IRIS Toxicological Review of Perfluorohexanesulfonic Acid (PFHxS) and Related Salts (Public Comment and External Review Draft)

IRIS

Perfluorohexanesulfonic Acid (PFHxS)

CASRN 355-46-4 | DTXSID7040150

Toxicological Review (PDF) (493 pp, 22.9 MB)
IRIS Summary (PDF) (6 pp, 403.3 KB)

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Overview
Background
Downloads

Notice

EPA announced the release of the IRIS Toxicological Review of Perfluorohexanesulfonic Acid (PFHxS) and Related Salts (Public Comment and External Review Draft) for a 60-day public comment period and external peer review. The deadline for comments is September 22, 2023.

Overview

In July 2023, the IRIS Program released the draft IRIS Toxicological Review of Perfluorohexanesulfonic Acid (PFHxS) and Related Salts for public comment and external peer review. The IRIS assessment of PFHxS will undergo an independent external scientific peer review managed by ERG, a contractor to EPA. Additional information about the peer review meeting is listed with the downloads below and located on the external peer review meeting site.

Citation

U.S. EPA. IRIS Toxicological Review of Perfluorohexanesulfonic Acid (PFHxS) and Related Salts (Public Comment and External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-23/056, 2023.

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Background

Perfluorohexanesulfonic Acid (PFHxS) and its related salts are members of the group of per and polyfluoroalkyl substances (PFAS). PFAS are not naturally occurring in the environment; they are man-made compounds that have been used widely over the past several decades in consumer products and industrial applications because of their resistance to heat, oil, stains, grease, and water. Concerns about PFHxS and other PFAS stem from the resistance of these compounds to hydrolysis, photolysis, and biodegradation, which leads to their persistence in the environment.

PFHxS is used in water- and stain-protective coatings for consumer products such as carpets, textiles, paper (including food-contact), packaging (including food-contact), textiles, and electronics. It has been used industrially as a surfactant to make fluoropolymers, as a surfactant or surface protection agent for cleaning and polishing products, and in other industrial fluids or water-proofing agents. It may also be present unintentionally as an impurity from industrial production processes. PFHxS has also been used in aqueous film-forming foam (AFFF) for fire suppression.

History/Chronology

Date	Description
01- Nov 2019	EPA released the Systematic Review Protocol for the PFHxS IRIS Assessment (Preliminary Assessment Materials). [Federal Register Notice Nov 8, 2019]
02- Jul 2020	EPA released an update to the Systematic Review Protocol for the PFBA, PFHxA, PFHxS, PFNA, and PFDA IRIS Assessments in response to public comments.
03- Jan 2023	EPA sent an interagency science consultation PFHxS draft for review and comment.
04- Jul 2023	EPA released the draft IRIS Toxicological Review of Perfluorohexanesulfonic Acid (PFHxS) and Related Salts for a 60-day public comment period and external peer review. EPA also released the interagency science consultation comments from reviewers. [Federal Register Notice: July 24, 2023]
05- Feb/Mar 2024	ERG, an independent contractor to the EPA, hosted multiple external peer review meetings for the review of the Integrated Risk Information System (IRIS) Assessment for PFHxS in late Febraury and early March.

Status

The toxicological review of Perfluorohexanesulfonic Acid (PFHxS) and related salts was released for a 60-day public comment period and external peer review. Following the external peer review meeting, the assessment will be revised, taking into consideration all public and external peer review comments received.

Additional Information

If you have a disability and the format of any material on our web pages interferes with your ability to access the information, please contact Dahnish Shams (shams.dahnish@epa.gov). To enable us to respond in a manner most helpful to you, please indicate the nature of the accessibility problem, the web address of the requested material, your preferred format in which you want to receive the material (electronic format (ASCII, etc.), standard print, large print, etc.), and your contact information.

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Download(s)

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.

If you have a disability and the format of any material on our web pages interferes with your ability to access the information, please reach out to us using the Contact Us about IRIS form for assistance. To enable us to respond in a manner most helpful to you, please indicate the nature of the accessibility problem, the web address of the requested material, your preferred format in which you want to receive the material (electronic format (ASCII, etc.), standard print, large print, etc.), and your contact information.