Guide · updated October 2026
Rat Poison Rules in California
Yes, mostly. California now prohibits residential use of all the common anticoagulant rat poisons: second-generation baits since 2021 (AB 1788), diphacinone since 2024 (AB 1322), and chlorophacinone and warfarin since 2025 (AB 2552). Three non-anticoagulant actives remain registered. For homes, the practical answer is trapping plus sealing.
Timeline
Three laws, five years
| Law | In effect | What it restricts |
|---|---|---|
| AB 1788 (2020) | January 1, 2021 | Most uses of second-generation anticoagulants (brodifacoum, bromadiolone, difenacoum, difethialone) |
| AB 1322 (2023) | January 1, 2024 | Diphacinone: residential use and most institutional and commercial uses prohibited; restricted-material status |
| AB 2552 (2024) | January 1, 2025 | Chlorophacinone and warfarin: residential and most other uses prohibited; also bars first-generation anticoagulants in wildlife habitat areas |
Summaries of California Department of Pesticide Regulation guidance. This is general information, not legal advice; rules and exemptions can change.
Who can still use them
The exemptions are narrow
According to the California Department of Pesticide Regulation, the remaining allowed uses include:
- Agricultural production sites such as farms, orchards and vineyards
- Mosquito and vector control districts doing public health work
- Government agencies and utilities protecting water infrastructure
- Medical waste generators and food processing facilities
- Public health emergencies declared by a health officer
DPR also notes that Branch 2 pest control companies cannot apply these products in residential areas outside the listed exemptions (DPR guidance).
Why the rules exist
Wildlife and pets
Anticoagulants work slowly, so a poisoned rat can be eaten by an owl, hawk, bobcat, fox or dog before it dies, passing the poison up the food chain. California’s Ecosystems Protection Act and the follow-up bills were written to cut that secondary poisoning. In the oak-wooded hills around Walnut Creek, where owls and other predators hunt rodents nightly, that matters.
What remains
Non-anticoagulant baits
UC IPM lists three active ingredients still registered for rodent control in California: bromethalin, cholecalciferol and zinc phosphide (UC IPM Pest Notes: Rats). They are still poisons. UC IPM says tamper-resistant bait stations must be used wherever children, pets, non-target mammals or birds could reach the bait, and bait inside a house can leave rodents dying in walls.
What to do instead
Trap and seal
- 01
Trap
Snap traps in tamper-resistant stations along runways; UC IPM calls them the safest, most effective and most economical option.
- 02
Seal
Close every gap over 1/4 inch with metal mesh or sheet metal so new rodents can’t move in.
- 03
Remove attractants
Pick fruit, thin ivy, cut limbs back 6 feet from the roof, store pet food and compost securely.
Questions
Frequently asked
Is rat poison illegal in California?
For homes, most of it. Residential use of second-generation anticoagulants, diphacinone, chlorophacinone and warfarin is prohibited, with narrow exemptions. Bromethalin, cholecalciferol and zinc phosphide remain registered, with label and station requirements.
Can a pest control company use poison at my house?
Not anticoagulants, outside the listed exemptions. DPR states Branch 2 pest control companies cannot apply them in residential areas except under limited exemptions.
Are the remaining baits safe around pets?
No bait is safe for pets to eat. UC IPM requires tamper-resistant stations wherever children, pets or other animals could reach bait. Trapping and sealing avoid the question.
Can I still buy rat poison online?
Product availability is not the same as legal use. Follow the label and California law; when in doubt, check with the county agricultural commissioner or DPR.
Next step
Get the house looked at
Call for the quickest answer, or send the form and expect a call back to set up an inspection and a written quote.
- Entry points found and listed
- Trapping, sealing and cleanup priced separately
- Warranty terms in writing
Sources used on this page
- AB 1788 (2020), California Ecosystems Protection Act, California Legislative Information
- California DPR: Diphacinone restricted-material status, prohibitions and allowed uses (AB 1322)
- California DPR: Chlorophacinone and warfarin prohibitions and allowed uses (AB 2552)
- AB 2552 (2024) bill text, California Legislative Information
- UC IPM Pest Notes: Rats (University of California, updated June 2025)