How to Kill Roaches with Borax

It’s not a secret that roaches are hard to kill. In fact, their resilience is frankly astounding. Cockroaches have been on earth for about 200 million years, which means they survived the events that led to the extinction of the dinosaurs.

Incredible facts about the durability of cockroachesRoaches

  • They can withstand radiation. Cockroaches were found alive and well in the ruins of Hiroshima and Nagasaki in 1945. Further study proved that roaches can survive up to 100,000 rads of radiation, when the bomb dropped at Hiroshima emitted only about 10,000 rads
  • They can live for up to 30 days without food. Because they are cold blooded, they don’t need a lot of food to fuel their metabolisms. They can live without food, but can also survive by eating things you may not think of as food, like the glue from book bindings or postage stamps
  • They can live for up to 7 days without water. For reference, human beings, with our more active continuous cell renewal processes, can only live for about half that amount of time.
  • Female cockroaches do not require males in order to lay eggs. Female cockroaches can reproduce by parthenogenesis, and never need to have access to a male in order to reproduce. Japanese scientists speculate that they do enjoy male company
  • Female cockroaches can lay an incredible number of eggs. Cockroaches place eggs into a sac called an ootheca. While the exact amount of eggs differs between different cockroach subspecies, an American cockroach can produce up to 90 oothecae in her lifetime, each one containing about 15 baby cockroach embryos
  • They quickly develop immunity to pesticides. Cockroaches breed so quickly and so prolifically that they quickly build up a resistance to pesticides. If even one female is exposed to a pesticide and survives, she has an increased chance of giving birth to pesticide resistant offspring
  • They can collapse their bodies. Cockroaches as high as 12 millimeters in height are capable of collapsing their exoskeletons down to just 3 millimeters in height to fit into small spaces and tight crevices. This ability to shrink enables them to quickly escape from threats and find safe nesting places in incredibly small spaces.
  • They can withstand crushing pressure. A cockroaches can withstand pressure of up to 900 times their own body weight without harm.

Suffice it to say that if you’re dealing with a cockroach infestation, it can be difficult to find a good way to eliminate the pests.

Does Borax Kill Roaches?

 BoraxBorax and boric acid have both been approved and used as pesticides since the 1940s. Generations of people have tried it and found it to be an effective way to kill roaches in the home. Not only does borax kill roaches, but the EPA considers it safe and non-toxic for humans, and roaches do not build up resistance to it over time.

Difference Between Borax and Boric Acid


While many people use the terms interchangeably when discussing pesticides, borax and boric acid are not the same thing. Borax, also known as sodium borate, is a salt of boric acid. Both are refined from the water-soluble mineral properties of the element boron. When it comes to killing roaches, the two compounds work in the same way, but boric acid is a much finer and lighter powder than borax. Boric acid poses more safety concerns for people and animals than borax. If you have any health or safety concerns, carefully read product labels to determine whether a pesticide contains boric acid or borax.

How does Borax Kill Roaches

Boric Acid

Borax harms and kills roaches in several different ways:

  • It dries them out. The fine powder form of borax gets onto the roach’s exoskeleton, and interferes with the waxy coating that keeps them hydrated and mobile. The powder both gives them fine scratches, and absorbs moisture from their exterior.
  • It damages their exoskeleton. The fine powder grains also work their way into the many joints of a cockroach exoskeleton, interfering with free movement and injuring the joints
  • It interferes with normal digestion. As cockroaches clean themselves to get rid of this itchy, irritating powder, they ingest the borax. Within their digestive system, it continues to absorb moisture and dehydrates them from the inside out
  • Furthermore, borax has a knock-on effect. When a roach eats borax, it doesn’t die right away. Instead, it carries the poison around inside its digestive system for a few days. When it does, other roaches will readily eat the dead roach, and, in so doing, they do ingest the borax, which goes on to kill them

As you can see, borax is a slow, but highly effective way to kill cockroaches, with a long-lasting effects. Properly used, borax can kill not just the adult roaches you see, but the whole nesting colony.

How to Use Borax to Kill Roaches

borax kill roaches

  • Place it in the roach’s traffic pattern, so that they walk through it. It will stick to them, and they will ingest it while cleaning themselves. The advantage of this method is that it doesn’t require any additional ingredients. It is most effective if you know where your roaches are coming from and their traffic patterns, so you can place it most effectively.
  • Combine borax with a bait, so that they eat it unintentionally while consuming the bait. The advantage of this method is that it will attract the roaches no matter where they are living, and traps can be contained and monitored

kill roaches

  • Clean thoroughly. Roaches are highly attracted to even small particles of food, so clean floors, counter tops, sinks, dishes, food storage areas, and empty trash bins and vacuum cleaners
  • Store food safely. Check your pantry, and move foods that are stored in paper food containers or plastic bags into tightly sealed containers to deter roaches from getting access to your dry goods
  • Monitor water sources. Roaches can live for much longer without food than without water. While they will seek and find water inside faucets, toilets, and drains, try to control excess water in your home. Do not leave standing water in dishes or cups in the sink, promptly empty the dishwasher and allow the inside to dry out, do not overwater houseplants to leave water in the pot, and be mindful of pet water dishes. Do what you can to restrict the availability of water

Taking these steps first will give you more insight into where your roaches might be living, to help with a placement method, and make your bait more attractive to them, if you are using the bait method.

To kill roaches with borax by getting it on their skin

kill roaches

Do not heavily sprinkle the borax powder. They will just walk around a thick line or a pile of the powder, and your goal is to get them to walk through it. You need to use a very fine, dusty “puff” of the powder in their traffic areas, to lay down a thin layer that they will walk through

The easiest way to achieve this is to use a flexible plastic bottle with a fine-tipped opening, similar to a squeeze bottle you might see for condiments in a restaurant. Put a penny or a pebble in the bottle so that you can shake it and keep the powder loose and fluffy, rather than letting it compact.

Fill it the bottle no more than halfway with borax powder. Aim the tip into fine cracks and crevices where you think roaches are entering your living environment. Quickly but gently squeeze the bottle to emit a powdery puff of air into the space. Repeat in targeted areas.

Roaches will walk through or over the fine powder, and it will stick to the waxy coating on their exoskeleton. They will ingest it while cleaning themselves, and die soon after.

While borax is considered safe for people and pets, eating and inhaling the powder should still be avoided, so it’s best to use this method strategically in cracks and crevices at roach-heavy sites. Avoid highly trafficked living areas (roaches won’t be there anyway), and keep it away from pet food or places where pets are likely to walk and get it on their feet.

To kill roaches with borax by baiting them to eat it

biting roaches

With this method, it’s not as important to create a fine dust; the roaches will be attracted and eat it even if it’s applied more heavily. It is a useful method if you aren’t sure where exactly your roaches are coming from. Roaches don’t like the taste of borax, so it needs to be disguised as something that appeals to them.

While many recipes online use sugar and/or cocoa powder as bait, these should be viewed with caution if you have children in the house, or anyone else who might be attracted to something sweet. Flour or cornstarch will also attract roaches as food, and not be as attractive to non-roach occupants. In fact, some cockroaches have even developed an aversion to sugary flavors, since it is so often used to bait traps.

Note that baiting can be particularly effective if you have implemented greater controls on water. By making your bait into a paste and reducing other water sources, it becomes even more attractive to roaches.

dead roaches

  • To mix your bait, combine 1 parts borax with 3 parts cornstarch or flour
  • Add enough water to make a paste
  • Spoon 1-2 teaspoons of the paste onto small plates or containers (discarded plastic tops from milk jugs work well)
  • These can be placed in roach-friendly but hard-to-reach environments, like beneath appliances or behind furniture
  • Replace them every 3-4 weeks for as long as you have a roach problem

While one should be cautious using sugar to bait roach traps, depending on your household, it is worth mentioning that borax powder and sugar-baited borax traps will work on ants as well as cockroaches, provided your roaches are interested in sugar.

Safe Use of Borax to Kill Roaches

kill roaches

While borax is widely considered to be safe, it does pose some health risks. The health risks primarily arise, not from the amounts considered safe to use in laundry, soaps, pesticides, etc., but from the cumulative risks of all the products it is found in.

Today, borax can be found in a variety of cleaning agents and detergents, pesticides, curing and preserving agents, pH control agents, fertilizers, vitamins, and a host of industrial uses. In the US, it is outlawed as a food additive, although it is used in traditional oriental cooking. In any one of these applications, borax is safe and non-toxic, but there is increased risk if it is present in many different everyday products for continuous, prolonged exposure.

The two ways that borax can pose a health risk are by inhalation and by consumption. Boric acid has finer particles, and is therefore easier to inhale, and has more potentially harmful effects than borax.

kill roaches

To keep your use of borax as safe as possible:

  • Avoid placing or using it on food preparation surfaces or in food storage areas
  • Avoid inhaling it, and avoid large scale use of borax powder (such as sprinkling it on a whole carpet)
  • Wash your hands after handling it
  • Store the container safely
  • Borax may pose a greater risk to children and pregnant women, who should avoid it.

As mentioned above, borax has been tested and proven safe, non-toxic, and highly effective at killing cockroaches. Prolonged exposure at high levels do elevate some risk factors, so it’s better to handle borax safely. When used correctly, it’s a remarkably effective way to kill cockroaches without posing a health risk to your family. If you want to kill cockroaches in a faster, you can consider som commercial products online.

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