What is the composition of ANFO?

• A. 94% Ammonium Nitrate; 6% Fuel Oil
• B. 60% Ammonium Nitrate; 40% Fuel Oil
• C. 70% Ammonium Nitrate; 30% Fuel Oil
• D. 50% Ammonium Nitrate; 50% Fuel Oil

Answer: (A)

ANFO is a mixture where the oxidizer, ammonium nitrate, provides the bulk of the mass, and a relatively small amount of fuel oil supplies the energy needed for detonation. The idea behind this formulation is to have a stable, inexpensive explosive that can be handled in bulk but still deliver enough power when detonated. Because the oxidizer dominates, the best answer is the one that shows mostly ammonium nitrate with only a small portion of fuel oil, which is the characteristic balance for standard ANFO. The other ratios would imply more fuel oil, changing the behavior and stability in ways that don’t match typical ANFO formulations. In real-world use, exact percentages can vary, but the general pattern remains: a large share of ammonium nitrate with a modest amount of fuel oil.