The label is the law. Read your product's label before you mix or apply; the rates here come from the labels listed under Sources.
- Active ingredient
- Bromethalin (CAS 63333-35-7)
- Chemical class
- Non-anticoagulant rodenticide; EPA notes it is toxic in a different way from the anticoagulants.[3]
- Mode of action
- Nerve poison (non-anticoagulant); insecticide resistance groups do not apply to rodenticides[2][1]
- Signal word
- Tomcat Rat Killer II (block bait with refillable bait station): Caution[1]
How to set it out
Wearing gloves, place one or two blocks in the station, set it at the point of highest rodent activity beside burrows or along runways, and replace bait when it is eaten or contaminated; the station can only be refilled with the block bait sold with it.[1]
Why secondary poisoning matters
Because pets and wildlife can be poisoned by eating rodents that ate the bait, collect dead rodents with gloves as the label directs and keep stations where pets cannot reach poisoned animals.[1]
Where it is used
Consumer rodenticides are sold only as ready-to-use bait stations containing block or paste bait; loose pellets are no longer permitted in consumer products.[3]
This product is for Norway rats, roof rats and house mice in and around buildings; do not place it further than 50 feet from a home or building, or anywhere it could contaminate food or food-contact surfaces.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Tomcat Rat Killer II (block bait with refillable bait station)[1] | Bell Laboratories, Inc. | 12455-140 | 0.01% | block bait in a weather- and child-resistant refillable station | Caution |
How to apply it, step by step
1. Protective gear
- Wear waterproof gloves whenever you handle the bait, refill the station, or pick up dead rodents or leftover bait.[1]
- Wash with soap and water after handling, and before eating, drinking or smoking.[1]
2. Before you spray
- It is only for Norway rats, roof rats and house mice, in and around buildings and no farther than 50 feet from the home or building.[1]
- Bromethalin is a nerve poison, not an anticoagulant. It is extremely toxic to fish, birds and wildlife, and pets or wild animals that eat a poisoned rodent can be poisoned too.[1]
- The station resists weather and tampering by children and dogs, so it may be used where children and pets can reach it, but don't let them play with it, and keep it and the refill blocks away from food and food-contact surfaces.[1]
- Find where rodents are active: beside burrows, along walls, by gnawed openings, in corners and concealed spots.[1]
3. Mixing
- No mixing: wearing gloves, put 1 or 2 bait blocks in the station; refill it only with the block bait sold with it.[1]
4. Applying
- Set the station where activity is highest, along a wall or in a corner where you've seen signs; it can sit flat or upright.[1]
- With more than one station, space them 15 to 30 feet apart.[1]
- Keep fresh bait in the stations for 10 days or until there are no fresh signs of rats or mice, replacing blocks that are eaten or spoiled while rodents are still visiting.[1]
5. After you spray
- Rodents eat a small amount and leave, so you likely won't find dead ones in the station, and there may be stretches of 2 or 3 days with little feeding.[1]
- Wearing gloves, collect and dispose of leftover bait and any dead rodents, then cut off food, water and shelter to discourage new ones; repeat the treatment if they come back.[1]
First aid
- If swallowed, call a poison control center, doctor or 1-877-854-2494 right away, have the person sip a glass of water if they can swallow, and don't induce vomiting unless told to.[1]
- If a pet eats the bait, call a veterinarian or 1-877-854-2494 at once; signs in animals include muscle tremors, loss of use of the hind legs and seizures.[1]
Storage, spills and disposal
Safety and environmental hazards
People
The label signal word is CAUTION: harmful if swallowed. Anyone who handles bait, refills a station, or picks up carcasses or unused bait must wear waterproof gloves.[1]
Pets
The label says to keep it away from domestic animals and pets, and if an animal eats bait, call a veterinarian at once. Its note to veterinarians says bromethalin is not an anticoagulant; poisoned animals may show muscle tremors, loss of hind-limb use or seizures, and treatment aims to limit absorption and manage brain swelling.[1]
Bees and pollinators
It is a rodent bait used in enclosed stations, and the label carries no bee-hazard statement.[1]
Fish and water
The label states it is extremely toxic to fish, birds and other wildlife, and that dogs, cats and predatory or scavenging birds and mammals might be poisoned by eating animals that have eaten the bait.[1]
Common questions
- What should I do if my dog ate bromethalin bait?
- Call a veterinarian immediately and bring the label. The label's note to veterinarians says it is not an anticoagulant, so treatment differs from warfarin-type baits.[1]
- Can I buy loose bromethalin pellets for home use?
- No. EPA allows consumer rodenticides only as ready-to-use bait stations with block or paste bait; pelleted baits are no longer permitted in consumer products.[3]
Sources
- U.S. EPA Pesticide Product Label System, “Tomcat Rat Killer II label, EPA Reg. No. 12455-140 (EPA-stamped, Sept. 8, 2020).” www3.epa.gov/pesticides/chem_search/ppls/012455-00140-20200908.pdf (accessed 2026-10-06)
- University of California Statewide IPM Program, “Home and Landscape Pesticide Active Ingredients Database: bromethalin.” ipm.ucanr.edu/home-and-landscape/pesticide-active-ingredients-database/active-ingredient-details/?uaiKey=106 (accessed 2026-10-06)
- U.S. EPA, “Restrictions on Rodenticide Products.” www.epa.gov/rodenticides/restrictions-rodenticide-products (accessed 2026-10-06)