Agriculture agency presents rodenticide risks and stewardship options as committee weighs H.326

The House Agriculture Committee heard from the Agency of Agriculture, Food and Markets about rodenticides, risks to non-target animals, and options to reduce exposure while preserving tools for pest control.

Steve Dornell, Agency of Agriculture, Food and Markets, told the committee that rodenticides fall into three groups: first-generation anticoagulants (for example, warfarin), second-generation anticoagulants (for example, brodifacoum) and non-anticoagulant products (bromethalin, cholecalciferol and zinc phosphide). He said the second-generation anticoagulants are more toxic and can cause mortality after a single feeding, and that some non-anticoagulant products — notably bromethalin — have no antidote.

Dornell said Vermont currently has roughly 47 first-generation products, 69 second-generation anticoagulant products, 11 formulations of cholecalciferol and about 80 bromethalin products registered. He said the second-generation anticoagulants are designated state restricted-use, so only certified applicators may purchase them.

On wildlife exposure, Dornell said Fish and Wildlife liver sampling has detected first- and second-generation rodenticides in species including fishers and bobcats, but that Fish and Wildlife has not correlated the presence of residues with specific mortalities. He told the committee the agency will work with Fish and Wildlife to obtain more recent data and develop recommendations to minimize exposure.

On federal action, Dornell summarized an Environmental Protection Agency evaluation of rodenticides under the Endangered Species Act and said that, in EPA’s analysis, “the rodenticides, if they're used properly, will have no effect on 88% of listed endangered species.” He added that EPA and other regulators have proposed or adopted measures — among them requirements that consumer-available bait be sold in tamper-resistant bait stations — to reduce non-target exposure.

Committee members raised a range of concerns. Representative Litsky relayed constituent suggestions that the committee consider requiring bait stations with one-way doors, limiting the number of bait boxes per location, restricting how long bait may be left, and other measures to reduce secondary poisoning of raptors, bobcats, foxes and pets. Representative Bauson asked about effects on indoor-outdoor domestic cats that repeatedly eat exposed rodents; Dornell said he did not have specific accumulation figures but reiterated that exposure is a function of how the product is used and the underlying rodent population.

Dornell emphasized integrated pest management and training for pest-control professionals and sellers as central tools to reduce non-target exposures, and said the agency has been educating retailers to package and sell bait stations with bulk baits and has produced outreach materials and a YouTube video. He described common poor practices — scattering loose bait, leaving bait in place without monitoring or carcass removal — as drivers of unintended exposure.

The committee discussed legislative options, including limiting some products to certified applicators or banning specific materials where no alternative exists, and acknowledged trade-offs between removing tools from the pest-control toolbox and protecting wildlife and pets. Dornell said an outright prohibition could hamper control of rodent populations in food-processing and farm operations, and that the agency prefers to develop practical stewardship practices in coordination with Fish and Wildlife and pest management professionals.

Ending: Committee members asked the chair to invite Fish and Wildlife to present its sampling methodology and findings and signaled they will continue the discussion in a future meeting; Dornell said the agency will participate in a work group to develop recommendations to minimize exposure while preserving effective rodent control.