PFAS-related damage: difficulties in establishing non-contractual liability

I.            Preliminary Remarks

Per- and polyfluoroalkyl substances (PFAS) is a group of several thousand synthetic industrial chemicals that are slow to degrade in the environment and referred to as "forever chemicals". They possess numerous beneficial properties. For example, they are grease, dirt, and water repellent and have been used for decades in a wide variety of products and processes. Typical applications include firefighting foams, non-stick coatings in pans and other kitchen utensils, coated paper and cardboard (e.g. takeout packaging or baking paper), ski wax, grease- and water-repellent textiles (e.g. outdoor clothing or protective gear), and cosmetics. PFAS are also found in climbing ropes, guitar strings, ammunition, and artificial turf, and the manufacture of electronic devices and electroplating.

The scientific community generally accepts that most PFAS are easily absorbed by organisms and accumulate in the human body, animals, sediments, and plants. Since 2024, perfluorooctanoic acid (PFOA) has been classified as carcinogenic, and perfluorooctanesulfonic acid (PFOS) as possibly carcinogenic.

In the EU, the regulatory framework regarding PFAS limits is becoming increasingly stringent. The EU Contaminants Regulation sets maximum levels for specific PFAS in certain foods while the EU Drinking Water Directive establishes limits that will be mandatory for 20 PFAS starting in January 2026. Stricter regulations apply to firefighting foams containing PFAS. Beginning 12 August 2026, the Packaging Ordinance will then prohibit packaging that comes into contact with food if it exceeds a certain PFAS concentration.

In Switzerland, Annex 2 of the Ordinance of the Federal Department of Home Affairs on Drinking Water and Water in Public Baths and Shower Facilities (TBDV) sets the maximum levels for certain PFAS (i.e. PFOS, PFHxS, and PFOA) in drinking water. The amendments to the EU Drinking Water Directive are to be incorporated into the TBDV as well. The maximum levels of PFAS in food of animal origin are then regulated in Switzerland by the Ordinance of the Federal Department of Home Affairs on Maximum Levels for Contaminants (VHK) in Annex 8a, Part B. Finally, the Ordinance on the Reduction of Risks relating to the Use of Certain Particularly Dangerous Substances, Preparations and Articles (ChemRRV) prohibits the manufacture, use, and placing on the market of certain substances and preparations containing PFAS.

There appear to be no precedents on this matter in Switzerland. The situation is different in Sweden, Belgium, Italy, Netherlands and Australia. The US has seen a significant expansion of PFAS litigation in recent years. 
 

II.           Bases for Non-Contractual Claims 

A.           Tort liability under Art. 41 et seq. Code of Obligations (CO) 

If a person suffers damage from products containing PFAS or being exposed to PFAS emissions, the injured party may be entitled to damages if the damage was caused at least through negligence and was unlawful or contrary to public policy. The harmful health effects of PFAS means the damage will typically consist of personal injury (e.g. medical and nursing costs, loss of earnings, or compensation for non-pecuniary damage).

1. Difficulties in determining standing to be sued 

Given the nature of the personal injuries typically involved, it is likely that, in most cases, it will no longer be possible to determine which products–and which potential defendants–were the source of PFAS exposure.

Situations in which the defendant can be more easily identified due to a particularly high level of PFAS contamination attributable to specific events must be assessed differently. This may be the case in the event of contamination of groundwater or soil caused by a specific source (e.g. a firefighting training site) and it can be proven that the injured party was located within the area of contamination.

2. Challenges in establishing causality 

Another significant hurdle in asserting claims for PFAS-related damage is causation as a prerequisite for a claim. As is well known, there must be an adequate causal link between the harmful act and the damage. In the event of legal enforcement, the injured party must allege and prove the causal link and its adequacy.

The injured party must demonstrate in detail that a specific PFAS emission or a specific product containing PFAS caused the specific damage. Proving this is often difficult for factual reasons because even if the injured party has been able to identify a specific defendant, this does not prove that the defendant’s PFAS emission or PFAS-containing product caused the damage in question. It must generally be accepted that, in addition to the PFAS emission or the PFAS-containing product of the respective defendant, other circumstances could also have been a (contributing) cause of the damage.

Many personal injury cases related to PFAS are likely to be of a multi-causal nature in that multiple PFAS products or PFAS emissions or other causative factors did not lead to a specific personal injury on their own, but only in combination with one another. Thematically, the issue of causality in cases of partial causation will regularly arise. Within the framework of natural causality, the harmful act need not be the sole cause of the damage. It must, however, be sufficiently significant to be considered on its own a conditio sine qua non of the damage. Proving this will be difficult due to the potential for exposure to PFAS over the course of a human lifetime.

3. Establishing unlawfulness is unproblematic in many cases 

The damage must then be caused unlawfully. According to the objective theory of unlawfulness, the infliction of damage must violate a general legal duty by either infringing upon an absolute right of the injured party or causing purely financial loss through a violation of a norm whose purpose is to protect against such damage.

In most cases, harmful PFAS products or emissions are likely to result in personal injury or soil contamination. In such cases, there are generally no difficulties in establishing the unlawfulness of the act, as the absolute rights of the injured party are violated—in particular, the right to life and physical integrity, and the right to property and possession. In exceptional cases where purely financial losses are involved, protective provisions such as Art. 26(1) or Art. 59a of the Federal Act on Environmental Protection (USG), and the relevant provisions in the TBDV and the VHK could be helpful.

4. No simple proof of fault 

Liability for damage can only be established if there is fault, and in the case of tort claims, the burden of proof lies with the injured party. As a rule, the question will be whether the party that placed a PFAS-containing product on the market or is otherwise responsible for PFAS emissions failed to exercise the due care required in commerce and acted negligently.

The objective standard requires, as a first step, that the injured party proves that at the time the product was placed on the market the harmful effects of the PFAS-containing product or PFAS emissions were generally known within the specific sphere of activity of the defendant. In a second step, the injured party must then demonstrate that the defendant’s PFAS-containing product or PFAS emission violated this standard of care and that the defendant therefore acted negligently.

As long as the production or use of PFAS in the industry was generally accepted for the relevant products, proving fault is likely to be associated with significant difficulties.

B.           Employer liability under Art. 55 CO

Another potential basis for a claim is the employer’s liability for damage caused by employees or other agents. In the context of a manufacturer’s liability for defective products, which is likely to be the most common application in the PFAS debate, employer liability has no longer held the same significance since the Product Liability Act (PrHG) came into force, even though there is a concurrence of claims between those based on the PrHG and those based on Art. 55 CO.

The hurdles regarding standing to be sued, causality and unlawfulness, which have already been discussed in the context of tort liability under Art. 41 CO, also apply here. Unlike the liability requirements under Art. 41 CO, however, the principal is liable without the injured party having to prove fault on the part of the principal or the agent. Instead, it is incumbent upon the principal–and thus falls within the principal’s burden of proof (Art. 8 of the Swiss Civil Code (CC))–to demonstrate that he exercised all due care required under the circumstances to prevent damage of this kind. It is also relevant here whether, at the time of the act or omission, the harmful effect of a specific PFAS-containing product or a PFAS emission was generally known within the specific scope of application in the business owner’s sphere of activity.

C.           Manufacturer's Liability under the Product Liability Act (PrHG) 

If the PFAS contained in a product are present in such high concentrations that they may cause damage, this could constitute a defect because the product does not provide the level of safety that one is entitled to expect, taking all circumstances into account. The Product Liability Act covers both personal injury and property damage, provided that the item is, by its nature, typically intended for private use or consumption and was primarily used privately by the injured party. The burden of proof regarding the product’s defectiveness lies with the injured party. The injured party must also prove that the product defect was the cause of the damage, which raises the same questions of causation as in tort liability.

Even if PFAS contamination of a product constitutes a defect under the PrHG, the manufacturer is not liable if it can prove that the defect could not have been detected based on the state of scientific and technical knowledge at the time the product was placed on the market.

D.           Liability of property owners under Art. 58 CO 

The liability of property owners under Art. 58(1) CO may apply in the context of PFAS emissions originating from a structure. This liability provision, however, covers only personal injury and property damage.

The hurdles regarding standing to be sued, causality and unlawfulness, which have already been discussed in the context of general tort liability under Art. 41 CO, also apply to Art. 58(1) CO. In contrast to the liability of the principal under Art. 55(1) CO, however, the owner of the work does not have the burden of proving due care to be exempt from liability. Nevertheless, the owner's liability is linked to the defective condition of the work, which entails an allegation of a breach of duty. Thus, the owner’s liability exhibits elements of fault-based liability. The objective standard discussed in the context of general tort liability is therefore also relevant to the liability of the owner of the work from the perspective of the defectiveness of the work. Although the objective functioning of a work must be assessed by the judge ex post, this does not mean, however, that the work must always incorporate the latest technical advances.

E.           Liability of the Landowner under Article 679 CC 

Another basis for non-contractual claims that may form the basis for claims related to PFAS emissions is the liability of the property owner as provided for in Art. 679 CC. Under this provision, a person who has suffered damage due to a landowner’s infringement of property rights or due to actual or imminent damage may sue for the removal of the damage, protection against imminent damage and damages.

This basis for liability not only establishes a claim for damages but also imposes a duty on the property owner to take action regarding imminent dangers emanating from their property. Furthermore, regarding damage already incurred, Art. 679(1) CC provides the injured party with a simpler basis for establishing liability, as the landowner’s liability –being strict liability–does not require proof of fault.

It should be noted that in such clearly identifiable cases–such as those that may arise at wastewater treatment plants or fire department training grounds–the other bases for liability discussed above may also apply, as their requirements can be more easily established in these instances. Such cases involving clear identification of the source of emissions and the resulting straightforward identification of the defendant are the exception rather than the rule in the context of PFAS-related damage.

III.          Conclusion 

Due to their persistent and widespread use, and the significant time lag between their release and the occurrence of damage, PFAS represent a source of damage that poses significant challenges to pursue a claim for damages. This article demonstrates that while it is certainly possible to classify PFAS under the legal principles governing non-contractual claims, their practical enforceability is consistently hampered by significant challenges regarding the attribution of liability, causality and the burden of proof regarding fault. It will be important to see how precedents on this issue will develop, such as whether certain concessions will be introduced to ease proof of some tests for establishing liability as they were with asbestos-related case-law.