Summary

Per- and polyfluoroalkyl substances (PFAS) are a group of > 10 000 substances that have been used in articles and chemical products for decades in a wide variety of sectors, ranging from impregnating agents for consumer and professional use to fire-fighting foams and materials for use in extreme conditions. However, their persistence (i.e. resistance to degradation) in combination with other problematic properties, such as bioaccumulation and toxicity, has raised concerns about this group of substances for the environment and human health. Therefore, PFAS have increasingly become subject to exposure/risk assessment and regulation. In the EU as well as globally (under the Stockholm Convention), groups of PFAS have been regulated and additional restriction proposals have been submitted. In the EU, restriction proposals of all PFAS jointly as a class have been submitted for use in firefighting foams

https://echa.europa.eu/sv/registry-of-restriction-intentions/-/dislist/details/0b0236e1856e8ce6

as well as broadly for all other uses

https://echa.europa.eu/sv/registry-of-restriction-intentions/-/dislist/details/0b0236e18663449b

Due to the large number of matrices in which PFAS can be used/found (e.g. articles and chemical products as well as environmental and biological samples), there is a need of robust and reliable (e.g. standardized and validated) analytical methods for the purpose of enforcement and compliance as well as for exposure- and risk assessment/management. Thus far, a broad range of analytical techniques have been developed and implemented for the analysis of PFAS. However, challenges still remain.

The primary objective of this project report is to describe the regulatory prerequisites for ensuring effective enforcement and compliance verification of restricted PFAS in chemical products and articles. This has involved assessing the current state of PFAS analysis methods, identifying the need for further method development, standardization, and validation of analyses for individual PFAS, precursor substances, and total organic fluorine/total fluorine (including screening methods), based on extensive literature reviews and interviews with experts in the field of PFAS analyses as well as with stakeholders from regulatory agencies.

The output of the project, presented in this report, consists of summaries of the various methods available for PFAS analysis, including their applications, commercial availability as well as advantages/disadvantages and limitations.

Further, challenges in PFAS analyses, experiences, and needs from the Nordic Enforcement agencies, and proposals for improving efficient enforcement/compliance of PFAS with regard to the analytical methods is described, including a proposed step-by-step generic approach.

Challenges identified consist of:

A lack of commercially available targeted PFAS analyses for all regulated PFAS and their derivatives. Polymeric PFAS cannot be analysed by targeted methods at all.
Standardised methods are not available for all types of samples that may be relevant for market surveillance.
Analytical methods are not accredited for all matrices of relevance (except for some environmental matrices, drinking water and feedstuff).
Available analysis methods of PFAS partly have a LOQ above the restriction limit value, or the experimental uncertainties are extremely high. This is especially true for challenging matrices like e.g., waxes.
A lack of reference standards leads to results that can differ significantly between laboratories.
Analyses may be cost intensive, which is a critical obstacle for an efficient enforcement.
All PFAS cannot be analysed with one analytical method. More complementary methods are needed to capture as many PFAS as possible from different classes.

Needs identified consist of:

Development towards commercially available, standardized, analyses that can identify and quantify all regulated PFAS and their derivatives (including polymeric PFAS).
Further development towards accredited analytical methods for all relevant matrices.
Achievable LOQs that are lower than the enforcement limit.
An approach for analysing PFAS at a reasonable cost level, including a potentially easy, low cost and fast screening method (preferable to be performed in the field, e.g. XRF), to be used as indicator for further testing.

In order to continually improve and validate test methods for PFAS analyses, ensuring their accuracy and reliability, the following key aspects are proposed:

Aspect	Need	Proposal
Standardized Analytical Methods	Develop and establish standardized analytical methods for PFAS analysis to ensure consistency and comparability of results across laboratories and regulatory agencies.	Collaborate with international standards organizations to create and update standardized methods for PFAS analysis, such as ASTM International and ISO. These methods should cover a wide range of PFAS compounds and matrices.
Method Validation and Certification	Rigorously validate analytical methods to demonstrate their accuracy, precision, sensitivity, and selectivity for various PFAS compounds and matrices.	Regulatory agencies and accredited laboratories should conduct method validation studies, and certified reference materials (CRMs) for PFAS should be developed and made available to laboratories for calibration and quality control.
Accredited Laboratories	Ensure that laboratories conducting PFAS analysis are accredited and follow strict quality assurance/quality control (QA/QC) procedures.	Establish accreditation programs specific to PFAS analysis and regularly assess laboratory performance through proficiency testing programs. Encourage laboratories to participate in interlaboratory studies for method validation and improvement.
Non-Targeted Screening Methods	Develop and refine non-targeted screening methods to identify known and emerging PFAS compounds in complex matrices.	Collaborate with researchers and analytical experts to advance non-targeted screening techniques, such as high-resolution mass spectrometry, and establish data libraries for PFAS compounds.
Method Harmonization	Harmonize analytical methods and reporting criteria among regulatory agencies and regions to facilitate data sharing and comparison.	Collaborate with international organizations and adopt standardized reporting formats and units of measurement for PFAS data. Develop mechanisms for sharing FAIR (findability, accessibility, interoperability and reusability) data among regulatory agencies and laboratories.
Method Detection and Reporting Limits	Establish method detection limits (MDLs) and reporting limits (RLs) that are appropriate for PFAS analysis in different matrices.	Regulatory agencies should define MDLs and RLs based on method performance data and the specific requirements of PFAS regulations.
Data Quality Assurance	Implement robust data quality assurance practices to ensure the accuracy and reliability of PFAS data.	Develop and enforce QA/QC protocols, including the use of CRMs, blank samples, and internal standards, to monitor and verify data quality throughout the analytical process.
Method Updates and Research	Stay updated on advancements in PFAS analysis and continuously improve analytical methods to address emerging PFAS compounds.	Establish research programs and collaborations to explore new analytical techniques and improve existing methods. Encourage the publication of method updates and improvements.

Finally, the following generic approach is proposed to analyse PFAS levels at a reasonable cost:

Administrative assessment without chemical analysis. This can be done by using routines, datasheets and chemical management systems of industries combined with interviews about chemical content and technologies used in chemical products and articles with typical PFAS functions. This step is dependent on the cooperation and full transparency of the company, as well as knowledge on the chemical content in the product.
Fast screening methods to determine the total amount of fluorine (TF) in the sample. Ideally, these methods are inexpensive, require little sample preparation and can be used for the screening of both chemical products and articles. Total amount of fluorine can be determined directly in the field without any sample preparation. However, these methods have higher detection limits, are often not specific enough, and are not always available in commercial laboratories.
Targeted analysis of selected samples identified by the screening methods. Many commercial laboratories can perform these methods, although not all PFAS can be measured by targeted methods (e.g. fluoropolymers). For some matrices, standard protocols are already available for a limited number of PFAS compounds (#50–60).
Non-targeted or suspect screening (NTS/SS using HRMS). This can deliver additional information where there is a large discrepancy between the total fluorine content and the PFAS identified by the targeted analysis.