Iraq Shell May Contain Sarin

  A 155-mm artillery shell said to contain the nerve agent sarin and rigged as a roadside bomb exploded near Baghdad International Airport on May 15. The explosion caused only minor injuries and didn’t contaminate the blast area. It has, however, raised many questions among chemical weapons experts that the Pentagon has yet to answer.

In Iraq two days after the explosion, U.S. military spokesman Brig. Gen. Mark Kimmitt described the shell as old, probably predating the 1991 Persian Gulf War, and binary in design. In a binary shell, two precursor chemicals—methylphosphonyl difluoride (DF) and isopropanol—would mix after firing to form sarin: O-isopropyl methylphosphonofluoridate, also known as GB.

Jonathan B. Tucker, senior researcher at the Monterey Institute of International Studies, is “baffled that Kimmitt was so specific” in describing the shell as binary “because Iraq denied having produced a true sarin binary artillery shell.” Kimmitt himself noted that Iraq had declared to the United Nations “all such rounds destroyed before the 1991 Gulf War.”

Ewen Buchanan, spokesman for the UN Monitoring, Verification & Inspection Commission, says Iraq did admit to a 1989 R&D program to create a sarin binary shell. “Iraq said it tested fewer than 100 warhead canisters for this system, claimed the tests were positive, but then said it didn’t go on to deploy the system,” he says.

A U.S. official and chemical weapons expert, who asks not to be named, confirms Buchanan’s point. “The only artillery projectile I know Iraq had contained mustard gas and was not binary.”

Another U.S. official, also a chemical weapons expert, speculates that if the shell was binary, “it could have been a one-off prototype.” Or it could have been a remnant of Iraq’s R&D program, as David Kay, who led the Iraq Survey Group searching for weapons of mass destruction, suggests.

Kay is “almost certain that it was a leftover shell,” but he questions whether it was binary. He is puzzled why the military thought it was binary. “If I had to rank probabilities, I would guess the shell was unitary and its sarin fill had become diluted and less potent.”

In his press briefing, Kimmitt said the shell was not marked as a chemical munition, but he never explained how the military determined it was a binary. Nor did he explain how sarin was detected.
The second U.S. official believes troops used the Army’s Chemical Agent Monitor to detect the agent. CAM is a portable unit that broadly distinguishes among G nerve agents like sarin, VX nerve agent, and mustard agent. It can’t identify the exact chemical agent and is notorious for yielding false positives.

Kay says he remains “agnostic on whether it will turn out to be sarin. We’ve got to see the results of the [confirmatory] tests” now being conducted. If it does turn out to be sarin, then, he says, “the real issue is resolving whether it was a singleton or did it come from a stockpile.” Kay admits that “this will be difficult but very important to determine.”

At his press briefing, Kimmitt said the survey group would determine whether the detonated shell pointed to Iraq’s possession of chemical weapons prior to last year’s invasion.