PROVIDENCE — Bills to restrict the use of certain rodenticides have passed the House and Senate and seem headed to the governor’s desk.

Lawmakers have pushed the legislation for several years, arguing that the poisons — a class of pesticides known as second-generation anticoagulant rodenticides (SGARs for short) — are killing the owls, hawks, and other natural predators that keep rodent populations in check while failing to solve the rat problem itself.

The House bill, introduced by Rep. Rebecca Kislask, D-Providence, would restrict the sale of SGARs in local stores and online and ban their use by state and municipal governments, medical waste facilities, warehouses, and agricultural sites. The bill also directs municipalities to participate in a voluntary pilot program to use rodent contraceptives to curb their expanding populations.

Similar legislation, sponsored by Sen. Melissa Murray, D-Woonsocket, was passed in the Senate on May 26. Both bills were heavily supported by environmental groups such as the Audubon Society of Rhode Island, which has made the legislation one of its marquee bills this year, Clean Water Action Rhode Island, and Save The Bay.

Each chamber must now pass the other’s bill before they go before Gov. Dan McKee for his possible signature.

The legislation would phase out anticoagulant rodenticides in stages: first-generation drugs, such as warfarin, would be banned for consumer sale by March 1, 2027; second-generation drugs banned for pest professionals by Jan. 1, 2028; and a full statewide ban on both by Jan. 1, 2029 — with limited exceptions for public health, agriculture, and food production.

Pest control companies commonly use SGARs in black box bait stations in buildings known to harbor rat infestations.

The poisons aren’t just lethal for rats; they’re also poisonous for the wildlife that eat rats. Sheida Soleimani, the founder and executive director of Congress of the Birds, the state’s only bird-specific wildlife rehabilitator, told lawmakers she sees birds in her care die daily because they had rodenticides in their system.

On Friday, Soleimani said she’s “overjoyed” about the legislation and hopeful for a future in which she won’t have to treat birds for SAGRs poisoning.

“In the long term this is going to make a huge difference,” she said. “We’re going to figure this out. I’m excited for what the future looks like not having to treat these birds harmed by these poisons.”

Soleimani said she received a call about a great horned owl on Friday morning that had been hit by a car and said she suspected immediately that the bird had ingested SGARs.

“The first thing I did was give the owl Vitamin K” to help its blood coagulate because she suspected SGARs poisoning, she said, adding that that was most likely the reason the bird was flying erratically enough to be hit by a car.

“Thinking about a future where I don’t have to give Vitamin K as the first line of defense blows my mind,” she said.

She said changes made to the wording of the legislation likely helped it pass this session.

“The slower rollout [of the ban] is the key to what makes this go through,” Soleimani said. “It gives people time to adapt. We’re not going to see this change overnight. We’re going to see integrated pest management, with municipalities providing alternatives to SAGRs. A few years down the road there will no longer be poisons for rats to ingest.”

Congress of the Birds admitted 148 birds of prey into its care in 2024, according to Soleimani, and all of them tested positive for anticoagulants in their blood. A total of 86 birds died or had to be euthanized because of it.

“Rodenticides are not an unnecessary evil, they are an unnecessary cruelty,” she said.

SGARs were first developed in the 1970s, in response to rodents becoming resistant to the first generation of rodenticides. They’re known for killing rats and mice after only a single night of feeding, but they pose a long-term problem to other wildlife because they stay in animal tissue far longer than the first generation of rodenticides. SGARs work by interfering with blood clotting, causing death from excessive bleeding.

The Environmental Protection Agency has banned the sale of such rodenticides in stores, and they are only accessible through commercial pest control companies.

Phoenix Wheeler, director of advocacy for the Audubon Society, said the benefits of rat poisons don’t outweigh the long-lasting risks and impacts to wildlife and the environment, and noted that rodent contraceptives are preferable to control rat populations.

“Rat poisons take five to 10 days to kill rats one by one, increase the risk for rodent diseases, increase ER and poison control center visits for children, saturate poisons up and down the food chain and waterways,” Wheeler said. “Contraceptives, while slightly more expensive, will prevent up to 15,000 rats a year from being born and come with much less risk to anyone.”

Pest control businesses, including representatives from the Big Blue Bug Solutions Pest Control and New England Pest Management Association, had opposed the bans on rodenticides.