Diatomaceous Earth: Natural Doesn't Always Mean Harmless

These days, many people are leaning toward safer and less toxic alternatives to help them keep insects out of their homes and businesses. One of the more popular options available to the general public is a product called Diatomaceous Earth.

Diatomaceous Earth is a dust formulation that acts as a desiccant when it is used to control insects. It consists of fossilized remains of diatoms, a type of hard-shelled algae. The fine powder absorbs lipids from the waxy outer layer of insects' exoskeletons, causing them to dehydrate^.   Arthropods die as a result of the water pressure deficiency, based on Fick's law of diffusion. [1]

Diatomaceous Earth is effective in treating most insect problems that are common to modern structures. It is slow acting, but when placed in areas not exposed to moisture, the dust can last almost indefinitely. While Diatomaceous Earth is generally a safe and environmentally friendly choice when looking for an effective way to get rid of what’s bugging you, there are some safety precautions that should be taken before using the product.

1)      Use gloves when handling the dust. “The absorbent qualities of (Diatomaceous Earth) can result in a significant drying of the hands if (the product is) handled without gloves.

2)      Use a dust mask while applying the dust. The flux-calcined form contains a highly crystalline form of silica, resulting in sharp edges. The sharpness of this version of the material makes it dangerous to breathe and a dust mask is recommended when working with it.

3)      Be aware of the Crystalline Silica content.  This is very important  The type of hazard posed by inhalation (of Diatomaceous Earth) depends on the form of the silica. "Crystalline silica poses a serious inhalation hazard because it can cause silicosis (lung contamination and irritation by crystalline of free silica (Si02). Crystalline describes the orientation of the Si02 molecules which occur in a fixed pattern in contrast to the non periodic, random molecular arrangement defined as amorphous. Exposure to free silica is an occupational hazard to workers). Amorphous silica can cause dusty lungs, but does not carry the same degree of risk as crystalline silica. Natural or dried diatomite generally contains very low percentages of crystalline silica. Diatomite produced for pool filters is treated with high heat (calcining) and a fluxing agent (soda ash), causing the formerly amorphous silicon dioxide to assume its crystalline form.” [2] 

“Both swimming pool grade and natural diatomaceous earth come from the same fossil sources but they are processed differently. The natural grades are mined, dried, ground, sled and bagged.  The pool grade is chemically treated and partially melted and consequently contains crystalline silica which can be a respiratory hazard. Thus, IT IS IMPERATIVE THAT ONLY NATURAL DIATOMACEOUS EARTH BE USED FOR INSECT CONTROL. This noncrystalline silica is not a hazard as the human body apparently can dissolve it."

Make sure the DE you use meets World Health Organization (WHO) safety standards. WHO cautions that DE with crystalline silica content over three percent (3%) is dangerous for ingestion by humans or animals. Swimming pool DE ranges from 60% to 70% free silica. [3

Diatomaceous Earth has been around a lot longer than we have…and will likely be here when we are gone. With a few common sense precautions, the dust can be a safe and responsible choice for keeping our homes and businesses pest-free. As with any pesticide or chemical product, the use of appropriate personal protective equipment (PPE) such as gloves and a dust mask can help us to enjoy the benefits of the product without being concerned with harmful side-effects

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[1] Wikipedia; Diatomaceous Earth

[2] Wikipedia; Diatomaceous Earth

[3] http://www.safe2use.com/safe-products/diatomaceous/diatomaceous_Earth.htm