It is extremely toxic to fish. Chronic exposure may cause liver and kidney damage. Rotenone is more acutely toxic than Malathion or Sevin. This product is used as a broad spectrum contact and stomach poison. It is useful against leaf feeders, degrades rapidly in air and sunlight with some residual effect.
Seed treatment releases insecticidal alkaloids.
The alkaloids are chemicals similar to caffeine, nicotine and cocaine. The mode of action is through nerve cell membranes causing loss of nerve function, paralysis and death. This pesticide is usually formulated with a synergist. The seed dust is the least toxic of the botanical insecticides. However, the purified alkaloid is very toxic, and it is a severe skin irritant.