The European Commission's The Scientific Committee on Consumer Products (SCCP) has deemed five hair-dye ingredients safe at recommended concentrations and labeled one with insufficient data.
HC Blue No. 12 reportedly has insufficient data to support its use, according to the SCCP. The dye, previously called Nitroblau, is used as a non-reactive, hair-coloring agent in semi-permanent hair-dye formulations and in oxidative hair-dye formulations at maximum concentrations of 1.5% and 0.75% respectively. The committee found that the dye's mutagenicity/genotoxicity is uncertain. Tests reportedly have shown the dye to induce gene mutations in bacteria and mammalian cells.
Adversely, 5-amino-4-chloro-o-cresol hydrochloride, HC Orange No. 2, Acid Red 33, 4-hydroxypropylamino-3-nitrophenol and 2-chloro-6-ethylamino-4-nitrophenol are said to pose no risk to consumer health at recommended use levels.
Finally, the committee maintained that it did not support the consumer patch test, stating that testing hair-dye sensitivity should be performed by professionals and not by consumers.