In the pest control world, finding all-natural, eco-friendly pest solutions is something of a holy grail. Even the coveted insecticidal neem oil can be bad for the environment in some circumstances.
But among all of the competition, two remedies stand out. In the left corner we have diatomaceous earth, and in the right corner is boric acid. Which of these two will come out on top when put in the ring together? It’s time to ring the bell and find out!
Introducing The Contenders
Both of these contenders are completely natural, placing them on even footing early on.
Boric Acid (AKA Borax)
One of the most famous borax products is 20 Mule Team Borax, named after the method in which boric acid was once transported from the mines.
While boric acid is often considered synonymous with borax, the latter is actually sodium borate, which is easily processed into boric acid. Thus while not exactly the same, the two are often considered similar enough to be confused for each other.
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Boric acid (or orthoboric acid) occurs naturally as the mineral sassolite and is a chemical combination of the elements boron, hydrogen, and oxygen. It dissolves easily in water and is a mild acid, making it valuable for a number of household, commercial, and medical purposes.
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While borax can be used as a viable substitute for boric acid (and is more readily available) in pest control, boric acid tends to be slightly more effective.
Food-Grade Diatomaceous Earth (AKA: DE)
We use a number of fossil-based products in our daily lives, from the evolution of oil to coal and diamond, to many forms of plastic. But few are as abundant and underrated as diatomaceous earth.
DE begins its life as a microscopic organism known as diatoms. These ancient organisms are fascinating on their own, but when their shells fossilize, that’s where the magic begins. As the name implies, DE is the crushed remains of these fossilized shells, ground into a fine powder.
Food-grade DE is crushed into a fine powder. In human hands, it’s not much different from the dust piles you find under your furniture each spring. It’s completely non-toxic to humans and pets, and can be found in some toothpaste brands.
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Non food-grade DE particles can be much larger and rougher and is often used in water filtration and industrial applications.
While the whitish powder feels soft to the touch, on the insect scale, it has the texture of broken glass, with razor-sharp edges. Some caution is generally recommended when using DE, such as wearing a dust mask, as (just like any other fine powder) it can be a bit irritating if breathed in.
Going the Rounds
Now that we’ve met our contenders, it’s time to let them fight it out over several rounds. While it’s unlikely we’ll get a KO from the fight, it’s guaranteed to be brutal with neither side pulling their punches.
Round 1: Safety Around Family
Immediately our contenders come out swinging. DE takes the early lead, being completely non-toxic to humans and pets when used as directed. While it can cause minor respiratory irritation if inhaled (potentially affecting people with asthma or dust allergies), food-grade DE is safe enough to be used in some toothpastes.
Boric acid, however, struggles in this round with some significant safety concerns. Historically, borax was a popular additive to milk in the 1800s to mask the taste of spoiled milk. This practice resulted in numerous developmental issues and deformities in children who drank the treated milk as babies.
See Also: How to Use Borax to Kill Roaches
Even today, ingesting borax or boric acid, while unlikely to be fatal, is known to produce harmful effects in children, adults, and pets.
The first round ends with DE coming out clearly on top regarding family safety, with boric acid needing more careful handling and storage around children and pets.
Round 2: Accessibility
In this round, boric acid takes the initiative, being readily available both online and in a wide range of stores. Borax can be found in any cleaning aisle and is most often used as a hypoallergenic laundry detergent, meaning you never have to go far to find some variation of boric acid or its sibling.
DE makes a quick recovery, being available online and in many locations that offer natural pesticides. While not quite as widespread as borax and boric acid, DE ends the round landing some solid punches but loses this round on points.
Round 3: Durability
Both of our contenders refused a drink between rounds, as both can be rendered ineffective when in contact with water. Boric acid will dissolve, while DE’s sharp edges are coated in water and it becomes a useless thin mud smear.
Read Also: Does Diatomaceous Earth Kill Black Widows?
When used indoors, DE will still need to be reapplied every few days because of how easily it’s shifted by gusts of wind or vibrations.
However, boric acid lands a winning blow in this round because it’s most often mixed with a bait substance such as sugar or peanut butter, which protects it from being easily dispersed and allows it to remain effective longer.
Round 4: General Effectiveness
After the last round, both contenders have gained a second wind. When it comes to insects, arachnids, and other tiny critters, the two are extremely effective and pose no risk of creating superbugs or resistance.
Boric acid is primarily effective against insects, though in very large quantities it can be harmful to small mammals like mice, while DE serves as a nasty irritant to the feet of larger pests, making it an effective deterrent.
This round ends in a draw, with both contenders showing impressive effectiveness against their primary targets—insects with exoskeletons.
Round 5: Kill Method
This is where we see each contender truly shine. DE is a solo operator that lacerates the protective waxy coating of any critter with an exoskeleton, causing them to lose moisture and die of dehydration. The death can take a couple of days, and all it takes is one step to seal a bug’s fate.
Meanwhile, boric acid is an internal killer that prefers working with a tasty partner to hide its presence. Once ingested, it disrupts the insect’s digestive system and affects its nervous system, destroying it from the inside out. This process also takes a couple of days.
In this final round, both contenders demonstrate powerful but different kill methods, fighting to a technical draw.
The Verdict
After five grueling rounds, our judges have tallied the scorecard. While DE landed a decisive blow in the safety round, boric acid countered strongly by winning both the accessibility and durability rounds. With the general effectiveness and kill method rounds ending in technical draws, boric acid edges out the victory by a split decision!
However, like many great rivalries in pest control, the true winner depends on your specific situation.
- Use boric acid in baits when you need a solution that lasts longer and is readily available everywhere.
- Turn to diatomaceous earth when safety is paramount and you need to dust known trails or around webs and nest entrances.
In many cases, the champion pest controller will employ both these natural powerhouses as part of their arsenal.
Morgan is a certified entomologist and pest control consultant and a member of the National Pest Management Association.
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