PFOA (perfluorooctanoic acid) is one of the most hazardous PFAS compounds. It is a proven carcinogen, the CDC says there is no safe level, and it was phased out over 10 years ago. Yet we still routinely see it in tests we perform. And that is borne out by the CDC’s NHANES biomonitoring study. Here, we look at why PFAS is so persistent and why this health problem isn’t going away anytime soon.
PFOA the miracle chemical
PFOA is one of the oldest commercially available PFAS compounds. It was first produced in the 1940s by 3M. PFOA was widely used in industry both directly and as a key element in the manufacture of other PFAS compounds. PFOA is a powerful surfactant (a compound that reduces the surface tension of liquids that come into contact with it). This means PFOA has often been used in applications such as stain-resistant coatings, greaseproof food containers, and similar.
PTFE
One of the most important early uses of PFOA was in the manufacture of DuPont’s non-stick PTFE compounds, marketed as Teflon. PFOA was an important surfactant additive that gave the PTFE desirable properties. Surfactants like PFOA are why oil and water tend to bead up when they are poured onto non-stick surfaces.
Gore-Tex
PTFE was originally used for its non-stick properties. But an accidental discovery by Bob Gore led to the invention of the eponymous GoreTex. He discovered that if you rapidly stretch PTFE fibers, they create ePTFE (expanded PTFE), a substance with a very fine microporous structure. A sheet of ePTFE has the unique property that water vapor can pass through the pores, but liquid water is unable to. This was the principle behind breathable waterproof membranes.
Growing concerns about PFOA
PFOA continued to be widely used as an industrial surfactant. But as early as the 1970s, there were some concerns about how it persists in the environment. By the 1990s, these concerns had grown significantly, and research was beginning to link PFOA with serious health effects in animals and humans.
Health effects of PFOA
PFOA is proven to be carcinogenic to humans. Earlier this year, the IARC (International Agency for Research on Cancer) released a new monograph looking at PFOA and PFOS (another infamous PFAS compound). In their summary they say:
The Working Group evaluated PFOA as carcinogenic to humans (Group 1) on the basis of sufficient evidence for cancer …
Other studies have linked PFOA with immunosuppression, thyroid problems, possible developmental disorders, and liver damage. Taken together, this makes PFOA one of the most concerning PFAS compounds we know of.
Phasing out PFOA
In 2000, 3M stopped producing PFOA, but DuPont set up their own plant to manufacture it instead. But the writing was on the wall, and by 2013, DuPont had phased out PFOA in Teflon and other products. Nowadays, almost all non-stick products are made using other surfactants, such as GenX. These so-called short-chain PFAS compounds break down more rapidly in the environment. This has led to some manufacturers promoting these products as “environmentally friendly” PFAS compounds, but the jury is still out about just how safe they are. However, due to the persistence of PFOA, it may take decades before we see it fully eliminated.
Not so fast
Unfortunately, PFOA is incredibly hard to break down. Some studies suggest that it may take decades for it to disappear. That makes it especially concerning as an environmental pollutant. Worryingly, some of its breakdown products are also highly toxic and hard to break down. PFOA is now pretty much ubiquitous in water sources around the world. For instance, a study last year found that the entire Great Lakes basin is polluted with PFOA and other PFAS compounds.
PFOA in humans
The CDC NHANES study has been looking at levels of PFOA and other PFAS in human samples for around 2 decades now. In their most recent dataset (dated to 2018), PFOA was seen in around 90% of people. We also routinely see PFOA in over 90% of home PFAS tests processed at our lab. That shows that it continues to be a problem a decade after its widespread use stopped.
Some positive signs
There’s little doubt that PFOA will continue to be a problem for some considerable time to come. However, there are some signs of hope that we may be able to reduce or even eliminate it in future. Researchers are looking into novel approaches to eliminate PFAS including PFOA. Some of these approaches look promising.
In another positive sign, over the last 20 years, the continuous NHANES program has shown a steady decline in the levels of PFOA seen in samples. This suggests that people are no longer directly exposed to the compound and their bodies can begin to eliminate it.
