Octylphosphonic acid is a phosphonate and corrosion inhibitor. It helps prevent the erosion or rusting of a can or dispenser. It also helps keep metallic household surfaces, such as taps and drains, free of corrosion. We know there are concerns about phosphates and their impact on waterways and surface water. However, octylphosphonic acid is used in low concentrations to limit the concentrations of total phosphate being used in SC Johnson products and potentially released to surface waters.