Request for data on PFAS

Background

Public health concern about human exposure to per- and polyfluoroalkyl substances (PFAS), including through drinking-water and food, is increasing and many PFAS share similar routes of human exposure and mechanisms of toxicity. A number of countries and authorities have published or proposed guidance values for PFAS in recent years that vary considerably, depending on the PFAS included, methodology used and a variety of other factors. There is a need to develop authoritative health-based values for key ingested PFAS, including for drinking water and as mixtures, that can be adopted and utilized by national and regional authorities.

Given the rapid expansion and evolution of PFAS research, including the number of PFAS assessed, WHO commissioned a landscape review to identify key ingested PFAS and health effects to support prioritization for further evaluation. The landscape review^[a], recommended the prioritization of 18 PFAS and 6 health outcome categories for further review. The 18 PFAS are polyfluorooctanesulfonic acid (PFOS), polyfluoroundecanoic acid (PFUnDA), polyfluoroheptanoic acid (PFHpA), polyfluorooctanoic acid (PFOA), polyfluoroheptanesulfonic acid (PFHpS), polyfluorobutanoic acid (PFBA), polyfluorotridecanoic acid (PFTrDA), polyfluorohexanoic acid (PFHxA), polyfluorotetradecanoic acid (PFTeDA), polyfluorobutanesulfonic acid (PFBS), polyfluorohexanesulfonic acid (PFHxS), polyfluoropentanoic acid (PFPeA/PFPA), polyfluorododecanoic acid (PFDoA), polyfluorononanoic acid (PFNA), polyfluorodecanoic acid (PFDA), polyfluorodecanesulfonic acid (PFDS), Perfluoro(2-propoxypropanoate) (HFPO-DA), and trifluoroacetic acid (TFA) and the 6 health outcome categories are cardiometabolic, hepatic, immune, developmental, reproductive, and cancer.

WHO has initiated a systematic evidence collection and review for these 18 PFAS and 6 health outcome categories to support evaluations by FAO/WHO Expert Committee on Food Additives (JECFA) and WHO Expert Group on Guidelines for Drinking-water Quality to establish WHO normative values in 2027.

Submission of data

Governments, interested organizations and individuals are invited to submit data for the toxicological evaluation to the 18 PFAS. Unpublished^[b] health effects data specific to the 6 health outcome categories for the 18 prioritized PFAS are of particular interest. In addition, to inform further assessment of potential exposure to PFAS in drinking-water, interested institutions and individuals are invited to submit data on occurrence of PFAS in the water cycle.

The submitted data should contain detailed reports of laboratory studies, including individual animal data, epidemiological evidence of human exposures and associated health endpoints, or examination of the occurrence of PFAS in the water cycle. Citations to relevant published studies should also be provided, where applicable. Summaries in the form of monographs are helpful, but they are not in themselves sufficient for evaluation.

Unpublished confidential studies that are submitted will be safeguarded and used only for evaluation purposes by WHO. Summaries or key studies that may be informative to health-based value derivation, will be published by WHO in the form of a WHO report or a journal article.

Data should be submitted in electronic format and be presented preferably using standard word processing or document formats, and include a “Table of contents” using fully descriptive file names. For large volume submissions or for any questions related to data submissions please contact the Secretariat.

Submissions of recent regulatory reviews or comprehensive literature reviews not yet published as of 22 January, with supporting publications are also encouraged.

Date for submission

The submission of data is requested before 31^st July 2026.  This deadline applies to all data.

Toxicological data

Information (e.g. study design and methods, data) relevant to the toxicological evaluations of the 18 prioritized PFAS and the 6 health outcome categories including the results of:

1. studies of humans with PFAS exposure via food, drinking water, or unknown sources, including epidemiological studies;
2. studies in traditional laboratory animal mammalian models with PFAS exposure via oral routes (for ≥ 28 days);
3. metabolism and pharmacokinetic studies;
4. genotoxicity studies, and
5. special studies designed to investigate specific effects, such as the mechanism of toxicity (including interactions among PFAS) should be sent to:

Attention: WHO Secretariat, e-mail: ipcsmail@who.int

For information being considered as critical for the toxicological assessment of these 18 PFAS to inform health-based value derivation, the WHO Secretariat may request further information, including raw data, from the data provider.

PFAS occurrence data in the water cycle

Data relevant to the occurrence, and quantification of PFAS in the water cycle including:

1. levels and patterns of occurrence (and in some cases co-occurrence) i.e., exact occurrence value of individual PFAS compound in the studied water sample with unit of measurement for occurrence data;
2. analytical techniques used by investigators or authorities for identifying and quantifying PFAS including limits of detection (method detection limits (MDL) and/or limits of quantification (LOQ) for each PFAS compound and matrix, (ideally using the same units as the occurrence measurements);
3. country and, where available, sub-national region in which the water samples were collected;
4. full name of the PFAS compound/abbreviation/CAS number;
5. water source or supply type (i.e. groundwater, surface water, drinking-water) and characterization of the type of water source sampled including if a contaminated site and source of contamination, before/after water treatment;
6. effects of water treatment processes on PFAS levels in finished drinking-water, capturing information on any treatment processes applied prior to sampling, including conventional treatment (e.g., coagulation, sedimentation, sand filtration, chlorination) and advanced or PFAS-targeted technologies (e.g., granular activated carbon, ion exchange, reverse osmosis, nanofiltration); and
7. sampling protocols should be sent to:

Attention: WHO Secretariat, e-mail: gdwq@who.int

Presentation of data

Please note that the above lists are not meant to be all-inclusive since it is recognized that other studies may, in some instances, assist in the evaluation.

All relevant data, both positive and negative, should be submitted. Data should be presented, summarized and referenced in a clear and concise manner.

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