Technological and industrial history of 20th-century Canada the Keele Valley Landfill was operated by the City of Toronto from 1983 until 2002, when it was closed because it was full. Chlorofluorocarbons (CFCs), the gas propellants used in aerosol spray cans, became a target for environmental concern in the 1970s and 1980s when research demonstrated that they had a harmful effect on the ozone layer in the atmosphere. The international Montreal Protocol of 1989 banned the use of these substances and they were subsequently replaced with volatile hydrocarbons. The problem with choice to reuse is still not available. There are many products that don't need to be recycled
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