1 Hot Issues in Fire Engineering August 2012 Research Centre for Fire Engineering, The Hong Kong Polytechnic University 1 August 2012 On the Proposed Design Fire in the New Fire Safety Code W.K. Chow Research Centre for Fire Engineering, Department of Building Services Engineering The Hong Kong Polytechnic University, Hong Kong, China Since 1998, small fire scenarios of only up to 5 MW have been assumed in hazard assessment for many big halls while applying Fire Engineering Approach (FEA) [1]. Such assumptions were commonly made for crowded large shopping malls and underground public transport interchanges. The heat release rates of the design fire were much lower than the ones of real big fires as experienced in many cases [2,3] before. Such a low design fire was even used many years ago in Chek Lap Kok Airport [4]. Perhaps, this might explain why long-throw sidewall sprinklers were added in some areas for catering. The Available Safe Egress Time (ASET) in an actual big fire will be much shorter than the estimated value derived from a small design fire. Occupants staying inside the crowded hall are exposed to more heat and smoke. It should be noted that apart from carbon dioxide and carbon monoxide, the tenability criteria does not include smoke toxicity of other toxic gases in the estimation of ASET in most FEA projects [1,5]. A very long ASET was estimated. The Required Safe Egress Time (RSET) was not estimated under crowded conditions. Human behavior in evacuation has not yet been studied systematically in the Far East. Therefore, RSET will be much longer than the estimated value. This flawed ASET/RSET approach, which assumes ‘robotic motion’, has already been criticized by world-class scholars [6]. Social awareness on fire hazard is low in the Far East. There are extra problems as ‘fire resistance dampers’ are not installed properly. The associated fire code has to be reviewed, as discussed in June 2012. Long ASET and short RSET presumed in FEA projects are therefore very dangerous [1,7]. It is proposed that more realistic fire scenarios with higher heat release rate should be assumed to derive reasonable values of ASET in new projects. Fire safety management must be enhanced immediately in existing projects with long ASET and short RSET, which are derived from the assumption of small fire scenarios and low design occupant loading