What is the purpose of the UN hazard class number on placards?

• A. Identifying the hazard class
• B. Providing the shipping weight
• C. Listing the chemical's name
• D. Indicating the color code

Answer: (A)

The main idea here is that the hazard class number on placards identifies the kind of danger the material poses. This number signals the general category of hazard (for example, flammable, toxic, corrosive, etc.), so responders can quickly decide on the appropriate actions, PPE, and firefighting or containment tactics. It’s part of an international system used to communicate risk at a glance, regardless of language or exact chemical identity.

The number isn’t about the shipping weight, it doesn’t list the chemical’s name, and it isn’t a color code—the placard conveys color and symbols separately from the hazard class number.