"Steve Walker" wrote in message
...

I've been on company fire training courses. Interestingly they were
suspended for a while when one of my colleagues set off a CO2 extinguisher
that turned out to have a leak from the pipe that joined the horn and he
suffered a cold-burn.

I remember being told that we mustn't touch the horn itself, only the handle
that's attached to it, because of the risk of cold burns.

The most memorable thing I remember was the demonstration of why you
shouldn't pour water on a burning-liquid (petrol or chip pan) fire. The
demonstrator set up two wide, shallow trays. One was filled with petrol, the
other with diesel. The petrol ignited as soon as a flame (on a long pole!)
was brought near the vapour. The diesel could not be ignited, and put out
the flame if it was touched onto the surface.

When the petrol fire was burning away nicely, the demonstrator poured a few
millilitres of water (again, on a long pole) onto the fire and the whole
thing exploded and shot burning petrol over a wide area. He then tried with
a CO2 extinguisher - that blew the petrol out of the tray onto the grass,
but the tray remained alight because the hot combustion gases heated the CO2
so it didn't lay as a blanket over the fuel. Foam or dry powder for liquid
fuel fires, IIRC.

I've never had to use the approved method of holding a fire blanket, but I
can still remember it: hold the blanket so the top edge faces towards you,
curled round so it's covering your fists which are facing palm towards you,
and lay the blanket gently *from front to back* (never the other way round)
over the chip pan until it covers the pan, when the flames will very quickly
go out because the fire is starved of oxygen. Leave the pan where it is
until the fire brigade arrive: don't move it *even after the flames have
gone out*. Obviously don't try to move it while it's on fire.