To coincide with the release of our updated FAQs on PFAS-free alternatives in green technologies, CHEM Trust sat down with Eleni Savvidou, a PhD researcher at Stockholm University. Eleni’s research focuses on understanding the occurrences of PFAS, how to analyse them, and what PFAS-free alternatives might look like in a range of consumer and technical applications, such as lithium-ion batteries.
What are PFAS?
PFAS is short for per-and polyfluoroalkyl substances. The Organisation for Economic Co-Operation and Development (OECD) defines them as fluorinated substances that, in their molecular structure, contain at least one carbon atom with either two or three fluorine atoms attached, and no hydrogen, chlorine, bromine, or iodine atoms attached to that same carbon atom. The OECD definition is broad and the PFAS covered within this definition have different chemical properties. However, what all PFAS have in common is that they are very persistent. This is mainly due to the strength of the carbon fluorine bond, which is the strongest bond you can find in organic chemistry. Therefore, either PFAS hardly degrade in the environment, or they can transform into other persistent PFAS. And, of course, some PFAS have been shown to be problematic.
Why are PFAS problematic?
PFAS are very persistent synthetic chemicals that hardly break down, meaning their concentrations will keep rising in the environment (like water, soil and air). PFAS can also build up in the bodies of organisms over time. Scientific evidence indicates adverse effects of the few PFAS that have been studied on human health and the environment, highlighting the need for a precautionary approach to managing PFAS. The effects of some PFAS are well understood and cannot be extrapolated to all. Each PFAS may act differently, but the combination of persistence and accumulation means that harmful effects are not avoidable in the long run.
Can you tell us more about the focus of your PhD research?
My research involves measuring PFAS in consumer products and investigating if these uses have any PFAS-free alternatives. I use the fluorine mass balance approach to determine whether PFAS are present. First, we measure the total fluorine content, which can be from either inorganic or organic sources. Then, we extract the sample to measure the organofluorine fraction, which is more likely to include PFAS, and combine this with targeted analysis to track down specific known PFAS. By comparing these three measurements, we can assess whether the fluorine detected can be explained by known compounds or whether there may be additional, unknown PFAS present in the product. I also analyse environmental samples to monitor PFAS emissions connected to lithium-ion batteries (LIBs). The next step in my research is to understand why certain PFAS are used in a product and if other materials or technologies could provide the same function as PFAS.
Are any PFAS used in Lithium-ion batteries?
PFAS are used in batteries. Polymeric PFAS, like the fluoropolymer Polyvinylidene Fluoride (PVDF), is used as a binder in the cathode, and low molecular weight PFAS, for instance, LiTFSI, are used in the electrolyte, mostly as additives to enhance performance.
Can you explain what fluoropolymers are?
Fluoropolymers are a subgroup of PFAS known as polymeric PFAS. They are repellent to water and oil, have special mechanical properties, and are resistant to heat, harsh chemicals, and other biological stressors. They are also not as toxic as other low molecular PFAS. But sometimes you hear the claim that because fluoropolymers are not toxic, they should be excluded from regulatory measures. However, the issue with fluoropolymers is their life cycle. Science has shown that there is a high risk of harmful low molecular weight PFAS being emitted into the environment during the manufacturing of fluoropolymers, during the use phase of fluoropolymer containing products (for example, incorrect handling of the product) and also during the end-of-life stage, i.e., when it goes to recycling or landfill. So, we must look at the big picture regarding fluoropolymers.
Have you found any PFAS-free alternatives in your research on Lithium batteries?
A lot of knowledge on new technology in the lithium battery sector is proprietary, which makes it tricky to have comprehensive information on the alternatives. What I have learnt during my PhD research is that PFAS added to the electrolyte to enhance the battery performance is not necessary for the functioning of the battery, and so it should be more feasible to phase out PFAS from the electrolyte. It is trickier to replace PFAS from the cathode, but some companies offer commercially available alternatives. One company offers nanocarbon material, other companies offer non-fluorinated water-soluble polymers and semi-solid battery chemistry. So, it is not impossible for the battery industry to replace PFAS from both electrolytes and cathodes.
Do you think the uPFAS restriction plays a role in the innovation of PFAS-free alternatives?
It is good that the uPFAS restriction addresses the whole class of PFAS, not just a few, which means that we can avoid shifting to other PFAS that are possibly even more problematic. It is an opportunity for the industry to be more conscious while designing chemicals to ensure they are safe and comply with the regulation. The restriction is not in place yet, but some companies are already motivated to phase out PFAS. Also, consumers nowadays are becoming more aware of the PFAS problem and are demanding PFAS-free products. So, if the demand for PFAS-free products is growing, the industry must also be willing to adapt to these requests. You can already see many companies labelling their products as being PFAS-free. So, the restriction will help in the innovation of safer products and technologies.
What would regulating PFAS mean for the EU’s competitiveness and businesses?
The incentive to regulate PFAS is not only a European matter, but regulatory activities are going on in other parts of the world, as well. This is a chance for European businesses to become leaders in more sustainable technologies. Regulating PFAS will not be a disadvantage for EU competitiveness. It is a misconception that the restriction will just come into effect tomorrow, and then the industry will have to stop using PFAS immediately. Some battery experts I spoke to estimated that it will take up to 7 years to replace PFAS. Given that the uPFAS restriction gives some sectors several years to come up with alternatives, industries have ample time to innovate. The uPFAS regulation is the start of a race for technology innovation.
Why should green technologies be PFAS-free?
Well, if it is called “green technologies”, then it is expected that these technologies provide an environmental benefit compared to other technologies. So far, the focus is on the CO2 emissions; we are trying to switch away from fossil fuel technologies and use technologies that are more climate-friendly. However, this does not mean that we should take the risk to shift from one problem to another, in this case, chemical pollution. There should be a balance, to use technologies with low CO2 emissions and climate impact, but also use materials that are safe for humans and the environment, including in the longer term, so that the safety and health of future generations are better protected.
