Mirex is a chlorinated hydrocarbon that was commercialized as an insecticide. It was later banned because it was harmful to the environment. This white crystalline odorless solid is a derivative of cyclopentadiene. It was popularized to control fire ants but by virtue of its chemical robustness and lipophilicity it was recognized as a bioaccumulative pollutant. However, the spread of the red imported fire ant was actually encouraged by the use of Mirex, as it also kills native ants that are highly competitive with the fire ants. The United States Environmental Protection Agency prohibited its use in 1976.