49 C.F.R. § 178.1070 – Tear test.

(a) General. The tear test must be conducted for the qualification of all of Flexible Bulk Containers design types.
(b) Special preparation for the tear test. Flexible Bulk Container design types must be filled its maximum permissible gross mass, the load being evenly distributed.
(c) Test method.
1. (1) A Flexible Bulk Container design type must be placed on the ground and a 300 mm (11.9 in) cut shall be made. This 300 mm (11.9 in) cut must:
  1. (i) Completely penetrate all layers of the Flexible Bulk Container on a wall with a wide face.
  2. (ii) Be made at a 45° angle to the principal axis of the Flexible Bulk Container, halfway between the bottom surface and the top level of the contents.
2. (2) The Flexible Bulk Container after being cut according to the provisions of § 178.1070(c)(1), must be subjected to a uniformly distributed superimposed load equivalent to twice the maximum gross mass of the package. This load must be applied for at least fifteen minutes. Flexible Bulk Containers that are 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 fifteen minutes.
(d) Criterion for passing the test. For all Flexible Bulk Container design types, the cut must not spread more than an additional 25% of its original length.