Restricting the Use of Rodenticides in the Environment

S. 644/H. 965: An Act restricting the use of rodenticides in the environment

MSPCA Position: Support
Sponsors: Representative Jim Hawkins and Senator Mike Moore
Status: Referred to Joint Committee on Environment and Natural Resources. Hearing held 10/27/2025. S. 644 voted favorably by Committee and pending in the Senate Clerk’s office.

This owl’s family unknowingly fed on rodents who had ingested rat bait that contained second generation anticoagulant rodenticides (SGARs) and over the course of a week they succumbed to its deadly effects. Photo: New England Wildlife Center

Overview: This legislation would restrict the use of Anticoagulant Rodenticides (ARs) in Massachusetts to protect wildlife, pets, people, and the environment.

What this bill will do: This bill will end the registration and reregistration of anticoagulant rodenticides (ARs), unless deemed necessary for a public health emergency by the Massachusetts Department of agriculture and resources (MDAR). This bill also gives the department the ability to establish a process and standards for the limited use of anticoagulant rodenticides by licensed applicators in public health emergencies.

Why is this legislation needed? Anticoagulant Rodenticides (ARs) are a particularly toxic group of poisons used as a form of rodent control. When ingested, ARs prevent the clotting of blood, and cause the animal who ingested it to sustain heavy internal bleeding, eventually causing death. The poison remains in the dead or dying rodent’s system for days. These poisons are broken into two categories: first generation known as FGARs (Chlorophacinone, Diphacinonon, and Warfarin) and second generation known as SGARs (Brodifacoum, Bromadiolone Difenacoum, and Difethialone). First-generation anticoagulant rodenticides last for approximately 7 days in an animal’s system, but SGARs are more potent and generally last for 4 weeks, making them more dangerous to other animals who ingest poisoned prey.

ARs impact non-targeted pets and wildlife populations, such as birds of prey, who rely on the poisoned rodents as a food source. As a result, the cats and dogs, hawks, eagles, owls, and bobcats who are exposed often suffer the same fatal hemorrhaging as their meal.

While ARs are prohibited for residential consumer purchase in the Commonwealth, commercial use is allowed for licensed pesticide companies.

Do you have a rodent problem?

• Rodent-proof your home. Lethal methods are a temporary fix, at best. Instead, remove or securely contain any potential food sources for rodents. Repair any exterior areas of your home to prevent rodents from coming inside. Read more about critter-proofing.
• If you choose to use a problem animal control company, ask questions so you know their practices. Look for an integrated pest management company that uses multiple approaches to pest control instead of relying solely on poisons. You can request that the company avoid using SGAR products including brodifacoum, bromadiolone, difenacoum, or difethialone.

In the news:

• Could banning some rat poisons lead to better pest control in Mass.? MassLive. February 19. 2025.
• Bald eagles are America’s national symbol. Let’s stop poisoning them. Boston Globe (editorial). July 3, 2023.
• ‘Particularly devastating’: Bald eagle ‘MK’ succumbs to poisoning after being rescued in Arlington, Boston.com. March 2, 2023.

Additional Resources:

• Learn more about rodenticides.
• Find out who your state senator and state representative are. Ask them to support this bill.
• Join the Animal Action Team to receive news and alerts on all of our efforts—and to learn how you can help.

Note: Pesticide Issues/Complaints/Questions can be left on the MDAR Pesticide Division Enforcement phone line at 617-626-1782. This is a recorded line. Please leave a message and an Inspector will return the call. Or if preferred the Complaint Form can be completed and submitted. Please use the following link: https://www.mass.gov/forms/pesticide-enforcement-complaint-form