What are the principle of ozone thinning/depletion?

The hole in the ozone layer is caused by a group of chemicals called chloroflourocarbons (CFC'S) CFC's are used in aerosol and air conditioning. Anyway these chemicals react with ozone, breaking it down. If enough ozone breaks down you will get holes in the ozone layer. the ozone layer, however naturally repairs itself, but this process takes time. If all CFC's are removed from production and disposed of properly, natural reactions in the earth's atmosphere will repair the ozone layer, though I'm not sure how long it will take.