A safety alert has been issued after a farmer fell eight metres from a ladder and suffered serious injuries while trying to extinguish a barley grain fire in a large grain silo. According to the WorkSafe WA alert, the farmer had climbed the external silo ladder to access the hatch on the roof. As he attempted to put out the fire by squirting water into the silo, the suspended grain dust in the silo caught fire, causing an explosion that blew off the roof.
The alert said squirting water into the silo introduced more air and may have raised more grain dust into the air, increasing the risk of a dust explosion inside the silo.
Four elements must be present for a grain dust explosion to occur, and in this case all were present:
1. Fuel - Small particles of dust were suspended in the space of the silo
2. Oxygen - Air supply was increased by opening the hatch on the silo roof
3. Confinement - Barley grain and dust was ignited in the confined space of the silo
4. Ignition Source - A grain dryer unit was in use at the time.
In the alert, WorkSafe WA said in similar circumstances the following actions were required:
1. Stay clear of the silo if smoke or steam is observed coming out of openings or if rumbling or vibration is evident.
2. Do not add water or foam to a fire contained within a silo or spray water on the external wall without first obtaining expert advice.
3. Contact the Department of Fire Emergency Services immediately for assistance and further advice.