HERMISTON -- Several issues at the Umatilla Chemical Agent Disposal Facility contributed to a worker being exposed last month to mustard agent, a chemical weapon, the Army has concluded.
An analysis of the cause of the incident at the Umatilla Chemical Depot has been completed and steps are being taken to correct issues it identified, according to a statement by the Army Chemical Materials Agency.
The state of Oregon has given approval to start a trial burn of the remaining mustard agent but that will not be done until corporate officials at URS, which is the incinerator contractor, and the Army review and approve corrections related to the contamination incident, said Hal McCune, protocol officer for the disposal facility. Some mustard agent already has been destroyed in earlier tests at the incinerator.
On March 17 two workers were calibrating a scale by sending weights on a conveyer belt into an area of the incineration plant where work had been done with mustard agent. A drop of liquid on the weights seeped through the coveralls of one of the workers.
The workers earlier had spotted the drop but assumed it was oil, McCune said. One of the workers later forgot it was there and sat on it.
Procedure at the incinerator requires workers to immediately evacuate if there is an unknown substance, and that was not strictly followed, McCune said. The contamination was not discovered until an alarm in an airlock sounded after they finished work and were leaving the area.
There also were possible communication issues between the workers and the control room where the workers were being watched via video.
A control room operator may have been distracted, McCune said. In addition, a policy that the workers and control room operators repeat back communications to each other to make sure they were clear was not followed as precisely as it could have been, he said.
In addition, the equipment should have been thoroughly decontaminated after last being used on mustard agent to prevent the drop from falling on the weights.
The analysis indicated issues fell into the categories of conduct of operations, procedural compliance, mustard agent awareness and entry planning process, according to the Army Chemical Materials Agency.
All crews are receiving refresher training to emphasize the importance of recognizing potential contamination and risks from contact with chemical agents.
During the contamination incident, workers had been approved to carry, rather than wear, gas masks. No mustard incineration was being done that week.
Until issues are resolved any worker going into certain areas of the plant must wear full protective gear, including a supplied air respirator. A review board with members from the Army and the Centers for Disease Control will review corrections made before workers may again enter the plant with less protective gear.
The worker who was contaminated developed a skin blister, but it is healing well, officials said. Blood tests confirmed the exposure.
It was the first contamination incident during incineration at the depot, and the third in the nation's chemical weapon disposal program.
The Herald requested the analysis document from the Army but did not receive it Monday.
-- Annette Cary: 582-1533; email@example.com.