IRIS Update Project


[10/09] EPA has announced the IRIS Update Project’s request for the submission of new and relevant scientific information on health effects for the identified assessments listed in the IRIS Project’s 2009 agenda. Information must be submitted within 60 days of the publication of this notice.

[03/09] The SAB announces the IRIS updated project in an March 2, 2009 Federal Register Notice.


EPA is conducting literature searches for these assessments in 2009. The overall purpose of these literature searches is to identify new and relevant information for each assessment. Relevant information is that which improves the scientific understanding of the agent’s toxicity in humans; new information is relevant information that is not included in the current online IRIS assessment. Based on the results of the literature searches and the information submitted in response to this announcement, EPA will evaluate assessments to determine whether they can be accommodated within the scope and resources of the IRIS Update Project. For this request, EPA is actively soliciting information from the public at the beginning of the assessment update process. As literature searches are completed, they will be posted both here and on the web site for public inspection.

The following IRIS assessments have been selected for inclusion in the IRIS Update Project agenda and are currently underway.  The IRIS posting dates are provided to aid the submitter in determining whether information may have already been considered in the current online IRIS assessment.

Substance Name
Assessment (IRIS posting date) CASRN
cancer (1998) 7440-39-3
RfD (1989), cancer (1990) 75-25-2
carbon disulfide
RfD (1990), RfC (1995) 75-15-0
RfD (1989), cancer (1990) 108-90-7
RfD (1988) 95-57-8
RfD (1988), cancer (1990) 95-48-7
RfD (1997), RfC (1997), cancer (1997) 98-82-8
cancer (1990) 75-34-3
RfD (1990) 105-67-9
RfD (1991) 51-28-5
RfD (1992) 121-14-2
RfD (1988), cancer (1991) 118-74-1
RfD (1991), cancer (1991) 7782-49-2
RfD (1988), cancer (1994) 79-00-5
cancer (1990) 88-06-2

The intent of the IRIS Update Project is to revisit all dose-response assessment toxicity values such as oral reference doses (RfDs), inhalation reference concentrations (RfCs), cancer oral slope factors, and cancer inhalation unit risks in IRIS with a posting or entry date of more than 10 years old.

IRIS is a database of human health effects that may result from chronic exposure to various chemical substances or other contaminants found in the environment. IRIS currently provides information on health effects associated with more than 500 chemical substances. The database includes substance-specific summaries of qualitative and quantitative health information in support of the first two steps of the risk assessment process, i.e., hazard identification and dose-response evaluation. Also, IRIS has included detailed Toxicological Reviews as support documents since 1995. Government and private entities use IRIS, combined with specific exposure information, to help characterize public health risks of chemical substances in a site-specific situation and thereby support risk management decisions designed to protect public health. IRIS is prepared and maintained by the EPA’s National Center for Environmental Assessment within the Office of Research and Development.

While separate from the regular IRIS program, the IRIS Update Project draws on the IRIS data base as the source of human health assessments in need of update. The purpose of the IRIS Update Project is to replace existing IRIS assessment toxicity values and their supporting information that are more than 10 years old with new and relevant scientific information on health effects. As updated assessments are completed as part of this process, they will be posted on IRIS.

The IRIS Update Project defines “assessment” as an individual IRIS toxicity value along with its supporting information. For example, the Project identifies the values for an oral RfD, an inhalation RfC, and a cancer evaluation along with supporting information, as three assessments. Certain IRIS entries, however, may contain values that do not qualify for the update process. For example, a particular substance with an oral RfD derived 15 years ago would qualify for the update process, but a cancer evaluation derived 3 years ago for that same substance would not qualify. Also, the IRIS Update Project will not address any substances or toxicity values that are not currently on IRIS.


Following the call for scientific information from the public regarding assessments on the agenda, EPA will:
  1. Conduct a comprehensive search of the current scientific literature on each assessment;
  2. Develop draft health assessment documents using state of the science methods and guidelines;
  3. Conducting a combined simultaneous review of the draft assessment documents by EPA and other Federal Agencies via the Federal Standing Science Review Committee (FSSRC);
  4. Solicit public comments on these draft assessments, followed by independent external peer review under the Federal Advisory Committee Act (FACA);
  5. Prepare final IRIS assessments that reflects public comments and independent expert review; and
  6. Replace existing assessments with the final updated IRIS assessments on the IRIS data base (at

Additional Information

Comments on the IRIS Update Project may be submitted and reviewed using the e-Government Web site. From the site, select “Environmental Protection Agency” and the keyword “EPA-HQ-ORD-2009-0132” (for the docket ID) to comment on this request.

For information on the public comment period, contact the Office of Environmental Information Docket; telephone: 202-566-1752; facsimile: 202-566-1753; or e-mail: For information on the IRIS Update project, contact Dr. Chon Shoaf, National Center for Environmental Assessment, (mail code: B243-01), Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC 27711; telephone: (919) 541- 4155, facsimile: (919) 541-1818; or e-mail: