Implementing the Chemical Weapons Convention

The 1993 Chemical Weapons Convention (CWC) opened for signature on 13 January 1993, and entered into force on 29 April 1997.

As of 24 March  2020, the CWC has 193 States Parties. Four states have yet to join the Convention: Israel (Signatory), the Democratic People’s Republic of Korea, Egypt and South Sudan. The Secretary-General of the United Nations is the Convention depositary. The Organisation for the Prohibition of Chemical Weapons (OPCW), based in The Hague, is responsible for the implementation of the Convention and consists of the Conference of the States Parties, the Executive Council and the Technical Secretariat.


Under Article II, paragraph 1 of the Convention, chemical weapons are defined on the basis of purpose (the ‘general purpose criterion’) as follows:

(a) Toxic chemicals and their precursors, except where intended for purposes not prohibited under this Convention, as long as the types and quantities are consistent with such purposes;
(b) Munitions and devices, specifically designed to cause death or other harm through the toxic properties of those toxic chemicals specified in subparagraph (a), which would be released as a result of the employment of such munitions and devices;
(c) Any equipment specifically designed for use directly in connection with the employment of munitions and devices specified in subparagraph (b).

Main obligations

Article I outlines CWC States Parties’ general obligations. By becoming a State Party to the CWC, states undertake never to use, develop, produce, stockpile, retain, transfer or otherwise acquire or retain any chemical weapons. They also undertake never to engage in any military preparations to use chemical weapons, or to assist, encourage or induce, in any way, anyone to engage in any activity prohibited to a state party under the Convention. Article I further ensures that States Parties undertake to destroy any chemical weapons, abandoned chemical weapons and chemical weapons production facilities that are under their control. In addition, States Parties undertake never to use riot control agents as a method of warfare.

NIM obligations

Once your state has become a party to the Convention, it will be bound by the content of the CWC and will have to implement its requirements. In particular, Article VI requires States Parties to adopt the necessary measures to ensure that toxic chemicals and their precursors are only developed, produced, otherwise acquired, retained, transferred, or used for peaceful purposes within their territory or anywhere under their jurisdiction or control. States parties must accordingly regulate and oversee activities involving the chemicals listed in Schedules 1, 2 and 3 of the Convention’s Annex on Chemicals.

Article VI also requires that these measures be implemented in a manner which avoids hampering the economic and technological development of States Parties and international cooperation in the field. Article XI of the CWC also enshrines and elaborates on this right of States Parties.

Article VII requires all States Parties to adopt the necessary measures to fulfil their obligations under the Convention, especially appropriate penal legislation. They must then inform the OPCW of the measures they have taken.