It was disappointing to see so much ink devoted to the refrigerant HFC-134a, which most of us have in our cars (C&EN, June 17, page 8, and March 18, page 11). Since this is a “global warming” threat, we must limit its use. With whom do we partner? China? Are you kidding?
The Obama Administration is promoting use of HFO-1234yf, a new refrigerant that the European Union has approved and that Gina McCarthy, newly appointed head of the Environmental Protection Agency, has approved for use in American cars. She has done this despite frightening data about the flammability of this compound from Mercedes-Benz and Volkswagen. Neither manufacturer will use this refrigerant in their new cars. They will pay the fines rather than switch from HFC-134a.
In simulated auto crashes, when HFO-1234yf was sprayed onto hot engines, the refrigerant burst into flames. The products of combustion were hydrogen fluoride, which etched the windshields, and trifluoroacetic acid.
HF is extremely toxic. If any of it were to come in contact with the occupants of a car, they would almost certainly be killed. And of course, the refrigerant generates trifluoroacetic acid as a secondary toxic pollutant that degrades very slowly, if at all, in the environment.
A. Frank Leo