See box on cancer. There are no humans studies of the potential of permethrin to cause cancer . The U.S. EPA has strict guidelines that require testing of pesticides for their potential to cause cancer. These studies involve feeding laboratory animals large daily doses of the pesticide for up to 2 years. These animals are compared with a group of animals that did not receive the chemical.
Animal studies help show whether a chemical is a potential human carcinogen.
If a pesticide does not cause cancer in animal tests, then the EPA considers it unlikely the pesticide will cause cancer in humans. There are no human studies of the potential of permethrin to cause reproductive or developmental effects. See box on half-life. Permethrin has an extremely low potential to move in soil. Half-life is the time required for half of the compound to degrade.