Refrigerants that are highly flammable and highly toxic belong to which group?

The correct group for refrigerants that are both highly flammable and highly toxic is B3. This classification specifically identifies materials that present significant hazards when it comes to safety.

In the context of refrigerants, safety is paramount since these substances are often handled and used in varying environmental conditions. Group B refers to refrigerants that have a lower flammability risk compared to those in Group A, which are non-flammable; however, the "3" designation indicates that these refrigerants also carry toxicity risks that require additional safety considerations during their use, storage, and disposal.

It's essential to recognize that Group A (including A2L refrigerants) denotes non-toxic and low-toxicity substances, while Group C includes refrigerants with less specific classification concerning flammability or toxicity. Understanding these classifications helps ensure safe practices within power engineering and refrigeration applications.