Should Coal Tar Products Carry Cancer Warnings?

This article addresses the controversy whether over-the-counter products that contain coal tar concentrations greater than 0.5% must carry cancer warnings. Evidence that topical coal tar is carcinogenic in laboratory animals and humans is reviewed. In addition, the potential risk of internal malignancies arising from the topical use of coal tar is discussed. The view is expressed that the California court decision that such products should carry cancer warnings is correct.