What was one of the challenges with older refrigerants like CFCs?

One significant challenge with older refrigerants like chlorofluorocarbons (CFCs) is their ozone depletion potential. CFCs were widely used due to their stability and effectiveness as refrigerants, but it was later discovered that when these substances are released into the atmosphere, they can break down ozone molecules in the stratosphere. This depletion of the ozone layer leads to increased ultraviolet (UV) radiation reaching the Earth's surface, which can cause various environmental and health issues, including an increased risk of skin cancer and harm to ecosystems.

The establishment of international agreements like the Montreal Protocol aimed to phase out the production and use of such ozone-depleting substances due to their harmful effects on the environment. Thus, the ozone depletion potential of CFCs is a crucial aspect of environmental science and refrigerant management, highlighting why their use was deemed unsustainable and led to the adoption of more environmentally friendly alternatives.