You check ingredient labels on food. You read what's in your skincare. But your clothes? Most people never think about what chemicals are on the fabric touching their skin 24 hours a day.
Your clothes spend more time against your skin than any skincare product. And the textile industry uses over 15,000 different chemicals in manufacturing — from dyes and finishes to softeners and water repellents. Here's what's actually on your fabric.
The Major Chemical Groups in Clothing
1. Formaldehyde and Formaldehyde Resins
What it does: Makes fabric wrinkle-resistant, prevents mildew during shipping, helps garments hold their shape.
Where you find it: "Wrinkle-free" and "easy-care" garments, non-iron shirts, synthetic fabrics, imported clothing (especially from countries without strict regulations).
Why it matters:
- Classified as a known human carcinogen by the International Agency for Research on Cancer (IARC)
- Causes contact dermatitis — red, itchy rashes — in sensitive individuals
- The "chemical smell" on new clothes is often formaldehyde off-gassing
- The US has no legal limit on formaldehyde in clothing — 13 other countries do
- Japan limits formaldehyde in baby clothes to 16 ppm. Some US-sold garments have tested at over 900 ppm
How to reduce exposure: Always wash new clothes before wearing. A single wash removes 60-80% of formaldehyde residues. Avoid "wrinkle-free" and "easy-care" labels — these almost always indicate formaldehyde treatment.
2. Azo Dyes
What they do: Produce vibrant colours cheaply. Azo dyes account for 60-70% of all synthetic dyes used in textiles.
Where you find them: Brightly coloured clothing, especially dark reds, oranges, and yellows. Most common in cheap, fast fashion garments.
Why they matter:
- Some azo dyes break down into aromatic amines, several of which are classified as carcinogenic
- The EU has banned 22 aromatic amines in textiles since 2002 — the US has no equivalent restriction
- Disperse dyes (a subclass) are the most common cause of textile contact dermatitis
- Dark-coloured synthetics (especially blues and blacks) are the worst offenders
How to reduce exposure: Choose lighter colours when possible. Look for OEKO-TEX certified garments, which are tested for harmful dye residues. Wash new clothes before wearing — especially dark and brightly coloured items.
3. PFAS ("Forever Chemicals")
What they do: Make fabric water-resistant, stain-resistant, and grease-resistant.
Where you find them: Waterproof jackets, stain-resistant clothing, outdoor gear, school uniforms treated for stain resistance, some workout clothes.
Why they matter:
- PFAS are called "forever chemicals" because they never fully break down in the environment
- Linked to cancer, thyroid disease, immune system suppression, reproductive harm, and liver damage
- A 2022 study found PFAS in 72% of stain-resistant clothing tested and 88% of waterproof garments
- PFAS can be absorbed through skin contact, especially when you sweat
- They accumulate in the body — the average half-life of some PFAS compounds is 3-7 years
How to reduce exposure: Avoid clothing marketed as "stain-resistant" or "water-repellent" unless it specifically states it's PFAS-free. For waterproof outerwear, look for brands using wax coatings or PFC-free DWR treatments instead.
4. Heavy Metals
What they do: Used as mordants (fixers) in textile dyeing, in metal hardware, and in some antimicrobial treatments.
Where you find them: Leather goods (chromium from tanning), brightly dyed fabrics (chromium, cobalt, copper as mordants), antimicrobial clothing (silver nanoparticles), zippers and buttons.
Why they matter:
- Chromium VI (used in leather tanning) is a known carcinogen and common contact allergen
- Lead has been found in textile dyes, especially in children's clothing from unregulated markets
- Nickel (in buttons, rivets, zippers) is the most common metal allergen — affects ~15% of women
How to reduce exposure: Choose vegetable-tanned leather over chrome-tanned. For metal hardware sensitivities, coat buttons and rivets with clear nail polish as a barrier. Choose OEKO-TEX certified garments.
5. Phthalates
What they do: Make plastic flexible. Used in plastisol prints (the rubbery graphics on t-shirts), PVC accessories, and some synthetic leather.
Where you find them: Printed t-shirts (especially the thick, rubbery kind), faux leather, PVC accessories, some shoe soles.
Why they matter:
- Classified as endocrine disruptors — they interfere with hormone function
- Linked to reproductive harm, developmental issues in children, and metabolic disruption
- Can leach from fabric, especially in heat and humidity
- Children are particularly vulnerable
How to reduce exposure: Avoid clothing with thick plastisol prints. Choose screen-printed or naturally dyed garments. Avoid PVC and faux leather.
Natural vs Synthetic: The Chemical Load Difference
Not all fabrics carry the same chemical burden:
| Fabric Type | Chemical Treatment Level | Notes |
|---|---|---|
| GOTS Organic Cotton | Lowest | No synthetic pesticides, strictly limited processing chemicals, full supply chain certification |
| Undyed Linen | Very Low | Flax requires few pesticides, natural colour needs no dye |
| Conventional Cotton | Moderate | 16% of global insecticides, but relatively fewer finishing chemicals than synthetics |
| Silk | Low-Moderate | Naturally smooth and lustrous, requires less chemical finishing |
| Viscose/Rayon | Moderate-High | Chemically intensive production process (carbon disulfide, sodium hydroxide) |
| Polyester | High | Formaldehyde resins, disperse dyes, antimony trioxide catalyst residues |
| Nylon | High | Similar chemical treatments to polyester, plus additional heat-setting chemicals |
The pattern is clear: natural fibres with minimal processing carry the fewest chemicals. The more synthetic and heavily processed a fabric is, the greater its chemical load.
How to Reduce Chemical Exposure from Clothing
- Always wash new clothes before wearing. This single step removes 60-80% of surface chemical residues.
- Choose natural fibres. Cotton, linen, silk, wool, and hemp carry fewer chemical treatments than polyester, nylon, and acrylic.
- Look for certifications. OEKO-TEX Standard 100 tests for over 100 harmful substances. GOTS covers the entire organic supply chain.
- Choose lighter colours. Dark and bright dyes require more chemical fixatives than light or undyed fabrics.
- Avoid "performance" finishes. Wrinkle-free, stain-resistant, water-repellent, and antimicrobial treatments almost always mean additional chemicals.
- Check fabric composition. Knowing what your clothes are made of is the first step. Natural fibres, organic certifications, and transparent brands all reduce your exposure.
The Certifications That Matter
- OEKO-TEX Standard 100 — tests finished products for over 100 harmful substances including formaldehyde, heavy metals, pesticides, and phthalates
- GOTS (Global Organic Textile Standard) — covers the entire supply chain from organic fibre to finished product, including all chemical inputs
- BLUESIGN — certifies that the manufacturing process meets strict environmental and safety standards
- EU REACH — the EU's chemical regulation framework that restricts the use of hazardous substances in products sold in Europe