Most studies on blast waves generated by gas explosions have focused on gas explosions occurring in open spaces. However, accidental gas explosions often occur in confined spaces and the blast wave generates from a bursting vessel as a result of an increase in pressure caused by the gas explosion. In this study, blast waves from bursting plastic vessels in which gas explosions occurred are investigated. The flammable mixtures used in the experiments were hydrogen-air mixtures at several equivalence ratios and a stoichiometric methane-air mixture. The overpressures of the blast waves were generated by venting high-pressure gas in the enclosure and volumetric expansion with a combustion reaction. The measured intensities of the blast waves were greater than the calculated values resulting from high-pressure bursting without a combustion reaction. The intensities of the blast waves resulting from the explosions of hydrogen-air mixtures were much greater than those of the methane-air mixture. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.