Summary
The January 2025 EPA IRIS Toxicological Review of Inorganic Arsenic (EPA/635/R-25/005Fa, CASRN 7440-38-2) is the finalized US Environmental Protection Agency reassessment of inorganic arsenic toxicity. It is one of the most consequential recent EPA actions on heavy metals, replacing prior IRIS values that had been operative for decades. The review derives quantitative reference values for non-cancer endpoints and updated cancer slope factors covering lung, bladder, and skin cancer endpoints, and represents the US federal scientific anchor for inorganic arsenic dose-response that downstream EPA, FDA, and state regulatory actions reference.
Key numbers
Pending detailed extraction of finalized reference values from full text. The document is approximately 100+ pages with substantial appendices. Key quantitative outputs to populate: oral RfD; inhalation RfC; cancer slope factor (oral); inhalation unit risk (cancer); critical study selection per endpoint.
Provenance notes
License us-government-work. The companion EPA_IRIS_InorganicArsenic_Summary.pdf (EPA/635/R-25/005Fc, SHA aae1317b) is the IRIS Chemical Assessment Summary version of the same January 2025 reassessment — same content, summary format. Both are ingested under the same January 2025 finalization event.
Wiki pages updated on ingest
Update history
The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.
| Commit | Date | Change | Description |
|---|---|---|---|
| a8052bb | 2026-08-09 | major | 5 sections added; narrative text revised |