Pyrogallol

What Is It?

In cosmetics and personal care products, Pyrogallol is used in the formulation of permanent hair dyes and colors.

Why Is It Used?

Pyrogallol imparts 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

Pyrogallol was the first synthetic organic dye to be used on human hair. It is used in permanent hair coloring systems where color is produced inside the hair fiber. It may also be used in combination with ferric ammonium citrate for coloring sutures used in surgery.

Safety Information

The Food and Drug Administration (FDA) lists Pyrogallol as a color approved for use for coloring sutures used in surgery. The safety of Pyrogallol has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel reviewed the scientific data and concluded that Pyrogallol was safe as a hair dye ingredient in the present practices of use and concentration.

CIR Safety Review:

Pyrogallol was not an eye irritant when tested at a concentration of 1%. It was slightly irritating and induced sensitization reaction in the skin. There were no developmental and no treatment-related effects in dermal studies of a hair dye containing Pyrogallol. The CIR Expert Panel noted that Pyrogallol was mutagenic in Salmonella typhimurium but also recognized that the compound was negative for carcinogenicity in three chronic skin painting studies.

More information about the safety of hair dyes.

FDA:

Link to the Code of Federal Regulations for Pyrogallol

The use of Pyrogallol in cosmetic products in Europe is prohibited (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

Pyrogallol is a benzenetriol used in oxidative (permanent) hair dyes. 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 dye precursors and couplers 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 dye precursors are oxidized by the hydrogen peroxide to combine with the couplers resulting in colorant 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, pH of the dyeing solution and the time of contact of the dyeing solution with the hair.