Definitions #
A four-digit code used worldwide to identify dangerous goods in transport, such as chemicals and explosives, so that everyone in the supply chain knows what is being shipped.
Technical A four-digit identifier assigned by the UN Committee of Experts to specific hazardous substances or articles, used in regulatory frameworks (IMDG, ADR) for labeling, documentation, and emergency response.
Example Each dangerous goods item on the packing list must show its UN number alongside the proper shipping name.
Etymology #
From 'United Nations' + 'number', referring to the numbering system established under the UN recommendations on the transport of dangerous goods.
Collocations #
- UN number assigned 指定 UN 编号，用于官方登记
- UN number required 危险品单据上要求标注 UN 编号
- list of UN numbers UN 编号清单，常见于法规附录
Real Business Examples #
- Ensure the UN number 1830 (sulfuric acid) is clearly marked on the container door before loading.
- We could not accept the shipment because the UN number was missing from the dangerous goods declaration.
Register & Variants #
- Register: formal
- BrE/AmE: 全球通用
Synonyms & Antonyms #
- Synonyms: UN No., UN identification number
Common Errors #
- Using the UN number alone without the proper shipping name Always include both the UN number and the official proper shipping name (PSN) on documents, as carriers require both for compliance.
- Confusing UN number with HS code HS codes classify goods for customs tariffs, while UN numbers identify hazards during transport; they are not interchangeable.
Confusable Terms #
- CAS Number vs UN Number
- CAS numbers identify chemical substances for chemical databases, whereas UN numbers identify hazards during transport.
Frequently Asked Questions
How is a UN number assigned??
The UN assigns numbers to dangerous goods through recommendations, and manufacturers or shippers must look up or request the appropriate number for their substance.
Do all dangerous goods require a UN number??
Yes, for most hazardous goods, but some articles and substances in limited quantities or excepted packages may benefit from exemptions.
Can a shipper make up a UN number??
No, numbers must be officially assigned by the UN, or the shipment will be rejected and may violate regulations.
Published: 2026-09-26 Category: Shipping