BPA in sportswear: the invisible health risk

Reports that synthetic sportswear contains Bisphenol A (BPA) are increasingly common. This is concerning, as exercise should support your health – not undermine it. BPA is a well-known endocrine-disrupting chemical that mimics estrogen. It can affect processes in our body that are essential for growth, reproduction, and metabolism. But how does this substance end up in our clothing? And more importantly: what does this mean for your health, and what alternatives are available?

What do the studies say?

A recent press release from the Center for Environmental Health (CEH) revealed that sports bras and tops from 19 popular sports brands contain toxic levels of BPA. These garments would expose wearers to up to 40 times the safe limit set by the state of California.^[1] The study tested 32 garments and found BPA in 90% of the samples, with concentrations up to 22 times higher than California's reporting threshold.^[2]

You might recognize the term "BPA-free" from water bottles and food containers. So it's natural to wonder: what does BPA actually do in sportswear?

Why is BPA in fabrics?

More than 60% of all clothing worldwide is made from synthetic fibers. Most of these are petrochemical, such as polyester and nylon – simply put: plastic.^[3] These synthetic fibers are often made from polyethylene terephthalate (PET), with BPA remaining as an intermediate or residual product.^[4]

BPA is a crucial building block for these plastics. In textiles, it is used to:

• extend the lifespan of fabrics by increasing strength and durability,
• make clothing moisture-regulating and anti-static through special coatings,
• and better fix dyes for vibrant, long-lasting colors.

These are precisely the properties often found in brightly colored, tight-fitting sports sets that promise "breathable" or "sweat-wicking" performance. Research shows that BPA is also used in thermal transfer prints – the method by which logos and designs are applied to sportswear.^[5]

What does this mean for our health?

BPA is a known endocrine disruptor: it mimics the female hormone estrogen and can thus disrupt natural processes in the body.^[6] The World Health Organization (WHO) classifies BPA as a chemical with endocrine-disrupting potential that requires special attention.^[7]

According to Dr. Jimena Díaz Leiva (CEH): "BPA mimics estrogen and can disrupt normal bodily functions, including metabolism, growth and development, reproduction, and more."^[1]

Specific health risks:

Pregnancy and fetal development: exposure can cause permanent changes in the fetus's DNA. Even temporary exposure during pregnancy can have lasting genetic effects on offspring through epigenetic modifications.^[8] Studies show that prenatal BPA exposure is associated with behavioral problems, impaired cognitive development, and an increased risk of obesity in children.^[9]

Fertility: in women, BPA can disrupt egg maturation, reduce the chance of implantation, and negatively affect IVF success rates.^[10] In men, it lowers testosterone production, reduces sperm quality, and can contribute to erectile dysfunction.^[11] A meta-analysis found consistent associations between BPA exposure and reduced male fertility.^[12]

Metabolism: BPA has been linked to obesity, insulin resistance, and type 2 diabetes.^[13] Research shows that BPA interferes with glucose regulation and increases fat storage in adipocytes (fat cells).^[14] A systematic review found that higher BPA levels are associated with a 1.5-fold increased risk of type 2 diabetes.^[15]

Cancer: research indicates an increased risk of breast and prostate cancer.^[16] BPA promotes the proliferation of hormone receptor-positive breast cancer cells and can contribute to tumor growth.^[17]

Cardiovascular system: higher BPA exposure is linked to increased blood pressure, coronary heart disease, and arteriosclerosis.^[18]

Immune system: BPA can disrupt immune function and exacerbate allergic reactions. Studies show that children with higher BPA levels are more likely to develop asthma and allergies.^[19]

How does BPA enter your body?

Our skin is our largest absorption organ. Substances that remain in direct contact with the skin for extended periods, such as sportswear, can migrate and enter our bodies. Studies show that chemicals from textiles can transfer to the skin, especially with perspiration.^[20]

Because sportswear is worn during intense exercise when we sweat a lot, the chance of absorption is particularly high. Sweat extracts chemicals from the fibers, making it easier for BPA to penetrate our body through the skin. Research shows that dermal absorption of BPA from textiles can be significant, with absorption rates of up to 27% within 24 hours of skin contact.^[21]

A study on BPA migration from sportswear found that during a typical 60-minute workout, up to 3.2 micrograms of BPA can be released from synthetic sportswear and absorbed through the skin.^[22] During intense exercise with increased body temperature and perspiration, this migration significantly increases.

BPA alternatives: not always safer

When BPA came under fire, manufacturers developed alternatives such as BPS (Bisphenol S) and BPF (Bisphenol F). These are now often used in "BPA-free" products. However, research shows that these alternatives have similar endocrine-disrupting effects and may even be more persistent in the environment.^[23]

One study found that BPS and BPF show similar estrogenic activity to BPA and can also disrupt thyroid function.^[24] Therefore, the term "BPA-free" is no guarantee of safety – it often just means a similar chemical has been used.

How GOTS and OEKO-TEX protect against BPA

BPA – the endocrine-disrupting substance we just discussed – is precisely what GOTS and OEKO-TEX Standard 100 protect against. These certifications offer distinct yet complementary protection.

The difference in approach: GOTS prevents BPA exposure by exclusively certifying natural fibers that do not contain BPA, while OEKO-TEX 100 tests the final product to ensure that BPA residues remain below detectable levels. For organic cotton sportswear with both certifications, this means absolute certainty: no synthetic fibers with BPA and a tested final product.

Are there alternatives?

Fortunately, there are choices that significantly reduce your exposure:

Choose natural materials

Avoid plastic fibers such as polyester, nylon, and acrylic. Opt for certified, plant-based fabrics like organic cotton, linen, or hemp. These natural fibers inherently contain no BPA and do not require synthetic coatings.

Be critical of claims

Labels like "moisture-wicking" or "anti-static" may indicate chemical coatings that include BPA. Also, "BPA-free" is no guarantee – ask for GOTS or OEKO-TEX certification for true certainty.

Check certifications

GOTS and OEKO-TEX Standard 100 are independently verified certifications that protect against BPA and other harmful chemicals. They offer transparency that marketing claims cannot match.

The more natural, the better

A small amount of elastane is sometimes present (as in our collection: 92% organic cotton + 8% elastane), but the higher the percentage of natural fibers, the lower your risk of BPA exposure.

Conclusion

BPA does not belong in clothing you wear daily, especially not in sportswear that is in direct and prolonged contact with your skin. Research shows that exposure through textiles can contribute to serious health risks, from hormonal disruption to fertility problems and metabolic diseases.

The CEH study on BPA in sportswear from 19 major brands is a wake-up call: synthetic sportswear can contain up to 40 times the safe limit of BPA. This means that every workout potentially brings exposure to endocrine-disrupting chemicals.

At NOHI NATURAL, we believe that clothing should support your health, not burden it. That's why we choose GOTS-certified organic cotton and avoid petrochemical fibers and toxic coatings like BPA. Our entire collection is both GOTS and OEKO-TEX® certified – double protection against BPA and other harmful chemicals.