Bromadiolone General Fact Sheet (2024)

• What is bromadiolone?
• What are some products that contain bromadiolone?
• How does bromadiolone work?
• How might I be exposed to bromadiolone?
• What are some signs and symptoms from a brief exposure to bromadiolone?
• What happens to bromadiolone when it enters the body?
• Is bromadiolone likely to contribute to the development of cancer?
• Has anyone studied non-cancer effects from long-term exposure to bromadiolone?
• Are children more sensitive to bromadiolone than adults?
• What happens to bromadiolone in the environment?
• Can bromadiolone affect birds, fish, and other wildlife?

What is bromadiolone?

Bromadiolone is a rodenticide meant to kill rats and mice. Anticoagulantslike bromadiolone work by preventing the blood from clotting. Unlike some other rat poisons, which require multiple days of feedingby an animal, bromadiolone can be lethal from one day's feeding.

Bromadiolone was first registered in the United States in 1980. It is an odorlesspowder that is white to yellow in color.

What are some products that contain bromadiolone?

Bromadiolone is in over 130 currently registered products. Generally, these products are pellets or baitblocks with 0.005% bromadiolone. Currently, they can be used in and around buildings and in some vehicles. Products sold in stores often containblue-green or red dye. This can help to identify that an animal has been exposed.

To reduce the risk of accidental poisonings of children and wildlife, bromadiolone products are only intended forsale to professionals. Most applications also require the use of a bait station to discourage access.

Always follow label instructions and take steps to minimize exposure. If anyexposures occur, be sure to follow the First Aid instructions on the product label carefully. For additional treatment advice, contact the Poison ControlCenter at 1-800-222-1222. If you wish to discuss a pesticide problem, please call 1-800-858-7378.

How does bromadiolone work?

In mammals, bromadiolone works by preventing the body from recycling vitamin K which is needed to clot blood.Once animals run out of vitamin K they can bleed to death. It can take several days for the body’s stores of vitamin Kto be exhausted. Therefore, exposed animals may take several days to eventually die.

How might I be exposed to bromadiolone?

You are most likely to come in contact with bromadiolone if you touch it oreat it. Children and animals may be exposed to bromadiolone if they find andeat granules or baits. Pets or wildlife may also be exposed if they eat anotheranimal which has been poisoned. Bromadiolone does not get up into the aireffectively. Therefore breathing it in is not likely. Because sale to the publichas been limited, you are more likely to be exposed to bromadiolone if yourjob involves applying pesticides. Exposure can be limited by reading and followinglabel directions.

What are some signs and symptoms from a brief exposure to bromadiolone?

Bromadiolone is toxic to mammals. It prevents the body from recycling vitamin K which is needed tomake the blood clot. Because the body has reserves of vitamin K, it may take a while to go through its supply. Therefore,symptoms may be delayed for up to 5 days after exposure and may not be noticed until immediately beforedeath.

Signs of poisoning in dogs can include bleeding from the mouth and nose, internal bleeding, bruising, bloody urineand stool, hypothermia, depression, lack of appetite, muscle weakness and pain, difficulty breathing, seizures, coma,and death. See the fact sheet on Pets and Pesticide Use.

People who have eaten bromadiolone have experienced symptoms such as nose bleeds, bleeding gums, bloodyurine, black tarry stools, and bruising. Other less commonly reported symptoms include headaches, sore throat, muscleaches, shortness of breath, abnormally heavy periods, and bloody mucus. Skin contact with bromadiolone cancause slight irritation. If it gets in the eyes, it can cause eye redness, swelling, and irritation.

What happens to bromadiolone when it enters the body?

Initially, most of the bromadiolone is broken down and leaves the body. In studies with rats for example, 89% ofthe dose left the body within 4 days. However, as time progresses, bromadiolone tends to leave the body at a muchslower rate. The half-life during this second stage has been reported to be as long as 170 days. It can take a long timefor bromadiolone to be excreted. This can allow for the buildup of bromadiolone in the body. This is especially true incases of long-term, low dose exposure.

Is bromadiolone likely to contribute to the development of cancer?

No. Cancer was not observed in studies when laboratory animals were exposed to bromadiolone. In studies with humancells in the laboratory, bromadiolone did not lead to cancer.

Has anyone studied non-cancer effects from long-term exposure to bromadiolone?

In several studies, pregnant animals were fed very small doses of bromadiolone for several days. No effects wereobserved in their babies. However, the mothers developed bleeding, pale eyes, weak muscles, and eventually died. Inother similar studies with adult rats and mice, researchers saw some changes in reproductiveorgans.

Are children more sensitive to bromadiolone than adults?

Children may be especially sensitive to pesticides compared to adults. However there are currently no data showing that children have increased sensitivity specifically to bromadiolone.From 1993-2008, the American Association of Poison Control Centers reported12,000-15,000 cases of accidental rodenticide exposure in children less than 6 years old. Inmost of those cases, the children had no symptoms, but a few children had severe poisoningsigns. To reduce risk to children, EPA requires bromadiolone to be packaged in tamperresistant bait stations if it’s used in a residential setting.

What happens to bromadiolone in the environment?

In studies with bromadiolone baits applied to soil, 45-78% of the bromadiolone broke down in the first 21 days. Somestudies indicate that it may take longer to break down if stored underground by animals where it has less exposureto the weather. Bromadiolone has a low potential to move in soil. When it was tested in four different soil types, 95% was found in the upper three centimeters. However, itwas more mobile in sandy soil. In water, a half-life of 392 days has been reported. However, in some water conditionsbromadiolone may not break down. Bromadiolone has a low potential to move up into the air.

Bromadiolone is not registered to be used near food. However, when it was applied to soil, only trace levels movedup into plants.

Can bromadiolone affect birds, fish, or other wildlife?

Rodent baits are designed to be attractive to animals. Bromadiolone can be highly toxic to most mammals and birds. Wildlife may eat these baitsdirectly or they may eat a poisoned animal. Because it can takethem several days to die, animals that consume a lethal dose maycontinue to eat the bait before they die. They also may be moresusceptible to capture by predators. Wild mammals, birds and otherwildlife that eat poisoned rodents may receive a lethal dose. Accumulationof bromadiolone in the tissues of owls, buzzards, and otherraptors in the wild has been well documented.

To fish, bromadiolone is moderately to very highly toxic. It is moderate to high in toxicity to other aquatic life. However, registered bromadioloneproducts may not legally be applied to water. Therefore, it is unlikely to come in contact with other aquatic life. Research with bromadiolone on snakes and earthworms hasdemonstrated no toxic effects.