Regarding fire safety, which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity?

• A. A1
• B. A2
• C. B1
• D. B2

Answer: (A)

In ASHRAE 34 labeling, there are two axes to consider: how flammable a refrigerant is and how toxic it is. The safest combination is no flame propagation (no flammability) and low acute toxicity (lower toxicity). That specific category represents the refrigerants that pose the smallest fire and health risks.

Why this is the best choice: it satisfies both critical safety criteria at once—no tendency to burn and minimal toxicity if released. Other categories either have some flammability or higher toxicity, so they don’t meet both conditions simultaneously.

So the correct idea is the refrigerant safety classification that denotes no flammability and lower toxicity, the one described by those dual safety characteristics.