Is Rat Poison Legal in California? Guide to Legal Rodenticides

Which poisons are legal to use in California?

As of today, any rodenticides containing brodifacoum, bromadiolone, difethialone, or difenacoum are prohibited for general use in the State of California, with the exception of licensed pest control experts. Use of these toxins within state parks, wildlife and conservation areas are forbidden unless carried out for agricultural purposes or by federal agencies.

Rodenticides containing warfarin, chlorophacinone, and diphacinone are not under any restrictions in California as these are classified as first-generation poisons and are considered to be less harmful.

Which types of rat poison are illegal in the State of California?

Since 1st July 2014, the use of second-generation rat poison was made illegal in the state of California and is now only licensed for use by accredited commercial and agricultural pest control services. In addition to the general public sales ban of second-generation rodenticides, the law also restricts the locations where these super-toxic poisons can be applied, limiting it to within 50 feet of any man-made structure.

Whilst rat poison is considered an effective solution for eradicating rats, there is a risk of secondary poisoning leading to the death of non-target species, specifically wildlife and pets. Therefore, in the State of California, a motion has been passed forbidding the general use of second-generation poisons but allowing the sale of first-generation anticoagulants either online or via home improvement stores.

rats in cage
Credit: sipa, Pixabay

Why California has banned the use of second-generation rodenticides

Rodenticides have always offered a successful solution for getting rid of rats and mice, however, the secondary poisoning that can endanger other animals and even humans has meant that the risks far outweigh the benefits.

First-generation rodenticides

In the 1940s and 1950s, first-generation rodenticides (FGARs) were developed in order to tackle the overwhelming number of rats and mice invading our cities and farms. First-generation poison works by using anticoagulants to thin the blood, preventing it from clotting. After consuming the bait over multiple feeds, the intended animal starts to suffer from uncontrolled internal bleeding or hemorrhaging. This can take up to a week in order for it to take effect.

Second-generation rodenticides

Second-generation rodenticides (SGARs) were introduced as a more potent class of poison amid fears that rats were becoming resistant to first-generation bait. These toxins can be consumed and ingested within one single feed so are considered to be much more potent. Able to remain in an animal’s body for over six months, even once deceased, these deadly toxins can work their way back up the food chain as other animals feed and come into contact with the affected rodent.

An alternative to using rat poison, such as a bucket mouse trap with a rolling log:

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Updates to the law on the use of rat poison in California

A recent state analysis carried out at the end of 2018, concluded that 85% of the surrounding wildlife, from mountain lions to bobcats and birds, have been inadvertently killed by these super-toxic rodenticides. In turn, this has prompted further debate and a revaluation of the bans and restrictions currently imposed on the use of second and first-generation rodenticides in the State of California.

A proposal (AB1788) has been put forward by the people of California to be the first state to completely prohibit the use of SGARs and FGARs in residential and commercial areas, as well as on state-owned land where animals, pets, and people are frequently exposed. That said, should a rodent or disease outbreak occur, an intervention would be permitted.

Wildlife concerns regarding rat poison

The circle of life leaves many carnivorous animals such as owls, eagles, foxes, mountain lions, and skunks being indirectly exposed to the dangers of rodenticides. Once a rat or mouse has digested some poison-laced bait, they simply keel over and die, leaving them looking like a tasty, yet highly toxic snack for predators.

mountain lions are being found dead due to rat poison in California
Mountain lions in California found dead due to 2nd generation poisoning.

Rodenticides have been documented to have been found in over 25 wild species, with park officials confirming that most mountain lions found dead in California had rat poison in their bodies. Quite often the poison is the primary cause, but if it doesn’t kill them instantly it can weaken them, making them susceptible to other diseases.

Safer solutions killing or trapping rats

The only safe solution is to use no poison at all, but as Los Angeles and San Francisco continue to feature in the top five most rat-infested cities in America,  it comes as no surprise to hear that the residents of California are seeking other pest control methods in order to control the influx of rats.

It is important that you take steps to prevent rodents from being attracted to your property by maintaining your backyard, making sure that your trash is safely stored away from your house, sealing up any openings and holes around your building, and ensuring that food remnants are not left hanging around.

If rodents continue to persist, then you could try a number of non-toxic solutions such as rat traps. Often used with natural baits, these are strongly recommended for use around children and pets. From humane to snap, electric, and gas, read our reviews on the best traps for catching rats.

How to use rat poison

If you feel that poisons are the only solution available to you, then you should always ensure that you use them responsibly and only in a secure rat trap. Only use the first-generation rodenticide and check the label for information on dosage and distribution. Click here for more information on the different types of rat poison baits available.


California is one of the first States in America to seriously consider the implications of using strong rodenticides and the impact they have on the surrounding wildlife. It is therefore commendable that they are taking steps to preserve their animals, plants, birds, and ecosystems in order to create a sustainable future for all.

Whilst California as a State is looking at changes to the law, Los Angeles has taken an innovative approach to pest control, and uses a working cat program as an alternative way to help rid the city of rats.