The dehydrochlorination behavior of plasticizer (DOP) and inorganic filler (CaCO(3)) contained in PVC samples and the properties of the activated carbons produced from those carbon residues have been investigated. In the dehydrochlorination process, both additives contributed not only to a decrease in HCl yield but also to the prolonged evolution of HCl. Part of the Cl species were observed to be stabilized as CaCl(2) by reaction with calcium ions when CaCO(3) was added. More than 80% of chlorine removal was achieved in all samples at 533 K. The use of potassium as an activation agent led to the production of activated carbon with a specific surface area greater than 1000 m(2)/g at the low temperature of 1023 K and assisted also in the elimination of residual Cl species by the formation of KCl during activation.