Understanding UN Packaging Codes: A Guide to Properly Classifying Dangerous Goods

dangerous goods packaging

When it comes to transporting hazardous materials, it is crucial to adhere to strict regulations to ensure the safety of everyone involved. One of the key components in this process is understanding UN packaging codes, which play a vital role in properly classifying dangerous goods for transportation.

What are UN Packaging Codes?

UN packaging codes, or UN numbers, are internationally recognised symbols assigned to specific hazardous substances or articles. These codes are regulated by the United Nations Committee of Experts on the Transport of Dangerous Goods and serve to identify and categorise dangerous goods for transportation purposes.

Each UN dangerous goods packaging code is unique to a particular hazardous material and provides essential information for safely handling, packaging, and transporting these substances.

The Structure of UN Packaging Codes

UN packaging codes are structured in a specific format, providing valuable information about the hazardous material transported. The code consists of four parts: the UN prefix, the substance identification number, the packaging group, and the compatibility group. For example, UN 1263 represents petroleum crude oil, which falls under the flammable liquids category and belongs to packaging group III.

The Significance of UN Packaging Codes

The use of UN packaging codes is crucial for several reasons. Firstly, they enable emergency responders and personnel involved in transportation to quickly identify the nature of the hazardous material in the event of an accident or spill. This rapid identification is essential for implementing the appropriate safety measures and containment procedures to minimise the risk of harm to the environment and public health.

Secondly, UN packaging codes play a pivotal role in properly packaging and labelling dangerous goods. Accurately classifying hazardous materials can determine the appropriate packaging requirements, ensuring that the goods are transported in containers that meet the necessary safety standards. This is particularly important for preventing leaks, spills, and other potential hazards during transit.

Properly Classifying Dangerous Goods

When classifying dangerous goods, it is essential to understand the criteria for assigning UN packaging codes. The classification process involves identifying the primary hazard class of the substance, such as flammable liquids, toxic substances, corrosive materials, or explosives. The secondary hazard class, if applicable, must also be considered.

Also, the physical and chemical properties of the substance and its potential impact on human health and the environment are taken into account during the classification process. This information is used to determine the appropriate UN packaging code, which in turn dictates the specific packaging and labelling requirements for the hazardous material.

It is important to note that proper classification of dangerous goods is a legal requirement and a moral obligation to ensure the safety of individuals and the environment.

Failure to accurately classify hazardous materials can result in serious consequences, including accidents, environmental contamination, and legal ramifications.

Packaging Groups

UN packaging codes also include packaging groups, which further specify the level of danger posed by the hazardous material. There are three dangerous goods packaging groups:

  1. Packaging Group I: Substances with high danger levels, such as highly toxic chemicals or extremely flammable materials.
  2. Packaging Group II: Substances with moderate danger levels, including moderately toxic chemicals and flammable liquids.
  3. Packaging Group III: Substances with low danger levels, such as mildly toxic chemicals and flammable liquids with lower flashpoints.

The packaging group assigned to a hazardous material determines the packaging type required for safe transportation. For example, substances in Packaging Group I may require more robust and secure packaging to prevent leakage or spillage. In contrast, those in Packaging Group III may have less stringent packaging requirements.

Compatibility Groups

In addition to packaging groups, UN packaging codes may also include compatibility groups, which indicate the compatibility of different hazardous materials during transportation. Compatibility groups are denoted by letters, with A being the least hazardous and C being the most hazardous in terms of potential reactions with other substances.

Understanding compatibility groups is crucial for safely transporting multiple hazardous materials in the same shipment. Considering the compatibility of different substances, the risk of chemical reactions, spills, or other hazards can be minimised, enhancing overall safety during transport.

Compliance with UN Packaging Codes

Compliance with UN packaging codes is a fundamental aspect of transporting hazardous materials. Shippers, carriers, and all parties involved in the transportation process must adhere to the regulations governing UN packaging codes. This includes:

  1. Accurately classifying dangerous goods.
  2. Using approved packaging materials.
  3. Affixing the appropriate labels and markings.
  4. Providing the necessary documentation for the shipment.

Furthermore, training and education on UN packaging codes and hazardous materials handling are essential for personnel involved in transporting and handling dangerous goods. Ensuring that all individuals are well-versed in the proper procedures for classifying, packaging, and transporting hazardous materials can significantly reduce the risk of incidents and accidents.


Understanding UN packaging codes is paramount for the safe and compliant transportation of hazardous materials. These codes serve as a universal language for identifying and classifying dangerous goods and providing vital information for packaging, handling, and transporting these substances. By accurately assigning UN packaging codes, the risk of incidents, accidents, and environmental harm can be mitigated, safeguarding the well-being of individuals and the ecosystem.

As the global economy continues to rely on transporting hazardous materials, all stakeholders involved in this process must remain vigilant in their adherence to UN packaging codes and associated regulations. This vigilance not only ensures legal compliance but, more importantly, prioritises the safety and security of all those impacted by the transportation of dangerous goods.