A2L refrigerants are a new class of "mildly flammable" cooling agents designed to replace high-GWP (Global Warming Potential) refrigerants like R-410A. These chemicals, such as R-454B and R-32, are more environmentally friendly and help manufacturers meet new EPA regulations. While they are slightly flammable, they are very difficult to ignite and are safe for residential use when installed in compliant systems. Technicians must use specific A2L-rated tools, such as spark-proof recovery machines and vacuum pumps, when working with these gases. The transition to A2L is a major industry shift occurring throughout 2025 and 2026.