Which placard is required for a load with a primary hazard of mass fire?

The placard for a load with a primary hazard of mass fire is designated as 1.3. This classification is used for explosives that pose a fire hazard and may present a significant risk of mass fire when involved in an incident. These materials can burn rapidly and produce significant heat and flames, potentially leading to a greater danger in storage and transportation environments.

In contrast, other classifications focus on different aspects of hazards; for example, 1.1 designates explosives that present a mass explosion hazard without conditions that could limit the damage. 1.2 is for explosives that pose a projection hazard with a low risk of mass explosion, while 1.4 classifies materials with only a minor explosion hazard and no significant risk of mass fire. This understanding helps in ensuring that the correct safety precautions and responses are applied to various categories of explosives during handling and transport.