PANNA: Action Alert: Cotton Pesticide Poses Reproductive Risks to Birds


Pesticide Action Network Updates Service (PANUPS)

Action Alert: Cotton Pesticide Poses Reproductive Risks to Birds

February 8, 1999

The American Bird Conservancy’s Pesticides and Birds Campaign urges the scientific, conservation and advocacy communities to call on the U.S. Environmental Protection Agency (EPA) to deny registration of the insecticide chlorfenapyr because of reproductive risks to birds. Chlorfenapyr has been characterized by EPA as “one of the most reproductively toxic pesticides to avian species that Environmental Fate and Effects Division has evaluated.” Because of the agency’s concerns regarding ecological risks, EPA’s Office of Pesticide Programs has opened a public comment period through February 19.

American Cyanamid has proposed use of chlorfenapyr (brand names Pirate and Alert) as an insecticide and miticide on cotton. It is touted as one of the most effective controls available for beet armyworm in chemically intensive cotton agriculture. Applications for use on citrus and vegetables and for termites and ants are also pending. Chlorfenapyr belongs to a new class of chemical called “pyrrole” — never before registered by EPA. When metabolized, it acts on the mitochondria and disrupts production of ATP (adenosine triphosphate), leading to cell death and, ultimately, mortality.

The following ecological concerns are detailed in the EPA risk assessment:

** In a chronic reproductive study of mallards, declines were seen in number of eggs laid (-41%), number of viable embryos (-44%), and number of normal hatchlings (-56%). A decrease in body weight of adult males and females (males: -14%; females -15%) was also evident and in females appeared in the first few weeks of exposure.

** American Cyanamid’s testing shows chlorfenapyr to be persistent in soils, with a half-life of one or more years. Applications made to the same fields in consecutive years can result in a build-up in the soil to as much 2.5 times the annual application rate. Such persisting residues could contribute to levels of dietary exposure higher than those suggested by a single year of application.

** Chlorfenapyr residues are found in avian food items including weed seeds, insects and foliage. Levels of chlorfenapyr in avian diets may be as much as 68 times higher than the EPA threshold for reproductive effects, and EPA states that these toxicological thresholds may be exceeded for up to five weeks after initial application to cotton crops.

** The timing of chlorfenapyr applications coincides with critical reproductive events for most, if not all, of the more than 50 avian species that, according to American Cyanamid, are associated with cotton fields. Many of the tested species are showing downward population trends in cotton growing states.

American Cyanamid has proposed numerous mitigation measures and restrictions for use of chlorfenapyr; however, EPA believes that such measures “still yield dietary exposure estimates that exceed chronic toxicity thresholds for birds.” In addition, EPA’s risk assessment does not include effects of ingestion of the chemical through preening or via drinking water, dermal exposures or inhalation of suspended particles. American Cyanamid also has not provided a field study of chlorfenapyr that specifically addresses avian reproductive effects.

At least 13 pesticides documented as causing die-offs in migratory birds are currently registered for use on cotton. The American Bird Conservancy is concerned that the addition of another chemical with evidence of reproductive risks for avian species is imprudent.

Send comments to the EPA by February 19 asking EPA to deny registration status for chlorfenapyr under Section 3 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) given its reproductive toxicity for birds. In addition, call for EPA to discontinue the registration process for all other applications of chlorfenapyr. Comments that add scientific information on chlorfenapyr and its particular effects on avian species are extremely valuable, as are comments on the scientific soundness of EPA’s ecological risk and/or economic benefit characterizations.

Include docket number OPP-34162 and send to:

Public Information and Records Integrity Branch, Information Resources and Services Division (7502C), Office of Pesticides Programs, Environmental Protection Agency, 401 M St. SW, Washington DC 20460. Email can be sent to opp-docket@ as an ASCII attachment without special characters or encryption codes.

Full text of the chlorfenapyr risk benefit assessment can be found at: Additional information can be found at the American Bird Conservancy web site:

Source/contact: Kelley R. Tucker, Director, Pesticides and Birds Campaign, American Bird Conservancy, 1250 24th St. NW, Washington, DC 20037; phone (202) 778-9666; fax (202) 778-9778; email



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