Question 1

What is a UN number?

Accepted Answer

A UN number is a four-digit code assigned by the United Nations to identify hazardous materials in international commerce. For example, UN1203 identifies Gasoline. These numbers appear on shipping papers, labels, and placards and are used by emergency responders to quickly identify dangerous goods.

Question 2

What is a hazard class?

Accepted Answer

A hazard class describes the primary type of danger a material presents. There are 9 hazard classes under the UN system: explosives (Class 1), gases (Class 2), flammable liquids (Class 3), flammable solids (Class 4), oxidizers (Class 5), toxic materials (Class 6), radioactive materials (Class 7), corrosives (Class 8), and miscellaneous hazardous materials (Class 9).

Question 3

What is a packing group?

Accepted Answer

A packing group (PG) indicates the degree of danger a hazardous material presents: PG I is high danger, PG II is medium danger, and PG III is low danger. Packing groups determine the type and strength of packaging required for safe transport.

Question 4

What is an ERG guide number?

Accepted Answer

An ERG guide number refers to a specific page in the Emergency Response Guidebook (ERG), published by PHMSA. Emergency responders use the ERG guide number from a UN placard or shipping paper to find immediate safety instructions for handling incidents involving that material.

Question 5

What is the difference between a UN number and an NA number?

Accepted Answer

UN numbers are internationally recognized codes used worldwide. NA (North America) numbers are used in the United States and Canada for materials not assigned a UN number, or for materials that have additional domestic classifications. Both systems use four-digit codes and appear in 49 CFR.

Question 6

Is UNLookup free to use?

Accepted Answer

Yes. UNLookup is free to use with no account or signup required. The tool is supported by advertising, which keeps it free for everyone.

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