What defines a substance classified as an explosive?

A substance classified as an explosive is defined as any article that is specifically designed to function by explosion. This definition captures the essential characteristic of explosives: their intended use is to produce a sudden, rapid release of energy through an explosion, which results from a chemical reaction. This energy release can rapidly produce gas, heat, and pressure, leading to an explosive effect.

Flammable liquids, toxic substances, and corrosive materials do not meet the criteria for being regarded as explosives. While they can pose significant hazards in their own right, they operate under different principles than those that define an explosive. An explosive is characterized by its capacity for a rapid and violent reaction, not simply by being hazardous or reactive under certain conditions.