Chlorine, for example, gives two chlorine radicals (Cl-) by irradiation with ultraviolet light.

This results in the desired product plus another chlorine radical.

This hydroxyl radical is then able to interact with non-soluble compounds like chlorofluorocarbons, and UV light breaks off chlorine radicals (Cl ).

A notable example is the catalytic role of chlorine free radicals in the breakdown of ozone.

Chlorine gas can be broken down by ultraviolet light to form atomic chlorine radicals.

In the stratosphere, CFCs break up due to UV-radiation, releasing their chlorine free radicals.

This vortex has a very cold core, and anything that gets dumped into its interior, such as atmospheric chlorine radicals, (i.e., ClO) stays there for a long time.

In a sharp contrast to true fluorocarbons, the chlorine atom produces a chlorine radical which degrades ozone.

Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical.

Each chlorine radical remains active as a catalyst unless it binds with another chlorine radical, forming a stable molecule and breaking the chain reaction.