2-Amno-6-Chloro-4-Nitrophenol

Conclusion

In a 1997 safety assessment of 2-amino-6-chloro-4-nitrophenol, the Cosmetic Ingredient Review (CIR) Expert Panel (Panel) stated that 2-amino-6-chloro-4-nitrophenol and its hydrochloride salt are safe for use in hair dye formulations at concentrations up to 2.0%. ¹ The Panel reviewed newly available studies since that assessment, ^{2 –11} along with updated information regarding types and concentrations of use and did not reopen this safety assessment. The Panel confirmed that 2-amino-6-chloro-4-nitrophenol and its hydrochloride salt are safe for use in hair dye formulations at concentrations up to 2.0%.

Discussion

A new margin of safety calculation, published in the opinion on 2-amino-6-chloro-4-nitrophenol released by the European Commission’s Scientific Committee on Consumer Products (SCCP) in 2006, ² concluded that a maximum use concentration of 2% in the finished product does not pose a risk to the health of the consumer, although the SCCP did note that this ingredient is a known sensitizer. According to the European Commission Health and Consumers Cosmetics CosIng database, 2-amino-6-chloro-4-nitrophenol has a maximum authorized concentration of 2.0% in nonoxidative hair dye products. In oxidative hair dye products, the maximum concentration applied to hair after mixing under oxidative conditions must not exceed 2.0%. ³ Appropriate labeling must be used.

Information supplied to the US Food and Drug Administration (FDA) by industry as part of the Voluntary Cosmetic Registration Program (VCRP) ⁵ indicates that 2-amino-6-chloro-4-nitrophenol was not reported to be used and 2-amino-6-chloro-4-nitrophenol hydrochloride was used in a total of 15 hair-coloring products in 1997. ¹ The VCRP data provided by FDA in 2012 indicated 2-amino-6-chloro-4-nitrophenol was being used in 62 hair dyes and colors requiring caution statements, although no uses were reported for the hydrochloride salt. The results of a 2012 industry survey ⁷ indicated that 2-amino-6-chloro-4-nitrophenol was being used in hair dyes and colors (all types requiring caution statements and patch tests) at a maximum concentration of 1.5%, and 0.4% in coloring hair rinses. These concentrations are lower than the maximum concentration allowed in the original CIR safety assessment ¹ and that allowed by the European Commission.

The Panel recognized that carcinogenicity data were not available. However, 2-amino-6-chloro-4-nitrophenol is not significantly absorbed through the skin and it is not genotoxic. ²

The CIR Expert Panel noted that hair dyes containing coal tar derivatives are exempt from certain adulteration and color additive provisions of the US Federal Food, Drug, and Cosmetic Act when the label bears a caution statement and patch test instructions for determining whether the product causes skin irritation. Although there has been recent concern expressed in Europe regarding the potential induction of sensitization that may result from the currently recommended self-test procedure for hair dyes, ^{9 –11} the Panel agreed that there was not a sufficient basis for changing the advice to consumers at this time.

The Panel concluded that the available epidemiology studies are insufficient to conclude there is a causal relationship between hair dye use and cancer or other toxicologic end points, based on lack of strength of the associations and inconsistency of findings. Use of direct hair dyes, while not the focus in all investigations, appears to have little evidence of any association with adverse events as reported in epidemiology studies. A detailed summary of the available hair dye epidemiology data is available at http://www.cir-safety.org/cir-findings.