Montreal Protocol (1973) and the international agreement signed (1985 & 1987). The treaty is structured around several groups of halogenated hydrocarbons that deplete stratospheric ozone. All of the ozone depleting substances controlled by the Montreal Protocol contain either chlorine or bromine (substances containing only fluorine do not harm the ozone layer). Some ozone-depleting substances (ODSs) are not yet controlled by the Montreal Protocol, including nitrous oxide (N2O) For a table of ozone-depleting substances controlled by the Montreal Protocol see: For each group of ODSs, the treaty provides a timetable on which the production of those substances must be shot out and eventually
Montreal Protocol including most of the major CFC producers, signed the Vienna Convention, which established a framework for negotiating international regulations on ozone-depleting substances. After the discovery of the ozone hole by SAGE 2 it only took 18 months to reach a binding agreement in Montreal, Canada. But the CFC industry did not give up that easily. As late as 1986, the Alliance for Responsible CFC Policy (an association representing the CFC industry founded by DuPont) was still arguing that the science was too uncertain to justify any action. In 1987, DuPont testified before the US Congress that "We believe there is