Evaluation of Analytical Endpoints to Predict Carcinogenic Potency of Mineral Oils

Abstract

We have compared three sample preparation and analysis methods currently used for estimating the biological activity of mineral oils. The Institute of Petroleum Method 346/80, the Mobil Oil PAC Method and the Multiple PAC Marker approach were evaluated using a number of mineral oils previously assayed by a modification of the Ames Salmonella mutagenesis assay and the two-year mouse skin-painting bioassay. Both the Mobil PAC and IP-346 methods correlated well with the dermal carcinogenic potency of the oils. No substantive difference was observed between the two methods in their ability to provide a measure of the biological activity of oil, sufficient to predict tumorigenic potency. On the other hand, no significant relationship was observed between the levels of individual or summed 10 unsubstituted PAC (Multiple Marker approach) and the biological activity of the oils. The lack of correlation is attributed to the fact that the unsubstituted PAC are not sufficiently representative of the predominantly alkylated PAC that compose the aromatic fraction of mineral oils.

Key Words:

• PAC
• Carcinogenicity
• Mutagenicity
• Mineral Oils
• Extraction