Used in water treatment processes to reduce chlorine demand and stabilize disinfection systems. Acts as a scavenger for hypochlorous acid, helping to minimize the formation of harmful disinfection byproducts such as trihalomethanes. Also employed in industrial cleaning formulations where controlled oxidation is needed. Its ability to modulate free chlorine levels makes it useful in cooling tower treatments and swimming pool sanitation. Additionally, it finds application in chemical synthesis as a sulfonating agent or intermediate in the production of specialty polymers and pharmaceuticals.