What Is It?
Toluene-2,5-Diamine and Toluene-2,5-Diamine Sulfate are used as ingredients in the formulation of permanent hair dyes, colors and tints. Toluene-3,4-Diamine may also be used in hair dye products.
Why Is It Used?
Toluene-2,5-Diamine, Toluene-2,5-Diamine Sulfate and Toluene-3,4-Diamine impart color to hair. The exact color obtained depends on the other ingredients that are added to the hair coloring product.
Toluene-2,5-Diamine, Toluene-2,5-Diamine Sulfate and Toluene-3,4-Diamine are used in permanent hair coloring systems where color is produced inside the hair A slender, threadlike structure that forms animal or plant tissue. This is accomplished through careful formulation of the product so that the ingredients interact in a highly controlled process.
The safety of Toluene-2,5-Diamine, Toluene-2,5-Diamine Sulfate and Toluene-3,4-Diamine has been assessed by the The Cosmetic Ingredient Review (CIR) was established in 1976 as an independent safety review program for cosmetic ingredients. The CIR Expert Panel consists of independent experts in dermatology, toxicology, pharmacolgy and veterinary medicine. The CIR includes participation by the U.S. Food & Drug Administration and the Consumer Federation of America. (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that Toluene-2,5-Diamine and Toluene-2,5-Diamine Sulfate were safe for use as hair dye ingredients.
The CIR Expert Panel concluded that the data were insufficient to assess the safety of Toluene-3,4-Diamine as a hair dye ingredient.
CIR Safety Review:
Dermal penetration studies of Toluene-2,5-Diamine and Toluene-2,5-Diamine Sulfate showed only small amounts penetrated the skin. Penetration was even lower when these ingredients were applied to the skin as part of hair dye formulations. No dermal penetrations studies of Toluene-3,4-Diamine were available. The toluene diamine ingredients exhibited low to medium acute toxicity. Toluene-2,5-Diamine was a mild eye irritant. Toluene-2,5-Diamine (2.5%), Toluene-2,5-Diamine Sulfate (5%) and Toluene-3,4-Diamine (5%) were not dermal irritants. However, Toluene-2,5-Diamine (1%) was a sensitizer, and Toluene-3,4-Diamine (1%) was a strong sensitizer.
The CIR Expert Panel cautioned that Toluene-2,5-Diamine may be a sensitizer to hairdressers who have frequent contact with hair dyes. Although Toluene-2,5-Diamine and Toluene-2,5-Diamine Sulfate were mutagenic in bacteria and some tests in mammalian cells, hair dyes containing these compounds were not carcinogenic following dermal exposure. Toluene-3,4-Diamine was inactive in a bacterial mutagenicity test, but positive in some tests in mammalian cells.
No carcinogenicity studies of Toluene-3,4-Diamine were identified. Based on available data, and the reported use of these ingredients only as components in hair dye products, the CIR Expert Panel concluded that Toluene-2,5-Diamine and Toluene-2,5-Diamine Sulfate were safe for use as hair dye ingredients. The CIR Expert Panel concluded that the data were insufficient to support the safety of Toluene-3,4-Diamine Sulfate for use in hair dyes. Additional data needed to support the safety of Toluene-3,4-Diamine Sulfate include dermal absorption data at concentrations and conditions of use, and carcinogenicity data.
More information about the safety of hair dyes.
In the European Union Cosmetics Regulation, Methylphenylenediamines, their N-substituted derivatives and their salts, including Toluene-2,5-Diamine and Toluene-2,5-Diamine Sulfate are restricted for use in oxidizing types of hair dyes at a maximum concentration of 10% as a free base in the finished product (see Annex III). Hair dyes containing these ingredients must be labeled as indicated in Annex III. Toluene-3,4-Diamine is not permitted for use in hair dyes and colors in the European Union (see Annex II).
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. The permanent hair dyeing formulations are often referred to as oxidative hair dyes which are generally marketed as two-component products. One component contains the compounds (precursors) that become the colorants and the other component is a stabilized solution of hydrogen peroxide. The two components are mixed immediately prior to use.
The precursors and peroxide diffuse into the hair shaft, where color formation takes place after the ingredients combine to produce the coloring mixture. The precursors are oxidized by the hydrogen peroxide to form the Ingredients that impart color to cosmetic products. In the United States, the FDA regulates which colorants may be used in cosmetics. molecules.
These molecules are too large to escape from the hair structure. The hydrogen peroxide in the oxidative hair dye product also serves as bleaching agent for the natural pigment of the hair. The color that is formed depends on the precursors and direct dyes present in the dyeing solution, A measurement of the acidity or basicity of a substance. pH is the negative logarithm (base 10) of the concentration of hydrogen ions in solution. Water has a concentration of hydrogen ions of 1.0 x 10-7, and thus has a pH of 7. A pH of 7 is considered neutral, a pH lower than 7 is considered acidic, and a pH higher than 7 is considered basic. of the dyeing solution and the time of contact of the dyeing solution with the hair.
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 Cosmetics Inventory http://ec.europa.eu/consumers/cosmetics/cosing/