This work has addressed the prediction of the impulse and the duration of vented explosions. The practical interest for this issue arises from the fact that the venting of an explosion from an enclosure produces reaction forces which must be calculated in order to properly design the structural supports. The FMRC Isothermal Vented Explosion Model was used as the foundation for the development of a new correlation, to replace those proposed by other studies that were found to be deficient. In addition to being based on a strong theoretical foundation, the correlation suggested by the FMRC model has been validated through extensive comparisons with experimental data, covering a range of dust explosions in vessel volumes from 0.64 to 95 m(3) (22.5 to 3355 ft(3)). The perspective provided by this result has made it possible to determine the reasons and the extent of the poor performance of previous correlations. In particular, the formula in the German guideline VDI 3673, which is correct only for a particular value of the vent ratio, yields predictions for the explosion duration and, therefore, for the impulse, which are as much as five to eight times those given by the FMRC correlation. On the other hand, an early proposal made by Brunner has been found to be essentially correct. The results achieved by FMRC through this work offer another example of how the judicious use of models can be combined with experimental information to generate significant improvements in aspects of vented dust explosions which are, otherwise, inadequately handled by empirical treatments. (C) 2000 Elsevier Science Ltd. All rights reserved.