UNNummern

UN numbers, or UNNummern in German contexts, are internationally recognized four-digit codes used to identify substances and articles that are subject to the transport of dangerous goods. The system assigns a unique UN number to each specific material or a group of related substances, enabling consistent identification across modes of transport. These numbers are maintained by the United Nations Committee of Experts on the Transport of Dangerous Goods and are used within the framework of the UN Recommendations on the Transport of Dangerous Goods, including the ADR, IMDG Code, and ICAO/IATA Dangerous Goods Regulations.

The UN number itself is not a hazard class; rather, it points to a defined shipping name and classification. It works together with other information such as the proper shipping name, hazard class, packing group, and special provisions to determine applicable transport rules, packaging, labeling, and emergency response requirements. UN numbers are four digits, with some numbers reserved for special classes or blends, and many entries include multiple packaging configurations.

Examples include UN 1090 for Acetone, UN 1203 for Gasoline, and UN 1993 for Flammable liquids, n.o.s. These numbers appear on shipping documents, on packaging markings, and on placards, providing responders and carriers with a consistent reference to the material involved.

History and governance: UN numbers were introduced in the mid-20th century as part of international efforts to harmonize dangerous goods transport. The system is administered by the UN Sub-Committee of Experts on the Transport of Dangerous Goods, with regional and national authorities implementing the corresponding regulations in ADR (Europe), IMDG (sea), and ICAO/IATA (air).