Pets & Animals Dogs, Tics and this Weather.

I think you're right it will not be food grade. All I know is diatomaceous earth is made from crushed up sea shells (or similar).
There is not much tech to this stuff. To make it "food grade" may only involve a price increase. LOL

 

Actually there is a difference. See: http://www.absorbentproductsltd.com/food-grade-diatomaceous-earth-vs-pool-grade.html

What is the difference between food chemical codex grade (food grade) and pool grade DE?

The difference here lies in the way that each type of DE is treated. Pool Grade DE is calcined, meaning that is treated with very high heat. This turns the silicon dioxide that is present in the DE into crystalline silica. Pool Grade diatomaceous earth, and most other calcined DE products, contain high concentrations of crystalline silica. In fact, some can range from 60 - 70% crystalline silica.


Crystalline silica is very dangerous and can be harmful to the health of humans and animals. For this reason, Pool Grade diatomaceous earth should NOT be used for any purpose other than filtration.


Most Food Chemical Codex Grade (Food Grade) diatomaceous earth products, on the other hand, are not calcined and are composed largely of amorphous silica. Food Chemical Codex Grade (Food Grade) DE products contain less than 1% crystalline silica and can be used in animal feed and for insect control. Food Grade diatomaceous earth, such as Red Lake Earth, unlike pool grade DE, is safe to be used around humans and animals.