Fire Extinguisher Guide: Which Type is Right for Your Workplace?

Fire Extinguisher Guide: Which Type is Right for Your Workplace?

In 2020/21 there were 11,916 fires in non-dwelling buildings in which fire and rescue services needed to be called out. That’s over 32 a day. During this time, many businesses and employees were working from home due to COVID-19 restrictions – just imagine how these numbers may skyrocket now that more and more people are returning to their workplaces.

Having fire extinguishers on-site at your workplace not only protects the employees who work there, important resources and materials and the structural integrity of the building itself, but it is also a legal requirement for any and all workplaces.

At MCFP, we specialise in fire safety. With so much information out there, it can be hard to find the best options – especially if you are a novice in the realm of fire safety equipment. Here, we will share our expert knowledge and walk you through an easy guide to fire extinguisher essentials, including how to select the right fire extinguisher types for your workplace.

Classes of Fires

An essential first step to fire safety is understanding what type of fires there are. If you know what fire it is that you’re dealing with, you can select the safest and most appropriate fire safety equipment. Choosing the wrong equipment can have catastrophic consequences.

Fires are divided into ‘classes’ depending on what type of material is burning. These are:

Class A

Class A fires involve ordinary combustible materials such as wood, paper and fabric. They tend to be the most common fires. A good rule of thumb for detecting a Class A fire is that if it produces ash, it is likely Class A.

Class B

Class B fires involve the burning of flammable liquids such as petrol, oil, paraffin, alcohol and even certain paints. They can be triggered by high temperatures or a spark.

Class C

Class C fires involve flammable gases such as butane and propane canisters, and even natural gases that are used when cooking or heating our homes. These fires can be highly explosive and dangerous.

Electrical

Electrical fires are simply in the name – fires involving electrical equipment.

Class F

Class F fires involve cooking or vegetable oils, and are sometimes referred to as ‘Kitchen Fires’.

Fires happen when you have fuel (something that burns), oxygen and heat occurring simultaneously. Therefore, to extinguish a fire, you need to remove one or more of these factors. That’s where fire extinguishers come in.

Fire Extinguisher Types

The five main fire extinguisher types are: Water, Foam, Dry Powder, CO2 and Wet Chemical.

Water

Water fire extinguishers are perfect for Class-A fires involving combustible organic material such as wood, paper and fabric. They absolutely should not be used on electrical fires – this can be very dangerous. These extinguishers use water to extinguish a flame as it has an extreme cooling effect on the fire.

There are four types of water extinguishers:

Mist

This water extinguisher uses a water mist to tackle the flames. By doing so, it creates a larger surface area to volume ratio meaning that the water particles evaporate quicker and so can absorb the heat from the fire faster. However, they tend to be slightly less powerful as the water droplets are lighter.

Jet

A jet water fire extinguisher directs a high-pressure stream of water at the fuel which cools and prevents re-ignition.

Spray

This water extinguisher projects a fine spray of water droplets at the fire. These extinguishers are a more eco-friendly option as they contain no harsh chemicals or additives – just plain tap water that is easy and cheap to refill. They also have a 35kV conductivity test certificate so if you accidentally use them on electrical fires you are covered from electric shocks up to 35kV.

Water With Additives

In these fire extinguishers, chemicals are added that reduce the surface tension of the water, making it more effective at putting out the fire. These extinguishers tend to be lighter and smaller but just as effective. Usually, they come with a spray nozzle for a more efficient spray arc.

Water-based fire extinguishers are recommended for most workplaces. However, specific workplaces that would benefit from them include:

Warehouses
Offices
Schools
Hospitals
Storage units
Textile factories
Retail businesses

All water fire extinguishers have a RED label.

Foam

Foam fire extinguishers are another universally recommended fire extinguisher for most workplaces. They are effective on both Class A and Class B fires (combustible materials and flammable liquids).

If the foam extinguisher has passed a 35kV conductivity test, it can be used on electrical appliances.

These fire extinguishers contain a foaming agent that creates a barrier between the fuel and the fire. The foam also acts as a cooling agent.

Foam extinguishers should be stored by exits in places where fire risks A and B have been detected. They should not be used on electrical equipment or kitchen fires.

Whilst foam fire extinguishers are a good universal choice for many workplaces, some places can particularly benefit from having them:

Offices
Warehouses
Factories
Garages
Hotels
Retail businesses

All foam fire extinguishers have a CREAM label.

Dry Powder

Dry Powder fire extinguishers are a good multi-purpose, all-round fire extinguisher as they can be used effectively on Class A, B and C fires. You can also get specialist ones fit for Class D fires.

In power fire extinguishers, the extinguisher tank contains a fire-fighting mixture of dry chemicals as well as compressed nitrogen to propel the chemicals out and across the fire. These powders smother the fire, absorbing heat and coating the fuel, preventing it from reaching an oxygen source. However, they do not have as great a cooling effect on the fuel, so there is a risk of reignition. Proceed with caution.

This fire extinguisher should be placed near the source of an identified fire risk. They are not ideal for enclosed spaces as inhaling the fumes can be harmful, and the dried powder residue can get everywhere (making clean-up difficult) and can damage electrical equipment.

Workplaces that would specifically need a Dry Powder extinguisher include:

Garage forecourts
Workplaces with large boiler rooms
LPG dispensing plants
Welding or flame cutting businesses

Dry Powder fire extinguishers have a BLUE label.

CO2 (Carbon Dioxide)

CO2 extinguishers are perfect for Class B and electrical fires.

They work by displacing the oxygen that the fire needs in order to ‘breathe’ and continue burning. Carbon Dioxide (CO2) is a ‘heavier’ gas than oxygen so it effectively pushes the oxygen away and smothers the fire. As there are no liquids involved in this process, it makes carbon dioxide extinguishers your safest bet for tackling electrical fires.

Again, be careful using these fire extinguishers in enclosed spaces – people, as well as fires, also need oxygen to breathe. After the fire has successfully been put out, ensure that the room is well-ventilated.

Do not use in chip pan fires as the CO2 will propel the oil everywhere, creating an even greater fire risk.

CO2 fire extinguishers are necessary for computer rooms or places where there is a lot of electrical appliances/equipment. Nowadays, this includes many businesses, so it’s your safest bet to have one around.

Strongly consider a CO2 extinguisher for:
Offices
Construction sites
Kitchens
Server rooms
Work vehicles should also carry a smaller 2kg extinguisher.

CO2 fire extinguishers have a BLACK label.

Wet Chemical

Wet chemical fire extinguishers are suited to Class A (organic combustible materials) and Class F (cooking oils) fires.

Wet chemical extinguishers contain potassium which reacts with cooking oil/fat and forms a layer of film over the oil, preventing oxygen from reaching it. It also has a cooling effect on the fuel.

This fire extinguisher is a perfect option for kitchens and canteens where there is a high risk of cooking oils catching alight, chip-pan and deep-fat fryer fires. An alternative or additional safety measure is fire blankets which are placed over burning pans – or wrapped around someone whose clothes have caught on fire – to smother the flames.

Like with the previous few extinguishers mentioned, the fumes in wet chemical fire extinguishers can be harmful to inhale – ensure the room is well-ventilated once you have successfully extinguished the fire.

Wet chemical extinguishers are vital for any workplace that has a professional kitchen and/or deep fat fryer:
Restaurants
Canteens
Fish and chip shops
Fried fast-food restaurants/trucks
Hotel kitchens

Wet Chemical fire extinguishers have a YELLOW label.

Choosing the Right Fire Extinguisher Types for Your Workplace

As you can see, there are lots of different types of fire extinguishers to choose from. However, it’s important to select the most appropriate ones for your workplace, not only to be the most effective but to comply with fire safety legislation.

Consider what type of workplace you are in and what fire risks may be there. Conduct a fire risk assessment to have a better idea of what risks are in your workplace. This will then shape what fire extinguishers you select.

You also need to take into consideration the size and weight of the fire extinguisher. Extinguishers have two main sizes: water equivalency (Class A) and range in square footage (Class B). Therefore, you would need to adapt the size and water capacity of your fire extinguishers depending on the size (in square feet) and capability of your employees to carry and use the extinguisher effectively.

Furthermore, the Regulatory Reform (Fire Safety) Order 2005 (RRO) requires workplaces to have at least two Class A fire extinguishers on every storey of the building (unless your workplace is particularly small in which case you may only need one) and never being 30m away from a fire extinguisher. This is also important to take into consideration when installing fire extinguishers in your workplace.

If this all sounds quite confusing, don’t worry – we can help. At MCFP, we can support you with fire risk assessments, and our friendly team of BAFE competent professionals will be happy to help with not only selecting the appropriate fire extinguisher types or your workplace, but with with supplying, installing and servicing fire extinguishers too. Contact us today to find out more or for a free quote.