Diatomaceous earth is a material derived from fossilised diatoms. Some products are used to control crawling insects, but not every diatomaceous earth powder is suitable for that purpose.
How does diatomaceous earth work?
On contact with an insect, an appropriate powder damages the protective waxy layer and promotes water loss. The insect must come into direct contact with the product; simply having powder in a room does not guarantee a result.
“Natural” does not mean risk-free
Breathing dust can irritate the respiratory tract; contact can irritate eyes and dry or irritate skin. Keep the product inaccessible to children and pets. Follow the protective measures on its label.
How should a product be selected?
Check that the label specifies the target pest, permitted application location and safety conditions. “Food grade” alone does not establish that a product is safe or effective for indoor pest control. Do not use swimming-pool filter material for this purpose.
Its role in a wider control plan
Diatomaceous earth does not replace pest identification, hygiene measures, restricting entry routes or monitoring. A specialist should assess whether it is needed and how it fits with other methods.
Sources: NPIC — diatomaceous earth fact sheet; NPIC — food-grade diatomaceous earth.
Read about pest control methods. For advice on selecting a service, contact CSMG.