UN number

UN number: A UN number is the four-digit identification number assigned to a hazardous material or group of materials, such as UN1203 for gasoline. It appears on shipping papers and, on bulk loads, on placards or orange panels, and responders use it to find the right emergency guide. Source

Where the numbers come from

In the United States, identification numbers are listed in the Hazardous Materials Table, alongside each material's proper shipping name, hazard class, packing group and labels. Source UN numbers are used internationally; NA numbers are North American numbers for materials without a matching UN entry, used only in domestic transport. For example, UN1203 is gasoline Source, while NA1993 covers diesel fuel and fuel oil. Source

Where it shows on the truck

• Shipping papers: every hazmat entry lists its ID number.
• Placards or orange panels: bulk packagings such as cargo tanks display the number.
• Packages: non-bulk packages are marked with the number.

In practice EXAMPLE

A fuel driver unloads gasoline at a station and picks up diesel at the rack for the next delivery. Before leaving the rack, they change the numbers on the tank from 1203 to 1993 to match the new load and the shipping papers. A wrong number tells responders the wrong product. Look up any number with the UN number lookup, and read the hazmat classes chart and our hauling guide.

Common numbers on the road

A few numbers appear again and again on tankers: 1203 for gasoline, 1993 for diesel and fuel oils or other flammable liquids, 1075 for liquefied petroleum gas, and 1005 for anhydrous ammonia. Similar-looking numbers can mean very different materials, so drivers and responders always confirm against the shipping papers rather than memory. When a tank changes products, its numbers must change with it before it leaves the rack.

NA numbers, used only within the United States, look the same on a placard but begin with NA on shipping papers. A load crossing into Canada or Mexico may need the UN description instead, so check with the shipper before an international run. Responders in each country use the same four digits to find the right emergency guide for the load.