Bromadiolone vs. Brodifacoum — What's the Difference?

Bromadiolone, developed in the 1970s, is a second-generation anticoagulant rodenticide designed to control populations of rats and mice resistant to first-generation anticoagulants. It works by inhibiting the vitamin K cycle, leading to fatal hemorrhaging in rodents after multiple feedings over several days. This delayed effect allows for its undetected ingestion by other members of the rodent population. Whereas brodifacoum, also a second-generation anticoagulant, is known for its extremely high potency and long half-life in the body.

While bromadiolone is considered safer for use in environments where non-target species might be exposed, due to its somewhat lower toxicity and shorter persistence in the environment, brodifacoum is restricted to indoor use or around industrial and agricultural settings to mitigate environmental risks. Bromadiolone's moderate persistence means it poses less risk of secondary poisoning, where animals that eat poisoned rodents are affected.

Bromadiolone's effectiveness is seen over a period of several days to a week, allowing for the eradication of entire colonies through the social behavior of rodents sharing the bait. On the other hand, brodifacoum's ability to kill after a single dose can disrupt infestations more rapidly, but it may not exploit the social feeding habits of rodents as effectively as substances requiring multiple feedings.

The use of bromadiolone is generally recommended for less severe infestations or maintenance control, where its slower action and lower risk to non-target animals are advantageous. Brodifacoum, with its stronger and quicker action, is preferred for tackling severe or stubborn infestations, but it comes with increased regulatory restrictions due to its higher environmental and non-target species risks.

Regulatory bodies often categorize bromadiolone for broader use, including residential areas, given its safety profile compared to more potent poisons. Brodifacoum, however, is subject to tighter controls, typically reserved for professional pest control operators, reflecting its higher toxicity and the greater care needed to avoid unintended harm.