FIRE CLASSIFICATION
what are Carbon dioxide extinguishers (CO2) best suited for?
CO2 extinguishers are ideal for places with a lot of electrical equipment such as offices or server rooms because they are safe to use on fires involving electrical apparatus.
How do CO2 extinguishers work?
CO2 extinguishers work by smothering the fire and cutting off the supply of air.
what colour label do carbon dioxide extinguishers have?
Carbon Dioxide Extinguishers (CO2) have a black label.
Do carbon dioxide extinguishers leave any residue?
Carbon dioxide extinguishers do not leave any residue, unlike a foam extinguisher.
What fires are Foam extinguishers best suited for?
Class A and B They are most suited to extinguishing liquid fires such as petrol or diesel and are more versatile than water jet extinguishers because they can also be used on solids such as wood and paper.
what classes can foam fire extinguishers be used on?
Class A and B fires.
What fire class do Carbon Dioxide Extinguishers (CO2) work on?
Class E They can also be used on Class B fires, those involving flammable liquids such paraffin or petrol.
wht colour label do foam extinguishers have?
Cream label.
What fire classes do you use powder extinguishers on?
Powder extinguishers are a good multi-purpose fire extinguisher because they can be used on Class A, B and C fires. They can also be used on fires involving electrical equipment however, they do not cool the fire so it can re-ignite.
What are the cons of using Powder extinguishers
Powder extinguishers can also create a loss of visibility and may create breathing problems.
what colour label do powder extinguishers have?
Powder extinguishers have a blue label.
How do foam extinguishes work?
The foam extinguishes liquid fires by sealing the surface of the liquid, preventing flammable vapour reaching the air and starving the fire of fuel.
Water extinguishers with additives are water extinguishers with foaming chemicals added. How do they work?
The water loses its natural surface tension meaning that it can soak into the burning materials more effectively. Adding the chemicals to the water means that a smaller extinguisher can produce the same fire rating as a larger, water only, extinguisher.
what are Powder extinguishers not suitable for?
They are not generally recommended for use inside buildings unless there is absolutely no alternative.
what are foam fire extinguishers not suitable for?
They are not suitable for use on free flowing liquid fires.
How do water jet extinguishers work?
Water jet extinguishers work by spraying a jet of water at the burning materials, cooling them and preventing re-ignition. They should not be used on live electrical equipment.
How do water spray extinguishers work?
Water spray extinguishers use a very fine spray of water droplets, each droplet is surrounded by air which is non-conductive. Most water spray fire extinguishers carry a 35 kV dielectric test approval which means they have been tested on a 35,000 Volt electrical source at one meter.
Class F
fires involving cooking oils such as in deep-fat fryers.
Class B
fires involving flammable liquids such as petrol, diesel or oils.
Class C
fires involving gases.
Class E
fires involving live electrical apparatus. (Technically 'Class E' doesn't exists however this is used for convenience here)
Class D
fires involving metals.
Class A
fires involving solid materials such as wood, paper or textiles.
what coloured labels do water extinguishers have?
red labels
How do water mist, or fog, extinguishers work?
they apply water in the form of mist, or fog, the droplets are much smaller than those from the water spray extinguisher. The smaller the droplet, the larger its surface area in relation to its size, the quicker the droplet evaporates which absorbs the heat energy faster. The downside is the smaller the droplet the less it weighs and therefore the less powerful the cloud of water.
There are four different types of water extinguishers:
water jet, water spray, water with additives and water mist or fog.
