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Choosing the right fire extinguisher

When it comes to choosing the right fire extinguisher, no single type of extinguisher is fully effective on every kind of fire. So before buying a fire extinguisher, it is vital to look carefully at what type of fire you could possibly have to deal with.  Choosing the wrong type of fire extinguisher for the job can be very dangerous, make the fire worse and risk injuring those attempting to fight the fire.

Types of fires

The fire classification system categorises fires into groups based on the type of fuel involved. Each fire class is represented by a letter of the alphabet (with the exception of 'electrical fires') and an easy to identify icon. This is designed to help users select the correct fire extinguisher to deal with a specific fire event.

The below table sets out this class rating system-

ClassificationIconFuel Type
Class ASolids such as paper, wood, soft furnishings and plastic.
Class BFlammable liquids such as paraffin, petrol and oil.
Class CFlammable gases such as propane, butane and methane
Class DMetals such as aluminium, magnesium and titanium
Class FCooking oils and fats
Electrical Fires involving electrical apparatus.
Former Class E - this type of fire can fall into any of the classes, as it is not the electricity burning but the surrounding materials set alight by the electric current.

Types of fire extinguishers

Fire extinguishers are available in different types, with each one having specific fire classes that they are suitable for use on. Fire extinguishers meeting the current British Standards (BS EN3) should have a red body (RAL 3000) and an agent specific colour band, covering between 5-10% of the surface, relating to the extinguisher contents.

Type of fire extinguisherColourFire classification 
WaterRedClass AWater extinguishers are used on Class A fires involving solid combustibles. They are not suitable for fires fuelled by flammable liquids or where electricity is involved.
FoamCreamClass A and BFoam is a versatile fire extinguisher which can be used for Class A and B fires. The foam agent helps to prevent re-ignition.
CO2BlackClass B and ECO2 fire extinguishers are used for fires involving electrical apparatus. CO2 is not a conductor and does not leave behind any harmful residue. 
Dry PowderBlueClass A, B and CDry powder extinguishers can be used on Class A, B, C and electrical fires. Dry powder is not recommended for use inside because there is a risk of inhalation. It can obscure vision and cause damage to goods and machinery.
Specialist PowderBlueClass DThese specialist poder extinguishers are suitable for use on metal fire but are ineffective on all other fires. L2 Specialist powder extinguishers are suitable for use on lithium metal fires. Note: Lithium-ion batteries do not contain lithium metal but instead liquid electrolytes, therefore these are rated as  class B fires.
Wet ChemicalYellowClass FWet chemical extinguishers are for fires involving cooking fats and oils. They are most suitable for use in restaurants and kitchens. They usually have an additional class A rating.

When choosing which fire extinguisher you need within your premises,  a fire risk assessment will help you to identify the fire risks and exactly which extinguisher would be needed should a fire happen.

UK fire extinguisher regulations state that you should have a minimum of two ‘Class A’  extinguishers (wood/ paper/ 'Carbonaceous' fires) on every storey of the building.  These can be in the form of water or foam extinguishers.

Exceptions to the rule would be if your premises are very small and it would be a hindrance to escape having two extinguishers, then only one may be needed - for example a small newspaper kiosk. - use our floor space calculator to work out how many Class A extinguishers you may need

Depending on the equipment in your premises, you are likely to need other types of fire extinguisher, as identified in your risk assessment.

The most common additional extinguishers are CO2 which are used to fight electrical fires. UK regulations  specify:

–   All premises with electrical equipment must have at least 2kg CO2 extinguishers
–   and where there is 415 volt rated equipment, then 5kg CO2 extinguishers are required

In the modern day of computers and electronic technology, there are very few cases where you won’t need a CO2 extinguisher. For this reason it is very common to see CO2 paired with foam or water extinguishers, thereby meeting UK fire extinguisher legal requirements.

Other types of extinguisher you may need depending on your premises are:

 –   Dry powder extinguishers: for gas risk areas, e.g. in boiler rooms (not recommended for other indoor use)
 –   Wet chemical extinguishers: for use in restaurants and kitchens where the source and fuel of fire can come from cooking oils and fats.  

If you do not have the skills, experience or resources to carry out a fire risk assessment Marsden Fire Safety can help.

Contact us …or call… 01282 691616