California has some of the strictest rodenticide laws in the United States, and they’ve gotten tighter in recent years. As of 2025, most anticoagulant rodenticides are off-limits for residents and unlicensed pest control operators. The main products still available to consumers are those containing bromethalin or cholecalciferol, sold in tamper-resistant bait stations.
What California Has Banned
California’s restrictions came in two major waves. The first was the California Ecosystems Protection Act of 2020 (Assembly Bill 1788), which took effect in January 2021 and banned the four second-generation anticoagulant rodenticides (SGARs): brodifacoum, bromadiolone, difenacoum, and difethialone. These are the potent, slow-acting poisons that were once the backbone of consumer rat and mouse control.
The second wave came through Assembly Bill 1322, which took effect January 1, 2024, and added diphacinone to the restricted list. Diphacinone is technically a first-generation anticoagulant, but California lawmakers treated it like an SGAR after the Department of Fish and Wildlife continued to find these chemicals accumulating in wild animals even after the 2021 ban.
In total, residents and unlicensed professionals in California cannot use rodenticides containing any of these active ingredients:
- Brodifacoum
- Bromadiolone
- Difenacoum
- Difethialone
- Diphacinone
- Chlorophacinone
- Warfarin
- Strychnine
That list effectively eliminates every anticoagulant rodenticide from consumer shelves in California. Warfarin and chlorophacinone, both first-generation anticoagulants, are also restricted. If you have old bait products with any of these ingredients in your garage, you cannot legally use them.
What You Can Still Buy and Use
The options left for California homeowners are non-anticoagulant rodenticides. These kill rodents through different mechanisms and, importantly, pose a lower risk of secondary poisoning (where a predator eats a poisoned rodent and gets sick itself). The main ones available are:
- Bromethalin: A neurotoxin that is the most common active ingredient in consumer rodent bait stations currently sold in California. It works quickly, typically within one to two days, and doesn’t accumulate in tissue the way anticoagulants do.
- Cholecalciferol (vitamin D3): Causes fatal calcium buildup in rodents. Also available in consumer bait stations.
- Zinc phosphide: Registered for rodent control but primarily used in agricultural settings rather than residential ones.
Federal regulations require that consumer rodenticide products for rats and mice be sold only in pre-loaded, tamper-resistant bait stations. You won’t find loose bait pellets or blocks on store shelves intended for home use. The bait station requirement applies nationwide but is especially relevant in California, where the remaining legal options are already limited.
Snap traps, electronic traps, and live-catch traps remain completely legal and are increasingly recommended by pest management professionals as the regulatory landscape tightens.
Exemptions for Agriculture and Public Health
The banned anticoagulants aren’t gone entirely. California law carves out specific exemptions for settings where rodent infestations pose serious public health or food safety risks. Licensed professionals can still use SGARs and diphacinone in these situations:
- Agricultural operations: Within 50 feet of agricultural buildings or structures on farms producing crops, livestock, poultry, or dairy products.
- Food storage and manufacturing: Warehouses storing food for human or animal consumption, canneries, slaughterhouses, breweries, wineries, and factories.
- Medical waste generators: Hospitals, dental offices, veterinary clinics, surgery centers, and pet shops.
- Pharmaceutical facilities: FDA-registered and inspected drug manufacturing sites.
- On-farm water infrastructure: Tanks, pipes, and conveyance systems.
Even within these exemptions, use in wildlife habitat areas (defined as state parks, state wildlife refuges, and state conservancies) remains broadly prohibited. A farmer with a grazing lease inside a state conservancy, for example, would not qualify for the agricultural exemption in that location. All exempt uses still require compliance with existing pesticide laws, and restricted materials like diphacinone must be purchased through licensed dealers.
Why California Banned These Products
The driving force behind these laws is wildlife poisoning. Anticoagulant rodenticides don’t just kill the rodent that eats the bait. The poison stays in the animal’s body for days or weeks, and any hawk, owl, bobcat, coyote, or fox that eats that rodent ingests a dose too. Over time, predators and scavengers accumulate dangerous concentrations from eating multiple poisoned prey.
Research from the Pacific Northwest illustrates the scale of the problem. A U.S. Geological Survey study found anticoagulant residues in 86% of turkey vultures and 51% of common ravens tested. Among exposed birds, brodifacoum (one of the now-banned SGARs) was present in 83% to 90% of cases. More than half of the exposed ravens and vultures had concentrations high enough to create a meaningful risk of poisoning, and roughly one in five exposed ravens carried levels associated with a 20% probability of toxicosis. Exposed birds showed elevated stress hormones and declining body condition, particularly females.
California’s Department of Fish and Wildlife continued documenting SGAR contamination in wildlife even after the 2021 ban took effect, which helped build the case for expanding restrictions to diphacinone in 2024.
Penalties for Illegal Use
Using a banned rodenticide in California is a misdemeanor. The Department of Pesticide Regulation and county agricultural commissioners enforce the law, and the penalties can be steep. Administrative fines reach up to $5,000 per violation for structural pest control and up to $15,000 per violation issued by a county agricultural commissioner. The state director can levy penalties up to $20,000 per violation.
If a case goes to court, the numbers climb further. Civil penalties range from $3,000 to $75,000 per violation depending on the specific code section, while criminal penalties can reach $50,000 to $100,000 per violation with up to a year of imprisonment. Pest control professionals also face license suspension or revocation. Authorities can issue cease-and-desist orders and seize products that violate the law.
How the Bans Could Change
California’s anticoagulant restrictions are technically temporary. Under the law, the Department of Pesticide Regulation must complete a reevaluation of each restricted chemical and, in consultation with the Department of Fish and Wildlife, determine whether additional restrictions are necessary to prevent significant harm to wildlife. The ban on each substance remains in place until DPR certifies that continued use would not cause unreasonable adverse effects on nontarget species. Until that certification happens, the prohibitions stand. No timeline has been set for completing those reevaluations.