Montreal protocol aims at

In August 1989,44 countries and EEC ratified the Montreal Protocol, which provides a mechanism to review the efficiency of control measures. In a policy statement called Helsinki Declaration, the attending nations agreed to phase out the production and consumption of controlled CFCs as soon as possible but not later than the year 2007. They also agreed to phase out the halons and to control and reduce other Ozone Depleting Substances (ODSS).