What characterizes an explosive fire?

An explosive fire is characterized by a rapid release of energy, which occurs when combustible materials undergo a combustion reaction that generates a large volume of gas and heat in a very short period of time. This rapid reaction creates a significant pressure wave and can lead to extensive damage and destruction in the surrounding area.

In these types of fires, the buildup of gases and flames is sudden and violent, resulting in a fireball or an explosion. Such fires can be a result of various factors, including the presence of volatile substances, improper storage of flammable materials, or specific ignition sources triggering a chain reaction.

In contrast, a gradual release of energy is associated with more traditional fires, where the combustion process is steady and prolonged. Similarly, fires that produce minimal smoke and heat or involve only solid fuels do not fit the explosive classification, as they either indicate slower processes or limitations in the types of materials being combusted.

Thus, the defining feature of an explosive fire is indeed its rapid release of energy, making option B the correct choice.