Maine Bans Homeowners from Purchasing Potent Rat Poisons in Effort to Protect Wildlife, Pets

AUGUSTA, Maine — Starting June 15, Maine homeowners will no longer be able to purchase several popular rat poisons from hardware stores or online retailers, after the state Board of Pesticides Control unanimously voted Friday to restrict second-generation anticoagulant rodenticides to licensed professionals only.

The ban targets four chemicals—brodifacoum, bromadiolone, difenacoum, and difethialone—which environmental and wildlife officials say pose a significant threat to birds of prey, mammals, and household pets through a process known as secondary poisoning.

"These chemicals don't kill rodents instantly," explained Courtney Marchelletta, a spokesperson for the Maine Department of Agriculture, Conservation and Forestry. "The weakened animal can wander for days before dying from internal bleeding, which creates opportunities for predators and scavengers to ingest concentrated doses of toxin."

A single great horned owl, for instance, can consume up to eight rats daily, making raptors particularly vulnerable to toxin buildup when hunting in areas where these rodenticides are used.

Wildlife Impact Documented

State wildlife biologists have documented the chemicals' presence throughout Maine's food chain. Half of the fishers—a forest-dwelling member of the weasel family—tested in 2020 carried the toxins. More alarming, every black bear tested in 2024 showed exposure to the chemicals.

The ban was triggered by legislation passed in 2025, which directed state officials to restrict outdoor use of potent rodenticides in residential settings. Maine joins California, Connecticut, and Vermont in limiting these products.

Hardware stores must remove affected products from shelves by June 15, and online retailers must stop shipping them to Maine residential addresses. Brands including d-CON, Havoc, Just One Bite, and Final will be affected. Tomcat remains available because it contains bromethalin, a different active ingredient not covered by the ban.

Licensed pest control professionals will still be able to purchase these products by showing their credentials to dealers. State inspectors will monitor compliance during routine visits to registered pesticide vendors and investigate potential e-commerce violations.

Calls for Expanded Restrictions

While applauding the vote, Maine Audubon policy advocate Anthony Erwin said the board didn't go far enough. The organization's advocacy aims to extend restrictions to first-generation anticoagulants, which persist in the environment for up to a month and accumulate in wildlife tissue.

"Restricting rodenticides aligns with Maine's legacy of protecting its natural heritage," Erwin said. "While this is a good first step, expanding the ban would better fulfill the law's intent and protect our wildlife from unnecessary harm."

First-generation anticoagulants require multiple feedings to kill their targets, increasing the likelihood they'll be consumed by unintended animals before proving lethal.

Pets and People at Risk

The risks extend beyond wild predators. The EPA estimates approximately 60 pets die annually from rodenticide exposure nationwide.

Jim and Lega Medcalf of Bridgton told lawmakers their dog, Starling, suffered severe liver and pancreas damage after a neighbor placed a bait box near the animal's outdoor enclosure. Albert Boardman of Brooksville testified that he lost a Labrador retriever to liver failure caused by these chemicals.

"Just last year I lost a beloved Labrador retriever to liver failure caused by SGARs," Boardman told the pesticide board. "The emergency veterinarian bill was in the thousands."

In South Portland, Brad Fox reported witnessing a child touch a rat dying from these chemicals at his public housing complex last September. When a state inspector investigated, he said current law offered no recourse.

Former Republican Senator Rick Bennett of Oxford, now an independent candidate for governor, authored the legislation that led to the consumer ban after a constituent lost a dog to secondary poisoning from the now-restricted chemicals.

Concerns from Farmers and Businesses

Critics of the ban worry it will disproportionately affect low-income residents, small businesses, and farmers who cannot afford professional pest control services.

"Rodent control is an important part of all pest control on the farm and indeed all food establishments," said Eric Seaman, a vegetable farmer from Litchfield, who urged lawmakers to preserve access for agricultural operations.

Ashley Luszczki of the Maine State Chamber of Commerce said the restriction would increase administrative burdens and costs for small businesses while creating unintended economic challenges.

Those holding existing product should follow disposal instructions on the label. The state conducts a pesticide disposal event each fall, and dealers may accept returns of unsold inventory or arrange hazardous waste disposal.

Wildlife and pest management experts encourage homeowners to focus on prevention—sealing foundation gaps, securing trash containers, and using snap traps—to avoid infestations requiring chemical intervention.

With the new regulations taking effect, regulators hope the next meal for an eagle, hawk, or family pet won't prove fatal.