What is ITER?

ITER is a free Internet database of human health risk values for over 600 chemicals of environmental concern from several organizations worldwide.  ITER is the only internet database that provides this data in a table format that allows side-by-side comparisons of risk values from different organizations.  Below the table is a synopsis that includes an explanation for any differences among the organizations' values.  ITER provides links to these organizations for more detailed information.  ITER currently contains data from:   

·        Agency for Toxic Substances and Disease Registry (ATSDR)

ATSDR derives minimal risk levels (MRLs), which are found in the Agency's Toxicological Profiles. 

 ·        Health Canada

Health Canada develops Tolerable Intakes/Concentrations and Tumorigenic Doses/Concentrations for Priority Substances under the Canadian Environmental Protection Act (CEPA).  These risk values for Health Canada are included on ITER.

      ·        International Agency for Research on Cancer (IARC)

We are currently adding IARC's data to ITER.  Look for announcements about this on ITER’s “What’s New” page.

IARC evaluates the cancer weight of evidence for chemicals over a wide range of human exposures and classifies chemicals according to potential for carcinogenicity.  The results of IARC analyses are published Monographs.  IARC cancer classification groups and detailed descriptions of these groups can be found in the Preamble to each monograph and at http://monographs.iarc.fr/ENG/Preamble/index.php.  The IARC evaluation considers the evidence of carcinogenicity in humans, the evidence of carcinogenicity in experimental animals, and other data relevant to the evaluation of carcinogenicity and its mechanisms.

·        National Institute of Public Health and the Environment (RIVM), The  Netherlands

RIVM is currently helping us add its data to ITER.  
      Look for upcoming announcements about this on ITER’s “What’s New” page. 

RIVM develops human-toxicological risk limits (i.e., maximum permissible risk levels, MPRs) for a variety of chemicals based on chemical assessments that are compiled in the framework of the Dutch government program on risks in relation to soil quality.  The MPRs updated in 2001 are currently being added to ITER.

• U.S. Environmental Protection Agency (EPA )

EPA derives risk values called reference concentrations (RfCs), reference doses (RfDs) and cancer assessments. All of these risk values from EPA’s Integrated Risk Information System (IRIS) are included on ITER. 

• Independent parties whose risk values have undergone peer review

Risk values developed by other parties (e.g. industry, consulting groups, or universities) are included on ITER (under the ITER column) after they have undergone an independent peer review (http://www.tera.org/peer).  This independent peer review is typically convened by TERA through its Peer Review Program, and if the expert panel concurs with an assessment, it may be made available to the public on the ITER database.  Over two-dozen independent risk values have been included on ITER, and are compared with the risk values from other organizations.  These independent values can only be found on ITER.  

Risk values are principally used as guidance or regulatory levels against which human exposures from contamination of air, food, soil, and water can be compared. The information on ITER is useful to risk assessors and risk managers needing human health risk values to make risk-based decisions. ITER allows the user to compare a number of key organizations' values and to determine the best value to use for the human exposure situation being evaluated.

How do I search ITER?

To search the database, click the Search ITER link on the ITER home page.  Enter a chemical name, portion of a name, or CAS number. (NOTE:  CAS numbers are the most effective way to search because it avoids the confusion about which chemical name is being used). You can also select from a list of all chemicals.

When your search results have been returned, you can view a chemical’s data online or you can generate and print a report for a chemical.   

View Chemical Data

If you would like to view the data for a chemical, click on its chemical name.  This will take you to the Level 1 table for that chemical, which contains red and gray circles for each organization and category (noncancer oral, cancer oral, noncancer inhalation, or cancer inhalation).  The red circles indicate that ITER contains data, and the gray circles indicate that ITER does not contain data for that particular organization or category.  (Note:  In some cases the organization may have data available but it has not yet been prepared for inclusion in ITER).  Click on the red circles to go to the Level 2 table, which displays the key elements for each organization’s risk value along with a synopsis explaining any differences among risk values.  At the bottom of the Level 2 table, you can click on the green circle(s) to go to Level 3 and obtain more information about a particular organization’s risk value (including a source and/or link for further information about that particular assessment).

Generate a Report

If you want to generate and print a report, click on the CAS number and the entire record for that chemical will be available to print.  You will first see the Level 1 table for that chemical with the red and gray circles to indicate whether or not ITER has data for that organization or category.  By clicking on a risk value category (noncancer oral, cancer oral, noncancer inhalation, or cancer inhalation), you will get both the Level 2 and Level 3 data for that chemical for all of the organizations on ITER.  You will then need to print each risk value category separately.

How was the information compiled?

The values and text on ITER have been extracted from existing published documents and data systems of the original health organizations.  TERA staff compiles information on the risk values into a consistent format, so that users can readily make comparisons across organizations.  In some cases, the organization itself extracts and prepares its data for ITER.  TERA staff performs necessary conversions so that direct comparisons can be made when appropriate, and write the synopsis text to help explain the similarities and differences between the values of the different organizations.  The following explains, in general, the sources for ITER data.

• ATSDR information was extracted from the ATSDR Toxicological Profile for each chemical. Toxicological Profiles are published in both draft and final forms by ATSDR. For information call the ATSDR TOX-INFO LINE at (404) 639-6000 or see http://www.atsdr.cdc.gov/mrls.html.

• Health Canada information was extracted from Assessment Reports prepared by Environment Canada and Health Canada under the CEPA Priority Substances Program.  These reports provide an assessment of risks to human health and are chemical specific.  The most recent assessment reports, Environment Canada and Health Canada’s Canadian Environmental Protection Act, 1999:  Priority Substances List Assessment Reports, are available online at http://www.ec.gc.ca/cceb1/eng/final/index_e.html.  Earlier reports were included in a 1994 publication, Evaluation of Risks to Health from Environmental Exposure in Canada. In: Environmental Carcinogenesis and Ecotoxicology Reviews, Part C of Journal of Environmental Science and Health. C12(2). This publication summarized the assessments of risks to human health of 44 Priority Substances that were written to fulfill the requirements of the CEPA. More detailed assessment reports and supporting documentation are available from the corresponding authors of each respective manuscript.  New assessments will continue to be added as they are released.
  
• IARC information was extracted from the Summary and Evaluations in the IARC Monographs for each chemical.  IARC Monographs are available at http://monographs.iarc.fr.    

• RIVM (The Netherlands) information is currently being extracted from the recently released 2001 document entitled, Re-evaluation of human-toxicological maximum permissible risk levels (RIVM report 711701025).  This report can be found at http://www.rivm.nl/bibliotheek/rapporten/711701025.html. 

• U.S. EPA information was extracted from the Integrated Risk Information System (IRIS). IRIS is EPA's official source for agency consensus risk values. IRIS is a computerized system available on-line at http://www.epa.gov/iris. For general information about IRIS, contact EPA's Risk Information Hotline at (513) 569-7254.

• Independent parties’ information is derived from their risk assessment documentation, which has undergone independent peer review (see http://www.tera.org/peer).

What are TERA’s plans for expanding ITER?

Remaining data from ATSDR and RIVM (The Netherlands) are currently being entered into ITER, and we are in the early stages of adding IARC cancer classifications. Additional plans include adding data from the World Health Organization/International Programme on Chemical Safety (WHO/IPCS).

ITER was developed by TERA as a public service, to provide the international risk assessment community with easy access to the health risk values of many organizations and to provide a way to distribute independently derived peer-reviewed values. We are extremely grateful to our sponsors, without whom ITER would not have been possible. Additional support is needed to both maintain and expand ITER, and to continue providing ITER as a free service to the risk assessment community.

We want your comments!

TERA is interested in feedback on the content and format of ITER, as well as your suggestions for adding other organizations to ITER. Please send us your comments by filling out our feedback form or directly by email to Andrea Wullenweber.