R-1234yf

2,3,3,3-Tetrafluoropropene, HFO-1234yf, is a hydrofluoroolefin (HFO) with the formula CH2=CFCF3. It is also designated R-1234yf as the first of a new class of refrigerants: it is marketed under the name Opteon YF by Chemours and as Solstice YF by Honeywell.[2]
HFO-1234yf has a global warming potential (GWP) of less than 1, compared to 1,430 for R-134a[ and 1 for carbon dioxide. This colorless gas is being used as a replacement for R-134a as a refrigerant in automobile air conditioners. It does break down into persistent organic pollutant short chain PFCAs.