Fire Classifications & Fire Extinguisher Types

Fire Classifications

All fires are grouped into classes, according to the type of materials that are burning. The classes of fire for the UK and Europe are slightly different to those used in the USA and Australia so remember to always read a fire extinguisher label carefully if you are overseas.

The following is a quick guide to the different types of fire.
Class A fires involve combustible materials such as paper, wood, cardboard, and most plastics.
Class B fires involve flammable or combustible liquids such as petrol, kerosene, paraffin, grease and oil.
Class C fires involve flammable gases, such as propane, butane and methane.
Class D fires involve combustible metals, such as magnesium, titanium, potassium and sodium.
Class F fires are specific to cooking oils and fats
Note: Electrical fires involving equipment such as electrical circuits or electronic equipment are sometimes accidentally referred to as Class-E fires, although the category does not officially exist under the European EN3 rating system. This is because electrical equipment is often the CAUSE of the fire, rather than the actual TYPE of fire. As such, most modern fire extinguishers specify on the label whether they should be used on electrical equipment.

Fire Extinguishers Sizes

Fire Extinguishers display a fire rating which indicates the size and type of fire that they can extinguish.
The letter is the type of fire it is capable of extinguishing and the number is the size of fire it can extinguish under test conditions (ie. 8A), the larger the number, the larger the fire it can extinguish.
Some fire extinguishers are suitable for tackling different types of fire and are often referred to as Multi Purpose Fire Extinguishers. For example, all fire extinguishers capable of extinguishing both class A and B fires carry a Fire Rating which is indicated by a number and letter. (Example: 21A/113B)
This rating indicates the extinguisher is capable of extinguishing a Class-A fire to the size 21 and a Class-B fire to the size 113 under test conditions. This performance exceeds the fire rating 8A/34B, however FOUR extinguishers rated to 8A/34B would be equivalent to ONE extinguisher rated to 21A/113B.

Fire Extinguisher Types & Colours

Under the European EN3 standard the markings on fire extinguishers have been standardized, and this information is presented in the following ways.
  • Every fire extinguisher is colour-coded for easy reference
  • A fire extinguishers rating is shown both as a letter (such as A or B) and also as a pictogram. (In addition, the fire extinguisher will also bear an additional pictogram if it is suitable for use on electrical equipment fires)
  • The precise fire rating for Class A and B fires is expressed as a number and letter combination, such as 8A / 34B
  • There should be clear operating instructions on how to use each type of extinguisher.
In the UK a fire extinguisher from a quality supplier should in addition be clearly marked with:
1. BSI Kitemark, indicating BAFE (British Approval for Fire Equipment)
2. CE Mark, along with the EN3 Standard
These marks confirm that the fire extinguishers comply with the Pressure Equipment Directive (PED) and are BAFE (British Approval for Fire Equipment) approved.
Fire extinguishers are remarkably sophisticated items of fire fighting equipment, and each type has been specially designed to tackle different types of fire.
Water Fire Extinguishers
Water fire extinguishers are filled with ordinary tap water. They are ideal for use on Class-A fires involving everyday materials such as paper, wood, fabric, furnishings, etc. Water fire extinguishers are solid red in colour. (read more)
Dry Powder Fire Extinguishers
Powder fire extinguishers are excellent all-round fire extinguishers suitable for use on Class-A, Class-B and Class-C fires. They are also are safe to be used on fires involving electrical equipment. (Remember to look for the electrical safety pictogram on the extinguisher body.) Powder fire extinguishers are painted red with a blue panel above the operating instructions. (read more)
Foam Fire Extinguishers
Aqueous film forming foam fire extinguishers (AFFF) are very popular due to their all-round abilities and are suitable for use on Class-A and Class-B fires. Foam fire extinguishers are red with a cream panel above the operating instructions. (read more)
Carbon Dioxide (CO2) Fire Extinguishers
Carbon dioxide or CO2 fire extinguishers are suitable for Class-B fires involving flammable liquids and are also recommended for fires involving live electrical equipment. Carbon dioxide fire extinguishers are painted bright red with a black panel above the operating instructions, and have a distinctive horn-shaped nozzle at the side or a hose with a horn on the larger models. (read more)
Metal Fire, Fire Extinguishers
A variety of specialist fire extinguishers are required to tackle the various Class-D flammable metal fires. All specialist flammable metal fire extinguishers are categorized as powder extinguishers, so UK metal fire extinguishers ones are painted red with a blue panel above the operating instructions. (read more)
Wet Chemical Fire Extinguishers
Wet chemical fire extinguishers were developed specifically for use on Class-F deep fat cooking fires. Wet chemical fire extinguishers are red with a yellow panel above the operating instructions. (read more)


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