- Image of Diatoms - Wikipedia
Diatomaceous earth, sometimes spelled diatomacious earth, is a naturally occurring substance that has a wide range of uses in pest control. Because it occurs naturally, it is often favored as a cheap, environmentally friendly method of pest control. It also has a wide range of other industrial uses, such as filtration or polishing.
What Is Diatomaceous Earth?
Diatomaceous earth is a siliceous sedimentary rock, produced naturally from the fossils of “diatoms” – a form of algae that has a hard shell. It is also called “diatomite” or “kieselgur”. It crumbles easily under slight pressure, into particles that range from under 1 µm to over 2 mm. It is slightly abrasive, and is highly absorbent for liquids.
How Does Diatomaceous Earth Kill Pests?
Diatomaceous earth is known as a mechanical insecticide. The small particle size gives it a very large surface area, and the structure (small, hollow particles) allows it to absorb lipids from the outer shell of the insect. Without the waxy outer layer to trap water, the insects quickly dehydrate and die. It is also favored because it is very cheap.
What Type of Bugs and Pests Does Diatomaceous Earth Kill?
Diatomite is used as a mechanical insecticide, as described above. It is also used to kill other arthropods such as spiders and some types of crustacean. It has some use for killing gastropods – snails and slugs – but this is often limited since these live in damp, humid environments, where dehydration is harder to effect. Another use is to kill fleas and bedbugs. If medical grade diatomite is used, it may be used to de-worm humans and other animals.
Diatomaceous Earth in Filtration
The structure of diatomaceous earth makes it ideal for use as a filtration agent. It is composed of very small particles, hollow in the middle, and it absorbs liquids readily. The most common use is as a filter medium in swimming pools, and it is sold under the names “Celaton” or “Celite”. It is also used to filter drinking water as part of the water treatment process, as well as beer, wine, and syrups.
Other Uses of Diatomite
Diatomite is used to make dynamite, as it easily absorbs nitroglycerine and makes it safer to transport. The same properties allow it to be used as an industrial absorbent to clean up chemical or toxic spills. It is the primary compound in certain types of cat litter. In the chemical process industry, it is used to bulk up paper, detergents and ceramics. It is also used in hydroponics, as it has properties similar to vermiculite.
Safety Concerns With Diatomaceous Earth
Diatomaceous earth is a naturally occurring material, and it is safe in most forms. Some types, however, such a flux-calcined diatomite, contain sharp edges and this makes it dangerous to breathe. The highly absorbent nature of diatomite also means that gloves should be worn when handling, to prevent hands from being dehydrated.
There are legal limits to exposure in most countries, especially for the maximum amount allowed in air in the breathing zone of workers.
Summary of Diatomaceous Earth
Diatomaceous earth is a naturally occurring material used in pest control, de-worming, killing bed bugs and fleas, and as a filtration agent. It is not a highly dangerous material, but it should be treated in the same way as other air-borne dusts. It may be bought in medical grade to de-worm humans and other mammals.
Martin Bell - Martin holds a B.Sc. degree in chemical engineering, and an M.Sc. degree in electronics and computing. He has spent more than 25 years ...
