What is the main environmental concern associated with CFCs?

The main environmental concern associated with CFCs (chlorofluorocarbons) is ozone depletion. CFCs are a type of halocarbon that were commonly used in refrigeration, air conditioning, aerosol propellants, and as solvents. When released into the atmosphere, CFCs can rise up to the stratosphere, where they are broken down by ultraviolet (UV) radiation, releasing chlorine atoms. These chlorine atoms can react with ozone (O3) molecules, leading to the breakdown of ozone into oxygen molecules (O2). The depletion of the ozone layer is significant because the ozone layer plays a crucial role in protecting life on Earth by absorbing the majority of the sun's harmful UV radiation.

This degradation of the ozone layer can lead to increased UV exposure, which is linked to higher rates of skin cancer, cataracts, and damage to ecosystems. The recognition of this issue led to international agreements like the Montreal Protocol, aimed at phasing out the production and use of CFCs and other ozone-depleting substances.