Pyrethrin II

372.46

372.45

204-462-6

DTXSID2042353

Viscous liquid

29183000

69.67000

4.43

1.1±0.1 g/cm3

192-193 °C @ Press: 7 x 10^-3 Torr

203.8±28.8 °C

1.528

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

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

3.98X10-7 mm Hg at 25 deg C

D19 +14.7° (isooctane-ether)

Henry's Law constant = 2.19X10-8 atm-cu m/mol at 25 °C (est)

Refined extract is a pale yellow mobile oil with a faint flowery order; unrefined extract is a dark greenish brown viscous liquid. Powder (ground flowers) is tan color. /Pyrethrins/|Hydrolyzed in water, and the process is speeded by acid or alkali.|Oxidizes readily in air and becomes inactive in air.|Hydroxyl radical reaction rate constant = 1.34X10-11 cu cm/molec-sec at 25 °C (est)

Non-corrosive

III

6.1(b)

2902

20/21/22-50/53

13-60-61

Xn,N

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

P261, P264, P270, P271, P273, P280, P301+P312, P302+P352, P304+P312, P304+P340, P312, P322, P330, P363, P391, P501

H302

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/

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

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]

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P261, P264, P270, P271, P273, P280, P301+P312, P302+P352, P304+P312, P304+P340, P312, P322, P330, P363, P391, and P501|P261, P264, P270, P271, P301+P312, P304+P340, P305+P351+P338, P312, P330, P337+P313, P403+P233, P405, and P501

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#5825]|Respirator Recommendations: Up to 125 mg/cu m: /Pyrethrum/[Table#5826]|For more Personal Protective Equipment (PPE) (Complete) data for PYRETHRIN II (9 total), please visit the HSDB record page.

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: 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.

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/

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 5 mg/cu m

Recommended Exposure Limit: 10 Hour Time-Weighted Average: 5 mg/cu m /pyrethrum/

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/

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).

The US Department of Housing in conjunction with the Environmental Protection Agency preformed a national study of residential pesticides measured from floor wipes from June 2005 to March 2006, pyrethrin II was detected in 2% of 468 samples taken with a maximum concentration of 156 ng/sq cm (0.12 ng/sq cm detection limit)(1).

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/

LD50 Rat male oral greater than 600 mg/kg|LD50 Mouse intraperitoneal less than 240 mg/kg|LD50 Cat female intravenous 1 mg/kg|LD50 Rat oral 1.2 g/kg|For more Non-Human Toxicity Values (Complete) data for PYRETHRIN II (8 total), please visit the HSDB record page.

/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/

Cases of asthmatic-like reactions have been reported in some individuals who had previous history of asthma with broad allergic background.|In persons with chronic respiratory disease and especially asthma, the inhalation of pyrethrum /and inadequately purified pyrethrins/ might cause exacerbation of symptoms due to its sensitizing properties. Skin disease: Pyrethrum can cause dermatitis which may be allergic in nature. Persons with preexisting skin disorders may be more susceptible to the effects of this agent. /Pyrethrum/|In a review of literature pertaining to pyrethrum, it was noted that many individuals who were sensitive to ragweed were also sensitive to pyrethrum, but that the sensitization effect arose mainly from a volatile oil contained in the pyrethrum extract, not from the pyrethrins. On the other hand, pyrethrins were implicated in two cases of severe asthmatic reactions to exposure to dog shampoo products containing pyrethrins.|About 50% of persons sensitive to ragweed exhibit cross-sensitivity to pyrethrum (ragweed and chrysanthemum are in the same botanical group).|Individuals sensitive to ragweed have shown cross-sensitivity to unrefined but not to refined pyrethrins; however, manufacturers of pyrethrins combinations warned that these products should not be used by ragweed-sensitive patients. /Pyrethrins/

Pyrethrin II is found in the flowers of Chrysanthemum cinerariaefolium and C. coccineum(1). Each pyrethrum flower contains about 3-4 mg pyrethrins(2).

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

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).

The rate constant for the vapor-phase reaction of pyrethrin II with photochemically-produced hydroxyl radicals has been estimated as 2.4X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 1.6 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of pyrethrin II with ozone has been estimated as 6.1X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 27 minutes at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). A base-catalyzed second-order hydrolysis rate constant of 1.1X10-2 L/mole-sec(SRC) was estimated using a structure estimation method(3); this corresponds to half-lives of 20 and 2.0 years at pH values of 7 and 8, respectively(3). Pyrethrin II contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).|Natural and synthetic pyrethrins in kerosene solutions similar to commercial formulations were stored in clear soft-glass bottles and exposed to sunlight through clear window glass. Transition photoproducts were observed by gas chromatography. ... No photo- products for pyrethrin I or II were observed, which may have polymerized or been converted into products of higher polarity.

An estimated BCF of 18 was calculated in fish for pyrethrin II(SRC), using a log Kow of 4.3(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of pyrethrin II can be estimated to be 2940(SRC). According to a classification scheme(2), this estimated Koc value suggests that pyrethrin II is expected to have slight mobility in soil.

The Henry's Law constant for pyrethrin II is estimated as 2.2X10-8 atm-cu m/mole(SRC) derived from its vapor pressure, 3.98X10-7 mm Hg(1), and water solubility, 9.0 mg/L(1). This Henry's Law constant indicates that pyrethrin II is expected to be essentially nonvolatile from water and moist soil surfaces(2). Pyrethrin II 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 5966 workers (390 of these were female) were potentially exposed to pyrethrin II in the US(1). Occupational exposure to pyrethrum, of which pyrethrin II is a component of, may occur through inhalation and dermal contact with this compound at workplaces where pyrethrin II is produced or used. Monitoring and use data indicate that the general population may be exposed to pyrethrin II via use of household insecticide products that contain this compound(SRC).

... The insecticide has been considered so innocuous that an ointment containing 0.75% pyrethrin was recommended for treatment of scabies, and such use led to only a few cases of dermatitis, some of doubtful relation to the treatment. Pyrethrins have been used extensively for the control of human body lice.|Head lice can be treated with pyrethrin 0.3% plus 3% piperonyl butoxide.

Because commercial formulations are irritating to the eyes and mucous membranes, they should not be used to treat P. pubis infestations of the eyelashes.|Individuals sensitive to ragweed have shown cross-sensitivity to unrefined but not to refined pyrethrins; however, manufacturers of pyrethrins combinations warned that these products should not be used by ragweed-sensitive patients. /Pyrethrins/|Local irritation incl erythema, pruritus, urticaria, edema, eczema, & slight corneal erosion & stromal edema may occur & ... contact with face, eyes, mucous membranes, & urethral meatus should be avoided. ... Pyrethrins with piperonyl butoxide should not be applied to acutely inflamed skin or raw, weeping surfaces. ... The drug should not be used more than twice in 24 hours. /Pyrethrins/

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.

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.

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/

The additives (e.g. petroleum distillate), when present, represent a greater toxic threat to the patient than the active ingredient itself. ... Emesis should not be induced when petroleum distillate additives are present unless the product ingested is estimated to contain a near lethal dose (1 g/kg) of pyrethrum or pyrethrins... Pulmonary & allergic sequelae are treated symptomatically with airway maintenance, oxygen, & ventilatory assistance as required. Standard drugs and management protocols may be used for treatment of bronchospasm & anaphylaxis. Seizures are treated with diazepam. /Pyrethrum and synthetic pyrethroids/|Antihistamines are effective in controlling most allergic reactions. Severe asthmatic reactions, particularly in predisposed persons, may require administration of inhaled B2-agonists and/or systemic corticosteroids. Inhalation exposure should be carefully avoided in the future. /Pyrethrum and pyrethrins/|Anaphylaxis-type reactions may require subcutaneous epinephrine, epinephrine, and respiratory support. /Pyrethrum and pyrethrins/|Contact dermatitis may require extended administration of topical corticosteroid preparations. This should be done under the supervision of a physician. Future contact with the allergen must be avoided. /Pyrethrum and pyrethrins/|For more Antidote and Emergency Treatment (Complete) data for PYRETHRIN II (10 total), please visit the HSDB record page.

/HUMAN EXPOSURE STUDIES/ When 200 people (177 women & 23 men) were patch tested with a 1% water dispersion of pyrethrins, no evidence of primary irritancy or of sensitization was found. /Pyrethrins/|/HUMAN EXPOSURE STUDIES/ Sensitivity was produced in 10-26% of unselected test populations by repeated application of pyrethrum ointment.|/SIGNS AND SYMPTOMS/ Injury to humans ... has most frequently resulted from allergic properties ... rather than ... direct toxicity. Although the allergy usually has been assoc with occupational or therapeutic contact, it is impossible to exclude the possibility of injury assoc with other kinds of exposure. Pyrethrum sensitivity may manifest itself in several forms. ... Contact dermatitis is by far the most common. The usual ... /outbreak/ is a mild erythematous vesicular dermatitis with papules in moist areas, & intense pruritus. In few cases, bullae appear. Edema & cracking develop in severe cases. Pyrethrum dermatitis may be made worse by exposure to sun. Several cases have shown ... "local anaphylaxis", characterized by dermatitis & sudden severe swelling of face, sometimes incl eyes & lips. A mild form accompanied by tachycardia, pallor, sweating, & fever was produced in ... experiments. Some individuals show manifestations of pyrethrum sensitivity similar to those seen in pollinosis, incl sneezing, serous nasal discharge, & nasal stuffiness.|/SIGNS AND SYMPTOMS/ With massive doses ingested orally, nervous system symptoms may occur, which incl excitation & convulsions leading to paralysis & accompanied by muscular fibrillation & diarrhea. Death is due to resp failure.|For more Human Toxicity Excerpts (Complete) data for PYRETHRIN II (27 total), please visit the HSDB record page.

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.

EPA Method PMD-PYR-TITR. Determination of Pyrethrins I and II by Hydrolysis, Steam Distillation, and Titration (Seil Method).