Briefing note: the alleged chemical attack in Douma on 7 April 2018, and other alleged chlorine attacks in Syria since 2014

Paul McKeigue, Jake Mason, David Miller, Piers Robinson

Research output: Working paperWorking paper and Preprints


Early statements by the US and French governments that a nerve agent had been used in the alleged chemical attack in Douma on 7 April 2018 were rebutted by the OPCW Fact-Finding mission which reported that neither environmental samples obtained on-site nor blood samples from purported victims contained any trace of nerve agent. This indicates that the US and French governments were poorly informed at the time of the US-led missile attack on Syria on 14 April.
The Prime Minister misled the House of Commons by stating on 16 April that the OPCW team had been prevented from visiting the Douma attack site by the Syrian authorities and the Russian military, and may also have misled the House by stating that the US-led missile attack was “specifically targeted at three sites” allegedly associated with chemical weapons (rather than targeted on Syrian military infrastructure as reported elsewhere).
The OPCW Fact-Finding Mission did not reach any conclusion as to whether a chemical attack had taken place. The detection of chlorinated organic compounds in environmental samples is consistent with release of chlorine from a gas cylinder at the two alleged attack sites, but this does not distinguish between a chemical attack and a staged incident.
Experts agreed that the images showing bodies of victims lying close together in an apartment building were not compatible with exposure only to chlorine, from which the victims would have been able to escape by moving to the windows or leaving the building. This is supported by experience of industrial accidents with chlorine in which those exposed are usually able to escape.
As no nerve agent degradation products were detected and the positions of the victims’ bodies are not compatible with death from chlorine exposure on the spot, the only remaining explanation is that the victims were killed by other means.
Other observations favour a managed massacre rather than a chemical attack as the explanation for the Douma incident:-
the positioning of the gas cylinders is more consistent with staging than with an air-dropped munition
at the site where most victims were shown, a fire was lit in the room underneath the gas cylinder.
For chlorine to be useful as a weapon, it would have to be released on an industrial scale as in 1915 rather than as a single cylinder or barrel dropped from the air.
Assessments by the OPCW Fact-Finding Mission that chlorine had been used as a weapon in Syria between 2014 and 2017 were based on secondary sources without on-site inspections. This violates a precept that OPCW had set for itself in 2013.
The conclusions of the Fact-Finding Mission that use of chlorine in alleged attacks in Syria between 2014 and 2018 was “likely” or supported “with a high degree of confidence” relied on witnesses and samples provided by purported non-governmental organizations with access to opposition-held areas of Syria. These organizations included:
a “CBRN Task Force” set up by an agent of the intelligence service of a state committed to one side in the Syrian conflict
Same Justice / CVDCS, a Brussels-based organization whose operations are not transparent
the White Helmets, who would themselves be implicated if these incidents were staged
In relation to one of the incidents from which the CBRN Task Force collected materials — the alleged chlorine barrel bomb attack in Talmenes on 21 April 2014 — the UN/OPCW Joint Investigative Mechanism found clear evidence of staging at one of the two alleged locations.
In a widely-publicized incident in Sarmin on 16 March 2015, the deaths of a family of six were allegedly caused by a chlorine barrel bomb. For this incident the alleged munition is implausible, the alleged mode of delivery is improbable, and the images of the child victims in hospital are consistent with drug overdose rather than chlorine exposure as the cause of death. Despite evidence that the incident had been staged, the Leadership Panel of the UN/OPCW Joint Investigative Mechanism — Gamba, Neritani and Schanze — relied on information obtained from unspecified “other sources” to conclude that a Syrian air force helicopter had dropped a chemical weapon.
Original languageEnglish
PublisherWorking Group on Syria, Propaganda and Media
Publication statusPublished - 20 Aug 2018


  • Douma
  • Syria
  • Chlorine
  • Chemical weapons
  • Propaganda
  • Assad
  • OPCW
  • Sarin

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