I thought Diatomaceous Earth was dangerous to breathe or ingest?
There are different grades of Diatomaceous Earth and many are dangerous. Never ingest or inhale crystalline Diatomaceous Earth for pools or products used for pest control that may contain other chemicals. Perma-Guard DE or Fossil Shell Flour is food grade and certified as organic. It has been approved as a food additive for grain storage. As the product is added to grains before they are processed, it does not have to be added to the ingredients on the label after processing.