How Does a Fire Blanket Work? When and How to Use One Safely
Fire blankets are an inexpensive and reliable piece of fire safety equipment found in many homes and workplace environments. But how do they work? And what kinds of fires can they be used for?
Before we dive into the details, here’s the short answer:
Ideal for small, contained fires such as cooktop or trashcan fires, fire blankets are used to completely smother the fire, starving it of the oxygen it needs to keep burning. They are typically made of glass fiber and folded into wall-mounted quick-release containers.
Later on, we’ll look briefly at the science behind how fire blankets work, but first let’s cover a few basic points about where, when, and how they are used.
When to use a fire blanket
Fire blankets are ideal for putting out small-scale fires in their early stages, known as incipient fires. They are particularly effective when used against fires in closed containers because it makes it easier to cover and cut off airflow.
The typical example is a cooktop (a.k.a. hob or stovetop) fire which you might experience if your cooking gets a little out of hand. They are also great for other small fires such as outdoor cooking equipment, trashcan fires, or even campfires.
For fires larger than the blanket itself, it’s not wise to attempt to put it out using a fire blanket. Not only is it unsafe to approach such a large fire so closely, it actually won’t do much to stop it either.
In these situations, it is better to use a fire extinguisher. Or, if things get really problematic, the best thing to do is to evacuate the building and get on the phone to emergency services without delay.
Where are fire blankets kept?
Although we normally associate fire blankets with kitchen fires, they’re also found mounted to the walls of laboratories, garages, workshops, offices, science classrooms, and in boats, campervans, caravans, and other large vehicles.
Typically they’re stored in wall-mounted contraptions sporting a quick-release mechanism for fast and easy access.
As you might expect for fire safety gear, these containers are often a vibrant red in appearance though they’re also available in more interesting and aesthetically pleasing designs, such as our EN 1869 certified Brothers4Change® fire blanket featuring a world map design.
Why not use a fire extinguisher instead?
While fire extinguishers are incredibly effective pieces of fire safety equipment, they are not without their drawbacks.
For one thing, extinguishers create quite a bit of mess and can even cause significant damage to the room and the things in it. In fact, acts of vandalism involving fire extinguisher discharge can cost thousands in cleanup and damages.
For something as simple as a small cooktop fire, using a fire extinguisher could mean hours spent cleaning up chemical residue from appliances and room surfaces nearby.
Worse, the dry chemical present in fire extinguishers can be corrosive to metals, causing damage to equipment and appliances, so much so that the aviation industry actually uses halogen extinguishers instead.
A fire blanket, on the other hand, minimizes mess as it tends to keep everything contained and there won’t be any messy chemical residues left behind except those produced by the fire itself.
Unlike extinguishers, blankets are very low maintenance. Pressure gauges should be checked monthly to verify that the extinguisher is still full, and in some places, it is required to have it serviced once a year by a qualified technician.
Extinguishers have a rather short discharge time, around 8 to 21 seconds, so for particularly resilient small fires, a fire blanket may actually be more effective.
Additionally, while fire extinguishers can be heavy and cumbersome devices, fire blankets are much lighter and easier to handle, an especially important factor for the physically less able among us.
Finally, fire blankets are an incredibly cost-effective fire safety measure. While extinguishers can cost anywhere from $30 to $300, a high-quality, certified domestic fire blanket costs only around $25.
How to use a fire blanket
Fire blankets are simpler and in many ways easier to use than fire extinguishers.
Normally the container for a fire blanket will have some brief instructions on how to extract and use it, and it’s usually a good idea to read that before deploying it.
In any case, here’s how you would generally use a fire blanket to put out a small fire.
Start by rolling up your sleeves so they’re not at risk of catching fire. Turn off the gas or electricity supply if it is safe to do so.
Then, after locating the fire blanket container, grab the fabric straps and pull the blanket out. Wrap the top edges of the blanket around your hands to protect them. Next, carefully place the fire blanket over the flames so that the entirety of the fire is covered and starved of oxygen.
Once it’s down, avoid touching the fire blanket or anything underneath it. Even after the fire is put out, it will still be very hot so you could still burn your hands. Leave it there for at least 30 minutes before touching it again.
If the fire is larger than the blanket, do not attempt to put it out with a fire blanket. As we discussed earlier, a fire extinguisher is more appropriate for larger fires.
Of course, if the fire has reached a scale that puts you or someone else in serious danger you should evacuate the building and call emergency services immediately.
Interestingly, fire blankets can also be used to protect a person from direct exposure to flames by wrapping them around the body.
If the only way to escape the building is to pass close by or through the fire, the blanket can be wrapped around the body, offering some protection against burns along the way.
In the unfortunate event of someone’s body or clothes catching fire, the blanket can be wrapped around the body and used in combination with the widely advised “stop, drop and roll” technique.
Can fire blankets be re-used?
The advice from authorities on fire safety is that fire blankets should be replaced after use. A used fire blanket may not be reliably effective the second time around.
Some fire blankets come with tamper indicators so you can see whether the blanket is good to use or needs replacement.
The good news is that fire blankets do not expire over time. Modern fire blankets can be kept mounted to your kitchen wall for 5 years or more and it will still be just as effective then as the day you bought it.
How fire blankets actually work
Now we get to the sciency bit. What is it about fire blankets that make them so effective at putting out fires?
Fire blankets work on the principle that fire needs oxygen in order to keep burning, and cutting off its supply of oxygen will therefore put it out. So the question is, how exactly does a blanket cut off its oxygen supply?
By placing a blanket of flexible fire-proof material over a small fire, covering it entirely, we can prevent air from flowing over it and therefore significantly reduce the amount of oxygen it’s able to take from the air in the room.
This is why it’s so important that the entirety of the fire is covered. It’s essential that all of the flames be completely smothered so that no part of the fire has access to sufficient oxygen to maintain the burning. If a part of the fire extends outside of the blanket’s coverage, then it can continue to burn and spread further.
What fire blankets are made of
When we think of blankets, we tend to think of them as flammable objects. So if a fire blanket is placed directly onto a fire then what’s to stop the blanket itself from catching fire? What kind of miraculous material are they made of?
Domestic fire blankets tend to be about 3 by 3 ft in size (1 square meter) and are made of woven glass fiber or kevlar with a layer of fire-retardant film inside. These non-flammable materials are resistant to extremely high temperatures.
Larger fire blankets for use in laboratory and industrial settings are sometimes made from wool, which is naturally flame-resistant thanks to its high nitrogen and water content, as well as the oxygen-hungry internal structure of its fibers. They are usually treated with a flame-retardant fluid as well.
Wool is also great for personal fires because it will not melt and stick to the skin.
Fire blankets were sometimes made from asbestos before it was known to be harmful. If you have a particularly old fire blanket in your home or workplace, you should contact an asbestos removal specialist as soon as possible.
Until then, it’s best not to go anywhere near it and definitely do not try to remove it yourself.
Should I buy a fire blanket?
Fire blankets are highly accessible and clean fire safety solutions for small-scale fires and they don’t cost a fortune either. For that reason, it’s hard not to recommend having one handy.
Don’t forget that blankets and extinguishers are not mutually exclusive. You can have both of these pieces of equipment kept in the same room to be used in conjunction when fighting fires in their early stages.
Get your brothers4change fire blanket here, with the knowledge that 10% of the profits are used to fund our ongoing work to make education more accessible in developing countries.
We hope that we’ve been able to answer all your burning questions (no pun intended).
Lastly, while Internet research is a wonderful thing, it would be wise to contact your local fire department for advice if you are in any doubt about fire safety practices at your home or workplace.