The 8 Chemicals
Health Hub / The chemicals
The 8 chemicals commonly linked to conventional underwear.
Where each one shows up in textile production, what the research says and where to read more.
Educational information, not medical advice.
How to read this page.
These eight groups of chemicals are used somewhere in conventional textile production: in farming, dyeing, finishing, elastic or cleaning. The strength of the evidence varies. Formaldehyde and trichloroethylene are classified carcinogens. For phthalates, parabens and BPA, researchers have found hormone-related associations that are still being confirmed.
Association isn’t causation
Most of the studies here show links, not proof. Many everyday exposures add up, including food packaging, personal care products and household items, and what you wear against your skin is one of the easiest to choose. We share the research so you can make informed choices, not to alarm you.
Pesticides & fungicides.
Found in: conventional cotton
Cotton uses about 2.5% of the world’s farmland but accounts for roughly 16% of insecticide sales, according to commonly cited estimates. Residues can persist in the fiber through processing.
Chronic pesticide exposure has been linked in research to endocrine disruption and reproductive health effects, including conditions such as endometriosis and fibroids.
Sources: PMC, 2022 · MDPI, 2024 · Related: Fibroids guide
Synthetic azo dyes.
Found in: dyed and printed fabrics
Azo dyes are the most widely used class of textile dyes. Under certain conditions, some can break down into aromatic amines, several of which are classified as known or suspected human carcinogens.
The EU restricts azo dyes that release 22 specific amines in textiles under REACH. The U.S. has no equivalent federal rule.
Sources: PubMed, 2016 · PubMed, 2021
Formaldehyde.
Found in: wrinkle-resistant and easy-care finishes
Formaldehyde resins are applied to textiles to reduce wrinkling and shrinkage, and formaldehyde can release from the fabric over time. It is classified as a human carcinogen and is a well-known cause of allergic contact dermatitis.
That is why certification programs such as OEKO-TEX set limits for formaldehyde in finished textiles.
Phthalates.
Found in: elastic, prints and plastic components
Phthalates soften plastics and synthetic materials, including some elastics and prints. They are well-established endocrine disruptors.
A 2022 PNAS study led by Northwestern researchers found that chemicals found in everyday products can activate fibroid growth in human cell models. Fibroids affect up to 70% of white women and 80% of Black women by age 50.
Sources: PNAS, 2022 · Northwestern summary · Related: Fibroids guide
PFAS (“forever chemicals”).
Found in: water-repellent and stain-resistant treatments
PFAS are a family of thousands of synthetic chemicals used to repel water, grease and stains. They do not break down readily in the environment or the body.
Exposure has been associated with immune effects, thyroid disease, altered hormone levels and some cancers. There is no federal limit on PFAS in apparel, though a handful of states, including California and New York, have begun restricting them in clothing.
Source: eBioMedicine, 2023
Parabens.
Found in: preservatives in some textiles and finishes
Parabens are preservatives used mainly in cosmetics and, less often, in textiles to limit microbial growth. They are weak estrogen mimics, meaning they can bind estrogen receptors.
Research has linked paraben exposure to altered reproductive hormone levels and disrupted ovarian function. A possible connection to breast cancer risk is still under investigation.
Source: Frontiers, 2024
BPA (bisphenol A).
Found in: some synthetic fabrics, coatings and plastic parts
BPA is a synthetic estrogen used in some plastics and resins. It can show up in synthetic fibers, coatings and plastic garment components.
It is among the most studied endocrine disruptors. Exposure has been associated with fertility problems, PCOS and other reproductive outcomes.
Source: PMC, 2023
Chlorinated solvents.
Found in: cleaning, degreasing and finishing
Solvents such as perchloroethylene (PERC) and trichloroethylene (TCE) are used to clean and degrease textiles during manufacturing, and residues can remain in the finished garment. TCE is classified as a known human carcinogen.
Exposure is linked to liver and kidney damage and nervous system effects. Factory workers face the highest exposure, which is why supplier standards matter for the people who make clothing as well as those who wear it.
Sources: EPA, TCE assessment · PMC, 2016
What you can do.
You can’t avoid every exposure, and you don’t have to. Where it’s easy, keep unnecessary exposure low:
- Choose certified organic cotton, such as GOTS and OEKO-TEX, for what you wear closest to your skin.
- Wash new underwear before wearing it, and use a fragrance-free detergent.
- Choose fresh food over heavily packaged food where you can.
To learn how to read labels and certifications, visit Fabric School. For the full picture on women’s health, return to the Health Hub.
This page is for educational purposes only and is not medical advice. Talk to a qualified healthcare provider about your health. The image at the top of this page is an AI-generated illustration.
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