The OIT test characterizes the thermo-oxidative stability of polyolefins, particularly polyethylene.

The Oxidation Induction Times Test (OIT), as carried out in a differential scanning calorimeter (DSC), is used to predict thermo-oxidative performance of a material.

Samples are heated up under a nitrogen atmosphere, typically to 200C. Oxygen is then introduced to the sample cell, and the length of time before the onset of degradation - as seen by the initiation of an exothermic process in the DSC trace - is measured.  

OIT is a sensitive measure of the level of anti-oxidative additives within the polymer.