How do I know if my floss has PFAS?

Today, we’re talking about a question I’ve been getting a lot lately:

How do I know if my floss has PFAS in it?

Here’s what I’d recommend:

1. Turn the box over and look for the fiber. Silk or nylon means the floss itself isn’t Teflon. (“Silky” is not the same thing as silk.) The fiber is the PFAS question. What’s on the floss is a separate one—that’s #3, below.
2. PTFE, polytetrafluoroethylene, or fluoropolymer? Put it back.
3. A flat slick tape sold on how well it glides, with nothing telling you where the glide comes from? Put it back.

Women who flossed with Glide had more PFAS in their blood

Researchers measured PFAS in the blood of 178 women and asked about their habits. The women who flossed with Oral-B Glide had higher levels of some PFAS compounds than the women who didn’t. Then they tested the floss and found fluorine in it.

Floss companies don’t have to tell you what’s in the box, and most don’t

There’s no federal law requiring a floss company to list what its floss is made of. So when you do see PTFE, polytetrafluoroethylene or fluoropolymer on a package, that’s definitive and you’re done. But most packages say nothing at all, and nothing isn’t an answer. That’s why the next two go by the look and the language instead of the label.

The shape of the floss tells you more than the box does

Slick solid strip → probably Teflon → go read the ingredients/materials. 

Soft and fuzzy → not Teflon.

Floss is made one of two ways. Either it’s spun from a bunch of tiny threads twisted together, like yarn or sewing thread—that’s nylon or silk. Or it’s one solid piece of plastic, like a narrow strip cut off a roll of packing tape. The solid-strip kind is the one to be suspicious of, because the plastic manufacturers use to make it has almost always been Teflon.

How to tell them apart in your hand: the thread-y kind feels soft and slightly fuzzy, and it frays into fibers if you tug at it. The solid-strip kind feels slick and plasticky, and it can’t fray, because there are no fibers in it. It’s one piece.

Something has to make floss slippery

Floss has to get through a tight contact without shredding, and something has to make that happen. The slickest tapes usually get it from PTFE. But this is not a hard-and-fast rule, as wax and propolis can also make nylon or silk floss glide.

Oral-B pulled the PTFE out of Glide

To be fair, Oral-B has announced that Glide is no longer made with PTFE, probably due to pushback they’ve gotten from informed consumers, like Ask the Dentist readers, or at the very least, thanks to new state-level laws in Minnesota, Colorado, and Maine. The company now calls it a “micro-textured fiber.” I used to buy Glide in bulk at Costco. I switched more than fifteen years ago, but I’m not going back. They haven’t said what replaced the PTFE, nobody outside the company has published testing on the new version, and old stock doesn’t leave shelves the day a formula changes. 

What I use

I use Fygg Propolis Silk Floss. Fygg is the company my daughter and I started, so yes, I’m biased.

I wanted to make a floss for a long time. I kept not doing it, because excellent silk flosses already exist. Radius (the one with no essential oils) is the brand I’ve recommended for years. If I couldn’t make something better, there was no point.

What I wanted was a floss whose coating did something for your mouth, not just something to make it slide. I think propolis can be that coating. It took a long time to find a maker that could apply it to silk, and I finally found one in Italy.

So Fygg floss has two ingredients: Seri.co-certified silk and propolis, made in Italy 🇮🇹with the highest standards. 

If Fygg isn’t available where you live (check here for outside the US: fygg.com/international), I recommend Radius Natural Biodegradable Silk, the unscented one without essential oils.

Whatever you take from this, don’t let it be “floss less”

Your mouth is not a sealed compartment, and the bacteria that drive gum disease do not stay in it—they’ve been found in the brains of people who died with Alzheimer’s, and in colorectal tumors. Flossing is the easiest, simplest, cheapest intervention we have to protect against this.

Dr. B

P.S. If you’re wondering what my oral care routine looks like, here it is: This toothpaste, this mouthwash alternative, this tongue scraper, this throat spray, these enzymes with meals, this Vitamin D3/K2, this CoQ10, this magnesium, this zinc, and these electrolytes.