Material Guide: How Sustainable is Polyester?

If you’re concerned about the environmental impact of fashion, you probably spend some time reading garment tags to find out what your clothes are made of. When looking at labels it doesn’t take a magnifying glass to notice that one fabric comes up more than most: polyester. Considering its prevalence it is important to know exactly what you’ve got rubbing against your skin. We ask the question, how sustainable is polyester?

When did polyester first arrive on the scene?

Polyester fabric hasn’t been around forever. Our grandparents were clothed in natural materials such as wool, linen and cotton and in fact, by the end of World World II, the latter accounted for over 80% of fibre consumed.

With chemical advances in the 1940s man-made fibres were introduced, and so began a gradual shift away from cotton, turning towards cheaper and faster to produce textiles. Nowadays, polyester dominates the clothing industry, with annual production exceeding 22.67 billion tonnes worldwide.

So what exactly is polyester ?

The term ‘polyester’ describes a category of polymers produced by mixing ethylene glycol (derived from petroleum) and terephthalic acid.

Putting aside the chemical jargon, polyester is a common plastic with a wide application that includes and extends beyond the fashion industry.

It ranks behind polyethylene (i.e. packaging and water bottles) and polypropylene (i.e. ropes, stationary and Australian bank notes) as the most commonly used plastic.

Polyester is not biodegradable

The majority of polyesters are not biodegradable meaning that the polyester fabric shirt you bought last season will not decompose for 20 years at best and 200 years at worst, depending on conditions.

What’s more, polyester is, in part, derived from petroleum and the oil manufacturing industry is the world’s largest pollutant.

Polyester dyes are not environmentally friendly

Ever noticed how polyester fabrics are stain resistant? That’s because it takes a special kind of dye to successfully colour polyester. These dyes, known as disperse dyes, are insoluble in water and, like polyester, are made up of a complex molecular structure that does not readily decompose.

Waste water from textile factories containing leftover dye is difficult to treat and, as such, enters the environment where its toxicity causes serious problems to plant and animal life.

In addition to causing environmental problems, polyester dyes are also toxic to humans. Dye workers worldwide report higher incidences of cancers and lung disease than the general population.

Polyester manufacturing is water-thirsty

Polyester is created through an energy-intensive heating process, requiring large quantities of water for cooling. If not managed properly this can result in groundwater levels dropping and reduced access to clean drinking water, particularly in vulnerable communities where polyester is often manufactured.

What about recycled polyester?

In the past few years, the sustainable fashion sphere has been introduced to recycled polyester. Recycled polyester is usually made from recycled plastic bottles, like in this jacket by Patagonia.  Buying recycled polyester means you’re minimising waste and cutting out the fossil fuel industry.

Be careful with fleeces though.  Studies have shown that these plastic microfibres are polluting waterways at an alarming rate. And that fleece made from recycled polyester may be more polluting than its original form.

More on those microfibres

Multiple studies have shown synthetic fibers to make up a good share of microplastics found in waters and are widely implicated as the source of pollution. In fact, it’s been suggested that more than 4,500 fibers can be released per gram of clothing per wash, according to the Plastic Soup Foundation.

Microfibers are so tiny they can easily move through sewage treatment plants. They do not biodegrade and bind with molecules from harmful chemicals found in wastewater. They are then eaten by small fishes and plankton, concentrating toxins and going up the food chain, until they reach us. The consequences on the human body have yet to be researched and revealed.

What can we do?

  1. Look for garments that are made from natural fibres, like organic cotton, and coloured using natural dyes.
  2. Choose well, buy less. Garments made with natural fibres have their own ethical considerations. Cotton is one of the thirstiest and dirtiest fabrics, though organic cotton fares considerably better. The wool industry has sometimes been criticised for its use of unethical practices. By choosing well and buying less, you’re helping to avoid the unsustainable over-production of fibres at a cost to the environment and the world’s most vulnerable people.
  3. Buy from secondhand and charity shops. An even better option to buying fewer new things is to buy more pre-loved garments from secondhand stores. Since polyester garments are both common and durable, you will find plenty recycled items in thrift shops that show few signs of wear and tear and will stand the test of time.
  4. Wash less and wash better. Solutions are starting to appear to avoid microfibres to be shed during washing such special laundry bags and laundry balls.
  5. Get informed and choose brands with policies that protect and respect the planet and the people making their products. The Good On You app helps you uncover brands who perform better on the issues you care about.