Which of the following refrigerants is considered an ozone-depleting substance?

Chlorofluorocarbons (CFCs) are classified as ozone-depleting substances because they release chlorine atoms when they are broken down in the stratosphere. This process occurs when CFCs are exposed to ultraviolet (UV) radiation, which leads to the destruction of ozone molecules. The ozone layer is vital for protecting life on Earth from harmful UV radiation.

CFCs were commonly used in refrigeration, air conditioning, and aerosol propellants, contributing significantly to ozone depletion, particularly in the 1980s. The recognition of their environmental impact led to international efforts to phase them out, notably through the Montreal Protocol.

In contrast, hydrofluorocarbons (HFCs) are not considered ozone-depleting substances as they do not contain chlorine or bromine and do not have the same destructive effect on the ozone layer. Natural refrigerants, such as ammonia and carbon dioxide, are also not associated with ozone depletion and are often viewed as more environmentally friendly alternatives. Perfluorocarbons (PFCs), while having a minimal impact on ozone, are of concern for their high global warming potential but not for ozone depletion. Therefore, the correct identification of CFCs as ozone-deple