Any substance that brings about a reduction in the ozone layer gas in our atmosphere. Generally CFC (chlorofluorocarbons), halon (used in spray cans), certain solvent materials as well as refrigerating material and chlorofluoromethane are common examples. Even thoug most of these are inert, they begin to decompose as they reach up higher in the atmosphere due to the usnlight. This causes damage to the ozone layer, damaging it in the process.
