Benzenesulfinic acid sodium salt is widely used as a reducing agent in various chemical reactions, particularly in organic synthesis. It is effective in reducing quinones to hydroquinones, which is useful in the production of dyes, pharmaceuticals, and antioxidants. Additionally, it serves as a key intermediate in the synthesis of sulfonamides, which are important in the development of antibacterial drugs. In the polymer industry, it is employed as a chain transfer agent to control molecular weight during polymerization processes. Its application also extends to electroplating, where it helps in the deposition of metals by acting as a stabilizing agent in plating baths. Furthermore, it is utilized in analytical chemistry for the determination of certain metal ions through redox titrations.