Dust the cause of the Bosley explosion?

Dust looks increasingly likely to have caused the deadly explosion last month at Bosley Wood Treatment, after the Health & Safety Executive issued a ban on activities until problems on site are put right.

Three workers died and a fourth worker is still missing following a massive explosion on 17 July. The HSE has now issued two enforcement notices preventing work until “dust issues” in sheds containing equipment and involved in the processing and bagging of dust have been resolved.

“These enforcement orders strengthen my suspicions. It looks increasingly likely that the blast was caused by dust,” safety expert Keith Plumb tells The Chemical Engineer.

Grinding and blending of wood and other natural fibres carried out in mills produces fine dust that can cause explosions. The blast collapsed a four-storey building at the mill, which is owned by Wood Treatment Ltd (WTL).

Plumb told tce his suspicions immediately after the blast, explaining: “Reports are that there were two explosions, which is typical of a dust explosion. It’s common in facilities that produce fairly low-value products – such as wood fibre – that the cost of keeping the place spotlessly clean are not that compelling. The first explosion – commonly in a piece of equipment – pushes all the dust into the air, which forms an explosive atmosphere that leads to a second explosion, which is commonly much worse than the first.”

In a statement emailed to tce, a HSE spokesperson confirmed the dust on site is an explosion risk, though wouldn’t be drawn on whether investigators suspected it caused the fatal blast.

“We are investigating the cause of the incident and are working with emergency services to try to establish the cause,” the spokesperson said.