Risk Assessment

Risk Assessment Guidance for Superfund (RAGS): Part F

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The U.S. Environmental Protection Agency (EPA) developed Risk Assessment Guidance for Superfund: Volume I Human Health Evaluation Manual (Part F, Supplemental Guidance for Inhalation Risk Assessment) ("Part F") to address human health risk related to inhalation exposures. Parts A, B, C, D and E of RAGS address other aspects of a human health risk assessment on a Superfund site.

RAGS Part F provides a methodology to use the type of human health toxicity values which are currently derived by the EPA Integrated Risk Information System (IRIS) as concentrations (Reference Concentrations for non-cancer effects and Inhalation Unit Risk values for cancer endpoints) rather than the earlier and now superseded intake-based approach used by the inhalation component of RAGS Part A. It should be noted that other inhalation toxicity values derived by other parties can also be used with RAGS Part F (provided that the toxicity values are presented as concentrations in air).

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Development and Availability

  • EPA held a workshop in 2003 addressing inhalation risk assessment in the EPA Superfund Program. That workshop formed the general consensus and the workgroup which developed RAGS Part F.
  • In 2007, internal EPA comments on RAGS Part F were received and addressed by the RAGS Part F workgroup.
  • In the Spring of 2008, an external peer review of RAGS Part F was conducted. Concurrent with that review, State risk assessors and some other non-EPA risk assessors also reviewed and commented on RAGS F. Both sets of those comments were reviewed by the RAGS Part F workgroup, and certain changes were made to RAGS Part F in consideration of those comments.
  • Early in 2009, after a draft of RAGS Part F had been distributed to EPA Regional Offices, RAGS Part F and an Implementation Memorandum were posted on the EPA Office of Solid Waste and Emergency Response risk assessment website.You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.

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Implementation and Use of the Guidance

In the development of RAGS Part F, the workgroup also developed and released this implementation memorandum which provides additional information about the intended use of this guidance on Superfund sites.

Questions regarding the use or application of RAGS Part F can be directed to EPA toxicologists or risk assessors in EPA's Regional Offices, or to the below members of the workgroup that developed this guidance. Users of the RAGS Part F guidance from outside of EPA are asked to coordinate the use of Part F on Superfund sites with the EPA Regional Office in which that site is located.

Name and Location Telephone Number Email Address
Chau Vu (Region 1) 617-918-1446 Vu.Chau@epa.gov
Michael Sivak (Region 2, workgroup leader) 212-637-4310 Sivak.Michael@epa.gov
Jennifer Hubbard (Region 3) 214-814-3328 Hubbard.Jennifer@epa.gov
Ofia Hodoh and
Kevin Koporec (Region 4)
404-562-0176 and
Hodah.Ofia@epa.gov and
no current contact (Region 5)    
no current contact (Region 6)    
Jeremy Johnson (Region 7) 913-551-7510 Johnson.Jeremy@epa.gov
Bob Benson and
Susan Griffin (Region 8)
303-312-7070 and
Benson.Bob@epa.gov and
Dan Stralka (Region 9) 415-972-3048 Stralka.Daniel@epa.gov
Marcia Bailey (Region 10) 206-553-0684 Bailey.Marcia@epa.gov
Michele Burgess, OSWER/OSRTI 202- 564-8006 Burgess.Michele@epa.gov

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Future Developments

This website will be used to provide guidance on implementation issues associated with inhalation risk and the use of RAGS Part F guidance. Thus, users of the RAGS Part F guidance should recognize that some of the values presented in the original version of RAGS Part F may be superseded by or replaced with newer values on this website.

Other EPA programs and other agencies and departments may also have developed information relevant to inhalation risk. Periodically, additional links to such information may be provided on this webpage.

Additional Information

Users of RAGS Part F may find additional information relevant to inhalation risk on the following EPA Office of Air Quality Planning and Standards (OAQPS) Risk Assessment and Modeling - Air Toxics Risk Assessment Reference Library.

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RAGS Part F Guidance Documents

You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.