49 CFR § 178.1055 - Stacking test.

---
identifier: "/us/cfr/t49/s178.1055"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 178.1055 - Stacking test."
title_number: 49
title_name: "Transportation"
section_number: "178.1055"
section_name: "Stacking test."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "HAZARDOUS MATERIALS REGULATIONS"
part_number: "178"
part_name: "SPECIFICATIONS FOR PACKAGINGS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97."
cfr_part: "178"
---


# 178.1055 Stacking test.

(a) *General.* The stacking test must be conducted for the qualification of all Flexible Bulk Containers design types.

(b) *Special preparation for the stacking test.* All Flexible Bulk Containers design types must be loaded to their maximum permissible gross mass.

(c) *Test method.* (1) All Flexible Bulk Containers must be placed on their base on level, hard ground and subjected to a uniformly distributed superimposed test load that is four times the design type maximum gross weight for a period of at least twenty-four hours.

(2) For all Flexible Bulk Containers, the load must be applied by one of the following methods:

(i) Four Flexible Bulk Containers of the same type loaded to their maximum permissible gross mass and stacked on the test Flexible Bulk Container;

(ii) The calculated superimposed test load weight loaded on either a flat plate or a reproduction of the base of the Flexible Bulk Container, which is stacked on the test Flexible Bulk Container.

(d) *Criteria for passing the test.* There may be no deterioration that renders the Flexible Bulk Container unsafe for transportation and no loss of contents during the test or after removal of the test load.