Type C Big Bags must be properly grounded. Accumulated static electricity is conducted to the ground by earthing bonds attached to the Big Bag.
Different types of electrostatic discharges are as follows :
Brush discharges: Generally, they are capable of igniting gases and vapors but no dust.
Corona discharges: Generally, they are not capable of igniting combustible atmospheres.
Spark discharges: Generally they are capable of igniting gases and vapors but no dust.
Propagating brush discharges: Not only gases and vapors but also dust could be ignited.