Major chemical forms, specific properties and applications of legacy PFAS, such as PFOS and PFOA, as well as PFAS alternatives / non-regulated PFAS are summarized together with the outline of their history of development and regulation. Data gaps and research needs are listed, and future management options are briefly discussed.

Per- and polyfluoroalkyl substances (PFAS) are a major environmental concern due to their persistence and their potential to cause adverse health effects. This article reviews the current knowledge of the partition and sorption properties of PFAS and discusses how these properties influence their environmental fate. Perfluorination of an alkyl chain increases molecular size without significantly altering van der Waals interactions, resulting in greater hydrophobicity and higher volatility from condensed phases. Perfluorination also affects the electronic properties of nearby functional groups, with a notable outcome being the lowering of pK_a. In a generic terrestrial environment, neutral PFAS are expected to distribute primarily into the atmosphere because of their high volatility and low propensity to partition into the water phase, unless they contain a strongly polar functional group such as a sulfonamide group. Ionic PFAS exhibit complex partition behavior in atmospheric, soil, and biological compartments. This behavior is strongly influenced by the composition of the aqueous phase and the solid matrix and remains an area of further investigation.

Per- and polyfluoroalkyl substances (PFAS) comprise a diverse group of chemicals with varying structures and physicochemical properties. Targeted analysis using highly selective and sensitive liquid chromatography–tandem mass spectrometry (LC-MS/MS) has been the primary method for quantifying individual PFAS compounds. This approach plays a central role in regulatory monitoring and toxicological assessment. However, comprehensive evaluation remains challenging for PFAS lacking analytical standards, including unknown precursors and transformation products.

To address these limitations, complementary “PFAS Total” quantification methods have been employed. These include extractable organic fluorine (EOF), adsorbable organic fluorine (AOF), and total oxidizable precursor (TOP) assay, which collectively aim to estimate the totality of PFAS burden. While PFAS Total methods can quantify substances such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), but they cannot comprehensively capture all PFAS species. Each method has an inherent “analytical window” depending on the detectable PFAS structures and properties.

Accordingly, a comprehensive PFAS assessment requires the appropriate selection and combination of analytical methods based on the purpose of monitoring, the target compounds, and the characteristics of the sample matrix. While targeted analysis remains indispensable, the practical implementation and standardization of PFAS Total screening techniques are essential for advancing environmental monitoring and achieving sustainable PFAS management. Future efforts should aim to integrate these approaches through both methodological development and regulatory frameworks.

High-resolution mass spectrometry (HRMS) generates data rich in analytical information. When combined with chromatography, this technology enables non-target analysis—an approach that identifies compounds without predetermined analytical targets. This methodology shows particular promise for PFAS research, where many fundamental questions about these contaminants remain unanswered. Non-target analysis may provide crucial insights needed to resolve ongoing PFAS-related challenges.

This review examines the value of HRMS data alongside complementary analytical techniques that enhance its capabilities. The discussion outlines key considerations for selecting and applying different analytical approaches, focusing on how to distinguish between various applications and implement them effectively in environmental analysis.

This paper reviews the status and challenges of monitoring PFAS (per- and polyfluoroalkyl substances) in aquatic environments, soil, and wildlife, and suggests future directions for field monitoring in Japan. Currently, attention in Japan is focused on PFAS contamination in rivers and drinking water, as well as PFAS adsorption to soil and groundwater contamination and associated risks, while the contamination status of wildlife remains unknown. PFAS accumulate in the liver, serum and kidneys of living organisms and have been implicated in lipid metabolism disorders and liver damage. Therefore, biomonitoring of higher trophic level species such as fish, birds and cetaceans is critical to understanding environmental contamination levels and ecological impacts. However, analytical techniques for this purpose remain limited.

In the future, it will be necessary to establish a comprehensive monitoring system for legacy PFAS, as well as emerging and alternative PFAS, and to introduce high-precision analytical methods. In addition, scientific knowledge that considers ecological impacts is needed for policy decisions that go beyond human health. To this end, Japan urgently needs to expand environmental monitoring and establish a comprehensive PFAS management strategy through international coordination.

Per- and polyfluoroalkyl substances (PFAS) are highly fluorinated organic compounds characterized by perfluoroalkyl chains such as CF₃- or -CF₂- groups. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the most studied PFAS, used in water/oil repellents, firefighting foams, and fluoropolymer production aid. Due to their chemical stability and resistance to biodegradation, PFAS persist in the environment and accumulate in wildlife and humans. Exposure occurs through contaminated water, air, food, and consumer products. Studies have shown regional differences in PFAS levels in Japan, with higher concentrations of drinking water in several locations of Kansai and Tokyo. Seafood is a substantial source of exposure, with PFNA and PFUnDA detected in fish and shellfish. Thus, blood levels of PFAS correlate with seafood intake and biomarkers like eicosapentaenoic acid. Human biomonitoring, especially via blood samples, is the most reliable method to assess PFAS exposure. PFOS and PFOA mainly distribute in blood and liver, with long half-lives (e.g., PFOA: 3.8 years). Since PFAS levels in urine and breast milk are low, blood plasma or serum is preferred for chemical analysis. Historical data show increasing PFAS levels in Japanese blood samples from the 1970s to 2000s, especially in Kyoto. Long-chain perfluoroalkyl carboxylic acids (e.g., perfluorononanoic acid, perfluoroundecanoic acid) are also prevalent and may affect lipid metabolism. Recent surveys in Okinawa, Osaka, and Gifu where local contaminations exist revealed high PFAS blood levels, exceeding guidance values recommended by German and U.S. agencies. These values were derived from epidemiological evidence on health risks of developmental effects, cholesterol elevation, and increased diabetes and cancer risks. The guidance recommends exposure reduction and clinical follow-up for individuals exceeding the threshold levels. Future efforts should focus on standardized analysis, identification of exposure sources, and comprehensive health risk assessments. Despite regulatory bans of selected PFAS, legacy contamination and ongoing exposure from other PFAS remain concerns.

In Japan, ecotoxicity testing of chemical substances, including per- and polyfluoroalkyl substances (PFAS), is conducted on algae, crustaceans, and fish in accordance with the test guidelines established by the Organization for Economic Cooperation and Development (OECD) or the Law Concerning the Evaluation of Chemical Substances and Regulation of Their Manufacture (Chemical Substances Control Law). Among PFAS, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are regulated both domestically and internationally under the Stockholm Convention on Persistent Organic Pollutants (POPs) and the aforementioned law, resulting in the accumulation of substantial ecotoxicity data. The POPs Convention, a recent treaty, encompasses PFOA and PFOA. Additionally, perfluorohexanesulfonic acid (PFHxS), newly designated under the POPs Convention, and long-chain perfluorocarboxylic acids (PFCAs), which are being evaluated as potential candidates for regulation under the Convention, are subjects of ongoing ecotoxicity data collection. This review presents the findings of these studies with a primary focus on fish. Furthermore, it has been noted that existing PFASs impact various biological functions, including the nervous, immune, and endocrine systems, as well as lethality and growth inhibition, which have been utilized as endpoints in ecotoxicity tests. This review also provides examples of studies on the effects reported in existing PFAS, as well as on alternative and new PFAS.

Per- and polyfluoroalkyl substances (PFAS) are highly persistent industrial chemicals with widespread human exposure. Epidemiological evidence published mainly since 2020 was reviewed, prioritizing systematic reviews, meta-analyses and key original studies. The strongest and most consistent associations are observed for dyslipidaemia (higher total/low-density lipoprotein), markers of liver injury and fatty liver disease and reduced vaccine antibody responses—particularly in children. Evidence also suggests associations with hypertensive disorders, type 2 diabetes, altered thyroid function, adverse birth outcomes (lower birthweight, shorter gestation), decreased fecundability and male reproductive endpoints (reduced semen quality); however, heterogeneity and exposure misclassification remain important limitations. For cancer, the International Agency for Research on Cancer classified perfluorooctanoic acid as carcinogenic to humans (Group 1) and perfluorosulphonic acid as possibly carcinogenic (Group 2B), supported by limited human evidence (kidney and testicular cancer) and strong mechanistic evidence. Regulatory benchmarks have tightened globally, reflecting concern about health risks at low exposure levels. Priority research needs include longitudinal studies at general-population exposures, mixture/next-generation PFAS, susceptible windows and clinical significance of biomarker shifts. This review synthesizes current human evidence to inform risk assessment and public health actions. The review also highlights that most toxicological findings are derived from exposure levels several orders of magnitude higher than those in the general population, underscoring the need to clarify the clinical relevance of subtle biomarker changes at low-dose exposures.

The Conference of the Parties of the Stockholm Convention on Persistent Organic Pollutants (POPs) listed ionic PFAS, such as PFOS, PFOA, and PFHxS. Considering the environmental behavior and contamination of ionic PFAS, investigations of PFAS have been conducted primarily in water environments. Recently, PFAS used in food contact materials are expected to be regulated internationally. The human health risk from PFAS exposure is concerning due to daily contact with industrial and consumer products, including food contact materials. This review provides an overview of PFAS concentrations in industrial and consumer products, and summarizes PFAS contamination in indoor environments, where consumer products are the primary emission sources.

This review presents effective methodologies for the mineralization of state-of-the-art industrial per- and polyfluoroalkyl substances (PFAS). These include both non-polymeric compounds—such as fluorinated ionic liquids and fluorochemicals used as electrolytes in secondary batteries—and polymeric materials like polyvinylidene fluoride (PVDF), fluoroelastomers (FKMs), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP). The discussed approaches employ subcritical water, with the ultimate goal of recovering fluorine from these substances.

Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were designated as “complementary items” in Japan’s drinking water quality management in 2020. A provisional target value of 50 ng/L was set for the combined value of these two substances. Perfluorohexanesulfonic acid (PFHxS) was classified as a “items for further study” in 2021 due to the lack of established toxicity assessments and unclear detection status in tap water, and no target value has been set for it yet. Currently, it has been decided that PFOS and PFOA in tap water will be upgraded to “water quality standards” subject to mandatory testing in April 2026. Further, seven PFASs other than PFHxS have been newly added to the items for further study. The standard analytical method for PFAS in drinking water (the notification method) is notified by the Ministry of the Environment, targeting PFOS, PFOA, and PFHxS. However, with the re-elevation of PFOS and PFOA to the water quality standards, the testing method are currently underway revisions. This review paper explains the trends and challenges in the regulation and testing methods for PFAS in Japan’s drinking water quality management.

National and international chemicals schemes employ often different selection and/or categorization of PFAS. Some employed grouping-type definitions based on the characteristic chemical structure, but others specified each chemical as the list of target chemicals of PFAS. Different management options are applied to specific or group of PFAS chemicals in each definition of PFAS. Although the list of target chemicals are sometimes largely different each other, however, the author thinks that starting definition of PFAS is somewhat common in all national/international schemes but different management considerations for variety of uncertainties and/or lack of information in PFAS chemicals result in different appearances among national and international schemes. Management actions corresponding to the uncertainties/lacking of the scientific information need to be established, probably by the appropriate combination of precautionary approach and risk assessment schemes depending on the different nature of information and management concern.