Arsenic, Inorganic

CASRN 7440-38-2

IRIS Toxicological Review of Inorganic Arsenic (Cancer) (External Review Draft, 2010)

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EPA's Science Advisory Board (SAB) conducted a review of the scientific basis supporting the human health cancer hazard and dose-response assessment of inorganic arsenic that will appear on the Integrated Risk Information System (IRIS) database. EPA revised the assessment and is now returning the assessment to the SAB and releasing the document to the public for a focused review of EPA's responses to the SAB recommendations.


U.S. EPA. IRIS Toxicological Review of Inorganic Arsenic (Cancer) (External Review Draft, 2010). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-10/001, 2010.

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Inorganic arsenic is used for hardening copper and lead alloys. It also is used in glass manufacturing as a decolorizing and refining agent, as a component of electrical devices, in the semiconductor industry, and as a catalyst in the production of ethylene oxide. Arsenic compounds are used as a mordant in the textile industry, for preserving hides, as medicinals, pesticides, pigments, and wood preservatives. Approximately 90% of the domestic consumption of arsenic is currently used with production of chromated copper arsenate (CCA), a wood preservative, the production of which is currently being phased out. Arsenic is also found naturally in the environment and is typically present in soil and water at detectable levels. Sources of human exposure to inorganic arsenic include drinking water, diet, air, and soils (which can contain naturally occurring arsenic or contamination from anthropogenic sources). This draft IRIS health assessment addresses only cancer human health effects that may result from chronic exposure to this chemical. An assessment of noncancer health effects of inorganic arsenic will be released for external peer review and public comment at a later date.


Date Description
01-1988EPA published the IRIS Health Hazard Assessment for Inorganic Arsenic.
02-1999NRC reviewed the 1988 IRIS assessment and the available health data for inorganic arsenic and made recommendations for updating the cancer assessment in Arsenic in Drinking Water.
03-2001NRC updated the NRC (1999) report and evaluated the toxicological risk and health effects of arsenic as relevant to the 2001 Arsenic Rule in Arsenic in Drinking Water – 2001 Update.
04-2001NRC reviewed the 2001 Primary Drinking Water Standard for inorganic Arsenic and made recommendations for applying epidemiologic data in the cancer health assessment.
05-2003EPA started a reassessment of the IRIS assessment for inorganic arsenic.
06-Jul 2005EPA submitted the reassessment of cancer assessment for inorganic arsenic to EPA's Science Advisory Board (SAB) for review.
07-Jun 2007SAB posted a response to the 2005 EPA reassessment of inorganic arsenic (cancer). [See related links (below) or Link to the SAB Report and Review Panel Meetings]
08-Oct 2008The draft IRIS Toxicological Review for Inorganic Arsenic (cancer) was submitted to OMB for interagency review.
09-Jun 2009EPA hosted an interagency science consultation on the draft IRIS Toxicological Review of Inorganic Arsenic.
10-Feb 2010EPA released the draft IRIS Toxicological Review for Inorganic Arsenic (cancer) to SAB and simultaneously to the public for review and comment, focusing on EPA's responses to the SAB (2007) report.
11-Oct 2010SAB announced a public teleconference to conduct a quality review of the draft report to be held on November 22, 2010. [Federal Register Oct 25, 2010]


This draft has been archived. The re-assessment will start again at step 1.

Supporting Documents: The file, Arsenic_Excel_Table (ZIP, 195 Kb), provides the data and analyses EPA used to derive the cancer risk estimates as described in Table 5-3 in the Toxicological Review of Inorganic Arsenic (Cancer) (External Review Draft) 2010. An additional file (Arsenic_Excel_Appendix (ZIP, 143 Kb), ) provides the data and analyses EPA used to derive the results presented in Appendix F (Tables F-1 and F-2). Information regarding the files can be found on the first tab (labeled Directions) of each individual Excel® file.

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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.

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