A UN number is the four-digit identification number assigned to a dangerous substance or group of substances by the United Nations Sub-Committee of Experts on the Transport of Dangerous Goods; for example, petrol is UN 1203 and paint is UN 1263. It is given in section 14 of the product's safety data sheet and is verified together with the proper shipping name in ADR Table A.
What is a UN number used for?
The same number applies to road (ADR), rail (RID), sea (IMDG) and air (IATA DGR). The number is the key that opens the entry in the dangerous goods list. That entry gives the class, packing group, labels, packing instruction, limited quantity limit, transport category, tunnel code and special provisions. A fire crew arriving at an accident scene also identifies the substance from the number on the orange plate and chooses the response method. The columns of the list are explained one by one in the ADR Table A entry.
What types of UN numbers are there?
| Type | Example | Note |
|---|---|---|
| Single substance | UN 1090 Acetone | A single chemically defined substance |
| Generic entry | UN 1263 Paint | Also covers varnish, lacquer, enamel and thinner |
| Not otherwise specified (N.O.S.) | UN 1993 Flammable liquid, N.O.S. | The technical name is added in brackets |
| Article | UN 3480 Lithium ion batteries | Not a substance but a product or part |
How do you find a UN number?
- Check the safety data sheet. Section 14 gives transport information: 14.1 UN number, 14.2 proper shipping name, 14.3 class, 14.4 packing group. How to read the sheet is explained in the SDS entry.
- Verify in Table A. Find the number and compare the name in column 2 with the product. The same number may have more than one entry; UN 1263 has PG I, II and III entries, and the correct group must be selected.
- If you need to search by name, use the alphabetical index (Table B) in ADR 3.2.2.
- If there is no sheet or the product is a mixture, classification is carried out by the manufacturer or a dangerous goods safety adviser according to the criteria in ADR Part 2.
- Check that it is up to date. The revision date of the sheet and the ADR edition used (currently ADR 2025) must be consistent with the documents.
How is it used with the proper shipping name?
The UN number is never written on its own; it is always used together with the proper shipping name (PSN). The order in the transport document is set out in ADR 5.4.1: UN number, shipping name, label numbers, packing group and tunnel code. Example: “UN 1263 PAINT, 3, II, (D/E)”. A trade name does not replace the shipping name. Other information that must appear in the document is in the ADR transport documents entry.
On the vehicle, the number appears on the bottom line of the orange plate; the top line shows the hazard identification number. On a tanker carrying petrol, the plate reads 33/1203. The meaning of the top line is explained in the Kemler code entry.
Common mistakes
- Writing the number without the “UN” prefix.
- Relying on a safety data sheet prepared years ago.
- Not adding the technical name to N.O.S. entries.
- Overlooking the packaging difference for automotive touch-up paint: spray cans are transported as UN 1950 Aerosols (Class 2), while bottles or pen-type products are transported as UN 1263 Paint.
- Confusing the UN approval code on the packaging with the UN number; they are different pieces of information (see UN-approved packaging).
How does Voltim Global support this?
In Voltim Global's dangerous goods transport, planning starts with the UN number: the entry in Table A gives the vehicle type, labels, limited quantity limit and tunnel restriction together. For this reason, the current version of the safety data sheet should be shared before the shipment date is confirmed.