Isobutane: Difference between revisions

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| ImageFileL1 = Isobutane4.png

| verifiedrevid = 443882541

| ImageSizeL1 = 100px

| ImageFileR1 = Isobutane simple.svg

| ImageNameL1 = Skeletal formula

| ImageNameR1 = Skeletal formula of isobutane

| ImageFileR1 = Isobutane.png

| ~~ImageSizeR1~~ = ~~100px~~

| Name =

| ImageFile =

| ImageNameR1 = Structural formula

| ImageFileL1 = Isobutane 1.svg

| ImageNameL1 = Chemical structure of isobutane with all atoms explicitly shown

| ImageFileL2 = Isobutane-3D-balls.png

| ImageFileL2_Ref = {{chemboximage|correct|??}}

| ImageSizeL2 = 100px

| ImageNameL2 = Ball-and-stick model

| ImageNameL2 = Ball and stick model of isobutane

| ImageFileR2 = isobutane3.png

| ImageFileR2_Ref = {{chemboximage|correct|??}}

| ImageSizeR2 = 110px

| ImageNameR2 = ~~Space-filling~~ model

| ImageNameR2 = Spacefill model of isobutane

| PIN = 2-Methylpropane<ref name=iupac2013_652>{{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= 652 |doi= 10.1039/9781849733069-FP001 |isbn= 978-0-85404-182-4 |quote= The names 'isobutane', 'isopentane', and 'neopentane' are no longer recommended.}}</ref>

| PIN = 2-methylpropane

| SystematicName =

| IUPACName = isobutane

| OtherNames = ~~methylpropane~~

| OtherNames = {{Unbulleted list|Isobutane|R600a}}

| IUPACName =

| Section1 = {{Chembox Identifiers

| CASNo = 75-28-5

| Abbreviations =

| CASNo_Ref = {{cascite|correct|CAS}}

| PubChem = 6360

| ChemSpiderID = 6120

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 6120

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = BXR49TP611

| UNII_Ref = {{fdacite|correct|FDA}}

| InChI = 1/C4H10/c1-4(2)3/h4H,1-3H3

| EINECS = 200-857-2

| InChIKey = NNPPMTNAJDCUHE-UHFFFAOYAY

| UNNumber = 1969

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| KEGG = D04623

| KEGG_Ref = {{keggcite|changed|kegg}}

| ChEBI = 30363

| ChEBI_Ref = {{ebicite|correct|EBI}}

| RTECS = TZ4300000

| Beilstein = 1730720

| Gmelin = 1301

| SMILES = CC(C)C

| StdInChI = 1S/C4H10/c1-4(2)3/h4H,1-3H3

| ~~StdInChIKey_Ref~~ = {{stdinchicite|correct|chemspider}}

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = NNPPMTNAJDCUHE-UHFFFAOYSA-N

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| CASNo = 75-28-5

}}

| CASNo_Ref = {{cascite|correct|CAS}}

| EINECS =

| SMILES = CC(C)C

| InChI =

| RTECS =

| MeSHName =

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 30363

| KEGG_Ref = {{keggcite|correct|kegg}}

| KEGG =

| ATCCode = }}

| Section2 = {{Chembox Properties

| C = 4 | H = 10

| C=4 | H=10

| Appearance = ~~colorless~~ gas

| Appearance = Colorless gas

| Odor = Odorless

| Density = 2.51 kg/m3, gas (15 °C, 1 [[Atmosphere (unit)|atm]]) 593.4 kg/m3, liquid

| ~~MeltingPtC~~ = ~~-159.6~~

| Density = {{ubl

| 2.51{{nbsp}}kg/m3 (at 15 °C, 100{{nbsp}}kPa)

| Melting_notes =

| 563 kg/m3 (at 15 °C, boiling liquid)

| BoilingPtC = -11.7

}}

| Boiling_notes =

| ~~Solubility~~ = ~~Insoluble~~

| MeltingPtC = −159.42

| MeltingPt_ref = <ref name=GESTIS>{{GESTIS|ZVG=25040}}</ref>

| SolubleOther =

| BoilingPtC = −11.7

| Solvent =

| MagSus = −51.7·10−6 cm3/mol

| pKa =

| BoilingPt_ref = <ref name=GESTIS/>

| pKb =

| Solubility = 48.9{{nbsp}}mg⋅L−1 (at {{convert|25|C}})<ref>{{cite web|title=Solubility in Water|url=https://pubchem.ncbi.nlm.nih.gov/compound/isobutane#section=Solubility|website=PubChem|publisher=National Center for Biotechnology Information|access-date=6 April 2017}}</ref>

| IsoelectricPt =

| VaporPressure = {{convert|3.1|atm|abbr=on}} (at {{convert|21|C|K F}})<ref>{{cite web |title=CDC - NIOSH Pocket Guide to Chemical Hazards - Isobutane |url=https://www.cdc.gov/niosh/npg/npgd0350.html |website=CDC - NIOSH Pocket Guide to Chemical Hazards |publisher=CDC |access-date=28 December 2018}}</ref>

| LambdaMax =

| HenryConstant = 8.6{{nbsp}}nmol⋅Pa−1⋅kg−1

| Absorbance =

| ConjugateAcid = [[Isobutanium]]

| SpecRotation =

}}

| RefractIndex =

| Section3 = {{Chembox Thermochemistry

| Viscosity =

| DeltaHf = −134.8{{nbsp}}–{{nbsp}}−133.6{{nbsp}}kJ⋅mol−1

| Dipole = }}

| DeltaHc = −2.86959{{nbsp}}–{{nbsp}}−2.86841{{nbsp}}MJ⋅mol−1

| Section7 = {{Chembox Hazards

| HeatCapacity = 96.65{{nbsp}}J⋅K−1⋅mol−1

| ExternalMSDS = [http://www.praxair.com/praxair.nsf/d63afe71c771b0d785256519006c5ea1/f5322947a3ab1c8285256e5b0068ef96/$FILE/Isobutane-Canada.pdf External MSDS]

}}

| EUClass = Highly flammable ('''F+''')

| Section4 = {{Chembox Hazards

| EUIndex =

| ExternalSDS = [https://www.lindeus.com/-/media/corporate/praxairus/documents/sds/isobutane-c4h10-safety-data-sheet-sds-p4613.pdf?la=en lindeus.com]

| MainHazards =

| GHSPictograms = {{GHS flame}}

| GHSSignalWord = '''DANGER'''

| HPhrases = {{H-phrases|220}}

| PPhrases = {{P-phrases|210}}

| NFPA-H = 1

| NFPA-F = 4

| NFPA-R =

| NFPA-R = 0

| ~~NFPA-O~~ =

| FlashPtC = −83

| AutoignitionPtC = 460

| RPhrases = {{R12}}

| ExploLimits = 1.4–8.3%

| SPhrases = {{S2}}, {{S9}}, {{S16}}

| IDLH = N.D.<ref name=PGCH>{{PGCH|0350}}</ref>

| RSPhrases =

| PEL = None<ref name=PGCH/>

| FlashPt = flammable gas

| REL = TWA 800{{nbsp}}ppm (1900 mg/m3)<ref name=PGCH/>

| Autoignition = 460 °C

| ExploLimits = 1.8–8.4%

| PEL = }}

| Section8 = {{Chembox Related

| OtherAnions =

| OtherCations =

| OtherFunctn = [[Butane]]

| Function = [[alkane]]

| OtherCpds = [[Isopentane]] [[Neopentane]] }}

}}

| Section5 = {{Chembox Related

| OtherFunction_label = alkane

| OtherFunction = [[Isopentane]]

}}

| Section6 =

}}

'''Isobutane''', also known as '''''i''-butane''', '''2-methylpropane''' or '''methylpropane''', is a [[chemical compound]] with [[molecular formula]] HC(CH3)3. It is an [[isomer]] of [[butane]]. Isobutane is a colorless, odorless gas.

It is the simplest [[alkane]] with a [[tertiary carbon]] atom. Isobutane is used as a precursor molecule in the [[petrochemical industry]], for example in the synthesis of [[isooctane]].<ref>{{cite web |url=http://www.chemistry.org/portal/a/c/s/1/acsdisplay.html?DOC=patentwatch%5Carchive%5C073106_patentwatch.html |title=Patent Watch, July 31, 2006. |access-date=August 8, 2006 |url-status=dead |archive-url=https://web.archive.org/web/20070311154937/http://www.chemistry.org/portal/a/c/s/1/acsdisplay.html?DOC=patentwatch%5Carchive%5C073106_patentwatch.html |archive-date=March 11, 2007}}</ref>

==Production==

'''Isobutane''', also known as '''methylpropane''', is an [[isomer]] of [[butane]]. It is the simplest [[alkane]] with a [[carbon-carbon bond|tertiary carbon]]. Concerns with depletion of the [[ozone layer]] by [[freon]] gases have led to increased use of isobutane as a gas for [[refrigeration]] systems, especially in domestic [[refrigerator]]s and [[freezer]]s, and as a [[propellant]] in [[aerosol spray]]s. When used as a [[refrigerant]] or a propellant, isobutane is also known as '''R-600a'''. Some portable camp stoves use a mixture of isobutane with [[propane]], usually 80:20. Isobutane is used as a feedstock in the [[petrochemical]] industry, for example in the synthesis of [[isooctane]].<ref>[http://www.chemistry.org/portal/a/c/s/1/acsdisplay.html?DOC=patentwatch%5Carchive%5C073106_patentwatch.html Patent Watch, July 31, 2006.]</ref>

Isobutane is obtained by [[isomerization]] of [[butane]].

Its UN number (for hazardous substances see shipping) is UN 1969.

[[File:ButaneIsomerization.svg|center|thumb|240px|Isomerization of butane]]

Isobutane is the R group for the [[amino acid]] [[leucine]].

== ~~Nomenclature~~ ==

==Uses==

Isobutane is the principal feedstock in [[alkylation unit]]s of refineries. Using isobutane, gasoline-grade "blendstocks" are generated with high branching for good combustion characteristics. Typical products created with isobutane are [[2,4-Dimethylpentane|2,4-dimethylpentane]] and especially [[2,2,4-Trimethylpentane|2,2,4-trimethylpentane]].<ref>{{cite encyclopedia |title=Alkylation |author=Bipin V. Vora |author2=Joseph A. Kocal |author3=Paul T. Barger |author4=Robert J. Schmidt |author5=James A. Johnson |year=2003 |encyclopedia=Kirk-Othmer Encyclopedia of Chemical Technology |doi=10.1002/0471238961.0112112508011313.a01.pub2 |isbn=0471238961}}</ref>

===Solvent===

[[Image:N&i-butane.png|thumb|left|Structures of the two isomers of butane]]

In the Chevron Phillips slurry process for making [[high-density polyethylene]], isobutane is used as a diluent. As the slurried polyethylene is removed, isobutane is "flashed" off, and condensed, and recycled back into the loop reactor for this purpose.<ref>{{Ullmann |title= Polyethylene |author= Kenneth S. Whiteley |doi= 10.1002/14356007.a21_487.pub2}}</ref>

Isobutane is the [[trivial name]] retained by the [[International Union of Pure and Applied Chemistry]] (IUPAC) in its ''1993 Recommendations for the Nomenclature of Organic Chemistry''.<ref>{{cite book | author=Panico, R.; & Powell, W. H. (Eds.) | title=A Guide to IUPAC Nomenclature of Organic Compounds 1993 | location=Oxford | publisher=Blackwell Science | year=1994 | isbn=0-632-03488-2}} http://www.acdlabs.com/iupac/nomenclature/93/r93_679.htm</ref>

Since the longest continuous chain in isobutane is only three carbon atoms, the systematic name is methylpropane. The position number (2-) is unnecessary because it is the only possibility in methylpropane.

===Precursor to ''tert''-butyl hydroperoxide===

== Uses ==

Isobutane is oxidized to [[tert-Butyl hydroperoxide|''tert''-butyl hydroperoxide]], which is subsequently reacted with [[propylene]] to yield [[propylene oxide]]. The [[tert-butanol]] that results as a by-product is typically used to make gasoline additives such as [[methyl tert-butyl ether]] (MTBE).

* As a [[refrigerant]].<ref>{{cite web|url=http://ec.europa.eu/environment/ozone/pdf/hcfc_technical_meeting_summary.pdf |title=European Commission on retrofit refrigerants for stationary applications |format=PDF |date= |accessdate=2010-10-29}}</ref>

The use in refrigerators started in 1993 when Greenpeace presented the Greenfreeze project with the German company Foron.<ref>http://www.greenpeace.org/usa/en/campaigns/global-warming-and-energy/green-solutions/greenfreeze/</ref>

===Miscellaneous uses===

Blends of pure, dry "isobutane" (R-600a) (commercial term used to describe isobutane mixtures) have negligible [[ozone depletion potential]] and very low [[Global Warming Potential]] (having a value of 3.3 times the GWP of carbon dioxide) and can serve as a functional replacement for [[Dichlorodifluoromethane|R-12]], [[Chlorodifluoromethane|R-22]], [[1,1,1,2-Tetrafluoroethane|R-134a]], and other [[chlorofluorocarbon]] or [[hydrofluorocarbon]] [[refrigerant]]s in conventional stationary refrigeration and air conditioning systems.

Isobutane is also used as a propellant for [[aerosol spray#Aerosol propellants|aerosol spray cans]].

Isobutane is used as part of blended fuels, especially common in fuel canisters used for [[camping]].<ref name="camp fuel">{{cite web |url=https://backpackinglight.com/canister_stove_faq/ |title=Frequently Asked Questions About Lightweight Canister Stoves and Fuels |first=Will |last=Rietveld |publisher=Backpacking Light (subscription required)|date=2005-02-08 |access-date=2022-06-03 |url-access=subscription}}</ref>

* As a propellant for aerosol cans and [[foam]] products.

==~~Safety Concerns~~==

==Refrigerant==

Isobutane is used as a [[refrigerant]].<ref>{{cite web |url=https://ec.europa.eu/clima/sites/default/files/docs/0007/hcfc_technical_meeting_summary_en.pdf |title=Technical Meeting on HCFC Phase-Out: Overview of Advantages and Disadvantages of Alternatives (Montreal, Canada; European Commission on retrofit refrigerants for stationary applications) |date=April 2008 |access-date=2021-05-21 |url-status=live |archive-url=https://web.archive.org/web/20090805150605/http://ec.europa.eu/environment/ozone/pdf/hcfc_technical_meeting_summary.pdf |archive-date=2009-08-05}}</ref> Use in refrigerators started in 1993 when [[Greenpeace]] presented the Greenfreeze project with the former East German company {{Interlanguage link|Foron (company)|lt=Foron|de|Foron}}.<ref>{{cite web |url=http://www.greenpeace.org/usa/en/campaigns/global-warming-and-energy/green-solutions/greenfreeze/ |title=GreenFreeze |publisher=Greenpeace |date=2010-03-15 |access-date=2013-01-02 |url-status=dead |archive-url=https://web.archive.org/web/20101005093019/http://www.greenpeace.org/usa/en/campaigns/global-warming-and-energy/green-solutions/greenfreeze/ |archive-date=2010-10-05}}</ref><ref>{{cite web |title=Greenfreeze: from a snowball to an industrial avalanche |author=Wolfgang Lohbeck |date=June 2004 |url=https://www.greenpeace.org/usa/wp-content/uploads/legacy/Global/usa/report/2007/7/greenfreeze-from-snowball-to.pdf |access-date=2021-05-21}}</ref> In this regard, blends of pure, dry "isobutane" (R-600a) (that is, isobutane mixtures) have negligible [[ozone depletion potential]] and very low [[global warming potential]] (having a value of 3.3 times the GWP of carbon dioxide) and can serve as a functional replacement for [[dichlorodifluoromethane|R-12]], [[chlorodifluoromethane|R-22]] (both of these being commonly known by the trademark [[Freon]]), [[1,1,1,2-Tetrafluoroethane|R-134a]], and other [[chlorofluorocarbon]] or [[hydrofluorocarbon]] [[refrigerant]]s in conventional stationary refrigeration and air conditioning systems.

Reports surfaced in late 2009 suggesting the use of isobutane as a refrigerant in domestic refrigerators was potentially dangerous. Several explosions resulting from the isobutane leaking into the refrigerator cabinet and a spark from the electrical system have been reported in the [[United Kingdom]].<ref>{{cite news| url=http://www.telegraph.co.uk/news/picturegalleries/howaboutthat/6120297/Exploding-fridges-ozone-friendly-gas-theory-for-mystery-blasts.html | work=The Daily Telegraph | location=London | title=Exploding fridges: ozone friendly gas theory for mystery blasts | first=John | last=Bingham | date=September 1, 2009 | accessdate=May 5, 2010}}</ref> Although unclear how serious this could be, at the time this report came out it was estimated 300 million refrigerators worldwide use isobutane as a refrigerant.

As a refrigerant, isobutane poses a fire and explosion risk in addition to the hazards associated with non-flammable CFC refrigerants. Substitution of this refrigerant for motor vehicle air conditioning systems not originally designed for isobutane is widely prohibited or discouraged.<ref>{{cite web |url=http://www.epa.gov/ozone/snap/refrigerants/hc12alng.html |title=U.S. EPA hydrocarbon-refrigerants FAQ |publisher=Epa.gov |access-date=2010-10-29}}</ref><ref>{{cite web |url=http://www.astreappliancerepair.com/wp-content/uploads/2014/07/hc_white_paper.pdf |title=Compendium of hydrocarbon-refrigerant policy statements, October 2006 |access-date=2014-08-01 |url-status=dead |archive-url=https://web.archive.org/web/20140808045013/http://www.astreappliancerepair.com/wp-content/uploads/2014/07/hc_white_paper.pdf |archive-date=2014-08-08}}</ref><ref>{{cite web |url=http://www.autoacforum.com/MACS/HCwarning.pdf |title=MACS bulletin: hydrocarbon refrigerant usage in vehicles |access-date=2010-10-29 |url-status=dead |archive-url=https://web.archive.org/web/20110105174944/http://www.autoacforum.com/MACS/HCwarning.pdf |archive-date=2011-01-05}}</ref><ref>{{cite web |url=http://www.sae.org/news/releases/05hydrocarbon_warning.htm |title=Society of Automotive Engineers hydrocarbon refrigerant bulletin |publisher=Sae.org |date=2005-04-27 |access-date=2010-10-29 |url-status=dead |archive-url=https://web.archive.org/web/20050505030057/http://www.sae.org/news/releases/05hydrocarbon_warning.htm |archive-date=2005-05-05}}</ref><ref>{{cite web |url=http://www.labour.gov.sk.ca/Default.aspx?DN=2fb5ac24-d90e-4408-bf40-559793bd8e96 |title=Saskatchewan Labour bulletin on hydrocarbon refrigerants in vehicles |publisher=Labour.gov.sk.ca |date=2010-06-29 |access-date=2010-10-29 |url-status=dead |archive-url=https://web.archive.org/web/20090701025850/http://www.labour.gov.sk.ca/Default.aspx?DN=2fb5ac24-d90e-4408-bf40-559793bd8e96 |archive-date=2009-07-01}}</ref><ref>[http://www.vasa.org.au/content/refriggas/index.php#Bookmark%202 VASA on refrigerant legality & advisability] {{webarchive |url=https://web.archive.org/web/20090113163519/http://www.vasa.org.au/content/refriggas/index.php#Bookmark |date=January 13, 2009}}</ref><ref>{{cite web |url=http://www.energy.qld.gov.au/zone_files/petroleum_pdf/safety_alert025.pdf |title=Queensland (Australia) government warning on hydrocarbon refrigerants |publisher=Energy.qld.gov.au |access-date=2010-10-29 |url-status=dead |archive-url=https://web.archive.org/web/20081217150006/http://www.energy.qld.gov.au/zone_files/petroleum_pdf/safety_alert025.pdf |archive-date=2008-12-17}}</ref>

Although these stories are only speculation, the use of a flammable gas as a refrigerant is quite dangerous and encompasses a great deal of risk. The normal risks a CFC or other toxic refrigerant would have when it escapes, are mainly related to depletion of breathable air and frosting at the point of escape. Isobutane has an explosion risk associated also (in addition to depletion of breathable air and frosting). This explosion risk is more dangerous directly to anyone in the vicinity should it accumulate and come into contact with any ignition source. To reduce the risk, the charge of refrigerators was reduced by more than 50% against R134a. The typical charge of a R600a freezer is 45g and of a refrigerator 20g. If 45g are lost at once, 1m³ of explosive gas can be created. The risk that all gas is lost outside in a short time is very low. For interior refrigeration applications, the R600a appliances should have a hidden condenser, so that the gas can not be lost. 20g is for example approximately 3-4 times the charge of a cigarette lighter. In Europe the limit is 150g for R600a applinces due to safety.

Vendors and advocates of hydrocarbon refrigerants argue against such bans on the grounds that there have been very few such incidents relative to the number of vehicle air conditioning systems filled with hydrocarbons.<ref>{{cite web |url=http://www.parliament.nsw.gov.au/prod/parlment/HansArt.nsf/V3Key/LA19971016015 |title=New South Wales (Australia) Parliamentary record, 16 October 1997 |publisher=Parliament.nsw.gov.au |date=1997-10-16 |access-date=2010-10-29 |url-status=dead |archive-url=https://web.archive.org/web/20090701025536/http://www.parliament.nsw.gov.au/prod/parlment/HansArt.nsf/V3Key/LA19971016015 |archive-date=1 July 2009}}</ref><ref>{{cite web |url=http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/V3Key/LC20000629051 |title=New South Wales (Australia) Parliamentary record, 29 June 2000 |publisher=Parliament.nsw.gov.au |access-date=2010-10-29 |url-status=dead |archive-url=https://web.archive.org/web/20050522080708/http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/V3Key/LC20000629051 |archive-date=22 May 2005}}</ref>

According to an MSDS (Material Safety Data Sheet) for isobutane, this gas should not be exposed to temperatures above 52 Celsius or 151 Fahrenheit while in a closed system such as a storage tank.<ref>http://www.praxair.com/praxair.nsf/24116e7e98e6297f8525705a006f3694/b7e46554268d4c55852575bc0067d5b6/$FILE/p4613d.pdf</ref> The range of flammability also factors into safety of this substance as a refrigerant. Flammable ranges for isobutane are between 1.8% - 8.4% and this creates a hazard when a leak forms in the refrigeration system. Many sources of ignition may be nearby so the unit could possibly explode due to the gas leak and cause major damage, not to mention injuries or death to persons nearby. This will create a problem for refrigeration technicians if a leak is reported. The leak must be checked in open air or well ventilated environments and the technician could risk injury to themselves or others. In essence, the refrigeration unit would need full replacement in most cases.

==Nomenclature==

Substitution of this refrigerant for motor vehicle air conditioning systems not originally designed for [[R600a]] is widely prohibited or discouraged, on the grounds that using [[Flammability|flammable]] hydrocarbons in systems originally designed to carry non-flammable refrigerant presents a significant risk of fire or explosion.<ref>{{cite web|url=http://www.epa.gov/ozone/snap/refrigerants/hc12alng.html |title=U.S. EPA hydrocarbon-refrigerants FAQ |publisher=Epa.gov |date= |accessdate=2010-10-29}}</ref><ref>[http://www.vasa.org.au/pdf/memberlibrary/hydrocarbons/hc_white_paper.pdf Compendium of hydrocarbon-refrigerant policy statements, October 2006]{{dead link|date=October 2010}}</ref><ref>{{cite web|url=http://www.autoacforum.com/MACS/HCwarning.pdf |title=MACS bulletin: hydrocarbon refrigerant usage in vehicles |format=PDF |date= |accessdate=2010-10-29}}</ref><ref>{{cite web|url=http://www.sae.org/news/releases/05hydrocarbon_warning.htm |title=Society of Automotive Engineers hydrocarbon refrigerant bulletin |publisher=Sae.org |date=2005-04-27 |accessdate=2010-10-29}}</ref><ref>{{cite web|url=http://www.shadetreemechanic.com/cc_hydrocarbon_refrigerants.htm |title=Shade Tree Mechanic on hydrocarbon refrigerants |publisher=Shadetreemechanic.com |date=2005-04-27 |accessdate=2010-10-29}}</ref><ref>{{cite web|url=http://www.labour.gov.sk.ca/Default.aspx?DN=2fb5ac24-d90e-4408-bf40-559793bd8e96 |title=Saskatchewan Labour bulletin on hydrocarbon refrigerants in vehicles |publisher=Labour.gov.sk.ca |date=2010-06-29 |accessdate=2010-10-29}}</ref><ref>[http://www.vasa.org.au/content/refriggas/index.php#Bookmark%202 VASA on refrigerant legality & advisability]{{dead link|date=October 2010}}</ref><ref>{{cite web|url=http://www.energy.qld.gov.au/zone_files/petroleum_pdf/safety_alert025.pdf |title=Queensland (Australia) government warning on hydrocarbon refrigerants |publisher=Energy.qld.gov.au |date= |accessdate=2010-10-29}}</ref>

The traditional name isobutane was still retained in the 1993 [[International Union of Pure and Applied Chemistry |IUPAC]] recommendations,<ref>{{cite book |editor=Panico, R. |editor2= Powell, W. H. |name-list-style= amp |title=A Guide to IUPAC Nomenclature of Organic Compounds 1993 |location=Oxford |publisher=Blackwell Science |year=1994 |isbn=0-632-03488-2}} https://www.acdlabs.com/iupac/nomenclature/93/r93_679.htm</ref> but is no longer recommended according to the 2013 recommendations.<ref name=iupac2013_652/> Since the longest continuous chain in isobutane contains only three carbon atoms, the [[preferred IUPAC name]] is 2-methylpropane but the [[locant]] (2-) is typically omitted in general nomenclature as redundant; C2 is the only position on a propane chain where a methyl substituent can be located without altering the main chain and forming the constitutional isomer ''n''-butane.

Vendors and advocates of hydrocarbon refrigerants argue against such bans on the grounds that there have been very few such incidents relative to the number of vehicle air conditioning systems filled with hydrocarbons.<ref>{{cite web|url=http://www.parliament.nsw.gov.au/prod/parlment/HansArt.nsf/V3Key/LA19971016015 |title=New South Wales (Australia) Parliamentary record, 16 October 1997 |publisher=Parliament.nsw.gov.au |date=1997-10-16 |accessdate=2010-10-29}}</ref><ref>{{cite web|url=http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/V3Key/LC20000629051 |title=New South Wales (Australia) Parliamentary record, 29 June 2000 |publisher=Parliament.nsw.gov.au |date= |accessdate=2010-10-29}}</ref> One particular test was conducted by a professor at the University of New South Wales that unintentionally tested the scenario of a sudden and complete refrigerant loss into the passenger compartment followed by subsequent ignition. He and several others in the car sustained burns to their face, ears, and hands, and several observers received lacerations from the burst glass of the front passenger window.<ref>[http://www.vasa.org.au/pdf/memberlibrary/hydrocarbons/maclaine-cross.pdf VASA news report on hydrocarbon refrigerant demonstrations]{{Dead link|date=August 2010}}</ref>

==References==

== External links ==

==External links==

*[http://www.inchem.org/documents/icsc/icsc/eics0901.htm International Chemical Safety Card 0901]

*[~~http~~://www.cdc.gov/niosh/npg/npgd0350.html NIOSH Pocket Guide to Chemical Hazards]

*[https://www.cdc.gov/niosh/npg/npgd0350.html NIOSH Pocket Guide to Chemical Hazards]

*[http://www.acdlabs.com/iupac/nomenclature/ IUPAC Nomenclature of Organic Chemistry] (online version of the "''Blue Book''")

*[http://www.airliquide.com/en/business/products/gases/gasdata/index.asp?Formula=&GasID=38&UNNumber=&EquivGasID=8&VolLiquideBox=&MasseLiquideBox=&VolGasBox=&MasseGasBox=&btnMSDS=0&MSDSLanguageBox=0&RD20=29&RD9=8&RD6=64&RD4=2&RD3=22&RD8=27&RD2=20&RD18=41&RD7=18&RD13=71&RD16=35&RD12=31&RD19=34&RD24=62&RD25=77&RD26=78&RD28=81&RD29=82 Data from Air Liquide]

[[Category:Alkanes]]

[[Category:Butane]]

[[Category:E-number additives]]

[[Category:Propellants]]

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