Chlorofluorocarbons (CFCs):

Chlorofluorocarbons (CFCs) are the primary cause for the ozone layer depletion. Industrial products including solvents, soaps, spray aerosols, insulating foams, ‘take-away’ containers and cooling utilities such as refrigerators and air conditioners use chlorofluorocarbons (CFCs). Over time, these substances accumulate in the atmosphere are carried by wind action into the stratosphere.

Once the chlorofluorocarbons (CFCs) are in the stratosphere, their molecules are broken up by the ultraviolet radiation from the sun which releases Chlorine atoms. The Chlorine atoms react with the Ozone, setting out a chemical cycle that destroys the good ozone. The U.S. Environmental Protection Agency (EPA) estimates that once Chlorine atom can break up more than 100,000 ozone molecules.

Natural causes of depletion of ozone layer:

Ozone layer has been found to be affected by certain natural phenomena such as Sun-spots and stratospheric winds. But this has been found to cause not more than 1-2% depletion of the ozone layer and the effects are also thought to be only temporary. It is also believed that the major volcanic eruptions have also contributed towards ozone depletion.

The ODS:

There are also other chemical substances that are generally grouped as Ozone Depleting Substances (ODS). Examples are methyl bromide use in pesticides, methyl chloroform used on making industrial solvents, and halos used in fire extinguishers. Just like the chlorofluorocarbons (CFCs), these substances also chemically react with the ozone which starts a chemical cycle that break up the good ozone.

Other chemicals:

Other chemicals that naturally present similar reactions with the good ozone include Clx, Hox and Noy which belong to the Chlorine, Hydrogen and Nitrogen families respectively.