When we talk about the most fire retardant materials, wool often isn’t top of mind. The thick natural fleece seems like it would go up in flames very easily and contribute to the spread of a fire. But is this actually the case? Is wool fire retardant, or is it highly flammable?
Wool is a great fire retardant material because it doesn’t burn in the same way as other combustible materials. It is much safer because the structure and properties actually encourage self-ignition. As a result, wool is a preferred material of choice in many industries.
Let’s take a closer look at why wool is such a great fire retardant material, how it compares to other synthetic materials, and how we can make use of these properties in different industries.
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What Makes Wool Fire Retardant?
There are lots of different properties in wool that combine to make this one of the better and safer fire retardant materials around. Here are 5 reasons wool make a great fire retardant.
- It has a very high ignition temperature. This one is pretty straightforward. The higher the ignition temperature of a material, the harder it is to set alight. This is ranked at 570-600 degrees Celsius or up to around 1110 degrees Fahrenheit. While other materials are even higher on the scale, this is pretty good for a natural material. It will take a while before this bursts into flames, and you have a problem to deal with.
- You need a lot of fuel for wool to burn. No fire can remain sustainable with the right fuel source. Something needs to burn and have a good enough oxygen supply to maintain the flame. The great thing about wool is that there is so much water and nitrogen in the material that it is harder to burn. The fire needs a lot more oxygen to get going, and that is unlikely. As a result, the fire may die out before it can spread.
- Wool is self-extinguishing. This ability to die out quickly couples with an insulating and smothering effect to keep the fire at bay. The wool fibers are arranged in a way to provide a strong insulating layer between the curls. It is why we love wool so much as a warm and cozy material for sweaters and blankets. That insulating layer can dampen any flames that begin to take effect before they can become too substantial.
- Wool doesn’t melt. This is a concern with synthetics where the polymers react to the heat, form a molten pool, and then drip onto other surfaces. At their worst, they can melt onto skin and cause dangerous burns. This can’t happen here. All you will get is ash. Even then, that ash is soft and dissipates to the point where it isn’t that hazardous.
- Burning wool does not give off much heat. Finally, there is a lack of heat emitted from the wool when it finally does burn. This isn’t too high because of the composition of the fibers. In a small isolated fire, this wouldn’t be as big a deal. In a major blaze, that lack of heat could help.
Wool Vs Synthetics
The fireproof properties of wool are a surprise because this is a natural material, and natural ones tend to burn more easily. Cotton is a good example.
It doesn’t take too high a heat for this to burn away to nothing. Synthetics do tend to have a higher tolerance to heat. However, this doesn’t make them safer.
Synthetics don’t burn at the same temperatures or intensities as natural materials such as wool or cotton. However, they do melt due to the high plastic content.
As a result, this can lead to molten material fusing with the skin during an incident. You can learn more about the risks of molten polyester in my guide on is polyester fire retardant.
Wool Vs Acrylic
Another factor to consider here is that there will be a difference between acrylic and wool. Acrylic is a common material for crafting and garment manufacture because of its soft feel, durability, and bright colors.
But, as a synthetic, the polymers mean the material will melt rather than burn. The melting point of acrylic yarn is said to be around just 300 degrees Fahrenheit.
That means it doesn’t take much for the structure of the yarn to become compromised. In fact, you might start seeing damage at 200 degrees.
This is a problem if you decide to use this cheaper yarn for your knitting or crochet projects over something like wool or cotton.
Under the right conditions, your scarf, throw, or sweater could degrade and melt. They won’t burn directly in contact with an open flame in the same way as cotton and wool, but they are still at risk.
There are similar problems if you choose an acrylic sweater rather than a wool one from a store.
They are more affordable with potentially more color and print options, but they could melt in a dryer or in contact with an iron.
The Use Of Fire Retardant Wool In The Fire Department And Military
Because wool is such a great fire-resistant material, it actually has a lot of potential uses when other materials aren’t suitable.
There are issues with using synthetic materials in emergency services or in the military because of the risk factors.
As mentioned before, there are concerns about materials melting and fusing with skin. This is a disaster when you have explosions or fires to deal with.
There are no such risks with wool and while it could burn in extreme conditions, it is a much safer choice as a thermal material, such as for linings or socks.
Can You Use Wool Fire Blankets?
The use of wool as a fireproof material also brings up the factor of fire blankets.
Traditionally, fire blankets are lightweight sheets that you unpack from their container on the wall and spread out over a kitchen fire.
This smothers the flames and makes it much easier to control the spread of a fire before the fire department arrives.
I wrote an entire article on whether a fire blanket can catch fire, click the link to check it out.
Typically, these are a mixture of materials including fire retardant fiberglass.
However, some companies sell wool fire blankets for the home. These are more decorative when stored and should allow for a similar effect when smothering the fire.
They are much nicer to have at home rather than installing an ugly fire blanket on your kitchen wall – especially when they are for rare emergencies.
Whether they are as effective will depend on the construction and company behind them.
However, industrial sites and commercial kitchens should still use the normal fire blankets, as recommended by fire marshals, for the best results.
Can You Use Wool As A Fireproof Insulation Material?
In a previous guide, I spoke about the benefits of using spray foam insulation because of its fire-retardant properties.
This substance is one of many options available when adding insulation to your home. You can also use fiberglass – much like the filling in those fire blankets – as well as natural materials like wool.
The benefits of wool insulation are that you get the same properties of a warm fleece, but for your home.
At the same time, the slow burn and fire retardant properties mean that this isn’t going to catch fire or accelerate a fire very easily.
You do, however, need to be sure that your materials are up to code and be aware of the risks of additional timber or paper materials in the batts.
Is Wool A Safe Fire Resistant Material?
Wool is actually a lot safer and more appealing as a fire-resistant fabric than some other options that are around.
While some people prefer synthetics for their high ignition point, you don’t get the same melting and chemical risks with wool.
Wool can provide safe natural insulation and protection. It can even slow the spread of fire in the right conditions.
It is easy to see why so many industries are turning to wool as an alternative option for safety.
So, don’t worry too much about the fire risk of wool blankets at home. They will eventually ignite but they won’t do too much harm, and you may even be able to smother a small blaze with one.
Should We Use More Wool For Fire Protection?
There is clearly a lot to appreciate about wool as a fire-resistant material. There are far more positive properties than expected when you factor in the slow burn rate, self-extinguishing properties, and the softer ash.
So, while it will eventually catch fire at high heat, it won’t do so with the same risks as other materials.
As a result, it is easy to see why so many industries, including the military and fire service, aren’t against the use of wool. In the right situations, it can be very beneficial.