Which division describes mass explosion hazard extremely insensitive (prilled ammonium nitrate with fuel)?

• A. Division 1.5
• B. Division 1.6
• C. Division 2.1
• D. Division 2.2

Answer: (A)

This item tests how explosives are classified by explosion hazard and sensitivity. Division 1.5 covers very insensitive explosive substances that still have a mass explosion hazard, meaning a large quantity could explode as a mass blast. Prilled ammonium nitrate with fuel is a classic example of an explosive that is extremely insensitive but can produce a mass explosion if a sufficient amount detonates. That’s why this choice fits Division 1.5.

Division 1.6 would apply to materials that are extremely insensitive with no significant mass explosion hazard, which isn’t the case here. The two remaining options describe gases (flammable or non-flammable/non-toxic), which are not relevant to solid/liquid explosive divisions.