PFAS in Dental Floss: What’s Really in That Little String?
If you told me a few years ago that I’d be reading lab reports about my dental floss, I would have laughed into my coffee. But here we are, and honestly, I’m glad we’re talking about it. Some popular dental flosses contain PFAS, the same “forever chemicals” linked to hormone disruption, immune issues, and more, and since floss goes directly in your mouth, that’s worth a closer look. The good news: there are genuinely great PFAS-free options out there, and switching is one of the easiest swaps you can make.
What’s Inside
- What Are PFAS and Why Are They in Floss?
- Health Risks: Why Your Mouth Is a Direct Route
- How to Identify PFAS-Free Floss
- Our Top PFAS-Free Picks
What Are PFAS and Why Are They in Floss?
PFAS stands for per- and polyfluoroalkyl substances, a family of thousands of synthetic chemicals built around an extremely strong carbon-fluorine bond. That bond is basically indestructible in nature, which is why these chemicals earned the nickname “forever chemicals.” They don’t break down in the environment, and they don’t break down easily in your body either.
In dental floss, the most common PFAS culprit is PTFE, better known as Teflon. Manufacturers coat floss with it because it creates a slick, smooth glide between teeth. It’s the same chemistry that keeps eggs from sticking to your frying pan, applied to a tiny string you run through your gums. Makes sense from a product-design standpoint, but less so from a health standpoint.
The scale of the problem is real. Mamavation tested 39 dental floss products at an EPA-certified laboratory and found that 13 out of 39 (that’s 33%) showed indications of PFAS. Organic fluorine levels, which serve as a PFAS marker, ranged from 11 parts per million all the way up to 248,900 ppm. Oral-B Glide came in with the highest reading Mamavation has ever found in any consumer product study. Four products exceeded 70,000 ppm: Oral-B Glide Pro-Health Deep Clean, Up & Up (Target) Smooth Slide, Colgate Total Mint Waxed, and Solimo (Amazon) Extra Comfort.
Procter & Gamble, the maker of Oral-B Glide, has confirmed it uses PTFE in its floss for “unique sliding performance and silkiness,” while stating it does not contain PFOS or PFOA. Here’s where it gets stickier, though: some companies have switched from PFOA to a substitute called GenX as a processing aid for manufacturing PTFE. GenX is raising serious red flags among researchers due to its toxicity at low concentrations and its ability to bioaccumulate in living tissue.
The safer alternatives are made with materials that simply don’t require PFAS: nylon, polyethylene, ultra-high-molecular-weight polyethylene (UHMWPE), silk, and bamboo fiber. None of these would be expected to contain PFAS at all.
Health Risks: Why Your Mouth Is a Direct Route
Here’s the part that made me put down my Oral-B Glide for good. When you floss, you often cause tiny amounts of bleeding in your gums. That means any chemicals on the floss have a fairly direct path to your bloodstream, skipping the usual filtering your gut provides.
Research backs this up. A study by Silent Spring Institute, the first of its kind, found that women who regularly used Oral-B Glide floss had higher blood levels of a PFAS called perfluorohexane sulfonic acid (PFHxS) compared to women who didn’t use that type of floss. Lead author Katie Boronow called it “the first study to show that using dental floss containing PFAS is associated with a higher body burden of these toxic chemicals.”
To be fair, scientists note that dental floss is a minor contributor to overall PFAS exposure for most people, and only a small percentage of the population is likely to exceed health thresholds from floss alone. The science is genuinely nuanced here.
That said, PFAS exposure in general has been linked to a pretty concerning list of health effects: altered immune and thyroid function, liver disease, disrupted insulin regulation, adverse reproductive outcomes including low infant birth weights, and increased risk of kidney and testicular cancer. Because PFAS are endocrine disruptors, meaning they interfere with hormone signaling, children can be especially vulnerable, with documented links to learning, behavioral, and growth problems.
The American Dental Association currently sees no cause for alarm from floss specifically and still encourages daily interdental cleaning. But as a mom who also happens to know a thing or two about chemistry, I’d rather just swap to a PFAS-free floss and not think about it again.
How to Identify PFAS-Free Floss
There’s no single universal certification for PFAS-free dental floss the way OEKO-TEX covers textiles, but here are the signals worth looking for:
| Signal | What It Means |
|---|---|
| “PTFE-free” or “PFAS-free” label | Brand self-declares; look for third-party backup |
| MADE SAFE Certified | Independent certification; Consumer Reports partnered with MADE SAFE to screen 17 flosses |
| Mamavation/EPA-lab tested | Third-party organic fluorine testing confirms low or no PFAS marker |
| Natural material (silk, bamboo, nylon, UHMWPE) | These materials are not expected to contain PFAS |
| ADA Accepted | Confirms safety and efficacy but does NOT specifically test for PFAS |
When in doubt, check the ingredient list for PTFE or “polytetrafluoroethylene,” and look for brands that have been independently tested or certified.
Our Top PFAS-Free Picks
These are the flosses I actually feel good about recommending, because they’re made from materials that don’t require PFAS coatings to do their job well.
Made from natural silk (or a vegan alternative), this floss sidesteps PFAS entirely by using a material that has never needed a synthetic coating to glide smoothly. The refillable glass dispenser is a bonus for anyone trying to reduce plastic waste at the same time.
Coated in plant-based wax and essential oils rather than synthetic chemicals, this organic bamboo-fiber floss is a straightforward PFAS-free choice for families who prefer natural personal care products. The refillable glass jar packaging is a nice touch too.
Cocofloss uses a woven polyester construction, no PTFE required, and its textured surface is actually designed to grab more plaque than a slick monofilament floss. This one is great for anyone who finds waxed floss unsatisfying.
RADIUS Vegan Xylitol Soft Floss - Mint, Non-Toxic, PFAS-Free Oral Care
ADA Accepted and vegan, this RADIUS floss relies on xylitol and plant-based wax rather than synthetic coatings. It’s a solid everyday pick for families who want third-party credibility alongside the PFAS-free claim.
Explicitly labeled as free from PFAS, PTFE, and Teflon, Dr. Tung’s stretchy, textured floss has a loyal following for good reason. It expands to fit the space between your teeth, making it especially comfortable for those with sensitive gums.
Swapping your dental floss might be the smallest change you make this week, but it’s one of the most direct ones, because this product literally touches your bloodstream. You don’t have to overhaul your whole bathroom cabinet overnight. Start with the floss, feel good about it, and keep going from there. If you want to keep exploring, the PFAS Free Life database is a searchable, regularly updated resource where you can check everything from floss to cookware to food packaging. We’re building a less “forever chemical” kind of life, one small swap at a time, and I’m so glad you’re here for it.