Hydrofluorocarbon

Hydrofluorocarbons (HFCs), organic compounds that contain fluorine and hydrogen atoms, are the most common type of organofluorine compounds. They are commonly used in air conditioning and as refrigerants [1] in place of the older chlorofluorocarbons such as R-12 and hydrochlorofluorocarbons such as R-21. They do not harm the ozone layer as much as the compounds they replace; however, they do contribute to global warming. Their atmospheric concentrations and contribution to anthropogenic greenhouse gas emissions are rapidly increasing, causing international concern about their radiative forcing.

Fluorocarbons with few C-F bonds behave similarly to the parent hydrocarbons, but their reactivity can be altered significantly. For example, both uracil and 5-fluorouracil are colourless, high-melting crystalline solids, but the latter is a potent anti-cancer drug. The use of the C-F bond in pharmaceuticals is predicated on this altered reactivity.[2] Several drugs and agrochemicals contain only one fluorine center or one trifluoromethyl group.

Unlike other greenhouse gases in the Paris Agreement, hydrofluorocarbons have other international negotiations.[3]

In September 2016, the so-called New York Declaration urged a global reduction in the use of HFCs.[4] On 15 October 2016, due to these chemicals contribution to climate change, negotiators from 197 nations meeting at the summit of the United Nations Environment Programme in Kigali, Rwanda reached a legally-binding accord to phase out hydrofluorocarbons (HFCs) in an amendment to the Montreal Protocol.[5][6][7]

References

  1. ↑ Milman, Oliver (22 September 2016). "100 countries push to phase out potentially disastrous greenhouse gas". The Guardian. London, UK. Retrieved 2016-09-22.
  2. ↑ G. Siegemund, W. Schwertfeger, A. Feiring, B. Smart, F. Behr, H. Vogel, B. McKusick "Fluorine Compounds, Organic" in "Ullmann's Encyclopedia of Industrial Chemistry" 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a11_349
  3. ↑ Davenport, Carol (July 23, 2016). "A Sequel to the Paris Climate Accord Takes Shape in Vienna". NYT. Retrieved 17 August 2016.
  4. ↑ "The New York Declaration of the Coalition to Secure an Ambitious HFC Amendment". Washington, DC: US Department of State. 22 September 2016. Retrieved 2016-09-22.
  5. ↑ Chris Johnston, Oliver Milman, John Vidal and agencies, "Climate change: global deal reached to limit use of hydrofluorocarbons", The Guardian, Saturday 15 October 2016 (page visited on 15 October 2016).
  6. ↑ "Climate change: 'Monumental' deal to cut HFCs, fastest growing greenhouse gases". BBC News. 15 October 2016. Retrieved 15 October 2016.
  7. ↑ "Nations, Fighting Powerful Refrigerant That Warms Planet, Reach Landmark Deal". New York Times. 15 October 2016. Retrieved 15 October 2016.
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