Is Diatomaceous Earth Safe?
The EPA describes silicon dioxide as diatomaceous earth, a naturally occurring material composed of the shells of minute single-celled algae, and says it and silica gel work physically, acting as abrasives and desiccants that remove the oily protective film covering insects' bodies so they dry out and die.
The form matters. The National Pesticide Information Center says silicon dioxide occurs in crystalline and amorphous forms, that most diatomaceous earth is amorphous but can contain very low levels of the crystalline form, and that long-term inhalation of the crystalline form is associated with silicosis, chronic bronchitis and other respiratory problems, while the amorphous form is only associated with mild, reversible lung inflammation. The EPA says crystalline silicon dioxide has long been associated with silicosis, a progressive lung disease which may result in lung cancer in humans, but that the amorphous form used in pesticide formulations has not been associated with silicosis.
Breathing dust is still uncomfortable. NPIC says that if breathed in, diatomaceous earth can irritate the nose and nasal passages, and that inhaling an extremely large amount may cause coughing and shortness of breath. It also notes that the FDA lists diatomaceous earth as generally recognized as safe, and that food grade products are purified and may be used as anticaking materials in feed or as clarifiers for wine and beer.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceThe EPA says silicon dioxide is diatomaceous earth, made of the shells of minute single-celled algae, and that it acts as an abrasive and desiccant that removes the protective film on insects so they dry out and die. US EPA ↗
- Government sourceNPIC says silicon dioxide has crystalline and amorphous forms, and that most diatomaceous earth is amorphous but can contain very low levels of crystalline silicon dioxide. National Pesticide Information Center, Oregon State University ↗
- Government sourceNPIC says long-term inhalation of crystalline silica is associated with silicosis, chronic bronchitis and other respiratory problems, while the amorphous form is only associated with mild, reversible lung inflammation. National Pesticide Information Center, Oregon State University ↗
- Government sourceNPIC says diatomaceous earth can irritate the nose and nasal passages if breathed in, and that people may cough and have shortness of breath if an extremely large amount is inhaled. National Pesticide Information Center, Oregon State University ↗
- Government sourceNPIC says the FDA lists diatomaceous earth as generally recognized as safe, and that food grade products are purified and may be used as anticaking materials in feed or as clarifiers for wine and beer. National Pesticide Information Center, Oregon State University ↗
- Government sourceThe EPA says crystalline silicon dioxide has long been associated with silicosis, which may result in lung cancer in humans, but amorphous silicon dioxide used in pesticide formulations has not been associated with silicosis. US EPA ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.