Chemicals / Complex Chemical Agents/ Chemical:
Permethrin (with special reference to Hedgehogs and Lagomorphs)

INFORMATION AVAILABLE

GENERAL CHEMICAL INFORMATION THERAPEUTIC INFORMATION [DOSE, FREQUENCY & ROUTE]

NUTRITIONAL INFORMATION

TOXICITY INFORMATION ENVIRONMENTAL INFORMATION
Information in this page has been entered to support the current volumes of Wildpro and further information will be added as new volumes are completed. This page is not intended to substitute for the manufacturer's data sheet and the information is not yet complete for all species, or for all contra-indications etc.

Before any pharmaceutical product is used, the manufacturer's data sheet, containing information on uses, dosage and administration, contra-indications, warnings etc., should always be consulted."

General Chemical Information

Summary 
Synthetic pyrethroid insecticide.  (B201.2.w2, W325.May01.WNV1)

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Names and Formulae
Type Synthetic pyrethroid. (B201.2.w2); Synthetic pyrethroid insecticide.(W325.May01.WNV1)
Alternative Names "Ambush; Ectiban; Pounce; 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid (3-phenoxyphenyl)methyl ester; (3-phenoxyphenyl)methyl (+/-)-cis,trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate; m-phenoxybenzyl (+/-)cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate; FMC 33297; indothrin; BW-21-Z; Eksmin; Kafil; Permasect; Perthrine; Pramex; Outflank; Talcord; Nix; Dragnet; (3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate; Ketokil; Biomist; Pertox; Persect; Anomethrin N; Antiborer 3768; Atroban; Chinetrin; Coopex; Corsair; Cyclopropanecarboxylic acid, 3-(2,2-dichlorovinyl)-2,2-dimethyl-, 3-phenoxybenzyl ester, (+-)-, (cis,trans)-; Diffusil h; Ecsumin; Efmethrin; Exmin; Ipitox; Kavil; Kestrel; Matadan; MP 79; NIA-33297; Outflank-stockade; Perigen; Perigen W; Permanone 10; Permanone 40; Permethrin, mixed cis,trans; 3-Phenoxybenzyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate; 3-Phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate; Spartan; Stomoxin; 3-phenoxy benzyl (1RS)-cis,trans-3-(2,2 dichlorovinyl)-2,2 dimethyl-cyclopropane carboxylate; PERMETHRIN [AMBUSH]; Permethrin." (W324)
Chemical Formula C21H20Cl2O3 (W324.Oct01.WNV1)
Chemical Structure (W325.May01.WNV1)
Molecular Weight 391.30 (W180.Feb02.WNV6; W325.May01.WNV1); 391.2932 (W324.Oct01.WNV1)
Related Chemicals --

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Physical Properties / Chemistry
Appearance

Odourless, colourless crystalline solid or a pale brown viscous liquid. (W180.Feb02.WNV6); colourless crystals to a viscous liquid. Colour, water white to pale yellow. (W325.May01.WNV1)

Melting point
  • 34 – 35C (W324.Oct01.WNV1); approximately 35C (analytical grade). (W325.May01.WNV1)
Boiling point 200C at 0.05 mm Hg (W324.Oct01.WNV1); 220C at 0.05 mm Hg. (W325.May01.WNV1)

Vapour pressure: <10 Torr. at 50C. <10 Torr. at 50C. (W325.May01.WNV1)

Density 1.19 (W324.Oct01.WNV1); specific gravity 1.190-1.272 at 20C. (W325.May01.WNV1)
Water solubility Insoluble. 0.00002 g/100 ml (W324.Oct01.WNV1); less than1 ppm. (W325.May01.WNV1)
Other solubility Soluble, miscible with most organic solvents except ethylene glycol. Soluble in acetone, ethanol, ether, and xylene. (W325.May01.WNV1)
Acid/Base --

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Pharmacology & General Information
Pharmacology
  • Act on the sodium channels in the nerve axons of parasites resulting in initial excitement followed by paralysis. (B201.2.w2)
Storage / Stability --
Legal Category (In UK) --

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References

Associated Techniques

ORGANISATIONS

ELECTRONIC LIBRARY
(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

Authors Debra Bourne (V.w5)
Referees Suzanne I. Boardman (V.w6); Becki Lawson (V.w26)

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Therapeutic Information

Uses/Indications
Activity
  • Appears to repel fleas from feeding, thereby preventing flea bites. (B201.2.w2)
  • Pyrethroids are contact poisons which rapidly penetrate the nervous system of an insect. They produce a quick "knock down" and are highly toxic to insects at very low rates of application. They are more effective against insects and less toxic to mammals than are the natural pyrethrins. (B250, W180.Feb02.WNV9)
Appropriate Use Indications:
  • UK: "Culicoides and lice on horses and donkeys; flies and lice on cattle; fleas and ticks on dogs; fleas on cats; ;ice and mites on pigeons; lice on dogs and cats." (B201.2.w2)
Limitations --
Notes --

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Pharmacokinetics and Drug Interactions
Absorption /Bioavailability --
Distribution --
Plasma Protein binding / Storage --
Elimination Route
  • Fate in humans and animals:
    • Permethrin is efficiently metabolized by mammalian livers.
    • Breakdown products, or "metabolites", of permethrin are quickly excreted and do not persist significantly in body tissues.
    •  When permethrin is administered orally to rats, it is rapidly metabolized and almost completely eliminated from the body in a few days. Only 3 to 6% of the original dose was excreted unchanged in the faeces of experimental animals. 
    • Permethrin may persist in fatty tissues, with half-lives of 4 to 5 days in brain and body fat. 
    • Permethrin does not block, or inhibit, cholinesterase enzymes. 

    (W180.Feb02.WNV6)

Elimination half-life / Clearance Rate --
Drug Interactions --

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Administration
Formulations available
  • Note different formulations may contain different proportions of the cis- and trans- forms. 
Doses / Administration Routes / Frequencies

Use of Drugs (Medication):

  • Before administration of any pharmaceutical product the manufacturer's datasheet must be consulted regarding operator safety, relevant withdrawal times etc.
  • Many drugs are not registered for use in particular species and additional care should be taken in their use, with proper regard for possible toxic effects. 
  • Consideration should be given to relevant legislation regarding the use of drugs.
  • In the UK, guidelines regarding the use of drugs are set out in the Royal College of Veterinary Surgeons' Guide to Professional Conduct 2000: (See: LCofC1 - RCVS Guide to Professional Conduct 2000 - Choice of Medicinal Products).

Erinaceus europaeus - West European Hedgehog:

Atelerix albiventris - Four-toed hedgehog:

Lagomorphs - Oryctolagus cuniculus domesticus - Domestic rabbit:

Ferrets - Mustela putorius furo - Ferret

  • Permethrin shampoo can be used as a treatment for fleas. (B602.10.w10, B339.9.w9, B627.16.w16, B632.06.w06, J34.17.w4, J213.3.w1)
Monitoring parameters --

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Withdrawal period / Withholding time
Notes Before the use of any pharmaceutical product in food-producing animals the label instructions for the product should be consulted regarding withdrawal requirements.

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Toxic Information

Toxic effects of Pharmaceutical Products
Contraindications / Precautions
  • Contraindicated for treatment of calves under one week old. (B201.2.w2)
  • Contra-indicated (unless otherwise indicated for a particular product) for treatment of puppies or kittens under twelve weeks old, nursing bitches, and pigeons less than one month old . (B201.2.w2)
  • Care should be taken to ensure other individuals do not lick the "spot-on" or "pour-on" products off a treated dog after application. (B201.2.w2)
Adverse Effects / Side Effects / Warnings
  • Dogs: administer "spot-on" and "pour-on" products in the evening, avoiding handling of the treated area for three to six hours and not allowing the dog to go swimming for 12 hours following application. (B201.2.w2)
Operator Warnings
  • Before the use of any pharmaceutical product the label instructions for the product should be consulted regarding operator safety/warnings.
  • Do not allow treated dogs to sleep with people, particularly children. (B201.2.w2)
Overdose / Acute Toxicity
  • Cats: hyperaesthesia with excitability, twitching and collapse. (B201.2.w2)

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Detailed Toxicological Information
Classification Permethrin is a moderately to practically non-toxic pesticide in EPA toxicity class II or III, depending on the formulation. Formulations are placed in class II due to their potential to cause eye and skin irritation.
  • Pyrethroids are considered to pose slight risks of acute toxicity to humans (Homo sapiens - Human), but at high doses, pyrethroids can affect the nervous system. (W179.Nov01.WNV13)
Acute Toxicity
  • Acute toxicity:
    • Permethrin is moderately to practically non-toxic via the oral route, with a reported LD50 for technical permethrin in rats of 430 to 4000 mg/kg. 
    • Via the dermal route permethrin is slightly toxic, with a reported dermal LD50 in rats of over 4000 mg/kg, and in rabbits of greater 2000 mg/kg. 
    • Permethrin caused mild irritation of both the intact and abraded skin of rabbits. 
    • Permethrin caused conjunctivitis when it was applied to the eyes. 
    • The 4-hour inhalation LC50 for rats was greater than 23.5 mg/L, indicating practically no inhalation toxicity. 
    • The toxicity of permethrin is dependent on the ratio of the isomers present; the cis-isomer being more toxic.

    (W180.Feb02.WNV6)

Tech (Rat) (Laboratory rat (Rattus norvegicus - Brown rat)): Oral LD50 430-4000 mg/kg. Value varies depending upon factors such as carrier, test species, etc. Dermal LD50 >2500 mg/kg. Inhalation LC50 >685 mg/m3 of air. (Rabbit) (Oryctolagus cuniculus - European rabbit (Domestic rabbit)): Dermal LD50 >2000 mg/kg.(W325.May01.WNV1)
Chronic Toxicity
Reproductive effects
  • Reproductive effects:
    • The fertility of female rats was affected when they received very high oral doses of 250 mg/kg/day of permethrin during the 6th to 15th day of pregnancy. 
    • It is not likely that reproductive effects will be seen in humans under normal circumstances. 

    (W180.Feb02.WNV6)

Teratogenic effects
  • Permethrin is reported to show no teratogenic activity. (W180.Feb02.WNV6)
Mutagenic effects
  • Permethrin is reported to show no mutagenic activity. (W180.Feb02.WNV6)
Carcinogenic effects
  • The evidence regarding the carcinogenicity of permethrin is inconclusive. (W180.Feb02.WNV6)

 

Organ toxicity
  • Permethrin is suspected of causing liver enlargement and nerve damage. 
  • Effects on the immune system have been noted in animal studies.

(W180.Feb02.WNV6)

Bird Toxicity
  • Effects on birds (Aves - Birds (Class)):
    • Permethrin is practically non-toxic to birds.
      • The oral LD50 for the permethrin formulation "Pramex" is greater than 9900 mg/kg in mallard ducks, greater than 13,500 mg/kg in pheasants, and greater than 15,500 mg/kg in Japanese quail. 

    (W180.Feb02.WNV6)

Aquatic organism activity
  • Effects on aquatic organisms:
    • Aquatic ecosystems are particularly vulnerable to the impact of permethrin. A fragile balance exists between the quality and quantity of insects and other invertebrates that serve as fish food. 
    • The 48-hour LC50 for rainbow trout is 0.0125 mg/L for 24 hours, and 0.0054 mg/L for 48 hours. The 48-hour LC50 in bluegill sunfish and salmon is 0.0018 mg/L. 
    • As a group, synthetic pyrethroids were toxic to all estuarine species tested. They had a 96-hour LC50 of less than or equal to 0.0078 mg/L for these species. 
    • The bioconcentration factor for permethrin in bluefish is 715 times the concentrations in water and is 703 in catfish. This indicates that the compound has a low to moderate potential to accumulate in these organisms. 

    (W180.Feb02.WNV6)

Other organism toxicity
  • Effects on other organisms:
    • Permethrin is extremely toxic to bees. 
      • Severe losses may be expected if bees are present at treatment time, or within a day thereafter. 
      • Permethrin should not be applied, or allowed to drift, to crops or weeds in which active foraging by bees takes place.

    (W180.Feb02.WNV6)

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Nutrient Information

Nutritional Data
Sources --
Biological Use --
Recommended Daily Allowance / Recommended level in food --
Stability in food (Storage time) --
Interactions --

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External / Environmental Information

External / Environmental Uses
Use Permethrin is a broad spectrum synthetic pyrethroid insecticide, used against a variety of pests, on nut, fruit, vegetable, cotton, ornamental, mushroom, potato, and cereal crops. It is used in greenhouses, home gardens, and for termite control. It also controls animal ectoparasites, biting flies, and cockroaches. It may cause a build up of mites by reducing mite predator populations. (W180.Feb02.WNV6)
  • For mosquito (Culicidae - Mosquitoes (Family)) control: pyrethroids are applied in an Ultra-Low-Volume Spray formulation, typically mixed with a synergist compound, piperonyl butoxide, which enhances the effectiveness of the active ingredient. The product is applied at rates of between 0.003 and 0.007 pounds of active ingredient per acre (equivalent to 2 to 3.5 fluid ounces of the mixed formulation per acre). (W179.Nov01.WNV13)

Formulation Permethrin is available in dusts, emulsifiable concentrates, smokes, ULV (ultra-low volume), and wettable powder formulations. (W180.Feb02.WNV6; W325.May01.WNV1)
Application method --
Application Concentration --
Persistence of Effect / Frequency of Application --
Operator Warnings/Precautions

"PROTECTIVE CLOTHING: Hat or other suitable head covering, long-sleeved shirt, long-legged trousers or coverall type garment (all of closely woven fabric covering the body, including the arms and legs), shoes, and socks." (W325.May01.WNV1)

"HANDLING AND STORAGE CAUTIONS: Keep out of lakes, streams, or ponds. Do not apply when weather conditions favor drift from treated areas. Do not contaminate water by cleaning of equipment, or disposal of wastes near a body of water. Avoid contact with eyes, skin, or clothing. Avoid breathing vapor or spray mist. Wash thoroughly after handling. Do not store near food, feed, heat, or open flame." (W325.May01.WNV1)

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Effects on the Environment
Effects in the aquatic environment

 

Effects on land  

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Persistence in the Environment
Breakdown in soil and groundwater
  • Permethrin is of low to moderate persistence in the soil environment, with reported half-lives of 30 to 38 days. 
  • Permethrin is readily broken down, or degraded, in most soils except organic types.
  • Soil microorganisms play a large role in the degradation of permethrin in the soil. The addition of nutrients to soil may increase the degradation of permethrin. 
  • It has been observed that the availability of sodium and phosphorous decreases when permethrin is added to the soil.
  • Permethrin is tightly bound by soils, especially by organic matter. Very little leaching of permethrin has been reported. It is not very mobile in a wide range of soil types. 
  • Because permethrin binds very strongly to soil particles and is nearly insoluble in water, it is not expected to leach or to contaminate groundwater. 

(W180.Feb02.WNV6)

Breakdown in water
  • The results of one study near estuarine areas showed that permethrin had a half-life of less than 2.5 days. 
  • When exposed to sunlight, the half-life was 4.6 days. 
  • Permethrin degrades rapidly in water, although it can persist in sediments. 
  • There was a gradual loss of toxicity after permethrin aged for 48 hours in sunlight at 0.05 mg/L in water.

(W180.Feb02.WNV6)

Breakdown in vegetation
  • Permethrin is not phytotoxic, or poisonous, to most plants when it is used as directed. 
  • Some injury has occurred on certain ornamental plants. 
  • No incompatibility has been observed with permethrin on cultivated plants. 
  • Treated apples, grapes, and cereal grains contain less than one mg/kg of permethrin at harvest time.

(W180.Feb02.WNV6)

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