Nerve gas; potent cholinesterase inhibitor similar in structure and activity to sarin and tabun, q.q.v. Prepn: Holmstedt, Acta Physiol. Scand. 25, suppl. 90, p 106 (1951); Protar 16, 131 (1950); G. Schrader, Die Entwicklung neuer Insektizide auf Grundlage organischer Fluor- und Phosphor-Verbindungen [Monographie Nr. 62 zu Angewandte Chemie und Chemie-Ingenieur-Technik (Verlag Chemie 1951)]; B. C. Saunders, Some Aspects of the Chemistry and Toxic Action of Organic Compounds Containing Phosphorus and Fluorine (Cambridge, 1957) p 94. Toxicity study: Loomis, Salafsky, Toxicol. Appl. Pharmacol. 5, 685 (1963). Brief description: B. L. Harris in Kirk-Othmer Encyclopedia of Chemical Technology vol. 5 (Wiley-Interscience, New York, 4th ed., 1993) pp 795-816.