Environmental Fate of Chlorpyrifos

Chlorpyrifos is a member of the organophosphorus or organophosphate class of insecticides. This class has become one of the most widely used groups of pest control chemicals. In 1989 nearly 40% of the $6.2 billion global insecticide market was comprised of organophosphates (OPs) (Phillips and McDougall 1990). Although Clermont (1854) had first synthesized tetraethylpyrophosphate (TEPP), it was not until much later that the insecticidal properties of this OP were described (Schrader 1942). This milestone led to further synthetic work with insecticidal OPs and thus provided the impetus that would lead to the launch of an entirely new class of insecticides. Early OPs found to be efficacious for insect control and thus brought into widespread use included parathion (1944) and malathion (1952) (Matsumura 1985). These successes stimulated further discovery work on the part of synthetic chemists and entomologists within a number of research organizations.