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Chemical structure of 1,3,3,3-tetrafluoropropene (HFO-1234ze)

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

HFO refrigerants are categorised as having zero ODP (Ozone Depletion Potential) and low GWP (Global Warming Potential) and so offer a more environmentally friendly alternative to CFCs, HCFCs and HFCs.

HFOs are being developed as "fourth generation" refrigerants with 0.1% of the global-warming potential of HFCs.[1][2][3] HFOs currently in use include 2,3,3,3-tetrafluoropropene (HFO-1234yf) and 1,3,3,3-tetrafluoropropene (HFO-1234ze).[1][4] 1-chloro-3,3,3-trifluoropropene (HFO-1233zd) is also under development.[5]


  1. ^ a b "HETEROGENEOUS CATALYSIS UNDER MICROWAVE HEATING" (PDF). La Chimica & L'Industria (in Italian). Società Chimica Italiana (4): 22. May 2012.
  2. ^ HFO, i nuovi gas refirgerant
  3. ^ Hydrofluoroolefins (HFOs) Archived 2012-02-04 at the Wayback Machine., European Fluorocarbons Technical Committee
  4. ^ Honeywell Sells Novel Low-Global-Warming Blowing Agent To European Customers, Honeywell press release, Oct. 7, 2008
  5. ^ Cheryl Hogue (2011). "Replacing the Replacements". Chemical & Engineering News. 89 (49): 31–32. doi:10.1021/cen-v089n049.p031.