Quantitative measurements by Fourier-transform infrared spectroscopy of toxic gas production during inhibition of JP-8 fires by CF_3Br and C_3F_7H

Abstract

Fourier-transform infrared spectroscopy is used to monitor gases generated during chemical inhibition of JP-8 fuel pool fires burning in air. Gas samples are taken from a location that approximates the position of an individual who is using a handheld extinguisher to subdue the fire. These gas samples are flowed through a 10-m path-length multipass optical cell placed in the sample beam of a Fourier-transform infrared spectrometer. Gas samples are analyzed before and during application of C(3)F(7)H (trade name FM200) and CF(3)Br (Halon 1301) to the fire. It is shown that application of these halogenated hydrocarbons to JP-8 pool fires produces significant quantities of acid gases (HF and HBr) and of CF(2)O. A calculation of the concentrations (in parts in 10(6)) of these gases and other gaseous combustion products, based on observed absorbances, is presented. We believe this is the first quantitative simultaneous measurement of HF, HBr, HCl, and CF(2)O production during chemical inhibition of real fires.