Try This 4,000 Year Old Non-Toxic Pesticide

Posted by Bradley Lewis on

non-toxic clay pesticide

Like calcium bentonite clay of volcanic origin, diatomaceous earth (DE) dates back 65 million years. However, it works completely differently than calcium bentonite clay – by mechanical action – and is also an inexpensive, effective and non-toxic pesticide.

What Is Diatomaceous Earth?

DE is quite simply the fossilized, skeletal remains of millions of tiny diatoms. These diatoms started their life as algae or plankton in oceans and lakes. Over millennia, diatoms have become part of the sediment build up on ocean floors and lake beds. When mined and milled to a fine powder, these diatoms – diatomaceous earth – make for a non-toxic and incredibly effective insect killer.


How DE Works

Some 4,000 years ago the Chinese and Egyptians used diatomaceous earth as a preservative against mold, moisture and pests in their grains, nuts, legumes and seeds.

When insects come in contact with DE, it sticks to and pierces their waxy outer layer. This causes dehydration by absorbing the insect’s bodily fluids and/or interferes with their breathing and mobility. Some pests – such as carpenter ants – die immediately. Others with harder exteriors may take several hours to a couple days to succumb.

Uses of DE

Food-grade diatomaceous earth has a multitude of uses including but not limited to:

• Garden insecticide

• Flea powder on animals, in stalls and on pet bedding

• Bed bug eliminator on mattresses and bedding

• Deodorize kitty litter, shoes, garbage cans

• Soak up motor oil and other industrial spills

• Resist mold and moisture

• Grain, nut, seed, legume, animal feed preservative

• Anti-parasitic and intestinal detoxifier

In addition to treating an insect infestation, DE is also a deterrent against future attacks. Once applied, PROVIDED IT IS KEPT DRY and remains undisturbed, an application lasts indefinitely. In the garden, food cellars and other storage areas, DE is nature’s gift that keeps on giving. Eco-friendly builders apply DE into the walls of new homes once framed and before sheet rock is installed.



While food-grade DE is non-toxic, it is drying to the skin so it is recommended that gloves be worn during application. It is also important to avoid breathing the airborne particles, so wearing a face mask is also recommended.

Diatomaceous earth does not discriminate. If you have beneficial insects in your garden – such as lady bugs – use caution where you apply DE. It should be applied topically on your plants and around your beds. Do not work DE into the soil, as it will kill earthworms and other beneficial organisms living in it.

There are three classifications of DE:

1. natural (unheated)

2. straight calcined (heated)

3. flux calcined (heated)

Only the first one listed – natural UNHEATED DE is used as food grade – and considered suitable for uses outlined here. The other types are commercial or industrial grade DE used in swimming pools, aquariums and the like. Look for pure, 100% food grade amorphous silicon dioxide. Avoid DE with any kind of synthetic OR NATURAL additive.

DE, the FDA and the EPA (Oh Joy!)

All pesticides sold in the United States are regulated by the Environmental Protection Agency (EPA). The EPA only “registers” pesticides. It does not test, nor approve of any product for insecticidal uses. However, the EPA does dictate languages that MUST appear on the ALL pesticide labels, regardless of whether they are safe or highly-toxic. The very same food-grade DE that people have mixed with water and ingested is also used as a pesticide carrying a label that some may find somewhat scary.

DE is not approved for human ingestion by the FDA in the United States. Nonetheless, for decades people have ingested food-grade diatomaceous earth. Like calcium bentonite clay, food-grade DE is considered Generally Regarded As Safe (GRAS) by the Food and Drug Administration (FDA).


Rose, Tui, Going Green Using Diatomaceous Earth How-To Tips, Denver CO: Outskirts Press, Inc., 2010


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