Used as an intermediate in the synthesis of dyes and pigments, particularly in the production of azo dyes, which are widely applied in textiles, paper, and leather industries. It also serves as a pH indicator in certain chemical reactions due to its ability to change color with varying acidity levels. Additionally, it is employed in research and development for creating specialized organic compounds and in analytical chemistry for detecting specific ions or molecules, such as in nitrite determination. Its sulfonic acid group makes it useful in modifying the solubility and reactivity of other chemicals in industrial processes.