What is PFAS?
We get PFAS into our bodies every day without realising it. They are chemicals found in many everyday products and can be harmful to humans and the environment. It is a collective name for poly- and perfluoroalkyl substances. This is a complicated name for some 6,000 chemicals.
What about the non-stick coating?
We know the synthetic non-stick coating from those cheap pans, which you purchase again and again every 1-2 years and which you are not allowed to poke with your fork.
For the somewhat tech-savvy among us: there are several types of non-stick coatings. Each non-stick coating contains many technical terms that we explain below.
Non-stick coating made of fluoropolymer
The non-stick coating contains a coating made of fluoropolymer, which is a type of plastic. This is used by manufacturers around the world as a non-stick coating in pans. This fluoropolymer is made from PFAS. Molecules of these fluoropolymers are very sturdy and water-repellent. That way, they ensure that food does not stick to your pan during frying.
Teflon non-stick coating
Teflon is the brand name for several plastic fluoropolymers such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene), ETFE (ethylene tetrafluoroethylene) and PFA (perfluoroalkoxy). It was discovered by DuPoint in 1938. Teflon first came into commercial use in 1949. In 1954, French engineer Marc Grégoire invented a method to bind Teflon to aluminium. He then founded a company with aluminium pans with, you guessed it, a Teflon coating. He called this company "Tefal", a combination of Teflon and aluminium.
Titanium non-stick coating
There are also pans with a titanium non-stick coating. The coating of these pans consists of PTFE and titanium. A layer of titanium dioxide particles is applied over the pan's aluminium. This makes the coating wear less quickly but this is still a synthetic non-stick coating using PFAS.
How toxic are all these substances?
Small crumbled bits of your non-stick pan that you swallow are not directly dangerous to humans, as the body does not break them down, and they simply leave the body again via the faeces. However, if bits of non-stick coating come off, or there are scratches in the pan, you should throw away such a pan immediately. As it is precisely on the frayed edges that monomers (such as hydrofluoric vapours) can form that can be toxic. A damaged plastic non-stick coating is also more likely to cause food to burn. Burnt-on food contains substances (such as PAHs) that are harmful to health.
Is PFAS toxic?
Once PFAS is processed into a polymer, such as Teflon or Teflon spray, these substances are (almost) non-toxic. In normal use, a pan with a fluoropolymer coating (such as a Teflon pan) is safe as long as the pan is not overheated, so never heat the pan 'dry', without butter, oil or other contents.
Is PTFE toxic?
PTFE can tolerate temperatures up to 260 degrees Celsius quite well, but above that temperature, the non-stick coating is no longer heat-resistant and deteriorates rapidly. On average, we roast our pork chops at a temperature between 200 and 230 degrees. Above that, your piece of meat will burn. But if you are not careful, things go wrong and a traditional frying pan reaches a temperature of 260° after only 4 minutes. So it is not that difficult to get a pan to a temperature where the Teflon layer gets too hot.
At temperatures above 350 degrees Celsius, PTFE starts to disintegrate and can release very low amounts of hydrofluoric acid vapours (an etching acid that damages the inner lining of the lungs), among other things. For humans, these fumes can be irritating and cause flu symptoms.
What about the story of the canaries in the mines?
Birds are very sensitive to these fumes and can even die from them. In fact, birds are very sensitive to toxic fumes. This is due to their efficient gas exchange. This is what enables geese, for example, to fly at high altitudes where there is little oxygen. But the downside is that they get poisoned quickly. Due to this sensitivity, canaries were used in mines in the past: if they fell off their sticks, apparently gas had been released and miners had to get out immediately. Birds are also easily affected in the house. Among other things, the animals are bothered by aerosol propellants, and you should never leave them in the kitchen while cooking.
The biggest problem of the synthetic non-stick pan
However, the real problem with synthetic non-stick coatings is manufacturing. You can only make it with PFAS, whichever of the more than 6,000 types. And after production, PFAS waste remains and has to be discharged somewhere, usually these fluorine compounds are discharged into surface water water and air. Via rivers, they end up in our drinking water and in dredging sludge. Rainfall causes them to settle on the soil, even far beyond production sites.
A characteristic feature of PFAS is that the chemicals have at least one carbon-fluorine bond, a chemical bond so strong that you can't just pull it off – like sticking two Lego bricks together with superglue. This ensures that PFAS virtually does not break down in nature and tends to accumulate in our bodies. It earned the substances the nickname 'forever chemicals'. In the Netherlands, excessive concentration in the soil regularly halts construction projects. And of the over 6,000 PFAS compounds produced by the industry (every PFAS molecule in the world is a manmade product), quite a few have even already been found in Antarctic ice, as well as in the blood of polar bears, for example. The problem is similar to DDT and dioxins – toxins we had to deal with before.
Is PFAS bad for humans?
Studies show that several of these PFAS molecules can be dangerous for humans. A large-scale study in the US state of Ohio, among local residents and workers at a DuPont plant where PFAS variant 'PFOA' was made, found a "plausible link" between long-term exposure to those substances and an increased risk of cancer, certain autoimmune diseases and unborn children malformations. So PFAS does do something in the body.
The adverse effects are as diverse as the substances themselves and depend on the degree of exposure. They include increased risks for kidney and testicular cancer and liver disease, for example. Some PFAS also increase cholesterol levels. PFAS bind well to the blood protein albumin and thus spread in the human body.
Recent research additionally suggests that PFAS affects our immune system. This shows a worrying link between PFAS and the amount of antibodies children produce after vaccination. This potentially leads to PFAS in our blood making vaccinations less effective, and our resistance to disease in general deteriorating. Moreover, that effect probably already occurs at the PFAS concentrations most of us already have in our blood.
Are PFAS alternatives also bad?
Industry is coming up with alternatives in the manufacturing process, such as GenX. The industry claimed that the substances used in GenX technology are safer because the residence time in the body is shorter (1 day versus, say, 4 years for PFOA), but unfortunately those substances ultimately prove just as persistent – it is in our water, soil and air. And we now know that it shares some toxic properties with PFOA.
What are we doing about it?
In 2020, an international group of scientists proposed that all PFAS be equalised before the law and that the use of all such PFAS substances be restricted. This is necessary because otherwise the chemical industry will replace banned substances with new, unregulated PFAS variants.
This fits well with a proposal announced by the Netherlands to the European Union in late 2019 to ban all more than six thousand known PFAS compounds in Europe. This would take 5 years to ban PFAS compounds. Currently, the substances are still covered by standard regulations.
Is there also good news?
At Princeton University in the US, a bacterium has been discovered – Acidimicrobium bacterium A6 – that can largely break down PFAS. The bacterium, as a kind of bite, causes the molecule to break down into carbon and fluorine, virtually eliminating the harmful effect. Efficacy has only been tested in the lab and not yet in the outdoor environment. Prerequisites are proper acidity and iron concentration in the soil, but there is a way around that. Further research and fieldwork is needed. However, a way has been found to break down these harmful substances, which is hopeful.
However, there are plenty of alternatives to PFAS. Switching to PFAS-free alternatives is often not only possible, but easy to do.