Is diatomaceous earth safe if eaten? A definitive guide to grades and risks

November 21, 2025 •

4 min read

According to the Food and Drug Administration (FDA), food-grade diatomaceous earth is generally recognized as safe (GRAS) for consumption in small, controlled amounts. However, this only applies to the specific food-grade variety, and the critical distinction between grades is the single most important factor when considering: is diatomaceous earth safe if eaten?

Quick Summary

Diatomaceous earth comes in different grades, and only food-grade is considered safe for ingestion in limited quantities, passing largely unabsorbed through the body. Industrial-grade DE, containing high crystalline silica, is toxic if consumed or inhaled. Inhalation of any grade poses health risks, so caution is required during handling.

Key Points

Grade is Paramount: Only food-grade diatomaceous earth is considered safe for ingestion; industrial or filter-grade is toxic and must never be consumed.
Minimal Absorption: When consumed, food-grade DE is not significantly absorbed by the body, passing through the digestive tract largely unchanged.
Inhalation is the Main Risk: The primary health hazard is inhaling DE dust, which can cause respiratory irritation and, with prolonged exposure, irreversible lung disease, especially with the high crystalline silica in industrial grade.
Limited Health Evidence: While anecdotal reports exist, scientific evidence for health benefits like detoxification or improved cholesterol from eating DE is limited or inconclusive.
Pet Safety: Food-grade DE is generally safe for pets to ingest in small amounts, but similar to humans, inhalation must be avoided due to respiratory risks.
Protective Handling: Always wear a mask and minimize dust creation when handling DE, especially in enclosed spaces, to prevent inhalation.

Understanding Diatomaceous Earth Grades: Food vs. Industrial

Diatomaceous earth (DE) is a naturally occurring, soft, sedimentary rock that is crumbled into a fine, off-white powder. It is composed of the fossilized remains of tiny aquatic organisms called diatoms, which are skeletons made of amorphous silica. The key to answering whether diatomaceous earth is safe if eaten lies in understanding the crucial distinction between its two primary grades: food-grade and industrial-grade.

Food-Grade Diatomaceous Earth

This grade is mined from dry, freshwater lake beds and consists of amorphous silica, which is a non-toxic form of silicon dioxide. Food-grade DE contains very low levels of crystalline silica, typically less than 1-2%. It is processed to meet strict safety standards, including limits on heavy metal content, which makes it safe for various applications. Uses for food-grade DE include:

An anticaking agent in animal feed
As a natural, non-toxic insecticide for controlling pests like fleas, bed bugs, and ants
Sometimes marketed as a dietary supplement for detoxification or digestive health

Industrial/Filter-Grade Diatomaceous Earth

This grade is typically sourced from saltwater deposits and is heat-treated through a process called calcination to alter its properties for filtration. This process increases the concentration of crystalline silica, which is harmful to mammals, particularly when inhaled. Industrial-grade DE is used in a variety of commercial applications, such as filtration for swimming pools and other liquids. This type is explicitly not safe for ingestion by humans or pets.

Is Food-Grade Diatomaceous Earth Safe to Eat? Debunking the Myths

While food-grade diatomaceous earth is considered safe for consumption, it's important to approach some of the health claims with skepticism. The most established safety aspect is that when ingested, very little is absorbed by the body, and most of it is rapidly excreted. For those who choose to use it as a supplement, it is typically mixed with water, though it does not dissolve completely.

Many of the promoted health benefits are largely anecdotal and not supported by robust scientific evidence. Claims include:

Detoxification: Some proponents suggest DE helps remove toxins and heavy metals. This idea stems from its use in industrial filtration, but there is no evidence this translates to the human digestive system.
Improved Hair, Skin, and Nails: Since silica is a component of connective tissues, some believe DE supplements will improve their appearance. Research is limited and a more reliable source of dietary silica can be found in various foods.
Cholesterol Management: One small, dated human study did show a reduction in cholesterol and triglycerides in participants who took DE for 8 weeks. However, larger, more rigorous placebo-controlled studies are needed to confirm these findings.

The Real Danger: Inhalation of Diatomaceous Earth

Regardless of the grade, the primary health risk associated with diatomaceous earth is inhalation of the fine dust. The microscopic particles, especially the high concentration of crystalline silica in industrial-grade DE, can irritate the nasal passages, throat, and lungs. Prolonged occupational exposure to respirable crystalline silica can lead to serious and irreversible lung diseases, such as silicosis, lung cancer, and chronic bronchitis. While food-grade DE contains minimal crystalline silica, excessive inhalation of any fine powder can be harmful. It is crucial to handle DE carefully and wear a dust mask, especially in poorly ventilated areas.

Comparison of Food-Grade vs. Industrial-Grade Diatomaceous Earth


Feature	Food-Grade Diatomaceous Earth	Industrial/Filter-Grade Diatomaceous Earth
Source	Freshwater deposits	Saltwater deposits
Silica Form	Amorphous (safer)	Higher concentration of crystalline (toxic if inhaled)
Processing	Dried and milled, low heat	Heat-treated (calcined)
Crystalline Silica	Typically <2%	Can be very high (e.g., 60-70%)
Ingestion Safety	Generally recognized as safe (GRAS) by FDA in small amounts	NOT safe for consumption
Inhalation Risk	Irritant; prolonged exposure carries risk	Severe risk of silicosis and other respiratory diseases
Primary Uses	Dietary supplement, animal feed additive, natural pesticide	Pool filters, industrial filtration

Using Diatomaceous Earth Safely Around Pets

For pet owners, understanding the risks is equally important. Food-grade DE is often marketed for internal parasite control or as a general supplement for pets. While small, controlled amounts of food-grade DE are generally considered safe for pets to ingest, the same inhalation risks for humans apply to animals. It is critical to avoid creating dust clouds when applying DE around pets. If using it for external pest control on carpets or bedding, apply it lightly and allow the dust to settle completely before allowing pets back into the area. Never use industrial-grade DE on or around pets.

Conclusion: Prioritize Safety by Choosing the Right Grade

Ultimately, whether diatomaceous earth is safe if eaten depends entirely on the grade. Food-grade DE, with its amorphous silica and low crystalline silica content, is generally considered safe for minor ingestion. However, the unsubstantiated health claims associated with it should be viewed with caution, and a doctor should always be consulted. On the other hand, industrial-grade DE, which is heat-treated for filtration purposes, is unequivocally unsafe to eat and poses significant health risks if consumed. Regardless of the grade, the most significant danger is inhalation. Proper safety measures, including wearing a dust mask, are essential during handling to protect both human and pet respiratory health. For more information on safe handling, refer to resources like the National Pesticide Information Center fact sheet on diatomaceous earth.

Frequently Asked Questions

Food-grade DE is minimally processed amorphous silica with very low levels of crystalline silica, deemed safe for human and animal consumption. Industrial-grade is heat-treated, significantly increasing its crystalline silica content, and is only safe for industrial uses like filtration, never for ingestion.

Ingestion of food-grade DE is generally not considered harmful in small quantities. Your body will not absorb it significantly, and it will be passed through your digestive system. Some people might experience minor stomach upset.

Inhaling fine DE dust can irritate the lungs and nasal passages. Prolonged or frequent exposure to industrial-grade DE, which contains high levels of crystalline silica, can cause silicosis, a serious and permanent lung disease.

Most of the health claims, such as detoxification and improved hair/skin, are anecdotal and lack substantial scientific research to back them up. A small study showed a positive effect on cholesterol, but more research is needed.

Only food-grade DE should be used around pets. In small amounts, it is generally considered safe for ingestion. However, pet owners must be careful to prevent inhalation of the dust by their pets during application.

No. Pool filter DE is industrial-grade and has a high concentration of crystalline silica, making it dangerous for residential use and toxic if inhaled or ingested by humans or pets. Always use food-grade DE for pest control in and around the home.

Always wear a dust mask to avoid inhaling the fine powder. Work in a well-ventilated area and avoid creating large dust clouds. It's also wise to wear gloves to prevent skin dryness, especially with prolonged exposure.