Report of the OPCW Fact-Finding Mission in Syria regarding an alleged incident in Khan Shaykhun, Syrian Arab Republic April 2017

S/1510/2017

29 June 2017

Original: ENGLISH

NOTE BY THE TECHNICAL SECRETARIAT REPORT OF THE OPCW FACT-FINDING MISSION IN SYRIA REGARDING AN ALLEGED INCIDENT IN KHAN SHAYKHUN, SYRIAN ARAB REPUBLIC APRIL 2017

1. On 4 April 2017 an incident was widely reported in the international press and social media alleging an attack involving the use of a chemical weapon in the Khan Shaykhun area of southern Idlib in the Syrian Arab Republic.

2. On 13 April at the Fifty-Fourth Meeting of the Executive Council, the Director-General informed the Council of the prompt action that had been undertaken by the OPCW Fact Finding Mission (FFM) in analysing all available information on the basis of which this was determined to be a credible allegation.

3. On 12 May 2017, the Secretariat issued a note S/1497/2017 providing an update to the States Parties on the activities of the FFM.

4. The FFM continued its work involving interviews, evidence management and sample acquisition.

5. The following is the report of the FFM regarding the alleged incident in Khan Shaykhun.

6. Based on its work, the FFM is able to conclude that a large number of people, some of whom died, were exposed to sarin or a sarin-like substance. The release that caused this exposure was most likely initiated at the site where there is now a crater in the road. It is the conclusion of the FFM that such a release can only be determined as the use of sarin, as a chemical weapon.

7. As regards the question of an on-site visit by the FFM to the scene of the incident, it is an area located outside the effective control of the Government of the Syrian Arab Republic. It is to be noted that the use of sarin or a sarin-like substance is not questioned. This is also evident from the position of the Government of the Syrian Arab Republic which provided to the FFM its own information and materials as evidence. Since the mandate of the FFM is confined to establishing only the fact of the use of chemical weapons, the security risks associated with a deployment to Khan Shaykhun far outweighed any additional corroboration of the facts that have already been established. The Director-General has therefore decided that the FFM will not undertake an on-site visit to Khan Shaykhun.

1. SUMMARY

1.1 The Fact-Finding Mission (hereinafter “FFM”) conducted a preliminary assessment of all available information immediately after reports of the incident in Khan Shaykhun, which, at the time of the incident, was not under the control of the Government of the Syrian Arab Republic, surfaced in the media on 4 April 2017. The nature and extent of the information available provided a credible basis for investigation, which resulted in the FFM being mandated to gather facts regarding this incident of alleged use of toxic chemicals as a weapon.

1.2 The FFM was led by and predominantly comprised of inspectors from the Technical Secretariat (hereinafter “the Secretariat”), and was supported by various other divisions and branches within the Secretariat. Interpreters were embedded in the team and were critical to the effective functioning of the mission.

1.3 With support as indicated above, the FFM made preparations to deploy. An advanced team departed within 24 hours of being alerted to the incident, with the main team departing 24 hours later to a neighbouring country, where casualties had been transported.

1.4 The conclusions were derived from analysis of biomedical specimens, interviews, and supplementary material submitted during the interview process. Additional data came from analysis of environmental samples. Evidence was cross-referenced and subsequently corroborated.

1.5 Whilst unable to visit the location shortly after the incident, the rapid deployment enabled the team to attend autopsies, collect biomedical specimens from casualties and fatalities, interview a wide variety of witnesses, and receive environmental samples.

1.6 The team received limited information on the dispersal mechanism and, therefore, was unable to make firm conclusions on that specific matter. However, the biomedical specimens, of which the FFM had full custody, provided incontrovertible evidence that people were exposed to sarin or a sarin-like substance.

1.7 The team concluded that a large number of people, some of whom died, were exposed to sarin. The release that caused exposure was likely to have been initiated in the crater in the road, located close to the silos in the northern part of the town. The team concluded that, based on such a release, the only determination that could be made was that sarin had been used as a weapon.