Sodium 5,8-dicarboxynaphthalene-2-sulfonate is primarily used in the textile industry as a dye intermediate. It plays a crucial role in the synthesis of azo dyes, which are widely employed for coloring fabrics, leather, and paper. Its sulfonate and carboxylate groups enhance water solubility, making it effective in dye formulations. Additionally, it is utilized in the production of fluorescent brightening agents, which are applied to textiles, detergents, and plastics to improve their visual whiteness and brightness. The compound’s stability and compatibility with other chemicals make it a valuable component in industrial dyeing processes.