ABSTRACT
Hair dyes have been in use for decades, yet even recent studies of their skin penetration potential have been restricted primarily to their evaluation in rats and dogs (1-6). Although undoubtedly useful, the results of these experiments are difficult to extrapolate to man and to relate to the percutaneous absorption that occurs under conditions of practical usage of fully formulated products. Sporadic attempts have been made to single out individual ingredients for studies in man (7,8), but these could not be readily quantitated.
