A report found that several brands of sports bras and athletic shirts could expose a person wearing them to up to 22 times the safe limit of bisphenol A (BPA), based on California standards. 

BPA is a chemical compound that can act like a hormone in the body and have a harmful effect on body functions such as metabolism, growth and reproduction, even at low doses. Per California’s Proposition 65, the maximum allowable dose level for BPA via skin exposure is 3 micrograms (mcg) per day, which means some of the garments could expose wearers to up to 66 mcg per day.

The nonprofit watchdog Center for Environmental Health (CEH) performed the testing on the sports bras and athletic wear over the past 6 months and recently sent legal notices to the brands, calling on them to reformulate their products without BPA. 

Related: These popular dry shampoos are being recalled due to potential cancer-causing ingredient

The sports bra brands tested include Athleta, PINK, Asics, The North Face, Brooks, All in Motion, Nike and FILA. The activewear shirt brands tested include The North Face, Brooks, Mizuno, Athleta, New Balance and Reebok. CEH only found BPA in polyester-based clothing containing spandex.

“We want brands to reformulate their products to remove all bisphenols including BPA. In the interim, we recommend limiting the time you spend in your activewear by changing after your workout,” the group said.

“Studies have shown that BPA can be absorbed through skin and end up in the bloodstream after handling receipt paper for seconds or a few minutes at a time. Sports bras and athletic shirts are worn for hours at a time, and you are meant to sweat in them, so it is concerning to be finding such high levels of BPA in our clothing,” said Kaya Allan Sugerman, Illegal Toxic Threats Program Director at CEH, in a press release.

What is BPA? 

Known as a hormone-disrupting chemical, BPA is used to harden plastic and can be found in everything from water bottles and food containers to linings used in canned foods, receipt paper, toys and flooring. And now, apparently, sports bras.

You’ve likely seen the “BPA-free” label on certain water bottles and other household objects, but BPA is hard to avoid completely, because it’s so commonly used. It’s everywhere, similar to the “forever chemicals” known as PFAS, which have even been found in breast milk. 

“People are exposed to BPA through ingestion, from eating food or drinking water from containers that have leached BPA, or by absorption through skin,” said Allan Sugerman. 

Related: PFAS exposure could significantly affect male fertility

One meta review study including more than 28,000 people found that BPA was detected in more than 90% of study subjects.

BPA can break down and leach out of products when exposed to water or heat, both of which occur when you’re sweating. Leached BPA can be absorbed through the skin in a matter of seconds or minutes. And most sports bras, which are tightly fitting, are worn for much longer than mere minutes. 

Why BPA is harmful

“The problem with BPA is it can mimic hormones like estrogen and block other hormone receptors, altering the concentration of hormones in our bodies, and resulting in negative health effects,” said Dr. Jimena Díaz Leiva, Science Director at CEH. 

BPA exposure has been well-studied in adults and has been linked to cancer, heart disease and diabetes, as well as infertility in both males and females.

The other concerning aspect is that BPA exposure could potentially be harmful to your developing baby if you’re already pregnant.

“Even low levels of exposure during pregnancy have been associated with a variety of health problems in offspring. These problems include abnormal development of the mammary glands and ovaries that can increase the likelihood of developing breast or ovarian cancer later in life. These effects occur even at low levels of exposure like those seen in people today,” said Dr. Díaz Leiva.

Related: Even without BPA, should you consider plastic baby bottles?

What to do now

Before you go burn all your bras (please don’t!), recognize that there’s still a lot we don’t know. The CEH report did identify high levels of BPA in the products, but we haven’t seen a clinical trial showing BPA in sports bras directly causes negative health effects (though given what we know about BPA exposure, there could be an association).

More research is definitely needed. But in the meantime, to reduce your BPA exposure: 

  • Opt for natural-fiber fabrics over polyester when possible
  • Wash your sports bras and athletic shirts on cold and line dry only 
  • Try to only wear sports bras and athletic shirts when exercising, and then remove them when finished
  • Swap any plastic water bottles or food containers for glass or steel
  • Skip the printed receipt whenever possible
  • Wash hands after handling receipt paper 
  • Keep exercising, as sweating may help the body release small amounts of BPA and other toxins (though the liver and kidneys do most of this important work)

Shop some of our favorite cotton sports bras as an alternative!

Pact Double Scoop Bra

Pact

$25

Double Scoop Bra

Made from organic cotton in a fair trade factory, these basic sports bras from Pact are a purchase you can feel good about all around. The Double Scoop Bra comes in a bunch of pretty colors from size XS-XXL.

Everlane Sports Bra

Everlane

$28

The Cotton Tank Bra

Supportive and silky soft, this Supima cotton style from Everlane is great for lower impact activities. The double layer construction keeps it comfy and breathable even on the hottest days!