A chemical reaction has been discovered that mineralizes chlorofluorocarbons (CFCs) and enables the complete destruction of these environmentally hazardous species. The reaction products are easily handled solids, including recyclable alkali metal halides. Under milder conditions, the same reaction causes partial defluorination of cyclic perfluoroalkanes to yield perfluoroarenes, which are valuable chemical intermediates. The vaporized substrates are passed over a packed bed of heated sodium oxalate; heating at 270 degrees to 290 degrees C causes mineralization, whereas healing at 230 degrees C causes aromatization.