We report a case of organophosphate poisoning with a commercial preparation of malathion (deliberate ingestion of Malathane Garden Spray: malathion 15% in isopropyl alcohol) in which the initial cholinergic crisis was followed by cardiac, pulmonary, neurological and renal manifestations. They occurred when erythrocyte and plasma cholinesterases were reactivating. A chemical analysis of the pesticide preparation revealed, apart from malathion itself, the presence of isopropylmalathion and O,O,S-trimethylphosphorothioate. Although pure malathion is regarded as one of the safest organophosphate insecticides, this observation underlines the possibility of severe complications after exposure to a preparation which has been stored for a long period of time.
Dive, A.-M., Mahieu, P., Van Binst, R., Hassoun, A., Lison, D., De Bisschop, H., Nemery, B., & Lauwerys, R. (1994). Unusual manifestations after malathion poisoning. Human & Experimental Toxicology, 13(4), 271-274. https://doi.org/10.1177/096032719401300409 (Original work published 1994)