UNITED                                     AGENCY
                               WASHINGTON. D.C.
                                 JUH 1 9  ?013
                                                                         bOL ID WASTE AND
                                                                       F-MSNGENCY RESPONSE

MEMSEM1MM

SUBJECT:  Tier 3 1 ovicily Value White Paper
                                   jX
FROM:      Becki Clark. Director   /
             Assessment and Remediation Division
TO:
Superfiinci National Policy Managers, Regions 1 - 10
The purpose of this memorandum is TO transmit the OSRTi document'entitled "Tier 3 Toxic ity
Value While Paper".

This documen' provides recommendations on processes to improve the transparency1 and
consistency of idc-nti tying, evaluating, selecting, and documenting Tier 3 loxicity values for uw
in the Supertund and Resource Conservation and Recovery Act (RCRA) programs. This
document is intended to supplement the.2003 "Human Health I'oxicity Values in Supcrfund Risk
Assessments" (O5WER Directive ^285.7-53} which recommends the hierarch>'ol'human health
toxicity values sources used for screening and baseline risk assessments at Superfund hazardous
waste sites.

This report can be found on the,internet at http'//epa.gov,j's.upcrHuid htm. Please contact Michele
Burgess at (703) 603-9003 if you have questions or concerns,

Auachmenl
       Mathy Stanislaus. OSWER
       Lisa Fuldt, OSWL'R
       Barry IBrecn. OSWER
       Lawrence \1. Statilon. OSWER/OKM

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                                                                          'iati Paper

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Suzanne Rud/inskj, USWER.ORCR
!>jvidUovd. OSWIHR'OBLR
ficcgie Cheaf/utm, OSWER/FFRRO
Cafolv« Hosksn>KC.VFFEO
John Miehautl OC'iC/SWERLO
OSRTI Manngers
Regional Superluiu! Branch Chiefs. Kei!si»iii. 1  - i'"'
Lisa Price. Huperfund Lead Region Ci^ordiiKHor, Region t
NARPM Ct^Chssirs
TRW ("omitjittcc Members

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