CO2 is one of the “natural” refrigerants along with ammonia and HCs. The EPA and GreenChill have been focusing on naturals for several years now. In addition to extending kudos to CO2 stores, GreenChill has applauded increasing use of ammonia systems in supermarkets and given Significant New Alternatives Policy (SNAP) approval to HCs in certain refrigeration applications, with plans to increase the number of applications.
The attention given to HFC refrigerants by the EPA has been for stores that have been reducing their charges of those f-gases.