UN Markings Guide
   - How to Read and Identify UN Packaging Codes

Understanding UN markings may seem complicated at first, but this breakdown of each element of UN markings describes how to easily read and identify the code. Take a look at this guide, which is an essential component of hazardous materials packaging.


Elements of UN Markings

UN Packaging Markings

Simplified examples of UN packaging markings in this image are for educational purposes only.
UN certified combination packages exist for shipping solid and liquid materials in a variety of outer packaging material types.

United Nations Symbol

The UN in the circle indicates packaging has been UN tested and certified. The UN symbol can either be included with a lowercase "u" over a lowercase "n" in a circle or as an uppercase "UN".


UN Markings Poster

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The UN Packaging Guide Poster provides quick reference to UN Packaging requirements for DOT hazmat training. This guide will take the guess work out of shipping and provide DOT hazardous materials training for you and your employees. The poster measures at 27" x 37" and is laminated on both sides.

Packaging Identification Codes



UN Packaging Marking Codes

Type of Container

1 - Drums/Pails
2 - Barrels
3 - Jerricans
4 - Boxes
5 - Bags
6 - Composite Packaging
7 - Pressure Receptical

Container Material

A - Steel
B - Aluminum
C - Natural Wood
D - Plywood
F - Reconstituted Wood
G - Fiberboard
H - Plastic
L - Textile
M - Paper
N - Metal other than Steel or Aluminum
P - Glass, Porcelain or Stoneware

Container Packaging Head or Material Wall Type

For Drums:
1 - Closed Head (Non-Removable Head)
2 - Open Head (Removable Head)

For Bags:
5M1 - Multiwall
5M2 - Multiwalled, Water-Resistant


Any one of the following three styles represents an example of the kind of packaging identification code that may be shown on a UN packaging.

  1. There may be a number-letter combination indicating a type of packaging and material of construction. For example:
         4D = Plywood Crate
         2D = Plywood Wooden Barrel
  2. There may be a number-letter combination indicating the type of packaging, material of construction and a subcategory within the type of packaging or variation. For example:
         1A1 = Non-Removable Head Steel Drum
         4GV = Fiberboard Box Variation II Packaging
  3. The description may also show a number-letter-letter-number combination. This mark includes the number six, indicating a composite type of packaging; two letters, the first indicating the inner receptacle's material and the second letter indicating the outer material; and the second number indicating the type of packaging (not a subcategory). For example:
         6HA1 = Composite Packaigng Consisting of a Plastic Inner, Steel Outer, Drum
         6DC4 = Composite Packaging Consisting of a Natural Wood Inner, Plywood Outer, Box


Packaging Group Level Equivalent



The letter X, Y, or Z indicates what packing group the package was tested to.
    X = Packing Group I (Highest Degree of Danger)
    Y = Packing Group II (Medium Degree of Danger)
    Z = Packing Group III (Lowest Degree of Danger)

Under the regulations, if a packaging has been tested to the highest degree of danger, it may be appropriate to place materials in that packaging which have a lower hazard. Therefore, the following is also correct:
    X = Packing Group I, II, III
    Y = Packing Group II, III
    Z = Packing Group III



Most Popular UN Packages

Sturdy Seal, 1 Liter, DOT-SP-9168 Exemption Packaging Dry Ice Packaging 173.13 Packaging, 1 x Kit, 16 oz. 4GV Packaging, 1 x Kit, 1 Liter 4GV Packaging, 2 x Kit, 1 Liter
Sturdy Seal, 1 Liter, DOT-SP-9168 Exemption Packaging Dry Ice Packaging 173.13 Packaging, 1 x Kit, 16 oz. 4GV Packaging, 1 x Kit, 1 Liter 4GV Packaging, 2 x Kit, 1 Liter

See More UN Packaging Products


Gross Mass or Specific Gravity



Gross Mass for Solids - For single or composite packagings intended to contain solids or combination packagings for all materials, the mark will include the maximum gross mass (kilograms) that the package can weight when filled (packaging plus its contents).

Specific Gravity for Liquids - For liquid hazardous materials in single or composite packagings, the mark will contain the maximum specific gravity allowable for that packaging.


Hydrostatic Test Pressure or S



Solids - For single or composite packagings intended to contain solids or combination packagings for all materials, the mark will include a capital "S".

Liquids - For liquid hazardous materials in single or composite packagings, the mark will contain the hydrostatic pressure the container was tested to; the hydrostatic pressure should be included in kPa (kilopascals) rounded down to the nearest 10 kPa.



Year and Location of Manufacture



Year of Manufacture - The marking must indicate the last two digits of the year of manufacture. (For example, 16 for 2016).

Manufacture Location Country Symbol - The symbol of the country where the manufacturing took place must be listed in the mark. For packaging produced in the United States, the mark would show "USA".



Identification of the Manufacturer or Approval Agency



The identification of the party who is certifying that the packaging meets all of the required testing must be included in the mark. This may be shown in the form of a name and address, symbol of the manufacturer, or code of the agency certifying compliance. If the symbol or code is used, both must be registered with PHMSA.



UN Markings Codes



UN Markings Infographic

UN Markings Code Infographic

Click to download the UN Markings Infographic PDF to enlarge.