Fluridone is an aquatic herbicide often used to control invasive plants. It is sold under the names Sonar, Avast! and Whitecap and is used in the United States to control hydrilla and Eurasian watermilfoil among other species. It is a systemic herbicide that works by interfering with carotene formation which leads to chlorophyll degradation. Fluridone is sold as a liquid and as a slow release solid because the herbicide level must be maintained for several weeks. The chemical was first reported as a possible herbicide for cotton fields in 1976. It was registered with the U.S. Environmental Protection Agency in 1986 and has low toxicity to animals with no restrictions on swimming or drinking in treated water bodies. Fluridone breaks downs in the environment over days or weeks with the major degradation product being N-methyl formamide. The half-life of fluridone in soils and sediments is nine months.