Toxicity of parathion, systox, octamethyl pyrophosphoramide, and methyl parathion in man

Abstract Experiments in human beings were undertaken to determine the levels of minimal toxicity of parathion, systox, OMPA, and methyl parathion. The study of parathion demonstrated that the level of minimal toxicity is 7.5 mg per day. Between 6.75 and 7.125 mg per day of systox produced minimal toxicity. In the case of OMPA the level of minimal toxicity was 1.5 mg per day. This compound is of further interest in that it was the only compound studied to which the red cell cholinesterase activity was more sensitive than the plasma cholinesterase activity. Although doses as high as 19.0 mg per day were evaluated in the study of methyl parathion, the level of minimal toxicity was not established.