A recent study has found PFAS, or “forever chemicals,” can cross the human skin barrier, something experts had believed was not a significant source of exposure before.
The study examined 17 PFAS chemicals found in products that often come in contact with the skin, including those used in fabrics, rain gear, waterproof mascaras and foundations.
“PFAS can be found in a lot of different cosmetics,” said Oddny Ragnarsdottir, a chemist and lead author of the study.
“It’s usually products that are marketed [as] water repellent or stain repellent.”
Ragnarsdottir said different PFAS chemicals behave differently in the body and in the environment, but there are similarities within the group.
“They’re both water soluble and oil soluble,” she said. “They have these unique properties which make them so exciting for manufacturers.”
But these properties also make them problematic for people’s health.
“We can eliminate them over time,” Ragnarsdottir said. “But it can take a long time” - years for some of the chemicals.
PFAS, or per- and polyfluoroalkyl substances, are a large group of nearly 15,000 chemicals that have been used in industry and consumer products since the 1940s, according to the U.S. Environmental Protection Agency. Only a small fraction of PFAS chemicals are well studied.
It is difficult to know which products contain PFAS, as companies are not required to label them.
Ragnarsdottir said people are most likely exposed to the group of toxic chemicals through diet and drinking water, but skin contact to PFAS can add up over time. A 2022 study had found high levels of PFAS in U.S. and Canadian school uniforms.
“It’s clothes that kids are wearing for eight hours a day,” Ragnarsdottir said. “Even though the absorption is going to be small, the exposure, the time you’re wearing the clothes, is such a long time. So over time, it’s going to kind of build up more and more.”
While PFAS chemicals do not occur naturally in the environment, they have been manufactured for many decades and occur in food, drinking water, air, soil, and many consumer products including food packaging, carpets and non-stick cookware.
The chemicals can cause many health problems, including increased cholesterol, obesity, decreased fertility, decreased vaccine efficacy, reduced immune response to infections, and prostate, kidney and testicular cancers, according to the EPA.
Ragnarsdottir said some companies now advertise they are PFAS-free.
“Be aware of what you are using on your skin,” Ragnarsdottir recommends. “If it’s something you use every day, it can accumulate over time.”