Fire extinguishers are meant for one common purpose which is to douse fire. However, different types of fires need different handling. When trying to improve one’s fire safety it is important to know that the right action at the right time can prevent the spread of fire and minimize losses whereas use of wrong equipment can worsen the condition and completely throw it out of control.
Broad Classification of Fire Extinguishers
There are four categories in which fire extinguishers can be divided:
- Class A: These extinguishers are meant for fires that involve organic solids like wood and paper
- Class B: These extinguishers are meant for fires that involve inflammable liquids
- Class C: These extinguishers are meant for fires that involve inflammable gases
- Class D: These extinguishers are meant for fires that involve metals
In certain countries class E is used to denote fires that involve electric equipments. Other countries use class C to denote both inflammable gases and liquids and class D is used for fires involving electric apparatus. In certain counties, electric fires are not denoted by any category as they can be caused by any reason and can involve different circumstances.
Class F is used in some countries for fires involving cooking oil and fat. Halon extinguishers were used earlier for but have been made illegal except for use in particular areas like the aircraft industry. If anyone has this extinguisher they should immediately dispose it by contacting the fire department to ensure safe disposal.
Some extinguishers can douse fires in multiple situations. They are marked with the respective combination of classes. For example, if an extinguisher can be used for both liquids and gases, they will have both class B and C printed on them. Pictorial representation is also present of all extinguishers to point the type of material that are involved in the fire.
Colour Coding
Different colors signals represent different material used in the extinguisher. The broad classification is:
Red
Use of water is made and this type can be used for fires involving combustible material like paper and wood
Most extinguishers are now have red signal with a panel of 5% margin above the red signal as a band or circle that denotes other colors which stand for different materials.
Cream
Foam is used and it can be used for fires involving combustible material and inflammable liquids
Blue
Dry powder is used and it can be used for fires involving combustible material and inflammable gases as well as liquids
Black
Represents carbon dioxide which is helpful in dousing fires with inflammable liquids and to some extent for combustible materials
Green
it represents halon which is currently illegal and was used for fires involving combustible materials
Fire Rating
All extinguishers that can be used for fires involving combustible materials and inflammable liquids have a rating attached to them. The number in the rating represents the extent of fire that can be controlled by the extinguisher, the larger the number, the larger the fire it can control. The letter in the rating represents the class like A, B or combination of two.
