Nature"s Wisdom DE contains Perma-guard de. PERMA-GUARD is the trade name known world wide for using a grade and quality of Diatomaceous Earth (DE) that is extremely pure. It was important to have a consistent shape diatom and no unwanted sediment. The shape of the diatom must be tubular with holes on the walls. It must be fresh water because the diatoms form a harder shell and is less fragile that those in salt water. Salt water deposits contain a mix of diatom species. These deposits shapes and sediments are inconsistent making them unusable for our products. Out of 600 deposits in the US only 4 are considered "food grade" by the FDA standards. Other food grade deposits still may contain higher amounts of sediment and clay that make them less effective. We have analysis of many other "Food Grade" deposits and are satisfied that we still obtain the diatomaceous earth for our products from the purest fresh water source.Perma-Guard products use Diatomaceous Earth, mother natures eco-friendly naturally organic material. Our products fit into the "living Green" lifestyle. Actually, DE is not an earth. It is the fossilized remains of microscopic shells created by one celled plants called DIATOMS.