Polyester has quietly conquered the global wardrobe. As a synthetic fiber primarily made from fossil fuels, it stands as the most widely used material in the entire fashion industry, relied upon by brands ranging from budget-friendly fast fashion houses to athleticwear giants. Yet, beneath its wrinkle-resistant, durable exterior lies an environmental footprint that has drawn increasing scrutiny from scientists, environmentalists, and conscious consumers alike.
Understanding how polyester is made, why its environmental toll is so severe, and whether hyped alternatives like recycled polyester truly offer a sustainable path forward is crucial for anyone looking to navigate the modern apparel market with a clear understanding of its ecological consequences.
When was polyester created?
Polyester fabric has not always been a fixture of human daily life. For generations, our ancestors were clothed almost exclusively in plant- and animal-based materials such as wool, linen, and cotton. By the end of World War II, natural fibers like cotton accounted for over 80% of all global fiber consumption, dominating the textile landscape.
However, rapid chemical advances in the 1940s introduced artificial fibers to the commercial market. This breakthrough marked the beginning of a gradual, systematic shift away from traditional agriculture-based textiles and toward cheaper, faster, and more scalable textile production methods.
In the decades since, polyester has steadily ascended to dominate the global clothing industry. It continues to be the most widely produced fiber by a wide margin, and its manufacturing scale is only increasing. According to data from Textile Exchange, polyester’s share of global fiber production climbed from 54% in 2022 to a staggering 59% of the entire global market in 2024. This relentless expansion highlights the fashion sector’s deep-rooted addiction to cheap, synthetic materials.
What is polyester?
To understand the ubiquity of the material, it helps to look at its chemical origins. The term “polyester” broadly describes a category of polymers produced by mixing ethylene glycol—which is derived from petroleum—and terephthalic acid or dimethyl terephthalate.
Stripped of complex chemical jargon, polyester is ultimately a common type of plastic with a remarkably wide range of applications extending far beyond the fashion industry. In terms of global plastic manufacturing volume, it ranks third behind polyethylene, which is used heavily for packaging and water bottles, and polypropylene, which finds its home in ropes, stationery, and modern banknotes. Within the apparel sector, the primary focus centers on PET (polyethylene terephthalate) polyester, the specific variant most commonly spun into yarn for garments.
As a fabric, polyester is favored for its resilience, quick-drying properties, and affordability. It is commonly utilized across a vast array of clothing categories, including high-performance sportswear and workout gear, dresses, everyday tops and blouses, trousers, socks, underwear, jackets, and internal garment linings. For the average consumer, checking garment tags will likely reveal that polyester forms the main fiber composition for at least a few items in their wardrobe, unless they have made a concerted effort to actively avoid synthetic materials.
Polyester is not biodegradable
One of the most pressing environmental crises associated with conventional polyester is its sheer persistence in the natural environment. Conventional polyester is entirely non-biodegradable. A polyester shirt purchased during last season’s trend cycle will not decompose anytime soon; at best, it will remain intact for roughly twenty years, and at worst, it will persist for hundreds of years in a landfill or ecosystem.
Despite ongoing technological innovations in the materials science space, polyester fibers as a whole are still not reliably biodegradable outside of controlled laboratory settings. Consequently, environmental experts do not consider any form of conventional polyester to be a lower-impact or more sustainable material at this stage of technological development.
Compounding this problem is the material’s reliance on fossil fuels. Because polyester is partially derived from petroleum, its production is directly tied to the oil manufacturing industry, which stands as the world’s largest single pollutant and a primary driver of global climate change.
Disperse dyes for polyester are harmful to the environment
The environmental degradation caused by polyester goes beyond its solid waste profile; the chemical treatments required to color the fabric present severe ecological and human health hazards. Traditional natural fabric dyes simply will not bond with synthetic fibers. To successfully color polyester, manufacturers must rely on specialized disperse dyes.
These synthetic colorants are insoluble in water and, much like polyester itself, possess a complex molecular structure that does not readily decompose when exposed to natural elements. Wastewater discharged from textile factories often contains significant amounts of leftover, untreated dye. When this toxic runoff enters local waterways and surrounding ecosystems, its toxicity causes profound disruptions and long-term damage to local plant and animal life.
In addition to driving environmental contamination, disperse dyes pose documented health risks to humans. Research indicates that certain synthetic dyes used in polyester production contain carcinogens and are capable of triggering severe skin sensitivity. Textile dye workers, in particular, have frequently reported high rates of dermatological issues and other chronic health concerns linked to long-term occupational exposure.
Polyester manufacturing is water-thirsty
The physical production of polyester is also an intensely resource-heavy endeavor. The fiber is created through an energy-intensive heating process that requires immense quantities of water for cooling stages. If these industrial cooling processes are not managed responsibly, they can result in local groundwater levels dropping precipitously.
This depletion often leads to a localized reduction in community access to clean drinking water—an impact that is disproportionately felt by vulnerable, low-income communities where polyester manufacturing facilities are frequently located.
Is recycled polyester sustainable?
In response to mounting public criticism regarding virgin synthetic fibers, the sustainable fashion sphere has increasingly championed recycled polyester as a seemingly progressive alternative. Touted as a greener replacement for virgin materials, recycled PET plastic is typically manufactured by melting down and repurposing used plastic bottles.
While turning waste plastic into clothing sounds like an intuitive solution for cleaning up industrial supply chains, the reality is far more complex. According to the Textile Exchange Material Market Report, the market share for recycled textiles stood at approximately 7.6% in 2024, down from 8.5% in 2021 and 7.9% in 2022. Furthermore, less than 1% of the total global fiber market derived from pre- and post-consumer recycled textiles in the same year, demonstrating that true textile-to-textile recycling is lagging severely behind industry marketing claims.
Journalistic investigations, such as those highlighted by The Guardian, have pointed out several structural flaws in the recycled polyester model. Mechanically recycled polyester cannot be recycled indefinitely; the polymer chains degrade with each thermal recycling cycle, limiting the number of times the material can be reused. This limitation raises serious concerns as fast-fashion brands increasingly rely on the material as a marketing badge of honor while continuing to scale production volumes. Moreover, relying on plastic bottles for clothing can inadvertently sustain the demand for single-use PET packaging.
Furthermore, recycled polyester is frequently blended with virgin polyester in garment construction, further cementing the industry’s reliance on fossil fuels. At the end of these blended garments’ useful lifespans, they are still almost universally destined for landfills rather than advanced recycling systems.
While chemical recycling—a burgeoning process that breaks down polyester into its foundational monomer components to create recycled material with identical properties to virgin polymer—offers a theoretical solution, it remains extremely limited in scale. Major fast-fashion labels are unlikely to adopt chemical recycling widely in the near future due to cost and infrastructure hurdles.
Consequently, when fast-fashion brands replace a small percentage of their massive collections with recycled-polyester products, it does not automatically transform them into environmentally responsible businesses. Their overall operational impact often remains profoundly wasteful across the board.
In addition, recycled polyester continues to shed microplastics just like its virgin counterpart. In fact, a study conducted by the Changing Markets Foundation revealed that recycled polyester creates, on average, 55% more microplastic pollution particles during washing than virgin polyester. Concurrently, research published by Greenpeace has exposed that workers laboring inside plastic recycling facilities face severe health risks due to routine exposure to hazardous chemicals.
More on those microfibres
The environmental threat posed by synthetic garments extends far beyond discarded clothing items and factory floors, manifesting invisibly in the world’s oceans and freshwater bodies. Multiple scientific studies have confirmed that synthetic fibers constitute a major share of the microplastics discovered in aquatic environments, directly implicating the apparel industry as a primary source of this pervasive pollution.
Research from the Plastic Soup Foundation suggests that the mechanical agitation of polyester, polyester-cotton blends, and acrylic fabrics inside standard washing machines can release as many as 700,000 microscopic fibers into wastewater during a single wash cycle. Because these microfibres are microscopically small, they easily bypass municipal sewage treatment plants without being captured.
Once released into open waterways, these non-biodegradable particles readily bind with chemical toxins present in wastewater. They are subsequently ingested by small fish, plankton, and filter-feeding organisms, concentrating those toxins as they travel upward through the marine food chain and ultimately reaching human populations. While the long-term toxicological consequences of microfibre accumulation within the human body are still being actively researched, the scale of environmental contamination has prompted mounting concern from scientists and public health advocates worldwide.
