The Chemistry of a Fire Extinguisher


A fire extinguisher is an active fire protection used to put out or control small fires usually in emergency situations and I am focusing on the foam fire extinguisher. I chose a fire extinguisher because fire fighting has always interested me and I plan on being a firefighter. My life has never been affected by a fire extinguisher but there are millions of people that have been saved by fire extinguishers.

Composition of ...

The foam fire extinguishers use the foam to cover the whole fire and smother it, taking away the air so the fire can not keep on burning. It is made of Diethylene Glycol Monobutyl Ether, 1-Propanol, and Hexylene Glycol. The AFFF or Aqueous Film Forming Foam is used for solid and regular fuels and also liquid fires like gasoline faster and without flashback. When you pull the pin it discharges the fire extinguisher and then you pull the trigger which depresses button releasing the extinguishing agent. The foam is in a liquid form, that is clear with a light straw color, with a mild sweet odor and has a PH of 7-8.5. It is completely soluble in water, not flammable, non explosive, and not an oxidizer. It is less vapor dense than air and has about the same density as water.

Main Chemicals, Compounds, Components

1. CO2

Carbon Dioxide

Linear Shape

It is a natural chemical compound composed of one carbon atom and two oxygen atoms.

2. Hexylene Glycol


It is an organic compound that is odorless and is a chiral diol.

Chemistry's Role

The first role chemistry plays in a fire extinguisher is when you pull the lever to fire the foam onto a fire you release Carbon Dioxide which then replaces all of the foam within the bottle. This is an example of single replacement reaction. Then the foam is next where chemistry is used. It is aqueous film forming foam and it needs a chemical reaction between water, fluoro tensides, and other various chemicals to create a fire fighting foams. A carbon based fire has an equation of CH4+2O2->CO2+2H2O which then the foam puts out the fire by smothering it or basically taking away the oxygen from the equation.

Background Research

A fire extinguisher is made by forming a tank out of steel and then the pressure vessel inside by aluminum. Then the chemicals are loaded into the tank, valve installed, and all other minor things including the hose are added on.

There are 7 different types of fire extinguishers ranging from foam to water to even dry powder.

Each fire extinguisher has different ratings for which type of fire they should be used for like a K rating means oil and fat fires for kitchens.


How fire extinguishers are made.

How fire extinguishers work.

Information about fire.

Carbon based fire equation.

How a fire works.

Different types of fire extinguisher.

How they are used and on what fire.

How a fire extinguisher works.

Just about everything.

What is in a fire extinguisher.

What is in a fire extinguisher.

Chemistry in Fire and more about fire extinguishers.

About the Author

I was born on August 6, 1996 in Billings Montana and have lived here ever since. Since my mom is a German citizen I am both a U.S citizen and a German citizen. When I was 6 months old I flew to Germany for the first time. And then just about every two years after that. Then nothing really happened for 16 years except I kept on eating and breathing. I am now 17 years old and have exactly 25 days left until I graduate. This has been my life.