Resmethrin (ISO)

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.

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.

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. Use dry powder, carbon dioxide, alcohol-resistant foam, sand. or earth for dealing with fires. DO NOT use water. Cool nearby drums with water spray. If pyrethroid products are involved in a major fire, or in a fire involving other products, advise the fire service that protective clothing and breathing apparatus should be worn. Also, warn the authorities that pyrethroids are highly toxic for fish, and that the use of water should be confined to the cooling of unaffected stock, thus avoiding the accumulation of polluted run-off from the site.

... /Store/ under dry conditions.

Store away from food and feedstuffs. ...

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, under lock and key, and out of reach of children, animals, and unauthorized personnel. Store in an area designated for insecticide storage, preferably without drains.

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.

Spillages of pesticides at any stage of their storage or handling should be treated with great care. Liquid formulations may be reduced to solid phase by evaporation. Dry sweeping of solids is always hazardous: these should be removed by vacuum cleaning /SRP: with HEPA filter/, or by dissolving them in water, or other solvent in the factory environment. /Pesticides/

... Spillages should be washed away with large volumes of water and detergent.

Spillage: Avoid exposure, if possible by the use of appropriate protective clothing and masks. Empty any product remaining in damaged or leaking containers into a clean empty drum, and label. Absorb spillage with lime, damp sawdust, sand, or earth and dispose of safely. If spillage is large, contain it by building a barrier of earth or sandbags. 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 re-use.

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.

It could be ... buried in noncrop land away from water. In each of these cases it would be better to mix the product with lime. Incineration would be an effective disposal procedure where permitted. If an efficient incinerator is not available, the product should be mixed with large amt of combustible material. Recommendable methods: Hydrolysis, landfill, incineration, & open burning. Not recommendable method: Discharge to sewer. Peer-review: Mix with sawdust and burn at a remote place. (Peer-review conclusions of an IRPTC expert consultation (May 1985))

Incineration would be an effective disposal procedure where permitted. ... /Pyrethrin products/

Empty containers may be decontaminated by washing three times with detergent and water. Additionally, the container should be soaked overnight in 5% sodium hydroxide. Impermeable gantlets should be worn for all decontamination procedures. A deep soakage pit should be provided for the rinsings. Decontaminated containers must not be used for storage or transport of food or drink. Containers not decontaminated should be burned or crushed and buried below topsoil. Care must be taken to avoid contamination of water sources.

Disposal: Waste containing resmethrin should be burnt in a proper 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: 5% sodium hydroxide (caustic soda) solution or saturated (7-10%) sodium carbonate (washing soda) solution can be used. For non-emulsifiable material: use a 1:1 mixture (by volume) of either of the above solutions and a water/oil soluble solvent, such as denatured alcohol, monoethylene glycol, hexylene glycol, or isopropanol. Cover the material with the hydrolysing agent and put aside to stand for 7 days. Before disposal of the resultant waste, the material 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 anywhere where there is any danger of run-off or seepage into streams, watercourses, open waterways, ditches, fields with drainage systems, or the catchment areas of boreholes, wells, springs, or ponds.

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.

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.

Do not enter or allow worker entry into treated areas during the restricted entry interval (REI) of 12 hours.

For more Preventive Measures (Complete) data for RESMETHRIN (14 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)

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)

/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 & 10000 ppm piperonyl butoxide ... /enlargement, margination, & cytoplasmic inclusions in liver cells of rats/ were well developed in only 8 days, but ... were not maximal. Changes were proportional to dosage & similar to those produced by DDT. Effects of the 2 ... were additive. /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)

As for every type I pyrethroid, bioresmethrin 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. (L857)

LD50; Species: /Callipepla californica/ (California quail, 5-6 month old male) oral >2000 mg/kg

LC50; Species: Coturnix japonica (Japanese quail, age 14 days, captive breeding colony) oral (via capsule) >5000 ppm for 5 days

LC50; Species: Anas platyrhynchos (Mallard duck, age 10 days, captive breeding colony) oral (via capsule) >5000 ppm for 5 days

LD50; Species: Anas platyrhynchos (Mallard duck, age 14 wk) oral (via capsule) >19.8 mg/kg for 14 days

For more Ecotoxicity Values (Complete) data for RESMETHRIN (76 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 3.1X10+5(SRC), determined from a measured log Kow of 5.43(2) and a regression derived equation(3), indicates that resmethrin is expected to be immobile in soil(SRC). Volatilization of resmethrin from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.3X10-7 atm-cu m/mole(SRC), calculated from its vapor pressure, 1.1X10-8 mm Hg(4), and water solubility, 0.0379 mg/L(2). Resmethrin is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). Hydrolysis in moist soil surfaces is expected to be an important fate process for resmethrin under alkaline conditions(SRC). The second order aqueous hydrolysis rate constant for resmethrin has been estimated to be 0.17 L/mole sec at 25 °C(SRC) using a structure estimation method(7), which corresponds to aqueous hydrolysis half-lives of 1.3 yrs, and 47 days at pH 7 and 8, respectively(SRC). Photolysis may also be an important fate process for this compound on soil surfaces(SRC). The photolysis half-life of resmethrin films on glass plates ranged from about 20 to 90 minutes when exposed to forenoon and midday sunlight conditions, respectively(8). Although biodegradation data for resmethrin were not available(SRC, 2009), the pyrethroid class of insecticides is readily degraded by microorganisms(5,6).

TERRESTRIAL FATE: Resmethin is expected to have a 30-day half-life in soil based on values of other pyrethroid compounds(1).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 3.1X10+5(SRC), determined from a log Kow of 5.43(2) and a regression-derived equation(3), indicates that resmethrin is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 1.3X10-7 atm-cu m/mole(SRC), derived from its vapor pressure, 1.13X10-8 mm Hg(5), and water solubility of 0.0379 mg/L(2). According to a classification scheme(6), an estimated BCF of 98 days(SRC), from its log Kow(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Hydrolysis is expected to be an important environmental fate process for resmethrin, particularly in alkaline waters(SRC). The second-order aqueous hydrolysis half-lives are 1.3 yrs and 47 days at pH 7 and 8, respectively(SRC), using a structure estimation method(8). Photolysis on surface waters is also expected to be an important fate process(SRC). The predicted near-surface half-life for the photosensitized oxidation of resmethrin in natural water has been reported as 0.2 hrs(9). Although biodegradation data for resmethrin were not available(SRC, 2009), the pyrethroid class of insecticides is readily degraded by environmental microorganisms(10,11).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), resmethrin, which has a vapor pressure of 1.13X10-8 mm Hg at 30 °C(2) is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase resmethrin may be removed from the air by wet or dry deposition. Resmethrin undergoes rapid photolysis in the environment with half-lives on the order of several minutes to a few hours(3-5).

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).

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)

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)

Using the Total Exposure Assessment Methodology (TEAM), air samples in residential households were collected over 24-hr periods in indoor, outdoor and personal air in two areas (Jacksonville, FL and Springfield/Chicopee, MA)(1); based upon air sample detections, the annual avg daily concn to resmethrin was estimated to be 0.1 ng/cu m in Jacksonville, FL(1); resmethrin was not detected in the MA area samplings(1).

/AQUATIC SPECIES/ Synthetic pyrethroids often have synergists added to improve effectiveness, yet decisions regarding the use of these pesticides are often based upon toxicity tests using technical material without the synergist, piperonyl butoxide ... Toxicity tests with brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) /were conducted/ to compare the toxicity of synergized and technical formulations of ...resmethrin ... The ability of exposed fish to swim against a current /was examined/. Fish exposed for 6 hr to synergized ... resmethrin had far less swimming stamina than those exposed to technical formulations.

/AQUATIC SPECIES/ This study investigated the toxicity of various concentrations of technical resmethrin and Scourge on adult and larval Palaemonetes pugio, a common grass shrimp species. Two types of tests were conducted for each of the resmethrin formulations using adult and larval grass shrimp life stages, a 96-hr static renewal aqueous test without sediment, and a 24-hr static nonrenewal aqueous test with sediment. For resmethrin, the 96-hr aqueous LC50 value for adult shrimp was 0.53 ug/L (95% confidence interval (CI): 0.46-0.60 ug/L), and for larval shrimp was 0.35 ug/L (95% CI: 0.28-0.42 ug/L). In the presence of sediment, technical resmethrin produced a 24-hr LC50 value for adult shrimp of 5.44 ug/L (95% CI: 4.52-6.55 ug/L), and for larval shrimp of 2.15 ug/L (95% CI: 1.35-3.43 ug/L). For Scourge, the 96-hr aqueous LC50 for adult shrimp was 2.08 ug/L (95% CI: 1.70-2.54 ug/L), and for larval shrimp was 0.36 ug/L (95% CI: 0.24-0.55 ug/L). The 24-hr sediment test yielded an LC50 value of 16.12 ug/L (95% CI: 14.79-17.57 ug/L) for adult shrimp, and 14.16 ug/L (95% CI: 12.21-16.43 ug/L) for larvae. Adjusted LC50 values to reflect the 18% resmethrin concentration in Scourge are 0.37 ug/L (adult), 0.07 ug/L (larvae) for the 96-hr aqueous test, and 2.90 ug/L (adult), 2.6 ug/L (larvae) for the 24-hr sediment test. Larval grass shrimp were more sensitive to technical resmethrin and Scourge than the adult life stage. The results also demonstrate that synergized resmethrin is more toxic to P. pugio than the nonsynergized form, and that the presence of sediment decreases the toxicity of both resmethrin and Scourge.

/AQUATIC SPECIES/ A comparative aquatic hazard assessment of resmethrin was conducted to investigate the need for its restricted use classification by the US. EPA as an adult mosquito control agent. ... Laboratory studies with constant 48- to 96-hr exposures show it is acutely toxic to fish and invertebrates in the 0.22-15.0 ug/L range. Daphnia magna, pink shrimp (Penaeus duorarum) and rainbow trout (Oncorhynchus mykiss) are the most sensitive and mollusks are the least sensitive species. Chronic laboratory studies indicate that the maximum acceptable toxicant concentrations (MATCs) for resmethrin and D. magna, Pimephales promelas, O. mykiss, and Cyprinodon variegatus are 0.58, 0.52, 0.43, and 10.3 ug/L, respectively. The acute-to-chronic ratios (1.1-7.3) for all species studied indicate that chronic toxicity will not be an issue for resmethrin. Furthermore, the characteristics of acute exposures (48- to 96-hr) used in the laboratory will not occur under field conditions because of the short half-life of resmethrin in fresh- and salt-water.

Redness.

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 resmethrin. (T36)

Following dermal exposure to bioresmethrin, feelings of numbness, itching, burning, stinging, tingling, or warmth may occur, that could last for a few hours. Dizziness, headache, nausea, muscle twitching, reduced energy, and changes in awareness can result from inhalation or ingestion of large amounts of bioresmethrin. Paralysis can occur after exposure. (L857)

Tolerances are established for residues of the insecticide resmethrin [5-(phenylmethyl)-3-furanyl] methyl 2,2-dimethyl-3-(2-methyl-1-propenyl) cyclopropanecarboxylate in or on food commodities at 3.0 ppm resulting from use of the insecticide in food handling and storage areas as a space concentration for spot/or crack and crevice treatment and shall be limited to a maximum of 3.00 percent of the active ingredient by weight, and as a space treatment shall be limited to a maximum of 0.5 fluid ounce of 3.0 percent active ingredient by weight per 1000 cubic feet of space provided that the food is removed or covered prior to such use. To assure safe use of the additive, its label and labeling shall conform to that registered with the U.S. Environmental Protection Agency, and shall be used in accordance with such label and labeling.

The Agency has completed its assessment of the dietary, occupational and ecological risk associated with the use of resmethrin apart from a species specific Endangered Species assessment ... . Based on this assessment, the Agency has sufficient information on resmethrin 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 resmethrin-containing products are eligible for reregistration provided that label amendments are made as outlined in this Reregistration Eligibility Decision /document/. ... Based on its evaluation of resmethrin, the Agency has determined that resmethrin products, unless labeled and used as specified in ... /the Reregistration Eligibility Decisiion/ document, would present risks inconsistent with FIFRA and FQPA. Accordingly, should a registrant fail to implement any of the reregistration requirements identified in this document, the Agency may take regulatory action to address the risk concerns from the use of resmethrin. If all changes outlined in ... /the Reregistration Eligibility Decisiion/ document are incorporated into the product labels, then all current risks for resmethrin will be adequately mitigated for the purposes of this determination. Once an Endangered Species assessment is completed, further changes to these registrations may be necessary ... .

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 future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Resmethrin is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0421; Pesticide type: insecticide; Registration Standard Date: 12/88; 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): Resmethrin; Data Call-in (DCI) Date(s): 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.

Used as insecticide for control of household and public health pests (including aerial application for mosquitoes) in residential, commercial, and industrial areas, animal dwellings, food handling/ storage facilities, and greenhouses; Also used for domestic and farm animals (in sprays and shampoos) and fabric protection; [HSDB]

Use restricted to certified applicators; Not registered in the US for agricultural applications; [HSDB]

Farming (Pesticides) [Category: Industry]

End-use products intended for wide area mosquito abatement programs /are/ Restricted Use Pesticides due to acute fish toxicity. For retail sale to and use only by certified applicators or persons under their direct supervision and only for those uses covered by the certified applicator's certification.

For resmethrin (USEPA/OPP Pesticide Code: 097801) 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./

Resmethrin is a synthetic Type I pyrethroid insecticide registered for control of insects in residential, commercial and industrial settings, and in animal living areas. Resmethrin is also registered for use in food handling establishments and as a restricted use pesticide when used in ULV spray to control adult mosquitoes in the interest of public health.

Esterification of 5-benzyl-3-furylmethyl alcohol (British patents 1168797-9) ... containing 20-30% of the (+/-)-cis isomer and 80-90% of the (+/-)-trans.

Esterification of ethereal 5-benzyl-3-furylmethyl alcohol with (+/-)-cis,trans-chrysanthemic acid chloride in benzene. After adding pyridine, and standing overnight, water is added and the organic layer washed with sulfuric acid, potassium bicarbonate, sodium chloride, dried and then distilled.

Preparation: M. Elliott, GB 1168797; idem, US 3465007 (both 1969 to National Research Development Corporation)

Resmethrin is an ester of chrysanthemic acid and 5-benzyl-3-furylmethyl alcohol. It is a racemic mixture of 4 optical isomers: [1R,trans]-, [1R,cis]-, [1S,trans]-, and [1S,cis]-isomer. In technical products the ratio of these isomers is roughly 4:1:4:1. The [1R,trans]-isomer is called bioresmethrin and the [1R,cis]- isomer, cismethrin. Among the isomers, the [1R,trans]-isomer has the highest insecticidal activity, followed by the [1R,cis]-isomer. ...It is formulated as an aerosol, an oil formulation, or an emulsifiable concentrate, sometimes in combination with other insecticides and/or synergists.

Resmethrin is formulated as ready-to-use pressurized liquid spray, emulsifiable concentrate, and soluble concentrate.

Resmethrin /formulations/ contain 70%(+/-)trans-isomer and 30%(+/-)cis-isomer.

FOR-SYN

For more Formulations/Preparations (Complete) data for RESMETHRIN (244 total), please visit the HSDB record page.

Pharmaceuticals

INSECTICIDES

The WHO Recommended Classification of Pesticides by Hazard identifies Resmethrin (technical grade) as Class III: slightly hazardous; Main Use: Insecticide.

For USDA meat and poultry inspection programs.

NIA 17370 discontinued by FMC Corporation

Compatible with other neutral insecticides and fungicides.

/Pyrethroids/ are modern synthetic insecticides similar chemically to natural pyrethrins, but modified to increase stability in the natural environment. /Pyrethroids/