The HVACR industry will likely soon be in the midst of another refrigerant change, which is causing a bit of unease amongst some. That’s because this time around, unlike the transition away from R-22 in 2010, some of the new refrigerants being proposed to replace R-410A in air conditioning equipment are mildly flammable — or, as ASHRAE classifies them, lower flammability (A2L) refrigerants.

The reason for this transition is different from the last, which concerned phasing out ozone-depleting refrigerants such as R-22. They were replaced with HFCs such as R-410A, which did not pose any harm to the ozone layer but are thought to contribute to global warming. Countries around the world responded by signing on to the Kigali Amendment to phase down the use of high-GWP refrigerants such as R-410A; however, finding a nonflammable, low-GWP replacement proved to be difficult.