A shell fired at an Iraqi air base last week where U.S. troops were operating did not contain mustard agent, a military spokesman said Tuesday.
{mosads}“Definitive lab tests conclude: No mustard agent present in munitions fired at Qayyarah West AB Sept 20,” tweeted Air Force Col. John Dorrian, spokesman for the U.S.-led coalition fighting the Islamic State in Iraq and Syria (ISIS).
Last week, Pentagon officials said ISIS fired a rocket approximately one foot long at Qayyarah air base in northern Iraq.
After it landed within the base, U.S. troops tested it and received a positive initial reading for mustard agent. A second reading turned up negative, but the Pentagon indicated last week that could have been due to sun exposure or the passage of time.
Fragments of the rocket were then sent to a lab for further testing.
On Thursday, Joint Chiefs of Staff Chairman Gen. Joseph Dunford told the Senate Armed Services Committee the military assessed a tar-like substance on the rocket to be sulfur mustard blister agent.
“It wasn’t particularly effective, but it was a concerning development,” he said.
But on Friday, Dorrian told reporters at a briefing that the first test done at the lab was inconclusive and that another, more advanced test needed to be done.
It was that final testing that determined there was no mustard agent.
Still, the Pentagon has expressed concern about ISIS’s desire to develop chemical weapons.
At the same hearing last week, Dunford said U.S. forces have carried out about 30 strikes against “emerging chemical capability.”
For example, he said, the coalition recently took out a pharmaceutical plant ISIS was using.
“We also are tracking a number of targets, one we struck last week, which is a pharmaceutical plant which is part of the chemical warfare network that ISIL has,” he said, using an alternate acronym for the terrorist organization. “And so we have been tracking this.”