1,1-Difluoroethane

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Contents

1,1-Difluoroethane [1]
Difluoroethane Difluoroethane.svg
Difluoroethane
Difluoroethane Difluoroethane.png
Difluoroethane
Difluoroethane3Dmodel.png
Names
Preferred IUPAC name
1,1-Difluoroethane
Other names
  • Difluoroethane
  • Freon 152a
  • Ethylidene difluoride
  • Ethylidene fluoride
  • HFC-152a
  • R-152a
  • DFE
  • Tinned Wind
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.000.788 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
RTECS number
  • KI1410000
UNII
  • InChI=1S/C2H4F2/c1-2(3)4/h2H,1H3 Yes check.svgY
    Key: NPNPZTNLOVBDOC-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C2H4F2/c1-2(3)4/h2H,1H3
    Key: NPNPZTNLOVBDOC-UHFFFAOYAM
  • FC(F)C
Properties
C2H4F2
Molar mass 66.05 g/mol
Density 900 g/L @ 25 °C
Melting point −117 °C (−179 °F; 156 K)
Boiling point −24.7 °C (−12.5 °F; 248.5 K)
Critical point (T, P)113.45 °C
0.54% @ 0 °C
Vapor pressure
  • 536 kPa (4020 mmHg) @ 21.1 °C
  • 510 kPa (5.1 bar) @ 20 °C
Viscosity 8.87 μPa·s (0.00887 cP) @ 25 °C
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Extremely flammable
GHS labelling:
GHS-pictogram-flamme.svg
Danger
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
4
0
Safety data sheet (SDS) SDS for 1,1-difluoroethane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

1,1-Difluoroethane, or DFE, 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 (refrigerant-152a) or HFC-152a (hydrofluorocarbon-152a). It is also used as a propellant for aerosol sprays and in gas duster products. As an alternative to chlorofluorocarbons, it has an ozone depletion potential of zero, a lower global warming potential (124) and a shorter atmospheric lifetime (1.4 years). [2] [3]

Production

1,1-Difluoroethane is a synthetic substance that is produced by the mercury-catalyzed addition of hydrogen fluoride to acetylene: [4]

HCCH + 2 HF → CH3CHF2

The intermediate in this process is vinyl fluoride (C2H3F), the monomeric precursor to polyvinyl fluoride.

Uses

With a relatively low global warming potential (GWP) index of 124 and favorable thermophysical properties, 1,1-difluoroethane has been proposed as an environmentally friendly alternative to R134a. Despite its flammability, R152a also presents operating pressures and volumetric cooling capacity (VCC) similar to R134a so it can be used in large chillers [5] or in more particular applications like heat pipe finned heat exchangers. [6]

In addition, 1,1-difluoroethane is also commonly used in gas dusters and numerous other retail aerosol products, particularly those subject to stringent volatile organic compound (VOC) requirements.

The molecular weight of difluoroethane is 66, making it a useful and convenient tool for detecting vacuum leaks in Gas chromatography–mass spectrometry (GC-MS) systems. The cheap and freely available gas has a molecular weight and fragmentation pattern (base peak 51 m/z in typical EI-MS, [7] major peak at 65 m/z) distinct from anything in air. If mass peaks corresponding to 1,1-difluoroethane are observed immediately after spraying a suspect leak point, leaks may be identified.

Safety

Difluoroethane is an extremely flammable gas, which decomposes rapidly on heating or burning, producing toxic and irritating fumes, including hydrogen fluoride and carbon monoxide. [8]

In a DuPont study, rats were exposed to up to 25,000 ppm (67,485 mg/m3) for six hours daily, five days a week for two years. This has become the no-observed-adverse-effect level for this substance. Prolonged exposure to 1,1-difluoroethane has been linked in humans to the development of coronary disease and angina. [9] Repeated or sufficiently high levels of exposure, particularly purposeful inhalation, can precipitate fatal cardiac arrhythmia. [10]

Abuse

Difluoroethane is an intoxicant with abuse potential. [10] [11] [12] [13] It appears to act primarily through GABAA and glutamate receptors. [14] [15] Fatalities linked to difluoroethane abuse include actress Skye McCole Bartusiak, singer Aaron Carter and wrestler Mike Bell. [16] Bitterants, added voluntarily to some brands to deter purposeful inhalation, are often not legally required; they do not negate or counteract difluoroethane's intoxicating effects.

Environmental abundance

Growth of HFC-152a in Earth's atmosphere since year 2000. HFC152a concentration.jpg
Growth of HFC-152a in Earth's atmosphere since year 2000.
HFC-152a measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) in the lower atmosphere (troposphere) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion. HFC-152a mm.png
HFC-152a measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) in the lower atmosphere (troposphere) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion.


Most production, use, and emissions of HFC-152a have occurred within Earth's more industrialized and populated northern hemisphere following the substance's introduction in the 1990s. Its concentration in the northern troposphere reached an annual average of about 10 parts per trillion by year 2011. [17] The concentration of HFC-152a in the southern troposphere is about 50% lower due to its removal rate (i.e. lifetime) of about 1.5 years being similar in magnitude to the global atmospheric mixing time of one to two years. [18]

See also

Related Research Articles

<span class="mw-page-title-main">Chlorofluorocarbon</span> Class of organic compounds

Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and propane.

<span class="mw-page-title-main">Refrigerant</span> Substance in a refrigeration cycle

A refrigerant is a working fluid used in cooling, heating or reverse cooling and heating of air conditioning systems and heat pumps where they undergo a repeated phase transition from a liquid to a gas and back again. Refrigerants are heavily regulated because of their toxicity and flammability and the contribution of CFC and HCFC refrigerants to ozone depletion and that of HFC refrigerants to climate change.

<span class="mw-page-title-main">Difluoromethane</span> Chemical compound

Difluoromethane, also called difluoromethylene, HFC-32Methylene Fluoride or R-32, is an organic compound of the dihalogenoalkane variety. Invented in 1964 by Hoechst AG (not Daikin) it has the formula of CH2F2. It is a colorless gas in the ambient atmosphere and is slightly soluble in water, with a high thermal stability. Due to the low melting and boiling point, (−136.0 and −51.6 °C [−212.8 and −60.9 °F; 137.2 and 221.6 K] respectively) contact with this compound may result in frostbite. In the United States, the Clean Air Act Section 111 on Volatile Organic Compounds (VOC) has listed difluoromethane as an exception (since 1997) from the definition of VOC due to its low production of tropospheric ozone. Difluoromethane is commonly used in endothermic processes such as refrigeration or air conditioning.

1,1,1,2-Tetrafluoroethane (also known as norflurane (INN), R-134a, Klea 134a, Freon 134a, Forane 134a, Genetron 134a, Green Gas, Florasol 134a, Suva 134a, HFA-134a, or HFC-134a) is a hydrofluorocarbon (HFC) and haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane) but with insignificant ozone depletion potential and a lower 100-year global warming potential (1,430, compared to R-12's GWP of 10,900). It has the formula CF3CH2F and a boiling point of −26.3 °C (−15.34 °F) at atmospheric pressure. R-134a cylinders are colored light blue. A phaseout and transition to HFO-1234yf and other refrigerants, with GWPs similar to CO2, began in 2012 within the automotive market.

<span class="mw-page-title-main">Gas duster</span> Product used for dusting devices

A gas duster, also known as tinned wind, compressed air, or canned air, is a product used for cleaning or dusting electronic equipment and other sensitive devices that cannot be cleaned using water.

<span class="mw-page-title-main">Chlorodifluoromethane</span> Chemical propellant and refrigerant

Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC). This colorless gas is better known as HCFC-22, or R-22, or CHClF
2. It was commonly used as a propellant and refrigerant. These applications were phased out under the Montreal Protocol in developed countries in 2020 due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), and in developing countries this process will be completed by 2030. R-22 is a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene.

Fluoroform, or trifluoromethane, is the chemical compound with the formula CHF3. It is a hydrofluorocarbon as well as being a part of the haloforms, a class of compounds with the formula CHX3 with C3v symmetry. Fluoroform is used in diverse applications in organic synthesis. It is not an ozone depleter but is a greenhouse gas.

R-410A is a refrigerant used in air conditioning and heat pump applications. It is a zeotropic but near-azeotropic mixture of difluoromethane (CH2F2, called R-32) and pentafluoroethane (CHF2CF3, called R-125). R-410A is sold under the trademarked names AZ-20, EcoFluor R410, Forane 410A, Genetron R410A, Puron, and Suva 410A.

Natural refrigerants are considered substances that serve as refrigerants in refrigeration systems. They are alternatives to synthetic refrigerants such as chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), and hydrofluorocarbon (HFC) based refrigerants. Unlike other refrigerants, natural refrigerants can be found in nature and are commercially available thanks to physical industrial processes like fractional distillation, chemical reactions such as Haber process and spin-off gases. The most prominent of these include various natural hydrocarbons, carbon dioxide, ammonia, and water. Natural refrigerants are preferred actually in new equipment to their synthetic counterparts for their presumption of higher degrees of sustainability. With the current technologies available, almost 75 percent of the refrigeration and air conditioning sector has the potential to be converted to natural refrigerants.

<span class="mw-page-title-main">2,3,3,3-Tetrafluoropropene</span> Chemical compound

2,3,3,3-Tetrafluoropropene, HFO-1234yf, is a hydrofluoroolefin (HFO) with molecular formula CH2=CFCF3. Its primary application is as a refrigerant with low global warming potential (GWP).

<span class="mw-page-title-main">1,1-Dichloro-1-fluoroethane</span> Chemical compound

1,1-Dichloro-1-fluoroethane is a haloalkane with the formula C
2H
3Cl
2F. It is one of the three isomers of dichlorofluoroethane. It belongs to the hydrochlorofluorocarbon (HCFC) family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment.

<span class="mw-page-title-main">Pentafluoroethane</span> Chemical compound

Pentafluoroethane is a fluorocarbon with the formula CF3CHF2. Pentafluoroethane is currently used as a refrigerant (known as R-125) and also used as a fire suppression agent in fire suppression systems.

<span class="mw-page-title-main">1-Chloro-1,1-difluoroethane</span> Chemical compound

1-Chloro-1,1-difluoroethane (HCFC-142b) is a haloalkane with the chemical formula CH3CClF2. It belongs to the hydrochlorofluorocarbon (HCFC) family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment. It is primarily used as a refrigerant where it is also known as R-142b and by trade names including Freon-142b.

<span class="mw-page-title-main">Hydrofluoroolefin</span> Class of chemical compounds

Hydrofluoroolefins (HFOs) are unsaturated organic compounds composed of hydrogen, fluorine and carbon. These organofluorine compounds are of interest as refrigerants. Unlike traditional hydrofluorocarbons (HFCs) and chlorofluorocarbons (CFCs), which are saturated, HFOs are olefins, otherwise known as alkenes.

<i>trans</i>-1,3,3,3-Tetrafluoropropene Chemical compound

trans-1,3,3,3-Tetrafluoropropene (HFO-1234ze(E), R-1234ze(E)) is a hydrofluoroolefin. It was developed as a "fourth generation" refrigerant to replace fluids such as R-134a, as a blowing agent for foam and aerosol applications, and in air horns and gas dusters. The use of R-134a is being phased out because of its high global warming potential (GWP). HFO-1234ze(E) itself has zero ozone-depletion potential (ODP=0), a very low global warming potential (GWP < 1 ), even lower than CO2, and it is classified by ANSI/ASHRAE as class A2L refrigerant (lower flammability and lower toxicity).

Fluorinated gases (F-gases) are a group of gases containing fluorine. They are divided into several types, the main of those are hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6). They are used in refrigeration, air conditioning, heat pumps, fire suppression, electronics, aerospace, magnesium industry, foam and high voltage switchgear. As they are greenhouse gases with a strong global warming potential, their use is regulated.

1,2-Difluoroethane is a saturated hydrofluorocarbon containing an atom of fluorine attached to each of two carbons atoms. The formula can be written CH2FCH2F. It is an isomer of 1,1-difluoroethane. It has a HFC name of HFC-152 with no letter suffix. When cooled to cryogenic temperatures it can have different conformers, gauche and trans. In the liquid form these are about equally abundant and easily interconvert. As a gas it is mostly the gauche form.

Life Cycle Climate Performance (LCCP) is an evolving method to evaluate the carbon footprint and global warming impact of heating, ventilation, air conditioning (AC), refrigeration systems, and potentially other applications such as thermal insulating foam. It is calculated as the sum of direct, indirect, and embodied greenhouse gas (GHG) emissions generated over the lifetime of the system “from cradle to grave,” i.e. from manufacture to disposal. Direct emissions include all climate forcing effects from the release of refrigerants into the atmosphere, including annual leakage and losses during service and disposal of the unit. Indirect emissions include the climate forcing effects of GHG emissions from the electricity powering the equipment. The embodied emissions include the climate forcing effects of the manufacturing processes, transport, and installation for the refrigerant, materials, and equipment, and for recycle or other disposal of the product at end of its useful life.

<span class="mw-page-title-main">Tetrachloro-1,1-difluoroethane</span> Chemical compound

Tetrachloro-1,1-difluoroethane or 1,1,1,2-tetrachloro-2,2-difluoroethane, Freon 112a, R-112a, or CFC-112a is an asymmetric chlorofluorocarbon isomer of tetrachloro-1,1-difluoroethane with formula CClF2CCl3. It contains ethane substituted by four chlorine atoms and two fluorine atoms. With a boiling point of 91.5°C it is the freon with second highest boiling point.

References

  1. ↑ 1,1-Difluoroethane at Sigma-Aldrich
  2. ↑ "Changes in Atmospheric Constituents and in Radiative Forcing" (PDF). Cambridge University Press. 2007. p. 212. Retrieved 11 May 2017. 18 February 2019
  3. ↑ "Global Warming Potentials of ODS Substitutes". U.S. Environmental Protection Agency. 2010. Archived from the original on 16 October 2010. Retrieved 20 September 2010.
  4. ↑ 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. (eds.). Ullmann's Encyclopedia of Industrial Chemistry. John Wiley & Sons. doi:10.1002/14356007.a11_349. ISBN   978-3527306732.
  5. ↑ Longo, Giovanni A.; Zilio, Claudio; Righetti, Giulia (2015). "Condensation of the low GWP refrigerant HFC152a inside a Brazed Plate Heat Exchanger". Experimental Thermal and Fluid Science. 68: 509–515. doi:10.1016/j.expthermflusci.2015.06.010.
  6. ↑ Righetti, Giulia; Zilio, Claudio; Mancin, Simone; Longo, Giovanni A. (2018). "Heat Pipe Finned Heat Exchanger for Heat Recovery: Experimental Results and Modeling". Heat Transfer Engineering. 39 (12): 1011–1023. Bibcode:2018HTrEn..39.1011R. doi:10.1080/01457632.2017.1358483. S2CID   126263840.
  7. ↑ Ethane, 1,1-difluoro- in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 2023)
  8. ↑ "1,1-Difluoroethane". WebWISER. U.S. National Library of Medicine. Retrieved 2 April 2022.
  9. ↑ "1,1-Difluoroethane". National Library of Medicine HSDB Database. 1994. Retrieved 8 June 2010.
  10. 1 2 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. S2CID   22312214.
  11. ↑ 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. doi:10.1520/JFS14284J. PMID   9397568.
  12. ↑ Hahn, T; Avella, J; Lehrer, M (2006). "A motor vehicle accident fatality involving the inhalation of 1,1-difluoroethane". Journal of Analytical Toxicology. 30 (8): 638–42. doi: 10.1093/jat/30.8.638 . PMID   17132266.
  13. ↑ "Autopsy: man in crash died from inhaling computer cleaner". The Times News. 10 March 2012. Archived from the original on 12 March 2012.
  14. ↑ Novotny, Clara B; Irvin, Sarah; Espiridion, Eduardo D (2019). "Acute Psychosis Following 1,1-Difluoroethane Inhalation". Cureus. 11 (9): e5565. doi: 10.7759/cureus.5565 . ISSN   2168-8184. PMC   6820689 . PMID   31695984.
  15. ↑ Custer, Adam; Corse, Andrew; Vazirani, Sondra (June 2020). "Difluoroethane Inhalant Abuse, Skeletal Fluorosis, and Withdrawal". Federal Practitioner. 37 (6): 288–289. ISSN   1078-4497. PMC   7357883 . PMID   32669782.
  16. ↑ Duke, Alan (22 July 2014). "'Patriot' actress Skye McCole Bartusiak dead at 21". CNN. Retrieved 24 February 2019.
  17. 1 2 "HFC-152a". NOAA Earth System Research Laboratories/Global Monitoring Division. Retrieved 12 February 2021.
  18. ↑ Greally, B.R.; et al. (2007). "Observations of 1,1-difluoroethane (HFC-152a) at AGAGE and SOGE monitoring stations in 1994–2004 and derived global and regional emission estimates". Journal of Geophysical Research. 112 (D06308). Bibcode:2007JGRD..112.6308G. doi: 10.1029/2006JD007527 .
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