Which of the following is NOT typically a factor in determining the cause of a fire?

The presence of flammable materials is a critical factor in determining the cause of a fire. Identifying these materials can help investigators ascertain how the fire began and its potential to spread. Understanding the relationship between weather conditions and fire behavior is also essential, as certain conditions, such as high winds or low humidity, can significantly influence fire spread and intensity.

Building codes compliance plays a role in fire investigations, particularly in assessing whether construction and safety standards were adhered to, which can affect the ignition and growth of a fire. However, firefighter training levels do not typically influence the investigation of a fire's cause. While trained firefighters are crucial for extinguishing fires and managing safety on the scene, their training does not provide insight into the origins or causes of the fire itself. Thus, the training levels of firefighters are not a determining factor in fire causation investigations.