Since the insects began fighting back in 1947,1 the war against them has demanded an increasingly diversified armamentarium, and the organic phosphate insecticides have played an important part in the battle. Unfortunately, this group of compounds, an outgrowth of wartime investigation of the chemically related nerve gases, are poisonous to man as well as to insects. For toxicologic purposes, they may be roughly divided into the highly toxic group, exemplified by parathion (O,O-diethyl-O-p-nitrophenyl thiophosphate) and TEPP (tetraethyl pyrophosphate), and those with less toxicity, such as malathion (O,O-dimethyl dithiophosphate of diethyl mercaptosuccinate). The former group is used primarily for agricultural insect control, whereas the latter compound has been approved for household use as well.
The incidence of human poisoning by organic phosphorus insecticides appears to be increasing in frequency. In 1957 in California3 there were 229 cases of occupational disease ascribed to organic phosphate insecticides, including one