Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. They are highly effective against insects, however, toxic to humans.
Among the commonly used organophosphates are parathion, malathion, methyl parathion, chlorpyrifos, diazinon, dichlorvos, phosmet, fenitrothion, tetrachlorvinphos and azamethiphos. Malathion is the most commonly used organophosphate insecticide in the United States (US). Forty organophosphate pesticides are registered in the US, with at least 73 million pounds used in agricultural and house-hold settings.