The Pine Bluff Arsenal's Binary Destruction Facility has destroyed its stock of DF, designed to be mixed with other chemicals in flight to create nerve agents, arsenal officials said this week.

The last of the nation's inventory of DF, methylphosphonic difluoride, was destroyed Thursday at the arsenal, officials announced in a news release. DF, a chemical precursor, was designed to mix with other agents to form the nerve agent sarin.

Employees began destroying DF, stored in more than 56,000 small canisters and seven drums, in December.

After an eight-week cleanup the facility will begin destroying another chemical precursor, called QL or diisopropyl aminoethylmethyl phosphonite. The chemical was designed to combine with other agents to form the nerve agent VX. The QL will be destroyed by July, according to the release.

The agents are part of the arsenal's "non-stockpile" chemical agents, which include items such as test vials and chemical precursors.

The arsenal has about 12 percent of the nation's stockpile of chemical weapons. The United States is working to destroy its stockpile by 2012 to comply with an international treaty.

The Pine Bluff Arsenal began incinerating chemical weapons on March 29, 2005 and to date has destroyed 34,207 GB rockets, about 38 percent of its complete stock. It has also destroyed 352,782 pounds of the GB nerve agent, about 5 percent of its stock.

This story was published Tuesday, April 11, 2006