UN numbers
A UN number is a four-digit number that identifies dangerous goods such as explosives, flammable liquids, oxidizers, and some acutely toxic substances.
Dangerous goods are substantially, but not completely, a subset of hazardous substances regulated under the HSNO Act. Some hazardous substances have their own UN numbers, while some groups of chemicals or products with similar properties have a common UN number.
New Zealand has implemented a new classification system for hazardous substances based on the seventh revised edition of the Globally Harmonised System (GHS 7). The GHS 7 was created by the United Nations and is an international hazard classification system for chemicals. The UN is also responsible for the classification system applied to the transport of dangerous goods. The hazards are communicated on labels and safety data sheets, which also include how to safely store, use and dispose of chemicals.
The GHS acts as a complement to the UN numbered system of regulated dangerous goods transport. Most of the dangerous goods’ classes and categories (except for radioactivity) correlate with the relevant classes and categories in the GHS.
Searching for UN numbers in our database
Some of the chemicals listed in our Chemical Classification and Information Database (CCID) also display UN numbers, but it’s not possible to search this database using UN numbers.
Chemical Classification and Information Database
Chemical hazard communication
The GHS and UN Recommendations on the Transport of Dangerous Goods (UNRTDG) Model Regulations (TDG) are two of the most important guidance documents in chemical hazard communication:
Globally Harmonized System of Classification and Labelling of Chemicals (GHS) (UNECE website)
Further information
New Zealand’s hazard classification system
UN Model Regulations Rev. 22 (2021) (UNECE website)
The International Maritime Dangerous Goods (IMDG) Code [paid]
IATA Dangerous Goods Regulations for air transport [paid]
Regulating dangerous goods (Ministry of Transport website)
Dangerous Goods Regulatory System Map (PDF, 1.61MB) (Ministry of Transport website)
NZ Standard NZS 5433:2020
The UNRTDG is also taken up in New Zealand in the NZ Standard NZS 5433:2020. The 2020 version contains updated technical content that allows users to follow up-to-date good practice and specifications. Section 2.1.7 of NZS 5433:2020 describes how UN numbers and “proper shipping names” are assigned to dangerous goods depending on their hazard classification and composition.
NZS 5433:2020 – Transport of dangerous goods on land [paid]
The list of UN numbers is no longer a part of this latest version of NZS 5433 but is available as a separate handbook, SNZ HB 5433:2021. This handbook is intended to provide support to users when assigning a UN number or confirming the identification of a listed dangerous good: