What is an essential characteristic of pyrolysis in relation to combustion?

Pyrolysis is a crucial process that involves the thermal decomposition of materials in the absence of oxygen, leading to the generation of solid, liquid, and gaseous products. One essential characteristic of pyrolysis is that it often precedes combustion. During the pyrolysis stage, organic materials, such as wood or plastic, are broken down into simpler compounds due to heat. This breakdown produces flammable gases and vapors that can be ignited, leading to combustion.

Understanding this relationship is vital in fire investigation, as pyrolysis creates the fuels necessary for combustion to occur. Furthermore, recognizing that pyrolysis occurs before combustion helps investigators determine the potential fire hazards associated with various materials and how fires may develop over time. This foundational knowledge is critical for fire scene analysis and the reconstruction of events leading to a fire or explosion.