Why were HFCs developed?

• A. To replace natural air cooling methods.
• B. To reduce greenhouse gas emissions in all sectors.
• C. To enhance ozone layer repair.
• D. As alternatives to ozone-depleting substances.

Answer: (D)

HFCs were developed to replace ozone-depleting substances like CFCs and HCFCs. Those older refrigerants and blowing agents release chlorine in the stratosphere, which catalytically breaks down ozone and thins the ozone layer. HFCs, containing hydrogen and fluorine, do not release chlorine, giving them little to no ozone depletion potential while providing similar performance in applications. That’s why they were adopted as alternatives under international efforts to protect the ozone layer. (Note: while they don’t harm the ozone layer, they are potent greenhouse gases, which has later led to efforts to reduce them for climate reasons.)