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Flucythrinate. TOXNET profile from Hazardous Substances Data Bank.


See for Updates: http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB

FLUCYTHRINATE
CASRN: 70124-77-5
For other data, click on the Table of Contents

Human Health Effects:

Human Toxicity Excerpts:

Experimental application of flucythrinate to the ear lobe of human volunteers at 130 ug/cm sq caused a marked paraesthesia which began 30 min after application and persisted for 24 hr. Flucythrinate produced the most severe paresthesia of the four pyrethroids tested. A second study using forearm skin and application at 13.8 mg/cm sq produced paresthesia after a delay of 4-5 hr lasting for 3 days, indicating that the thinner facial skin is more sensitive than other areas.
[Hayes WJ, Laws ER, eds; Handbook of Pesticide Toxicology V2 p.597 (1991)]**PEER REVIEWED**

May be fatal if ingested or absorbed through the skin.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

Synthetic pyrethroids are neither cutaneous sensitizers nor irritants. Although these compounds do not cause signs of inflammation (edema, erythema, vesiculation), they do produce paresthesias after contact. Typically, symptoms begin several hours after cutaneous exposure, peak in the evening, and resolve by the following day. /Synthetic pyrethroids/
**PEER REVIEWED**

Contact allergy from pyrethroids ... has not been observed. /Pyrethroids/
[Zenz, C. Occupational Medicine-Principles and Practical Applications. 2nd ed. St. Louis, MO: Mosby-Yearbook, Inc, 1988. 146]**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/
[Gilman, A.G., T.W. Rall, A.S. Nies and P. Taylor (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 8th ed. New York, NY. Pergamon Press, 1990. 1629]**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. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**

The chief effect from exposure ... is skin rash particularly on moist areas of the skin. ... May irritate 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. 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 flucythrinate occurs through dermal contact and inhalation of dust and sprays, especially to workers applying the compound as an insecticide(1).
[(1) Parmeggiani L; Encyl Occup Health & Safety 3rd ed. Geneva, Switzerland: International Labour Office pp. 1616-46 (1983)]**PEER REVIEWED**


Emergency Medical Treatment:

Emergency Medical Treatment:

EMT Copyright Disclaimer:
Portions of the POISINDEX(R) database are provided here for general reference. THE COMPLETE POISINDEX(R) DATABASE, AVAILABLE FROM MICROMEDEX, SHOULD BE CONSULTED FOR ASSISTANCE IN THE DIAGNOSIS OR TREATMENT OF SPECIFIC CASES. Copyright 1974-1998 Micromedex, Inc. Denver, Colorado. All Rights Reserved. Any duplication, replication or redistribution of all or part of the POISINDEX(R) database is a violation of Micromedex' copyrights and is strictly prohibited.

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.

[Rumack BH: POISINDEX(R) Information System. Micromedex, Inc., Englewood, CO, 2001; CCIS Volume 110, edition exp November, 2001. Hall AH & Rumack BH (Eds):TOMES(R) Information System. Micromedex, Inc., Englewood, CO, 2001; CCIS Volume 110, edition exp November, 2001.] **PEER REVIEWED**

Antidote and Emergency Treatment:

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**

FOR LIFE-THREATENING ALLERGIC REACTION TO PYRETHRUM (SEVERE ASTHMA OR ANAPHYLAXIS), GIVE 0.1 TO 0.5 ML OF 1:1000 ADRENALIN INTRAMUSCULARLY, OR SLOWLY INTRAVENOUSLY. REPEAT IF NECESSARY TO RELIEVE RESPIRATORY DISTRESS & MAINTAIN BLOOD PRESSURE. IV AMINOPHYLLINE (10 ML, SLOWLY) MAY BE INDICATED. GIVE HYDROCORTISONE (50-100 MG), OR EQUIVALENT STEROID, INTRAVENOUSLY. LESS SEVERE ALLERGIC REACTIONS (RHINITIS) CAN BE MANAGED WITH ANTIHISTAMINES & DECONGESTANTS, GIVEN ORALLY. HYPERSENSITIVITY PNEUMONITIS MAY REQUIRE OXYGEN, STEROIDS, ANTIBIOTICS & SEVERAL DAYS BEDREST, DEPENDING ON SEVERITY. /PYRETHRUM, PYRETHRINS, PYRETHROIDS, AND PIPERONYL BUTOXIDE/
[Morgan, D.P. Recognition and Management of Pesticide Poisonings. EPA 540/9-80-005. Washington, DC: U.S. Government Printing Office, Jan. 1982. 44]**PEER REVIEWED**

DO NOT ADMIN OR INSTILL MILK, CREAM, OR OTHER SUBSTANCES CONTAINING VEGETABLE OR ANIMAL FATS, WHICH ENHANCE ABSORPTION OF LIPOPHILIC SUBSTANCES, SUCH AS ... PYRETHROIDS. DIAZEPAM (VALIUM (R)), 5-10 MG IN ADULT, 0.1 MG/KG IN CHILDREN, GIVEN ORALLY OR SLOWLY IV, SHOULD CONTROL NERVOUSNESS & TREMORS IN RARE CASES ... AFTER EXTRAORDINARY EXPOSURE TO ... PYRETHROIDS. /PYRETHRUM, PYRETHRINS, PYRETHROIDS, AND PIPERONYL BUTOXIDE/
[Morgan, D.P. Recognition and Management of Pesticide Poisonings. EPA 540/9-80-005. Washington, DC: U.S. Government Printing Office, Jan. 1982. 44]**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-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. A550/Aug 87]**PEER REVIEWED**

Rats fed 300 ppm for 28 days showed severe motor symptoms, and rats fed 150 ppm showed moderate motor symptoms. In both cases these disappeared within 48 hr of reverting to normal diet. Flucythrinate has no teratogenic or mutagenic activity.
[Hayes WJ, Laws ER, eds; Handbook of Pesticide Toxicology V2 p.597 (1991)]**PEER REVIEWED**

In 2 yr feeding trials, rats receiving 60 mg/kg diet showed no ill-effects. Non-mutagenic in the Ames test. No teratogenic effects were observed in investigations on rats and rabbits.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

Non-irritating to skin and eyes (rabbits), but undiluted formulations may be irritating. No skin sensitization.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**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-systemic insecticide with contact action. Causes paralysis initially, with death occurring later. Has some acaricidal activity. /Pyrethrins/
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A357/Aug 87]**PEER REVIEWED**

Non-systemic insecticide with contact and stomach action.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Non-Human Toxicity Values:

LD50 Rat male oral 81 mg/kg
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LD50 Mice female oral 76 mg/kg
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LD50 Rat female oral 67 mg/kg
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LD50 Rabbit percutaneous >1000 mg/kg
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LC50 Rat inhalation 4.85 mg/l air/4 hr
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Ecotoxicity Values:

LD50 Mallard duck oral >2510 mg/kg
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LD50 Bobwhite quail oral 2708 mg/kg
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LC50 Mallard duck dietary 4885 mg/kg diet/8 day
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LC50 Bob white quail dietary 3443 mg/kg diet/8 day
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

LC50 Bluegill sunfish 0.71 ug/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. A550/Aug 87]**PEER REVIEWED**

LC50 Channel catfish 0.51 ug/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. A550/Aug 87]**PEER REVIEWED**

LC50 Rainbow trout 0.32 ug/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. A550/Aug 87]**PEER REVIEWED**

LC50 Sheepshead minnow 1.6 ug/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. A550/Aug 87]**PEER REVIEWED**

LD50 Honey bee 0.078 ug/bee (topical application as a dust)
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Metabolism/Pharmacokinetics:

Metabolism/Metabolites:

Flucythrinate is rapidly metabolized by ester cleavage and oxidation.
[Hayes WJ, Laws ER, eds; Handbook of Pesticide Toxicology V2 p.597 (1991)]**PEER REVIEWED**

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 WJ, Laws ER, eds; Handbook of Pesticide Toxicology V2 p.588 (1991)]**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 WJ, Laws ER, eds; Handbook of Pesticide Toxicology V2 p.588 (1991)]**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:

In rats, following oral administration, 60-70% is eliminated within 24 hours, and >95% within 8 days, in the feces and urine. In the feces, the parent compound makes up most of the material excreted, but in the urine and in tissue, several metabolites are present. The major route of degradation is through hydrolysis, with subsequent hydroxylation of the hydrolysis products.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

/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**


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 WJ, Laws ER, eds; Handbook of Pesticide Toxicology V2 p.588 (1991)]**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**


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:

MEDICATION (VET): ectoparasiticide
[Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 645]**QC REVIEWED**

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:

Flucythrinate's use as an insecticide releases the compound directly to the environment through applications in sprays and other application routes. If released to the atmosphere, flucythrinate will degrade rapidly in the vapor phase by reaction with photochemically produced hydroxyl radicals (estimated half-life of 6 hr). Particulate phase flucythrinate will be removed physically from air by wet and dry deposition. If released to soil or water, flucythrinate can degrade through biodegradation, hydrolysis and photodegradation. Various persistence studies have suggested that flucythrinate will have environmental half-lives of roughly one week to several weeks in soil or natural water. Estimated log Koc values of 4.31-4.75 suggest that partitioning from water to sediment and suspended matter will occur; also these log Koc values suggest that leaching should not occur in most soils. Persistence in sediment is expected to be longer than in the water-phase. Occupational exposure to flucythrinate occurs through dermal contact and inhalation of dust and sprays, especially to workers applying the compound as an insecticide. (SRC)
**PEER REVIEWED**


Probable Routes of Human Exposure:

Occupational exposure to flucythrinate occurs through dermal contact and inhalation of dust and sprays, especially to workers applying the compound as an insecticide(1).
[(1) Parmeggiani L; Encyl Occup Health & Safety 3rd ed. Geneva, Switzerland: International Labour Office pp. 1616-46 (1983)]**PEER REVIEWED**


Artificial Pollution Sources:

Flucythrinate's use as an insecticide(1) releases the compound directly to the environment through applications in sprays and other application routes(1,SRC).
[(1) Worthing CR, Walker SB; The Pesticide Manual 8th ed. Lavenham, Suffolk, England: Lavenham Press Ltd p. 409 (1987)]**PEER REVIEWED**


Environmental Fate:

TERRESTRIAL FATE: In soil, there is low mobility and no leaching with a half- life of ca 2 months.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

AQUATIC FATE: Rapidly hydrolysed in water under alkaline conditions, but more slowly under neutral or acidic conditions.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

TERRESTRIAL FATE: Flucythrinate can degrade in soil through aqueous hydrolysis and biodegradation. Photodegradation can occur on surfaces exposed to sunlight. Flucythrinate hydrolyzes in water with half-lives of 52 days at pH 5 and 6.3 days at pH 9 and 27 deg C(1); hydrolysis will be more important in alkaline soil than in neutral or acidic soil. One sediment persistence study found flucythrinate to have a half-life of about 16 days, with sterile-control tests suggesting that most degradation was occurring through biotic means(2). A field study measured flucythrinate half-lives of 9.4-11.9 days in an agricultural soil(3). A laboratory study using a silt loam soil observed degradations of 28.6-45.6% in 6 weeks under dry conditions(4). Laboratory tests have shown that flucythrinate photodegrades on glass and plant surfaces(5). Estimated Koc values of log 4.31-4.75(6,SRC) suggest that flucythrinate will not leach(SRC).
[(1) Worthing CR, Walker SB; The Pesticide Manual 8th ed. Lavenham, Suffolk, England: Lavenham Press Ltd p. 409 (1987) (2) Schimmel SC et al; J Agric Food Chem 31: 104-13 (1983) (3) Agnihotri NP, Jain HK; Pesticides 31: 163-73 (1987) (4) Smith S, Willis GH; Soil Sci 144: 67-71 (1987) (5) Chattopadhyaya S, Dureja P; Pestic Sci 31: 163-73 (1991) (6) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 5-4, 5-10 (1990)]**PEER REVIEWED**

AQUATIC FATE: Flucythrinate is expected to degrade in water through hydrolysis, biodegradation and photodegradation. It hydrolyzes in water with half-lives of 52 days at pH 5 and 6.3 days at pH 9 and 27 deg C(1); hydrolysis will be more important in alkaline water than in neutral or acidic water. A seawater-sediment persistence study found flucythrinate to have a half-life of about 16 days with sterile-control tests suggesting that most degradation was occurring through biotic means(2). An agricultural water-sediment persistence study found that flucythrinate disappeared entirely within 15 days in the water(3); however, it persisted beyond 20 days in the sediment(3). In a seawater solution study, flucythrinate had a 6.1 day half-life when exposed to sunlight, but only a 38 day half-life under no-sunlight conditions(2) thus suggesting that photodegradation may be important in some environmental waters(SRC). Estimated Koc values of log 4.31-4.75(4,SRC) suggest that partitioning from the water column to sediment and suspended matter will occur(SRC).
[(1) Worthing CR, Walker SB; The Pesticide Manual 8th ed. Lavenham, Suffolk, England: Lavenham Press Ltd p. 409 (1987) (2) Schimmel SC et al; J Agric Food Chem 31: 104-13 (1983) (3) Agnihotri NP, Jain HK; Pesticides 31: 163-73 (1987) (4) Lyman WJ et al; Handbook of Chemical Property Estimation Methods Washington, DC: Amer Chem Soc pp. 5-4, 5-10 (1990)]**PEER REVIEWED**

ATMOSPHERIC FATE: Based upon a reported vapor pressure of 8.7X10-8 mm Hg at 25 deg C(1), flucythrinate can exist in both the vapor and particulate phases in the ambient atmosphere(2,SRC). It will degrade rapidly in the vapor phase by reaction with photochemically produced hydroxyl radicals with an estimated half-life of about 6 hr(3,SRC). Particulate phase flucythrinate and aerosols released to air during spray applications of flucythrinate insecticide will be removed from air physically by dry and wet deposition(SRC).
[(1) Wauchope RD et al; Rev Environ Contam Toxicol 123: 1-36 (1991) (2) Bidleman TF; Environ Sci Technol 22: 361-7 (1988) (3) Atkinson R; Environ Toxicol Chem 7: 435-42 (1988)]**PEER REVIEWED**


Environmental Biodegradation:

In a laboratory study using sediment and seawater collected from a salt marsh near Escambia County, Florida flucythrinate was observed to have a half-life of about 16 days(1); however, when the media were sterilized, flucythrinate showed no appreciable degradation after 28 days of incubation(1), thus suggesting that degradation was occurring through biotic means(SRC).
[(1) Schimmel SC et al; J Agric Food Chem 31: 104-13 (1983)]**PEER REVIEWED**


Environmental Abiotic Degradation:

The rate constant for the vapor phase reaction of flucythrinate with photochemically produced hydroxyl radicals has been estimated to be 6.36X10-11 cu cm/molecule-sec at 25 deg C which corresponds to an atmospheric half-life of about 6 hours at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1,SRC). The aqueous hydrolysis rate of flucythrinate at 27 deg C has been reported as follows(2); 50% loss in 40 days at pH 3, 52 days at pH 5 and 6.3 days at pH 9. Flucythrinate absorbs light strongly in the environmental spectra (>290 nm)(3); when exposed to sunlight, thin films of flucythrinate on glass surfaces were observed to have a half-life of about 8 days(3); on bean leaves, the photodegradation half-life was about 3 days(3); only minor degradation occurred on dark control glass and leaf surfaces(3); the faster rate on leaf surfaces was thought to result from photo-sensitization by chlorophyll and plant waxes(3). In a seawater solution study, flucythrinate had a 6.1 day half-life when exposed to sunlight, but only a 38 day half-life under no-sunlight conditions(4).
[(1) Atkinson R; Environ Toxicol Chem 7: 435-42 (1988) (2) Worthing CR, Walker SB; The Pesticide Manual 8th ed. Lavenham, Suffolk, England: Lavenham Press Ltd p. 409 (1987) (3) Chattopadhyaya S, Dureja P; Pestic Sci 31: 163-73 (1991) (4) Schimmel SC et al; J Agric Food Chem 31: 104-13 (1983)]**PEER REVIEWED**


Environmental Bioconcentration:

Based upon a measured log Kow of 6.20(1) and a water solubility of 0.06 mg/L (taken from the USDA's evaluated database of pesticide properties)(2), the BCF for flucythrinate can be estimated to be 30,000 and 3,000, respectively, from recommended regression-derived equations(3,SRC). In a 28-day laboratory study, a steady-state BCF of 2300 was measured in eastern oysters (Crassostrea virginica)(1).
[(1) Schimmel SC et al; J Agric Food Chem 31: 104-13 (1983) (2) Wauchope RD et al; Rev Environ Contam Toxicol 123: 1-36 (1991) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 5-4, 5-10 (1990)]**PEER REVIEWED**


Soil Adsorption/Mobility:

Based upon a measured log Kow of 6.20(1) and a water solubility of 0.06 mg/L (taken from the USDA's evaluated database of pesticide properties)(2), the log Koc for flucythrinate can be estimated to be 4.75 and 4.31, respectively, from regression-derived equations(3,SRC). According to a suggested classification scheme(4), these estimated Koc values suggest that it is immobile in soil(SRC). In a field study conducted in New Delhi, India (farm soil, pH 8.1 organic content 0.3%) flucythrinate did not leach below a 7.5 cm depth after a 40-day observation period(5).
[(1) Schimmel SC et al; J Agric Food Chem 31: 104-13 (1983) (2) Wauchope RD et al; Rev Environ Contam Toxicol 123: 1-36 (1991) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 5-4, 5-10 (1990) (4) Swann RL et al; Res Rev 85: 23 (1983) (5) Agnihotri NP, Jain HK; Pesticides 31: 163-73 (1987)]**PEER REVIEWED**


Volatilization from Water/Soil:

Based upon a water solubility of 0.06 mg/L(1) and a vapor pressure of 8.7X10-9 mm Hg at 25 deg C(1), the Henry's Law constant for flucythrinate can be estimated to be 8.61X10-8 atm-cu m/mole(SRC). This value of Henry's Law constant indicates flucythrinate is essentially non-volatile from water(2); therefore, volatilization from water will not be an important fate process(SRC).
[(1) Wauchope RD et al; Rev Environ Contam Toxicol 123: 1-36 (1991) (2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-15 to 15-29 (1990)]**PEER REVIEWED**


Environmental Standards & Regulations:

FIFRA Requirements:

Tolerances are established for residues of the insecticide flucythrinate in or on the following raw agricultural commodities: Apples; cabbage; cattle, fat; cattle (meat byproducts and meat); corn (fodder and forage); corn grain; cottonseed; goats, fat; goats (meat byproducts and meat); hogs, fat; hogs (meat byproducts and meat); horses, fat; horses (meat byproducts and meat; lettuce, head; milk; milk, fat; pears; sheep, fat; and sheep (meat byproducts and meat).
[40 CFR 180.400 (7/1/91)]**PEER REVIEWED**

A tolerance is established for residues of the insecticide flucythrinate in or on the food commodity cottonseed oil, resulting from application of the insecticide to the growing crop.
[40 CFR 185.3300 (7/1/91)]**PEER REVIEWED**

A tolerance is established for residues of the insecticide flucythrinate in or on the processed feed apple pomace (dry) when present therein as a result of application of the insecticide to the growing crop.
[40 CFR 186.3300 (7/1/91)]**PEER REVIEWED**

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Flucythrinate is found on List B. Case No: 2290; Pesticide type: Insecticide; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): (+-)-flucythrinate; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."
[USEPA/OPP; Status of Pesticides in Registration, Reregistration and Special Review p.183 (Spring, 1998) EPA 738-R-98-002]**QC REVIEWED**


Acceptable Daily Intakes:

FAO/WHO ADI: 0.02 mg/kg
[FAO/WHO; Pesticide Residues in Food - 1990. Evaluations Part 1 - Residues p.422 Plant Prod Protect Paper 103/1 (1990)]**QC REVIEWED**


Allowable Tolerances:

Tolerances are established for residues of the insecticide flucythrinate in or on the following raw agricultural commodities: Apples: 1.0 ppm; Cabbage: 2.0 ppm; Cattle, fat: 1.0 ppm; Cattle (meat byproducts and meat): 0.1 ppm; Corn (fodder and forage): 3.00 ppm; Corn grain: 0.05 ppm; Cottonseed: 0.1 ppm; Goats, fat: 1.0 ppm; Goats (meat byproducts and meat): 0.1 ppm; Hogs, fat: 1.0 ppm; Hogs (meat byproducts and meat): 0.1 ppm; Horses, fat: 1.0 ppm; Horses (meat byproducts and meat): 0.1 ppm; Lettuce, head: 2.0 ppm; Milk: 0.1 ppm; Milk, fat: 2.0 ppm; Pears: 0.05 ppm; Sheep, fat: 1.0 ppm; and Sheep (meat byproducts and meat): 0.1 ppm.
[40 CFR 180.400 (7/1/91)]**PEER REVIEWED**

A tolerance of 0.2 ppm is established for residues of the insecticide flucythrinate in or on the food commodity cottonseed oil, resulting from application of the insecticide to the growing crop.
[40 CFR 185.3300 (7/1/91)]**PEER REVIEWED**

A tolerance of 10.0 ppm is established for residues of the insecticide flucythrinate in or on the processed feed apple pomace (dry) when present therein as a result of application of the insecticide to the growing crop.
[40 CFR 186.3300 (7/1/91)]**PEER REVIEWED**


Chemical/Physical Properties:

Molecular Formula:

C26-H23-F2-N-O4
[Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 645]**PEER REVIEWED**


Molecular Weight:

451.48
[Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 645]**PEER REVIEWED**


Color/Form:

Viscous liquid
[Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 645]**PEER REVIEWED**


Boiling Point:

108 deg C at 0.35 mm Hg
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Density/Specific Gravity:

1.189 at 22 deg C
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Solubilities:

Sol in acetone, xylene, 2-propanol
[Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 645]**PEER REVIEWED**

In water at 21 deg C, 0.5 mg/l. In ... corn oil 560, cottonseed oil 300, soya bean oil 300, hexane 90 (all in g/l at 21 deg C).
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Spectral Properties:

Index of refraction: 1.541 at 25 deg C/D
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Vapor Pressure:

0.0012 mPa at 25 deg C
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Other Chemical/Physical Properties:

Dark amber viscous liquid, with a faint ester-like odor. /Technical flucythrinate/
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Chemical Safety & Handling:

Skin, Eye and Respiratory Irritations:

Immediately irritating to the eye. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**

The chief effect from exposure ... is skin rash particularly on moist areas of the skin. ... May irritate 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. 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:

Incompatibility: Strong oxidizers. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**

... Incompatible with lime & ordinary soaps because acids & alkalies speed up processes of hydrolysis. /Pyrethrins/
[Farm Chemicals Handbook 1986. Willoughby, Ohio: Meister Publishing Co., 1986.,p. C-198]**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 and pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**

Wear eye protection to prevent: Reasonable probability of eye contact. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**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. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**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. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**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. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**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. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**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. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**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. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**


Preventive Measures:

Use with adequate ventilation, and wear goggles or a face shield when handling.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

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. /Pyrethrum/
[Farm Chemicals Handbook 1986. Willoughby, Ohio: Meister Publishing Co., 1986.,p. C-198]**PEER REVIEWED**

Contact lenses should not be worn when working with this chemical. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**

Workers should wash: Promptly when skin becomes contaminated. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**

Work clothing should be changed daily: If it is reasonably probable that the clothing may be contaminated. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**PEER REVIEWED**

Remove clothing: Promptly if it is non-impervious clothing that becomes contaminated. /Pyrethrins/
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 190]**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**

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.
**QC REVIEWED**


Stability/Shelf Life:

Stable to light.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

Stable for > 1 year at 37 deg C, > 2 years at 25 deg C. /Technical flucythrinate/
[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. 409]**PEER REVIEWED**

Hydrolysis rates (half-lives in days): ca 40 at pH3, 52 at pH6, 6.3 at pH 9, 40 in distilled water (all at 27 deg C; ca 40 at pH 3, 31 at pH 6, 2.6 at pH 9, 29 in distilled water (all at 35 deg C).
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

Pyrethrins ... /are/ stable for long periods in water-based aerosols where ... emulsifiers give neutral water systems. /Pyrethrins/
[Farm Chemicals Handbook 1986. Willoughby, Ohio: Meister Publishing Co., 1986.,p. C-198]**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:

Spillages of pesticides at any stage of their storage or handling should be treated with great care. Liquid formulations may be reduced to solid phase by evaporation. Dry sweeping of solids is always hazardous: these should be removed by vacuum cleaning, or by dissolving them in water, or other solvent in the factory environment. /Pesticides/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 1619]**PEER REVIEWED**

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:

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**

Group I Containers: Combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) should be disposed of in pesticide incinerators or in specified landfill sites. /Organic or metallo-organic pesticides/
[40 CFR 165.9(a) (7/1/90)]**PEER REVIEWED**

Group II Containers: Non-combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) must first be triple-rinsed. Containers that are in good condition may be returned to the manufacturer or formulator of the pesticide product, or to a drum reconditioner for reuse with the same type of pesticide product, if such reuse is legal under Department of Transportation regulations (eg 49 CFR 173.28). Containers that are not to be reused should be punctured ... and transported to a scrap metal facility for recycling, disposal or burial in a designated landfill. /Organic or metallo-organic pesticides/
[40 CFR 165.9(b) (7/1/90)]**PEER REVIEWED**


Occupational Exposure Standards:

Manufacturing/Use Information:

Major Uses:

The active ingredient is no longer contained in any registered pesticide products ... "cancelled."
[USEPA/OPP; Status of Pesticides in Registration, Reregistration and Special Review p.183 (Spring, 1998) EPA 738-R-98-002]**QC REVIEWED**

Control of a wide range of insect pests, particularly on cotton (bollworms, leafworms, sucking insects, whiteflies, beetles, etc) and fruit trees (Lepidoptera, Homoptera, Coleoptera, etc). Also used on vines, strawberries, citrus fruit, bananas, pineapples, olives, coffee, cocoa, hops, vegetables, soya beans, cereals, maize, lucerne, sugar beet, sunflowers, tobacco, and ornamentals. Efficacy at higher temperatures is greater than for several other pyrethroid insecticides.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**

Insecticide /Pyrethrins/
[Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 1267]**PEER REVIEWED**

MEDICATION (VET)
**QC REVIEWED**

MEDICATION
**QC REVIEWED**


General Manufacturing Information:

Synthetic pyrethroid insecticide with contact and stomach poison activity.
[Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989. 645]**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; ULV liquid; water-dispersible granules.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Laboratory Methods:

Analytic Laboratory Methods:

Product analysis is by high performance liquid chromatography and gas liquid chromatography. Residues may be determined by gas liquid chromatography.
[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. 410]**PEER REVIEWED**

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:

Clark JR et al; Toxicity of pyrethroids to Marine Invertebrates and Fish: A Literature Review and Test Results with Sediment-Sorbed Chemicals. Environ Toxicol Chem 8 (5): 393-401 (1989). Data on acute and chronic toxicity of permethrin, fenvalerate, cypermethrin, and flucythrinate to marine invertebrates and fishes are reviewed.

Miyamoto J; Environ Health Perspect 14: 15-28 (1976). Degradation, metabolism, and toxicity of synthetic pyrethroids.

Miyamoto J, et al; Pure Appl Chem 53: 1967-2022 (1981). The chemistry, metabolism, and residue analysis of synthetic pyrethroids.

Hutson DH; Progress in Drug Metabolism 3: 215-252 (1979). The metabolic fate of synthetic pyrethroid insecticides in mammals.

Gammon DW; Fundam Appl Toxicol (5) 1: 9-23 (1985). Correlations between in vitro and in vivo mechanisms of pyrethroid insecticide action.

Casida JE et al; Ann Rev Pharmacol Toxicol 23: 413-38 (1983). The mechanisms of selective action of pyrethroid insecticide are discussed.

Papadopoulou-Mourkidou E; Residue Rev 89: 179-208 (1983). A review with many references on analysis of allethrin & other pyrethroid insecticides.


Synonyms and Identifiers:

Synonyms:

AC-222705
**PEER REVIEWED**

(+ -)-cyano-(3-phenoxyphenyl)methyl (+)-4-(difluoromethoxy)-alpha-(methylethyl) benzeneacetate
**PEER REVIEWED**

Cybolt
**PEER REVIEWED**

Cythrin
**PEER REVIEWED**

4-(Difluoromethoxy)-alpha-(1-methylethyl)benzeneacetic acid cyano(3-phenoxy- phenyl)methyl ester
**PEER REVIEWED**

Guardian
**PEER REVIEWED**

Pay-off
**PEER REVIEWED**

(RS)-alpha-cyano-3-phenoxybenzyl (S)-2-(4-difluoromethoxyphenyl)-3- methylbutyrate
**PEER REVIEWED**

(RS)-cyano-(3-phenoxyphenyl)methyl (S)-4-(difluoromethoxy)-alpha-(1-methylethyl) -benzeneacetate
**PEER REVIEWED**

Stock Guard
**PEER REVIEWED**


Formulations/Preparations:

Emulsifiable concentrate; ULV liquid; water-dispersible granules.
[Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987.,p. A550/Aug 87]**PEER REVIEWED**


Administrative Information:

Hazardous Substances Databank Number: 6647

Last Revision Date: 20010808

Last Review Date: Reviewed by SRP on 3/11/1993


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 03/13/2000, 2 fields 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 06/08/1999, 6 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.
Complete Update on 03/17/1997, 2 fields added/edited/deleted.
Complete Update on 02/28/1997, 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, 59 fields added/edited/deleted.