If you purchased a period underwear product made by Thinx, you may now be entitled to a refund thanks to a class action settlement announced in November.

The plaintiffs in the lawsuit accused Thinx of using, and failing to inform customers about, potentially harmful chemicals known as PFAS in underwear.

Thinx, which launched in 2013 and is based in New York, has agreed to pay $4 million to pay for claims brought by clients and court-approved attorneys’ fees, expenses and service awards that may be owed to the customers. The company has also agreed to provide up to an additional $1 million if needed to cover valid claims.

«As part of the settlement, Thinx agreed to take numerous steps to ensure that PFASs are not intentionally added to products at any stage of production, which speaks directly to the concerns of Plaintiffs and class members,» Erin Ruben, attorney for the plaintiffs, they said in a statement. «We are very pleased that the settlement provides consumers with this important non-cash relief in addition to cash back.»

Thinx denied all of the plaintiffs’ allegations as part of the settlement, emphasizing that the settlement was not an admission of guilt.

«We take customer health and product safety seriously,» a company spokesperson said in a statement. «We can confirm that PFASs have never been part of our product design. We will continue to take steps to help ensure that PFASs are not added to our products.»

PFAS, or perfluoroalkyl and polyfluoroalkyl substances, are a family of synthetic chemicals used in the manufacture of consumer products, including food packaging, cosmetics, or textiles such as raincoats or sportswear, due to their ability to resist stains, fat and water.

The presence of PFAS appears to have been first reported in January 2020 in the Sierra Club magazine, «Sierra,» with the headline, «My period underwear has toxic chemicals in it.» Reporter Jessian Choy sent his Thinx to a University of Notre Dame nuclear scientist, who found high levels of PFAS, «especially in the inner layers of the crotch.»

That went against Thinx’s claims that its products were «certified» organic, Choy wrote.

PFAS are known as «forever chemicals» because they can remain permanently in the air, water, and soil. Exposure to PFAS has been associated with low birth weight, high cholesterol, thyroid disease and an increased risk of certain types of cancer, such as Liver cancer.

“With the extent that we are seeing PFAS in the environment and in our bodies, and the truly harmful effects that occur at low levels of exposure, we need to act with more urgency to remove PFAS from all garments,” said Erika Schreder. , scientific director of Toxic-Free Future, an environmental health research and advocacy group.

«We would be particularly concerned about exposure through the skin from a textile worn next to the skin for prolonged periods,» he added, citing preliminary evidence that PFAS can cross the skin barrier and potentially enter the bloodstream.

Thinx customers can receive a $7 rebate for each purchase of up to three pairs of underwear for the Thinx period as reflected in Thinx records, or for which valid proof of purchase is provided.

Claims can be filed here.