Here’s some info on the hazards of DE:
Inhalation Dangers
The major danger of food grade diatomaceous earth arises from the fact that it is a powder and is made from silica. A person can inhale powder into the lungs and become ill. The Centers for Disease Control and Prevention states that inhaled silica can cause a range of diseases such as silicosis. Other diseases of the lungs can also be made more likely from inhaling silica, such as tuberculosis. Exposure to silica may also be involved in the development of other non-lung related diseases such as autoimmune problems and chronic kidney disease. These dangers are more likely to occur with repeated exposures to the substance.
Irritation Risks
The diatomaceous earth powder particles can also cause irritation because of their small size and abrasive properties. If a person is exposed to the powder, the powder can get into the eyes, which are sensitive to dust. The eyes may become red and scratched, although this effect is temporary. The dust can also irritate the lining of the throat and the inside of the nose.
Cancer Risks
Food grade diatomaceous earth is not intrinsically carcinogenic, but the changes to the lungs that a person can suffer from through silica exposure can lead to lung cancer.