Thermal stability of ethylene-propylene terpolymer (EPDM) loaded with various metallic oxides (PbO, CuO, NiO, Fe2O3, Cr2O3, TiO2, ZrO2) was assessed by the oxygen uptake method. The effects of 5 phr oxide of thermal aging of elastomer were investigated under isothermal (180 degreesC) and isobaric (air at normal pressure) conditions. The influence of this was pointed out. Some mechanistic considerations on the oxidative degradation of EPDM are presented.