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Final Risk Mitigation Decision for Ten Rodenticides
Current as of May 28, 2008
After fully assessing human health and ecological effects, as well as benefits, EPA is announcing measures to reduce risks associated with ten rodenticides:
- Brodifacoum
- Bromadiolone
- Bromethalin
- Chlorophacinone
- Cholecalciferol
- Difenacoum
- Difethialone
- Diphacinone
- Warfarin
- Zinc phosphide
New safety measures announced by the U.S. Environmental Protection Agency will protect children from accidental exposure to rodent-control products. These measures will also reduce the risk of accidental poisonings of pets and wildlife. With the Agency's risk mitigation measures in place, rodenticide products will be safe, effective, and affordable for all consumers.
On this page:
- Rodenticide Safety Concerns
- Final Risk Mitigation Measures
- Summary of New Restrictions
- Proposed Mitigation Measures are Protective and Flexible
- Integrated Pest Management Will Improve Effectiveness
- More Information
Rodenticide Safety Concerns
Rodenticides are important products for controlling mice, rats and other rodents that pose threats to public health, critical habitats, native plants and animals, crops, and food supplies. However, these products also present human and environmental safety concerns.
Exposures to Children - Rodenticides are an important tool for public health pest control, including controlling mice and rats around the home; however, the use of these products has been associated with accidental exposures to thousands of children each year. Fortunately, only a small number of exposed children experience medical symptoms or suffer adverse health effects as a result of their exposure.
The Agency believes, however, that the number of exposure incidents is unacceptably high. Further, data indicate that children in low income families are disproportionately exposed. EPA's risk mitigation measures address this situation by significantly reducing the likelihood of rodenticide exposure to children, including those children who may be disproportionately at risk for exposure.
Risks to Wildlife - Rodenticides pose significant risks to non-target wildlife including birds, such as hawks and owls, and mammals, including raccoons, squirrels, skunks, deer, coyotes, foxes, mountain lions, and bobcats. Rodenticides applied as bait products pose risks to wildlife from primary exposure (direct consumption of rodenticide bait) and secondary exposure (predators or scavengers consuming prey with rodenticides present in body tissues). Several reported incidents have involved Federally listed threatened and endangered species, for example the San Joaquin kit fox and Northern spotted owl, in addition to the Bald eagle, which is protected under the Bald and Golden Eagle Act.
Differences Among the Rodenticides - The ten rodenticide active ingredients covered by this action can be divided into three categories:
- first-generation anticoagulants: warfarin, chlorophacinone, and diphacinone;
- second-generation anticoagulants: brodifacoum, bromadiolone, difenacoum, and difethialone; and
- non-anticoagulants: bromethalin, cholecalciferol and zinc phosphide.
The anticoagulants interfere with blood clotting, and death can result from excessive bleeding. Bromethalin is a nerve toxicant that causes respiratory distress. Cholecalciferol is vitamin D3, which in small dosages is needed for good health in most mammals, but in massive doses is toxic, especially to rodents. Zinc phosphide causes liberation of toxic phosphine gas in the stomach.
The second-generation anticoagulants are especially hazardous for several reasons. They are highly toxic, and they persist a long time in body tissues. The second-generation anticoagulants are designed to be toxic in a single feeding, but since time-to-death is several days, rodents can feed multiple times before death, leading to carcasses containing residues that may be many times the lethal dose. Predators or scavengers that feed on those poisoned rodents may consume enough to suffer harm.
Final Risk Mitigation Measures
EPA's decision reduces rodenticide exposures to children and wildlife, while still allowing residential users, livestock producers, and professional applicators access to a variety of effective and affordable rodent control products.
Childrens' Risk Mitigation - To minimize children's exposure to rodenticide products used in homes, EPA is requiring that all rodenticide bait products available for sale to consumers be sold only in bait stations. Loose bait such as pellets will be prohibited as a bait form. A range of different types of bait stations will meet the new requirements, providing flexibility in cost.
- Tier 1 – Tamper-resistant for children and dogs; weather resistant; tested according to EPA protocols; indoor and outdoor use;
- Tier 2 – Tamper-resistant for children and dogs; tested according to EPA protocols; indoor use only;
- Tier 3 – Tamper-resistant for children; tested according to EPA protocols; indoor use only; and,
- Tier 4 – Self-certification; packaging not reasonably anticipated to release other than small quantities of bait; resistant to opening by a child less than six years old; indoor use only; non-refillable (one-time-use only).
Tiered Bait Station Requirements for Consumer-Use Products
Ecological Risk Mitigation - To reduce wildlife exposures and ecological risks, EPA will require sales and distribution and packaging restrictions for products containing four of the ten rodenticides that pose the greatest risk to wildlife (the second-generation anticoagulants – brodifacoum, bromadiolone, difenacoum, and difethialone) to prevent purchase on the consumer market.
- The terms and conditions of registration for products containing brodifacoum, bromadiolone, difenacoum, and difethialone must be amended to specify that the registrants will control distribution of the products so that they shall only be distributed to or sold in agricultural, farm and tractor stores or directly to PCOs and other professional applicators, and that registrants will not sell or distribute products containing brodifacoum, bromadiolone, difenacoum, and difethialone in channels of trade likely to result in retail sale in hardware and home improvement stores, grocery stores, convenience stores, drug stores, club stores, big box stores, and other general retailers.
- The Agency is requiring second-generation anticoagulant bait products to be sold in packages that contain ≥ 8 pounds of bait for products that are labeled for use only inside of and around agricultural buildings, and not for use in and around homes.
- For second-generation anticoagulant bait products intended for use by professional applicators, the minimum permissible amount of bait per package is 16 pounds.
- For second-generation anticoagulant bait products in packages with at least 8 but not more than 16 pounds of bait, labels must state that products may only be used in and around agricultural buildings (e.g., barns, hen houses), and bear the statement “Do not use this product in homes or other human residences.”
Sale and Distribution Restrictions
Minimum Package Size Requirements
Use Site Restriction
Summary of New Restrictions
“Consumer Size” Products (Products containing ≤ 1 pound of bait)
- May not contain brodifacoum, difethialone, bromadiolone, or difenacoum (the second-generation anticoagulants)
- Loose bait forms such as pellets are prohibited
- Each retail unit must include a pre-loaded bait station
- Bait refills may be sold with pre-loaded bait stations in a single retail unit
Second-Generation Anticoagulant Products for Use Around Agricultural Buildings
- Products must contain at least eight pounds of bait.
- Bait stations are required for all outdoor, above-ground placements of second-generation anticoagulant products.
- Bait stations are required indoors if exposure to children, pets, or non-target animals is possible.
- Product labels must indicate that the product is for use only in and around agricultural buildings and that use in residential use sites is prohibited.
- Distribution to and sales in “consumer” stores including grocery stores, drug stores, hardware stores, club stores will be prohibited.
Second-Generation Anticoagulant Products for Professional Applicators
- Products must contain at least 16 pounds of bait.
- Bait stations are required for all outdoor, above-ground placements of second-generation anticoagulants.
- Bait stations are required indoors if exposure to children, pets, or non-target animals is possible.
- Distribution to and sales in “consumer” stores including grocery stores, drug stores, hardware stores, club stores will be prohibited.
Proposed Mitigation Measures are Protective and Flexible
In January 2007, to decrease the incidence of children's accidental exposures to rodenticides, EPA proposed a requirement that all rodenticides sold "over the counter" for residential use be available only in tamper-resistant bait stations. The proposal also included a requirement that the second-generation anticoagulants be classified for restricted use, to minimize impacts on non-target wildlife.
EPA's final rodenticide decision achieves the same goal of protection of children and wildlife. In response to comments concerning the costs of tamper-resistant bait stations to protect children and pets, the Agency adopted a tiered bait station system that allows for a variety of effective bait stations at a range of prices. Provisions are also being put into place to prevent the sale and distribution of the more highly toxic products on the consumer market, while maintaining their availability for agricultural production and pest control operators. EPA believes that these steps will significantly reduce the amount of product in the environment, providing additional protection for wildlife from poisonings by these more toxic and persistent products.
The Agency also evaluated and incorporated comments in its final decision from a wide range of stakeholders, and continues its discussions with several federal agencies, including the Centers for Disease Control, the the Department of Housing and Urban Development, the U.S. Department of Agriculture, and the U.S. Fish and Wildlife Service.
Integrated Pest Management Will Improve Effectiveness
Integrated pest management (IPM), a multi-faceted approach to pest control, is essential for effective management of rodents in and around households. In most situations, mice and rats cannot be controlled using rodenticides alone. Effective rodent control also requires sanitation, rodent-proofing, and removal of rodent harborage. Without habitat modification to make an area less attractive to rodents, even eradication will not prevent new populations from recolonizing the area. Non-chemical devices such as snap traps are also affordable and effective methods for rodent control.
EPA is working in partnerships with the Centers for Disease Control and Prevention (CDC) and the Department of Housing and Urban Development (HUD) to promote IPM in low-income housing and other settings where pest pressures are significant.
For More Information
EPA's Final Risk Mitigation Decision for Ten Rodenticides (May 28, 2008) and supporting documents are available in docket EPA-HQ-OPP-2006-0955 at Regulations.gov.
The Final Risk Mitigation Decision for Ten Rodenticides (May 28, 2008) (PDF) (60 pp, 2.8 MB, about PDF) is available from the docket in Regulations.gov.
The Controlling Rodents Web page provides information about preventing, identifying, and treating rodent infestations. It also addresses regulation of rodent-control products and safe pesticide use.
For more information, please contact Laura Parsons (parsons.laura@epa.gov), 703-305-5776. 