:1,1,1,2-Tetrafluoroethane

1,1,1,2-Tetrafluoroethane is a non-flammable gas used primarily as a "high-temperature" refrigerant for domestic refrigeration and automobile air conditioners. These devices began using 1,1,1,2-tetrafluoroethane in the early 1990s as a replacement for the more environmentally harmful R-12. Retrofit kits are available to convert units that were originally R-12-equipped.

File:Tetrafluoroethane liquid.jpg

Other common uses include plastic foam blowing, as a cleaning solvent, a propellant for the delivery of pharmaceuticals (e.g., inhaler canisters such as for bronchodilators), wine cork removers, gas dusters ("canned air"), and in air driers for removing the moisture from compressed air. 1,1,1,2-Tetrafluoroethane has also been used to cool computers in some overclocking attempts. It is the refrigerant used in plumbing pipe freeze kits. It is also commonly used as a propellant for airsoft airguns. The gas is often mixed with a silicone-based lubricant.

1,1,1,2-Tetrafluoroethane is also being considered as an organic solvent, both as a liquid and a supercritical fluid.{{cite book |doi=10.1021/bk-2005-0908.ch003 |chapter=1,1,1,2-Tetrafluoroethane (R-134a): A Selective Solvent for the Generation of Flavor and Fragrance Ingredients |title=Natural Flavors and Fragrances |series=ACS Symposium Series |year=2005 |last1=Corr |first1=Stuart |isbn=0-8412-3904-5 |volume=908 |page=41}}{{cite journal|doi=10.1039/B412697A|title=Solubility of unsaturated carboxylic acids in supercritical 1,1,1,2-tetrafluoroethane (HFC 134a) and a methodology for the separation of ternary mixtures|year=2005|last1=Abbott|first1=Andrew P.|last2=Eltringham|first2=Wayne|last3=Hope|first3=Eric G.|last4=Nicola|first4=Mazin|journal=Green Chemistry|volume=7|issue=4|pages=210 }}

{{cite journal|doi=10.1039/B507554H|title=Hydrogenation in supercritical 1,1,1,2 tetrafluoroethane (HFC 134a)|year=2005|last1=Abbott|first1=Andrew P.|last2=Eltringham|first2=Wayne|last3=Hope|first3=Eric G.|last4=Nicola|first4=Mazin|journal=Green Chemistry|volume=7|issue=10|pages=721|hdl=2381/604|url=https://lra.le.ac.uk/bitstream/2381/604/1/10.1039_b507554h.pdf|access-date=18 September 2019|archive-date=19 July 2018|archive-url=https://web.archive.org/web/20180719170805/https://lra.le.ac.uk/bitstream/2381/604/1/10.1039_b507554h.pdf|url-status=dead|hdl-access=free}}

It is used in the resistive plate chamber particle detectors in the Large Hadron Collider.Anushree Ghosh [http://www.hecr.tifr.res.in/~bsn/INO/rpc-anushree.pdf STUDY OF GLASS RESISTIVE PLATE CHAMBERS (RPC) AND CALCULATION OF EFFICIENCY] {{Webarchive|url=https://web.archive.org/web/20110807185247/http://www.hecr.tifr.res.in/~bsn/INO/rpc-anushree.pdf |date=7 August 2011 }}. INO Graduate Training Programme DHEP, TIFR, Mumbai.M. Capeans, I. Glushkov, R. Guida, F. Hahn, S. Haider (CERN, Switzerland) [https://web.archive.org/web/20101116193636/http://project-wp7.web.cern.ch/PROJECT%2DWP7/Documents/Roberto_IEEE2009%20v2.pdf RPC operation at the LHC experiments in an optimized closed loop gas system]. Medical Imaging Conference. 25–31 October 2009. It is also used for other types of particle detectors, e.g. some cryogenic particle detectors.{{cite journal |url=http://highenergy.physics.uiowa.edu/HEP/Files/Talks/RadHardPaper.pdf |journal=AIP Conference Proceedings |doi=10.1063/1.2396941 |bibcode=2006AIPC..867...84N |title=Rad Hard Active Media For Calorimeters |year=2006 |last1=Norbeck |first1=E. |last2=Olson |first2=J. E. |last3=Moeller |first3=A. |last4=Onel |first4=Y. |volume=867 |page=84 |url-status=dead |archive-url=https://web.archive.org/web/20120323165423/http://highenergy.physics.uiowa.edu/HEP/Files/Talks/RadHardPaper.pdf |archive-date=23 March 2012}} It can be used as an alternative to sulfur hexafluoride in magnesium smelting as a shielding gas.[http://pubs.usgs.gov/of/2001/of01-166/of01-166.pdf Magnesium recycling in the United States in 1998]. (PDF). USGS. Retrieved 21 August 2011.

1,1,1,2-Tetrafluoroethane was introduced in the early 1990s as a replacement for dichlorodifluoromethane (R-12), which has massive ozone depleting properties.{{cite journal| author= Franklin J |title=The Atmospheric Degradation and Impact of 1,1,1,2-Tetrafluorethane (Hydrofluorocarbon 134a)| url= https://archive.org/details/sim_chemosphere_1993-10_27_8/page/1565 |journal=Chemosphere |year=1993|pages=1565–1601|volume=27|doi=10.1016/0045-6535(93)90251-Y| issue= 8|bibcode=1993Chmsp..27.1565F}} Even though 1,1,1,2-Tetrafluoroethane has insignificant ozone depletion potential (ozone layer) and negligible acidification potential (acid rain), it has a 100-year global warming potential (GWP) of 1430 and an approximate atmospheric lifetime of 14 years. Its concentration in the atmosphere and contribution to radiative forcing have been growing since its introduction. Thus it was included in the IPCC list of greenhouse gases.{{cite book

| chapter =Changes in Atmospheric Constituents and in Radiative Forcing.

| title = Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change

| chapter-url =http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf | author =Forster, P.

| date =2007 |url-status=live| archive-url= https://web.archive.org/web/20100724041021/http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf| archive-date= 24 July 2010 |display-authors=etal

}}

File:HFC-134a mm.png) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion.]]

File:Mauna Loa HFC-134a (CH2FCF3) concentration.png

R-134a began being phased out from use in the European Union, starting in the mid 2010s, by a directive of 2006, recommending the replacement of gases in air conditioning systems with a GWP above 100.{{CELEX|id=32006L0040|text=Directive 2006/40/EC of the European Parliament and of the Council of 17 May 2006 relating to emissions from air-conditioning systems in motor vehicles and amending Council Directive 70/156/EEC}}

1,1,1,2-tetrafluoroethane is subject to use restrictions in the US and other countries as well. The Society of Automotive Engineers (SAE) has proposed that it be best replaced by a new fluorochemical refrigerant HFO-1234yf (CF{{sub|3}}CF=CH{{sub|2}}) in automobile air-conditioning systems.[http://refrigerants.dupont.com/Suva/en_US/pdf/DP_HW_2nd_European_Workshop_MAC.pdf HFO-1234yf A Low GWP Refrigerant For MAC] {{webarchive|url=https://web.archive.org/web/20090227134615/http://refrigerants.dupont.com/Suva/en_US/pdf/DP_HW_2nd_European_Workshop_MAC.pdf|date=27 February 2009}}. Refrigerants.dupont.com (17 August 2011). Retrieved 21 August 2011. As of model year 2021, newly manufactured light-duty vehicles in the United States no longer use R-134a.

California may also prohibit the sale of canned R-134a to individuals to avoid non-professional recharge of air conditioners.[http://www.r744.com/articles/494/california_restricts_use_of_hfc-134a_in_cars California restricts use of HFC-134a in cars]. 27 June 2007. R744.com. Retrieved 21 August 2011. A ban had been in place in Wisconsin since October 1994 under ATCP 136 prohibiting sales of container sizes holding less than {{convert|15|lbs|abbr=in}} of 1,1,1,2-tetrafluoroethane, but this restriction applied only when the chemical was intended to be a refrigerant. However, the ban was lifted in Wisconsin in 2012.[http://www.legis.state.wi.us/rsb/code/atcp/atcp136.pdf Chapter ATCP 136. MOBILE AIR CONDITIONERS; RECLAIMING OR RECYCLING REFRIGERANT]. State.wi.us. (PDF). Retrieved 21 August 2011. During the time that it was active, this Wisconsin-specific ban contained loopholes. For example, it was legal for a person to purchase gas duster containers with any amount of the chemical because in that instance the chemical is neither intended to be a refrigerant{{hsp}} nor is HFC-134a included in the § 7671a listing of class I and class II substances.[http://www.epa.gov/ozone/science/ods/classone.html Class I Ozone-depleting Substances]. EPA.gov. Retrieved 21 August 2011.

Tetrafluoroethane is typically made by reacting trichloroethylene with hydrogen fluoride:{{Cite web|url=http://www.solvay.us/en/binaries/PSS-Tetrafluoroethane-164368.pdf|title = Solvay in North America {{pipe}} Solvay}}

:CHCl=CCl{{sub|2}} + 4 HF → CF{{sub|3}}CH{{sub|2}}F + 3 HCl

It reacts with butyllithium to give trifluorovinyl lithium:{{cite journal|doi=10.1039/CC9960000049|title=The hydrofluorocarbon 1,1,1,2-tetrafluoroethane (HFC-134a) as a ready source of trifluorovinyllithium|year=1996|last1=Burdon|first1=James|last2=Coe|first2=Paul L.|last3=Haslock|first3=Iain B.|last4=Powell|first4=Richard L.|journal=Chemical Communications|pages=49}}

:CF{{sub|3}}CH{{sub|2}}F + 2 BuLi → CF{{sub|2}}=CFLi + LiF + 2 BuH

File:R134a container.png

Mixtures with air of the gas 1,1,1,2-tetrafluoroethane are not flammable at atmospheric pressure and temperatures up to 100 °C (212 °F). However, mixtures with high concentrations of air at elevated pressure and/or temperature can be ignited.{{cite report | author=DuPont | author-link=DuPont | title=DuPont HFC-134a— Properties, Uses, Storage, and Handling | url=https://www.chemours.com/Refrigerants/en_US/assets/downloads/h45945_hfc134a_push.pdf | year=2004 | access-date=5 August 2016 | archive-date=4 October 2016 | archive-url=https://web.archive.org/web/20161004165547/https://www.chemours.com/Refrigerants/en_US/assets/downloads/h45945_hfc134a_push.pdf | url-status=dead }} Contact of 1,1,1,2-tetrafluoroethane with flames or hot surfaces in excess of 250 °C (482 °F) may cause vapor decomposition and the emission of toxic gases including hydrogen fluoride and carbonyl fluoride,{{cite news|author=Honeywell International |title=MSDS # GTRN-0047 For Genetron 134aUV|date= December 2005|author-link=Honeywell International}} however the decomposition temperature has been reported as above 370 °C.{{Cite web|title=SAFETY DATA SHEET according to Regulation (EU) 2015/8301/7 Harp 134a|url=http://www.harpintl.com/downloads/pdf/msds/HARP-R134a-CLP.pdf|accessdate=2024-11-17}} 1,1,1,2-Tetrafluoroethane itself has an {{LD50}} of 1,500 g/m{{sup|3}} in rats, making it relatively non-toxic, apart from the dangers inherent to inhalant abuse. Its gaseous form will displace air in the lungs. This can result in asphyxiation if excessively inhaled.{{cite journal |author1=Alexander D. J. |author2=Libretto S. E. |s2cid=19669317 | title=An overview of the toxicology of HFA-134a (1,1,1,2-tetrafluoroethane)| journal=Hum. Exp. Toxicol.| year=1995 | volume=14| pages=715–20 | doi=10.1177/096032719501400903 | pmid=8579881 | issue=9 }}{{cite journal |author1=G. E. Millward |author2=E. Tschuikow-Roux | title= Kinetic analysis of the shock wave decomposition of 1,1,1,2-tetrafluoroethane| year =1972| volume = 76| issue= 3| pages = 292–298| doi =10.1021/j100647a002| journal= The Journal of Physical Chemistry}} This contributes to most deaths by inhalant abuse.

Aerosol cans containing 1,1,1,2-tetrafluoroethane, when inverted, become effective freeze sprays. Under pressure, 1,1,1,2-tetrafluoroethane is compressed into a liquid, which upon vaporization absorbs a significant amount of thermal energy. As a result, it will greatly lower the temperature of any object it contacts as it evaporates.

File:Freon 134a refrigerant for car AC 001 (cropped).jpg

For its medical uses, 1,1,1,2-tetrafluoroethane has the generic name norflurane. It is used as propellant for some metered dose inhalers.{{cite journal | doi = 10.1186/s13223-017-0202-0| pmid = 28670327| title = Asthma pressurised metered dose inhaler performance: Propellant effect studies in delivery systems| journal = Allergy, Asthma & Clinical Immunology| volume = 13| pages = 30| year = 2017| last1 = Sellers| first1 = William F. S.| pmc = 5492461| doi-access = free}} It is considered safe for this use.{{Cite journal | pmc = 4408662 | quote = This propellant has been shown to be safe and nonanaesthetic in standard inhaler doses | year = 2015 | last1 = Shah | first1 = S. B | title = Anaesthetic in the garb of a propellant | journal = Indian Journal of Anaesthesia | volume = 59 | issue = 4 | pages = 258–260 | last2 = Hariharan | first2 = U | last3 = Bhargava | first3 = A. K | doi = 10.4103/0019-5049.155011 | pmid=25937660 | doi-access = free }}{{Cite journal | pmid = 10780756| year = 2000| last1 = Huchon| first1 = G| title = Comparison of the safety of drug delivery via HFA- and CFC-metered dose inhalers in CAO| journal = The European Respiratory Journal| volume = 15| issue = 4| pages = 663–9| last2 = Hofbauer| first2 = P| last3 = Cannizzaro| first3 = G| last4 = Iacono| first4 = P| last5 = Wald| first5 = F| doi=10.1034/j.1399-3003.2000.15d07.x| doi-access = free}}{{cite web | url = https://www.osha.gov/dts/chemicalsampling/data/CH_270935.html | publisher = Occupational Safety & Health Administration | title = 1,1,1,2-Tetrafluoroethane | access-date = 3 February 2018 | archive-date = 3 February 2018 | archive-url = https://web.archive.org/web/20180203181157/https://www.osha.gov/dts/chemicalsampling/data/CH_270935.html | url-status = dead }} In combination with pentafluoropropane, it is used as a topical vapocoolant spray for numbing boils before curettage.{{cite web | url = https://www.drugbank.ca/drugs/DB13116 | publisher = DrugBank | title = Norflurane}}{{cite web | url = https://www.webmd.com/drugs/2/drug-91869/norflurane-pentafluoropropane-topical/details | title = Norflurane-Pentafluoropropane Aerosol, Spray | publisher = WebMD}} It has also been studied as a potential inhalational anesthetic,{{cite journal|last1=Shulman M, Sadove MS|title=1,1,1,2-tetrafluoroethane: an inhalational agent of intermediate potency |journal=Anesthesia and Analgesia |year=1967 |volume=46 |issue=5 |pages=629–635 |doi=10.1213/00000539-196709000-00029|s2cid=5868484 |doi-access=free }} but it is nonanaesthetic at doses used in inhalers.

• List of refrigerants
• Tetrabromoethane
• Tetrachloroethane

{{Reflist}}

{{Commonscat|1,1,1,2-Tetrafluoroethane}}

• {{ICSC|1281|12}}
• [https://web.archive.org/web/20120626113012/http://www.fluorocarbons.org/chemical-families/hfcs/hfc-products-applications European Fluorocarbons Technical Committee (EFCTC)]
• [https://web.archive.org/web/20020706203049/http://ptcl.chem.ox.ac.uk/MSDS/TE/1,1,1,2-tetrafluoroethane.html MSDS at Oxford University]
• [http://www.inchem.org/documents/cicads/cicads/cicad11.htm Concise International Chemical Assessment Document 11], at inchem.org
• [http://www.csgnetwork.com/r134apresstempconv.html Pressure temperature calculator]
• {{Cite web |url=http://www.symp14.nist.gov/PDF/JOI11UST.PDF |title=The Coexisting Curve of the Refrigerant HFC 134a: Some Scaling Models |access-date=11 September 2007 |archive-url=https://web.archive.org/web/20060929201020/http://www.symp14.nist.gov/PDF/JOI11UST.PDF |archive-date=29 September 2006 |url-status=dead}}
• [http://www.tfandf.com/ R134a 2 phase computer cooling] {{Webarchive|url=https://web.archive.org/web/20080618154640/http://www.tfandf.com/ |date=18 June 2008 }}

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