What’s Up With Claims That Polyester Clothing Can Make People Sick?

Polyester is one of the most widely used synthetic fibers in clothing today, favored for its durability, wrinkle resistance, and affordability. However, growing concerns have emerged around claims that polyester clothing can make people sick. What lies behind these claims? Are they backed by science, or are they just fashion rumors? Here’s a comprehensive look.

The Origin: What Is Polyester Made Of?

Polyester is a plastic-based synthetic fabric primarily made from polyethylene terephthalate (PET), derived from petroleum. To transform it into wearable fabric, polyester undergoes chemical processing and is treated with various substances to improve qualities like wrinkle resistance, water repellency, and stain protection.

Regulatory Stance: What’s the Official Word?

Major regulatory bodies such as the U.S. Consumer Product Safety Commission (CPSC), the European Chemicals Agency (ECHA), and the International Agency for Research on Cancer (IARC) have not classified finished polyester fabric as carcinogenic or inherently harmful to consumers under normal use. Polyester clothing, bedding, and upholstery are generally regarded as safe when worn and used as intended.

Chemical residues and finishing agents on polyester fabrics may pose irritant, allergic, or hormone-disrupting risks, but these issues are generally regulated through chemical restrictions and residue limits, not by classifying polyester fabric itself as dangerous.

Chemical residue limits in polyester and other textile products are verified by specialized, accredited third-party labs using advanced analytical methods to protect consumer health.

Why Polyester Clothes Might Cause Health Problems

The potential health risks related to polyester clothing come less from the polyester fiber itself and more from the chemical additives and the fabric’s physical properties:

1. Chemical Treatments and Residues:
Polyester garments are often treated with chemicals such as:

Antimony: Used as a catalyst in polyester manufacturing and classified as a possible carcinogen based on inhalation in animal studies, but tightly bound in fabric and low risk for normal wear.
Formaldehyde: Used to make fabrics wrinkle-free, but classified as a probable carcinogen and known to cause skin irritation, asthma flare-ups, and respiratory issues.
PFAS (Per- and Polyfluoroalkyl Substances): Known as “forever chemicals,” used to add water and stain resistance. PFAS exposure has been linked to hormone disruption, immune system effects, liver inflammation, fertility problems, and increased cancer risk.
Phthalates and Flame Retardants: These can disrupt endocrine function and potentially affect reproduction.
Other additives like dyes and antimicrobial agents can also cause allergic reactions or skin sensitivity.

2. Chemical Absorption Through the Skin:
Clothing is in direct, prolonged contact with the skin, the body’s largest organ. Heat, sweat, and friction, especially during physical activity, can enhance absorption of these chemicals into the body, increasing possible health risks.

3. Skin Irritation and Allergies:
Because polyester does not breathe well and traps heat and moisture, it can create a breeding ground for bacteria and exacerbate skin conditions like eczema, dermatitis, hives, and acne, especially in sensitive individuals.

4. Respiratory and Systemic Effects:
New polyester products can off-gas volatile organic compounds (VOCs), which may trigger headaches, dizziness, and respiratory irritation in sensitive people.

5. Impact on Hormones and Fertility:
Scientific studies have linked some chemical additives associated with polyester to endocrine disruption. For example, studies suggest some polyester underwear may impair male fertility by affecting sperm quality and facial hair growth, while similar chemicals could affect female ovulation cycles.

Certifications are Available but Optional

How would we know if each of these is tested for each garment we purchase?

Certifications like OEKO-TEX Standard 100 and Global Organic Textile Standard (GOTS) indicate the textile has undergone independent third-party testing for harmful chemicals, including formaldehyde, heavy metals, pesticides, phthalates, flame retardants, allergenic dyes, and VOCs.

OEKO-TEX Standard 100 certifies the entire finished item (fabric, dyes, buttons, etc.) meets strict chemical safety limits and is updated annually with the latest science. GOTS focuses on organic textiles but also restricts and tests chemical inputs rigorously.

These certifications provide consumer assurance that the garment complies with chemical residue regulations verified by accredited labs. Without such labels, there is no direct guarantee each garment has been individually tested, though many reputable brands do conduct batch testing internally.

Only a small percentage of garments are chemically tested individually, but testing is performed on statistically valid samples per batch or lot. Certifications require regular independent testing and auditing to assure compliance for the overall production. For most consumers, certifications on tags provide the best confidence that chemical limits are met without individual garment testing.

Does Polyester Cause Cancer?

Current research does not conclusively link wearing finished polyester clothing to cancer. However, some chemicals used in polyester manufacturing, such as formaldehyde and antimony compounds, are classified as possibly carcinogenic, primarily based on studies involving occupational exposure to raw materials, processing chemicals, or inhalation of fumes during manufacturing—not typical consumer use.

Environmental and Microplastic Concerns Affecting Health

Polyester sheds microplastic fibers during washing, which enter waterways and the food chain, raising concerns about human ingestion and broader environmental health impacts. These microplastics could pose unknown long-term health risks.

What About Heat and Polyester?

Polyester is a thermoplastic that melts at around 260°C, and if overheated (e.g., open flames, industrial ironing), it can release harmful fumes like acetaldehyde and formaldehyde. Normal wearing, washing, and ironing do not pose this risk.

What About Old Polyester that has been Washed Many Times?

Your old 100% polyester Nike workout shirt likely poses minimal immediate health risk, especially if it is over 5 years old and has been washed many times. Over time, many of the chemical finishes (such as formaldehyde, PFAS, and other additives) commonly used on polyester wear out or wash away, reducing potential exposure to harmful substances.

Chemical Absorption and Sensitivities: Even older polyester clothing can still trap heat and moisture, which may irritate skin or induce allergic reactions in sensitive individuals. If you experienced vertigo the day after wearing it, for example, while this is unlikely to be solely caused by the shirt, some people can react variably to chemical residues, especially in activewear worn while sweating. Vertigo can have many causes—if it persists or repeats, you should seek medical advice.

How to Reduce Health Risks from Polyester Clothing

Wash New Clothes Before Wearing: This helps remove surface chemicals and residues. Washing textiles before consumer use was shown to reduce many residues significantly, indicating that initial chemical residue levels are also controlled partly through industry protocols.
Choose Mineral and Organic Fabrics When Possible: Natural fibers like cotton, linen, or bamboo breathe better and typically involve fewer toxic chemicals.
Look for Certifications: OEKO-TEX, bluesign, and similar labels ensure lower chemical use.
Avoid Tight-Fitting Polyester During Exercise: This reduces heat and sweat buildup, lowering chemical absorption.
Air Out New Clothes and Store Them Properly to minimize off-gassing of VOCs.
Be Mindful of Skin Sensitivities and opt for untreated or minimal-treatment fabrics if you experience irritation.

The Best Polyester Alternatives

Cotton

It is generally considered safer for your skin and health to buy cotton clothing over polyester, especially if you have sensitive skin or allergies. Cotton is a natural fiber that is breathable, soft, and typically processed with fewer toxic chemicals compared to polyester, which is a synthetic fabric made from petroleum and often treated with chemicals like formaldehyde, phthalates, and dyes that can irritate the skin or disrupt hormones. However, conventional cotton farming uses pesticides and fertilizers that can leave residues unless the cotton is organic. So, the safest choice is often organic cotton, which avoids harmful chemicals in both farming and processing. While polyester offers durability and wrinkle resistance, cotton’s natural properties generally make it the healthier option for prolonged skin contact.

Flax (Linen)

Flax fibers are processed into linen fabric, which is naturally breathable, biodegradable, and generally considered safe and non-toxic. Studies show linen has antioxidant properties that may protect skin cells and reduce oxidative stress. The processing of flax into fabric can involve some chemical retting and finishing agents, but organic linen avoids harmful pesticides and chemicals common in conventional flax farming. Linen’s natural properties make it hypoallergenic and less likely to irritate sensitive skin, and it has a long history as a wound dressing due to its regenerative benefits. However, to ensure chemical safety, look for organic or GOTS-certified linen to minimize exposure to residual chemicals.

Hemp

Hemp fabric, made from fibers of the hemp plant, is another natural, highly sustainable textile option. It generally requires fewer pesticides and fertilizers than cotton and flax and is considered hypoallergenic and antimicrobial. Like flax, hemp is breathable and biodegradable and tends to resist mold and bacteria naturally. The processing of hemp may involve some chemical treatments depending on the manufacturer, but organic and minimal-chemical hemp fabrics are widely available. Hemp is often recommended for sensitive skin and eco-conscious consumers because it combines durability with chemical safety, especially when certified organic.

Other Natural Fibers (Wool, Silk, Cotton Alternatives)

Other natural textile fibers like wool and silk have unique health and environmental profiles. Wool is naturally insulating and moisture-wicking but can cause irritation for some allergic individuals. It generally involves fewer chemical treatments compared to synthetics if processed traditionally. Silk is smooth and hypoallergenic but may be produced with chemicals depending on processing methods. Cotton alternatives like organic cotton or blends of natural fibers offer lower chemical exposure risks when grown and processed without pesticides and harmful finishing treatments. Choosing certified organic and minimally processed natural fibers is the safest route to avoid chemical residues common in synthetic and conventionally grown textiles.

Try Taking a Break from Polyester

Putting away all polyester clothing for several months to see if it helps your health could be a reasonable experiment, especially if you suspect irritation, allergies, or other symptoms related to wearing synthetic fabrics. Polyester traps heat and moisture, which can promote bacterial growth and skin irritation, and may contribute to skin issues or sensitivities. Additionally, polyester sheds microplastics that can accumulate in the environment and potentially affect human health. Taking a break from polyester allows your body and skin to recover from any ongoing irritation or chemical exposure. If your symptoms improve during this period, it may indicate sensitivity to polyester or its chemical residues. However, if symptoms persist or worsen, it’s important to consult a healthcare provider, as other factors could be involved. Meanwhile, favor breathable, natural fibers like cotton, flax, or hemp to reduce potential risks.

The Bottom Line

Claims that polyester makes people sick arise from valid concerns about the chemical treatments used in its production and the physical nature of the fabric itself. While the fiber “polyester” alone is not inherently toxic, the cumulative effects of long-term skin exposure to chemical additives, trapped moisture and heat, and potential hormonal disruption are meaningful and supported by scientific evidence.

Consumers searching for safer options should be aware of these risks and take practical steps to minimize exposure, particularly by selecting untreated or naturally based textiles and washing synthetic clothing before use.

Ultimately, the growing attention to polyester health concerns reflects a broader call for greater transparency and regulation regarding textile chemicals — helping everyone make informed choices about what they wear next to their skin.