Skip to Content


Integrated Risk Information System (IRIS); Announcement of 2001 Program; Request for Information

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


Environmental Protection Agency.


Notice; announcement of IRIS 2001 program and request for scientific information on health effects that may result from chronic exposure to chemical substances.


The Integrated Risk Information System (IRIS) is an Environmental Protection Agency (EPA) data base that contains EPA scientific consensus positions on human health effects that may result from chronic exposure to chemical substances in the environment. On January 12, 2000, EPA announced the 2000 IRIS agenda and solicited scientific information from the public for consideration in assessing health effects from specific chemical substances (65 FR 1863). A supplementary notice issued May 17, 2000 (65 FR 31309) added two additional substances to the agenda. Most of the health assessments listed in the two notices are in progress or near completion. Today, EPA is adding some additional health assessments to the IRIS agenda. This notice describes the Agency's plans, and solicits scientific data and evaluations for consideration in EPA's new assessments.


Please submit information in response to this notice by April 23, 2001.


Please send relevant scientific information to the IRIS Submission Desk in accordance with the instructions provided under “Submission of Information” in this notice.

Start Further Info


For information on the IRIS program, contact Amy Mills, National Center for Environmental Assessment (mail code 8601D), U.S. Environmental Protection Agency, Washington, DC 20460, or call (202) 564-3204, or send electronic mail inquiries to For general questions about access to IRIS, or the content of IRIS, please call the Risk Information Hotline at (513) 569-7254.

End Further Info End Preamble Start Supplemental Information



IRIS is an EPA data base containing Agency consensus scientific positions on potential adverse human health effects that may result from chronic (or lifetime) exposure to chemical substances found in the environment. IRIS currently provides health effects information on over 500 specific chemical substances.

IRIS contains chemical-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. IRIS information includes the reference dose for non-cancer health effects resulting from oral exposure, the reference concentration for non-cancer health effects resulting from inhalation exposure, and the carcinogen assessment for both oral and inhalation exposure. Combined with specific situational exposure assessment information, the summary health hazard information in IRIS may be used as a source in evaluating potential public health risks from environmental contaminants.

The IRIS Program

EPA's process for developing IRIS consists of: (1) An annual Federal Register notice announcing EPA's IRIS agenda and call for scientific information from the public on the selected chemical substances, (2) a search of the current literature, (3) development of health assessments and draft IRIS summaries, (4) peer review within EPA, (5) peer review outside EPA, (6) EPA consensus review and management approval, (7) preparation of final IRIS summaries and supporting documents, and (8) entry of summaries and supporting documents into the IRIS data base.

Assessments Completed in FY 2000 and Early FY 2001

The following assessments were completed and entered into IRIS in FY 2000 and early FY 2001. These assessments were listed in the Federal Register of January 12, 2000. All health endpoints, cancer and non-cancer, were assessed unless otherwise noted. Where information was available, both qualitative and quantitative assessments were developed.

NameCAS No.
Benzene (oral carcinogenicity)71-43-2
Chloral hydrate75-87-6
Chlorine dioxide10049-04-4
Chlorite (sodium salts)7758-19-2
Ethylene glycol monobutyl ether111-76-2
Vinyl chloride75-01-4

Assessments in Progress—Completion Planned for FY 2001 or FY 2002

The following assessments are underway or generally complete, and are planned for entry into IRIS in FY 2001 or FY 2002. These assessments were announced in the January 12, 2000, or May 17, 2000, Federal Registers. All health endpoints, cancer and non-cancer, are being assessed unless otherwise noted. Pesticides Start Printed Page 11166denoted with an asterisk (*) will have only oral reference dose and carcinogenicity endpoints assessed. For all endpoints assessed, both qualitative and quantitative assessments are being developed where information is available.

NameCAS No.
Ammonium perchlorate (and associated salts)7790-98-9
Antimony and compounds7440-36-0
Arsenic, inorganic7440-38-2
Benzene (non-cancer endpoints)71-43-2
Carbon tetrachloride56-23-5
Dichloroacetic acid79-43-6
Diesel emissions[N.A.]
Ethylene dibromide106-93-4
Ethylene dichloride107-06-2
Ethylene oxide75-21-8
Hydrogen sulfide7783-06-4
Methyl chloride74-87-3
Methyl isobutyl ketone (MIBK)108-10-1
Methyl mercury (noncancer endpts)22967-92-6
Methyl tert-butyl ether (MTBE)1634-04-4
Methylene chloride75-09-2
Nickel (soluble salts)[N.A.]
Polychlorinated biphenyls (PCBs) (noncancer endpts)1336-36-3
Refractory ceramic fibers[N.A.]
2,3,7,8-TCDD (dioxin)1746-01-6
Tetrachloroethylene (“perc”)127-18-4
Uranium (natural)7440-61-1
Vinyl acetate108-05-4
Zinc and compounds7440-66-6

The following assessments in progress have been delayed and are now expected in FY 2003:

NameCAS no.
Hexahydro-1,3,5-trinitro-triazine (“RDX”)121-82-4
Silica (crystalline)14808-60-7

Completed IRIS summaries and support documents for the substances listed above will be provided on the IRIS web site at​iris. This publicly-available web site is EPA's primary location for IRIS documents. In addition, external peer review drafts of IRIS documents can be found via the “What's New” page of the IRIS web site, as discussed in the January 12, 2000 Federal Register notice. Interested parties should check the “What's New” page frequently for the availability of these drafts.

In addition to the assessment of the individual polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene, EPA conducted a literature review and will be sponsoring a workshop on approaches to assessing the health effects of a larger set of PAHs. As mentioned in the January 12, 2000 Federal Register, additional health assessments on this class of chemicals will be considered for initiation in FY 2001.

Assessment Development Input From External Parties

In addition to the opportunity for public input via the IRIS Submission Desk described above, EPA is testing ways to involve the public in the development of health assessment documents that are submitted to EPA by external parties as supporting documents for IRIS. This was described in the January 12, 2000, Federal Register notice. Considerable expertise in assessing health risks exists outside of EPA, such as in other government agencies, industries, universities, professional organizations, and other non-governmental organizations. Cooperation between EPA and external parties in the assessment development process can improve the quality of IRIS supporting documents by providing greater scientific input to EPA's assessments.

EPA announced in the January 12, 2000 and May 17, 2000, Federal Register notices that external parties are developing several assessment documents with dialogue and feedback from EPA. Currently, external party assessments are addressing ethylene oxide, ethylbenzene, styrene, toxaphene, hexachlorobenzene, and hexahydro-1,3,5-trinito-triazine (“RDX”). When complete, EPA will consider these documents, in whole or in part, as possible sources or supporting documents for IRIS assessments. In FY 2001, EPA will continue to evaluate its experience with these externally-generated assessments in terms of process efficiency and quality of the documents produced. If the experience is positive, EPA will consider inviting similar involvement on future health assessments in the IRIS program.

Information Requested on New Assessments for FY 2001

EPA will continue building and updating the IRIS data base. The Agency recognizes that many of the assessments on IRIS need updating to incorporate new scientific information and methodologies. Further, many additional substances are candidates for adding to IRIS. However, due to limited resources in the Agency to address the spectrum of needs, EPA developed a list of priority substances for attention beginning in FY 2001. The following list of substances are priorities for IRIS due to one or more reasons: (1) Agency statutory, regulatory, or program implementation need; (2) new scientific information or methodology is available that might significantly change current IRIS information; (3) interest to other levels of government or the public; (4) most of the scientific assessment work has been completed while meeting other Agency requirements, and only a modest additional effort will be needed to complete the review and documentation for IRIS.

The following IRIS health assessments have recently begun or will be started in FY 2001, with completion expected in FY 2003. It is for these substances that the Agency is primarily requesting information from the public for consideration in the assessments. Unless otherwise noted, noncancer and cancer endpoints will be assessed for each substance. Pesticides denoted with an asterisk (*) will have only oral reference dose and carcinogenicity endpoints assessed. For all endpoints assessed, both qualitative and quantitative assessments are being developed where information is available. Start Printed Page 11167

NameCAS No.
Azinphos Methyl*86-50-0
Methyl Parathion*298-00-0
Polycyclic Aromatic Hydrocarbons (PAHs)[Various]

Submission of Information

As in previous Federal Registers announcing the annual IRIS agenda, EPA is soliciting public involvement in new assessments starting in FY 2001. While EPA conducts a thorough literature search for each chemical substance, there may be other articles or unpublished studies we are not aware of. We would greatly appreciate receiving scientific information from the public during the information gathering stage for the list of “new assessments” listed above. Interested persons should provide scientific comments, analyses, studies, and other pertinent scientific information. The most useful documents for EPA are unpublished studies or other primary technical sources that we may not otherwise obtain through open literature searches. Also note that if you have submitted certain information previously then there is no need to resubmit that information. Information from the public is being solicited for 60 days via this notice.

Procedures for Submission

Similar to the process described in the January 12, 2000, Federal Register, submissions will be handled in a three-step process:

1. Submission Inventory: First, you should simply provide a list within 60 days of this notice briefly identifying all the information (reports, papers, articles, etc.) you wish to submit. The list should specify by name and CASRN (Chemical Abstract Service Registry Number) the chemical substance(s) to which the information pertains, state the type of assessment that is being addressed (e.g., carcinogenicity), and describe briefly the information to be submitted for consideration. Where possible, documents should be listed in scientific citation format, that is, author(s), title, journal, and date. Your cover letter should state that the correspondence is an IRIS submission, describe in general terms the purpose of the submission, and include names, addresses, and telephone numbers of persons to contact for additional information. Mail two copies of the submission to the IRIS Submission Desk, c/o Courtney R. Johnson, National Center for Environmental Assessment (8601D), U.S. Environmental Protection Agency, Washington, DC 20460.

Alternatively, you may submit the submission inventory and cover letter electronically to Electronic information must be submitted in WordPerfect format or as an ASCII file. Information will also be accepted on 3.5″ floppy disks. All information in electronic form must be identified as an IRIS submission.

2. EPA Replies to Submission Inventory: In the second step, EPA will compare the submission inventory to existing files and identify the information that should be submitted. This step will help prevent an influx of duplicative information. You will receive notification requesting full submission of the selected material.

3. Full Submission of Selected Material: In the third step, you should send in the information indicated by EPA within 30 days of EPA's reply. Prompt response to EPA will ensure that your material can be considered in the assessment in a timely fashion. Submittals should include a cover letter addressing all of the points in item 1 above. In addition, when you submit results of new health effects studies concerning existing substances on IRIS, you should include a specific explanation of how and why the study results could change the information in IRIS.

Please send two copies, at least one of which should be unbound, to the IRIS Submission Desk, as described in Step 1. The IRIS Submission Desk will acknowledge receipt of your information.

Confidential Business Information (CBI) should not be submitted to the IRIS Submission Desk. CBI must be submitted to the appropriate EPA Office via established procedures for submission of CBI (see 40 CFR, Part 2, Subpart B). If you believe that a CBI submission contains information with implications for IRIS, please note that in the cover letter accompanying the submission to the appropriate office.

You may also request to augment your submission with a scientific briefing to EPA staff. Such requests should be made directly to Amy Mills, IRIS Program Manager (see FOR FURTHER INFORMATION).

Start Signature

Dated: January 18, 2001.

George W. Alapas,

Acting Director, National Center for Environmental Assessment.

End Signature End Supplemental Information

[FR Doc. 01-2175 Filed 2-21-01; 8:45 am]