Flashover And Fire Analysis: A Discussion Of The Practical Use Of Flashover Analysis In Fire Investigations

By: Patrick Kennedy and Kathryn C. Kennedy
Tel: (941) 351-6409
Email Mr. Kennedy
Website: www.kennedy-fire.com

Abstract

Properly understanding the phenomenon of flashover and applying that understanding to fire investigation and analysis can be very valuable tools in unraveling the mysteries of a fire's origin, cause, and development. Nevertheless, many current practitioners in the fire investigation and analysis community misunderstand, or fail to fully understand, flashover. This lack of understanding being the case, the effective use of the analysis of a flashover event in a fire investigation is seldom done, or not done properly. Thereby the potential value of flashover analysis to an effective fire investigation is frequently lost.

There are several considerations associated with flashover and fire analysis for the modern fire investigator or fire analyst to understand in order to use the science effectively. These elements include proper working definitions of flashover and "full room involvement;" understanding the nature of the flashover phenomenon itself; methods for using flashover in investigations; and debunking commonly held misconceptions about flashover. The "problem" to be solved before a fire investigator or analyst can effectively use flashover in investigations is to reach a true understanding of each of these elements.

This paper endeavors to present historical research on the definitions and understanding of flashover; report current, peer-reviewed, practical definitions of flashover and "full room involvement;" give a basic applied-science understanding of the nature of flashover; discuss and debunk a number of commonly held misconceptions about flashover; provide some guidance in using flashover in fire investigations; list some areas of valuable information which can be gleaned from flashover analysis; and provide a basic scientific bibliography of published flashover research. It is also the intent of this discussion to present the topic in a format that reaches all the wide range of levels of education and experience in the fire investigation and analysis community.

Introduction

With the original publication of the National Fire Protection Association's (NFPA) National Fire Code© NFPA 921 - Guide for Fire and Explosion Investigations in 1992, the practical use of science in fire investigations first became expressed in a widely read, peer-reviewed, fire investigation text.¹ Subsequent editions of NFPA 921 have expanded upon, further explained, and directed fire investigation professionals to these scientific principles and how these principles should be applied to fire investigations. Even before the publication of the first edition of NFPA 921, issues of the understanding and use of science in fire investigations were being taught in the National Association of Fire Investigator's (NAFI) National Fire, Arson, and Explosion Investigation Training Programs. While at the same time, other widely attended training seminars were missing the boat, teaching "old-wives'-tales" and pseudo-science. Some still are!

Among these scientific issues, the use of flashover in the analysis of a fire was widely recognized as both important and subject to controversy. The National Bureau of Standards - Center for Fire Research (now the National Institute of Standards and Technology - Building and Fire Research Laboratory) and other fire research facilities, worldwide were already reporting scientific research into the nature of flashover as early as the early 1970's.²

Transition to scientifically based fire investigation from anecdotally based fire investigation has been problematical. In a one-page article published by the Arizona Chapter of the International Association of Arson Investigators (IAAI) in 1991, the two fire investigator authors lamented the use of "this 'new theory of flashover'" to win the release of incarcerated individuals convicted of arson in two separate cases. In the article the authors questioned the validity of "laboratory" tests over "...what happens in the real world."³

The authors of the article wrote in part:

. . .Continue to read rest of article (PDF).

Share |

Patrick Kennedy is the Principal Expert Fire and Explosion Analyst for John A. Kennedy and Associates, the world's oldest established fire investigation firm. With over forty-five years of professional experience, Patrick Kennedy is also the senior-most active fire analyst, with more years of experience that any other active fire investigation professional.

DO NOT REPRODUCE WITHOUT WRITTEN PERMISSION BY AUTHOR.