reprinted in:
A.W. Hofmann, (1868) "Zur Kenntnis des Methylaldehyds", Annalen der Chemie und Pharmacie (Annals of Chemistry and Pharmacy), vol. 145, no. 3, pages 357–361.
A.W. Hofmann (1868) "Zur Kenntnis des Methylaldehyds", Journal für praktische Chemie (Journal for Practical Chemistry), vol. 103, no. 1, pages 246–250.
However, it was not until 1869 that Hofmann determined the correct empirical formula of formaldehyde. See: A.W. Hofmann (5 April 1869) "Beiträge zur Kenntnis des Methylaldehyds", Monatsbericht der Königlich Preussischen Akademie der Wissenschaften zu Berlin, vol. ?, pages 362–372. Reprinted in:
A.W. Hofmann (1869) "Beiträge zur Kenntnis des Methylaldehyds," Berichte der Deutschen Chemischen Gesellschaft (Reports of the German Chemical Society), vol. 2, pages 152–159.
^Read, J. (1935). Text-Book of Organic Chemistry. London: G Bell & Sons.
^Chen, J; Chen, W; Zhang, J; Zhao, H; Cui, J; Wu, J; Shi, A (27 September 2023). "Dual effects of endogenous formaldehyde on the organism and drugs for its removal". Journal of Applied Toxicology. 44 (6): 798–817. doi:10.1002/jat.4546. PMID37766419. S2CID263125399.
^"Ingredients of Vaccines - Fact Sheet". Center for Disease Control. Archived from the original on 2019-04-21. Retrieved 2018-08-04. 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.
^"Formaldehyde in indoor air of new apartments in Greece"(PDF). Retrieved 2024-12-24. by George Mantanis, Eleni Vouli, Chariclea Gonitsioti and Georgios Ntalos; Presentation at the COST Action E49 Conference “Measurement and Control of VOC Emissions from Wood-Based Panels”, 28-30 Nov. 2007, WKI, Braunschweig, Germany
^"Indoor Air Pollution in California"(PDF). Air Resources Board, California Environmental Protection Agency. July 2005. pp. 65–70. Archived from the original(PDF) on 2019-03-01. Retrieved 2012-05-19.
^"Formaldehyde". Occupational Safety and Health Administration. August 2008. Archived from the original on 2019-04-11. Retrieved 2009-09-01.
^Turner JH, Reh DD (June 2012). "Incidence and survival in patients with sinonasal cancer: a historical analysis of population-based data". Head Neck. 34 (6): 877–85. doi:10.1002/hed.21830. PMID22127982. S2CID205857872.
^Butticè, Claudio (2015). "Solvents". In Colditz, Graham A. (ed.). The SAGE Encyclopedia of Cancer and Society (Second ed.). Thousand Oaks: SAGE Publications. pp. 1089–1091. doi:10.4135/9781483345758.n530. ISBN9781483345734. Archived from the original on 2021-10-14. Retrieved 2015-10-27.
^M. Koontz, H. Rector, D. Cade, C. Wilkes, and L. Niang. 1996. Residential Indoor Air Formaldehyde Testing Program: Pilot Study. Report No. IE-2814, prepared by GEOMET Technologies, Inc. for the USEPA Office of Pollution Prevention and Toxics under EPA Contract No. 68-D3-0013, Washington, DC
^Zug KA, Warshaw EM, Fowler JF, Maibach HI, Belsito DL, Pratt MD, Sasseville D, Storrs FJ, Taylor JS, Mathias CG, Deleo VA, Rietschel RL, Marks J (2009). "Patch-test results of the North American Contact Dermatitis Group 2005-2006". Dermatitis. 20 (3): 149–60. doi:10.2310/6620.2009.08097. PMID19470301. S2CID24088485.
^"Formaldehyde allergy". DermNet NZ. New Zealand Dermatological Society. 2002. Archived from the original on 2018-09-23. Retrieved 2019-04-25.
^"Formaldehyde Emission Standards for Composite Wood Products". Regulations.gov. United States Federal Register. 12 December 2016. Archived from the original on 10 August 2019. Retrieved 21 December 2019. 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.
^Blum, Deborah, 1954- (2018-09-25). The poison squad: one chemist's single-minded crusade for food safety at the turn of the twentieth century. Go Big Read (Program). New York, New York. ISBN9781594205149. OCLC1024107182.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
^"Was Death in the Milk?". The Indianapolis News. 1900-07-31. p. 5. Archived from the original on 2018-11-17. Retrieved 2014-08-20 – via Newspapers.com.
Rinus Michels Informasi pribadiNama lengkap Marinus Jacobus Hendricus MichelsTanggal lahir 9 Februari, 1928Tempat lahir Amsterdam, BelandaTanggal meninggal 3 Maret 2005Tempat meninggal Aalst, BelgiaPosisi bermain StrikerInformasi klubKlub saat ini -Karier senior*Tahun Tim Tampil (Gol) 1946-1958 Ajax Amsterdam 264 (122) Tim nasional‡1950 - 1954 Belanda 5 (0) Kepelatihan1953-19541960-19641964-19651965-19711971-19751974-19741975-19761976-19781979-19801980-19841984-19851986-19881988-19891990-1...
Jacqueline BeerJacqueline Beer, 1962LahirJacqueline Vangramberg14 Oktober 1932 (umur 91)Paris, FranceNama lainJacqueline BaerPekerjaanActressTahun aktif1955–1979Suami/istriJean Antonio Garcia Roady (1955-?) Thor Heyerdahl (m. 1991–2002) his death Jacqueline Beer atau Jacqueline Vangramberg terkadang ditulis Jacqueline Baer (lahir 14 Oktober 1932),[1] adalah mantan Aktris televisi dan Film Hollywood. Dia adalah ratu...
Resistenza polaccaparte della seconda guerra mondialeSoldati nel distretto di Wola durante la rivolta di VarsaviaData27 settembre 1939-25 luglio 1945 LuogoPolonia Casus belliInvasione tedesco-slovacca della Polonia EsitoLiberazione della Polonia Schieramenti Stato Segreto Polacco Armata Nazionale Battaglione Chłopskie Forze Armate Nazionali Governo Provvisorio della Polonia Guardia del Popolo (1942-1944) Armata Popolare (1944) Supporto da: Governo in esilio della Polonia...
Portuguese football referee This biography of a living person includes a list of general references, but it lacks sufficient corresponding inline citations. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. Please help to improve this article by introducing more precise citations. (September 2015) (Learn how and when to remove this template message) In this Portuguese name, the first or mat...
Research library of economics German National Library of EconomicsDeutsche Zentralbibliothek für Wirtschaftswissenschaften (ZBW)ZBW main building in KielLocationDüsternbrooker Weg 120, 24105 KielNeuer Jungfernstieg 21, 20354 Hamburg, GermanyTypeNational library, Research libraryScopeEconomics, Finance, BusinessEstablished1919CollectionItems collectedbooks, journals, electronic mediaSize4.43 million items[1]27,119 journal titlesAccess and usePopulation servedresearchers, business cli...
Disambiguazione – Se stai cercando l'omonimo ginnasta norvegese, vedi Bjarne Johnsen (ginnasta). Questa voce sull'argomento calciatori norvegesi è solo un abbozzo. Contribuisci a migliorarla secondo le convenzioni di Wikipedia. Segui i suggerimenti del progetto di riferimento. Bjarne Johnsen Nazionalità Norvegia Calcio Ruolo Attaccante CarrieraSquadre di club1 19??-19?? Brann? (?)Nazionale 1923 Norvegia5 (3) 1 I due numeri indicano le presenze e le reti segnate, per le so...
Pergam ekor ungu Ducula rufigaster Status konservasiRisiko rendahIUCN22691724 TaksonomiKerajaanAnimaliaFilumChordataKelasAvesOrdoColumbiformesFamiliColumbidaeGenusDuculaSpesiesDucula rufigaster Quoy dan Gaimard, 1830 lbs Pergam ekor ungu (Ducula rufigaster) adalah spesies burung yang masuk ke dalam famili Colombidae dan banyak ditemukan di Papua Nugini dengan nama lokal Sempuran/Yorsang[1]. Habitat dari burung ini adalah di hutan rendah hingga ketinggian 600 mdpl. Ciri fisik Burung in...
American baseball player (born 1939) For the Australian rules footballer, see Jack Fisher (footballer). For other people named John Fisher, see John Fisher (disambiguation). Baseball player Jack FisherPitcherBorn: (1939-03-04) March 4, 1939 (age 85)Frostburg, Maryland, U.S.Batted: RightThrew: RightMLB debutApril 14, 1959, for the Baltimore OriolesLast MLB appearanceSeptember 26, 1969, for the Cincinnati RedsMLB statisticsWin–loss record86–139Earned run a...
Public library system in Ohio, U.S. Toledo Public Library redirects here. For the library in Toledo, Spain, see List of libraries in Spain. Toledo Lucas County Public LibraryMain Library, Michigan Street EntranceLocation325 N Michigan St, Toledo, Ohio 43604, USATypePublic libraryEstablished1838BranchesMain Library and 20 branchesAccess and useCirculation5,882,449[1]Population served441,815[1]Members269,997[1]Other informationBudget$37,856,309[1]DirectorJason Ku...
Kalimpong Koordinat 27°06' LU 88°47' BT[pranala nonaktif permanen] Negara Bagian Benggala Barat Distrik Darjeeling Ketinggian 1.247 m Wilayah 1.056,5 km² Penduduk (2001) 40.143 jiwa Kepadatan 38,01/km² Kode • Pos • Telepon 734 301+03552 Zona waktu (UTC +5:30) Kalimpong adalah sebuah stasiun bukit (hill station/hill town) di Perbukitan Siwalik, Negara Bagian Benggala Barat, India. Di kota kecil ini bertempat kantor administrasi Subdivisi Kalimp...
Railway station in Tatebayashi, Gunma Prefecture, Japan TI11Tatara Station多々良駅Tatara Station in September 2021General informationLocationHinatacho 987, Tatebayashi-shi, Gunma-ken 374-0076JapanCoordinates36°16′25″N 139°30′00″E / 36.2736°N 139.5000°E / 36.2736; 139.5000Operated by Tōbu RailwayLine(s) Tōbu Isesaki LineDistance78.6 km from AsakusaPlatforms2 side platformsOther informationStation codeTI-11WebsiteOfficial websiteHistoryOpened27 August 1...
قصة ليزي الصنف دراما - رعب الموضوع تشاهد ليزي مقتل زوجها الكاتب وترفض التخلي عن أعماله مأخوذ عن قصة ليزي تاريخ الصدور 4 يونيو 2021 (الولايات المتحدة) مدة العرض (موسم واحد) 8 حلقات 50-52 دقيقة للحلقة الواحدة البلد تشيلي - الولايات المتحدة اللغة الأصلية الإنجليزية مواقع التصوير ...
Turkish offensive against the SDF in Afrin Operation Olive BranchPart of the Rojava conflict, Turkish involvement in the Syrian Civil War, and the Kurdish–Turkish conflict (2015–present) Turkish-backed opposition control SDF control Syrian Army controlFor a more detailed, up-to-date, interactive map, see here.DateMain combat phase:20 January[a] – 24 March 2018[9](2 months and 4 days)Main insurgency phase:[10][11][12&...
Katedral TrondheimGereja Katedral Santo Olav di TrondheimSt. Olav domkirkeKatedral Trondheim, 2016LokasiTrondheimNegaraNorwegiaDenominasiGereja Katolik RomaSejarahTanggal konsekrasi1973AdministrasiKeuskupanPrelatur Teritorial Trondheim Katedral Santo Olav[1] (bahasa Norwegia: St. Olav domkirke) adalah sebuah gereja katedral Katolik yang menjadi pusat kedudukan dan takhta bagi Prelatur Trondheim, milik Gereja Katolik di Norwegia.[2][3] Katedral ini dibangun di atas ...
ثورة عالميةملصق يحمل عبارة الرفيق لينين ينظف الأرض من القاذوراتمعلومات عامةصنف فرعي من ثورة تعديل - تعديل مصدري - تعديل ويكي بيانات الثورة العالمية نظرية ماركسية للقضاء على الرأسمالية في العالم بأكمله من خلال الاعتماد على الوعي الطبقي الثوري المنظم للطبقة العاملة، وأضحت ...
Public high school in the United StatesRoxbury Memorial High SchoolExternal view of the high school, circa May 1927Location205 Townsend StreetRoxbury, MassachusettsUnited StatesCoordinates42°18′58″N 71°05′04″W / 42.3161°N 71.0845°W / 42.3161; -71.0845InformationTypePublic high schoolEstablished1926Closed1960Girls HeadmasterWinifred H. Nash (1956)Boys HeadmasterPaul B. Crudden (1956)FacultyGirls • 51 (1956) Boys • 46 (1956)[2]EnrollmentGirls • ...