Class Action Alleges Thinx Women’s Underwear Contains ‘Forever Chemicals,’ Silver Nanoparticles

A proposed class action alleges Thinx women’s underwear is falsely advertised in that the supposedly safe, healthy and sustainable hygienic undergarments contain polyfluoroalkyl substances (PFAS) and silver nanoparticles.

The 41-page complaint out of New York says that independent, third-party testing done by the plaintiff, an Okeechobee, Florida resident, has confirmed the existence of the harmful substances, seemingly contradicting Thinx’s “unvarying representations that the product is nontoxic, harmless, sustainable, organic, environmentally friendly, and otherwise safe for women and the environment.”

According to the case, Thinx has intentionally concealed the true nature of its products, which it touts as a more sustainable approach to feminine hygiene, while misrepresenting the results of third-party testing, concealing the nature of its “anti-odor” technology and telling consumers that some of its underwear is organic. The lawsuit says the PFAS chemicals in Thinx underwear stem from the products’ “moisture-wicking” and “leak-resistant” qualities, while the alleged silver nanoparticles stem from the items’ treatment with an antimicrobial coating.

“Thinx’s misbranding is intentional, and it renders the Thinx Underwear worthless or less valuable,” the lawsuit alleges, contending that consumers would not have bought the items, or would have paid less for them, had they known they contained harmful chemicals.

Which Thinx products are included in the lawsuit?

The Thinx products mentioned in the complaint include the cotton brief, cotton bikini, cotton thong, sport, hiphugger, hi-waist, boyshorts, French cut, cheeky and thong styles.

Thinx underwear contains “material and trace amounts” of PFAS, case says

As the case tells it, Thinx is well aware of the demand for reusable menstrual hygiene products and has become a leader in the market at a time when there is growing public concern about the chemicals in and environmental impact of typical single-use period products. The company touts Thinx as “washable, reusable underwear” designed to replace pads and tampons, or to be worn with pads and menstrual cups for extra protection, the suit relays.

“Without exception, every advertisement, marketing campaign, instructional video, and public statement produced and distributed in relation to Thinx’s products encourages customers to use the Thinx Underwear the same way as traditional menstrual products and/or underwear,” the lawsuit stresses.

Despite the praise Thinx has drawn for its mission, independent, third-party testing, which the suit attests is “industry standard” for detecting and determining whether certain materials comply with quality and safety benchmarks, has found that the company’s products contain short-chain PFAS at “material and trace amounts,” the complaint states.

The case relays that PFAS are a category of human-made chemicals that may be used to enhance the performance of textiles and apparel. Per the suit, PFAS are frequently used in outdoor apparel, for instance, to make it water repellant or stain resistant. The carbon-fluorine bonds in PFAS are among the strongest in nature, allowing the substances to persist in the human body and environment over time, according to the complaint.

The lawsuit theorizes that Thinx uses PFAS to “enhance the performance” of its underwear, including its “moisture-wicking” and “leak-resistant” properties.

Silver nanoparticles linked to Thinx antimicrobial treatment, suit claims

The lawsuit goes on to relay that although Thinx represents on its website that its underwear does not contain toxic metals or engineered nanoparticles, the products’ treatment with Agion, an antimicrobial coating, for odor protection causes silver and copper nanoparticles to linger on the fabric. Per the case, it is the size of the nanoparticles that poses a problem for humans.

Nanoparticles are small-scale substances which are undetectable to the human eye. Whether they are engineered or naturally occurring, it is a nanoparticle’s size that creates a hazard since these small particles can readily enter the human body through inhalation, ingestion, and skin absorption.”

The filing further argues that even if a nanoparticle is naturally occurring, it is not automatically rendered safer than one that is engineered.

“Thus, Thinx’s representation that it does not include ‘engineered nanoparticles’ is misleading to a reasonable consumer,” the suit charges, adding that Thinx fails to disclose on product packaging that its underwear contains silver nanoparticles.

Importantly, the lawsuit says silver nanoparticles pose a particular risk to the female body, especially when present in period products, given that they have been found to cause “ultrastructural changes to the vaginal mucosa, urethra and rectum” and adverse effects on vaginal bacteria.

“Thinx does not reveal to consumers that Agion is an antimicrobial, or that it contains silver and copper nanoparticles which are known to migrate and pose a safety hazard to the female body and the environment,” the case alleges. “Thus, Thinx’s representations that its Underwear does not contain harmful chemicals, toxic metals or engineered nanoparticles is inaccurate and misleading.”

Thinx underwear is not organic either, case claims

Lastly, the lawsuit argues that four styles of cotton Thinx underwear are not organic as advertised because the presence of PFAS disqualifies the items for Global Organic Textile Standards (GOTS) certification. Per the suit, GOTS is the worldwide leading processing standard for organic fibers and ultimately determines when a textile may be classified as organic.

In reality, the lawsuit says, Thinx does not hold any independent organic certifications, conform to industry standards for organic clothing or use exclusively organic cotton.

Who’s covered by the lawsuit?

The case looks to represent all individuals in the United States who have purchased the Thinx underwear at issue during the maximum period permitted by law.

I’ve bought some Thinx underwear. How do I get involved?

When a class action case like this is initially filed, there’s usually nothing you need to do to join or ensure that you’re included in the litigation. Fact is, it’s only if and when a lawsuit settles that a consumer would have to act. This might involve submitting a claim form online or by mail.

If the suit settles and you’re one of the people who are “covered,” you would most likely receive a notice by mail and/or email. This notice will probably contain certain important information on, for example, how to file a claim, the rundown on your legal rights, what proof you might need to claim your money, and more.

Most class action lawsuits take some time to work through the legal process, usually en route to a settlement, dismissal or arbitration.

For now, Thinx underwear buyers, and anyone else interested in class action lawsuit and settlement news, should sign up for ClassAction.org’s free weekly newsletter.

A PDF of the legal complaint can be found below.