State how CFCs break ozone in the stratosphere.

The breakdown of ozone by CFCs in the stratosphere is brought about in the following way:

1. Chlorofluorocarbons are broken down by ultraviolet radiations in the stratosphere.
2. By products of the breakdown of CFCs results in increase in levels of free radicals of atomic chlorine [Cl].
3. The free radicals initiate and catalyse a chain reaction by reacting with ozone to form chlorine monoxide (ClO) and oxygen (O₂). These reactions are capable of breakdown of over 1,00,000 ozone molecules resulting in ozone depletion.