During a kiln shutdown, industrial cleaning contractors were vacuuming dust from inside the kiln dust room. Suddenly a large amount of material poured into the room via the inlet chute, filling the air with a thick cloud of dust. All three contractors in the room managed to make their way to the exit. While doing so, one of the contractors stumbled and fell, which led to alkaline dust entering his eyes and respiratory system.

The cause of the inflow of material is thought to have been a blockage in the inlet chute that suddenly released itself while the contractors were in the room. This potential hazard had been underestimated during the planning and risk assessment of the job. With hindsight, it is recognized this assessment relied too heavily on the fact that this had never happened before rather than whether or not it could happen

• The corrective action following the incident is to install a slide valve into the chute which will be closed during entry into the room to completely eliminate the possibility of dust blockages or build-up releasing and entering to room.


• When planning a task and undertaking risk assessments consider what potentially could go wrong rather than relying on previous experience of the task.