How to Extinguish Electrical Fires: Carbon Dioxide Extinguishers First

Electrical fires are one of the most dangerous, misunderstood, and common types of fire in everyday environments. They often occur without warning and spread extremely quickly. Because they involve electrical current and high temperatures, these fires require specific methods to be safely extinguished. Unlike ordinary combustible fires, improperly handled electrical fires not only result in property damage but can also directly endanger lives.

In this article, we delve into and explore electrical fires and their extinguishing methods, focusing on the key role of carbon dioxide (CO₂) extinguishers—the best fire extinguishers for electrical fires—to help you choose the safest and most effective firefighting solution.

1. Understanding Electrical Fires and Their Dangers

Electrical fires occur when the heat generated by an electrical current ignites surrounding combustible materials. They are typically caused by short circuits, overloads, aging equipment, or faulty wiring. Characteristics include:

High Temperature and Arcing: A short circuit can generate arcs reaching thousands of degrees Celsius, powerful enough to instantly ignite surrounding combustible materials.

The Risk of Continuous Power Supply: As long as the power supply is not disconnected, the fire has the potential to persist and even spread. High Potential for Reignition: Some electrical equipment may reignite due to residual heat even after power is removed.

Toxic Fumes: Burning wire insulation releases toxic gases (such as hydrogen chloride).

Due to the high risk of electrical fires, the resulting damage is also significant. According to the National Fire Protection Association (NFPA), electrical fires account for approximately 13% of household fires in the United States, resulting in billions of dollars in property damage annually.

2. How to Extinguish Electrical Fires?

Due to the electrical nature of electrical fires, and the fact that the equipment and equipment involved in the fire may be delicate and expensive, a non-conductive, residue-free, and fast-cooling extinguishing agent is required. Carbon dioxide fire extinguishers are an ideal choice.

CO2 fire extinguishers contain pressurized liquid carbon dioxide. Upon discharge, it rapidly vaporizes into a gas with a greater density than air. This gas quickly surrounds the burning material, reducing or eliminating the oxygen concentration around it and interrupting the combustion reaction. Simultaneously, the vaporization of the carbon dioxide gas absorbs heat from the surrounding area, providing a cooling effect that further lowers the temperature of the burning material and aids in extinguishing the fire. Furthermore, carbon dioxide is a gas that is non-conductive and leaves no residue, making it ideal for electronic equipment environments.

3. Why are carbon dioxide fire extinguishers the preferred choice for electrical fires?

In addition to the dangers of high temperatures, electrical fires also present the danger of electric current, necessitating a non-conductive fire extinguishing agent like carbon dioxide. For this reason, the non-conductive, residue-free properties of carbon dioxide fire extinguishers, combined with their unique fire extinguishing mechanism, make them the preferred choice for locations with electrical fire risks, such as data centers, laboratories, substations, and server rooms.

While effectively extinguishing electrical fires, carbon dioxide fire extinguishers also offer the following advantages:

3.1 Non-conductive, ensuring user safety

CO₂ is an inert gas and does not form a conductive medium. Its non-conductive properties make it ideal for extinguishing fires involving live equipment, preventing electric shock and ensuring the safety of rescuers.

3.2 No residue, minimizing damage to delicate equipment

After extinguishing a fire, CO₂ completely evaporates and cools down, preventing damage to electronic components and reducing the risk of high temperatures.

3.3 Rapid cooling, effectively suppressing re-ignition

CO₂ vaporizes, dissipating a significant amount of heat, providing a significant cooling effect. It also reduces the oxygen concentration around the burning material, effectively preventing re-ignition.

3.4 Environmentally friendly and non-toxic

CO₂ is a non-toxic gas, harmless to the environment, and does not cause pollution after use.

4. How to properly use a CO₂ fire extinguisher to extinguish an electrical fire?

Not only must you choose the right type of fire extinguisher, but you must also use it correctly to be effective. Improper use can effectively control the fire, putting you in danger. The following are professional steps for using a CO₂ fire extinguisher to extinguish an electrical fire:

4.1 Determine the size of the fire

Small, controllable electrical fires can be extinguished directly with a CO₂ fire extinguisher. However, if a fire is large and spreading, especially if it has spread to large equipment or high-voltage electrical systems, you should evacuate immediately and contact the fire department. 

4.2 When extinguishing a small electrical fire, prioritize disconnecting the power supply if possible.

Electrical fires are live electrical fires, and the danger of electrical current is just as great as the fire itself. While CO2 fire extinguishers can extinguish live electrical fires, disconnecting the power supply first significantly reduces the risk, allowing you to focus more on firefighting, improving firefighting efficiency, and developing a firefighting plan.

Tip: Never use water-based or foam fire extinguishers, as this poses a risk of electric shock! ABC dry powder fire extinguishers can be effective for initial electrical fires, but the dry powder is highly polluting and corrosive, potentially causing secondary damage to electronic equipment. If there is a choice, CO2 fire extinguishers are recommended.

4.3 Using a CO2 fire extinguisher

A fire extinguisher must be used correctly to maximize its effectiveness. The correct procedure is as follows:

Remove the safety pin and hold the nozzle securely (avoid direct contact with metal parts to prevent frostbite).

Maintain a safe distance (1.5-2 meters) and aim the spray at the base of the flame.

Use sweeping spray, avoiding point-blank fire, to ensure the CO2 fully covers the burning area. Watch for rekindling. Rekindling may occur after the CO₂ dissipates, so continuous monitoring is required.

4. Precautions

4.1 Do not overuse CO₂ fire extinguishers in confined spaces. Excessive CO₂ concentrations can cause suffocation and other risks.

4.2 The cylinder temperature drops rapidly during CO₂ discharge. Avoid touching it with bare hands to prevent frostbite.

4.3 CO₂ fire extinguishers are only suitable for Class B fires (in the early stages) and electrical fires.

4.4 When using a CO₂ fire extinguisher indoors, ensure the fire is completely extinguished and there is no risk of rekindling. Ventilate the fire promptly.

5. How to Prevent Electrical Fires

Fire extinguishing is only a last resort; prevention is key. The key to preventing electrical fires is to reduce the possibility of electrical failures and overloads at the source and maintain safe habits in daily electrical use. 1. Use qualified, certified electrical appliances and sockets, and promptly replace old or damaged plugs and cords.

2. Install a leakage protector in distribution boxes that, upon detecting a leakage, shuts off power in milliseconds.

3. Buildings should undergo professional electrical safety inspections (insulation resistance, ground resistance, and line load testing) every 1–3 years.

4. Distribute loads appropriately to avoid overloading sockets and power strips.

5. Update wiring promptly to prevent aging issues.

6. Maintain proper ventilation and cooling for electrical equipment, and avoid stacking flammable materials near electrical appliances.

7. Develop good electrical habits, such as turning off the power when leaving and avoiding wet hands when operating electrical appliances.

Additional measures for special scenarios:

Computer rooms/data centers: Install temperature and humidity monitoring and automatic fire alarm systems, equipped with carbon dioxide or clean gas fire extinguishing systems.

Factory workshops: Install overload protectors and temperature alarms for high-power mechanical equipment.

Electric vehicle parking lots: Install combined smoke and temperature detectors, and implement centralized charging and timed power-off systems.

In summary, fighting electrical fires requires specialized knowledge and appropriate equipment. Carbon dioxide fire extinguishers, due to their non-conductive, residue-free, and rapid fire extinguishing properties, are the best choice. Proper use of CO₂ fire extinguishers, combined with scientific preventative measures, can significantly reduce the risk of electrical fires and protect personnel and equipment.