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Danger of PFAS in underwear isn’t rocket science

Conflicting evidence suggests that Thinx menstrual underwear marketed to adults and teens is contaminated with polyfluoroalkyl substances (PFAS). Dr. Graham Peaslee, a University of Notre Dame nuclear scientist, was asked to conduct a study on the underwear in question by a reporter for Sierra Club’s magazine. His findings, if accurate, are alarming.

Elevated levels of PFAS were detected in his tests on “the inside layers of the crotch”. If PFAS was present in the menstrual underwear, this would undoubtedly be one of the worst places because it could easily be absorbed by the wearer. PFAS as we know has been linked to everything from fertility issues to cancer. Dr. Peaslee’s tests found PFAS levels of 3,624 parts per million in their standard line of menstrual underwear, and their underwear “marketed at teens, had 2,053 parts per million." The underwear was labeled by Thinx as “organic cotton”.

For their part, Thinx is “vigorously” contesting the report, and defending their monitoring of toxic chemicals. Thinx informed Fast Company that their products either “meet or exceed safety standards”. Their CEO Maria Molland said that based on their own third party testing, “PFAS chemicals were not detected in Thinx products.” Thinx went so far as to provide documentation of lab tests conducted less than six months ago showing no signs of PFAS.

So where does this leave us? Well, it’s hard to say really. One publication reports increased levels of PFAS, and the manufacturer provides their own evidence showing none. It seems as though at this time, it may be best to steer clear of these or similar menstrual underwear until more conclusive evidence is introduced.

To read Fast Company’s full report on the study and Thinx’s response, follow this link: