HFO-1234yf is a hydrofluoroolefin with the formula CH2=CFCF3. It has been proposed as a replacement for R134a as a refrigerant in automobile air conditioners. HFO-1234yf is the first in a new class of refrigerants acquiring a global warming potential (GWP) rating one 335th that of R134a (and only 4 times higher than carbon dioxide, which can also be used as a refrigerant but which has properties significantly different from those of R134a, especially requiring operation at around 5 times higher pressure) and an atmospheric lifetime of about 400 times shorter. It was developed to meet the European directive 2006/40/EC that went into effect in 2011 requiring that all new car platforms for sale in Europe use a refrigerant in its AC system with GWP below 150.NamesIUPAC name2,3,3,3-tetrafluoroprop-1-eneOther namesHFO-1234yf; R1234yf; R-1234yf; 2,3,3,3-TetrafluoropropyleneIdentifiersCAS Number754-12-1 ChemSpider2057041 Jmol 3D modelInteractive imageInteractive imagePropertiesChemical formulaC3H2F4Molar mass114 g/molAppearancecolorless gasDensity1.1 g/cm3 at 25 °C (liquid); 4, air = 1 (gas)Boiling point−30 °C (−22 °F; 243 K)Solubility in water198.2 mg/l at 24 °C, 92/69/EEC, A.6log P2.15, n-octanol/water, 92/69/EEC, A.8Vapor pressure6,067 hPa at 21.1 °C; 14,203 hPa at 54.4 °C