Hyrogen generated from use of incinerator bottom ash suspected
Barhale has issued a Safety Alert concerning the use of foam concrete containing incinerator bottom ash (IBA) on their projects following an explosion.
The alert suggests the foam concrete was placed into a dry well extending beneath a metal floor. It is believed that hydrogen generated built up beneath the floor and that the gas/air mixture was ignited by sparks from a grinder used the following morning.
HSE is investigating the incident.
Comment: This short video gives a good account of foam concrete.
First principles suggest that where hyrogen can be generated from a product the user assessment should consider: (a) avoiding the risk by subsitution with non-hydrogen generating substances (b) avoiding confined spaces (c) effective ventilation and (d) avoidance of work producing ignition sources, unless the area has been certified gas free.