Used in hair dye formulations as a coupler to produce a range of natural-looking shades, especially warm brown and auburn tones. It reacts with primary intermediates like p-phenylenediamine in oxidative dyes to form larger colored compounds within the hair shaft. Its small molecular size allows for good penetration into the hair, ensuring long-lasting color. Also found in some industrial dye applications for textiles and photography chemicals due to its aromatic amine structure. Requires careful handling due to potential skin sensitization.