Used as a key intermediate in the synthesis of sulfa drugs and other pharmaceuticals, particularly in the preparation of sulfonamide-based antibiotics. It serves as a sulfonating agent in organic reactions where controlled introduction of sulfonate groups is required. Also employed in the development of ion-conductive materials for batteries and fuel cells due to its ionic stability. Additionally, finds use in textile and dye industries as a modifier to improve dye fixation and water solubility of certain colorants.