Responding to the
Use of Chemical Weapons

The Chemical Weapons Convention codified an international norm against chemical weapons, to which all States must adhere. Protecting this norm requires constant vigilance. While the work of the OPCW is largely focused on preventing the use of chemical weapons – through its verification activities, destruction of existing stockpiles, and capacity building in Member States – it must also be ready to respond if and when chemical weapons are used. There are different ways in which the OPCW can respond to the use or alleged use of chemical weapons, ranging from carrying out a formal investigation to providing emergency assistance.

If a Member State considers that chemical weapons have been used against it, or it is threatened by actions prohibited by the Convention taken by another country, it can request assistance from the OPCW.

Article X of the Convention sets out the procedure for requesting and receiving emergency assistance. If there is proof that there are casualties due to the use of chemical weapons and immediate action is called for, the Director-General is authorised to take emergency measures to provide assistance.

Investigations of Alleged Use

The Chemical Weapons Convention provides for formal investigations to be carried out by the Secretariat should there be allegations of the use of chemical weapons. These investigations are technical in nature and are designed to establish whether or not chemical weapons have been used, not to identify who used them. 

There are two ways in which an investigation of alleged use (IAU) of chemical weapons can be triggered. Both involve requests from States Parties. Article X of the Convention describes the procedure. The first is by submission of a request for a challenge inspection in a situation in which another State Party is alleged to have used chemical weapons. The second is by submission of a request for assistance in accordance with Article X to the Director-General in a situation in which chemical weapons are alleged to have been used against the requesting State Party, or riot control agents are alleged to have been used against it as a method of warfare. In the case of an Article X request of this sort, an IAU is conducted with two purposes: 1) to establish facts related to the alleged use, and 2) to provide a basis upon which the Executive Council can take a decision with regard to whether or not to instruct the Secretariat to take further action to assist the requesting State Party.

Once an IAU has been triggered, the Director-General will dispatch a team at the earliest opportunity (preferably within 24 hours) and inform the Executive Council and all other States Parties of this. Upon entering the State Party in question, the  team is to have the right to access any areas that could have been affected by chemical weapons and also to other areas, such as hospitals and refugee camps. Members of the team may take chemical, environmental and biomedical samples for analysis on-site or off-site at an OPCW-designated laboratory. Team members may also interview victims, eyewitnesses and medical personnel and participate in autopsies. Within 24 hours of arriving, the inspection team is to send a situation report to the Director-General. A preliminary report is to be sent within 72 hours of the team’s return to The Hague, while a final report is to be submitted within 30 days. The Director-General is to transmit these reports to the Executive Council and all other States Parties. The Executive Council is to consider the reports and take appropriate decisions.

The OPCW also responds in cases of alleged use of chemical weapons either involving non-States Parties or taking place in territory not controlled by States Parties. Under such circumstances, the Organisation is to cooperate closely with the Secretary-General of the United Nations and make OPCW resources available if so requested. Such a situation occurred in 2013 when the organisation participated in UN investigations into the use of chemical weapons in the Syrian Arab Republic, which was not then a State Party to the Convention. Investigators interviewed survivors and other witnesses, identified munitions used, collected biomedical and environmental samples and sent the samples to OPCW-designated laboratories for analysis. The investigations concluded that chemical weapons had been used.

Fact-Finding Mission

In response to persistent allegations of chemical weapons use in Syria, the OPCW Fact Finding Mission (FFM) was set up in 2014 “to establish facts surrounding allegations of the use of toxic chemicals, reportedly chlorine, for hostile purposes in the Syrian Arab Republic”. The FFM is required to study available information relating to allegations of use of chemical weapons in Syria, including information provided by the Syrian Arab Republic and others.

Since May 2014, the OPCW has deployed the FFM in numerous occasions to the Syrian Arab Republic and outside of Syria and has kept States Parties informed of its work. The FFM interviews witnesses and obtains samples and physical evidence for analysis. 

In 2015, the OPCW Executive Council and the UN Security Council endorsed the continual operation of the FFM.

The FFM’s findings established the facts surrounding allegations of the use of toxic chemicals as weapons in Syria and confirmed that chemical weapons had been used. The FFM’s findings were the basis for the work of the OPCW-UN Joint Investigative Mechanism (JIM), an independent body established by the UN Security Council (Resolution 2235, 7 August 2015). The JIM’s purpose was to identify the perpetrators of the chemical weapon attacks confirmed by the Fact Finding Mission. The JIM’s mandate expired in November 2017.


Rapid Response and Assistance

The Convention facilitates the exchange among States Parties of information and equipment that can help to protect populations against the effects of a chemical-weapons attack. It also mandates the Technical Secretariat to provide assistance to States Parties that request it. The OPCW’s Rapid Response and Assistance Mission (RRAM) fulfils this task in emergency situations. It can be deployed upon request of a State Party to the Chemical Weapons Convention that is in need of urgent assistance due to a chemical weapons attack.

Comprised of a group of experts from the OPCW Technical Secretariat, the RRAM possesses capabilities to provide advice on a range of different scenarios that may occur during a chemical weapons attack. The RRAM can also support a State Party in coordinating response efforts with other international organisations.

The RRAM periodically performs field exercises to ensure that it is ready to respond if called upon.

Technical Assistance Visits

The Technical Secretariat provides advice and assistance, upon request, to States Parties that do not seek an investigation or a rapid response, but do wish to benefit from the Secretariat’s technical expertise. For example, such expertise may be needed for identifying chemical agents used in an attack.  The Secretariat is mandated by the Convention to provide such technical assistance, which may include visits to the State Party concerned.

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