Mastering Class B Fires: A Comprehensive Guide to Flammable Liquids and Fire Safety

We all know what a fire is. But did you know there are different types of fires? Fires are classed by the fuel used to create them. From your typical solid combustible materials such as paper and wood to flammable liquids and even metals, various items can fuel a fire. In this guide, we delve into one specific class of fire: Class B fires. So what is a Class B fire, and what is the safest way to extinguish it?

What is a Class B Fire?

Class B fires are known as the flammable liquids fire class. This means flammable liquids that are ignited can easily cause fires as they have lower ignition temperatures. When heated up to extreme temperatures, fires are formed and can spread rapidly. Examples of flammable liquids causing Class B fires include: 

  • Petrol 
  • Oil 
  • Alcohols 
  • Paraffin
  • Acetone 
  • Some paints  

To prevent fires, flammable liquids should be kept away from ignition sources. One way to ensure this is to put them in meticulously designed flammable liquid storage cabinets. Not only will this safeguard your staff from harm but you will also be complying with multiple industry standards such as COSHH (Control of Substances Hazardous to Health). 

How To Put Out Class B Fires

You may think that putting out a fire is as easy as grabbing a fire extinguisher or throwing water over the flames, but not understanding the ins and outs of different fire classes can actually cause more harm than good. 

In this section, we break down the elements that go into creating a fire and the types of extinguisher you should use on a Class B fire to safely tackle these fires. 

Elements of a Fire

To create a fire, you need four components: fuel, oxygen, heat and a chemical reaction started by an ignition source. In terms of a Class B fire, the flammable liquid acts as the fuel; oxygen will come from the surrounding air and the ignition source could be a spark or open flame. 

Fires can be easily created by combining all these elements. However, by removing one of these elements, fires can also be successfully extinguished. But what is the best and safest way to extinguish a fire?

The Types of Fire Extinguisher You Should Use to Put Out a Class B Fire 

The most obvious choice of fire extinguisher to use to put out a Class B fire is a Class B fire extinguisher. This particular fire extinguisher is designed to tackle Class B fires specifically.  These extinguishers work by removing the oxygen from the surrounding area of the fire, essentially suffocating the fire.  

Types of Class B fire extinguisher include: 

  • CO2 Fire Extinguishers: The most common method of extinguishing Class B fires, they smother the fires by removing oxygen. 
  • Dry Powder Extinguishers: Works by inhibiting the chemical reaction causing the fire. 
  • Foam Fire Extinguishers: Removes oxygen from the surrounding air.  

Fire blankets are also an effective method of extinguishing a Class B fire, as they work by removing oxygen from the surrounding area. 

Do Not Use Water! 

Using water to extinguish a Class B fire is an absolute no-no. As Class B fires are fuelled by flammable liquids such as oils, water cannot be used, as water and oil do not mix. When poured onto the fire, water will simply vaporise, turning it into steam. This can cause the fire to spit out hot oil, causing harm to individuals and spreading the fire further. 

How To Prevent Class B Fires

Class B fires can be prevented by storing flammable liquids in the appropriate containers. For example, specially designed flammable liquid storage cabinets are the best way to store flammable liquids. They are labelled with clear signs and include spill trays to collect any spilt flammable liquids. These storage cabinets also ensure you are compliant with industry standards!

Other steps you should take to prevent Class B fires are to: 

  • Only store the amount of flammable liquids you need, no more than necessary. 
  • Keep all flammable liquids away from sources of ignition. 
  • Ensure all employees understand the correct way to handle flammable liquids. 

Tackle Class B Fires Safely with Fire and Safety Centre

Fires can be easily prevented by following the correct procedures. In terms of Class B fires, the proper storage of flammable liquids and training when handling flammable liquids can reduce the risk of creating Class B fires. At Fire and Safety Centre, we can help you store your flammable liquids easily and safely. Our flammable liquid storage cabinets are designed with effective storage and security in mind. 

Remember to have the appropriate measures in place to tackle Class B fires, too! With dry powder extinguishers, foam fire extinguishers and CO2 fire extinguishers, you can safely handle Class B fires in the case of an emergency. Prevent and extinguish Class B fires safely with Fire and Safety Centre today! 

Class B Fires FAQs

What are Class B fires?

Class B fires are defined as fires with a fuel source of flammable liquids, such as petrol, oils, alcohol, and even some paints. Fires are categorised by their fuel sources. Other fuels include solid combustible materials such as paper and wood (Class A), electrical components (Class C) and combustible metals (Class D). 

What is a Class B fire caused by?

Class B fires are caused by flammable liquids. However, with the proper storage and training surrounding flammable liquids, the risk of fire can be greatly reduced. Flammable liquids can be safely stored in flammable liquid storage cabinets, reducing the risk of spillages and clearly signposting where flammable liquids are stored. 

What is the best extinguisher for a Class B fire?

There are various ways to extinguish Class B fires. The most common method is to use a CO2 fire extinguisher. This method effectively removes oxygen from the surrounding area of the fire, smothering it. 

Other methods of extinguishing Class B fires include using dry powder or foam fire extinguishers or a fire blanket. You must not use water to attempt to put out a Class B fire as this can cause the fire to spit, harming yourself and others around you and potentially spreading the fire further. 

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