THE AUTHORS:<\/strong> On Tuesday, 24 March 2026, as part of the 10th edition of Paris Arbitration Week, the law firm VingtRue Avocats <\/strong>hosted a seminar on the rising wave of per- and polyfluoroalkyl substances (\u201cPFAS<\/strong>\u201d) related claims, and their impact on dispute resolution. The panel, which was moderated by Ms Sarah Becker<\/strong> (Environmental lawyer and Partner at VingtRue Avocats), included Prof. Sandrine Clavel<\/strong> (Professor of law at Paris-Saclay University), Dr Tiffany Thomas<\/strong> (Scientist and PhD in chemistry), and Mr Tony Cole<\/a> <\/strong>(Independent arbitrator JAMS<\/a>; Reader, Leicester Law School).<\/p>\n\n\n\n The conference opened with an introduction by Ms Sarah Becker regarding the nature of the crisis currently unfolding in environmental law. PFAS are frequently characterised as \u201cforever chemicals\u201d due to their unique chemical properties. These man-made substances are ubiquitous in everyday consumer products, from non-stick cookware to water-resistant clothing and firefighting foams. They possess a carbon-fluorine bond that is among the strongest in organic chemistry, preventing them from breaking down naturally over time. Consequently, they persist indefinitely in the environment and accumulate within the human body, leading to significant long-term health and ecological concerns.<\/p>\n\n\n\n Ms Becker highlighted that the legal landscape surrounding PFAS is shifting from a regulatory concern to a major litigation front. In France, \u201cmultiple proceedings\u201d are currently underway involving claims from over two hundred individuals against the chemical giants Arkema and Daikin. This litigation is centred on the pollution of the Vall\u00e9e de la Chimie near Lyon, where local residents allege systemic contamination of the soil and water tables. These cases raise fundamental questions about how the legal system should handle class claims where the harm is diffuse, the causation is hard to prove, and the scientific evidence is exceptionally complex.<\/p>\n\n\n\n A central challenge discussed was the evolution of the regulatory framework worldwide. For a long period of time, PFAS were largely unregulated in Europe, creating a period of legal uncertainty for industries. However, besides European regulations (such as REACH) and sectorial French regulations notably on drinking water, on 27 February 2025, a law on PFAS (Law n\u00b02025-188), was adopted, establishing three main pillars for future enforcement. First, the European Union has moved towards a general prohibition on the use of PFAS, albeit with certain exemptions and exclusions for \u201cessential uses\u201d where no viable alternatives currently exist. Second, new and more stringent standards have been implemented regarding the quality of drinking water, forcing municipalities to invest in advanced filtration systems. Third, industrial actors now face specific obligations regarding water discharges, including the mandatory monitoring of substances released into local water systems. Despite these steps, Ms Becker argued that the current framework remains relatively light compared to the magnitude of the environmental stakes at hand, leaving much of the burden of proof on the victims and local authorities.<\/p>\n\n\n\n Dr Thomas provided a deeper scientific perspective on the technical hurdles inherent in PFAS litigation. As a scientist expert frequently testifying in court, she explained that PFAS is a broad class of chemistry encompassing up to seven million distinct compounds according to the revised Organisation for Economic Co-operation and Development (\u201cOECD\u201d) definition of 2021. This staggering variety means that a \u201cone size fits all\u201d legal approach is impossible. From a litigation standpoint, the core difficulty lies in establishing what the relevant parties knew and when. While some safety data sheets explicitly mention PFAS, many others do not name the compounds or use proprietary trade names, complicating the task of tracing liability through complex global supply chains.<\/p>\n\n\n\n Dr Thomas further emphasised the \u201ctest method\u201d dilemma. As there is currently no single, universally reliable method to quantify the presence or concentration of the thousands of different PFAS substances in a given product or environment, different testing laboratories use different methods that can yield vastly different results for the same sample. For legal practitioners and arbitrators, this lack of standardisation requires a constant and sophisticated dialogue with scientific experts to ensure that the data presented in a dispute is both accurate and relevant to the specific legal claim being made. Scientific uncertainty often becomes a weapon used by defendants to dispute the causation between chemical exposure and the alleged health defects arising therefrom.<\/p>\n\n\n\n Ms Becker then shifted the focus toward the role of international arbitration. While PFAS has been a major focus in the United States and the United Kingdom for over a decade, it has only recently begun to appear on the radar of the international arbitration community. Ms Becker noted that several areas of law are likely to see an increase in PFAS-related disputes. In contract law, specifically regarding Share Purchase Agreements (\u201cSPA\u201d), buyers are increasingly seeking recourse against sellers for undisclosed environmental liabilities discovered after a transaction.<\/p>\n\n\n\n Furthermore, insurance law is becoming a primary battleground. As insurance companies move to explicitly exclude PFAS-related risks from their policies, businesses find themselves in arbitration with their insurers over the scope of coverage for past and future pollution claims. The interpretation of \u201coccurrence-based\u201d versus \u201cclaims-made\u201d policies will be crucial in determining who bears the financial weight of these environmental disasters.<\/p>\n\n\n\n Prof. Clavel analysed why arbitration might be a more suitable forum than national courts for these disputes, even for claims involving non-governmental organisations (\u201cNGOs<\/strong>\u201d) or third-party victims. She identified several procedural advantages. Environmental pollution cases often involve multiple causes, multiple parties, and require extreme technical expertise that traditional judges may lack. Arbitration allows the parties to select adjudicators who possess the specific scientific or industrial background necessary to understand the evidence. It also offers a flexible procedural framework that facilitates the cross-examination of expert witnesses and the management of massive amounts of technical documentation.<\/p>\n\n\n\n Moreover, Prof. Clavel highlighted the issue of neutrality. Depending on where the pollution occurred, parties may face local courts that are perceived as biased, politically influenced, or simply lack the competence to handle such specialised litigation. Arbitration provides a neutral level playing field that is particularly important when a dispute involves a multinational corporation and a local community. It offers a degree of confidentiality that can be beneficial for sensitive industrial data, while also allowing for amicus curiae interventions from civil society to ensure a degree of transparency.<\/p>\n\n\n\n Finally, the discussion turned to the legal basis for bringing third parties, such as pollution victims, into the arbitration process when no prior contract exists. Prof. Clavel explained that while this is often complex, several theories are gaining traction in practice. Parties may agree to a submission agreement (known in French law as a compromis) after the harm has occurred, recognising the efficiency of the arbitral process. Additionally, scholars are examining alternative jurisdictional foundations, specifically focusing on the concepts of \u201cimplied\u201d authority and the \u201csocial licence to operate,\u201d These theories often rely on the principle of the sovereignty of people over their natural resources, a key principle of public international law. Under this view, if a company exploits natural resources and creates negative externalities, i.e., pollution, it must be held accountable to the local population through a fair and accessible dispute resolution mechanism.<\/p>\n\n\n\n Prof. Clavel concluded by underscoring the need to balance, on the one hand, the strengths of procedural creativity and the ability to explore new legal possibilities that arbitration offers against the requirements of public interest and transparency, on the other hand. Mr Cole added that, unlike local courts, arbitration is not strictly bound by precedent, allowing it to explore innovative solutions and even cooperate with local judiciaries to address the unique complexities of \u201cforever chemical\u201d contamination.<\/p>\n\n\n\n This article was originally published in PBA Bulletin on 17 April 2026, as part of a special edition curated by Paris Baby Arbitration (PBA)<\/a>, in collaboration with Jus Mundi <\/a>and Jus Connect<\/a>.<\/p>\n\n\n\n
Souka\u00efna El Mansouri<\/strong>, Trainee Lawyer at the EFB<\/strong> (\u00c9cole de Formation du Barreau)
April Hoang<\/strong>, Master 2 International and European Law Candidate, Universit\u00e9 C\u00f4te d\u2019Azur<\/strong><\/p>\n\n\n\n
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As part of Paris Arbitration Week 2026, Paris Baby Arbitration (PBA)<\/a><\/strong>, in collaboration with Daily Jus<\/a><\/strong> and Jus Mundi<\/a><\/strong>, brings together contributions in a special edition of PBA Bulletin<\/a>,<\/strong> sharing reflections and perspectives from across this year\u2019s events.<\/em><\/h4>\n<\/blockquote>\n\n\n\n
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