[4] In 1952, Dr. Ranajit Ghosh, a chemist working for ICI at their Plant Protection Laboratories at Jealott's Hill was investigating the potential of organophosphate esters of substituted aminoethanethiols for use as pesticides.

[5][6] The toxicity of these substances had not passed unnoticed by the British Government, as some of the compounds had already been sent to their research facility at Porton Down for evaluation.

[citation needed] The US then went into production of large amounts of the chemically similar, but much more toxic VX in 1961.

[7] It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S.

11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.