As mentioned in another answer, Bromadiolone
is an anticoagulant. It is classified as extremely poisonous. When we bought it the packaging said that it would not go up the food chain. This was a lie.
We used it on possums and rats on our previous property that was 10 acres. It came in different pellet sizes for mice, rats, rabbits etc. But birds such as hawks and chicken that fed on these dead animals also died a horrible death. I would not recommend that it be used under any circumstances.
I am sure that the chemical eventually becomes inactive, but it definitely goes up the food chain.
I found this Mouse plague: bromadiolone will obliterate mice, but it’ll poison eagles, snakes and owls, too. I am glad that it supports our findings.
But there is also this that suggests that it has a half life of 14 days in the soil. So it is probably alright in compost. But I would still not use it.