Section 178.818 - Tear test(a)General. The tear test must be conducted for the qualification of all flexible IBC design types.(b)Special preparation for the tear test. The flexible IBC must be filled to not less than 95 percent of its capacity and to its maximum net mass, the load being evenly distributed.(c)Test method. Once the IBC is placed on the ground, a 100-mm (4-inch) knife score, completely penetrating the wall of a wide face, is made at a 45° angle to the principal axis of the IBC, halfway between the bottom surface and the top level of the contents. The IBC must then be subjected to a uniformly distributed superimposed load equivalent to twice the maximum net mass. The load must be applied for at least five minutes. An IBC which is designed to be lifted from the top or the side must, after removal of the superimposed load, be lifted clear of the floor and maintained in that position for a period of five minutes.(d)Criterion for passing the test. The IBC passes the tear test if the cut does not propagate more than 25 percent of its original length.Amdt. 178-103, 59 FR 38074, July 26, 1994, as amended at 66 FR 45386 , Aug. 28, 2001