dental floss

How many times has your dentist told you to floss your teeth? Lots, right? But flossing can be a drag, especially if you use the unwaxed kind. It gets stuck or shreds. That’s why waxed or slippery floss is so popular. But a new study raises questions about the chemicals used to make dental floss and other substances slippery. PFAS stands for a tongue twister: polyfluoroalkyl substances. They’re found in lots of nonstick chemicals and they are suspected of causing substantial mischief, including thyroid problems.

PFAS Are Hard to Avoid:

There are a bunch of PFASs. They’re all impossible to pronounce. Here are just a few example:

PFOA (perfluorooctanoic acid)

PFOS (perfluorooctanesulfonic acid)

PFNA (perfluorononanoic acid)

PFHxS (perfluorohexanesulfonic acid)

PTFE (polytetrafluoroethylene)

These PFASs are used in all sorts of places you might not suspect. They are found in nonstick cookware and stain-repellent sprays. Carpets and furniture may be coated with PFAS to prevent stains from sticking to the fibers. Grease-resistant packaging may also have PFAS. Think pizza boxes or paper containers that hold French fries. Most surprising to us, though, was the report that suggested there are PFASs in some dental floss products (Journal of Exposure Science & Environmental Epidemiology, online, Jan. 8, 2019).

Why Should We Care About PFAS?

The authors of the article cited above state:

“Given their extensive use and persistent nature, it is unsurprising that PFASs have been detected in water and soil, and in the bodies of almost all Americans. Exposure to the long-chain PFASs perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) has been linked to kidney and testicular cancer, decreased semen quality, and ulcerative colitis in adults, and to thyroid disease, immune response, and lowered sex and growth hormones in children.”

PFAS and Thyroid Problems:

There appears to be a link between exposure to PFASs and thyroid disease. One chemical in particular, PFOA, has been associated with both hypo and hyperthyroidism. This was the conclusion of of the C8 Science Panel (July 30, 2012).  These scientists evaluated exposure of residents in Parkersburg, WV, to PFOA.

Ask veterinarians about the epidemic of hyperthyroidism in cats. It is a mystery, but there is tantalizing research to suggest that higher levels of PFASs in the environment could be associated with increasing amounts of feline hyperthyroidism (Wang, et al, Environmental Toxicology and Chemistry, Sept. 19, 2018). Another class of chemicals, PBDEs that are used as flame retardants, may also be contributing. If you are interested, here is a fascinating article by Emily Anthes in The New York Times (May 16, 2017) titled “The Mystery of the Wasting House-Cats.”

What About Dental Floss?

The article in the Journal of Exposure Science & Environmental Epidemiology (online, Jan. 8, 2019) describes blood levels of PFASs in 178 middle-aged women.

The investigators found:

“Flossing with Oral-B Glide was associated with higher levels of PFHxS. All three Glide products that we tested contained fluorine, consistent with available information that Oral-B Glide is made with PTFE and supporting our hypothesis that Oral-B Glide is a potential exposure source for PFASs. In addition, three other flosses also tested positive for fluorine, including two of three store-brand products advertised as ‘compare to Oral-B Glide’ on the package, and one described online as ‘single strand Teflon®fiber’.”

The researchers conclude:

“While this study did not capture all the potentially important sources of PFASs, our results strengthen the evidence for exposure to PFASs from food packaging and implicate exposure from PTFE-based dental floss for the first time—a finding that warrants prompt follow-up in a future study.”

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  1. Jillie
    Charleston, S.C.
    Reply

    I’ve used the store-brand un-waxed dental TAPE for years. Tape is wider, a bit stronger, and does a more thorough job of removing food bits from between my teeth. Thanks to an article I read here on The Peoples’ Pharmacy, I now floss before I brush; my teeth feel cleaner.

  2. Harold
    San Diego
    Reply

    After having read People’s Pharmacy for nearly two years, I have become a Jain. I sit naked in a temple fasting and using a fan to prevent imbibing unseen creatures. The only thing I read are People’s Pharmacy downloads with their daily declarations of pervasive toxicity and carcinogens,

  3. Randee
    NC
    Reply

    I would appreciate some advice about how to avoid this in dental floss. Is there any product on the market that would be safer to use?

    • Denise
      Plano
      Reply

      I buy “Eco•Dent VeganFloss” at my local health food store. “100% vegan waxed with all-natural essentials oils” the label says.

    • L
      MN
      Reply

      RADIUS – Natural Biodegradable Silk Floss is coated with calendula wax. I love it.

  4. Steve
    PA
    Reply

    Just when I thought I’d guarded against every chemical that might worsen my fibromyalgia pain, we have hormone disruption by dental floss, used religiously by all of us in First World countries. Unbelievable, is nothing safe? Will sellers use anything, with known or unknown risks, to make a profit? Don’t their families use floss?

  5. john
    usa
    Reply

    While perfloro acids have been linked to health problems, polytetraluroethylene (PTFA) has not UNLESS it is heated to high temperature (ie cooking) where it can break down to release degradation products like perfloro acids or is contaminated with those compounds during manufacture. Testing the dental flossing agents for fluorine is meaningless as that test is not specific enough. Those products need to be tested for the problematic prefluoro acids – only then can we know whether there is a health issue from the presence of those compounds.

  6. Colorado
    CO
    Reply

    My dentist has me using an oral product that is supposed to build up my enamel. I believe it contains fluorine as well. And I recently changed to Oral B floss because I was sick and tired of the other brand getting caught and tearing on my numerous crowns.

  7. Diana C S
    NC
    Reply

    Eco brand of dental floshas no PFAs.. It’s also in a cardboard container instead of a plastic one.
    Order it from Vitacost.com or Swanson.

    • Emily
      Michigan
      Reply

      Thanks for letting us know about Eco dental floss. I just ordered some.

    • Lisa
      Orange County CA
      Reply

      Thank you for sharing that useful information on a safe product!

  8. Cid
    Clifton Park, NY
    Reply

    Is there anything on the packaging of dental flosses that we can look for to check if they have these harmful substances? What should we look for since floss doesn’t have the nutrition or information panel that many foods and other products have?

  9. Penelope
    FLorida
    Reply

    The flossers I use say they have “shred resistant nylon mint floss.” How do I find out if they have PFAs?

  10. Mary Jane
    NYC
    Reply

    For years, I have flossed with unwaxed, buying on-line from POH. Because it is unwaxed, it allows me to scrape the surface of the tooth, and it’s easier to floss under the gum line. The major commercial brands of unwaxed floss are inferior, in my view.

    • Dot
      Cary NC
      Reply

      Where do you get POH???

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