Evolved gas analysis of building materials to investigate their behaviour in fires

Abstract

As building materials are becoming more synthetically composed and lightweight, there has been a shift in both fire behaviour and associated hazards. Fires are burning faster, reaching higher temperatures, and are expected to be producing more toxic compounds compared to construction materials based on natural products. Currently, it is not known how these modern building materials off-gas in a fire and therefore how they contribute to the observed changes in fire conditions, nor is it known what compounds are released when these materials are exposed to fire conditions. The associated hazards are therefore also unknown, including the exposure of first responders and the general public, and the effect these building materials have on fire dynamics. The development of field-portable instruments to assess these hazards is also hampered, as more knowledge is required for selecting target compounds for on-site monitoring. In order to assess the influence of modern building materials on the dynamics and hazards associated with fires, this study aimed to determine the temperatures at which selected construction materials start to thermally decompose and therefore off-gas. If off-gassing is found to occur at low temperatures, during the developmental stages of a fire, it could potentially explain the accelerated changes in fire behaviour. It is also during these low temperature stages that victim escape times are crucial and therefore, depending on the compounds produced, off-gassing may play a key factor in inhibiting escape. In addition, the types of compounds being off-gassed are potentially also related to the levels of oxygen present. The second aim of this study was therefore to assess the degree at which materials off-gas, and how off-gassing is likely to vary depending on aerobic or anaerobic conditions. Overall, this research acts as a pilot study to provide the grounds for future work on identifying any hazardous compounds that are potentially generated at contemporary residential/factory fires.

Date of Award	2018
Original language	English