How to Choose a Fire Extinguisher
Choosing the right fire extinguisher is tough. The main things to consider are:
- Fire rating
- Approvals and certificates
- The number of extinguishers
Classes of fire
A fire’s class indicates what type of fuel the fire burns. Different extinguishers are suitable for use on different classes.
- Class A: Ordinary combustibles (wood, paper, cloth, rubber, plastics)
- Class B: Flammable liquids (oil, petrol, gasoline, greases)
- Class C: Flammable gases (gas, propane, hydrogen)
- Class D: Combustible metals (magnesium, titanium, etc)
- Class E: Electrical fires
- Class F: Cooking fats, oils and electrical equipment
Extinguishers and their classes
If you get confused, extinguishers are clearly marked, stating which classifications of fire they can tackle.
Choosing the right number of extinguishers
The number of extinguishers you need will depend on the size and purpose of your premises. To know for certain, you will need to carry out a detailed risk assessment.
As a starting point, it’s helpful to look at some basic principles. In the event of a fire, you should never have to:
- Travel more than 25 metres to get to a fire extinguisher
- Go through more than 2 doors to find an extinguisher
- Go to a different floor level to reach an extinguisher
The bigger the better?
You’d be forgiven for assuming that the bigger an extinguisher is, the better it is. Surprisingly, size isn’t everything.
Sometimes, smaller extinguishers are designed to tackle larger fires. For instance, a smaller water fire extinguisher may contain an additive that makes it more effective than a larger water extinguisher without the additive.
It’s a much better idea to go by the fire rating.
What is a fire rating?
A fire extinguisher’s fire rating is a number, followed by a letter. The number tells you what size fire it can fight, and the letter tells you what class of fire it can combat. For instance, if an extinguisher had a fire rating of 13A, it would be able to tackle a 13sq ft, class A fire.
This is where your risk assessment comes in. Once you’ve identified your risk zones, you can calculate how many square feet the area is, and purchase an extinguisher with a suitable fire rating.
It’s important to know that multi-class fire extinguishers will have a separate fire rating for each class of fire it tackles. This is because it may be more effective at fighting one type of fire than it will be at fighting another.
Chrome vs. red
In terms of safety, red is always best, simply because it’s easier to spot. However, if style is important in your office, you might opt for a chrome extinguisher. It will do the job just as well, but will blend in better with your furnishings.
Of course, most offices are equipped with laptop, desktops, printers, scanners, phones, heaters…the list goes on. It’s needless to say that electrical fires are a big risk in most workplaces.
Wet chemical, dry powder and CO2 fire extinguishers are safe to use on electrical fires. However, given the option, CO2 extinguishers are preferable as they won’t cause additional damage to your devices.
Dry powder fire extinguishers are the only ones recommended for use in vehicles. This is because they are suitable for fighting class a, b and c fires.
When purchasing a dry powder extinguisher, make sure that it uses ABC powder, the most common type. Other agents, such as L2, M28 or BC powder won’t be suitable for vehicles.
Legally, all commercial vehicles must be fitted with at least one 2kg ABC dry powder fire extinguisher.
Water vs. Water additive extinguisher
Water and water additive extinguishers are very similar. The only difference is that water additives, as the name implies, contain an additive which makes them more effective at fighting fires.
What this means for you, is that compared to water extinguishers, water additives will be smaller with a higher fire rating. This has the benefit of making them easier to handle.
However, simple water extinguishers do tend to be cheaper.
To ensure that you are purchasing a good quality extinguisher, make sure it has approval from relevant governing bodies. Here’s what you should look out for:
- British Standards approval (or BS EN)
- BAFE certification
- CE kitemarked
- MED (ships wheel) certified
- 35kV conductivity of discharge test
- Stichting Milieukeur Approval (Netherlands Environmental Certification)
photo credit: Tal Bright
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