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 is an extremely toxic compound of the organophosphate family. It is not present in nature. At room temperature, the pure compound is a clear and viscous liquid. However, impurities imparted during its manufacture are almost always present, turning it into a yellow or brown liquid. Exposed to environs, it slowly volatizes into the atmosphere, with the vapor having a slight fruity or almond-like odor. As the compound has a much higher molecular mass compared to air, Tabun gas tends to accumulate in low-lying areas.
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.
Novichok is a family of nerve agents, some of which are binary chemical weapons. The agents were developed at the GosNIIOKhT state chemical research institute by the Soviet Union and Russia between 1971 and 1993. Some Novichok agents are solids at standard temperature and pressure, while others are liquids. Dispersal of solid form agents is thought possible if in ultrafine powder state.
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 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.
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."
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.
VS is a nerve agent of the V-series. Its chemical structure is very similar to the VX nerve agent, but the methyl group on the phosphorus atom is replaced by an ethyl group.
Octamethylene-bis(5-dimethylcarbamoxyisoquinolinium bromide) (4-673-745-01) is an extremely potent carbamate nerve agent. It works by inhibiting acetylcholinesterase, causing acetylcholine to accumulate. Since the agent molecule is positively charged, it does not cross the blood brain barrier very well.
VP, also known as EA-1511, is an extremely toxic organophosphate nerve agent of the V-series.
EA-2613 is an extremely toxic organophosphate nerve agent. It's an extremely potent acetylcholinesterase inhibitor that is resistant to atropine and oxime treatment.
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. MFPCh is a relatively unstable compound and degrades rapidly in storage, so despite its enhanced toxicity it was not deemed suitable to be weaponised for military use.
EA-1356 is an organophosphate nerve agent of the G-series. It is highly resistant to enzymatic degradation in the body. The nerve agent was tested at Edgewood Arsenal in Maryland among many other chemicals tested on humans. A novel enzyme was patented by the US Army in 2018 to break down EA-1356. It is a schedule 1 substance by the Chemical Weapons Convention standards. It is under the category of munitions of ML7.b.1.a.
4-686-293-01, also known as Agent 1-10, is a highly potent experimental carbamate nerve agent, patented in May 1967 by the US army. Due to its high molecular weight and thermal stability, it can remain embedded within various surfaces and clothes for prolonged periods of time. The agent can be decontaminated using bleach or hot caustic soda. The main effector pathway is through the inhibition and antagonization of acetylcholinesterase, achieved by the presence of quaternary ammonium groups in the structure. Perceived as one of the most potent agents in chemical warfare - it can be disseminated through aerosols, explosives or smoke generating munitions.
