Nerve agent

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. Poisoning by a nerve agent leads to constriction of pupils, profuse salivation, convulsions, and involuntary urination and defecation, with the first symptoms appearing in seconds after exposure. Death by asphyxiation or cardiac arrest may follow in minutes due to the loss of the body's control over respiratory and other muscles. Standard treatment for nerve agent poisoning is a combination of an anticholinergic to manage the symptoms, and an oxime as an antidote. The most mass-produced nerve agents in history are VX/VR, sarin, and soman. The G-series consists of the earliest nerve agents discovered from the late 1930s, which are typically volatile and dangerous via inhalation as aerosols. The V-series, discovered after the 1950s, are far less volatile and more persistent, and threaten via skin absorption, requiring a full body suit. Both series, and some Novichok-series compounds, are organophosphate compounds, while other Novichok agents, and some carbamate nerve agents, have non-organophosphate chemistry. Some are formed by binary chemical weapon munitions, such as the US M687 artillery shell which formed sarin by mixing its chemical precursors. The first nerve agents were discovered by IG Farben in Nazi Germany. The extreme toxicity of tabun was learned in 1936, followed by sarin in 1938 and soman in 1944. The Wehrmacht became the first military to stockpile nerve agent munitions, but they were not used for fear of Allied retaliation. France, the Soviet Union, the United Kingdom, and the United States all captured and studied German nerve munitions. During the Cold War,...