Tetramethrin

Pesticides

Insecticides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Pyrethrins/Pyrethroids

Pesticide (Tetramethrin) -> USDA PDB

log Kow = 4.73

4.49

1.108 at 20 °C/20 °C

1.11 g/cm³

Relative density (water = 1): 1.1

White crystalline solid

Colorless crystals

Methanol (53 g/kg), hexane (20 g/kg), xylene (1 g/kg), acetone, toluene.

In acetone, ethanol, methanol, hexane, n-octanol all >2 g/100 mL

In water, 1.83 mg/L at 25 °C.

Solubility in water: none

Solubility in water: none

68-70 °C

MP: 60-80 °C /Technical/

60-80 °C

0.00000708 [mmHg]

7.1X10-6 mm Hg at 30 °C

Vapor pressure, Pa at 20 °C:

Vapor pressure, Pa at 20 °C: 10

Warning

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P203, P260, P264, P270, P273, P280, P301+P317, P308+P316, P318, P330, P391, P405, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for 4% (8 of 199) of reports.

Warning

H302 (44.7%): Harmful if swallowed [Warning Acute toxicity, oral]

Hazard Traits - Environmental tox

2002/2076

Tetramethrin: HSNO Approval: HSR003266 Approved with controls

The 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.)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Combustible. Liquid formulations containing organic solvents may be flammable.

Liquid formulations containing organic solvents may be flammable.

USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document - Tetramethrin EPA 738-R-08-008 (June 2008). 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 May 28, 2009: http://www.epa.gov/pesticides/reregistration/status.htm]

WHO; Environmental Health Criteria 98: Tetramethrin p.45 (1990)

California Environmental Protection Agency/Department of Pesticide Regulation; Toxicology Data Review Summary for Tetramethrin (7696-12-0).[Available from, as of May 11, 2009: http://www.cdpr.ca.gov/docs/risk/toxsums/toxsumlist.htm]

USEPA, Office of Prevention, Pesticides, and Toxic Substances; Revised HED Human Health Risk Assessment for Tetramethrin (7696-12-0) (February 2008). EPA Docket No.: EPA-HQ-OPP-2008-0014-0005.

International Program on Chemical Safety; Health and Safety Guide No. 31: Tetramethrin (1989).[Available from, as of May 28, 2009: http://www.inchem.org/documents/hsg/hsg/hsg031.htm]

The Agency has previously identified and required the submission of the generic (i.e., active ingredient-specific) data required to support reregistration of products containing the active ingredient tetramethrin. The Agency has completed its review of these generic data, and has determined that the data are sufficient to support reregistration of all products containing tetramethrin. The Agency has completed its assessment of the human health and ecological risks associated with the use of pesticide products containing the tetramethrin. The Agency has determined that tetramethrin-containing products are eligible for reregistration provided that label amendments are made as outlined in Chapter V /of the Reregistration Eligibility Decision document/. ... Based on its evaluation of tetramethrin, the Agency has determined that products containing tetramethrin, unless labeled and used as specified in this /Reregistration Eligibility Decision/ document, would present risks inconsistent with FIFRA. Accordingly, should a registrant fail to implement any of the label changes identified in this /Reregistration Eligibility Decision/ document, the Agency may take regulatory action to address the risk concerns from the use of tetramethrin. If all changes outlined in this document are incorporated into the product labels, then all current risks for tetramethrin 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. Tetramethrin is found on List B. Case No: 2660; Pesticide type: Insecticide; Case 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): (1-Cyclohexene-1,2-dicarboximido)methyl 2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylate; Data Call-in (DCI) Date(s): 06/10/91, 10/13/95; AI 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.

A pyrethroid. This compound is an ester and nitrile. Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides.

Tetramethrin

Marine pollutant

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Use powder, AFFF, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Use powder, AFFF, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

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.

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

Provision to contain effluent from fire extinguishing.

Provision to contain effluent from fire extinguishing. Keep in a well-ventilated room.

Use carbon dioxide, foam, or dry chemical /on fires involving pyrethroids/. /Pyrethrum/

Fire-fighting: Self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive-pressure mode. /Pyrethrum/

Some solvents in pyrethroid formulations are highly flammable. DO NOT USE WATER to extinguish fires. Use dry powder, carbon dioxide, or alcohol-resistant foam, sand, or earth. Cool nearby drums with water spray. Whenever pyrethroid products are involved in a major fire, instruct the fire service to wear protective clothing and breathing apparatus. Inform the fire service and the relevant authorities that pyrethroids are toxic for fish, and that water should be used only to cool the unaffected stock. In this way, the accumulation of polluted run-off from the site is prevented.

Ventilate well. Store in closed drum in a cool, dry place.

Pyrethrins with piperonyl butoxide topical preparations should be stored in well-closed containers at a temperature less than 40 °C, preferably between 15-30 °C. /Pyrethrins/

Store technical material and formulations away from heat, in a locked area, designated for pesticide storage only. Keep out of reach of children, unauthorized personnel, and animals, and away from food and animal feed. Prevent spills from leaking into watercourses.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a POTW is acceptable only after review by the governing authority. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must meet Hazardous Material Criteria for disposal.

Spillage: Keep spectators away from leaking or spilled product. Prohibit smoking and the use of naked flames in the immediate vicinity. Transfer any product remaining in damaged or leaking containers into a clean, empty drum, and label the drum. Absorb spillage with lime, damp sawdust, sand, or earth, or other absorbent material and place in a secure container for safe disposal. Contain a large spillage by building a barrier of earth or sandbags. Prevent liquid from spreading to other cargo, vegetation, or waterways. Decontaminate empty, damaged, or leaking containers with a 10% sodium carbonate solution added at the rate of at least 1 L per 20-L drum. Puncture containers to prevent reuse.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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 quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or other waters unless in accordance with the requirements of a National Pollutant Discharge Eliminations System (NPDES) permit and the permitting authority has been notified in writing prior to discharge.

Waste that contains tetramethrin should be burnt in an appropriate high-temperature incinerator with effluent scrubbing. Where no incinerator is available, contaminated absorbents or surplus products should be decomposed by hydrolysis at pH 12 or above. Contact with a suitable hydrolysing agent is required to ensure degradation of the active ingredient to a safe level. For emulsifiable material, use 5% sodium hydroxide (caustic soda) solution or saturated (7-10%) sodium carbonate (washing soda) solution. For non-emulsifiable material, use a 1:1 mixture (by volume) of caustic soda or washing soda and a water/oil soluble solvent such as denatured alcohol, monoethylene glycol, hexylene glycol, or isopropanol. Cover the material with a hydrolysing agent and let it stand for 7 days. Before disposal, the waste must be analysed to ensure that the active ingredient has been degraded to a safe level. Never pour untreated waste or surplus products into public sewers or where there is any danger of run-off or seepage to streams, watercourses, open waterways, ditches, fields with drainage systems, or to the catchment areas of boreholes, wells, springs, or ponds.

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.

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. Collect leaking and spilled liquid in sealable containers as far as possible. Cautiously neutralize remainder with alkaline materials. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit 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.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.

Users should wash hands before eating, drinking, chewing gum, using tobacco, or using the toilet.

For more Preventive Measures (Complete) data for TETRAMETHRIN (12 total), please visit the HSDB record page.

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. (L363)

/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/

Pyrethroid 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 pyrethriod poisoning. (L857)

LD50; Species Colinus virginianus (Bobwhite quail) oral >1000 mg/kg

LD50; Species: Anas platyrhynchos (Mallard duck) oral >1000 mg/kg

LC50; Species: Anas platyrhynchos (Mallard duck, age 10 days) diet >5620 ppm for 8 days

LC50; Species: Colinus virginianus (northern bobwhite, age 14 days) diet >5620 ppm for 8 days

For more Ecotoxicity Values (Complete) data for TETRAMETHRIN (17 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 790(SRC), determined from a log Kow of 4.73(2) and a regression-derived equation(4), indicates that tetramethrin is expected to have very low mobility in soil(SRC). Volatilization of tetramethrin from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.7X10-6 atm-cu m/mole(SRC) derived from its vapor pressure, 7.08X10-6 mm Hg(3), and water solubility, 1.83 mg/L(3). Tetramethrin is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure(SRC). Direct photolysis on soil surfaces may be an important fate process based on a photolysis half-life of approximately 1 hour(5). Although environmental biodegradation in soil data specific to tetramethrin were not available, the pyrethroid class of insecticides is degraded readily by environmental microorganisms(6,7).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 790(SRC), determined from a log Kow of 4.73(2) and a regression-derived equation(4), indicates that tetramethrin is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(5) based upon an estimated Henry's Law constant of 1.7X10-6 atm-cu m/mole(SRC) derived from its vapor pressure, 7.08X10-6 mm Hg(3), and water solubility, 1.83 mg/L(3). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 950 hours and 290 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 34(SRC), from its log Kow(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is moderate, provided the compound is not metabolized by the organism(SRC). Although environmental biodegradation in water data specific to tetramethrin were not available(SRC, 2009), the pyrethroid class of insecticides is degraded readily by environmental microorganisms(8,9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tetramethrin, which has a vapor pressure of 7.08X10-6 mm Hg at 30 °C (2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase tetramethrin is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 3 hours(SRC), calculated from its rate constant of 1.3X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase tetramethrin may be removed from the air by wet or dry deposition(SRC). Tetramethrin contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.

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).

Both type I and type II 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. They also inhibit calium channels and Ca2+, Mg2+-ATPase. (T10, T18, L857)

/OTHER TERRESTRIAL SPECIES/ Acute toxicities of ... insecticides /including/ tetramethrin ... to the third instar of the silkworm, Bombyx mori (L.), were determined by feeding the insect with the insecticide-treated mulberry, Morus albus (L.), leaves. Twenty-four and 48 hr after treatment, toxicity levels of all insecticides to the silkworm were in the very high or high range, and the LC50 values of ... tetramethrin ... were 3.86 and 2.83 mg/liter. ...

/OTHER TOXICITY INFORMATION/ Synthetic pyrethroids have been shown to be toxic for fish, aquatic arthropods, and honeybees in laboratory tests. But, in practical usage, no serious adverse effects have been noticed because of the low rates of application and lack of persistence in the environment. The toxicity of synthetic pyrethroids in birds and domestic animals is low. /Synthetic pyrethroids/

Redness. Burning sensation.

Redness.

Redness. Burning sensation.

Redness.

Following oral exposure, severe fine tremor, marked reflex hyperexcitability, sympathetic activation can occur. Nausea, vomiting and abdominal pain commonly occur and develop following ingestion. Sudden bronchospasm, swelling of oral and laryngeal mucous membranes, and anaphylactoid reactions have been reported after inhalation. Hypersensitivity reactions characterized by pneumonitis, cough, dyspnea, wheezing, chest pain, irritability to sound and touch, and bronchospasm may occur too . Dermatitis is the main effect of a dermal exposure to tetramethrin. (T36)

The substance is very toxic to aquatic organisms. This substance does enter the environment under normal use. Great care, however, should be taken to avoid any additional release, for example through inappropriate disposal.

The substance is very toxic to aquatic organisms. Avoid release to the environment in circumstances different to normal use.

Initial medical screening: Employees should be screened for history of certain medical conditions ... which might place the employee at increased risk from /pyrethroid/ exposure. Chronic respiratory disease: In persons with chronic respiratory disease, especially asthma, the inhalation of /pyrethroids/ might cause exacerbation of symptoms due to its sensitizing properities. Skin disease: /Pyrethroids/ can cause dermatitis which may be allergic in nature. Persons with pre-existing skin disorders may be more susceptible to the effects of this agent. Any employee developing the above-listed conditions should be referred for further medical examination. /Pyrethrum/

The Agency has previously identified and required the submission of the generic (i.e., active ingredient-specific) data required to support reregistration of products containing the active ingredient tetramethrin. The Agency has completed its review of these generic data, and has determined that the data are sufficient to support reregistration of all products containing tetramethrin. The Agency has completed its assessment of the human health and ecological risks associated with the use of pesticide products containing the tetramethrin. The Agency has determined that tetramethrin-containing products are eligible for reregistration provided that label amendments are made as outlined in Chapter V /of the Reregistration Eligibility Decision document/. ... Based on its evaluation of tetramethrin, the Agency has determined that products containing tetramethrin, unless labeled and used as specified in this /Reregistration Eligibility Decision/ document, would present risks inconsistent with FIFRA. Accordingly, should a registrant fail to implement any of the label changes identified in this /Reregistration Eligibility Decision/ document, the Agency may take regulatory action to address the risk concerns from the use of tetramethrin. If all changes outlined in this document are incorporated into the product labels, then all current risks for tetramethrin 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. Tetramethrin is found on List B. Case No: 2660; Pesticide type: Insecticide; Case 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): (1-Cyclohexene-1,2-dicarboximido)methyl 2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylate; Data Call-in (DCI) Date(s): 06/10/91, 10/13/95; AI 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.

P - Antiparasitic products, insecticides and repellents

QP - Antiparasitic products, insecticides and repellents

Type I and type II pyrethroids are known to modulate the sodium channel to cause persistent openings during depolarization and upon repolarization. Although there are some similarities between the two types of pyrethroids in their actions on sodium channels, the pattern of modification of sodium currents is different between the two types of pyrethroids. In the present study, interactions of the type I pyrethroid tetramethrin and the type II pyrethroid deltamethrin at rat hippocampal neuron sodium channels were investigated using the inside-out single-channel patch clamp technique. Deltamethrin-modified sodium channels opened much longer than tetramethrin-modified sodium channels. When 10 uM tetramethrin was applied to membrane patches that had been exposed to 10 uM deltamethrin, deltamethrin-modified prolonged single sodium currents disappeared and were replaced by shorter openings which were characteristic of tetramethrin-modified channel openings. These single-channel data are compatible with previous whole-cell competition study between type I and type II pyrethroids. These results are interpreted as being due to the displacement of the type II pyrethroid molecule by the type I pyrethroid molecule from the same binding site or to the allosteric interaction of the two pyrethroid molecules at separate sodium channel sites.

Pyrethroid insecticides may be classified into two groups: type I pyrethroids lack a cyano group in the alpha-position, whereas type II pyrethroids have a cyano group. Both types prolong the sodium channel current thereby causing hyperexcitability ... . The mechanism of pyrethroid modulation of sodium currents was studied by the whole-cell patch-clamp technique with rat dorsal root ganglion neurons. Both deltamethrin (type II) and tetramethrin (type I) acted on both tetrodotoxin-sensitive and tetrodotoxin-resistant channels in a qualitatively similar manner and some quantitative differences were derived from different kinetics. During repetitive stimulation in the presence of deltamethrin, leak current increased due to accumulation of prolonged tail currents, explaining the apparent use-dependent modification. For tetramethrin-modified channels, such accumulation was much less because of faster kinetics. Slowing of the kinetics of sodium channel activation by deltamethrin was revealed even after the fast inactivation had been removed by papain. The kinetics of deltamethrin-modified sodium channels was fitted better by the equation that contained two activation components than that with one component. Deltamethrin caused a large shift of the conductance-voltage curve in the direction of hyperpolarization. Cell-attached patch-clamp experiments revealed that deltamethrin had much smaller mobility in the cell membrane than tetramethrin. It was concluded that the apparent use dependence of deltamethrin modification of sodium channels was due primarily to the accumulation of prolonged tail currents during repetitive stimulation and that the sodium channel activation mechanism is the major target of pyrethroids.

Tetramethrin greatly prolongs the sodium current during step depolarization and the sodium tail current associated with step repolarization of the squid axon membrane. Non-linear current-voltage relationships for the sodium tail current were analyzed to assess the open sodium channel properties, which included the permeation of various cations, calcium block, and cation selectivity. Tetramethrin had no effect on any of these properties. It was concluded that tetramethrin modifies the sodium channel gating mechanism without affecting the pore properties.

1R,trans-Tetramethrin markedly prolongs the open time of single sodium channels recorded by the gigaohmseal voltage clamp technique in a membrane patch excised from the N1E-115 neuroblastoma cell. Single channel conductance is not altered by tetramethrin. The modification by tetramethrin occurs in an all or nothing manner in a population of sodium channels. The observed tetramethrin-induced modification of single sodium channels is compatible with previous sodium current data from axons.

For more Mechanism of Action (Complete) data for TETRAMETHRIN (14 total), please visit the HSDB record page.

In mammals, the principal metabolite is 3-hydroxycyclohexan-1,2-dicarboximide

Acetone powder preparations of milkweed bugs, cockroaches, houseflies, cabbage loopers (Trichoplusia ni Hubner) and yellow mealworms (Tenebrio molitor L.) hydrolyzed both (+)-trans- and (+)-cis-isomers of tetramethrin. Of these two isomers, the (+)- trans-isomer was cleaved more rapidly.

When phthalthrin was applied topically to houseflies, chromatography of extracts indicated the presence of chrysanthemic acid and N-hydroxymethyltetrahydrophthalimide. Three other compounds were not identified.

When alcohol- or acid-labelled [1RS,trans]-tetramethrin (1 mM/L) was incubated for 1 hr at 37 °C with 30 mg protein of a rat liver subcellular fraction (i.e. nuclei plus mitochondria, microsomes, and soluble fraction), the microsomes and nuclei plus mitochondria fractions were active in degrading tetramethrin. Rat microsomal fraction degraded [1R,trans]-tetramethrin to chrysanthemic acid, N-(hydroxymethyl)-3,4,5,6-tetrahydrophthalimide, and 3,4,5,6-tetrahydrophthalimide in the absence of NADPH. In the presence of NADPH, tetramethrin was more rapidly degraded to yield oxidized tetramethrin (wt-alc-, wt-ald-, and wt-acid-tetramethrin), oxidized chrysanthemic acid (wt-alc-, wt-ald-, and wt-acid-chyrsanthemic acid), 3,4,5,6-tetrahydrophthalimide, and unidentified metabolites in larger amounts. The major metabolite 3,4,5,6-tetrahydrophthalimide was shown to be produced non-enzymatically from N-(hydroxymethyl)-3,4,5,6-tetrahydrophthalimide. The degradation rate of tetramethrin was greatly reduced by the inhibition of ester hydrolysis with paraoxon.

For more Metabolism/Metabolites (Complete) data for TETRAMETHRIN (11 total), please visit the HSDB record page.

The reactions occuring during metabolism of tetramethrin are: ester cleavage; loss of the hydroxymethyl group from the alcohol moiety; reduction of the 1-2 bond of the alcohol moiety; oxidation at the isobutenyl methyl moiety of the acid and at the 2-, 3-, and 4-positions of the alcohol moiety; conjugation of the resultant acids and alcohols with glucuronic acid; and cis/trans isomerization. The metabolites are excreted in the urine and faeces in more or less equal amounts. (L870)

Following a single oral or subcutaneous admin to Sprague-Dawley rats of [1R,trans]- or [1R,cis]-tetramethrin, labelled with (14)C in the acid or alcohol moieties at concn of 3.2-5.3 mg/kg, the radiocarbon was rapidly & almost completely eliminated from the rat body. The total recoveries 7 days after admin were 93-97% for the trans isomer & 90-101% for the cis isomer (approx equal amounts being eliminated in urine & feces). In the cases of the oral dose of acid-labelled tetramethrin, 1-3% of the radiolabel was excreted as (14)CO2, whereas in other cases (14)CO2 accounted for <1% of the dose. The tissue residue 7 days after admin was very low. The trans isomer yielded somewhat more complete radiolabel recovery & lower tissue residues than the cis isomer. In addtn, acid labelling resulted in slightly lower tissue residues than did alcohol labelling. However, there were no significant differences, according to sex or admin route, in the total radiocarbon recoveries & tissue residue levels.

Tetramethrin is readily absorbed & excreted by rats. Following a single oral admin of [1RS,trans]-tetramethrin, labelled with (14)C at the carbonyl group of the alcohol moiety, to male Wistar rats at a concn of 500 mg/kg, 47% & 42% of the radiolabel were excreted into the urine & feces, respectively, during the subsequent 2 days & 95% was recovered during the 5 day period that followed dosing. The tissue levels during the first 2 days after admin were very low & the tetramethrin content in tissues was <0.01% of the dosed radioactivity. Unmetabolized trans-tetramethrin was not excreted into the urine, & the major metabolite was 3-hydroxy-cyclohexane-1,2-dicarboximide in free & glucuronide forms. N-(Hydroxymethyl)-3,4,5,6-tetrahydrophthalimide, & cyclohexane-1,2-dicarboximide were identified as minor urinary & fecal metabolites.

1. The toxicokinetics of cis- & trans-tetramethrin isomers were investigated using the isolated perfused rat liver preparation. 2. The concn of cis- & trans-tetramethrin decr rapidly in the plasma perfusate & was initially replaced by N-(hydroxymethyl)3,4,5,6-tetrahydrophthalimide & then by 3,4,5,6-tetrahydrophthalimide. Plasma perfusate concn of the intact cis-isomer were higher than those of the trans-isomer. Concn of N-(hydroxymethyl)3,4,5,6-tetrahydrophthalimide & 3,4,5,6-tetrahydrophthalimide were higher in livers treated with the trans-isomer. 3. Tetramethrin & its metabolites were rapidly excreted in the bile. Bile from livers perfused with trans-isomer contained higher concn of parent isomer & metabolites N-(hydroxymethyl)3,4,5,6-tetrahydrophthalimide & 3,4,5,6-tetrahydrophthalimide, than did bile from livers treated with the cis-isomer.

Bile collected from rats treated by iv injection with (14)C labeled isomers of the pyrethroid insecticide tetramethrin /was analyzed/. For both the cis & trans isomers, the excretion of radioactivity into the bile was rapid; 25% of the admin radioactivity was excreted within 1 hr of dosing. Within an 8 hr period, approximately 41% of the admin dose of either isomer was excreted in the bile. Tetramethrin isomers & their metabolites were also rapidly excreted in bile in isolated perfused rat liver studies ... & accounted for approximately 18% of the admin radioactivity with 15 min. 3 hr after admin of the tetramethrin isomer to the reservoir of the isolated perfused rat liver system, 41% of the admin radioactivity was excreted in bile. Kennedy comment for SRP76: ADE(8) Same information as ADE(4)-delete

For more Absorption, Distribution and Excretion (Complete) data for TETRAMETHRIN (8 total), please visit the HSDB record page.

Used as a pyrethroid insecticide; [CAMEO]

Farming (Pesticides) [Category: Industry]

For tetramethrin (USEPA/OPP Pesticide Code: 069003) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

Potent synthetic pyrethroid insecticide.

Insecticide

Commercial applications include space sprays, broadcast surface treatments, and crack and crevice treatments in a variety of industrial and institutional sites including: indoor non-food areas; animal premises (not used for human consumption); and outdoors as localized space and contact sprays on ornamental plants and perimeter treatments (sidewalks, entranceways, outside surfaces of buildings, etc.).

N-hydroxymethyl-3,4,5,6-tetrahydrophthalimide + (1RS)-cis/trans-chrysanthemic acid (esterification)

Preparation of racemic mixture: T. Kato et al., JP 65 8535; eidem, US 3268398 (1965, 1966 both to Sumitomo).

Formulation Types: Pressurized liquid, ready-to-use (RTU) liquids, emulsifiable concentrates, and liquid concentrates.

Aerosol, oil liquid, emulsifiable concentrate.

Technical material 85% active ingredient. ... Oil based and water based sprays as well as aerosol sprays made up of tetramethrin in combination with piperonyl butoxide, resmethrin, methylated naphthalenes.

Aerosol dispenser; emulsifiable concentrate; dustable powder; ultra-low volume liquid; oil; emulsion, oil in water

For more Formulations/Preparations (Complete) data for TETRAMETHRIN (298 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies Tetramethrin as unlikely to present an acute hazard in normal use; Main Use: Other use for plant pathogens.

Available commercially as the racemic of (1R)-enriched product.

It is a mixture of four stereoisomers. The cis:trans ratio is reported to be 1:4 and optical ratio of 1R:1S is 1:1 (racemic). Thus its composition is roughly 4:1:4:1 for the (1R,trans), (1R,cis), (1S,trans) and (1S,cis) isomers. The (1R,trans)isomer is the most active biologically of the isomers, followed by the [1R,cis] isomer. Neo-Pynamin Forte is a mixture of the (1R,cis,) and (1R,trans) isomers in the ratio of 1:4.

The commercial product is a mixture of isomers.

For more General Manufacturing Information (Complete) data for TETRAMETHRIN (6 total), please visit the HSDB record page.