Used in environmental and water quality testing to calibrate instruments for measuring nitrite levels in drinking water, wastewater, and natural water sources. Essential in agricultural labs to monitor soil nitrite content, helping manage fertilizer use and prevent crop damage. Widely applied in food and beverage industries to control nitrite concentrations in cured meats and processed foods, ensuring compliance with safety regulations. Also used in research and clinical labs for biochemical assays and studies involving nitrogen cycling and microbial activity.