Toxins & Microplastics in Dental Floss
- Alayne
- Sep 21, 2025
- 5 min read
Updated: Dec 21, 2025
Not Flossy
Most big-name brands of dental floss are made from nylon (a petroleum-based synthetic polymer), polyester (a petroleum-based synthetic fiber), or PTFE (a fossil fuel derived synthetic fluoropolymer). PTFE floss typically has a flat, ribbon-like design and is touted as being stronger with the ability to 'glide' easily between teeth. A popular, more familiar brand name for PTFE is Teflon. Warnings about Teflon-coated cookware have circulated for some time, so why the radio silence when PTFE is in a product that we run through our teeth?
Nylon, polyester, and PTFE are thermoplastics. Dental floss made from thermoplastics release microplastics if they become shredded during use. Friction from flossing also causes plastic particles to shed into the mouth. The particles are collected in saliva and subsequently swallowed. Ingested microplastics and the chemicals they carry enter the bloodstream and circulate to organs like the heart, liver, spleen, and brain. Chemicals and microplastics can also gain direct access to the bloodstream if gum damage or bleeding is encountered while flossing.
Chemical coatings like PFAS, forever chemicals, add to the pile-on of toxins in dental floss. A Consumer Reports investigation conducted in 2024 discovered concerning levels of PFAS in several popular dental floss brands. Additionally, be wary of synthetic fragrances, synthetic flavorings, and waxes derived from petroleum as they contribute to the chemicals that can be absorbed during flossing.
In This Post:
Toxins & Microplastics in Dental Floss
Microcrystalline Wax
Petroleum-based synthetic wax that may contain impurities like PAHs, known carcinogens, and toxins like 1,4-dioxane, a known carcinogen that also causes numerous health conditions like reproductive harm, liver and kidney damage, and nervous system damage. Flammable. Not biodegradable. Harmful to aquatic life.
Nylon
Fossil-fuel based thermoplastic derived from petroleum. One of the most common materials used in conventional dental floss. Capable of shedding microplastics and nanoplastics as a result of the friction that is created against teeth during flossing. Made of twisted strands, it is prone to shredding which also causes microplastics to be released. Not biodegradable.
PFAS (per- and polyfluoroalkyl substances)
A large, complex group of synthetic chemicals. Referred to as forever chemicals because of their persistence in human bodies and the environment. Studies have revealed that exposure to these chemicals can lead to hormone disruption, adverse reproductive and developmental outcomes, liver damage, cardiovascular issues, weakened immune function, altered thyroid function, lipid and insulin dysregulation, and an increased risk of certain cancers. Not biodegradable.
Polyester aka PET (polyethylene terephthalate)
Synthetic fiber derived from petroleum-based chemicals. Identified as an endocrine disruptor that alters developmental and reproductive health. Polyester is a fiber version of PET, both classified thermoplastics that release microplastics and nanoplastics during flossing. Can be associated with PFAS and synthetic, petroleum-based wax (microcrystalline wax) coatings. Not biodegradable.
PP (polypropylene)
Predominantly petroleum-based thermoplastic which, like its counterparts PET and nylon, releases microplastics and nanoplastics during flossing. A by-product of refining crude oil and natural gas. Can be associated with PFAS and synthetic, petroleum-based wax (microcrystalline wax) coatings. Not biodegradable and persists for hundreds of years in the environment contributing to plastic pollution.
PTFE (polytetrafluoroethylene)
Synthetic thermoplastic fluoropolymer derived from fossil fuel. Capable of shedding microplastics during flossing. PTFE is a type of PFAS, but it is not considered as harmful due to its larger molecular size which prevents it from being as easily absorbed by the human body. Can be associated with PFAS and synthetic, petroleum-based wax (microcrystalline wax) coatings. Not biodegradable.
Worth Noting
PLA (polylactic acid)
Plant-based thermoplastic also referred to as a bioplastic. Derived from (likely GMO) corn, sugarcane, and sugar beets. Considered a safer option, but studies have shown it is only biodegradable in industrial composting facilities (at high temperatures and in specific conditions), not in soil, home compost, or landfill environments.
Toxin-free Flossing
Look for natural alternatives like silk, bamboo, or plant-based materials that are plastic-free. Select brands that come in refillable or recyclable glass jars, metal tins, or paper boxes.
To avoid PFAS in your dental floss, choose brands that clearly state they are PFAS-free or are completely natural. Switching to a PFAS-free alternative or selecting a brand that uses natural materials and is coated with natural waxes like beeswax, coconut oil, or candelilla wax will limit your exposure to this harmful group of chemicals.
Non-Toxic Alternative
I've had trouble with natural flosses shredding or breaking between tight contacts (where two teeth touch). For my latest trial, I turned to the brand that makes the toothpaste tablets that I use and adore. Allow me to introduce you... meet Canary floss. I didn't try it right away because I wasn't sure about PLA. In spite of it being made from PLA, (in this case, corn-based) with added activated charcoal, it will stay in my routine because it is super strong. This little bundle of thread is a beast. It's priced well for a natural floss, and it is the best floss I've used thus far (between natural and toxic alike). The coating is natural candelilla wax, and it's free of plastic and all of the other chemicals covered in this post. Its packaging is recyclable, and it holds 30m (98ft) of floss. PLA and charcoal are not toxins, but some studies have shown PLA doesn't break down well in the environment and charcoal may be abrasive on enamel.
I will continue to investigate silk and bamboo options and report back if and when I find a favorite. In the meantime, I'll stay friends with my little powerhouse, Canary.
Canary Dental Floss
Free of Microplastics and PFAS
Use Wyld25 for 25% off first order
Free shipping over $35
Excellent customer service and timely shipping
Orders placed via Collaboration Links attribute commissions at no expense to you.
As an Amazon Associate, I earn from qualifying purchases via Amazon links.
Canary's Non-Toxic Personal & Homecare Products:
Nano Hydroxyapatite Toothpaste Tablets
Foaming Hand Soap
Bar Soap
Clay Face Masks
Plastic-free Bamboo Toothbrushes
Alcohol-free Mouthwash
Clean Branding Hype
Be vigilant when seeking a fully natural brand. I failed to recognize the advertising smokescreen of a brand that boasted it was made from bean wax, coconut oil, and natural coconut flavor. The formula was vegan, cruelty-free, free of beeswax, mineral oil, phthalates, and parabens. It appeared to be a great option. Unfortunately, it left a greasy mouthfeel and shredded very easily leaving strands of floss wedged between teeth. I went back to investigate a little further to be sure I didn't choose a new brand made of the same materials. Come on... the floss was nylon. I prefer to offer great non-toxic options as opposed to throwing not so clean brands to the wolves, but to spare you of making the same mistake, the brand was Keeko.
Another brand that comes out of the gate marketing safe ingredients is Cocofloss. It looks trendy, it has a price tag that separates it as an elite version of floss, it's free of PTFE, PFAS, parabens, and sulfates... the catch... it's polyester (so it's plastic), and it's coated with microcrystalline wax, synthetically flavored, and packaged in plastic.
Reach Pop is a more mainstream brand that designates itself as being stylish, PFAS-free, made of 384 interlaced micro-threads, and coated with vegan wax, but what is not stated outright is that the floss is nylon with ambiguously listed bright 'colors' and 'flavors'. Okay, so it's packaged in 100% RPET recycled plastic - it's still plastic, just like the floss.
To brush up on your non-toxic dental care, visit my Canary Toothpaste Review and Toxins in Traditional Toothpaste & Natural Toothpaste posts.
Comments