Which Fire Extinguisher?

In an emergency it is vitally important that you are prepared and know what to do. Here at The Training Fox, we pride ourselves on helping you be exactly that. Our training courses are designed to equip you with the information that you require, and we back this up with our Legislation page and our articles.

In this month’s article we look at the important subject of fire extinguishers. With so many fire extinguishants available, it is important that you select the correct one for the correct job. This month we aim to help you with this choice by looking at how to identify the contents of an extinguisher, what to use it on and how to check that the extinguisher is safe to use, although this should be checked before the need arises!

Back in the 1990s identification of fire extinguisher contents was easy as the whole of the canister was the identified colour, however in 1998 an EU directive directed that extinguishers should be red and have 5% of the identifying colour on it.

Water Extinguisher

The water extinguisher is the most common fire extinguisher.

What is the identifying Colour of the Water extinguisher?
Red

What are the Contents of this extinguisher?
Pressurised water

What can I use this extinguisher on?
The water extinguisher is best used on Class A fires:

• Wood,
• Paper,
• Straw,
• Textiles,
• Coal etc.

How does this extinguisher extinguish the fire?
The water extinguisher works by cooling the fire surface and soaking the burning materials in water.

How close to the fire do I need to be with this extinguisher?
It is recommended that you are 6 to 8 metres away from the fire you are trying to extinguish.

What should I not use this extinguisher for?
When using a Water extinguisher, you should not attempt to extinguish fires caused by:

• Electrical equipment,
• Cooking oils or fat pan fires,
• Flammable metal fires for example:
  • Magnesium (Mg),
  • Titanium (Ti),
  • Aluminium (AI),
  • Sodium (Na), and
  • Lithium (Li).

Foam Extinguisher

What is the identifying Colour of the Foam extinguisher?
Cream

What are the Contents of this extinguisher?
Inside the Foam extinguisher there is a mix of water and foam concentrate, often referred to as Aqueous Film Forming Foam (AFF Foam).

What can I use this extinguisher on?
The foam extinguisher is best used on Class A fires:

• Wood,
• Paper,
• Straw,
• Textiles,
• Coal etc.

This extinguisher can also be used on Class B fires:

• Petrol,
• Oil, and
• Paint.

How does this extinguisher extinguish the fire?
A water based foaming agent floats on top of the burning liquid and smothers the flames at the surface, this prevents the fire of restarting, however there is a limited cooling effect from this extinguisher.

How close to the fire do I need to be with this extinguisher?
The distance you need to be from the fire when using this type of extinguisher will depend on the discharge device of the unit. You should consult the extinguisher for more information – Remember to do this BEFORE there is a need to use the extinguisher.

What should I not use this extinguisher for?
When using a Water extinguisher, you should not attempt to extinguish fires caused by:

• Cooking oils or fat pan fires,
• Flammable metal fires for example:
  • Magnesium (Mg),
  • Titanium (Ti),
  • Aluminium (AI),
  • Sodium (Na), and
  • Lithium (Li).

• Electrical equipment (Unless stated otherwise).

Carbon Dioxide (CO₂) Extinguisher

What is the identifying Colour of the CO₂ extinguisher?

Black

What are the Contents of this extinguisher?

Non-Flammable Carbon Dioxide (CO₂) gas which is under high pressure.

What can I use this extinguisher on?

The CO₂ extinguisher is best used on Class B fires:

• Petrol,
• Oil, and
• Paint.

As well as Electrical equipment (Class E) even if the equipment is live!

How does this extinguisher extinguish the fire?

Carbon Dioxide starves the fire of oxygen, replacing it with CO₂ and therefore smothering the fire.

How close to the fire do I need to be with this extinguisher?

It is recommended that you are 1 to 1.5 metres away from the fire you are trying to extinguish.

What should I not use this extinguisher for?

When using a CO₂ extinguisher, you should not attempt to extinguish fires caused by:

• Cooking oil, fat pan fires,
• Flammable metal fires for example:
  • Magnesium (Mg),
  • Titanium (Ti),
  • Aluminium (AI),
  • Sodium (Na), and
  • Lithium (Li).

Are there any specific issues I should be aware of with this extinguisher?

You Should NOT use in confined spaces as CO₂ is an asphyxiant.

You should be aware that the fire may re-ignite as this extinguisher does not cool very well.

The discharge horn and hose may freeze and could cause cold burns if in direct contact with the skin, therefore whilst discharging ensure that you do not hold the horn or the hose!

Powder Extinguisher

What is the identifying Colour of the Powder extinguisher?

Blue

What are the Contents of this extinguisher?

Sometimes this extinguisher is referred to as a dry powder extinguisher as it contains a very fine powder that smothers the fire.

What can I use this extinguisher on?

The Powder extinguisher is the most versatile of extinguishers, and it can be used on pretty much all types of fires, except for class F fires (See Wet Chemical below!)

Most types of fire, including electrical equipment. (Can cause damage to the equipment).

The Powder extinguisher can be used in Class A

• Wood,
• Paper,
• Straw,
• Textiles,
• Coal etc.

This extinguisher can also be used on Class B fires:

• Petrol,
• Oil, and
• Paint.

It can also be used on Class C Fires:

• Butane (C₄H₁₀),
• Ammonia (NH₃),
• Propane (C₃H₈).

Some specialist Powder extinguishers are also designed for Class D fires:

• Flammable metal fires for example:
  • Magnesium (Mg),
  • Titanium (Ti),
  • Aluminium (AI),
  • Sodium (Na), and
  • Lithium (Li).

These types of extinguishers are also safe to be used on Electrical fires (Class E).

How does this extinguisher extinguish the fire?

The powder coats the fuel and smothers the fire.

How close to the fire do I need to be with this extinguisher?

It is recommended that you are 6 to 8 metres away from the fire you are trying to extinguish.

What should I not use this extinguisher for?

When using a Powder extinguisher, you should not attempt to extinguish fires caused by:

• Cooking oils or fat pan fires
• Be aware that some Powder extinguishers should not be used on Flammable metal fires for example although some can, therefore ensure you have checked the extinguisher in advance of it needing to be used:
  • Magnesium (Mg),
  • Titanium (Ti),
  • Aluminium (AI),
  • Sodium (Na), and
  • Lithium (Li).

Are there any specific issues I should be aware of with this extinguisher?

Powder types can vary; this will affect they types of fire they should be used on.

These extinguishers should NOT be used in confined places as they can affect visibility and people with breathing problems.

You should also be aware that, like most powders, the contents will spread widely and can affect the internal components of PCs, laptops, printers, TVs etc and make them non-usable.

Our fun fact about Powder extinguishers is that they can strip the paint of a car!

Wet Chemical Extinguisher

What is the identifying Colour of the Wet Chemical extinguisher?

Yellow

What are the Contents of this extinguisher?

A Wet Chemical extinguisher contains a special solution, primarily Potassium Acetate (C₂H₃KO₂)

What can I use this extinguisher on?

This the only type of extinguisher that can be used on Class F fires:

• Cooking Oils for example:
  • Vegetable oil,
  • Rapeseed oil,
  • Olive Oil,
  • Sunflower oil etc
• Cooking Fats for example:
  • Lard,
  • Butter,

In addition, this extinguisher can be used on Class A fires:

• Wood,
• Paper,
• Straw,
• Textiles,
• Coal etc.

How does this extinguisher extinguish the fire?

A fine mist is delivered that has a cooling effect on the flames. Salts in the solution react with the animal fats and vegetable oils to form a layer at the surface that smothers the fire

How close to the fire do I need to be with this extinguisher?

It is recommended that you are 3 to 5 metres away from the fire you are trying to extinguish.

What should I not use this extinguisher for?

The Wet Chemical Extinguisher Should NOT be used on:

• Petrol,
• Oil,
• Paint, and
• Mineral Oils.

Are there any specific issues I should be aware of with this extinguisher?

It is important that you check manufacturer’s instructions for other uses, these checks should be completed before you attempt to extinguish a fire.

Overview of the Classes of Fires

How to check a Fire Extinguisher is ready to be used

There are some simple steps that can be taken in advance of needing a fire extinguisher that you should do on a periodic basis in your workplace to ensure that you have what you need in that emergency.

• Ensure that the fire extinguish is correctly sited in its place, and has an identification label for it, whether this be on the wall or on the extinguisher stand in addition to the extinguisher itself. This will also help with identifying when the extinguisher has been moved and not replaced.
• A Fire Extinguisher IS NOT a doorstop, if seen this must be removed and replaced to its correct placement Immediately!
• It is important that the extinguisher is not obstructed, if you see this rectify it immediately or report it to someone who can.
• Check that there are no signs of tampering, and that the safety tag is in place.
• Is the safety pin in place?
• There should be no signs of rust or leaks on the extinguisher, if you see this report, it and get the service company to replace as soon as possible.
• There should be a service on the extinguisher showing that it has been serviced in the last 12 months.
• Have a look at the pressure gauge, ensure that the needle is in the green zone showing that it has the correct pressure inside and ready for use.

When should I fight a fire?

You should only ever attempt to fight a fire if:

• Someone raised the alarm,
• The emergency services have been called,
• The correct type of extinguisher is available,
• You are competent and have been trained how to use the extinguisher,
• A safe escape route is available,
• The fire is smaller than a wastepaper bin.

Never be tempted to fight a fire if:

• The room is filling with smoke or the fire is spreading,
• Other hazards are present (such as chemicals or gas cylinders),
• The fire is not reducing, or more than one extinguisher is required.

We hope that this month’s article has helped to demystify the confusion around fire extinguishers.
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