CAS No. 68359-37-5

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ACTIVITY: Insecticide (pyrethroid)

CAS Name: Cyclopropanecarboxylic acid, 3-(2,2-dichloroethenyl)-2,2-dimethyl-, cyano (4-fluoro-3-phenoxyphenyl)methyl ester

Note: CAS No. 68359-37-5 for cyfluthrin and beta-cyfluthrin is the same

Structure for Cyfluthrin:

Adverse Effects:

Body Weight Decrease

Environmental Effects:

Highly toxic to Fish, Aquatic Invertebrates.

High risk to Honey Bees and other Arthropod species.

Regulatory Information
(only comprehensive for the US)
US EPA Registered: Yes
US EPA PC Code: 128831
California Chemical Code 3956
Registered use in
(includes only a limited list of countries)

Australia, Denmark, Finland, Germany, Hungary, Madagascar, New Zealand, South Africa, Tanzania, Uganda, US (See Beta-cyfluthrin active products)

Maximum Residue Levels permitted in food commodities

EU: Almonds

Other Information
Molecular Formula: C22H18Cl2 F NO3
Entry Year: 1991 
Manufacturers: Bayer  
Other Names: See Beta-cyfluthrin active products
also, Bay, Bulldock, Ducat,
FCR 4545, OMS 3051
Manufacture site:

Mitchell Cotts
Chemicals Ltd.,
Mirfield West Yorkshire

Of special interest:
PAN Data
Material Safety Data Sheets & Labels

2004-2006 - US EPA CHEERS study in Jacksonville, Duval County, Florida. This 2-year study of children's exposure to selected pesticides and chemicals has ignited enormous controversy. Cyfluthrin (I, II, III, IV, total) was one of 16 pesticides selected to be monitored in children (ages 0-3 years). See FAN's updates on this study. Also, 4-fluoro-3-phenoxybenzoic acid, (CAS No. 77279-89-1), a breakdown product of Cyfluthrin, will be analyzed in biological media. It's molecular structure is

Note: the CDC's "Third National Report on Human Exposure to Environmental Chemicals," expected to be released sometime in 2005, includes 4-fluoro-3-phenoxybenzoic acid in its list of chemicals.

December 2002 - beta-cyflutrin: Review report for the active substance beta-cyfluthrin Finalised in the Standing Committee on the Food Chain and Animal Health at its meeting on 3 December 2002 in view of the inclusion of beta-cyfluthrin in Annex I of Directive 91/414/EEC. EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE- Also available at:
June 2002 - beta-cyfluthrin: In Australia when Beta-cyfluthrin is used "As the active constituent in contained bait stations used in orange, mandarin, mango, lychee, carambola and persimmon trees, where direct contact will not occur with the fruit" no maximum residue levels are required. Ref: June 2002. Table 5. Uses of substances where maximum residue limits are not necessary. Australian National Registration Authority for Agricultural Veterinary Chemicals. The MRL Standard. Maximum residue limits in food and animal feedstuff.
April 17, 2002. Bayer's acquistion of Aventis. Discussion of beta-cyfluthrin and cyfluthrin. European Commission press release.
December 10, 2001 - beta-cyfluthrin / cyfluthrin. Australia: "Current List. RECORD OF APPROVED ACTIVE CONSTITUENTS FOR CHEMICAL PRODUCTS."

Toxicol Sci. 2006 Jan;89(1):271-7.
Relative potencies for acute effects of pyrethroids on motor function in rats.

Wolansky MJ, Gennings C, Crofton KM.

National Research Council, Research Triangle Park, North Carolina 27711, USA.

The prevalence of pyrethroids in insecticide formulations has increased in the last decade. A common mode-of-action has been proposed for pyrethroids based on in vitro studies, which includes alterations in sodium channel dynamics in nervous system tissues, consequent disturbance of membrane polarization, and abnormal discharge in targeted neurons. The objective of this work was to characterize individual dose-response curves for in vivo motor function and calculate relative potencies for eleven commonly used pyrethroids. Acute oral dose-response functions were determined in adult male Long Evans rats for five Type I (bifenthrin, S-bioallethrin, permethrin, resmethrin, tefluthrin), five Type II (beta-cyfluthrin, lambda-cyhalothrin, cypermethrin, deltamethrin, esfenvalerate) and one mixed Type I/II (fenpropathrin) pyrethroids (n = 8-18 per dose; 6-11 dose levels per chemical, vehicle = corn oil, at 1 ml/kg). Motor function was measured using figure-8 mazes. Animals were tested for 1 h during the period of peak effects. All pyrethroids, regardless of structural class, produced dose-dependent decreases in motor activity. Relative potencies were calculated based on the computed ED30s. Deltamethrin, with an ED30 of 2.51 mg/kg, was chosen as the index chemical. Relative potency ratios ranged from 0.009 (resmethrin) to 2.092 (esfenvalerate). Additional work with environmentally-based mixtures is needed to test the hypothesis of dose-additivity of pyrethroids.

Note: Of the pesticides cited above, the following are fluorinated: bifenthrin, tefluthrin, beta-cyfluthrin, lambda-cyhalothrin.

1999. FAO Specificiations and Evaluations for Plant Protection Products. Uses: beta-cyfluthrin is an insecticide, acting as a contact and stomach poison. It combines a rapid knock-down effect with long lasting efficacy. It is not systemic in plants. It is used in agriculture, horticulture (field and protected crops) and viticulture. It is also used against migratory locusts and grasshoppers and in public health and hygiene.
Insecticide products - partial list

Beta-cyfluthrin and cyfluthrin have the same toxicological profile. Beta-cyfluthrin has an approximately 2 to 5 times higher acute toxicity than cyfluthrin. The NOELs of subacute and subchronic studies are in the same range.
Ref: December 2002 - Beta-cyflutrin: Review report for the active substance beta-cyfluthrin Finalised in the Standing Committee on the Food Chain and Animal Health at its meeting on 3 December 2002 in view of the inclusion of beta-cyfluthrin in Annex I of Directive 91/414/EEC. EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL

US Federal Register

Date Published Docket Identification Number Details
November 8, 2006 EPA-HQ-OPP-2006-0084

Notice of Receipt of Requests to Voluntarily Cancel Certain
Pesticide Registrations

EPA Registration Number Product Name Registrant
000264 AL-06-0004 Baythroid XL Bayer Cropscience LP
2 T.W. Alexander Drive, Research
Triangle Park NC 27709
March 4, 2004 ORD-2003-

Announcement: Longitudinal Study of Young Children's Exposures in their Homes to Selected Pesticides, Phthalates, Brominated Flame Retardants, and Perfluorinated Chemicals (A Children's Environmental Exposure Research Study--CHEERS).

Abstract: The U.S. EPA's Office of Research and Development's National Exposure Research Laboratory proposes to conduct a two-year longitudinal field measurement study of young children's (aged 0 to 3 years) potential exposures to current-use pesticides and selected phthalates, polybrominated diphenyl ethers, and perfluorinated compounds that may be found in residential environments. The study will be conducted in Duval County, Jacksonville, Florida over a two-year period from 2004 to 2006. Sixty young children will be recruited into this study in two cohorts: (1) infants recruited into the study soon after birth, and, (2) children recruited into the study at approximately 12 months of age.

Part A: Supporting Statement - EPA ICR Number: 2126.01 - 61 pages
From Table 2:
• Of 16 pesticides included in this study, 4 are fluorinated:
Bifenthrin, Fipronil, lamda-Cyhalothrin, and Cyfluthrin I, II, III, IV, total
• Perfluorinated chemicals:
Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS)

From Table 3: List of chemicals to be analyzed in biological media:
• one is fluorinated: 4-fluoro-3-phenoxybenzoic acid
• Perfluorooctanoic acid/Perfluorooctane sulfonate

•• See Update on CHEERS study

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