Bifenthrin

Bifenthrin (CAS# 82657-04-3), an insecticide is a synthetic derivative of a class of compounds called pyrethrins that are found in chrysanthemum flower extracts. Bifenthrin was first registered for use by the United States Environmental Protection Agency (U.S. EPA) in 1985. IUPAC name for bifenthrin is: 2-methylbiphenyl-3-ylmethyl (Z)-(1RS,3RS)-3-(2-chloro-3,3,3-trifluoroprop-l-enyl)-2,2-dimethylcyclopropanecarboxylate. Bifenthrin containing products are used on cereals, cotton, corn, alfalfa, hay, grass seed, some fruits, ornamentals, and vegetables. Products containing bifenthrin are used against a wide range of insects and mites. Bifenthrin is designed to be effective by contact or ingestion. Bifenthrin is highly toxic to mice when ingested, with an acute oral LD50 of 43 mg/kg. Bifenthrin is moderately toxic to rats when ingested, with an acute oral LD50 ranging from 53.4 to 210.4 mg/kg. Bifenthrin is neurotoxic and targets voltage-gated sodium channels in neurons. Its low toxicity in mammals has resulted in widespread use both in agricultural and urban applications. Unfortunately, bifenthrin is highly toxic to aquatic animals including fish and invertebrates. The high toxicity of bifenthrin in nontarget organisms has resulted in bifenthrin being classified as a restricted use pesticide by the USEPA. There is no evidence that bifenthrin has any significant toxicity to humans or higher mammals. In rodents the neurotoxicity is found to be reversible. Bifenthrin is classified by USEPA as a Category C, possible human carcinogen; however, this rating is based on an increased rate of urinary bladder tumors in mice, adenoma, and adenocarcinoma of the liver in male mice, and bronchioalveolar adenomas and adenocarcinomas of the lung in some female mice. No human data were found on carcinogenic effects of bifenthrin. Globally, pyrethroid pesticides, including bifenthrin are used in pest control of agricultural crops including cotton in Australia, India, and China. Pyrethroids are also often used in vector control in countries such as India, Mexico, Thailand, and Africa. Bifenthrin, while not initially approved by the WHO for this use, has shown promise as an effective agent for use in insecticide-impregnated mosquito nets. Bifenthrin's likelihood of contaminating ground water is low because of its soil-binding property and low water solubility. However, it can contaminate surface waters through runoff. There is no antidote available for this compound.