Even garments labeled “100% cotton” are often held together with polyester thread – making it impossible to avoid plastic in our clothing. Almost all your clothes contain plastic – even ones labeled “100% cotton”.
Learn how this hidden plastic affects durability, recycling, and microplastic pollution.
Polyester’s hidden presence
Clothing labels list the fabric content – this can be cotton, polyester, wool, or even a blend.
But they don’t tell you about the thread holding your clothes together, which is almost always plastic polyester.
Rise of polyester
Polyester became popular after World War II. There were shortages of other fabrics and crease-resistant polyester clothing reduced domestic burdens for women.
Today, polyester dominates. About 60 million tonnes of polyester were produced in 2023, making up 54% of fibre production.
The ‘miracle’ fibre
Polyester thread made seams stronger and reduced manufacturing costs.
It’s so durable that it became the industry standard – even in garments made from natural fibres.
It’s resistant to chemicals, moisture, and wear – allowing us to wear our clothes for longer.
Durability but disposable
Polyester allows our clothes to last longer – but our fashion culture doesn’t.
Most garments today are only worn 7 to 10 times before being discarded. This means polyester thread, designed for longevity, is wasted on clothing we barely use.
So, what happens to all that plastic once it leaves our wardrobes?
Polyester lingers
Polyester threads shed microfibres – tiny plastic filaments that contain hazardous chemicals.
- 2566 chemicals are used in or released from polyester
- 31% are known hazards
- For most of the rest, we have no idea what their impact will be
- There’s growing evidence that microplastics are seriously harmful – increasing the risk of stroke, heart attacks, and dementia
End of lifecycle
Polyester thread complicates textile waste management:
- In theory, textile-to-textile recycling is currently far easier if the entire garment is made of one fibre. Non-polyester clothing with polyester thread is harder (or near impossible) to recycle
- Threads won’t biodegrade, they’ll instead leak chemicals into our environment and break down into microplastics
- Greenhouse gasses are emitted when polyester breaks down, driving climate change
Illusion of choice
While we wish to choose natural fibres, plastic is unavoidable. It’s in our drinking water, in every natural habitat, and even in our 100% cotton clothing.
What can you do?
Since polyester thread allows our clothes to be more durable, the most impactful thing you can do is wear your clothes for as long you possibly can.
Sources
- Ellen MacArthur Foundation
- The Guardian
- Polyester: A Cultural History (Smelik, 2023)
- Science History Institute
- Superior Threads
- The Treatment of Microfibers report written by Veronica Bates Kassatly and Terry Townsend
