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Chemical-Specific Toxicity Values
Introduction
Note to Users: There has been a change in the toxicity value hierarchy from EPA. The following hierarchy of sources is recommended in evaluating chemical toxicity for Superfund sites:
- Integrated Risk Information System (IRIS) and cited references. Changes are made in this database as new chemicals or chemical information becomes available, but there may be data gaps. Visit http://www.epa.gov/iris/ or call the IRIS HOTLINE at (301) 345-2870 for further information.
- The Provisional Peer Reviewed Toxicity Values (PPRTV) and cited references developed for the EPA OSWER Office of Superfund Remediation and Technology Innovation (OSRTI) programs.
- Other toxicity values.
The "other" level of the hierarchy includes several sources of toxicity values that are commonly consulted by the EPA Superfund program when a relevant toxicity value is not available from either IRIS or the PPRTV database. They include:
- California Environmental Protection Agency (Cal EPA) toxicity values, available on Cal EPA's internet website at http://www.oehha.ca.gov/risk/chemicalDB/index.asp;
- The Agency for Toxic Substances and Disease Registry (ATSDR) Minimal Risk Levels (MRLs, addressing noncancer effects only), available on ATSDR's internet website at http://www.atsdr.cdc.gov/mrls.html ;
- The EPA Superfund Health Effects Assessment Summary Tables (HEAST) database and cited references; and
- Additional sources of toxicity values.
Note: Do not consult either the toxicity tables (Appendix A) in the Superfund Public Health Evaluation Manual (SPHEM, U.S. EPA, 1986) or the September 1988 Public Health Risk Evaluation Data Base (PHRED); these sources were superceded as guidance by Risk Assessment
Guidance for Superfund, 1989 (RAGS) and are likely to contain numerous values that have since become out-of-date.
Both RCRA and Superfund hazardous waste programs accept the primacy of human health toxicity values contained in IRIS. Toxicity values placed on IRIS have undergone Agency consensus review. When HEAST was being published on a quarterly basis, if a new toxicity value was placed on IRIS, the corresponding value was removed from HEAST. Beginning in 2002, as HEAST toxicity values are replaced with new provisional
peer-reviewed toxicity values (PPRTVs), the corresponding value will be removed from HEAST, and the PPRTV will be placed in the PPRTV database.
The database of chemical-specific toxicity values contains
the human health toxicological information needed to perform risk evaluations
and assessments. This database contains information taken from the United
States Environmental Protection Agency's (EPA's) Integrated Risk Information
System (IRIS ), the Health Effects
Assessment Summary Tables (HEAST-rad
HEAST-nonrad),
EPA Provisional Peer Reviewed Toxicity Values (PPRTVs)
Database, and other information sources. In this database, all information
is referenced. Additionally, the database contains supplemental information
which clarifies some issues. If a user needs additional information about
the application or contents of the following database, please contact an
RAIS technical
assistant .
All users should note that the toxicity values contained in
this database were developed for use in risk evaluations and assessments
utilizing methods presented in Risk Assessment Guidance for Superfund: Volume I -
Human Health Evaluation Manual (RAGS). Individuals intending to use these values
with methods not consistent with RAGS should consult with risk assessment professionals,
including those at their regulatory agencies and at the Center for Risk Excellence.
Additionally, values with footnotes of r, u, v, w, and x
may not be applicable for use at some sites. These footnotes indicate that
the toxicity values have been withdrawn from IRIS, are provisional, or have been derived
from other information. (However, EPA Region IV has approved these values for use in
the assessment and evaluation of sites on the Oak Ridge Reservation in Oak Ridge,
Tennessee.) Finally, note that this database incorporates information not considered
in EPA's Soil Screening Guidance. In particular, the dermal toxicity values and
radionuclide toxicity values presented in the database are not covered
in the Soil Screening Guidance.
Chemicals
Radionuclides
Federal Radiation Council Data and Guidance
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