As regulators and growing public awareness have put the screws on some of the more well-known PFAS chemicals, other variants are marketed as safe and are rarely scrutinised. One such chemical is PTFE – an unregulated chemical in the PFAS family – which is used in a plethora of consumer products, giving materials that desired non-stick function.
The question is – is PTFE really as safe as manufacturers claim?
When you drive your car, hurl yourself down a ski slope or cook your dinner you have most likely come into contact with the chemical PTFE. You can find it in such diverse products as non-stick cookware, ski wax, car interiors and dental floss.
PTFE, or polytetrafluoroethylene (promise you don’t need to remember that), belongs to a subgroup of PFAS called fluorinated polymers, and PTFE is by far the most popular one in the group; it makes up approximately half the market.
One of the most familiar uses is in Teflon, but that’s just one of its applications. PTFE is a chemical substance that has unique properties that make it very popular in a wide range of products. It has excellent heat resistance, electrical insulation properties and is extremely water repellent. Its non-stick properties make it ideal for coatings on items such as baking trays and other kitchen utensils. You can also find it in membranes in outdoor jackets and other textiles.
As awareness around the problematic effects of PFAS chemicals has started to grow, the notion of PTFE as safe to use has persisted among its proponents, even though there is not much evidence for anything, really. There are still many unknowns when it comes to the effects of PTFE, as is often the case with chemicals.
“There are no regulations in place that require chemical producers to disclose PTFE production”
Unfortunately you can’t just consider the finished product – the frying pan in your hand. You have to look beyond this “use phase”, before the PTFE was applied to the product. The thing is that a chemical has two more such phases in its life: the production and the waste phase. When you bring these additional phases, and the available science, into the analysis, well, then PTFE, you’re not looking so great there, buddy.
Let’s start with production.
We don’t know where they are produced
Little is known about where PTFE and other fluorinated polymers are produced in the world as there are no regulations in place that require chemical producers to disclose this.
Within the EU, the European Pollutant Release and Transfer Register requires chemical manufacturers to report emissions into the air, water, and land from a number of pollutants. But producers of fluorinated polymers do not have to specify that they produce these particular substances. What you can do is measure the amount of PFAS in the air to indicate fluorinated polymer production sites, since you need PFAS as a production aid when manufacturing fluorinated polymers. In other words – production of fluorinated polymers can be a source of PFAS emissions.
According to a recent report from the EEA, several harmful substances have been reported in wastewater or river water downstream of plants known to be manufacturing fluorinated polymers.
Emissions of PFOA, PFNA and other by-products from production sites have been documented in both China and the United States over the years. The emissions have been shown to lead to widespread environmental contamination of air, soil, water, and food.
One example is from a Dutch manufacturing plant belonging to the chemical company Chemours. PFOA was detected in leaves and grass within three kilometres northeast of the plant, with concentrations decreasing with distance. It was advised not to consume vegetables grown within a radius of one kilometre of the plant.
Burning of PTFE creates PFAS
Ok, so now we know that in order to produce PTFE you need to use PFAS, which is obviously a huge problem.
“In order to produce PTFE you need to use PFAS”
To understand the issues with the waste phase we need to make a quick visit to the chemistry class. PTFE in its finished form is made up of several thousands of carbon atoms that are chained together in a molecular structure called a polymer, or fluoropolymer in the case of PTFE.
The fact that PTFE is a polymer makes it different from other chemicals in the PFAS family. Many well-known PFAS, like PFOA, only consist of seven to fourteen carbon atoms, and others have even less than seven. In comparison to PTFE, most other PFAS are short chained.
Now, everyone with a microscope agrees that these short-chained, non-polymeric PFAS are very problematic, but there are fewer studies on polymers such as PTFE, simply because no one really asked for that.
The problem with PTFE is that when it gets really hot, the long molecular chain collapses into, yes you guessed it, a short chain. And when does PTFE get really hot? When you fry something in your frying pan is one example, but an even better one is when you throw the frying pan away for good. Then it is incinerated like the vast majority of all other garbage (even though some would like you to believe that we are recycling our waste instead of burning it).
All evidence points to PFAS being formed when PTFE is incinerated. And where do these substances go? They are not collected and treated at the incineration plant, that’s for sure.
The end result is that PFAS released from PTFE have been found in urban wastewater treatment plants, both from households and industry. Typically, traditional wastewater treatment processes are not designed to degrade persistent chemicals, which means they do not remove PFAS from water or sludge.
Sewage sludge from wastewater treatment plants is often applied to agricultural fields or sent to landfills for disposal. Either way, the bad stuff ends up in the soil. Currently there are no EU criteria for organic contaminants in soil, which means there are no limit values for PFAS or any legal obligation to monitor for them in wastewater sludge.
There have been several instances of widespread pollution from treatment plants in both Europe and the United States. Court cases have been settled in the United States, where companies have been forced to pay fines for contaminating surrounding communities and livestock.
“There are several alternatives that perform equally well”
Will PTFE be banned anytime soon?
So, with all this evidence showing that PTFE might not be so great after all, surely regulators must be cooking (no pun intended) something up?
Actually, yes. Within the EU, five member states (Sweden, Germany, Denmark, Netherlands, Norway) are working on a restriction that aims to ban the use of all PFAS, about 5,000 substances, except for “essential uses”. The definition of PFAS used in this restriction includes fluoropolymers, such as PTFE. Such a broad restriction has the potential to make a big impact on preventing and minimising human and environmental exposure to PFAS.
But well before the restriction comes into effect, many companies have already started moving away from the use of PTFE.
For some uses, such as PTFE membranes in outdoor jackets, or PTFE-coated frying pans, such as Teflon, there are several alternatives that perform equally well. In cosmetics, which is another sector where the use of PTFE (and other PFAS) has been extensive, many alternatives have been identified.
For other, industrial and “professional” uses, for example in pipes and coatings, there are still areas where there is a lack of alternatives. In addition, PTFE is a versatile substance, with a diverse array of functions in different products, so there are no silver bullet alternative that can always do the job. Instead many different alternatives, with different chemistries and properties, are necessary to replace the use of PTFE.
At ChemSec we expect there will be big changes in the industry in the coming years. The looming restriction combined with the strong urge from many brands to move away from PFAS and PTFE, and the growing availability of safer alternatives certainly is positive. But in the meantime, before that happens, be wary when someone claims that PTFE in their particular product is safe.