Used in hair dye formulations as a coupler to produce stable, long-lasting color. It reacts with primary intermediates like p-phenylenediamines in oxidative dyes to form larger colored molecules that remain in the hair shaft. Offers good color range, especially in natural shades like brown and black. Also valued for lower skin irritation potential compared to other aminoazoles. Suitable for permanent and semi-permanent hair color products. Its hydrophilic nature helps with solubility and even distribution in formulations.