International Day for the Preservation of the Ozone Layer of the hole in the ozone layer was observed 30 years after the protocol was signed. Due to the nature of the gases responsible for ozone depletion their chemical effects are expected to continue for between 50 to 100 years. International Day for the Preservation of the Ozone Layer September 16 was designated by the United Nations General Assembly as the International Day for the Preservation of the Ozone Layer. This designation had been made on December 19, 2000, in commemoration of the date, in 1987, on which nations signed the Montreal Protocol on Substances that Deplete the Ozone Layer.
Montreal Protocol Mexico following with a similar proposal in 2010. After seven years of negotiations, in October 2016 at the 28th Meeting of the Parties to the Montreal Protocol in Kigali, the Parties to the Montreal Protocol adopted the Kigali Amendment whereby the Parties agreed to phasedown HFCs under the Montreal Protocol. The amendment to the legally-binding Montreal Protocol will ensure that industrialised countries bring down their HFC production and consumption by at least 85 per cent compared to their annual average values in the period 2011-2013. A group of developing countries including China, Brazil and South Africa are mandated to reduce