Which refrigerant class has the least ozone depletion potential?

• A. Class 1
• B. Class 2
• C. Class 3
• D. Class 4

Answer: (B)

The correct answer is that Class 2 refrigerants have the least ozone depletion potential (ODP). Class 2 refrigerants are characterized by their minimal impact on the ozone layer, as they do not contain chlorine atoms, which are primarily responsible for ozone depletion. These refrigerants include many hydrofluorocarbons (HFCs), which have been developed as alternatives to older substances that contribute significantly to ozone depletion.

In contrast, Class 1 refrigerants contain chlorine and bromine, which are harmful to the ozone layer and have higher ODP values. Class 3 substances might include those with more ODP than Class 2 but less than Class 1, while Class 4 typically constitutes those with virtually no ODP, aligning closely with Class 2 but is not as commonly referenced in this context. Understanding the ozone depletion potential is critical for selecting refrigerants that are safer for the environment and comply with various international protocols aimed at protecting the ozone layer.