In 60 years, no leaking mustard agent had ever been detected at the Army's Aberdeen Proving Ground (APG) storage area in Maryland. That changed when an alarm sounded recently in an igloo holding ton-sized containers of the chemical warfare agent awaiting disposal via neutralization.
The trace amount (7.68 mg/m3) of mustard vapor detected by the alarm was confirmed using mini Chemical Agent Monitors that were inserted into the storage igloo, says Jeff Lindblad, spokesman for the Army Chemical Materials Agency. No liquid agent was found.
“Whatever leaked has not escaped from the storage building,” APG spokesman George Mercer says. He adds, “Since the original detection, no additional vapor has been detected inside the structure.” The storage igloo is located within the Edgewood Area of APG and a few hundred yards from the building where agent neutralization actually takes place.
No workers were exposed to the blister agent. After temporarily relocating workers at the neutralization facility, destruction of the agent resumed.
Since April 2003, Lindblad says just over 294 tons of mustard agent has been destroyed. Complete destruction of the Aberdeen stockpile is projected to be achieved this December at a cost of more than $850 million.
Mustard agent is corrosive, and pinpoint holes could have been created in the thick-walled carbon steel containers. As Edgewood Chemical Activity Civilian Executive Mary Jo Civis explains, “There have been instances at other stockpile sites where a very small amount of vapor has leaked from a container, then sealed itself and stopped leaking.” APG officials are still trying to locate the leak.