Guitar Strings and Prozac: The Paradox of PFAS

From guitar strings to pharmaceuticals, cookware to pizza boxes, makeup to waterproof clothing, it's a sure bet that most of us have per- and polyfluoroalkyl substances (PFAS) in our homes; we might even use products containing them on a daily basis. So are all PFAS bad?

There are tens of thousands of PFAS in existence, “which makes studying and regulating PFAS individually, or even as small mixtures, infeasible,” noted the authors of the study “The Implications of PFAS definitions using fluorinated pharmaceuticals,” published in the journal iScience by a group of Boston University researchers. “Multiple PFAS definitions based on structure have been proposed, yet these definitions do not consider the implications for the full suite of organofluorine chemicals.”

“For this group of compounds, the definitions offer different and conflicting views of what is and is not 'PFAS,'” said study lead author Emily Hammel in an interview with Boston University's School of Public Health.

Some definitions are ambiguously written and have multiple interpretations, she added, noting, “The reality is that this is a very large class of chemicals used in a variety of applications, and there may not be a universally useful definition. The real danger is not adopting any definition, for fear of not having a perfect definition, and the consequential delay in decision making.”

Chemicals classified as PFAS run the gamut from compounds used in the manufacture of the widely used pharmaceuticals studied by the Boston University researchers to Gore-Tex technology used for weather-ready clothing lines like The North Face to coated guitar strings that are prized for their longevity, and those are just a few of thousands of uses.

A workbook that accompanies the Boston University study lists 360 organofluorine pharmaceuticals that have been approved and used globally between 1954 and 2021. The most inclusive definitions include several top prescribed pharmaceuticals such as Prozac, Lipitor, and the COVID-19 antiviral treatment Paxlovid. These prescription medications contain organic fluorine, a compound often used in pharmaceuticals to reduce drug side effects and enable the medicines to work longer.

Rob Campbell, industry expert and former senior solutions advisor for 3E, shared the study and its accompanying workbook as part of a larger discussion about PFAS. “The worksheet compares 360 drug compounds against various PFAS definitions,” he explained. “Maybe you will find some of your own medications on this worksheet. All I can say is that my life and that of my friends and family are better because of some of these PFAS.”

As awareness of PFAS grows, some advocates are calling for widespread bans on their use. However, as industry works to develop substitutes for banned or controversial PFAS such as perfluorooctanoic acid (PFOA), concerns are emerging that these replacement chemicals may not be any safer in the long term.

Global Discussion Around Strategy

As many PFAS are toxic, persistent, and widely detected in the environment and human serum, their use has prompted a “global discussion around their cost and benefits, essential uses, and effective strategies for regulation,” shared the authors of the BU study.

“The large number of PFAS and the substitution of legacy compounds such as PFOA and PFOS [perfluorooctane sulfonate] by newer compounds - about which less is known although they may turn out to be just as problematic - has prompted movement away from the traditional chemical-by-chemical regulation toward regulation of these compounds as a class in both the U.S. and Europe,” they added.

Campbell notes that determining “essential” vs “non-essential” uses for substances in the PFAS family is a major point of debate. How will authorities/societies decide what is “essential” versus a “non-essential” use for a PFAS compound? For example, the statin Campbell takes could be considered a PFAS, he said. In addition to Atorvastatin (Lipitor), Fluoxetine (Prozac), and Paxlovid, other common medications that could be considered PFAS include Sitagliptin (Januvia), Ciprofloxacin (Cipro), and Fluticasone Propionate (Flonase).

“This goes beyond a pure natural science debate and blurs into the social science world. I see the statin I take as essential to my long-term health,” said Campbell. “But someone else might say, 'Statins are a PFAS and if you eat fruits, vegetables, and grains then you don't need statins, and [so let's] eliminate a whole group of PFAS.'”

Exposure to PFAS has been linked to negative health consequences, such as several types of cancer, impaired thyroid and liver function, higher cholesterol, reduced immune response, ulcerative colitis, and various cancers. However, the issue with these chemicals is not necessarily their use in pharmaceuticals, but what happens afterwards, said Wendy Heiger-Bernays. “We don't know very much about how pharmaceuticals degrade once they leave the body. If we used a definition of PFAS for environmental monitoring that was broad enough to include some of these pharmaceuticals, it could be a great opportunity to better understand how organofluorine chemicals behave in the environment.”

The Many Sources of PFAS

Heiger-Bernays is a coauthor of the landmark 2025 study, “High organofluorine concentrations in municipal wastewater affect downstream drinking water supplies for millions of Americans,” which determined that the six PFAS regulated by the U.S. Environmental Protection Agency (EPA) found in drinking water accounted for less than 10% of extractable organofluorine (EOF) in wastewater influent and effluent. Prescription drugs are responsible for approximately 75% of the organic fluorine entering wastewater treatment facilities and 62% of the organic fluorine found in treated water released back into the environment.

Using a national model that simulates connections between wastewater discharges and downstream drinking water intakes, Heiger-Bernays and the other study authors estimated that the sources of drinking water for up to 23 million Americans could be contaminated above regulatory thresholds by wastewater-derived PFAS alone. “These results emphasize the importance of further curbing ongoing PFAS sources and additional evaluations of the fate and toxicity of fluorinated pharmaceuticals,” they noted.

While many of us are becoming more aware of PFAS and their uses, it's unlikely top of mind when we order a pizza for delivery, reach for a bag of microwave popcorn, ask for a biodegradable to-go container for restaurant leftovers, take our medication, grab our hiking boots, apply eyeliner and mascara, practice guitar, or sip some tap water. The reality is that many if not most of those products or their packaging contain PFAS and are useful for the very reasons that make them so persistent and long-lasting in the environment: they are water-resistant, grease-resistant, and non-stick.

Often the most severe health effects are found in workers who are exposed to PFAS in relatively high concentrations over longer periods of time, rather than in the average consumer who gets a take-out meal once a week. Still, with certain PFAS and PFOA being highly regulated or even banned, chemical companies are scrambling to fill the gap and bring potentially less-hazardous replacements to market.

Are Substitutes Safer?

As defined by the EPA, “PFAS are a family of thousands of synthetic organic chemicals that contain a chain of carbon-fluorine bonds, one of the strongest chemical bonds. Many PFAS are highly stable, water- and oil-resistant, and exhibit other properties that make them useful in a variety of consumer products and industrial processes. Owing to these properties, PFAS do not easily degrade naturally and thus accumulate over time.”

Industry has developed and adopted alternative short-chain PFAS to replace long-chain PFAS. Many short-chain PFAS are structurally similar to their long-chain predecessors and are manufactured by the same companies. It was initially thought that the short-chain PFAS developed to replace long-chain PFAS were a safer alternative since the human body can eliminate short-chain PFAS more quickly, lessening concerns about biopersistence. However, an EPA analysis indicates exposure to short-chain PFAS results in many of the same health consequences that are a concern with long-chain PFAS exposure. In fact, some short-chain PFAS accumulate in the body more quickly than previously thought.

As concerning, notes the EPA, “Publicly available health, toxicity, and hazard assessments of short-chain PFAS are limited. Available information suggests short-chain PFAS generally pose less risk to overall human health and exhibit lower persistence in humans than long-chain PFAS such as PFOA and PFOS. However, short-chain PFAS are environmentally persistent and some demonstrate potential to cause adverse effects on animal and human health.”

“In reality, everyone has something around the home with one type of PFAS or another,” says Campbell. “The classic of course is non-stick (Teflon) pans, which are a high molecular weight polymer that is a member of the broad PFAS family. W. L. Gore & Associates - maker of Gore-Tex textiles for outdoor wear and firefighter gear - has been in the news recently due to PFAS and has an interesting fact sheet about one of the substances they use, which is a PFAS polymer (ePTFE).”

Often, a PFAS developed for one use ends up having multiple uses, often in seemingly unrelated products, something that has occurred with Gore's polymer, said Campbell.

PFAS and Guitar Strings

The scientists, researchers, and lab technicians at Gore, as part of their research into creating a better type of push-pull cable, tried coating guitar strings with their polymer. While the coated guitar strings worked great as cables, they didn't sound wonderful as guitar strings. (As the company noted: “Picture a guitar strung with day-old spaghetti.” A couple of musicians at Gore, realizing that a coating that extended the life of guitar strings without sacrificing sound quality had value, decided to experiment, and their efforts led to the development of a popular brand of coated guitar strings called Elixir, which feature protective polymer coatings that extend string life and reduce corrosion.

“Essentially, the strings are coated with a thin web of polymer, which means your fingers are never in contact with the metal of the string. This can be very handy for guitar players whose sweat makes the string rust and deteriorate quickly. When I was a teenager, I could rust a set of guitar strings in an afternoon of playing,” remembered 3E Senior Reporter Graham Freeman, who plays guitar when he's not writing about sustainability and ESG.

With Elixer strings, “I could make a set last about a year before the polymer started to wear off and [the strings] needed to be replaced,” he said.

His guitar, custom made by a luthier in Montreal, has 10 strings: six normal strings on the top and four descending bass strings on the bottom. The bass strings require heavier gauges than are found in a set of Elixir strings, and Elixirs only come in sets of six, so his bottom four bass strings were standard bronze acoustic strings. Freeman says he used Elixir strings for about 10 years, stopping around five years ago.

Now, he mixes and matches from different sets of uncoated strings, admitting, “Restringing is now very expensive, very complicated, and requires considerable planning, but I’m happier with the result and it doesn’t deliver microplastic directly into my bloodstream.” (Editor's Note: 3E reached out to Elixer for comment but did not receive a response.)

Concerns about exposure to PFAS via guitar strings were voiced by Matt Dunn, in his blog “Stop Buying Coated Guitar Strings.” When not writing about some of his favorite topics - playing guitar, testing new guitar-related equipment, or punk rock - Dunn is an environmental scientist, with a Ph.D. from the University of Rhode Island in oceanography with a focus on PFAS.

In his blog, Dunn talks about PFAS and their use in the manufacture of coated guitar strings. “…[S]ome PFAS can stay in your body for around a decade,” wrote Dunn. “So why in the world do we need to use this in guitar strings of all places? Good question.”

Dunn recently sat down with 3E to discuss PFAS and how they can hide in plain sight, such as in coated guitar strings, and why it was important to him to share that message with his audience of musicians.

“I wanted to make it understandable for them, because they're really smart, intelligent people, but they're not Ph.D.s, they're not technical scientists,” said Dunn. “And I'm really focused on making sure that science and policy and regulations and risks can be explained to people in an accessible way, because science has struggled with that in the past… How to deal with the public? How to talk to them, reach them?”

Essential Uses and Why It Matters

In his blog, Dunn discusses the concept of the essential use principle: reducing the amount of PFAS produced by limiting use of PFAS to only those that are “absolutely, completely necessary.”

“…Your coated guitar strings are not essential,” he explained to his audience of musicians. “Even if they make up only a small amount of the total PFAS production and use, it is something you can do right now to make a big difference. Stop buying them, spread the word, buy regular old un-coated guitar strings, and let's get PFAS out of the guitar industry for good.”

Dunn said the musician community remains interested in the topic and clarified that the point of his blog was not to scare guitar players into thinking that using PFAS-coated guitar strings will harm them, but to educate them about PFAS in general. “I tried to explain it’s not necessarily that there’s PFAS in your strings and it’s going into your hands and killing you,” said Dunn.

Choosing other strings is a way musicians “can reduce the demand for PFAS and fluorinated chemistry, which will ultimately be good for the environment because it’ll reduce the amount that’s made, reduce the amount that’s emitted. Do we need coated guitar strings that are covered in PFAS? No, we don’t need that.” As a result of Dunn's blog, a company named Stringjoy reached out and told him it is making coated guitar strings using enamels that are free of chemicals of concern, so musicians who want coated strings either for endurance or sound quality have another option.

Ask most companies manufacturing or utilizing PFAS in their products and they'll tell you their uses are “essential,” and they're not necessarily wrong, said Terry Wells, associate director, Regulatory Research, 3E. “It's difficult to say what's an acceptable use or not. Take pharmaceuticals for example: Do the benefits outweigh the risks?”

There are people taking some pharmaceuticals, she noted, who would argue that the risks are acceptable and are worth it. There are other PFAS that likely could be eliminated without causing a ripple effect of harmful side effects, such as even more toxic substitutions, economic hardship, or health concerns.

“The first rule of toxicology is that the dose makes the poison,” said Wells, who has a background in toxicology, citing a quote credited to Paracelsus, who reportedly said, “All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison.”

In other words, a “toxic” substance can produce the harmful effect associated with its toxic properties only if it reaches a susceptible part of the body in a high enough concentration to do harm. “Since many of these chemicals and their environmental fate are not well characterized, it is not clear if all PFAS should be treated equally,” said Wells.

Ultimately, the debate centers on what is “essential” for society in today's world, suggested Campbell, and how are politicians and regulators dealing with this when they look to ban/restrict substances used to make products? It also touches on the topic of “regrettable substitution,” he added. What will be done to replace the chemical of concern and will the alternative have less of an impact on human health and the environment than the substance being banned or restricted?

“The debate about guitar string materials seems trivial in a time when people are starving and don't have access to water and bullets and bombs are raining down on them,” Campbell admitted. “But for a small group of stakeholders - in this case classical guitar players and the string makers - this is a fight worth fighting.”

The same is true of other products that contain PFAS and their end users, he noted. “Risk management is a tricky thing. For my part, I will just stick to pre-recorded classic rock and thereby not encourage the use of coated strings on live guitars.”

Editor's note: 3E is expanding news coverage to provide customers with insights into topics that enable a safer, more sustainable world by protecting people, safeguarding products, and helping businesses grow. Deep Dive articles, produced by reporters, feature interviews with subject matter experts and influencers as well as exclusive analysis provided by 3E researchers and consultants.

About the contributors: Terry Wells is a Senior Regulatory Research Manager at 3E and an experienced product safety specialist with a demonstrated history of working in the software industry. She draws upon her operational background and expertise to write about Product Compliance, Hazard Communication, and Product Safety for 3E. Adnan Malik is a Production Specialist and Graphic Designer on 3E’s News team.