- Establishment of reentry intervals for organophosphate-treated cotton fields based on human data: III. 12 To 72 hours post-treatment exposure to monocrotophos, ethyl- and methyl parathion. Ware, G.W., Morgan, D.P., Estesen, B.J., Cahill, W.P. Arch. Environ. Contam. Toxicol. (1975)