Public statement: The International Ozone Commission, on the 38th anniversary of the Montreal Protocol, underscores the success of the protocol, and stresses the value of continued observations, modeling, and research.
The 38th International Day for the Preservation of the Ozone Layer, September 16, 2025, marks the anniversary of the signing of the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. This protocol, a treaty signed by every country in the world and hailed as among the most successful international agreements to date, controls the production and use of ozone depleting substances (ODSs) such as chlorofluorocarbons (CFCs) and the other substances used as initial CFC replacements.