h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Although the entry on the topic of fire extinguishers is quite exhaustive there are some things you might want to add.

The first thing that comes to my mind is that I don't believe that a CO2-extinguisher creates a foam. It rather sprays a lot of CO2 onto the fire in order to decrease the halt of oxygen in the atmosphere surrounding the fire. The fire will hopefully be put out by this because it is lacking the oxygen that it needs to continue the oxidation process a fire is. CO2-extinguishers also produce some "CO2-snow" that is very cold and great to chill your beer with if you don't have any ice.

Furthermore there are some types of extinguishers that are not mentioned. First there is the powder extinguisher. Useful against almost any kind of fires and very effective against petrol fires. My personal favourite. However the powder does not taste very good, so you should avoid to get it in your mouth. Second there is the foam extinguisher, which is exactly what it sounds like. Finally there is the halon extinguisher which works almost like a CO2 one, but it also works like a "negative catalyst" and breaks the chemical reaction chain of the fire. Although effective, I believe that nowadays halon is only allowed on aircrafts (where the high efficiency is needed) since it breaks down the ozone layer.

I admit I did send this article of a little bit too early. I'm just now in the process of revising it. This topic and the article was far from thoroughly researched.
I apreciate your comments. They will certainly be added to this article.