Most clothing contains trace amounts of industrial chemicals left over from manufacturing, and some of these substances are genuinely harmful. The fabrics themselves, whether polyester, cotton, or nylon, aren’t inherently dangerous, but the dyes, finishes, coatings, and plasticizers applied during production can introduce formaldehyde, heavy metals, PFAS, phthalates, and carcinogenic dye byproducts into the garments you wear against your skin every day.
The good news: for most people, everyday clothing poses a low acute risk. The concern is cumulative, low-level exposure over years, particularly for young children, people with sensitive skin, and anyone regularly wearing heavily treated performance or fast-fashion garments.
Formaldehyde in Wrinkle-Resistant Clothing
Formaldehyde is one of the most common chemical finishes in clothing. It helps bind dyes to fabric, prevents colors from running, resists wrinkles, and inhibits mildew. If you’ve ever bought a shirt labeled “easy care,” “wrinkle-free,” or “permanent press,” it was almost certainly treated with a formaldehyde-based resin.
The EU classifies formaldehyde as a strong skin sensitizer. It can cause skin irritation, allergic reactions, and respiratory issues, especially in people who are already sensitized. Studies show that only about 1 to 4 percent of people react to formaldehyde at high concentrations, but once you’ve become sensitized, even levels as low as 30 parts per million can trigger a skin reaction.
Safety limits vary by how close the garment sits to your body. New Zealand’s product safety guidelines, which mirror international norms, set these thresholds: no more than 30 ppm for baby clothes, no more than 100 ppm for clothing touching adult skin, and no more than 300 ppm for items like outerwear that don’t sit directly against skin. Washing a new garment before wearing it reduces free formaldehyde significantly, which is why some labels specifically recommend it.
PFAS in Waterproof and Stain-Resistant Gear
PFAS, sometimes called “forever chemicals,” are used to make fabrics repel water, oil, and stains. You’ll find them in rain jackets, outdoor gear, stain-resistant school uniforms, and some athletic wear. These compounds don’t break down in the environment or in your body, and they’ve been linked to immune suppression, thyroid disruption, and certain cancers at high exposure levels.
Research from the EPA shows that PFAS compounds appear in all children’s textile products tested, with certain fluorinated alcohols being the most abundant. However, the dermal absorption rate of PFAS from clothing is relatively low. Studies have found that exposure from wearing water-repellent clothing is small compared to what you take in through food and drinking water. Breathing in household dust contaminated by PFAS-treated textiles actually contributes more exposure than skin contact does.
That said, some neutral PFAS compounds may absorb through skin more readily than the better-studied ionic forms. The science on this is still catching up with the sheer number of PFAS variants in use. The European Commission’s textile ecolabel restricts PFOA, one of the most studied PFAS compounds, to just 0.05 milligrams per kilogram of fabric.
Phthalates in Printed Graphics
Phthalates are petroleum-derived plasticizers used to make PVC soft and flexible. In clothing, they show up primarily in plastisol screen-printing inks, the kind that create those thick, rubbery graphic prints on t-shirts and children’s clothing. Plastisol ink is a mixture of PVC resin, pigments, and phthalates, and because phthalates aren’t chemically bound to the PVC, they can leach out over time.
This is a particular concern for infants and toddlers who chew on their clothing. Six phthalates are now restricted or banned in children’s products in most regulated markets. The EU prohibits five specific phthalates in any plastic component of clothing above 0.1 percent concentration, with two additional phthalates restricted specifically in children’s garments where a child might mouth the material. Phthalates are known endocrine disruptors, meaning they interfere with hormone signaling, and have been associated with reproductive and developmental effects in animal studies.
Azo Dyes and Carcinogenic Byproducts
Azo dyes are the largest class of synthetic dyes used in textiles, responsible for a wide range of vibrant colors. The dyes themselves aren’t always the problem. The danger comes when certain azo dyes break down, through sweat, saliva, or bacterial action on the skin, and release aromatic amines, some of which are known or suspected carcinogens.
The Australian Industrial Chemicals Introduction Scheme identifies several aromatic amines of concern that can form when these dyes degrade, including compounds with established genotoxic and carcinogenic potential. The International Agency for Research on Cancer has classified some of these breakdown products as possibly carcinogenic to humans. Several specific azo dyes, including Sudan I and Ponceau MX, are banned outright in cosmetics across the EU, ASEAN nations, Canada, and New Zealand, and the EU restricts their use in textiles to no more than 30 milligrams per kilogram of fabric.
Brightly colored, deeply dyed garments from manufacturers that don’t test for restricted substances are more likely to contain problematic azo dyes. Dark reds, oranges, and yellows historically carry higher risk.
Heavy Metals in Dyes and Accessories
Heavy metals enter clothing through coloring agents, fiber stabilizers, and metal accessories like zippers and rivets. Chromium, lead, cadmium, nickel, and cobalt are the most commonly detected. Hexavalent chromium, used in some leather tanning and dye processes, is classified as toxic and carcinogenic.
Heavy metals disrupt normal cell function by inhibiting enzymes and throwing off the body’s balance of essential minerals. At sustained exposure levels, they can damage organs, affect the nervous system, and contribute to the development of tumors and genetic mutations. Skin contact with nickel and chromium in metal clothing components is also a well-established trigger for contact allergies.
Antimony in Polyester
Polyester is the world’s most widely used textile fiber, and nearly all of it is manufactured using antimony trioxide as a catalyst. Residues of antimony remain in the finished fabric. Testing by the German Federal Institute for Risk Assessment found antimony concentrations between 87 and 147 milligrams per kilogram in polyester clothing, while broader studies have measured concentrations ranging from 1 to 200 milligrams per kilogram.
The International Agency for Research on Cancer classifies antimony trioxide as possibly carcinogenic to humans, with inhalation being the primary risk pathway. Antimony can leach from polyester when exposed to sweat. The real-world health significance of wearing polyester against your skin remains debated, but the presence of a Group 2B carcinogen in such a ubiquitous fabric is worth knowing about, especially for people who wear polyester workout clothes during heavy sweating.
How to Reduce Your Exposure
Wash new clothes before wearing them. This single step reduces free formaldehyde, loosely bound dyes, and surface chemical residues. It won’t eliminate everything, but it meaningfully lowers your initial exposure.
Look for OEKO-TEX Standard 100 certification, which tests finished products for hundreds of harmful substances. The 2025 standards tightened the limit for bisphenol A (BPA) from 100 milligrams per kilogram down to 10, and set a specific cap on PFAS at 250 micrograms per kilogram. The EU’s REACH regulation restricts 33 carcinogenic, mutagenic, or reproductively toxic substances in clothing sold in Europe as of November 2020.
Beyond certifications, practical choices help. Choose untreated natural fibers like organic cotton, linen, and wool when possible. Be cautious with heavily printed children’s clothing, especially thick plastisol graphics. Skip “wrinkle-free” and “stain-resistant” labels if you want to minimize chemical treatments. For outdoor gear, look for brands that have moved to PFAS-free water repellency, which several major manufacturers now offer. Children’s clothing deserves the most scrutiny, since kids have higher surface-area-to-body-weight ratios, developing organ systems, and a tendency to put fabric in their mouths.