Most people don’t think twice about the dental floss they use. It’s just floss, right? A tiny, seemingly harmless piece of string meant to clean between your teeth. But here’s the problem—most floss on the market today is far from innocuous. Even the so-called “eco-friendly” options sold at health food stores or marketed as natural often hide a dirty secret. Many floss brands are made from synthetic materials like nylon or, even worse, Teflon. Yes, the same Teflon used in non-stick cookware and industrial plumbing tape lurks in many popular floss brands.

If that makes you think twice about what you’re putting in your mouth, it should. Every time you floss with a plastic-based product, you could be exposing yourself to toxic chemicals, microplastics, and harmful compounds that have no business near your teeth and gums.

The Hidden Dangers in Your Floss

When most people think about Teflon, they think about frying pans. That slick, non-stick surface that makes eggs slide right off the pan is made from polytetrafluoroethylene, or PTFE, a chemical that belongs to a class of compounds called per- and poly-fluoroalkyl substances (PFAS). These chemicals are known as “forever chemicals” because they don’t break down easily in the environment or in the human body. Once PFAS enter your system, they accumulate over time, affecting everything from immune function to hormone balance.

So why would Teflon be in your dental floss? Some brands coat their floss with PTFE to create a smoother glide between your teeth. It sounds harmless enough, but the problem is that these chemicals don’t just stay on the floss. Tiny particles can break off and get into your mouth as you floss. If your gums bleed—something that’s common when flossing—those particles have a direct entry point into your bloodstream.

PFAS exposure has been linked to a host of serious health problems, including hormone disruption, liver damage, immune system suppression, fertility issues, thyroid dysfunction, and even certain types of cancer. Given how often flossing is recommended—daily, according to most dentists—the idea of exposing yourself to a known toxin every single day should be enough to make you rethink what you’re using.

Microplastics in Your Mouth

Even if your floss isn’t coated in Teflon, there’s still a good chance it’s made from nylon, polyester, or another synthetic material.^[1] These materials shed microplastics, tiny plastic particles that can break off and get lodged in your gums or swallowed. If you think microplastics are just an environmental issue, think again. Scientists have now detected them in human blood, lungs, and even in placentas, raising serious concerns about long-term health consequences.

Microplastics don’t just pass through the body unnoticed. Studies suggest they can trigger inflammation, disrupt gut health, and introduce toxic compounds that interfere with normal cellular function. The idea that flossing—something done in the name of health—could be contributing to toxic buildup in your body is unsettling, to say the least.^[2]

And it’s not just affecting you. Every piece of plastic floss you throw away adds to the billions of tons of plastic waste polluting the planet. Unlike natural fibers, plastic floss does not break down. Instead, it lingers in landfills and oceans, further contributing to the environmental crisis.

Why Even “Eco-Friendly” Floss Can Be Deceptive

Walk into a health food store, and you’ll likely see floss marketed as “natural,” “eco-friendly,” or “biodegradable.” But don’t be fooled. Many of these products still contain synthetic ingredients or misleading claims that make them seem safer than they actually are. Some brands market themselves as biodegradable but only degrade under industrial composting conditions—something that most people don’t have access to.

Other brands swap out some synthetic materials but still include harmful coatings or chemical additives. Unless you’re reading ingredient labels carefully and researching what each floss is actually made of, it’s easy to assume you’re buying a safe product when you’re not.

The Best Alternatives: Natural Floss Options That Won’t Poison You

The good news is that you don’t have to stop flossing altogether—you just need to switch to a safer option. The best flosses are made from 100% silk or other natural fibers coated with beeswax or another natural wax. These flosses don’t contain synthetic chemicals, microplastics, or toxic coatings, making them a much healthier choice.

Silk floss is not only non-toxic but also fully biodegradable, meaning it won’t contribute to plastic pollution. It may feel a little different from the ultra-slick plastic floss you’re used to, but it’s just as effective at removing plaque and food particles. In fact, many people find that silk floss actually does a better job of gripping debris between the teeth.

The only downside? Natural floss is harder to find. Most major stores don’t carry it, meaning you’ll likely need to order it online. But when the trade-off is protecting your long-term health and avoiding exposure to toxic chemicals, a little extra effort is more than worth it.

Rethinking Your Dental Routine

Most people don’t consider dental care a potential source of toxic exposure, but it’s time to change that mindset. We live in a world where toxic chemicals are everywhere, from our food to our water to the air we breathe. While we can’t control every exposure, we can make conscious choices about the products we put directly into our bodies.

Flossing is an important part of oral health, but only if you’re using the right floss. Otherwise, you could be doing more harm than good. Switching to a natural floss is a simple but powerful way to reduce your daily toxic load. It’s a small habit that, over time, can make a big difference in your overall health.

And this isn’t just about you. If you have family members, friends, or anyone else you care about, share this information with them. Most people have no idea that their floss is toxic, and the more awareness we create, the more we can push for truly safe and effective products.

Flossing should be about keeping your teeth clean—not exposing yourself to harmful chemicals every time you clean between your teeth. It’s time to ditch the plastic floss and make the switch to something that actually supports your health. Your teeth, gums, and body will thank you.

References:

1. Jiao, Yan, et al. “Association Between Serum Levels of Perfluoroalkyl and Polyfluoroalkyl Substances and Dental Floss Use: The Double-Edged Sword of Dental Floss Use-A Cross-Sectional Study.” Journal of Clinical Periodontology, Jan. 2025.
2. Lee, Yongjin, et al. “Health Effects of Microplastic Exposures: Current Issues and Perspectives in South Korea.” Yonsei Medical Journal, vol. 64, no. 5, May 2023, pp. 301–08.