If there’s one type of fire that causes hesitation during an emergency, it’s an electrical fire.

The worry is understandable—using the wrong extinguisher on live electrical equipment can make the situation much worse and even put you at risk of electrocution.

So, which fire extinguisher is safe for electrical fires? And what should you have on hand to protect your people, property, and equipment?

Let’s break it down.

What Is an Electrical Fire?

An electrical fire starts as a result of faulty or overloaded electrical equipment, such as:

• Extension leads and overloaded sockets
• Wiring faults or short circuits
• Overheating appliances
• Computers, printers, and office equipment
• Industrial machinery or server cabinets

These fires fall under Class E in older terminology, but in modern UK fire classification, electrical fires aren’t given a separate class. Instead, they’re treated as a type of risk that certain extinguishers are rated safe to use on.

Safe Fire Extinguishers for Electrical Fires

✅ CO₂ (Carbon Dioxide) Extinguishers – Best Choice

CO₂ extinguishers are the most widely recommended and commonly used extinguisher for electrical fires.

Why they’re suitable:

• CO₂ is non-conductive, so it won’t cause electrocution
• It leaves no residue, making it ideal for use around computers, data rooms, and electronics
• It works by displacing oxygen to smother the fire

Where to use:

• Server rooms, offices, retail spaces
• Industrial equipment, plant rooms
• Anywhere with live electrical panels or IT infrastructure

Make sure the CO₂ extinguisher is fitted with a frost-free horn to prevent cold burns during use.

✅ Dry Powder (ABC) Extinguishers – Secondary Option

Dry powder extinguishers are also safe to use on electrical fires up to 1000 volts.

Why they’re suitable:

• The powder is non-conductive, making it safe for low-voltage fires
• They’re multi-purpose, so you can use the same extinguisher on Class A (solids), B (liquids), and C (gases) fires too

However:

• They create a lot of mess and can damage sensitive equipment
• The powder can obscure visibility, especially indoors
• Not ideal for confined spaces or server rooms

Use them only when a CO₂ extinguisher isn’t suitable, or as a backup in more industrial environments.

Fire Extinguishers to Avoid on Electrical Fires

🚫 Water extinguishers – Conduct electricity and can cause electrocution if used on live equipment

🚫 Foam extinguishers – Some are rated for electrical fires if tested to BS EN 3, but it’s not their primary purpose

🚫 Wet chemical extinguishers – Designed for Class F (cooking oil) fires, not for use on electrical sources

Always check the label or signage before using an extinguisher in an emergency.

Signage and Identification

Fire extinguishers suitable for electrical fires should be clearly marked. Look for:

• A lightning bolt symbol
• The wording “Safe for use on live electrical equipment“
• Red casing with black panel for CO₂ or blue panel for dry powder

At ESI, we also ensure that extinguisher signage is installed correctly, showing which extinguishers are safe for electrical risks and where they’re located.

What About Portable Electrical Equipment?

If you have portable electrical equipment—like in a holiday let, office, or workshop—make sure:

• A CO₂ extinguisher is nearby
• Your fire risk assessment includes electrical hazards
• Equipment is regularly PAT tested and inspected

Final Thoughts

So, what’s the best fire extinguisher for electrical fires?

✅ CO₂ extinguishers are the gold standard—non-conductive, clean, and effective
✅ Dry powder extinguishers are a good backup in the right environment
❌ Never use water or foam unless specifically rated for electrical use

Having the right extinguisher—and knowing how to use it—could prevent serious injury, damage, or downtime.

At ESI: Electrical Safety Inspections, we supply, install, and service fire extinguishers across Farnborough, Camberley, Reading, Guildford, and the wider Hampshire, Surrey, and Berkshire areas.

Need help choosing the right extinguisher for your premises?
📞 Get in touch today and let ESI keep your business safe and compliant.