| GHS-Einstufung | WarningH302: Harmful if swallowed [Warning Acute toxicity, oral]P261, P264, P270, P271, P272, P273, P280, P301+P317, P302+P352, P304+P340, P317, P321, P330, P333+P317, P362+P364, P391, and P501 (click each P-code to see the statement)This chemical does not meet GHS hazard criteria for 0.2% (1 of 519) of reports.H302+H332 (13.5%): Harmful if swallowed or if inhaled [Warning Acute toxicity, oralacute toxicity, inhalation] |
|---|
| Regulatorische Informationen | Chemical: Cyclopropanecarboxylic acid, 3-(2,2-dichloroethenyl)-2,2-dimethyl-, (3-phenoxyphenyl)methyl esterPermethrin is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)00/817/ECPermethrin: HSNO Approval: HSR003111 Approved with controlsThe New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.) |
|---|
| DOT-Kennzeichnung | Class 9 |
|---|
| Brandgefahren | Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:Combustible. Liquid formulations containing organic solvents may be flammable. Gives off irritating or toxic fumes (or gases) in a fire. |
|---|
| Gesundheitsgefahren | Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: |
|---|
| Gefahrenübersicht | A skin, eye, and respiratory tract irritant[ICSC] May be a skin sensitizer[eChemPortal: ESIS] May cause irritationMay cause skin sensitizationTargets the CNS in high-dose animal studies[MSDSonline] Rapidly metabolizedDoes not accumulate in bodyCauses hyperactivity and tremors in high-dose feeding studies of experimental animalsExposed workers complain of skin and eye irritationNo skin sensitization in animal studies[INCHEM PDS: Permethrin] See Imiprothrin. |
|---|
| FDA-Anforderungen | The Approved Drug Products with Therapeutic Equivalence Evaluations identifies currently marketed prescription drug products, including permethrin, approved on the basis of safety and effectiveness by FDA under sections 505 of the Federal Food, Drug, and Cosmetic Act. |
|---|
| Reaktive Gruppe | Esters, Sulfate Esters, Phosphate Esters, Thiophosphate Esters, and Borate Esters |
|---|
| EG-Einstufung | Symbol: Xn, NR: 20/22-43-50/53S: (2)-13-24-36/37/39-60-61 |
|---|
| UN-Einstufung | UN Hazard Class: 6.1UN Pack Group: III |
|---|
| Special Reports | USEPA/Office of Prevention, Pesticides and Toxic SubstancesReregistration Eligibility Decision Document - Permethrin EPA 738-R-09-306 (May 2009). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of January 27, 2014: http://www.epa.gov/pesticides/reregistration/status.htm]U.S. Dept Health & Human Services/Agency for Toxic Substances & Disease RegistryToxicological Profile for Pyrethrins and Pyrethroids (September 2003) PB2004-100004). The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects information for the hazardous substance described here. Each peer-reviewed profile identifies and reviews the key literature that describes a hazardous substance's toxicologic properties. Other pertinent literature is also presented, but is described in less detail than the key studies.[Available from, as of March 11, 2014: http://www.atsdr.cdc.gov/toxprofiles/index.asp]Clark JR et alToxicity of Pyrethroids to Marine Invertebrates and Fish: A Literature Review and Test Results with Sediment-Sorbed Chemicals. Environ Toxicol Chem 8 (5): 393-401 (1989). Data on acute and chronic toxicity of permethrin, fenvalerate, cypermethrin, and flucythinate to marine invertebrates and fishes are reviewed.Mian LS, Mulla MSEffects of Pyrethroid Insecticides on Nontarget Invertebratesin Aquatic Ecosystems. J Agric Entomol 9 (2): 73-98 (1992). This review presents data on the impacts of pyrethroid insecticides on nontarget aquatic invertebrates.For more Special Reports (Complete) data for PERMETHRIN (10 total), please visit the HSDB record page. |
|---|
| FIFRA-Anforderungen | Tolerances are established for the combined residues of the insecticide cis- and trans-permethrin isomers [cis-(3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylate] and [trans-(3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylate] in/on the following food commodities:[Table#6277]Tolerances with regional registration, as defined in section 180.1(l) are established for the combined residues of the insecticide cis- and trans-permethrin isomers [cis-(3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylate] and [trans-(3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylate] in/on the following food commodities:[Table#6278]The Agency has completed its assessment of the dietary, occupational, residential, and ecological risk associated with the use of pesticide products containing the active ingredient permethrin. Based on a review of these data and on public comments on the Agency's assessments for the active ingredient permethrin, the Agency has sufficient information on the human health and ecological effects to make decisions as part of the tolerance reassessment process under FFDCA and reregistration process under FIFRA, as amended by FQPA. The Agency has determined that permethrin-containing products are eligible for reregistration provided that: (i) the risk mitigation measures outlined in this document are adopted and (ii) label amendments are made to reflect these measures. ... Based on its evaluation of permethrin, the Agency has determined that permethrin products, unless labeled and used as specified in this document, would present risks inconsistent with FIFRA. Accordingly, should a registrant fail to implement any of the risk mitigation measures identified in this document, the Agency may take regulatory action to address the risk concerns from the use of permethrin. If all changes outlined in this document are incorporated into the product labels, then all current risks for permethrin will be adequately mitigated for the purposes of this determination under FIFRA.As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Permethrin is found on List B. Case No: 2510Pesticide type: InsecticideCase Status: OPP is reviewing data from the pesticide's producers regarding its human health and/or environmental effects, or OPP is determining the pesticide's eligibility for reregistration and developing the Reregistration Eligibility Decision (RED) document.Active ingredient (AI): 3-(Phenoxyphenyl)methyl (+-)cis,trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylateData Call-in (DCI) Date(s): 08/09/91, 01/02/92, 04/11/94, 03/03/95, 10/13/95AI Status: The producers of the pesticide has made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner. |
|---|
| Reactivity Profile | A pyrethroid derivative. |
|---|
| Brandbekämpfung | Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:Use powder, AFFF, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water. |
|---|
| Erste-Hilfe-Maßnahmen | Fresh air, rest.Remove contaminated clothes. Rinse and then wash skin with water and soap.First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.Rinse mouth. Refer for medical attention . |
|---|
| Erste Hilfe | Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: |
|---|
| Sichere Lagerung | Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Keep in a well-ventilated room. |
|---|
| Freisetung ohne Brand | Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: |
|---|
| Entsorgungsverfahren | SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air qualitypotential migration in soil or watereffects on animal and plant lifeand conformance with environmental and public health regulations. |
|---|
| Verschüttetes entsorgen | Personal protection: filter respirator for organic gases and particulates adapted to the airborne concentration of the substance. Do NOT wash away into sewer. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations. |
|---|
| Preventive Measures | Avoid contact with eyes, skin, or clothing. Avoid breathing vapor or spray mist. Wash thoroughly after handling.SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.Mixing /of permethrin/, if not mechanical, should always be carried out with a paddle of appropriate length. Avoid contact with mouth and eyes. Before eating, drinking or smoking, hands and other exposed skin should be thoroughly washed with alkaline soap. |
|---|
| Isolation and Evacuation | Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: |
|---|
| Eye Prevention | Wear face shield. |
|---|
| Fire Prevention | NO open flames. |
|---|
| Inhalation Risk | No indication can be given about the rate at which a harmful concentration of this substance in the air is reached on evaporation at 20 °C. |
|---|
| Körperbelastung | The concentration of permethrin in the urine of an agricultural worker exposed to the pesticide during application to cabbage was 0 (before application), 0 (after application), 1.8 (6 hrs), 2.8 (17 hrs), 1.4 (26 hrs), 1.9(30 hrs), and 1.6 (40 hrs) ng/mg(1). A person who packed conifer seedlings for 6 hrs in a tunnel in Sweden (whose face was close to the plants) excreted 0.26 ug/mL permethrin acid metabolite in the urine the following morningin the afternoon, excretion was below the detection limit(2). |
|---|
| Treatment | Following oral exposure, the treatment is symptomatic and supportive and includes monitoring for the development of hypersensitivity reactions with respiratory distress. Provide adequate airway management when needed. Gastric decontamination is usually not required unless the pyrethrin product is combined with a hydrocarbon. Following inhalation exposure, move patient to fresh air. monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with inhaled beta2 agonist and oral or parenteral corticosteroids. In case of eye exposure, irrigate exposed eyes with copious amounts of room temperature water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility. If the contamination occurs through dermal exposure, remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician may need to examine the area if irritation or pain persists. Vitamin E topical application is highly effective in relieving parenthesis. (T36) |
|---|
| Wechselwirkungen | The effects of pyrethroids were studied on phosphoinositide breakdown in guinea pig synaptoneurosomes. Similar to other agents that activate voltage-dependent sodium channels, type I and type II pyrethroids stimulated phosphoinositide breakdown. Type II pyrethroids, like deltamethrin and fenvalerate, were more potent and, at least for deltamethrin, more efficacious than type I pyrethroids, like allethrin, resmethrin and permethrin. The effects of type II pyrethroids could be partially inhibited by the sodium channel blocker tetrodotoxin. The effects of allethrin and resmethrin were not affected by 5 microM tetrodotoxin. Stimulation of phosphoinositide breakdown by fenvalerate was additive to the stimulation elicited by the receptor agonists carbamylcholine and norepinephrine, but not to the stimulation elicited by sodium channel agents (batrachotoxin, scorpion venom and pumiliotoxin B). Stimulation by allethrin was not additive to the stimulation elicited either by receptor agonists or sodium channel agents. A submaximal concentration of allethrin, a type I pyrethroid, did not greatly affect the dose-dependent stimulation elicited by a type II pyrethroid, deltamethrin, while a higher concentration of allethrin prevented further stimulation by type II pyrethroids. A local anesthetic, dibucaine, which inhibits sodium channel activation, inhibited phosphoinositide breakdown induced by type II, but not by type I pyrethroids, except at higher concentrations. Thus, type II pyrethroids appear to stimulate phosphoinositide breakdown in synaptoneurosomes in a manner analogous to other sodium channel agents, while type I pyrethroids elicit phosphoinositide breakdown by a different mechanism, probably not involving sodium channels./Pyrethroid/ detoxification ... important in flies, may be delayed by the addition of synergists ... organophosphates or carbamates ... to guarantee a lethal effect. ... /Pyrethroid/Piperonyl butoxide potentiates /insecticidal activity/ of pyrethrins by inhibiting the hydrolytic enzymes responsible for pyrethrins' metabolism in arthropods. When piperonyl butoxide is combined with pyrethrins, the insecticidal activity of the latter drug is increased 2-12 times /Pyrethrins/At dietary level of 1000 ppm pyrethrins and 10000 ppm piperonyl butoxide ... /enlargement, margination, and cytoplasmic inclusions in liver cells of rats/ were well developed in only 8 days, but ... were not maximal. Changes were proportional to dosage and similar to those produced by DDT. Effects of the 2 ... were additive. /Pyrethrins//Nuclear magnetic resonance/ (NMR) combined with pattern recognition was recently introduced as a new technique for rapid xenobiotic toxicity evaluation. In this article, metabolic changes in the biofluid of rats after 90-day oral treatment with propoxur, permethrin and a combination of these two pesticides were investigated. Propoxur dosing induced increased urinary taurine, creatinine and glucose, whereas urinary lactate and acetate were increased in the highest permethrin dose group. Urinary acetate, alanine, lactate and trimethylamine levels were increased in the mixture group, accompanied by decreased urinary tricarboxylic acid cycle intermediates. In addition, the highest dose of the mixture displayed raised 3-D-hydroxybutyrate, acetate and lactate levels in the serum sample. Chronic exposure to a combination of propoxur and permethrin may induce hepatotoxicity and nephrotoxicity. An increase in acetate, alanine and formate in the urine could be a potentially sensitive biomarker of the chronic, combined effects of permethrin and propoxur. |
|---|
| Zielorgane | Hepatic |
|---|
| Gesundheitliche Auswirkungen | As for every type I pyrethroids , permethrin effects typically include rapid onset of aggressive behavior and increased sensitivity to external stimuli, followed by fine tremor, prostration with coarse whole body tremor, elevated body temperature, coma, and death. Paresthesia, severe corneal damage, hypotension and tachycardia, associated with anaphylaxis can also occur following permethrin poisoning. (L857) |
|---|
| Ökotoxizitätswerte | LD50Species: Anas platyrhynchos (Mallard Duck) age 19 monthsoral via capsule >2000 mg/kgLC50Species: Anas platyrhynchos (Mallard Duck) age 7 daysdiet (chemical incorporated into food) >5200 ppm for 8 daysSpecies: Anas platyrhynchos (Mallard Duck) adultoral via capsule >9868 mg/kgSpecies: Anas platyrhynchos (Mallard Duck) age 14 daysoral via capsule >4640 mg/kgFor more Ecotoxicity Values (Complete) data for PERMETHRIN (55 total), please visit the HSDB record page. |
|---|
| Umweltverhalten | TERRESTRIAL FATE: Based on a classification scheme(1), Koc values ranging from 10,471 to 86,000(2), indicate that permethrin is expected to be immobile in soil(SRC). Volatilization of permethrin from moist soil surfaces is possible(SRC) given an estimated Henry's Law constant of 2.4X10-6 atm-cu m/mole(SRC), derived from its vapor pressure, 5.18X10-8 mm Hg(3), and water solubility, 0.0111 mg/L(3). However, adsorption to soil is expected to attenuate volatilization(SRC). Permethrin is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure. Permethrin is susceptible to biodegradation in soil and sediment as demonstrated by incubation studies using sterile and non-sterile conditions(4,5). Degradation in soil and sediments occurs through biodegradation and abiotic hydrolysis(6). Permethrin is susceptible to direct photolysis on soil surfaces exposed to sunlight(3)cis- and trans-permethrin photolysis half-lives of 23.1 and 36.8 days have been measured in water respectively(3). The degradation half-life of permethrin in aerobically incubated soil was less than 4 weeks, and the degradation of the trans-isomer was more rapid than the cis-isomer(7). Faster degradation of the trans-isomers versus the cis-isomers was also observed in soil and sediment studies(8). In two Japanese soils, both the 1R, trans- and 1R, cis-isomers were rapidly degraded under dry conditions with half-lives of less than 2 days(9). Under anaerobic conditions in flooded silt loam soils, degradation half-lives were 32-34 days for 14C-labeled trans-permethrin and greater than 64 days for 14C-labeled cis-permethrin(7). Field dissipation half-lives for permethrin generally fall in the range from 6 to 106 days with 42 days as a selected value for modeling(2). Under aerobic conditions, the field dissipation half-life is roughly 30 days (4-40 day range) and under anaerobic conditions, the field dissipation half-life is roughly 108 days (3-204 day range)(2).AQUATIC FATE: Based on a classification scheme(1), Koc values ranging from 10,471 to 86,000(2), indicate that permethrin is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is possible(3) based upon an estimated Henry's Law constant of 2.2X10-6 atm-cu m/mole(SRC), derived from its vapor pressure, 5.18X10-8 mm Hg(4), and water solubility, 0.00111 mg/L(4). Using this Henry's Law constant and an estimation method(5), volatilization half-lives for a model river and model lake are 39 days and 289 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The estimated volatilization half-life from a model pond exceeds 100 years if adsorption is considered(6). According to a classification scheme(7), BCF values of approximately 560 and 480 for rainbow trout (Oncorhynchus mykiss) and sheepshead minnow (Cyprinodon vagiegatus), respectively(8,9), suggests the potential for bioconcentration in aquatic organisms is high(SRC). At pH 4, pH 5 and pH 7 (25 °C), permethrin is stable towards abiotic hydrolysis(2,4). At pH 9, the abiotic hydrolysis rate constant is 0.0139 per day at 25 °C(2) which corresponds to a half-life of 50 days(SRC). The hydrolysis half-lives of cis- and trans-permethrin at pH 9(25 °C, sterile water) have been measured as 42.3 and 37.7 days respectively(4). In water, a photolysis rate constant of 0.021 per day has been reported(2) which corresponds to photodegradation half-life of 33 days(SRC). In sterile buffer solutions (pH 4) exposed to irradiation equivalent to natural sunlight (Tokyo, 35 deg N, April-June), cis- and trans-permethrin had photolysis half-lives of 23.1 and 38.6 days respectively(4)using synthetic humic water, the photolysis half-lives decreased to 14.6 and 25.5 days respectively(2). The photolysis half-life of permethrin in seawater exposed to outdoor light was determined to be 14 days(9). Photolysis half-lives of 27.1 and 19.6 hrs were determined for respective cis- and trans-isomers in 800 mL pond water exposed to sunlight(10). Faster photodegradation in humic and natural waters can result from reaction with photo-oxidant species such hydroxyl radicals, peroxy radicals and singlet oxygen(11). Permethrin is susceptible to biodegradation as demonstrated by incubation studies using sterile and non-sterile conditions(9,12). The biodegradation half-life of permethrin in a sediment-seawater solution was less than 2.5 days(9)under sterile conditions there was no significant change in permethrin concentration(9).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), permethrin, which has a vapor pressure of 5.18X10-8 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere(SRC). Vapor-phase permethrin is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and ozone(SRC)the half-life for reaction with hydroxyl radicals in air is estimated to be 17 hours(SRC), calculated from its rate constant of 2.3X10-11 cu cm/molecule-sec at 25 °C(3)the half-life for reaction with ozone in air is estimated to be 49 days(SRC), calculated from its rate constant of 2.3X10-19 cu cm/molecule-sec at 25 °C(3). Particulate-phase permethrin may be removed from the air by wet and dry deposition(SRC). Permethrin absorbs light in the environmental spectrum(4) and has been shown to photodegrade in sunlight(2)therefore, permethrin can degrade through direct photolysis(SRC). |
|---|
| Lebensmitteluntersuchungswerte | During October 1, 1981 and September 30, 1986, permethrin was found in 309 U.S. agricultural commodity samples at a concentration range of >0-0.05 ppm, 155 samples at 0.05-0.1 ppm, 283 samples at 0.1-0.5 ppm, 104 samples at 0.5-1.0 ppm, 51 samples at 1.0-2.0 ppm, and 17 agricultural commodity samples at a concentration >2.0 ppm(1). This study does not distinguish between domestic and imported commodities or between surveillance and compliance samples(1). During October 1, 1981 and September 30, 1986, permethrin was found in 89 U.S. domestic agricultural commodities conducted by surveillance sampling at a concentration range of >0-0.05 ppm, 75 samples at 0.05-0.1 ppm, 217 samples at 0.1-0.5 ppm, 100 samples at 0.5-1.0 ppm, 47 samples at 1.0-2.0 ppm, and 11 domestic agricultural commodities at a concentration >2.0 ppm(2). During October 1, 1981 and September 30, 1986, permethrin was found in 234 U.S. imported agricultural commodities conducted by surveillance sampling at a concentration range of >0-0.05 ppm, 97 samples at 0.05-0.1 ppm, 36 samples at 0.1-0.5 ppm,1 sample at 0.5-1.0 ppm, and 1 imported agricultural commodity sample at a concentration 1.0-2.0 ppm(2). As part of the FDA Total Diet Study in 1992-1993, the max concentration of permethrin (total) in domestic and imported tomatoes was 0.28 ppm (24% of samples) and 0.38 ppm (26% of samples), respectively(3)the average concentration (weighted) in imported tomatoes was 0.03 ppm(3).cis-Permethrin Concentrations - FDA Total Diet Study Market Baskets (1991-93) (1).[Table#6279]Permethrin food detections(1-4).[Table#6280] |
|---|
| Unerwünschte Wirkungen | Neurotoxin - Other CNS neurotoxinAdverse effects reported during the treatment of scabies with permethrin include increased or new onset of pruritus, burning, or a stinging sensation. These dermatologic adverse events were mild in severity and temporary. There have also been reports of stinging when applying 1% permethrin for pediculosis capitis. |
|---|
| Expositionspfade | The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.Inhalation (L857)oral (L857)dermal (L857)eye contact (L857).
Poorly absorbed through the skin. |
|---|
| Milk Concentrations | Very small amounts /of permethrin/ are distributed into milk in animals. |
|---|
| Toxizitätsübersicht | Carcinogenesis, mutagenesis, and impairment of fertility: 6 carcinogenicity bioassays were evaluated with permethrin. No tumorigenicity has been observed in the rat studies. However, the 3 mouse studies saw an increase in pulmonary adenomas. In one of these studies, there was a raised incidence of pulmonary alveolar-cell carcinomas and benign liver adenomas in female mice. Permethrin exhibited no mutagenic potential in genetic toxicity studies (in vitro and in vivo). Permethrin did not adversely impact reproductive function when given orally at a 180 mg/kg/d dose in a 3-generation rat study.Pyrethroids exert their effect by prolonging the open phase of the sodium channel gates when a nerve cell is excited. They appear to bind to the membrane lipid phase in the immediate vicinity of the sodium channel, thus modifying the channel kinetics. This blocks the closing of the sodium gates in the nerves, and thus prolongs the return of the membrane potential to its resting state. The repetitive (sensory, motor) neuronal discharge and a prolonged negative afterpotential produces effects quite similar to those produced by DDT, leading to hyperactivity of the nervous system which can result in paralysis and/or death. Other mechanisms of action of pyrethroids include antagonism of gamma-aminobutyric acid (GABA)-mediated inhibition, modulation of nicotinic cholinergic transmission, enhancement of noradrenaline release, and actions on calcium ions. (T18, L857) |
|---|
| Landesrichtlinien für Trinkwasser | (FL) FLORIDA 350 ug/L |
|---|
