As the complexity of buildings increases so does the need for effective fire protection systems such as fire alarms, emergency lighting, evacuation routes and portable fire fighting equipment such as extinguishers. As buildings are extended and changed so should the corresponding systems. This is a critical and complex topic and not all aspects can be covered in a single article.
The information that follows is a basic guide to fire extinguishers. Please always seek professional advice when choosing fire extinguishers and other fire protection systems for your business and home.
What are the Classes of Fire?
Fires are classified according to the kind of fuel involved in a fire. The ability of a fire extinguisher to put out a fire is indicated by letters relating to the relevant fire classes.
Class of Fire
CLASS A – Involving solid materials such as wood, paper or textiles.
CLASS B – Flammable liquids, such as petrol, diesel and paraffin. Not alcohol or cooking oil.
CLASS C – Flammable gases, such as LPG, Propane, Butane and natural gas
CLASS D – Flammable metals, such as magnesium swarf
CLASS F – Cooking fats and fryer oils
Electrical – Such as an electrical appliance or wiring
Suitable Fire Extinguisher
It is important to remember that extinguishers are not designed to fight large fires.
CLASS A – Water, foam or multi-purpose dry powder extinguishers
CLASS B – Foam
CLASS C – Powder
CLASS D – Specialist Powder
CLASS F – Wet chemical
Electrical – Powder, CO2
Choosing Fire Extinguishers
CO2 fire extinguishers
Water fire extinguishers
Foam fire extinguishers
Wet chemical fire extinguishers
Powder fire extinguishers
Dry powder fire extinguishers can be used for class A (burning solids) class B (burning liquids) and class C (burning gas) fires. They cannot be used on fat fires and deep fat fryer fires. Their powerful jet would spread the burning fat. They are known to cause breathing problems and so their use in small spaces is not recommended. The residue of the powder is messy and difficult to clean up after use.
Powders are the most multi- purpose and will extinguish a fire quickly. They have little cooling effect and therefore the fire can re-ignite if not completely out.