Fenitrothion is a broad-spectrum organophosphate insecticide with low mammalian toxicity. It is not fully effective against Rhyzopertha dominica. This residual insecticide has been used in several countries but is not registered for use in the United States against stored-product insects. It is not covered by patents, and the composition varies among manufacturers. Applications of 5–10 mg/kg can provide protection for nine to 12 months. There is minimal penetration into the grain, so all but 10% of the insecticide is removed by milling and all but 1–2% by cooking.