PFAS: How key answers about the controversial chemicals

Two years ago, the EU presented a restriction proposal for the fluorochemical PFAS. However, the industry lobby has come out in strong opposition. What are these chemicals and why are they so controversial? The most important questions and answers.

What are PFAS?

The abbreviation PFAS stands for per- and polyfluorinated alkyl substances. These are artificially produced substances that essentially consist of carbon (chemical symbol C) and fluorine (chemical symbol F). According to the definition, they contain at least one so-called CF2 or CF3 group. PFAS molecules can look very different. Some are rather small and compact, others have a skeleton of long carbon chains. Their properties are correspondingly different. For example, PFAS can be gaseous, liquid or solid. Some dissolve well in water, others in fats. And some do neither.

Many PFAS provide smooth surfaces to which neither dirt, grease nor water adhere. They are extremely stable and can withstand high and low temperatures. Even many aggressive chemicals cannot harm them.

A database of the Organization for Economic Cooperation and Development (OECD) lists more than 4,700 PFAS variants. In its latest restriction proposal, the EU assumes that there are more than 10,000.

Which products contain PFAS?

PFAS are found in many everyday objects. They can be found in coatings for pans or baking tins, in cable sheathing, seals, medical tubing, membranes for weather jackets, high-tech water filters, fuel cells and electrolysis cells as well as in lithium-ion batteries.

PFAS is also used to impregnate textiles, such as carpets, sofas and curtains, as well as food papers and cartons. Fluorochemicals can also be found in bicycle chain grease, ski wax, adhesives, paints and lubricants – as well as in medical agents and pesticides. And they are used as propellants and refrigerants in heat pumps or refrigerated counters in supermarkets.

Other products do not contain PFAS, but are produced with their help. One reason: PFAS help to provide the clean environment required for many industrial processes. This is particularly true for the chemical and semiconductor industries. Components for electronic devices such as cell phones or computers, for example, are manufactured with the help of PFAS.

Because PFAS have now spread throughout the environment, they also find their way unintentionally into a wide variety of products. For example, they have been found in drinking water, fish, meat and eggs, but also in orange juice and tampons.

What are the different types of PFAS?

A distinction is made between, among others:

• Fluoropolymers or fluoroplastics: the most famous representative is polytetrafluoroethylene, trade name Teflon (DuPont). Fluoropolymers are chemically rather inactive, similar to other plastics – as long as they do not contain any emulsifier residues and are not overheated. They can be found in coatings for pans and baking tins, in seals, cable insulation and membranes for weather jackets. They are also found in batteries and fuel and electrolysis cells, for example for hydrogen production, as well as in medical tubes and implants. As wetting agents, they are also standard reagents in electroplating and semiconductor production.
• PFAS emulsifiers: They are mainly needed to build up the long chains of fluoropolymers. They include the already banned acids PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanoic acid) and their substitutes, for example GenX (trade name). PFOA and PFOS are now banned under the Stockholm Convention. GenX and others are on the list of substances of very high concern under the EU chemicals regulation REACH.
• Polymers with fluorinated side chains: These polymers carry several other carbon chains on their carbon backbone, to which the fluorine atoms are then attached. These chains act like chemical spikes that structurally reinforce the beading effect. These polymers are used as impregnating agents, for example for carpets, sofa fabrics or shoes. They can also be used to coat burger papers or pizza boxes. They are also found in ski wax, bicycle chain grease and other lubricants. They are considered more problematic than fluoropolymers as they can lose their side chains. And these in turn are related to PFAS emulsifiers, which are harmful to health.
• F-gases: These PFAS are found as refrigerants in supermarket refrigerated counters, heat pumps and car air conditioning systems, for example.
• Special case TFA: Trifluoroacetic acid (TFA) is the smallest and most mobile PFAS variant and a degradation product of many others. TFA is very mobile and is difficult to filter out of drinking water.

Are PFAS harmful to health?

PFAS are generally not acutely toxic. However, some representatives of this group of substances are known to accumulate in the body and then weaken the immune system, contribute to obesity, disrupt fat metabolism, impair fertility and reduce the birth weight of newborns. Effects on brain development, liver and kidney damage and cancers, such as testicular cancer, are also associated with PFAS representatives such as PFOA and PFOS. PFOA and PFOS have been classified as proven or probable carcinogens since 2023.

Fluoroplastics or "fluoropolymers", such as those found in frying pans or medical implants, are less of a concern. Like other plastics, the molecules usually have no chemically active groups. They do not bind to receptors in body cells, where they could trigger potentially harmful processes. They therefore generally do not pose a direct health risk – provided they do not contain any impurities from production and are not overheated. If fluoropolymers break down into tiny micro- or nanoparticles, they – can penetrate biological cells like any micro- or nanoplastic –, with currently unknown consequences. The biggest problem with fluoropolymers is that they are usually manufactured using other – PFAS, which are potentially harmful to health because they are similar to PFOA –.

The effects of the vast majority of PFAS in the environment or in the body are simply unknown.

Do people die from PFAS?

There are no valid studies on this. A study on the socio-economic consequences of PFAS initiated by the Nordic Council, an association of mainly Scandinavian countries, estimates that more than 12,000 people die every year in the EU as a result of high PFAS exposure.

How do people ingest PFAS?

PFAS are mainly ingested through drinks and food. However, the substances are also found in the air and in house dust. Some PFAS accumulate in the body in fatty tissue and organs, including in breast milk. These include, for example, PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanesulfonic acid), the best-studied and already regulated representatives of the substance group.

According to the Federal Environment Agency (UBA), PFAS are found in the blood of almost everyone, including in Germany. In a nationwide monitoring study, the UBA team found high levels of PFOA in blood samples from children and adolescents. So high, in fact, that "based on current knowledge, health damage can no longer be ruled out with sufficient certainty" in one in five test subjects. And two to three percent of the blood samples were so contaminated with the chemical PFOS that health effects "can certainly be expected". European biomonitoring has come to similar conclusions. The first results were available 15 years ago.

How do PFAS get into the environment?

PFAS are released from products such as ski wax or chain grease, from textiles during washing or lubricants from construction machinery. For a long time, they were also sprayed in large quantities in fire-fighting foam.

Fluorochemicals are also blown into the air from factory chimneys and washed into rivers with industrial wastewater. Wastewater treatment plants do not stop them completely. How much PFAS is released into the air from waste incineration plants and factory chimneys has not yet been systematically investigated.

Researchers are now finding PFAS all over the world, even in Antarctica and the Tibetan highlands. They fall from the sky with the rain, for example. Although contamination with already regulated representatives of the substance group such as PFOA and PFOS is tending to decrease, other fluorochemicals are increasingly being found.

A recent study by the German Federal Environment Agency also found an accumulation of PFAS in recycling processes, for example in paper and textiles.

Why are PFAS a problem in the environment?

Neither sunlight nor microorganisms can harm the chemical bond between the carbon and fluorine atoms in PFAS. It is one of the most stable of all. The substances remain in the environment for decades or centuries, accumulating there – and thus also in the food chain. Every new PFAS entry into soils, rivers and the air adds to the existing pollution, which is constantly increasing. Fluorochemicals are therefore also referred to as "persistent" or "forever chemicals".

What exactly does "persistent" mean?

Persistent chemicals remain in the environment for a very long time and spread there.

In addition to PFAS, examples include the insecticide DDT and polychlorinated biphenyls (PCBs), which were used as flame retardants in electronic products, among other things. These substances have been banned for decades under the Stockholm Protocol, which applies practically worldwide. Nevertheless, they can still be found in the environment and in almost everyone's body.

Can PFAS be removed from the environment?

Once PFAS have been released into the soil, water and air on a large scale, it is practically impossible to remove them completely. In order to protect people and animals locally, localized measures, such as purifying drinking water, help to limit the damage. To additionally prevent groundwater contamination, contaminated soil can be washed, walls can be built in the ground and contaminated water can be kept away from the surrounding water by pumping. However, these methods are very expensive.

What are the limits for PFAS?

The guide values for PFAS contamination in the environment, drinking water and food have been drastically reduced in recent years, in some cases by a factor of more than a thousand, so much so that the quantities found in environmental samples are higher in many places. The strictest guideline values for PFAS in one liter of drinking water or seawater worldwide are now in the range of billionths to millionths of a milligram.

For foodstuffs, the European Food Safety Authority has set new maximum levels for the four PFAS representatives (PFOA, PFOS, PFHxS and PFNA), which together currently account for around 90 percent of contamination. The values are derived from the so-called TWI value for products such as eggs, meat or fish. According to this, a person should not ingest more than a total of 4.4 nanograms (billionths of a gram) of these PFAS per kilogram of body weight. According to the Federal Institute for Risk Research, around one in two Germans exceeds this guideline value.

According to the EU regulation, a maximum value of 0.10 micrograms per liter for the sum of the concentrations of 20 specific PFAS will apply to drinking water from 2026 and an additional limit value of 0.02 micrograms per liter for the four PFAS mentioned above from 2028.

What are politicians doing?

Five countries have submitted a proposal to regulate the PFAS substance group as a whole: Germany, the Netherlands, Denmark, Sweden and Norway. Products and processes for which there are already PFAS-free alternatives should be banned within 18 months of the corresponding regulations coming into force, for example PFAS-coated pans, ski wax, cosmetics or chain grease. For applications for which alternatives have yet to be established or found, such as medical implants, transitional periods of up to 13.5 years could apply.

The various transitional periods and exemptions are based on an approach laid down in the Montreal Protocol on banning substances that damage the ozone layer. The Protocol distinguishes between essential and non-essential uses. An application is essential if it is necessary for health or safety or critical for the functioning of society and there is no better alternative in terms of health and the environment.

More than 5,600 comments were received in response to the proposal, mainly from industry and its lobby groups. The objections are currently being discussed in the relevant EU bodies according to the areas of application. It will probably be a few years before the proposal becomes a regulation.

How can I protect myself (and others) from health hazards caused by PFAS?

According to the authorities, it is hardly possible to protect yourself by taking action. In general, however, regular ventilation and damp mopping will help to reduce exposure to harmful substances. In addition, all PFAS that do not have to be produced do not cause any problems elsewhere, for example for people living in production or processing factories with poor environmental management.

For some products, it is quite easy to switch by using pans made of iron or stainless steel, uncoated baking pans and the like. Creams or weather jackets without PFAS have been available for a long time. There are also fluorine-free alternatives for shoe spray, ski wax and chain grease. However, it is often impossible to tell from the outside whether they contain PFAS or not. Pollutant apps can help with research at the supermarket shelf.

What are the costs of PFAS pollution?

So far, there are only estimates. The Nordic Council, an association of mainly Scandinavian countries, puts the health-related costs of PFAS pollution in the European Economic Area at between 52 and 84 billion euros per year. A team from New York University recently came up with similar figures for the USA, with costs of between five and a half and more than 60 billion euros for therapies, medication and lost working hours. Further billions per year are added for the purification of drinking water, the management of contaminated groundwater, landfill or the washing of contaminated soil.

What does industry say?

Industry associations are opposing the plans to regulate the entire PFAS substance group. They warn of the loss of competitiveness, innovative strength and jobs. The Federation of German Industries (BDI), for example, demands in a position paper that PFAS should continue to be assessed individually for possible harmful effects. The Association of the German Plastics Industry pro-K and international manufacturers are calling for fluoroplastics to be exempt from PFAS regulation. They do not cause any damage to health and the majority of them can be produced without PFAS. According to the lobby, there are no suitable alternatives for many applications.

This article first appeared on t3n.de.

(olb)