The physical and chemical action of fire suppressants

This work measures the suppression action of inert gas phase agents in extinguishing an air/liquid organic fuel pool fire. It then gives a predictive model for determining the physical contribution involved in non-inert agent fire suppression. Chemical suppression effectiveness can then be calculated. Further, studying the CF3Y and SF5Y (Y = F, Cl, Br, I) series allows quantitation of chemical suppression action of the individual radical moieties. CF3 is shown to be a strong chemical suppressant while SF5 is a flame promoter. CF3Br (Halon 1301) suppression action is 20% physical, 25% chemical due to CF3, and 55% chemical due to Br. Such quantitation provides guidance in selecting alternative fire suppressants to replace ozone layer depleting halons.