I invite you to join me on a fun challenge: Get all of your sports clothes together, read their material labels, and answer this one question - how many of your sportclothes have at least as one of their ingredients polyester? 

Chances are that almost all, if not all of your sports clothes are made out of polyester. And I bet that even your regular clothes rank high on polyester, too. 

But why do I ask you to join me on that silly challenge? What’s so special about polyester? And why should you care?

Well, first of, it is something that most of us wear next to our skin almost every single day - and when we do high-intensity sports, our skin is fully squeezed against it.

And don’t we want to know what our skin touches and absorbs for thousands of hours over our lifetime? 

Second, polyester is a form of plastic. As we are facing enormous challenges with a worldwide plastic overload that damages our planet, this is another reason why we should take a closer look.

Today I will give you a quick insight into the first part of the polyester deep-dive and share with you some interesting facts about polyester and human health. Its effect on the environment I will share with you in a future post.


Before we’ll go any deeper, let me give you a brief intro to polyester. 

Polyester ia a synthetic fiber usually derived from crude oil and is the world’s most commonly used fiber. It makes up more than 65 percent of the fibers used in the textile industry, and even overtook cotton usage in 2002. 

But why is polyester in almost all of the clothes we wear? Any guesses?

Polyester has a couple of good features which is why you will find it in so many of your clothes today:  It is light, strong and can be easily dyed and blended with other fibers. Also, it doesn’t wrinkle much, it is easy to wash and relatively cheap - and has fuelled the growth of fast fashion so dramatically. 

And it is the “everyone’s darling” in the sportswear world. 

Demand for polyester has been skyrocketing over time: Whereas in 1980, the volume of global polyester production was 5.2 million tons, by 2014 it reached 46.1 million tons.

That’s quite a massive increase, isn’t it?


But as with everything in life, we need to flip the coin and look on the other side of it as well. 

As an avid sport addict who has been wearing sports clothes made out of polyester for years, I  started wondering what polyester is actually made out of and if it would do any harm to my body.

Also, I had friends complaining about rashes and itches they had gotten when wearing polyester - which was another reason for me to dig deeper and try to bring some light into something that I always took for granted and never ever questioned.


I started to dig deep into the subject, trying to find any data or studies that dealt with chemicals in our clothing and its connection to human health. Surprisingly, it wasn’t all too easy to find any good data. 

While the use of chemicals in textile production is common knowledge and you will find lots of information on that, very little has been done so far to disclose the potentially harmful compounds hiding in our clothes.

But I didn’t leave empty-handed and actually found a very interesting study done by Stockholm University in 2015

Reading it through it only confirmed, sadly, what I had feared in the back of my head for many years. 

The study focused on screening different textile materials that are common in clothing, like cotton and polyester. Their tests revealed the presence of thousands of compounds in the materials - and they especially looked at the ones that had skin penetrating properties and toxic characteristics. 

When it comes to polyester, the study showed that the concentrations of these chemicals were notably higher in their polyester samples compared to garments made from cotton and blended material. 

For instance, they found an 800 times higher concentration of quinolines in polyester samples compared to garments exclusively made out of cotton. 

Quinoline is a chemical compound primarily extracted from coal tar and petroleum that potentially can have health-hazardous effects

There are also two other chemical compounds, benzothiazole and benzotriazole.The highest concentration of them was found in a sample made from 100% polyester.

These two compounds that have been shown to have acute toxicity in various test systems and cause allergies and irritations. Benzotriazole was found to be mutagenic and estrogenic in aquatic organisms and they can bioaccumulate in birds, fish and invertebrates. 

They can also be absorbed by the skin. A transfer to skin experiment revealed that benzothiazoles are released from textile clothes, and that both compounds have been detected in urine samples collected from general populations.

Even aromatic amines have been found in highest amounts in polyester samples. Aromatic amines are mainly used in the production of azo-dyes, can be absorbed by the body, and can increase the risk of certain cancers. 

To sum it up, differences in the concentrations of these chemical components is related to the fiber type used in the garment, and higher amounts could be found in textiles manufactured from polyester. 

But keep in mind that this doesn’t mean that other textiles such as cotton are completely free of these chemicals either - but they are to a lesser extent.


Have you ever noticed that your polyester shirt gets smelly really fast when you are doing a workout? 

Well, there is a reason for that stingy smell. 

Pungent bacteria grow more readily on certain workout shirts, particularly those made from synthetic textiles like polyester, according to a research from Chris Callewaert and his colleagues from Ghent University. 

They found that skin germs feast on chemicals in sweat, turning them into pungent odour compounds, which the bacteria then release.       

Polyester shirts harbor more Micrococci bacteria than e.g. more natural fiber shirts like cotton. 

The researchers even did a test and took a few pungent species of bacteria and coated them with different fabrics, including polyester, nylon and cotton. Cotton grew much fewer smelly germs, while the microbes swarmed over polyester. 

As a response to these results, many textile manufacturers now started adding antimicrobials to their clothes.

The flipside of this - these chemicals eliminate all kinds of germs, the bad and the good ones, which could have harmful effects on our immune systems. 


So there you have it, my friends. 

Though polyester has a couple of benefits and is an “everyone’s darling” in the sportswear world, it doesn’t come without major effects on our health and even odour development.

Next time you do a sportswear materials challenge and check your sports clothes in your closet, maybe there will be more clothes made from more natural materials? The choice is yours.

While clothes made from more natural fibers are of course not perfect either, they are a better choice for your body and health. And some of them can even keep up with the demands of a high-intensity workout. More on that in later posts.

Now, I opened this post with a challenge and will close it with a question. 

What is keeping you from choosing more natural materials as your sports clothes? Please answer in the comments below. 


Rest assured that Tripulse will not choose polyester as the material of choice, but will make sure to offer you much healthier alternatives. So that your workouts to come can be truly beneficial for your health. 

To learn more about the exciting world of sustainable textiles, sports and sustainability, and to be the first to know when we´ll launch our sportswear, just leave your email address and sign up for our Tripulse news below. 

    December 04, 2019 — Franziska Mesche


    Krista said:

    I must know more

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