What to Know About PFAS: A Story of Polyfluorinated Chemicals

What to Know About PFAS: A Story of Polyfluorinated Chemicals

Sep 9, 2021

Sep 9, 2021

What do over 5,000 known environmental contaminants of concern have in common? Well, if we're talking about the family of per- and polyfluoroalkyl substances (spoiler alert: we are), then they are all known in shorthand as PFAS. Media and scientists alike have been latching onto PFAS like that little sheet of toilet paper getting stuck to your nice new shoes. The truth is that PFAS is even more prevalent than Nicholas Cage in random movies that I said I would watch but never did (National Treasure is still a national treasure, though, IMO). I'm here to set the record straight with a 101-level intro on what PFAS are (including the two biggest and baddest of them all, PFOA, aka perfluorooctanoic acid, and PFOS, aka perfluorooctane sulfonate), where they came from, and how they impact the environment and humans. Stay tuned, because this stuff is really going to 'fluor' you.

TLDR: If you don't really want to learn the ins and outs here (which I don't recommend, but can totally appreciate), and just want to know how to avoid PFAS (hint: you can't really, but we should all try), skip to the end for some helpful tips.


PFAS are an ever-expanding collection of synthetic, manufactured chemicals with very useful properties that you may have heard referred to as 'forever chemicals'. Many PFAS and PFAS-based polymers, like Teflon, can be applied to create surfaces that reject water without absorbing it. They can also repel oils, grease, and other stains, remain unaffected by chemicals, and withstand temperatures of over 600°F without melting. How do they do it? Well, they have carbon-fluorine (C-F) bonds throughout the molecule, which are one of the strongest chemical bonds in all of chemistry - stronger than those between parent and child, human and dog, and 10-year old me and my Pokemon cards (I had a holographic Blastoise before I lost it, NBD). This super strong bond doesn't allow for most chemical reactions and it acts as a blocker to other liquids trying to pass through. That's where the'forever chemicals' designation comes from - they are very stable in the environment and, as a result, they take a long time to break down. More on that later.

The C-F chemical bond is crucial to so much of the stuff we use: PFAS and materials made out of PFAS are found in more of our everyday products than you might think. They are in non-stick cookware, stain-resistant carpeting, cosmetics, water-resistant clothes, paints, and personal care products. They've even been found as a coating on biodegradable straws (makes sense, right? You want liquid to stay in the straw until it reaches your mouth and not come oozing out the sides).

Let's interrupt our PFAS broadcast for a quick 'Greenwashing Alert'. Remember how we've said that 'biodegradable' stuff does not naturally biodegrade in landfills or the environment and most items listed as such must actually be sent to a special facility? This time, we want to expand on this crazy straw thing. So, we just said that PFAS is a 'forever chemical'. Well, a study fromChemospherein August of 2021 looked at 38 different brands of paper and plant-based straws (like the ones you grab at your favorite coffee shops) and out of those 38, 36 of them had detectable levels of PFAS, which means that even if that paper straw does degrade, that PFAS will still be left behind...forever. That's not all. Two-thirds of the PFAS present on the straw actually leached into the liquid the straw was in after a short period of time. Fortunately, most of the longer-chain PFAS stayed put... more on that later. On the contrary, out of the 5 plastic straws tested, zero PFAS were detected. This is a real conundrum and some professors at McGill University actually wrote a letter about their PFAS-related fears when Canada proposed a federal ban on single-use plastics in 2020. They noted that replacing single-use plastics with PFAS-lined paper products 'may solve one problem, [but] may create new ones.' Sounds like PFAS might be a'regrettable substitute'...


There are a lot of good reasons to use PFAS-based products and I definitely get the appeal:Eggs that don't stick to the pan on an early Sunday morning; shoes that stay dry when you walk through the rain; carpets that stay clean when your elderly cat decides he hates you that day and vomits everywhere...and the list goes on. But, we wouldn't be Finch if we didn't do a bit of research into what's actually going on here. If we're being honest, some of the results are more concerning than Michael's actions during the first season of The Office. With almost 5,000 individual chemicals within the PFAS family, it would be impossible to cover them all. Instead, we decided to draw you the PFAS family tree and start with some of the most prevalent and well-studied PFAS: PFOA and PFOS.

PFOA and PFOS are both ‘long-chain' PFAS. This basically means that they have seven or more carbon atoms linked together, with fluorine atoms attached to each carbon atom. PFOA and PFOS were originally invented and produced by 3M and DuPont starting in the 1940s and 1950s and were primarily used as a water and oil repellent, and as a precursor to water-repelling polymers like Teflon. As early as the 1960s, DuPont became aware of the potential health impacts of both chemicals, especially PFOA, which they referred to as 'C8'. Through lab studies on animals (animal testing is another predicament we won't have time to cover today), they found that these chemicals could increase the size of livers, bind to blood proteins, cause birth defects, and potentially lead to cancer. Later, they found detectable levels of PFAS chemicals in workers' blood and found birth defects in the children of multiple pregnant factory workers. Yet, these findings were not reported to the EPA, and over 1.7 million pounds ofC8 powder were pumped into surrounding rivers or released into the air without anyone knowing. If you're ever wondering about the importance of regulating our water supplies, this here is a doozy of a reason.

We've all likely heard the story (or seen the movie) of Erin Brockovich, the legal clerk who uncovered the truth about chromium-6 contamination in her state's drinking supply. But less talked about is the hero of this PFAS story, Rob Billot. In 1999 (the year before the Erin Brockovich movie came out), Billot, a corporate lawyer, took on a farmer's case about cows getting sick and dying after drinking horribly green water from the Ohio River. In the process, he found that both 3M and DuPont knew their products were causing harm to workers, the environment, and the surrounding communities for almost five decades, but kept some of that information hidden. By the 1990's, DuPont had developed a version of the chemical that stayed in the human body for shorter periods of time and was far less detrimental to human health. That sounds like progress, but since the use of PFAS, specifically C8, was so important to the company's bottom line (worth more than $1 billion per year), they never changed to the safer version of the chemical and instead kept producing C8 and continued leaking it into the nearby river.

Long story short, our hero, Rob Billot eventually composed a now-famous, 900-page letter to the EPA about what he found and was literally never hired as a corporate lawyer again. The EPA fined DuPont $16 million and DuPont paid another $70 million in a class action lawsuit settlement (notably less than 5% of their profits from one year's worth of C8 sales), which was less a slap on the wrist and more of a tickle on the hand. Fortunately, the money from the class action lawsuit was used to conduct studies on the health of people in the region, which eventually led to a heftier (but still insufficient, in my opinion) $671 million settlement. We highly suggest this NY Times piece on Rob Billot or the 2019 movie Dark Waters if you want to learn more about this case.

All in all, studies now show that community members near the plant have PFOA levels in their blood that are fivetimes higher than the rest of the country and six major diseases have been linked to C8 releases, including a doubled rate of kidney cancer mortality compared to the rest of the country. PFAS use in firefighting foam has led to increases in PFAS levels in firefighters' blood and may be linked to their higher likelihood of developing cancer. Even if you don't live by this plant or help fight fires, it is now known that 99% of Americans have detectable levels of PFAS in their blood and about 110 million people have potentially concerning levels of PFAS in their drinking water. To see if your water supply is impacted, check out this resource from the Environmental Working Group.


While PFAS problems have been brewing for more than 80 years, the history of contamination from GenX, aka ammonium (2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate), is much younger than those old Boomers, PFOS and PFOA.

I'm going to come right out and say it: I absolutely hate GenX. GenX is persistent and annoying, its existence is concerning, it can be hard to stomach, and honestly, just because it's been around for more than 40 years doesn't mean we want it in our lives anymore. To be clear, I don't mean my parents' generation, I mean the chemical GenX.

GenX only has six carbon atoms (compared to long-chain that has seven or more), so it was considered to be a short-chain PFAS. While GenX was invented decades ago, it didn't see much use until 2010, when it replaced PFOA (aka C8) as a safer alternative in the production of Teflon or other waterproof polymers. Why don't we trust when companies tell us something is 'safe' you ask? Well, in 2016, it was discovered that Chemours (a subsidiary of, yes, you guessed it, DuPont) was releasing GenX into the Cape Fear Riverin North Carolina. While this release has since stopped, GenX has been potentially linked to cancers in laboratory tests and some believe the chemical was in the drinking water supply for almost a decade. Not really the safest option in the world, but with that said, it is still believed that short-chain PFAS are a somewhat safer option than longer-chained PFOS and PFOA in producing waterproof polymers. Progress is good, but we still need to push for even more.

GenX isn't the only short-chained molecule on the block. A hot off the presses peer-reviewed study from August of 2021 in the journalEnvironmental Science & Technology Letters looked at 231 cosmetic products to try and find PFAS. Even though only 8% of the cosmetics tested had any PFAS listed as an ingredient, an eye-popping number (52% of them) were shown to likely have a high concentration of PFAS. This was especially true in foundation, eye products, mascara, and lip products. The most commonly detected PFAS across the board was6:2 FTOH, which has been linked to kidney disease, developmental problems, and cancer, among other health effects. It has also been noted to be more toxic thanC6, the standard forrelativelynon-toxic short chain PFAS.

Fortunately, while 6:2 FTOH and other PFAS were detected in many cosmetics, they tended to be atlevels significantly below those expected to cause any harm. Another study also found that 6:2 FTOH didn't meet the requirements to be classified as a hazardous chemical to eyes or skin, according to the UN Standards. So, as long as you don't make a buffet of all of the mascara and foundation at your local drug store, there isn't too much to worry about on this chemical. That being said, since the science on short-chain PFAS is still pretty new, we will be monitoring the science as it comes out. And, we are still strong advocates of PFAS-free materials for environmental reasons and have offered up a few PFAS-free cosmetic lines at the end of this article.

Luckily for all of us, PFAS contamination and health concerns are being taken much more seriously by industry, governments, and citizens. Earlier this year, more than 20 years after the Billot case, US states like Maine, Connecticut, New York, Vermont, and Minnesota began banning the use of PFAS infood packaging and cosmetics, citing the known health hazards. These bans will be phased in over the next 4-10 years. Meanwhile, in February of this year, the EPA officially announced health advisories on products containing long-chain PFAS. This follows the EPA's voluntary industry phase out of PFOA initiated in 2006, which has effectively stopped the manufacture and import of PFOA and PFOS.

As a result, companies like 3M and DuPont have had to use safer chemicals to produce polymers like Teflon or other water repellent materials to make sure that there are no releases to the environment and that there are no hazardous non-polymer PFAS stuck to the Teflon. Clothing and textile companies are also looking to improve their supply chains for the 'side-chain fluorinated polymers' that keep your fabric dry. In 2013, Patagonia announced a search for PFAS alternatives for water-proofing and has temporarily switched from suppliers that use C8 to ones that use the shorter and safer polyfluorinated chemical, C6 (a PFAS similar to GenX, but largely considered to be safer). Gore-Tex, who's entire waterproof product line is based on the use of Teflon, has also heavily invested in Teflon made with less hazardous polyfluorinated chemicals. Fast food companies like Wendy's and McDonald's are phasing the use of PFAS out of their wrappers and the NRDC has even helped statesphase out PFAS from firefighting foam.

However, until scientists can crack the code for high-performance water-proofing without Teflon or safer production of Teflon, PFAS, especially short-chained chemicals like GenX and C6, will inevitably still be used around the world.


What can you do to protect your health and the environment, knowing that PFAS are, well, everywhere?

Cleaning PFAS out of water is one of the greatest challenges facing water treatment plants today due to the high costs and need for more advanced technologies. If your water supply is contaminated according to the Environmental Working Group's Tap Water Database, consider installing a high-quality water filter. A Duke study found that while not all in-home water filters can completely remove PFAS, using any filter is better than using none at all. The most effective filters were under-the-sink reverse osmosis and two-stage filters, which removed about 94% of PFAS, including GenX. (We recommend copy/pasting that line and asking a plumber or hardware store staff for help finding one... because no one needs to remember that off the cuff.) Under the sink activated carbon filters were a bit less predictable, with some removing all of the PFAS and some removing none at all. On average though, carbon filters removed about 75% of the PFAS, and 11 out of the 13 activated carbon pitchers performed well.

About to throw out all of your waterproof gear due to waterproofing fears? Please don't. Teflon/PTFE has been labeled a 'polymer of low concern' by the Organization for Economic Co-operation and Development, meaning it is relatively safe in clothing. Teflon and other fluorinated polymer's biggest issues come from worker exposure to PFAS and chemical releases during manufacturing.

While many manufacturers of carpets, furniture, and cookware have figured out how to waterproof their products without fluorinated chemicals, it has been a bit harder for clothing companies to do the same. This is because non-fluorinated waterproofing is either not as water resistant, or just too uncomfortable to wear. However, you should still try to look into non-fluorinated waterproof clothes next time you shop for outdoor gear. Luckily, the Green Science Policy Institute created a list of PFAS-free brands and items for you to reference.

While Teflon can't hurt you through your skin, it can have an impact when you ingest it. Try your best to avoid non-stick pots and pans, especially if they do not say 'PFAS-Free'. A review of the scientific literature by EWG notes that around 400°F, Teflon particles start to release from pans. When you hit around 680°F, a handful of toxic fluorinated compounds, including some PFAS begin to off-gas. To put those temperatures in perspective, a preheated grill is usually around 700°F and the surface of a pan usually reaches around 750°F after sitting on the stove-top for 8 minutes. Instead of Teflon, we suggest opting for cast iron, ceramic, or steel pans to avoid PFAS fumes and the need for PFAS in manufacturing. There are also some PFAS-free alternatives that use nanoscale ceramic-like materials to make their pans non-stick, so you can still cook your eggs in relative peace.

5. While American companies have followed the rules of the EPA PFOA Stewardship Program and have stopped manufacturing and importing C8/PFOA and PFOS, they are still importing goods that can contain C8/PFOA. The UN unanimously approved an international ban on around 150 PFOA-based substances, and the European Union has done the same. However, there is no universal ban on producing fluorinated polymers (like Teflon) with long-chained PFAS. 18 countries, including China, South Korea, and Russia, have not fully agreed to the ban, so C8 is still being manufactured and used internationally to produce some consumer goods. Therefore, to protect the citizens of those countries from PFAS-related illnesses, consider avoiding water-resistant products that are manufactured in those countries until they accept the ban. The full list of those countries can be found here: