DE - if I understand the way DE works ...no reason to put it in the food ..
Diatomite is used as an insecticide, due to its abrasive and physico-sorptive properties. The fine powder absorbs lipids from the waxy outer layer of insects' exoskeletons, causing them to dehydrate. Arthropods die as a result of the water pressure deficiency, based on Fick's law of diffusion. This also works against gastropods and is commonly employed in gardening to defeat slugs. However, since slugs inhabit humid environments, efficacy is very low. It is sometimes mixed with an attractant or other additives to increase its effectiveness. Medical-grade diatomite has been studied for its efficacy as a de-worming agent in cattle; in both studies cited the groups being treated with diatomaceous earth did not fare any better than control groups.
it works good on the outside but should be used with care
as it can be toxic to breathe in
Inhalation of crystalline silica is harmful to the lungs, causing silicosis. Amorphous silica is considered to have low toxicity, but prolonged inhalation causes changes to the lungs. Diatomaceous earth is mostly amorphous silica, but contains some crystalline silica, especially in the saltwater forms. In a study of workers, those exposed to natural DE for over 5 years had no significant lung changes, while 40% of those exposed to the calcined form had developed pneumoconiosis. Today's common D.E. formulations are safer to use as they are predominantly made up of amorphous silica and contain little or no crystalline silica.
I don't use DE and I looked the ones I recently culled carefully for bugs, None. I try to keep a pile of wood ash in there coop, I have a outside wood boiler that produces lots of it but only run it in the winter. I can't say that this is why 'no bugs' but I hope it helps. Some people swear by DE and have good things to say about it. All I know is it is not good for using the 'deep litter method' (I thought that was the only way until BYC, never heard of 'poop boards' and cleaning coops, Lol!) so I don't use it.
Silicosis!!! My dad has it! Not something to mess around with, if you use DE, or ANY concrete products, thinset mortar etc, wear a dust mask when mixing! Dad has it from yrs of working in bluestone quarries, I worked in them for many years also, no dust mask, cut off saw, tracer saw, kicking up dust like a huge cloud of smoke, heck you just cough and snot it out right? Nope! He started getting light headed, passing out almost, went to the hospital, doc said he had silicosis, stone dust has clogged his lungs. He asked 'well can't you just flush it out?' Nope, said the stone dust was like concrete in his Alveoli (air sacks) in his lungs, depleted lung function, lack of sufficient oxygen for the rest of his life. Dad uses water on his score saw now, always used water on the big block saw anyways, but not very often on the score saw, makes a muddy mess, sucks dragging the little water hose around, but no dust. He'll cut rock until he dies I figure, I miss it and would love to get back into it, I'm seventh generation bluestone quarry from my mom's side, lots of $ in it, great to be self employed, but the wife thinks a guaranteed paycheck weekly and health ins. is worth more than my happiness, Lol!