The literature for this review was searched by CAS-On-Line procedures so as to provide the most up-to-date references for this somewhat focussed review. The decision as to include a reference or not was somewhat arbitrary, however, it was based on whether or not the article addressed itself to the antioxidant activity in hydrocarbon oils. For instance, articles on jet fuel antioxidants were generally not included. Nomenclature may appear inconsistent e.g. the use of episulfidevsthiirane. Insofar as possible names were used as they appeared in the original articles so that references made to that article would hopefully be less confusing to the reader.