The thermal and catalytic degradation of mixed plastics containing poly(vinyl chloride) (PVC) was carried out at 360-430 degrees C under atmospheric pressure by semibatch operation. The boiling-point distributions of organic chlorine compounds in the oil obtained from the degradation of mixed plastics PE/PVC, PP/PVC, and PS/PVC were determined by gas chromatography. Organic chlorine compounds were distributed in a range of boiling points 36-174 degrees C, equivalent to the boiling points of normal paraffins n-C-6-n-C-10. It is suggested that the organic chlorine compounds were produced by the reaction of HCl deriving from PVC to the products obtained from the degradation of PE, PP, and PS. Solid acid catalyst (silica-alumina) was effective for the degradation of PVC mixed plastic. Iron oxides were efficient chlorine sorbents for the dechlorination of degradation products.