Mapping the Ratification Status of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction


In this post, we explore the ratification status of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction (CWC). It was adopted by the United Nations Conference on Disarmament in Geneva on September 3, 1992, and it entered into force on April 29, 1997. 

The CWC builds on the 1925 Geneva Protocol, which bans the use of chemical and biological weapons in warfare. The protocol emerged in response to public outcry sparked by the use of these weapons during World War 1. The Geneva Protocol, however, had one important weakness. It did not expressly forbid the production, research, or stockpiling of these weapons. To address this shortcoming, the international community negotiated the Biological Weapons Convention (BWC) in 1972 and in the CWC, 20 years later.

Similar to the BWC, the CWC shares the overarching goal of eliminating chemical weapons. It achieves this goal by explicitly prohibiting the production, research, and stockpiling of chemical weapons and by mandating that all state parties to the CWC must dismantle and destroy any chemical weapons within their possession.

In line with the CWC’s Article XXI, it entered into force on April 29, 1997, 180 days after the 65th state party ratified the treaty. The United Nations Treaty Collection’s website stores data on the ratification status of many international treaties. We used these data to map the CWC’s current ratification status. We classified UN member states into three categories. States that have not signed or ratified the CWC are labeled as states that have taken “no action.” States that have signed the instrument, but not ratified it, are considered “signatory states”, while a state that has ratified the treaty is cataloged as a “state party.”

convention chem weapons

As depicted in this map, most of the UN’s members are state parties to the CWC, demonstrating broad international support for the elimination of chemical weapons and their programs. 

To secure state parties’ full compliance with the CWC, the treaty established the Organization on the Prohibition of Chemical Weapons (OPCW). This body is composed of three organs: the Conference of the States Parties, the Executive Council, and the Technical Secretariat. The first session of the Conference of the States Parties convened in 1997, a week after the treaty entered into force. This conference plays an important role in assessing states’ compliance with the treaty’s provisions. It also provides directives to the Executive Council and the Technical Secretariat in their efforts to enforce the prohibition of chemical weapons.

The CWC requires state parties to provide a comprehensive set of documents to the OPCW, which includes, among other things, declarations detailing the quantity and precise location of their chemical weapons, any existing facilities used to produce these weapons, and a broad strategy for the elimination of these stockpiles. The Technical Secretariat is tasked with verifying the progress of states towards eliminating their chemical weapons. 

The OPCW also produces annual reports. These documents can help us gauge international support for the CWC’s objectives. For example, in the latest Annual Report, published in 2022, the OPCW notes that it has verified the destruction of 98.87% of declared Category 1 weapons and 100% of both declared Category 2 and Category 3 weapons. 

Despite a high degree of compliance with the CWC, enforcing the treaty continues to be difficult. In 2017, investigations following the use of Sarin gas in Syria, the OPCW, in conjunction with France and the United Kingdom, detected chemical markers in the gas that matched markers in the Syrian government’s declared chemical weapons stockpiles. Russia’s opposition to these findings is a reminder that politics can often interfere in the OPCW’s work and it can prevent the international community from sanctioning state parties that have violated the CWC’s requirements. 

Want to learn more about this legal instrument?

Data on this convention’s ratification status is available on the World Politics Data Lab’s GitHub page. The most recent dataset was uploaded to the repository on October 1, 2023.

For more information on the convention’s history and its current application, please refer to the following academic writings:

Krutzsch, W., Myjer, E. and Trapp, R. (2014) The Chemical Weapons Convention: A Commentary, Oxford University Press.

Robinson, J.P. (1996). “Implementing the Chemical Weapons Convention,” International Affairs 72(1): 73-89.

About the authors:

Scott Feinstein is studying Philosophy and International Relations at Drew University. 

Tyler Schmied is a sophomore, double majoring in International Relations and French at Drew University.

Editor’s note: This post is part of a long-term project. Students enrolled in Drew University’s Semester on the United Nations, Principles in International Law and International Human Rights have been and will be collecting data on the ratification status of treaties deposited in the United Nations Treaty Collection. For more information on this project and its learning goals, click here.