Electrical Fire Extinguishers
You’ve probably seen electrical fires described as ‘class E’ fires. However, in the UK and Europe, electrical fires don’t have a class. This is because electrical equipment is often involved in other types of fires, such as cooking fires.
So if a fire extinguisher is suited for use on electrical devices, it will be marked with a lightning bolt. The lightning bolt can be found on an extinguisher’s cylinder, next to the classes of fire it can be used on.
Which extinguisher is best?
If you need an electrical fire extinguisher, your best bet is a CO2 fire extinguisher
. Other fire extinguishers will either put you at risk of receiving an electrical shock, or they could cause damage to electrical appliances.
What’s the 35kV conductivity discharge test?
Water and electricity do not mix, so water-based fire extinguishers are not designed for use on fires involving live electrical equipment. However, you may see that some of them are marked as having passed the 35kV conductivity discharge test.
Most water fire extinguishers won’t have passed the test, but many water additive and foam fire extinguishers will have.
This doesn’t mean that you can use them to fight electrical fires. What it does mean is that you can use them in the presence of live electrical equipment. You should still take care to avoid doing even that, if you can.
Wet chemical fire extinguishers, releasing only a fine mist will pass the 35kV conductivity discharge test.
What about dry powder fire extinguishers?
Dry powder fire extinguishers are safe to use on electrical fires. However, something to bear in mind is that the dry powder is corrosive and can therefore damage electrical equipment.
Of course, this doesn’t matter for the device that is being burned, but offices are packed with pieces of electrical equipment, so surrounding devices could be harmed, too.