Necessity of testing combustibles under well-developed fires

Flashover might occur rapidly as a consequence of an arson fire in a small enclosure such as a retail shop in the Far East. Testing the products, especially those made of new synthetic materials modified with additives, in well-developed fires after flashover is necessary. This refers to both full-scale burning tests on the product and bench-scale tests under higher radiative heat fluxes. Starting a room fire test with a small fire source as in the room calorimeter and stopping it upon reaching flashover would only give the 'flashover propensity.' This is good enough only for designing fire safety provisions under accidental fires. Information on the heat release rate, burning duration, smoke generation rate and the toxicity of real-scale fires cannot be determined. In this article, the necessity of testing combustibles under post-flashover conditions in fire hazard assessment is pointed out. Several arrangements in retail shops are described to support the argument. Equations in the literature on estimating the maximum heat release rates for well-developed fires in those small spaces are assessed.