Nerve agents, sometimes also called nerve gases, are a class of organic chemicals that disrupt the mechanisms by which nerves transfer messages to organs. The disruption is caused by the blocking of acetylcholinesterase (AChE), an enzyme that catalyzes the breakdown of acetylcholine, a neurotransmitter. Nerve agents are irreversible acetylcholinesterase inhibitors used as poison.
Sarin is an extremely toxic organophosphorus compound. A colourless, odourless liquid, it is used as a chemical weapon due to its extreme potency as a nerve agent. Exposure can be lethal even at very low concentrations, where death can occur within one to ten minutes after direct inhalation of a lethal dose, due to suffocation from respiratory paralysis, unless antidotes are quickly administered. People who absorb a non-lethal dose and do not receive immediate medical treatment may suffer permanent neurological damage.
Tabun or GA is an extremely toxic synthetic organophosphorus compound. It is a clear, colorless, and tasteless liquid with a faint fruity odor. It is classified as a nerve agent because it can fatally interfere with normal functioning of the mammalian nervous system. Its production is strictly controlled and stockpiling outlawed by the Chemical Weapons Convention of 1993. Tabun is the first of the G-series nerve agents along with GB (sarin), GD (soman) and GF (cyclosarin).
VX is an extremely toxic synthetic chemical compound in the organophosphorus class, specifically, a thiophosphonate. 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. In its pure form, VX is an oily, relatively non-volatile liquid that is amber-like in colour. Because of its low volatility, VX persists in environments where it is dispersed.
Cyclosarin or GF is an extremely toxic substance used as a chemical weapon. It is a member of the G-series family of nerve agents, a group of chemical weapons discovered and synthesized by a German team led by Gerhard Schrader. The major nerve gases are the G agents, sarin (GB), soman (GD), tabun (GA), and the V agents such as VX. The original agent, tabun, was discovered in Germany in 1936 in the process of work on organophosphorus insecticides. Next came sarin, soman and finally, cyclosarin, a product of commercial insecticide laboratories prior to World War II.
VG is a "V-series" nerve agent chemically similar to the better-known VX nerve agent. Tetram is the common Russian name for the substance. Amiton was the trade name for the substance when it was marketed as an insecticide by ICI in the mid-1950s.
Chemical, biological (CB) — and sometimes radiological — warfare agents were assigned what is termed a military symbol by the U.S. military until the American chemical and biological weapons programs were terminated. Military symbols applied to the CB agent fill, and not to the entire weapon. A chemical or biological weapon designation would be, for example, "Aero-14/B", which could be filled with GB, VX, TGB, or with a biological modification kit – OU, NU, UL, etc. A CB weapon is an integrated device of (1) agent, (2) dissemination means, and (3) delivery system.
From 1948 to 1975, the U.S. Army Chemical Corps conducted classified human subject research at the Edgewood Arsenal facility in Maryland. The purpose was to evaluate the impact of low-dose chemical warfare agents on military personnel and to test protective clothing, pharmaceuticals, and vaccines. A small portion of these studies were directed at psychochemical warfare and grouped under the prosaic title of the "Medical Research Volunteer Program" (1956–1975). The MRVP was also driven by intelligence requirements and the need for new and more effective interrogation techniques.
GV, also known as EA-5365, is an organophosphate nerve agent. GV is a part of a new series of nerve agents with properties similar to both the "G-series" and "V-series". It is a potent acetylcholinesterase inhibitor with properties similar to other nerve agents, being a highly poisonous vapour. Treatment for poisoning with GV involves drugs such as atropine, benactyzine, obidoxime, and HI-6.
The Dugway sheep incident, also known as the Skull Valley sheep kill, was a March 1968 sheep kill that has been connected to United States Army chemical and biological warfare programs at Dugway Proving Ground in Utah. Six thousand sheep were killed on ranches near the base, and the popular explanation blamed Army testing of chemical weapons for the incident, though alternative explanations have been offered. A report, commissioned by Air Force Press Officer Jesse Stay and first made public in 1998, was called the "first documented admission" from the Army that a nerve agent killed the sheep at Skull Valley.
VR is a "V-series" unitary nerve agent closely related to the better-known VX nerve agent. It became a prototype for the series of Novichok agents. According to chemical weapons expert Jonathan Tucker, the first binary formulation developed under the Soviet Foliant program was used to make Substance 33, differing from VX only in the alkyl substituents on its nitrogen and oxygen atoms. "This weapon was given the code name Novichok."
Isopropyl aminoethylmethyl phosphonite, also known as O-(2-diisopropylaminoethyl) O′-ethyl methylphosphonite, is a precursor chemical to the nerve agent VX and VR-56. It is a colorless liquid with a strong fishy odor, and is slightly soluble in water.
EA-3148 is a "V-series" nerve agent related to the better-known compounds VX and VR. It was studied by both the US and Soviet chemical weapons programmes during the Cold War, and is notable as the only V-series organophosphate nerve agent specifically identified in public domain sources as having a higher absolute potency as an acetylcholinesterase inhibitor than VX. However, both the US and Soviet investigations of the compound concluded that despite its high potency, the physicochemical properties of the substance made it unsuitable for weaponisation, and further research was not conducted.
A-234 is an organophosphate nerve agent. It was developed in the Soviet Union under the FOLIANT program and is one of the group of compounds referred to as Novichok agents that were revealed by Vil Mirzayanov. In March 2018 the Russian ambassador to the UK, Alexander Yakovenko, claimed to have been informed by British authorities that A-234 had been identified as the agent used in the poisoning of Sergei and Yulia Skripal. Vladimir Uglev, one of the inventors of the Novichok series of compounds, said he was "99 percent sure that it was A-234" in relation to the 2018 Amesbury poisonings, noting its unusually high persistence in the environment.
EA-3990 is a deadly carbamate nerve agent. It is lethal because it inhibits acetylcholinesterase. Inhibition causes an overly high accumulation of acetylcholine between the nerve and muscle cells. This paralyzes the muscles by preventing their relaxation. The paralyzed muscles include the muscles used for breathing.
EA-4056 is a deadly carbamate nerve agent. It is lethal because it inhibits acetylcholinesterase. Inhibition causes an overly high accumulation of acetylcholine between the nerve and muscle cells. This paralyzes the muscles by preventing their relaxation. The paralyzed muscles includes the muscles used for breathing.
Octamethylene-bis(5-dimethylcarbamoxyisoquinolinium bromide) (4-673-745-01) is an extremely potent carbamate nerve agent. It works by inhibiting the acetylcholinesterase, causing acetylcholine to accumulate. Since the agent molecule is positively charged, it does not cross the blood brain barrier very well.
V-sub x, also known as GD-7, is an organophosphate nerve agent of the V-series, the phosphonate analog of the organophosphate insecticide demeton. EA-5478 is the pinacolyl analogue.
Ethylsarin (GE), also known as EA-1209, TL-1620 or T-2109, is an organophosphate nerve agent of the G-series. It is the ethylphosphonofluoridate analog of sarin. It has 1/8 the toxicity of sarin and is 2-3 times more persistent.
Methylfluorophosphonylcholine (MFPCh) is an extremely toxic chemical compound related to the G-series nerve agents. It is an extremely potent acetylcholinesterase inhibitor which is around 100 times more potent than sarin at inhibiting acetylcholinesterase in vitro, and around 10 times more potent in vivo, depending on route of administration and animal species tested. MFPCh is resistant to oxime reactivators, meaning the acetylcholinesterase inhibited by MFPCh can't be reactivated by cholinesterase reactivators. MFPCh also acts directly on the acetylcholine receptors. However, despite its high toxicity, methylfluorophosphonylcholine is a relatively unstable compound and degrades rapidly in storage, so it was not deemed suitable to be weaponised for military use.
