h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Ref, 'Beware — this dust can be dangerous: nine custard factory workers were badly burned in 1981 when a cloud ignited and exploded at the Banbury plant.', it is worth pointing out that any dust made from 'organic' (i.e. carbon-based) materials can be explosive. Custard powder itself can be explosive. I use this as a demo for schopol children. One has a custard powder tin with the lid in place. A candle is placed at the bottom centre and ignited. The lid is put in place. Immediately (i.e. before the candle has time to burn the oxygen in the tin, a cloud of custard powder is 'injected' (via a disposable pipette) into a hole placed in the side of the tin at flame height. An explosion ensues, which is sugfficient to cause the tin lid to hit the ceiling.

A coal dust explosion almost certainly caused the catastrophic explosionb which caused the Lusitania to sink in WW1. The ship was returning to the UK from a trans-Atlantic voyage from the States when it was hit by a torpedo. The size of the explosion surprised the U-boat captain and went some way to giving credence to a story that the Lusitania was carrying munitions. In truth, the hold was almost empty of solid coal, and insrttead contained mainly coal dust, which exploded when the torpedo entered.

See A4803284 for an account of the Lusitania.

Here's a video which shows a custard powder explosion, produced more or less how I described it above. Unfortunately, there's no commentary.

http://video.google.co.uk/videoplay?docid=8006412193907793532#