Which substance has ozone depletion potential (ODP)?

The correct choice highlights a substance with ozone depletion potential (ODP), specifically CFC-based refrigerants used in HVAC systems. CFCs, or chlorofluorocarbons, are chemical compounds that have been widely used as refrigerants and aerosol propellants. When released into the atmosphere, they can break down ozone molecules in the stratosphere, leading to the depletion of the ozone layer, which protects the Earth from harmful ultraviolet radiation.

CFCs possess chlorine atoms, which are particularly damaging to ozone. Each chlorine atom can destroy thousands of ozone molecules before it is removed from the stratosphere. The significance of ODP lies in its quantification of the potential for a substance to contribute to ozone layer depletion compared to a reference substance, typically trichlorofluoromethane (CFC-11), which has an ODP of 1. This characteristic has led to global regulations, such as the Montreal Protocol, aimed at phasing out substances that deplete the ozone layer, including CFCs.

Other listed substances, such as HFCs (hydrofluorocarbons), ammonia, and propane, do not have ozone depletion potential. HFCs, while potent greenhouse gases, were developed