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The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.

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E X T O X N E T

Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996

Flucythrinate

Trade and Other Names:Trade names include AASTAR, AC 222705, Cybolt, Fuching Jujr, OMS 2007, and Pay-Off.

Regulatory Status: Flucythrinate is a highly toxic pesticide in EPA toxicity class I. Pesticides containing flucythrinate must bear the Signal Word DANGER on the product label because of its high oral toxicity and potential to cause eye irritation. For some applications, flucythrinate may be classified as a Restricted Use Pesticide (RUP) by the EPA. RUPs may be purchased and used only by certified applicators.

Chemical Class: pyrethroid

Introduction: Flucythrinate is a synthetic pyrethroid used to control insect pests in apples, cabbage, field corn, head lettuce, and pears, and to control Heliothis spp. in cotton, which is its primary use. It is available in emulsifiable concentrate, water-dispersible granules and wettable powder formulations. The AASTAR product also contains phorate, and it may also be found in formulation with chlorpyrifos, dimethoate, methomyl, or phenthoate. Unless otherwise stated, the information presented here refers to the technical product.

Formulation: It is available in emulsifiable concentrate, water-dispersible granules, and wettable powder formulations. The AASTAR product also contains phorate, and it may also be found in formulation with chlorpyrifos, dimethoate, methomyl, or phenthoate. Unless otherwise stated, the information presented here refers to the technical product.

Toxicological Effects:

• Acute toxicity: Flucythrinate is highly toxic via the oral route. The oral LD50 for technical flucythrinate is 81 mg/kg in male rats [35], 67 mg/kg in female rats and 76 mg/kg in mice [12]. Flucythrinate is moderately toxic via the dermal route with a reported dermal LD50 in rabbits of greater than 1000 mg/kg and in guinea pigs of greater than 2000 mg/kg [36]. Flucythrinate can cause mild to severe skin irritation [35]. It failed to produce allergic reactions in guinea pigs [2,36]. Skin application on human volunteers caused more severe paresthesia (i.e., abnormal sensations such as burning or tingling) on the earlobes than on the forearms. This condition lasted for approximately 24 hours after application on earlobes and 4 to 5 hours on forearms [36]. When 13.8 mg/cm2 was applied to the forearms of volunteers, paresthesia appeared 4 to 5 hours later and lasted for 3 days [36]. Flucythrinate may also cause extreme eye irritation [36]. Flucythrinate is moderately toxic via the inhalation route. The 4-hour inhalation LC50 for technical flucythrinate in rats is 4.85 mg/L [12].
• Chronic toxicity: Rats fed 15 mg/kg/day for 28 days showed severe motor symptoms (involuntary muscular movement), and rats fed 7.5 mg/kg/day showed moderate motor symptoms. In both cases, symptoms disappeared within 48 hours after resumption of a normal diet [2]. Symptoms exhibited by animals in other short-term feeding studies include vomiting, diarrhea, incoordination, excessive salivation and urination, and hypersensitivity [2]. No adverse effects were observed when rats and dogs were fed flucythrinate for 90 days at doses of up to 3 mg/kg/day for rats and 3.75 mg/kg/day for dogs [35]. Dogs fed 7.5 mg/kg/day for 2 years exhibited vomiting and decreased body weight gain. Rats fed 6 mg/kg/day for 2 years also exhibited decreased body weight gain [2].
• Reproductive effects: In a three-generation reproductive study, rats given 1.5, 3 or 6 mg/kg/day showed reduced parental and pup weights, and decreased pup survival. Reduced litter size occurred at 3 and 6 mg/kg/day [2,35]. It is unlikely that reproductive effects due to flucythrinate will be seen under normal circumstances in humans.
• Teratogenic effects: Flucythrinate does not cause birth defects [12]. No teratological effects were observed in studies with rats or rabbits [12]. The highest dose tested was 8.0 mg/kg/day for rats and 60 mg/kg/day for rabbits [35].
• Mutagenic effects: Ames tests using several strains of bacteria exposed to concentrations as high as 1000 ug/plate and a rat dominant-lethal test at up to 10.0 mg/kg showed no evidence that flucythrinate causes mutations [2,35].
• Carcinogenic effects: No tumor formation was observed in mice or rats fed doses of up to 6 mg/kg for 24 months [11].
• Organ toxicity: Pyrethroids primarily affect the central nervous system. Long-term, high-dose feeding studies have shown liver and kidney effects.

• Fate in humans and animals: Flucythrinate is rapidly metabolized in mammals [12]. When flucythrinate was administered orally to rats, 15 to 24% was eliminated in the urine and 37 to 65.6% was eliminated in the feces during the first 24 hours. Within 8 days, 95.8 to 100% of the dose was eliminated in either urine or feces. A large amount of the chemical recovered in the feces was unaltered flucythrinate, suggesting that this portion passed through the gut without being absorbed into the bloodstream [36]. Metabolites of flucythrinate are considered to be of no toxicological significance [11].

Ecological Effects:

• Effects on birds: Pyrethroids are practically non-toxic to bird species. The oral LD50 for flucythrinate in the mallard duck is greater than 2510 mg/kg and in the bobwhite quail is 2708 mg/kg, and the 8-day dietary LC50s are 4885 ppm and 3443 ppm in mallard ducks and bobwhite quail, respectively [12].
• Effects on aquatic organisms: The pyrethroid insecticides are very highly toxic to fish with 96-hour LC50 values generally below .001 mg/L in many species tested [12,20]. Fish sensitivity to the pyrethroids may be explained by their relatively slow metabolism and elimination of these compounds. The half-lives for elimination of several pyrethroids by trout are all greater than 48 hours, while elimination half-lives for birds and mammals range from 6 to 12 hours [21]. Flucythrinate accumulated in the edible tissues of bluegill sunfish to 487 times the concentration in surrounding waters [37].
• Effects on other organisms: The compound is highly toxic to bees, with a reported topical application (contact) LD50 of 0.078 ug per bee [12].

Environmental Fate:

• Breakdown in soil and groundwater: Flucythrinate is of low to moderate persistence with reported field half-lives of 21 to 60 days [25]. Observed persistence will vary according to soil type and other variables. Most residues will be found in the top 3 inches of soil [37]. It is nearly insoluble in water and has a very strong tendency to bind to soil particles [25]. Therefore, it is unlikely to be mobile or to contaminate groundwater.
• Breakdown in water: In pond waters and in laboratory degradation studies, pyrethroid concentrations decrease rapidly due to sorption to sediment, suspended particles, and plants. Microbial and photodegradation also occur [37].
• Breakdown in vegetation: No data are currently available.

Physical Properties:

• Appearance: Flucythrinate is a dark amber, viscous liquid with a faint odor.
• Chemical Name: (R,S)-alpha-cyano-3-phenoxybenzyl-(S)-2-(4-difluoromethoxyphenyl)-3-methylbutyrate [12]
• CAS Number: 70124-77- 5
• Molecular Weight: 451.40
• Water Solubility: 0.5 mg/L @ 21 C [12], insoluble in water
• Solubility in Other Solvents: s. in acetone, xylene, isopropanol, and most organic solvents [12]
• Melting Point: Not Available
• Vapor Pressure: 0.0012 mPa @25 C [12]
• Partition Coefficient: 2.0792 [12]
• Adsorption Coefficient: 100,000 [25]

Exposure Guidelines:

• ADI: 0.02 mg/kg/day [29]
• MCL: Not Available
• RfD: Not Available
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

American Cyanamid Co.
One Cyanamid Plaza
Wayne, NJ 07470-8426

• Phone: 201-831-2000
• Emergency: 201-835-3100
  

References:

References for the information in this PIP can be found in Reference List Number 2

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.