Tetramethrin

331.41

331.41

231-711-6

Z72930Q46K

0334|0335

2588

DTXSID6032649

White crystalline solid|Colorless crystals

P - Antiparasitic products, insecticides and repellents

2925190024

63.7

4.73

Tetramethrin appears as colorless crystals with slight odor. Non corrosive. Used as an insecticide.

1.108 g/cm³ @ Temp: 20 °C

68-70 °C

180-190 °C @ Press: 0.1 Torr

227.9±28.7 °C

1.558

Solubility in water: none

0-6°C

Vapour pressure, Pa at 20°C: 10

Oral-Rat LD50: 4640 mg/kg; Oral-Mouse LD50: 1000 mg/kg

Combustion produces toxic nitrogen oxide gas

Slight pyrethrum-like odor

Henry's Law constant = 1.69X10-6 atm-cu m/mol at 25 °C (est)

Hydroxyl radical reaction rate constant = 1.27X10-10 cu cm/molec-sec at 25 °C (est)

Hydrolysis occurs with strong acid or base.

Amides and Imides

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.

Non-corrosive

III

9

UN 2588

2

20-50/53

24/25-61-60

GZ1730000

Xn,N

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

Stable. Incompatible with strong oxidizing agents.

P273-P501

H410

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.

Incompatible with mineral carriers such as kieselguhr, acidic clays and kaolin.|Incompatibility: Strong oxidizers. /Pyrethrins/|... Incompatible with lime & ordinary soaps because acids & alkalies speed up processes of hydrolysis. /Pyrethrins/

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]

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways. (ERG, 2016)|Combustible. Liquid formulations containing organic solvents may be flammable.|Liquid formulations containing organic solvents may be flammable.

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P201, P202, P260, P264, P270, P273, P281, P301+P312, P308+P313, P309+P311, P330, P391, P405, and P501|H400 (99.65%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|Aggregated GHS information provided by 290 companies from 11 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|Aggregated GHS information provided by 2 companies from 1 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H320: Causes eye irritation [Warning Serious eye damage/eye irritation]|P260, P264, P270, P305+P351+P338, P309+P311, P337+P313, P405, and P501

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2016)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. (ERG, 2016)|Mixers, Loaders, Applicators and other handlers must wear long-sleeve shirt and long pants, and shoes plus socks.|Employees should be provided with and required to use dust- and splash-proof safety goggles where /pyrethroids/ ... may contact the eyes. /Pyrethroids/|Employees should be provided with and be required to use impervious clothing, gloves, and face shields (eight-inch minimum). /Pyrethroids/

Combustible. Liquid formulations containing organic solvents may be flammable.

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.

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: 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.

The chief effect from exposure ... is skin rash particularly on moist areas of the skin. ... May irritate the eyes. /Pyrethroids/

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.

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

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.

The substance is irritating to the eyes and skin.

NO open flames.

PREVENT DISPERSION OF DUST!|PREVENT GENERATION OF MISTS!

Use ventilation, local exhaust or breathing protection.

Protective gloves.

Wear safety goggles.

INDOOR: Tetramethrin was detected at a median concentration of 0.1 mg/kg in 13 dust samples from German houses and 0.1 mg/kg in another set of 4 German houses(1). Tetramethrin was detected at a mean concentration of 4.5 ug/sq m in one of six settled dust samples collected from Central New York farmers' non-air conditioned homes in 1999(2). A mean concentration of 3.5 ug/sq m was detected in four out of ten samples of carpet dust from the same farmers' homes; a mean concentration of 1.5 ug/sq m was detected in a second series of samples taken after participants vacuumed(2).

moderately toxic

/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/

LD50 Mouse oral >20,000 mg/kg|LD50 Mouse dermal >15,000 mg/kg|LD50 Rat oral >20 g/kg|LD50 Mouse (male) sc 2020 mg/kg /1R,cis/trans)-/|For more Non-Human Toxicity Values (Complete) data for TETRAMETHRIN (21 total), please visit the HSDB record page.

/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/

Tetramethrin's production may result in its release to the environment through various waste streams; its use as an insecticide(1) will result in its direct release to the environment(SRC).

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 rate constant for the vapor-phase reaction of tetramethrin with photochemically-produced hydroxyl radicals has been estimated as 1.3X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 3 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 8.8X10-2 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 2.5 years and 91 days at pH values of 7 and 8, respectively(2). Tetramethrin is susceptible to alkaline hydrolysis(4). Hydrolysis of tetramethrin yields 3.4.5.6-tetrahydrophthalic acid(4,5). Tetramethrin contains chromophores that absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 34 was calculated for tetramethrin(SRC), using a log Kow of 4.73(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

The Koc of tetramethrin is estimated as 790(SRC), using a log Kow of 4.73(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that tetramethrin is expected to have low mobility in soil.

The Henry's Law constant for tetramethrin is estimated as 1.7X10-6 atm-cu m/mole(SRC) derived from its vapor pressure, 7.08X10-6 mm Hg(1), and water solubility, 1.83 mg/L(1). This Henry's Law constant indicates that tetramethrin is expected to volatilize rapidly from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 951 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 294 days(SRC). Tetramethrin's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Tetramethrin is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 9,244 workers (1,759 of these were female) were potentially exposed to tetramethrin in the US(1). The NOES Survey does not include farm workers. Occupational exposure to tetramethrin may occur through inhalation of dust particles and dermal contact with this compound at workplaces where tetramethrin is produced or used(SRC). Use data indicate that the general population may be exposed to tetramethrin via inhalation and dermal contact with consumer products containing tetramethrin(SRC).

Pyrethrins with piperonyl butoxide are used for topical treatment of pediculosis (lice infestations). Combinations of pyrethrins with piperonyl butoxide are not effective for treatment of scabies (mite infestations). Although there are no well-controlled comparative studies, many clinicians consider 1% lindane to be pediculicide of choice. However, some clinicians recommend use of pyrethrins with piperonyl butoxide, esp in infants, young children, & pregnant or lactating women ... . If used correctly, 1-3 treatments ... are usually 100% effective ... Oil based (eg, petroleum distillate) combinations ... produce the quickest results. ... For treatment of pediculosis, enough gel, shampoo, or solution ... should be applied to cover affected hair & adjacent areas ... After 10 min, hair is ... washed thoroughly ... treatment should be repeated after 7-10 days to kill any newly hatched lice. /Pyrethrins/

Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics. (See all compounds classified as Insecticides.)

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.

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.

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.

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. (ERG, 2016)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim calm and warm. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. (ERG, 2016)

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.

Emergency and supportive measures: Treat bronchospasm and anaphylaxis if they occur. Observe patients with a history of large ingestions for at least 4-6 hours for any signs of CNS depression or seizures. /Pyrethrins and pyrethroids/|Decontamination: Inhalation: Remove victims from exposure and give supplemental oxygen if needed. Skin: Wash with copious soap and water. Topical application of vitamin E in vegetable oil was reported anecdotally to relieve paresthesias. Eyes: Irrigate with copious water. After irrigation, perform a fluorescein examination and refer the victim to an ophthalmologist if there is evidence of corneal injury. Ingestion: In the majority of cases, a subtoxic dose has been ingested and no decontamination in necessary ... Gastric lavage is not necessary after small to moderate ingestions if activated charcoal can be given promptly. /Pyrethrins and pyrethroids/|Enhanced elimination: These compounds are metabolized rapidly by the body, and extracorporeal methods of elimination would not be expected to enhance their elimination. /Pyrethrins and pyrethroids/|Skin decontamination. Wash skin promptly with soap and water ... . If irritant or paresthetic effects occur, obtain treatment by a physician. Because volatilization of pyrethroids apparently accounts for paresthesia affecting the face, strenuous measures should be taken (ventilation, protective face mask and hood) to avoid vapor contact with the face and eyes. Vitamin E oil preparations (dL-alpha tocopheryl acetate) are uniquely effective in preventing and stopping the paresthetic reaction. They are safe for application to the skin under field conditions. Corn oil is somewhat effective, but possible side effects with continuing use make it less suitable. Vaseline is less effective than corn oil. Zinc oxide actually worsens the reaction. /Pyrethroids/|For more Antidote and Emergency Treatment (Complete) data for TETRAMETHRIN (9 total), please visit the HSDB record page.

/HUMAN EXPOSURE STUDIES/ In a semi-closed patch test, an aqueous emulsion containing 1.0% tetramethrin was applied to the skin of 200 human volunteers (aged 15-80, both male and female), using cotton gauze, for 4 days. After 2 weeks, an additional application was made in a same manner. Dermatological examination showed that tetramethrin is neither a primary irritant nor a human skin sensitizer.|/SIGNS AND SYMPTOMS/ Synthetic pyrethroids are neuropoisons acting on the axons in the peripheral and central nervous systems by interacting with sodium channels in mammals and/or insects. A single dose produces toxic signs in mammals, such as tremors, hyperexcitability, salivation, choreoathetosis, and paralysis. ... At near-lethal dose levels, synthetic pyrethroids cause transient changes in the nervous system, such as axonal swelling and/or breaks and myelin degeneration in sciatic nerves. They are not considered to cause delayed neurotoxicity of the kind induced by some organophosphorus compounds. / Pyrethroids/|/SIGNS AND SYMPTOMS/ The clinical manifestations of inhalation exposure to pyrethrins can be local or systemic. Localized reactors confined to the upper respiratory tract include rhinitis, sneezing, scratchy throat, oral mucosal edema, and even laryngeal mucosal edema. Localized reaction of the lower respiratory tract include cough, shortness of breath, wheezing, and chest pain. An asthmalike reaction occurs with acute exposures in sensitized patients. Hypersensitivity pneumonitis characterized by chest pain, cough, dyspnea, & bronchospasm may occur in an individual chronically exposed. /Pyrethrum and synthetic pyrethroids/|/SURVEILLANCE/ There are approximately 98 reported incidents in the OPP Incident Data System database over the last five years (2002 to /2007/) for products containing tetramethrin. Since there are no pesticide products for which tetramethrin is the sole active ingredient, reported incidents cannot be solely attributed to exposure to tetramethrin. The incidents are classified as mild to moderate human incidents (less than 1% involved major effects). The majority (approximately 85%) of incidents with documented health effects reported either no effects or mild effects resulting from tetramethrin related exposures. The majority of the symptoms included respiratory irritation, shortness of breath, blisters, welts, hives, dizziness, rashes, coughing, and eye irritation, which are similar to that of other pyrethroid compounds. The Poison Control Centers incidents involved a wide range of effects including cardiovascular, gastrointestinal, respiratory, dermal, and ocular effects.|For more Human Toxicity Excerpts (Complete) data for TETRAMETHRIN (7 total), please visit the HSDB record page.

2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylic acid, ester with N-(hydroxymethyl)-1-cyclo hexene 1,2-dicarboximide

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

Redness. Burning sensation.

Redness.

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.

Method: EPA 1660; Procedure: high performance liquid chromatography with ultraviolet detection; Analyte: tetramethrin; Matrix: municipal and industrial wastewater; Detection Limit: 2 ug/L.|EPA-B Method PMD-TFK. Determination of Tetramethrin and d-Phenothrin by Internal Standard Gas Chromatography.

Agrochemicals -> Insecticides