What would you do if you were faced with a fire?

Your colleague is shouting for you. You go to see what’s happening and realise a fire’s broken out.  It’s small and you think it’s safe to try to extinguish it. But time is of the essence and you need to be able to react quickly. Would you feel confident knowing which extinguisher to use and then actually using it?

Experience tells us that for many of our clients this is an issue. That’s why as part of our installation service our engineers are taking the time to talk through the types of extinguishers that are being installed and explaining how they should be discharged in an emergency situation. Because without doubt when you are faced with a real fire it’s extremely stressful.

Choosing the right fire extinguisher

First of all it’s vital that you are using the right fire extinguisher. Using the wrong type can be extremely dangerous; not only can it potentially make the fire worse, it could also cause serious injury. So you need to be able to recognise what kind of fire you’re dealing with.

Fires usually fall into one of these main categories:

• Class A: Freely burning fires fuelled by ordinary combustible materials such as wood, cloth, paper and cardboard.
• Class B: Fires fuelled by flammable liquids like oils, grease and petrol.
• Class C: Fires fuelled by flammable gases.
• Class D: Fires involving combustible metals such as magnesium, lithium and sodium.
• Electrical: Although sometimes referred to as ‘Class E’, electrical fires aren’t considered to be a fire class on their own as electricity is actually a source of ignition that will feed the fire until it’s removed. When the electricity supply’s been isolated, the fire can usually be dealt with according to its category. But if you can’t isolate the supply, then you must use a non-electrical conducting extinguishing agent.
• Class F: Fires fuelled by cooking oils and fats.

Clearly some of these categories might not be a risk in your particular workplace. That’s why it’s important to have your premises professionally assessed so you have the right extinguishers installed.

The main types of fire extinguishers

So now you’ve established the kind of fire you’re dealing with, which extinguisher should you use? All fire extinguishers in the UK have labelling located close to the top (as you’ll see from the photo of our new-look extinguishers) to make identification as rapid and straightforward as possible.

• Water

Water fire extinguishers should be used for Class A fires only; in other words, fires that involve ordinary combustible solid materials like textiles, paper or wood. They work by cooling burning material. They should NEVER be used on fires involving electrical equipment because of the risk of electric shock.

• Foam

Foam extinguishers can be used on Class A fires and they are also suitable for Class B (flammable liquids) too. The foam smothers the fire and starves it of oxygen to extinguish the flames.

• Carbon Dioxide

Carbon Dioxide (CO) fire extinguishers can be used on electrical fires and on Class B flammable liquid fires.  They work by reducing the oxygen level so there isn’t enough for the fire to feed on. CO is ice cold when it’s released which helps prevent the fire reoccurring. But it also means the user must be very careful; you can get serious cold burns if your skin comes into contact with the horn. Some extinguisher horns are frost-free but never touch them just to be on the safe side.

• Powder

Thanks to a high extinguishing capacity relative to their weight and also their versatility (they can be used on Class A, B, C and electrical fires) powder fire extinguishers became very popular. However, they have some serious limitations.

Firstly, powder extinguishers should not be used indoors unless it’s specifically mitigated by a health and safety risk assessment. This is because the powder can cause a sudden reduction of visibility and can impair breathing, both of which could temporarily jeopardise escape, rescue or other emergency actions. Secondly, the powder is extremely fine and can trigger asthma attacks as well as cause considerable damage to most materials it comes into contact with.  

The powder works by inhibiting the chemical reactions inside the fire. However, it doesn’t form a protective coat once a fire is extinguished so re-ignition can easily occur. So while powder extinguishers can in theory be used on Class A fires they don’t extinguish deep-seated or smouldering fires very well making a water-based extinguisher a much better choice.

• Wet Chemical

Wet chemical fire extinguishers are mainly used for Class F cooking oil or fat fires. They release a chemical spray that reacts with the cooking fat or oil to form a layer of non-combustible soap-like emulsion which extinguishes the flame and seals the surface so re-ignition can’t take place.

Be prepared

Hopefully you’ll never need to use a fire extinguisher. But it’s better to be prepared in case you ever do.

That’s why our engineers are providing advice during installation and that’s why it’s worth making yourself familiar with how extinguishers work right now rather than when you’re in a situation where you must use one. If you or your colleagues could benefit from some further practical experience of using extinguishers there are short courses available. And don’t forget to make sure your fire extinguishers are always in good working order by getting them serviced annually by a BAFE registered engineer.