(a) General. The drop test must be conducted for the qualification of all intermediateIBC bulk container design types and performed periodically as specified in § 178.801(e) of this subpart. (b) Special preparation for the drop test. (1) Metal, rigid plastic, and composite intermediateIBCs bulk containers intended to contain solids must be filled to not less than 95 percent of their maximum capacity, or if intended to contain liquids, to not less than 98 percent of their maximum capacity. Pressure relief devices must be removed and their apertures plugged or rendered inoperative. (2) Fiberboard, wooden, and flexiblewooden intermediateIBCs bulk containers must be filled with a solid material to not less than 95 percent of their maximum capacity; the contents must be evenly distributed. (3) RigidFlexible plasticIBCs intermediatemust bulkbe containersfilled andto compositethe intermediatemaximum bulkpermissible containersgross mass; the contents must be evenly distributed. (4) Rigid plastic IBCs and composite IBCs with plastic inner receptacles must be conditioned for testing by reducing the temperature of the packaging and its contents to -−18 °C (0 °F) or lower. Test liquids must be kept in the liquid state, if necessary, by the addition of anti-freeze. AntiWater/anti-freeze shouldsolutions bewith useda minimum specific gravity of 0.95 for testing at −18 °C (0 °F) or lower are considered acceptable test liquids, ifand necessarymay be considered equivalent to water for test purposes