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Characteristics of Fire Scenarios in Which Sublethal Effects of Smoke Are Important.


pdf icon Characteristics of Fire Scenarios in Which Sublethal Effects of Smoke Are Important. (220 K)
Peacock, R. D.; Averill, J. D.; Reneke, P. A.; Jones, W. W.

Fire Technology, Vol. 40, No. 2, 127-147, April 2004.

Keywords:

compartment fires; fire models; incapacitation; smoke; toxicity; scenarios; heat release rate; gas yields; computer models; geometry

Abstract:

A number of simulations were performed using the CFAST zone fire model to predict the relative times at which smoke inhalation and heat exposure would result in incapacitation. Fires in three building types were modeled: a ranch house, a hotel, and an office building. Gas species yields and rates of heat release for these design fires were derived from a review of real-scale fire test data. The incapacitation equations were taken from draft 14 of ISO document 13571. Sublethal effects of smoke were deemed important when incapacitation from smoke inhalation occurred before harm from thermal effects occurred. Real-scale HCl yield data were incorporated as available; the modeling indicated that the yield would need to be 5 to 10 times higher for incapacitation from HCl to precede incapacitation from narcotic gases, including CO COd2, HCN and reduce O2. The results suggest that occupancies in which sublethal effects from open fires could affect escape and survival include multi-room residences, medical facilities, schools, and correctional facilities. In addition, fires originating in concealed spaces in any occupancy pose such a threat. Sublethal effects of smoke are not likely to be of prime concern for open fires in single- or two-compartment occupancies (e.g., small apartments and transportation vehicles) themselves, although sublethal effects may be important in adjacent spaces; buildings with high ceilings and large rooms (e.g., warehouses, mercantile); and occupancies in which fires will be detected promptly and from which escape or rescue will occur within a few minutes.