What is the Unhealthiest Fabric to Wear?

Consumers are becoming steadily less willing to accept the old marketing line that a garment’s label tells the whole story. Behind the soft feel or bright finish of many modern clothes lies an industrial supply chain that applies dozens of chemical treatments to fibres, and in the case of synthetic textiles, sheds microscopic plastic fragments into the world. When judged on the combination of short-term harms to skin and respiratory systems, longer-term chemical exposure and the emerging evidence on microplastics, synthetic, petroleum-derived fabrics such as polyester and nylon consistently emerge as the least healthy choices for everyday wear. Reporting and research over the past few years has drawn attention to how these fabrics are treated and where the risk lies. 

Why Are Synthetics Singled Out

Polyester and related synthetics are cheap, durable and ubiquitous. That commercial advantage, however, comes with two related problems: they are almost always processed with a cocktail of finishing chemicals, and they shed microfibres during wear and laundering. Investigations into mainstream sports and activewear have found treatments including PFAS (the so-called “forever chemicals”), phthalates and a range of dye- and finishing-agents designed to make garments water-repellent, crease-free or fast-coloured. Those substances can transfer from fabric to skin, especially in sweaty conditions, and some are known to be endocrine disruptors or irritating to sensitive people. Recent reporting of the sportswear sector summarised both the chemical exposures and the industry’s efforts to find bio-based alternatives. 

Separate work has emphasised the microplastic angle. When polyester is washed, rubbed or subject to friction, it releases tiny fibres, microplastics that travel into wastewater and ultimately into the environment. Microplastics have been detected in seafood, drinking water and, in some contested studies, human tissues. Scientists caution that while the pathways from fibre to human harm are still being resolved, microplastics can carry chemical additives and have been linked in observational studies to inflammation and other markers that correlate with serious diseases. That convergence of chemical load and particulate exposure is what makes synthetics especially worrying as an everyday skin contact material. 

Natural Fibres Are Not Risk-Free

Declaring synthetics the “unhealthiest” does not mean natural fibres are automatically harmless. Conventional cotton, the most commonly used natural fibre, is heavily dependent on pesticides and other agrochemicals in many producing countries. Occupational studies of cotton farmers show repeated pesticide exposure is associated with acute poisoning symptoms, skin and eye irritation, and longer-term neurological complaints.

Those harms are principally occupational, but residues can remain on fibres through harvest and processing, and cheap garments are not always washed or processed in ways that eliminate residues. In short: a cotton T-shirt can be preferable to polyester in terms of microplastics, but if it is conventionally grown and poorly processed, it still carries chemical risks, particularly for the people who grow and manufacture it. Click here to discover why organic cotton matters. 

Chemical Finishes and the Fashion Supply Chain

Beyond base fibre, many garments are altered by finishing agents: formaldehyde-based fixatives to stop creasing, biocides to prevent mould during storage, flame retardants in children’s clothing or workwear, and disperse dyes used on synthetic fabrics. Formaldehyde is a known irritant and has been implicated in occupational health studies when exposure is prolonged; some flame retardant additives have been associated with thyroid dysfunction and neurodevelopmental issues in laboratory and epidemiological work.

The problem here is cumulative exposure: we wear treated garments daily, live in environments dusted with treated textile fibres, and often encounter those same chemical classes in other consumer products. That multiplicative exposure is why public-health commentators now look at textiles as part of a broader chemical-safety puzzle rather than an isolated nuisance. 

Case Studies and Measurable Effects

Practical examples help ground the debate. Investigative reporting on mainstream brands’ workout gear has found PFAS and other finishes in widely sold garments, and follow-up pieces have explored how those chemicals can migrate during intense exercise; these reports prompted some brands to trial PFAS-free alternatives. Environmental groups and academics have documented microfibre shedding rates during laundry cycles and estimated household contributions of hundreds of grams of microplastics per year, depending on clothing mix and washing behaviour.

On the farming side, studies from cotton-growing regions record frequent acute pesticide symptoms among workers, explaining why standards such as organic certification exist and why some buyers choose certified organic cotton despite its higher price. Those case studies point to where interventions can make a practical difference: production, finishing and consumer care.

What Consumers Can Reasonably Do

For shoppers who want to reduce personal and environmental risk, a few pragmatic steps follow from the evidence. First, prefer garments that declare simple, traceable fibre content and that carry reputable third-party certifications (for example, certified organic cotton or OEKO-TEX®) where available. Second, favour clothes with minimal chemical finishes: avoid heavily water-repellent or “wrinkle-free” claims if you can’t verify the treatment. Third, reduce shedding by washing synthetics less frequently when practical, using lower temperature cycles and a front-loading machine, and consider installing a microfibre filter for laundry. Finally, support brands that disclose supply-chain details and test their products: transparency tends to correlate with lower chemical use and better worker protections. These choices won’t eliminate all risk, but they shift demand toward safer manufacturing practices.

Click here to browse our 100% Organic Cotton (GOTS certified collection). Our printing inks are biodegradable, we deliver in non-plastic packaging and give 25% of gross profits to charities linked to our designs. 

Conclusion

If “unhealthy” is judged by the combination of chemical exposure, particulate shedding and wider environmental harms that feed back into human health, petroleum-based synthetics such as polyester and nylon sit at the top of the concern list. Natural fibres present their own problems, especially where intensive pesticide use and poor processing are involved, but they do not shed microplastics on the same scale and are easier to source in lower-impact forms. The clearest takeaway is not a single black-and-white verdict but a set of trade-offs: choose fibres and brands carefully, look for credible certification, and treat clothing as part of the broader chemical and environmental systems that affect health. Click here to read our article on what certifications to look for when shopping for clean, ethically sourced clothing garments. The industry is changing, slowly and unevenly; informed consumer demand appears to be one of the most effective levers for accelerating that change.