The Vigo Ordnance Plant, also known as the Vigo Chemical Plant or simply Vigo Plant, was a United States Army facility built in 1942 to produce conventional weapons. In 1944 it was converted to produce biological agents for the U.S. bio-weapons program. The plant never produced any bio-weapons before the end of World War II but did produce 8000 pounds of an anthrax simulant. The plant was transferred to Pfizer after the war; the company operated it until announcing its closure in 2008.