An explosion can occur if which substance comes in contact with oil?

• A. High pressure oxygen
• B. Hydrogen gas
• C. Nitrogen
• D. Water

Answer: (A)

Oil acts as fuel, and a strong oxidizer makes combustion happen extremely rapidly. When oil is exposed to high-pressure oxygen, the oxygen concentration is so great that the oil can ignite and burn violently in a short time, often leading to an explosion. The high pressure also helps trap and release energy quickly, increasing the danger.

Hydrogen gas is flammable, but just contacting oil doesn’t automatically cause an explosion; it needs the right oxidizer and ignition conditions. Nitrogen is inert and won’t support combustion. Water can cause a dangerous steam flash if it suddenly contacts very hot oil, but that’s a different hazard than the explosive reaction produced by an oil–oxidizer combination.