Which old household appliances are the most dangerous for the environment?

During the early 1970s, two American chemists - M. Molina and S. Rowland - identified the theoretical threat of ozone depletion by the release of chlorofluorocarbons (used as a refrigerator coolant). Initially, the reaction was sceptical, but when in 1983 scientists discovered ozone hole, the abstract threat suddenly became real.