Read the full article by Ketura Persellin (Environmental Working Group)

“Period products have come under fire in the past for containing high levels of the ‘forever chemicals‘ known as PFAS. Now another manufacturer of period underwear is in legal hot water because their products allegedly contain PFAS.

The Canadian company Knix Wear is being sued by two California women because of marketing claims they say are misleading. The underwear is ‘PFAS free’ and ‘designed to be both safe and effective’ – despite allegedly containing the chemicals, which have been proven to harm human health, according to the proposed class action lawsuit filed in the U.S. District Court for the Northern District of California.

Another manufacturer, Thinx, became the subject of scrutiny two years ago, when tests showed its products likely contained high levels of PFAS. Today the company faces its own class action lawsuit in California.

PFAS are known as forever chemicals because they do not break down in the environment. Some PFAS also build up in the body for long periods. PFAS chemicals can cause numerous health harms, including weakened childhood immunity, low birth weight, endocrine disruption, increased cholesterol levels, weight gain in children and dieting adults, and other health problems.

According to the complaint against Thinx, ‘some customers have developed physical symptoms including irregular menstrual cycles, urinary tract infections, yeast infections, thyroid issues and unexplained infertility.’ A separate lawsuit against Thinx was filed in Massachusetts in 2021.

In 2020, Sierra Club blogger Jessian Choy described sending samples of unworn Thinx and Lunapads, another brand of menstrual underwear, for testing to Graham Peaslee, Ph.D., a University of Notre Dame professor of chemistry and biochemistry and co-author of a study that found nearly half of roughly 400 fast-food wrappers tested contained fluorinated chemicals. (EWG Senior Scientist David Andrews was also a co-author.)

Results from Peaslee’s tests of the period products showed high levels of total fluorine, a very strong indication of PFAS: 3,264 parts per million, or ppm, in one pair of Thinx and 2,053 ppm in a pair of BTWN, a Thinx brand marketed to teens and tweens.”…