HC Red No. 7

What Is It?

HC Red No. 7, which refers to Hair Colorant Red No. 7, is a dark brick red to brown powder. HC Red No. 7 is used in the formulation of semi-permanent hair dyes, colors and tints.

Why Is It Used?

HC Red No. 7 helps to impart 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 Red No. 7 is used in semi-permanent hair coloring systems that are usually applied in a shampoo base and contain thickeners, alkalizers, and foam stabilizers. The color that is produced results from careful formulation of the product so that the ingredients interact in a highly controlled process.

Safety Information

The safety of HC Red No. 7 has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that HC Red No. 7 was safe as a hair dye ingredient in the practices of use and concentrations as described in the safety assessment.

CIR Safety Review:

Approximately 0.10% of the applied HC Red No. 7 was absorbed through human dermatomed skin samples. The NOEL (No Observed Adverse Effects Level) in a subchronic oral toxicity study was 50 mg/kg/day. HC Red No. 7 was not a dermal or ocular irritant, but lymphoproliferative responses indicated that HC Red No. 7 should be considered a moderate sensitizer.

The NOEL for maternal toxicity was 50 mg/kg/day and the NOAEL for developmental toxicity was 200 mg/kg/day in a prenatal toxicity study of HC Red No. 7. HC Red No. 7 was non-mutagenic at the hprt locus but mutagenic at the TK locus in lymphoma cells, was mutagenic in several Salmonella typhimurium strains, was not active in an unscheduled DNA synthesis assay, and was the results were unclear in a micronucleus assay in human lymphocyte cultures.

No carcinogenicity studies were available. As reviewed by the CIR Expert Panel, HC Red No. 7 appeared to be a moderate sensitizer. The CIR Expert Panel also noted that mutagenicity studies available for HC Red No. 7 gave both positive and negative results. Based on the available data, it was concluded that, at most, this ingredient was a weak mutagen. Due to its low dermal absorption potential and its use as a semi-permanent hair dye, the CIR Expert Panel believed there was low risk of genotoxicity and that HC Red No. 7 was safe as a hair dye ingredient.

More information about the safety of hair dyes.

In Europe, HC Red No. 7 is permitted for use in non-oxidative hair dye products at a maximum concentration of 1%. See Annex III for additional information about the use of HC Red No. 7 in hair dye products.

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. HC Red No. 7 is an aromatic compound also known as 2-amino-5-(2-hydroxyethylamino) nitrobenzene. In cosmetics and personal care products, HC Red No. 7 functions as a hair colorant.