Final answer:
UN identification numbers must be displayed on cargo tank trucks, certain bulk packages, and vehicle containers containing small quantities of hazardous materials.
Step-by-step explanation:
UN identification numbers must be displayed on:
- Cargo tank trucks: These are trucks used to transport bulk quantities of hazardous materials in tanks. Displaying UN identification numbers on these trucks helps to identify the type of hazardous material being transported.
- Certain bulk packages: Bulk packages are containers, such as drums or barrels, used to transport large quantities of hazardous materials. Displaying UN identification numbers on these packages helps to ensure proper handling and emergency response measures.
- Vehicle containers containing small quantities of hazardous materials: These are containers, such as toolboxes or storage compartments, in vehicles that carry small quantities of hazardous materials. Displaying UN identification numbers on these containers helps to alert emergency responders to the presence of hazardous materials.