A2L Refrigerants

The AIM Act and EPA regulations are phasing down high-GWP refrigerants, driving rapid adoption of A2L alternatives. A2L refrigerants introduce mild flammability risks along with traditional concerns around oxygen displacement. While they are much less flammable than hydrocarbon (A3) refrigerants, A2Ls can ignite under certain conditions if concentrations approach their lower flammability limit and an ignition source is present. At the same time, like many refrigerants, they are heavier than air and can accumulate in enclosed or low-lying spaces, potentially displacing oxygen and creating an asphyxiation hazard at high concentrations. Because of this dual risk—flammability and reduced oxygen levels—modern safety approaches focus on early leak detection, proper ventilation, and system design controls to prevent hazardous conditions from developing. Detection requirements vary by standard: UL 60335-2-40 requires equipment integrated detection systems based on factors such as refrigerant type and charge. ASHRAE 15-2024 and CSA B52:23 govern building and system safety, requiring refrigerant detection in occupied spaces where concentration limits could be exceeded and in machinery rooms, where detection, ventilation, and alarms are typically mandatory.