In the introduction to understanding fires in commercial kitchen exhaust systems, commonly called restaurant grease fires, we highlighted the importance of understanding cooking appliances, combustible grease, and the effects of fire spread.
In this article we will discuss the purpose of fire investigation. The fundamental Origin and Fire Cause Objectives of a fire investigation are to:
- Determine the origin of the fire, the location where the ignition source and the fuel came together to start a fire.
- Determine the fire cause, the circumstances or conditions that brought the ignition source, fuel, and oxygen together resulting in the fire.
- Determine the development and spread of the fire.
An example of the purpose of an investigation applied to commercial cooking equipment related fire investigation would be as follows:
- The origin (location) of the fire was in the area of a deep fat fryer.
- The fire cause was the ignition of cooking oil in the fryer, and the ignition was brought about by the failure of the fryer’s high limit switch.
- A fire resulted. It spread into the hood and duct system, where the accumulation of grease residues was a factor in the spread of the fire into the rest of the building.
In many cases, the purpose of the investigation may go beyond determining fire origin and cause, and include the examination of circumstances that led to property damage, bodily injury or loss of life — the cause of the loss. Further, the investigative assignment may require that the investigator determine, through analysis of the facts, the responsibility of a party or parties regarding those circumstances or conditions that brought about the cause of the loss.
In the above fryer fire example, in investigating the cause of the loss, the investigator may conclude that the fire spread beyond the hood and duct system to involve the structure due to an operational failure of the fire-extinguishing system. A detailed examination of the cooking and exhaust equipment and its installation and maintenance may determine that other parties are responsible for the failures. (Note: The 2004 edition ofNFPA 921 Guide for Fire and Explosion Investigations makes an important distinction between the terms “Fire Cause” and “Cause.” See NFPA 921 Chapter 3, Definitions.)
The scope of a specific fire investigation will depend on the role of the investigator. Typically, a fire department investigator or fire marshal will be concerned with the three fundamental Origin and Fire Cause objectives listed above in addition to the determination of whether the cause was accidental or intentional. The findings may lead to improved fire prevention.
A fire investigator retained by an insurance company may have a broader responsibility beyond Fire Origin and Cause to also make a determination regarding those factors contributing to the Cause of the Loss. Further, with the assistance of engineers or equipment experts, an examination and analysis may include the determination of specific equipment failures and parties responsible for those failures.
By Phil Ackland
