C Hlorpyrifos , P Art 1 : T Oxicology

Chlorpyrifos (see Figure 1) is the most widely used insecticide in the United States, both in crop production and in nonagricultural applications.1 Its nonagricultural use in the United States is estimated at between 9 and 12 million pounds per year.1 Agricultural use estimates vary: the U.S. Environmental Protection Agency (EPA) estimates that between 10 and 15 million pounds are used annually,1 while the U.S. Department of Agriculture (USDA) estimates agricultural uses at 21 million pounds per year.2 (See Figure 2 for details.) Chlorpyrifos is a broad spectrum insecticide3 and has many uses. Nationwide, USDA estimates show that the primary agricultural uses are on corn, alfalfa, and cotton.2 (See Figure 3 for details.) In California, where pesticide use reporting is more comprehensive than in other states, the priplications are made annually. Over 17 percent of U.S. households use chlorpyrifos. Most of the chlorpyrifos products are used in the kitchen, bathroom, and other living spaces.5 (See Figure 5.) Chlorpyrifos has been registered in the U.S. since 1965,6 and is manufactured by DowElanco, formerly the Dow Chemical Company. Common brand names are Dursban (for household products) and Lorsban (for agricultural products).3