Diphacinone vs Bromethalin (Which Is Better)

Rodents are painful to deal with. To control the rodent population, you may opt to go for rodenticides. They are a proven method to keep rats away from your property. Two main types of rodenticides are diphacinone and bromethalin.

But which is better – diphacinone vs bromethalin?

Both diphacinone and bromethalin are very effective rodenticides. Diphacinone works a lot faster but exists longer in the environment. Whereas, the death of a rat after consuming bromethalin can occur after weeks.

It is like slow poisoning. Bromethalin doesn’t stay in the environment for too long.

That’s the key difference between the two rodenticides. But there’s still a lot to know about these two rat poisons. If you can spare some minutes, we would like to invite you to read our dedicated segment on these rodenticides.

So, without any further ado, let’s start!

Overview of Diphacinone And Bromethalin

diphacinone vs bromethalin

Diphacinone and bromethalin are two widely used and known rodenticides to use in your household.

If you are struggling to control the rodent population, you can use these rat poisons and expect the rodents to leave your property soon.

Diphacinone is a quick rodenticide. Containing dimethoate as the active ingredient of this rat poison, it can kill rats within a few hours. It is commonly used as a bait trap for rats. You can use it indoors as well as outdoors. 

It reduced the blood flow of the rats after consumption. The lack of blood flow stops their brain function and induces seizures. So, once the rats consume it, they are guaranteed to die in 2-3 hours. It’s deadly for them.

A competitor to diphacinone, bromethalin is a slow poison. The active ingredient of this rat poison is Bromethalin – 0.01%.

You can feed this to the rats by placing it along the walls, in gnawed openings, or corners of the room if you want to use it indoors.

Bromethalin makes the rats sick and kills the rats rather slowly after ingestion. It can take weeks and even months for the rats to die. It induces drooling, vomiting, increased heart rate, as well as labored breathing in the rats before they die.

Both diphacinone and bromethalin are considered single-dose rat poison. It is registered by the US Environmental Protection Agency. So, it has no effect on the environment. But it can kill ants and other small animals as well.

These rodenticides can be used to kill roof rats, meadow voles, cotton rats, house mice, norway rats, and other kinds of rats.

If you want try poisons of repellents other than diphacinone and bromethalin, you may check out the following recommendations –

Diphacinone vs Bromethalin – In-depth Comparison

In this section, we’ll be looking at a comprehensive comparison between the two rodenticides, diphacinone and bromethalin. They are both capable rat poisons, but they have some differences that may help you to choose.

In chemical structure, they may be a lot different. But here we will be considering its working procedure while drawing the line between the two. So, here are the detailed differences that you may want to know about –

Killing Power And Time

The amount of time diphacinone and bromethalin takes to kill rats are polar opposite. Diphacinone is a fast poison. Whereas, bromethalin is slower compared to diphacinone. We are looking at weeks and months of difference.

After ingestion, it takes around two hours for diphacinone to start its action. You can expect the rat who consumed this poison to be dead within 2-3 hours.

If you want a rodenticide that will start to work quicker, diphacinone should be your pick.

On the contrary, bromethalin works very slowly. It works like chronic poisoning to the rats and kills them in a few weeks.

The killing period may sometimes get to months even. It doesn’t harm the environment much. As the killing time suggests, diphacinone is a lot more lethal compared to bromethalin.

Its quick action on rats can be deemed as more powerful. The active ingredient of diphacinone, dimethoate, is quite a bit stronger than bromethalin.

Method of Killing

Both rodenticides have different killing approaches. Diphacinone is a lethal poison that attacks the blood flow of rats. By inducing a lack of blood flow, they force the rats to go into seizures within a few minutes of starting their action.

As a result, their brain stops functioning and then their heartbeats get lower to non-existence. There are no other visible signs that can be identified.

On the other hand, bromethalin doesn’t start its action this fast.

After ingestion of bromethalin, it takes weeks and even months to kill the rodent. The chronic poisoning method of bromethalin makes the rats ill first and then die eventually.

With bromethalin, there are many visible signs. The rat that ingested this poison will start vomiting, drooling, and breathing heavily before dying. It increases the heart rate and induces a heart attack in the poisoned rat.

Environmental Aspect

If we compare Diphacinone and Bromethalin on the environmental aspect, the weaker poison will turn out to be better. Here, the weaker poison is bromethalin.

After its usage, bromethalin stays active for around three months in the environment of the place you applied to. So, it’s quite short-lived and doesn’t impact the environment much.

On the other hand, diphacinone can last about a year or even longer than that. It can be a bit annoying knowing it’s affecting your backyard.

Though it’s rated safe for the environment, these small details may discourage you to buy this rodenticide.

The Verdict

Now that we have an in-depth view of the differences between diphacinone and bromethalin, we can make verdicts on them. Clearly, diphacinone is the better rat poison if you are okay with it hanging around for a year.

It all comes down to what type of rodenticide you prefer. If you are looking for a quick and lethal rodenticide, diphacinone may be the optimum choice for you. But if you have pets, we strongly suggest you avoid them.

Here is a list of our recommended diphacinone-based rat killers –

On the other hand, if you want a safer and slow poisoning rodenticide, bromethalin should be your pick. But it will take weeks or even months to kill rats. So, keep that in mind too.


Is diphacinone safe for pets?

No. As it is a strong rodenticide, it will affect your pets quite a bit. So, keep your pet away from diphacinone. It can be dangerous.

Do diphacinone and bromethalin affect other animals?

Yes, it can affect other small animals. That’s why we don’t recommend you to leave it open at places. The best would be to use it as bait for traps.

Can diphacinone and bromethalin kill roof rats?

Yes, both rodenticides can kill roof rats. They fall victim to these rat poisons very easily.

Wrap Up!

So, that’s it for today. Hope you know which rodenticide between diphacinone vs bromethalin will be a better choice for you. If you are still confused about it, you can contact a professional who can help you with it.

If you have any feedback, do let us know. Best of luck!

1 thought on “Diphacinone vs Bromethalin (Which Is Better)”

  1. Diphacinone: I have heard that an anticoagulant like warfarin will cause rats to seek water…wandering in the open, vulnerable to predation by wildlife.
    Does diphacinone effect rats in this way?
    What are the impacts to wildlife predators that eat diphacinone-poisoned rats?
    What are the impacts on wildlife that eat bromethalin poisoned rats?

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