The Trench


Green is the colour

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The Organisation for the Prohibition of Chemical Warfare (OPCW) is about to investigate the various allegations of the use of chlorine in Syria over the past few weeks. It is the right decision. It is the only decision possible in view of the many witness accounts and footage available on internet sites. However, the hope that the announcement of the fact-finding mission on 29 April might deter the perpetrator from future chlorine attacks was quickly dashed: a new chlorine bombing took place a day later.
The symbolism of the date cannot be overstated. 29 April was the 17th anniversary of the entry into force of the Chemical Weapons Convention (CWC). 29 April is the UN’s annual Day of Remembrance for all Victims of Chemical Warfare. And now, 29 April is also the day on which for the first time the potential violation of the ban on the use of chemical weapons (CW) by a state party to the CWC was officially recognised. A mere six months after Syria joined the convention. And 99 years after chlorine ushered in the age of modern chemical warfare.
On the same day, a British newspaper, The Daily Telegraph, felt the need to headline that it had the proof that Assad launched the chlorine attacks. It caused a stir, not in the least because the article ended with the claim that the newspaper’s investigation was on a par with OPCW procedures. Hardly.
No stranger to the battlefield of world opinion
It is worth recalling that initial accounts on the chemical attack at Khan al-Assal (near Aleppo) on 19 March 2013 referred to chlorine. Early press reports mentioned 26 fatalities, a figure that would eventually rise into the low thirties, and scores of otherwise harmed individuals. I was not convinced that the observed effects correlated with claims about the agents used. In a March 2013 brief for the EU Institute for Security Studies I wrote:

This claim is intrinsically problematic. Exposure to chlorine stored in a warehouse or near a production installation hit by a shell could account for respiratory problems and skin irritation, but not for a high number of fatalities. One would need a very high volume of the agent to obtain lethal doses in open air; the explosion would most likely destroy part of the agent; and highly recognisable evidence of corrosion at the site of attack could not be missed.
More recent accounts specify that Islamic extremists filled a home-made rocket with chlorine dissolved in a saline solution. The agent would thus amount to Eau de Javel (bleach). Even in its highest industrial concentration of 40%, the agent cannot explain the fatalities, even if one were to assume that a very large number of home-made rockets hit the target in a tight cluster.

A month later, I remained just as unconvinced. In the meantime, having reviewed all CW references I had collected since the start of the Syrian civil war, I was struck by how stories on a particular incident may change with time. As a rule of thumb, everything ultimately turned into sarin. And as suggested in the quote above, sarin could become bleach. It is worth retracing that metamorphosis.
The Khan al-Assal attack of 19 March prompted the Syrian Government to request the UN Secretary General to conduct an investigation of alleged use. As already mentioned, reports at the time were referring to chlorine or witnesses recalling a chlorine smell. Chlorine was also what the Syrian government reportedly cited in its letter to Ban Ki-moon. Already early in December 2012, the Syrian Foreign Ministry had warned of possible insurgent use of CW in letters to the UN. It alluded to a Syrian-Saudi factory SYSACCO near al-Safirah (southeast of Aleppo), which had just been captured by militants from the jihadist Al-Nusra Front. That factory produced  sodium hydroxide (caustic soda) and hydrochloric acid (HCl). Not only did this claim prepare a plausible foundation for the chlorine allegations three months later, it also got close to the bleach (sodium hypochlorite), commercially known as Eau de Javel in Europe.
Four days after the alleged attack we learned that ‘the Syrian military believe that a home-made locally-manufactured rocket was fired, containing a form of chlorine known as CL17, easily available as a swimming pool cleaner. They claim that the warhead contained a quantity of the gas, dissolved in saline solution’. Now, what form of chlorine is Cl17? A look at the Mendeleev’s Periodic Table teaches us that Cl is the chemical abbreviation of chlorine and 17 is its chemical number. However, this demystified CL17 is contained in a saline solution, which is, of course, sodium hypochlorite. I use it to disinfect my toilet. Eau de Javel as a chemical warfare agent, that was new to me. (However, do note the source of that story.)
So, please forgive me if I seem to demand a higher level of convincing.
Questions I would like to see answered

  • From some of the footage available on the internet, I do think that a toxic substance must have affected a number of people. However, I am less sure about the more precise elements in the accusations. For example, based on the pictures of one of the flasks, I gather that a substance (in this case, liquid chlorine, I presume, but then letters with white powder are also often marked ‘anthrax’) was contained in a small industry-standard vessel (apparently of Chinese origin & and marked Cl2). What I would like to know is how much explosive it would take to break open such a container? How much chlorine (if this is what was inside) would have been destroyed or burned by that explosion? What are the dynamics of chlorine release in the scenario that the amount of explosives is sufficient just to break the seal / valve of the vessel? I have been told that such an amount would be very small, but how does the resulting aperture affect the dynamics of gas release? Was the vessel contained inside a drum (i.e., a confined space), as some reports suggest? If so, how does that affect the dynamics of the explosion and gas release? What would the impact of an explosive devise have on the rate of release of the chlorine and how much of the chlorine would actually remain after the rupture of the container?
  • How much chlorine (if this was what it was) was inside the vessel? How would sufficient chlorine be built up locally to seriously injure or even kill people? In what environment was the chlorine released (e.g., closed space of a room or outside in the open air)? Chlorine is perceptible to humans in very low concentrations, so why would people remain in close vicinity of the devise long enough to absorb a harmful dose of chlorine? Following the blast, I have been told, people in close proximity of the bomb may be dazed and confused and in their disorientation may consequently not escape from the area. Was this the case?
  • Would an industry-standard container rupture simply by dropping it from a helicopter?
  • One film clip on Brown Moses’ blog shows a helicopter dropping something, followed by a – in my mind – big flash. Would chlorine withstand the forces and heat of such a detonation? Detonation of chlorine was pretty ineffective in Iraq (at least as regards the impact of chlorine on the targeted group of people).
  • Are there any reports of corroded metals in the vicinity of the area of release? (Moisture in the air acts as a catalyst for chemical reactions with chlorine, and the agent is very aggressive on metals and alloys.)
  • Why do press reports refer to a ‘yellow’ smoke or powder (as one Beirut-based journalist described the observations to me)? Chlorine tends more towards pale green, sometimes with a yellowish hue. However, the yellow might dominate in a sun-swamped environment and an overall sandy-colour backdrop. I do not know. A BBC clip (2nd clip, middle article, final seconds) posted on 28 April, shows yellow smoke from a barrel bomb attack in which no chlorine was used. So, can we see similarities of symptoms and phenomena between different types of attack, but which witnesses do not or cannot differentiate? Another example: as for the reports of a chlorine smell near the scene of the Khan al-Assal attack in March 2013, chemical weapons expert and chief operating officer of SecureBio, Hamish de Bretton-Gordon, then said that conventional high explosives can also produce an odour which might be mistaken for chlorine.
  • Would one expect a hissing sound as the chlorine under pressure escapes from the container? Have we seen any such witness accounts?
  • Are we looking at a case of what I call ‘opportunistic use of toxic chemicals’, where people (government soldiers, their allies, or insurgents) took hold of containers at an industrial site and improvised a new device of war? In other words, are we looking at a case of deliberate preparation for chemical warfare by whoever is responsible for the events?

A good call
The OPCW Director-General’s decision is the right one. Ambiguity and speculation must be removed—and fast. The lack of precise timing (or explanation of the necessary preparations and precautions) in the OPCW press statement is worrying, and not just because this is the first time the organisation is called upon to launch an investigation of use all by itself (in previous investigations the OPCW assisted the UN Secretary-General, as Syria was not yet a party to the CWC). Chlorine is a very volatile element, so the critical question is how long the agent might reside in the soil, on other surfaces or inside containers? The answer is not long, especially not in the heat of Syria.
Still, the exercise should not be futile. Investigations of alleged use typically apply various methods (medical analysis, identification of plausible witnesses and corroboration of individual stories, matching pictures and film footage based on the stories by the carefully selected witnesses, etc.), whose independent results should contribute to building a more or less consistent picture of events. The OPCW inspectors would deploy sophisticated detection equipment. Any evidence brought back from the incident sites would be subject to strict procedures to preserve the chain of custody and then divided over multiple OPCW-certified laboratories for analysis.
And oh, just as a small afterthought: with an OPCW investigation, one of course does not have to wonder who has paid the piper.

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