The sprays and cloths that have helped bespectacled mask-wearers clear up foggy lenses throughout the coronavirus pandemic may contain high levels of “forever chemicals,” scientists found.
Researchers from Duke University tested four top-rated anti-fogging sprays and five top-rated anti-fogging cloths available on Amazon and found that all nine products contained perfluoroalkyl and polyfluoroalkyl substances (PFAS) — the group of thousands of toxic compounds linked to kidney, liver, immunological, developmental and reproductive issues.
The scientists, who published their findings on Wednesday in Environmental Science & Technology, saw that the products contained fluorotelomer alcohols (FTOHs) and fluorotelomer ethoxylates (FTEOs), two types of PFAS that they said have largely “flown under the scientific radar until now.”
While PFAS are most notorious for polluting waterways via firefighting foam, they are also known to appear in household items like nonstick pans, toys, makeup, food packaging and waterproof apparel. But their presence in the antifogging products that have become a pandemic staple is a new finding.
“It’s disturbing to think that products people have been using on a daily basis to help keep themselves safe during the COVID pandemic may be exposing them to a different risk,” Heather Stapleton, a professor of environmental chemistry and health at Duke, said in a press statement.
“Ironically, it was advertised as safe and nontoxic,” added Stapleton, who initiated the study after reviewing the ingredients on an anti-fogging spray she had bought for her nine-year-old daughter. “It said to spray it on your glasses and use your fingers to rub it around.”
None of the other eight products that she tested listed the ingredients, she explained, adding that it was nearly impossible to know whether they contained harmful chemicals without using high-resolution mass spectrometry.
But Stapleton and her colleagues had such capabilities in their laboratory, and ultimately found that the sprays contained up to 20.7 milligrams of PFAS per milliliter of solution, which postdoctoral researcher Nicholas Herkert described as “a pretty high concentration.”
The current Environmental Protection Agency (EPA) health advisory — which provides guidance only and is not a regulatory standard — is 70 parts per trillion, or equivalent to 70 nanograms per liter, for two specific types of PFAS, PFOS and PFOA.
This means that the concentration of FTOHs and FTEOs in these sprays is almost 300 million times more than the EPA’s health advisory level for PFOS and PFOA.
“If we were to assume that FTOHs and FTEOs have similar toxicity to PFOA and PFOS, then one spray from these bottles would expose you to PFAS at levels that are several orders of magnitude higher than you’d receive from drinking a liter of water that contains PFAS at the current EPA health advisory limit for safe consumption,” Herkert said in a statement.
Because their study is only the second ever to explore FTEOs, and involved a small sample size, the scientists acknowledged that further research is necessary. They called for broader studies that include both in vivo and in vitro testing as the logical next step.
Although the health risks of FTOHs and FTEOs remain unknown, previous research has suggested that when FTOHs are inhaled or absorbed through the skin, they can break down into PFOA and other PFAS compounds known to be toxic, according to Herkert. Meanwhile, the FTEOs used in all four sprays exhibited significant cell-altering cytotoxicity, he added.
“Because of COVID, more people than ever —including many medical professionals and other first-responders — are using these sprays and cloths to keep their glasses from fogging up when they wear masks or face shields,” Stapleton said in the statement. “They deserve to know what’s in the products they’re using.”