In the last decade the importance of the isoconversional methods on the thermal characterisation of different samples has grown, due to their possibility of predicting the materials behaviour and lifetime. The present work tried to determine the correlation between the as determined laboratory prediction and the PVC practical behaviour on industrial pilots. In order to achieve this goal, PVC samples containing with different inorganic stabilisers were subjected to the thermal degradation during some nonisothermal experiments and dynamic heat tests. We have used two isoconversional methods, i.e. that proposed by Flynn-Wall-Ozawa and the one of Sergey Vyazovkin. In order to estimate the lifetime prediction, both methods use kinetic parameters of the thermal decomposition, such as: activation energy (Ea), reaction order (n) and the preexponential factor obtained at least three different heating rates (5, 10 and 15 ºC/min). The lifetime prediction (tf) concerns the time at when the mass loss reaches 1% weight at the industrial processing temperature of PVC (180 ºC – see for example the figure below) and at the exploitation temperature of the final PVC products (25 ºC).figureThe study has proved that the proposed isoconversional methods give good prediction results from the practical point of view.