EPA IRIS — Inorganic Arsenic Toxicological Review (January 2025)

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 (EPA IRIS iAs 2025). It supersedes prior IRIS arsenic values that had been operative for decades, and represents the US federal scientific anchor for inorganic arsenic dose-response that downstream EPA, FDA, and state regulatory actions reference (EPA IRIS iAs 2025).

The full quantitative outputs (oral RfD, inhalation RfC, oral cancer slope factor, inhalation unit risk, critical study identification per endpoint) require detailed extraction from the approximately 100+ page review document and are pending consolidation (EPA IRIS iAs 2025). Once those values are extracted from the full text, this regulation page will record them with the verbatim agency-stated values.

Sources

• EPA IRIS iAs 2025 — EPA, January 2025. IRIS Toxicological Review of Inorganic Arsenic (EPA/635/R-25/005Fa).