Arson Investigation – FINALLY, After 21 Years, the IAAI Endorses NFPA921

arsonThe phenomenon of “flashover,” by which any ‘compartment fire’ (ie: a fire in a room) can produce all the traditionally accepted signs of arson, was discovered in 1991.  Watch a video of flashover occurring here.

The NFPA (National Fire Protection Association), which is the recognized authoritative body on fire science, published the first edition of its standard NFPA921 (Guide for Fire and Explosion Investigations) in 1992, and it included a recognition of the phenomenon of flashover.  Consequently, it was declaring that all the “rules” and “indicators” that had been used by arson investigators for decades to determine if a fire was arson were wrong.  NFPA921 was immediately met with “stonewall” resistance from the US fire inspection community, including the IAAI (International Association of Arson Investigators).


The process of dragging fire investigation into the reality of science has been long and arduous.  The IAAI eventually offered a grudging acknowledgement of NFPA921, but it was not until January 12, 2013 (just three months ago) that the IAAI issued a “full” endorsement of NFPA921.  Their official position statement follows:

IAAI Position Statement

On January 12, 2013, the Board of Directors unanimously adopted the following statement as the official position of the IAAI: 

It is the position of the International Association of Arson Investigators that National Fire Protection Association (NFPA) Document 921 is widely recognized as an authoritative guide for the fire investigation profession. In addition, NFPA 921 is an important reference manual, and sets forth guidance and methodology regarding the determination of the origin and cause of fires. This Association uses NFPA 921, along with other documents including NFPA 1033, as a foundation for its training and certification programs.

The position statement also includes this “qualifier.”:

(The statement reaffirms the IAAI’s long standing recognition of the importance of NFPA 921 to the knowledge and methodology of fire investigation. “Authoritative” means the guide is an accepted source of information, and known to be accurate and reliable. By its own terms the document is not a “standard,” and is subject to revision and updating on a periodic basis to allow it to remain current with the expanding scientific and technical knowledge in the fire investigation field.)


Meanwhile – while the US fire inspection community was tenaciously resisting NFPA921, untold numbers of people have been convicted and imprisoned, or sentenced to death, for setting fires that were not, in fact, arson.

Any arson conviction prior to the mid-90’s is certainly a candidate for review, and my personal judgement would be that any arson conviction prior to 2000 is suspect.  However, there are still old-school, misinformed, uneducated fire inspectors out there who are sticking to the old (wrong) ways.  I’m personally aware of two such instances in which this is the case – one from 2007 and one from 2012 – believe it or not.

2 responses to “Arson Investigation – FINALLY, After 21 Years, the IAAI Endorses NFPA921

  1. Good to see these developments; but would disagree that flashover was “discovered” in 1991. It was known and recognised for many years before that. The contribution of flashover to the Kings Cross fire in 1987, the Bradford stadium fire in 1985 and the Stardust disco fire in 1981 was recognised at the time. Even during my first training in fire investigation in 1989 I was taught about flashover. Sad fact is some people choose to ignore things which dont fit into their particular theory.

    • Andrew,
      Thank you for your comment on this. Is it possible that flashover was recognized in the UK prior to 1991 but not in the US?

      I know that NFPA921 was immediately embraced and adopted in the UK at publication in 1992, while in the US it was ignored.

      To my knowledge, the first “official” recognition of flashover in the US is when John Lentini conducted the “Lime Street Fire” experiment in 1991.

      Click to access TheLimeStreetFire-AnotherPerspective.pdf

      Phil Locke

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s