Most of us don’t always think about the flammability of a material when purchasing an item of clothing, but there are some cases where this does need to be considered – for example, when ironing, making pot holders, or heat drying.
One popular fabric used by many people is polyester, and chances are that you have quite a few pieces of polyester clothing in your closet. Even though polyester is so popular, not many people know how flammable it is, and how it stands up to heat.
How flammable is polyester? Polyester, a synthetic fabric, is not highly flammable. It is naturally flame retardant, but at high temperatures, it can melt. You also need to consider if the polyester is blended with other materials, as those materials might be more flammable.
If you are interested to know more, keep reading to find out about polyester flammability, and how it stands up to heat.
Is Polyester Flame Retardant?
Just about every material will burn at the right heat, but a material that is flame retardant will only burn at high temperatures and will burn very slowly. Polyester is a synthetic material, and like most other synthetic materials, it is flame-resistant.
Natural fibers such as cotton and wool burn quite easily, and often these are treated with other chemicals that make them more flame retardant. Some of the chemicals used to treat these fabrics include halogenated hydrocarbons, phosphate-based compounds, and antimony oxides.
The weave and thickness of a polyester fabric also determine how flame retardant it is, as if there is quite a bit of space between the fibers, there is more oxygen present, which means that it is likely to be more flammable.
Tightly woven, thick polyester has a higher chance of being more flame retardant, as there is less space between fibers for there to be a good supply of oxygen for a fire to burn quickly.
The Difference Between Flame Resistant, Flame-Retardant, And Flame Proof
Often, the terms flame resistant, flame retardant, and flameproof are used interchangeably, but these are not the same things, and there is a technical difference between them all.
Firstly, flame-resistant fabrics are made from certain fibers that have a special chemical structure that resists against burning. These fabrics will still catch fire at very high temperatures, but mostly if the fabric is removed from the heat source, the fire would go out.
Flame retardant fabrics are fabrics that have been treated with certain chemicals to allow them to burn slowly and to be able to self-extinguish. These fabrics will burn in high temperatures, but with the special treatment, the spread of the fire is slowed down quite a bit, and the flammability is lessened.
Lastly, flame-proof fabrics are made from special properties such as asbestos and glass, which do not burn. These are not widely found outside of very specialized circumstances and uses.
These three terms should not be used interchangeably, especially when their properties need to be known for safety reasons!
How Flammable Is Polyester?
How flammable polyester is depends on how it is used. When polyester fibers are used in a synthetic fabric, they are not flammable. However, polyester fabric is slightly flammable, but it is more flame-resistant.
Polyester fabric will melt at a very high temperature, but it will not burn. Removing the burning polyester fabric from the heat source should cause the fire to extinguish itself.
It is not a good idea to assume that because the polyester fabric is flame resistant, that it is fine to use in extremely hot temperatures. It might not catch fire easily, but it will melt, and melted polyester on your skin is not something you would want to experience.
Polyester does not burn easily at a chemical level, which is where it gets its flame resistance from. It is made from chemicals that come from petroleum, and these components include flame retardant commoners.
Even though at a chemical level, polyester does not burn easily, it could be blended with other materials, which could be more flammable, and which could make polyester flame resistance redundant.
Poly blended fibers are made by twisting polyester fibers with fibers of another fabric, and these are then woven together. So having the flame-resistant polyester mixed with possibly naturally flammable fibers means the fabrics flammability is increased.
Can Polyester Melt?
Polyester might not catch fire easily, but it does melt. Even though polyester is flame resistant and it does not burn easily, it can melt at temperatures of 482°F, or 260°F.
While most of us should not be exposed to such high temperatures when wearing an item of polyester clothing, there is a chance that polyester could melt when being ironed, or even when the dryer is set onto a high heat.
It is best to just never expose the polyester fabric to high temperatures as even though it might not go up in flames, it is best to not risk it melting.
When sitting around a fire, try and sit a little distance away. The actual heat from the flames might not be enough to cause any damage, but some sparks flying around can easily melt a hole in a polyester sweater, blanket, or even socks!
Polyester can melt, and melted polyester is not fun to deal with. Instead, avoid exposing polyester to heat, especially if you do not know whether it has been blended with other fabrics, as it might not be as flame-resistant.
What Is A Flammability Rating?
Flammability ratings are requirements that fabrics need to meet to be safe to use, and often the law dictates what items of clothing or bedding need to have as a flammability rating to be safe to use. For example, children’s clothing needs to have a good flammability rating to be safe to use.
Most fabrics need to go through a flammability test to determine whether they are safe to sell or not. Through the flammability test, it can be measured how a fabric burns after being exposed to a flame for one second.
This test does not necessarily measure if the fabric catches fire, but rather how long it takes for the fire to spread across the fabric. So if the item catches fire, but allows you enough time to deal with the flames, it is given a better flammability rating.
There are a few different flammability ratings. The first is Class 1 Normal Flammability, then Class 2 Intermediate, and Class 3 Rapid and Intense Burning.
Clothing should be rated as Class 1, non-clothing items can be Class 2, and any items that fall into Class 3 are not usually allowed to be sold.
There are other fire-resistance tests given to sleepwear and other bedding and mattresses, but these are quite complicated, and help to ensure safety even when asleep.
Which Are The Most Flammable Fabrics?
The most flammable fabrics are often natural fibers. Silk and cotton are two natural fibers that are considered flammable, and cotton and linen in particular burn easily.
One natural fiber that does not actually burn easily is wool. It only burns at very high temperatures, and unlike synthetic fabrics, it does not melt when exposed to heat. It has a dense weave, which means that there is not much oxygen found in the fabric, so any fire will not spread very quickly.
Here is a little more on different fabrics, and how flammable they are compared to polyester:
- Cotton – Cotton is flammable and burns easily. The burning point of cotton is 200°F, and when it burns, it burns orange and it does not melt. Cotton shrinks when exposed to a flame.
- Nylon – Nylon is a synthetic fabric and does not burn easily. The burning and melting point of nylon is 428°F, and it melts down into small plastic beads.
- Kevlar – Kevlar does not burn easily and is difficult to catch on fire. If it does manage to catch on fire, Kevlar self-extinguishes the flame once the heat source has been removed. This only happens at around 800°F.
- Polyester – Polyester is not very flammable and will melt at 482°F. While polyester is quite difficult to burn, it will melt easily when exposed to high temperatures.
- Wool – Wool is very difficult to burn and it does not melt. The burning temperature of wool is 1,058°F, which is considerably high.
- Poly-Cotton – Poly-cotton is a blend of polyester and cotton. It does burn easily, due to the inclusion of cotton, and will burn at 356°F. Poly-cotton does resist flame, but it will melt and burn down.
The Flammability Rating Of Polyester
Polyester is not easy to burn, and the chemical structure of polyester means that it meets most flammability requirements.
Polyester falls into Class 1 fabrics, as it is difficult to burn, and it will self-extinguish once it is removed from the flame. Due to this rating, it is a popular choice for children’s pajamas.
When determining the polyester flammability rating, it is important to ensure that there are no other fabrics mixed in with the polyester, as this could affect the rating.
Will Polyester Melt In The Dryer?
While polyester does not burn easily, it can melt. This might make you a bit nervous to put any polyester fabric in the dryer, especially if it is set to high heat.
Technically, it is possible to melt polyester clothing inside a dryer, if the temperatures are high enough, but the chances of it happening is not very high. Your polyester shirt should be fine when placed in the dryer, and you shouldn’t open the door to a hot, melted mess.
One thing to consider however is that while the clothing might not melt, there is a chance that it could warp and lose its shape when placed into the dryer on a high heat. When placing polyester into the dryer, it is best to set it onto a low heat.
A good benefit of polyester is that it does dry quickly, so you could always avoid the dryer altogether and rather hang items of clothing outdoors to dry safely, and not have to worry about the polyester clothing warping or losing shape!
Will Polyester Burn When Ironed?
Irons provide a very high heat directly to clothes, so you do have to be careful with the fabrics that you iron. An iron will not necessarily cause your polyester fabric to catch on fire, but there is a chance that it could melt the polyester.
The bottom line is that it is best to avoid ironing polyester, and to avoid creases, you should hang up polyester clothing straight after it has been washed, to avoid any creases forming in the first place. Steamers can also be used to remove wrinkles from clothing, at a much safer heat.
If you do end up using your iron on polyester clothing, you could look to see if the iron has a handy polyester setting. For when your iron does not have this setting, choose the lowest setting possible. Also, make sure to check the label of the clothing you are wanting to iron for further instructions.
If you are then still nervous to iron your polyester clothing, you could place a thin, heat-resistant fabric down between the iron and the clothing, to prevent the direct heat from melting the polyester clothing.
Can Polyester Catch Fire?
Polyester can definitely catch fire, just like every other substance if it is exposed to high heat. Generally, polyester will burn at a higher heat than most other fabrics, such as linen or cotton, and some other synthetic fabrics.
This is considered a good thing, but there is also a downfall to it. When polyester gets hot enough, it might not catch fire, but it will melt. Molten polyester is much like molten plastic, and the burns it can cause can be so severe. It can stick to the skin and have devastating effects.
However, while it melts and this can be so harmful, it should not stay on fire if the heat source or the flame is removed.
Polyester is not very flammable, and it does not burn easily. It will catch fire or melt when exposed to a temperature of 440°F or above, depending on the thickness of the fabric and how tight the weave is.
It is important to remember that polyester can also be blended with other fibers, such as cotton, which then changes how flammable the fabric might be. Cotton, like most other natural fibers, is flammable, so when blended with polyester, makes it more flammable too.
Polyester will not catch fire easily, but it can melt when exposed to high heat, which in some cases can cause more damage than the fabric actually lighting on fire.
Always check the flammability rating of the clothing or fabric you purchase and make sure to check the label for heat settings when placing the fabric in the dryer or when using an iron.
Does polyester melt in fire?
Polyester, just like nylon, will melt before it catches on fire. When exposed to a flame, polyester will pull away from the flame and melt into a plastic-like material. Polyester burns much more slowly when it does catch on fire, compared to cotton and other natural fibers, and often when polyester catches on fire, it will extinguish the flame once the source has been removed.
Can you use a heat press for 100% polyester?
It is a bit of a risk using a heat press on 100% polyester, as polyester can melt at high heat. When using a heat press for 100% polyester, it is best to keep it below 300°F to be safe.
Up Next: Polyester Vs. Polypropylene – What’s The Difference?