text: The development of VR started in 1957, after the Soviet Union obtained information about detection of high level of toxicity in phosphorylthiocholines (the same year Lars-Erik Tammelin published his first articles on fluorophosphorylcholines and phosphorylthiocholines in Acta Chemica Scandinavica) by a team from the Soviet Union's Scientific Research Institute No. 42 (NII-42). Sergei Zotovich Ivin, Leonid Soborovsky, and Iya Danilovna Shilakova jointly developed this analogue of VX. They completed their work in 1963 and were later awarded the Lenin Prize for their achievement. A binary weapon comprising two less toxic precursors which mixed during flight to form Substance 33 was later developed by a team led by Nikolai Kuznetsov.
  In 1972 the Soviets opened Cheboksary Khimprom, a manufacturing plant for VR in Novocheboksarsk. All facilities in USSR produced 15,557 tons of VR according to their declaration to the Organisation for the Prohibition of Chemical Weapons (OPCW), although most if not all of this has now been destroyed under disarmament treaties.