After nhalation of D.E., mild irritation may occur in the respiratory system, mucus membranes, and lungs but it will be rapidly eliminated from lung tissue. Asthmatics should avoid using it in confined areas. However, with daily exposure, minor amounts can accumulate in lung tissue and lymph nodes, causing minor to moderate scarring and/or silicosis in mammalian respiratory systems. Since the Avian respiratory system is much more complex than ours, taking up most of a bird's body, excess dust entering the respiratory system can form caseous (damaged or necrotic tissue that has cheesy consistency) tracheal plugs in the bronchi junction (where the lungs connect to the trachea), obstructing breathing.Hello all, I enjoy reading all the advice on here , so thanks. I have been investigating lime use too. As far as D.E goes...having silica in it....is that bad for your (and chickens) respiratory system? Is it the same 'silica' that is now being highlighted in stone bench manufacturing that causes Silicosis??