Which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity?

The classification of refrigerants by ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) includes categories that indicate both flammability and toxicity levels. The designation of B1 refers to refrigerants that possess a high level of flammability and may exhibit higher toxicity.

The classification B2 indicates refrigerants that are flammable but have lower toxicity. Therefore, they do not qualify as safe options.

On the other hand, A1 is the classification that denotes refrigerants with no flammability and lower toxicity. This means that refrigerants classified as A1 are considered the safest for use in various applications, as they pose minimal risks in terms of fire and health effects.

Considering these classifications, A1 is the most appropriate designation for refrigerants that indicate no flammability and present lower toxicity levels, making them highly suitable and safe for general use.