Toxic Chemical Discovered in Dental Floss

Geez-o-pete, when researchers say toxic chemicals like PFAS are ubiquitous, that is not an overstatement. A recent scientific research study has revealed that the toxic chemical compound PFAS has been discovered in some brands of dental floss. (PFAS is a flame retardant and grease resistant industrial chemical compound also found in processed food packaging, stain-resistant furniture and carpeting and nonstick cookware.)  People who use certain types of dental floss may be exposing themselves to this toxic chemical.


Study methods

The study, led by the Silent Spring Institute and the Public Health Institute in Berkeley, California, tested the blood of 178 women to look for evidence of PFAS.

Scientists used multiple regression analysis to investigate associations between six self-reported behaviors hypothesized to influence PFAS exposure and serum concentrations of six PFAS chemicals in 178 middle-aged women enrolled in the Child Health and Development Studies, about half of whom are African American. Blood samples were collected in 2010–2013, and participants were interviewed about behavior in 2015–2016.



Results showed that African American women had lower levels of perfluorooctanoic acid (PFOA) and perfluorohexanesulfonic acid (PFHxS) compared with non-Hispanic white women. In African Americans, but not others, frequent consumption of prepared food in coated cardboard containers was associated with higher levels of four PFASs.

Flossing with Oral-B Glide, having stain-resistant carpet or furniture, and living in a city served by a PFAS-contaminated water supply were also associated with higher levels of some PFASs.


Additional testing

The second part of the study tested different floss brands for a “marker” of PFAS chemicals.  The researchers tested 18 floss products for the presence of fluorine, a “marker” for PFAS chemicals. Some of these products were branded as Oral-B Glide while others had package labels that said “compare to Oral-B Glide,” according to the study.


Results: Dental floss testing positive for fluorine, the marker for PFAS chemicals

In total, six products tested positive for fluorine. They were: CVS Health EaseBetween SuperSlip Dental Floss Waxed, Oral-B Glide Pro-Health Mint and Glide Pro-Health Original, Crest Glide Deep Clean Cool Mint Floss, Safeway Signature Care Mint Waxed Comfort Floss, and Colgate Total Dental Floss Mint.


The health risks

PFAS are found in the blood of people across the world, according to the Centers for Disease Control and Prevention (CDC). Some scientific studies have linked exposure to these chemicals with health problems.

Exposure to the long-chain PFASs perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) has been linked to kidney and testicular cancer, decreased semen quality, and ulcerative colitis in adults [3,4,5], and to thyroid disease, immune response, and lowered sex and growth hormones in children.



See other studies we have posted on PFOAs/PFAS/PFOS here, here, here, here, here, here and here.


Solutions: Consumers can choose a dental floss that may be safer such as those non-mainstream brands offered at health food stores.  But given these latest study findings perhaps the best alternative is to dump the string all together and switch over to the new water flossing devices.  A water flosser, is an oral pulsating irrigator–a device that aims a pulsating stream of water between your teeth and at the gum-line.  (Some devices offer multiple settings for the force of streams and a gum massage option.) A water flosser can help remove food particles from between your teeth and at the gum-line and might help reduce bleeding and gum disease. Of course you should consult with your dentist about whether this is an appropriate option for you.


Journal reference: Boronow, K.E., et al (2019).  Serum concentrations of PFASs and exposure-related behaviors in African American and non-Hispanic white women, Journal of Exposure Science & Environmental EpidemiologySee the study here.