How to Use 20 Mule Team Borax to Kill Roaches

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Boric acid is extremely lethal to cockroaches and is found in 20 Mule Team Borax, a common household chemical often used to enhance the performance of laundry detergent. If you're dealing with a roach problem, borax can help you exterminate these unwanted house guests. You can use the borax in powder form to dust areas where roaches hide or you can use it to make bait stations that will attract and kill the roaches.


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Things You'll Need

  • Borax powder

  • Sugar or flour

  • Squeezable container with tip or insecticide duster

  • Pebbles or pennies

  • Damp cloth

  • Drill (optional)

  • Shelf paper (optional)

  • Jar lids (optional)

How to Eliminate Roaches Using a Dusting of 20 Mule Team Borax

Step 1: Make Your Insecticide

Mix the borax with equal parts sugar or flour. Place a few pebbles or pennies in the bottom of your squeeze container to prevent clumping and then add the insecticide mixture until the container is two-thirds full. Don't overfill, as a lack of airspace will cause too much powder to be ejected when you squeeze the bottle.



  • Store and use your insecticide only ​where children and pets can't reach it​ and never apply the insecticide to countertops and other surfaces that come in contact with food.
  • Wipe away any excess powder that peeks out of cracks and crevices with a damp towel.
  • Borax can cause ill effects if ingested, absorbed through open wounds, inhaled or placed in the eyes. Maladies may include redness and irritation of the eyes as well as damage to the cornea. Inhalation may cause sore throat or coughing and ingestion or absorption may cause nausea, vomiting, diarrhea and stomach pain. ​Seek medical attention if you experience these symptoms​.

Step 2: Kill Your Unwanted Guests

Shake your container and then use it to squeeze a very thin layer of borax in places where roaches like to hide. Apply only enough powder to be just visible to the naked eye, as roaches will avoid large piles and clumps. Place the powder in small cracks and crevices near moisture and warmth where roaches hide, such as inside electrical outlets, in cracks between cabinets, around baseboards and wherever plumbing pipes and walls meet, including under sinks. Remember to spread some of the borax under and behind kitchen appliances such as stoves, refrigerators and dishwashers as well.



  • Roaches love to hide in the hollow spaces behind the kick plates and trim pieces under and above cabinetry. Remember to dust here, even if you have to drill a few small holes for access.
  • If you must treat cabinets that hold food or utensils, the University of Missouri Extension recommends emptying them first and washing them with warm, soapy water. Apply the insecticide and cover it with shelf paper before placing any food and cookware back into the cabinet. You can also place a little of the powder in a jar lid to keep it contained, then place the lid in cupboards and cabinets.
  • A bottle made for insecticide dusting will have a much narrower tip than other squeeze bottles and will work better for treating small cracks and crevices.

Step 3: Replace as Needed

Borax is effective as long as it stays dry. Replace your borax dust only if it gets wet or you can no longer see the application.

How to Eliminate Roaches Using 20 Mule Team Borax as a Bait

Things You'll Need

  • 1 cup borax powder

  • 1/4 cup sugar

  • 1/4 cup minced onion

  • 1 tablespoon corn starch

  • 1 tablespoon water

  • Sandwich baggies

Step 1: Make the Bait

To make your own borax roach bait, Toxic Free North Carolina recommends mixing together the borax powder, sugar, cornstarch, onion and water to make a paste. Roll the paste into small balls and place 2 or 3 balls into each sandwich bag.


Step 2: Place the Bait

Place the open bait bags in areas where you have seen roaches and in places they like to hide, such as under appliances and sinks. Make sure the bait ball is ​tucked where children and pets won't find it​.

Step 3: Change the Bait

Replace the bait periodically when it has been consumed or has dried out.