Certified Fire Investigator Practice Exam

What is a common misconception about spalling concrete and crazing of glass?

1. They are indicators of structural failure

2. They indicate the use of accelerants

3. They can help determine fire temperature

4. They are signs of infrequent maintenance

The correct answer is: They indicate the use of accelerants

The belief that spalling concrete and crazing of glass indicate the use of accelerants is a common misconception because these phenomena can occur for reasons unrelated to accelerants. Spalling concrete happens when surface layers of concrete flake or chip away due to exposure to extreme heat during a fire, while crazing of glass refers to the pattern of fine cracks formed on the surface of glass when it experiences rapid temperature changes. Both of these conditions are influenced primarily by the intensity and duration of heat during a fire rather than the presence of accelerants. In forensic fire investigation, it is essential to differentiate between the effects of fire exposure and the influence of accelerants, as making assumptions can lead to incorrect conclusions about the cause of a fire. Understanding the actual impact of heat on building materials helps in accurately assessing fire dynamics and does not inherently suggest the introduction of accelerants. Therefore, this misconception could lead investigators to focus on an incorrect avenue of inquiry when assessing the fire scene.