Fire Safety Science Digital Archive

Tests have been carried out on various extinguishing agents using a tubular propane burner. The Rate of Heat Release (RHR) was measured using oxygen calorimetry. Thermal decomposition products were identified and quantified using wet chemistry and ion chromatography. Some agents were found to increase the RHR. In addition the generation of fluorinated decomposition products was higher for the replacement chemicals, and the amount of thermal decomposition products was found to be linearly related to the extinguishing time and the mass burning rate. The flammability limits of mixtures of propane and agent with air were determined in explosion chambers with volumes of 8, 13 and 784 liters using sparks of 0.7-150 Joule across a 4-5 mm electrode gap. The results indicate that the combination of a relatively hi& spark energy in a small volume and a 1 psi combustion criterion overestimates the inerting concentration needed for room protection.