Robert,

Here are a few references that you will be interested in. There is another scenario that no one wants to admit happens. That is, refueling the engine while the fan is running. The following references will provide you with some data to help evaluate if positive samples could be the result of engine exhaust, the exisitence of gasoline prior to the fire, or contamination from fuel spills after the fire. I have included some research related to contamination by the "tracking" of ignitible liquids through a fire scene. I hope this is helpful to you.

Sincerely,

Doug Carpenter

1) Ferrino-McAllister, J., Carpenter, D., and Roby, R., “Comparison of Gasoline Weathering on Carpet Samples Exposed to Various Thermal Environments”, Proceedings of the 2nd International Symposium on Fire Investigations Science and Technology, National Association of Fire Investigations, Sarasota, FL, 2006.

2) Lang, T. and Dixon, B. M., “The Possible Contamination of Fire Scenes by Use of Positive Pressure Ventilation Fans”, Journal of the Canadian Society of Forensic Science, 33 (2):55-60 (2000).

3) Lang, T. and Eynon, T., “A Case Review of Possible Fire Scene Contamination by Gasoline-Powered Positive Pressure Ventilation Fans,” TWGFEX 2004 Symposium For Fire and Explosion Debris Analysis and Scene Investigation, Orlando, Florida, November 17 - 20, 2004.

4) Koussiafes, Perry Michael, “Evaluation of Fire Scene Contamination by Using Positive-Pressure Ventilation Fans”, Fire Science Communications, Vol. 4, No. 4., October 2002.

5) Folkman, Kuehl, Groves, and Beveridge, “Evaporation Rate of Gasoline from Shoes, Clothing, Wood, and Carpet Materials and Kerosene from Shoes and Clothing”, Canadian Society of Forensic Sciences Journal, Vol. 23, No. 2 & 3, 1990.

6) Armstrong, A., Babrauskas, V., Holmes, D., Martin, C., Powell, R, Riggs, S., Young, L., “The Evaluation of the Extent of Transporting or “Tracking” an Identifiable Ignitable Liquid (Gasoline) Throughout Fire Scenes During the Investigative Process”, Journal of Forensic Sciences, Vol. 49, No. 4, July 2004.

Douglas J. Carpenter, MScFPE, CFEI, PE, FSFPE
Vice President & Principal Engineer
Combustion Science & Engineering, Inc.
8940 Old Annapolis Road, Suite L
Columbia, MD 21045
(410) 884-3266
(410) 884-3267 (fax)
www.csefire.com