As I mentioned in another topic, we had an "Introduction to Motorsport" day for MG Car Club members on Saturday.
Part of the day was some fire-extinguisher training. We had some volunteers from the Lilydale CFA come along to do it. They put some water into a large metal tray, then float a mixture of diesel and Prepsol on top and light it. You then take turns trying to put it out.
We were invited to bring along old expired 0.9 kg extinguishers from our cars to try. I had two that were out of date. The older one was made in 1998, so was 14 years old!
The instructor said three out of four people will run out of powder in a small extinguisher before putting out the fire on their first attempt.
He was a bit annoyed that I put it out straight away, and only used half the powder
(I did do one of these sessions 7-8 years ago. It was my idea to hold another one. )