International Journal on Engineering Performance-Based Fire Codes, Volume 8, Number 2, p.50-53, 2006 50 ASSESSING FIRE BEHAVIOUR OF MATERIALS BY STANDARD TESTS W.K. Chow Research Centre for Fire Engineering, Area of Strength: Fire Safety Engineering The Hong Kong Polytechnic University, Hong Kong, China (Received 12 July 2005; Accepted 8 August 2005) ABSTRACT Consequent to so many big building fires in Hong Kong, there are concerns on new materials used. How fire behaviour of materials should be assessed is discussed in this short note. The current tests required in Hong Kong are briefly reviewed. The fire tests desired are then discussed. The importance of testing the materials properly is pointed out. 1. INTRODUCTION The number of fires due to accidents or whatever causes appears to increase recently. The Garley Building fire was the first terrible one in Hong Kong since 1996 [1]. After that, there were other residential fires due to burning furniture and a big karaoke arson fire. The Garley Building fire, together with the underground railway fire in South Korea [2] might be regarded as the two biggest ones in the Far East from 1996 to 2003. There are different views [e.g. 3] on those incidents, either on inadequacy of fire safety regulations or improper safety management. Anyway, people are quite worried about building fire safety, especially in those new architectural features such as supertall buildings where evacuation with lift will take at least 30 minutes [4]! The occupant loading in shopping malls, public transport terminals, multi- purpose commercial buildings and even offices can be very high. Observed values can be even higher than the design figures specified in the local codes on means of escape [5]. This suggests that fire safety management should be implemented properly, a separate issue to be reported later. An accidental fire started from igniting a small heat source might lead to hazardous consequences if the fire safety provisions, both hardware passive building construction or active fire engineering system and software safety management, are not adequate. Further, many new materials such as sandwich panels [e.g. 6-8] are used for thermal and sound insulation partitions. Their fire behaviour should be watched carefully as their central core might be made of cellular plastics such as polyurethane foam. Accidental fires that had burnt up the whole double-deck bus made of sandwich panels are good examples in demonstrating the potential hazard [9]. Everything except the engine chassis in three such fires disappeared within 15 minutes. Standard tests on assessing the fire behaviour of materials specified by the local government departments [5,10-12] taking care of fire safety were developed years ago. British Standards 476 on test of ignitability [13], non-combustibility [14], surface spread of flame [15] and fire resistance [16,17] are referred to. Apart from some fire resistance tests, the others are on smaller samples of materials with a single component. They are not appropriate for testing materials with several components such as sandwich panels [6-8]. These older tests on materials are for assessing whether the materials can be ignited by a pilot flame without radiation heat flux [13]; whether there is combustion under a small chamber with a certain thermal environment [14]; and flame spreading under a standard furnace [15]. The standard fire tests [16,17] on fire resistance are for assessing stability, integrity and insulation of construction elements. All these are based on thermal aspects, say from the temperature-time curves with wood. As pointed out before [18,19], updated tests and standards should be recommended to assess the fire behaviour of materials. This cannot be achieved without in-depth investigations. The materials should be tested, at least on whether it is easy to ignite when heat supplied from external sources is higher than the heat lost [20], on the heat release rate [20-22], the amount of smoke and combustion products generated [20,22], smoke toxicity [23] and flame spread [24]. 2. FIRE TESTS DESIRED Updated standard tests for assessing the fire behaviour of materials should be properly reviewed first. Feasibility studies of the tests are then