Confined After-Burning of Display Pyrotechnics and Explosives

Display pyrotechnics are solid mixtures which react with relative slow rates of reaction with the terminal effect of light, heat, smoke or sound resulting from an exothermic oxidationreduced chemical reaction. They are intended to be used mainly for entertainment industry in open environment and are classified as UN 1.3 or 1.4, i.e. substances and articles which give rise only to considerable radiant heat and minor or no blast or projection effects. These classifications and definitions seem to assure that they cannot behave as explosives. However, a recent experimental campaign [1] has recently demonstrated that when large amount of fireworks are stored in closed environment, explosive behavior can be observed, thus confirming the en mass explosion behavior already described by McIntyre & Rindner [2] for pyrotechnics