Dust

[Tom Sutton]

A ceiling stretches over the whole of the hall and is made of non flammable silicone coated mesh. Over the past ten or more years an even coating of light fluffy dust has accumulated over the whole ceiling. The dust is like the dust you would find under furniture.
 
Does anybody have examples of this kind of dust contributing to or causing fires?

[wee brian]

Kings cross

[Tom Sutton]

Thanks WB but would that dust be impregnated with oil and all other sorts of grunge not just dust, which the situation is presented to me.

[wee brian]

most of it is human skin so its full of animal fats - yuck

[John Webb]

The mass of material per unit area is very small - what I would expect to see if it was ignited is a short-duration 'flash' fire running quickly through the material. What happens after that depends on what is in contact with the dust at the time of the fire - what are walls/ceiling covered with above the false ceiling, for example? What ignition sources are present close to the dust to ignite it in the first place? Can it be vacuumed up every few years if it is perceived as a hazard?

[wee brian]

I agree. If theres a risk of ignition it may be worth a clean up.

[kurnal]

Nearest thing will be the old cotton fly that caused so many flash fires in the mills. In those days the flash fires would easily ignite the yarns or fabrics, though often helped by lubricating oil mixed with the fly close to the machinery.
If its an assembly building I would have it cleaned off pronto. A flash fire may not jeopardise the hall but may cause minor burns to a large number of people. Whatever they do dont beat it off though unless prepared for a dust explosion!