A refrigerant classed as lower toxicity (A) and lower flammability (2L).
Refrigerants carry a safety group made of a letter for toxicity (A lower, B higher) and a number for flammability (1 no flame propagation, 2L lower flammability, 2 flammable, 3 higher flammability). A2L refrigerants such as R-32 and R-454B are hard to ignite and burn slowly, but they can burn.
Working with them means using tools and recovery equipment suited to flammable refrigerants, controlling ignition sources where refrigerant could be released, and following each unit's installation requirements, which can include minimum room area and leak detection.
Exam work areas
A · Safety and trade practice D · Installing systems and controls