What consumers should know about pfas and dental floss

Concerns about dental floss have drawn fresh attention to a broader question that has been hanging over many consumer products for years: when a product is meant to help your health, what happens if it also contains chemicals that may be harmful? Public reporting has focused on floss brands that may use fluorinated materials, while researchers have looked for signs that certain flossing habits may be linked with higher levels of some PFAS in blood.

The short version is that the science does not show that flossing itself is dangerous. It does show that some floss products have been part of the wider PFAS story, and that the evidence base is still too limited to say exactly how much exposure comes from floss compared with food, water, dust, or other consumer items. https://www.atsdr.cdc.gov/HAC/pha/willowgrove/Evaluation_of_PFAS_in_Drinking_Water_FS-508.pdf

What happened

PFAS, short for per- and polyfluoroalkyl substances, are a large class of manufactured chemicals used for water, stain, and grease resistance. They have appeared in a wide range of products over time, including firefighting foam, nonstick cookware, stain-resistant fabrics, and some personal care and consumer goods. AP has reported on the way these chemicals have shown up across everyday products in the U.S., underscoring how difficult it can be to trace a single exposure source. https://apnews.com/article/f99eddb12d52583cf763613001e2eb8c

Dental floss became part of that conversation after studies suggested that certain types of floss may contain PFAS or PFAS-related materials. One study in African American and non-Hispanic white women reported that use of PTFE-based dental floss was implicated as a possible exposure pathway, but the authors also said more data were needed to confirm the finding and to show how the chemicals might move from floss into the body. https://pubmed.ncbi.nlm.nih.gov/30622332/

Why it matters

The concern is not just that PFAS are present somewhere in the environment. It is that these chemicals are persistent, widely detected, and associated in human research with a range of health concerns. The CDC says evidence links PFAS exposure with some health effects, while also noting that findings are inconsistent for other outcomes and that more research is needed. https://www.atsdr.cdc.gov/pfas/about/health-effects.html

That does not mean a particular consumer product automatically causes disease. It does mean that, when a product is used routinely and comes into direct contact with the mouth, people reasonably want to know whether it adds to their exposure burden. The question is especially important because PFAS are already so widespread that most people are exposed through more than one route. https://www.atsdr.cdc.gov/media/pdfs/2025/07/MSS-Community-PFAS-Blood-Levels-Fact-Sheet-508.pdf

What the evidence actually shows

The strongest evidence tied specifically to floss is observational, not experimental. In the 2019 study often cited in this area, flossing with Oral-B Glide was associated with higher PFHxS levels in blood among some participants. Another more recent cross-sectional study of U.S. adults found that dental floss users had higher serum PFOA than non-users, but lower levels of some other PFAS and a lower overall PFAS burden score. Because these studies are cross-sectional, they can identify associations but cannot prove that floss caused the blood-level differences. https://pubmed.ncbi.nlm.nih.gov/30622332/

A major review prepared for the National Academies concluded that it is still not clear whether dental floss is an important route of PFAS exposure. The review pointed to small sample sizes, timing problems between blood collection and questionnaire data, and mostly nonsignificant results in the floss literature. In other words, the signal is suggestive, but not definitive. https://www.ncbi.nlm.nih.gov/books/NBK584698/?report=reader

That uncertainty matters. If a study finds a higher level of one PFAS in people who reported using one brand of floss, that does not automatically mean all floss poses the same risk, or that the effect would be meaningful compared with other sources such as drinking water or food packaging. It also does not tell us how much exposure, if any, comes from the flossing action itself versus the product’s materials or manufacturing process. https://pubmed.ncbi.nlm.nih.gov/30622332/

What remains uncertain

Several questions remain open. Researchers have not settled how much PFAS from floss can migrate into saliva or be absorbed through oral tissues. They also have not established whether changing floss types measurably lowers blood levels in a way that matters clinically. The available studies are useful for raising a flag, but they are not enough to define a direct health risk for any one person. https://pmc.ncbi.nlm.nih.gov/articles/PMC6380931/

Another uncertainty is the broader product landscape. Because PFAS are used across many industries, consumer exposures can be mixed together. That makes it difficult to isolate the effect of a single product, especially when people also encounter PFAS through household dust, food-related materials, treated fabrics, cosmetics, or contaminated water in some communities. https://apnews.com/article/f99eddb12d52583cf763613001e2eb8c

Practical context for readers

For most people, the biggest takeaway is balance: flossing remains an important part of oral hygiene, but it is reasonable to ask what the floss is made of. A randomized clinical trial found that flossing as part of daily oral care improved gingival inflammation compared with brushing alone, supporting the idea that interdental cleaning can matter for gum health. https://pubmed.ncbi.nlm.nih.gov/35451656/

If you are shopping for floss and want to reduce the chance of PFAS exposure, look for product labeling that clearly indicates PFAS-free or fluorine-free materials, and consider asking a dentist or hygienist what options are available. Because labeling practices vary, consumers may need to compare brands rather than assume that all floss is made the same way. That said, the available evidence does not justify skipping flossing altogether if it is part of your oral care routine. https://www.ncbi.nlm.nih.gov/books/NBK584698/?report=reader

People worried about PFAS exposure more broadly may also want to pay attention to more established sources, such as drinking water in affected communities, food packaging, and household products. The CDC notes that PFAS research is still evolving and that the health picture depends on the chemical, the exposure level, and the route of exposure. https://www.atsdr.cdc.gov/pfas/about/health-effects.html

The bottom line

Dental floss has become part of the PFAS discussion because some products appear to contain fluorinated materials and because a few studies have found associations with certain blood PFAS levels. But the evidence is not strong enough to say floss is a major exposure source, and it does not show that flossing should stop. For now, the most accurate message is that consumers can ask questions, choose products with simpler ingredient profiles when possible, and still keep flossing as part of routine oral care. https://www.ncbi.nlm.nih.gov/books/NBK584698/?report=reader

If you have specific questions about PFAS exposure from a product you use often, a clinician or dentist can help you think through the relative risks and benefits in the context of your overall health routine.