The Earth's ozone layer is on track to heal, thanks to the work of dozens of countries that signed a landmark international environmental agreement initiated 20 years ago.

Known as the "Montreal Protocol," this ambitious treaty requires countries to phase out production and use of compounds that deplete ozone in the stratosphere. Initially signed by 24 countries Sept.16, 1987 in Montreal, this treaty today covers 191 countries and is widely hailed as the most successful international environmental agreement to date.

"Twenty years ago, the community of nations came together to adopt a global strategy for the global challenge of ozone depletion. Today, we at EPA join our international partners in celebrating the anniversary of the Montreal Protocol – a shining example of how human ingenuity, leadership and determination can create a healthier, better world," said EPA Administrator Stephen L. Johnson.

Each of the countries that signed the Protocol has measurable goals and actions for achieving success. These include phasing out production and use of ozone-depleting substances such as chlorofluorocarbons, halons, carbon tetrachloride, and methyl chloroform. Scientific evidence demonstrates that these compounds significantly deplete the stratospheric ozone layer, which shields the planet from damaging ultraviolet radiation.

The United States has implemented key parts of the Montreal Protocol more rapidly and at significantly less cost than originally anticipated. With the help of many partners, EPA has also approved more than 300 alternatives to ozone-depleting substances for industrial, commercial, and consumer uses. Many of these new technologies also save energy and reduce emissions of greenhouse gases.

As a result of U.S. efforts combined with those worldwide to phase out ozone depleting substances, the ozone layer has not grown thinner since 1998 over most of the world. Antarctic ozone is projected to return to pre-1980 levels around 2060 to 2075. EPA estimates that between 1990 and 2165, an estimated 6.3 million U.S. lives will be saved as a result of these international actions to protect and restore the ozone layer.

Sept. 16, 2007, is International Ozone Day and marks the 20th Anniversary of the signing of the Montreal Protocol. The United States and various partner countries around the world are meeting in Montreal to discuss the importance of continuing the progress made to protect the ozone layer, and to celebrate the important achievements of the past 20 years and the people and programs that work to protect the Earth's ozone layer.

More information about the 20th Anniversary of the Montreal Protocol: http://www.epa.gov/ozone/intpol/index.html