Pyrethrin II

Pesticides

Veterinary substances, Acaricides, Insecticides

Soluble in ethanol, ether, carbon tetrachloride

Soluble in petroleum ether (less sol than pyrethrin I), kerosene, ethylene dichloride, nitromethane

In water, 9.0 mg/L (temperature not specified)

When heated to decomp it emits acrid smoke and irritating fumes.

Pyrethrins are decomp by exposure to light with loss of insecticidal activity. /Pyrethrins/

Specific optical rotation: -6 deg at 20 °C/D (diethyl ether, percentage concentration = 5%)

Specific optical rotation: +14.7 deg at 19 °C/D (isooctane-ether)

Oxidizes rapidly and becomes inactive in air.

Pyrethrums are highly unstable in the presence of light, moisture, and air. Whole flowers decompose more slowly than ground flowers or dust. Stored powders lose about 20% of their potency in one year. The potency of the pyrethrums can best be preserved in sealed, lightproof containers kept at lower temperatures. /Pyrethrum/

Pyrethrins are decomposed by exposure to light with loss of insecticidal activity. They are rapidly oxidized and inactivated by air. /Pyrethrins/

... As the pyrethrins approach 100% purity, their stability decreases; pyrethrin I & II are less stable than the other compounds. /Pyrethrins/

Stable >10 yr in absence of light, at ambient temperature.

Warning

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

P261, P264, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P317, P321, P330, P362+P364, P391, and P501 (click each P-code to see the statement)

Warning

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

P261, P264, P264+P265, P270, P271, P301+P317, P304+P340, P305+P351+P338, P319, P330, P337+P317, P403+P233, P405, and P501 (click each P-code to see the statement)

Chemical: Cyclopropanecarboxylic acid, 3-(3-methoxy-2-methyl-3-oxo-1-propenyl)-2,2-dimethyl-, 2-methyl-4-oxo-3-(2,4-pentadienyl)-2-cyclopenten-1-yl ester, [1R-[1.alpha.[S*(Z)],3.beta.(E)]]-

Pyrethrin II: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Pyrethrins, EPA 738-R-06-004 (June 2006). 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 1, 2012: http://www.epa.gov/pesticides/reregistration/status.htm]

Tolerances for residues of the insecticide pyrethrins ((1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienylcyclopenten-1-yl (1R,3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (pyrethrin 1), (1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienyl-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropane-carboxylate (pyrethrin 2), (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (cinerin 1), (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylate (cinerin 2), (1S)-2-methyl-4-oxo-3-(2Z)-2-pentenyl-2-cyclopenten-1-yl (1R, 3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (jasmolin 1), and (1S)-2-methyl-4-oxo-3-(2Z)-pentenyl-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylate (jasmolin 2)), the insecticidally active principles of Chrysanthemum cinerariaefolium, which are measured as cumulative residues of pyrethrin 1, cinerin 1, and jasmolin 1 are not to exceed the following:[Table#5826]

When applied to growing crops, in accordance with good agricultural practice, the following pesticide ... /chemical is/ exempt from the requirement of a tolerance: pyrethrins. ... /This pesticide is/ not exempted from the requirement of a tolerance when applied to a crop at the time of or after harvest. /Pyrethrins/

The Agency has completed its assessment of the dietary, occupational, residential, and ecological risk associated with the use of pesticide products containing the active ingredient pyrethrins. Based on a review of these data and on public comments on the Agency's assessments for the active ingredient pyrethrins, the Agency has sufficient information on the human health and ecological effects to make decisions as part of the tolerance reassessment process under FFDCA and reregistration process under FIFRA, as amended by FQPA. The Agency has determined that products containing pyrethrins are eligible for reregistration provided that: (i) the risk mitigation measures outlined in this document are adopted and (ii) label amendments are made to reflect these measures. ... Based on its evaluation of pyrethrins, the Agency has determined that pyrethrins products, unless labeled and used as specified in this 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 pyrethrins. If all changes outlined in this document are incorporated into the product labels, then all current risks for pyrethrins will be adequately mitigated for the purposes of this determination. /Pyrethrins/

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. Pyrethrum powder other than pyrethrins and pyrethrin coils are found on List B. Case No: 2580; 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): Pyrethrum powder other than pyrethrins, pyrethrin coils; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled." /Pyrethrum powder other than pyrethrins; Pyrethrin coils/

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1 lb or 0.454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b). /Pyrethrins/

Pyrethrin II is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance. /Pyrethrins/

Acute toxicity - category 4

Acute toxicity (Oral) - Category 4

Acute Tox. 4 *

49 638 81; Pyrethrins (pyrethrins) (hazardous substance, liquid, not otherwise specified)

49 638 86; Pyrethrins (pyrethrum extract, not less than 25% pyrethrum) (hazardous substance, liquid, not otherwise specified)

49 638 72; Pyrethrins (agricultural insecticides, not elsewhere classified, liquid) (hazardous substance, liquid, not otherwise specified)

49 638 77; Pyrethrins (agricultural insecticides, not elsewhere classified, other than liquid) (hazardous substance, solid, not otherwise specified)

49 638 68; Pyrethrins (insecticides, other than agricultural, not elsewhere classified) (hazardous substance, solid, not otherwise specified)

The constituents pyrethrin I and II in pure form are said to be irritating to eyes and mucous membranes.

Pyrethrum may irritate the eyes. /Pyrethrum/

... Incompatible with lime and ordinary soaps because acids & alkalies speed up processes of hydrolysis. /Pyrethrins/

Strong oxidizers. /Pyrethrum/

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

Extinguishant: Carbon dioxide, foam, or dry chemical. /Pyrethrum/

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) /Pyrethrins/

If pyrethrum is spilled, the following steps should be taken: 1) Ventilate area of spill. 2) For small quantities, sweep onto paper or other suitable material, place in an appropriate container and burn in a safe place (such as a fume hood). Large quantities may be reclaimed; however, if this is not practical, dissolve in a flammable solvent (such as alcohol) and atomize in a suitable combustion chamber. /Pyrethrum/

Environmental considerations: Water spill: If dissolved, in region of 10 ppm or greater concentration, apply activated carbon at ten times the spilled amount. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates. /Pyrethrins/

Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. /Pyrethrins/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

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 permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. 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 be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

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

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 by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

The worker should immediately wash the skin when it becomes contaminated. /Pyrethrum/

Work clothing that becomes wet or significantly contaminated should be removed and replaced. /Pyrethrum/

For more Preventive Measures (Complete) data for PYRETHRIN II (7 total), please visit the HSDB record page.

Tolerances for residues of the insecticide pyrethrins ((1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienylcyclopenten-1-yl (1R,3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (pyrethrin 1), (1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienyl-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropane-carboxylate (pyrethrin 2), (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (cinerin 1), (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylate (cinerin 2), (1S)-2-methyl-4-oxo-3-(2Z)-2-pentenyl-2-cyclopenten-1-yl (1R, 3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (jasmolin 1), and (1S)-2-methyl-4-oxo-3-(2Z)-pentenyl-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylate (jasmolin 2)), the insecticidally active principles of Chrysanthemum cinerariaefolium, which are measured as cumulative residues of pyrethrin 1, cinerin 1, and jasmolin 1 are not to exceed the following:[Table#5819]

When applied to growing crops, in accordance with good agricultural practice, the following pesticide ... /chemical is/ exempt from the requirement of a tolerance: pyrethrins. ... /This pesticide is/ not exempted from the requirement of a tolerance when applied to a crop at the time of or after harvest. /Pyrethrins/

Wear appropriate personal protective clothing to prevent skin contact. /Pyrethrum/

Wear appropriate eye protection to prevent eye contact. /Pyrethrum/

Respirator Recommendations: Up to 50 mg/cu m: /Pyrethrum/[Table#5820]

Respirator Recommendations: Up to 125 mg/cu m: /Pyrethrum/[Table#5821]

For more Personal Protective Equipment (PPE) (Complete) data for PYRETHRIN II (9 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. (T36)

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/

There is no evidence that synergists incr toxicity of the pyrethrins to mammals. /pyrethrins/

Antioxidants used to help protect insecticidal residues of pyrethrins include minute concn of pyrocatechol, pyrogallol, & hydroquinone; 1-benzene-azo-2-naphthol is used to protect against the effects of sunlight.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ ... Extract containing pyrethrum & piperonyl butoxide /was applied/ to chorio-allantoic membrane /of chick embryo/ & produced damaged testes with absence of gonadocytes in the surviving chicken embryo. /Pyrethrum extract/

Pyrethrin 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 pyrethrin poisoning. (L857)

LD50; Species: Frog injection 0.75 mg/kg

LD50; Species: /Anas platyrhynchos/ (Mallards) females 1-4 months; Concentration: >10,000 mg/kg /Pyrethrum/

LC50; Species: /Ictalurus punctatus/ (Channel catfish); Conditions: static test; Concentration: 114 ug/L for 96 hr /Pyrethrins/

LC50; Species: /Ictalurus punctatus/ (Channel catfish); Conditions: flow through test; Concentration: 132 ug/L for 96 hr (flow through test) /Pyrethrins/

For more Ecotoxicity Values (Complete) data for PYRETHRIN II (11 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 2940(SRC), determined from a structure estimation method(2), indicates that pyrethrin II is expected to have slight mobility in soil(SRC). Volatilization of pyrethrin II from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.2X10-8 atm-cu m/mole(SRC), based upon its vapor pressure, 3.98X10-7 mm Hg(3), and water solubility, 9.0 mg/L(3). Pyrethrin II is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Although biodegradation data for pyrethrin II are not available, the pyrethrin class of insecticides is degraded readily by environmental microorganisms(4,5) and based upon its structure, pyrethrin II is also expected to biodegrade readily(4,5). The overall disappearance half-life of pyrethrin II in soil was determined to be 3.1 days(6).

TERRESTRIAL FATE: The concentration of pyrethrin II in a silt loam soil (Franklin County, KY) following application of a multi-purpose insecticide containing pyrethrins decreased slowly with time(1); after 1 hr, 1, 4, 8, 12, 18, 24, and 30 days, the concentration of pyrethrin II was 0.900, 0.140, 0.103, 0.023, 0.001, 0.001, 0.001, and 0.001 ug/g, respectively(1).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 2940(SRC), determined from a structure estimation method(2), indicates that pyrethrin II is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 2.2X10-8 atm-cu m/mole(SRC), derived from its vapor pressure, 3.98X10-7 mm Hg(4), and water solubility, 9.0 mg/L(4). According to a classification scheme(5), an estimated BCF of 18(SRC), from a log Kow of 4.3(4) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Although biodegradation data for pyrethrin II are not available, the pyrethrin class of insecticides is degraded readily by environmental microorganisms(7,8) and based upon its structure, pyrethrin II is also expected to biodegrade readily(7,8). A base-catalyzed second-order hydrolysis rate constant of 1.1X10-2 L/mole-sec(SRC) was estimated using a structure estimation method(9); this corresponds to half-lives of 20 and 2.0 years at pH values of 7 and 8, respectively(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), pyrethrin II, which has a vapor pressure of 3.98X10-7 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase pyrethrin II 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 1.6 hours(SRC), calculated from its rate constant of 2.4X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Vapor-phase pyrethrin II is also degraded in the atmosphere by reaction with ozone(SRC); the half-life for this reaction in air is estimated to be 27 minutes(SRC), calculated from its rate constant of 6.1X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase pyrethrin II may be removed from the air by wet or dry deposition(SRC). Pyrethrin II contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

Pyrethrins 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. (L857, A560)

/OTHER TERRESTRIAL SPECIES/ Metabolic rates of reptiles vary with body temperature; therefore, the sensitivity of reptiles to a particular dose level of a pesticide might be expected to vary as well. The purpose of the present study was twofold: To evaluate the effects of temperature on the toxicity to green anole lizards (Anolis carolinensis) of a single concentration of a natural pyrethrin pesticide via percutaneous exposure, and to compare the effects of temperature (20 vs 35 °C) on the toxicity of different concentrations of pyrethrins to green anoles. When lizards were exposed to a solution that contained 300 mg/L of pyrethrins, the mortality of lizards maintained at 15 and 20 °C was significantly higher (p<0.01) than the mortality of lizards maintained at 35 and 38 °C. In addition, the median lethal concentrations of pyrethrins for lizards maintained at 20 and 35 °C were 77.6 and greater than 300 mg/L, respectively. Therefore, temperature clearly influenced the sensitivity of lizards to pyrethrin pesticides. /Pyrethrin pesticides/

The clinical manifestations of inhalation exposure to pyrethrins can be local or systemic. Localized reactions confined to the upper respiratory tract include rhinitis, sneezing, scratchy throat, oral mucosal edema, and even laryngeal mucosal edema. Localized reactions 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, and bronchospasm may occur in an individual chronically exposed. Large amounts may cause nausea, vomiting, tinnitus, headache, and other central nervous system disturbances. (A566)

The concentration of pyrethrin II in a runoff water (Franklin County, KY) following application of a multi-purpose insecticide containing pyrethrins was 32.7, 19.5, and 20.6 ng/L at 11, 29, and 45 days following treatment(1); the amount of runoff water for each collection period was 469, 782, and 156 L/acre, respectively(1).

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/

Tolerances for residues of the insecticide pyrethrins ((1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienylcyclopenten-1-yl (1R,3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (pyrethrin 1), (1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienyl-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropane-carboxylate (pyrethrin 2), (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (cinerin 1), (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylate (cinerin 2), (1S)-2-methyl-4-oxo-3-(2Z)-2-pentenyl-2-cyclopenten-1-yl (1R, 3R)-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate (jasmolin 1), and (1S)-2-methyl-4-oxo-3-(2Z)-pentenyl-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylate (jasmolin 2)), the insecticidally active principles of Chrysanthemum cinerariaefolium, which are measured as cumulative residues of pyrethrin 1, cinerin 1, and jasmolin 1 are not to exceed the following:[Table#5826]

When applied to growing crops, in accordance with good agricultural practice, the following pesticide ... /chemical is/ exempt from the requirement of a tolerance: pyrethrins. ... /This pesticide is/ not exempted from the requirement of a tolerance when applied to a crop at the time of or after harvest. /Pyrethrins/

The Agency has completed its assessment of the dietary, occupational, residential, and ecological risk associated with the use of pesticide products containing the active ingredient pyrethrins. Based on a review of these data and on public comments on the Agency's assessments for the active ingredient pyrethrins, the Agency has sufficient information on the human health and ecological effects to make decisions as part of the tolerance reassessment process under FFDCA and reregistration process under FIFRA, as amended by FQPA. The Agency has determined that products containing pyrethrins are eligible for reregistration provided that: (i) the risk mitigation measures outlined in this document are adopted and (ii) label amendments are made to reflect these measures. ... Based on its evaluation of pyrethrins, the Agency has determined that pyrethrins products, unless labeled and used as specified in this 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 pyrethrins. If all changes outlined in this document are incorporated into the product labels, then all current risks for pyrethrins will be adequately mitigated for the purposes of this determination. /Pyrethrins/

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. Pyrethrum powder other than pyrethrins and pyrethrin coils are found on List B. Case No: 2580; 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): Pyrethrum powder other than pyrethrins, pyrethrin coils; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled." /Pyrethrum powder other than pyrethrins; Pyrethrin coils/

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1 lb or 0.454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b). /Pyrethrins/

Pyrethrin II is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance. /Pyrethrins/

The symptoms of pyrethrin poisoning follow the typical pattern ... : (1) excitation, (2) convulsions, (3) paralysis, and (4) death. The effects of pyrethrins on the insect nervous system closely resemble those of DDT, but are apparently much less persistent. Regular, rhythmic, and spontaneous nerve discharges have been observed in insect and crustacean nerve-muscle preparations poisoned with pyrethrins. The primary target of pyrethrins seems to be the ganglia of the insect central nervous system although some pyrethrin-poisoning effect can be observed in isolated legs. /Pyrethrins/

Electrophysiologically, pyrethrins cause repetitive discharges and conduction block. /Pyrethrins/

The primary site of action for pyrethrins ... is the sodium channel of nerve cells. Using a variety of methods, including voltage clamp and patch clamp techniques, it has been shown that pyrethrins ... slow the closing of sodium channel gates following an initial influx of sodium during the depolarizing phase of an action potential, which results in a prolonged sodium tail current.

Following absorption through the chitinous exoskeleton of arthropods, pyrethrins stimulate the nervous system, apparently by competitively interfering with cationic conductances in the lipid layer of nerve cells, thereby blocking nerve impulse transmissions. Paralysis & death follow. /Pyrethrins/

The interactions of natural pyrethrins and 9 pyrethroids with the nicotinic acetylcholine (ACh) receptor/channel complex of Torpedo electronic organ membranes were studied. None reduced (3)H-ACh binding to the receptor sites, but all inhibited (3)H-labeled perhydrohistrionicotoxin binding to the channel sites in presence of carbamylcholine. Allethrin inhibited binding noncompetitively, but (3)H-labeled imipramine binding competitively, suggesting that allethrin binds to the receptor's channel sites that bind imipramine. The pyrethroids were divided into 2 types according to their action: type A, which included allethrin, was more potent in inhibiting (3)H-H12-HTX binding and acted more rapidly. Type B, which included permethrin, was less potent and their potency increased slowly with time. The high affinities that several pyrethroids have for this nicotinic ACh receptor suggest that pyrethroids may have a synaptic site of action in addition to their well known effects on the axonal channels. /Pyrethrins and Pyrethroids/

Pyrethrins are extensively metabolized, the residues of the parent compound in feces and urine representing only 10%. Six metabolites were identified and two major metabolic pathways were suggested, the first involving oxidation of the double-bond and/or the methyl groups and the second involving hydrolysis of the ester bond. Pyrethrins I are metabolized mainly through oxidative processes, while pyrethrins II are metabolized through a combination of hydrolytic and oxidative processes.

... Within 48 hr of oral admin of (14)C-pyrethrin II to rats, 53% of the (14)C was recovered as exhaled carbon dioxide ... . The ... (14)C recovered from urine ... /was/ 7% ... some of the orally admin material is excreted in feces, at least partially in metabolized form. Three compounds have been isolated from urine & identified by NMR & mass spectra. All three are produced by ... pyrethrin I & II. All three are the result of oxidation of ... the acid & alcoholic moieties leaving the main structure of the molecule intact.

The oral administration of radio-labelled pyrethrin I, or pyrethrin II, to rats produced several urinary metabolites. Each contained a trans-2-carboxyprop-1-enyl side chain resulting from oxidation of the chrysanthemate isobutenyl group or hydrolysis of the pyrethrate methoxy-carbonyl group. Also, the cis-2',4'-pentadienyl side chain of pyrethrin I and pyrethrin II was oxidized at the penta-2,4-dienyl group to give a cis-4',5'-dihydroxypent-2'-enyl group, a 4' conjugate of this diol, or a trans-2',5'-dihydroxypent-3'-enyl group.

The 2-methylpropenyl group of (S)-bioallethrin (A) and the pentadienyl group of pyrethrin II are selectively oxidized by m-chloroperoxybenzoic acid in dichloromethane to yield the 7,8-epoxide (1) from A and a mixture of the 8',9'- and 10',11'-epoxides (7 and 8) from pyrethrin II. These epoxides are hydrated in aqueous acid to the corresponding diols and other hydroxy derivatives produced by opening of the cycloprophyl ring or migration of the adjacent double bond. The epoxy and hydroxy derivatives are identified by two dimensional NMR techniques. Mouse liver enzymes do not detectably hydrate epoxide 1 but quickly hydrate epoxides 7 and 8 without migration of the double bond. HPLC analyses of the microsomal metabolites of pyrethrins I and II identify the 10',11'-diols as major metabolites and the 8',9'-diols as minor products.

For more Metabolism/Metabolites (Complete) data for PYRETHRIN II (12 total), please visit the HSDB record page.

Following ingestion, pyrethrins are hydrolysed by various digestive enzymes in the gastro-intestinal tract. However, a small portion of the insecticidally active compounds or its derivatives are absorbed, as shown by their toxicity and their effect on the liver. Pyrethrins may also be absorbed following inhalation or dermal contact. They are rapidly distributed to most tissues, particularly to those with a high lipid content, and are concentrated in central and peripheral nervous tissues. Pyrethrins or their metabolites are not known to be stored in the body or to be excreted in the milk, but no study of the matter has employed modern methods. The major metabolic pathways for pyrethrins are hydrolysis of the central ester bond, oxidative attacks at several sites, and conjugation reactions, to produce a complex array of primary and secondary water-soluble metabolites that undergo urinary excretion. The principal metabolite of pyrethrin II has a carboxylgroup on the isobutenyl group of the acid moiety and a cis-4',5'-dihydroxypent-2'-en1'-yl group in the lcohol moiety. In addition, pyrethrin II suffers attack on the pentadienyl side chain, possibly forming a 4'-5'-epoxide that is a precursor of two isomeric diols. Esterification also occurs during the metabolism of pyrethrin II. Metabolism is believed to involve nonspecific microsomal carboxyesterases and microsomal mixed function oxidases, which are located in nearly all tissue types, with particularly high activities in the liver. Metabolites, such as chrysanthemummonocarboxylic acid, are excreted in the urine and faeces. (L857, L889, A263).

Pyrethrins are absorbed from the gastrointestinal tract following oral administration. Studies in male rats receiving 3 mg/kg orally resulted in almost complete absorption and metabolism within 100 hours. No pyrethrin was observed in urine, although substantial quantities of metabolites were present. In feces, small quantities of the parent pyrethrin were observed, again accompanied by metabolites.

Pyrethrins are absorbed through intact skin when applied topically. When animals were exposed to aerosols of pyrethrins with piperonyl butoxide being released into the air, little or none of the combination was systemically absorbed. /Pyrethrins/

The pyrethrins or their metabolites are not known to be stored in the body or to be excreted in the milk...

Following a single oral pyrethrin II dose to rats, 53% of the admin dose appeared as CO2 & 7% appeared in urine. After an equivalent dose of pyrethrin I, 0.3% could be accounted for as CO2 & 46% of the dose was eliminated in urine.

For Pyrethrin II /a component of pyrethrum/ (USEPA/OPP Pesticide Code: 069006) there are 0 labels match. /SRP: Not registered for current 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./

Pyrethrins are botanical insecticides ... used in these four general ways: (i) pre-harvest and postharvest uses on many agricultural crops; (ii) direct and indirect treatments of livestock animals and premises; (iii) treatments of commercial and industrial facilities and storage areas where raw and processed food/feed commodities are stored or processed; and (iv) wide area mosquito abatement use in areas which include aquatic areas. /Pyrethrins/

Because of their safety, pyrethrum extracts are used extensively in stock sprays, aerosols, industrial sanitation sprays, and to protect stored food in warehouses. /Pyrethrins/

Control of a wide range of insects and mites in public health, stored products, animal houses, and on domestic and farm animals. Control of chewing and sucking insects and spider mites ... Personal insect repellents and for human head lice control. /Pyrethrins/

Household insecticide /as a component of Pyrethrins/.

Breathing in contaminated air; drinking contaminated water or eating contaminated foods; skin and eye exposure (L857).

Approximately 200,000 lbs of pyrethrins are sold every year. Approximately 9% of the total amount of pyrethrins applied is used on agricultural commodities. Other sites where pyrethrins are applied include: 40% on indoor food areas (e.g. farm premises, food processing, dairies), 35% on indoor residential settings (e.g. pets, household domestic dwellings), 10% on indoor non-food areas (e.g. commercial, institutional industrial premises), and 6% on terrestrial non-food areas (e.g. show animals, turf, recreational areas). /Pyrethrins/

/Pyrethrins:/ Livestock buildings, 36%; public health pest control, 17%; structural pest control, 33%; landscape maintenance, 5%; other uses (e.g. vegetables, cattle, flowers, industrial applications), 9% (1984) /California consumption and use/

Cyclopropanecarboxylic acid, 3-[(1E)-3-methoxy-2-methyl-3-oxo-1-propen-1-yl]-2,2-dimethyl-, (1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadien-1-yl-2-cyclopenten-1-yl ester, (1R,3R)-: ACTIVE

The WHO Recommended Classification of Pesticides by Hazard identifies pyrethrins (technical grade) as Class II: moderately hazardous; Main Use: insecticide. /Pyrethrins/

Pyrethrum extract contains six closely related insecticidal esters ... The six individual esters are not available commercially and are more economically produced as botanicals than by chemical manufacture.

Purified separate isomers or mixtures of isomers are available only in laboratory; they are too expensive for practical use. /Pyrethrins/

Kenya flowers contain ca. 1.3% of the toxic constituents, pyrethrins and cinerins; Japanese flowers, ca. 1%; and Dalmatian flowers, ca. 0.7%.

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