The photocatalyzed oxidative decompositions of solid particles of polyvinylchloride (PVC; size about 100 to 200 mu m), of the polyvinylidene chloride copolymer (95% PVC/5% PVLC; size similar to 400-600 mu m), and a PVC film have been examined in suspensions of titania and zinc oxide illuminated by UV light and/or by natural sunlight. Dechlorination and evolution of carbon dioxide were monitored, the latter occurring by the intermediacy of acetic and formic acids. The photodegradation of polymer specimens was enhanced in TiO2/water media by such added oxidants as hydrogen peroxide and potassium persulfate. Photocorrosion of these particulates was also examined by scanning electron microscopy.