Oddly enough guys,
When the electrical cabling and switchgear that fed the Glenbrook steel mill caught fire over here back in the early '90's, the initial fire-fighting effort by workers at the place caused a lot of equipment to be junked.
The reason being old BCF (Bi-carbonate foam) extinguishers that were used caused the electrical gear to corrode beyond recognition, Dry powder also has this effect.
Personally, I would use C02 as my preferred extinguisher for most types of fire, where not given any other choice, C02 in an extinguisher has better "knock-down" properties than any other extinguisher of it's size, you just have to know how to place the agent well.
But bear in mind, an extinguisher of any type is meant for a small fire, if the fire you are fighting grows larger, get the hell out of it's way and never, but never, let the fire get between you and your means of exit!
Just my $0.02 worth.
