Addressing Electrical Fires in Commercial Spaces

Phil Black - PII Editor 16/03/2020

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Electrical fires represent just one of many types of fires that can break out in commercial spaces. How such fires are handled largely determines the outcome. Obviously, minimising the impact of electrical fires rests in avoiding them altogether. There is no need to put out a fire that never starts.

The realities of fire are such that building designers have to take all risks into account when planning for new buildings. So do property owners. Both must account for things like fire causes, fire suppression systems, risk mitigation, etc.

Here in the UK, fire risk assessments are a normal part of life for commercial property owners and their tenants. Regulations call for certain actions meant to minimise the risks of fire long after a building is designed and constructed. Fire risk assessments simply do not allow building owners and tenants to ignore the risks.

More About Electrical Fires

Electrical fires are a very specific kind of fire. These days, electrical fires are more often referred to as ‘energised electrical fires' to distinguish them from those fires that start through some sort of electrical means but still continue to burn even after the electricity is cut off.

An energised electrical fire is one that starts due to some sort of electrical malfunction. It is a fire that burns even as electrical current continues to be fed to whatever is burning. The presence of ongoing electrical current precludes the use of water to put out such fires. Why is water problem? Because it is a great conductor of electricity.

If a person were to attempt to put out an electrical fire with a water-based fire extinguisher, he/she could be electrocuted in the process. Electrocution is also a very real risk with water-based fire suppression systems. And of course, water-based suppression can damage sensitive electrical equipment.

Electrical Fire Classification

Electrical fires used to be classified as Class E fires here in the UK. That classification was eliminated a few years back when guidance was updated. Now, the only distinction is whether or not an electrical fire is still energised. If not, the fire is classified under one of the other classifications depending on what continues to burn. Fires that remain energised are just electrical fires with no special classification.

Things are different in the US. There, all electrical fires are Class C fires. Such fires can fall under one of the other classifications if power is cut off. This matters because there are different means of extinguishing different kinds of fires.

Whether in the UK or the US, you never want to try to extinguish an energised electrical fire with water. Foams and some powders are also out of the question. Instead, the best way to fight an energised electrical fire is to starve it of oxygen. There are some powders that do this very well. A better option in many cases is the carbon dioxide (CO2) fire extinguisher.

Carbon dioxide extinguishers are the best fire extinguishers for electrical fires because they displace oxygen. The carbon dioxide molecules actually remove oxygen from the immediate space, thereby preventing one of the necessary ingredients of combustion.

CO2 Extinguishers Minimise Damage

CO2 extinguishers and fire suppression systems are gradually gaining ground in the commercial sector. Think of a typical data centre, for example. A data centre is loaded with highly sensitive servers that would be easily damaged by water, foams, and powders. A CO2 system can effectively shut down a fire in seconds without harming sensitive equipment.

The idea of deploying carbon dioxide fire suppression systems in commercial properties is to minimise the damage when fires do occur. If it is not clear why doing so is important, try to remember the last news article you read about a commercial or residential fire.

Such articles often talk about smoke and water damage. In many cases, smoke and water do more damage than the actual fire itself. Commercial properties filled with sensitive equipment are especially sensitive to water and smoke. A carbon dioxide fire suppression system eliminates the peripheral damage from a typical electrical fire.

Dealing with Small Electrical Fires

We will close this post by briefly addressing small electrical fires. These do occur in commercial spaces. A small electrical fire might be caused by something like a malfunctioning microwave in the break room. One would ideally want access to a CO2 fire extinguisher to put it out, but there are other ways to deal with such a fire.

The first thing would be to unplug the microwave if at all possible. If not, perhaps there is a circuit box nearby from where power could be cut off. Putting out the actual fire could be as easy as throwing a coat or tablecloth on top to smother it. It could also be smothered with baking soda or salt.

Electrical fires have their own unique properties that determine how they are dealt with. Building designers, property owners, and tenants all have to be cognisant of the risks of electrical fires and how to avoid them.