What are fire extinguishers made of?

We answer one of your most frequently asked questions in our latest blog post – what are fire extinguishers made of?
At Jim’s Test & Tag, we get a lot of questions about fire extinguishers. It’s only natural since our fire extinguisher servicing has become one of our most popular services.

To find out what goes into the making of your fire extinguisher, check out the rest of our article. If you have any questions about extinguishers, please let us know. We’d love to address it in our next article.

What are fire extinguishers made of?

Fire extinguishers are made of different parts.

Pressurised cylinder – this cylindrical tank is flat on the top and bottom, and curved on the edges. It is made out of metal and contains the extinguishing agent and the propellant. Most extinguisher tanks are made out of steel. This strong material can withstand high pressure and extreme temperatures.
Valve – The valve assembly is attached to the release lever and the squeeze handle. The handles are made out of metal and can be operated after removing the metal locking pin. Some extinguishers also have a pressure gauge attached to the valve. The valve is usually made out of aluminium or brass. For more information about fire extinguisher use, check out our blog about how to use a fire extinguisher.
Hose – The hose is made out of flexible pipe and is attached to the nozzle. The hose is usually made out of rubber. The flexibility and strength of the hose provides a channel for the pressurised contents and helps you direct the extinguishing agent onto the flame.
Extinguishing agent – The contents of your extinguisher are pressurised during the manufacturing process. Each extinguisher contains a different agent designed to smother different classes of fire.
Propellant- The propellant is a type of gas that is combined with the extinguishing agent during the pressurising process. This gas is what helps to propel the contents from the extinguisher when the valve is released.

What are extinguishing agents made of?

What are fire extinguishers made of? Now that you know all about the outside components of a fire extinguisher, let’s talk about the inside.

Fire extinguishers come with a variety of different extinguishing agents inside of them. Each different formula is designed to deal with a different class of fire.

Dry Powder

Fire extinguisher powder comes in a variety of solutions. ABE powder is generally made out of a mix of monoammonium phosphate and ammonium sulfate.

Wet Chemical

Wet chemical extinguishers generally contain potassium acetate with potassium citrate or potassium bicarbonate.

Foam

Foam extinguishers are made up of foam, water, and air. The foam generally contains organic solvents, foam stabilisers, and corrosion inhibitors.

Water

This one is pretty self-explanatory! This cylinder will have water inside, mixed with the gas propellant.

C02

These tanks contain carbon dioxide in a liquid form. When this liquid is released into the air, it interacts with the oxygen molecules that are feeding the flame and neutralises them, cutting off the supply.