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Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS)

IARC Monographs on the Identification of Carcinogenic Hazards to Humans Volume 135

IARC

2025

ISBN-13

978-92-832-0292-9

Other languages

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This volume of the IARC Monographs provides evaluations of the carcinogenicity of two agents, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), and their corresponding isomers and salts.

PFOA and PFOS are per- and polyfluoroalkyl substances (PFAS) that are extremely resistant to degradation. First produced in the 1940s, PFOA has extensive uses, including in fluoropolymer manufacture and applications; in surface coatings conferring stain-, oil-, and water-resistance on household products, carpets, textiles, leather products, and food and feed packaging; in electrics and electronics; and in construction materials. With some similar uses to those of PFOA, PFOS additionally has applications in aqueous film-forming foams used in firefighting; in the fabrication of imaging devices and semiconductors; in photolithography and electroplating; and in insulation, dyes, and ink.

PFOA and PFOS occur ubiquitously in the environment, with high levels at pollution sources such as industrial sites and in firefighter-training areas and waste deposits. They may also be present in contaminated food, especially fish, seafood, and eggs. Occupationally exposed populations can have high levels of exposure, mainly via inhalation. The general population in contaminated areas is mainly exposed via drinking-water, and the general population in communities that are not near pollution sources is mainly exposed via diet and drinking-water.

An IARC Monographs Working Group reviewed evidence from epidemiological studies, cancer bioassays in experimental animals, and mechanistic studies to assess the carcinogenic hazard to humans of exposure to these agents and concluded that:

  • PFOA is carcinogenic to humans (Group 1);
  • PFOS is possibly carcinogenic to humans (Group 2B).
 
These supplementary tables are available online only.
 
Please report any errors to imo@iarc.who.int.
 
The following tables were produced in draft form by the Working Group and were subsequently fact-checked but not edited:
 
 
The following tables were produced in draft form by the Working Group, fact-checked, and edited:
 
 
 
 
 
These supplementary tables are available online only.
 
Please report any errors to imo@iarc.who.int.
 
The following tables were produced in draft form by the Working Group and were subsequently fact-checked but not edited:
 
 
 
These supplementary tables are available online only.
 
Please report any errors to imo@iarc.who.int.
 
The following tables were produced in draft form by the Working Group and were subsequently fact-checked but not edited:
 
 
 
These supplementary online-only tables contain summaries of the findings (including the assay name, the corresponding key characteristic, the resulting “hit calls” both positive and negative, and any reported caution flags) for those chemicals evaluated in the present volume that have been tested in high-throughput screening assays performed by the United States Environmental Protection Agency (US EPA) and the United States National Institutes of Health. The results were generated by the Working Group using the software “kc-hits” (key characteristics of carcinogens – high-throughput screening discovery tool) available from https://gitlab.com/i1650/kc-hits.git (Reisfeld et al., 2022), using the US EPA Toxicology Forecaster (ToxCast) assay data and the curated mapping of key characteristics to assays available at the time of the evaluations performed for IARC Monographs Volume 135. Data were available for perfluorooctanoic acid (PFOA), ammonium perfluorooctanoate (APFO), perfluorooctanesulfonic acid (PFOS), and potassium perfluorooctanesulfonate.
 
Please report any errors to imo@iarc.who.int.