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United States National Library of Medicine National Institutes of Health

Fact Sheet
Integrated Risk Information System (IRIS)

IRIS is a toxicology data file on the National Library of Medicine's (NLM) Toxicology Data Network (TOXNET®). It contains data in support of human health risk assessment. It is compiled by the U.S. Environmental Protection Agency (EPA) and contains over 500 chemical records. IRIS data, focusing on hazard identification and dose-response assessment, is reviewed by work groups of EPA scientists and represents EPA consensus. Among the key data provided in IRIS are EPA carcinogen classifications, unit risks, slope factors, oral reference doses, and inhalation reference concentrations.

Web Access/Searching

IRIS is accessible, free of charge, via TOXNET at:

Users can search by chemical or other name, chemical name fragment, Chemical Abstracts Service Registry Number (RN), and/or subject terms. Search results can easily be viewed, printed or downloaded. Search results are displayed in relevancy ranked order. Users may select to display exact term matches, complete records, or any combination of data from the following broad groupings:

Chronic Health Hazard Assessment for Noncarcinogenic Effects
Carcinogenicity Assessment for Lifetime Exposure
Oral RfD References
Inhalation RfC References
Carcinogenicity Assessment References

Users can easily conduct their IRIS search strategy against other databases: Hazardous Substances Data Bank®, Chemical Carcinogenesis Research Information System, GENE-TOX, TOXLINE®, ChemIDplus®, and ITER®.

Further Information

For further information about IRIS or TOXNET, contact:

IRIS Representative
Specialized Information Services
National Library of Medicine
Two Democracy Plaza, Suite 510
6707 Democracy Boulevard, MSC 5467
Bethesda, MD 20892-5467
Fax: (301) 480-3537
Telephone: (301) 496-1131

For comments on IRIS content, contact:

EPA's Risk Information Hotline, Cincinnati OH, (513) 569-7254

For general information on NLM services, contact:

National Library of Medicine
Customer Service
8600 Rockville Pike
Bethesda, MD 20894
Telephone: 1-888-FINDNLM (1-888-346-3656)

A complete list of NLM Fact Sheets is available at:
(alphabetical list)
(subject list):

Or write to:

Office of Communications and Public Liaison
National Library of Medicine
8600 Rockville Pike
Bethesda, Maryland 20894

Phone: (301) 496-6308
Fax: (301) 496-4450

Last reviewed: 09 May 2008
Last updated: 09 May 2008
First published: 01 January 1994
Metadata| Permanence level: Permanent: Stable Content