Used in corrosion inhibition, particularly in cooling water systems and metal treatment processes, where the combination of nitrate and nitrite anions helps form protective oxide layers on metal surfaces, preventing rust and degradation. Commonly applied in industrial boilers, heat exchangers, and automotive antifreeze formulations to enhance system longevity. Also utilized in concrete admixtures to prevent chloride-induced corrosion of steel reinforcements in bridges and buildings. In some cases, employed in controlled-release fertilizers to manage nitrogen supply in agriculture, balancing plant uptake and environmental impact.