HC Yellow No. 2

What Is It?

HC Yellow No. 2 refers to the direct Hair Colorant Yellow No. 2. HC Yellow No. 2 is used in the formulation of permanent or semi-permanent hair dyes, colors and rinses.

Why Is It Used?

HC Yellow No. 2 helps to impart a color to hair. The exact color obtained will depend on the other ingredients that are used in the preparation and the starting color of the hair.

Scientific Facts

HC Yellow No. 2 is used in semi-permanent hair coloring systems that are usually applied in a shampoo base and contain thickeners, alkalizers, and foam stabilizers.

Safety Information

The safety of HC Yellow No. 2 has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that HC Yellow No. 2 was safe for use in hair dyes at concentrations up to 3%.

The limitation on the concentration was based upon the available clinical sensitization data. In 2011, as part of the scheduled re-evaluation of ingredients, the CIR Expert Panel considered available new data on HC Yellow No. 2 and reaffirmed the above conclusion.

CIR Safety Review:

The CIR Expert Panel reviewed data on subchronic and chronic feeding studies with 1.25% HC Yellow No. 2 in which reduced body weight gain was observed and changes in various organ sizes and clinical chemistry values were induced. The only histologic change attributed to this hair dye ingredient was a small increase in pigment in the spleen.

The compound was only a minor ocular irritant when tested at a concentration of 10%. It was neither a sensitizer nor photosensitizing agent at 10%. It was not a developmental toxicant. HC Yellow No. 2 was negative in a dominant lethal assay and it was not mutagenic in the four bacteria strains tested, both with or without metabolic activation. In a repeat insult patch test (RIPT) using 3% HC Yellow No. 2, two volunteers of 98 had a positive reaction to the test substance. In another RIPT study, 1 of 104 volunteers had a sensitization reaction to 3% HC Yellow No. 2. It was concluded that HC Yellow No. 2 was safe for use in hair dyes at concentrations up to 3%.

More information about the safety of hair dyes

In Europe, HC Yellow No. 2 may be used in non-oxidative hair dyes at a maximum concentration of 1% and in oxidative hair dyes at a maximum concentration of 0.75%. Please see Annex III for additional information concerning the use of HC Yellow No. 2 in hair dye products in Europe.

Link to the EU Cosmetic Regulation: http://europa.eu/legislation_summaries/consumers/product_labelling_and_packaging/co0013_en.htm

More Scientific Information

Hair dyeing formulations belong to three categories — temporary, semi-permanent and permanent coloring of hair. Semi-permanent coloring preparations generally provide color through several shampooings.

These materials are often low molecular weight pre-formed dyes which can penetrate the hair shaft to some extent.

Semi-permanent hair dyes may also be called direct dyes, or non-oxidative dyes. HC Yellow No. 2 is an aromatic compound also known as Ethanol, 2-(o-nitroanilino)-. It is a direct, non oxidative hair dye.


The FDA’s factsheet on Hair Dye Products http://www.fda.gov/Cosmetics/ProductandIngredientSafety/ProductInformati…

Search the FDA Code of Federal Regulations http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm

EU Cosmetic Ingredients Inventory http://ec.europa.eu/consumers/cosmetics/cosing/