Arsenic, Inorganic

Overview

In 1991, EPA’s Integrated Risk Information System (IRIS) Program finalized the oral, non-cancer evaluation of inorganic arsenic. This document outlines in Section I (Health Hazard Assessments for Noncarcinogenic Effects) the conclusions that were reached, including the derivation of the toxicity value(s). Supporting information and explanations of the methods used are provided in guidance documents located on the EPA website. This 1991 evaluation has been replaced by the EPA assessment posted to IRIS in 2025. This 1991 IRIS document remains available as a historical reference.

• IRIS Summary of Inorganic Arsenic (Noncancer) (PDF)  (27  pp, 176.8 KB, about PDF)

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Document Related Link(s)

• IRIS Toxicological Review of Inorganic Arsenic (Public Comment and External Review Draft)
• Updated Problem Formulation and Systematic Review Protocol for the Inorganic Arsenic IRIS Assessment
• IRIS Toxicological Review of Inorganic Arsenic (Interagency Science Consultation Draft, 2022)
• Bmd Model Code and Bmd Modeling Results for the Inorganic Arsenic IRIS Assessment (External Review Draft)
• IRIS Toxicological Review of Inorganic Arsenic (Interagency Science Discussion Draft, 2024)
• IRIS Toxicological Review of Inorganic Arsenic (Final Report, 2025)