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The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.

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E X T O X N E T

Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996

Allethrin

Trade and Other Names: Trade names for allethrin include Alleviate, Pynamin, d-allethrin, d-cisallethrin, Bioallethrin, Esbiothrin, Pyresin, Pyrexcel, Pyrocide and trans-allethrin.

Regulatory Status: Pesticides containing allethrin are toxicity class III- slightly toxic, and bear the Signal Word CAUTION on the product label. Containers of technical grade d-trans-allethrin bear the Signal Word WARNING.

Chemical Class: pyrethroid

Introduction: Allethrin is a nonsystemic insecticide that is used almost exclusively in homes and gardens for control of flies and mosquitoes, and in combination with other pesticides to control flying or crawling insects. Another structural form, the d-trans- isomer of allethrin, is more toxic to insects and is used to control parasites living within animal systems. It is available as mosquito coils, mats, oil formulations, and as an aerosol spray. Allethrin is a pyrethroid, a synthetic compound that duplicates the activity of the pyrethrin plant. It has stomach and respiratory action and paralyzes insects before killing them. Unless stated otherwise, information in this profile refers to unpurified allethrin.

Formulation: It is available as mosquito coils, mats, oil formulations and as an aerosol spray. Toxicological Effects:

• Acute toxicity: Allethrin is slightly toxic by dermal absorption and ingestion. Short-term dermal exposure to allethrin may cause itching, burning, tingling, numbness, or a feeling of warmth, but not dermatitis [2]. Exposure to large doses by any route may lead to nausea, vomiting, diarrhea, hyperexcitability, incoordination, tremors, convulsive twitching, convulsions, bloody tears, incontinence, muscular paralysis, prostration and coma. Allethrin is a central nervous system stimulant. Heavy respiratory exposure caused incoordination and loss of bladder control in mice and rats [2]. The toxicity of allethrin varies with the amounts of different isomers present. The oral LD50 for allethrin is 1100 mg/kg in male rats, 685 mg/kg in female rats, 480 mg/kg in mice, and 4290 mg/kg in rabbits [12,7]. For d-allethrin the oral LD50 is 1320 mg/kg in rats. The dermal LD50 is greater than 2500 mg/kg in rats [12,19].
• Chronic toxicity: Not Available
• Reproductive effects: No data are currently available.
• Teratogenic effects: No developmental defects were seen in the offspring of rats given doses as high as 195 mg/kg/day [7].
• Mutagenic effects: Allethrin has been found to be mutagenic under certain conditions in strains of the bacterium Salmonella typhinurium [18]. However, tests of d-allethrin (bioallethrin) for DNA damage and mutation were negative [19]. Thus, allethrin appears to have little or no mutagenic activity.
• Carcinogenic effects: Rats fed very high doses of d-allethrin for 2 years did not develop cancer [19].
• Organ toxicity: Rats fed 75 mg/kg/day of d-allethrin exhibited decreased body weight gain, increased liver weights and, in females only, increased levels of serum liver enzymes [19]. A six-month study with dogs fed d-allethrin (bioallethrin) showed effects on the liver at 5 mg/kg/day [19]. A dose of 50 mg/kg/day allethrin for two years produced no detectable effect in dogs [19].

• Fate in humans and animals: Following oral administration, allethrin is readily absorbed and metabolized in mammalian systems to less toxic compounds which may be more easily eliminated by the body [12].

Ecological Effects:

• Effects on birds: Allethrin is practically non-toxic to birds. The oral LD50 for allethrin is 2030 mg/kg in bobwhite quail and greater than 2000 mg/kg in mallards [12,19]. The dietary LD50 is 5620 ppm for d-allethrin in mallards and bobwhite quail [19].
• Effects on aquatic organisms: The pyrethroid insecticides, including allethrin, are toxic to fish. Fish sensitivity to the pyrethroids may be explained by their relatively slow metabolism and elimination of these compounds. The half-lives for elimination of several pyrethroids by trout are all greater than 48 hours [20,21]. Generally, the lethality of pyrethroids to fish increases with increasing ability to dissolve in fat [22]. The LC50 (96-hour) for channel catfish is 30 mg/L. The toxicity of allethrin compounds ranges from an LC50 of 0.0026 mg/L for d-allethrin in coho salmon to an LC50 of 0.08 mg/L for s-bioallethrin in fathead minnows [19].
• Effects on other organisms: Allethrin is slightly toxic to bees [19]. Its LD50 is 0.003 to 0.009 mg per bee [19].

Environmental Fate:

• Breakdown in soil and groundwater: No data are currently available.
• Breakdown in water: In pond waters and in laboratory degradation studies, pyrethroid concentrations decrease rapidly due to sorption to sediment, suspended particles and plants. Microbial and photodegradation also occur [19].
• Breakdown in vegetation: No data are currently available.

Physical Properties:

• Appearance: Allethrin is yellow to amber colored viscous liquid with a mild or slightly aromatic odor [12]. It may decompose when exposed to heat or light.
• Chemical Name: 2-methyl-4-oxo-3-(2-propenyl)-2-cyclopenten-1-yl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate [12]
• CAS Number: 584-79-2 (allethrin); 42534-61-2 (d-allethrin)
• Molecular Weight: 302.40
• Water Solubility: Allethrin and d-allethrin are insoluble in water [12]
• Solubility in Other Solvents: alcohol v.s.; hexane v.s.; xylene v.s.; petroleum ether v.s. [12]
• Melting Point: 4 C [12]
• Vapor Pressure: 16 mPa @ 30 C [12]
• Partition Coefficient: 4.9604 [12]
• Adsorption Coefficient: Not Available

Exposure Guidelines:

• ADI: Not Available
• MCL: Not Available
• RfD: Not Available
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

Sumitomo Chemical Co., Ltd.
5-33, Kitahama 4-chome
Chuo-ku Osaka 541 Japan

• Phone: 81-6-220-3693
• FAX: (FAX) 81-6-220-3492
  

References:

References for the information in this PIP can be found in Reference List Number 2

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.