Bulk Solids Containers (Silos)
Silos can contain non-hazardous and hazardous materials in a granular form. Even non-regulated materials such as grain and sugar should be considered hazardous either from an explosion hazard and/or asphyxiation hazard.
Photo of three cylindrical storage tanks.  Worn white in color.  They are possisioned next to a dark grey piece of industrial equipment.