The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer International agreement to limit CFC production ; stratospheric ozone.It culminated in 1987 with the U.N. Montreal Protocol, a landmark agreement banning CFCs and other ozonedepleting substances. Delegates from rich and poor nations approved an agreement today intended to protect the earth's fragile ozone shield. India to phase out CFC production on that country.