The long-term thermal stability of postused CaCO3-filled Polypropylene was evaluated through accelerated heat aging tests for about 2000 h. The material from old garden chairs was recycled by applying the remelting-restabilization technique while using different stabilization systems in selected concentrations. To study the effect of heat aging on the material properties, crystallinity content, tensile strength, and tensile impact strength together with time to embrittlement were monitored. The results illustrate that the restabilization recipe is of crucial importance for improving the long-term thermal stability of the postused chair material, ensuring its reuse in the original application. Best long-term performance is achieved by combining a filler deactivator with appropriate heat and light stabilizer systems. (C) 2003 Wiley Periodicals, Inc.