Polyester: Is it fire retardant?


Polyester is a very popular material in widespread use. Ever since its invention, designers have appreciated the fabric for its strength, potential in contemporary clothing, and adaptability. You will find it everywhere because it is also considered to be safe for the home. But, is polyester really fire retardant or flammable, and how should this affect our choices?

Polyester is not generally considered to be a fire retardant. However, polyester is seen as a great fire-resistant material because of its high heat tolerance and the fact it doesn’t easily ignite. Polyester won’t burst into flames and is, therefore, not especially flammable. But, it can melt and cause a host of other issues in a fire.

Because of these conflicting statements, it is hard to judge just how safe polyester is as a material for clothing and the home. There are understandable concerns about the melting point and chemicals in polyester.

But, if it isn’t flammable, surely it is safer than other options? Let’s take a closer look at the risk factors. How flammable is polyester, what happens when it melts, and why do some people think twice before using it?

Is Polyester Flammable?

Every material is flammable to a degree. At some point, the conditions will become such that the fire will compromise the structure of the material, causing it to burn or melt. With polyester, the biggest risk is melting rather than burning because of the composition of the materials and the high melting point. This might sound preferable to something going up in flames and contributing to the spread of a fire. But, there are additional risks, as you will see below.

What Is The Melting Point Of Polyester?

One reason that manufacturers champion polyester as a fire-safe material is that it will only ignite at roughly 440 degrees Celsius, or 824 degrees Fahrenheit.

It would take a lot for a fire to reach that intensity and then cause the material to actually combust. Therefore, polyester can be considered to be fire retardant.

However, the melting point is much lower. Polyester will melt at around 220 degrees Celsius, which is 428 degrees Fahrenheit.

This isn’t that hot when you think about it. We can set the oven to around 400 degrees Fahrenheit to cook our meals.

The plates on our irons can get to between 356-428 Fahrenheit on an average setting. So, it doesn’t take much more for the fibers to reach the limit and start to melt.

You can see this if you accidentally iron polyester on too high a setting or if you put it in a hot dryer.

So, it isn’t much of a surprise to learn that materials can melt more significantly in a fire.

Why Is Polyester A Dangerous Material?

As mentioned before, the main issue with polyester isn’t whether or not it will burn, but whether it will melt.

Polyester is a synthetic material that involves a lot of polymers and plastics to create that durable textile we want.

Plastic isn’t going to catch fire in the same way as a natural material like cotton or wool. It will simply melt.

While this doesn’t sound so bad when it comes to the spread of a house fire, there are other problems to keep in mind.

First of all, molten plastic leads to some pretty nasty chemical gases and fumes. If you were to breathe these in alongside the smoke from the fire, it could be fatal.

Studies on burning polyester and plastics highlight the toxicity of the material in a blaze. In one case, the fumes were enough to kill rats.

We might not have the same lung capacity as a rat, nor the same vulnerability to the polymers, but this still isn’t going to do us much good.

Secondly, that molten material runs the risk of melting into other materials and fusing. The main concern here is polyester clothing or bedding catching alight and melting when in contact with human skin.

This may sound like an extreme situation, and it is, but it is also one that you want to avoid at all costs.

I remember when I was in the fire academy, a lot of instructors were adamant that we should never wear polyester clothing under our turnout gear for this very reason.

When plastic gets hot enough to melt, it can lead to horrific burns on its own. If you are in a blaze hot enough to melt polyester, you are looking at some serious burns to your skin anyway.

The molten polyester can fuse with that burned skin, creating what some burns experts refer to as a second skin of plastic.

Those that survive the blaze are then subjected to a long process of surgical procedures to remove the plastic, treat the skin, and try and restore the functionality of the limb.

These could result in life-changing and disfiguring injuries.

Ban On Polyester In The Military

These horrific risk factors are why there is a ban on certain polyester-based clothing in the US military. Some soldiers love to train in shirts that have polyester and similar synthetics.

These performance-enhancing shirts can wick away moisture and provide more comfort, making them popular with sports teams.

However, officials worry about what would happen if a soldier on the front line were to get caught in an explosion from an attack or a roadside IED.

The ferocity of the impact and severe heat could be enough to melt the fabric onto the soldier’s skin. They would have a greater chance of surviving unscathed without these dangerous synthetics.

Is Polyester Safe To Wear?

Polyester is widely regarded as a safe material to wear because its melting point is high. It would take a severe incident for the material to reach a high enough temperature to melt while it is on the body.

So, you can go about your day wearing polyester in your shirts, suits, and more without fearing that it will go up in flames.

But, these cases within the armed forces highlight worst-case scenarios we can’t ignore.

Concerns over the safety of polyester aren’t confined to extreme cases in the military. We also have to be careful how we use polyester around the home.

One concern is polyester in bedding and drapes. If a fire were to break out in the middle of the night, those sheets of fabric could melt into pools of molten plastic and omit those dangerous gasses.

They wouldn’t go up in flames as quickly as cotton, but they wouldn’t necessarily be any safer. This also leads to concerns about polyester clothing in bed, such as a child’s pajamas.

If a child were to evacuate an inferno in those materials, what are the chances of the sleeve catching alight and melting onto their arm?

Contact with controlled fire and high heat is also an issue, so you do have to be careful laundering clothes and wearing polyester around open flames.

A dropped cigarette or contact with a lighter could lead to areas of molten fibers. They may only be a small spot, but you can’t do much about them once they happen.

Many companies will add flame retardants to polyester to make them even safer.

However, there are concerns about additional health risks. So, is this a good idea?

Polyester And Chemical Flame Retardants

While there are natural flame retardant properties to polyester as a strong synthetic polymer, there are times when manufacturers will add additional chemicals to increase the fire resistance.

This sounds great on paper if you want to use polyester around the home, especially 100% polyester on outdoor furnishings.

However, there are risks involved here.

I actually wrote an entire article on whether fire retardants are toxic. Click the link to check out the article.

Brominated flame retardants within the material are still dangerous chemicals. There are concerns that these chemicals can leach out through contact with the air and skin.

This is also true for the phthalates in the compounds.

There are links between these chemicals and damage to the immune, nervous, and endocrine systems, as well as hormone disruption.

None of these are what you want for your child when they are lying in bed in their polyester nightwear under polyester covers.

What About Polyester/Cotton Blends?

A good alternative to 100% polyester is something with a cotton blend. This reduces the amount of potentially hazardous polyester.

It is a good idea to check the composition of clothing and bedding before buying them to see whether they lean more toward one side than the other.

A higher percentage of polyester has a better fireproof rating because it is harder for the material to catch alight.

But, a higher percentage of cotton means that there isn’t the same risk of the sheet completely melting.

Is Fire Resistant Polyester A Safe Fireproof Product?

To summarize, there are two clear sides to the arguments for and against the use of polyester as a fire retardant material.

The high burning point does mean that your polyester clothing, upholstery, and more won’t go up in flames in a fire.

But, the lower melting point brings its own concerns over the safety of the material in a blaze.

In the end, it is completely up to you whether you choose to wear polyester and bring it into your home. If you do, be aware of the risks at high temperatures and use it safely.

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