Used primarily in hair dye formulations due to its ability to develop stable, long-lasting color when oxidized. It contributes to the production of dark brown to black shades in permanent and semi-permanent hair color products. Also employed in some industrial dye applications for textiles and polymers where intense color and lightfastness are required. Its reactivity makes it suitable for use in combination with other aromatic amines to achieve a broad spectrum of hues. Due to potential skin sensitization, its use is regulated in many regions and often limited to professional applications with strict handling guidelines.