The most standard fire extinguisher available today is a dry chemical powder extinguisher. It contains ammonium phosphate, which is the only multi-class powder which means it will work on A, B, and C fires. STOP-FYRE is in the liquefied gas extinguisher category, which is also effective on A, B, and C fires. Sodium bicarbonate powder extinguishers are typically the white ones that you see at Walmart and they are only effective on B and C class fires.In some rare cases you can find an old Halon extinguisher. These are no longer made so be cautious about buying them online unless you trust the seller because the agent may have already been used and the extinguisher refilled with something else but the label still states “Halon”.
Typical foam fire extinguishers extinguish class A fires. You can find some varieties that work on B and C fires, but the main ingredient in a foam fire extinguisher is water, so it is not advised to use them on electrical fires.
CO2 fire extinguishers are very ineffective on Class A, but decent for B and C. You don’t find those very often because they are usually really heavy and awkward. Another reason you don’t find them is because of the concern over their safety. Because carbon dioxide will not liquefy no matter how much pressure is used, the operating pressure is 600 psi or more, which is quite high. Also, the effective range is only about three feet away from the fire. Oftentimes you’ll get an electric shock, believe it or not when you use CO2 fire extinguishers believed to be caused from buildup of static electricity.
Water fire extinguishers are simply pressurized water and only effective on Class A fires. You must add antifreeze to them in cold climates because otherwise they can freeze in the wintertime and break from the water expanding during freezing.