The method of treating halogen-containing plastic refuse which comprises charging same to a bath for immersion therein, the bath being constituted of an inorganic carbonate, such as from the class consisting of alkali and alkaline earth metals; such bath being in a highly particulate condition. The bath is heated to, and maintained at, the appropriate temperature for effecting thermal decomposition of the plastic but below calcination temperature. Such method includes preventing discharge to the atmosphere of the halogenic material released.