UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
rrn c im* SOLID WASTE AND
TLD ~ D J?Q|4 EMERGENCY RESPONSE
OSWER Directive 9200.1-120
MEMORANDUM
SUBJECT: Human Health Evaluation Manual, Supplemental Guidance: Update of Standard
Default Exposure Factors ,
FROM: Dana Stalcup, Acting DirectorV^^^ '
Assessment and Remediation Division
Office of Superfund Remediation and Technology Innovation
TO: Superfund National Policy Managers, Regions 1-10
Purpose
The mission of the Superfund program is to protect human health and the environment consistent
with the Comprehensive Environmental Response, Compensation and Liability Act, as amended,
(CERCLA) and as implemented by the National Oil and Hazardous Substances Pollution
Contingency Plan. The purpose of this directive is to update the Interim Final Standard Exposure
Factors Guidance (1991), which is reflected in the attached table and is to be used:
• in the CERCLA remedial investigation and feasibility study process (e.g., assessing
baseline health risks, developing preliminary remediation goals, evaluating risks of
remedial alternatives),
• to evaluate health risks in the CERCLA removal program, and
• in the process of five-year reviews of selected remedies.
This guidance update supplements the Risk Assessment Guidance for Superfund: Human Health
Evaluation Manual, Part A (RAGS, Part A) that was issued October 13, 1989. This guidance
supersedes and replaces certain portions of OSWER Directive 9285.6-03, issued March 25, 1991
and updates the Risk Assessment Guidance for Superfund. Part E, issued July 2004 (RAGS, Part
E). Other cleanup programs in the Office of Solid Waste and Emergency Response (OSWER)
are welcome and encouraged to adopt the recommended exposure factors, much as they have
historically adopted other aspects of the Risk Assessment Guidance for Superfund (RAGS).
Internet Address (URL) • http;//www.epa.gov
Recycled/Recyclable • Printed with Vegetable OH Based Irks on 100% Postconsumer, Process Chlorine Free Recycled Paper
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Background
In September 2011, EPA's National Center for Environmental Assessment, Office of Research
and Development (ORD/NCEA) issued a substantive update to its exposure assessment
recommendations. Exposure Factors Handbook- 20II Edition, referred to as EFH 2011 herein,
provides information and recommendations on various physiological and behavioral factors
commonly used in assessing exposure of adults and children to environmental chemicals.
ORD/NCEA's recommended values for exposure factors are based on the results of studies
deemed to be the most up-to-date and scientifically sound, based upon data available up to July
2011, and incorporates revisions made to the Child-Specific Exposure Factors Handbook, which
was last updated and published in 2008. EFH 2011 is not a Superfund-specific document; rather,
it provides a summary of the latest developments in exposure science and provides
recommendations for a broad range of EPA programs.
Following the publication of EFH 2011, regional risk assessors received inquiries from other
EPA program offices, states, the regulated community, and other interested parties regarding the
applicability of the ORD/NCEA's recommendations for use in human health risk assessments.
During the October 2011 to August 2012 period, the OSWER Human Health Regional Risk
Assessors Forum (OHHRRAF) reviewed the recommendations in EFH 2011 in the context of the
default exposure factors used in the Superfund program and to derive Regional screening levels.
As a result of a consensus-driven process, the OHHRRAF identified several Superfund-specific
default exposure factors that warranted updating, based upon recommendations from
ORD/NCBA in EFH 2011. This guidance incorporates and adopts the updates recommended by
the OHHRRAF.
Objective
This guidance has been developed to reduce variability and uncertainty in the exposure
assumptions used by Regional Superfund staff to characterize exposures to human populations
for human health risk assessments.
Implementation
This guidance supplements the Risk Assessment Guidance for Superfund: Hitman Health
Evaluation Manual (RAGS), Part A through E, Where numerical values differ from those
presented in Part A or E, the factors presented in this guidance should be considered updates to
the older values. As new data become available, this Directive may be modified accordingly.
This report can be found at wwvv.cpa.gpy/oswer/riskassessmeni/sup_erfiind_hh_cxposurc.htm
Please contact Richard Kapuscinski at (703) 305-7411 if you have questions or concerns.
Attachment
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cc: Mathy Stanislaus, OSWER
Barry Breen, OSWER
Lawrence M. Stanton, OSWER/OEM
Barnes Johnson, OSWER/ORCR
David Lloyd, OSWER/OBLR
Reggie Chcatham, OSWER/FFRRO
Carolyn Hoskinson, OSWER/OUST
Elliott Gilberg, OECA/OSRE
Dave Kling, OECA/FFEO
John Michaud, OGC/SEWRLO
OSRT! Managers
Regional Superfund Branch Chiefs, Regions 1-10
Lisa Price, Superfund Lead Region Coordinator, Region 6
OSWER/OSRTI Human Health Regional Risk Assessors Forum
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CITATIONS
U.S. Environmental Protection Agency (EPA). 201 1. Exposure Factors Handbook 201 1 Edition
(Final). National Center for Environmental Assessment, Office of Research and Development,
Washington D.C. Currently available on-line at
U.S. Environmental Protection Agency (EPA). 2009. Risk Assessment Guidance for Superfund
(RAGS), Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for
Inhalation Risk Assessment). EPA 540-R-070-002, OSWER 9285.7-82. Office of Superfund
Remediation and Technology Innovation. Washington, DC. January. Currently available on-line
J£Oj/^
U.S. Environmental Protection Agency (EPA). 2008. Child-Specific Exposure Factors
Handbook. PA/600/R-06/096F. National Center for Environmental Assessment, Office of
Research and Development. Washington D.C. September. Currently available on-line at
U.S. Environmental Protection Agency (EPA). 2004. Risk Assessment Guidance for Superfund
(RAGS), Volume I: Human Health Evaluation Manual (Part E, Supplemental Guidance for
Dermal Risk Assessment), Final. Office of Superfund Remediation and Technology Innovation.
Washington, DC. July. Currently available on-line at
^
U.S. Environmental Protection Agency (EPA). 2001. Risk Assessment Guidance for Superfund
(RAGS), Volume I: Human Health Evaluation Manual (Part D, Standardized Planning,
Reporting and Review of Superfund Risk Assessments), Final. December. Currently available on-
line at htt2i//v^wj.m!^^
U.S. Environmental Protection Agency (EPA). 2001. Comprehensive Five- Year Review
Guidance. OSWER 9355. 7-03B-P, EPA 540-R-0 1-007. Office of Emergency and Remedial
Response. Washington, DC. June. Currently available on-line at
http:/yw\vvv._epa.gov/superfund/acconij)/5\'car/index.htni
U.S. Environmental Protection Agency (EPA). 1991. Risk Assessment Guidance for Superfund
(RAGS), Volume 1: Human Health Evaluation Manual (Part C, Risk Evaluation of Remedial
Alternatives), Interim. Publication 9285.7-01C. Office of Emergency and Remedial Response.
Washington, DC. October. Currently available on-line at
http://w\¥w.epa.gov/os\veiynskassessmeiit/ragscjindex.htnT.
U.S. Environmental Protection Agency (EPA). 1991. Risk Assessment Guidance for Superfund
(RAGS), Volume I: Human Health Evaluation Manual (Part B, Development of Risk-based
Preliminary Remediation Goals), Interim. EPA 540-R-070/003. Publication 9285.7-01B. Office
of Emergency and Remedial Response. Washington, DC. December. Currently available on-line
at hUp://\vwwjgpa,gQV/QS_w
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Attachment 1. Recommended Default Exposure Factors (2014)
Symbol
Definition (units)
Previous Default Value
Currently
Recommended Value
Source of current recommendation
Source of previous recommendation
Ingestion and Dermal Contact Rates
IRWC
IRWa
IRSC
IRSa
IR,W
I ROW
SAsc
SA«
SAB,,
SA«
SAwa
AFC
AFa
AFOW
BWC
BWa
BWW
Resident Drinking Water Ingestion
Rate - Child (L/day)
Resident Drinking Water Ingestion
Rate - Adult (L/day)
Resident Soil Ingestion Rate -
Child (mq/day)
Resident Soil Ingestion Rate -
Adult (mg/day)
Indoor Worker Soil Ingestion Rate
(mg/day)
Outdoor Worker Soil Ingestion
Rate (mg/day)
Resident skin surface area - child
(cm2)
Resident skin surface area - adult
(cm2)
Worker skin surface area - adult
(cm2)
Resident Water Surface area -
child (cm2)
Resident Water Surface area -
adult (cm2)
Resident soil adherence factor -
child (mg/cm2)
Resident soil adherence factor -
adult (mg/cm2)
Worker soil adherence factor -
adult (mg/cm2)
Resident Body Weight - child (kg)
Resident Body Weight - adult (kg)
Worker Body Weight (kg)
1
2
200
100
50
100
2,800
5,700
3,300
6,600
18,000
0.2
0.07
0.2
15
70
70
0.78
2.5
200
100
50
100
2,373
6,032
3,527
6,365
19,652
0.2
0.07
0.12
15
80
80
U.S. EPA 201 la, Tables 3-15 and 3-33; weighted
average of 90th percentile consumer-only ingestion of
drinking water (birth to <6 years)
U.S. EPA 201 la, Table 3-33; 90th percentile of
consumer-only ingestion of drinking water (> 21 years)
U.S. EPA 2011a (Table 5-1); "upper-bound values"
accounting for both soil and dust ingestior
U.S. EPA 199 la (pp. 6 and 15); EFH 2011 only
provides a central tendency value
U.S. EPA 199 la (pp. 9-10, 15); EFH 2011 values not
provided
U.S. EPA 199 la (pg. 15), same as adult resident; EFH
2011 value not provided
U.S. EPA 201 la, Tables 7-2 and 7-8; weighted average
of mean values for head, hands, forearms, lower legs,
and feet (male and female, birth to < 6 years)(forearm
and lower leg-specific data used when available, ratios
for nearest available age group used elsewhere (per
EPA 201 lb))
U.S. EPA 201 la, Tables 7-2 and 7-12; weighted
average of mean values for head, hands, forearms,
and lower legs (male and female, 21+ years)(forearm
and lower leg-specific data used for males and female
lower leg; ratio of male forearm to arm applied to
female arm data).
US EPA 2011a, Table 7-2; weighted average of mean
values for head, hands, and forearms (male and
female, 21+years) (similar assumptions for forearms
as used in EPA2011b)
U.S. EPA 201 la, Table 7.9; weighted average of mean
values for male and female children <6 years.
U.S. EPA 201 la, Table 7.9; weighted average of mean
values for male and female adults, 21-78.
U.S. EPA 2004 (Exhibit 3-5), RAGS Part E
U.S. EPA 2004 (Exhibit 3-5), RAGS Part E
U.S. EPA 201 la, Table 7-20 and Section 7.2.2;
arithmetic mean of weighted average of body part-
specific (hands, forearms, and face) mean adherence
factors for adult commercial/industrial activities
U.S. EPA 201 la, Table 8-1; weighted average of mean
body weights (birth to <6 years)
U.S. EPA 201 la, Table 8-3; weighted mean values for
adults 21 - 78
U.S. EPA 201 la, Table 8-3; weighted mean values for
adults 21 - 78
U.S. EPA 1989 (Exhibit 6-11)
U.S. EPA 1989 (Exhibit 6-11)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 2002 (Exhibit 1-2)
U.S. EPA 2002 (Exhibit 1-2)
U.S. EPA 2002 (Exhibit 1-2)
U.S. EPA 2004 (Exhibit 3-2)
U.S. EPA 2004 (Exhibit 3-2)
U.S. EPA 2002 (Exhibit 1-2)
U.S. EPA 2002 (Exhibit 1-2)
U.S. EPA 2002 (Exhibit 1-2)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
Exposure Frequency, Exposure Duration, and Exposure Time Variables
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Attachment 1. Recommended Default Exposure Factors (2014)
Symbol
EFr
EFW
EFIW
EFOW
EDr
EDC
EDa
EDW
EDiw
EDOW
ETra
ETrs
ETW
ET«
ETrw
ETrwc
ETrwa
Definition (units)
Resident Exposure Frequency
(days/yr)
Worker Exposure Frequency
(days/yr)
Indoor Worker Exposure
Frequency (days/yr)
Outdoor Worker Exposure
Frequency (days/yr)
Resident Exposure Duration (yr)
Resident Exposure Duration - child
(yr)
Resident Exposure Duration -
adult (yr)
Worker Exposure Duration - (yr)
Indoor Worker Exposure Duration
(yr)
Outdoor Worker Exposure
Duration (yr)
Resident Air Exposure Time
(hours/day)
Resident Soil Exposure Time
(hours/day)
Worker Air Exposure Time (hr/hr)
Worker Soil Exposure Time
(hours/day)
Resident Water Exposure Time
(hours/day)
Resident Water Exposure Time -
child (hours/event)
Resident Water Exposure Time -
adult (hours/event)
Previous Default Value
350
250
250
225
30
6
24
25
25
25
24
24
8
8
24
1
0.58
Currently
Recommended Value
350
250
250
225
26
6
20
25
25
25
24
24
8
8
24
0.54
0.71
Source of current recommendation
U.S. EPA 199 la (pg. 15); value not provided in EFH
2011
U.S. EPA 199 la (pg. 15); value not provided in EFH
2011
U.S. EPA 199 la (pg. 15); value not provided in EFH
2011
U.S. EPA 2002; value not provided in EFH 2011
EPA 201 la, Table 16-108; 90th percentile for current
residence time.
U.S. EPA 199 la, Pages 6 and 15
EDr (26 years) - EDc (6 years)
U.S. EPA 199 la (pg. 15); EFH 2011 only provides a
central tendency value
U.S. EPA 199 la (pg. 15); EFH 2011 only provides a
central tendency value
U.S. EPA 199 la (pg. 15); EFH 2011 only provides a
central tendency value
The whole day
The whole day
The work day
The work day
The whole day
U.S. EPA 201 la, Table 16-28; weighted average of
90th percentile time spent bathing (birth to <6 years)
U.S. EPA 201 la, Tables 16-30 and 16-31; weighted
average of adult (21 to 78) 90th percentile of time
spent bathing/ showering in a day, divided by mean
number of baths/showers taken in a day.
Source of previous recommendation
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1991a (pg. 15)
The whole day
The whole day
The work day
The work day
The whole day
U.S. EPA 2004
U.S. EPA 2004
Miscellaneous Variables; values not provided in EFH 2011
ATr
ATW
ATiw
ATOW
Averaging time - resident
(days/year)
Averaging time - composite
worker (days/year)
Averaging time - indoor worker
(days/year)
Averaging time - outdoor worker
(days/year)
365
365
365
365
365
365
365
365
U.S. EPA 1989 (pg. 6-23)
U.S. EPA 1989 (pg. 6-23)
U.S. EPA 1989 (pg. 6-23)
U.S. EPA 1989 (pg. 6-23)
U.S. EPA 1989 (pg. 6-23)
U.S. EPA 1989 (pg. 6-23)
U.S. EPA 1989 (pg. 6-23)
U.S. EPA 1989 (pg. 6-23)
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Attachment 1. Recommended Default Exposure Factors (2014)
Symbol
LT
IRfeh
IRproduce
Definition (units)
Lifetime (years)
Fish Ingestion Rate (mg/day)
Consumption of homegrown
produce (g/day)
Previous Default Value
70
5.4 x 104
42 (fruit); 80 (veg)
Currently
Recommended Value
70
**
**
Source of current recommendation
U.S. EPA 1989 (pg. 6-22), pending additional input
from NCEA
Recommend using site-specific values
Recommend using site-specific values
Source of previous recommendation
U.S. EPA 1989 (pg. 6-22)
U.S. EPA 1991a (pg. 15)
U.S. EPA 1990
References for Cited Sources:
U.S. EPA 1989. Risk assessment guidance for Superfund. Volume I: Human health evaluation manual (Part A). Interim Final. Office of Emergency and Remedial Response. EPA/540/1-89/002.
U.S. EPA 1990. Exposure Factors Handbook. Office of Health and Environmental Assessment. EPA/8-89/043, March 1990.
U.S. EPA 1991a. Human health evaluation manual, supplemental guidance: "Standard default exposure factors". OSWER Directive 9285.6-03.
U.S. EPA 1991b. Risk Assessment Guidance for Superfund. Volume I: Human Health Evaluation Manual (Part B. Development of Risk-Based Preliminary Remediation Goals). Office of Emergency and Remedial
Response. EPA/540/R-92/003. December 1991
U.S. EPA. 1996a.Soil Screening Guidance: User's Guide. Office of Emergency and Remedial Response. Washington. DC. OSWER No. 9355.4-
23 http://www.epa.gov/superfund/health/conmedia/soil/index.htmtfuser
U.S. EPA. 1996b. Soil Screening Guidance: Technical Background Document. Office of Emergency and Remedial Response. Washington. DC. OSWER No. 9355.4-
17Ahttp://www.epa.gov/superfund/health/conmedia/soil/i ntrotbd.htm
U.S. EPA. 1997a. Exposure Factors Handbook. Office of Research and Development, Washington, DC. EPA/600/P-95/002Fa.
U.S. EPA 2000. Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds. Part I: Estimating Exposure to Dioxin-Like Compounds. Volume 3—
Properties, Environmental Levels, and Background Exposures. Draft Fi
U.S. EPA. 2001. WATER9. Version 1.0.0. Office of Air Quality Planning and Standards. Research Triangle Park. NC.
U.S. EPA 2002. Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites. OSWER 9355.4-24. December 2002.http://www.epa.gov/superfund/health/conmedia/soil/index.htm
U.S. EPA 2004. Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment) Final. OSWER 9285.7-02EP.July
2004. Document and website http://www.epa.gov/oswer/riskassessment/rags
U.S. EPA. 2005. Guidance on Selecting Age Groupsfor Monitoring and Assessing Childhood Exposures to Environmental Contaminants. EPA/630/P-03/003F. November. 2005.
U.S. EPA 2009. Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for Inhalation Risk Assessment) Final. OSWER 9285.7-82.2009.
U.S. EPA 2011a. Exposure Factors Handbook: 2011 Edition. EPA/ 600/ R-090/052F. September 2011.
EPA. 2011b. "Regional Screening Levels (Formerly PRGs), User's Guide." November. On-Line Address: http://www.epa.gov/reg3hwmd/risk/human/rb-concentration table/usersguide.htm
Users are directed to the Exposure Factors Handbook (2011) as a source for specific age-group exposure factors as described in EPA, 2005.
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