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Montreal protocol  is an international treaty that has been put in place to protect the Ozone layer by reducing the production of those substances that cause ozone depletion. According to this protocol, the level of production of CFC's should not exceed 150% of the calculated level of production in 1986.
Montreal Protocol is an international treaty that was signed at Montreal (Canada) in 1987 to control the emission of ozone depleting substances. It came into effect in the year 1989. It was designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for its depletion. According to the treaty the use, production and emission of Chloroflorocarbons(CFCs) was decreased . The CFCs were replaced by Hydroflorocarbons( HFCs) which proved to be less harmful to the ozone and atmosphere.