49 C.F.R. § 178.1050 – Top lift test.

(a) General. The top lift test must be conducted for the qualification of all of Flexible Bulk Containers design types to be lifted from the top.
(b) Special preparation for the top lift test. Flexible Bulk Container design types must be filled to six times the maximum permissible gross mass, the load being evenly distributed.
(c) Test method.
1. (1) A Flexible Bulk Container must be lifted in the manner for which it is designed until clear of the floor and maintained in that position for a period of five minutes.
2. (2) If not tested as indicated in paragraph (c)(1) of this section, a Flexible Bulk Container design type must be tested as follows:
  1. (i) Fill the Flexible Bulk Container to 95% full with a material representative of the product to be shipped.
  2. (ii) Suspend the Flexible Bulk Container by its lifting devices.
  3. (iii) Apply a constant downward force through a specially designed platen. The platen will be a minimum of 60 percent and a maximum of 80 percent of the cross sectional surface area of the Flexible Bulk Container.
  4. (iv) The combination of the mass of the filled Flexible Bulk Container and the force applied through the platen must be a minimum of six times the maximum net mass of the Flexible Bulk Container. The test must be conducted for a period of five minutes.
  5. (v) Other equally effective methods of top lift testing and preparation may be used with approval of the Associate Administrator.
(d) Criteria for passing the test. For all Flexible Bulk Containers design types designed to be lifted from the top, there may be no damage to the Flexible Bulk Container or its lifting devices that renders the Flexible Bulk Container unsafe for transport, and no loss of contents.