[en] The thermally stimulated current (TSC) technique is utilized to study the degradation of a commercial poly (vinyl chloride) (PVC) formulation. Dose-rate and irradiation-environment effects previously observed in mechanical and chemical tests can be seen using this technique. The type of information obtained from TSC measurements is discussed, and the data are interpreted in terms of degradation mechanisms occurring in PVC. This study illustrates the limitations of applying TSC and other relaxation spectroscopy techniques to commercial dielectric formations where relaxation peaks are often broadened and resolution is limited