Different stages of colour of bed plus auto-refrigeration indicate chlorine was used in Douma
At April 7 2018 Syrian armed forces are suspected to have dropped yellow cylinders filed with chlorine from a helicopter on houses in Douma. Two cylinders were filmed and photographed initially soon after the dropping and a couple of days later.
One of the two cylinders ended its free fall on a bed. The location where the cylinder fell is still not publically known although Douma resistance and Russian journalists went to the location and filmed the cylinder.
The cylinder failed to release its content which was likely chlorine. Photos show the valve still attached to the cylinder. However footage showing yellow stains on the bed suggest that the cylinder was slowing leaking some of its content.
Not only that, photos made at several moments during the days after the cylinder was dropped show that initialy the cylinder and the valve were partly frozen. Ice on a cylinder which is leaking chlorine has been documented before and was even filmed.
Different stages of staines
The first known video on internet showing the cylinder on the bed was published in the afternoon of April 8, by Bilal Abu Salah, someone who is involved in the resistance.
The video shows a white pillow with no yellow stains. The valve and the cylinder itself show a white layer which could be dust or ice.
This photo shows some more details of both the pillow and the cylinder. The photo was made by Yaser al-Doumani and published on Twitter at April 9. He also published a video on Facebook showing himself in the bedroom. When the video was made is not clear. Likely at the next morning after the alleged chemical attack took place.
At April 26 2018, Russian media TV Zvezda, showed footage of the same yellow cylinder. The footage was likely made by the Russian armed forces at April 9 during their inspection of the two apartments. The white layer on the cylinder itself is gone. Also the valve is clean.
The reason could be :
- the white layer on the cylinder filmed in the footage of Yaser al-Doumani and Bilal Abu Salah was ice. The ice was melted when TV Zvezda filmed the cylinder
- the white layer on the cylinder was dust and someone removed the dust.
Ice on a cylinder is called auto-refrigeration, a phenomenon that occurs when a pressurized chlorine cylinder is punctured.
This Al Jazeera video shows a yellow cylinder similar to the two cylinders found in Douma. A yellow coloured liquid is released from the cylinder while the cylinder is partly covered in ice.
This video published by the Chlorine Institute explains the ice on a chlorine cylinder which has been punctured. Once the chlorine level inside the cylinder reaches the puncture point of the level of the valve, auto-refigeration starts. A visible frost layer will form on the outside of the cylinder at the liquid line. So at the lower level of the cylinder.
The Al Jazeera video show frost on the lower part of the cylinder
This image also shows a layer of frost on a chlorine cylinder. This is a detailed image. The cylinder was used in a chemical attack at January 22 2018, Douma, Damascus. At least 3 chlorine filled rockets based on modified Iranian 107mm rockets. More details about the rockets in this Bellingcat blogpost. One of the photo shows ‘made in Germany’ and the logo of a Germany company called Krempel. Krempel told German newspaper that is sold material called Pressspan to people in Iran.
This is a video explaning auto-refrigeration.
So frost seems to best explanation for the white layer observed on the Douma cylinder found on top of a bed.
The upper half of the cylinder shows what appears to be frost. So this means the cylinder was turned around shortly before the video was made.
The valve also shows frost. The image below shows the two states of the valve. The big image is a screenshot of the video published by Bilal Abu Salah at April 8. The insert is a screenshot of the TV Zvezda footage. (Photo compilation by Michael Kobs)
Russia held a press briefing in the Hague where it showed Syrians who lived in Douma. This is a screenshot of the briefing showing the cylinder.
The bed in the footage of TV Zvezda shows more stains than in the April 8 released footage. For example the pillow now has yellow stains as well. Yellow stains indicate the content of the cylinder was chlorine.
The April 8 released video shows a white pillow. Also the video does not show yellow stains on the bed, while the TV Zvezda video shows an almost complete yellow bed.
Conclusion
The frost on the cylinder combined with the increasing number of yellow coloured stains on the bed is a strong indication of a cylinder filled with chlorine was on the bed in a house in Douma. The cylinder was slowly leaking its content because of a small gap in or close to the valve.
