In the class of nerve agents, it was developed for military use in chemical warfare after translation of earlier discoveries of organophosphate toxicity in pesticide research.

To avoid a state of constant muscle contraction, the acetylcholine is then broken down (hydrolysed) into the inactive substances acetic acid and choline by AChE.

This results in initial violent contractions, followed by sustained supercontraction restricted to the fluid (sarcoplasm) of the subjunctional endplate and prolonged, depolarizing neuromuscular blockade.

[22] The extreme toxicity of VX is partly due to the fact that the inhibitor was designed to be an excellent structural mimic for the transition state of the natural substrate (acetylcholine) of acetylcholinesterase.

[25][26] The X-ray structures revealed the specific parts of the VX molecule that interact with key residues and sub-sites of the target enzyme.

The structural kinetic of phosphorylation followed by aging also showed an unexpected conformational change in the catalytic triad suggestive of an "induced fit" between the VX molecule and acetylcholinesterase.

Early symptoms of skin contact include local sweating and muscular twitching at the area of exposure, followed by nausea or vomiting.

Early symptoms of exposure to VX vapor include rhinorrhea (runny nose) and tightness in the chest with shortness of breath (bronchial constriction).

[31][32][33] An individual known to have been exposed to a nerve agent, or who exhibits definite signs or symptoms of nerve-agent exposure is generally given the antidotes atropine and pralidoxime (2-PAM), and in the case of convulsions an injected sedative or antiepileptic such as diazepam.

[citation needed] Controlled studies in humans have shown that minimally toxic doses cause 70–75% depression of erythrocyte cholinesterase within several hours of exposure.

The serum level of ethyl methylphosphonic acid (EMPA), a VX hydrolysis product, was measured to confirm exposure in one poisoning victim.

The best-known of these is probably VX, assigned the UK Rainbow Code Purple Possum, with the Russian V-Agent (VR) coming a close second (Amiton is largely forgotten as VG).

In their conclusion, the researchers estimated that 2.12 μg/kg of VX delivered intravenously over the course of several hours would be the maximum tolerable dosage and that any more would risk death in a human subject.

[39][40] UN toxicologists obtained trace elements of VX from soil, water, and plant samples taken from areas where Cuban troops had recently carried out counter-insurgency operations.

The VX victim, whom Shoko Asahara had suspected as a spy, was attacked at 7:00 am on December 12, 1994, on the street in Osaka by Tomomitsu Niimi and another AUM member, who sprinkled the nerve agent on his neck.

Doctors in the hospital suspected at the time he had been poisoned with an organophosphate pesticide, but the cause of death was pinned down only after cult members arrested for the Tokyo subway sarin attack confessed to the killing.

[citation needed] The U.S. had obtained soil samples identified as containing O-ethyl hydrogen methylphosphonothioate (EMPTA), a chemical used in the production of VX which may also have commercial applications.

[39] In 1969, the U.S. government cancelled its chemical weapons programs, banned the production of VX in the United States, and began the destruction of its stockpiles of agents by a variety of methods.

Early disposal included the U.S. Army's CHASE (Cut Holes And Sink 'Em) program, in which old ships were filled with chemical weapons stockpiles and then scuttled.

[55] Efforts to destroy these agents began in 2019, with the goal of eliminating the United States entire stockpile of chemical weapons by September 30, 2023.

[56] In fiscal year 2008, the U.S. Department of Defense released a study finding that the United States had dumped at least 112 tonnes (124 short tons) of VX into the Atlantic Ocean off the coasts of New York/New Jersey and Florida between 1969 and 1970.

Technical and political issues regarding this secondary byproduct resulted in delays, but the depot completed their VX stockpile destruction in August 2008.

The program was established as an alternative to the incineration process successfully used by the Army Chemical Materials Agency, which completed its stockpile destruction activities in March 2012.

[66] The fifth episode of the 2020 anime series The Millionaire Detective Balance: Unlimited features a tear gas bomb with canisters loaded with VX gas and placed inside a cabinet of a safe room within the embassy; the protagonist Daisuke Kambe and two other characters were trapped inside the room after relocating themselves due to security reasons, and figuring out how to escape before the bomb detonates.

The album VIVIsectVI by the industrial band Skinny Puppy contains a song about chemical weapons called "VX Gas Attack".

In the video game Everybody's Gone to the Rapture, VX is alluded to as a nerve agent used by the government to contain a pattern which infects and kills humans and other animals.

In the book Ice Cold, the eighth Rizzoli and Isles novel by Tess Gerritsen, VX gas is featured and responsible for many deaths.

The second episode of the TV series Seal Team (season 1) focuses on a chemical weapons lab in an abandoned hospital, producing VX gas.

"VX components" are displayed as an item for purchase on the computer, which is logged into Araknet, a dark web created by the protagonists of the series.

Metal Gear includes references to VX nerve gas in its plotlines, often as a lethal chemical threat within its espionage and warfare scenarios.