David61
Crowing
If you read the label it will say 0.25---permethrinPoultry dust is a fine powder, it will create a cloud of dust during the application process, especially if a bird gets excited & flaps their wings a bit! I do wear a face mask, cuz it takes a few minutes to treat 30 birds. But I feel the cloud dissipates fairly quickly, so as not to pose any lingering problems - perhaps it's a heavier particle, but I don't know that for sure. YMMV depending on your coop/setup, the # of birds, whether you do it indoors or outdoors.
It is not like DE in that the particles of DE have razor-sharp edges, meant to cut bugs to ribbons. It can have the same effect on any other living tissue. I've never used it, I'm not sold on its safety.