What is char?

Char refers specifically to the burned or pyrolyzed carbonaceous material that remains after organic materials, such as wood or other carbon-containing substances, undergo combustion or thermal decomposition. This process occurs when heat is applied, leading to the breakdown of materials and the alteration of their chemical structure. The resulting char is typically dark, brittle, and porous, consisting primarily of carbon and ash.

In the context of fire investigations, understanding char is crucial because its characteristics can provide vital clues about the fire's origin, intensity, and the materials involved. For example, the depth of char penetration into a substrate can indicate the temperature and duration of the fire. Additionally, different materials produce different types of char, allowing investigators to gather evidence about what was burning in a particular scene.