CYFLUTHRIN
CASRN: 68359-37-5 For other data, click on the Table of Contents
Human Health Effects:
Human Toxicity Excerpts:
Recently, synthetic pyrethroids have been shown to elicit cutaneous paresthesias
in workers handling this insecticide. /Pyrethroids/ [Zenz, C., O.B. Dickerson, E.P. Horvath. Occupational Medicine.
3rd ed. St. Louis, MO., 1994 119]**PEER REVIEWED**
The allergenic properties of pyrethroids /with early pyrethrum preparations/
are marked in comparison with other pesticides. Many cases of contact dermatitis
and respiratory allergy have been reported. Persons sensitive to ragweed pollen
are particularly prone to such reactions. Preparations containing synthetic
pyrethroids are less likely to cause allergic reactions than are the preparations
made from pyrethrum powder. /Pyrethroids/ [Hardman, J.G., L.E. Limbird, P.B. Molinoff, R.W. Ruddon, A.G.
Goodman (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics.
9th ed. New York, NY: McGraw-Hill, 1996. 1687]**PEER REVIEWED**
There have been very few systemic poisonings of humans by pyrethroids. /Pyrethroids/
[Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.35 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Pyrethroids are not cholinesterase inhibitors. /Pyrethroids/ [Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.35 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Extraordinary absorbed doses may rarely cause incoordination, tremor, salivation,
vomiting, diarrhea, and irritability to sound and touch. /Pyrethroids/ [Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.35 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Some pyrethroid (eg, deltamethrin, fenvalerate, cyhalothrin, lambda-cyhalothrin,
flucythrinate, and cypermethrin) may cause a transient itching and/or burning
sensation in exposed human skin. /Synthetic pyrethroids/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.13 (1990)]**PEER
REVIEWED**
Skin, Eye and Respiratory Irritations:
Immediately irritating to the eye. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
The chief effect from exposure ... is skin rash particularly on moist areas
of the skin. ... May irritate the eyes. [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 1]**PEER REVIEWED**
Medical Surveillance:
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/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 1]**PEER REVIEWED**
Probable Routes of Human Exposure:
Occupational exposure to cyfluthrin may occur through dermal contact at facilities
where this compound is produced or used. The general population may be exposed
to cyfluthrin through dermal contact with this compound. (SRC) **PEER REVIEWED**
Emergency Medical Treatment:
Emergency Medical Treatment:
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The following Overview, *** PYRETHRINS ***, is relevant for this HSDB
record chemical.
Life Support:
o This overview assumes that basic life support measures
have been instituted.
Clinical Effects:
SUMMARY OF EXPOSURE
0.2.1.1 ACUTE EXPOSURE
o The mammalian toxicity of natural pyrethrins is
generally low. Very young children are perhaps more
susceptible to poisoning because they may not hydrolyze
the pyrethrum esters efficiently. In humans, allergic
reactions are the main toxic manifestations of
pyrethrin exposure.
1. Pyrethrum and the pyrethrins produce typical type I
motor symptoms in mammals. Severe type I poisoning
may include the following signs in humans:
Severe fine tremor
Marked reflex hyperexcitability
Sympathetic activation
Paresthesia (dermal exposure)
o DERMAL - These compounds are not primary irritants.
The chief effect, however, from exposure is dermatitis.
The usual lesion is a mild erythematous dermatitis with
vesicles, papules in moist areas, and intense pruritus;
a bulbous dermatitis may also occur. Pyrethrins can
cause allergic dermatitis and systemic allergic
reactions.
o INHALATION is the major route of exposure, with airway
irritation as the primary toxic effect. Following
inhalation, a stuffy, runny nose and scratchy throat
are common. Hypersensitivity reactions including
wheezing, sneezing, shortness of breath and
bronchospasm may be noted.
o OCULAR - Eye exposures may result in mild to severe
corneal damage that generally resolves with
conservative care.
o Piperonyl butoxide and other compounds are often added
to pyrethrin insecticides as synergists and may
contribute to toxicity.
o Synthetic pyrethroids, which are related to pyrethrins,
are covered in a separate management.
HEENT
0.2.4.1 ACUTE EXPOSURE
o A stuffy, runny nose and scratchy throat following
inhalational exposure may be noted.
o Eye exposures may result in mild to severe corneal
damage, decreased visual acuity and periorbital edema.
CARDIOVASCULAR
0.2.5.1 ACUTE EXPOSURE
o Hypotension and tachycardia, associated with
anaphylaxis, may occur.
RESPIRATORY
0.2.6.1 ACUTE EXPOSURE
o Hypersensitivity reactions characterized by
pneumonitis, cough, dyspnea, wheezing, chest pain, and
bronchospasm may occur. Rare cases of respiratory
failure and cardiopulmonary arrest have been reported.
NEUROLOGIC
0.2.7.1 ACUTE EXPOSURE
o Paresthesias, headaches, and dizziness are common.
Massive exposure may result in hyperexcitability and
seizures, but this is rare.
GASTROINTESTINAL
0.2.8.1 ACUTE EXPOSURE
o Nausea, vomiting and abdominal pain commonly occur and
develop within 10 to 60 minutes following ingestion.
DERMATOLOGIC
0.2.14.1 ACUTE EXPOSURE
o Irritant and contact dermatitis may develop. Erythema
which mimics sunburn has also been noted after
prolonged repeated exposure.
ENDOCRINE
0.2.16.1 ACUTE EXPOSURE
o Type I motor symptoms following severe poisoning may
result in sympathetic activation.
IMMUNOLOGIC
0.2.19.1 ACUTE EXPOSURE
o Sudden bronchospasm, swelling of oral and laryngeal
mucous membranes, and anaphylactoid reactions have been
reported after pyrethrum inhalation. Hypersensitivity
pneumonitis characterized by cough, shortness of
breath, chest pain, and bronchospasm may be noted.
GENOTOXICITY
o Pyrethrum is not mutagenic in bacterial reversion tests
(Ray, 1991).
Laboratory:
o Pyrethrin plasma levels are not clinically useful or
readily available.
o Monitor for allergic responses such as asthma or contact
dermatitis.
Treatment Overview:
ORAL EXPOSURE
o There is no specific antidote for pyrethrin poisoning.
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.
o ALLERGIC REACTION: MILD: antihistamines with or
without epinephrine. SEVERE: oxygen, aggressive
airway management, antihistamines, epinephrine (ADULT:
0.3 to 0.5 mL of a 1:1000 solution subcutaneously;
CHILD: 0.01 mL/kg; may repeat in 20 to 30 min),
corticosteroids, ECG monitoring, and IV fluids.
INHALATION EXPOSURE
o INHALATION: 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
beta2 agonist and corticosteroid aerosols.
EYE EXPOSURE
o DECONTAMINATION: Irrigate exposed eyes with copious
amounts of tepid water for at least 15 minutes. If
irritation, pain, swelling, lacrimation, or photophobia
persist, the patient should be seen in a health care
facility.
DERMAL EXPOSURE
o DECONTAMINATION: 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.
o Vitamin E topical application is highly effective in
relieving paresthesias.
Range of Toxicity:
o The minimal lethal dose of pyrethrum is not established,
but is probably in the range of 10 to 100 grams.
o Hypersensitivity reactions may be noted, especially
following a chronic dermal or inhalation exposure.
Patients with underlying asthma may be predisposed to
severe bronchospastic reactions after exposure.
No specific antidote known. Symptomatic treatment. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Treatment is supportive, and most casual exposures require only decontamination.
Topical vitamin E may ameliorate the paresthesias that accompany contact with
synthetic pyrethroids containing an alpha-cyano group (e.g., fenvalerate, cypermethrin,
flucythrinate). /Synthetic pyrethroids/ [Ellenhorn, M.J. and D.G. Barceloux. Medical Toxicology - Diagnosis
and Treatment of Human Poisoning. New York, NY: Elsevier Science Publishing
Co., Inc. 1988. 1081]**PEER REVIEWED**
To minimize absorption of pyrethrins and piperonyl butoxide following ingestion,
gastric lavage should be performed immediately and saline cathartics administered.
Treatment of overdosage mainly involves symptomatic and supportive care. /Pyrethrins/
[McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2126]**PEER REVIEWED**
Skin contamination should be removed by washing with soap and water. If irritant
or paresthetic effects occur, treatment by a physician should be obtained. Because
/vapor exposure/ of pyrethroid apparently accounts for paresthesia affecting
the face, strenuous measures should be taken (ventilation, protective face mask
and hood) to avoid vapor contact with the face and eyes. Vitamin E Oil preparations
(dl-alpha tocopheryl acetate) are uniquely effective in preventing and stopping
the paresthetic reaction. They are safe for application to the skin under field
conditions. Corn oil is somewhat effective, but possible side effects with continuing
use make it less suitable. Vaseline is less effective than corn oil and zinc
oxide actually worsens the reaction. /Pyrethroids/ [Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.36 EPA540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Eye contamination should be treated immediately by prolonged flushing of the
eye with copious amounts of clean water or saline. If irritation persists, professional
ophthalmologic care should be obtained. ... Extraordinary measures should be
taken to avoid eye and skin contamination with this product. Should accidental
eye contamination occur, expert ophthalmologic care should be obtained after
flushing the eye free of the chemical with copious amounts of clean water. /Pyrethroids/
[Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.36 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Ingestion of pyrethroid insecticide presents relatively little risk. However,
if large amounts have been ingested, empty the stomach by intubation, aspiration,
and lavage. Based on observations in laboratory animals, large ingestions of
either allethrin, cismethrin, fenvalerate or deltamethrin would be the most
likely to generate neurotoxic manifestations. /Pyrethroids/ [Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.36 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
If only small amounts of pyrethroid have been ingested, or if treatment has
been delayed, oral administration of activated charcoal and cathartic probably
represents optimal management. /Pyrethroids/ [Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.36 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Animal Toxicity Studies:
Non-Human Toxicity Excerpts:
Non-irritating to skin, but a primary eye irritant (rabbits). [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
In 2 yr feeding trials, no effect level for rats was 50, mice 200 mg/kg diet;
non-carcinogenic and non-teratogenic in rats, and non-mutagenic in in vitro
and in vivo tests. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Non-toxic to bees (depending on mode of application). [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
The type II pyrethroids /including cyfluthrin/ produce a complex poisoning
syndrome and act on a wide range of tissues. They give sodium tail currents
with relatively long time constants, which may be the reason for their ability
to act on the whole range of excitable tissues. Type II poisoning in rats involves
progressive development of nosing and exaggerated jaw opening similar to that
seen in response to an irritant placed on the tongue, salivation which may be
profuse, increasing extensor tone in the hind limbs causing a rolling gait,
incoordination progressing to a very coarse tremor, choreoform movements of
the limbs and tail often precipitated by sensory stimuli, generalized choreoathetosis
(writhing spasms), tonic seizures, apnea, and death. At lower doses more subtle
repetitive behavior is seen. In dogs, similar symptoms are seen but salivation
and upper airway hypersecretion and gastrointestinal symptoms are more prominent.
[Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide
Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc.,
1991. 590]**PEER REVIEWED**
Cyfluthrin is extremely toxic to fish and aquatic organisms but is practically
non-toxic to upland game birds and waterfowl. [Purdue University; National Pesticide Information Retrieval
System, Cyfluthrin Fact Sheet No. 164 (1987)]**PEER REVIEWED**
Synthetic pyrethroids are neuropoisons acting on the axons in the peripheral
and central nervous systems by interacting with sodium channels in mammals and/or
insects. A single dose produces toxic signs in mammals, such as tremors, hyperexcitability,
salivation, choreoathetosis, and paralysis. ... At near-lethal dose levels,
synthetic pyrethroids cause transient changes in the nervous system, such as
axonal swelling and/or breaks and myelin degeneration in sciatic nerves. They
are not considered to cause delayed neurotoxicity of the kind induced by some
organophosphorus compounds. /Synthetic prethroids/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.13 (1990)]**PEER
REVIEWED**
Extreme doses /of pyrethroids/ have caused convulsions in laboratory animals.
/Pyrethroids/ [Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.35 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Synthetic pyrethroids have been shown to be toxic for fish, aquatic arthropods,
and honeybees in laboratory tests. But, in practical usage, no serious adverse
effects have been noticed because of the low rates of application and lack of
persistence in the environment. The toxicity of synthetic pyrethroids in birds
and domestic animals is low. /Synthetic pyrethroids/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.13 (1990)]**PEER
REVIEWED**
The Type II /poisoning/ syndrome, also known as the "CS syndrome," is produced
by those esters containing the alpha-cyano substituent and elicits intense hyperactivity,
incoordination, and convulsions in cockroaches, whereas rats display burrowing
behavior, coarse tremors, clonic seizures, sinuous writhing (choreoathetosis),
and profuse salivation without lacrimation; hence the term CS (choreoathetosis/salivation)
syndrome. /Pyrethroid esters containing the alpha-cyano substituent/ [Amdur, M.O., J. Doull, C.D. Klaasen (eds). Casarett and Doull's
Toxicology. 4th ed. New York, NY: Pergamon Press, 1991. 593]**PEER REVIEWED**
The in vitro effects of pyrethroids on the mitogenic responsiveness of murine
splenic lymphocytes to concanavalin A and lipopolysaccharide were determined.
Allethrin was the most potent inhibitor, with effective concn in the range of
1X10-6 to 1.5X10-5 M. The results support the possibility of immune suppression
by pyrethroid exposure. /Pyrethroids/ [Stelzer KJ, Gordon MA; Res Commun Chem Pathol Pharmacol 46 (1):
137-50 (1984)]**PEER REVIEWED**
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 and death follow. /Pyrethrins/ [McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2125]**PEER REVIEWED**
Non-Human Toxicity Values:
LD50 Rat male oral 500-800 mg/kg, and in female rat 1,200 mg/kg [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
LD50 Mouse male oral 300 mg/kg, and in female mouse 600 mg/kg [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
LD50 Rat oral circa 500 mg/kg (in polyethyleneglycol) [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LD50 Rat oral circa 270 mg/kg (in xylene) [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LD50 Mouse oral circa 140 mg/kg [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LD50 Rat percutaneous (24 hr) >5,000 mg/kg [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LC50 Rat inhalation circa 0.1 mg/L/4 hr (aerosol) [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LC50 Rat inhalation 0.53 mg/L/4 hr (dust) [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
NOEL Rat 125 mg/kg diet /90-day trial/ [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
NOEL Dog 60 mg/kg diet /90-day trial/ [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
Ecotoxicity Values:
LC50 Golden orfe 330.9 ng/L/96 hr /Conditions of bioassay not specified/ [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LC50 Rainbow trout 89 ng/L/96 hr /Conditions of bioassay not specified/ [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LC50 Carp 0.022 mg/l/96 hr /Conditions of bioassay not specified/ [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
LC50 Bluegill sunfish 28 ng/L/96 hr /Conditions of bioassay not specified/
[Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
LD50 Japanese quail oral >2,000 mg/kg [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
Metabolism/Pharmacokinetics:
Metabolism/Metabolites:
The metabolic pathways for the breakdown of the pyrethroids vary little between
mammalian species but vary somewhat with structure. ... Essentially, pyrethrum
and allethrin are broken down mainly by oxidation of the isobutenyl side chain
of the acid moiety and of the unsaturated side chain of the alcohol moiety with
ester hydrolysis playing and important part, whereas for the other pyrethroids
ester hydrolysis predominates. /Pyrethrum and pyrethroids/ [Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide
Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc.,
1991. 588]**PEER REVIEWED**
The relative resistance of mammals to the pyrethroids is almost wholly attributable
to their ability to hydrolyze the pyrethroids rapidly to their inactive acid
and alcohol components, since direct injection into the mammalian CNS leads
to a susceptibility similar to that seen in insects. Some additional resistance
of homeothermic organisms can also be attributed to the negative temperature
coefficient of action of the pyrethroids, which are thus less toxic at mammalian
body temperatures, but the major effect is metabolic. Metabolic disposal of
the pyrethroids is very rapid, which means that toxicity is high by the intravenous
route, moderate by slower oral absorption, and often unmeasureably low by dermal
absorption. /Pyrethroids/ [Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide
Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc.,
1991. 588]**PEER REVIEWED**
FASTEST BREAKDOWN IS SEEN WITH PRIMARY ALCOHOL ESTERS OF TRANS-SUBSTITUTED
ACIDS SINCE THEY UNDERGO RAPID HYDROLYTIC & OXIDATIVE ATTACK. FOR ALL SECONDARY
ALCOHOL ESTERS & FOR PRIMARY ALCOHOL CIS-SUBSTITUTED CYCLOPROPANECARBOXYLATES,
OXIDATIVE ATTACK IS PREDOMINANT. /PYRETHROIDS/ [The Chemical Society. Foreign Compound Metabolism in Mammals.
Volume 5: A Review of the Literature Published during 1976 and 1977. London:
The Chemical Society, 1979. 469]**PEER REVIEWED**
Pyrethrins are reportedly inactivated in the GI tract following ingestion.
In animals, pyrethrins are rapidly metabolized to water soluble, inactive compounds.
/Pyrethrins/ [McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2125]**PEER REVIEWED**
Synthetic pyrethroids are generally metabolized in mammals through ester hydrolysis,
oxidation, and conjugation, and there is no tendency to accumulate in tissues.
In the environment, synthetic pyrethroids are fairly rapidly degraded in soil
and in plants. Ester hydrolysis and oxidation at various sites on the molecule
are the major degradation processes. /Synthetic pyrethroids/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.13 (1990)]**PEER
REVIEWED**
Absorption, Distribution & Excretion:
/PYRETHROIDS/ READILY PENETRATE INSECT CUTICLE AS SHOWN BY TOPICAL LD50 TO
PERIPLANETA (COCKROACH) ... /PYRETHROIDS/ [White-Stevens, R. (ed.). Pesticides in the Environment: Volume
1, Part 1, Part 2. New York: Marcel Dekker, Inc., 1971. 75]**PEER REVIEWED**
WHEN RADIOACTIVE PYRETHROID IS ADMIN ORALLY TO MAMMALS, IT IS ABSORBED FROM
INTESTINAL TRACT OF THE ANIMALS & DISTRIBUTED IN EVERY TISSUE EXAMINED.
EXCRETION OF RADIOACTIVITY IN RATS ADMIN TRANS-ISOMER: DOSAGE: 500 MG/KG; INTERVAL
20 DAYS; URINE 36%; FECES 64%; TOTAL 100%. /PYRETHROIDS/ [MIYAMOTO J; ENVIRON HEALTH PERSPECT 14: 15-28 (1976)]**PEER
REVIEWED**
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/
[McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2125]**PEER REVIEWED**
Although limited absorption may account for the low toxicity of some pyrethroids,
rapid biodegradation by mammalian liver enzymes (ester hydrolysis and oxidation)
is probably the major factor responsible. Most pyrethroid metabolites are promptly
excreted, at least in part, by the kidney. /Pyrethroids/ [Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.35 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
In animals, beta-cyfluthrin was largely and very quickly eliminated; 98% was
eliminated after 48 hr via the urine and the feces. [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 251]**PEER REVIEWED**
Mechanism of Action:
The synthetic pyrethroids delay closure of the sodium channel, resulting in
a sodium tail current that is characterized by a slow influx of sodium during
the end of depolarization. Apparently the pyrethroid molecule holds the activation
gate in the open position. Pyrethroids with an alpha-cyano group (e.g., fenvalerate)
produce more prolonged sodium tail currents than do other pyrethroids (e.g.,
permethrin, bioresmethrin). The former group of pyrethroids causes more cutaneous
sensations than the latter. /Synthetic pyrethroids/ [Ellenhorn, M.J. and D.G. Barceloux. Medical Toxicology - Diagnosis
and Treatment of Human Poisoning. New York, NY: Elsevier Science Publishing
Co., Inc. 1988. 1081]**PEER REVIEWED**
Interaction with sodium channels is not the only mechanism of action proposed
for the pyrethroids. Their effects on the central nervous system have led various
workers to suggest actions via antagonism of gamma-aminobutyric acid (GABA)-mediated
inhibition, modulation of nicotinic cholinergic transmission, enhancement of
noradrenaline release, or actions on calcium ions. Since neurotransmitter specific
pharmacological agents offer only poor or partical protection against poisoning,
it is unlikely that one of these effects represents the primary mechanism of
action of the pyrethroids, and most neurotransmitter release is secondary to
increased sodium entry. /Pyrethroids/ [Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide
Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc.,
1991. 588]**PEER REVIEWED**
The symptoms of pyrethrin poisoning follow the typical pattern of nerve poisoning:
(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/ [Matsumura, F. Toxicology of Insecticides. 2nd ed. New York,
NY: Plenum Press, 1985. 147]**PEER REVIEWED**
Electrophysiologically, pyrethrins cause repetitive discharges and conduction
block. /Pyrethrins/ [Matsumura, F. Toxicology of Insecticides. 2nd ed. New York,
NY: Plenum Press, 1985. 147]**PEER REVIEWED**
The interaction of a series of pyrethroid insecticides with the sodium channels
in myelinated nerve fibers of the clawed frog, Xenopus laevis, was investigated
using the voltage clamp technique. Of 11 pyrethroids, 9 insecticidally active
cmpd induced a slowly decaying sodium tail current on termination of a step
depolarization, whereas the sodium current during depolarization was hardly
affected. /Pyrethroids/ [Vijverberg HP M et al; Biochem Biophys Acta 728 (1): 73-82 (1983)]**PEER
REVIEWED**
The biochemical process by which various pyrethroid insecticides alter membrane-bound
ATPase activities of the squid nervous system was examined. Of the 5 ATP-hydrolyzing
systems tested, only Ca(2+)-stimulated ATPase activities were clearly affected
by the pyrethroids. The natural type /I/ pyrethroid, allethrin, primarily inhibits
Ca-ATPase activity. /Pyrethroids/ [Clark JM, Matsumura F; Pestic Biochem Physiol 18 (2): 180-90
(1982)]**PEER REVIEWED**
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/ [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London:
Williams and Wilkins, 1982. 75]**PEER REVIEWED**
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/ [Abbassy MA et al; Pestic Biochem Physiol 19 (3): 299-308 (1983)]**PEER
REVIEWED**
... Pyrethroid esters /containing the alpha-cyano substituent/ produce an
even longer delay /than those lacking the substituent/ in sodium channel inactivation,
leading to a persistent depolarization of the nerve membrane without repetitive
discharge, a reduction in the amplitude of the action potential, and an eventual
failure of axonal conduction and a blockade of impulses. /Pyrethroid esters
containing the alpha-cyano substituent/ [Amdur, M.O., J. Doull, C.D. Klaasen (eds). Casarett and Doull's
Toxicology. 4th ed. New York, NY: Pergamon Press, 1991. 595]**PEER REVIEWED**
The primary target site of pyrethroid insecticides in the vertebrate nervous
system is the sodium channel in the nerve membrane. Pyrethroids without an alpha-cyano
group (allethrin, d-phenothrin, permethrin, and cismethrin) cause a moderate
prolongation of the transient increase in sodium permeability of the nerve membrane
during excitation. This results in relatively short trains of repetitive nerve
impulses in sense organs, sensory (afferent) nerve fibers, and, in effect, nerve
terminals. On the other hand the alpha-cyano pyrethroids cause a long lasting
prolongation of the transient increase in sodium permeability of the nerve membrane
during excitation. This results in long-lasting trains of repetitive impulses
in sense organs and a frequency-dependent depression of the nerve impulse in
nerve fibers. The difference in effects between permethrin and cypermethrin,
which have identical molecular structures except for the presence of an alpha-cyano
group on the phenoxybenzyl alcohol, indicates that it is this alpha-cyano group
that is responsible for the long-lasting prolongation of the sodium permeability.
Since the mechanisms responsible for nerve impulse generation and conduction
are basically the same throughout the entire nervous system, pyrethroids may
also induce repetitive activity in various parts of the brain.
The difference in symptoms of poisoning by alpha-cyano pyrethroids, compared
with the classical pyrethroids, is not necessarily due to an exclusive central
site of action. It may be related to the long-lasting repetitive activity in
sense organs and possibly in other parts of the nervous system, which, in a
more advance state of poisoning, may be accompanied by a frequency-dependent
depression of the nervous impulse. /Synthetic pyrethroids/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.89 (1990)]**PEER
REVIEWED**
Pyrethroids also cause pronounced repetitive activity and a prolongation of
the transient increase in sodium permeability of the nerve membrane in insects
and other invertebrates. Available information indicates that the sodium channel
in the nerve membrane is also the most important target site of pyrethroids
in the invertebrate nervous system. /Synthetic pyrethroids/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.90 (1990)]**PEER
REVIEWED**
In the electrophysiological experiments using giant axons of cray-fish, the
Type II pyrethroids retain sodium channels in a modified continuous open state
persistently, depolarize the membrane, and block the action potential without
causing repetitive firing. /Pyrethroids type II/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.87 (1990)]**PEER
REVIEWED**
Diazepam, which facilitates GABA reaction, delayed the onset of action of
deltamethrin and fenvalertae, but not permethrin and allethrin, in both the
mouse and cockroach. Possible mechanisms of the Type II pyrethroid syndrome
include action at the GABA receptor complex or a closely linked class of neuroreceptor.
/Pyrethroids type II/ [WHO; Environmental Health Criteria 99: Cyhalothrin p.87 (1990)]**PEER
REVIEWED**
Non-systemic insecticide with contact and stomach action. Acts on the nervous
system, with rapid knockdown and long residual activity. [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 250]**PEER REVIEWED**
Interactions:
/Pyrethroid/ detoxification ... important in flies, may be delayed by the
addition of synergists ... organophosphates or carbamates ... to guarantee a
lethal effect. ... /Pyrethroid/ [Buchel KH (ed); Chemistry of Pesticides p.19 (1983)]**PEER REVIEWED**
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/ [McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2125]**PEER REVIEWED**
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/ [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London:
Williams and Wilkins, 1982. 78]**PEER REVIEWED**
Pharmacology:
Therapeutic Uses:
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/ [McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2125]**PEER REVIEWED**
Interactions:
/Pyrethroid/ detoxification ... important in flies, may be delayed by the
addition of synergists ... organophosphates or carbamates ... to guarantee a
lethal effect. ... /Pyrethroid/ [Buchel KH (ed); Chemistry of Pesticides p.19 (1983)]**PEER REVIEWED**
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/ [McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2125]**PEER REVIEWED**
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/ [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London:
Williams and Wilkins, 1982. 78]**PEER REVIEWED**
Environmental Fate & Exposure:
Environmental Fate/Exposure Summary:
Cyfluthrin's production and use as an insecticide may result in its release
to the environment through a variety of waste streams. Based on an experimental
vapor pressure of 2.0X10-9 mm Hg at 25 deg C, cyfluthrin is expected to exist
primarily in the particulate phase in the ambient atmosphere. Particulate phase
cyfluthrin may be physically removed from the atmosphere by wet and dry deposition.
Volatilization from moist soil surfaces is not expected based on an estimated
Henry's Law constant of 5.8X10-10 atm-cu m/mol. Cyfluthrin is expected to be
immobile in soils based upon a measured Koc value of 33,800. Volatilization
from dry soil surfaces is not expected based upon the vapor pressure of this
compound. Biodegradation is expected to be an important environmental fate process
for this compound. The initial products of cyfluthrin anaerobic biodegradation
are 3-(2,2-dichlorovinyl)2,2-dimethylcyclopropancarboxcylic acid and 4-fluoro-3-phenoxybenzoic
acid. In water, cyfluthrin is expected to adsorb to sediment or particulate
matter based on its experimental Koc value. This compound is not expected to
volatilize from water surfaces given its estimated Henry's Law constant. Photolysis
is expected to be an important environmental fate process for cyfluthrin. An
experimental half-life of 16 hours was measured for cyfluthrin in aqueous solution
when irradiated with light at environmentally significant wavelengths. A measured
BCF value of 400 was obtained for cypermethrin, an insecticide which is structurally
similar to cyfluthrin. The potential for bioconcentration of cyfluthrin in aquatic
organisms is considered high based on the measured BCF value of cypermethrin.
The general population may be exposed to cyfluthrin through dermal contact with
this compound where it is used as an insecticide. (SRC) **PEER REVIEWED**
Probable Routes of Human Exposure:
Occupational exposure to cyfluthrin may occur through dermal contact at facilities
where this compound is produced or used. The general
population may be exposed to cyfluthrin through dermal contact with this compound.
(SRC) **PEER REVIEWED**
Artificial Pollution Sources:
Cyfluthrin's production and use as an insecticide(1) will result in its release
to the environment through a variety of waste streams(SRC). [(1) Budavari S; The Merck Index - Encyclopedia of Chemicals,
Drugs, and Biologicals 12th ed. p 466. Rahway, NJ: Merck and Co Inc (1995)]**PEER
REVIEWED**
Environmental Fate:
TERRESTRIAL FATE: Based on a recommended classification scheme(1), an experimental
Koc value of 33,800(2), indicates that cyfluthrin will have no mobility in soil(SRC).
Volatilization of cyfluthrin is not expected from moist soil surfaces(SRC) given
an estimated Henry's Law constant of 5.8X10-10 atm-cu m/mole(SRC), determined
from an experimental vapor pressure of 2.0X10-9 mm Hg at 25 deg C(3) and water
solubility of 2.0 mg/l at 25 deg C(4). Volatilization from dry soil surfaces
is not expected based upon the vapor pressure of this compound(SRC). Biodegradation
is expected to be an important fate process for this compound(3,5,SRC). Over
90% biodegradation was observed under anaerobic soil conditions during a 140
day incubation period(5). The initial products of cyfluthrin anaerobic biodegradation
are 3-(2,2-dichlorovinyl)2,2-dimethylcyclopropancarboxcylic acid and 4-fluoro-3-phenoxybenzoic
acid(5). Photolysis is expected to be an important environmental fate process
for cyfluthrin(6,SRC). An experimental half-life of 16 hours was determined
for cyfluthrin in aqueous solution when irradiated with light at environmentally
significant wavelengths(6). Approximately 75% photodegradation was observed
for cyfluthrin applied to cotton fabrics when irradiated with a lamp designed
to simulate 96 hours of natural sunlight(7). [(1) Swann RL et al; Res Rev 85: 23 (1983) (2) Kordel W et al;
Chemosphere 27:1611-26 (1993)(3) Tomlin C; The Pesticide Manual 10th ed p 248.
Cambridge, UK: The Royal Society of Chemistry (1995) (4) Shiu WY et al; Rev
Environ Contam Toxicol 116: 15-187 (1990) (5) Smith S et al; Bull Environ Contam
Toxicol 55: 142-48 (1995) (6) Jenson-Korte U et al; Sci Tot Environ 62: 335-40
(1987) (7) Hussain M et al; Pestic Sci 28: 345-55 (1990)]**PEER REVIEWED**
AQUATIC FATE: Based on a recommended classification scheme(1), a measured
Koc value of 33,800(2), indicates that cyfluthrin is expected to adsorb to suspended
solids and sediment in water(SRC). Cyfluthrin is not expected to volatilize
from water surfaces(3,SRC) based on an estimated Henry's Law constant of 5.8X10-10
atm-cu m/mole(SRC), determined from an experimental vapor pressure of 2.0X10-9
mm Hg at 25 deg C(4) and water solubility of 2.0 mg/l at 25 deg C(5). Biodegradation
is expected to be an important fate process for this compound(4,6,SRC). Over
90% biodegradation was observed under anaerobic soil conditions during a 140
day incubation period(6). The initial products of cyfluthrin anaerobic biodegradation
are 3-(2,2-dichlorovinyl)2,2-dimethylcyclopropancarboxcylic acid and 4-fluoro-3-phenoxybenzoic
acid(6). Photolysis is expected to be an important environmental fate process
for cyfluthrin(7,SRC). An experimental half-life of 16 hours was measured for
cyfluthrin in aqueous solution when irradiated with light at environmentally
significant wavelengths(7). A measured BCF value of 400 was obtained for cypermethrin,
an insecticide which is structurally similar to cyfluthrin(8). The potential
for bioconcentration of cyfluthrin in aquatic organisms is considered high based
on the measured BCF value of cypermethrin(9,SRC). [(1) Swann RL et al; Res Rev 85: 23 (1983) (2) Kordel W et al;
Chemosphere 27:1611-26 (1993) (3) Lyman WJ et al; Handbook of Chemical Property
Estimation Methods. Washington DC: Amer Chem Soc pp. 4-9, 5-4, 5-10, 15-1 to
15-29 (1990) (4) Tomlin C; The Pesticide Manual 10th ed p 248. Cambridge, UK:
The Royal Society of Chemistry (1995) (5) Shiu WY et al; Rev Environ Contam
Toxicol 116: 15-187 (1990) (6) Smith S et al; Bull Environ Contam Toxicol 55:
142-48 (1995) (7) Jenson-Korte U et al; Sci Tot Environ 62: 335-40 (1987) (8)
Freitag D et al; Chemosphere 14: 1589-1616 (1985) (9) Franke C et al; Chemosphere
29: 1501-14 (1994)]**PEER REVIEWED**
ATMOSPHERIC FATE: Based on an experimental vapor pressure of 2.0X10-9 mm Hg
at 25 deg C(1), cyfluthrin is expected to exist primarily in the particulate
phase in the ambient atmosphere. Particulate phase cyfluthrin may be physically
removed from the atmosphere by wet and dry deposition(SRC). [(1) Tomlin C; The Pesticide Manual 10th ed p 248. Cambridge,
UK: The Royal Society of Chemistry (1995)]**PEER REVIEWED**
Environmental Biodegradation:
Biodegradation is expected to be an important environmental fate process for
cyfluthrin(1,SRC). Over 90% biodegradation was observed under anaerobic soil
conditions during a 140 day incubation period(1). The initial products of cyfluthrin
anaerobic biodegradation are 3-(2,2-dichlorovinyl)2,2-dimethylcyclopropancarboxcylic
acid and 4-fluoro-3-phenoxybenzoic acid(1). [(1) Smith S et al; Bull Environ Contam Toxicol 55: 142-48 (1995)]**PEER
REVIEWED**
Environmental Abiotic Degradation:
Aqueous hydrolysis is not expected to be an important environmental fate process
for cyfluthrin(SRC). A base-catalyzed second order rate constant of 6.1X10-3
L/mol-sec(SRC) was estimated using a structure estimation method(1); this corresponds
to half-lives of 35.9 and 3.5 years at pH values of 7 and 8, respectively(1,SRC).
Photolysis is expected to be an important environmental fate process for cyfluthrin(2,SRC).
An experimental half-life of 16 hours was measured for cyfluthrin in aqueous
solution when irradiated with light at environmentally significant wavelengths
(> 290 nm)(2). Approximately 75% photodegradation was observed for cylfluthrin
applied to cotton fabrics when irradiated with a lamp designed to simulate 96
hours of natural sunlight(3). [(1) Mill T et al; Environmental Fate and Exposure Studies. Development
of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides. EPA Contract
NO. 68-02-4254, Menlo Park, CA: SRI International (1987) (2) Jenson-Korte U
et al; Sci Tot Environ 62: 335-40 (1987) (3) Hussain M et al; Pestic Sci 28:
345-55 (1990)]**PEER REVIEWED**
Environmental Bioconcentration:
A measured BCF value of 400 was obtained for cypermethrin, an insecticide
which is structurally similar to cyfluthrin(1). The potential for bioconcentration
of cyfluthrin in aquatic organisms is considered high based on the measured
BCF value of cypermethrin(2,SRC). [(1) Freitag D et al; Chemosphere 14: 1589-1616 (1985) (2) Franke
C et al; Chemosphere 29: 1501-14 (1994)]**PEER REVIEWED**
Soil Adsorption/Mobility:
The experimental Koc value of cyfluthrin is 33,800 under non-specified soil
conditions(1). According to a recommended classification scheme(2), this experimental
Koc value suggests that cyfluthrin will have no mobility in soil(SRC). [(1) Kordel W et al; Chemosphere 27: 1611-26 (1993) (2) Swann
RL et al; Res Rev 85: 23 (1983)]**PEER REVIEWED**
Volatilization from Water/Soil:
The Henry's Law constant for cyfluthrin is estimated as 5.8X10-10 atm-cu m/mole(SRC)
from its experimental value for vapor pressure, 2.0X10-9 mm Hg(1), and experimental
water solubility, 2.0 mg/l(2). This value indicates that cyfluthrin will not
volatilize from water surfaces(3,SRC). Cyfluthrin's Henry's Law constant and
vapor pressure indicate that volatilization from moist and dry soil surfaces
are not important environmental fate processes(SRC). [(1) Tomlin C; The Pesticide Manual 10th ed p 248. Cambridge,
UK: The Royal Society of Chemistry (1995) (2) Shiu WY et al; Rev Environ Contam
Toxicol 116: 15-187 (1990) (3) Lyman WJ et al; Handbook of Chemical Property
Estimation Methods. Washington DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)]**PEER
REVIEWED**
Environmental Standards & Regulations:
FIFRA Requirements:
Tolerances are established for residues of the insecticide cyfluthrin (cyano(4-fluoro-3-phenoxyphenyl)methyl
3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate ... in or on the
following raw agricultural commodities: alfalfa, forage; alfalfa, hay; carrots;
cattle, fat; cattle, meat; cattle mbyp; cottonseed; eggs; goats, fat; goats,
meat; goats, mbyp; hogs, fat; hogs, meat; hogs, mbyp; hops, fresh; horses, fat;
horses, meat; horses, mbyp; milkfat (reflecting 0.08 ppm in whole milk); peppers;
poultry, fat; poultry, meat; poultry, mbyp; radishes; sheep, fat; sheep, meat;
sheep, mbyp; sugarcane; sunflower, forage; sunflower, seed; and tomato. [40 CFR 180.436(a) (7/1/96)]**PEER REVIEWED**
Time-limited tolerances are established for residues of the insecticide cyfluthrin
(cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate
... in or on the following raw agricultural commodities: corn, forage and fodder,
field and pop; corn, grain, field and pop; corn, sweet, (K+CWHR); corn, sweet,
fodder; and corn, sweet, forage. [40 CFR 180.436(b) (7/1/96)]**PEER REVIEWED**
A time-limited tolerance, to expire on november 15, 1997, is established for
residues of the insecticide cyfluthrin (cyano(4-fluoro-3-phenoxyphenyl)methyl
3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate ... in or on the
following food commodities: cottonseed oil; tomato, concentrated products. [40 CFR 185.1250(a) (7/1/96)]**PEER REVIEWED**
A tolerance ... is established for residues of the insecticide cyfluthrin
(cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate
... in food commodities exposed to the insecticide during treatment of food-handling
establishments where food and food products are held, processed, prepared, or
served. [40 CFR 185.1250(c) (7/1/96)]**PEER REVIEWED**
A tolerance is established for residues of the insecticide cyfluthrin (cyano(4-fluoro-3-phenoxyphenyl)methyl
3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate) ... in or on dried
hops resulting from application of the insecticide to hops. [40 CFR 185.1250(d) (7/1/96)]**PEER REVIEWED**
Acceptable Daily Intakes:
FAO/WHO ADI: 0.02 mg/kg [FAO/WHO; Pesticide Residues in Food - 1992. Evaluations Part
1 - Residues p.869 Plant Prod Protection Paper 118 (1992)]**PEER REVIEWED**
Allowable Tolerances:
Tolerances are established for residues of the insecticide cyfluthrin (cyano(4-fluoro-3-phenoxyphenyl)methyl
3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate ... in or on the
following raw agricultural commodities: alfalfa, forage 5.00 ppm (expiration
date 11/15/97); alfalfa, hay 10.00 ppm (expiration date 11/15/97); carrots 0.20
ppm (expiration date 11/15/97); cattle, fat 1.00 ppm (expiration date 11/15/97);
cattle, meat 0.40 ppm (expiration date 11/15/97); cattle mbyp 0.40 ppm (expiration
date 11/15/97); cottonseed 1.0 ppm (expiration date 11/15/97); eggs 0.01 ppm
(expiration date 11/15/97); goats, fat 1.00 ppm (expiration date 11/15/97);
goats, meat 0.40 ppm (expiration date 11/15/97); goats, mbyp 0.40 ppm (expiration
11/15/97); hogs, fat 1.00 ppm (expiration date 11/15/97); hogs, meat 0.40 ppm
(expiration 11/15/97); hogs, mbyp 0.40 ppm (expiration date 11/15/97); hops,
fresh 4.0 ppm (expiration date: none); horses, fat 1.00 ppm (expiration date
11/15/97); horses, meat 0.40 ppm (expiration date 11/15/97); horses, mbyp 0.40
ppm (expiration date 11/15/97); milkfat (reflecting 0.08 ppm in whole milk)
2.50 ppm (expiration date 11/15/97); peppers 0.50 ppm (expiration date 11/15/97);
poultry, fat 0.01 ppm (expiration date 11/15/97); poultry, meat 0.01 ppm (expiration
date 11/15/97); poultry, mbyp 0.01 ppm (expiration date 11/15/97); radishes
1.00 ppm (expiration date 11/15/97); sheep, fat 1.00 ppm (expiration date 11/15/97);
sheep, meat 0.40 ppm (expiration date 11/15/97); sheep, mbyp 0.40 ppm (expiration
date 11/15/97); sugarcane 0.05 ppm (expiration date 11/15/97); sunflower, forage
1.00 ppm (expiration date 11/15/97); sunflower, seed 0.02 ppm (expiration date
11/15/97); and tomato 0.20 ppm (expiration date 11/15/97). [40 CFR 180.436(a) (7/1/96)]**PEER REVIEWED**
Time-limited tolerances are established for residues of the insecticide cyfluthrin
(cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate
... in or on the following raw agricultural commodities: corn, forage and fodder,
field and pop 0.01 ppm (expiration date 7/5/99); corn, grain, field and pop
0.01 ppm (expiration date 7/5/99); corn, sweet, (K+CWHR) 0.05 ppm (expiration
date 7/5/99); corn, sweet, fodder 15.00 ppm (expiration date 7/5/99); and corn,
sweet, forage 30.00 ppm (expiration date 7/5/99). [40 CFR 180.436(b) (7/1/96)]**PEER REVIEWED**
A time-limited tolerance, to expire on november 15, 1997, is established for
residues of the insecticide cyfluthrin (cyano(4-fluoro-3-phenoxyphenyl)methyl
3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate ... in or on the
following food commodities: cottonseed oil 2.0 ppm; tomato, concentrated products
0.5 ppm. [40 CFR 185.1250(a) (7/1/96)]**PEER REVIEWED**
A tolerance of 0.05 ppm is established for residues of the insecticide cyfluthrin
(cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate
... in food commodities exposed to the insecticide during treatment of food-handling
establishments where food and food products are held, processed, prepared, or
served. [40 CFR 185.1250(c) (7/1/96)]**PEER REVIEWED**
A tolerance of 20.0 ppm is established for residues of the insecticide cyfluthrin
(cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate)
... in or on dried hops resulting from application of the insecticide to hops.
[40 CFR 185.1250(d) (7/1/96)]**PEER REVIEWED**
Chemical/Physical Properties:
Molecular Formula:
C22-H18-Cl2-F-N-O3 [Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals,
Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 432]**PEER REVIEWED**
Molecular Weight:
434.29 [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
Color/Form:
Yellowish-brown oil [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
Viscous amber partly crystalline oil. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Odor:
Aromatic solvent odor at room temp [Purdue University; National Pesticide Information Retrieval
System, Cyfluthrin Fact Sheet No. 164 (1987)]**PEER REVIEWED**
Melting Point:
60 deg C [Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th
ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 3-139]**PEER REVIEWED**
Octanol/Water Partition Coefficient:
log Kow = 5.94 [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 248]**PEER REVIEWED**
Solubilities:
Solubility in water is 2 mg/l at 20 deg C. [Shiu WY et al; Rev Environ Contam Toxicol 116: 15-187 (1990)]**PEER
REVIEWED**
Spectral Properties:
Index of refraction: 1.5511 at 23 deg C/D [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
Vapor Pressure:
2.03X10-9 mm Hg at 25 deg C [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 248]**PEER REVIEWED**
Other Chemical/Physical Properties:
Colorless oil; specific optical rotation: -15.0 deg at 20 deg C/D (concentration
by volume= 1.0 g in 100 ml chloroform)/(1R)(3R)(alphaR)-cyfluthrin. [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
Pasty yellow mass; contains 23-26% (R 1R)-cis- + (S 1S)-cis- enantiomers (mp
57 deg C), 16-19% (S 1R)-cis-(mp 74 deg C), 33-36% (R 1R)-trans- + (S 1S)-trans-(mp
66 deg C), 22-25% (S 1R)- trans- + (R 1S)-trans-(mp 102 deg C) /Technical cyfluthrin/
[Worthing, C.R. and S.B. Walker (eds.). The Pesticide Manual
- A World Compendium. 8th ed. Thornton Heath, UK: The British Crop Protection
Council, 1987. 205]**PEER REVIEWED**
Crystals from m-hexane; mp: 68-69 deg C; specific optical rotation: -2.1 deg
at 20 deg C/D (concentration by volume= 1.0 g in 100 ml chloroform) /(1R)(3S)(alpha
S)-cyfluthrin/ [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
Crystals; mp: 50-52 deg C; specific optical rotation: +24.5 deg at 20 deg
C/D (concentration by volume= 1.0 g in 100 ml chloroform) /(1R)(3R)(alpha S)-
Cyfluthrin/ [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
Chemical Safety & Handling:
Skin, Eye and Respiratory Irritations:
Immediately irritating to the eye. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
The chief effect from exposure ... is skin rash particularly on moist areas
of the skin. ... May irritate the eyes. [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 1]**PEER REVIEWED**
Fire Potential:
/Pyrethrins/ ... burn with difficulty. /Pyrethrins/ [Bureau of Explosives; Emergency Handling of Haz Matl in Surface
Trans p.434 (1981)]**PEER REVIEWED**
Fire Fighting Procedures:
Use carbon dioxide, foam, or dry chemical /on fires involving pyrethroids/.
/Pyrethrum/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 2]**PEER REVIEWED**
Fire-fighting: Self-contained breathing apparatus with a full facepiece operated
in pressure-demand or other positive-pressure mode. /Pyrethrum/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 5]**PEER REVIEWED**
Extinguish fire using agent suitable for type of surrounding fire. /Pyrethrins/
[Bureau of Explosives; Emergency Handling of Haz Matl in Surface
Trans p.434 (1981)]**PEER REVIEWED**
Hazardous Reactivities & Incompatibilities:
Incompatible with azocyclotin. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Incompatibility: Strong oxidizers. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
... Incompatible with lime & ordinary soaps because acids & alkalies
speed up processes of hydrolysis. /Pyrethrins/ [Farm Chemicals Handbook 1997. Willoughby, OH: Meister Publishing
Co., 1997.,p. C311]**PEER REVIEWED**
Protective Equipment & Clothing:
Employees should be provided with and required to use dust- and splash-proof
safety goggles where /pyrethroids/ ... may contact the eyes. /Pyrethroids/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 3]**PEER REVIEWED**
Employees should be provided with and be required to use impervious clothing,
gloves, and face shields (eight-inch minimum). /Pyrethroids/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 2]**PEER REVIEWED**
Wear appropriate equipment to prevent: Repeated or prolonged skin contact.
/Pyrethrum / [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Wear appropriate eye protection to prevent eye contact. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Recommendations for respirator selection. Max concn for use: 50 mg/cu m: Respirator
Classes: Any chemical cartridge respirator with organic vapor cartridge(s) in
combination with a dust, mist, and fume filter. May require eye protection.
Any supplied-air respirator. May require eye protection. Any self-contained
breathing apparatus. May require eye protection. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Recommendations for respirator selection. Max concn for use: 125 mg/cu m:
Respirator Classes: Any supplied-air respirator operated in a continuous flow
mode. May require eye protection. Any powered, air-purifying respirator with
organic vapor cartridge(s) in combination with a dust, mist, and fume filter.
May require eye protection. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Recommendations for respirator selection. Max concn for use: 250 mg/cu m:
Respirator Classes: Any chemical cartridge respirator with a full facepiece
and organic vapor cartridge(s) in combination with a high-efficiency particulate
filter. Any self-contained breathing apparatus with a full facepiece. Any supplied-air
respirator with a full facepiece. Any powered, air-purifying respirator with
a tight-fitting facepiece and organic vapor cartridge(s) in combination with
a high-efficiency particulate filter. May require eye protection. /Pyrethrum/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Recommendations for respirator selection. Max concn for use: 5,000 mg/cu m:
Respirator Class: Any supplied-air respirator with a full facepiece and operated
in a pressure-demand or other positive pressure mode. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Recommendations for respirator selection. Condition: Emergency or planned
entry into unknown concn or IDLH conditions: Respirator Classes: Any self-contained
breathing apparatus that has a full facepiece and is operated in a pressure-demand
or other positive pressure mode. Any supplied-air respirator with a full face
piece and operated in pressure-demand or other positive pressure mode in combination
with an auxiliary self-contained breathing apparatus operated in pressure-demand
or other positive pressure mode. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Recommendations for respirator selection. Condition: Escape from suddenly
occurring respiratory hazards: Respirator Classes: Any air-purifying, full-facepiece
respirator (gas mask) with a chin-style, front- or back-mounted organic vapor
canister having a high-efficiency particulate filter. Any appropriate escape-type,
self-contained breathing apparatus. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Preventive Measures:
Skin that becomes contaminated with /pyrethrum/ should be promptly washed
or showered with soap or mild detergent and water. /Pyrethrum/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 3]**PEER REVIEWED**
Clothing contaminated with /pyrethrum/ should be placed in closed containers
for storage until provision is made for the removal of /pyrethrum/ from the
clothing. /Pyrethrum/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 2]**PEER REVIEWED**
Respirators may be used when engineering and work practice controls are not
technically feasible, when such controls are in the process of being installed,
or when they fail or need to be supplemented. Respirators may also be used for
operations which require entry into tanks or closed vessels, and in emergency
situations. /Pyrethrum/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 2]**PEER REVIEWED**
Employees who handle /pyrethrum/ ... should wash their hands thoroughly with
soap or mild detergent and water before eating, smoking, or using toilet facilities.
/Pyrethrum/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.).
NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH)
PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office,
Jan. 1981. 3]**PEER REVIEWED**
Avoid contact with skin. Keep out of any body of water. Do not contaminate
water by cleaning of equipment or disposal of waste. Do not reuse empty container.
Destroy it by perforating or crushing. Bury or discard in a safe place away
from water supplies. /Pyrethrins/ [Farm Chemicals Handbook 1997. Willoughby, OH: Meister Publishing
Co., 1997.,p. C311]**PEER REVIEWED**
SRP: The scientific literature for the use of contact lenses in industry is
conflicting. The benefit or detrimental effects of wearing contact lenses depend
not only upon the substance, but also on factors including the form of the substance,
characteristics and duration of the exposure, the uses of other eye protection
equipment, and the hygiene of the lenses. However, there may be individual substances
whose irritating or corrosive properties are such that the wearing of contact
lenses would be harmful to the eye. In those specific cases, contact lenses
should not be worn. In any event, the usual eye protection equipment should
be worn even when contact lenses are in place. **PEER REVIEWED**
Contact lenses should not be worn when working with this chemical. /Pyrethrum/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
The worker should immediately wash the skin when it becomes contaminated.
/Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Workers whose clothing may have become contaminated should change into uncontaminated
clothing before leaving the work premises. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
Work clothing that becomes wet or significantly contaminated should be removed
and replaced. /Pyrethrum/ [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June
1994. 270]**PEER REVIEWED**
If /pyrethrins/ are not involved in a fire: keep /pyrethrins/ out of water
sources and sewers. Build dikes to contain flow as necessary. /Pyrethrins/ [Bureau of Explosives; Emergency Handling of Haz Matl in Surface
Trans p.434 (1981)]**PEER REVIEWED**
Stability/Shelf Life:
Pyrethrins ... /are/ stable for long periods in water-based aerosols where
... emulsifiers give neutral water systems. /Pyrethrins/ [Farm Chemicals Handbook 1997. Willoughby, OH: Meister Publishing
Co., 1997.,p. C311]**PEER REVIEWED**
Thermally stable @ room temp. [Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium.
10th ed. Surrey, UK: The British Crop Protection Council, 1994. 250]**PEER REVIEWED**
Storage Conditions:
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/ [McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug
Information 92. Bethesda, MD: American Society of Hospital Pharmacists, Inc.,
1992 (Plus Supplements 1992). 2125]**PEER REVIEWED**
Cleanup Methods:
Environmental consideration - Land spill: Dig a pit, pond, lagoon, or 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/
[Bureau of Explosives; Emergency Handling of Haz Matl in Surface
Trans p.434 (1981)]**PEER REVIEWED**
Environmental consideration - Water spill: If /pyrethrins/ are dissolved,
apply activated carbon at ten times the spilled amount in the region of 10 ppm
or greater concn. Use mechanical dredges or lifts to remove immobilized masses
of pollutants and precipitates. /Pyrethrins/ [Bureau of Explosives; Emergency Handling of Haz Matl in Surface
Trans p.434 (1981)]**PEER REVIEWED**
Disposal Methods:
SRP: At the time of review, criteria for land treatment or burial (sanitary
landfill) disposal practices are subject to significant revision. Prior to implementing
land disposal of waste residue (including waste sludge), consult with environmental
regulatory agencies for guidance on acceptable disposal practices. **PEER REVIEWED**
Incineration would be an effective disposal procedure where permitted. If
an efficient incinerator is not available, the product should be mixed with
large amounts of combustible material and contact with the smoke should be avoided.
/Pyrethrin products/ [Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens,
1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 762]**PEER REVIEWED**
The following wastewater treatment technology has been investigated for chlorinated
pesticides: Concentration process: Resin adsorption. /Chlorinated pesticides/
[USEPA; Management of Hazardous Waste Leachate, EPA Contract
No.68-03-2766 p.E-195 (1982)]**PEER REVIEWED**
The following wastewater treatment technology has been investigated for chlorinated
pesticides: Concentration process: Resin adsorption. /Chlorinated pesticides/
[USEPA; Management of Hazardous Waste Leachate, EPA Contract
No.68-03-2766 p.E-195 (1982)]**PEER REVIEWED**
Occupational Exposure Standards:
Manufacturing/Use Information:
Major Uses:
Agricultural insecticide [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
Control of chewing and sucking insects on oilseed rape (cabbage stem flea
beetleand rape winter stem weevil), cereals (Caphids vectors of BYDV), ornamentals,
maize, cotton, groundnuts, potatoes, rice, lucerne, tobacco, sugar beet, deciduous
fruit, and vegetables. Control of insect pests, especially houseflies, mosquitos,
and cockroaches in public health, stored products, and domestic usage. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
MEDICATION **PEER REVIEWED**
Manufacturers:
Bayer Inc., Hq, One Mellon Center, 500
Grant St, Pittsburgh, PA 15219-2502, (412) 394-5500; Agriculture Division, Hawthorn
Rd, PO Box 4913, Kansas City, MO 64120; Production
Site: Kansas City, MO 64120, Shawnee, KS 66216 [SRI. 1996 Directory of Chemical Producers-United States of America.
Menlo Park, CA: SRI International, 1996. 786]**PEER REVIEWED**
General Manufacturing Information:
Synthetic pyrethroid insecticide. Commercial product is mixture of 8 isomers,
the (1R)-isomers primarily responsible for the bioactivity. [Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals,
Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 466]**PEER
REVIEWED**
The technical product consists of a mixture of 4 diastereoisomeric pairs.
/Technical cyfluthrin/ [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Compatible with most other pesticides but incompatible with azocyclotin. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Non-phytotoxic when used as directed. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
/Pyrethroids/ are modern synthetic insecticides similar chemically to natural
pyrethrins, but modified to increase stability in the natural environment. /Pyrethroids/
[Morgan DP; Recognition and Management of Pesticide Poisonings.
4th ed. p.34 EPA 540/9-88-001. Washington, DC: U.S. Government Printing Office,
March 1989]**PEER REVIEWED**
Formulations/Preparations:
Emulsifiable concentrate; water-in-oil emulsion; ULV liquid; wettable powder;
granules. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Mixed formulations: (cyfluthrin+)phoxim; dichlorvos + propoxur [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Laboratory Methods:
Analytic Laboratory Methods:
Pyrethrins ... in pesticide formulations are analyzed using gas chromatography
equipped with flame ionization detection. Average recovery is 98% with a precision
of 0.0044-0.011. /Pyrethrins/ [Association of Official Analytical Chemists. Official Methods
of Analysis. 15th ed. and Supplements. Washington, DC: Association of Analytical
Chemists, 1990,p. V1 172]**PEER REVIEWED**
... Liquid chromatography method has been developed to quantitate pyrethrins
in pesticide formulations. ... Detection was monitored at 240 nm. ... Percent
coefficients of variation ranged from 1.39 to 9.68 with the majority less than
5.00. ... /Pyrethrins/ [Bushway RJ; J Assoc Off Anal Chem 68 (6): 1134-6 (1985)]**PEER
REVIEWED**
Pyrethrins were detected in soils by gas chromatography after extraction with
hexane. /Pyrethrins/ [Siltanen H et al; Ryrethrum Post 14 (3): 65-7 (1978)]**PEER
REVIEWED**
Low level pyrethrin formulations are extracted with tetrahydrofuran and determined
via capillary gas chromatography with electron capture detection. ... Analysis
of 5 formulations gave an average standard deviation of 3.3%. /Pyrethrins/ [Stringham RW, Schutz RP; J Assoc Off Anal Chem 68 (6): 1137-9
(1985)]**PEER REVIEWED**
Special References:
Special Reports:
Purdue University; National Pesticide Information Retrieval System, Cyfluthrin
Fact Sheet No. 164 (1987)
Emulsifiable concentrate; water-in-oil emulsion; ULV liquid; wettable powder;
granules. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Mixed formulations: (cyfluthrin+)phoxim; dichlorvos + propoxur [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook.
2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p.
A799/Aug 87]**PEER REVIEWED**
Administrative Information:
Hazardous Substances Databank Number: 6599
Last Revision Date: 20010808
Last Review Date: Reviewed by SRP on 9/18/1997
Update History:
Field Update on 08/08/2001, 1 field added/edited/deleted.
Field Update on 05/16/2001, 1 field added/edited/deleted.
Complete Update on 09/12/2000, 1 field added/edited/deleted.
Complete Update on 06/12/2000, 1 field added/edited/deleted.
Complete Update on 02/08/2000, 1 field added/edited/deleted.
Complete Update on 02/02/2000, 1 field added/edited/deleted.
Complete Update on 09/21/1999, 1 field added/edited/deleted.
Complete Update on 08/27/1999, 1 field added/edited/deleted.
Complete Update on 06/03/1998, 45 fields added/edited/deleted.
Field Update on 06/03/1998, 1 field added/edited/deleted.
Field Update on 11/01/1997, 1 field added/edited/deleted.
Field Update on 05/09/1997, 1 field added/edited/deleted.
Field Update on 05/01/1997, 2 fields added/edited/deleted.
Field Update on 03/06/1997, 1 field added/edited/deleted.
Complete Update on 10/20/1996, 1 field added/edited/deleted.
Complete Update on 05/14/1996, 1 field added/edited/deleted.
Complete Update on 02/01/1996, 1 field added/edited/deleted.
Complete Update on 08/21/1995, 1 field added/edited/deleted.
Complete Update on 11/28/1994, 1 field added/edited/deleted.
Complete Update on 03/01/1994, 50 fields added/edited/deleted.