Federal Register: December 10, 2001 (Volume 66, Number 237)
DOCID: FR Doc 01-30457
ENVIRONMENTAL PROTECTION AGENCY
Environmental Protection Agency
FRL ID: [FRL-7115-1]
NOTICE: NOTICES
ACTION: Reports and guidance documents; availability, etc.:
DOCUMENT ACTION: Notice of availability, request for comment, request for data.
SUBJECT CATEGORY:
Notice of Availability of the Draft Supplemental Guidance for Dermal Risk Assessment, Risk Assessment Guidance for Superfund, Volume I, Part E
DATES: You may submit comments and data until February 8, 2002. Comments received after that date may be considered to the extent feasible.
DOCUMENT 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''.
SUMMARY:
Superfund; dermal risk assessment,
SUPPLEMENTAL 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 peerreviewed 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 IHuman 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 Dermalwater Pathway
2.2 Choosing Contaminants of Concern for the Dermalsoil 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 (K
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
SoiltoSkin Adherence Factors
Recommended Soil Adherence Factors
Dermal Absorption Fraction from Soil
Ageadjusted 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 Routetoroute 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 WaterUncertainties Associated with the Model for DA
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 Da
A.1.2 Model Validation
A.2 Estimation of K
A.3 Estimation of K
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 K
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. 0130457 Filed 12701; 8:45 am]
BILLING CODE 656050P
FOR FURTHER INFORMATION CONTACT
Contact the RCRA/Superfund Call Center
at (800) 4249346; from the Washington, DC, metropolitan area call
(703) 4129810. The Telecommunications Device for the Deaf (TDD) number
is (800) 5537672; from the Washington, DC, metropolitan area the
number is (703) 4123323. 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 2022602230, email
hofmann.lee@epa.gov.