Contrary to the thermal stability, which refers to an inert atmosphere, oxidative stability deals with the stability of materials under oxidative conditions, i.e., under air or oxygen. According to USP <891>, interactions between a sample and its surrounding atmosphere is a strength of TGA investigations.
However, DSC can also be used to study oxidation, sometimes under increased pressure in a high-pressure DSC (35 bar).
DSC oxidation tests on oils or greases (under atmospheric pressure as well as under increased pressure) are typically carried out in so-called SFI crucibles (SFI stands for solid-fat-index). Due to their special bottom shape, these Al crucibles keep the liquid sample on its original position in the middle of the crucible bottom.