PFAS polymers in focus: supporting Europe’s zero pollution, low-carbon and circular economy ambitions

This briefing is underpinned by an earlier joint report from the EEA’s European Topic Centres on Waste and Materials in a Green Economy (ETC WMGE) and Climate Change Mitigation and Energy (ETC CME) (ETC/WMGE & ETC/CME, 2021) supplemented with information from more recent literature.

Introduction

Per- and polyfluoroalkyl substances (PFAS) — also known as forever chemicals — have received increasing attention over the last two decades. This is due to growing awareness of the negative impacts that these substances have on human health and the environment. Ongoing efforts in the European Union (EU) to restrict PFAS as a group have been justified by their high persistence and other concerning properties present in certain PFAS subgroups. These include their bioaccumulation in humans and wildlife, high mobility (they can move through the environment and pollute drinking water sources), long-range transport potential  (they can pollute areas far away from emission sources) and their accumulation in plants (they can pollute food sources), and (eco)toxicological effects that may impact on humans and the environment (BAuA et al., 2023).

This large and heterogenous group of chemicals consists of more than 10,000 individual substances, which can broadly be divided into polymeric and non-polymeric forms. PFAS polymers constitute a significant part of the total use of PFAS in the EU. It is estimated that they make up between 24-40% of the total volume of PFAS on the EU market (BAuA et al., 2023). They are widely used in consumer products such as textiles, non-stick pans, electronics and furniture. They are also used in industrial production — for example in machinery, filters, lubricants, seals and membranes. Increasingly, they are also used in green technologies that promise to deliver solutions for a low-carbon economy.  However, despite their widespread use most of our knowledge about their detrimental effects relates to the non-polymeric forms. This leaves significant knowledge gaps about the impacts of PFAS polymers, except for the well-established fact that they are very persistent.

Polymers are generally considered relatively less problematic than the monomers (building blocks) from which they are made. This is due to the polymers having a larger molecular size, which limits their uptake into living cells (and therefore limits their potential toxicity). However, PFAS polymers can have several environmental and human health impacts at different stages of their life cycle. Concerns have been raised about the chemicals used to manufacture them (feedstock chemicals and PFAS monomers) and the different by-products generated during their chemical synthesis. There are  additional environmental and human health concerns prompted by the degradation over time of certain PFAS polymers into smaller, persistent and bioavailable compounds. The different types of impacts are further described in the different life-cycle steps outlined below.

Pollutants are emitted along PFAS polymer life cycles

Chemicals used to make the PFAS polymers and chemicals emitted along the life cycles of PFAS polymers (see Figure 1) have led to significant impacts and pollution.

Figure 2. The life cycle of PFAS polymers, from production to waste

Production of PFAS polymers

The PFAS polymer production phase typically takes place in ‘closed systems’. Nevertheless, there are repeated cases of workers  — as well as the environment and communities surrounding factories —  having been heavily polluted from PFAS escaping these closed systems. ‘Teflon flu fever’ is a term workers use to describe the symptoms experienced after high exposure to fumes from the PFAS polymer polytetrafluorethylene (PTFE). Across Europe and the US, there are cases of polymerisation aids — such as PFOA and GenX and a variety of synthesis by-products — having polluted the soil, drinking water, food and people living close to the factories (ETC/WMGE & ETC/CME, 2021).

A less studied issue is the release of volatile fluorinated substances. These are potent climate gases or substances that can degrade the ozone layer. They are used as feedstock chemicals to produce some fluoropolymers or can be formed as synthesis by-products. For example, the greenhouse gas trifluoromethane (HFC-23) and the ozone-depleting substance dichlorofluoromethane (HCFC-22) are formed as by-products in PTFE production. HFC-23 has a global warming potential 12,400 times greater than CO₂. Estimates suggest that in 2018, 1,800 tonnes of HFC-23 were emitted as a by-product — this figure resulting from PTFE production alone (ETC/WMGE & ETC/CME, 2021). To date, few monitoring studies exist on the emissions of such greenhouse gases, ozone depleting substances and other fluorinated gases from PFAS production facilities.

Manufacturing of products with PFAS polymers

During the products’ manufacturing phase, PFAS polymers are made into products or are applied as films on or mixed into other products. At this point, the polymers or PFAS additives, impurities, synthesis by-products or degradation products may be released. Emissions may occur when the PFAS polymers are being applied, for example as surface coatings, which can expose workers or alternatively be ventilated with the air, or via insufficiently cleaned wastewater or spills.

Use of products containing PFAS polymers

In the use phase, fluorinated polymers can offer clear advantages in terms of performance; this relates to durability, repellence, decrease of friction, heat resistance and also their ability to stabilise emulsions — of oil and water, for example. These advantages have resulted in fluorinated polymers being used extensively in a wide range of products. Consequently, this has led to a dependency on some product types that fulfil critical roles in our society. In addition, PFAS polymers are used in products that are considered important in combatting climate change; these include fuel cells, lithium-ion batteries, solar panels and semiconductors. There are many claims about the necessity of using fluorinated polymers in applications that support a transition to a digital and low carbon economy. It can be a challenge to identify these uses, for which no suitable alternatives are available. At the same time, PFAS polymers are contained in many everyday products that can lead to pollution and for which suitable alternatives are available. As an example, PFAS polymers can enter the environment via wastewater, for example when washing textiles containing PFAS. PFAS can be released from the wastewater treatment-plants, either to the aquatic environment via discharge water or be deposited in sewage sludge, which is sometimes spread on (agricultural) soils (EEA, 2024).       

Waste and recycling

During the end-of-life phase, PFAS polymers may again be degraded into substances which have the potential to harm human and ecosystem health and the ozone layer and/or are greenhouse gases. This can happen via waste disposal through landfilling or incineration. The presence of polymeric PFAS in the environment may therefore be a significant long-term source of non-polymeric PFAS (EEA, 2024). The widespread use of PFAS polymers in a diverse array of products — and in rather small amounts in each product — means that it is difficult and costly to set up collection and separate destruction schemes for all of these products. Tracking or identification of PFAS content in products at the waste stage is currently only feasible for certain product types with separate collection systems. This means that products containing PFAS are often mixed with other waste streams.

Recycling of PFAS containing materials may result in prolonged exposure. In the case of recycling textiles, for example, PFAS might be introduced into new product types where they were not intended to be used. PFAS containing products at the end-of-life stage can hence result in uncontrolled exposure to humans and releases to the environment as a result of recycling. Alternatively, they can act as a barrier to recycling by moving materials out of circularity and into landfill or incineration.

Landfilling of products made of PFAS polymers can lead to the PFAS contaminating leachates. All PFAS polymers are extremely persistent in the environment. To date, their potential degradation over time into smaller molecules is not well understood. However, it is expected that one of the main types of PFAS polymers — side-chain fluorinated polymers — can degrade and form non-polymeric PFAS in the environment (OECD, 2021). Even the highly-resistant fluoropolymers will be fragmented into smaller molecules by weathering and physical stress over time, which may increase PFAS uptake into living organisms (Lohmann et al., 2020).

Very few studies have investigated which substances are formed and in which quantities when PFAS containing waste are burned in incineration plants or during uncontrolled burning of waste. Laboratory studies and material performance tests clearly show that a variety of fluorinated gases and acids such as trifluoroacetic acid (TFA) are formed at temperatures below about 1000°C (ETC/WMGE & ETC/CME, 2021). Above approximately 1050-1400°C, complete breakdown to hydrogen fluoride (HF) occurs, meaning that no PFAS will be left. However, the EU Waste Incineration Directive (EU, 2000) only requires a temperature of 850°C for non-hazardous waste; this suggests that the PFAS polymers may not be fully degraded in waste incineration facilities. One study reports that the incineration of specific fluoropolymers could account for up to 14% of the TFA burden in rainwater (Cui et al. 2019). However, another study found a very high degree of mineralisation (complete break-down) of the PFAS polymers during incineration under optimum conditions at two temperature settings of 860°C and 1095°C (Gehrmann et al., 2024). TFA is now widely found in rainwater and drinking water across the globe (Arp et al., 2024). However, based on our limited knowledge and conflicting results, it is currently not known if waste incineration of products containing PFAS is a significant contributor to this pollution.

Table 1 below contains a summary of the potential benefits and risks from the use of PFAS polymers in relation to the environment and health policies.

Table 1. Potential benefits and risks from the use of PFAS polymers in relation to various environment and health policies

Conclusion and next steps

Although the synthesis of PFAS polymers takes place in closed systems, evidence shows that emissions of non-polymeric PFAS can occur all along the life cycle. They can be emitted at all stages, from ingredient production to producing the polymer; from reshaping it into a product to  the product’s use, from its recycling or reuse of the product to its disposal by land filling or incineration. The resulting pollution has spread widely and has accumulated in water, air, soil, people, biota and food. Although many resources are being targeted at the development of remediation methods and while progress is undoubtedly being made, it is currently practically and economically impossible to clean up the pollution with currently-available techniques.

The EU chemicals strategy for sustainability (CSS) (EC, 2020) included several actions that have targeted PFAS polymers including an envisaged approach to address PFAS as a group of chemicals. Other actions include focusing on pollution along the life cycles of chemicals and products and to include persistent and mobile pollutants (PMT/vPvM) as a hazard category under CLP (classification, labelling and packaging regulation).

PFAS polymers currently have important uses in a wide range of systems and specificities, including green technologies, medical devices, defence and aerospace. In general, they help increase the durability and performance of products, which creates benefits for society. However, as illustrated in this briefing, the PFAS life cycle can also potentially impact on the environment and human health, with some also being linked to climate change. These effects bring their overall benefits into question. This briefing also underlines the need to address the different types of impacts caused at the different life-cycle steps of PFAS polymer production, use and end-of-life, so that important impacts are not overlooked.

A recently-proposed universal PFAS restriction under REACH, brought forward by Denmark, Germany, the Netherlands, Norway and Sweden, aims to ban all PFAS (including PFAS polymers) except for certain uses which have time-limited derogations (BAuA et al. 2021). In a recent communication from ECHA and the dossier submitters, it was stated that restriction options, other than a ban, were also being considered for some uses (ECHA et al., 2024).

Evaluation of the future use of PFAS polymers, as being currently performed in the context of the proposed REACH restriction, addresses the possibilities for substitution and also includes the possibility to take into account the importance of specific uses to society. The proposal is currently being discussed by the scientific committees in ECHA, after which it will be referred to the European Commission for decision.

In this context, the Commission has expressed its commitment to bring clarity for PFAS as part of the Chemicals Industry Package expected for late 2025.