
Polyisocyanurate#Fire_risk - delhanty
https://en.wikipedia.org/wiki/Polyisocyanurate#Fire_risk
======
delhanty
I submitted this in relation to the tragic fire at Grenfell Tower, London 2
days ago.

Also relevant is the article referenced by Wikipedia:

[http://www.probyn-miers.com/perspective/2016/02/fire-
risks-f...](http://www.probyn-miers.com/perspective/2016/02/fire-risks-from-
external-cladding-panels-perspective-from-the-uk/)

Edit: more specifically I was interested in the following. In the relevant
article it states:

>The most common forms of insulation cores for composite panels in use in the
UK at the end of the 20th century, in order of decreasing probability of fire
propagation, [4] were:

>polystyrene (EPS),

>polyurethane (PUR),

>polyisocyanurate (PIR),

>phenolic,

>mineral fibre.

And then:

>PIR, a variant of PUR having improved fire properties, is difficult to ignite
and exhibits a pronounced charring which enables it to withstand fire for
longer, but is ultimately combustible.

OK - so PIR "is ultimately combustible".

But then there is also the convection effect of cavities:

>If flames become confined or restricted by entering cavities within the
external cladding system, they will become elongated as they seek oxygen and
fuel to support the combustion process. This process can lead to flame
extension of five to ten times that of the original flame lengths, regardless
of the materials used to line the cavities.

So maybe what is needed is an sufficiently hot trigger - e.g. an exploding
fridge or tumbler drier - and a PIR clad tower block like Grenfell Tower can
become an inferno.

Unfortunately, it seems that all this was known and understood by the fire
authorities in the UK and that they had been communicating it to government
for years, but nothing was done.

------
PaulHoule
People often aren't aware of the fire dangers of plastics.

If you get a chance you might see a demo from your local fire department of
how quickly a synthetic fiber couch will burn up and fill a room with smoke.
Have a few beers, smoke in bed and you can die from the fumes just like that.

