Organophosphorus compounds are organic compounds that contain phosphorus. They are used mainly as insecticides and herbicides as an alternative to chlorinated hydrocarbons, which persist in the environment. Among the best known and most widely used of these insecticides are malathion and parathion. The most extensively used of these herbicides is glyphosate, best known by its trade name Roundup.
Some organophosphorus compounds can also be extremely toxic to humans and thus there are ongoing concerns about the safety of their use for agricultural workers and even for consumers who eat crops exposed to these chemicals. This high toxicity has resulted in organophosphorus compounds being used as nerve gases, among the best known of which are sarin and tabun.