Editing Chemical Weapons Convention (section)

==Key points of the Convention==
* Prohibition of production and use of [[Chemical weapon|chemical weapons]]
* Destruction (or monitored conversion to other functions) of chemical weapons production facilities
* Destruction of all chemical weapons (including chemical weapons abandoned outside the state parties territory)
* Assistance between State Parties and the OPCW in the case of use of chemical weapons
* An OPCW inspection regime for the production of chemicals which might be converted to chemical weapons
* International cooperation in the peaceful use of chemistry in relevant areas

===Controlled substances===
{{main|Schedules of substances annexed to the Chemical Weapons Convention}}
The convention distinguishes three classes of controlled substance,<ref name=opcw-20141207/><ref>{{Cite web|url=https://www.opcw.org/chemical-weapons-convention/annexes/annex-chemicals/annex-chemicals|title=Annex on Chemicals|website=OPCW}}</ref> chemicals that can either be used as weapons themselves or used in the manufacture of weapons. The classification is based on the quantities of the substance produced commercially for legitimate purposes. Each class is split into Part A, which are chemicals that can be used directly as weapons, and Part B, which are chemicals useful in the manufacture of chemical weapons. Separate from the precursors, the convention defines toxic chemicals as "[a]ny chemical which through its chemical action on life processes can cause death, temporary incapacitation or permanent harm to humans or animals. This includes all such chemicals, regardless of their origin or of their method of production, and regardless of whether they are produced in facilities, in munitions or elsewhere."<ref>{{cite web|title=CWC Article II. Definitions and Criteria|url=http://www.opcw.org/chemical-weapons-convention/articles/article-ii-definitions-and-criteria/|work=Chemical Weapons Convention|publisher=[[Organisation for the Prohibition of Chemical Weapons]]|access-date=7 September 2013}}</ref>

*[[List of Schedule 1 substances (CWC)|Schedule 1]] chemicals have few, or no uses outside chemical weapons. These may be produced or used for research, medical, pharmaceutical or chemical weapon defence testing purposes but production at sites producing more than 100&nbsp;grams per year must be declared to the [[Organisation for the Prohibition of Chemical Weapons|OPCW]]. A country is limited to possessing a maximum of 1 tonne of these materials. Examples are [[sulfur mustard]] and [[nerve agent]]s, and substances which are solely used as precursor chemicals in their manufacture. A few of these chemicals have very small scale non-military applications, for example, milligram quantities of [[nitrogen mustard]] are used to treat certain cancers.
*[[List of Schedule 2 substances (CWC)|Schedule 2]] chemicals have legitimate small-scale applications. Manufacture must be declared and there are restrictions on export to countries that are not CWC signatories. An example is [[thiodiglycol]] which can be used in the manufacture of mustard agents, but is also used as a solvent in [[ink]]s.
*[[List of Schedule 3 substances (CWC)|Schedule 3]] chemicals have large-scale uses apart from chemical weapons. Plants which manufacture more than 30 tonnes per year must be declared and can be inspected, and there are restrictions on export to countries which are not CWC signatories. Examples of these substances are [[phosgene]] (the most lethal chemical weapon employed in [[World War I]]),<ref>{{cite web|title=CDC Facts about Phosgene|url=https://emergency.cdc.gov/agent/phosgene/basics/facts.asp|access-date=13 April 2017}}</ref> which has been used as a chemical weapon but which is also a precursor in the manufacture of many legitimate organic compounds (e.g. [[pharmaceutical|pharmaceutical agents]] and many common [[pesticides]]), and [[triethanolamine]], used in the manufacture of nitrogen mustard but also commonly used in toiletries and detergents.


Many of the chemicals named in the schedules are simply examples from a wider class, defined with [[Markush structure|Markush]] like language. For example, all chemicals in the class "''O-Alkyl (<=C10, incl. cycloalkyl) alkyl (Me, Et, n-Pr or i-Pr)- phosphonofluoridates chemicals''" are controlled, despite only a few named examples being given, such as [[Soman]].

This can make it more challenging for companies to identify if chemicals they handle are subject to the CWC, especially Schedule 2 and 3 chemicals (such as Alkylphosphorus chemicals).  For example, Amgard 1045 is a flame retardant, but falls within Schedule 2B<ref>{{Cite web|url=https://www.opcw.org/resources/declarations/most-traded-scheduled-chemicals-2022|title=Most Traded Scheduled Chemicals 2022|website=OPCW}}</ref> as part of Alkylphosphorus chemical class. This approach is also used in controlled drug legislation in many countries and are often termed "class wide controls" or "generic statements".

Due to the added complexity these statements bring in identifying regulated chemicals, many companies choose to carry out these assessments computationally, examining the chemicals structure using in silico tools which compare them to the legislation statements, either with in house systems maintained a company or by the use commercial compliance software solutions.<ref>{{Cite web|url=https://www.scitegrity.com/controlled-substances|title=Regulated Chemicals &#124; Controlled Substance Lists &#124; Scitegrity|website=www.scitegrity.com}}</ref>

A treaty party may declare a "single small-scale facility" that produces up to 1 tonne of Schedule 1 chemicals for research, medical, pharmaceutical or protective purposes each year, and also another facility may produce 10&nbsp;kg per year for protective testing purposes. An unlimited number of other facilities may produce Schedule 1 chemicals, subject to a total 10&nbsp;kg annual limit, for research, medical or pharmaceutical purposes, but any facility producing more than 100 grams must be declared.<ref name=opcw-20141207>{{cite web |url=https://www.opcw.org/fileadmin/OPCW/Fact_Sheets/Fact_Sheet_7_-_Schedule_of_chemicals.pdf |title=Monitoring Chemicals with Possible Chemical Weapons Applications |id=Fact sheet 7 |publisher=Organisation for the Prohibition of Chemical Weapons |date=7 December 2014 |access-date=18 March 2018 |archive-date=14 July 2017 |archive-url=https://web.archive.org/web/20170714154953/https://www.opcw.org/fileadmin/OPCW/Fact_Sheets/Fact_Sheet_7_-_Schedule_of_chemicals.pdf |url-status=dead }}</ref><ref name=sipri-5>{{cite report |page=45 |url=https://www.sipri.org/sites/default/files/files/PP/SIPRIPP05.pdf |title=Non-Compliance with the Chemical Weapons Convention - Lessons from and for Iraq |author=Jean Pascal Zanders, John Hart, Richard Guthrie |id=Policy Paper No. 5 |publisher=Stockholm International Peace Research Institute |date=October 2003 |access-date=14 March 2018}}</ref>

The treaty also deals with carbon compounds called in the treaty "discrete organic chemicals", the majority of which exhibit moderate-high direct toxicity or can be readily converted into compounds with toxicity sufficient for practical use as a chemical weapon.<ref>{{Cite web|url=http://www.chemlink.com.au/chemweap.htm|title=Chemical Weapons Convention|website=www.chemlink.com.au}}</ref> These are any carbon compounds apart from long chain polymers, oxides, sulfides and metal carbonates, such as [[organophosphate]]s. The OPCW must be informed of, and can inspect, any plant producing (or expecting to produce) more than 200 tonnes per year, or 30 tonnes if the chemical contains phosphorus, sulfur or fluorine, unless the plant solely produces explosives or hydrocarbons.

===Category definitions===
Chemical weapons are divided into three categories:<ref>{{Cite web|url=https://www.armscontrol.org/factsheets/cwcglance|title=The Chemical Weapons Convention (CWC) at a Glance &#124; Arms Control Association|website=www.armscontrol.org}}</ref>
* Category 1 - based on Schedule 1 substances
* Category 2 - based on non-Schedule 1 substances
* Category 3 - devices and equipment designed to use chemical weapons, without the substances themselves