What is pyrolysis?

Pyrolysis is defined as the decomposition of organic matter through the application of heat in the absence of oxygen. This process breaks down complex materials into simpler compounds, typically resulting in the production of gases, liquids, and solid residues—such as charcoal. Pyrolysis is a crucial concept in understanding how materials behave when exposed to high temperatures, particularly in fire scenarios.

For example, during a fire, understanding pyrolysis helps firefighters and fire investigators recognize how fuels ignite and contribute to fire spread. The process is a critical factor in fire dynamics and illustrates why certain materials ignite more readily when heated.

Other options presented do not encapsulate the definition or process of pyrolysis. The boiling off of water is a distinct phenomenon related to the physical state change of water rather than decomposition. Ignition refers to the start of combustion, while smoke spread pertains to the movement of particulates and gases, neither of which directly relate to the thermal decomposition of materials characteristic of pyrolysis.