Editing Nerve agent (section)

==Classes==
There are two main classes of nerve agents. The members of the two classes share similar properties and are given both a common name (such as ''Sarin'') and a two-character [[NATO]] identifier (such as GB).

===G-series===
[[File:GA-3D-balls-by-AHRLS-2011.png|left|thumb|200x200px|Chemical form of the nerve agent [[Tabun (nerve agent)|Tabun]], the first ever synthesized.]]
[[File:Nerve agent G series.svg|thumb|400x400px|The G series of nerve agents.<ref>{{cite book | chapter-url = https://ke.army.mil/bordeninstitute/published_volumes/chemwarfare/Ch5_pg155-220.pdf | archive-url = https://web.archive.org/web/20130217100615/https://ke.army.mil/bordeninstitute/published_volumes/chemwarfare/Ch5_pg155-220.pdf | archive-date = 17 February 2013 | url-status = dead | first1 = Frederick R. | last1 = Sidell | first2 = Jonathan | last2 = Newmark | first3 = John | last3 = McDonough | name-list-style = vanc | chapter = Chapter 5: Nerve Agents | title =  Medical Aspects of Chemical Warfare| pages = 155–219 }}</ref>]]
The ''G-series'' is thus named because German scientists first synthesized them. G series agents are known as non-persistent, meaning that they evaporate shortly after release, and do not remain active in the dispersal area for very long. All of the compounds in this class were discovered and synthesized during or prior to [[World War II]], led by [[Gerhard Schrader]] (later under the employment of [[IG Farben]]).<ref>{{cite journal |last1=Costa |first1=Lucio G |title=Organophosphorus Compounds at 80: Some Old and New Issues |journal=Toxicological Sciences |date=1 March 2018 |volume=162 |issue=1 |pages=24–35 |doi=10.1093/toxsci/kfx266 |doi-access=free|pmid=29228398 |pmc=6693380 }}</ref>

This series is the first and oldest family of nerve agents. The first nerve agent ever synthesized was GA ([[Tabun (nerve agent)|Tabun]]) in 1936. GB ([[Sarin]]) was discovered next in 1939, followed by GD ([[Soman]]) in 1944, and finally the more obscure GF ([[Cyclosarin]]) in 1949. GB was the only G agent that was fielded by the US as a munition, in rockets, [[aerial bombs]], and [[artillery shell]]s.<ref name = "FM 3-8"/>

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===V-series===
[[File:VX-S-enantiomer-3D-balls.png|thumb|Chemical form of the nerve agent [[VX (nerve agent)|VX]].]]
[[File:Nerve agent V series.svg|thumb|400px|The V series of nerve agents.]]
The ''V-series'' is the second family of nerve agents and contains five well known members: [[VE (nerve agent)|VE]], [[VG (nerve agent)|VG]], [[VM (nerve agent)|VM]], [[VR (nerve agent)|VR]], and [[VX (nerve agent)|VX]], along with several more obscure analogues.<ref name='red":4"' />

The most studied agent in this family, [[VX (nerve agent)|VX]] (it is thought that the 'X' in its name comes from its overlapping isopropyl radicals), was invented in the 1950s at [[Porton Down]] in [[Wiltshire]], England. Ranajit Ghosh, a chemist at the Plant Protection Laboratories of [[Imperial Chemical Industries]] (ICI) was investigating a class of organophosphate compounds (organophosphate esters of substituted aminoethanethiols). Like Schrader, Ghosh found that they were quite effective pesticides. In 1953 and 1954, ICI conducted [[field trials]], intending to market the material as an [[acaricide]] with the common name [[VG (nerve agent)|amiton]]. Development was halted, as it was too toxic for safe use.<ref name=JH50>{{Cite book |last=Calderbank |first=Alan |title=Jealott's Hill: Fifty years of Agricultural Research 1928-1978 |publisher=Imperial Chemical Industries Ltd. |year=1978 |isbn=0901747017 |editor-last1=Peacock |editor-first=F.C. |pages=49–54 |url=https://archive.org/details/jealottshillfift0000peac/page/49 |chapter=Chapter 6: Organophosphorus Insecticides |url-access=registration}}</ref> The toxicity did not escape military notice and some of the more toxic materials had been sent to Porton Down for evaluation. After the evaluation was complete, several members of this class of compounds became a new group of nerve agents, the V agents (depending on the source, the V stands for Victory, Venomous, or Viscous). The best known of these is probably [[VX (nerve agent)|VX]], with [[VR (nerve agent)|VR]] ("Russian V-gas") coming a close second (amiton is largely forgotten as VG, with G probably coming from "G"hosh). All of the V-agents are persistent agents, meaning that these agents do not degrade or wash away easily and can therefore remain on clothes and other surfaces for long periods. In use, this allows the V-agents to be used to blanket terrain to guide or curtail the movement of enemy ground forces. The consistency of these agents is similar to oil; as a result, the contact hazard for V-agents is primarily – but not exclusively – dermal. VX was the only V-series agent that was fielded by the US as a munition, in rockets, [[artillery shell]]s, airplane spray tanks, and [[landmine]]s.<ref name="FM 3-8">''FM 3–8 Chemical Reference handbook''; US Army; 1967</ref><ref>[http://www.cma.army.mil/fndocumentviewer.aspx?docid=003677713 "U.S. Army Destroys Entire Stockpile of VX Spray Tanks"] {{webarchive|url=https://web.archive.org/web/20090206182557/http://www.cma.army.mil/fndocumentviewer.aspx?docid=003677713 |date=2009-02-06 }}, U.S. Army Chemical Materials Agency, December 26, 2007, accessed January 4, 2007</ref>

Analyzing the structure of thirteen V agents, the standard composition, which makes a compound enter this group, is the absence of [[Halide|halides]]. It is clear that many agricultural pesticides can be considered as V agents if they are notoriously toxic. The agent is not required to be a phosphonate and presents a dialkylaminoethyl group.<ref>{{cite report |first1=P. B. |last1=Coulter |first2=J. J. |last2=Callahan |first3=R.S. |last3=Link |work=U. S. Army Chemical Warfare Laboratories Technical Report |id={{DTIC|AD0314520}} |title=Physical Constants of Thirteen V Agents }}</ref> The toxicity requirement is waived as the VT agent and its salts (VT-1 and VT-2) are "non-toxic".{{sfn|Mager|1984|p=[{{GBurl|NsYdE70JxMkC|p=51}} 51]}} Replacing the sulfur atom with selenium increases the toxicity of the agent by orders of magnitude.{{sfn|Mager|1984|p=[{{GBurl|NsYdE70JxMkC|p=57}} 57]}}

===Novichok agents===
{{Main|Novichok agent}}
The Novichok (Russian: {{Lang|ru|Новичо́к}}, "newcomer") agents, a series of [[organophosphate]] compounds, were developed in the [[Soviet Union]] and in Russia from the mid-1960s to the 1990s. The Novichok program aimed to develop and manufacture highly deadly chemical weapons that were unknown to the West. The new agents were designed to be undetectable by standard NATO chemical-detection equipment and overcome contemporary chemical-protective equipment.

In addition to the newly developed "third generation" weapons, binary versions of several Soviet agents were developed and were designated as "Novichok" agents.

===Carbamates===
Contrary to some claims,<ref>{{Cite web|url= https://www.theguardian.com/uk-news/2018/mar/13/novichok-nerve-agents-russia-salisbury-spy|title= Novichok nerve agents – what are they?|last= Sample|first= Ian | name-list-style = vanc |date= 2018-03-13|website= the Guardian|language= en|archive-url= https://web.archive.org/web/20180318035538/http://www.theguardian.com/uk-news/2018/mar/13/novichok-nerve-agents-russia-salisbury-spy|archive-date= 2018-03-18|url-status= live|access-date= 2018-03-19}}</ref> not all nerve agents are [[organophosphate]]s. The starting compound studied by the United States was the [[carbamate]] EA-1464, of notorious toxicity.<ref name=":6">SUMMARY OF MAJOR EVENTS and PROBLEMS. United States Army Chemical Corps (U). FISCAL YEAR 1960. p-116</ref> Compounds similar in structure and effect to EA-1464 formed a large group, including compounds such as [[EA-3990]] and [[EA-4056]].<ref name=":6" /> The Family Practice Notebook claims carbamate-based nerve agents can be three times as toxic as VX.<ref>{{Cite web |title=Nerve Agent Exposure |url=https://fpnotebook.com/ER/Toxin/NrvAgntExpsr.htm |access-date=2023-07-09 |website=fpnotebook.com}}</ref> Both the United States<ref name=red":4">{{Cite book|title= Handbook of chemical and biological warfare agents | first = D Hank | last = Ellison | name-list-style = vanc |date= 2008|publisher= CRC Press | isbn = 978-0-8493-1434-6 | edition = 2nd | location = Boca Raton | oclc = 82473582 }}</ref> and the Soviet Union<ref>{{cite journal |url= http://archiv.uni-nke.hu/downloads/aarms/docs/Volume6/Issue1/pdf/15vasa.pdf |archive-url= https://web.archive.org/web/20180314042412/http://archiv.uni-nke.hu/downloads/aarms/docs/Volume6/Issue1/pdf/15vasa.pdf |url-status= dead |archive-date= 2018-03-14 |first1= Györgyi |last1= Vásárhelyi |first2= László |last2= Földi |name-list-style= vanc |title= History of Russia's chemical weapons |journal= AARMS |date= 2007 |volume= 6 |issue= 1 |pages= 135–146 }}</ref>
developed carbamate-based nerve agents during the [[Cold War]]. Carbamate-based nerve agents are sometimes grouped in academic literature with Fourth Generation Novichok agents, as they were added to the CWC schedule on banned agents at the same time,<ref>{{Cite web |title=New nerve agents added to Chemical Weapons Convention |url=https://cen.acs.org/policy/chemical-weapons/New-nerve-agents-added-Chemical-Weapons-Convention/97/web/2019/12 |access-date=2023-07-09 |website=cen.acs.org}}</ref> despite their significant differences in chemical makeup and mechanisms of action.<ref name=":7">{{cite journal |last1=Palermo |first1=Giulia |last2=Kovarik |first2=Zrinka |last3=Hotchkiss |first3=Peter J. |title=Newly scheduled carbamate compounds: A synopsis of their properties and development, and considerations for the scientific community |journal=Toxicology |date=October 2022 |volume=480 |pages=153322 |doi=10.1016/j.tox.2022.153322 |pmid=36115648 |bibcode=2022Toxgy.48053322P }}</ref> Carbamate-based nerve agents have been identified as Schedule 1 Nerve Agents,<ref name=":7" /> the highest classification possible under the CWC, reserved for agents with no identified alternate use, and those that can cause the most harm.<ref>{{Cite web |title=Annex on Chemicals |url=https://www.opcw.org/chemical-weapons-convention/annexes/annex-chemicals/annex-chemicals |access-date=2023-07-09 |website=OPCW |language=en}}</ref>

===Insecticides===
Some [[insecticide]]s, including [[carbamates]] and [[organophosphates]] such as [[dichlorvos]], [[malathion]] and [[parathion]], are nerve agents. The metabolism of [[insect]]s is sufficiently different from [[mammal]]s that these compounds have little effect on [[humans]] and other [[mammals]] at proper doses, but there is considerable concern about the effects of long-term exposure to these chemicals by [[farm workers]] and [[animals]] alike. At high enough doses, [[acute (medical)|acute]] toxicity and death can occur through the same mechanism as other nerve agents. Some insecticides such as [[demeton]], [[dimefox]] and [[paraoxon]] are sufficiently toxic to humans that they have been withdrawn from agricultural use, and were at one stage investigated for potential military applications.{{citation needed|date=August 2021}}
Paraoxon was allegedly used as an [[assassination]] weapon by the [[apartheid]] South African government as part of [[Project Coast]]. Organophosphate [[pesticide poisoning]] is a major cause of disability in many developing countries and is often the preferred method of suicide.<ref name=pmid15550429>{{cite journal | vauthors = Buckley NA, Roberts D, Eddleston M | title = Overcoming apathy in research on organophosphate poisoning | journal = BMJ | volume = 329 | issue = 7476 | pages = 1231–3 | date = November 2004 | pmid = 15550429 | pmc = 529372 | doi = 10.1136/bmj.329.7476.1231 }}</ref>