The gas primarily responsible for the depletion of the ozone layer is chlorofluorocarbons (CFCs). Chlorofluorocarbons (CFCs) are synthetic compounds that are widely used in aerosol propellants and refrigerants. They were found to be the main contributors to the ozone layer.
When released into the atmosphere, CFCs can reach the stratosphere, where they are degraded by ultraviolet (UV) radiation, releasing chlorine atoms. These chlorine atoms are extremely reactive and can catalytically destroy ozone molecules (O3) via a series of chemical processes, resulting in ozone depletion.