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UN number
A UN number is the serial number the UN system assigns to a dangerous substance or article, such as UN1203 for gasoline or UN3480 for lithium ion batteries. It travels with the proper shipping name, class and packing group on the transport document, and its entry in the dangerous goods list sets the packaging, quantity limits and modes allowed.
Reading the entry
| Field | What it means | Gasoline |
|---|---|---|
| UN number | The serial number assigned under the UN system | UN1203 |
| Proper shipping name | The name used on documents — in the US, the Roman-print name in § 172.101 | Gasoline |
| Class | The main hazard | 3, flammable liquids |
| Packing group | I high, II medium, III low danger | II |
The IMDG Code's dangerous goods list says the number is assigned by the UN Sub-Committee of Experts on the Transport of Dangerous Goods, and lists UN1203 as motor spirit or gasoline. Articles, such as batteries, are not given a packing group. Wording drifts between codes: IMDG calls packing group III low danger, the US rules call it minor danger.
Worked example: what the number allows by air
UN1203 gasoline: passenger aircraft up to 5 L a package · cargo aircraft up to 60 L · UN3480 lithium ion batteries: passenger aircraft forbidden · cargo aircraft up to 35 kg net a package → a box holding 40 kg of batteries must be repacked before it can flyLimits from the US hazardous materials table, 49 CFR 172.101 (eCFR, 9 October 2026). A package forbidden on passenger aircraft but allowed on cargo aircraft carries the CARGO AIRCRAFT ONLY label.
For articles listed by name, such as batteries, the US net-quantity limit applies to the whole article less its packaging, not only to its hazardous part.
The mistake people make
Picking the number from the product's trade name instead of its form and hazard. Lithium ion batteries shipped on their own are UN3480; the same batteries contained in equipment are a separate entry, UN3481, with different limits. A wrong number puts the wrong limits on the document, and a passenger flight may carry what it should have refused.
FAQ
UN number: common questions
- Who assigns UN numbers?
- The UN system. The IMDG Code says each number is assigned by the UN Sub-Committee of Experts on the Transport of Dangerous Goods, and the same number appears in the US hazardous materials table — UN1203 for gasoline in both.
- What is a packing group?
- A degree of danger within a class: I high, II medium, III low — 'minor' in US rules. Articles such as batteries are not assigned one.
- What is the UN number for lithium batteries?
- UN3480 for lithium ion batteries shipped on their own, and UN3481 for lithium ion batteries contained in equipment. In the US table, UN3480 is forbidden on passenger aircraft and limited to 35 kg a package on cargo aircraft.
Sources
- Resolution MSC.556(108), IMDG Code Amendment 42-24 — IMO, 23 May 2024
- 49 CFR 172.101 — Hazardous materials table (eCFR)
- 49 CFR 171.8 — Definitions and abbreviations (eCFR)
- UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Rev. 20, Vol. I — United Nations, 2017
Related terms
- Dangerous goods (DG)Term
- Dangerous goods declaration (DGD)Term
- Air waybill (AWB)Term
- Packing listTerm
- HS codeTerm
On Traqo: Dangerous goods — the nine classes and the code for each mode.