Does Boric Acid Kill Roaches?

pest control technician using boric acid to get rid of cokroaches

Cockroach infestations are never a good sight. While some people feel disgusted by their presence, others fear getting infected by any hidden virus roaches may carry. Either way, getting rid of roaches is the best thing you can do to your home.

The first line of defense against these pests is to prevent them from entering your home and growing in numbers. Know that roaches are a problem, whether they are inside or outside. They only need a sweet scent of food to come inside your home and make their colonies.

So, how to kill roaches when they have successfully invaded your home? Out of all other remedies, boric acid can be an excellent choice. This compound affects crucial bodily systems of roaches, nervous and digestive systems, and blows up their exoskeleton.

Let’s learn what boric acid is and how it kills roaches’ infestations within a few days.

Does Boric Acid Kill Roaches?

Boric acid kills roaches within a few hours of consumption. It is a popular and cost-effective remedy to eliminate roaches and their infestations.

Boric acid comes from borax (not safe for roaches) and consists of hydrogen and (boron) sodium borate salts as its primary ingredients. Both of these elements work wonders in killing roaches. You can use boric acid in powder, gel, and dust forms.

While deadly to roaches, it has little to no danger to humans and pets. When boric acid combines with peanut butter or sugar, it lures cockroaches into eating the poison and die. In addition, boric acid has a positive electrostatic charge, so it sticks to roaches’ legs and bodies.

The roaches carry this poison to their homes and spread it to other cockroaches. Soon, the entire nest gets the compound on their bodies. Then, when they groom themselves, boric acid enters their bodies, poisons them, and eventually kills them.

Remember that boric acid is designed to eliminate indoor cockroaches only. Using it outdoors, especially in your gardens, may affect your plants. That’s because boric acid has boron that plants need in small amounts. However, too much boron can be toxic to plants.

What Does Boric Acid Do to Roaches?

Cockroach-lying on a brown rock

Boric acid attaches to the cockroaches’ bodies when they crawl over them. Since it has a positive electrostatic charge, it severely affects the roaches’ nervous system after getting into their bodies. Boric acid in dust form works more effectively in pest control.

It kills cockroaches by:

  • Harming their digestive systems
  • Poisoning their nervous systems
  • Damaging their exoskeletons

Boric acid takes a tremendous toll on roaches’ nervous systems. When this happens, roaches struggle to move and even balance their bodies. As a result, they can’t search for food when paralyzed and flipped on their backs. They either starve from dehydration or hunger.

Boric acid also targets the cockroach’s digestive system, making it hard for them to search for food and yield energy. Thus, they die eventually.

Boric acid has exceptional abrasive properties that cause immense damage to roaches’ exoskeletons. However, it works well with direct contact with the roaches.

The instant way to kill cockroaches is by making them consume boric acid. However, eliminating them may take more time if it stays on their exterior bodies.

What Types of Cockroaches Does Boric Acid Kill?

Boric acid kills almost all types of cockroaches, including German and American roaches. If you have any other pest infestation in your home, like spiders and ants, boric acid will also eliminate them.

It works the same way on every type of cockroach — affecting their exoskeleton, harming their digestive system, and damaging their nervous systems.

How Effective Is Boric Acid Against Cockroaches?

A study published in the Journal of Economic Entomology tells us that ingested boric acid kills 100% of cockroaches in less than 0.5% concentrations. It has been used as an insecticide against pests, including cockroaches, before the invention of synthetic pesticides.

Its effectiveness is proven for both ingestion and direct physical contact. However, it is a slow-acting roach killer as it takes a few days to eliminate the cockroach, but the effectiveness is worth the wait.

Keep in mind that you’ll have to use boric acid regularly to get rid of roaches completely.

What Do You Mix With Boric Acid to Kill Cockroaches?

Boric acid may not be as effective when used alone. So, you need to combine it with foods that cockroaches love and attract to. These include meat, sugar, peanut butter, debris, garbage, and waste. More particularly, they love something sweet.

The best combination is powdered sugar and boric acid or peanut butter in exchange for sugar. Here is how you can prepare two mix-ins with boric acid:

Boric Acid and Sugar


  • ½ cup sugar
  • 1 ½ cup boric acid


  • Latex gloves
  • Bowl and spoon
  • Paper plate


  1. Always wear latex gloves while handling boric acid.
  2. Now, combine sugar and boric acid in a bowl and mix it with a spoon.
  3. Sprinkle the mixture directly in the infected areas.
  4. Alternatively, you can also place it on a paper plate.

Boric Acid and Peanut Butter


  • ½ cup peanut butter
  • ⅛ cup boric acid powder


  • Bowl and spoon
  • Latex gloves
  • Bottle caps


  1. Slip on latex gloves to avoid any sort of skin irritation.
  2. Take the bowl and combine peanut butter and powdered boric acid. Give it a good mix.
  3. Now, transfer the mixture into bottle caps and put them in a container to smoothly transport them to infected areas.
  4. Place these bottle caps in those areas where pets and kids can’t reach easily. These areas can be under and behind furniture, stove, fridge, kitchen pipes, bathroom sinks, pantries, and inside cabinets.
  5. Once done, wash the bowl and spoon to clean any remaining mixture. Lastly, wash your hands thoroughly.

How Long Does it Take Boric Acid to Kill Roaches?

Boric acid takes approximately 72 hours or three days to eliminate a roach. It can even kill the last cockroach from your home if you use it properly. However, remember that roaches can spread several diseases, so stay cautious while dealing with large roach infestations.

Is Boric Acid Dangerous to Humans?

Boric acid is a common active ingredient in many chemical products, such as antiseptics, pesticides, and flame retardants. Although it’s effective in killing roaches and other insects, ingesting or inhaling boric acid is dangerous to humans.

If in case you ingest or inhale boric acid, the first thing to do is seek medical attention from poison control.

However, boric acid is still considered a safe method to get rid of cockroach infestations. It sticks to the roaches’ bodies and eventually enters their systems to kill them. Since cockroaches love sweets, meat, and greasy meals, boric acid and peanut butter or sugar bait is an effective way to target them.

Things to Keep in Mind When Using Boric Acid on Roaches

Boric acid can be dangerous to animals and humans. So, you need to consider some preventive measures to avoid any mishaps when using boric acid. Here are some things to keep in mind:

Do it Correctly

Boric acid works wonders on cockroaches, but they need a proper application to show the desired results. Thus, it’s essential to track the activities of pests to identify the right spots for placing the boric acid baits. In addition, researching roaches will help you learn more about their signs, habitants, and treatment methods.

Place the Baits Carefully

Putting boric acid at the right spots makes all the difference. You can’t place the boric acid baits on your kitchen countertops or places accessible to your kids or pets. Although it isn’t deadly for humans, it can cause severe irritation when it gets in the eyes.

Take Some Additional Steps

It’s easier to prevent the roaches from entering your home than eradicate their infestations. Thus, you need to clean drains, seal cracks, and use baking soda (or any other substitute) to deter cockroaches. This way, roaches will think twice before entering your home.


How Does Boric Acid Kill Cockroaches?

Boric acid sticks to cockroaches’ bodies when they walk over the sprinkled dust. Then, these cockroaches carry the poison to their nests and infect other roaches. Boric acid damages the exoskeleton of these pests from the outside. They also affect the nervous system and digestive system of the roaches from the inside. As a result, roaches flip over and starve to death.

Is Boric Acid Harmful to Pets?

Yes, boric acid is harmful to pets when they ingest or inhale it. In case this happens, immediately rush to your vet.

Where Should I Place Boric Acid Baits?

It’s better to place the boric acid baits in places where your pets or kids can’t reach them. These could be the tiny spaces under your furniture and cabinets.

Final Thoughts

Cockroaches are unpleasant to humans, whether they roam around the kitchen or bathroom. Therefore, it’s better to take actionable steps to fight these pests as soon as you spot one or two of them.

You can rely on boric acid to kill roaches as it works effectively in killing and eliminating these tiny nuisances.

Remember that boric acid does not help you get rid of cockroach eggs, and it may not be powerful on its own. Instead, you need to mix it with suitable mix-ins, so that cockroaches ingest them and die. Put these baits in all the narrow areas.

If you think boric acid isn’t working on these roaches, contact a professional pest control service as soon as possible.