Diatomaceous Earth (DE) is a naturally occurring, soft, sedimentary rock that easily crumbles into a fine, white powder. This powder is primarily composed of the fossilized remains of diatoms. The shells of these organisms are made from silica, making DE a concentrated source of silicon dioxide. In the home, DE is commonly used as a non-toxic insecticide for pest control, an anti-caking agent in food, and a filter medium. The question of whether DE is safe, particularly for children, depends entirely on its specific form and how it is handled in the home environment.
Understanding the Two Forms of Diatomaceous Earth
The safety of diatomaceous earth is conditional upon which of its two main commercial forms is being used. The first form is Food Grade DE, which is largely composed of amorphous silica. This type is minimally processed and must contain less than 1% crystalline silica. Food Grade DE is the only type considered safe for use in household pest control, as a food additive, or as a dietary supplement.
The second form is Filter Grade (or Pool Grade) DE, which is treated with high heat in a process called calcination. This heat treatment converts much of the amorphous silica into crystalline silica, resulting in a product that can contain up to 60% crystalline silica. Crystalline silica is substantially more hazardous to mammals, especially when inhaled.
Assessing Ingestion and Skin Contact Risk
Accidental exposure to Food Grade DE, whether through ingestion or skin contact, is generally considered low-risk. If a child accidentally swallows Food Grade DE, it is not chemically toxic because the body does not absorb it. The substance passes through the digestive system largely unchanged. However, due to its highly abrasive and absorbent qualities, ingestion may sometimes cause mild and temporary digestive upset. This can include slight constipation or localized irritation in the gastrointestinal tract. Regarding skin exposure, DE’s abrasive nature and ability to absorb oils may cause dryness or mild irritation.
The Primary Hazard: Inhalation Exposure
The most significant safety concern associated with diatomaceous earth is the risk posed by inhalation. The substance is a very fine, light powder, and any application that causes it to become airborne creates a respiratory hazard. When inhaled, the microscopic particles can irritate the delicate lining of the nasal passages and airways. Acute exposure may result in symptoms such as coughing, shortness of breath, and irritation of the throat.
This is particularly concerning for children, whose respiratory systems are still developing, or for those with pre-existing conditions like asthma. The chronic risk is substantially higher if the DE used contains crystalline silica, such as in Filter Grade products. Repeated or prolonged inhalation of crystalline silica can lead to serious, long-term respiratory conditions, including silicosis and chronic bronchitis. Therefore, any use of DE in the home must prioritize preventing the creation of airborne dust clouds.
Guidelines for Safe Household Use Around Children
Careful application and storage practices are required in any household with children.
Application Methods
When using Food Grade DE for pest control, the product should be applied only in areas inaccessible to infants and toddlers. This includes dusting it lightly into cracks, crevices, wall voids, or behind fixed appliances. To further reduce airborne dust, consider applying the DE as a thin, light dusting rather than a thick layer, or mixing it with water to form a slurry for application. It is important to ensure that children and infants are removed from the area during the application and cleanup process until the dust has fully settled.
Storage
Treating diatomaceous earth like any other pest control agent is necessary for safety. The product must be stored securely in its original, labeled container, completely out of reach of children, to prevent accidental access.