What’s Inside a Fire Extinguisher: Your Questions Answered

What's Inside a Fire Extinguisher: Your Questions Answered

Whether you’re a property manager or a business owner, it pays to know as much about fire safety as you can. When it comes to fire safety tools, fire extinguishers are one of the most widely used and are required in all U.S. businesses

While you may be familiar with how to use your fire extinguisher, what’s inside this tool may be more of a mystery to you. Read on to learn more about the insides of your fire extinguisher. And find out what makes them such an important tool.

Fire Extinguishers: What’s Inside?

The type of materials used inside your fire extinguisher depends on the type of extinguisher you own. There are a few main fire-suppressant materials that can make up your fire extinguisher, including:

  • Water
  • Carbon dioxide
  • Dry chemicals

Fire extinguishers generally contain a small amount of fire-suppressant material. This suppressant is intensely pressurized to ensure it can reach the flames when sprayed. For this reason, fire extinguishers are effective only when used on small, contained fires. 


Water is one of the most effective extinguishing materials, making it a popular choice for fire extinguishers. Models that contain water are extremely useful for putting out fires fueled by wood, paper or even cardboard. 

However, water extinguishers cannot be used to put out electrical fires or those that involve inflammable liquids. The water may exacerbate these fires, so it’s best to use an extinguisher filled with another material in these cases. 

Carbon Dioxide

Carbon dioxide extinguishers are also a popular choice for commercial spaces. In these models, carbon dioxide is stored as a liquid and expands to form a gas once it hits the atmosphere. Since CO2 is heavier than oxygen, it can displace the air around the burning fuel and effectively put out the flame.

Carbon dioxide extinguishers are commonly used in places like offices because they are safe to use around costly electronic equipment and leave no residue behind. 

Dry Chemicals

Dry chemical extinguishers are composed of powder made from small particulates that transform into foam once sprayed. This powder can be made from numerous extinguishing agents, including:

  • Sodium bicarbonate (or, baking soda)
  • Potassium bicarbonate 
  • Monoammonium phosphate 

Once the baking soda hits the flames it begins to decompose and release carbon dioxide. The carbon dioxide, combined with the insulating properties of the foam, effectively smothers the fire. 

The Fire Extinguisher Services Your Property Needs

When it comes to protecting your property or business, only the best in fire safety will do. Since 1941, ACE Fire Extinguisher Services has equipped property and facility managers across the East Coast with the tools they need to protect against devastating fires. 

Keep yourself and your properties safe from costly and damaging fires. Contact ACE Fire Extinguisher Services today to get started.