1,1-Difluoroethane
| 1,1-Difluoroethane[1] | |
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1,1-Difluoroethane |
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Other names
difluoroethane |
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| Identifiers | |
| CAS number | 75-37-6  |
| PubChem | 6368 |
| ChemSpider | 6128 |
| UNII | 0B1U8K2ME0 |
| ChEMBL | CHEMBL325493 |
| RTECS number | KI1410000 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C2H4F2 |
| Molar mass | 66.05 g/mol |
| Density | 2.7014 g/L @ 25 °C |
| Melting point |
-117 °C, 156 K, -179 °F |
| Boiling point |
-25 °C, 248 K, -13 °F |
| Solubility in water | 0.54% @ 0 °C |
| Vapor pressure | 4020 mmHg/536 kPa @ 21.1 °C
5.1 bar/510 kPa @ 20 °C |
| Viscosity | 0.00887 cP (8.87 µPa·s) @ 25 °C |
| Hazards | |
| MSDS | MSDS for 1,1-difluoroethane |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
1,1-Difluoroethane is an organofluorine compound with the chemical formula C2H4F2. This colorless gas is used as a refrigerant, where it is often listed as R-152a or HFC-152a. As an alternative to chlorofluorocarbons, it has an ozone depletion potential of zero, a lower global warming potential (120) and a shorter atmospheric lifetime (1.4 years).[2] It has recently been approved for use in automobile applications as an alternative to R-134a.
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[edit] Production
1,1-Difluoroethane is produced by the mercury-catalyzed addition of hydrogen fluoride to acetylene:[3]
- HCCH + 2 HF → CH3CHF2
The intermediate in this process is vinyl fluoride, the monomeric percursor to polyvinyl fluoride.
[edit] Uses
In addition to serving as a refrigerant, 1,1-difluoroethane is also commonly used in gas duster (commonly thought of as "canned air"), and many consumer aerosol products, especially those subject to stringent VOC requirements.
[edit] Safety
The practice of huffing canned air can be extremely dangerous or fatal. The intentional inhalation of 1,1-difluoroethane caused a fatal cardiac arrhythmia in a 42 year-old man.[4] Several reports of fatal car crashes have been linked to drivers huffing 1,1-difluoroethane.[5][6]
In a Du Pont study, rats were exposed to up to 25,000ppm (67,485 mg/m3) for six hours daily, five days a week for two years. This has become the NOAEL for this substance. Prolonged exposure to difluoroethane has been linked in humans to the development of coronary heart-disease and angina.[7]
[edit] See also
[edit] References
- ^ 1,1-Difluoroethane at Sigma-Aldrich
- ^ "Global Warming Potentials of ODS Substitutes". U.S. Environmental Protection Agency. 2010. Archived from the original on 16 October 2010. http://web.archive.org/web/20101016052146/http://www.epa.gov/ozone/geninfo/gwps.html. Retrieved 20 September 2010.
- ^ Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine (2010). "Fluorine Compounds, Organic". In Bohnet, Matthias; Bellussi, Giuseppe; Bus, James et al. Ullmann's Encyclopedia of Industrial Chemistry. John Wiley & Sons. doi:10.1002/14356007.a11_349.
- ^ Avella J, Wilson JC, Lehrer M (March 2006). "Fatal cardiac arrhythmia after repeated exposure to 1,1-difluoroethane (DFE)". The American Journal of Forensic Medicine and Pathology 27 (1): 58–60. doi:10.1097/01.paf.0000202715.71009.0e. PMID 16501351.
- ^ Broussard LA, Brustowicz T, Pittman T, Atkins KD, Presley L (November 1997). "Two traffic fatalities related to the use of difluoroethane". Journal of Forensic Sciences 42 (6): 1186–7. PMID 9397568.
- ^ Hahn T, Avella J, Lehrer M (October 2006). "A motor vehicle accident fatality involving the inhalation of 1,1-difluoroethane". Journal of Analytical Toxicology 30 (8): 638–42. PMID 17132266. http://openurl.ingenta.com/content/nlm?genre=article&issn=0146-4760&volume=30&issue=8&spage=638&aulast=Hahn. Retrieved 06 June 2010.
- ^ "1,1-Difluoroethane". National Library of Medicine HSDB Database. 1994. http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@rn+75-37-6. Retrieved 8 June 2010.
