The results are reported in SI, Figure to Figure It has been reported in the literature that autoxidation phenomena in TPO induce chain scissions which ultimately strongly degrade the mechanical properties of the polymers . Nevertheless, in our present study, the variations in mechanical properties over time are not representative. Furthermore, there is no significant difference between formulations with and without additives under the conditions of the norm EN 14575:2005. These standardized conditions do not therefore appear to be sufficiently discriminating for these systems.