View source for Butanone

{{Short description|Chemical compound (CH3C(O)CH2CH3)}}
{{chembox
| Watchedfields  = changed
| verifiedrevid  = 443491626
| Reference      = <ref>''[[Merck Index]]'', 11th Edition, '''5991'''.</ref>
| Name           = Butanone
| ImageFile      = Butanone-skeletal-structure.svg
| ImageClass     = skin-invert
| ImageSize      = 160px
| ImageName      = Skeletal formula of butanone
| ImageFileL1    = Butanone-3D-balls.png
| ImageClassL1 = bg-transparent  
| ImageNameL1    = Ball-and-stick model of butanone
| ImageFileR1    = Butanone-3D-vdW.png
| ImageClassR1 = bg-transparent  
| ImageNameR1    = Space-filling model of butanone
| ImageFile2     = Methyl ethyl ketone 45ml.jpg
| ImageName2     = methyl ethyl ketone
| PIN            = Butan-2-one<ref name=iupac2013>{{cite book | title =  Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = [[Royal Society of Chemistry|The Royal Society of Chemistry]] | date = 2014 | location = Cambridge | page = 725 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4}}</ref>
| OtherNames     = {{ubl
 | 2-Butanone
 | Ethyl methyl ketone<ref name=iupac2013 />
 | Ethylmethylketone
 | Methyl ethyl ketone (MEK; [[deprecated]]<ref name=iupac2013 />)
 | Methylpropanone
 | Methylacetone
 }}
| IUPACName      = 
| Section1       = {{Chembox Identifiers
| CASNo = 78-93-3
| CASNo_Ref = {{cascite|correct|CAS}}
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 28398
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 15849
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 6321
| EINECS = 201-159-0
| PubChem = 6569
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C02845
| RTECS = EL6475000
| Gmelin = 25656
| Beilstein = 741880
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 6PT9KLV9IO
| UNNumber = 1193
| InChI = 1/C4H8O/c1-3-4(2)5/h3H2,1-2H3
| InChIKey = ZWEHNKRNPOVVGH-UHFFFAOYAW
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C4H8O/c1-3-4(2)5/h3H2,1-2H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = ZWEHNKRNPOVVGH-UHFFFAOYSA-N
| SMILES = O=C(C)CC
| SMILES1 = CCC(=O)C
  }}
| Section2       = {{Chembox Properties
| C=4 | H=8 | O=1
| Appearance = Colorless liquid
| Odor = Mint or acetone-like<ref name=PGCH/>
| Density = 0.8050{{nbsp}}g/mL
| Solubility = 27.5{{nbsp}}g/100{{thinsp}}mL
| MeltingPtC = −86
| BoilingPtC = 79.64
| pKa = 14.7
| Viscosity = 0.43{{nbsp}}[[Poise (unit)|cP]]
| RefractIndex = 1.37880
| VaporPressure = 78{{nbsp}}mmHg (20{{nbsp}}°C)<ref name=PGCH/>
| MagSus = −45.58·10<sup>−6</sup> cm<sup>3</sup>/mol
| LogP = 0.37<ref name="chemsrc">{{Cite web|url=https://www.chemsrc.com/en/cas/78-93-3_1101392.html|title=butan-2-one_msds}}</ref>
  }}
| Section3       = {{Chembox Structure
| MolShape =
| Dipole = 2.76{{nbsp}}[[Debye|D]]
  }}
| Section4       = 
| Section5       = 
| Section6       = 
| Section7       = {{Chembox Hazards
| ExternalSDS = [https://web.archive.org/web/20180417143435/http://www.kleanstrip.com/uploads/documents/GME71_SDS-1635.4.pdf Safety Data Sheet]
| GHSPictograms = {{GHS02}}{{GHS07}}<ref name="SDS" />
| GHSSignalWord = '''Danger'''<ref name="SDS" />
| HPhrases = {{H-phrases|225|319|336}}<ref name="SDS">{{cite web |title=Safety Data Sheet - Klean Strip - Methyl Ethyl Ketone (MEK) |url=http://www.kleanstrip.com/uploads/documents/GME71_SDS-1635.4.pdf |website=Kleanstrip.com |publisher=Klean Strip |access-date=5 November 2019 |archive-url=https://web.archive.org/web/20180417143435/http://www.kleanstrip.com/uploads/documents/GME71_SDS-1635.4.pdf |archive-date=17 April 2018 |language=en |date=15 April 2015}}</ref>
| PPhrases = {{P-phrases|233|210|280|240|241|243|242|264|261|271|370+378|303+361+353|305+351+338|337+313|304+340|312|403+235|501|403+233|405}}<ref name="SDS" />
| NFPA-H = 1
| NFPA-F = 3
| NFPA-R = 0
| FlashPtC = −9
| AutoignitionPtC = 505
| LD50 = {{ubl
 | 2737{{nbsp}}mg/kg (oral, rat)
 | 4050{{nbsp}}mg/kg (oral, mouse)<ref name=IDLH/>
 }}
| PEL = TWA 200{{nbsp}}ppm (590{{nbsp}}mg/m<sup>3</sup>)<ref name=PGCH>{{PGCH|0069}}</ref>
| ExploLimits = 1.4–11.4%<ref name=PGCH/>
| IDLH = 3000{{nbsp}}ppm<ref name=PGCH/>
| REL = TWA 200{{nbsp}}ppm (590{{nbsp}}mg/m<sup>3</sup>) ST 300{{nbsp}}ppm (885{{nbsp}}mg/m<sup>3</sup>)<ref name=PGCH/> 
| LC50 = {{ubl
 | 12667{{nbsp}}ppm (mammal)
 | 13333{{nbsp}}ppm (mouse, 2{{nbsp}}hr)
 | 7833{{nbsp}}ppm (rat, 8{{nbsp}}hr)<ref name=IDLH>{{IDLH|78933|2-Butanone}}</ref>
 }}
  }}
| Section8       = {{Chembox Related
| OtherFunction_label = [[ketone]]s
| OtherFunction = {{ubl|[[Acetone]]|[[3-Pentanone]]|[[3-Methylbutanone]]}}
  }}
}}

'''Butanone''', also known as '''methyl ethyl ketone''' ('''MEK''') or '''ethyl methyl ketone''',{{efn|The international standards group [[IUPAC]] has [[deprecated]] the term ''methyl ethyl ketone'', and now recommends using ''ethyl methyl ketone'' instead.<ref name=iupac2013 />}} is an [[organic compound]] with the [[chemical formula|formula]] CH<sub>3</sub>C(O)CH<sub>2</sub>CH<sub>3</sub>. This colorless liquid [[ketone]] has a sharp, sweet odor reminiscent of [[acetone]]. It is produced industrially on a large scale, but occurs in nature only in trace amounts.<ref name=Ullmann>Wilhelm Neier, Guenter Strehlke "2-Butanone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002.</ref> It is partially soluble in water, and is commonly used as an industrial solvent.<ref name="TurnerMcCreery"/> It is an [[isomer]] of another solvent, [[tetrahydrofuran]].

==Production==
Butanone may be produced by oxidation of [[2-butanol]]. The [[dehydrogenation]] of 2-butanol is [[catalyst|catalysed]] by [[copper]], [[zinc]], or [[bronze]]:
:CH<sub>3</sub>CH(OH)CH<sub>2</sub>CH<sub>3</sub>   →   CH<sub>3</sub>C(O)CH<sub>2</sub>CH<sub>3</sub>  +  H<sub>2</sub>

This is used to produce approximately 700 million kilograms yearly. Other syntheses that have been examined but not implemented include [[Wacker oxidation]] of [[2-butene]] and oxidation of [[isobutylbenzene]], which is analogous to the industrial production of [[acetone]].<ref name=Ullmann/> The [[cumene process]] can be modified to produce phenol and a mixture of acetone and butanone instead of only phenol and acetone in the original.<ref name=cumeneprocess>{{Cite web |url=http://www.chemistry.org/portal/a/c/s/1/feature_pro.html?id=c373e908e6e847ac8f6a17245d830100 |title=Direct Routes to Phenol |access-date=2017-12-13 |archive-url=https://web.archive.org/web/20070409042033/http://www.chemistry.org/portal/a/c/s/1/feature_pro.html?id=c373e908e6e847ac8f6a17245d830100 |archive-date=2007-04-09 |url-status=dead }}</ref>

Both liquid-phase oxidation of heavy [[naphtha]] and the [[Fischer–Tropsch]] reaction produce mixed oxygenate streams, from which 2-butanone is extracted by fractionation.<ref>Ashford's Dictionary of Industrial Chemicals, Third edition, 2011, {{ISBN|978-0-9522674-3-0}}, pages 6013-4</ref>

== Applications ==
===Solvent===
Butanone is an effective and common solvent<ref name="TurnerMcCreery">{{Cite book| last = Turner| first = Charles F.|author2=McCreery, Joseph W.| title = The Chemistry of Fire and Hazardous Materials| publisher = Allyn and Bacon, Inc.| year = 1981| location = Boston, Massachusetts| pages = 118| isbn = 0-205-06912-6}}</ref> and is used in processes involving [[natural gum|gum]]s, [[resin]]s, [[cellulose acetate]] and [[nitrocellulose]] coatings and in vinyl films.<ref name="Apps p101">{{Cite book| last = Apps| first = E. A.| title = Printing Ink Technology| publisher = Leonard Hill <nowiki>[Books]</nowiki> Limited| year = 1958|location = London| pages = [https://archive.org/details/printinginktechn00apps/page/101 101]| url =https://archive.org/details/printinginktechn00apps| url-access = registration}}</ref> For this reason it finds use in the manufacture of plastics, textiles, in the production of [[paraffin wax]], and in household products such as [[lacquer]], [[varnish]]es, paint remover, a denaturing agent for [[denatured alcohol]], [[adhesive|glues]], and as a cleaning agent. It is a prime component of plumbers' priming fluid, used to clean PVC materials. It has similar solvent properties to [[acetone]] but boils at a higher temperature and has a significantly slower evaporation rate.<ref name="Fairhall">{{Cite book| last = Fairhall| first = Lawrence T.| title = Industrial Toxicology| publisher = The Williams and Wilkins Company| year = 1957| location = Baltimore| pages = 172–173}}</ref> Unlike acetone, it forms an [[azeotrope]] with water,<ref name="Langes">''Lange's Handbook of Chemistry'', 10th ed. pp1496-1505</ref><ref name="crc">''CRC Handbook of Chemistry and Physics'', 44th ed. pp 2143-2184</ref> making it useful for azeotropic distillation of moisture in certain applications. Butanone is also used in [[dry erase marker]]s as the solvent of the erasable dye.

The hydroxylamine derivative of butanone is [[methylethyl ketone oxime]] (MEKO), which also find use in paints and varnishes as an anti-skinning agent.

===Plastic welding=== <!-- courtesy note per WP:RSECT: [[Polystyrene cement]] links here -->
As butanone dissolves [[polystyrene]] and many other plastics, it is sold as "model cement" for use in connecting parts of [[scale model]] kits.  Though often considered an [[adhesive]], it is functioning as a [[plastic welding|welding]] agent in this context.

===Other uses===
Butanone is the [[Precursor (chemistry)|precursor]] to [[methyl ethyl ketone peroxide]], which is a catalyst for some [[polymerization]] reactions such as crosslinking of unsaturated polyester resins. [[Dimethylglyoxime]] can be prepared from butanone first by reaction with [[alkyl nitrites|ethyl nitrite]] to give [[diacetyl monoxime]] followed by conversion to the dioxime:<ref>{{OrgSynth | author = Semon, W. L. | author2 = Damerell, V. R. | title = Dimethylglyoxime | collvol = 2 | collvolpages = 204 | year = 1943 | prep = cv2p0204}}</ref>
:[[File:Preparation_of_dimethylglyoxime.png|class=skin-invert-image|400px]]

In the [[peroxide process]] on producing [[hydrazine]], the starting chemical ammonia is bonded to butanone, oxidized by hydrogen peroxide, bonded to another ammonia molecule.
:[[File:Pechiney-Ugine-Kuhlmann process.png|class=skin-invert-image|506px]]
In the final step of the process, hydrolysis produces the desired product, hydrazine, and regenerates the butanone.
:Me(Et)C=NN=C(Et)Me + 2 H<sub>2</sub>O → 2 Me(Et)C=O + N<sub>2</sub>H<sub>4</sub>

==Safety==
===Flammability===
Butanone can react with most oxidizing materials and can produce fires.<ref name="TurnerMcCreery"/> It is moderately explosive, requiring only a small flame or spark to cause a vigorous reaction.<ref name="TurnerMcCreery"/> The vapor is heavier than air, so it can accumulate at low points. It is explosive at concentrations between 1.4 and 11.4%.<ref name=medrev/> Concentrations in the air high enough to be flammable are intolerable to humans due to the irritating nature of the vapor.<ref name="Fairhall"/> Butanone fires should be extinguished with [[carbon dioxide]], dry agents, or [[Firefighting foam|alcohol-resistant foam]].<ref name="TurnerMcCreery"/>

The ignition of butanone vapor was the [[proximate cause]] of the 2007 [[Xcel Energy Cabin Creek fire]], resulting in the deaths of five workers in a hydroelectric [[penstock]]. After the incident, the [[U.S. Chemical Safety and Hazard Investigation Board]] specifically noted the danger posed by butanone in confined spaces, and suggested [[1,1,1-trichloroethane]] or [[limonene]] as safer alternatives.<ref>{{cite web |url=https://www.csb.gov/file.aspx?DocumentId=5703 |title=Investigation Report: Xcel Energy Hydroelectric Plant Penstock Fire |author=U.S. Chemical Safety and Hazard Investigation Board |author-link=U.S. Chemical Safety and Hazard Investigation Board |date=August 2010 |publisher=U.S. Chemical Safety and Hazard Investigation Board}}</ref>

===Health effects===
Butanone is a constituent of [[tobacco smoke]].<ref name="TalhoutSchulz2011">{{cite journal|last1=Talhout|first1=Reinskje|last2=Schulz|first2=Thomas|last3=Florek|first3=Ewa|last4=Van Benthem|first4=Jan|last5=Wester|first5=Piet|last6=Opperhuizen|first6=Antoon|title=Hazardous Compounds in Tobacco Smoke|journal=International Journal of Environmental Research and Public Health|volume=8|issue=12|year=2011|pages=613–628|issn=1660-4601|doi=10.3390/ijerph8020613|pmid=21556207|pmc=3084482|doi-access=free}}</ref> It is an [[irritation|irritant]], causing irritation to the eyes and nose of humans.<ref name="Fairhall"/>  Serious animal health effects have been seen only at very high levels. There are no long-term studies with animals breathing or drinking it,<ref name=iris>{{cite web|title=Methyl ethyl ketone (MEK) (CASRN 78-93-3)|url=http://www.epa.gov/iris/subst/0071.htm|archive-url=https://web.archive.org/web/20000823044616/http://www.epa.gov/iris/subst/0071.htm|url-status=dead|archive-date=August 23, 2000|website=Integrated Risk Information System (IRIS)|publisher=EPA|access-date=16 March 2015|date=26 September 2003}}</ref> and no studies for carcinogenicity in animals breathing or drinking it.<ref name=tox>{{cite web|title=US Toxicological review of Methyl ethyl ketone In Support of Summary Information on the Integrated Risk Information System (IRIS)|date= September 2003|url=http://www.epa.gov/iris/toxreviews/0071tr.pdf|archive-url=https://web.archive.org/web/20100403164814/http://www.epa.gov/iris/toxreviews/0071tr.pdf|url-status=dead|archive-date=April 3, 2010|publisher=US Environmental Protection Agency|access-date=16 March 2015|pages=152}}</ref>{{rp|96}}
There is some evidence that butanone can [[potentiator|potentiate]] the toxicity of other solvents, in contrast to the calculation of mixed solvent exposures by simply adding exposures.<ref>{{cite journal | doi = 10.1136/oem.2005.022400| title = Solvent neurotoxicity| date = 2006| last1 = Dick| first1 = F. D.| journal = Occupational and Environmental Medicine| volume = 63| issue = 3| pages = 221–226| pmid = 16497867| pmc = 2078137}}</ref>

{{As of|2010}}, the United States Environmental Protection Agency (EPA) listed butanone as a toxic chemical. There are reports of neuropsychological effects. It is rapidly absorbed through undamaged skin and lungs. It contributes to the formation of [[ground-level ozone]], which is [[ground-level ozone#Health effects|toxic in low concentrations]].<ref name=medrev>{{cite journal |archive-url=https://web.archive.org/web/20220121103345/http://www.jofcr.com/jcrarchives/vol28/v28i4thompson.pdf|archive-date=2022-01-21|url=http://www.jofcr.com/jcrarchives/vol28/v28i4thompson.pdf|title=Implications for cognitive rehabilitation and brain injury from exposure to Methyl Ethyl Ketone (MEK): a review|author=Simon B.N. Thompson|journal=Journal of Cognitive Rehabilitation|date=Winter 2010|volume=28(Winter)|pages=4–14}}</ref>

===Regulation===

Butanone is listed as a Table II precursor under the [[United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances]].<ref>[http://www.incb.org/pdf/e/list/red.pdf List of Precursors and Chemicals Frequently Used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances Under International Control] {{webarchive |url=https://web.archive.org/web/20080227224025/http://www.incb.org/pdf/e/list/red.pdf |date=February 27, 2008 }}, International Narcotics Control Board</ref>

Emission of butanone was regulated in the US as a [[hazardous air pollutant]], because it is a [[volatile organic compound]] contributing to the formation of [[tropospheric]] (ground-level) [[ozone]]. In 2005, the [[US Environmental Protection Agency]] removed butanone from the list of [[hazardous air pollutant]]s (HAPs).<ref>Federal Register Volume 70, Issue 242 (December 19, 2005)</ref><ref>{{cite web|author1=Barbara Kanegsberg |title=MEK No Longer a HAP |url=http://www.bfksolutions.com/index.php/newsletter/archived-newsletters/133-mek-no-longer-a-hap |publisher=Bfksolutions newsletter |access-date=2 April 2015 |date=n.d. |url-status=dead |archive-url=https://web.archive.org/web/20150402144959/http://www.bfksolutions.com/index.php/newsletter/archived-newsletters/133-mek-no-longer-a-hap |archive-date=2 April 2015 }} After technical review and consideration of public comments, EPA concluded that potential exposures to butanone emitted from industrial processes may not reasonably be anticipated to cause human health or environmental problems.{{citation needed|date=March 2015}}</ref><ref>{{Cite web|url=http://www.pcimag.com/articles/85504-epa-de-lists-mek-from-caa-hap-list|title=EPA De-Lists MEK from CAA HAP List|website=www.pcimag.com|access-date=2016-07-30}}</ref>

== See also ==
* [[Butyraldehyde]] 
* [[Butane]]
* [[n-Butanol|''n''-Butanol]]
* [[2-Butanol]]

==Notes==
{{Notelist}}

==References==
{{Reflist|30em}}

==External links==
*[http://www.inchem.org/documents/icsc/icsc/eics0179.htm International Chemical Safety Card 0179]
*[https://web.archive.org/web/20060302121404/http://www.npi.gov.au/database/substance-info/profiles/57.html National Pollutant Inventory: Methyl Ethyl Ketone Fact Sheet]
*[https://www.cdc.gov/niosh/npg/npgd0069.html NIOSH Pocket Guide to Chemical Hazards]
*[https://archive.today/20121213073826/http://www.epa.gov/ttn/atw/hlthef/methylet.html US EPA Datasheet]
*{{CPID|id=215|name=Methyl ethyl ketone}}

{{Authority control}}

[[Category:Alkanones]]
[[Category:Ketone solvents]]
[[Category:Pollutants]]
[[Category:Commodity chemicals]]
[[Category:Sweet-smelling chemicals]]