An evaluation of the epidermal carcinogenic potential of cutting fluids.

Epidermal cancer in humans has been associated with industrial exposure to products derived from unrefined petroleum distillates. Because of this association many of these products, including cutting fluids, are now normally produced from highly refined lubricant base oils. Since highly refined oils are not dermally carcinogenic, one would predict that formulated products prepared from these oils would similarly be non-tumorigenic. However, there are experimental data that suggest that fresh cutting fluids might be dermally carcinogenic and that industrial usage might increase the carcinogenic hazard. The current studies evaluated solvent-extracted lubricant base oils and several products, including fresh and used cutting fluids and certain related industrial oils. These materials were all tested for tumorigenic potential in mouse epidermal carcinogenesis bioassays. None of the solvent-extracted lubricant base oils were dermal carcinogens. Similarly, the cutting fluids and industrial oils formulated from these base oils were not dermally carcinogenic. Finally, there was no evidence that industrial usage influenced the carcinogenic potential of these oils. It was concluded that solvent-extracted oils and the products derived from these oils pose minimal skin cancer hazards when used under appropriate conditions in industrial settings.