Diatomaceous Earth, known as “DE†for short, is a very fine, chalk-like white powder. It is made up of the fossilized remains of single-celled aquatic microorganisms called diatoms. In a nutshell, it is ancient phytoplankton. Diatomaceous earth is found naturally in sedimentary rock and mined to use in industrial products, swimming pool filters, as an organic insecticide, in pharmaceuticals, cosmetics, and even in food.
The diatoms that make up DE have tiny rock-hard shells. Those shells are made of silica, which happens to be one of the hardest substances on earth. Fun fact: the Earth’s crust is 59 percent silica, and the main constituent of more than 95 percent of all known rocks.​
DE will harm any target insect that comes in contact with it, whether they’re directly dusted with it, or they walk over it later. That is…. as long as the DE is dry.
The main drawback with using diatomaceous earth is that when it gets wet, it’s rendered far less effective.
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inhalation exposure. It is not healthy for humans or animals to inhale fine diatomaceous earth dust.​​