Complex sentence: Permethrin does not present any notable genotoxicity or immunotoxicity in humans and farm animals, but is classified by the United States Environmental Protection Agency (EPA) as a likely human carcinogen, based on reproducible studies in which mice fed permethrin developed liver and lung tumors.
Split into simpler sentences: Permethrin does not present any notable genotoxicity or immunotoxicity in humans and farm animals, although it is believed to cause cancers. Permethrin is classified by the United States Environmental Protection Agency (EPA) as a likely human carcinogen, based on reproducible studies in which mice fed permethrin developed liver and lung tumors.