ross_M - BCF is used because it is extraordinarily effective: It works, and works fast. If you need to cool after smothering, you can follow up with water, assuming no elex are involved.
I'm interested in the discussion about toxicity. Both the fire and its' by-products (smoke, fumes, heat) are infinitely more 'toxic' and dangerous than the amount of BCF that you can spray around the cabin, even using all the available extinguishers - All of them will kill you much quicker than BCF fumes. The biggest danger is to the operator of the extinguisher in a confined space (toilet) which is why a smokehood is a good idea if the initial spray doesn't work and you're in for a prolonged session.