Is Diatomaceous Earth Eco-Friendly and Harmless to Humans?

Diatomaceous earth

So, you’ve got some unwanted bugs in your life that you’d like to kick to the curb. And you prefer to keep things organic. 

You’ve heard of diatomaceous earth (DE). Yet, you’re questioning your ability to even spell or pronounce it, let alone understand and use it. 

Good news: here comes a rundown on what diatomaceous earth is and what it can do for you. 

Today, we at Clean Air Gardening are going to discuss whether it is eco-friendly and harmless to your health (spoiler: it is). 

But first up: a quick bit of environmental science. 

What is Diatomaceous Earth?

diatomaceous earth dust, used to treat bed bugs and flea pests

Diatomaceous earth, also known as DE, is a naturally occurring, soft, sedimentary rock. It is used in a crumbled, and white powder form. 

Diatomaceous earth comes from the root word “diatom,” which is a group of microalgae found in water and soil throughout the world.

Diatomaceous earth consists of the fossilized remains of diatoms. The diatoms remains are mined and ground up to produce usable DE. 

The typical composition of oven-dried diatomaceous earth looks like this:

  • 86% silicon dioxide 
  • 5% sodium
  • 3% magnesium
  • 2% iron
  • 4% other minor constituents

As you can see, the main component is silicon dioxide, also known as silica. 

Silica is an oxide of silicon, most commonly found in quartz, sand, and living organisms. 

Why Diatomaceous Earth Is Used

Diatomaceous earth is used for a wide variety of purposes. In addition to the insect control uses (which we’ll be discussing later), here are a few other common uses of diatomaceous earth:

  • Industrial water filtration
  • Swimming pool filtration 
  • Absorbent for liquids
  • Cat litter
  • Dietary supplement
  • Toothpaste ingredient

The uses of DE generally relate to its excellent ability to absorb water. 

Diatomaceous Earth and Pest Control 

Diatomaceous earth works great as an insect killer. It’s a natural alternative to toxic chemical pesticides. 

Using diatomaceous earth is a mechanical, rather than a chemical form of pest control. 

Quick Fact: A mechanical pest control is one that provides a protective barrier between plants and insects. 

These pest controls are used by gardeners seeking non-toxic, eco-friendly pest control. 

How it Works

The fine particles of diatomaceous earth dust have sharp edges. Therefore, the powder clings to the bodies of insects as they walk over it. 

Then, the sharp edges scratch and cut an insect’s outer body. This results in the organism drying out and dying. 

Some species will die after contact with diatomaceous earth. Others will simply avoid the area where it is applied. 

DE is effective on all sorts of bugs. This includes fleas, ants, cockroaches, and even bed bugs. 

Diatomaceous Earth for Indoor Use

diatomaceous earth treats flea, ant, and bed bug infestations of house plants

Use diatomaceous earth indoors to treat unwanted house guests. 

It can help with earwigs, millipedes, centipedes, silverfish, cockroaches, ants, and fleas. 

Lightly coat a thin layer on an affected area. Small amounts of treatment will produce the best results. 

Apply diatomaceous earth behind cabinets and appliances, surrounding garbage cans, and on pipes. Spread it anywhere where intruders are found. 

Diatomaceous earth may also be used in your potting soil mix for indoor plants. Yet, be sure to research the particular soil needs of any plant before preparing its mix. 

See below for a discussion of health concerns related to using diatomaceous earth indoors.

Diatomaceous Earth for Lawn and Garden

apply diatomaceous earth dust to garden plants to control flea and other pest populations

Diatomaceous earth is safe and helpful for getting rid of unwanted insects in your lawn and garden. 

It’s also useful when applied to a variety of other affected outdoor areas. This could be patios, windows, and building foundations. 

Just like with indoor use, lightly coat a thin layer of diatomaceous earth to an affected area. This will help clear out the unwanted insects.  


Diatomaceous earth can help protect your lawn from unwanted insects. 

During the spring and summer rainy season, bugs are most active. Treat your lawn once per month during this time of year.

Diatomaceous earth applied to your lawn will help keep out numerous unwelcome visitors. These include ticks, termites, slugs, and others.

However, DE will not harm earthworms or beneficial microorganisms. 

Apply by hand, or use a spreader. For efficiency, mix your DE with fertilizer or seed and distribute it together. 


Diatomaceous earth is a great natural pesticide for garden use. 

DE will help to control numerous garden intruders. These include aphids, slugs, snails, roaches, ants, and beetles. 

Apply DE after watering your plants. The moisture will help the dust stick to the plant surfaces. 

Additionally, apply DE on the ground at the roots of your plants. 

Here are a few specific garden applications for diatomaceous earth:

Garden Location
Where to Apply DE
Planted area Leaf surfaces (not flowers) Leaf-eating insect control
Planted area On the ground around plants Slug and snail control
Potted plants Mixed in with potting soil Improve soil porosity
Compost heap Sprinkle on top of heap Maggot/fly control

As described above, DE is a mechanical control rather than a chemical control. Therefore, insects are not able to build up a tolerance to it. 

You want to keep your DE application safe for the health of bees and other pollinators. So, simply avoid applying the dust on flowers. 

Quick Fact: DE is not harmful to worms or microorganisms that live in your soil.

Diatomaceous Earth and Human Health

It’s important to know if the products you buy will be safe for your health. And the health of your pets. 

There are two main forms of silica: crystalline and amorphous (non-crystalline). 

Likewise, there are two main forms of diatomaceous earth. 

Diatomaceous earth is either:

  • Food Grade – contains 0.5-2.0% crystalline silica
  • Filter Grade – contains around 60-90% crystalline silica

Inhalation of crystalline silica is harmful to the lungs. It can result in the disease silicosis. 

Therefore, filter grade DE is toxic to humans. It’s used for industrial purposes, such as water filtration. 

Food grade DE is not toxic. 

Food grade DE is what you want to purchase for your home and garden needs. Be sure you can see “food grade” written on the product packaging. Otherwise, you might be buying the filter grade DE that is used for swimming pool filters. 

Diatomaceous earth sold in this form is absolutely safe to use around your family and your pets. This includes individuals with weak immune systems or chemical sensitivity. 

Note: Food grade DE is approved for use by the United States EPA and FDA. 

Today, we’re focused on home and garden uses for DE. However, DE is also sometimes used as a dietary supplement or toothpaste ingredient. 

Here is Professor Stuart B. Hill of McGill University on DE and human health: 

“The only health precautions that need to be taken are that if large areas are being treated with a power duster, the applicator should wear a mask to prevent inhalation. Because DE is made of silica, people sometimes mistakenly think that DE causes silicosis. …however, pesticide quality DE is usually over 97 percent amorphous silica, which does not cause silicosis. …Indeed, inhalation of road dust and grain dust is likely to be more harmful than DE.”

Inhalation of a large amount of any sort of dust is unpleasant and potentially harmful. So, during a large application of DE it’s advisable to wear a mask. 

However, as noted by Professor Hill, inhalation of DE is less harmful to health than inhalation of common road dust. 

Natural Pest Control with Diatomaceous Earth

Diatomaceous Earth is available from Clean Air Gardening in two-pound bags. Click here for a product description.

One bag is effective for treating 800 to 1,000 square feet. 

Skip the toxic chemicals. Consider diatomaceous earth as a natural insect control treatment.

Featured image:

snail on patio with text overlay tips for using diatomaceous earth around the home and garden

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