Diatomaceous earth (DE) is a naturally occurring, silica-rich sedimentary mineral made from the fossilised remains of tiny aquatic organisms called diatoms.
Diatoms have been part of the earth's ecology for millions of years. Over time, their microscopic remains accumulated to form deep, chalky deposits known as diatomite. These deposits are mined and finely ground into a powder with a texture similar to talcum powder.
Diatomaceous earth is also used as a natural, mineral-based insect control product. It has been used in grain storage and other applications as a physical means of controlling insects.
Food Grade vs Pool Grade
There are different grades of diatomaceous earth, and it is important to use the correct type.
Food grade DE is the type commonly used around the home, garden and animals.
Pool grade DE has been heat-treated and is intended for use in swimming pool filtration. It should not be fed to animals.
Always check the product label to ensure you are using the appropriate grade for your intended purpose.
What Does Diatomaceous Earth Contain?
Diatomaceous earth is primarily composed of silica, together with naturally occurring minerals and trace elements. Its exact mineral composition varies according to its geological source.
Some DE products may contain minerals such as calcium, magnesium, sodium and iron, together with trace elements.
Is Diatomaceous Earth Safe?
Food grade DE is generally considered suitable for a range of animal and household applications when used according to the product directions.
Although DE is not considered a conventional chemical poison, the fine dust can irritate the eyes and respiratory system. Avoid breathing the dust when applying it. A suitable dust mask or respirator should be worn when handling larger quantities, and application should be carried out in a well-ventilated area.
When adding DE to animal feed, avoid creating airborne dust. Mixing it thoroughly into moist food can help minimise dust inhalation.
Once the dust has settled, the risk of inhalation is greatly reduced.
Suggested Animal Feeding Rates
The following are traditional Greenpet guidelines for food grade DE:
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Horses: ½–1 cup daily mixed into feed
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Dogs: 1 teaspoon–1 tablespoon daily mixed into moist food
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Cats: 1 teaspoon daily mixed into moist food
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Chickens: Up to 5% of feed
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Goats: Up to 10% of grain feed
Always use food grade DE and follow the directions supplied with the particular product.
Using Diatomaceous Earth Around the Home
Food grade DE can also be used as a dry powder around areas where insects are present. It works through physical action rather than by conventional chemical poisoning, so thorough application to areas where insects hide is important.
For household use, pay particular attention to:
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Around room edges and skirting boards
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Along door frames
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Under furniture
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Gaps and cracks in walls
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Around mattress edges and the bed base
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Around and underneath sofa cushions
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Along carpet edges
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Behind picture frames and mirrors
Allow the DE to remain in place for several days before vacuuming, then reapply if required. Regular cleaning and vacuuming can also help remove insects and eggs from the environment.
Take care when applying DE around pets and people to minimise airborne dust.
Using Diatomaceous Earth in the Garden
DE can be applied around plants and garden areas where insects are a problem.
It may also be used around the base of fruit trees and on tree trunks, depending on the intended application and the directions for the particular product.
For spray applications, follow the manufacturer's recommended mixing and application rates rather than relying on a general rate, as different DE products vary.
Important Note
Only use food grade diatomaceous earth around animals or where ingestion could occur. Pool grade DE should never be fed to animals.
Because DE is a very fine powder, avoid inhaling it during application and take care to prevent unnecessary exposure to the eyes and respiratory system.