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
- Cholecalciferol (CAS 67-97-0)
- Chemical class
- Vitamin D3; a non-anticoagulant rodenticide that disrupts calcium balance.[2]
- Mode of action
- Calcium mobilizer: toxic doses of vitamin D3 overwhelm the body's calcium control, causing high blood calcium; vitamin K does not reverse it[2][1]
- Signal words
- Terad3 Blox: Caution[1]
d-CON XIX Kills Rats and Mice refillable bait station (registered as TC 413): Caution[3]
How it works
Vitamin D helps the body keep calcium in balance. The body's calcium control has to be overwhelmed before cholecalciferol becomes toxic, so rodents must eat several doses and there is a lag between eating it and signs of poisoning.[2]
Because it is not an anticoagulant, vitamin K1 is not the antidote. The label directs veterinarians to induce vomiting or give activated charcoal and, if signs develop, to treat high blood calcium with fluids and drugs.[1]
Signs of poisoning may last weeks
Cholecalciferol can be stored in the body, so signs of poisoning may last for weeks.[2]
Where it is used
Terad3 Blox, the professional block, is labeled for house mice, Norway rats and roof rats in and within 100 feet of man-made structures, and may not be sold in containers of less than 4 pounds.[1]
The d-CON station is for use only inside homes: its label rules out outdoor use and any area pets can reach, though the station resists tampering by children and may go where they can reach.[3]
For rats: 2 to 8 blocks per placement, 15 to 30 feet apart, kept supplied for 10 days or until feeding stops. For mice: 1 block per placement every 8 to 12 feet for 15 days.[1]
Tamper-resistant bait stations are mandatory outdoors above ground and wherever children, pets or non-target animals could reach the bait.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Terad3 Blox[1] | Bell Laboratories, Inc. | 12455-106 | 0.075% | bait block | Caution |
| d-CON XIX Kills Rats and Mice refillable bait station (registered as TC 413)[3] | BASF Agricultural Solutions US, LLC | 7969-395 | 0.075% | bait blocks in a child-resistant station (indoor use only) | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| d-CON XIX Kills Rats and Mice refillable bait station (registered as TC 413) | Inside homes (d-CON child-resistant station) | Norway rats, roof rats and house mice | 2 bait blocks (13.89 g each) per peg in the station[3] A station holds up to 6 blocks. Space extra stations 15 to 30 feet apart and keep fresh bait in them for at least 15 days or until rodent signs stop. |
How to apply it, step by step
1. Protective gear
- Wear gloves to handle the station and bait, and again whenever you pick up dead rodents, exposed bait or a used station.[3]
- It carries the CAUTION signal word and is harmful if swallowed: keep it away from people and pets, and wash your hands with soap and water after handling the station.[3]
2. Before you spray
- Use it only inside homes, against Norway rats, roof rats and house mice, never outdoors or anywhere pets can reach. The station resists tampering by children and may go in indoor areas they can reach.[3]
- Don't put it where it could contaminate food or surfaces that touch food.[3]
- Look for feeding areas along walls, by gnawed openings, in corners and concealed places, and wherever you've seen rodents or their signs.[3]
3. Mixing
- There's nothing to mix. Wearing gloves, open the station with both hands (one thumb pushes the outer latch while you squeeze the other latches and lift the lid), slide 2 bait blocks onto each peg, 6 at most, and push the window down until all 4 clips snap shut.[3]
4. Applying
- Set the station along a wall or in a corner, out of pets' reach and with the entrance holes exposed, where activity is heaviest; add more stations every 15 to 30 feet.[3]
- Keep fresh bait in place for at least 15 days or until signs of rats or mice stop, and replace blocks that are eaten or contaminated.[3]
5. After you spray
- Wearing gloves, collect and dispose of dead rodents and leftover bait, and cut back on the rodents' food, water and shelter to discourage a new infestation; repeat the treatment if they return.[3]
- Throw away the gloves after loading or refilling the station, then wash your hands thoroughly.[3]
First aid
- If swallowed, call a poison control center or doctor right away, have the person sip a glass of water if able, don't induce vomiting unless told to, and give nothing by mouth to an unconscious person. Have the package with you when you call or go for treatment.[3]
- If a pet eats bait, call a veterinarian at once. This bait isn't an anticoagulant: the label's notes direct physicians and veterinarians to treat high blood calcium.[3]
Storage, spills and disposal
Safety and environmental hazards
People
Signal word CAUTION: harmful if swallowed or absorbed through the skin. Poisonings of people are very rare. The label tells physicians to treat high blood calcium, for example with calcitonin.[1][2]
Pets
Pets have been poisoned. In animals, vomiting, diarrhea, loss of appetite and depression may develop 12 to 36 hours after eating it, and the kidneys may fail within one or two days; survivors may have permanent kidney and muscle damage. Call a veterinarian at once.[2][1]
Bees and pollinators
The label lists no bee hazard; its warnings are about fish, birds and mammals.[1]
Fish and water
The label says it is toxic to fish, birds and other wildlife, and that predators and scavengers might be poisoned by eating animals that ate the bait; NPIC notes that its secondary risk has not been measured.[1][2]
Common questions
- Is there an antidote for vitamin D3 rat poison?
- There is no vitamin K-type antidote; veterinarians treat the high blood calcium it causes, so a pet that ate it needs care quickly.[1][2]
- How fast does cholecalciferol poisoning show in dogs?
- Vomiting, diarrhea, loss of appetite and depression may appear within 12 to 36 hours, and kidney failure can follow within one or two days.[2]
- Is there a vitamin D3 rat poison for homeowners?
- Yes. d-CON's refillable bait stations with 0.075% cholecalciferol, registered as TC 413, are labeled for Norway rats, roof rats and house mice inside homes.[3]
- How fast does a d-CON vitamin D3 bait station work?
- Its label says rats and mice begin to die as early as day 3 after feeding begins, and calls for fresh bait for at least 15 days or until signs of activity stop.[3]
Sources
- U.S. EPA Pesticide Product Label System, “Terad3 Blox label, EPA Reg. No. 12455-106 (EPA-stamped, Apr. 30, 2021).” www3.epa.gov/pesticides/chem_search/ppls/012455-00106-20210430.pdf (accessed 2026-10-06)
- National Pesticide Information Center, “Rodenticides Topic Fact Sheet.” npic.orst.edu/factsheets/rodenticides.html (accessed 2026-10-06)
- U.S. EPA Pesticide Product Label System, “TC 413 (d-CON cholecalciferol rat and mouse bait station) label, EPA Reg. No. 7969-395 (EPA-stamped, Dec. 20, 2023).” www3.epa.gov/pesticides/chem_search/ppls/007969-00395-20231220.pdf (accessed 2026-11-08)