Mamavation report doesn’t provide sufficient evidence for the claim that Band-Aids contain “cancer-causing forever chemicals”

Claims that Band-Aids cause cancer or that Band-Aids contain cancer-causing chemicals began spreading on social media in early April 2024. Examples can be seen in these TikTok videos, one of which received more than 448,000 views to date. An article by the Daily Mail also made the same claim, with its headline “Cancer-causing forever chemicals found in BAND-AIDS”.

The claims are based on an article by the blog Mamavation, published on 2 April 2024, which reported that it sent 40 adhesive bandages from 18 different brands to a laboratory to test for “indications of toxic PFAS ‘forever chemicals’”, specifically by measuring organic fluorine levels on the bandages.

Mamavation reported that 26 of the 40 tested bandages contained organic fluorine at levels above ten parts per million (ppm), and that overall, organic fluorine levels ranged from 11 to more than 300 ppm.

However, the tests don’t provide sufficient evidence for the claim that Band-Aids and other adhesive bandages cause cancer or contain cancer-causing chemicals.

Experts whom Science Feedback spoke to cautioned that the type of testing conducted by Mamavation was non-specific and unequipped to address the question of whether adhesive bandages pose a cancer risk. They also highlighted the fact that there are thousands of PFAS (also known as “forever chemicals”) and while two in particular have been implicated in cancer risk, we cannot reliably assume that all PFAS chemicals pose the same cancer risk. We explain below.

What are PFAS and how might they endanger human health?

Per- and polyfluoroalkyl substances (PFAS) are a large family of human-made chemicals. Exactly how large this family is differs from source to source, but authoritative sources generally agree there are at least a few thousand PFAS.

A 2019 briefing from the European Environment Agency (EEA) stated that PFAS comprise “more than 4,700 chemicals”, while the U.S. Environmental Protection Agency (EPA)’s CompTox database counts more than 15,000 chemicals as PFAS. The PubChem database, using a revised definition from the Organisation for Economic Co-operation and Development from 2021, contains over seven million chemicals as members of the PFAS family^[1].

These chemicals typically contain a chain of carbon atoms bonded to fluorine atoms. The carbon-fluorine chemical bond is one of the strongest bonds known to chemistry, which lends many PFAS their exceptional properties, like water repellency and heat resistance. These properties have led to their widespread use in a variety of products ranging from firefighting foams to nonstick cookware to water-repellent clothing.

However, the strength of the carbon-fluorine bond has turned out to be a double-edged sword: while it’s key to the desirable properties of many PFAS, it’s also the reason why they persist and accumulate in the environment, potentially for centuries. And this has implications for human health, since PFAS can also accumulate in living things.

Most people are exposed to PFAS through everyday items like food, water, and clothing (see Figure 1 below). However, certain groups are more likely to have a higher level of exposure, such as those who work with PFAS or PFAS-containing materials and those who live near PFAS-producing facilities.

The EEA has called PFAS “emerging chemical risks”, citing studies finding that certain PFAS are associated with various health issues, such as cancer, reduced fertility, and poorer immune function.

Similarly, the U.S. Agency for Toxic Substances and Disease Registry (ATSDR) website also describes numerous potential health effects from PFAS exposure, such as increases in blood cholesterol levels, lowered immune response to vaccines, and pregnancy-induced hypertension and preeclampsia.

Dan Jones, a professor and assistant director of the Center for PFAS Research at Michigan State University, told Science Feedback that animal studies have shown increases in the incidence of some cancers associated with PFAS exposure^[2]. Epidemiological studies have also shown that kidney and testicular cancers in humans are associated with PFAS exposure^[3-6]. Some studies have also found associations with liver cancer^[7] and leukemia^[8].

However, one of the biggest challenges in studying the health risks posed by PFAS is that there are so many of these chemicals. Health effects have only been established for “a small number” of PFAS, Jones said. Also, studies generally tend to test only one chemical at a time, whereas in the real world, people are exposed to a variety of PFAS at a variety of levels.

Two PFAS in particular, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are among the most studied in terms of their health effects.

Ian Cousins, a professor of contaminant chemistry at Stockholm University, told Science Feedback that scientific evidence for PFAS’ ability to cause cancer generally relates to these two chemicals. Indeed, in December 2023, the International Agency for Research on Cancer (IARC) classified PFOA as a Group 1 carcinogen, while PFOS was labeled as a Group 2B carcinogen.

Non-profit Cancer Research U.K. explained the IARC classifications:

“IARC’s classification system reflects whether something has the potential to cause cancer (its ‘hazard’), but it doesn’t tell us how dangerous that thing is (its level of risk).  

By classifying PFOA as Group 1, IARC is saying that, overall, scientific evidence suggests it has the potential to cause cancer. That doesn’t mean it poses the same level of risk as other things in the group. Active smoking, second-hand smoke and air pollution are all in Group 1 as well, but they come with very different levels of risk […]

PFOS is now in Group 2B, meaning the evidence on the potential for it to cause cancer is still inconclusive. This is the same category as things like aloe vera and bracken ferns, but, again, this doesn’t tell us the level of risk (if there is one).” 

Concerns over the effects of PFAS on the environment and health have moved governments to regulatory action aimed at reducing and eventually eliminating PFAS use and production. Both PFOA and PFOS are no longer produced in the U.S. and the European Union, for example. However, numerous other PFAS still remain in use.

Mamavation findings don’t provide sufficient evidence showing adhesive bandages cause cancer

Experts whom Science Feedback spoke to highlighted a critical limitation in the Mamavation tests. Specifically, in order to actually identify health risks, Mamavation needed to test for specific PFAS rather than just organic fluorine levels. [Read scientists’ full remarks below].

Dan Jones said that while the Mamavation results provided “an indicator of the potential presence of harmful PFAS chemicals”, they cannot reliably tell us whether the PFAS detected on the bandages actually posed a cancer risk.

This goes back to the fact that PFAS comprise thousands of chemicals and they don’t all share the same properties. Some PFAS may present risks, he said, but others may be “mostly harmless”.

Therefore, specific PFAS need to be identified in order to understand whether the PFAS on the bandages pose a cancer risk, said Cousins. He concluded that the Mamavation tests didn’t provide sufficient evidence for the claim since they only measured organic fluorine content.

Oliver Jones, a professor of chemistry at RMIT University, said that Mamavation’s approach of only measuring organic fluorine levels was “not really good practice” and that identifying specific PFAS would have been necessary.

He also highlighted the importance of careful sample handling in PFAS testing, given that PFAS is everywhere. “You have to be very careful how you take and store samples to avoid contaminating them,” he said. “If care was not taken, it is not inconceivable that at least some of the organic fluorine that was detected got onto the adhesive bandage from other sources.”

Lastly, he also raised the issue of reproducibility as the Mamavation article didn’t mention details of how many samples of each adhesive bandage they tested.

“If they only tested one or two samples, that is not enough to draw conclusions about every single adhesive bandage of that type,” he explained. “It is possible they just tested some that happened to have PFAS in them”, he said, but this alone wouldn’t provide sufficient grounds to conclude that all bandages of that type would contain the same amount of PFAS.

He emphasized that when it came to discussing the toxicity of a certain substance, it’s critical to keep in mind the dose.

“The first rule of toxicology club is ‘the dose makes the poison’,” he said. “Everything is toxic in the right amount, even water. The question is not if something is toxic or not, but if it’s toxic at the dose to which we are exposed.”

Given the ubiquity of PFAS and the fact that most people already have significant levels of PFAS in their bodies, he considered the potential health risk from PFAS on adhesive bandages to be “very small”.

For context, the National Health and Nutrition Examination Survey in the U.S., which has measured the blood levels of specific PFAS since 1999, noted that the average blood levels of PFOA and PFOS in the general population in 2017 was 1.4 micrograms per liter and 4.3 micrograms per liter, respectively. One microgram is one millionth of a gram.

“While I think we should be trying to reduce PFAS and conducting more research into its effects, I don’t think we need to worry about using an adhesive bandage for a cut,” he said.

There is scientific evidence showing that PFAS can cause cancer, but only for specific substances such as PFOA and PFOS. The best collection of evidence can be found here.

Whether the organic fluorine levels reported by Mamavation have implications for cancer risk depends on the types of PFAS. There isn’t sufficient evidence if they have only measured the fluorine content. You would need to know the specific substances. This can be determined through specific analyses of the band-aids, bandages etc., which we can do, as shown in this study. Note also that skin absorption of even cancer-causing PFAS is very low.

This news article shows that we don’t know which types of PFAS were used [in the adhesive bandages], as the test is non-specific. The article also suggests that fluoropolymers (e.g. PTFE) are commonly used in adhesive bandages and fluoropolymers will not cause cancer.

There is epidemiological evidence associating PFAS exposures to kidney and testicular cancers in humans^[3]. Several studies have shown increases in incidences of some cancers in animal models, though extrapolation of these results to humans may not be appropriate.

Cancer may not be the most sensitive health outcome of PFAS exposures. There are other well-documented effects. The Agency for Toxic Substances and Disease Registry has described numerous other potential health effects from PFAS exposures in addition to certain cancers. These include increase in blood cholesterol levels, decreased infant birth weight, lower immune system responses to some vaccines, and pregnancy-induced hypertension and preeclampsia.

There have also been other recent studies that suggested that exposure to PFAS was associated with altered metabolic processes in children and increased risk of cardiovascular problems.

Thus, it is likely that health problems other than cancer will be of higher frequency than PFAS-related cancers. But this will depend on the level of exposure and perhaps combinations of exposure to PFAS and other substances. Unfortunately, we still know very little about the effects of many PFAS chemicals in use or the range of human exposures.

The risks of cancer from adhesive bandages are uncertain because PFAS comprises a group of thousands of chemicals, but health effects have only been established for a small number of PFAS chemicals. The Mamavision study only measured total organic fluorine, but not individual PFAS chemicals, some of which may present risks but others may be mostly harmless. These results should be used as an indicator of the potential presence of harmful PFAS chemicals, but don’t provide definitive information about what the risks might be.

I’m not aware of any studies that have measured how much of specific PFAS from bandages is absorbed into tissues or the bloodstream, so I don’t think there is enough information to assess whether the levels detected in bandages present significant risks to human health.

It is important to note that there are many other routes through which we are exposed to PFAS (drinking water, foods, food packaging, household dusts, and numerous consumer products), and virtually everyone already has significant amounts of PFAS in their blood and tissues.

I consider it unlikely that exposure to PFAS from bandages contributes a significant fraction of human exposures, but perhaps we should focus on whether it is essential to have such substances in the products we buy because they persist in the environment for many years—this is why they are called “forever chemicals”—and can be transported globally into water and food systems.

This means that PFAS in a bandage that is disposed of in the trash may end up in a landfill, and from there the PFAS chemicals may leach into groundwater, migrate into surface waters (lakes, streams, and oceans) ending up being concentrated in aquatic organisms (e.g. fish) and eventually into us.

The EPA just finalized rules regulating the maximum levels of a small group of PFAS chemicals in drinking water systems.  These new regulations propose:

1. A Maximum Contaminant Level Goal, a non-enforceable health-based goal, at zero for PFOA and PFOS. This reflects the latest science showing that there is no level of exposure to these contaminants without risk of health impacts, including certain cancers.
2. Enforceable Maximum Contaminant Levels at four parts per trillion for PFOA and PFOS, individually in drinking water, requiring public water systems to take actions to reduce levels of these chemicals in drinking water that exceed these amounts. This standard will reduce exposure to these PFAS in our drinking water to the lowest levels that are feasible for effective implementation. Contaminants in drinking water are more tightly regulated than contaminants in consumer products and foods, as different agencies and legislation is involved.

There is some evidence that some PFAS are associated with a higher risk of cancer. This evidence is really only for one compound, perfluorooctanoic acid (PFOA), which was discussed in the book “Exposure” by Robert Bilott and the film “Dark Waters”. However, context is important. Association is not causation and the important caveat here is that the levels of PFAS that we are talking about are very high as the people concerned were living near or working in PFOA-related chemical plants for many years.

There is very limited evidence for other PFAS causing cancer. Cancer itself is also not one disease but a catch-all term for hundreds of unique diseases whose common feature is that they develop when cells in your body no longer listen to normal cues and start to grow out of control. You can see what the American Cancer Society says about PFAS here.

Also, we really need to think carefully about saying something causes cancer, because unless you discuss dose it is meaningless. For example, we know that UV rays from the sun cause skin cancer—that’s why we put on sunscreen in summer—but most of us are happy to go outside in winter with no sunscreen because we know we won’t get exposed to enough UV to cause a problem. Similarly, we know alcohol causes cancer, but most of us are fine to drink a glass of wine or beer even though it technically contains a carcinogen.

Thus, headlines like “chemical X may cause cancer” are really misleading as they don’t provide context or understand there is a difference between hazard and risk.

I would say it is very unlikely for PFAS in adhesive bandages to affect cancer risk. The concentrations we are talking about are exceedingly small and if they stay on the skin, there is no route of exposure.

When we’re evaluating the risks of a chemical we need to consider things like the dose (how much of the compound we are exposed to), the route (how we are exposed), and the duration (how long we are exposed for). For example, if you drink a glass of water you are fine. But if you were to inhale the same amount of water into your lungs you would drown.

The other thing is that we don’t know how these samples were handled before they got to the lab. PFAS are in a lot of things we come into contact with every day and when you sample for PFAS in the environment, you have to be very careful in how you take and store samples to avoid contaminating them. If care was not taken, it is not inconceivable that at least some of the organic fluorine that was detected got onto the adhesive bandage from other sources. It does not seem like the samples were gathered in a scientific way from what I have read in the article.

Measuring organic fluorine as a proxy for PFAS is not really good practice. It is better to measure the individual PFAS compounds as there is no discussion about the dose. The first rule of toxicology club is “the dose makes the poison”. Everything is toxic at the right amount, even water. The question is not if something is toxic or not, but if it is toxic at the dose to which we likely are exposed.

Something else that might be worth considering is that I could not find details of how many samples were tested per adhesive bandage. For example, if they only tested one or two samples that is not enough to draw conclusions about every single adhesive bandage of that type. It is possible they just tested some that happened to have PFAS in them, and the results alone don’t mean that all bandages of that type will have the same amount.

In the case of PFAS, although certain PFAS have been associated with health effects in humans, these effects were only seen at levels many times greater than that listed in the Mamavation article and after a much longer period of exposure. So, in my view, the risk from adhesive bandages is very small. You are likely exposed to more PFAS from other areas already.

It is also worth noting that many compounds that are currently listed as PFAS weren’t classified as PFAS until the Organisation for Economic Co-operation and Development (OECD) expanded its definition of PFAS in 2021 to include over seven million compounds^[1] and not all seven million compounds have the same properties.

So while I think we should be trying to reduce PFAS in the environment and conducting more research into their effects, I don’t think we need to worry about using an adhesive bandage for a cut.

REFERENCES

• 1 – Schymanski et al. (2023) Per- and Polyfluoroalkyl Substances (PFAS) in PubChem: 7 Million and Growing. Environmental Science and Technology.
• 2 – National Toxicology Program. (2023) NTP Technical Report on the Toxicology and Carcinogenesis Studies of Perfluorooctanoic Acid (CASRN 335-67-1) Administered in Feed to Sprague Dawley (Hsd:Sprague Dawley® SD®) Rats (Revised). Available from: https://www.ncbi.nlm.nih.gov/books/NBK560147/
• 3 – Steenland and Winquist. (2021) ​​PFAS and cancer, a scoping review of the epidemiologic evidence. Environmental Research.
• 4 – Shearer et al. (2020) Serum Concentrations of Per- and Polyfluoroalkyl Substances and Risk of Renal Cell Carcinoma. Journal of the National Cancer Institute.
• 5 – Vieira et al. (2013) Perfluorooctanoic Acid Exposure and Cancer Outcomes in a Contaminated Community: A Geographic Analysis. Environmental Health Perspectives.
• 6 – Purdue et al. (2023) A Nested Case-Control Study of Serum Per- and Polyfluoroalkyl Substances and Testicular Germ Cell Tumors among U.S. Air Force Servicemen. Environmental Health Perspectives.
• 7 – Goodrich et al. (2022) Exposure to perfluoroalkyl substances and risk of hepatocellular carcinoma in a multiethnic cohort. JHEP Reports.
• 8 – Jones et al. (2023) Maternal serum concentrations of per- and polyfluoroalkyl substances and childhood acute lymphoblastic leukemia. Journal of the National Cancer Institute.