CLAIM:
Polyester and nylon clothing, being plastic-based, shed micro- and nanoplastics that carry hormone-disrupting chemicals, and wearing these synthetic fabrics can interfere with the body’s hormonal system, making them unsafe for regular use.
FACT:
Scientific evidence shows that polyester and nylon shed microplastic fibres and contain chemical additives such as dyes and plasticisers, some of which are linked to skin sensitisation and hormone disruption. Experts advise limiting prolonged exposure and favouring natural fabrics like cotton, linen and silk when possible.
In a viral Instagram reel posted by Katherine Sara, founder of Layere, a sustainable clothing brand that focuses on non-toxic, organic cotton essentials such as activewear and pyjamas, the fashion–health debate around synthetic fabrics has resurfaced. She explains why she has chosen to completely avoid polyester and nylon in her wardrobe.
She walks viewers through how polyester is made, explaining that it begins with crude oil or discarded plastic bottles, which are broken down, melted at extremely high temperatures, and converted into a thick liquid.
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While visually it may resemble cloth, Katherine stresses that “it’s still plastic,” warning that when such garments are worn or washed, they shed micro- and nanoplastics that can carry hormone-disrupting chemicals.
Are synthetic fabrics like polyester and nylon harmful to human health?
Synthetic fabrics have come under increasing scrutiny for their potential impact on both human health and the environment. According to the UN Environment Programme, “About 60 per cent of material made into clothing is plastic, which includes polyester, acrylic and nylon textiles. These synthetic fabrics are lightweight, durable, affordable and flexible. But here’s the catch: every time they're washed, they shed tiny plastic fibres called microfibres, a form of microplastics—tiny pieces up to five millimetres in size.”
This concern is supported by scientific research. According to a 2018 study, microplastic fibres from textiles are a major source of environmental contamination, entering oceans via wastewater and other pathways.
The study measured shedding from three materials - acrylic, nylon, and polyester, using different knit gauges and techniques. It found that all textiles shed fibres, with polyester fleece releasing the highest amounts, averaging 7,360 fibers/m²/L per wash, compared with regular polyester fabrics at 87 fibers/m²/L. The study concluded that “loose textile constructions shed more, as did worn fabrics, and high twist yarns are to be preferred for shed reduction,” highlighting ways to mitigate microfiber pollution.
In addition to fibre shedding, chemicals used in synthetic fabrics also raise concerns. A 2021 study analysing children's polyester clothing found 21 azobenzene disperse dyes, 12 of which were confirmed and quantified at concentrations up to 9,230 μg dye/g of fabric. Researchers noted that “individual dyes in apparel were quantified at concentrations up to 9230 μg dye/g shirt, with geometric means ranging 7.91-300 μg dye/g shirt,” emphasising that some synthetic dyes are known to have sensitising, mutagenic, or carcinogenic properties.
Further research has examined the broader impact of synthetic textiles on microplastic pollution. A 2025 study developed a comprehensive model quantifying microplastic fibre (MPF) emissions across the lifecycle of synthetic textiles, using Australia as a case study. The study found that “30.9 ± 0.56 kilotonnes of MPFs were released cumulatively between 1988 and 2023, nearly half of which were airborne from household drying and wearing.” The researchers warned that without intervention, emissions could rise 43 per cent by 2050, though integrated strategies could reduce emissions by up to 65 per cent.
The same study highlighted the potential human health implications, stating that “synthetic fabrics, such as polyester and nylon, which are frequently used in fast and ultra-fast fashion, provide favourable conditions that encourage bacterial adhesion and growth. Their hydrophobic properties facilitate them to absorb sebum, sweat, and other organic matter, offering a steady nutrient supply for bacteria.” It also noted that microfibers shed during wear and laundering can become airborne and inhaled, “potentially causing inflammation, oxidative stress, and even migrating to other tissues.”
“Such exposure raises concerns about their role in respiratory diseases and systemic toxicity,” the study said.
What should we wear then: expert advice
Dr Rashmi Niphadkar, fertility specialist at Nova IVF Fertility, Pune, explains that synthetic fabrics such as polyester and nylon can affect hormonal health due to multiple chemical exposures involved in their production.
According to her, what makes these fabrics potentially disruptive is not just the polymer itself, but four major contributors - chemical additives used during manufacturing, synthetic dyes, chemical finishing treatments, and the release of microplastics. “All of these act as endocrine-disrupting chemicals,” she says.
Dr Niphadkar points out that some of the commonly used chemicals in synthetic fabrics are already well known for their hormonal effects. “Bisphenol A (BPA), for example, is present in polyester resins and is an estrogen-mimicking chemical,” she explains. “When we wear such fabrics, these chemicals can leach onto the skin, and the skin is our largest organ of absorption.”
She adds that phthalates, another widely used group of chemicals, are of particular concern. “Phthalates act as anti-androgens. They interfere with testosterone production,” Dr Niphadkar says, noting their established link with reproductive health issues.
Other substances, such as antimony and PFAS, are used as catalysts and processing agents in polyester manufacturing. According to her, these chemicals are also endocrine disruptors, can be reproductively toxic, and may cause skin irritation.
“In clinical practice, we are seeing fertility issues on the rise,” Dr Niphadkar observes. “We’re seeing thyroid disturbances, reduced ovarian reserve in women, and falling sperm counts in men. Many of these trends are consistent with long-term exposure to endocrine-disrupting chemicals, including those found in synthetic fabrics like polyester and nylon.”
When asked about safer alternatives, she says natural fabrics are clearly preferable. “Cotton and organic cotton, linen, and silk are definitely better options,” she says. “They may not be wrinkle-free or easy-care like synthetics, but they are far safer for the body.”
However, Dr Niphadkar also urges caution even with fabrics marketed as ‘natural’. “Materials like bamboo, viscose or hemp still undergo significant chemical processing. You can’t take a bamboo plant and directly wear it,” she explains. “From raw fibre to finished clothing, dyes and chemicals are often involved.”
This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS.
