What is Rotenone?

Rotenone is a naturally-occurring compound derived from the roots of tropical plants in the genus Derris, Lonchocarpus or Tephrosia. It has been used for centuries by natives in Central and South America to catch fish for food. Rotenone has been used as a pesticide since the mid 1800s and by fish managers in the U.S. since the 1930s to remove unwanted or invasive fish. Rotenone is an active ingredient in many insecticides used on both home gardens and commercially-raised food crops. Rotenone is a common ingredient in insecticides for ornamental gardens, greenhouses, and stored grain and is also used to treat lice on domestic animals such as dogs and horses.

Currently, rotenone is commercially available as either a wettable-powder or liquid and is registered by the Environmental Protection Agency (EPA) as a restricted-use pesticide for fish management. Readily absorbed through the gills, rotenone is lethal to fish because it blocks the biochemical process that allows fish to utilize the oxygen in their blood during cellular respiration. Because of the low concentration used for fish management, rotenone use poses little threat to birds or mammals, including humans. Rotenone is quickly degraded by light, warm temperatures and organic materials. It can also be neutralized with potassium permanganate.