Used as an intermediate in the synthesis of azo dyes and pigments, particularly for producing bright yellow to red shades with good lightfastness. Commonly employed in textile dyeing for cotton and other cellulosic fibers due to its strong affinity for these materials. Also utilized in the manufacture of optical brightening agents for paper and laundry detergents, enhancing whiteness by absorbing UV light and emitting blue fluorescence. Its sulfonic acid groups improve water solubility, making it suitable for liquid formulations in industrial applications.