ESRM 03 is the forensic aspect of Fire safety risk management. It involves the investigation and determination of root cause incidents surrounding related fire and explosion incidents. It focuses on investigative methodologies used to determine the possible cause of fire and explosion incidents. The course contend used in this module is based on NFPA 921: Guide for fire and explosion investigation.

The fundamental Objectives of a fire investigation are to:

  • To determine the origin of the fire (i.e. the location where the ignition source and the fuel came together that resulted in a fire)
  • To determine the fire cause (i.e. conditions that brought the ignition source, fuel, and oxygen together that resulted in the fire)
  • To determine the development and spread of the fire
  • To identify who was responsible for the fire

In Nigeria, the fundamental principles for determining the causes of fires did not involve science, but it was rather based on the experience of the investigator and most times this resulted in conclusions that were not tested to determine their validity.  NFPA committee calls this process “negative corpus,” which relied on a process of elimination of scenarios to determine the causes of fire rather than supporting evidence or scientifically supported conclusions.

Fire investigation cannot be left to the discretion of an individual without adequate proof to back up the theory. We may have heard during reports of fire incidence, when the investigator is queried the reply would be “That is the only thing that can cause the fire, what else is there”, (in which the investigator would have eliminated certain scenario to arrive at the conclusion) but where is the proof can it withstand scrutiny. In fire investigation, the three most important things are: fire origin, fire cause, and responsibility. The determination of the fire origin, through a systematic process, is the beginning point for an investigator’s findings and opinions. For the results to be objective and reliable, the origin must be determined first, then the fire cause.

NFPA 921 sets the bar for scientific-based investigation and analysis of fire and explosion incidents. Referenced in the field, in training, and in court, it is the foremost guide for rendering accurate opinions as to incident origin, cause, responsibility, and prevention. Section 17.1 states in part: “Generally, if the origin of a fire cannot be determined, the cause cannot be determined, and generally, if the correct origin is not identified, the subsequent cause determination will also be incorrect. The purpose of determining the origin of the fire is to identify in three dimensions, the location where the fire began.”

In NFPA 921 Chapter 4, Basic Methodology, states that the scientific method is applicable to the field of fire investigation as a systematic approach in developing and testing origin and fire cause hypotheses. NFPA 921 considers the scientific method to be a principle of inquiry that forms a basis for legitimate scientific and engineering processes, including fire incident investigation.

An investigator does not need to be a fire scientist. NFPA 921 does provide a systematic method for selecting, testing and accepting or discarding possible fire cause hypotheses. Further, when testing a hypothesis, an investigator does not necessarily need to utilize scientific tests or experiments in order to arrive at a conclusion. A hypothesis may be supported by cognitive testing, or a “thought experiment.”




NFPA 921 brought the scientific method into the fire investigation process, providing credible and reliable evidentiary bases for determining the origin and cause of a fire. Included in that guidance of fire cause determination was the categorization of the cause of a fire into one of four classifications.
The scope of a fire investigation may go beyond determining fire origin and cause, and include the investigation of circumstances that led to property damage, bodily injury or loss of life and also the responsibility of a party or parties regarding those circumstances or conditions that brought about the cause of the loss.

Fire investigation is very important especially for insurance companies to for determine if a claim is legit, and also for documentation and improvement purposes. That is why a guide such as the NFPA 921 which is accepted in many countries in litigation cases where if the guide is quoted as used for the basis of the investigation, the court accepts such document over testimonies of event.
To understand more on the Scientific approach to fire investigation, fire incidence classification and how to conduct a standard acceptable fire investigation, kindly register for the NFPA 921 training coming up in MAY 2017.

Post Author: David Chibueze