VX
The phosphorylthiocholine class of compounds was discovered independently by Ranaji
Goshem of ICI and by Lars-Erik Tammelin of the Swedish Institute of Defense Research in
1952. Shortly thereafter, the U.S. Army began a systematic investigation of this class of
compounds at Edgewood Arsenal; as a result, VX was developed and stockpiled by the United
States. A closely related compound referred to as V gas was manufactured and stockpiled by
the Soviet Union.
VX is a colorless liquid that is both less volatile and less soluble in
water than GB. It is also distinguished from GB by its increased potency and stability in
the environment. It will persist for several days to several weeks at normal temperatures.
VX has the chemical name methylphosphonothioic acid,
S-[2-[bis(1-methylethyl)amino]ethyl] O-ethyl ester, and has the molecular formula
C11H26NO2PS and formula weight 267.37.
The lethal concentration-exposure time is 10 mg-min/m3 . VX
will penetrate the skin; the lethal dose by the percutaneous route is about 6 mg-min/m3
15.
VX, or a closely related substance, was responsible for the death of
6,000 sheep at Dugway Proving Ground, Utah, in March, 1968.
