The destruction of ozone layer is caused by one factor only which is Cholorofluorocarbons.
The main cause of the ozone hole was found to be gases that contained Cholorofluorocarbons (CFCs), Halons and Freons. Found commonly in aerosol cans and released by many electronic appliances, these were seen to decrease the level of ozone in the stratosphere. All of these gases contain chlorine, which is a major cause behind the thinning of the ozone layer.
The presence of chlorine within CFC’s break down the ozone gases in ozone layer which increases the chances of ozone depletion. Till date, CFC’s have accounted for about 80% of ozone depletion