Re: Call me old fashioned
"I learned a new thing on a fire course. "
Reminds me of the office course given by the local fire brigade. They ignited petrol in a large flat metal tray - like a BBQ. We each then tried the "layer" technique using a CO2 gas extinguisher. After a few people had had their go - the tray became hot enough for the petrol to spontaneously re-ignite after each blast. That's why a CO2 powder extinguisher should be used on such materials.
Still remember the course's mantra: "To stop a fire remove material, oxygen, or heat".
A couple of weeks later a pipe-smoking colleague dropped a partly extinguished match into his litter bin. Being full of paper and plastic cups it burst into flames. I grabbed the CO2 gas extinguisher from the corridor - remembered to remove the safety pin - and pointed the nozzle at the waste paper basket. Unfortunately I was too close - and the contents of the bin were blasted into the air. Fortunately that killed the flames - but the office flat surfaces were then peppered with a rain of sticky burnt plastic soot particles.