A sixth sample of mustard agent from the Pine Bluff Arsenal has been sent to an off-post laboratory for analysis.

The small sample was sent Friday, specially packaged for safe shipment via Army air transportation. Arsenal officials said Monday the samples were being used to verify the physical and chemical characteristics of the compound stored in one-ton containers at the arsenal.

Mustard is a blister agent. The containers are the last munitions that are scheduled for incineration at the arsenal.