Citation

Clarke FB, Hirschler MM. J. Fire Sci. 1991; 9(5): 406-423.

Copyright

(Copyright © 1991, SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The newly-developed "NIBS" smoke toxicity test uses a new measure of hazard, "IT50," the irradiation time necessary to produce sufficient smoke to kill half the animals exposed. The IT50 reflects ease of ignition and burning rate as well as the toxic potency of the smoke. Analysis reveals, however, that the amount of carbon monoxide produced under test conditions is considerably less than would be expected under the flashover conditions the test purports to simulate. Calculating the IT50's on the basis of more realistic carbon monoxide yields reduces the spread of values considerably and causes most of the significant differences between products to disappear. The IT50 is shown to have two other serious drawbacks as well: (1) it is of least utility for products with the most hazardous smoke characteristics, and (2) it cannot be used to characterize a given product's contribution to the overall smoke hazard of a burning compartment. Use of the NIBS test apparatus to measure ignition time and mass loss rate, as well as toxic potency, may have merit but use in its present form to simulate the conditions of flashover appears to be inappropriate.