Fire extinguishers consist of a hand-held cylindrical pressure-vessel, usually made of steel or aluminum, and an agent, which can be discharged to extinguish a fire. There are two main types of fire extinguishers: stored pressure and cartridge-operated. Stored pressure fire extinguishers are the most common type and, of these, the ones that have a dry chemical as the agent are most common. The dry chemical is typically mono ammonium sulfate, sodium bicarbonate or potassium bicarbonate – all of which are considered non-toxic.
There are five primary types of fire extinguishers, each designed to put out different kinds of fires. There are also multipurpose fire extinguishers that might be labeled “B-C” or “A-B-C.” Most home improvement stores carry multipurpose fire extinguishers that cover Class A through Class C.
When to use a Fire Extinguisher
Fire extinguishers can be helpful on a small fire. Consider the use a fire extinguisher on a potential fire once all of the following conditions have been met:
Have I alerted others in the building that there’s a fire?
Has someone called the fire department?
Am I physically able to use a fire extinguisher?
Is the fire small and contained in a single object (like a pan or a wastebasket)?
Am I safe from the fire’s toxic smoke?
Do I have a clear escape route?
Use a fire extinguisher when all of these questions are answered “yes.” If you’re unsure about whether or not it’s safe to use a fire extinguisher, and for all other situations, alert others, leave the building, and call 911 from a mobile or neighbor’s phone. It is not recommended that children use fire extinguishers.
Original source can be found here.