A.K.A Carbon Dioxide.
It is an alternative refrigerant being explored to replace R134a.
And here you thought R134 was benign.
European Union will phase out any refrigerant with a Global Warming Potential (GWP) of over 150 beginning 2011. R134a scores at 1,410, while Carbon Dioxide (R744) comes in with a score of 1 (one).
Unfortunately, Carbon Dioxide at 5% volume is toxic to humans.
Another refrigerant being considered is R152a with GWP level of 124.
Got this from Road & Track.
