What’s the Difference Between a CO₂ and an ABC Fire Extinguisher?
When it comes to fire safety, not all extinguishers are created equal. The two most common types used in residential, commercial, and industrial settings are CO₂ and ABC fire extinguishers. While both are essential fire suppression tools, they operate very differently and are designed for different types of fires.
Understanding the difference between these two fire extinguishers helps ensure you have the right equipment for your environment. Here's a breakdown of how each one works, what types of fires they’re designed to put out, and the key differences to consider.
What Is a CO₂ Fire Extinguisher?
A CO₂ (carbon dioxide) fire extinguisher uses pressurized CO₂ gas to smother a fire by removing the oxygen it needs to burn. In addition to suffocating the flame, CO₂ also has a cooling effect on the fuel source.
CO₂ extinguishers are best suited for:
Class B fires involving flammable liquids such as gasoline or oil
Class C fires involving electrical equipment
Because CO₂ extinguishers don’t leave any residue behind, they are ideal for environments with sensitive electronics. According to the National Fire Protection Association (NFPA), CO₂ extinguishers are safe to use on energized electrical equipment and are commonly found in data centers, laboratories, and commercial kitchens.
Unlike some other extinguishers, however, CO₂ units are not effective on Class A fires (involving ordinary combustibles) and are not recommended for outdoor use where wind can disperse the gas before it has an effect.
What Is an ABC Fire Extinguisher?
An ABC fire extinguisher is a multipurpose extinguisher filled with monoammonium phosphate, a dry chemical that interrupts the chemical reaction of a fire. As its name suggests, it is designed to combat Class A, B, and C fires.
ABC extinguishers are commonly used for:
Class A fires (wood, paper, cloth)
Class B fires (flammable liquids)
Class C fires (electrical equipment)
Due to their versatility, ABC extinguishers are widely used in homes, schools, offices, and warehouses. They are considered a standard choice for general fire protection. The Canadian Centre for Occupational Health and Safety (CCOHS) highlights their importance in workplaces with mixed fire hazards.
It’s important to note that ABC extinguishers leave behind a powdery residue that can damage electronics and may require thorough cleanup after use.
How to Choose the Right Extinguisher
Choosing between a CO₂ and an ABC extinguisher depends on the specific fire risks in your environment. If your workspace contains electronics or flammable liquids, a CO₂ extinguisher may be the safer and cleaner option. For general protection in homes or commercial buildings, an ABC extinguisher provides broader coverage.
In many cases, businesses may benefit from having both types available. The Government of Canada’s home fire safety recommendations suggest keeping multiple extinguishers on hand for different areas of a property.
Maintenance and Testing Considerations
Regardless of the type, all fire extinguishers require routine maintenance. This includes visual inspections, pressure checks, and periodic servicing. For businesses and facilities that use SCBA (self-contained breathing apparatus) cylinders, regular hydrostatic testing is required to comply with safety regulations.
Hydrostatic testing ensures that pressurized cylinders—including CO₂ tanks—are structurally sound and safe for continued use. The CSA Group provides guidance on maintenance standards for pressurized safety equipment in Canada.
Final Thoughts
Both CO₂ and ABC fire extinguishers are critical tools in fire protection, but they serve different purposes. CO₂ extinguishers are clean and effective for electrical fires and flammable liquids, while ABC extinguishers offer all-around coverage for the most common types of fires.
Being informed about the differences helps you make the right choice for your safety needs—and ensures you’re prepared in case of an emergency.
About Rapid CO₂
Based in Ottawa, Ontario, Rapid CO₂ is a trusted local provider of fire protection equipment and services. We specialize in CO₂ fire extinguisher sales and service, ABC fire extinguisher sales and service, specialty fire extinguishers and pressurized water units Whether you're protecting a home, business, or industrial site, our team ensures your fire safety equipment is up to code and ready to perform when it matters most.
For service call 613.299.8412.
