# Methanediol > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Methanediol > Markdown URL: https://mediated.wiki/source/Methanediol.md > Source: https://en.wikipedia.org/wiki/Methanediol > Source revision: 1351298677 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Redirect-distinguish|Methylene glycol|Ethylene glycol}} {{Short description|Organic compound (CH2(OH)2); simplest geminal diol}} {{Chembox |Watchedfields = changed |verifiedrevid = 447495694 |ImageFile2 = Methanediol-3D-balls.png |ImageFile2_Ref = {{chemboximage|correct|??}} |ImageSize2 = 100 |ImageName2 = Ball and stick model of the methanediol |ImageClass2 = bg-transparent |ImageFileL1 = Methanediol-2D.png |ImageFileL1_Ref = {{chemboximage|correct|??}} |ImageNameL1 = Skeletal formula of methanediol with some explicit hydrogens added |ImageClassL1= skin-invert |ImageFileR1 = Methanediol-3D-vdW.png |ImageFileR1_Ref = {{chemboximage|correct|??}} |ImageNameR1 = Spacefill model of methanediol |ImageClassR1 = bg-transparent |PIN = Methanediol{{Cite web|title = Methanediol - Compound Summary|url = https://pubchem.ncbi.nlm.nih.gov/compound/79015|work = PubChem Compound|publisher = National Center for Biotechnology Information|access-date = 20 October 2011|location = USA|date = 26 March 2005|at = Identification and Related Records}} |OtherNames = {{unbulleted list|Formaldehyde hydrate|Formaldehyde monohydrate|Methylene glycol}} |Section1={{Chembox Identifiers |Abbreviations = MADOL |CASNo = 463-57-0 |CASNo_Ref = {{cascite|correct|??}} |UNII_Ref = {{fdacite|correct|FDA}} |UNII = 6Z20YM9257 |PubChem = 79015 |ChemSpiderID = 71348 |ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |EINECS = 207-339-5 |ChEBI = 48397 |ChEBI_Ref = {{ebicite|correct|EBI}} |Beilstein = 1730798 |SMILES = OCO |StdInChI = 1S/CH4O2/c2-1-3/h2-3H,1H2 |StdInChI_Ref = {{stdinchicite|correct|chemspider}} |StdInChIKey = CKFGINPQOCXMAZ-UHFFFAOYSA-N |StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} }} |Section2={{Chembox Properties |C=1 | H=4 | O=2 |Appearance = Colourless liquid |Density = {{val|1.199|u=g/cm3}} {{Citation needed|date=October 2021}} |BoilingPtC = 194 |BoilingPt_notes = at 101 kPa {{Citation needed|date=October 2021}} |VaporPressure = 16.1 Pa {{Citation needed|date=October 2021}} |RefractIndex = 1.401 {{Citation needed|date=October 2021}} |pKa = 13.29{{cite journal|last=Bell|first=R. P.|author2=McTigue, P. T.|title=603. Kinetics of the aldol condensation of acetaldehyde|journal=Journal of the Chemical Society (Resumed)|year=1960|page=2983|doi=10.1039/JR9600002983}} }} |Section3={{Chembox Hazards |FlashPtC = 99.753 }} }} '''Methanediol''', also known as '''formaldehyde monohydrate''' or '''methylene glycol''', is an [organic compound](/source/organic_compound) with [chemical formula](/source/chemical_formula) {{chem2|CH2(OH)2}}. It is the simplest [geminal diol](/source/geminal_diol). In aqueous solutions it coexists with [oligomer](/source/oligomer)s (short polymers). The compound is closely related and convertible to the industrially significant derivatives [paraformaldehyde](/source/paraformaldehyde) ({{chem2|(CH2O)_{''n''} }}), [formaldehyde](/source/formaldehyde) ({{chem2|H2C\dO}}), and [1,3,5-trioxane](/source/1%2C3%2C5-trioxane) ({{chem2|(CH2O)3}}). Methanediol is a product of the [hydration reaction](/source/hydration_reaction) of formaldehyde. The [equilibrium constant](/source/equilibrium_constant) for hydration is estimated to be 103, Eric V. Anslyn, Dennis A. Dougherty (2006), [https://books.google.com/books?id=gY-Sxijk_tMC&pg=PA544 ''Modern physical organic chemistry'']. University Science Books. {{ISBN|1-891389-31-9}}. 1095 pages{{chem2|CH2(OH)2}} predominates in dilute (<0.1%) solution. In more concentrated solutions, it oligomerizes to {{chem2|HO(CH2O)_{''n''}H}}.{{Ullmann|doi=10.1002/14356007.a11_619|title=Formaldehyde|year=2000|last1=Reuss|first1=Günther|last2=Disteldorf|first2=Walter|last3=Gamer|first3=Armin Otto|last4=Hilt|first4=Albrecht|isbn=3527306730}} ==Occurrence== The dianion, methanediolate, is believed to be an intermediate in the crossed [Cannizzaro reaction](/source/Cannizzaro_reaction). Gaseous methanediols can be generated by [electron irradiation](/source/electron_irradiation) and sublimation of a mixture of [methanol](/source/methanol) and [oxygen](/source/oxygen) ices.{{cite journal |last1=Zhu |first1=Cheng |last2=Kleimeier |first2=N. Fabian |last3=Turner |first3=Andrew M. |last4=Singh |first4=Santosh K. |last5=Fortenberry |first5=Ryan C. |last6=Kaiser |first6=Ralf I. |title=Synthesis of methanediol [CH 2 (OH) 2 ]: The simplest geminal diol |journal=Proceedings of the National Academy of Sciences |date=4 January 2022 |volume=119 |issue=1 |article-number=e2111938119 |doi=10.1073/pnas.2111938119 |doi-access=free | pmid=34969838 |pmc=8740743 |bibcode=2022PNAS..11911938Z }} Methanediol is believed to occur as an intermediate in the decomposition of [carbonyl](/source/carbonyl) compounds in the atmosphere, and as a product of [ozonolysis](/source/ozonolysis) on these compounds. ==Safety== Methanediol, rather than formaldehyde, is listed as one of the main ingredients of "[Brazilian blowout](/source/Brazilian_hair_straightening)", a hair-straightening formula marketed in the [United States](/source/United_States). The equilibrium with formaldehyde has caused concern since formaldehyde in hair straighteners is a health hazard.{{Cite web|url=https://www.osha.gov/SLTC/formaldehyde/hazard_alert.html|title=Hair Smoothing Products That Could Release Formaldehyde|publisher=Occupational Safety and Health Administration|website=www.osha.gov}}{{cite web|title=Industry News|author=SpecialChem|url=http://www.specialchem4cosmetics.com/markets/hair-care/news.aspx?id=5947&lr=chal2d161210&li=100091733}}{{Dead link|date=January 2026 |bot=InternetArchiveBot}} Research funded by the Professional Keratin Smoothing Council (PKSC), an industry association that represents selected manufacturers of professional-use only keratin smoothing products, has disputed the risk.{{cite journal|last1=Golden|first1=R.|last2=Valentini|first2=M.|title=Formaldehyde and methylene glycol equivalence: Critical assessment of chemical and toxicological aspects|journal=[Regulatory Toxicology and Pharmacology](/source/Regulatory_Toxicology_and_Pharmacology)|date=July 2014|volume=69|issue=2|pages=178–186|doi=10.1016/j.yrtph.2014.03.007|pmid=24709515|doi-access=free}} ==See also== * [Orthoformic acid](/source/Orthoformic_acid) (methanetriol) * [Orthocarbonic acid](/source/Orthocarbonic_acid) (methanetetrol) ==References== {{Reflist}} {{Alcohols}} Category:Hydrates Category:Carbohydrates Category:Geminal diols Category:Sugar alcohols --- Adapted from the Wikipedia article [Methanediol](https://en.wikipedia.org/wiki/Methanediol) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Methanediol?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.