What are PFAS?
As mentioned above, PFAS are man-made fluorinated compounds found in many everyday products. Their widespread use is due to their ability to repel water, heat, stains, and oil on many surfaces.2 The concern with these materials is that they decompose very slowly, posing significant impacts to the environment and individual health.
PFAS are made up of carbon and fluorine atoms that form very strong bonds that give them hydrophobic and oleophobic properties. The number of carbon atoms present determines whether a PFAS is short- or long-chain.3 The longer the carbon chain, the more likely the PFAS will accumulate in the environment. Short-chain PFAS persist for as long as long-chain PFAS, but can move more easily in plants, animals, bacteria, soil and water. In contrast to long-chain, short-chain PFAS are more likely to be repelled by water and therefore more difficult to remove from large bodies of water.3 There are more than 4,730 PFAS, and their half-lives are unknown but are estimated to last more than 1,000 years in soil and more than 40 years in water.4 We're beginning to understand why these substances are called “forever chemicals.”
Exposure to PFAS has been linked to increased risk of cancer, asthma, altered immune responses, thyroid disease, liver function, kidney damage, and altered pregnancy outcomes.3 A systematic review and meta-analysis evaluating the association between PFAS and human reproductive hormones concluded that PFAS affect reproductive hormones by regulating gene expression.5 After analysing the results of various studies, they found a statistically significant association between two subgroups of PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), and testosterone levels in men. There was also a statistically significant correlation between another subgroup of PFAS, perfluorohexane sulfonic acid (PFHxS), and estradiol levels in women.5
PFAS are found in many products, but humans are most commonly exposed to PFAS through food, contaminated water, inhalation of dust and airborne particles, and absorption through the skin.3 Most PFAS are not metabolized and are typically eliminated through urine, excretion, menstruation, breastfeeding, and the placenta.
According to the National Health and Nutrition Examination Survey (NHANES), blood PFAS concentrations have been steadily declining since 1999 as the Environmental Protection Agency (EPA) has regulated manufacturers to reduce PFAS emissions.6 However, careful efforts must continue to be made to reduce these and other non-biodegradable chemicals, especially in oral care products.
PFAS in Dentistry
These “forever chemicals” may be in products you never thought about. Most notably, PFAS are found in some dental floss, along with nylon and polyester, which allow these dental floss products to slide between your teeth.7 Interestingly, federal law does not require companies to be fully transparent about the ingredients and materials used in their floss, which can make it difficult for clinicians and patients to determine which product is best for them.7
One study evaluated the potential impact of PFAS from dental products left on the teeth, such as night guards and whitening trays, on personal health and the environment. Measurements of several PFAS found trace amounts in night guards, similar to concentrations found in dental floss and tape. The study investigated the potential for PFAS leaching from the use of these products and the environmental impacts if disposed of in landfills.8 Although daily use of these products contains far less PFAS than is found in food, soil, and drinking water, these products still contain significant amounts of PFAS, and dental manufacturers are looking at ways to develop products that are free of these substances.
Another study conducted in 2022 evaluated 39 different types of floss for PFAS and found that one-third of the samples contained the chemicals, with levels ranging from 11 ppm to 248,900 ppm.9 Although there is increasing awareness of these substances and their impact on the environment and individual health, there appears to be very little research being done at present.
Considering PFAS reduction and biodegradability options
The dental professional's role in the effort to eliminate the use of products containing PFAS depends on the preferences and beliefs of the clinician. Patients may have been using certain products that may contain PFAS for years and are not willing to change. It is important to raise patient awareness about the impact these ingredients can have over time on the environment and overall health. Empowering patients to make informed decisions about not only the products they are using, but also where their food comes from and what's in their water are all ways we can work harder to eliminate the use of PFAS.
Many companies are also looking for ways to eliminate waste in their products. In dental care, products such as disposable large volume aspirators and air water syringe tips made from recycled plastic, biodegradable face masks, sugarcane saliva aspirators, and biodegradable gauze are options that help reduce carbon footprints. In personal oral hygiene, products such as bamboo toothbrushes, silk floss, and toothpaste tablets serve as alternatives to reduce plastic and waste.
While these options may not be suitable for every patient or practitioner, it is important for those looking to reduce PFAS intake and excess waste from dental offices to be aware of product alternatives.
Small steps through patient education
The food we eat, the water we drink, and the products we use contain widespread substances that take years to biodegrade. Recent studies point to these “forever chemicals” as contributing to a variety of health conditions. This is driving product manufacturers to consider alternatives to past practices so that healthier options can be prioritized for the environment and personal health. As oral care providers, we can take small steps toward reducing our carbon footprint by educating our patients about zero-waste oral care products and incorporating biodegradable options into our dental care.
References
- Weiss K. New Colorado law bans sales of dental floss, clothing, other household products containing toxic “forever chemicals.” CBS News. Updated June 24, 2024. Accessed July 1, 2024. https://www.cbsnews.com/colorado/news/new-colorado-law-ban-sales-dental-floss-clothes-household-products-containing-toxic-forever-chemicals/
- ChemSec SIN List. Accessed July 1, 2024. https://sinlist.chemsec.org/chemical-groups/fluorinated-compounds/
- India-Aldana S, Yao M, Midya V, et al. PFAS exposure and the human metabolome: a systematic review of epidemiological studies. Representative of Curr Pollut. 2023;9(3):510-568. doi:1007/s40726-023-00269-4
- PFAS “Forever Chemicals”: ​​The Invisible Threat of Persistent Chemicals. CHEM Trust. Accessed July 3, 2024. https://chemtrust.org/pfas/
- Li L, Guo Y, Ma S, Wen H, Li Y, Qiao J. Associations between exposure to perfluoroalkyl compounds (PFAS) and human reproductive hormones: a systematic review and meta-analysis. Environmental Studies 2024;241:117553. doi:1016/j.envres.2023.117553
- PFAS Information for Clinicians – Agency for Toxic Substances and Disease Registry. Reviewed January 18, 2024. Accessed July 2, 2024. https://www.atsdr.cdc.gov/pfas/resources/pfas-information-for-clinicians.html
- Cook S. How to choose dental floss that is free of PFAS and other harmful chemicals. Consumer ReportsApril 10, 2024. Updated May 15, 2024. Accessed July 2, 2024. https://www.consumerreports.org/toxic-chemicals-substances/dental-floss-without-pfas-and-other-harmful-chemicals-a9722832754/
- Massarsky A, Parker JA, Gloekler L, et al. “Assessing the potential human and ecological effects of PFAS in leave-on dental products.” Toxic Industrial Health. 2024;40(3):91-103. doi:1177/07482337231224990
- Fisher D. Testing has found that some dental floss contains high amounts of PFAS. Environmental Health NewsSeptember 14, 2022. Accessed July 8, 2024. https://www.ehn.org/pfas-floss-2658203711/better-flossing-products