No abstract

This paper identifies those fire conditions most often present when smoke toxicity is the cause of death. It begins with a review of the evidence that smoke-inhalation deaths are in the majority in fire fatalities in the United States. Next, there is an analysis of the evidence from the national fire experience showing the connection between post-flashover fires and smoke-inhalation deaths. Third is a presentation of real-scale fire test results demonstrating that postflashover conditions are necessary to produce enough smoke to cause smoke-inhalation deaths in the cases where they actually occur. The fourth component is a sampling of results from computer simulations of fires, affirming and broadening the results from the fire tests. It is concluded that smoke-inhalation deaths occur predominantly after fires have progressed beyond flashover. This conclusion then provides a focus for smoke toxicity measurement in particular and fire hazard mitigation in general. INTRODUCTION AND PURPOSEFor decades, students of the United States fire problem have known that most fire deaths are due not to burns but to toxic gas effects, oxygen deprivation, and other effects of what has been loosely referred to as 'smoke inhalation'. ' -4 What has been less well understood is the fire circumstances under which smoke-inhalation effects are most important in causing these deaths. This information has considerable potential relevance to an understanding of the relative roles of different products in contributing to lethal conditions in fires. This in turn underlies fire performance evaluation, whether by laboratory testing of products, computer-based calculation or, most likely, a combination of the two.The purpose of this paper is to identify, through analysis of national fire incidence data and the results of fire tests and computer models of fires, those fire conditions most often associated with deaths due to one-time inhalation of fire smoke. (The paper does not address deaths resulting from chronic exposure to smoke.) These diverse sources of information all clearly indicate that in the United States deaths occur predominantly after fires have progressed to or beyond flashover and usually involve victims located in a room other than the room or area where the fire originated. This finding has implications for the fire conditions most relevant to fire toxicity assessment in general and smoke toxicity measurement in particular. BACKGROUND

No abstract

SUMMARYThis paper compares the responses of wall-size partition assemblies, composed of either type X or type C gypsum wallboard panels over steel studs, when each was exposed to an intense room fire. The exposures lasted from the time of ignition to beyond flashover. Heat flux gauges provided time histories of the energy incident on the partitions, while thermocouples provided data on the propagation of heat through the partitions and on the progress toward perforation. Visual and infrared cameras were used to image partition behaviour during the fire exposure. Contraction of the seams of the two types of assemblies occurred under similar thermal conditions on the unexposed surface. However, there were noticeable differences in cracking behaviour. Reduced scale experiments were performed in conjunction with the realscale fire tests to provide insight into the contraction and cracking behaviour of the different gypsum board types. Results obtained from these experiments are discussed.

No abstract