What is it?
Pyrocatechol, also called catechol, is a chemical coupling agent that occurs as a colorless to white crystalline solid. Pyrocatechol is used in the formulation of permanent hair dyes, colors, and tints.
The safety of Pyrocatechol has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that Pyrocatechol was unsafe for use in leave-on products, and that the available data were insufficient to determine whether Pyrocatechol was either safe or unsafe as used in hair dyes.
Why is it used in cosmetics and personal care products?
Pyrocatechol 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.
Pyrocatechol is used in permanent hair coloring systems where color is produced inside the hair fiber. This is accomplished through careful formulation of the product so that the ingredients interact in a highly controlled process.