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 Codes
- UN Symbol
- Packaging Identification Codes
- Packaging Group Level Equivalent
- Gross Mass or Specific Gravity
- Hydrostatic Test Pressure or Solids
- Year and Location of Manufacturer
- Identification of the Manufacturer or Approval Agency
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".
Packaging Identification Codes
Type of Container
1 - Drums/Pails
A - Steel
Container Packaging Head or Material Wall Type
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.
- 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
- 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
- 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
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.
More Training Aids from Labelmaster
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
Click to download the UN Markings Infographic PDF.