In accordance with the standard BS EN 3, fire extinguishers in the United Kingdom and all over Europe are Red RAL 3000 and a band or circle of a second colour covering at least 5% of the surface area of the fire extinguisher indicates the content of the fire Extinguisher - and the class of fire it can be used on.

There are six fires classes recognised in the UK. Each class of fire has a different type of fuel.

Class A fires are fires where the combustible substances are organic solids such as paper and wood,

Class B fires the combustible substances are liquids,

Class C fires involve flammable gases,

Class D fires involve metals,

Class E fires involve live electrical items

Class F fires the combustible substances such as cooking fat or oils.

Type BS EN 3 Colour Code Fire Class
Water Signal Red A
Foam Red with a Cream panel above the operating instructions A B sometimes E
Dry Powder Red with a Blue panel above the operating instructions A B sometimes C E
Carbon Dioxide CO2 Red with a Black panel above the operating instructions B E
Wet Chemical Red with a Canary Yellow panel above the operating instructions A F
Class D Powder Red with a Blue panel above the operating instructions D

The capacity of fire extinguishers are established according to the class of fire using numbers and letters such as 13A, 55B.