[Federal Register Volume 67, Number 250 (Monday, December 30, 2002)]
[Notices]
[Pages 79611-79629]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-32853]


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ENVIRONMENTAL PROTECTION AGENCY

[OPPT-2002-0066; FRL-7286-6]


Endocrine Disruptor Screening Program, Proposed Chemical 
Selection Approach for Initial Round of Screening; Request for Comment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: This notice sets forth for public comment the approach EPA 
plans to use for selecting the first group of chemicals to be screened 
in the

[[Page 79612]]

Agency's Endocrine Disruptor Screening Program (EDSP). Following 
consideration of comments on this draft approach, EPA will issue a 
second Federal Register notice setting forth its approach for selecting 
the first group of chemicals and the chemicals it proposes for this 
initial list. Following comment on the draft list of specific 
chemicals, EPA will issue the final list.
    Because the list of chemicals produced using the proposed approach 
will be a list of chemicals that the Agency, in its discretion, has 
decided should be tested first, based primarily upon exposure 
potential, it should not be construed as a list of known or likely 
endocrine disruptors nor characterized as such. Nothing in the approach 
for selecting the initial list would provide a basis to infer that any 
of the chemicals selected for the list interferes with or is suspected 
to interfere with the endocrine systems of humans or other species.
    EPA anticipates that it will modify its chemical selection approach 
for subsequent Tier 1 screening lists based on experience gained from 
the results of testing of chemicals on the initial list, the 
feasibility of incorporating different categories of chemicals (e.g., 
non-pesticide substances) and additional pathways of exposure, and the 
availability of new priority-setting tools (e.g., High Throughput Pre-
screening (HTPS) or Quantitative Structure Activity Relationship (QSAR) 
models).

DATES: Comments, identified by docket ID number OPPT-2002-0066, must be 
received on or before March 1, 2003.

ADDRESSES: Comments may be submitted electronically, by mail, or 
through hand delivery/courier. Follow the detailed instructions as 
provided in Unit I. of the SUPPLEMENTARY INFORMATION.

FOR FURTHER INFORMATION CONTACT: For general information contact: 
Barbara Cunningham, Acting Director, Environmental Assistance Division 
(7408M), Office of Pollution Prevention and Toxics, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (202) 554-1404; e-mail address: [email protected].
    For technical information contact: Greg Schweer, Exposure 
Assessment Coordination and Policy Division (7203M), Office of Science 
Coordination and Policy, Environmental Protection Agency, 1200 
Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: 
(202) 564-8469; e-mail address: [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    This action is directed to the public in general, and may be of 
particular interest to those persons who are or may be required to 
conduct testing of chemical substances under the Toxic Substances 
Control Act (TSCA), the Federal Food, Drug and Cosmetic Act (FFDCA), 
the Safe Drinking Water Act (SDWA), or the Federal Insecticide, 
Fungicide, and Rodenticide Act (FIFRA). Since other entities may also 
be interested, the Agency has not attempted to describe all the 
specific entities that may be affected by this action. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the technical person listed under FOR FURTHER 
INFORMATION CONTACT.

B. How Can I Get Copies of this Document and Other Related Information?

    1. Docket. EPA has established an official public docket for this 
action under docket identification (ID) number OPPT-2002-0066. The 
official public docket consists of the documents specifically 
referenced in this action, any public comments received, and other 
information related to this action. Although a part of the official 
docket, the public docket does not include Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. The official public docket is the collection of materials 
that is available for public viewing at the EPA Docket Center, Rm. 
B102-Reading Room, EPA West, 1301 Constitution Ave., NW., Washington, 
DC. The EPA Docket Center is open from 8:30 a.m. to 4:30 p.m., Monday 
through Friday, excluding legal holidays. The EPA Docket Center Reading 
Room telephone number is (202) 566-1744 and the telephone number for 
the OPPT Docket, which is located in EPA Docket Center, is (202) 566-
0280.
    2. Electronic access. You may access this Federal Register document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr/.
    An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA Dockets. You may 
use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public 
comments, access the index listing of the contents of the official 
public docket, and to access those documents in the public docket that 
are available electronically. Although not all docket materials may be 
available electronically, you may still access any of the publicly 
available docket materials through the docket facility identified in 
Unit I.B.1. Once in the system, select ``search,'' then key in the 
appropriate docket ID number.
    Certain types of information will not be placed in the EPA Dockets. 
Information claimed as CBI and other information whose disclosure is 
restricted by statute, which is not included in the official public 
docket, will not be available for public viewing in EPA's electronic 
public docket. EPA's policy is that copyrighted material will not be 
placed in EPA's electronic public docket but will be available only in 
printed, paper form in the official public docket. To the extent 
feasible, publicly available docket materials will be made available in 
EPA's electronic public docket. When a document is selected from the 
index list in EPA Dockets, the system will identify whether the 
document is available for viewing in EPA's electronic public docket. 
Although not all docket materials may be available electronically, you 
may still access any of the publicly available docket materials through 
the docket facility identified in Unit I.B.1. EPA intends to work 
towards providing electronic access to all of the publicly available 
docket materials through EPA's electronic public docket.
    For public commenters, it is important to note that EPA's policy is 
that public comments, whether submitted electronically or in paper, 
will be made available for public viewing in EPA's electronic public 
docket as EPA receives them and without change, unless the comment 
contains copyrighted material, CBI, or other information whose 
disclosure is restricted by statute. When EPA identifies a comment 
containing copyrighted material, EPA will provide a reference to that 
material in the version of the comment that is placed in EPA's 
electronic public docket. The entire printed comment, including the 
copyrighted material, will be available in the public docket.
    Public comments submitted on computer disks that are mailed or 
delivered to the docket will be transferred to EPA's electronic public 
docket. Public comments that are mailed or delivered to the docket will 
be scanned and placed in EPA's electronic public docket. Where 
practical, physical objects will be photographed, and the photograph 
will be placed in EPA's electronic public docket along with a brief 
description written by the docket staff.

[[Page 79613]]

C. How and To Whom Do I Submit Comments?

    You may submit comments electronically, by mail, or through hand 
delivery/courier. To ensure proper receipt by EPA, identify the 
appropriate docket ID number in the subject line on the first page of 
your comment. Please ensure that your comments are submitted within the 
specified comment period. Comments received after the close of the 
comment period will be marked ``late.'' EPA is not required to consider 
these late comments. If you wish to submit CBI or information that is 
otherwise protected by statute, please follow the instructions in Unit 
I.D. Do not use EPA Dockets or e-mail to submit CBI or information 
protected by statute.
    1. Electronically. If you submit an electronic comment as 
prescribed in this Unit, EPA recommends that you include your name, 
mailing address, and an e-mail address or other contact information in 
the body of your comment. Also include this contact information on the 
outside of any disk or CD ROM you submit, and in any cover letter 
accompanying the disk or CD ROM. This ensures that you can be 
identified as the submitter of the comment and allows EPA to contact 
you in case EPA cannot read your comment due to technical difficulties 
or needs further information on the substance of your comment. EPA's 
policy is that EPA will not edit your comment, and any identifying or 
contact information provided in the body of a comment will be included 
as part of the comment that is placed in the official public docket, 
and made available in EPA's electronic public docket. If EPA cannot 
read your comment due to technical difficulties and cannot contact you 
for clarification, EPA may not be able to consider your comment.
    i. EPA Dockets. Your use of EPA's electronic public docket to 
submit comments to EPA electronically is EPA's preferred method for 
receiving comments. Go directly to EPA Dockets at http://www.epa.gov/edocket, and follow the online instructions for submitting comments. 
Once in the system, select ``search,'' and then key in docket ID number 
OPPT-2002-0066. The system is an ``anonymous access'' system, which 
means EPA will not know your identity, e-mail address, or other contact 
information unless you provide it in the body of your comment.
    ii. E-mail. Comments may be sent by e-mail to [email protected], 
Attention: Docket ID Number OPPT-2002-0066. In contrast to EPA's 
electronic public docket, EPA's e-mail system is not an ``anonymous 
access'' system. If you send an e-mail comment directly to the docket 
without going through EPA's electronic public docket, EPA's e-mail 
system automatically captures your e-mail address. E-mail addresses 
that are automatically captured by EPA's e-mail system are included as 
part of the comment that is placed in the official public docket, and 
made available in EPA's electronic public docket.
    iii. Disk or CD ROM. You may submit comments on a disk or CD ROM 
that you mail to the mailing address identified in Unit I.C.2. These 
electronic submissions will be accepted in WordPerfect or ASCII file 
format. Avoid the use of special characters and any form of encryption.
    2. By mail. Send your comments to: Document Control Office (7407M), 
Office of Pollution Prevention and Toxics (OPPT), Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001.
    3. By hand delivery or courier. Deliver your comments to: OPPT 
Document Control Office (DCO) in EPA East Building Rm. 6428, 1201 
Constitution Ave., NW., Washington, DC. Attention: Docket ID Number 
OPPT-2002-0066. The DCO is open from 8 a.m. to 4 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the DCO is 
(202) 564-8930.

D. How Should I Submit CBI To the Agency?

    Do not submit information that you consider to be CBI 
electronically through EPA's electronic public docket or by e-mail. You 
may claim information that you submit to EPA as CBI by marking any part 
or all of that information as CBI (if you submit CBI on disk or CD ROM, 
mark the outside of the disk or CD ROM as CBI and then identify 
electronically within the disk or CD ROM the specific information that 
is CBI). Information so marked will not be disclosed except in 
accordance with procedures set forth in 40 CFR part 2.
    In addition to one complete version of the comment that includes 
any information claimed as CBI, a copy of the comment that does not 
contain the information claimed as CBI must be submitted for inclusion 
in the public docket and EPA's electronic public docket. If you submit 
the copy that does not contain CBI on disk or CD ROM, mark the outside 
of the disk or CD ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and EPA's 
electronic public docket without prior notice. If you have any 
questions about CBI or the procedures for claiming CBI, please consult 
the technical person listed under FOR FURTHER INFORMATION CONTACT.

E. What Should I Consider as I Prepare My Comments for EPA?

    You may find the following suggestions helpful for preparing your 
comments:
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide copies of any technical information and/or data you used 
that support your views.
    4. Provide specific examples to illustrate your concerns.
    5. Offer alternative ways to improve the proposed approach.
    6. Make sure to submit your comments by the deadline in this 
notice.
    7. To ensure proper receipt by EPA, be sure to identify the docket 
ID number assigned to this action in the subject line on the first page 
of your response. You may also provide the name, date, and Federal 
Register citation.

II. Introduction

A. What Action is the Agency Taking?

    In this notice, EPA is setting forth, and requesting public comment 
on, the approach EPA plans to use for selecting an initial group of 
chemicals to be screened in the Agency's EDSP. EPA anticipates that it 
will modify its chemical selection approach for subsequent Tier 1 
screening lists based on experience gained from the results of testing 
of chemicals on the initial list, the feasibility of incorporating 
different categories of chemicals (e.g., non-pesticide substances) and 
additional pathways of exposure, and the availability of new priority-
setting tools (e.g., HTPS or QSAR models). EPA developed its EDSP in 
response to a Congressional mandate in section 408(p) of FFDCA ``to 
determine whether certain substances may have an effect in humans that 
is similar to an effect produced by a naturally occurring estrogen, or 
such other effects as [EPA] may designate'' (21 U.S.C. 346a(p)). When 
carrying out the program, the statute requires EPA to ``provide for the 
testing of all pesticide chemicals.'' The statute also provides EPA 
with discretionary authority to ``provide for the testing of any other 
substance that may have an effect that is cumulative to an effect of a 
pesticide chemical if the Administrator determines that a substantial 
population may be exposed to such a substance.'' In addition, section 
1457 of SDWA provides EPA with discretionary authority to provide

[[Page 79614]]

for testing, under the FFDCA section 408(p) screening program, ``of any 
other substances that may be found in sources of drinking water if the 
Administrator determines that a substantial population may be exposed 
to such substance.''
    EPA is following a tiered approach in implementing the requirements 
of section 408(p) of FFDCA. The core elements of the tiered approach 
are priority setting, Tier 1 screening, and Tier 2 testing. Tier 1 will 
be comprised of a battery of screening assays to identify substances 
that have potential to interact with the estrogen, androgen, or thyroid 
hormone systems. The purpose of Tier 2 is to determine whether the 
substance may cause endocrine-mediated effects via or involving 
estrogen, androgen, or thyroid hormone systems, determine the 
consequences to the organism of the activities observed in Tier 1, and 
establish the relationship between doses of an endocrine-active 
substance administered in the test and the effects observed. (Federal 
Register issue of December 28, 1998 (63 FR 71542, FRL-6052-9, Docket 
Control Number OPPTS-42208).
    At the request of EPA, a joint subcommittee of the EPA Science 
Advisory Board (SAB) and the FIFRA Scientific Advisory Panel (SAP) 
reviewed a set of scientific issues related to the development of the 
Agency's EDSP. One of the recommendations of the SAB/SAP Subcommittee 
(Ref. 1) was that EPA should initiate the Tier 1 screening program with 
a set of 50 to 100 chemicals and then convene a panel of independent 
scientists to review the screening data for the purpose of evaluating 
and optimizing the Tier 1 screening battery. EPA is proposing to adopt 
this SAB/SAP recommendation to initially select and screen 
approximately 50 to 100 chemicals to help the Agency further refine the 
EDSP. The Agency intends to submit the data received from the screening 
to an independent external panel of experts and request an evaluation 
of whether the program could be improved or optimized, and if so, how.
    EPA has stated its intention to consider a broad universe of 
chemicals as potential candidates for testing under the EDSP including 
pesticide chemicals, non-pesticide commercial chemicals, mixtures, and 
environmental contaminants (63 FR 71542). However, for the first group 
of chemicals to be tested, EPA is intending to focus only on pesticide 
active ingredients and high production volume (HPV) chemicals with some 
pesticidal inert uses (i.e., the chemicals that are specifically 
mandated for testing under section 408(p) of FFDCA). The pesticide 
inerts to be considered are those with relatively large overall 
production volumes considering both pesticide and non-pesticide uses. 
This approach will allow EPA to focus its initial endocrine screening 
efforts on a smaller and more manageable universe of chemicals that 
emphasizes early attention to the pesticide chemicals that Congress 
specifically mandated EPA to test for possible endocrine effects.
    The purpose of this notice is to describe the approach that EPA 
plans to use to select this initial set of chemicals to undergo Tier 1 
screening. EPA is proposing to use an approach based in part on the 
compartment-based priority setting approach described in the December 
28,1998, Federal Register notice (FRL-6052-9) in which EPA provided 
details about, and requested comment on, its EDSP. The proposed 
approach focuses on human exposure-related factors rather than using a 
combination of exposure- and effects-related factors. The approach 
would, however, exclude from the first group of chemicals to undergo 
Tier 1 screening any chemical for which the available effects 
information clearly shows an endocrine-mediated effect. Such chemicals 
would be considered for proposed Tier 2 tests, mechanistic or special 
studies, or hazard assessment. Similarly, the approach for this initial 
list also would exclude substances that EPA anticipates have low 
potential to cause endocrine disruption (e.g., certain FIFRA List 4 
inerts, most polymers with number average molecular weight greater than 
1,000 daltons, strong mineral acids, and strong mineral bases). 
Although EPA's general focus in this approach is on pesticide active 
ingredients and inerts with relatively greater potential human 
exposure, EPA believes that the proposed approach will also identify 
chemicals with high potential for exposure of humans from non-pesticide 
uses and/or chemicals with widespread environmental exposures to other 
organisms. EPA does not intend to develop an ordinal ranking of 
priorities of the chemicals within any list developed using the 
proposed approach.
    Because the list of chemicals produced using the proposed approach 
will be a list of chemicals that the Agency, in its discretion, has 
decided should be tested first, based primarily upon exposure 
potential, it should not be construed as a list of known or likely 
endocrine disruptors nor characterized as such. Nothing in the approach 
for selecting the initial list would provide a basis to infer that any 
of the chemicals selected for the list interferes with or is suspected 
to interfere with the endocrine systems of humans or other species.
    EPA has decided to defer consideration of nominations from the 
public until subsequent testing lists in order to keep this initial 
effort administratively simpler and ensure that a set of test results 
can be obtained in a relatively prompt timeline to aid the Agency in a 
mid-course evaluation of the EDSP Tier 1 screening battery. In 
addition, EPA has decided that the prudent approach would be to gain 
experience with the Tier 1 screening battery on single chemicals before 
the tests are used with mixtures. EPA also is proposing to exclude from 
consideration for the initial Tier 1 screening list chemicals that are 
no longer produced or used in the United States. The Agency thinks that 
the added administrative complexity of determining who should be 
responsible for testing such chemicals could unnecessarily delay EPA's 
selection of an initial list for Tier 1 screening.

B. What is the Agency's Authority for Taking this Action?

    In this notice, EPA is proposing an approach for selecting an 
initial set of chemicals to go through endocrine disruptor screening. 
EPA has a number of authorities at its disposal to require screening 
and testing for endocrine disrupting effects. As explained previously, 
FFDCA section 408(p) requires EPA ``to determine whether certain 
substances may have an effect in humans that is similar to an effect 
produced by a naturally occurring estrogen, or such other effects as 
[EPA] may designate.'' (21 U.S.C. 346a(p)). The statute requires EPA to 
``provide for the testing of all pesticide chemicals.'' It defines 
``pesticide chemical'' as ``any substance that is a pesticide within 
the meaning of the Federal Insecticide, Fungicide, and Rodenticide Act, 
including all active and inert ingredients of such pesticide.'' (FFDCA 
section 201(q)(1) (21 U.S.C. 231(q)(1)). The statute also provides EPA 
with discretionary authority to ``provide for the testing of any other 
substance that may have an effect that is cumulative to an effect of a 
pesticide chemical if the Administrator determines that a substantial 
population may be exposed to such a substance'' (21 U.S.C. 346a(p)(3)). 
In addition, section 1457 of SDWA provides EPA with discretionary 
authority to provide for testing, under the FFDCA section 408(p) 
screening program, ``of any other substances that may be found in 
sources of drinking water if the Administrator determines

[[Page 79615]]

that a substantial population may be exposed to such substance.'' (42 
U.S.C. 300j-17). Several other Federal statutes also provide EPA with 
authority to require testing of certain substances, including FIFRA and 
TSCA. EPA may use any or all of these authorities to require testing of 
substances to determine whether a substance may cause endocrine 
effects.

III. Background

A. EPA's Endocrine Disruptor Screening Program

    EPA initially set forth the EDSP in the Federal Register issue of 
August 11, 1998 (63 FR 42852, FRL-6021-3, Docket Control Number OPPTS-
42206) and solicited public comment on the program in the December 28, 
1998, Federal Register notice (FRL-6052-9). The program set forth in 
these notices was based on the recommendations of the Endocrine 
Disruptor Screening and Testing Advisory Committee (EDSTAC) which was a 
committee chartered under the Federal Advisory Committee Act. The 
Committee was comprised of members representing the commercial chemical 
and pesticides industries, Federal and State agencies, worker 
protection and labor organizations, environmental and public health 
groups, and research scientists. EPA charged EDSTAC to advise the 
Agency regarding:
    1. Methods for chemical selection and priorities for screening,
    2. A set of available, validated screening assays for early 
application,
    3. Ways to identify new and existing screening assays and 
mechanisms for their validation,
    4. Processes and criteria for deciding when additional tests beyond 
screening would be needed and how to validate such tests, and
    5. Processes for communicating to the public about EDSTAC's 
agreements, recommendations, and information developed during priority 
setting, screening, and testing.
    In response to this charge, EDSTAC recommended that EPA's EDSP 
address both potential human and ecological effects; examine effects on 
estrogen, androgen, and thyroid hormone-related processes; and include 
non-pesticide chemicals, contaminants, and mixtures in addition to 
pesticides (Ref. 2). Based on these recommendations, EPA developed a 
tiered approach for the EDSP. The core elements of the proposed 
approach are: Priority setting, Tier 1 screening, and Tier 2 testing. 
Tier 1 is envisioned as a battery of screening assays that would 
identify substances that have the potential to interact with the 
estrogen, androgen, and thyroid hormone systems. The purpose of Tier 2 
is to determine whether the substance could, in fact, cause endocrine 
effects mediated by estrogen-, androgen-, and thyroid-related 
processes, and establish the relationship between doses of an 
endocrine-active substance administered in the test and any effects 
observed (December 28, 1998, Federal Register notice (FRL-6052-9)).
    In addition, based on EDSTAC's recommendations, EPA proposed in the 
December 28, 1998, Federal Register notice (FRL-6052-9) an approach to 
establish the priority of chemicals for Tier 1 screening. The approach 
reflected the concern that the quantity and quality of exposure and 
effects information would be uneven across chemicals. EPA wanted to 
ensure that data-rich and data-poor chemicals were not directly 
compared in the priority setting process because data-poor chemicals 
might tend to be ranked low under such an approach. Thus, the approach 
set forth in the December 28, 1998, Federal Register notice (FRL-6052-
9) was to set up categories of information relating to the production, 
release, exposure and hazard of chemicals and to group the chemicals 
according to what data were available. This approach was termed a 
``compartment-based approach.'' The compartment-based approach was 
based on exposure- and effects-related compartments even though it was 
recognized that effects or toxicity data relevant to endocrine 
disruption would be extremely limited for the majority of chemicals. To 
partly compensate for the lack of relevant toxicity data, EPA proposed 
to conduct a HTPS on all non-pesticide active ingredient chemicals with 
a production volume in excess of 10,000 pounds per year. HTPS 
activities are discussed more fully in Unit IV.C. EPA developed the 
Endocrine Disruptor Priority Setting Data Base (EDPSD) to assist in 
assigning chemicals to compartments and setting priorities. More 
information on the EDPSD is available at: http://www.epa.gov/scipoly/oscpendo/prioritysetting/.
    EPA currently is implementing its EDSP in three major parts. The 
Agency is:
    1. Developing and validating Tier 1 screening level assays, 
selecting the appropriate screening assays for the Tier 1 battery based 
on the validation data, and developing and validating Tier 2 tests.
    2. Developing an approach for selecting an initial set of chemicals 
to go through Tier 1 screening.
    3. Developing the procedures the Agency will use to require 
screening.
    This notice deals only with the development of the approach that 
EPA will use to select the initial set of chemicals for Tier 1 
screening.

B. SAB/SAP Review

    EPA asked the SAB and the SAP to review jointly the Agency's 
proposed EDSP as described in the December 28, 1998 Federal Register 
notice (FRL-6052-9). The Agency's charge to the SAB/SAP Subcommittee 
was broad and complex consisting of 18 questions in four broad areas:
    1. Scope of the program.
    2. Priority setting.
    3. HTPS.
    4. Screening and testing.
    The Subcommittee met on March 30-April 1, 1999. Its report was 
published the following July (Ref. 1). In general, the SAB/SAP 
Subcommittee agreed with the program that EPA had developed for 
conducting endocrine disruptor screening. The following are 
recommendations from the Subcommittee with respect to the scope of the 
program and setting of priorities for Tier 1 screening.
    In the December 28, 1998, Federal Register notice (FRL-6052-9), EPA 
explained that it was considering 87,000 substances as potential 
candidates for testing under the EDSP. The SAP/SAB Subcommittee 
expressed some reservations about the ambitious scope of the universe 
of chemicals that EPA envisioned as potentially being included in the 
Program. The Subcommittee felt that developing massive amounts of 
screening data on a large universe of chemicals would not necessarily 
expedite the development of the appropriate underpinning that the 
Agency needs before it proceeds with the screening of the large 
universe of chemicals that it anticipates will be included in the EDSP. 
The Subcommittee also expressed concern that it did not see a provision 
for mid-course correction or optimization of the Program. Thus, the 
Subcommittee recommended that the EPA implement the EDSP on 50 to 100 
compounds and submit the data to independent review with an eye toward 
eliminating methods that do not work and optimizing the program.
    The Subcommittee also recommended against including mixtures in the 
initial set of chemicals to be tested. The Subcommittee thought that 
the question of testing mixtures should be deferred until accepted 
single-compound methods had been successfully completed.
    The Subcommittee also found that the compartment-based approach to 
priority setting was supportable when ranking is

[[Page 79616]]

based on both effect and exposure data. It suggested that the greatest 
weight should be given to chemicals for which there are data that 
indicate actual human or environmental exposure and effects. Lower 
weight should be given to agents for which the data are indicative of 
probable exposure (in food or drinking water) or probable effects (from 
animal studies). The lowest weight and priority should be given to 
chemicals for which the data are indicative of possible exposure (based 
on release or production volume) or possible effects (from in vitro or 
HTPS assays). The Subcommittee expressed concern that the lack of 
effects data on the universe of chemicals currently in commercial use 
would lead to a database that only identifies known problem chemicals 
that are already well studied. To overcome this obstacle, the 
Subcommittee encouraged the development of new techniques including 
QSAR and molecular modeling to help identify the bio-available, 
potentially active compounds for further testing in the EDSP. The 
Subcommittee supported the concept of nominations by citizens but 
recommended that the process needed further definition.
    Finally, the Subcommittee agreed with EPA's assessment that the 
HTPS system, which EPA subjected to a demonstration project, was not 
ready for use but that the concept was still valuable. The Subcommittee 
encouraged EPA to be open to other types of assays for HTPS including 
receptor binding, gene chip and microassays, and computer modeling. The 
Subcommittee also gave some guidance regarding further development and 
employment of HTPS including the need for standardization and 
validation of any system to be used in priority setting.

C. Previous Public Comments on Priority Setting

    In addition to comments provided by the SAB/SAP Subcommittee, 
comments provided by the public on priority setting in response to 
EPA's EDSP Proposed Statement of Policy in the December 28, 1998, 
Federal Register notice (63 FR 71542, FRL-6052-9, Docket Control Number 
OPPTS-42208) and at two public meetings on the Endocrine Disruptor 
Priority Setting Data Base held on January 20, 1999 (Federal Register 
issue of December 28, 1998 (63 FR 71568, FRL-6052-8, Docket Control 
Number OPPTS-42207)) and June 5-6, 2000 (Federal Register issue of May 
19, 2000 (65 FR 31900, FRL-6559-9, Docket Control Number OPPTS-42212)) 
have been helpful to the Agency in developing the approach presented in 
this notice for selecting the first group of chemicals to be screened 
in the EDSP.

IV. EPA's Approach to Selecting the Initial Set of Chemicals to Undergo 
Tier 1 Screening

    On the basis of EPA's experience to date and comments received from 
the SAB/SAP Subcommittee and the public, EPA is setting forth its 
approach for selecting the first group of chemicals to be screened in 
the EDSP. Based on the SAB/SAP recommendations, EPA is proposing to 
select and screen approximately 50 to 100 chemicals drawn from 
pesticide active ingredients and HPV chemicals with some pesticidal 
inert uses (HPV/Inert chemicals) to help the Agency further refine the 
EDSP. As recommended by the SAP/SAB Subcommittee, the Agency intends to 
submit the data received from the screening to an independent external 
panel of experts and request an evaluation of whether the program could 
be improved or optimized, and if so, how. EPA does not intend to 
develop an ordinal ranking of priorities of the chemicals within this 
initial list.
    EPA is proposing to use an approach based in part on the 
compartment-based priority setting approach described in the December 
28, 1998, Federal Register notice (FRL-6052-9) that provided details 
about the EDSP. That document proposed approach focuses on exposure-
related factors rather than using a combination of exposure- and 
effects-related factors. The approach would, however, exclude from the 
first group of chemicals to undergo Tier 1 screening any chemical for 
which the available effects information clearly shows an endocrine-
mediated effect. Such chemicals would be considered for proposed Tier 2 
tests, mechanistic or special studies, or hazard assessment. Similarly, 
the approach for this initial list also would exclude substances that 
EPA anticipates have low potential to cause endocrine disruption (e.g., 
certain FIFRA List 4 inerts, most polymers with number average 
molecular weight greater than 1,000 daltons, strong mineral acids, and 
strong mineral bases). Although EPA proposes to use in this approach 
many of the exposure-data sets previously identified for use in the 
EDPSD, EPA is not proposing to directly use the EDPSD itself at this 
time in light of the narrower scope and focus of this initial list. EPA 
anticipates that it will modify its chemical selection approach for 
subsequent Tier 1 screening lists based on experience gained from the 
results of testing of chemicals on the initial list, the feasibility of 
incorporating different categories of chemicals (e.g., non-pesticide 
substances), and the availability of new priority-setting tools (e.g., 
HTPS and QSAR models).
    EPA is proposing to use several bodies of data to identify 
pesticide active ingredients for screening in the first use of the Tier 
1 battery. These data focus on human exposure by different pathways:
    1. As a consequence of consumption of food containing pesticide 
residues.
    2. As a consequence of consumption of drinking water containing 
pesticide residues.
    3. As a consequence of residential use of pesticide products.
    4. Through occupational contact with pesticide-treated surfaces.
For each of the four pathways, EPA has identified existing data that it 
believes will help to identify active ingredients likely to be among 
those having either relatively more widespread or higher levels of 
human exposure than would be expected for other active ingredients. EPA 
proposes to give higher priority for inclusion on the list for initial 
screening to chemicals likely to have human exposure via multiple 
pathways, with the highest priority being given to substances having 
exposure through all four pathways, followed by those having exposure 
via three pathways, etc. Details on EPA's proposed approach for 
selecting pesticide active ingredients are presented in Unit V.
    EPA is proposing to use a generally similar approach to identify 
HPV/Inert chemicals to be included in the initial list for screening in 
the Tier 1 battery. However, EPA generally has more extensive 
information of known quality available to assess potential exposure to 
pesticide active ingredients via food, water, occupational and 
residential exposure pathways than is available to assess exposure to 
HPV/Inert chemicals. In addition, EPA generally has more extensive 
information available on usage (including both agricultural and 
residential) of active ingredients than is available for HPV/Inert 
chemicals (including both pesticidal and non-pesticidal uses of those 
same substances). For these reasons, the specific data and approaches 
EPA has identified for selecting an initial set of HPV/Inert chemicals 
for endocrine disruptor screening differs somewhat from those proposed 
for selecting pesticide active ingredients.
    For HPV/Inert chemicals, EPA will focus on several indicators of 
the potential for human exposure, including production volume, specific 
pathways of exposure, and presence in human tissues. First, EPA will 
review existing

[[Page 79617]]

databases to identify chemicals that are both pesticide inerts and HPV 
(defined as chemicals that are manufactured or imported into the United 
States for all uses in amounts equal to or greater than 1 million 
pounds per year) chemicals (HPV/Inert). This first step will focus 
initial Tier 1 screening of pesticide inerts on chemicals with higher 
potential human exposure on the basis of large amounts produced or 
imported each year in the United States. Second, EPA will review 
existing data to identify HPV/Inert chemicals that have been found to 
be present in: Human tissue, ecological tissues that have human food 
uses (i.e., fish tissues), drinking water, and/or indoor air. Using 
this approach, an HPV/Inert chemical appearing in monitoring data from 
one or more of these media, would be a higher priority for testing than 
an HPV/Inert chemical that does not appear in monitoring data from any 
of the media. Details on this priority setting approach for HPV/Inert 
chemicals are presented in Unit VI.
    While EPA's general focus in this approach is on pesticide active 
ingredients and HPV/Inert chemicals with relatively greater potential 
human exposure, this focus does not necessarily mean that the list 
developed using this approach will not contain substances which also 
have potentially high levels of environmental exposure to ecological 
receptors. As explained in Units V. and VI., EPA believes that the 
approach proposed to select an initial list of pesticide active 
ingredients and HPV/Inert chemicals for screening, while focused on 
human exposure, will also capture many chemicals with widespread 
environmental exposures to other organisms.
    This proposed approach for selecting the initial list of chemicals 
to undergo Tier 1 screening differs from the more general EDSP priority 
setting approach outlined in EPA's December 28, 1998, Federal Register 
notice (FRL-6052-9) in several aspects: EPA would focus chemical 
selection for this initial list on the subset of chemicals subject to a 
statutory mandate for screening (i.e., pesticide chemicals); EPA would 
use exposure data as the primary basis for chemical selection rather 
than using HTPS, QSARs or other hazard data in conjunction with 
exposure data; EPA would defer consideration of nominations from the 
public; and EPA would not include mixtures in this initial list. The 
reasons for these proposed changes are as follows:

A. Focusing on the Subset of Chemicals Subject to a Statutory Mandate 
for Screening

    For the initial Tier 1 screening list, EPA is proposing to focus 
only on pesticide active ingredients and HPV chemicals with some 
pesticidal inert uses (i.e., the chemicals that are specifically 
mandated for testing under section 408(p) of FFDCA) as candidates. The 
pesticide inerts to be considered are those with relatively large 
overall production volumes considering both pesticide and non-pesticide 
uses. This approach will allow EPA to focus its initial endocrine 
screening efforts on a smaller and more manageable universe of 
chemicals that emphasizes early attention to the pesticide chemicals 
that Congress specifically mandated EPA to test for possible endocrine 
effects.

B. Using Exposure Data as the Primary Basis for Chemical Selection

    In response to the recommendations of EDSTAC, EPA had stated its 
intention to incorporate effects information into an overall chemical 
prioritization scheme in conjunction with exposure information for 
identifying chemicals to undergo screening and testing for endocrine 
disruption potential. However, in light of the limited availability of 
data for many chemicals that would indicate their relative potential 
for disrupting endocrine systems and the delays in identifying adequate 
HTPS or QSAR approaches that are discussed in Units IV.C. and IV.D., 
the Agency is proposing to use a simpler and narrower approach based 
primarily on exposure for this initial selection of a limited number of 
chemicals for screening under the EDSP.
    A relatively broad range of toxicity data generally are available 
for pesticide active ingredients regulated under FIFRA, but in most 
cases it has not yet been established how the available data might be 
confidently used to predict the endocrine disruption potentials of 
these chemicals. This may be due, for example, to the non-specific 
nature of an effect or effects observed, questions related to whether 
the mode of action of a given effect or effects is or are endocrine 
system-mediated in whole or in part, or the lack of relevant data to 
make a judgement altogether. A more limited set of toxicity data 
generally is available for pesticide inert ingredients.
    Nevertheless, for certain chemicals the available data may provide 
a sufficiently clear indication of an endocrine-mediated effect or 
perturbation to warrant exclusion from the first group of chemicals to 
undergo Tier 1 testing. Such chemicals would be considered for proposed 
Tier 2 tests, mechanistic or special studies, or hazard assessment. 
Similarly, based on a review of the available information, there are 
certain other substances which EPA anticipates have low potential to 
cause endocrine disruption (e.g., certain FIFRA List 4 inerts, most 
polymers with number average molecular weight greater than 1,000 
daltons, strong mineral acids, and strong mineral bases). EPA 
anticipates also excluding certain of these substances from the first 
group of chemicals to undergo Tier 1 testing.
    Therefore, except for purposes of exclusion (e.g., there are 
sufficient data to determine that a chemical has endocrine-mediating 
activity), effects data are not being considered in this approach for 
identifying the initial group of chemicals for Tier 1 screening. This 
does not necessarily mean, however, that toxicity data will not be used 
in identifying subsequent groups of chemicals for Tier 1 screening.
    Because the list of chemicals produced using the proposed approach 
will be a list of chemicals that the Agency, in its discretion, has 
decided should be tested first based primarily upon exposure potential, 
it should not be construed as a list of known or likely endocrine 
disruptors nor characterized as such. Nothing in the approach for 
selecting the initial list would provide a basis to infer that any of 
the chemicals selected for the list interferes with or is suspected to 
interfere with the endocrine systems of humans or other species.

C. HTPS

    Recognizing the limitations on existing hazard data, EPA proposed 
in the December 28, 1998, Federal Register notice (FRL-6052-9) the use 
of in vitro HTPS to assist in sorting and priority setting. The plan 
was to use HTPS to pre-screen up to 15,000 chemicals that are produced 
in quantities exceeding 10,000 pounds per year. HTPS data would define 
one of the compartments in the EDPSD and provide a criterion for 
identifying high priority chemicals. EPA sponsored a limited 
demonstration of an HTPS system utilizing reporter gene assays for the 
estrogen receptor (ER), androgen receptor (AR), and thyroid receptor 
(TR). The reporter gene assays used in this demonstration project 
employed a human cell line that naturally contains the receptor. A 
reporter element was then introduced into these cells so that when a 
substance binds to a receptor it would activate the genetic machinery 
in the cell. This activation could be detected in a quantitative 
manner. The SAB/SAP

[[Page 79618]]

Subcommittee agreed with EPA that the demonstration HTPS system did not 
work well enough in its present form to serve as a tool for priority 
setting (Ref. 1). The assays had too much variability and too low of a 
response to be useful without modifications to boost their sensitivity. 
EPA concluded that the HTPS approach still holds promise but that it 
has potential for success only after substantial additional research. 
EPA decided to defer its plans for using HTPS and to explore the 
potential for using QSAR models to address the problem of inadequate 
hazard data to prioritize chemicals. Nonetheless, the SAB/SAP 
Subcommittee believed that HTPS is a promising tool for priority 
setting and EPA agrees. EPA has issued a Request For Application (RFA) 
under its Science to Achieve Results (STAR) research grants program to 
solicit new approaches that may lead to the development of HTPS to 
assist in the prioritization of chemicals for screening for endocrine 
disrupting activity (http://es.epa.gov/ncer/rfa/current/2003high_throughput.html). EPA is also following the work being conducted in 
Japan on ER and AR transcriptional activation-based HTPS systems. EPA 
will consider the applicability of new HTPS approaches to future 
priority setting in the EDSP as those approaches are further developed 
and refined.

D. QSAR Models

    At the time EPA decided to suspend its efforts under the EDSP on 
HTPS, it was aware of at least two QSAR models that were being 
developed to predict the potential of a chemical to bind to cellular 
ER. QSAR offers one important advantage over HTPS. It could provide 
data on thousands of chemicals without testing them in the laboratory. 
Such a tool could save millions of dollars in chemical testing costs, 
but still, if valid, be able to predict whether a new molecule that had 
never been synthesized or an untested existing chemical would be likely 
to interact with the ER or AR. EPA designed a program to validate two 
QSAR models within a defined chemical domain and activity range of 
interest to EPA. The comparative molecular field analysis (CoMFA) model 
developed by Federal Food and Drug Administration's (FDA) National 
Center for Toxicological Research and the common reactivity pattern 
(COREPA) model developed at the University of Bourgas were evaluated. 
EPA asked each of the modeling teams to predict the relative ER binding 
of 6,649 high production chemicals on the TSCA inventory. EPA selected 
50 chemicals predicted to be positive by each model and approximately 
200 chemicals selected from the 6,649 at random and tested almost all 
in an ER binding assay. Thus, a total of nearly 300 chemicals were 
tested to validate the models. Each model predicted about 300 of the 
6,649 chemicals to be positive. There were 78 chemicals that were 
predicted to be positive by both models (Ref. 3). A comparison of model 
predictions with laboratory results did not meet EPA's expectations 
because, although both models demonstrated relatively high specificity, 
both models also demonstrated low sensitivity. EPA believes that the 
performance problems associated with the models are likely due to the 
chemical training set being significantly dissimilar in terms of 
structures and binding potency ranges compared to the TSCA HPV 
chemicals. EPA is continuing to encourage the development and 
refinement of QSARs and beginning in Fiscal Year 2002 redirected $4 
million to a computational toxicology initiative to integrate modern 
computing and information technology, not limited to just QSARs, with 
the technology of molecular biology and chemistry to improve EPA's 
ability to prioritize chemicals for screening and testing, and its risk 
assessments.

E. Deferring Consideration of Nominations From the Public

    For the initial Tier 1 screening list, EPA proposes to focus on 
pesticide active ingredients and HPV chemicals with some pesticidal 
inert uses (i.e., the chemicals that are specifically mandated for 
testing under section 408(p) of FFDCA) as candidates. EPA believes that 
nominations from the public are important because they provide a 
mechanism to identify chemicals which may result in high exposures in 
local communities but which would not otherwise receive national 
attention. However, EPA has decided to defer consideration of 
nominations from the public until subsequent testing lists in order to 
keep this initial effort administratively simpler and ensure that a set 
of test results can be obtained in a relatively prompt timeline to aid 
the Agency in a mid-course evaluation of the EDSP Tier 1 screening 
battery.

F. Not Testing Mixtures

    EPA has decided that the prudent approach would be to gain 
experience with these tests on a variety of single chemicals before it 
addresses mixtures. This judgement is consistent with advice from the 
SAB/SAP Subcommittee (Ref. 1).

G. Excluding Chemicals that are no Longer Produced or Used in the 
United States

    EPA also is proposing to exclude from the initial Tier 1 screening 
list any chemicals that are no longer produced or used in the United 
States. The Agency thinks that such chemicals would not warrant high 
priority for testing at this time. Although some of the databases that 
EPA proposes to consider may report past detections of such chemicals, 
the discontinuation of their use and manufacture means that exposure to 
these substances is likely declining. Moreover, EPA anticipates that it 
will have to resolve significant practical difficulties (such as 
determining who EPA could require to conduct the testing) before it 
attempts to require testing of these substances. This combination of 
reasons leads the Agency to propose excluding discontinued chemicals 
from the initial group of chemicals to undergo testing in the Tier 1 
screening battery.

V. Approach for Selecting Pesticide Active Ingredients

    EPA is proposing to use several sets of criteria for identifying 
pesticide active ingredients to be given priority for screening in 
EPA's initial application of the Tier 1 battery. These criteria would 
focus on human exposure by different pathways: As a consequence of 
consumption of food containing pesticide residues; as a consequence of 
consumption of drinking water containing pesticide residues; as a 
consequence of residential use of pesticide products; and through 
occupational contact with pesticide-treated surfaces. For each of the 
four pathways, EPA would review existing databases that can help the 
Agency to identify active ingredients generally expected to be among 
those having either widespread or high levels of human exposure.
    While EPA's general focus is on pesticide active ingredients with 
relatively greater potential human exposure, this focus does not 
necessarily mean that the list of active ingredients will not contain 
substances which also have potentially high levels of environmental 
exposure to ecological receptors. Many of the pesticide active 
ingredients having greater potential for human exposure will also have 
greater potential for exposure to wildlife. For example, one pathway of 
human exposure, drinking water, is also a pathway through which aquatic 
life and many terrestrial species are exposed. Most of the databases 
that EPA will consider in evaluating active ingredients

[[Page 79619]]

for exposure through drinking water contain monitoring data collected 
on raw surface water, i.e., before the water enters a Community Water 
System. Thus, these monitoring data show the levels of pesticide 
residues which fish, amphibians, and other aquatic species will 
encounter. Similarly, when data show higher and more widely distributed 
levels of pesticide residues in food, EPA thinks that such residues 
generally tend to reflect greater usage and/or persistence of the 
pesticide on crops and thus, greater environmental loads. Accordingly, 
EPA believes that the approach proposed to evaluate pesticide active 
ingredients, while focused on human exposure, will also capture many 
active ingredients with widespread environmental exposures.

A. The Food Pathway

    Every person eats food and a significant portion of food contains 
some amount of pesticide residues, although usually at very low levels. 
Therefore, pesticide residues in food have the potential to cause 
widespread human exposure. Pesticides have different use patterns and 
have different physical and chemical properties that affect how they 
move in the environment and how quickly they break down. As a result, 
there are often significant differences among pesticides in the 
proportion of food containing residues and in the levels of such 
residues. People also consume different amounts of different foods. All 
of these factors mean that people ingest greater quantities of some 
pesticide active ingredients than of others.
    To evaluate the interplay of these different variables, EPA 
proposes to identify the pesticide active ingredients which are most 
frequently found as residues on the top twenty foods that people 
consume. First, EPA will examine the most recent Continuing Survey of 
Food Intake by Individuals (CSFII) to determine the mean amount of each 
raw agricultural commodity consumed in the general population. The 
CSFII is a database derived from a survey performed by the U. S. 
Department of Agriculture (USDA) in 1994-1996 and supplemented with 
additional survey responses collected in 1998. USDA collected food 
diary information from over 20,000 individuals who were interviewed on 
two non-consecutive days, generally spaced 3 to 10 days apart. After 
appropriate statistical weighting, the survey, in the aggregate, is 
representative of the U. S. population in terms of age, gender, major 
ethnic groups, and socio-economic status. Moreover, sampling was 
representative of different days of the week, seasons of the year, and 
parts of the country. Extensive quality control procedures assured that 
the data collected in the survey were accurate and reliable. More 
information on USDA's food surveys and the CSFII (`94-`96) is available 
through http://www.barc.usda.gov/bhnrc/foodsurvey.
    Using the CSFII information, EPA has converted the reported food 
consumption for each survey respondent into the constituent raw 
agricultural commodities. For example, if a person reported having 
eaten 6 ounces of beef stew, EPA estimated the amount of beef, carrot, 
potato, and each other raw agricultural commodity used in making that 
quantity of beef stew. EPA made similar conversions for each of the 
different finished foods reported in the CSFII--from apple pie to 
yogurt. Then EPA estimated the total amount of each of the various raw 
agricultural commodities eaten over the course of the day, for example 
summing the amount of apple consumed from drinking cider and eating 
apple sauce. This individual food consumption database provides the 
basis for identifying the top twenty foods consumed, in terms of mean 
daily consumption for the general population. List 1 of this unit lists 
these raw agricultural commodities.

List 1.--Top Twenty Foods
(Foods accounting for the largest quantity of food intake by 
individuals (arranged alphabetically))
1. Apple
2. Banana
3.Beef
4.Carrot
5.Chicken
6.Corn, Field
7.Corn, Sweet
8.Egg
9.Grape
10.Lettuce
11.Milk
12.Onion
13.Orange
14.Pork
15.Potato
16.Rice
17.Soybean, oil
18.Sugar
19.Tomato
20.Wheat

    Having identified the top 20 foods, EPA would characterize the 
pesticide residue levels on these foods using information collected by 
two Federal agency monitoring programs, the USDA Pesticide Data Program 
(PDP) and the Surveillance Monitoring Program conducted by FDA's Center 
for Food Safety and Applied Nutrition. PDP has been collecting 
pesticide residue data since 1991. PDP is designed to provide a 
nationally representative database on the distribution of pesticide 
residues in food as close as possible to the actual time of consumption 
as practical. Using analytical methods that have been standardized and 
validated, and following strict quality control procedures, USDA has 
focused on foods highly consumed by children throughout the year. Over 
the years of operation, PDP has collected data on over 290 different 
pesticides and 50 different commodities. Additional information can be 
found at http://www.ams.usda.gov/science/pdp/index.htm. The FDA 
Surveillance Monitoring Program is designed primarily for enforcement 
of pesticide tolerances on imported foods and domestic foods shipped in 
interstate commerce. Domestic samples are collected as close as 
possible to the point that the food enters the distribution system. FDA 
samples imported food at the port of entry into the United States. 
Additional information on the FDA program appears at http://
www.cfsan.fda.gov/[sim]dms/pesrpts.html.
    Because of the differences in how samples are collected and 
handled, EPA would rely on the PDP database when both sources cover the 
same pesticides and commodities. The FDA Surveillance data covers 
different pesticides and commodities in different years from the PDP 
monitoring. (For example, in 1999, FDA used analytical methods capable 
of detecting 366 different active ingredients.) Therefore, in making 
its weight-of-the-evidence judgment, EPA would consider the FDA 
information as a supplement to the information from the PDP database.
    EPA proposes to examine the PDP and FDA Surveillance databases to 
identify the pesticide active ingredients which appear on the largest 
proportion of the samples, focusing on the twenty foods which make up 
the largest part of the U.S. diet. Generally, EPA would give higher 
weight to pesticides that appear frequently on multiple foods. In 
reviewing these data, EPA will take into account qualitatively any risk 
mitigation measures implemented since residues levels were monitored.
    EPA recognizes that this approach would be more likely to give 
higher priority to the pesticides which are the subject of routine 
monitoring in either PDP or FDA's Surveillance program. Both programs 
rely primarily on ``multi-residue methods'' that are capable of 
detecting many different chemical substances using a single analytical 
procedure. Active ingredients which

[[Page 79620]]

require specialized analytical methodology may not be looked for and 
thus would be unlikely to be included for consideration in the food 
pathway. This limitation particularly applies to newer pesticide active 
ingredients. Notwithstanding these limitations, EPA believes that the 
approach described is a practicable approach for identifying pesticide 
active ingredients with widespread or high levels of exposure.

B. The Water Pathway

    Significant portions of the general population may be exposed to 
pesticide residues in drinking water. Although monitoring data indicate 
that most pesticide active ingredients are rarely detected, analytical 
surveys in virtually every region of the country have detected a number 
of active ingredients in ground and surface water used as sources of 
drinking water. Monitoring also indicates that, even when found in 
water, residue levels vary significantly both seasonally and regionally 
for a single pesticide, as well as across pesticides. Particularly for 
surface water, residues tend to occur in pulses that can last days to 
weeks to months, depending on the type of water body and the pesticide. 
Because almost every person consumes some water every day, either in 
prepared foods or beverages (e.g., coffee, tea, or reconstituted juice) 
or simply by drinking water, exposure to pesticides through the 
drinking water pathway can be widespread and repeated. And, while such 
exposure is usually neither as widespread nor of the same magnitude as 
pesticide exposure through food, a significant portion of the 
population in a particular region of the country can be exposed.
    To assess relative exposure to different pesticides in water, EPA 
would examine a number of different databases that contain the results 
of programs to monitor surface and ground water for the presence of 
pesticide residues. These databases, which contain data collected by 
Federal and State agencies, academicians, pesticide companies, and 
others, are summarized in this unit:
    1. EPA Pesticides in Ground Water Database (PGWDB). The PGWDB was 
created to provide a more complete picture of ground-water monitoring 
for pesticides in the United States. It is a collection of ground-water 
monitoring studies conducted by Federal, State, and local governments; 
the pesticide industry; and private institutions between 1971-1991. The 
PGWDB compiles, in tabular format, data from monitoring of raw ground-
water\1\ and contains data only from studies in which pesticides were 
included as analytes. Some of the data limitations include: age of the 
data; differences in the design of studies; lack of historical 
pesticide use or hydrological information; and lack of information on 
well use, sampling practices, and laboratory procedures. Further 
details can be found in EPA Pesticides in Ground Water Database, A 
Compilation of Monitoring Studies: 1971-1991 National Summary (Ref. 4).
    2. EPA Chemical-Specific Monitoring Data. Pesticide registrants 
have conducted and submitted to the Agency targeted surface water and 
ground water monitoring studies for approximately 50 pesticide active 
ingredients. The Agency decides whether to require monitoring of raw 
surface or ground water for a pesticide based on the environmental fate 
characteristics (persistence and mobility) of the pesticide; the 
current or proposed use patterns for the pesticide; and other 
information that would indicate potentially significant levels of the 
pesticide could be present in water. The design of monitoring studies 
takes into consideration application rate, crops, and the location of 
potentially more vulnerable use sites. These studies are performed 
under Good Laboratory Practice regulations, and contain internal 
quality assurance procedures. When submitted, the monitoring data 
undergo primary and secondary review by Agency scientists.
    3. Heidelberg College's Monitoring Data. Heidelberg College's Water 
Quality Laboratory (WQL) conducts research, monitoring and educational 
programs that address the impacts of agricultural and urban land use on 
the water resources of Ohio, the Midwest, and the Lake Erie and Great 
Lakes ecosystems. The WQL began studying pesticides in 1981. These 
studies now provide the longest and most detailed record of pesticide 
residues in raw water available for any river system in the United 
States. The WQL maintains a modern, highly automated water chemistry 
laboratory with capabilities rarely found within academic research 
settings. While much of the WQL's program is organized within the 
context of a large-scale, long-term agricultural ecosystem study, the 
lab also conducts research related to public drinking water supplies 
(finished water), urban runoff, industrial and municipal pollution 
sources and changing biological communities in Lake Erie. Further 
details can be found on the web at: http://www.heidelberg.edu/WQL/index.html.
    4. U.S. Geological Survey (USGS)/EPA Reservoir Monitoring Study. 
The USGS/EPA Reservoir Monitoring study was a pilot monitoring program 
initiated by USGS and EPA to provide information on pesticide 
concentrations in drinking water and to assist in the implementation of 
the Food Quality Protection Act (FQPA) of 1996. Drinking-water 
utilities that withdrew water from reservoirs were sampled in 1999 and 
2000. Water samples were collected from raw water (at the intake point) 
and from finished drinking-water (at the tap prior to entering the 
distribution system). At some sites, samples were also collected at the 
reservoir outflow. Sampling frequencies were designed to measure long-
term mean and short-term peak concentrations of pesticides in drinking 
water. The analytical methods used for analyzing the pesticides in the 
water samples included 178 different pesticides and degradation 
products. Additional information on the USGS/EPA Reservoir Monitoring 
Study can be found in Pesticides in Select Water Supply Reservoirs and 
Finished Drinking Water, 1990-2000: Summary of Results from a Pilot 
Monitoring Program (Ref. 5).
    5. Environmental Monitoring and Assessment Program (EMAP). EMAP is 
an EPA research initiative designed to support the development of tools 
necessary to monitor and assess the status and trends of national 
ecological resources. Research is conducted on various ecosystems 
(e.g., estuaries, forests, rangelands, and lakes). Sediment samples 
were collected in 18 States at various times between 1990 and 1998. 
This data source provides information about the contaminants present in 
sediment/soil which humans and wildlife may contact. EMAP includes 
relevant data for over 170 chemicals and three separate data sets for 
estuary sediments. Extensive field and laboratory QA/QC procedures were 
performed during the collection and analysis of the samples. Further 
details can be found on the web at: http://www.epa.gov/emap/.
    6. National Sediment Inventory (NSI). The Water Resources 
Development Act (WRDA) of 1992 directed EPA, in consultation with the 
National Oceanic and Atmospheric Administration (NOAA) and the U.S. 
Army Corps of Engineers (USACE), to conduct a national survey of data 
regarding the quality of sediments in the United States. To comply with 
the WRDA mandate, EPA's Office of Science and Technology initiated the 
NSI. The NSI

[[Page 79621]]

is a database that documents the composition of sediment in rivers, 
lakes, oceans, and estuaries. The NSI tissue residues studies 
(primarily fish) help assess sediment quality and can be used to assess 
potential exposure of humans to these chemicals through the consumption 
of fish. Also, sediment chemistry data are evaluated for theoretical 
bioaccumulation potential. The NSI includes data collected by a variety 
of Federal, State, regional, local, and other monitoring programs from 
1980 through 1999. It includes over 4.6 million analytical observations 
for over 50,000 monitoring stations across the country of sediment 
chemistry, tissue residues, and sediment toxicity data. NSI's minimum 
data requirements include monitoring program identification, sampling 
date, latitude and longitude coordinates, and measured units. EPA 
retains additional data such as QA/QC information, if available, but 
did not require that information for a data set to be included in NSI. 
Additional limitations of the compiled data include the mixture of data 
sets derived using different sampling strategies, incomplete sampling 
coverage, and the age and quality of the data. Because the data 
analyzed in this report were collected over a relatively long period of 
time, conditions may have changed since the sediment was sampled. 
Further details on the NSI database and the National Sediment Quality 
Survey, which the NSI was developed to support, can be found at: http://www.epa.gov/waterscience/cs/nsidbase.html and http://www.epa.gov/waterscience/cs/draft/survey.html.
    7. National Drinking Water Chemical Occurrence Database (NCOD). 
NCOD is a repository of drinking water quality data, mandated by 
Congress in the 1996 SDWA Amendments. NCOD contains national occurrence 
data from public water systems and from ambient water from the USGS 
National Water Information System. It includes information on regulated 
and unregulated contaminants, containing physical, chemical, microbial, 
and radiological information for both detects and non-detects. NCOD-
drinking water contains relevant data for over 120 chemicals, and 
includes samples from both raw and finished water. Currently, NCOD-
drinking water contains occurrence only for those water systems that 
have been reported by States to EPA's Safe Drinking Water Information 
System. While data sets will be updated over time, they may reflect a 
lag time of at least six months. Further details can be found on the 
web at: http://www.epa.gov/safewater/data/ncodgateway.html.
    8. National Stream Quality Accounting Network (NASQAN) Data. 
NASQAN, a monitoring and data-collection program conducted by the USGS, 
is designed to characterize raw surface water in large sub-basins of 
rivers, determine regional source areas for chemicals, and assess the 
effects of human influences on observed concentrations and amounts of 
chemicals. Since 1995, NASQAN has focused on monitoring the water 
quality of four of the nation's largest river systems: the Mississippi, 
the Columbia, the Colorado, and the Rio Grande. A network of 40 
stations monitors the concentrations of a broad range of chemicals 
including pesticides, major ions, and trace elements. NASQAN contains 
relevant data for over 70 chemicals. NASQAN samplers collect quality 
control (QC) samples to evaluate the quality of sampling data. However, 
the data in NASQAN do not characterize ambient water quality throughout 
the United States, only for four river basins and sub-basins. Further 
details can be found on the web at: http://water.usgs.gov/nasqan/.
    9. The National Water Quality Assessment Program (NAWQA). Congress 
appropriated funds in 1986 for the USGS to design and implement a 
program to address questions related to status and long-term trends in 
raw surface- and ground-water quality at national, regional, and local 
scales. The USGS began a pilot program in seven project areas to 
develop and refine a plan for the National Water-Quality Assessment 
(NAWQA) Program. In 1991, the USGS began full implementation of the 
program. The NAWQA program builds upon an existing base of water-
quality studies of the USGS, as well as those of other Federal, State, 
and local agencies. The NAWQA Program was designed to study 60 of the 
Nation's most important river basins and aquifer systems, which are 
referred to as study units. A national map of these study units shows 
that they are distributed throughout the Nation and cover a diversity 
of hydrogeologic settings. More than two-thirds of the Nation's 
freshwater use occurs within the study units and more than two-thirds 
of the people served by public water-supply systems live within their 
boundaries. The 60 study units have been divided into groups of 20 
study units each, and their intensive data-collection phases have been 
staggered to allow efficient and effective use of resources. The first 
20 studies began in 1991, the second group began in 1994, and the third 
group began study in 1997. Due to funding constraints, only 14 of the 
original first group of 20 study units began a second cycle of study in 
the year 2000. The cycle is intended to continue into the future with a 
total of 52 study units so as to provide both short-term information 
necessary for today's water-resource management decisions, and the 
long-term information needed for policy decisions. Further details can 
be found on the web at: http://wwwga.usgs.gov/nawqa/main.nawqa.html.
    EPA notes that most of the monitoring databases report results from 
samples of ``raw,'' or untreated, water, rather than ``finished'' 
drinking water prepared by a drinking water facility for its customers. 
To the extent that treatment methodologies (such as flocculation, 
softening, filtration, chlorination, sedimentation, etc.) either remove 
or transform the pesticide residue in the source water, residues found 
in the raw water may not represent exposure of the public consuming the 
finished water. EPA has considered the impacts of various treatment 
methodologies on different classes of pesticides found in raw water and 
concluded that conventional water treatment processes (such as 
coagulation/flocculation, sedimentation, and filtration) can have 
little or no effect on the removal of certain pesticides (Ref. 6). 
Thus, the Agency regards the results of monitoring raw or ambient water 
as an appropriate indicator of potential human exposure.
    Many other factors affect the interpretation of a set of water 
monitoring data. Monitoring is most likely to detect the presence of 
pesticide residues in water if it is conducted in an area where the 
pesticide has been used, and samples are collected at a time when 
residues are likely to occur. Moreover, the analysis must employ 
methods sensitive enough to detect any residue. Often, however, 
monitoring reports lack sufficient information to evaluate how well 
these factors were considered. Consequently, evaluation of water 
monitoring data requires considerable judgment. See the discussion of 
considerations affecting the evaluation of water monitoring data in 
Estimating the Drinking Water Component of a Dietary Exposure 
Assessment (Ref. 7) and the EPA Background Paper for the FIFRA 
Scientific Advisory Panel Meeting on Monitoring Strategies for 
Pesticides in Surface-Derived Drinking Water (Ref. 8).
    The limitations on an individual data set can be overcome, to some 
extent, by consideration of multiple sets of data and multiple 
databases. EPA thinks that, when considered collectively, the databases 
discussed in Unit V.B. are not

[[Page 79622]]

as vulnerable to criticism as a single data set. Generally, all of 
these databases include studies with high levels of quality control, 
and together they provide wide temporal and spatial coverage for a 
large number of pesticides. Thus, the Agency believes the databases in 
Unit V.B. would provide a reliable basis for drawing conclusions about 
the relative potential of different active ingredients to leach into 
ground water or run off into surface water in different parts of the 
country.
    In light of these considerations, EPA proposes to review the 
multiple databases to identify those active ingredients which appear 
relatively more frequently and/or in more geographical areas than other 
pesticides. Because the scope of monitoring varies from pesticide to 
pesticide, EPA would use a weight-of-the-evidence approach to assess 
the frequency and geographic distribution of pesticide residues in 
water.
    EPA's reliance on these databases would necessarily have some 
limitations. For example, most monitoring looks only for the ``parent'' 
compound, i.e., the pesticide active ingredient, rather than for 
environmental degradation products or compounds formed by chemical 
reactions during the treatment of raw water sources in a drinking water 
facility. Further, like food residue monitoring programs, monitoring 
efforts rely on multi-residue methods that may not detect certain 
compounds or classes or compounds. Notwithstanding these limitations, 
EPA believes that the approach described is a practicable approach for 
identifying pesticide active ingredients generally expected to be among 
those having either widespread or high levels of human exposure.

C. The Residential Use Pathway

    Human exposure to pesticides may occur as the result of use of 
pesticidal products in and around homes, schools, businesses, public 
areas, golf courses, and similar sites. Such use patterns, collectively 
referred to as ``residential use,'' include: Lawn and garden 
treatments, insect repellants, termite, and other indoor insect 
control, fumigation products, products applied to pets for flea or tick 
control, household sanitizers and disinfectants, and many more.
    EPA proposes to use pesticide product labeling information as the 
primary indicator of pesticides whose use involves potential human 
exposure by this pathway. EPA would review its databases and identify 
those active ingredients approved for residential use. Aside from 
products approved only for limited exposure uses, such as rodenticides 
applied in tamper resistant bait boxes, all currently registered 
residential use pesticides would be identified as having higher 
priority with respect to the residential use pathway.
    The Agency recognizes that registration of a pesticide for 
residential use does not necessarily mean that it would be widely used 
or that its use would entail significant levels of human exposure. EPA, 
however, generally lacks information to compare the extent of 
application of different active ingredients for residential uses. 
Moreover, EPA does not have a basis for distinguishing among various 
residential use patterns on the basis of which consistently have 
potential for higher levels of human exposure. Thus, EPA does not 
regard its proposed basis for selecting priority chemicals for this 
pathway as being as effective in setting priorities among active 
ingredients as the criteria proposed for the other pathways. 
Nonetheless, residential use pesticides involve potential exposures to 
the general population, the Agency believes it would be appropriate to 
consider giving priority to some of these products.

D. Occupational Exposure Pathways

    Occupational exposure can occur either as a person mixes, loads, or 
applies a pesticide product (i.e., during pesticide use), or as a 
person, during some other occupational activity, comes in direct, 
repeated contact with pesticide residues present on previously treated 
surfaces (i.e., post-application exposure). Although numerically 
smaller than the populations exposed to pesticides through food, 
drinking water, and residential use, individuals receiving occupational 
exposures generally experience significantly higher levels of exposure 
than the larger groups encounter by the other pathways. Based on 
available data and current agricultural practices, the number of 
workers exposed through post-application is greater than the number of 
workers exposed through mixing, loading, and applying pesticides. As a 
result, EPA proposes to focus on post-application exposures.
    Many factors affect the post-application exposure of agricultural 
workers, most notably the type of work activity and the level of 
residue present on pesticide-treated surfaces. As will be discussed in 
more detail in Unit V.D., different activities involve differing levels 
of contact with pesticide-treated surfaces and therefore can lead to 
different levels of exposure. Exposure levels also depend on the amount 
of residue available on a treated surface. This, in turn, depends on 
the amount of pesticide initially applied, how quickly the material 
degrades or is taken up by the plant, and how soon after application 
the worker contacts the treated surface. Pesticides show a large range 
of variation in application rates, application timing, and 
environmental fate characteristics with the result that there are 
significant differences in the levels of dislodgeable residues on 
treated surfaces encountered by workers.
    In identifying active ingredients for priority consideration by 
this pathway, EPA proposes to rank pesticides on the basis of their 
potential for post-application exposure of agricultural workers. This 
group includes farmers and farmworkers who reenter pesticide-treated 
fields and orchards to care for or harvest the crop. A relatively 
recent database developed by the Agricultural Reentry Task Force (ARTF) 
clearly indicates that certain work activities in particular crops lead 
to higher levels of exposure than other post-application work 
activities (Ref. 9). For example, harvesting fruit in orchards or 
pruning vines in a grape vineyard requires extensive contact with plant 
foliage that is likely to contain pesticide residues. When the worker 
touches the foliage, a certain amount of the residue transfers to the 
worker's skin or clothing. The greater the contact is, the higher the 
residue transferred and the higher the ensuing exposure.
    EPA will review the ARTF's transfer coefficient studies to identify 
those work activities and crops which have the highest potential for 
post-application exposure. The ARTF is a consortium of pesticide 
companies that formed a joint venture to develop data for use in EPA 
assessments of worker risk. The ARTF conducted a series of carefully 
controlled studies that measured the amount of pesticide residue 
present on workers' clothing after a specific period of time working in 
a crop with known amounts of pesticide residue on the crop foliage. The 
ARTF set of data is very extensive, covering over 100 different crops 
--essentially all crops, including greenhouses and ornamental crops, in 
which workers might come into contact with pesticide-treated leaf 
surfaces. The studies permit the calculation of a standardized 
``transfer coefficient'' for the crop and activity.\2\ Activities 
having

[[Page 79623]]

higher transfer coefficients should result in higher levels of worker 
exposure, all other factors being equal.
    EPA proposes to identify the crops having approximately the dozen 
highest transfer coefficients and then to identify the pesticides 
having the highest levels of use on those crops. Specifically, EPA 
would estimate the total number of acre treatments for each pesticide 
on all of the top crops and then rank the pesticides on the basis of 
the highest totals.\3\ The Agency would obtain information about the 
number of acre-treatments for each pesticide from a variety of public 
and private data sources including USDA's National Agriculture 
Statistics Service, California's Department of Pesticide Regulation, 
and Doane Marketing Research.
    The USDA's National Agricultural Statistics Service (NASS) has, for 
more than 10 years, conducted annual surveys of pesticide use in a 
large number of crops, surveying thousands of agricultural producers in 
any given year. NASS conducts their use survey every year for a set of 
row crops. NASS also surveys pesticide usage on other crops, 
alternating every year between a group of fruit and nut crops and a 
group of vegetable crops (i.e., selected fruits/nuts were surveyed in 
1997, 1999, 2001; selected vegetables were surveyed in 1996, 1998, and 
2000). NASS surveys states representing a majority of national 
production for a crop and reports a number of statistics for 
insecticide, fungicide, and herbicide use including: percent crop 
treated, application rate, numbers of applications, acreage grown. 
Using these data, EPA can estimate the total acre-treatments for the 
pesticides used on crops with the highest transfer coefficients. More 
information on NASS pesticide use data can be found at: http://www.pestmanagement.info/nass/.
    The State of California has reported annually on all agricultural 
pesticide usage in the State for almost 10 years. This data collection 
effort is managed by the California Department of Pesticide Regulation 
(CDPR), and includes an extensive array of treatment information on 
crops including timing, location, area, and rate. These data allow EPA 
to calculate acre-treatments for pesticides on crops grown in 
California. In cases where crops with high transfer coefficients are 
grown in California, but not reported by NASS, CDPR data would be 
extremely useful. For those crops reported by both CDPR and NASS, data 
from both sources would serve to validate estimates. More information 
on CDPR pesticide usage data can be found at:http://www.cdpr.ca.gov/docs/pur/purmain.htm.
    EPA's third major source of pesticide use information is 
AgroTrak\TM\, a product of Doane Marketing Research, Inc. (referred to 
here simply as Doane). Doane maintains a proprietary national database 
of agricultural pesticide use summarizing data from surveys of 
thousands of agricultural producers across a wide range of row and 
specialty crops. Doane has conducted an annual survey for more than 15 
years, and among the statistics they publish for a given crop/chemical 
combination are acres grown, acres treated, and acre-treatments. These 
data represent an important source of data, and can be compared to NASS 
and CDPR data to fill data gaps, or serve as another point of 
validation. Doane's survey can be particularly useful because their 
national survey covers fruits and vegetables producers every year. More 
information on Doane Marketing Research can be found at: http://www.doanemr.com/.
    Basing its priorities for this pathway on the number of acre-
treatments of crops with worker activities having high transfer 
coefficients should identify pesticides that have potential for 
relatively higher worker exposure. The combined criteria of crops with 
high transfer coefficients and pesticides used on such crops should 
identify those active ingredients with potential for high worker 
exposures. The use of the additional criterion of total acre-treatments 
should identify pesticides with the widest use, and thus the potential 
for exposures for the largest number of workers.
    The proposed criteria, however, would not account for any of the 
characteristics specific to the use of a particular pesticide on a crop 
that could decrease or increase the potential for exposure--application 
rate, application timing, and environmental fate characteristics. 
Consequently, the priority listing may not completely reflect where the 
highest post-application exposures exist.
    Nevertheless, EPA believes that the approach described is a 
practicable approach for identifying those pesticide active ingredients 
with the potential for either widespread or high levels of exposure to 
post-application workers.

E. Integration of Pathway Priorities for Pesticide Active Ingredients

    This unit addresses how EPA would integrate the information 
developed on priorities through the analysis of the four exposure 
pathways discussed in Units V.A. through V.D. As its first step, the 
Agency would apply the criteria proposed for each pathway to produce 
four lists of candidate chemicals for potential screening in the 
endocrine disruptor Tier 1 battery. EPA expects that a number of 
pesticide active ingredients would be identified for more than one 
pathway, and that some chemicals will appear only on the list for a 
single pathway. In choosing which active ingredients it would recommend 
for screening, EPA would give higher priority to chemicals that 
appeared on multiple lists, with the substances appearing on four lists 
receiving the highest priority, followed by the group of chemicals 
appearing on three lists, followed by chemicals on only two lists. To 
the extent necessary to establish priorities within these four groups, 
EPA would propose to give greater priority to chemicals which appear on 
the list for the food pathway (which generally involves the most 
widespread exposure of the four pathways), followed by the list for the 
occupational pathway (which generally involves the highest per capita 
levels of exposure of the different pathways). As a final step, EPA 
would review the available effects information to identify any chemical 
for which the information clearly indicates an endocrine-mediated 
effect/perturbation. Such chemicals would be considered for proposed 
Tier 2 tests, mechanistic or special studies, or hazard assessment. 
During this step, EPA also would identify substances that EPA 
anticipates would have low potential to cause endocrine disruption. EPA 
would consider excluding substances in either category from the first 
group of chemicals to undergo Tier 1 testing.
---------------------------------------------------------------------------

    \1\ ``Raw'' water refers to a water source that has not been 
treated in a drinking water facility. Water that has been treated is 
referred to as ``finished'' water.
    \2\ The transfer coefficient is calculated by dividing the 
amount of residue found on workers, expressed as milligrams (mg), by 
the amount of dislodgeable residue found on the crop foliage, 
expressed as mg per square centimeter (cm2), and dividing this value 
by the length of time spent in the activity, expressed in hours 
(hr). The resulting coefficient for each activity is expressed as 
cm\2\/hr and quantitatively reflects the extent to which the 
activity involves contact with pesticide-treated surfaces in a 
manner that dislodges the residues present on the surface.
    \3\ Acre-treatments are measured as the number of times an acre 
of crop may have been treated with a pesticide. For example, if two 
acres were each treated one time in a season, that would represent 
two acre-treatments. If a single acre were treated two times in a 
season, that would also represent two acre-treatments.
---------------------------------------------------------------------------

VI. Approach for Selecting Pesticide HPV/Pesticide Inert Chemicals

    EPA is proposing to use several sets of criteria for identifying 
HPV/Inert chemicals that should be given priority for screening in the 
Tier 1 battery. In general, the Agency is proposing an approach for 
HPV/Inert chemicals that is similar to that proposed for pesticide 
active ingredients. EPA will focus on several indicators of the 
potential for human exposure including production volume, specific 
pathways of exposure, and presence in human tissues. While EPA's 
general focus is on HPV/Inert chemicals with relatively greater 
potential human exposure, this focus

[[Page 79624]]

does not necessarily mean that the list of chemicals produced will 
contain no substances which have potentially high levels of 
environmental exposure to ecological receptors. Many of the HPV/Inert 
chemicals having greater potential for human exposure will also have 
greater potential for exposure to wildlife. For example, the databases 
to be reviewed for ecological biological monitoring data will directly 
identify certain chemicals to which aquatic organisms have been exposed 
(see Unit VI.B.). Similarly, several of the monitoring databases that 
will be reviewed for the drinking water pathway contain monitoring data 
collected on raw surface water, i.e., before the water enters a 
Community Water System (see Unit VI.C.). Thus, these surface water 
monitoring data will show the levels of chemical to which fish, 
amphibians, and other aquatic species are exposed. Accordingly, EPA 
believes that the approach proposed to evaluate pesticide HPV/Inert 
chemicals, while focused on human exposure, will also capture HPV/Inert 
chemicals with widespread environmental exposures.
    EPA generally has more extensive information of known quality 
available to assess potential exposure to pesticide active ingredients 
via food, water, occupational and residential exposure pathways than is 
available to assess exposure to HPV/Inert chemicals. In addition, EPA 
generally has more extensive information available on usage (including 
both agricultural and residential) of active ingredients than is 
available for HPV/Inert chemicals (including both pesticidal and non-
pesticidal uses of inerts). For these reasons, the databases available 
to evaluate potential human exposure of the two classes also differ.
    First, EPA will review existing databases to identify chemicals 
that are both pesticide inerts and HPV chemicals (HPV/Inert). HPV 
chemicals are those chemicals manufactured or imported into the United 
States in amounts equal to or greater than one million pounds per year. 
The HPV chemicals are identified through information collected under 
the TSCA Inventory Update Rule (IUR). Organic chemicals that are 
manufactured or imported into the United States in amounts equal to or 
greater than 10,000 pounds per year are subject to reporting under TSCA 
IUR every 4 years. Second, EPA will review existing data bases to 
identify HPV/Inert chemicals that are present in human tissue, or 
ecological tissues that have human food uses, or drinking water or 
indoor air. Third, EPA will prioritize these chemicals based on the 
number of data bases in which that the chemical was found. Thus, HPV/
Inert chemicals appearing in four types of monitoring data would be 
given higher priority than those appearing in only one type of 
monitoring data. EPA may also give higher priority to those HPV/Inert 
chemicals that appear in human tissues than to those chemicals that 
only appear in water, air, or ecological tissues.
    As a final step, EPA would review the available effects information 
to identify any chemical for which the information clearly indicates an 
endocrine-mediated effect/perturbation. Such chemicals would be 
considered for proposed Tier 2 tests, mechanistic or special studies, 
or hazard assessment. During this step, EPA also would identify 
substances that EPA anticipates would have low potential to cause 
endocrine disruption (e.g., certain FIFRA List 4 inerts, most polymers 
with number average molecular weight greater than 1,000 daltons, strong 
mineral acids, and strong mineral bases). EPA would consider excluding 
substances in either category from the first group of chemicals to 
undergo Tier 1 testing.

A. HPV/Inert Chemicals in Human Biological Monitoring Data

    EPA proposes to review the following data sources to determine 
which HPV/Inert chemicals have been detected in human biological 
samples.
    1. Third National Health and Nutrition Examination Survey (NHANES 
III). The Third National Health and Nutrition Examination Survey 
(NHANES III) was conducted between 1988 and 1994 on 33,994 people. The 
survey was designed to obtain nationally representative information on 
the health and nutritional status of the U.S. population through 
interviews and direct physical examinations. Several studies (e.g., 
high blood pressure, immunization status, nutritional blood measures, 
etc.) were conducted under NHANES III. One study relevant to this 
priority setting exercise is Ashley et al (1994) (Ref. 10). This NHANES 
volatile organic compound (VOC) article contains relevant human 
biomonitoring data for over 40 chemicals. Standard quality assurance/
quality control (QA/QC) procedures such as sample duplicates and blanks 
were used in the NHANES III study. The study participants in the 
special study are not statistically representative of the U.S. 
population.
    2. National Report on Human Exposure to Environmental Chemicals. 
The National Report on Human Exposure (Ref. 11) is a Centers for 
Disease Control and Prevention (CDC) report that provides exposure 
information about people participating in an ongoing national survey of 
the general U.S. population--the NHANES. This report provides 
information on concentrations of 27 environmental chemicals measured in 
blood and/or urine in the U.S. population. These chemicals include 
metals; organophosphate pesticide metabolites; phthalate metabolites 
and cotinine, a marker of exposure to tobacco smoke. This report will 
be updated with additional biomonitoring data for these same or 
different chemicals on an annual basis. It is anticipated that a second 
report will be issued in late 2002 with human biomonitoring information 
on an additional 75 chemicals.
    3. National Human Adipose Tissue Survey (NHATS). The EPA's OPPT 
operated the National Human Monitoring Program (NHMP) until the early 
1990s. The NHMP's primary activity was conducting NHATS, which analyzed 
human adipose tissue specimens to monitor human exposure to potentially 
toxic chemicals. A nationwide network of pathologists and medical 
examiners from 47 standard metropolitan statistical areas (SMSAs) 
collected tissue specimens from cadavers and surgical patients that 
were then analyzed for certain chemicals. Throughout the 1970s and 
early 1980s, the chemical residues of primary interest were 
organochlorine pesticides and polychlorinated biphenyls (PCBs). In 
1982, VOCs and semivolatile organic compounds (SVOCs) were included in 
the survey. NHATS contains relevant human biomonitoring data for over 
150 chemicals. Quality control samples, such as method and equipment 
blank samples, control samples, and spike samples, were collected to 
evaluate the quality of sampling data. Data are available for years 
1970 through 1987; however, a standard set of summarized data 
parameters are not available. (Refs. 12-25).
    4. Total Exposure Assessment Methodology Study (TEAM Study). The 
TEAM Study was designed to develop methods to measure individual total 
exposure (exposure through air, food, and water) and resulting body 
burden of toxic and carcinogenic chemicals, and to apply these methods 
within a probability-based sampling framework to estimate the exposures 
and body burdens of urban populations in several U.S. cities. The TEAM 
Study reports the results of eight monitoring studies performed in five 
communities during different seasons of the year. Breath, personal air, 
outdoor air, and water samples were collected for 30 VOCs. (Refs. 26-
28).
    Established methods were used to collect and analyze TEAM Study 
data.

[[Page 79625]]

 Quality control and quality assurance samples collected and analyzed 
include reagent blanks, field blanks, duplicate samples, and spiked 
samples. Data were reported for water using units of measure different 
than those used for air and breath samples. Environmental and 
biological data are generally lognormally distributed; thus, the data's 
central tendency is generally best represented using a geometric mean. 
Geometric means are provided for all compounds that were measured in 
50% or more of the samples. For most of the compounds that were 
measured in less than 50% of the samples, a minimum quantifiable limit 
that can be used for ranking the data was provided.

B. HPV/Inert Chemicals in Ecological Biological Monitoring Data 
Relevant to Human Exposure

    EPA proposes to review the following data sources to determine 
which HPV/Inert chemicals have been detected in non-human tissues 
potentially relevant to human ingestion exposure.
    1. National Sediment Inventory Fish Tissue Data (NSI Fish Tissue 
Data). This database is described in Unit V.B.
    2. National Fish Tissue Study. EPA is conducting a screening-level 
study to estimate the national distribution of selected persistent, 
bioaccumulative and toxic chemical residues in fish tissue from lakes 
and reservoirs of the continental United States. This 4-year study will 
define the national background levels for 265 chemicals in fish, 
establish a baseline to track the progress of pollution control 
activities, and identify areas where contaminant levels are high enough 
to warrant further investigation. The national fish tissue survey is 
the first survey of fish tissue to be based on a random sampling 
design. This sampling design will allow EPA to develop national 
estimates of the mean levels of persistent, bioaccumulative, and toxic 
chemicals in fish tissue. It will also provide data on the largest set 
of persistent, bioaccumulative, and toxic chemicals ever studied in 
fish. More details can be found at: http://www.epa.gov/waterscience/fishstudy/results.htm.

C. HPV/Inert Chemicals in Drinking Water Monitoring Data

    EPA proposes to review the following data sources to determine 
which HPV/Inert chemicals have been detected in drinking water and in 
potential sources of drinking water.
    1. National Drinking Water Chemical Occurrence Data Base (NCOD Data 
Base). This database is described in Unit V.B.
    2. National Human Exposure Assessment Survey (NHEXAS). EPA designed 
the NHEXAS program to address some of the limitations of single-
chemical and single-media exposure route studies. The purpose of NHEXAS 
is to evaluate comprehensive human exposure to multiple chemicals from 
multiple routes on both a community and regional scale, as well as its 
association with environmental concentrations and personal activities. 
EPA completed Phase 1 field sample collection and laboratory analyses 
of NHEXAS in 1998. EPA used established methods to collect and analyze 
NHEXAS data. Quality control and quality assurance samples collected 
and analyzed include reagent blanks, field blanks, duplicate samples, 
and spiked samples. Samples were split and analyzed in multiple 
laboratories; when appropriate audit samples were available, they were 
also analyzed. Data are reported for different media using different 
units of measure and different measures of central tendency. For 
example, arsenic concentrations are reported in micrograms per kilogram 
([mu]g/Kg) for beverages and food and in micrograms per liter ([mu]g/L) 
for water. Sometimes the central tendency value is reported as an 
arithmetic mean, sometimes as a median, and sometimes as a 90\th\ 
percentile. (Refs. 29-32).
    3. Total Exposure Assessment Methodology Water Data (TEAM Water 
Data). The TEAM Study is described in Unit VI.A.
    4. National Stream Quality Accounting Network (NASQAN) Data. This 
database, which contains information on surface water monitoring 
studies, is described in Unit V.B.
    5. The National Water Quality Assessment Program (NAWQA). This 
database, which contains information on surface water and ground water 
monitoring studies, is described in Unit V.B.

D. HPV/Inert Chemicals in Indoor Air Monitoring Data

    EPA proposes to review the following data sources to determine 
which HPV/Inert chemicals have been detected in residential indoor air.
    1. Office of Research and Development Published Literature. The 
following eight EPA/ORD-authored journal articles and reports provide 
indoor air monitoring data: Brown et al. (1994), Daisey et al. (1994), 
Kelly et al. (1994), Immerman and Schaum. (1990), Samfield (1992), Shah 
et al. (1988), Sheldon et al. (1992), and Shields et al. (1996). (Refs. 
33-40).
    2. NHEXAS. The NHEXAS program was designed to evaluate 
comprehensive human exposure via indoor and outdoor air to multiple 
chemicals on a community and regional scale. Samples were collected of 
both the indoor and outdoor air that people breathe. Preliminary 
results of Phase I of NHEXAS were reported in 15 journal articles 
published in 1999. Four of these 15 journal articles provided 
information that is applicable to indoor air monitoring. (Refs. 30-32, 
41).
    3. Total Exposure Assessment Methodology (TEAM). The TEAM Study is 
described in Unit VI.A.

E. Integration of Pathway Priorities for HPV/Inert Chemicals

    This unit addresses how EPA would integrate the information 
developed on priorities through the analysis of the four types of 
exposure monitoring data discussed in Units VI.A through VI.D (human 
biological data, ecological biological data relevant to human exposure, 
drinking water data, and indoor air data). As its first step, the 
Agency would produce four lists of candidate chemicals, one for each 
type of monitoring data, for potential screening in the endocrine 
disruptor Tier 1 battery. EPA expects that a number of chemicals will 
be identified in more than one type of monitoring data and that some 
chemicals will appear only in a single type of monitoring data. In 
choosing which HPV/Inert chemicals it would recommend for screening, 
EPA would give higher priority to chemicals that appeared in multiple 
types of monitoring data, with the HPV/Inerts appearing in four types 
receiving the highest priority, three types the next highest priority, 
etc. To the extent it becomes necessary to establish priorities within 
these four types of monitoring data, EPA would propose to give greater 
priority to HPV/Inerts which appear in human biological monitoring data 
followed by drinking water/indoor air monitoring data (weighted 
equally), followed by ecological biological monitoring data relevant to 
human exposure. As a final step, EPA would review the available effects 
information to identify any chemical for which the information clearly 
indicates an endocrine-mediated effect/perturbation. Such chemicals 
would be considered for proposed Tier 2 tests, mechanistic or special 
studies, or hazard assessment. During this step, EPA also would 
identify substances that EPA anticipates would have low potential to 
cause endocrine disruption (e.g., certain FIFRA List 4 inerts, most 
polymers with number average molecular weight greater than 1,000 
daltons, strong mineral acids, and strong mineral

[[Page 79626]]

bases). EPA would consider excluding substances in either category from 
the first group of chemicals to undergo Tier 1 testing.

VII. Issues for Comment

    In developing this proposed approach for selecting the first group 
of chemicals to be screened in the Agency's EDSP, EPA discussed a 
number of alternative approaches and identified a series of questions 
to elicit information from the public that would help in the evaluation 
of alternative approaches. In addition to the specific questions in 
this unit, EPA invites comment on additional alternative approaches.

A. Overall Approach for Selecting the Initial Set of Chemicals to 
Undergo Tier 1 Screening

    1. Focusing on the subset of chemicals subject to a statutory 
mandate for screening. EPA is intending to focus only on pesticide 
active ingredients and HPV chemicals with some pesticidal inert uses 
(i.e., the chemicals that are specifically mandated for testing under 
section 408(p) of FFDCA) as candidates for the first group of chemicals 
to be screened. The pesticide inerts to be considered are those with 
relatively large overall production volumes considering both pesticide 
and non-pesticide uses. This approach will allow EPA to focus its 
initial endocrine screening efforts on a smaller and more manageable 
universe of chemicals that emphasizes early attention to the pesticide 
chemicals that Congress specifically mandated EPA to test for possible 
endocrine effects. Please comment on this proposed decision.
    2. Limited use of effects information. Because the amount and type 
of toxicological data available to identify or characterize endocrine-
related human health or ecological effects is not considered by the 
Agency to be adequate to support determinations of the endocrine 
disruption potential of most pesticide chemicals, EPA has proposed an 
approach that would use effects information only to exclude certain 
chemicals from the first group of chemicals to undergo Tier 1 
screening. The approach would exclude from the first group of chemicals 
to undergo Tier 1 screening any chemical for which the available 
effects information is determined by EPA to clearly shows an endocrine-
mediated effect. Such chemicals would be considered for proposed Tier 2 
tests, mechanistic or special studies, or hazard assessment. Similarly, 
the approach for this initial list also would exclude substances that 
EPA anticipates have low potential to cause endocrine disruption (e.g., 
certain FIFRA List 4 inerts, most polymers with number average 
molecular weight greater than 1,000 daltons, strong mineral acids, and 
strong mineral bases). Please comment on this proposed decision and 
comment on the types of studies/data which could be evaluated by the 
Agency to aid in making exclusion decisions.
    3. Focus on human exposure; no separate criteria pertaining to 
exposure of ecological receptors. While EPA's general focus in this 
approach is on pesticide active ingredients and HPV/Inerts with 
relatively greater potential for human exposure, this focus does not 
necessarily mean that the list developed using this approach will not 
contain substances which have potentially high levels of environmental 
exposure to ecological receptors. EPA believes that the proposed 
approach, while focused on human exposure, will also identify many 
chemicals with widespread environmental exposures to other organisms. 
If EPA should consider such exposures separately, please identify 
databases and criteria appropriate for setting priorities.
    4. Deferring consideration of nominations from the public. For the 
initial Tier 1 screening list, EPA proposes to focus on pesticide 
active ingredients and HPV chemicals with some pesticidal inert uses. 
EPA believes that nominations from the public are important because 
they provide a mechanism to identify chemicals which may result in high 
exposures in local communities but which would not otherwise receive 
national attention. However, EPA has decided to defer consideration of 
nominations from the public until subsequent testing lists are proposed 
by EPA to keep this initial effort administratively simpler and ensure 
that a set of test results can be obtained in a relatively prompt 
timeline to aid the Agency in a mid-course evaluation of the EDSP Tier 
1 screening battery. Please comment on this proposed decision.
    5. Defer testing of mixtures. EPA believes that experience with the 
Tier 1 tests on a variety of single chemicals needs to be attained 
before the tests are used with mixtures. Therefore, EPA is proposing to 
defer consideration of testing of mixtures until subsequent testing 
lists are proposed by EPA. This judgement is consistent with advice 
from the SAB/SAP Subcommittee. Please comment on this proposed 
decision.
    6. Excluding chemicals that are no longer produced or used in the 
United States. EPA also is proposing to exclude from the initial Tier 1 
screening list any chemicals that are no longer produced or used in the 
United States. The Agency thinks that the added administrative 
complexity of determining who should be responsible for testing such 
chemicals could unnecessarily delay EPA's selection of an initial list 
for Tier 1 screening. Please comment on this proposed decision.
    7. Number of chemicals to be selected for the initial testing list. 
The SAB/SAP Joint Subcommittee which reviewed EPA's proposed EDSP in 
1999 felt that developing massive amounts of screening data on a large 
universe of chemicals would not necessarily expedite the development of 
the appropriate underpinning that the Agency needs to broaden this 
effort. The Subcommittee also expressed concern that it did not see a 
provision that would allow for mid-course correction or optimization of 
the Program. Thus, the Subcommittee recommended that EPA should 
initiate the Tier 1 testing program with a set of 50 to 100 chemicals 
and then convene an external panel of independent scientists to review 
the screening data for the purpose of evaluating whether the Tier 1 
screening program could be improved or optimized, and if so, how. EPA 
is proposing to adopt this SAB/SAP recommendation. Please comment on 
this proposed decision.
    8. Integration of lists generated by the pesticide active 
ingredient approach and the pesticide inert approach. As discussed in 
Unit IV, EPA is proposing to use similar but somewhat different sets of 
criteria for identifying pesticide active ingredients and inerts that 
should be given priority for screening in the Tier 1 battery. EPA 
generally has more extensive information of known quality available to 
assess usage and potential exposure to pesticide active ingredients 
than is available to assess exposure to HPV/Inert chemicals. Thus, the 
databases available to evaluate potential human exposure of the two 
classes also differ. EPA has not yet decided on the method to use to 
select the initial list of chemicals for screening from the separate 
lists that will be generated by the proposed approaches for pesticide 
active ingredients and HPV/Inert chemicals. Several alternative methods 
are being considered including the following. After looking at the 
separate lists, once they are generated, there may be natural break 
points. For example, if the top category for pesticide active 
ingredients (i.e., those chemicals which appear on lists for each of 
the four pathways) yields 60 actives and the top category for HPV/Inert 
chemicals (i.e., those chemicals which appear on lists for each of the 
three pathways and in human biomonitoring samples) yields

[[Page 79627]]

30, the Agency may select these 90 chemicals. Another approach being 
considered is a simple ratio approach. Because there are approximately 
an equal number of pesticide actives as HPV/Inerts, one way to produce 
a combined list would be to select approximately 50% of the chemicals 
from the active list and 50% from the HPV/Inert chemicals list. Please 
comment on these and other approaches that EPA could use to integrate 
the lists.

B. Approach for Selecting Pesticide Active Ingredients

    1. The Agency considered approaches that did not focus on the four 
separate pathways of human exposure. Please comment on the following 
issues.
    i. The advantages and disadvantages of setting priorities based on 
the overall extent of pesticide use, for example total pounds applied 
or total acres treated.
    ii. Should all four pathways be considered? If not, please comment 
on which pathways should and should not be included.
    2. Within separate pathways, EPA considered a variety of 
alternative approaches. Please comment on the following issues.
    i. Food pathway. Would ranking pesticides by the extent of use on 
the top 20 crops be appropriate, given that it would be simpler and 
more quantitative than the approach proposed in this Notice?
    ii. Water pathway. With regards to the proposed databases, should 
other databases be included, and should any be dropped?
    iii. Residential use pathway. Should any additional criteria be 
used to set priorities within the universe of active ingredients with 
residential uses? For example, should EPA give higher or lower priority 
to particular use patterns because they are consistently likely to lead 
to greater or lesser levels of human exposure? Are there databases that 
could provide information on the extent of residential use of 
pesticides that would support setting priorities within this group?
    iv. Occupational pathway. Are there criteria that would recognize 
how the differences in rate and timing of application of a pesticide or 
its environmental fate properties might affect levels of post-
application exposure? Also, please comment on whether EPA should employ 
criteria to set priorities for active ingredients based on their levels 
of exposure for mixers, loaders, and applicators. If EPA should 
consider such exposure in setting priorities for the occupational 
pathway, please identify databases and criteria appropriate for setting 
priorities. Also, please comment on whether EPA should consider 
criteria for the occupational pathway that employs data from reports on 
the incidence of adverse effects among workers, such as data collected 
by the California's Pesticide Illness Surveillance Program (PISP) (see, 
for example, the PISP report for 2000, http://www.cdpr.ca.gov/docs/dprdocs/pisp/2000pisp.htm) or the National Institute of Occupational 
Safety and Health's Sentinel Event Notification System for Occupational 
Risk (see http://www.cdc.gov/niosh/pestsurv/default.html).
    3. EPA's proposed approach to setting its overall priority for 
pesticide active ingredients that combines the analysis for each of the 
four pathways generally gives each pathway equal weight. Alternative 
approaches are also possible. Please comment on the following issues.
    i. Should a different approach be used to integrate the information 
from the four different pathways, for example by assigning different 
weights to the pathways?
    ii. Should there be any limit on the number of active ingredients 
included on the list for a single pathway?
    iii. Should any factors other than the pathway lists and the 
hazard-based considerations be included in the integrative step?
    iv. Should EPA attempt to explicitly consider magnitude of the 
environmental concentrations of chemicals in this approach and, if so, 
how?

C. Approach for Selecting Pesticide HPVolume/Pesticide Inert Chemicals

    1. EPA's proposed approach for setting screening priorities for 
pesticide inert ingredients that are also HPV chemicals uses four types 
of monitoring data. These are human biomonitoring data, ecological 
biomonitoring data relevant to human exposure, water monitoring data 
and indoor air monitoring data. Please comment on the following issues.
    i. Should the selection of priority HPV/Inert chemicals be based 
upon all four types of monitoring data? If not, please comment on which 
type of monitoring data should and should not be included.
    ii. Should other types of exposure information be used instead of 
or in addition to monitoring data?
    2. Within the four separate types of monitoring data, EPA 
identified and selected sources of monitoring data for use in priority 
setting for HPV/Inert chemicals. Please comment on the following 
issues.
    i. The appropriateness of the data sources identified in this 
proposed approach.
    ii. For human biological monitoring data, are there additional 
sources of data that EPA should consider?
    iii. For ecological biological monitoring data relevant to human 
exposure, are there additional sources of data that EPA should 
consider?
    iv. For water monitoring data, are there additional sources of data 
that EPA should consider?
    v. For indoor air monitoring data, are there additional sources of 
data that EPA should consider?
    3. EPA's proposed approach to setting its priorities for HPV/Inert 
chemicals combines the analysis for each of the four types of 
monitoring data and generally gives each type of monitoring data equal 
weight. However, if necessary to establish priorities within these four 
types of monitoring data, higher weight would be assigned to human 
biomonitoring data than to the other three types of monitoring data. 
Alternative approaches are also possible. Please comment on the 
following issues.
    i. Should a different approach be used to integrate the information 
from the four different types of monitoring data, for example by 
assigning different weights initially to all types of monitoring data?
    ii. Should there be any limit on the number of HPV/Inert chemicals 
included on the list for a single type of monitoring data?
    iii. Should any factors other than the lists of HPV/Inert chemicals 
found in the four types of monitoring data and the hazard-based 
considerations be included in the integrative step?

VIII. References

    The Agency's actions are supported by the references listed in this 
unit and cited in this notice. These references are available in the 
public record for this notice under docket ID number OPPT-2002-0066. 
(See Unit I.B. for information on how to access this docket).
    1. EPA, Science Advisory Board. Review of EPA's Proposed 
Environmental Endocrine Disruptor Screening Program. July 1999. EPA-
SAB-EC-99-013. Available at: http://www.epa.gov/science1/pdf/ec13.pdf.
    2. EPA. Endocrine Disruptor Screening and Testing Advisory 
Committee Final Report. August 1998. Available at: http://www.epa.gov/scipoly/oscpendo/history/finalrpt.htm.
    3. EPA. Evaluation of SAR Predictions of Estrogen Receptor Binding 
Affinity. EPA Contract No. 68-W-01-023, Work

[[Page 79628]]

Assignment No. 2-3, Battelle Memorial Institute. August 1, 2002.
    4. EPA. EPA Pesticides in Ground Water Database, A Compilation of 
Monitoring Studies: 1971-1991 National Summary, EPA 734-12-92-001. 
September 1992.
    5. USGS. Pesticides in Select Water Supply Reservoirs and Finished 
Drinking Water, 1999-2000: Summary of Results from a Pilot Monitoring 
Program. 2001. USGS Open File Report 01-456.
    6. EPA. The Incorporation of Water Treatment Effects on Pesticide 
Removal and Transformation in Food Quality Protection Act Drinking 
Water Assessments. November 21, 2001. Available at: http://www.epa.gov/pesticides/trac/science/#drinking.
    7. EPA. Estimating the Drinking Water Component of a Dietary 
Exposure Assessment. Revised November 2, 1999. Available at: http://www.epa.gov/pesticides/trac/science/#drinking.
    8. EPA. EPA Background Paper for the FIFRA Scientific Advisory 
Panel Meeting on Monitoring Strategies for Pesticides in Surface-
Derived Drinking Water. June 2002. Available at: http://www.epa.gov/scipoly/sap/2000/june/drinkingwatersurvey.pdf.
    9. EPA. Science Advisory Council on Exposure, Policy Number 003.1, 
Agricultural Transfer Coefficients.
    10. Ashley, David L.; Bonin, Michael A.; Cardinall, Frederick L.; 
McCraw, Joan M.; and Wootan, Joe V. Blood Concentrations of Volatile 
Organic Compounds (VOCs) in a Nonoccupationally Exposed U.S. Population 
and in Groups with Suspected Exposure. Clinical Chemistry (1994) 40: 
1401-1404.
    11. CDC. National Report on Human Exposure to Environmental 
Chemicals. March 2001. http://www.cdc.gov/nceh/dls/report/reportsummary.htm.
    12. EPA. Chlorinated Dioxins and Furans in the General U.S. 
Population: NHATS FY87 Results--Executive Summary. EPA-560/5-91-003. 
May 1991.
    13. Cramer, Paul H.; Stanley, John S.; Bauer, Karin; Ayling, Randy 
E.; Thornburg, Kelly R.; and Schwemberger, John. Brominated Dioxins and 
Furans in Human Adipose Tissue: Final Report. EPA-560/5-90-005 (NTIS 
PB91-103507). April 11, 1990.
    14. Cramer, Paul H.; Stanley, John S.; and Thornburg, Kelly R. Mass 
Spectral Confirmation of Chlorinated and Brominated Diphenylethers in 
Human Adipose Tissues: Final Report. EPA-560/5-90-012 (NTIS PB91-
159699). June 15, 1990.
    15. Mack, Gregory A. and Mohadjer, Leyla. Baseline Estimates and 
Time Trends for Beta-benzene hexachloride, Hexachlorobenzene, and 
Polychlorinated Biphenyls in Human Adipose Tissue 1970-1983. EPA-560/5-
85-025. September 30, 1985.
    16. Onstot, J.D.; Ayling, R.E.; and Stanley, J.S. Characterization 
of HRGC/MS Unidentified Peaks from the Analysis of Human Adipose 
Tissue: Volume I--Technical Approach. EPA-560/5-87-002A (NTIS PB88-
100367). May 1987.
    17. Onstot, J.D.; Ayling, R.E.; and Stanley, J.S. Characterization 
of HRGC/MS Unidentified Peaks from the Analysis of Human Adipose 
Tissue: Volume II --Appendices. EPA-560/5-87-002B (NTIS PB88-100375). 
May 1987.
    18. Onstot, J.D. and Stanley, J.S. Identification of SARA Compounds 
in Adipose Tissue. EPA-260/5-89-003 (NTIS PB90-132564). August 1989.
    19. Orban, John E.; Stanley, John S.; Schwemberger, John G.; and 
Remmers, Janet C. Dioxins and Dibenzofurans in Adipose Tissue of the 
General US Population and Selected Subpopulations. American Journal of 
Public Health. (1994) 84: 439-445.
    20. EPA. Semivolatile Organic Compounds in the General U.S. 
Population: NHATS FY86 Results--Volume I. EPA-747-R-94-001. July 1994.
    21. Stanley, John S. Broad Scan Analysis of the FY82 National Human 
Adipose Tissue Survey Specimens: Volume I--Executive Summary. EPA-560/
5-86-035 (NTIS PB87-177218). December 1986.
    22. Stanley, John S. Broad Scan Analysis of the FY82 National Human 
Adipose Tissue Survey Specimens: Volume II--Volatile Organic Compounds. 
EPA-560/5-86-036 (NTIS PB87-177226). December 1986.
    23. Stanley, John S. Broad Scan Analysis of Human Adipose Tissue: 
Volume III--Semivolatile Organic Compounds: Final Report. EPA-560/5-86-
037 (NTIS PB87-180519). December 1986.
    24. Stanley, John S. Broad Scan Analysis of Human Adipose Tissue: 
Volume IV-- Polychlorinated Dibenzo-p-Dioxins (PCDDs) and 
Polychlorinated Dibenzofurans (PCDFs): Final Report. EPA-560/5-86-038 
(NTIS PB87-177234). December 1986.
    25. Stanley, John S. and Stockton, Rodney A. Broad Scan Analysis of 
the FY82 National Human Adipose Tissue Survey Specimens: Volume V--
Trace Elements. EPA-560/5-86-039 (NTIS PB87-180527). December 1986.
    26. EPA. The Total Exposure Assessment Methodology (TEAM) Study: 
Elizabeth and Bayonne, New Jersey, Devils Lake, North Dakota, and 
Greensboro, North Carolina: Volume II. Part 2. EPA-600/6-87/002b (NTIS 
PB88-100078). June 1987.
    27. EPA. The Total Exposure Assessment Methodology (TEAM) Study: 
Selected Communities in Northern and Southern California: Volume III. 
EPA-600/6-87/002c (NTIS PB88-00086). June 1987.
    28. Wallace, Lance. Project Summary: The Total Exposure Assessment 
Methodology (TEAM) Study. EPA/600/S6-87/002. September 1987.
    29. Thomas, Kent W.; Pelizzari, Edo D.; and Berry, Maurice R. 
Population-based dietary intakes and tap water concentrations for 
selected elements in EPA Region V National Human Exposure Assessment 
Survey (NHEXAS). Journal of Exposure Analysis and Environmental 
Epidemiology. (1999) 9: 402-413.
    30. Clayton, C.A.; Pellizzari, E.D.; Whitmore, R.W.; Perritt, R.L.; 
and J.J. Quackenboss. National Human Exposure Assessment Survey 
(NHEXAS): distributions and associations of lead, arsenic and volatile 
organic compounds in EPA Region 5. Journal of Exposure Analysis and 
Environmental Epidemiology. (1999) 9: 381-392.
    31. O'Rourke, Mary Kay; Van de Water, Peter K.; Jin, Shan; Rogan, 
Seumas P.; Weiss, Aaron D.; Gordon, Sydney M.; Moschandreas, Demetrios 
M.; and Lebowitz, Michael D. Evaluations of primary metals from NHEXAS 
Arizona: distributions and preliminary exposures. Journal of Exposure 
Analysis and Environmental Epidemiology. (1999) 9: 435-445.
    32. Robertson, Gary L.; Lebowitz, Michael D.; O'Rourke, Mary Kay; 
Gordon, Sydney; and Moschandreas, Demetrios. The National Human 
Exposure Assessment Survey (NHEXAS) study in Arizona--introduction and 
preliminary results. Journal of Exposure Analysis and Environmental 
Epidemiology. (1999) 9: 427-434.
    33. Brown, S.K.; Sim, M.R.; Abramson, M.J.; and Gray, C.N. 
Concentrations of Volatile Organic Compounds in Indoor Air--A Review. 
Indoor Air. (1994) 4: 123-124.
    34. Daisey, J.M.; Hodgson, A.T.; Fisk, W.J.; Mendell, M.J.; and 
Brinke, J. Ten. Volatile Organic Compounds In Twelve California Office 
Buildings: Classes, Concentrations and Sources. Atmospheric 
Environment. (1994) 28: 3557-3562.
    35. Kelly, Thomas J.; Mukund, R.; Spicer, Chester W.; and Pollack, 
Albert J. Concentrations and Transformations of Hazardous Air 
Pollutants. Environmental Science and Technology. (1994) 28: 378A-387A.

[[Page 79629]]

    36. Immerman, Frederick W. and Schaum, John L. Final Report of the 
Nonoccupational Pesticide Exposure Study (NOPES). EPA/600/3-90/003 
(NTIS PB90-152224). January 1990.
    37. Samfield, Max M. Indoor Air Quality Data Base for Organic 
Compounds. EPA-600-R-92-025 (NTIS PB92-158468). February 1992.
    38. Shah, Jitendra J. and Singh, Hanwant B. Distribution of 
Volatile Organic Chemicals in Outdoor and Indoor Air. A National VOCs 
Data Base. Environmental Science and Technology. (1988) 22: 1381-1388.
    39. Sheldon, L.; Clayton, A.; Jones, B.; Keever, J.; Perritt, R.; 
Smith, D.; Whitaker, D.; and Whitmore, R. Indoor Pollutant 
Concentrations and Exposures: Final Report. California Air Resources 
Board, Contract A833-156. January 1992.
    40. Shields, Helen C.; Fleischer, Daniel M.; and Weschler, Charles 
J. Comparisons among VOCs Measured in Three Types of U.S. Commercial 
Buildings with Different Occupant Densities. Indoor Air. (1996) 6: 2-
17.
    41. Gordon, Sydney M.; Callahan, Patrick J.; Nishioka, Marcia G.; 
Brinkman, Marielle C.; O'Rourke, Mary Kay; Lebowitz, Michael D.; and 
Moschandreas, Demetrios J. Residential Environmental Measurements in 
the National Human Exposure Assessment Survey (NHEXAS) Pilot Study in 
Arizona: Preliminary Results for Pesticides and VOCs. Journal of 
Exposure Analysis and Environmental Epidemiology. (1999) 9: 546-470.

IX. Statutory and Executive Order Reviews

    This notice is not subject to review by the Office of Management 
and Budget (OMB) under Executive Order 12866, entitled Regulatory 
Planning and Review (58 FR 51735, October 4, 1993). Nevertheless, OMB 
participated in an interagency review of this notice and any comments 
or suggestions received during that review, have been addressed.
    Since this notice does not impose any requirements, and instead 
seeks comments and suggestions for the Agency to consider in developing 
its approach for selecting the first group of chemicals to be screened 
in the Agency's EDSP, the various other review requirements that apply 
when an agency imposes requirements do not apply to this notice. As a 
part of your comments on this document, however, you may include any 
comments or information that would facilitate the Agency's 
consideration of approaches for selecting the first group of chemicals 
to be screened in the Agency's EDSP, including but not limited to 
potential impacts on small entities covered by the Regulatory 
Flexibility Act (RFA) (5 U.S.C. 601 et seq.), the availability of 
voluntary consensus standards pursuant to section 12(d) of the National 
Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law 
104-113, section 12(d) (15 U.S.C. 272 note), and potential paperwork 
burden and costs, as well as any suggested methods for minimizing 
respondent burden, including through the use of automated collection 
techniques, related to the collection of this information as described 
by the Paperwork Reduction Act (PRA) (44 U.S.C. 3501 et seq.). The 
Agency will consider such comments during the development of the 
approach and will take appropriate steps to address any applicable 
requirements.

List of Subjects

    Environmental protection, Chemicals, Endocrine disruptors, 
Pesticides and pests.


    Dated: December 23, 2002.
Stephen L. Johnson,
Assistant Administrator for Prevention, Pesticides and Toxic 
Substances.

[FR Doc. 02-32853 Filed 12-24-02; 11:49 am]
BILLING CODE 6560-50-S