Permethrin From Wikipedia the free encyclopedia Jump to navigation search Permethrin 3 Phenoxybenzyl IUPAC name 1RS cis trans 3 2 2dichlorovinyl 2 2dimethylcyclopropanecarboxylate Identifiers CAS number SMILES show Properties Molecular formula C21H20Cl2O3 Molar mass 391 28 g mol Appearance colourless crystals Density 1 19 g cm solid Melting point Boiling point Solubility in 34 C 307 K 200 C 473 K Insoluble 5 5 x 10 3 ppm water Hazards MSDS External MSDS Main hazards Irritating to skin and eyes damaging to lungs Related compounds Related pyrethroids Bifenthrin Deltamethrin Except where noted otherwise data are given for materials in their standard state at 25 C 100 kPa Infobox references Permethrin is a common synthetic chemical widely used as an insecticide acaricide and insect repellent It belongs to the family of synthetic chemicals called pyrethroids and functions as a neurotoxin affecting neuron membranes by prolonging sodium channel activation It is not known to harm most mammals or birds It generally has a low mammalian toxicity and is poorly absorbed by skin Contents hide 1 Uses 2 Stereochemistry 3 Toxicity 4 References 5 See also 6 External links edit Uses In agriculture permethrin is mainly used on cotton wheat maize and alfalfa crops and is also used to kill parasites on chickens and other poultry It is also extensively used in Europe as a timber treatment against wood boring beetle woodworm Its use is controversial since as a broad spectrum chemical it kills indiscriminately as well as the intended pests it can harm beneficial insects including honey bees aquatic life 1 and small mammals such as mice Recently in South Africa residues of permethrin were found in breast milk together with DDT in an area that experienced DDT treatment for malaria control as well as the use of pyrethroids in small scale agriculture 2 Permethrin is toxic to cats and many cats die each year after being given flea treatments intended for dogs or by contact with dogs who have recently been treated with permethrin 3 Permethrin is also used in healthcare to eradicate parasites such as head lice and mites responsible for scabies and in industrial and domestic settings to control pests such as ants and termites However the British National Formulary states that permethrin has low efficacy in eradicating head lice Permethrin kills ticks on contact with treated clothing According to the Connecticut Department of Public Health it has low mammalian toxicity is poorly absorbed through the skin and is rapidly inactivated by the body Skin reactions have been uncommon 4 Permethrin is also used on humans for lice or scabies the common prescription is Pertmethrin with 5 concentration for scabies and OTC over the counter treatment for head lice crabs is usually permethrin with 1 concentration Permethrin is used in tropical areas to prevent mosquito borne disease such as dengue fever and malaria Mosquito nets used to cover beds may be treated with a solution of permethrin This increases the effectiveness of the bed net by killing parasitic insects before they are able to find gaps or holes in the net Malaria kills 1 3 million people per year and permethrin is believed to have very low if any toxicity in humans Military personnel training in malaria endemic areas may be instructed to treat their uniforms with permethrin as well An application should last several washes edit Stereochemistry Permethrin has four stereoisomers two enantiomeric pairs arising from the two stereocentres in the cyclopropane ring The trans enantiomeric pair is known as transpermethrin 1R trans acid moiety known as biopermethrin 1S trans acid moiety one cis enantiomer the other cis enantiomer edit Toxicity Permethrin is extremely toxic to fish Extreme care must be taken when using products containing permethrin near water sources Permethrin is also highly toxic to cats 5 Flea and tick repellent formulas intended and labeled for dogs may contain permethrin like k 9 Advantix and Advantage Multi for Dogs and cause feline permethrin toxicosis in cats specific flea and tick control formulas intended for feline use such as those containing fipronil should therefore be used for cats instead Permethrin is classified by the US EPA a likely human carcinogen based on reproducible studies in which mice fed permethrin developed liver and lung tumors 6 Carcinogenic action in nasal mucosal cells for inhalation exposure is suspected due to observed genotoxicity in human tissue samples and in rat livers the evidence of increased preneoplastic lesions lends concern over oral exposure 7 8 edit References 1 R H Ian 1989 Aquatic organisms and pyrethroids Pesticide Science 27 4 429 457 doi 10 1002 ps 2780270408 2 H Bouwman B Sereda and H M Meinhardt 2006 Simultaneous presence of DDT and pyrethroid residues in human breast milk from a malaria endemic area in South Africa Environmental Pollution 144 3 902 917 doi 10 1016 j envpol 2006 02 002 3 P J Linnett 2008 Permethrin toxicosis in cats Australian Veterinary Journal 86 12 32 35 4 Kirby C Stafford III February 1999 Tick Bite Prevention Connecticut Department of Public Health 5 BBC NEWS UK Cats killed by flea treatment 6 Permethrin Facts US EPA June 2006 7 M Tisch P Schmezer M Faulde A Groh and H Maier 2002 Genotoxicity studies on permethrin DEET and diazinon in primary human nasal mucosal cells European Archives of Oto Rhino Laryngology 259 3 150 153 doi 10 1007 s004050100406 8 K Hakoi R Cabral T Hoshiya R Hasegawa T Shirai and N Ito 1992 Analysis of carcinogenic activity of some pesticides in a medium term liver bioassay in the rat Teratogenesis Carcinogenesis and Mutagenesis 12 6 269 276 doi 10 1002 tcm 1770120605 edit See also Insect repellents from natural sources such as plants Methoprene edit External links Pesticide link to Parkinson Disease Permethrin Fact Sheet National Pesticide Information Center Permethrin treated Clothing Hot Topic National Pesticide Information Center Permethrin Pesticide Information Profile Extension Toxicology Network Permethrin chemical data Example of permethrin river poisoning broken link