What does the UN number on hazmat shipping documentation represent?

• A. The internationally recognized identification number for hazardous materials
• B. The weight of the package
• C. The hazard class only
• D. The packaging type

Answer: (A)

The UN number is the internationally recognized identification code for hazardous materials used in transport. It’s a unique four-digit code assigned to each material or article, shown on hazmat shipping papers, labels, and safety guides so anyone involved in handling or responding to an incident can instantly know exactly what substance is involved. This number works with the proper shipping name and other details to standardize communication across all modes of transport. It’s not the weight of the package, nor does it by itself indicate the hazard class or packaging type.