According to Chris Lind, director of technology and regulatory affairs, Mauser USA LLC, the best way to design safe packaging is to follow the United Nations recommendations, which require passing minimum performance tests. These requirements have been adopted in one form or another by most countries around the world.

History of U.N. Regs

In a presentation at the Spring Meeting of the Petroleum Packaging Council in St. Augustine, Florida, United States, Lind explained that U.N. requirements originated in recommendations made in 1956 by the U.N. Economic and Social Council on the transportation of dangerous goods. In 1996, their recommendations were divided into two parts. One controls shipments by sea; the other controls shipments by air.

In addition, Lind said, The Manual of Tests and Criteria was created in 1984 and contains technical information about the hazard classification of dangerous goods. The manual outlines criteria, test methods and procedures to be used to classify dangerous goods. Classification is done according to the provisions of the Model Regulations found in Parts 2 and 3 of the U.N. Recommendations, as well as the provisions of the Globally Harmonized System of Classification and Labeling of Chemicals (GHS).

The manual supplements national and international regulations that are derived from the U.N. recommendation, said Lind. These recommendations are not obligatory or binding on individual countries. However, they are implemented and enforced by regulatory agencies in most countries, including Western Europe, Transport Canada, United Kingdom and the U.S.

Performance-Oriented Packaging

Performance-oriented packaging is required to ensure the health and safety of the public and to protect the environment, Lind explained. The concept of performance-oriented packaging was introduced into international regulations in 1989. It simply means packaging able to perform to a specified level of integrity when subjected to a specific set of performance tests. Packaging manufacturers and fillers must supply proof that packages safely contain hazardous materials and withstand normal conditions of transportation, said Lind.

The U.N. rating of qualified containers dictates which hazardous materials can be transported in a certain package, he added. Three groups are used to classify the degree of danger. Packing Group I is for hazardous materials with the highest degree of danger. Packing Group II contains a lesser degree of danger than Group I. Packing Group III is for the least hazardous materials that still pose a threat to health and the environment.

Lind said, One issue that may crop up in the future is that GHS provides for the reclassification of several corrosives from Packing Group II and III to Packing Group I. The International Confederation of Plastics Packaging Manufacturers (ICPP) estimates two to six million intermediate bulk containers would effectively be removed from the global market because most IBCs are not authorized for Packing Group I chemicals.

The fillers must use suitably rated drums, if available. This will have a tremendous impact on the supply chain and the status and availability of packaging.

As noted above, the general requirement of U.N. testing for all packaging types is to ensure that the design can withstand normal conditions of transportation. However, Lind said, these are considered only minimum requirements. Each package must be manufactured and assembled so as to successfully pass the prescribed tests and to conform to the general requirements for integrity of a U.N.-rated package.

Each test sample must be closed in preparation for testing, and tests must be carried out as if the package has been prepared for transport. Special preparations may be required depending on package type and required test.

Bulk Packaging

U.N.-rated packaging includes bulk (or large) packaging and non-bulk packaging. Bulk packaging is further classified as flexible bulk containers (FBCs) and intermediate bulk containers (IBCs). Bulk packaging is defined as having:

Maximum capacity greater than 450 liters as a receptacle for a liquid;

Maximum net mass greater than 400 kilograms and a maximum capacity greater than 450 liters as a receptacle for a solid; or

Water capacity greater than 454 kg as a receptacle for a gas.

Lind said, Flexible bulk containers intended for transporting hazardous materials must be waterproof and sift-proof, and remain completely closed during transport to prevent the release of contents. They must also resist and not react with the hazardous material they contain. Finally, FBCs cannot be used for more than two years from the date of manufacture.

IBCs are rigid or flexible portable packaging other than a cylinder or tank that is designed for mechanical handling. IBCs can be metal, plastic, fiberboard, wood or flexible composites. They have a maximum volumetric capacity of 3 cubic meters (3,000 liters). Tests on U.N.-rated IBCs must be performed in a prescribed sequence and include the tests shown in Table 1.

Drop: All IBCs must be drop tested periodically, said Lind. Samples must be dropped onto a rigid, non-resilient, smooth, flat and horizontal surface. The point of impact must be the most vulnerable part of the IBC base.

Drop heights are 1.8 meters for Packing Group I, 1.2 m for Packing Group II, and 0.8 m for Packing Group III. Following the drop, the IBC must be restored to the upright position and elevated off the ground for observation and evaluation.

Leakage: Lind said, All IBCs intended to contain liquids or solids that are loaded or discharged under pressure must be tested for leaks. The test must be run for a suitable length of time using air at a gage pressure of not less than 20 kiloPascal. Leaks are detected by coating the seams and joints with a heavy oil, soap solution or other suitable method.

Hydrostatic Pressure: All IBCs intended to contain liquids or solids that are loaded or discharged under pressure must be tested, said Lind. Hydrostatic gage pressure must be measured at the top of the IBC. The test must be carried out for at least 10 minutes, applying a pressure not less than the IBCs design rating. No leaks must be detected.

Non-Bulk Packaging

Lind said, The non-bulk packaging group is the most diverse in terms of variety, size, shape, composition and U.N.-rating capabilities. Non-bulk packaging is defined as having:

A maximum capacity of 450 liters as a receptacle for a liquid;

A maximum net mass of 400 kg and a maximum capacity of 450 liters as a receptacle for a solid; or

A water capacity of 454 kg as a receptacle for a gas.

Tests for non-bulk packaging include drop, leakage, hydrostatic pressure, stacking and vibration.

Drop: The drop test must be conducted to qualify all packaging types and be performed periodically, said Lind. For other than flat drops, the center of gravity of the test package must be vertically over the point of impact. Where more than one orientation is possible for a drop test, the orientation most likely to result in failure must be used. Table 2 lists the drop heights for non-bulk packaging.

Stacking: Test duration is 24 hours, except that plastic drums, jerricans and certain composite packaging intended for liquids are tested for 28 days at 40 degrees C or higher. There must be no visible buckling.

Dynamic Compression: Lind said, Packaging can be tested using a dynamic compression testing machine and must be conducted at room temperature on an empty, unsealed package. Compression must be applied end to end, and the speed of the compression tester must be 1.25 centimeters per minute 0.635 cm/min. The dynamic force must be 1.5 times the static load used on the stacking test. It can be used for in-production tests and annual requalification.

Vibration: Three sample packages, selected at random, must be filled and closed as for shipment and placed on a vibration table with a 2.5-cm peak-to-peak displacement. Lind noted, The test must be performed for one hour at a frequency that causes the package rise from the vibrating platform to such a degree that a piece of material of approximately 1.6-mm thickness can be passed between the bottom of the package and the platform. Immediately following the vibration test, the package must be turned on its side and observed for evidence of leakage.

Hydrostatic Pressure: Lind said, This test is required for all metal, plastic and composite packages intended to contain liquids. The test is not required for the inner packaging of combination packages, except for packages transported by air. The test lasts for 5 minutes for a steel drum and 30 min for a plastic drum. No leaks must be detected.

If the material to be transported is replaced for test purposes by a non-hazardous material, the test material must have the same or higher specific gravity, and other physical properties that might influence the results must correspond as closely as possible to those of the hazardous material.

Lind said, Water can be used for the liquid drop test for steel drums. Also, additives, such as bags of lead shot, can be used to produce the required total package mass, as long as their placement does not affect test results.