Class 1 Explosives are materials capable of an instantaneous release of energy.

• A. A slow burn
• B. A chemical change upon heating
• C. Explosives are materials capable of an instantaneous release of energy
• D. They are non-reactive

Answer: (C)

Explosives are defined by releasing their energy essentially instantly, which creates a shock wave and a surge of high-pressure gas. That rapid energy release is the defining trait of Class 1 materials, setting them apart from substances that merely burn slowly (a deflagration) or from materials that only undergo a chemical change when heated. Saying they are non-reactive contradicts what explosives do, and a slow burn doesn’t produce the instantaneous energy pulse characteristic of an explosion. So the statement that explosives are capable of an instantaneous release of energy best captures what Class 1 explosives are.