What is Boric Acid (Borax)?

Boric acid or borax is a naturally-occurring compound found in sea-water, plants, and most fruits.

Borax has been a household item for a little over a century.

You’ll see it commonly used in household products, such as laundry detergent and multi-purpose cleaning solutions.

But borax can do more than clean your house.

It is also a popular all-natural pest control product.

Borax works well in terminating a variety of pests, including spiders, fungi, algae, molds, mites, and weeds.

And if used correctly, it is one of the best ways to eliminate cockroaches.

How Does Boric Acid Kill Roaches?

Borax is deadly to roaches when consumed.

Once the roaches consume borax, it makes its way into their nervous and digestive systems, killing them within 24 hours.

While roaches do not have an appetite for borax, they will do it by accident.

You can trick cockroaches into eating boric acid by making a bait or applying a layer of the powder where they live and travel.

How To Use Boric Acid to Kill Roaches

You can use Borax to kill roaches in a variety of ways.

Here are some ideas.

1. Boric Acid Bait Recipies

You can use Borax to kill roaches by turning it into a bait.

As mentioned, roaches are not attracted to Borax.

But they will be if you mix it with something that they want to eat, such as sugar, jelly, peanut butter, or cocoa powder.

Here are a few recipes you can try:

Egg yolks

1. Boil four eggs and remove the egg yolks.
2. Add ½ cup of boric acid and ½ cup of sugar
3. Mix until you reach playdough like consistency.
4. Add sugar to achieve the desired consistency.

Peanut Butter

Mix 1 teaspoon of peanut butter for every two tablespoons of Borax.

Cocoa Powder and Flour

Mix one tablespoon cocoa powder, one tablespoon boric acid, and two tablespoons white flour.
Add a few drops of water until consistency reaches a dough-like texture.

Place recipes on surfaces where the roaches commonly live and travel.

You’ll also want to switch up your bait every few weeks.

Roaches can learn to avoid your bait overtime.

Studies show that some populations of cockroaches have learned how to avoid glucose since it’s typically used in commercial bait.

To keep your bait effective, keep switching your recipes.

2. Boric Acid Powder / Dust

Spread a thin layer of Borax powder or dust in high traffic areas.

Roaches regularly groom by running their antennae through their mouths and eyes.

So while the immediate contact with Borax will not kill them, they will eventually consume the boric acid that gets on them.

The great thing about killing cockroaches this way is that it effectively spreads the poison to other roaches.

Cockroaches don’t typically groom themselves until they are in the harborage area, which works well to your advantage.

When using powdered Borax, I recommend applying about 2 grams of Borax per meter squared.

Studies show that at 2 grams per meter squared, roaches have a 30% mortality rate within 24 hours and a mortality rate of 100% after 15 days.

You can use a duster or pump to treat areas that are difficult to reach, such as inside holes and crevices.

Using a pump or duster will also allow you to control how much boric acid you apply on surfaces.

3. Boric Acid Spray

Another standard method you will see online is using boric acid as a spray.

But, I wouldn’t recommend this method as it’s not as effective.

Spraying boric acid on surfaces has a little residual effect on cockroaches and is typically not sufficient to be lethal.

There are other solutions you can use to kill roaches with a spray that is much more effective.

Instead of Borax, you can use bleach or detergent as a spray to kill cockroaches. Both work much faster and better than boric acid.

Where to Apply Boric Acid to Kill Roaches?

Apply boric acid where roaches live and travel.

Some excellent places to start are small crevices and holes in your kitchen and bathroom walls and floors.

You’ll also want to apply boric acid under appliances, kitchen, and bathroom cabinets.

Keep boric acid powder out of direct access or movement of humans and pets.

Although low in toxicity, boric acid should be inhaled or ingested due to health concerns.

Make sure you handle it with care when applying.

Here are a few tips:

Avoid placing these on countertops or common areas where people touch, eat, or prepare food.
Keep boric acid out of common walkways. Footsteps and constant movement will cause dust particles to enter the air.
Keep your stock of boric acid in a secure location where your kids and pets can’t reach.

How Long Does It Take For Boric Acid To Work?

Studies show that at 2 grams per meter squared, roaches have a 30% mortality rate within 24 hours and a mortality rate of 100% after 15 days.

The 100% mortality rate comes from the fact that Borax allows for horizontal transfer.

That is, roaches spread Boric Acid to other cockroaches.

For minor infestations, you can expect to eliminate your roaches within 15 days.

For medium or large infestations, it will take much longer.

Common Mistakes When Using Boric Acid

1. Applying Too Much Dust

A little goes a long way when it comes to applying borax powder.

Apply to much dust, and the roaches will avoid it.

For best results, you want to apply just enough that the powder is barely visible.

An easy way to apply a perfect amount is to use a dusting bulb. This tool will let you spread the powder with precision.

I also recommend a duster to apply the right amount into small crevices and hard to reach places.

2. Applying Boric Acid To the Wrong Places

To make the most out of borax, you need to apply it in strategic places.

As mentioned, roaches are not attracted to boric acid.

So you shouldn’t just randomly place them around your home.

Before you begin treating your home boric acid, it is best to determine what type of roach you have.

Different types of roaches like to hide in different locations. As such, your approach on how to treat them should be different as well.

Apply a sticky trap to have a good look at exactly what you’re dealing with.

Once you know what type of cockroach you have, you’ll be able to predict where they commonly hide and travel.

For more information on how to treat typical household roaches, read these articles:

3. Using Boric Acid Alone

Mixing Borax with food is one of the best ways you can do it for roaches.

As mentioned, roaches are not attracted to Borax.

But they will be if you mix it with something that they want to eat, such as sugar, jelly, peanut butter, or cocoa powder.

Remember to switch up your bait every few weeks.

Roaches can learn to avoid your bait overtime.

To get the best results from boric acid, you’ll also want to use it in conjunction with other pest control methods.

The different possible applications when treating cockroaches include:

IGR’s
Granules
Traps
Powder /Dust Bait

Of the list, I recommend using boric acid along with IGR’s and sticky traps.

Seal up all entry points in your home to prevent cockroaches from coming in.

Finally, use sticky traps to monitor the activity and infestation level in your home.

If there is no improvement in the number of cockroaches on your sticky trap after 15 days, re-address your strategy.

Frequently Asked Questions (FAQ)

Is Boric Acid Safe For Boric Pets and Humans?

While boric acid has a higher toxicity level than Demacrous Earth, both have relatively low amounts.

Boric acid toxicity ranges from minor to severe.

Some minor side-effects of boric acid on humans are skin and eye irritation.

More severe side-effects include headaches, muscle weakness, and respiratory issues.

In extreme cases, boric acid can lead to kidney failure.

Boric acid can also be toxic to pets when ingested in large amounts.

In particular, it can cause minor side effects such as irritation, diarrhea, and vomiting in pets.

It’s best to keep boric acid away from pets and children.

When applying boric acid, remember to use a face mask and gloves for safety.

Also, be sure to keep it out of common areas or in areas where kids and pets have access to it.

How to Kill Cockroach Eggs with Boric Acid?

Boric acid cannot kill cockroach eggs.

Roach eggs are protected by a shell casing called ootheca.

The casing prevents any toxic chemicals from penetrating and reaching the eggs.

You can, however, kill baby roaches the minute they hatch by applying boric acid on the ootheca.

The young will die as soon as they walk on the boric acid.

That said, boric acid is not a very good way to kill roaches’ babies because the eggs are often well hidden.

If you want to stop roaches from populating, I recommend using IGRs.

IGR’s are like “birth control” for roaches.

It stops infestations by making adult roaches unable to reproduce.

It also blocks the roaches’ ability to turn into an adult.

If juvenile roaches are unable to grow into reproductive adults, their population will eventually die.

What Safety Gear Do I Need When Applying Boric Acid?

When using boric acid, using a mask and gloves are sufficient to protect you.

Avoid touching boric acid directly when mixing or applying it because it can cause irritations.

How Much Boric Acid I Need?

A little goes a long way when it comes to applying borax powder.

Apply to much dust, and the roaches will avoid it.

For best results, you want to apply just enough that the powder is barely visible.

For baits, ½ cup of boric acid is typically enough to make several bait batches.

A good rule of thumb is to keep your bait proportions at least 1:1.

What Is the Best Boric Acid Recipe?

Peanut butter bait is the best boric recipe.

Many roaches today are developing an aversion to sugar, making many recipes useless.

But since peanut butter is made primarily of protein, they remain to be an effective bait.

And it’s easy to make too. All you need to do is mix one teaspoon of peanut butter for every two tablespoons of Borax.

Is Boric Acid Safe for Children?

Keep Boric acid away from children.

While boric acid has relatively low amounts of toxicity, it can cause minor to severe side effects when consumed and inhaled.