AbstractTwo concepts in the chemiluminescence research‐the heterogeneous model and the kinetic approach‐are discussed. The analysis of published data obtained by a highly sensitive photon‐counting system reveals the contradictory nature of the heterogeneous model and proves its inconsistency. On the other hand, the kinetic approach has been successfully applied to evaluation of thermal oxidation in a variety of systems, ABS compositions in particular. Emulsion grade ABS were found to be essentially less stable than ionic mass polymerization products. Among the antioxidants studied, Santonox R is clearly more efficient than Irganox 1076. In emulsion grades the superiority of Santonox R to Irganox 1076 is reflected primarily in larger induction period, while in ionic resin it is mostly due to smaller oxidation rate constant values. The introduction of UV stabilizers by themselves has no influence on durability in either ionic or emulsion resins. Similarly to systems without UV stabilizers, Santonox R is more efficient than Irganox 1076 in mixtures with UV stabilizers as well. The comparative study of various ABS‐coloring agent compositions by chemiluminescence and DSC reveals much greater sensitivity of the former. While DSC lets one make only a trivial conclusion that the introduction of an antioxidant improves stability, chemiluminescence shows the differences in durability as large as 3 to 4 times for the samples DSC fails to distinguish. In addition, chemiluminescence furnishes a significant insight on the factors affecting stability. The DSC thermal oxidative stability data can be related to resistance to oxidation during processing, whereas the chemiluminescence results are expected to be useful in predicting materials' lifetime at service tempe