Numerous new videos of the rockets known to have been associated with the Aug. 21st chemical attack are now available. Thankfully, some of the videos show the surrounding area so that we can observe the damage to the area around the rocket landing area.
The first video is a video I missed in my post on August 23. In this video, we see clearly that the narrator is showing that the rocket completely cleared the area of vegetation. One commentator had questioned that crops would be planted at this time of year in Syria, but in the video we can see an adjacent parcel full of growing crops. The narrator is down on the ground with a nice closeup of the damage to the crops. Fuel air explosive are known for their ability to clear vegetation. Human Rights Watch, in its “Backgrounder on Russian Fuel Air Bombs”, writes, “According to one Russian military scientist writing for the Russian military magazine Voyennyye Znaniya (Military Knowledge) . . . “fuel-air explosives are capable…of completely destroying in a given area vegetation and agricultural crops that have been planted.”
Also, notice the small crater. If the rocket exploded upon impact, rather than exploded in the air, I would expect that we would see a larger blast crater given the surrounding damage.
It seems highly improbable that a weapon designed to spread a chemical agent to cause death would contain an explosive charge powerful enough to destroy and flatten vegetation in a large blast radius, as well as destroy concrete walls. I’ve reviewed the literature on chemical delivery systems and not seen any chemical weapons designed with close the explosive force that this rocket displays in this video. This makes sense because a large explosion would likely destroy the chemical agent.
Syria Analysis 
What are the chances that both types of weapons have been used? The place has been being shelled for weeks?
Thanks for your question. I certainly think it is possible that there are two or three fills in these rockets: high explosive, fuel air, and chemical agent intended for dispersion (non-explosive). However, the rockets with HE fills have been marked with yellow. The rocket #197 in the video is not marked with color, and in my opinion it is clearly a fuel air explosive. For the rocket not to be a fuel air explosion, the narrator would be wrong, or lying, as to the damage caused by it. In addition, nothing except a fuel air explosion explains the vegetation being blasted away, because there is no blast crater anywhere nearby in the video. The building could have been damaged previously, but the placement of the remains of the rocket and pieces of the warhead at the base of the destroyed walls causes great suspicion that the rocket caused the damage. Further, if another blast from a bomb or rocket destroyed that building three stories high, where is the blast crater? There would be a large crater in the ground from such a blast filled with high explosives.
Many have said that it certainly seems irrational for the Syrian regime to use chemical weapons while the UN inspectors were in Damascus. Many chemical experts believe that the symptoms are inconsistent in some ways with sarin. If we know that some of the rockets were fuel air explosives (from rocket #197 and others), then what about the ones that didn’t detonate properly, which we know happens with frequency given the difficulties of producing fuel air detonations, difficult even for the United States Military. We know that undetonated fuel air explosives create lethal clouds of deadly chemicals. In my revision of my 8/23/13 post, I do some back of the envelope calculations to show that the resulting lethal cloud from just one undetonated rocket could be very large and kill many people.
Nobody is claiming that this August 21 #197 rocket in the video is a CW. I think most agree with you that it is a FAE weapon. You can see the ground scorched in a radius and the building partly demolished.
The CW is probably delivered by the BM14 (grad) rocket.
This rocket has red lettering. These have been identified as possible CW rockets by many people and were analyzed by the UN chemical weapons inspectors as well. The Syrian rebels in these videos (and in other videos) are alleging that these are chemical weapons.
Minor point: The BM14 does not launch a grad rocket, it launches a 140mm rocket.
On one of these cannister parts we see the brown stuff on its inside (0:37) A few, but not all of the munitions that are allegedly CW are tainted with this brown goo. Sarin is known to be a colourless fluid, and indeed, some of the munitions have no visible trace of what was in them. But this one has.