Which Hazard Division is Mass Fire?

• A. HD 1.1
• B. HD 1.2
• C. HD 1.3
• D. HD 1.4

Answer: (A)

Hazard divisions classify how explosive materials behave in a detonation scenario. A mass explosion hazard means that if the entire quantity detonates, it would produce a powerful blast affecting a large area. The term “Mass Fire” in this context points to that kind of catastrophic blast potential—it's about the big, whole-load explosion, not just a fire or a few fragments. That’s why this is the best match for the mass-fire concept.

The other divisions describe different hazard profiles: a projection hazard where fragments are hurled from the package with little or no mass explosion; a fire hazard where the primary concern is sustained heat and flame with no significant blast; and a minor explosion hazard where the blast risk is limited and primarily affects only the immediate vicinity.