HC Yellow No. 5 is a direct hair dye. Hair dyes containing HC Yellow No. 5, as “coal tar” hair dye products, are exempt from the principal adulteration provision and from the color additive provision of the Federal Food, Drug, and Cosmetic Act of 1938 when the label bears a caution statement and “patch test” instructions for determining whether the product causes skin irritation. Preliminary testing on or by individuals should be done using an open patch test that is evaluated at 48 h after application of the test material. Users, therefore, would be able to determine their individual reactions to hair dye products containing HC Yellow No. 5. Absorption of HC Yellow No. 5 is minimal through skin ( < 0.2%). The oral LD50 for rats is 555.56 mg/kg. No significant toxic effects were observed after chronic oral exposure of HD Yellow No. 5 to dogs. Mild dermal irritation, but no dermal sensitization or ocular irritation was observed in laboratory animals. Results of fertility and reproductive performance, teratology, and developmental studies were negative. HC Yellow No. 5 was found to be nonmutagenic and noncytotoxic in standard laboratory assays. A current review of the hair dye epidemiology literature identified that use of direct hair dyes, although not the focus in all investigations, appears to have little evidence of an association with cancer or other adverse events. Based on the available safety test data on HC Yellow No. 5, the Panel determined that this ingredient likely would not have carcinogenic potential as used in hair dyes. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that HC Yellow No. 5 is safe as a hair dye ingredient in the practices of use and concentration as described in this safety assessment.
Common Challenges in Safety: A Review and Analysis of AAALAC Findings