Dust explosions are a serious hazard in the process industries. They have resulted in the destruction of process plants and equipment, injury to workers, and loss of production. The five factors required for a dust explosion are: (1) fuel, (2) oxidant, (3) confinement, (4) dispersion, and (5) ignition source. These factors are often embodied in an “explosion pentagon.” Disruption of any one of these factors can prevent a dust explosion from occurring. Before mitigation of a dust explosion can take place, one has to realize the full extent of the explosion potential of the dust/powder material in the intended process environment. This can be achieved by focusing on the many ways that these five components can come together in a specific process condition to form a pentagon.

This risk constitutes two components: the probability of the explosion and the severity of the consequences. Both factors have to be fully realized to evaluate the dust explosion risk. Currently, standard test protocols are followed to establish a relative measure of these two factors. However, these standard test methods may not reflect the true process environment and interpretation of the results are required.

The purpose of this work is to review test methodologies for assessing the magnitude of an explosion in a process environment and the ease at which the dust explosion can be initiated. This article will also critique how they may be applied to “real-world” process environments and potential mitigation steps to break the “explosion pentagon.” © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005