Many thanks to this anonymous contributor for a 5-star question.
Diatomite, also known as diatomaceous earth (DE), was formed millions of years ago through fossilization of countless gazillions of tiny hard-shelled algae called diatoms. DE is most commonly used today as a medium in swimming pool filters.
One of DE's most notable properties is its ability to absorb fat-soluble molecules including oils and waxes, which lends itself to pest control. When DE comes in contact with an arthropod such as a flea, it absorbs liquids from the insect's exoskeleton causing death by dehydration. Similarly, in the case of gastropods (common garden snails and slugs), DE absorbs body fluids but with very low efficiency.
There is no question whether diatomaceous earth is an effective mechanical insecticide for outdoor use (although such a broad spectrum pest control often causes collateral damage by killing beneficial insects in the same area). But as for indoor use around pets and children, I have certain concerns. And as for drinking the stuff, don't uncork that bottle just yet.
Since 86% of diatomaceous earth is composed of silica, the most common saltwater form (crystalline silica) should not be handled without wearing a dust mask. The health hazard posed from inhaling this industrial grade DE is called silicosis, a serious lung disease characterized by inflammation and scarring (nodular lesions) in the upper lungs. Victims of silicosis develop labored breathing, fever, and a bluish tint to the skin.
In fairness to the DE industry, food-grade diatomite contains a lower percentage of crystalline silica resulting in an equally reduced risk of developing silicosis. However, DE's most notable property of absorbing fat-soluble molecules (see above) brings yet another health hazard into play. DE readily absorbs fat-soluble vitamins such as A, D, E and K thus depleting the body of nutrients essential to good health.
At this point I am suddenly struck with the irresistible urge to put in a shameless plug for TripleSure Natural Flea & Tick Spray for Dogs & Cats; and FourGuard Herbal Parasite Formula for Dogs & Cats & Humans. The safe and natural ingredients found in these products have been used on humans and animals for thousands of years.
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