Pyrethrins

700.9

328.203857

232-919-8

1475

3077|3352

DTXSID8034873

Refined extract is pale yellow mobile oil; unrefined extract is a dark greenish brown viscous liquid; powder (ground flowers) is a tan color.|Brown, viscous oil or solid.

P - Antiparasitic products, insecticides and repellents

29400010

113

5.9 (pyrethrin II)

Pyrethrins, [solid] appears as colorless to white liquids (or tan dusts). Primarily a threat to the environment. Immediate steps should be taken to limit spread to the environment. Easily penetrate the soil, contaminate groundwater or nearby waterways. Toxic by inhalation, skin absorption and/or ingestion. Used as pesticide. Practically insoluble in water.

0.84-0.86 g/cm³

90-95 °C(lit.)

338°F (Pyrethrin I), 392°F (Pyrethrin II), 279°F (Cinerin I), 361°F (Cinerin II)

75 °C

1.524

0.2 (pyrethrin I) and 9 (pyrethrin II) mg l -1 (ambient temp.)

2-8°C

2.7×10 -3 (pyrethrin I) and 5.3×10 -5 (pyrethrin II) Pa

Oral-Rat LD50: 200 mg/kg; Oral-Mouse LD50: 370 mg/kg

Flammable; spicy and irritating smoke is released from the fire

Characteristic odor of carrier

Henry's Law constant = 6.55X10-7 atm-cu m/mol at 25 °C (est)

Not compatible with alkaline material|Incompatible with lime and ordinary soaps because acids and alkalies speed up the process of hydrolysis. /Pyrethrins/|Hydroxyl radical reaction rate constant = 2.81X10-10 cu cm/molec-sec at 25 °C (est)

Oxidize relatively rapidly in air. Water emulsifiable.

Esters, Sulfate Esters, Phosphate Esters, Thiophosphate Esters, and Borate Esters

PYRETHRINS decompose rapidly in base; may generate heat with caustic solutions. May also react with acids to liberate heat. Generate flammable hydrogen with alkali metals and hydrides.

Class IIIA Combustible Liquid: Fl.P. at or above 140°F and below 200°F.

Non-corrosive

III

6.1(b)

UN 2810 6.1/PG 3

3

20/21/22-50/53

13-60-61

UR4200000

Xn,N

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

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

P273-P280-P501

H302-H312-H332-H410

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.

Pediculicide active ingredients. The active ingredients of the product consist of the combination of pyrethrum extract (providing a concentration of pyrethrins of 0.17 to 0.33 percent) with piperonyl butoxide (2 to 4 percent) in a nonaerosol dosage formulation.

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]

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, be aware of possible short circuiting as this product is transported in a charged state. (ERG, 2016)|Combustible. Risk of fire and explosion on contact with oxidizing agents.|Flammable - 2nd degree

|Warning|H302 (100%): 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|Aggregated GHS information provided by 3 companies from 3 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. Avoid inhalation of asbestos dust. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Skin: Wear appropriate personal protective clothing to prevent skin contact. Eyes: Wear appropriate eye protection to prevent eye contact. Wash skin: The worker should immediately wash the skin when it becomes contaminated. Remove: Work clothing that becomes wet or significantly contaminated should be removed and replaced. Change: Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premise. (NIOSH, 2016)|Wear appropriate personal protective clothing to prevent skin contact.|Wear appropriate eye protection to prevent eye contact.|Respirator Recommendations: Up to 50 mg/cu m:[Table#5802]|Respirator Recommendations: Up to 125 mg/cu m:[Table#5803]|For more Personal Protective Equipment (PPE) (Complete) data for PYRETHRUM (9 total), please visit the HSDB record page.|(See protection codes)

Combustible when exposed to heat or flame.

Fire-fighting: Self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive-pressure mode.|Extinguishant: Carbon dioxide, foam, or dry chemical.|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.|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.|Work clothing that becomes wet or significantly contaminated should be removed and replaced.|For more Preventive Measures (Complete) data for PYRETHRUM (7 total), please visit the HSDB record page.

Pyrethrum may irritate the eyes.

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/

Personal protection: filter respirator for organic gases and particulates adapted to the airborne concentration of the substance. Ventilation. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

Separated from strong oxidants and food and feedstuffs. Well closed. Provision to contain effluent from fire extinguishing.

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed.

The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the nervous system.

Repeated or prolonged contact may cause skin sensitization. Repeated or prolonged inhalation may cause asthma.

NO open flames. NO contact with oxidizing agents.

PREVENT GENERATION OF MISTS!

Use ventilation (not if powder), local exhaust or breathing protection.

Protective clothing.

Wear safety goggles or eye protection in combination with breathing protection.

| 2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury.| 1 - Materials that must be preheated before ignition can occur. Materials require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur.| 0 - Materials that in themselves are normally stable, even under fire conditions.

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/

SOURCE DOMINATED: Pyrethrum was not detected in air samples taken before or up to 13 days after the application of Whitmire PT 565+ (0.25% pyrethrins, 0.25% d-trans allethrin) to a community college cafeteria, applied concentration was not determined(1).

highly toxic

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 increase toxicity of the pyrethrins to mammals. /Pyrethrins/|/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/

/OTHER TOXICITY INFORMATION/ The estimated lethal dose of pyrethrum in humans is over 1 g/kg.

LD50 Rat oral 584 to 900 mg/kg (irrespective of grade or solvent)|LD50 Rat percutaneous greater than 1500 mg/kg|LD50 Rat intraperitoneal 167 to 798 mg/kg (irrespective of grade or solvent)|LD50 Mouse oral 273 to 796 mg/kg (irrespective of grade or solvent)|For more Non-Human Toxicity Values (Complete) data for PYRETHRUM (10 total), please visit the HSDB record page.

Cases of asthmatic-like reactions have been reported in some individuals who had previous history of asthma with broad allergic background.|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).|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.|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/

A natural insescticide obtained by extraction of chrysanthemum flowers native to Kenya, Ecuador, and Japan ... The constituents are pyrethrins I and II, cinerins I and II, and jasmolins I and II.|The plant, Chrysanthemum cinerariaefolium, and its flowers are the source of the principles.

Pyrethrum's production may result in its release to the environment through various waste streams; its use as an insecticide and 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 10,000(SRC), determined from a structure estimation method(2), indicates that pyrethrum is expected to be immobile in soil(SRC). Volatilization of pyrethrum from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6.6X10-7 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Pyrethrum is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.0X10-6 mm Hg at 25 °C(SRC), determined from a fragment constant method(4). Pyrethrum is a mixture of pyrethrin compounds and specific biodegradation data are not available(SRC). However, the pyrethrin class of insecticides is degraded readily by ambient microorganisms; therefore, pyrethrum is expected to biodegrade readily(5,6).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 10,000(SRC), determined from a structure estimation method(2), indicates that pyrethrum 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 6.6X10-7 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 290(SRC), from an estimated log Kow of 6.15(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Hydrolysis of pyrethrum is not expected to be environmentally relevant based on estimated half-lives of 790 and 79 years at pH values of 7 and 8, respectively(8). Pyrethrum is a mixture of pyrethrin compounds and specific biodegradation data are not available(SRC). However, the pyrethrin class of insecticides is degraded readily by ambient microorganisms; therefore, pyrethrum is expected to biodegrade readily(9,10). Based on data where aqueous suspensions of pyrethrin I exposed to sunlight experienced 23.2% photodecomposition after only 15 min of exposure(11) pyrethrum is expected to photodegrade rapidly in the environment.|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), pyrethrum, which has an estimated vapor pressure of 3.0X10-6 mm Hg at 25 °C(SRC), determined from a fragment constant method(2),will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase pyrethrum is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and ozone(SRC); the half-lives for these reactions in air are estimated to be 1.4 hours and 30 minutes(SRC), calculated from rate constants of 2.8X10-10 and 5.6X10-16 cu cm/molecule-sec at 25 °C(SRC), respectively, that were derived using a structure estimation method(3). Particulate-phase pyrethrum may be removed from the air by wet or dry deposition(SRC). Pyrethrum contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

Pyrethrins are decomp by exposure to light with loss of insecticidal activity. They also are rapidly oxidized and inactivated by air. /Pyrethrins/|The rate constant for the vapor-phase reaction of pyrethrum with photochemically-produced hydroxyl radicals has been estimated as 2.8X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 1.4 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of pyrethrum with ozone has been estimated as 5.6X10-16 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 30 minutes at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). Hydrolysis of pyrethrum is not expected to be environmentally relevant based on a base-catalyzed second-order hydrolysis rate constant of 2.8X10-4 L/mole-sec(SRC) that was estimated using a structure estimation method(3); this corresponds to half-lives of 790 and 79 years at pH values of 7 and 8, respectively(3). Pyrethrum contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC). Based on data where aqueous suspensions of pyrethrin I exposed to sunlight experienced 23.2% photodecomposition after only 15 min of exposure(5), pyrethrum is expected to photodegrade rapidly in the environment.

An estimated BCF of 290 was calculated in fish for pyrethrum(SRC), using an estimated log Kow of 6.15(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of pyrethrum can be estimated to be 10,000(SRC). According to a classification scheme(2), this estimated Koc value suggests that pyrethrum is expected to be immobile in soil.

The Henry's Law constant for pyrethrum is estimated as 6.6X10-7 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that pyrethrum is expected to be essentially nonvolatile from water and moist soil surfaces(2). Pyrethrum is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.0X10-6 mm Hg(SRC), determined from a fragment constant method(3).

GROUNDWATER: According to the Pesticides In Ground Water Database, pyrethrum was not detected (detection limit not specified) in 10 ground water samples from Alabama sampled in 1988, eight ground water samples collected in California 1984 to 1985 and 126 ground water samples collected in Virginia 1989 to 1990(1).

For fiscal years 1988 and 1989, 13,065 food samples were collected and analyzed for pesticide residues by 10 state laboratories (CA, NY, FL, IN, MA, MI, NC, OR, VA and WI); pyrethrum was detected in 9 samples (concentrations not reported)(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 11,296 workers (1537 of these were female) were potentially exposed to pyrethrum in the US(1). Occupational exposure to pyrethrum may occur through inhalation and dermal contact with this compound at workplaces where pyrethrum is produced or used. Monitoring and use data indicate that the general population may be exposed to pyrethrum via ingestion of food with residual pesticide, and dermal contact with household insecticides containing pyrethrum(SRC).

MEDICATION (VET): ectoparasiticide|Pyrethrins ... are also extensively used in veterinary flea powders for cats and dogs.|Pyrethrins with piperonyl butoxide are used for topical treatment of pediculosis (lice infestations). Combinations of pyrethrins with piperonyl butoxide are not effective for treatment of scabies (mite infestations). Although there are no well-controlled comparative studies, many clinicians consider 1% lindane to be pediculicide of choice. However, some clinicians recommend use of pyrethrins with piperonyl butoxide, esp in infants, young children, & pregnant or lactating women ... . If used correctly, 1-3 treatments ... are usually 100% effective ... Oil based (eg, petroleum distillate) combinations ... produce the quickest results. ... For treatment of pediculosis, enough gel, shampoo, or solution ... should be applied to cover affected hair & adjacent areas ... After 10 min, hair is ... washed thoroughly ... treatment should be repeated after 7-10 days to kill any newly hatched lice. /Pyrethrins/|scabicide|For more Therapeutic Uses (Complete) data for PYRETHRUM (7 total), please visit the HSDB record page.

Commercial /liq/ formulations /such as A-200 pyrinate, RID/ are irritating to eyes & mucous membranes & ... should not be used to treat Phthirus 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/

/OTHER TOXICITY INFORMATION/ The estimated lethal dose of pyrethrum in humans is over 1 g/kg.

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

The pyrethrins or their metabolites are not known to be stored in the body or to be excreted in the milk...|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 esters constituting pyrethrum mixtures are rapidly detoxified by hydrolysis in the GI tract & to some extent in tissues of adult warm-blooded animals. The chrysanthemum monocarboxylic acid formed is excreted in urine. Pyrethrins or their metabolites are not known to be stored in body or ... excreted in milk, but no study of this matter has employed modern methods. ... recent studies have begun to describe ... extensive metabolism that pyrethrins undergo, mainly in liver. ... various active ingredients undergo significantly different biotransformation. ... So far it has not been possible to identify the ... numerous compounds that result from hydrolysis of the esters.|Pyrethrins are reportedly inactivated in the GI tract following ingestion. In animals, pyrethrins are rapidly metabolized to water soluble, inactive compounds. /Pyrethrins/|Essentially, pyrethrum & allethrin are broken down mainly by oxidation of the isobutenyl side chain of the acid moiety & of the unsaturated side chain of the alcohol moiety with ester hydrolysis playing an unimportant part, whereas for the other pyrethroids ester hydrolysis predominates. These reactions can take place in both liver & plasma & are followed by hydroxylation & conjugation to glucuronides or sulfates, which are then excreted in the urine. A number of factors modify the rate of break- down, notably stereospecificity, with trans isomer hydrolysis being catalyzed by esterases but cis isomer hydrolysis being catalzyed at a rather lower rate by oxidases. This slower breakdown of cis isomers may contribute to their greater mammalian toxicity, but their higher inherent affinity for the sodium channel complex is thought to be the predominant factor. An addtl influence on the rate of metabolism is the presence of an alpha-cyano group, which slows both hydrolysis & oxidation.|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.|After isolation and identification of the metabolites, the distribution of metabolites was determined in urine and feces. The major metabolite in urine at all doses was chrysanthemum dicarboxylic acid. In feces, a significant amount of parent compound was present (< 10% at the low dose), but another metabolite was the most prevalent at all doses. The two metabolites represented over one-third of the total excreted radiolabel. Male and female rats metabolized pyrethrins I in a similar manner, regardless of the dose, and the difference between males and females was quantitative rather than qualitative.

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.|Electrophysiologically, pyrethrins cause repetitive discharges and conduction block. /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 (3H)-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/|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/|Mode of action of pyrethrum & related cmpd has been studied more in insects & in other invertebrates than in mammals. This action involves ion transport through the membrane of nerve axons &, at least in invertebrates & lower vertebrates, it exhibits a negative temperature coefficient. In both of these important ways & in many details, the mode of action of pyrethrin & pyrethroids resembles that of DDT. Esterases & mixed-function oxidase system differ in their relative importance for metabolizing different synthetic pyrethroids. The same may be true of the constituents of pyrethrum, depending on strain, species, & other factors. /Pyrethrins and pyrethroids/

The primary extract /of pyrethrum powder/ yields, after concentration, a dark viscous material containing approximately 30 to 35% pyrethrins and about 50% impurities (oleoresin concentrate), which may be diluted and standardized to contain 25% pyrethrins (oleoresin extract). The oleoresin may be processed further to form a refined extract containing 50 to 55% total pyrethrins and about 23% impurities.

Exposure Routes: inhalation, ingestion, skin and/or eye contact Symptoms: Erythema, dermatitis, papules, pruritus, rhinorrhea (discharge of thin mucus); sneezing; asthma Target Organs: respiratory system, skin, central nervous system (NIOSH, 2016)

Eye: If this chemical contacts the eyes, immediately wash the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Contact lenses should not be worn when working with this chemical. Skin: If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly. Breathing: If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform mouth-to-mouth resuscitation. Keep the affected person warm and at rest. Get medical attention as soon as possible. Swallow: If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2016)|(See procedures)

Fresh air, rest. Refer for medical attention.

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.

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/|Other toxic manifestations caused by other ingredients must be treated according to their respective toxic actions, independent of pyrethrin-related effects. /Pyrethrum and pyrethrins/|For more Antidote and Emergency Treatment (Complete) data for PYRETHRUM (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 PYRETHRUM (26 total), please visit the HSDB record page.

Pyrethrin

The substance can be absorbed into the body by inhalation, through the skin and by ingestion.|inhalation, ingestion, skin and/or eye contact

Erythema, dermatitis, papules, pruritus, rhinorrhea (discharge of thin nasal mucus); sneezing; asthma

Headache. Nausea. Vomiting.

Redness. Pain.

Redness. Pain.

respiratory system, skin, central nervous system

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/

The active ingredients in pyrethrum extract consist of a mixture of four compounds in approximately the following percentage: pyrethrin I, 40%; pyrethrin II, 36%; cinerin I, 12%; and cinerin II, 12%. The current commercial product is a more or less purified form of the mixture. Highly purified separate isomers although available for research purposes /have been/ too expensive for practical use.|Pyrethrum is the natural extract derived from the flowers of Chrysanthemum cinerariaefolium and Chrysanthemum cineum. ... The six active insecticidal compounds of pyrethrum are called pyrethrins. The individual pyrethrins are pyrethrin I, pyrethrin II, cinerin I, cinerin II, jasmolin I, and jasmolin II. These compounds are esters of two carboxylic acids (chrysanthemic acid and pyrethric acid) and three cyclopentenolones (pyrethrolone, cinerolone, and jasmolone).|In the United States, the pyrethrum extract is standardized as 45-55% w/w total pyrethrins. The typical proportion of Pyrethrins I to II is 0.2:2.8, while the ratio of pyrethrins:cinerins:jasmolins is 71:21:7.|Aerosol, liquid, ready-to-use solution, dust, wettable powder, microencapsulate, impregnated material, pressurized gas, pressurized liquid, pressurized spray, combustible coil, micro-emulsion, dilutable concentrate, shampoo, towelette, pour-on (spot-on), and water-based concentrate. Pyrethrins are usually formulated with synergists, such as piperonyl butoxide and MGK-264, which lack pesticidal effects of their own, but enhance the pesticidal properties of other chemicals. /Pyrethrins/|For more Formulations/Preparations (Complete) data for PYRETHRUM (612 total), please visit the HSDB record page.

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 PYRETHRUM (6 total), please visit the HSDB record page.

AOAC Method 936.05. Pyrethrin in Pesticide Formulations by Mercury Reduction. Detection limit unspecified.|AOAC Method 982.02. Pyrethrins and Piperonyl Butoxide in Pesticide Formulations by Gas Chromatography. Detection limit unspecified. /Pyrethrins/|EPA Method PMD-PYR-GC1. Determination of Pyrethrins in Formulations by Gas Chromatography. Detection limit unspecified.|EPA Method PMD-PYR-GC2. Determination of Pyrethrins, MGK-264, and Piperonyl Butoxide in Pet Shampoos by Gas Chromatography. Detection limit unspecified.|For more Analytic Laboratory Methods (Complete) data for PYRETHRUM (15 total), please visit the HSDB record page.

Sample matrix: plasma; Analyte: pyrethrins; Preparation method: dilute centrifuged plasma with water; cleanup on a solid phase extraction column; elute with methanol; Analytical method: reverse phase high performance liquid chromatography; Sample detection limit: 0.167 mg/L; Percent Recovery: 70-72%. /Pyrethrins/|Exposure to pyrethrins ... is most commonly evaluated by the analysis of urine and blood using gas chromatography (GC) combined with electron capture detection (ECD), flame ionization detection (FID), or mass spectrometry (MS) and high performance liquid chromatography (HPLC) coupled with ultraviolet (UV) detector. Recovery is generally high, and sensitivity is in the parts per billion (ppb) range.|Residues analysis of pyrethrins in milk and tissue of dairy cows. The insecticide is extracted from the samples and partitioned between acetonitrile and petroleum ether. Clean up of the extracts is effected by Florisil column and thin layer chromatography. The determination step is accomplished by gas liquid chromatography using an electron capture detector. Recoveries in milk by FDA laboratories ranged from 50% at the 0.02 ppm level to 88% at the 0.1 ppm level. Product Application: Residues in milk and meat, fat and meat by products of cattle, goats hogs, horses and sheep, poultry, tissues and eggs. Sensitivity: 0.05 ppm on whole milk basis.

Agrochemicals -> Insecticides|Human Drugs -> FDA Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) -> Active Ingredients|Fire Hazards -> Flammable - 2nd degree|INSECTICIDES