The depletion in the ozone layer is caused by Chlorofluorocarbons (CFCs).

Explanation:
Chlorofluorocarbons (CFCs) cause ozone depletion by releasing chlorine atoms when they are exposed to ultraviolet (UV) radiation in the stratosphere.

The chlorine atoms then react with ozone (O₃) molecules and break them apart, forming oxygen (O₂) molecules and a chlorine oxide molecule (ClO).

The chlorine oxide molecule can then react with a free oxygen atom (O) to form another molecule of oxygen (O₂) and regenerate the chlorine atom, which can then repeat the cycle of ozone destruction. This process is known as the “ozone-depleting cycle.”

One of the reasons that CFCs are particularly effective at causing ozone depletion is that they are very stable and can remain in the atmosphere for many years without breaking down. This means that the chlorine atoms they release can continue to react with ozone for a long time, causing significant damage to the ozone layer.