Suvarna Garge (Editor)

Chemical Weapons Convention

Updated on
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Drafted  3 September 1992
Location  Paris and New York
Signed  13 January 1993
Effective  29 April 1997
Chemical Weapons Convention

Signed and ratified   Acceded  Signed but not ratified   Non-signatory
Condition  Ratification by 65 states

The Chemical Weapons Convention (CWC) is an arms control treaty which outlaws the production, stockpiling, and use of chemical weapons and their precursors. The full name of the treaty is the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction and it is administered by the Organisation for the Prohibition of Chemical Weapons (OPCW), an intergovernmental organization based in The Hague, Netherlands. The treaty entered into force in 1997. The parties' main obligation under the convention is to prohibit the use and production of chemical weapons, as well as the destruction of all current chemical weapons. The destruction activities are verified by the OPCW.


As of April 2016, 192 states have given their consent to be bound by the CWC. Israel has signed but not ratified the agreement, while three other UN member states (Egypt, North Korea and South Sudan) have neither signed nor acceded to the treaty. Most recently, Angola deposited its instrument of accession to the CWC on 16 September 2015.

As of October 2016, about 93% of the world's declared stockpile of chemical weapons had been destroyed. The convention has provisions for systematic evaluation of chemical production facilities, as well as for investigations of allegations of use and production of chemical weapons based on intelligence of other state parties


Intergovernmental consideration of a chemical and biological weapons ban was initiated in 1968 within the 18-nation Disarmament Committee, which, after numerous changes of name and composition, became the Conference on Disarmament (CD) in 1984. On 3 September 1992 the Conference on Disarmament submitted to the U.N. General Assembly its annual report, which contained the text of the Chemical Weapons Convention. The General Assembly approved the Convention on 30 November 1992, and the U.N. Secretary-General then opened the Convention for signature in Paris on 13 January 1993. The CWC remained open for signature until its entry into force on 29 April 1997, 180 days after the deposit of the 65th instrument of ratification (by Hungary). The convention augments the Geneva Protocol of 1925 for chemical weapons and includes extensive verification measures such as on-site inspections. It does not, however, cover biological weapons.

Organisation for the Prohibition of Chemical Weapons (OPCW)

The convention is administered by the Organisation for the Prohibition of Chemical Weapons (OPCW), which acts as the legal platform for specification of the CWC provisions. The Conference of the States Parties is mandated to change the CWC and pass regulations on implementation of CWC requirements. The Technical Secretariat of the organization conducts inspections to ensure compliance of member states. These inspections target destruction facilities (where permanent monitoring takes place during destruction), chemical weapons production facilities which have been dismantled or converted for civil use, as well as inspections of the chemical industry. The Secretariat may furthermore conduct "investigations of alleged use" of chemical weapons and give assistance after use of chemical weapons.

The 2013 Nobel Peace Prize was awarded to the organization because it had, with the Chemical Weapons Convention, "defined the use of chemical weapons as a taboo under international law" according to Thorbjørn Jagland, Chairman of the Norwegian Nobel Committee.

Key points of the Convention

  • Prohibition of production and use of 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

    The convention distinguishes three classes of controlled substance, chemicals which 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."

  • 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 above 100 grams per year must be declared to the OPCW. A country is limited to possessing a maximum of 1 tonne of these materials. Examples are sulfur mustard and nerve agents, 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.
  • Schedule 2 chemicals have legitimate small-scale applications. Manufacture must be declared and there are restrictions on export to countries which 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 inks.
  • 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, which has been used as a chemical weapon but which is also a precursor in the manufacture of many legitimate organic compounds, and triethanolamine, used in the manufacture of nitrogen mustard but also commonly used in toiletries and detergents.
  • The treaty also deals with carbon compounds called in the treaty discrete organic chemicals. These are any carbon compounds apart from long chain polymers, oxides, sulfides and metal carbonates, such as organophosphates. 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.

    Member states

    165 states signed the CWC prior to its entry into force in 1997, allowing them to ratify the agreement after obtaining domestic approval. Following the treaty's entry into force, it was closed for signature and the only method for non-signatory states to become a party was through accession. As of April 2016, 192 states, representing over 98 percent of the world's population, are party to the CWC. Of the four United Nations member states that are not parties to the treaty, Israel has signed but not ratified the treaty, while Egypt, North Korea, and South Sudan have neither signed nor acceded to the Convention. Neither has the State of Palestine, which since becoming a UN observer state is eligible to accede to the Convention. Taiwan, though not a Member State, has stated that it complies with the treaty.

    Key organizations of member states

    Member states are represented at the OPCW by their Permanent Representative. This function is generally combined with the function of Ambassador. For the preparation of OPCW inspections and preparation of declarations, member states have to constitute a National Authority.

    World stockpile of chemical weapons

    A total of 72,524 metric tonnes of chemical agent, 8.67 million chemical munitions and containers, and 97 production facilities have been declared to OPCW.

    Timeline of destruction

    The treaty set up several steps with deadlines toward complete destruction of chemical weapons, with a procedure for requesting deadline extensions. No country reached total elimination by the original treaty date although several have finished under allowed extensions.

    Progress of destruction

    As of October 2016, 67,098 of 72,524 (93%) metric tonnes of chemical agent have been verifiably destroyed. More than 57% (4.97 million) of chemical munitions and containers have been destroyed.

    Five State Parties, namely Albania, an unspecified state party (widely believed to be South Korea), India, Libya, and Syria, have completed the destruction of their stockpiles. Russia and the United States, which declared the largest amounts of chemical weapons, are in the process of destruction. The deadline set for both countries of April 2012, however, was not met. The destruction of Libya's Category 1 chemical weapons was completed in 2014; destruction of its chemical weapon precursors is scheduled to finish in 2016. Iraq has yet to start destruction. Japan and China started in October 2010 the destruction of World War II era chemical weapons abandoned by Japan in China by means of mobile destruction units and reported destruction of 35,203 chemical weapons (75% of the Nanjing stockpile).

    Iraqi stockpile

    The U.N. Security Council ordered the dismantling of Iraq's chemical weapon stockpile in 1991. By 1998, UNSCOM inspectors had accounted for the destruction of 88,000 filled and unfilled chemical munitions, over 690 metric tons of weaponized and bulk chemical agents, approximately 4,000 tonnes of precursor chemicals, and 980 pieces of key production equipment. The UNSCOM inspectors left in 1998.

    In 2009, before Iraq joined the CWC, the OPCW reported that the United States military had destroyed almost 5,000 old chemical weapons in open-air detonations since 2004. These weapons, produced before the 1991 Gulf War, contained sarin and mustard agents but were so badly corroded that they could not have been used as originally intended.

    When Iraq joined the CWC in 2009, it declared "two bunkers with filled and unfilled chemical weapons munitions, some precursors, as well as five former chemical weapons production facilities" according to OPCW Director General Rogelio Pfirter. The bunker entrances were sealed with 1.5 meters of reinforced concrete in 1994 under UNSCOM supervision. As of 2012, the plan to destroy the chemical weapons was still being developed, in the face of significant difficulties. In 2014, ISIS took control of the site.

    Syrian destruction

    Syria, which had long been suspected of possessing chemical weapons, acknowledged them in September 2013 and agreed to put them under international supervision. On 14 September Syria deposited its instrument of accession to the CWC with the United Nations as the depositary and agreed to its provisional application pending entry into force effective 14 October. An accelerated destruction schedule was devised by Russia and the United States on 14 September, and was endorsed by United Nations Security Council Resolution 2118 and the OPCW Executive Council Decision EC-M-33/DEC.1. Their deadline for destruction was the first half of 2014. Syria gave the OPCW an inventory of its chemical weapons arsenal and started its destruction in October 2013, 2 weeks before its formal entry into force, while applying the convention provisionally. All Category 1 materials were destroyed by August 2014.

    Financial support for destruction

    Financial support for the Albanian and Libyan stockpile destruction programmes was provided by the United States. Russia received support from a number of nations, including the United States, the United Kingdom, Germany, the Netherlands, Italy and Canada; some $2 billion given by 2004. Costs for Albania's program were approximately 48 million U.S. dollars. The U.S. had spent $20 billion and expected to spend a further $40 billion.

    Known production facilities (of chemical weapons)

    Fourteen States Parties have declared chemical weapons production facilities:

  • 1 non-disclosed state party (referred to as "A State Party" in OPCW-communications; said to be South Korea)
  • As of May 2015, all 97 declared production facilities had been inactivated and 93% (90) have been certified as destroyed or converted to civilian use.


    Chemical Weapons Convention Wikipedia