Despite the fact that dentists recommend kids start flossing when they have two teeth that touch (usually age two or three), most people need a lot of convincing. Let’s be real — flossing can be annoying, and sometimes it just feels like one more activity separating your head from hitting the pillow at bed time. While our reluctance to floss shows in the numbers (the global toothpaste market was almost 19 times bigger than the dental floss market in 2020), we still use a ton of it. The US alone goes through about 3 million miles of floss per year — that’s equivalent to the mileage of more than 1,075 one-way road trips between New York and LA. So, what environmental damage does all of this mileage of dental floss bring? Let’s dig into the materials used to create this stuff and consider what happens when we’re done using it.

What to be wise on:

Flossing helps lift and release food that’s stuck between your teeth. It reduces the amount of bacteria in your mouth and helps to prevent plaque build-up, which can contribute to cavities and gum disease. 

Dental floss is made up of two main components that help get the job done: string and a coating that allows it to slide easily and comfortably between tight spaces in your teeth. The most environmentally problematic aspects of dental floss result from the materials used in these string-and-coating combos.

A FEW TAKEAWAYS:    

Steer clear of nylon. It sticks around forever (well, not forever, but you get the picture), and could be coated in PFAS (which actually does last forever). And remember not to throw your floss in the toilet! 

TLDR: Just tell me what to look for.

Here are some of our favorite floss options based on price-point, materials used (read on below for why this is important), and customer reviews. 

What we love

This floss is more cost effective than some of our other preferred options, and it comes in a reusable bamboo container that eliminates the need for all of that plastic packaging. 81% of customers love it for its slightly gritty texture that cleans their teeth well and doesn’t irritate their gums.

What could be better: 

Some customers say that this floss frays and breaks too easily.

What we love:

This floss is made just of silk thread coated in candelilla wax and mint. Customers love the fact that it comes with a stainless steel container that won’t shatter if dropped and they say it doesn’t get stuck in their teeth.

What could be better: 

This product is made in China, meaning a higher likelihood of workers’ rights violations. Some customers also say this floss is too fragile and breaks easily.

What we love:

This floss comes in an endlessly reusable glass container that helps you eliminate all of those traditional, hard-to-recycle plastic floss containers. This floss has super-simple components: silk thread coated in candelilla wax and mint oil. 66% of customers love this floss, saying that it is fine enough to fit into tight spaces and doesn’t fray. 

What could be better: 

Some users say that this floss breaks too easily and sometimes gets stuck in the container.

What we love:

This floss is made of just two materials: silk thread and a coating of candelilla wax. 70% of users love it for the way it glides easily between teeth without breaking, and for its lightweight paper container. Both the paper container and the floss itself are 100% backyard compostable. Just make sure to remove the metal floss cutter before throwing the packaging into your compost bin. 

What could be better: 

Some customers say this floss is too thick for fine crevices between teeth.

THE FACTORS TO CONSIDER:

Materials

The Stringy Stuff

Nylon

Conventional floss is made of nylon, a synthetic material derived from crude oil (aka fossil fuels). Nylon takes more than 80 years to decompose and when it’s being produced it emits nitrous oxide, a greenhouse gas that is 300 times more potent than carbon dioxide. That’s a no from us. And yet, x% of dental flosses we’ve rated contain the stuff. 

Bamboo

Bamboo fiber has cropped up as an alternative to nylon, which is great because it grows super-fast and its cultivation can be gentle on land and soil. If you purchase bamboo floss, though, be sure it is coated with only a biodegradable vegetable-based wax (like candelilla wax) and doesn’t contain any polylactic acid (PLA). 

PLA

Polylactic acid (aka PLA) is a bioplastic made out of cornstarch...so it must break down, right? Not so fast. Although PLA will decompose faster than traditional plastic, it requires specific conditions to degrade. We’re aware that this runs counter to the mainstream messaging on compostable plastic. It feels like when something is compostable, you should be able to basically leave it anywhere and have it magically disappear. Poof! In reality, PLA must be properly composted in the right type of facility — a waste stream that most people do not have access to on a daily basis — in order to fully break down. For that reason, it’s a bit inaccessible, so not our fave floss material. 

Silk

Silk farms exist mostly in hot climates like Thailand, but must be kept at 65 degrees Fahrenheit for optimal cocoon production, which means they end up using an immense amount of energy for air conditioning. The humidity control and steaming systems required in production are also energy suckers. Every geographic region has a unique “energy mix”, which is the combination of primary energy sources used in meeting the region’s needs. A given region’s energy mix can come from a combination of fossil fuels (think oil and coal), nuclear energy, and renewable energy (think wind and solar). Due to the location of most silk factories, the energy required for silk production likely comes from coal-fueled plants, which release more greenhouse gases per unit of energy generated than any other source. Gross. There are ethical issues with this material too; PETA reports that about 3,000 silkworms must be killed to make one pound of silk. Worms are people too! 

Despite silk’s flaws, we’d choose it over nylon floss most days. Silk floss is typically coated in a vegetable-based wax (like candelilla wax) rather than PFAS, and is biodegradable, so when it ends up in the ocean (which floss often does — more on that later), it will more likely break down over time. 

The Coatings

PFAS

PFAS are synthetic, manufactured chemicals that are very stable in the environment and thus take a long time to break down (which is why they’re known as “forever chemicals”). They have some very useful properties, including their ability to make things waterproof and slick (i.e. perfect for floss), and are often found in non-stick cookware, fast-food wrappers, and... dental floss. PFAS allow dental floss to easily slide between your teeth, but they also happen to be toxic chemicals linked to heart disease and cancer. (Read our in-house scientist’s recent roundup on all things PFAS for more information.) And yet… 

Candelilla Wax

Candelilla wax is a vegetable wax derived from the leaves of the Candelilla plant, which grows in northern Mexico and the southwestern U.S. While the wax itself is a great alternative to artificial coating like PFAS, the manufacturing process required to produce the wax can be dangerous. To extract the wax, Candelilla plants are placed in iron cauldrons with a mixture of water and sulfuric acid, which can cause burns, injury, and blindness. The fact that many people who work with candelilla wax do not receive proper personal protective equipment before handling this chemical makes it all the more dangerous. 

Packaging

When you think of floss containers, you probably think of those pesky little plastic dispensers with a metal cutter, right? Unfortunately, those plastic containers are pervasive and pretty hard to recycle due to the fact that they’re rarely marked with recycling info and almost always contain those tiny metal pieces. For this reason, we’re really into the newer, increasingly popular, and endlessly reusable glass floss containers. If you need a disposable packaging option and have the ability to swing the extra cost, opt for a paper package like what’s offered by Package Free. 

End of life

Floss is disposable by design — we’re supposed to use it once and then toss it. Because a lot of floss is being used (and used only once), a lot of waste… and fatbergs… are being created. 

Fatbergs are a combination of non-biodegradable solids (like floss) and fat that find their way down our pipes. These solids and fats combine into giant masses that block sewers and can wreak havoc on sewage systems. Fatbergs ultimately clog sewers and destroy infrastructure, and their removal requires a lot of resources. In New York in 2018, the removal of fatbergs cost more than $18 million. 

The key takeaway? Never flush your floss down the toilet (even if it’s made of biodegradable materials like silk and bamboo). While floss and other items can accidentally find their way into our pipes and have detrimental effects on our systems, intentionally flushing floss guarantees this. To dispose of floss properly, put it directly into the trash — floss cannot be recycled. And as with everything, be conscious of how much floss you’re using. Maybe challenge yourself to get the job done with a fraction of the floss you normally use. 

What About the Non-Stringy Stuff?

We’ve dedicated most of this Wise Guide to traditional floss, because that’s what most people use. However, there are a few other products that serve the same function. 

Have you ever used those handy-dandy floss picks? While they may be convenient, they’re not so great for the environment, even compared to the nylon floss stuff. We did a little back-of-the-envelope math on the environmental impacts of the plastic and nylon used over 150 flosses, for both traditional floss packages and floss picks. We looked at the 18 most important impacts that a product can have on the environment. Our results showed that materials used in floss picks were significantly worse for the environment in 16 of the 18 categories, from water consumption to land use. For example, when considering toxicity to freshwater creatures, the environmental impact of floss picks was 10 times higher than that of normal floss. On top of that, the materials used to make 150 floss picks produced 3 times more greenhouse gases than a normal 55-yard container of floss. Ditch the picks! 

Other (more promising) alternatives include oral irrigators, or water flossers, which use water to clean between your teeth. These puppies can help you eliminate all of those unwanted miles of floss, but that doesn’t mean that all waste is eliminated — keep in mind that instead, they’re using water. From a price-point perspective, water flossers can be pretty expensive compared to traditional floss (though they do last longer). WaterPik, a fan fave, is around $70. With ‘normal’ (nylon) floss clocking in at around $2.50 per container, we would need to go through about 28 of those containers to get to the cost of a water flosser — and who really flosses that often. But WaterPik does come with a three-year warranty, meaning it’s supposed to last about that long (and could very well last longer). If you floss twice a day, 365 days a year, and use between 12 and 18 inches of floss each time, it would take you between 2.5 and 3.8 years to use that much floss. Seems like the WaterPik may be a good deal, after all.