Facts That Have Entered the Public Domain About Sarin, Syria, and Hexamine

As the first anniversary of the dreadful August 21 2013 attacks approaches, it is important review what we know for certain.  Although theories abound on the internet, it is very important to remind ourselves of the information that is now in the public domain, either through deliberate disclosure or through leaks that are now well verified.  Hypotheses about 8/21 need to use these facts as a basis.  Any theoretical narrative to explain what happened on 8/21 must account for the facts that we already know. The following facts are firmly established in the public domain.

Sarin was used on 8/21

We know that the chemical warfare agent Sarin was used.  We know this definitively because of several information sources:

• Sarin exposure was diagnosed in blood samples taken by the UN/OPCW team.  These samples were analyzed using a fluoride reactivation process which results in both high confidence and specificity. In other words, with this particular laboratory procedure we know that it was specifically Sarin in the blood samples and not some other chemical.  Readers are directed to page 26 of the UN report for a description of the method and further technical references.
• Sarin was specifically found in the field environmental samples taken on 28-29 August by the OPCW team.  In particular, Sarin was found in 12 samples: 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30, as indicated in the UN’s report (pages 44-50)
• In addition to the 12 samples where Sarin itself was found, there were a number of samples that contained either or both methylphosphonic acid (MPA) or isopropyl methylphosphonic acid (IMPA).  The former is a generic degradation product of nerve agents, while the latter is a highly specific degradation product of Sarin.  In other words, you really only see IMPA in situations where there is or was Sarin

The ‘Volcano Rocket’ and a 140mm Rocket were means of dispersal on 8/21

Both people on the ground in the area where the 8/21 attacks occurred and the UN/OPCW were able to determine that there were two different methods of dispersing Sarin during the attack:

• The Volcano Rocket – The Zamalka part of the 8/21 attack was perpetrated by Volcano rockets.  Various full descriptions are available online.  This New York Times article discusses some of the characteristics of the rocket system. It appears to be able to contain approximately 50 liters of chemical agent.  Because the various examples seen in the field
  
  
• The 140mm rocket – The Modamiyah attack, which was smaller in size and apparent effect than the Zamalka attack, used an apparent 140mm rocket.  Less information is available in the public domain about this smaller rocket.  Unlike the Volcano, neither the UN/OPCW team nor local people have found an intact remnant or dud.  What we do have is pictures of the motor section.  If the 140mm rocket was constructed similar to analogous US and USSR chemical rockets it would have an explosive bursting charge sufficient to shred the case of the rocket, leaving only fragments.  The UN/OPCW team found fragments but not an intact or even semi-intact 140mm rocket.

Other interesting chemicals were at the scene of the 8/21 attacks.

The Sarin that is produced by a binary process (not the same thing as binary weapon) combines a chemical known as methylphosphonic difluoride (DF) with isopropyl alcohol to create a mixture of Sarin and hydrogen fluoride (HF – hydrofluoric acid).  Some of these interesting chemicals include:

• DIMP – The chemical diisopropyl methylphosphonate (DIMP) was found in a large number of the samples.   DIMP is a known byproduct of the basic chemical reaction that creates Sarin using the DF and Isopropyl Alcohol reaction.
• Trinitrotoluene and trinitroazine – These are conventional explosives and may have been used as the bursting charge
• Dimethylmethylphosphonate – This is a precursor of DF, several steps further back down the production process.  It is a precursor of methylphosphonic dichloride, which in turn is used to make DF.  Its presence could be as a contaminant in the Sarin left over from the manufacturing process.
• Methylphosponofluoridic Acid (MPFA) – This substance is a degradation product of DF.  It is also a degradation product of Sarin under some circumstances.

• Hexamine, also known as hexamethylenetetramine.  This was found in numerous field samples at the sites investigated by the OPCW/UN team.  It has numerous industrial uses.  However, up to the point of the UN report, it has had little or no published use in chemical warfare.  The fact that it was specifically reported as an “other interesting chemical” in the UN report.

Things that were NOT reported at the scene

It is also revelatory what was NOT reported in the laboratory analysis.  By inference, the reported lack of certain substances can be considered as being in the public domain.  It should be noted that the lack of a particular substance doesn’t mean it wasn’t there, just that it did not get collected or detected by the UN/OPCW team. The lack of the following are interesting:

• DF – No DF was present.  This is not surprising as the vapor pressure of DF is quite high and any residual DF would have either degraded or evaporated.  This is expected given the period of time elapsed between the attack and the site visits to collect evidence.
• Isopropanol – Again, some isopropyl alcohol might have been expected immediately after dispersal, but as this is quite a volatile substance.
• Other Amines – No other amines were found, including isopropylamine.  Once again, many amines of possible use as additives would likely have evaporated given the elapsed time.
• Amine-HF complexes – No amine-HF complexes, such as hexamine-HF salts, were noted.

Various inferences can be draw from the lack of these particular substances, which I will address in later articles.

The Syrian government made interesting declarations to the OPCW

Syria deposited its “Instrument of Accession” to the Chemical Weapons Convention on 14 September 2013. Syria made declarations to the OPCW as part of the process. While the full declaration has not been released into the public domain, several salient facts have emerged.

• The Assad Regime had an active chemical weapons research and production program.  According to the UN/OPCW Joint Mission: ”Syria has declared quantities of chemical weapons agent, related chemical materials and the production, mixing and filling facilities associated with such systems.”
• A portion of the Syrian chemical arsenal was kept as binary components, not as finished chemical warfare agent. Link
• A significant inventory of precursors, additives, and feedstock chemicals was declared. Many of these chemicals were listed in an OPCW document in November 2013.   Interestingly, this document listed 80 tons of hexamine.
• There was a non-trivial waste stream associated with the chemical weapons program.  There same document listed nearly 8 million liters of waste effluent from chemical weapons production.  This is indicative of very significant production activity.

Various interesting facts and statements have leached out since December 2013

Other interesting information has slipped into the public domain through other outlets than official UN/OPCW documents.

• The Syrian program had both mobile and static “mixing and filling” equipment.  Link
• The chemical demilitarization project being undertaken on the American ship the MV Cape Ray is not handling actual Sarin, merely the precursor DF. This is another admission that the nerve agent arsenal in Syria was maintained in the form of binary components, not as finished agent.
• On 13 December 2013, Ake Sellstrom and Scott Cairns, head and deputy respectively of the UN/OPCW team that collected the evidence, gave witness testimony that was recorded by the US TV network C-SPAN (link). In their statements, it was revealed that hexamine was possibly used as an acid scavenger in the Sarin used on 8/21.
• Ake Sellstrom was interviewed by Gwyn Winfield, editor of CBRNe World magazine.  His interview contained the following statement:

GW – Why was hexamine on the list of chemical scheduled to be destroyed – it has many other battlefield uses as well as sarin? Did you request to put it on the list or had the Syrian’s claimed that they were using it?

AS – “It is in their formula, it is their acid scavenger.”