This paper is a report of an experimental programme of work to develop inexpensive dust explosion propagation prevention devices. Two types of device were investigated: one is intended for use with charge chutes attached to process vessels and one is intended for use with pipes attached to process vessels. Three dusts were used with K-S1 values up to 308 bar m s(-1). Both devices were found to be effective and resulted in the elimination or significant reduction in the flame from the charge chute or the pipeline. Crown copyright (C) 2003 Published by Elsevier Science Ltd. All rights reserved.