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UN Packaging

Customer Guide to UN Packaging

The DOT packaging regulations requiring Performance-Oriented Packaging (POP), are based upon UN recommendations on the shipment of hazardous materials.

With the passage of HM-181 in 1992, the U.S. DOT has, for the most part, done away with construction specifications of packaging and has converted to performance-oriented methods, whereby a package is required to pass a series of tests to determine its suitability to package certain materials.

The applicability of the hazardous materials regulations was extended to all intrastate shipments of hazardous materials by highway effective October 1, 1998, as published in the final rule, Docket HM-200 dated January 8, 1997. This final rule also provided exceptions for "materials of trade", "agricultural operations" and certain non-specification packaging used in commerce.

Packaging for hazardous materials is now dependent on the hazard classification of a product and its physical attributes. The "UN" marking on the package indicates the level to which the package is tested and passed.

Click here for a Hazardous Materials Glossary of Terms.

The Information Required for Packaging Hazardous Materials

To determine proper packaging used for shipment of hazardous materials, certain information about the product being shipped is required, and the shipper should have up-to-date copies of CFR 49 Parts 100-185 (revised as of 10/1/96). If shipping by air, copies of IATA (International Air Transport Association) and ICAO (International Civil Aviation Organization) regulations are a must. The UPS Guide for Shipping Ground and Air Hazardous Materials (can be found at the link provided) They have some of their own packaging requirements in addition to the UN requirements. For shipments to foreign countries, the shipper is required to be aware of the regulations of the country of destination for products being shipped to that country.

Minimum product information required would be the product's:

  • UN number (according to the hazardous materials table, CFR 49 part 172.101)

  • Proper shipping name

  • Hazard classification

  • Packing group

  • Product density

  • Vapor pressure (for liquids),

  • Maximum gross weight (of the container with lading, in kilograms for solids)  

Hazardous Classifications and Packing Groups

Materials are grouped as to the specific hazard they present. The groups are: 


  • Explosives

  • Gases

  • Flammable Liquids

  • Flammable Solids

  • Oxidizers

  • Poisonous Materials

  • Corrosive Materials

  • Miscellaneous.


Some products may present multiple hazards. In those cases the Federal Regulations have tables to determine which hazard takes precedence.

Within each hazard classification there are three packing groups (I, II, & III). Packing Group I presents the greatest risk (the most regulated), Packing Group II presents a moderate risk (moderately regulated), and Packing Group III presents the least risk (the least regulated).

In the marking of packaging with a "UN number", Group I corresponds to a marking of "X", Group II to a marking of "Y", and Group III to a marking of "Z".

How to Read a UN Number or Marking

The marking that is applied to a UN certified package indicates the type of package and the levels to which the packaging has been approved. The following describes the sequence of numbers and letters that appear in a UN marking and what they designate.

Contents of UN Markings
The markings associated with performance criteria indicate the type of package and the levels to which the package has been approved. Each set of information is separated by a slash mark (/). The following explains each set of numbers and letters in the sequence.

Relative Density (Specific Gravity) or Gross Mass 
A designation of Specific Gravity or Gross Mass for which the packaging has been successfully tested should follow the Performance Standard Code.

a) Stand alone packagings intended to contain liquids must be marked
with the specific gravity rounded down to the first decimal.

b) Packagings intended for solids or that have inner packagings must
be marked with the maximum gross mass (weight) in kilograms.


Designation of "S" for Solids or the Hydrostatic Pressure Test Rating in Kilopascals
An "S" in upper case should follow the gross mass to designate that the package is only intended for solids or inner packagings. Single or Composite packagings intended for liquids should reflect the Hydrostatic test pressure in kPa (kilopascals), rounded down to the nearest 10 kPa.

Year of Manufacture
The last two digits of data indicate the year the packaging was manufactured.

Examples of UN Markings

Shipper's Responsibilities

It is the responsibility of the packager/shipper to determine the proper packaging specification for each lading, and that the packaging is compatible with the lading. The shipper determines that the packaging is authorized, properly manufactured, assembled, and marked.

It is the shipper's responsibility to ensure that the package is assembled, closed, or otherwise prepared for transport in full compliance with the specification standard under which the packaging was manufactured, including any instructions or conditions set forth by the manufacturer.

If the shipper assembles a package, fills it with a hazardous material and closes it, and does not depart from the manner in which the manufacturer certifies the package for use, the shipper can safely assume the package is capable of meeting UN standards. The shipper may not alter or amend a package design or specification without assuming full responsibility for doing so.

The shipper may request copies of the manufacturer's certification for compliance to demonstrate that each container conforms with the performance testing of CFR 49, Part 178.600.

Manufacturer's Responsibilities

The manufacturer designs, constructs, and tests packaging in accordance with CFR 49, Part 178. The manufacturer is responsible to assist the shipper in assuring compliance (such as providing the instructions or assistance on how to properly prepare and close a package to comply with the specification standard).

The manufacturer is also responsible for notifying the shipper of all specification shortfalls or any steps the shipper must take to conform to the applicable specification (e.g. the procedure to be followed when closing a package after filling).

Testing Requirements

The packaging manufacturer is responsible for performing and documenting design qualification testing and periodic retesting in accordance with Part 178, Subpart M for all packaging manufactured to U.S. standards (refer to 178.601 through 178.609). All test records are to be kept at each location where the packaging is manufactured and at each location where design qualification tests are performed. Records are to be kept as long as the packaging is produced and for at least two years thereafter.

Design Qualification Testing

Design qualification testing is performed to determine the capabilities of a packaging. The following are the required tests for Performance Oriented Packaging:

Drop Test

To ensure and protect against Hazardous Materials from leaking or escaping if the package is dropped during conditions of transport.

Packages as prepared for transportation are dropped from the appropriate height onto a rigid, horizontal and flat surface. The number and type of drops depend on the packaging being tested. The drop height will depend on the Packing Group and Specific Gravity of the material for which the packaging may be used.

Leakproofness Test

To ensure that the package will not leak or permit liquids to escape as a result of the normal build up of air pressure within the packaging under conditions of transport. This test must be performed on all packaging intended to contain liquids, except the inner packaging of combination packaging. It must also be performed during production of each packaging before its intended initial use for the containment and transport of hazardous materials.

The packaging being tested will be placed under water and restrained. A minimum internal pressure will be applied to the packaging that is appropriate for the Packing Group for which it is being tested.

Hydrostatic Pressure Test

To ensure that the packaging will not leak under pressure.

Packaging to be tested are filled with water or other suitable liquids so as to eliminate all air pockets. The appropriate amount of pressure is applied internally through a fitting that has been installed on the packaging for this purpose. The pressure must be maintained for 5 minutes for metal and composite glass, porcelain, or stoneware, and for 30 minutes for plastic and composite packaging of plastic material.

Stack Test

To ensure the ability of the packaging to remain intact and hold its contents under normal stacking conditions during transport.

Test samples are to be subject to a force applied to the surface of the sample equivalent to the total weight of identical packages which may be stacked on it during transport. The minimum stack height is no less than 3 meters (10 ft.).

Vibration Test

In addition to the forementioned tests, non-bulk packagings must be capable of withstanding the vibration test specified under (178.601).

The packaging is placed on a vibrating platform and restrained from horizontal movement, but free to bounce, rotate, and move vertically. The test must be performed for one hour and at a frequency that causes the package to be raised from the platform in such a manner that a piece of material such as steel strapping or paperboard can be passed between the bottom of the package and the platform. After the test, the package must be check for leaks.

Periodic Retesting

Periodic retesting must be done at intervals of sufficient frequency to ensure that the packaging produced by the manufacturer is capable of passing the design qualification tests. For single or composite packaging, the periodic retest is to be done no less than once each 12 months. For combination packaging the retesting must be done no less than once each 24 months. The requirements of the periodic retest are the drop, leakproofness, hydrostatic pressure, and stacking tests.

Limited Quantities

As used in 49 CFR the term Limited Quantity means a material that is packaged in accordance with a "limited quantity" paragraph or sub paragraph contained within the Packaging Section to which you are referred to column (8A) of the Hazardous Materials Table.

Shipments eligible to be shipped as limited quantities are generally excepted from one or more of the requirements of 49 CFR such as labeling, DOT Specification Packaging, Placarding, etc. These exceptions can result in substantial cost savings and increased transportation efficiency.

It should be noted that although the packaging does not have to be in a UN Specification Packaging, all packaging and packages, including those for which there is an exception, must meet the general packaging requirements contained in Subpart B of Part 173.


The information appearing in this catalog has been provided to give our customers, particularly those that are unfamiliar with UN Packaging Regulations, a brief overview of what UN packaging is all about, and some of the basic requirements. Fox Valley Containers, Inc. or the author does not make any warranty or representation, either express or implied, with respect to the completeness or absolute accuracy of this information; nor does either assume any liability of any kind resulting from the use of, or reliance upon, any information, conclusion, procedure, or opinion contained in this section. Furthermore, they assume no responsibility for maintaining or notifying of changes, additions or terminations.

Contact the Department of Transportation for formal interpretations of the regulations governing the Transportation of Hazardous Materials.

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