Worker apparently burned by mustard gas at Oregon weapons depot

A worker prepping chemical weapons for destruction at Oregon's Umatilla Depot appears to have been burned by a mustard agent in what may be the first exposure-related injury since the depot began incinerating its chemical-weapons stockpile in 2004.

The Army is still investigating the incident, but officials "feel pretty certain at this point that it was mustard," said Greg Mahall, spokesman for the depot. Another worker likely was exposed but hasn't shown any telltale skin blistering.

The Army says no chemicals were released into the environment and the public was not at risk. The injured employee already is back at work.

The incident began Wednesday afternoon when a pair of workers in masks, gloves, boots, aprons and cotton coveralls were inside an air-locked industrial plant weighing a propane-tanklike canister filled with mustard gas before an upcoming test of the Army's latest incineration process.

The men finished and moved to leave when the Army's sensitive sampling monitors warned a chemical agent was in the air. The men were rushed to doctors, where they were watched until a small blistering rash appeared on one man's back.

"It's not like the movies where acid splashes on you and you go 'Ow, ow, ow,' " Mahall said. "It will sit on you for two to four hours before starting to blister."

Around the country, the Army has had dozens of false alarms and true accidental releases of poisons from aging chemical weapons, including four in as many months at a munitions depot in Kentucky last year. But exposure incidents are rare.

"In the history of Umatilla, it's never happened before," Mahall said. "In the entire Army program, we've only had one other, a worker in Utah who made a full recovery."

The worker's exposure appears to have been slight, and Army officials have sent blood samples to a lab to make sure they identified it correctly. Investigators are reviewing videotapes of the incident to understand what happened, though it's expected to be weeks before they know for certain.

Used during World War I, mustard gas was an excruciating poison, causing internal and external bleeding, vomiting and burning of the eyes and bronchial tubes. It was a painfully slow killer, often taking weeks to do its job. But mustard was among the least horrific things stored at Umatilla.

For decades, some of the nastiest weapons created by humans were stored at the site in 1,001 underground concrete igloos — enough poisons to kill millions of people. They were transported by rail cars that also carried rabbits, which served as an early-warning system for leaks.

There were nearly 3,800 tons of VX gas, less than a drop of which could kill within minutes. Most was loaded in 100,000 deteriorating rockets. There were thousands of nerve agents packed into bombs and land mines, and spray tanks designed to sprinkle poison gas over battlefields.

Although the federal government's effort to rid the nation of chemical weapons is ongoing, the Army already has destroyed Umatilla's nerve agents. What remains are the blistering agents stored in metal canisters.

Craig Welch: 206-464-2093 or cwelch@seattletimes.com