Because oxidation is a process that causes materials to deteriorate over time, its effects or potential for those effects are not always apparent when new products are tested.
Material behavior is fundamentally determined by the equivalence of time and temperature. But that principle tends to be lost on processors and designers. Here’s some guidance.
The industry can choose between continuing to perform DTUL tests that provide single points that are part of a curve never seen, or perform the test that provides the entire curve.