Fire and explosion forensics is the study of incidents involving fires and explosions. Investigators apply scientific methods and use advanced technologies to find the origin and cause of the incident, assess liability, mitigate future risk, and provide documentation for any future legal jurisdiction purposes.

Based on NFPA 921, a fire is a rapid oxidation process, which is an exothermic chemical reaction, resulting in the evolution of light and heat in varying intensities. On the other hand, an explosion is the sudden conversion of potential energy (chemical or mechanical) into kinetic energy with the production and release of gases under pressure, or the release of gas under pressure. These high-pressure gases then do mechanical work such as moving, changing, or shattering nearby materials. An explosion may or may not occur as the result of a fire. Likewise, an explosion may also precede a fire.

The blast effect is the outward or inward rush of gasses, commonly called the pressure wave, and includes heat from an explosion’s origin. This is followed by the return of the pressure wave, which is called the negative wave.

Apart from the fire damage analysis and interpretation, fire and explosion investigators can determine if a fire was initiated deliberately by identifying multiple fires, unusual arrangement of fuel packages, signs of fire trailers, tampering of equipment, interpretation of any malicious intentions in fire patterns and behavior of fire spread. Sophisticated techniques and technologies such as material composition and properties testing, 3D imaging, aerial photography or Ignitable Liquid Residue (ILR) analysis using gas chromatography-mass spectrometry (GC-MS) are often adopted in the investigations, providing significant information and assistance.

A vehicle fire can be caused by a variety of reasons, including but not limited to: