As PFAS regulation expands and the list of PFAS-related contaminants continues to grow, successful environmental programmes depend on testing strategies that connect analytical results to ecological risk, regulatory compliance and action.
Environmental PFAS testing is no longer just about finding compounds. It is about understanding what the results mean for environmental risk, regulatory obligations and future action.
Today, PFAS can be measured in water, soil, sediment, leachate, air emissions/immission, ambient air monitoring, landfill gas, biota, waste materials and at sites impacted by aqueous film-forming foam (AFFF). The challenge for regulators, water utilities, consultants, and industry is no longer simply detection. It is assessing the presence or absence of a broad range of PFAS-related substances, within the limits of current analytical capability, and connecting those findings to the decision that matters.
A drinking water investigation, a landfill assessment, an industrial emissions study or an AFFF-impacted site do not present the same risks. They should not automatically use the same analytical methods or generate the same evidence. Effective PFAS testing begins by defining the environmental decision to be made, then selecting the data needed to support that decision.
Testing should start with the risk question
PFAS are recognised globally for their persistence, mobility and resistance to degradation. These characteristics have made them useful in many industrial and consumer applications, but they also make environmental releases particularly difficult to manage. Several PFAS, including PFOS, PFOA and PFHxS-related substances, are listed under the Stockholm Convention, reflecting international concern regarding their impacts on human health and the environment.¹
For environmental stakeholders, the key issue is not simply whether a limited list of PFAS is present: it is how to understand the overall presence of PFAS-related substances, what their presence means and which risks need to be evaluated.
Is the objective to demonstrate compliance? Identify a contamination source? Delineate a groundwater plume? Support remediation? Assess exposure? Evaluate treatment performance? Understand future liability?
Each objective requires different evidence and often a different analytical strategy.
A drinking water compliance programme may demand a defined list of regulated compounds and very low reporting limits. A site investigation may require broader screening to identify unknown sources. Landfill leachate assessments may benefit from ultrashort-chain PFAS analysis, while TOP Assay analysis may be needed to consider precursor compounds that can transform over time into terminal PFAS.
Method selection is therefore not merely an analytical decision. It is a risk-based assessment decision.
Across Europe, evolving regulatory frameworks, including the EU Drinking Water Directive, national PFAS monitoring programmes and emerging requirements under the Packaging and Packaging Waste Regulation, are reinforcing the need for testing strategies aligned with specific compliance objectives. Different regulatory questions increasingly require different analytical approaches.²
SGS has supported environmental PFAS investigations for more than two decades through a global network of specialist laboratories covering water, soil, sediment, biosolids, plant materials, air, soil gas, waste, biota and firefighting foams.³
The limits of a single method
Standardisation is improving across PFAS analysis, with recognised methods and guidance continuing to develop in different regions. In Europe, ISO methods such as ISO 21675 support PFAS analysis in water matrices, while other approaches are used depending on the sample type, regulatory context and project objective. In the US, EPA Method 1633 supports PFAS measurement across multiple environmental matrices, including groundwater, wastewater, leachate, sediment and biosolids. Additional methods are also being developed for air emissions and volatile fluorinated compounds.⁴
However, no single method answers every environmental question.
Targeted analysis remains essential for compliance monitoring, human risk evaluation and routine environmental investigations because it provides reliable quantification of known compounds. Its limitation is straightforward: it only reports compounds included within the selected method.
Organic fluorine approaches such as Adsorbable Organic Fluorine (AOF), Extractable Organic Fluorine (EOF), and Total Organic Fluorine (TOF) provide broader indications of organofluorinated content that may not be captured by target lists alone.
The Total Oxidisable Precursor (TOP) assay helps assess whether precursor compounds may transform into terminal PFAS over time. This can be particularly relevant when evaluating future risk, remediation effectiveness and long-term liability.
Non-target analysis or screening can support investigations where site histories are uncertain or contamination sources are not fully understood. It can help identify PFAS that conventional target lists may miss and establish a more appropriate list of parameters to monitor.
A practical reality of PFAS investigation
Different testing approaches answer different questions:
- Targeted analysis supports compliance, human risk evaluation and routine monitoring;
- TOP assay helps assess future risk from precursor compounds;
- ‘Total PFAS’ screening provides broader indications of fluorinated content;
- Non-target screening can help identify unknown PFAS; and
- Ultrashort-chain testing can provide insights into highly mobile compounds, some of which are starting to appear in compliance-monitoring discussions.
A robust PFAS strategy combines methods according to the environmental question being asked, rather than relying on a single analytical result.
AFFF: Where legacy contamination meets future planning
AFFF demonstrates why many PFAS investigations must look backwards and forwards simultaneously.
For decades, AFFF was used to extinguish high-hazard flammable liquid fires at airports, military installations, refineries, industrial areas and fire-training facilities. Many legacy formulations contained PFAS that are now the focus of environmental investigations and regulatory scrutiny.⁵
At AFFF-impacted sites, contamination may affect soil, groundwater, surface water, wastewater, sediment and leachate. Testing programmes often support source identification, plume delineation, risk assessment, remediation planning and long-term monitoring.
At the same time, organisations are transitioning to fluorine-free alternatives, creating a dual challenge: understanding historical contamination while generating evidence to support future management decisions.⁶
Because AFFF sites frequently involve complex PFAS mixtures, uncertain histories and multiple environmental pathways, a simple yes-or-no answer is rarely sufficient. Effective investigations often require a combination of targeted analysis, precursor assessment and source characterisation.
Emerging risk: TFA and ultrashort-chain PFAS
As PFAS science evolves, increasing attention is being paid to ultrashort-chain (USC) PFAS, including trifluoroacetic acid (TFA).
These compounds are highly mobile in water and may originate from direct industrial sources or from the transformation of more complex fluorinated substances. Traditional target lists very often do not include them, which can result in an incomplete understanding of site conditions.
SGS technical material reinforces this point. In landfill leachate work, ultrashort PFAS contributed a significant proportion of the total PFAS measured by concentration, with TFA reported as the highest-concentration PFAS in both landfill leachate sites assessed. In the same work, ultrashort PFAS represented more than 80% of total PFAS by concentration at one site and around 30% at another.⁷
Recent monitoring also points to growing relevance for TFA in drinking water assessment,11 although this does not mean every project should automatically include ultrashort-chain analysis. It means that testing strategies should remain responsive to emerging science, regulatory developments and site-specific risk.
Regulatory attention is also developing. EPA’s proposed sixth Unregulated Contaminant Monitoring Rule, published in July 2026, proposes national drinking water occurrence monitoring for 30 chemical contaminants, including seven ultrashort organofluorine compounds.⁸
Expanding PFAS assessment beyond water and soil
PFAS investigations are increasingly extending into air, emissions and vapour pathways. This is more than an expansion of analytical scope; it reflects a better understanding of how PFAS can move between environmental compartments.
Air emissions, atmospheric transport and deposition can contribute to PFAS movement into soil, surface water, groundwater and biota. Applications now include stack emissions, ambient air/immission monitoring, indoor air assessment, landfill gas investigations, soil vapour studies and occupational hygiene programmes. Different exposure pathways require different sampling designs, quality controls and analytical methods.⁹
Interest in air monitoring is being driven by growing attention to industrial emissions, PFAS destruction technologies, landfill gas and atmospheric deposition. In a one-year-long PFAS air and deposition monitoring study conducted by the Minnesota Pollution Control Agency, air samples were collected at four sites using high-volume active samplers. PFBA, PFOS, PFBS and PFOA were detected in 100% of samples, while PFHxS was detected in 99%.12
Landfill gas is also emerging as an important pathway to consider. In a study of three municipal solid waste facilities, 13 of 27 PFAS were detected in landfill gas, dominated by fluorotelomer alcohols. The study also indicated that comparable amounts of fluorine from PFAS were being released from waste into leachate and gas.13
These examples reinforce a central point: PFAS risk is rarely confined to one matrix. Generating defensible results depends not only on laboratory capability but also on robust sampling procedures, quality assurance measures, reporting limits and data interpretation.
What good PFAS data should include
A robust PFAS testing programme should include documented methods, appropriate quality control, clear reporting limits, sample qualifiers, chain of custody, sample preparation and analysis dates, and a clear case narrative explaining any issues that may affect interpretation.⁹
Moving from tests to evidence
There is rarely a single PFAS test capable of answering every environmental question.
This principle underpins PFASafe®, SGS’s framework for aligning analytical approaches with environmental objectives. By combining targeted analysis, fluorine-based screening, precursor evaluation and non-target techniques where appropriate, PFASafe helps build a more complete understanding of PFAS occurrence and risk.10
A drinking water programme may focus on regulated compounds and low reporting limits. A landfill investigation may combine targeted analysis with broader screening approaches. An AFFF assessment may require targeted analysis together with TOP Assay and source characterisation. An air programme may need to connect emissions data with deposition, exposure pathways and site-specific risk.
The objective is not to generate more data. It is to generate evidence that is proportionate, technically defensible and suitable for decision-making.
Evidence that supports action
The next phase of PFAS management will not be defined by detection alone. It will be defined by the quality of the evidence used to support environmental decisions.
SGS’s environmental PFAS work reflects this principle in practice. Projects have included investigations of PFAS contamination in military drinking water systems, validation of analytical methods for waste-incineration emissions and landfill leachate studies combining targeted analysis and TOP assay.³
For water utilities, evidence supports the protection of drinking water sources. For regulators, it provides confidence in compliance data. For industrial operators, it helps manage legacy contamination and future liabilities. For consultants, it helps build site investigations that withstand technical and regulatory scrutiny.
The goal is not to test more for the sake of testing more. It is to test smarter, with a clearly defined objective, an appropriate analytical strategy and a realistic understanding of what the resulting data can support.
Through IMPACT NOW for sustainability, SGS helps organisations transform scientific understanding into practical environmental action. In PFAS testing, that means moving from uncertainty to evidence, enabling clearer decisions, more targeted interventions and more responsible long-term management of environmental risk.
When decisions affect water resources, remediation investments, regulatory compliance and public confidence, the testing strategy can be just as important as the analytical result.
About the author
Luca Fagiuoli, Global Business Development Manager for Environmental Testing at SGS, leads global business development activities for environmental testing services at SGS and coordinates the company’s global PFAS working group. His work focuses on supporting industry, environmental consultants and public-sector organisations with testing programmes that address emerging environmental challenges, regulatory requirements and sustainability objectives.
About SGS
SGS is the world’s leading Testing, Inspection and Certification company. We operate a network of over 2,500 laboratories and business facilities across 115 countries, supported by a team of over 100,000 dedicated professionals. With more than 145 years of service excellence, we combine the precision and accuracy that define Swiss companies to help organisations achieve the highest standards of quality, compliance and sustainability.
Our brand promise – when you need to be sure – underscores our commitment to helping organisations address complex environmental, health and safety challenges with confidence. SGS EHS Solutions provides the technical expertise, regulatory insight and practical support needed to assess risk, achieve compliance and advance sustainability objectives, including in rapidly evolving areas such as PFAS management and remediation.
SGS is publicly traded on the SIX Swiss Exchange under the ticker symbol SGSN.
References
- Stockholm Convention, PFAS listed under the Convention: PFOS, PFOA and PFHxS.
- European Union, Drinking Water Directive (EU) 2020/2184; European Commission PFAS monitoring guidelines, 2024; Packaging and Packaging Waste Regulation (EU) 2025/40.
- SGS, Environmental PFAS: A comprehensive suite of sampling and testing services.
- ISO 21675:2019; US EPA Method 1633A; US EPA Other Test Methods 45 and 50.
- SGS, The importance of PFAS testing on aqueous film-forming foams, 2025.
- US Government Accountability Office, Firefighting Foam: DOD Is Working to Address Challenges to Transitioning to PFAS-Free Alternatives, 2024.
- Obal, T., Ultrashort PFAS: Understanding their measurement and relevance for remediation monitoring, SGS, 2025.
- US EPA, Proposed Sixth Unregulated Contaminant Monitoring Rule (UCMR 6), 2026.
- Obal, T., Advances in Monitoring PFAS in Air, SGS, 2026; PFAS in Air: Laboratory Challenges and Opportunities, SGS, 2025.
- Fagiuoli, L., PFAS Testing Strategy: Which Tests Fit Your Needs?, SGS, 2026.
- Crini, G. et al., ‘Assessment of trifluoroacetic acid in tap and bottled water’, Discover Water, 5, 86, 2025.
- Minnesota Pollution Control Agency, PFAS Air and Deposition Monitoring Report, 2022.
- Lin, A.M. et al., ‘Landfill gas: A major pathway for neutral PFAS release’, Environmental Science & Technology Letters, 11, 730–737, 2024.
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