Did a one day course at Liverpool Fireman's Training Centre with a colleague, as we were appointed Office Fire Wardens for our respective "Floors".
We were tasked with putting out a tray of burning oil, and then re charging the extinguishers and repeating.
Can't remember if it was powder or not, but, it didn't do the job as we didn't recharge the extinguishers correctly.
On the way home, my colleague remarked, "Good job we wernt packing Parachutes eh?"