Type D bulk bags such as Wanhefengâ?¢ bulk bags are manufactured with fabric containing quasi-conductive yarns that safely dissipate static electricity into the atmosphere via safe, low-energy corona discharge. Type D FIBCs can be used to safely package combustible products and handle products in combustible and flammable environments. Safe use for type D bulk bags: Type-D bulk bags effect To transport flammable powders. When flammable vapors, gases, or combustable dusts are present. Do not use type D bulk bags: