How Diatomaceous Earth works
Diatomaceous Earth, from Perma-guard, or 'Fossil Shell Flour' are the fossilised remains of one-celled plants (phytoplankton) called diatoms, from an ancient lakebed in Nevada in the South Western region of the USA.
Examined under a microscope and magnified 7000x, these tiny diatoms appear as spiny honeycombs or tiny cheese-grater-like cylinders. These microscopic cylinders are extremely hard and sharp — on the hardness scale, diamonds rate a 9, DE around a 7, and insect exo-skeletons are typically only a 3.
This hard, abrasive, spiny structure is what makes DE useful against crawling insects such as ants, fleas, flies and cockroaches. When insects come into contact with DE, the sharp particles cling to and abrade the insect's outer cuticle, wearing through the waxy layer that helps it retain moisture. This disrupts the insect's ability to hold onto body fluids, and can lead to dehydration over time. Because this is a physical, mechanical process rather than a chemical one, there's no chemical residue left behind, and insects can't build up immunity or tolerance to it the way they might with a chemical pesticide.
DE is a desiccant. It absorbs moisture – several times its own weight.
The insect must come into direct contact with DE for it to have an effect, which is why it's applied in areas where pests travel or nest. Because of how it works, Fossil Shell Flour is used extensively in domestic and commercial settings as a natural pest control option, and holds OMRI organic registration.
Perma-Guard's Diatomaceous Earth deposit is 89–95% amorphous silica, and also contains 15 essential trace minerals, including phosphorous, selenium, calcium, sodium, potassium, magnesium, copper, zinc and iron.
Silica is the second most plentiful element on Earth after oxygen, yet very few foods provide it in meaningful amounts. It's a recognised component of the body's bones, tendons, skin, cartilage and blood vessels.
As Dr Barbara Hendel notes in her 2003 book Water & Salt, silica is considered one of the most important trace minerals for overall health.
Fossil Shell Flour particles carry a negative electrical charge, which is relatively uncommon among natural minerals. Substances such as heavy metals, bacteria, viruses, pesticide residues and E. coli typically carry a positive charge — one of the properties that makes Fossil Shell Flour useful as a natural soil conditioner and stored-grain protectant.
Fossil Shell Flour has achieved OMRI registration in the US, and both the United States FDA and the New Zealand Food Safety Authority (NZFSA) have assessed it as GRAS — "Generally Recognized As Safe." It also holds NZ BioGro Organic registration, approved as a livestock feed supplement and soil conditioner.
All Diatomaceous Earth is NOT created equal!
Make sure the DE you buy is fresh-water sourced, uncalcined, and BioGro & OMRI registered food-grade Fossil Shell Flour.
Freshwater diatom deposits vary significantly by location — the diatom species present, and their shape and structure, differ from source to source around the world. Perma-Guard Fossil Shell Flour™ is sourced from a single, extremely pure freshwater deposit of the diatom Aulacoseira, dating back to the Miocene epoch, prized for its consistent tubular shape and structure.
Pool-filter grade DE, for example, is heat-treated (calcined) and contains much higher levels of crystalline silica, a recognised health hazard if inhaled. Always choose food-grade, uncalcined DE, like Perma-Guard Fossil Shell Flour.