Ozone layer exists at an altitude of 25-30 km (in the stratosphere). It absorbs the harmful UV radiation coming from the sun and hence protects life on the earth. So, it is important to maintain the ozone shield.
Formation of O3
Depletion of Ozone layer (Creation of ozone hole) is taking place due to reaction with NO (produced from natural sources or human activity or in the exhaust gases of engines of supersonic planes) or by reaction with chlorofluorocarbons (CFCs), called freons (produced from aerosol sprays used in propellants or from refrigerators where they are used as coolants).
