Since yesterday, they've been saying that a number of barrels were found in northwestern Iraq that in early tests appeared to contain chemicals. But today they have more information:

"The New York Times quoted Capt. Ryan Cutchin of Mobile Exploitation Team Bravo — one of the specialist teams deployed in Iraq (news - web sites) — as saying further testing by his unit had shown that the barrel's contents were not chemical weapons. He also said that initial suspicions that two vehicles at the site were mobile chemical laboratories had proved wrong.