The Chagama River in Konan, Shiga Prefecture, where PFAS levels exceeding the guideline value were detected. (Courtesy of Shiga Prefecture)
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Recently, there have been scattered reports of high concentrations of PFAS (per- and polyfluoroalkyl substances) in rivers, dams, and wells across Japan. PFAS toxicity to the human body is a growing concern, and as overseas regulation has tightened, Japan has followed suit with stricter rules of its own. This article explains the rising risk PFAS poses for domestic and foreign companies alike.
First in a series
What is PFAS?
PFAS is a collective term for over 10,000 types of man-made organofluorine compounds, sometimes called "forever chemicals." Because of properties such as water- and oil-repellency and thermal and chemical stability, they have long been used in a wide range of applications, including solvents, surfactants, surface treatments for textiles, leather, paper, and plastics, lubricants, firefighting foam, and semiconductor materials.
However, concerns over toxicity to the human body, including carcinogenicity, have grown. Moreover, because PFAS resist breakdown, they persist and accumulate in the environment, spreading contamination widely. This is leading to increased regulation.
Tough Regulation, Bigger Payouts
Strict PFAS regulations have been introduced, particularly in the United States and European Union. In the US, standards have been set for PFOS/PFOA (a type of PFAS) in drinking water, and PFOS/PFOA have been designated as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which imposes cleanup liability for hazardous substances in soil.
A proposal before the EU would restrict the manufacture, marketing, and use (including import) of all 10,000+ PFAS types.
There have also been reports of large civil damages suits and criminal penalties. For example, a chemical manufacturer sued by US municipal water authorities over PFAS contamination of drinking water reportedly settled for roughly $12.5 billion.
In Italy, former executives—including a Japanese national—at a chemical manufacturer were reportedly sentenced to prison terms ranging from two years eight months to 17 years six months for contaminating groundwater with PFAS discharged from a factory.
The company's parent (a Japanese entity) reportedly became liable for a combined €63 million to citizens and public bodies and €56.8 million to Italy's Ministry of Environment and Energy Security.
As described above, PFAS is strictly regulated overseas, and companies that cause PFAS contamination face the risk of massive liability. Japanese companies are no exception.
Rising Disputes in Japan
Domestically, the Act on the Regulation of Manufacture and Evaluation of Chemical Substances (Chemical Substances Control Law) designates PFOS, PFOA, and PFHxS as regulated PFAS. In principle, this bans their manufacture and import. Individual violators face up to 3 years' imprisonment or a fine of up to ¥1 million (about $6,200), and the company they belong to may face a fine of up to ¥100 million ($620,000).
In 2025, water quality standards for tap water and mineral water were also established by law. At present, no standard values have been set for PFAS in factory wastewater or soil, but given the trend of tightening regulation abroad, further tightening in Japan is fully expected.
There have been no reports yet of domestic civil suits over PFAS contamination. However, there are reports of local governments seeking damages from companies found to have caused PFAS contamination, and pollution mediation proceedings have been filed over PFAS contamination. These suggest that legal disputes are likely to increase going forward.
Not Someone Else's Problem
Even companies that do not directly manufacture or import PFAS are not free of PFAS-related risk. For example, if PFAS-containing parts or products are found to have entered a company's procurement or manufacturing supply chain, the question arises whether this violates the Chemical Substances Control Law noted above.
Moreover, marketing a product as PFAS-free (including failing to disclose PFAS content) can expose a company to claims from downstream parties for false labeling under the Unfair Competition Prevention Act or for non-conformity with contract terms under the Civil Code.
Furthermore, if high concentrations of PFAS are detected in factory wastewater or soil (so-called residual PFAS), or if PFAS-containing firefighting foam leaks due to an accident involving a building's fire suppression equipment, neighboring residents or landowners could seek damages.
Because public concern about PFAS is high, leaks or contamination tend to receive major media coverage. Even without naming the company, the source can often be identified from information about the affected area, thereby creating reputational risk. As a consequence, even companies that seem unrelated to PFAS may face risks of regulatory violations, liability for damages, and reputational harm.
Regulatory Management and Dealing with Authorities
As described above, PFAS risk is not something companies can ignore. Chemical substance regulations, including those governing PFAS, are complex and require compliance with rules in Japan, the EU, the United States, and other overseas markets. These are frequently revised, making it essential to track the latest developments.
In practice, once PFAS issues surface, companies may be required to report to authorities or receive administrative guidance from them. In such cases, consultation and coordination with multiple authorities would be required, including prefectural governments having jurisdiction over regulations concerning discharges into public bodies of water, municipalities having jurisdiction over private well water, and public health centers. Because these regulations are frequently revised, timely legal guidance is essential to staying abreast of developments in Japan and overseas.
Furthermore, each of these agencies could take a different position, making the response far from straightforward.
Companies may also be required to explain the situation to nearby residents and other stakeholders. Finally, the timing and content of any public statements must be carefully coordinated with those made by the authorities.
RELATED:
Step Up Research on Whether PFAS Causes Cancer in Humans
Authors: Kenji Sarukura, Partner, and Kota Kato, Associate
Ushijima and Partners, Attorneys-at-Law
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