DE is odorless and nontoxic. For ants just sprinkle a light layer of it around the bottoms of your plants, on the floor or ground.
This stuff is used in grains, rice, most things that get stored for any amount of time....We eat it(food grade). Notice how your corn meal doesn't come with weavels anymore?? There are differernt grades of it...you just need to watch if other things have been added to it....
OSHA: Diatomaceous Earth: A soft siliceous solid composed of skeletons of small prehistoric aquatic plants. Contains primarily silica. Silica: Group 3, not classifiable as to its carcinogenicity to humans (Amorphous Silica)

I would think to be too worried about this stuff would compare to living in a bubble for fear of what may be in the air....and is most surely safer than any pot you'll ever smoke.

DE is amazing stuff, is totally natural----the uses are endless.....

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"I'd love to see things from your point of view.....I just cant get my head that far up my ass"--stolen