[Federal Register Volume 66, Number 237 (Monday, December 10, 2001)]
[Notices]
[Pages 63706-63707]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-30457]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-7115-1]


Notice of Availability of the Draft Supplemental Guidance for 
Dermal Risk Assessment, Risk Assessment Guidance for Superfund, Volume 
I, 
Part E

AGENCY: Environmental Protection Agency.

ACTION: Notice of availability, request for comment, request for data.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) has developed 
and is requesting public comment on a draft Risk Assessment Guidance 
for Superfund: Volume I Human Health Evaluation Manual (Part E, 
Supplemental Guidance for Dermal Risk Assessment) (RAGS Part E). EPA is 
also requesting data pertinent to reducing the uncertainty and 
variability in assessing the risks from dermal exposure. RAGS Part E is 
available electronically on the Internet at http://www.epa.gov/superfund/programs/risk/ragse/index.htm. This guidance is intended to 
assist risk assessors and others in addressing concerns resulting from 
the evaluation of dermal exposure risk assessment pathways. It proposes 
a consistent methodology for assessing the exposures from the dermal 
pathway for Superfund human health risk assessments. It incorporates 
and updates principles of the EPA (1992) interim report, ``Dermal 
Exposure Assessment: Principles and Applications''.

DATES: You may submit comments and data until February 8, 2002. 
Comments received after that date may be considered to the extent 
feasible.

ADDRESSES: You are invited to submit written comments and data to: EPA, 
Superfund Docket RAGS Part E, Mail Code 5202G, 1200 Pennsylvania Ave, 
NW., Washington, DC 20460. For cost savings the draft RAGS Part E 
document is available electronically on the Internet at http://www.epa.gov/superfund/programs/risk/ragse/index.htm. EPA plans to print 
the document only after it is finalized. The Superfund Docket, 
containing the RAGS Part E document and public comments, is physically 
located at 1235 Jefferson Davis Highway, Arlington, Virginia. 
Appointments to review the docket can be made by calling (703) 603-
9232.

FOR FURTHER INFORMATION CONTACT: Contact the RCRA/Superfund Call Center 
at (800) 424-9346; from the Washington, DC, metropolitan area call 
(703) 412-9810. The Telecommunications Device for the Deaf (TDD) number 
is (800) 553-7672; from the Washington, DC, metropolitan area the 
number is (703) 412-3323. For technical inquiries, you may contact Lee 
Hofmann, Office of Solid Waste and Emergency Response, Mail Code 5101, 
U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460: telephone number 202-260-2230, email 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    In January 1992, the Office of Health and Environmental Assessment 
(OHEA), in the Office of Research and Development (ORD) of the U.S. 
Environmental Protection Agency (EPA) issued an interim report, Dermal 
Exposure Assessment: Principles and Applications (DEA). The DEA 
provided guidance for conducting dermal exposure assessments and was 
peer-reviewed by EPA's Science Advisory Board. A Workgroup was 
subsequently formed to develop guidance for Superfund based on the DEA. 
In August 1992, a draft Superfund Interim Dermal Risk Assessment 
Guidance was circulated for comment but was never issued. This current 
guidance supersedes the 1992 Superfund document.
    This 2001 Superfund RAGS Part E, Supplemental Guidance for Dermal 
Risk Assessment (RAGS Part E) is the result of Superfund RAGS Part E 
Workgroup

[[Page 63707]]

meetings from FY 95 through FY 01 on issues associated with the 
characterization of risk resulting from the dermal exposure pathway. 
RAGS Part E updates recommendations presented in the DEA, and 
incorporates additional information from the Exposure Factors Handbook 
(U.S. EPA, 1997a) and scientific literature, as cited. Users of this 
guidance are strongly encouraged to review and understand the material 
presented in the DEA. This guidance is considered interim, pending 
release of any update to the DEA from ORD. As more data become 
available, RAGS Part E may be updated.
    This Supplemental Guidance for Dermal Risk Assessment (RAGS Part E) 
has undergone external peer review in January 1998 and in February 
2000. Also, EPA's Risk Assessment Forum conducted a Peer Consultation 
Workshop on this document in December 1998.

Elements of the RAGS Part E Approach

    Risk Assessment Guidance for Superfund: Volume I-Human Health 
Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk 
Assessment) (RAGS Part E) is structured to be consistent with the four 
steps of the Superfund risk assessment process: hazard identification, 
exposure assessment, toxicity assessment, and risk characterization. 
RAGS Part E is organized into six chapters and four appendices. To 
provide an indication of the scope of the document, we have included 
the Table of Contents below:

1.0  Introduction and Flowchart
    1.1  Introduction
    1.2  Organization of Document
    1.3  Flowcharts
2.0  Hazard Identification
    2.1  Choosing Contaminants of Concern for the Dermal-water 
Pathway
    2.2  Choosing Contaminants of Concern for the Dermal-soil 
Pathway
3.0  Exposure Assessment
    3.1  Estimation of Dermal Exposures to Chemicals in Water
    3.1.1  Standard Equation for Dermal Contact with Chemicals in 
Water
    3.1.2  Exposure Parameters
    --Permeability coefficient for compounds in water (Kp 
in cm/hr)
    --Chemical concentration in water
    --Skin surface area
    --Event time, frequency and duration of exposure
    3.2  Estimation of Dermal Exposure to Chemicals in Soil
    3.2.1  Standard Equation for Dermal Contact with Chemicals in 
Soil
    3.2.2  Exposure Parameters
    --Skin Surface Area
    --Soil-to-Skin Adherence Factors
    --Recommended Soil Adherence Factors
    --Dermal Absorption Fraction from Soil
    --Age-adjusted Dermal Factor
    --Event Time, Exposure Frequency and Duration
    3.3  Estimation of Dermal Exposure to Chemicals in Sediment
4.0  Toxicity Assessment
    4.1  Principles of Route-to-route Extrapolation
    4.2  Adjustment of Toxicity Factors
    4.3  Calculation of Absorbed Toxicity Values
    4.4  Direct Toxicity
5.0  Risk Characterization
    5.1  Quantitative Risk Evaluation
    5.1.1  Risk Calculations
    5.1.2  Risks for All Routes of Exposure
    5.2  Uncertainty Assessment
    5.2.1  Hazard Identification
    5.2.2 Exposure Assessment
    --Dermal Exposure to Water--Uncertainties Associated with the 
Model for DAevent
    --Dermal Exposure to Soil
    5.2.3  Toxicity Assessment
    5.2.4  Risk Characterization
6.0  Conclusions/Recommendations
    6.1  Summary
    6.2  Exposures Not Included in Current Dermal Guidance
    6.3  Recommendations
7.0  References

Appendix A: Water Pathway
    A.1  Dermal Absorption Model
    A.1.1  Calculation of Parameters in Daevent
    A.1.2  Model Validation
    A.2  Estimation of Kp for Organic Compounds
    A.3  Estimation of Kp for Inorganic and Ionized 
Organic Compounds
    A.4  Uncertainty Analysis
    A.5  Screening Procedure for Chemicals in Water
    A.6  Procedures for Calculating Dermal Dose
    A.6.1  Stepwise Procedure for Calculating Dermal Dose Using 
Given Equations
    A.6.2  Stepwise Procedure for Calculating Dermal Dose Using 
Spreadsheets
Appendix B: Screening Tables and Reference Values for The Water 
Pathway
    Table B.1: Flynn Data Set
    Table B.2: Predicted Kp for 200's Organic 
Contaminants In Water
    Table B.3: Calculation of Dermal Absorbed Dose for Organic 
Chemicals in Water
    Table B.4: Calculation of Dermal Absorbed Dose for Inorganic 
Chemicals in Water
Appendix C: Soil Pathway
Appendix D: Sample Calculations
    RAGS Part E focuses on dermal contact with soil and water, and 
it does not provide guidance on quantifying dermal absorption of 
chemicals resulting from exposure to vapors. The Superfund RAGS Part 
E Workgroup agreed with the finding in the DEA report that many 
chemicals, with low vapor pressure and low environmental 
concentrations, cannot achieve adequate vapor concentration to pose 
a dermal exposure hazard. For chemicals with the potential to 
achieve adequate vapor concentrations, this guidance assumes that 
they are primarily absorbed through the respiratory tract.

Goals

    EPA welcomes feedback on this draft RAGS Part E document. EPA is 
seeking public comment at this time in order to ensure hearing the 
widest range of views and obtaining all information relevant to the 
development of policy. In addition, EPA is soliciting data pertinent 
to reducing uncertainty and variability in assessing risks from 
dermal exposure. EPA will review public comments received on the 
draft RAGS Part E document and will make appropriate changes in the 
document. EPA expects to respond in a summarized manner to the 
principal comments received on the draft RAGS Part E document as a 
matter of public information.

    Dated: November 30, 2001.
Michael H. Shapiro,
Principal Deputy Assistant Administrator, Office of Solid Waste and 
Emergency Response.
[FR Doc. 01-30457 Filed 12-7-01; 8:45 am]
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