For decades chlorpyrifos (CPS) has been one of the most widely used organophosphate insecticides for a variety of agricultural and public health applications.

The extensive use of CPS inevitably results in exposure to a small number of the human population. It is believed that the chemical is metabolically oxidized to its oxygen analog, chlorpyrifos oxon (CPO), which can cause acute toxicity in humans by the inhibition of acetylcholinesterase in the central nervous systems.

The metabolical oxidization of CPS to CPO...