The use of dimethyl sulphoxide (DMSO) extract by the IP 346 method as an indicator of the carcinogenicity of lubricant base oils and distillate aromatic extracts

Report no. 94/51: Untreated lubricant base oils have been associated in the past with the development of human skin cancer to give a better understanding of these health effects, industry has conducted an extensive range of long-term dermal carcinogenicity studies with the objective of identifying the influence of different types of refinery processing and to establish the important base oil compositional factors.

The studies have led to improved refining techniques and to the development of simple markers for control purposes based on a standard analytical test.However, with the increasing emphasis on the regulatory classification and labelling of petroleum products, it is proposed that the same markers can be effectively used for the classificatiorl of base oils.

The report describes the development of markers for the prediction of base oil carcinogenicity and examines the relative merits of two particular candidates,one based on dimethyl sulphoxide extraction by method IP 346 and the other based on benzo(a)pyrene (Bap) concentration.