Hold That Anti-Fogging Spray: Duke University Researchers Find Forever Chemicals in Commonly Used Eyeglass Products

By Jerri-Lynn Scofield, who has worked as a securities lawyer and a derivatives trader. She is currently writing a book about textile artisans.

To those of a certain age, ‘toxic chemical ‘ brings to mind oozing dumps of muck, which poisonlocal communities while regulators  dither about remediation and clean-up, let alone prevention. Think Love Canal.

Today ‘forever chemicals’ – per- and polyfluoroalkyl substances (PFAS)—long-lasting, man-made chemicals used in many consumer products – are ubiquitous and found most closer to home. On their face, don’t appear to be scary.

Few would be surprised to hear the Trump administration’s record on regulating forever chemicals wasn’t good. Biden’s  Environmental Protection Agency (EPA) recently announced it will establish a national drinking water standard by March 2023. Philippe Grandjean, adjunct professor of environmental health at Harvard T.H. Chan School of Public Health lauds these plans, according to a press release from Harvard’s T.H. Chan School of Public Health:

I’m thrilled about it. Any support we can conjure for the EPA to get going is good, because we’re so far behind in limiting the use of these dangerous chemicals. PFAS are used in many products, such as waterproof clothing, nonstick cookware, firefighting foams, cosmetics, food packaging, cleaning supplies, and electronics. We know that the blood of nearly all Americans contains some PFAS, which we call “forever chemicals” because they don’t break down in the body. And we’ve shown with two decades of intensive research that PFAS are linked to serious health issues such as kidney and testicular cancer, weakened immune system, endocrine disruption, fertility problems, and decreased birth weight.

A new EPA drinking water standard alone falls well short of the comprehensive regulatory approach that’s required to address the health threats posed by forever chemicals. As in so many other areas, the European Union policy is far ahead of the U.S. (While there’s no question that EU policy is superior to that of the U.S., I leave aside for the moment whether that EU policy is itself adequate.)

According to Grandjean:

The European Union (EU) is way ahead of the U.S. on regulating PFAS. In September 2020, the European Food Safety Authority (EFSA) set a new safety threshold for the four most common PFAS. The EPA’s limit is for only two PFAS—PFOS and PFOA—and it’s more than 30 times higher than the European limit, and it pertains only to drinking water. So that illustrates how far behind the U.S. is.

In setting their limit, the EFSA took into account toxicity to the immune system posed by PFAS, which is expressed by lowered antibody responses to childhood vaccines—an effect that we first reported in JAMA in 2012. The EFSA’s exposure limit is meant to ensure that women of reproductive age do not accumulate too much of a PFAS burden. The strategy makes sense, in my opinion, because PFAS compounds tend to pass through the placenta during pregnancy, so that a mother will share her accumulated burden of these compounds with the next generation. In addition, our 2015 study found that when the mother is breastfeeding—something that is strongly recommended by the CDC and WHO—these compounds are excreted through human milk. The infant may reach a blood concentration of PFAS that is 10-fold higher than the mother’s. And this happens at the most vulnerable stage of life, when various organs and biochemical functions are being fine-tuned. If something goes wrong at this stage, it will likely stay with us for the rest of our lives and affect our disease risks later on.

For example, in a study we published recently, we found that, even in nine-year-old children, their accumulated PFAS exposures were associated with elevated cholesterol, an outcome that was thought only to affect adults. And people who have high cholesterol as children or young adults are also likely to have high cholesterol later in life.

Grandjean was asked to outline what the government approach should be to regulating forever chemicals. His response:

I’m willing to accept that some PFAS compounds may pose fewer human health risks. But I would like to see the proof of their safety before they’re allowed to be used in products, rather than finding out 10 to 15 years down the road that these compounds don’t break down in the body, that they accumulate, and that women pass them down to their children via the placenta or through breastfeeding.

We should not do this experiment again on humanity. Industry has hidden the dangers of PFASs from us for decades. They knew about PFAS toxicity since the 1970s but didn’t share the information with the EPA until 2000. We should not allow similar secrecy to happen again.

Anti-Fogging Sprays

Well, the sensible approach to regulating forever chemicals that Grandjean outlined is unlikely to be implemented anytime soon. Meanwhile, Duke University researchers released a study this week suggesting many eyeglass wearers may be inadvertently and unnecessarily exposing themselves directly to forever chemicals by using anti-fogging sprays. During the pandemic, use of these agents has skyrocketed, as they reduce fogging that sometimes accompanies wearing a mask. According to The Guardian:

Anti-fogging sprays and cloths often used to prevent condensation on eyeglasses from wearing a mask or on face shields may contain high levels of potentially toxic PFAS “forever chemicals”, according to a new study led by Duke University.

Researchers tested four of the top-rated anti-fogging sprays as well as five top-rated anti-fogging cloths sold by Amazon. In all nine products, experts found fluorotelomer alcohols (FTOHs) and fluorotelomer ethoxylates (FTEOs), two types of per- and polyfluorinated alkyl substances (PFAS).

“Our tests show the sprays contain up to 20.7 milligrams of PFAS per milliliter of solution, which is a pretty high concentration,” said study lead Nicholas Herkert, a postdoctoral researcher at Duke’s Nicholas School of the Environment.

Echoing Grandjean, Herkert noted the two types of forever chemicals used in anti-fogging sprays – FTOHs and FTEOs – haven’t been studied extensively so that the health risks they pose are unknown. Nonetheless, The Guardian reports:

[R]esearch currently suggests that FTOHs inhaled or absorbed through the skin could break down in the body and become toxic, long-lasting PFAs.

The FTEOs used in all four anti-fogging sprays were also analyzed in the new study and exhibited substantial cell-altering toxicity and conversion to fat cells during lab tests, said Herkert.

Alas, beyond the universe of anti-fogging sprays, The Guardian also reports that there’s been scant research on the health threats posed by use of such chemicals despite their widespread use in other common consumer products. I’m fairly cynical about the deficiencies of  U.S. regulation of threats to human health and safety, but even I was shocked by how little research has been done on one class of these chemicals:

“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,” said Heather Stapleton, a distinguished professor of environmental chemistry and health at Duke.

This study, conducted by Herkert and Stapleton with researchers from Duke University, Wayne State University, and the University of North Carolina at Charlotte, is only the second ever to focus on FTEOS. The researchers published their peer-reviewed study on 5 January in the journal Environmental Science & Technology.

Herkert and Stapleton said that more research would be needed to expand on initial findings, with larger studies involving tests on living organisms being the next step. Studies that include a larger sample size of sprays and cloths could also help identify other unknown chemicals being used in these products

Now, I wear glasses and as I’ve aged, my prescription has become more complicated. So I now use various pairs for correcting my sight at different distances, rather than relying on a single set of progressive lenses. Although I can’t read without using the correct glasses, I can function without my distance glasses. When I’m enmasked, I can skip the glasses, and therefore fogging isn’t an issue.

But from my diving experiences, I know how difficult it is to function when one’s diving mask fogs up. Divers resort to various stratagems to prevent this from happening, such as prepping a new mask by rubbing the inside with toothpaste. Before entering the water, many – myself included – apply either a thin layer of baby shampoo, or in the absence of that, saliva, aka spit, to the inside of the diving mask. I’ve found these home remedies to be effective in preventing fogging.

I wonder whether other remedies might work to prevent spectacles from fogging that don’t expose the user to the possible health risks of forever chemicals.


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  1. Mantid

    Thanks Jerri-Lynn. You write “I’m fairly cynical about the deficiencies of U.S. regulation of threats to human health and safety”. I’d agree and go a step further by saying “I’m fairly certain about the deficiencies of U.S. regulation …..”. What a world!

  2. allan

    Re: `I wonder whether other remedies might work …’, in the context of masking, using hypoallergenic tape
    or, even better, double-sided tape in strategic locations around the edge of the mask
    (which depend on the mask and the geometry of your face) seems to work pretty well.

    Of course, who knows whether the hypoallergenic tape has forever chemicals in it …

      1. allan

        The Badger seal seems to be designed for surgical masks (ASTM) or more informal masks.
        Early on I bought a commercial product which might or might not be based on the Badger.
        It’s not designed for N95 or similar grade respirators,
        and won’t do much if anything for the rigid N95s.
        For the the softer, boxy ones, which I have grown to prefer, it defeats the advantage of
        having a good sized open space in front of the mouth, which helps with voice projection.
        But everybody has their own needs, preferences and budget.

  3. KLG

    Just another reason why my browser opens to naked capitalism on all of my computers!

    The chemical industry recognizes no precautionary principle! If a compound doesn’t kill its manufacturers, handlers, and users outright, then all is good. Until it isn’t, which usually is too late.

  4. seanohal

    Most interesting. Dark Waters is a surprisingly good movie about PFAS and the corporate cover-up around them. It’s a product of Hollywood, so a mawkish film at times, but forms a good introduction to what is a serious environmental catastrophe.

  5. Arizona Slim

    My darned glasses fog up like nobody’s business. I’ve asked my optician about anti-fogging spray, and let’s just say that he wasn’t enthusiastic about the idea.

    However, I have found that a couple of my masks, when adjusted ju-u-u-ust right, don’t cause me to look like I need a foghorn.

    1. Jen

      Don’t know if you’ve tried the 3M Aura, but I just did and whoa! Life changing! The nose bridge bit has foam as well as metal sealing that sucker tight. Was in the supermarket with it the other day and had a moment where I was like, am I actually wearing a mask? The don’t fit every face shape but man, if they fit yours, it’s night and day.

    2. petal

      Slim, I second Jen’s suggestion. Once I started wearing one, no more fogging glasses. They’re great. And I can wear one all day at work and it’s not torture.

  6. Grumpy Engineer

    Our tests show the sprays contain up to 20.7 milligrams of PFAS per milliliter of solution, which is a pretty high concentration.

    One milliliter of a water-based solution weighs 1 gram, or 1000 milligrams. 20.7 milligrams of PFAS per milliliter of solution is more than 2% by weight. The EPA limit for PFAS in food is about 20 ppt (parts per trillion). I realize that people don’t explicitly eat anti-fogging spray, but a 2% concentration of PFAS seems awfully high. A billion times what we’d tolerate in food. If even mere millionth of what you spray on your glasses ends up in your eyeballs, it’s a thousand times too much.

  7. Dave in Austin

    So if you go to the company’s annual meeting and spray the stuff on everyone…

    I clean my glasses with 1 drop of Dawn in a spray bottle of water; excellent surfactant and it seems to help with fogging I think.

    Any idea what the antifogging mechanism is?

  8. Wukchumni

    Smith no-fog cloth will set you back a few bucks and last for years. I used one of my ski goggles today that is probably 10 years old.

  9. Michael

    My solution to the fogging problem is to tape the mask to the nose using easy to remove medical adhesive tape. This also reduces airflow and increases the security of the mask.

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