We have all encountered PFAS or per- and polyfluoroalkyl substances in some way, shape, or form. Most commonly, in cookware such as non-stick pans, food packaging, cosmetics, waterproof fabrics, and firefighting foams. But what are PFAS, why are they so dangerous, and how are people working to remove PFAS from the environment or even destroy them?
The first form of PFAS came in the form of polychlorotrifluoroethylene (PCTFE), discovered by German scientists Fritz Schloffer and Otto Scherer. While PCTFE may have been the first of the PFAS chemical family, its prominence paled in comparison to a PFAS chemical we are more familiar with and even used daily: Polytetrafluoroethylene, or better known as Teflon. Trademarked by DuPont in 1945, the discovery of the substance came by accident as DuPont scientist Roy J. Plunkett and his assistant Jack Rebok discovered a frozen and compressed block of fluorocarbon tetrafluoroethylene had formed a waxy, white solid that would eventually become the Teflon that we know today. However, there wasn’t a big fanfare,e as while Teflon was now a thing, it essentially did nothing due to the fact that its molecular structure, re which consists of carbon-fluorine bonds, which are the strongest single bond in organic chemistry. That combined with a variety of other factors that make PFAS so inersuch ashas fluorine atoms that not only tightly pack themselves around the carbon backbone but also multiple fluorine atoms will bond to the same carbon atom, in which both of these protect the carbon chain that keeps the chemical together. And this made it relatively useless since you can’t do something with a chemical that doesn’t want to do any itself, plus Teflon was expensive to make. Until World War II came.
During the United States’ Manhattan Project’s goal of creating an atomic bomb. To power the nuclear fission that caused the atomic bomb to be so destructive came in the form of splitting uranium-235. Teflon came to play in the creation of the atomic bomb. To refine U-235, engineers at the Oak Ridge government facility tasked with refining uranium, used a process called gaseous diffusion that forced uranium hexafluoride gas through miles and miles of pipes, each containing thousands of filters that would separate the uranium. However, uranium hexafluoride is extremely corrosive and ate away at the gaskets and valve seals that not only regulated the flow of the gas, but kept it contained. That was until DuPont employees who were working at Oak Ridge offered to use Teflon to keep the gas contained. It succeeded.
After the war, Teflon soon found a place we are most familiar with, cookware. Due to the nonstick properties of Teflon, cookware lined with the substance made it so that food would not stick to pans without oil. The first pan using Teflon that was introduced in the US was called the “Happy Pan” invented Marion A. Trozzolo but the inventor of nonstick pans is credited to French inventor Marc Gregoire. Teflon was also used in other applications such as waterproofing for rain coats and hiking boots. With Teflon being so widespread, innovation of this family of chemicals came forth, however, this innovation came as a double edge sword as making PFAS and using products containing the chemical released them into the environment and also into the body.
Due to the almost indestructible nature of the PFAS, they aren’t broken down by anything, instead they linger in the environment contaminating soil, rivers, lakes, groundwater, and even the remote glaciers of Antarctica. The chemical is also known to bioaccumulate meaning that PFAS are absorbed faster than they are excreted thus allowing them to build up inside an organism. Additionally, PFAS are also known to biomagnify meaning that PFAS or any other substance increases in an organism’s tissues the higher up the food chain. Most importantly, humans have been found to carry PFAS, in fact, according to the Centers for Disease Control, 99% of the U.S population has PFAS in their blood. For the regular everyday person, most people are exposed to PFAS via drinking water, eating food contaminated with PFAS by food grown with contaminated soil or items packaged in grease-resistant packaging. As of currently, while there are numerous chemicals in the PFAS family, two that have been widely studied and strictly regulated by the EPA: PFOS (perfluorooctanesulfonic acid) and PFOA (perfluorooctanoic acid). According to the CDC, these two chemicals have been linked with adverse health outcomes when they get into the body. These include, increased cholesterol levels, lower effectivity of vaccines, changes in liver enzymes, kidney and testicular cancer, small birth weight as PFAS can cross through the placenta, and pregnancy-induced hypertension and preeeclampsia in pregnant women. Additionally, the EPA also states that PFAS exposure causes developmental delays or effects in the children and interferes with hormones in the body.
With how much PFAS are in the environment, it seems that they can’t be removed from the environment, however some solutions have come up in order to remove PFAS specifically from drinking water. One water treatment already in standard use and widely used is activated carbon filtration. Used mainly to absorb natural organic compounds, taste and odor compounds, and synthetic organic chemicals in drinking water treatment systems also works in removing PFAS like PFOA and PFOS. This is due to the fact that granular active carbon (GAC) is highly porous and has a high surface area that allows contaminates to get stuck within the pores of GAC but not water thus cleaning the water. Additionally, reverse osmosis and nanofiltration, two other widely used and popular ways to purify water are also extremely effective at removing PFAS. By forcing water through high pressure membranes, reverse osmosis and nanofiltration, water can be cleaned while PFAS gets caught in the filters thus freeing the water from PFAS contamination. In terms of disposing of the chemicals, there a few methods as the bonds between the PFAS molecules are so strong that it essentially makes them indestructible via natural processes. However, chemists at Northwestern University figured out how to destroy the chemicals using low temperatures and inexpensive chemicals already in wide use. The chemists identified that at the end of each PFAS molecule, there is a charged group; often charged oxygen atoms. By targeting this weak spot in the PFAS chain by heating it up alongside dimethyl sulfoxide and sodium hydroxide, it split the oxygen off the chain, leaving behind a now reactive PFAS tail.
However, as reality goes, prevention is better than the cure and there are plenty of steps that can be taken to at least reduce the amount of PFAS you are exposed to. In terms of limiting PFAS in your water, if you are concerned about possible PFAS contamination, reach out to your local utility company and ask about they are addressing PFAS and ask them to test the water. In the case that some companies do not have this information, you can also test the water yourself using EPA-developed testing methods especially if you get your water from a private well. Additionally, you can also install an at-home water treatment certified to remove PFAS. You can also contact your state environmental protection agency regarding any questions about PFAS in drinking water and waterways. In terms of reducing PFAS you consume, try limiting eating food stored in nonstick or grease-resistant packaging such as burger wrappers or pizza boxes. Fun fact, microwave popcorn bags are notorious for having high levels of PFAS along with other prepackaged foods so try buying and consuming as little of those as possible.. Additionally, if you want to transition away from Teflon coated pans, consider using cast iron, ceramic, stainless steel, or carbon steel pans. Avoiding products labeled as “waterproof” or “stain proof” will also lower your exposure to PFAS since those products often use those chemicals to have those properties.
Despite the ubiquity of per- and polyfluoroalkyl substances in our environment, food, water, products, and body, steps are being taken to eventually phase them out and alongside the EPA’s strict regulation to any PFAS chemical in drinking water, eventually PFAS will not be such of a problem and hopefully not forever chemicals anymore.
