http://www.msnbc.com/news/895392.asp

Excerpt:

April 8 — Conclusive testing is still under way, but the latest tests indicate that barrels found in central Iraq do not contain chemical weapons agents as first suspected, U.S. military sources said on Tuesday. Other suspicious finds — especially rockets potentially packed with sarin and mustard gas — were also still being investigated.

SAMPLES FROM the sites investigated Monday were being sent to the United States for more definitive tests. If any of the discoveries were confirmed, it would be the first find of chemical weapons during the war.
The barrels discovered Monday by troops of the Army’s 101st Airborne Division had been buried at a pesticide plant in Hindiya, 20 miles southeast of Karbala. The barrels initially tested positive for the nerve agents sarin and Tabun, as well as mustard agent, a blistering chemical first used in World War I.
NBC’s Dana Lewis said the 15 barrels appeared to have been recently buried in a pit and indicated that troops also found weapons in the pesticide plant, suggesting that it might have been a disguised military facility. He said the troops were led to the site by an Iraqi.
Subsequent, more sensitive, tests turned out to be negative, U.S. military sources officers said Tuesday.
“The latest tests turned out negative,” one source said.
In a separate find, soldiers with the 1st Brigade of the 101st Airborne on Tuesday discovered an unknown number of barrels near Najaf, south of Karbala, NBC News reported.
Soldiers who opened one barrel experienced nausea, vomiting and a rash. Preliminary testing of the substances was under way.