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Lambda cyhalothrin, an insecticide, belongs to the pyrethroid chemical class of pesticides. It was registered with the EPA in 1988. Because of its close similarities to cyhalothrin, studies are sometimes conducted with cyhalothrin to evaluate the effects of lambda cyhalothrin (#NPTN). It forms strong bonds with soil and is mostly insoluble in water, so it is an unlikely water contaminant. It can be a corrosive irritant to the eyes and skin.

Lambda cyhalothrin may be marketed as Charge, Excaliber, Grenade, Hallmark, Icon, Karate, Matador, OMS 0321, PP321, Saber, Samurai , and Sentinel. It is commonly mixed with buprofezin, pirimicarb, dimethoate, and tetramethrin (#EXTOXNET).

Chemical Description

Lambda cyhalothrin is a synthetic pyrethroid. It is a colorless to beige solid with a mild odor, and it may have a yellowish color when in solution (#NPTN). Lambda cyhalothrin has a very low solubility in water, and bonds strongly with soil. Its half-life in soil is 4 to 12 weeks. It melts at 49.2 degrees C (#EXTOXNET).

Lambda cyhalothrin is available in powders, pellets, and small capsules. It is also placed in ear tags for cattle (#NPTN).


Lambda cyhalothrin targets a wide range of insects including aphids, Colorado beetles, and butterfly larvae. It is also used to control insects identified as potential disease vectors, such as cockroaches, mosquitoes, ticks, and flies (#EXTOXNET).

In commercial applications, lamba cyhalothrin is used on food crops, non-food crops, in greenhouses, in and around hospitals, for cattle (in ear tags), and in termite treatments. Residential use can be both indoors and outdoors on homes, ornamental plants, and lawns (#NPTN).

Human Health Effects

Lambda cyhalothrin can have corrosive effects on both the skin and eyes. Workers handling it reported facial tingling and burning, which lasted six hours to two days. Ingested lambda cyhalothrin is moderately toxic, although mammals are found to metabolize and excrete lambda cyhalothrin rapidly. The EPA identifies lambda cyhalothrin as a group D carcinogen, an undetermined human carcinogen (#NPTN).

Exposure to lambda cyhalothrin may occur through inhalation, dermal absorption, or ingestion. Inhalation may cause burning sensations, convulsions, coughing, labored breathing, shortness of breath, and sore throat. Contact with the skin and eyes may cause redness and pain. Ingestion can cause abdominal pain and coughing (#PANNA). Extreme levels of exposure can also cause seizures and coma (#NPTN). The effects of respiratory diseases and skin disorders may intensify with exposure to lambda cyhalothrin (#NLM).

Environmental Health Effects

Like other pyrethroids, lambda cyhalothrin disrupts the nervous system in insects, causing paralysis and death (#NPTN). It is highly toxic to bees, for which the oral LD50 is 38 ng/bee, and the contact LD50 is 909 ng/bee (#EXTOXNET).

Lambda cyhalothrin has a very low toxicity in birds. The oral LD50 in mallard duck is greater than 3,950 mg/kg (#EXTOXNET).

Lambda cyhalothrin is very toxic to fish. Some studies have indicated that the chemical may accumulate in these organisms (#NPTN).

In mammals, lambda cyhalothrin is absorbed and excreted relatively rapidly. Residue may accumulate in fat, in which the half-life is 23 days for rats and dogs. In a study with beagle dogs, 82-93% of orally and intravenously administered cyhalothrin was excreted after seven days (#NLM). When ingested, the chemical is moderately toxic to mammals. In rats, the oral LD50 was 79 mg/kg in males and 56 mg/kg in females (#NPTN).

Because of its high affinity for soil and low water solubility, lambda cyhalothrin is unlikely to contaminate water sources (#EXTOXNET).


Lambda cyhalothrin is listed as a Restricted Use Pesticide, and may only be purchased and used by certified applicators (#EXTOXNET). Residential users may purchase products with a lower concentration of lambda cyhalothrin for unrestricted use.

Precautionary Notes

Burning lamba cyhalothrin products will degrade the chemical into toxic fumes (#NIOSH). Because lambda cyhalothrin is often mixed with other pesticides, users should check for and understand the risks behind any other active ingredients. Due to the high toxicity to aquatic organisms, exercise caution if using lambda cyhalothrin near a water source. Persons with respiratory or skin diseases should avoid lambda cyhalothrin.


Extension Toxicology Network. Lambda Cyhalothrin. [Accessed 7-10-10].

National Institute for Occupational Safety and Health. Lambda-Cyhalothrin. [Accessed 7-10-10].

National Library of Medicine: Toxicology Data Network. Cyhalothrin. (May 2001). [Accessed 7-10-10].

National Pesticide Telecommunications Network. Lambda-Cyhalothrin General Fact Sheet. [Accessed 7-10-10].

Pesticide Action Network North America . Cyhalothrin, Lambda. [Accessed 7-10-10].

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