Montreal Protocol Enacted

Date: January 1, 1989 • Location: London, United Kingdom

The Montreal Protocol comes into force, stopping the use of chemicals contributing to ozone depletion.

The Montreal Protocol, officially the Montreal Protocol on Substances That Deplete the Ozone Layer, is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It was agreed on 16 September 1987, and was entered into force on 1 January 1989. Since then, it has undergone several amendments and adjustments, with revisions agreed to in 1990 (London), 1992 (Copenhagen), 1995 (Vienna), 1997 (Montreal), 1999 (Beijing), 2007 (Montreal), 2016 (Kigali) and 2018 (Quito).