The purpose of the Atmosphere America event in Washington, D.C., this past summer was to present a business case for so-called natural refrigerants like R-290 (propane), R-600a (isobutene), R-717 (ammonia), and R-744 (CO2), among others.
In that context, the concern was not so much in regulatory action against f-gases, but that naturals could provide cost-effective refrigeration and cooling solutions. The purpose of the case histories was to show real-world applications with measureable results.