What is the toxicity of permethrin?
Animals: • Rats fed high doses of permethrin exhibited tremors, salivation, hyperactivity, hyperexcitability, urination, defecation and incoordination (1). See box on laboratory testing. • In a study involving newborn and adult rats, the newborn rats were found to be more sensitive to permethrin than the adults. The enzymes that break down permethrin in the body are not completely developed in the newborn rats. The incomplete development of the liver enzymes made the newborn animals more sensitive to permethrin than mature animals (2) Laboratory Testing: Before pesticides are registered by the US EPA, they must undergo laboratory testing for short-term and long-term health effects. Laboratory animals are purposely fed high enough doses to cause toxic effects. These signs of poisoning are not expected in humans or pets since the amount of a pesticide that people and pets may be exposed to is low compared to the doses fed to laboratory animals. Humans: • Permethrin has low to moderate to
