Food-grade DE is diatomaceous earth that is safe for consumption by humans, and farmers often add it to stored grain to dehydrate and kill bugs. Gardeners also use food-grade DE as organic pest control, and some individuals dilute it in water and drink it as a detox supplement.
Other types of diatomaceous earth, including the type used in pool filters, aren't safe for human consumption. While food-grade DE is safe to consume, the fine dust can cause nasal irritation and shortness of breath when it is inhaled. It also can irritate the eyes and skin if individuals don't protect themselves when applying the dust.