Fires can happen anywhere, so it’s crucial to have the right tools to put them out. CO2 fire extinguishers are a popular choice for certain types of fires. In this guide, we’ll talk about how they work, when to use them, and when not to use them. Plus, we'll explore alternative fire safety tools that are just as handy during a fire emergency.

What Is a CO2 Fire Extinguisher?

As the term suggests, a CO2 fire extinguisher is filled with carbon dioxide gas under high pressure. This type of fire extinguisher works by removing oxygen from a fire and cooling it down. 

Carbon dioxide fire extinguishers have red cylinders, black labels, and hard black horns (or hoses for larger sizes). They work on Class B (flammable liquids) and Class C (electrical) fires.

In addition, CO2 fire extinguishers don’t leave residue. As a result, they’re perfect for places like server rooms, labs, and places with sensitive equipment. Common sizes range from two to five kilograms, with the latter being the most popular. 

How Does a CO2 Fire Extinguisher Work?

A CO2 fire extinguisher works by displacing oxygen. Oxygen is one of the three components of the fire triangle. Fire can’t keep burning without it, so removing it puts the fire out. 

When you squeeze the handle, the carbon dioxide stored as a liquid under high pressure is released as gas. This gas displaces the oxygen around the fire. The carbon dioxide also comes out extremely cold, which helps cool the fuel.

What Is a CO2 Fire Extinguisher Used For?

A carbon dioxide fire extinguisher can put out a fire quickly, but only if you use it properly. Unfortunately, you can’t use CO2 fire extinguishers on all types of fires. Here’s what a CO2 fire extinguisher is used for: 

Class B Fires: Flammable Liquids and Gases

Class B fires involve flammable liquids or gases like gasoline, oil, alcohol, paint thinner, and propane. They can happen in homes, workplaces, or industrial settings. For instance, spilled gasoline in a garage or spray paint fumes near a heat source can lead to Class B fires.

Once ignited, Class B fires spread rapidly and emit toxic fumes. Using water to extinguish a Class B fire is a bad idea because it can spread the fire. However, CO2 fire extinguishers are highly effective. They suffocate the flames by removing oxygen without causing damage or contamination.

Class C Fires: Electrical Equipment

Class C fires are caused by live electrical equipment, such as computers, generators, or overloaded outlets. These fires can spread quickly, especially if wiring is hidden in walls. Malfunctioning appliances like toasters or space heaters can also spark Class C fires, making them a risk in homes and offices.

CO2 extinguishers are the go-to for Class C fires because they don’t conduct electricity and don’t leave residue. Hence, they won’t damage sensitive electronics.  

How to Use CO2 Fire Extinguishers

Using a carbon dioxide fire extinguisher might look tricky, but the PASS fire extinguisher method makes it easy. Here’s how to use a CO2 fire extinguisher properly:

1. Pull the Safety Pin

Start by pulling the safety pin on the CO2 fire extinguisher. This unlocks the handle so you can use it. Some extinguishers may have a tamper seal. If yours does, twist or break it first to remove the pin.

2. Aim At the Base of the Fire

Next, aim the extinguisher’s nozzle or hose at the base of the fire. Don’t aim it at the flames. You should target the base because that’s where the fuel is.

3. Squeeze the Handle

Firmly squeeze the handle or lever to release the CO2. Avoid squeezing too hard too quickly, as this can waste the agent. A steady squeeze gives you more control.

4. Sweep From Side to Side

Lastly, sweep the nozzle side to side at the base of the fire. Move slowly and ensure you cover the entire area to smother the flames. Keep going until the fire is completely out. Make sure to watch the area out for reignition.

Remember, your safety is the priority. Only use CO2 extinguishers on manageable fires. A small flame can turn into a major fire in 30 seconds, so be careful. If the fire is spreading quickly or you feel unsafe, evacuate and call for help immediately. 

What Is a CO2 Fire Extinguisher Not Used For?

CO2 fire extinguishers are great for certain fires, but they’re not designed for everything. Here’s what a CO2 fire extinguisher is not used for: 

Class A Fires: Ordinary Combustibles

Class A fires involve solid materials like wood, paper, fabric, and plastics. These materials burn slowly and leave embers, which carbon dioxide extinguishers can’t handle effectively. They work by displacing oxygen but are not strong enough to get rid of embers. Embers can reignite after the carbon dioxide dissipates. Foam or water fire extinguishers are better for Class A fires because they cool and soak fuel. This completely extinguishes the flames and prevents the fire from reigniting.

Class D Fires: Combustible Metals

Class D fires are caused by combustible metals like magnesium, titanium, and sodium. These materials burn at extremely high temperatures and can react violently with many extinguishing agents. CO2 fire extinguishers don’t work on them because they can’t absorb the intense heat or totally cool down the fire. Carbon dioxide might even cause the fire to spread. The best option for Class D fires is a Class D fire extinguisher, which suppresses burning metals safely.

Class K Fires: Cooking Oils and Fats

Class K fires involve cooking oils, fats, or grease. CO2 fire extinguishers don’t work on them because they can’t completely cool the oil. Worse, the force of CO2 discharge can splatter the burning oil and spread the fire. You should use Class K fire extinguishers instead. They cool the burning oil and form a soapy barrier, which prevents the fire from reigniting.

Which Is Better: ABC or CO2 Fire Extinguisher?

ABC and CO2 fire extinguishers are effective but serve different purposes. The better option depends on the type of fire you’re dealing with and what you value most. 

ABC fire extinguishers are multi-purpose and work on Class A, Class B, and Class C fires. They use a dry chemical that smothers flames and prevents re-ignition, making them a solid option for homes, offices, and cars.

On the other hand, CO2 fire extinguishers work best against Class B and C fires. They displace oxygen to suffocate flames without leaving residue. This makes them perfect for putting out fires involving sensitive equipment. However, they’re ineffective against Class A fires or anything with embers that can reignite.

An ABC fire extinguisher is better if you want versatility. But if your main concern is protecting sensitive equipment like servers, CO2 fire extinguishers are the better choice. 

Why Are CO2 Fire Extinguishers So Expensive?

CO2 fire extinguishers are expensive because of how they’re made and the extinguishing agent used. Carbon dioxide is stored under high pressure, which requires special equipment. This makes manufacturing and testing CO2 extinguishers more complex and expensive.

They’re available in smaller handheld units, like a 5-lb extinguisher, but can go up to much larger 100-lb tanks used in industrial settings. The larger the unit, the more expensive it becomes.

Another reason why CO2 fire extinguishers are expensive is the effectiveness of carbon dioxide in certain situations. While ABC extinguishers are versatile, a CO2 extinguisher works better for fires involving electrical equipment or flammable liquids and gases. It also doesn’t leave residue. Though they cost more, the benefits of CO2 fire extinguishers make them worth it for specific needs.

CO2 Fire Extinguisher Alternatives

While carbon dioxide fire extinguishers help a lot, they can be expensive, heavy, and difficult to store. They might also leave a mess that’s hard to clean up. 

A fire spray is an easy-to-use, lightweight, and affordable alternative to  CO2 fire extinguishers. Prepared Hero’s fire spray is also biodegradable and non-toxic. Unlike a fire extinguisher, you can safely use it around your family and pets. 

Here’s a table summarizing the differences between Prepared Hero’s fire spray and a regular carbon dioxide fire extinguisher:

Another alternative is a fire blanket, which depletes the fire’s oxygen supply. By doing this, it puts out small fires in seconds. It also doesn’t leave a mess because it simply covers the fire.

Unlike carbon dioxide fire extinguishers, Prepared Hero’s fire blanket doesn’t expire. You can reuse it as many times as you want as long as it’s not damaged. Plus, you can use it to save someone on fire. 

Here’s a table summarizing the differences between Prepared Hero’s fire blanket and a regular CO2 fire extinguisher:

Do you want reliable, easy-to-use, and affordable tools to put out small fires before they become raging infernos? Check out Prepared Hero’s fire prevention tools here, and get up to 51% off on certain items. Stay prepared, hero!