I read the bag and it says dont breath it dont do this and that. I wanted to put it out in a pan for my chickens to dust in Will that be ok will it cause problems if they breath it? I am pretty confused since I know food grade is used in deworming and in feed, I also know that it is good to eliminate flies and lice ect I wondered about spreading it in the horse manure pile to eliminate bugs and maybe in the horse pasture in the manure areas. Any thoughts ??? The other thing is I purchased at the feed store and I asked for Food Grade she said it was but I dont find anything on the bag that says food Grade. Any thoughts.