What is Diatomaceous Earth?
Diatomaceous Earth is a naturally occurring soft, sedimentary rock that crumbles easily to a fine white to off-white powder depending on other particles that get mixed in with it during excavation. The typical chemical composition is 80-90 % silica, with 2-4 % alumina, and 0.5 -2 % iron oxide, and other trace elements, making it an inert product. It does not get degraded by microbes or sunlight and will continue to be effective as an insecticide as long as it is dry and not wet.
It can be easier to spread over a lawn with a spray gun and water solution but will not be effective till it dries out.
It can hold up to 200 times its own weight in water; does not emit vapors and does not dissolve in water, though it is easily mixed with food and water and comes in many different shapes and sizes.
Diatomaceous earth (DE) is made up of the fossilized remains of diatoms (a type of hard-shelled algae) found in both fresh and saltwater environments, often 12 to 13 million years old. Diatomaceous Earth is mostly amorphous silica, but some saltwater varieties can contain Crystalline Silica and no more than 1% of crystalline Silica is allowed (in America) by the FDA. See “Did you know” notes below about Crystalline Silica.
It is used for many and varied applications such as; a filtration aid; absorbent for liquids and industrial waste and spills; mechanical insecticide; reinforcing filler in plastics & rubber; a mild abrasive in metal polishes, toothpaste and facial scrubs; kitty litter; an activator in blood clotting studies; thermal insulation and many more.
Alfred Nobel found that DE adsorbed nitro-glycerine making it more stable. His patented product we all know as ‘dynamite’.
As DE is a totally NATURAL non–chemical insecticide, insects cannot develop any immunity to it, as they might with a chemical insecticide. Its abrasive properties (like a piece of sharp glass) damage the waxy exoskeleton of an insect absorbing the lipids of their outer protective layer causing them to dehydrate and die. Glass is mostly made from silica so you can imagine what a sharp piece of glass is doing to a little insect.
Slugs cannot travel over an absorbing & abrasive layer of DE, however in humid climates they can be harder to treat with DE which may need to be mixed with other products (such as Pyrethrum products) to improve its effectiveness.
While DE is deadly to many insects (including termites), it is harmless to humans as it cannot penetrate human skin. But it can be breathed into your lungs and irritate the mucous membranes so a mask must be worm when handling large quantities of fine DE. Once the dust has settled it will not normally irritate you.
Some Bonsai growers use DE as a soil additive or even pot their Bonsai into 100% DE as it retains water & nutrients, drains rapidly and lets oxygen circulate within the growing media. This makes it very effective for Hydroponics but in a large size and not the fine 30 or 10 micron size.
DE is often used in grain silos to keep out and or kill any grain eating insects that would otherwise destroy the grain. (we use it to store wheat for propagating wheat grass). Because DE is not attractive to insects, to put it into heaps & expect it to work is a mistake as it needs to be applied directly onto the insect or where the insects will come in close contact with it.
DE can be used as a barrier to control adult flea beetles, sawfly, codling moth, twig borer, thrips, mites, cockroaches, slugs, snails, aphids, earwigs, silverfish, bed bugs, fleas and many more.
Some say the micron size must be no larger than 12 to be an effective insecticide, and must not be heat treated (calcinated) making it dangerous to humans.
Diatomite Fines is 30 microns in size, grey in colour, looks like muddy water when mixed with water, and tastes minutely gritty. In fact the grittiness is hardly noticeable unless you feel it between your fingers next to the 10 micros
DE – Absorba-cide. Absorba-cide is 10 microns in size, very fine, looks a little whiter than Diatomite Fines, is clearer when mixed with water and when swallowed is not noticeably gritty at all. But it is twice the price of the larger 30 micron size.
Either one can be swallowed or mixed with food. It all depends on how much you want to pay but there is very little difference between the two.
However we cannot endorse or recommend its use as a human food supplement as it is not prepared under sterile conditions and nor has it been officially tested and approved for human consumption though it is approved for use in grain silos. And some of this is bound to get into the food chain.
The micron size generally determines the use. EG: Kleensorb is 2-7mm in size and is mainly used as kitty litter or waste spillage. Larger sizes are used for hydroponics or garden mixes. When you handle very fine DE in large quantities be sure and wear goggles to protect your eyes; a face mask to prevent inhalation; gloves to protect your skin; and moisturizer for when it dries out your skin.
Today’s Did You Know…?
When Diatomaceous Earth is heated in a calcinator to below its melting point using extreme temperatures, it transforms into Crystalline Silica causing cancer or silicosis of the lungs if inhaled. This form of DE was once used in pool filtration systems but is now banned in Australia because of its cancerous causing qualities (which upset many people as it was such an effective pool filter system). This Diatomaceous Earth is therefore not considered ‘Food Grade’ DE and is apparently still available in America. So if you live over there be sure you are buying the right product (Food Grade) especially if you intend to ingest it or use it for your animals.
Food Grade’ DE refers to uncalcinated DE. ie: Diatomaceous Earth that has not been heated to extreme temperatures to change its physical properties. As DE comes in many shapes and sizes you would only want to ingest the very small micron sizes. You could hardly ingest DE the size of Kitty Litter (though nice to know it won’t hurt your kids if they accidentally get into the kitty litter – yuk), so naturally the best size to ingest is from 30 microns to 10 microns though I have seen it sold on line at 300 microns which is a third of a mm and would be quite gritty.
But remember we cannot endorse or recommend its use as a human food supplement as it is not prepared under sterile conditions and nor has it been officially tested and certified for human consumption though it has been tested and certified for use in grain silos. We sell the 30 micros DE for animals but you can send through a custom order for 10 microns (Absorba-Cide – very fine) if you want to pay the extra money.