Lawsuit Investigation: Is Your Menstrual Underwear Toxic?

Attorneys working with ClassAction.org are investigating whether class action lawsuits can be filed on behalf of people who purchased Thinx, Ruby Love and Knix menstrual underwear.

Reports have surfaced that some versions of the underwear contain toxic chemicals known as per- and polyfluoroalkyl substances (PFAS), which have been linked to cancer, fertility issues and other health problems.

Period Underwear and PFAS: What’s the Link?

PFAS can be used in clothing, including menstrual underwear, for their ability to resist stains and repel water.

While it’s impossible to directly test for the vast majority of the 9,000 PFAS in existence, the composting industry developed a way to instead test for fluorine, a chemical that, at certain levels, can indicate the presence of PFAS in an item or product.

Thinx

Thinx came under scrutiny in January 2020 when Sierra Club magazine reporter Jessian Choy wrote that she had sent several unused pairs of the underwear to a University of Notre Dame scientist for testing and that the results were “bad news.”

According to her report, the underwear indeed tested positive for PFAS, including on the inside layers of the crotch.

Specifically, the article stated that the Thinx organic brief contained 3,264 parts per million (ppm) of fluorine and that the organic BTWN Shorty underwear for teens contained 2,053 ppm. These amounts were “high enough to suggest they were intentionally manufactured with PFAS,” Choy wrote.

The manufacturer of Thinx has maintained that its underwear is safe and does not contain PFAS; however, concerns persist surrounding the testing methods the company used to support its statements.

For instance, its choice of toxicology lab and whether the company tested for all 5,000 PFAS used in manufacturing – or just some of them – are among the issues that have cropped up.

Ruby Love

In August 2021, Mamavation, a website dedicated to helping women avoid potentially toxic products, reported that a pair of Ruby Love underwear tested by an EPA-certified laboratory was found to contain more than 20 ppm of fluorine. Because the underwear had a detectable amount of fluorine, the website stated that it could not recommend the Ruby Love brand.

Knix

Mamavation also had two pairs of Knix period underwear tested for PFAS. According to a July 2021 report, the pair of Knix Boyshorts was found to contain 43 ppm of fluorine, while 373 ppm were detected in the Knix High Rise underwear. The website called Knix’s claim that its period underwear is 100% free from PFAS “incredibly ironic,” especially given the Knix High Rise pair had one of the highest levels of fluorine detected in its study. 

What Are PFAS and How Are They Dangerous?

PFAS are a group of man-made chemicals that include PFOA and PFOS, which have been described by the Environmental Protection Agency as “very persistent in the environment and the human body.” This means the chemicals don’t break down over time and have the potential to accumulate. In fact, PFAS are often referred to as “forever chemicals.”

Reports that certain menstrual underwear may contain PFAS are particularly concerning being as the garments are worn near the vagina, a particularly absorbent part of a woman’s body.

How Can a Class Action Lawsuit Help?

A class action lawsuit could help provide clarity on whether certain menstrual underwear products contain PFAS and, if successful, could force the companies to change the way they manufacture and/or advertise their products. Further, women could have a chance to be reimbursed for the money they spent on the underwear. 

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