Society, Energy, and Environment

PPRTV Assessments Electronic Library

This website is maintained by Oak Ridge National Laboratory to provide enhanced search capabilities of PPRTVs. The formal EPA website for PPRTVs is presented at https://www.epa.gov/pprtv.

CONTACT

For content and library information please contact:

Debra Stewart (stewartdj@ornl.gov)
(865) 576-5450
For technical issues please contact:
Katie Noto (boluska@ornl.gov)


DISCLAIMERS

This electronic library of PPRTV assessments is a replicate of the official EPA PPRRV website and should therefore not be cited as the source of PPRTVs. Users of this website should ensure that values are current at the time of use. This electronic library will be periodically updated with current values.

OVERVIEW

The PPRTV values currently represent the second tier of human health toxicity values for the EPA Superfund and Resource Conservation and Recovery Act (RCRA) hazardous waste programs. See a more complete discussion of the hierarchy below. Both the Superfund and RCRA programs accept the primacy of human health toxicity values contained in EPA's Integrated Risk Information System (IRIS). Values placed on IRIS have undergone internal and external peer review. The toxicity values in PPRTVs have been developed specifically for EPA's Superfund program and have not undergone the multi-program review and consensus required for toxicity values to be placed in IRIS.

BACKGROUND / HIERARCHY OF HUMAN HEALTH TOXICITY VALUE SOURCES

On December 5, 2003 the EPA Office of Superfund Remediation and Technology Innovation (OSRTI) revised its hierarchy of human health toxicity values for Superfund risk assessments, establishing the following three tiers as the new hierarchy.

  1. Integrated Risk Information System (IRIS)
  2. Provisional Peer-Reviewed Toxicity Values (PPRTVs)
  3. Other (Peer Reviewed) Values, including
    • Agency for Toxic Substance and Disease Registry's (ATSDR) Minimal Risk Levels (MRLs)
    • California Environmental Protection Agency (CalEPA) values
    • EPA's Health Effects Assessment Summary Tables (HEAST)

Note: Additional tier 3 sources may be identified in the future.

Users of this electronic library are referred to the IRIS electronic library (http://www.epa.gov/iris/) for Agency consensus values. When no IRIS value is available and a PPRTV from this electronic library is used, it is important to remember that the numbers alone (i.e., a PPRTV) tell very little about the adverse effects of a chemical or the quality of evidence on which risk assessment information is based.

STRUCTURE OF THE ELECTRONIC LIBRARY

The PPRTV electronic library provides human health risk assessment information for chemical contaminants. This information is divided into the following sections:

  1. The "PPRTV Homepage" provides general information about this independent PPRTV library.
  2. "Quickview" contains an alphabetized electronic library of the contaminants addressed in the PPRTV electronic library. Click on a contaminant name to view the PPRTVs and associated metadata for that contaminant. IF IRIS values exist for that contaminant, links to the IRIS electronic library will be provided. The PPRTV Derivation Support Documents, which provide a risk characterization for the contaminant and the types of exposure and risk assessed, can be accessed under "Quickview" by clicking the "PPRTV Derivation Support Document" link.
  3. "Users' Guide: Chemical Toxicity" provides information about the types of toxicity values and assessments contained in the electronic library and how the toxicity values are derived.
  4. "PPRTV Derivation Support Documents" contains an alphabetical compilation of all available PPRTV Derivation Support Documents and also shows the year of their preparation and the CASRN for that contaminant. Individual assessments can also be accessed from this page by clicking on the name of a contaminant.