IRIS Toxicological Review of Hexavalent Chromium (External Review Draft, 2022)

Abstract

In October 2022, EPA publicly released the draft hexavalent chromium assessment for review and comment. The IRIS Toxicological Review of Hexavalent Chromium provides the scientific support and rationale for the hazard and dose-response assessment of exposure to hexavalent chromium. Following public comment, the assessment will undergo an independent external scientific peer review managed by EPA’s Science Advisory Board (SAB).
Cr(VI) is a naturally occurring metal that has been most commonly used commercially to prevent rust and corrosion and can be found in a variety of industries, including pigment manufacturing, chrome plating, and stainless-steel production. The general population may be exposed to Cr(VI) compounds when they inhale ambient air, and ingest water or food containing Cr(VI). EPA’s previous IRIS assessment on Cr(VI) was posted in 1998. This new draft assessment updates the information based on the latest science. The draft assessment provides a comprehensive systematic review of hundreds of studies on cancer and multiple noncancer health effects of inhalation and oral exposure to Cr(VI), resulting in a state-of-the-science human health assessment.

Impact/Purpose

The IRIS Toxicological Review of Hexavalent Chromium (draft) provides scientific support and rationale for the hazard and dose-response assessment pertaining to chronic exposure to hexavalent chromium via ingestion.

Status

Following public comment and external peer review, the assessment will be revised prior to final posting to the IRIS Web site.

Citation

U.S. EPA. IRIS Toxicological Review of Hexavalent Chromium (External Review Draft, 2022). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-22/191, 2022.

Date	Description
01- Apr 2014	EPA released preliminary meeting materials for chromium (VI), part 1, in preparation for the June 2014 Bimonthly Public Science Meeting.
02- Jun 2014	EPA hosted a public science meeting to discuss preliminary meeting materials for chromium (VI), part 1.
03- Aug 2014	EPA released preliminary meeting materials for chromium (VI), part 2, in preparation for the October 2014 Bimonthly Public Science Meeting.
04- Oct 2014	EPA hosted a public science meeting to discuss preliminary meeting materials for chromium (VI), part 2.
05- Mar 2019	EPA released the Systematic Review Protocol for the Hexavalent Chromium IRIS Assessment (Preliminary Assessment Materials). [Federal Register Notice Mar 15, 2019]
06- Apr 2019	EPA announced that they will host a public science meeting on April 24, 2019 (by webinar) to discuss the draft document.
07- Feb 2022	EPA initiated an interagency science consultation on the draft IRIS Toxicological Review of Hexavalent Chromium.
08- Oct 2022	EPA released an update to the CrVI protocol (preliminary assessment materials), see related links for details.
09- Oct 2022	EPA released the draft IRIS Toxicological Review of Hexavalent Chromium (External Review Draft) for public comment and subsequent external peer review by EPA’s Science Advisory Board (SAB). Also, the EPA-led Interagency Science Consultation draft was released with comments. [Federal Register Notice Oct 20, 2022]
10- Dec 2024	EPA released an update to the IRIS Chloroform (inhalation) protocol.

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 Hexavalent Chromium (External Review Draft) (PDF)  (507  pp, 6.6 MB, about PDF)
• IRIS Toxicological Review of Hexavalent Chromium - Supplemental Information (External Review Draft) (PDF)  (433  pp, 13.0 MB, about PDF)
• Appendix A: Systematic Review Protocol for the Hexavalent Chromium IRIS Assessment (Updated Oct 2022) (PDF)  (158  pp, 2.1 MB, about PDF)
• Review of EPA’s draft IRIS Toxicological Review of Hexavalent Chromium (Report number EPA-SAB-23-009)
• Charge to the External Reviewers (PDF)  (8  pp, 234.4 KB, about PDF)
• IRIS TOXICOLOGICAL REVIEW OF HEXAVALENT CHROMIUM (FINAL REPORT, 2024) (PDF)  (538  pp, 944.1 MB, about PDF)
• An Update to the Systematic Review Protocol for the IRIS Toxicological Review of Chloroform (Inhalation) (Dec 2024) (PDF)  (151  pp, 2.5 MB, about PDF)

Related Link(s)

• IRIS Toxicological Review of Hexavalent Chromium Part 1: Experimental Animal Studies (Preliminary Assessment Materials, 2014)
• IRIS Toxicological Review of Hexavalent Chromium Part 2: Human, Toxicokinetic, and Mechanistic Studies (Preliminary Assessment Materials, 2014)
• Updated Systematic Review Protocol for the Hexavalent Chromium IRIS Assessment (Preliminary Assessment Materials, 2019)
• IRIS Toxicological Review of Hexavalent Chromium (Interagency Science Consultation Draft, 2022)

HERO Project

• Primary Literature Search References Sorted by Author (Chromium VI)

Docket

Comments on the assessment may be submitted and reviewed using the Docket ID EPA-HQ-ORD-2014-0313