In case the plug socket begins to smoke, or the appliance catches fire, the last thing you will want is to grab the wrong extinguisher. Fires caused by electricity differ from a typical fire and using the wrong extinguisher will only worsen the situation. But what is the fire extinguisher that is used to put out fires caused by electricity? The quick answer is either a CO2 extinguisher or a dry powder extinguisher.
In this guide, we’ll clear up a common myth. First, there’s no such thing as a “Class E” fire in the UK, even though you’ll see it mentioned all over the internet. We’ll then walk through the actual UK fire classes, which extinguisher works best on electrical fires and why, what colour to look for on the extinguisher itself, and the things you should and shouldn’t do if you’re ever faced with one. We’ll also cover the best option to keep at home and a quick word on lithium battery fires, which are becoming more common than people realise.
What Class of Fire Is an Electrical Fire?
Short answer: it isn’t one. In the UK, fires are grouped by what’s burning: wood, liquid, gas and so on. Electricity itself doesn’t burn, so it was never given its own class.
You may have seen “Class E” mentioned for electrical fires. That’s an American term, not a British one, and it’s where most of the confusion comes from. To break it down:
- In the US, Class C means electrical fires
- In the UK, Class C means gas fires (like methane or propane)
- There is no Class E in the UK at all
So instead of a class letter, an electrical fire is treated as a risk, not a category. Extinguishers safe for electrical use simply carry a lightning bolt symbol on the label, along with a voltage rating (usually up to 1,000 volts). That symbol indicates it’s safe to use, not a class letter.
The UK Fire Classes at a Glance
Here’s a simple breakdown of the classes of fire you’ll come across in the UK:
| Class | What It Covers |
| Class A | Ordinary combustibles — wood, paper, textiles |
| Class B | Flammable liquids — petrol, oil, paint |
| Class C | Flammable gases — methane, propane, butane |
| Class D | Burning metals — magnesium, lithium |
| Class F | Cooking oils and fats |
Electrical fires sit outside this list. They’re marked separately with the lightning bolt safety symbol rather than a class letter.
Which Fire Extinguisher Is Used for Electrical Fires
Now to the part most people are actually searching for what type of fire extinguisher for electrical fire situations actually works. There are three safe options:
CO2 Extinguishers
- Cuts off the oxygen around the fire
- Doesn’t conduct electricity, so it’s safe on live wiring, sockets and appliances
- Leaves no residue, which is why you’ll spot them near computers, server rooms and office equipment
Dry Powder Extinguishers
- Smothers the fire and stops the chemical reaction keeping it burning
- Doesn’t conduct electricity either, so it’s just as safe on live electrics
- Not great indoors; discharging one fills the room with a thick cloud that cuts visibility and isn’t nice to breathe in
- Better suited to workshops, garages or outdoor electrical fire risks assessment.
Water Mist Extinguishers (dielectrically tested only)
- Regular water conducts electricity and should never go near an electrical fire
- Some water mist extinguishers are specially tested and rated safe for live equipment up to a certain voltage
- Less common, so always check the label before assuming a water-based extinguisher is safe
You may also like to read: How Do Water Fire Extinguishers Work?
What Colour Is an Electrical Fire Extinguisher?
A common question people ask is what colour fire extinguisher for electrical fire use should look like. In the UK, extinguishers are red-bodied with a coloured label band showing the agent inside:
- Black band: CO2 extinguisher
- Blue band: dry powder extinguisher
Neither colour is officially “the electrical fire colour” on its own; the colour tells you what’s inside the extinguisher, while the lightning bolt symbol on the label confirms it’s safe for electrical use. Always check for that symbol rather than relying on colour alone.
Why You Should Never Use Water or Foam on an Electrical Fire
This one’s worth repeating because it genuinely saves lives: never use water for electrical fire situations. Water conducts electricity, so spraying it on live equipment risks sending a shock straight back through the jet to whoever’s holding it. Foam extinguishers carry water too, so the same risk applies.
It’s also worth remembering that unplugging an appliance doesn’t always make it safe. The wiring behind the socket, or the consumer unit itself, can still be live even after the obvious source is switched off. That’s why cutting the power at the source, not just the plug, matters so much.
Safety Tips: What to Do (and Not Do) During an Electrical Fire
Do:
- Cut the power at the switch or consumer unit if you can reach it safely
- Use a CO2 or dry powder extinguisher, aimed at the base of the fire
- Keep the distance stated on the extinguisher label, usually around a metre
- Get everyone out and away if the fire grows past what the extinguisher can handle
- Call 999 if the fire spreads or you’re not confident tackling it
Don’t:
- Never use water, foam, or an untested wet chemical extinguisher
- Don’t touch the appliance or wiring before the power is off
- Don’t assume it’s safe just because it’s unplugged
- Don’t try to fight a fire that’s already spreading or producing heavy smoke
- Don’t go back into the room until it’s been properly checked
Best Fire Extinguisher for Electrical Fires at Home
For most homes, a small CO2 extinguisher is a solid choice, especially if you’ve got a home office, TV setup, or anything electronic worth protecting from powder residue. A compact 2kg CO2 extinguisher is usually enough for a flat or house.
Good spots to keep one:
- Near your consumer unit or fuse board
- In the kitchen, close to major appliances
- Wherever you’ve got a cluster of electronics home office, media unit, and so on
If the budget is tight, a multi-purpose dry powder extinguisher rated for electrical use will still do the job, just be mindful of the visibility issue if you ever need to use it indoors.
A Quick Note on Battery Fires
Not every “electrical fire” is the same these days. Lithium-ion batteries, the kind in laptops, e-bikes, e-scooters and phones, can catch fire in a way that’s quite different from a socket or wiring fire. They burn hotter, can reignite after appearing to go out and don’t always respond well to a standard CO2 or powder extinguisher.
This is now recognised with its own dedicated category, Class L, introduced under BS ISO 3941:2026. If you own an e-bike or charge lithium batteries regularly, it’s worth looking into an extinguisher or fire blanket specifically rated for lithium battery fires, rather than relying on a general-purpose one.
Final Thoughts
If you remember nothing else, remember this: CO2 or dry powder for an electrical fire, never water or foam, and cut the power the moment it’s safe to do so. There’s no official “class” for electrical fires in the UK, just a clear safety marking that tells you an extinguisher can be trusted near live equipment. Keep the right one within reach, know where it is and you’ll be prepared if you ever need it.
FAQs
What should I do if my electrical fire extinguisher expires?
Get it serviced or replaced straight away. An expired extinguisher may not discharge properly when you need it, so don’t wait for an emergency to find out.
Can I use the same fire extinguisher for multiple fire types?
Yes, if it’s a multi-purpose one. ABC dry powder extinguishers cover solids, liquids and electrical fires, making them a practical all-in-one choice.
What’s the safest fire extinguisher for home use?
A CO2 or ABC dry powder extinguisher. Both are safe on electrical fires and cover most household fire risks.
What fire extinguisher is best for mixed fire hazards?
An ABC-rated dry powder extinguisher, since it’s designed to handle solids, flammable liquids, and electrical fires in one unit.
How often should I replace my electrical fire extinguisher?
Most extinguishers need servicing annually and full replacement every 5–10 years, depending on the manufacturer’s guidance. Check the label for the exact interval.
