Homemade Boric Acid Roach Killer

Updated July 18, 2017

Cockroaches are unwelcome household pests with good reason. They pick up bacteria and viruses from sewers and garbage cans in their travels and deposit them in our homes. They can also trigger allergies and asthma in susceptible individuals. Cockroaches have long resisted human efforts to eradicate them despite the use of toxic chemicals. Boric acid, which is on the low end of the toxicity scale, was registered for the control of cockroaches in 1948. Using boric acid to make a homemade roach killer gives you a way to fight infestations without hiring an exterminator.

Measure equal amounts of boric acid and sugar in a medium-sized bowl. Stir with a spoon until well blended. The total amount you will need depends on the number of areas you'll be treating. Start with 2 cups each of boric acid and sugar. Mix more if you need it and store any excess in a container with a tight-fitting lid.

Pour the boric acid mixture into a plastic squeeze bottle. The bottles used for serving ketchup and mustard work well because they have a narrow applicator tip that helps distribute the blend. Use a funnel to avoid making a mess. Fill only to the halfway point and drop in two or three pennies. If the mixture clogs the applicator tip during application, just give the bottle a few shakes and the coins will help break up any clumps. Cover the tip before you shake.

Create one bait station for each bathroom, three for the kitchen, and one for the laundry room. Use small lids or shallow containers. Sprinkle a light dusting of the boric acid mixture into each. If pets or small children will be in the house, make closed bait stations instead of using open containers. Closed stations can be made by cutting small entry holes along the base of plastic containers with a knife or a small pair of scissors. Add a dusting of boric acid roach killer to the bottom of each bait station and close the lid.

Apply your homemade roach killer by pointing the tip of the bottle toward cracks and crevices near sinks and bathtubs where cockroaches are likely to hide. Squeeze the bottle and release to puff the powder into the cracks. Repeat until you've treated all visible crevices.

Place a bait station under each sink, behind the refrigerator and stove, and behind the washing machine. Cockroaches like dark, damp places and areas where food is readily available. Your goal is to make it easy for cockroaches to make contact with the boric acid blend while they're hanging out in their favourite spots.

Reapply the mixture to cracks and crevices weekly and add a sprinkle to the bait stations. As long as it remains dry, the homemade roach killer should continue to work. Be patient. It will take at least two weeks to see a decrease in the cockroach population.


Keep boric acid away from food preparation surfaces and storage areas.

Things You'll Need

  • 2 cups boric acid
  • 2 cups sugar
  • Medium bowl
  • Spoon
  • Plastic squeeze bottle
  • 3 pennies
  • Shallow plastic containers
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About the Author

Sandra Corbitt-Sears has been self-employed as a writer, editor and webmaster for over 17 years. She has held positions as a university career counselor, employee assistance program counselor and department administrator. Corbitt-Sears earned a Bachelor of Arts degree in psychology from the University of Nebraska at Lincoln and a Master of Science degree in counseling and guidance from the University of Nebraska at Omaha.