How is the depth of char related to the intensity of exposure to fire?

The depth of char in fire-damaged materials provides critical insight into the intensity and duration of exposure to fire. When materials like wood or certain types of insulation are exposed to high levels of heat, they undergo a process called pyrolysis, where they decompose thermally and produce char. The deeper the char layer, the more prolonged and intense the heat exposure has been. This is because a greater depth of char requires more time for the heat to penetrate and affect the material; therefore, a deeper char effectively indicates a greater intensity of exposure to fire. Firefighters and investigators assess char depth to determine fire behavior, sources of ignition, and the fire's duration, all of which are critical for understanding fire dynamics and for post-incident analysis.

Other options suggest misunderstandings about the relationship: deeper char does not indicate less exposure, nor does it imply no relationship exists. Similarly, shallow char would relate to less intense fire exposure, rather than high intensity.