Perfluorohexanoic Acid (PFHxA)

CASRN 307-24-4 | DTXSID3031862

Toxicological Review (PDF) (250 pp, 1.2 MB, about PDF)
IRIS Executive Summary (PDF) (70 pp, 468.8 KB, about PDF)
Toxicological Review of Perfluorohexanoic Acid (PFHXA) and Related Salts - Supplemental Information

IRIS Toxicological Review of Perfluorohexanoic Acid (PFHxA) and Related Salts (Interagency Science Consultation Draft, 2021)

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Overview
Background
Downloads

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Archived files are provided for reference purposes only. The file was current when produced, but is no longer maintained and may now be outdated. Persons with disabilities having difficulty accessing archived files may contact the IRIS Webmaster for assistance. Please use the contact us form if you need additional support.

Overview

In February 2022, the draft IRIS Assessment of Perfluorohexanoic Acid (PFHxA) and Related Salts (Public Comment and External Review Draft) and the draft charge to external peer reviewers were released for a 60-day public review and comment period. The Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and White House Offices before public release. Consistent with the May 2009 IRIS assessment development process, all written comments on IRIS assessments submitted by other federal agencies and White House Offices are made publicly available. Accordingly, interagency comments and the interagency science consultation materials provided to other agencies, including interagency review drafts of the Toxicological Review and the charge to external peer reviewers, are posted on this site.

Background

Perfluorohexanoic Acid (PFHxA) and its related salts are members of the group of per and polyfluoroalkyl substances (PFAS). Concerns about PFHxA and other PFAS stem from the resistance of these compounds to hydrolysis, photolysis, and biodegradation, which leads to their persistence in the environment. 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.

PFHxA is a breakdown product of other PFAS that are used in stain-resistant fabrics, paper food packaging, and carpets; it is also used for manufacturing photographic film, and it is used as a substitute for longer chain perfluoroalkyl carboxylic acids (PFCAs) in consumer products. PFHxA has been found to accumulate in agricultural crops and has been detected in household dust, soils, food products, and surface, ground, and drinking water.

As such, exposure is possible via inhalation of indoor or outdoor air, ingestion of drinking water and food, and dermal contact with PFHxA-containing products.

History/Chronology
Date	Description
Nov 2019	EPA released the Systematic Review Protocol for the PFAS IRIS Assessment (Preliminary Assessment Materials). [Federal Register Notice Nov 8, 2019]
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.
Aug 2021	EPA sent an interagency science consultation PFHxA draft for review and comment.
Feb 2022	EPA released the draft IRIS Toxicological Review of Perfluorohexanoic Acid (PFHxA) and Related Salts for a 60-day public comment period and external peer review. EPA also released the interagency science consultation documents, comments from reviewers, and EPA's response to major comments. [Federal Register Notice: Feb 2, 2022 ]

Status

The Perfluorohexanoic Acid (PFHxA) and Related Salts IRIS assessment was released for public comment in Jan 2022. Following the public comment period, there will be an external peer review. The assessment will then be revised taking into consideration public and peer review comments.

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.

IRIS Toxicological Review of Perfluorohexanesulfonic Acid (PFHxA) Interagency Consultation Draft (PDF) (185 pp, 5.6 MB, about PDF)
PFHxA Supplemental Information (Interagency Consultation Draft) (PDF) (67 pp, 1.1 MB, about PDF)
Charge to Reviewers - Aug 2021 (PDF) (5 pp, 208.0 KB, about PDF)
1. ATSDR PFHxA IASC Comments Sep 2021 (PDF) (3 pp, 166.0 KB, about PDF)
2. DoD PFHxA IASC Comments Sep 2021 (PDF) (12 pp, 493.2 KB, about PDF)
3. EOP PFHxA IASC Comments Sep 2021 (PDF) (4 pp, 134.8 KB, about PDF)
4. NIEHS PFHxA IASC Comments Sep 2021 (PDF) (7 pp, 111.3 KB, about PDF)
5. NIOSH PFHxA IASC Comments Sep 2021 (PDF) (3 pp, 175.8 KB, about PDF)

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