Perhaps you get a bit lost trying to understand the different classes of fires and different types of fire extinguishers. After all, it can be easy to assume a fire is a fire and you can use any extinguisher to put it out. But that simply isn’t true.
And it can be dangerous to think otherwise, especially when it comes to Class B fires. Using the wrong extinguisher to try to put out a Class B fire can have serious consequences, including adding to the intensity of the fire and increasing the risk you put yourself and others in.
So, what exactly is a Class B fire?
A Class B fire is one which involves flammable liquids. Examples of flammable liquids include petrol, oil, turpentine, paraffin, alcohol and certain paints.
What Causes Class B Fires?
A Class B fire occurs when a flammable liquid ignites. Flammable liquids can ignite with a simple spark, or when heated up to extremely high temperatures. The former is why people are advised not to smoke cigarettes when filling their car up with petrol, as the sparks from a cigarette can cause a dangerous, intense, and large-scale fire.
It is therefore highly recommended that you keep flammable liquids away from any potential risks. Furthermore, you should be well prepared for the eventuality of a Class B fire.
How to Safely Extinguish a Class B Fire
The absolute worst thing you can do to try and put out a Class B fire is to use water.
Remember your science lessons when your teacher poured water into a beaker of oil, and the two liquids layered? Well, they literally don’t mix. When water comes into contact with a Class B fire, it immediately vaporises into steam, which in turn spits out the oil and intensifies the fire. The resultant explosive ball of flames spreads the fire quicker.
So what can you do to safely put out a Class B fire? You can use an appropriate Class B fire extinguisher. These include:
- Dry powder fire extinguishers are the most effective, as they spray a multi-purpose powder that smothers and suffocates the fire by inhibiting the chemical reactions causing the fire.
- Foam fire extinguishers are a good choice as they spray foam that acts as a smothering and cooling agent, while also sealing harmful vapours under a layer of film.
- CO2 fire extinguishers are also safe to use as they smother the fire, removing it of oxygen.
Another option is to use a fire blanket. However, you should only use a fire blanket if it is larger than the fire, such as those in a saucepan, and will securely cover and smother the flames.
Class B Fire Extinguisher Colour Codes
Knowing the colour code for the fire extinguishers mentioned above can help you easily and quickly identify them in an emergency situation.
- Dry powder fire extinguishers have a blue strip located at the top.
- Foam fire extinguishers have a cream strip.
- CO2 fire extinguishers have a black strip.
Preventing a Class B Fire
As they can be very dangerous, it pays to take precautions to prevent a class B fire from breaking out.
You should never store more flammable liquid than absolutely necessary, and keep them well away from sources of ignition.
If it’s possible, you could also consider storing liquid in flammable storage cabinets made of steel. They work by creating a temporary barrier between a potential fire outside and the flammable liquid stored in them, for around 30 minutes.
Remember not to use water, and instead have appropriate fire extinguishers close by, just in case.
Key Takeaways on Class B Fires
When it comes to fire safety, having the right knowledge will allow you to contain a Class B fire and prevent it from spreading any further. Always remember to use the right fire extinguisher.
However, it is important to mention that you should never put yourself or anyone else at risk if the fire is out of your control. Only proceed if you are entirely sure that it is safe to do so.
If you need further advice or you have more questions regarding class B fires and our specialist fire extinguishers, learn more from our FAQs or get in touch with our expert team.
