A TOXICOLOGICAL REVIEW OF TOPICAL EXPOSURE TO WHITE MINERAL-OILS

White mineral oils have a long history of safe use by humans in orally ingested and topically applied products. A re-evaluation of the use o f certain mineral hydrocarbons in the preparation of food items by reg ulators in the UK, however, has prompted additional safety studies and a critical assessment of the toxicological effects of white mineral o ils. As white mineral oils are present in many topically applied drug and non-drug products, it is of interest to review the toxicological e ffects of mineral oil produced by this route of exposure. Specifically , the concern regarding the safety of white mineral oils has arisen, i n part, from results of subchronic (e.g. 90 day) feeding studies that reported the presence of granulomas in liver and histiocytosis in mese nteric lymph nodes of Fischer 344 rats after oral ingestion of select white mineral oils. In contrast to these subchronic oral studies, repe ated topical exposure to white mineral oils has not been found to prod uce liver granulomas, histiocytosis in the mesenteric or other lymph n odes, or any local or systemic toxicity including tumour formation in Fischer 344 rats, C3H mice, New Zealand White rabbits or beagle dogs a t similar or higher exposures (mg/kg/day). On the basis of these findi ngs and reports of negligible epidermal penetration of topically appli ed white mineral oils, there is no evidence of any hazard identified f or topical exposure to white mineral oils at any dose in multiple spec ies. This conclusion is supported by the long and uneventful human use of white mineral oils in drug and non-drug topically applied products .