Used as a disinfectant standard in water quality testing to calibrate instruments and validate methods for measuring residual chlorine and chloramine levels. Commonly applied in environmental labs, drinking water treatment plants, and wastewater facilities to ensure accurate monitoring of disinfection processes. Also used in pharmaceutical and industrial applications where controlled oxidation or antimicrobial activity needs verification. Its standardized concentration allows for consistent performance in analytical procedures, including titrations and colorimetric assays.