Used as an intermediate in the synthesis of azo dyes and pigments, particularly for producing red and orange shades. It couples readily with diazonium salts to form colored compounds used in textile, leather, and paper dyeing. Also employed in the formulation of indicators for pH and metal ion detection due to its responsive functional groups. Its sulfonate groups enhance water solubility, making it suitable for applications requiring aqueous processing. Additionally, it serves in electroplating baths as a brightening agent and in analytical chemistry for the detection of certain cations.