[Federal Register Volume 64, Number 24 (Friday, February 5, 1999)]
[Notices]
[Pages 5796-5799]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-2781]


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ENVIRONMENTAL PROTECTION AGENCY

[OPP-00542B; FRL-6060-7]


Pesticides; Science Policy Issues Related to the Food Quality 
Protection Act

AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of availability.

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SUMMARY: EPA is announcing the availability of the revised version of 
the pesticide science policy document originally entitled ``Guidance 
for Identifying Pesticide Chemicals That Have a Common Mechanism of 
Toxicity, for Use in Assessing the Cumulative Toxic Effects of 
Pesticides.'' This document was made available as a draft document on 
August 6, 1998, for public comment (63 FR 42031) (FRL-5797-7). The 
title of the document has been changed to ``Guidance for Identifying 
Pesticide Chemicals and Other Substances That Have a Common Mechanism 
of Toxicity.'' The revised guidance document describes the approach 
that EPA will use for identifying and categorizing pesticide chemicals 
and other substances that cause a common toxic effect by a common 
mechanism, for purposes of assessing the cumulative toxic effects of 
such substances. Interested parties may request a copy of the Agency's 
revised guidance document and responses to public comments as set forth 
in Unit I. of this document. This notice is the fifth in a series of 
science policy issues related to the Tolerance Reassessment Advisory 
Committee (TRAC).
FOR FURTHER INFORMATION CONTACT: For questions concerning the revised 
document ``Guidance for Identifying Pesticide Chemicals and Other 
Substances That Have a Common Mechanism of Toxicity,'' contact by mail: 
Dr. Stephen C. DeVito, Office of Pesticide Programs, Health Effects 
Division (7509C), Environmental Protection Agency, 401 M St., SW, 
Washington, DC 20460; telephone number: (703) 308-9584; fax number 
(703) 308-7157; e-mail: [email protected] .

SUPPLEMENTARY INFORMATION:

I. General Information

A. How Can I Get Additional Information or Copies of This Document or 
Other Documents?

    1. Electronically. You may obtain electronic copies of this 
document and the science policy paper at http://www.epa.gov/
pesticides/. On the Office of Pesticide Program Home Page select 
``TRAC'' and then look up the entry for this document. You can also go 
directly to the listings at the EPA Home page at the Federal Register 
-- Environmental Documents entry for this document under ``Laws and 
Regulations'' (http://www.epa.gov/fedrgstr/) to obtain this notice and 
the science policy paper.
    2. Fax on Demand. You may request to receive a faxed copy of this 
document, as well as supporting information, by using a faxphone to 
call (202) 401-0527 and selecting item 6055 for ``Guidance for 
Identifying Pesticide Chemicals and Other Substances That Have a Common 
Mechanism of Toxicity.'' You may also follow the automated menu.
    3. In person or by phone. If you have any questions or need 
additional information about this action, you may contact the 
appropriate technical person identified in the ``FOR FURTHER 
INFORMATION CONTACT'' section of this document. In addition, the 
official record for the science policy paper listed in the SUMMARY 
section of this document, including the public versions, has been 
established under the docket control number OPP-00542. A detailed 
summary of the comments and of the Agency's response to the comments is 
available in the same docket file. A public version of each record, 
including printed, paper versions of any electronic comments, which 
does not include any information claimed as Confidential Business 
Information (CBI), is available for inspection in Rm. 119, Crystal Mall 
#2, 1921 Jefferson Davis Highway, Arlington, VA, from 8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays. The Public 
Information and Records Integrity Branch telephone number is 703-305-
5805.

II. Background

    On August 3, 1996, the Food Quality Protection Act of 1996 (FQPA) 
was signed into law. Effective upon signature, the FQPA significantly 
amended the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) 
and the Federal Food, Drug, and Cosmetic Act (FFDCA). Among other 
changes, FQPA established a stringent health-based standard (``a 
reasonable certainty of no harm'') for pesticide residues in foods to 
assure protection from unacceptable pesticide exposure; provided 
heightened health protections for infants and children from pesticide 
risks; required expedited review of new, safer pesticides; created 
incentives for the development and maintenance of effective crop 
protection tools for farmers; required reassessment of existing 
tolerances over a 10-year period; and required periodic re-evaluation 
of pesticide registrations and tolerances to ensure that scientific 
data supporting pesticide registrations will remain up-to-date in the 
future.
    Subsequently, the Agency established the Food Safety Advisory 
Committee (FSAC) as a subcommittee of the National Advisory Council for 
Environmental Policy and Technology (NACEPT) to assist in soliciting 
input from stakeholders and to provide input to EPA on some of the 
broad policy choices facing the Agency and on strategic direction for 
the Office of Pesticide Programs. The Agency has used the interim 
approaches developed through discussions with FSAC to make regulatory 
decisions that met FQPA's standard, but that could be revisited if 
additional information became available or as the science evolved. As 
EPA's approach to implementing the scientific provisions of FQPA has 
evolved, the Agency has sought independent review and public 
participation, often through presentation of many of the science policy 
issues to the FIFRA Scientific Advisory Panel (SAP), a group of 
independent, outside experts who provide peer review and scientific 
advice to EPA's Office of Pesticide Programs (OPP).
    In addition, as directed by Vice President Albert Gore, EPA has 
been working with the U.S. Department of Agriculture (USDA) and another 
subcommittee of NACEPT, the Tolerance Reassessment Advisory Committee 
(TRAC), chaired by the EPA Deputy Administrator and the USDA Deputy 
Secretary, to address FQPA issues and implementation. TRAC

[[Page 5797]]

comprises more than 50 representatives of affected user, producer, 
consumer, public health, environmental, states and other interested 
groups. The TRAC has met five times as a full committee from May 27 
through September 16, 1998.
    The Agency has been working with the TRAC to ensure that its 
science policies, risk assessments of individual pesticides, and 
process for decision making are transparent and open to public 
participation. An important product of these consultations with TRAC is 
the development of a framework for addressing key science policy 
issues. The Agency decided that the FQPA implementation process would 
benefit from initiating notice and comment on the major science policy 
issues.
    The TRAC identified nine science policy issue areas they believe 
were key to implementation of FQPA and tolerance reassessment. The 
framework calls for EPA to provide one or more documents for comment on 
each of the nine issues by announcing their availability in the Federal 
Register. In addition to comments received in response to these Federal 
Register notices, EPA will consider comments received during the TRAC 
meetings. Each of these issues is evolving and in a different stage of 
refinement. Accordingly, as the issues are further refined by EPA in 
consultation with USDA and others, they may also be presented to the 
SAP.
    In accordance with the framework described in a separate notice 
published in the Federal Register of October 29, 1998 (63 FR 58038) 
(FRL-6041-5), EPA is issuing a series of draft documents concerning 
nine science policy issues identified by the TRAC related to the 
implementation of FQPA.

III. Summary of Revised Science Policy Guidance Document

    This Federal Register notice announces the availability of a 
revised version of the EPA pesticide science policy guidance document 
that has been retitled ``Guidance for Identifying Pesticide Chemicals 
and Other Substances That Have a Common Mechanism of Toxicity.'' The 
guidance document describes the approach that EPA will use for 
identifying and categorizing pesticide chemicals and other substances 
that cause a common toxic effect by a common mechanism, for purposes of 
assessing the cumulative toxic effects of such substances. 
Specifically, the guidance document describes:
    1. EPA's interpretation of common mechanism of toxicity with 
respect to making a determination of safety under FFDCA as amended by 
FQPA.
    2. The specific steps that need to be taken for identifying 
mechanisms of toxicity of pesticides and other substances that cause a 
common toxic effect.
    3. The types of data (and their sources) that are needed for doing 
so.
    4. How these data are to be used in reaching conclusions regarding 
commonality of mechanisms of toxicity.
    5. Criteria the Agency will use for categorizing pesticides and 
other substances for purposes of conducting cumulative risk 
assessments.
    The Agency plans to use this guidance as the initial step in its 
process to assess the possibility of cumulative toxicity to human 
health that may be caused by pesticides and other substances that are 
toxic from a common mechanism. The Agency is currently developing 
guidance for conducting cumulative risk assessments that it will use to 
characterize the potential for cumulative toxicity to human health that 
may result from exposure to pesticides and other substances that have a 
common mechanism of toxicity. That guidance will be made available for 
public comment in June, 1999.

IV. Summary of Agency's Response to Public Comments

    In the Federal Register of August 6, 1998 (63 FR 42031)(FRL-5797-
7), EPA announced the availability of a draft version of the document 
described in Unit III. of this document and solicited public comment. 
The original public comment period ended on September 6, 1998, but was 
extended to October 8, 1998, at 63 FR 47290, September 4, 1998 (FRL-
6028-7). The Agency received comments from 16 different organizations. 
The Agency would like to thank these organizations for critically 
reviewing the document, and for providing recommendations to improve 
the science policy described therein. All comments were considered by 
the Agency in revising the document. The comments and the Agency's 
responses to these comments are briefly summarized below.
    Many of the public comments were similar in content, and pertained 
to general issues dealing with grouping chemicals for purposes of 
cumulative risk assessment, or specific sections within the draft 
document. To facilitate review and consideration of the comments for 
purposes of revising the document, the Agency grouped the comments in 
accordance to nature of the comment, or issue or section of the 
document with which they addressed. Hence, comments were grouped as 
follows: Purpose and introduction of the guidance document; exposure 
issues; consideration of substances other than pesticides; definitions 
of terms; and assessing cumulative toxicity. Following is a brief 
summary of the more significant comments received in these areas, along 
with EPA's general responses. A more detailed summary of the comments 
and the Agency's response to the comments is available as described in 
Unit I. of this document.

A. Purpose and Introduction of the Guidance Document

    Several commentors appear to have misunderstood the purpose of the 
document. These commentors were of the impression that the primary 
purpose of the document is to describe the approach EPA will use to 
assess cumulative toxicity and risk from pesticides that have a common 
mechanism of toxicity. However, the purpose of the document, as stated 
in the draft version, is to describe the process that EPA will use for 
identifying pesticides and other substances that cause a common toxic 
effect by a common mechanism of toxicity.

B. Exposure Issues

    A number of commentors raised the issue of exposure. One commentor 
suggested that grouping of chemicals should be based only on causing a 
common toxic effect by a common mechanism, excluding exposure as a 
criterion for grouping. Other commentors suggested that EPA should do 
an exposure assessment first and use exposure as a basis for grouping. 
The Agency will not use exposure as a criterion for grouping chemicals 
that cause a common toxic effect by a common mechanism. Exposure will 
be considered, however, during the assessment and characterization of 
cumulative effects of pesticides that have a common mechanism of 
toxicity.
    Several commentors stated that there is a lack of detail or 
discussion on how the Agency plans to assess exposure when conducting 
cumulative risk assessments on chemicals that have been grouped by 
common mechanism of toxicity. Some commentors stated that the document 
needs to be expanded to include more detail on how the Agency will 
conduct cumulative risk assessments on pesticides that have a common 
mechanism of toxicity. Two commentors suggested that the guidance 
document should be revised to include examples on how the Agency will: 
Apply the common mechanism guidelines; assess cumulative toxicity; and 
conduct cumulative risk

[[Page 5798]]

assessments. The Agency's response to these comments is as follows. 
First, the Agency will make available in the near future specific 
examples of how it will apply its guidance for identifying pesticide 
chemicals that have a common mechanism of toxicity. Secondly, the 
primary purpose of the document is to describe the approach that EPA 
will use to identify pesticides that have a common mechanism of 
toxicity, and not how the Agency will assess exposure to such 
pesticides and the cumulative risks that they may pose. The Agency is 
currently preparing a document that will describe the approach it will 
use to conduct cumulative risk assessments. That document will provide 
details on exposure analyses.
    Some commentors stated that EPA should not restrict cumulative risk 
assessments to only those pesticides within a common mechanism group 
for which there is concomitant (i.e., simultaneous) exposure (as stated 
in the draft version), whereas other commentors stated that the Agency 
should restrict cumulative risk assessments to only those pesticides 
within a group for which there is concomitant exposure. The Agency 
agrees that cumulative toxicity may result from exposures that are not 
concomitant, and cumulative risk assessments performed by the Agency on 
pesticides within a common mechanism group should not be restricted to 
only those for which there is concomitant exposure. In addition to 
concomitant exposure, the Agency will also consider other factors that 
may affect the potential for two or more chemicals that cause a common 
toxic effect by a common mechanism to cause cumulative toxicity.

C. Consideration of Substances Other than Pesticides

    One commentor suggested that the guidance document needs to be 
expanded to include guidance on how the Agency will conduct cumulative 
risk assessments on pesticides that are not toxic via a common 
mechanism of toxicity. The Agency did not include such guidance because 
it is beyond the scope of the document. Some commentors pointed out 
that the focus of the guidance document is only on identifying 
pesticides that have a common mechanism of toxicity, and not on 
identifying other (i.e., non-pesticide) substances that have a 
mechanism of toxicity common with that of a given pesticide or 
pesticides. The Agency agrees that the focus of the draft document is 
on identifying and grouping pesticide substances that have a common 
mechanism of toxicity. Although the Agency intends to use the approach 
described in the document to identify pesticide substances and other 
substances that cause a common toxic effect by a common mechanism, this 
intent was not made clear in the draft version. The Agency has changed 
the title of the document and has made other editorial changes 
throughout the document that broaden its scope to include substances 
not used as pesticides. The Agency wishes to make clear that it will 
include other substances that are toxic from a mechanism common with 
that of a given pesticide or pesticides in a cumulative risk 
assessment.

D. Definitions of Terms

    A number of commentors questioned the Agency's definitions of 
certain terms used in the document, and had opposing opinions on how 
these terms should be defined. For example, several commentors 
questioned the Agency's definitions of ``mechanism of toxicity'' and 
``common mechanism of toxicity.'' Some commentors believe that the 
Agency's definitions for these terms are either too broad, unclear, or 
need to be made more simple and rigorous. Other commentors believe that 
the Agency's definitions are too narrow. Another commentor believes 
that the Agency's definition is clear and appropriate. The Agency 
reviewed its definitions of the terms listed in Section II 
(``Definitions of Specific Terms...'' ) of the document, and believes 
that its definitions of the terms ``mechanism of toxicity'' and 
``common mechanism of toxicity'' are clear and consistent with the 
intent of FQPA. However, the Agency has included additional discussion 
in the revised version in Section III that adds further clarification 
to these terms. One commentor disagreed with the Agency's definition of 
``cumulative toxic effect.'' This commentor stated that there does not 
need to be an overall increase in toxicity to be cumulative, and 
suggested that the Agency remove the part of its definition that states 
there is an overall increase in toxicity. The Agency agrees with the 
commentor, and has clarified its original definition of ``cumulative 
toxic effect'' in the revised version of the document.

E. Assessing Cumulative Toxicity.

    Some of the commentors had comments pertaining to Section IV of the 
document: ``Policies for Assessing the Cumulative Toxic Effects Posed 
by Two or More Pesticides That Are Toxic By a Common Mechanism.'' One 
commentor wanted the Agency to clarify this section. Several commentors 
questioned the example that poses a hypothetical pharmacokinetic 
interaction between two substances and describes how EPA will consider 
such an interaction in its evaluation of cumulative toxicity. The 
Agency has revised this section of the document. As mentioned above, 
the Agency is currently developing a document that will describe in 
detail and provide examples of how the Agency will accumulate toxicity 
and assess cumulative risks posed by pesticides that are toxic from a 
common mechanism. The document will discuss the policies, practices and 
factors the Agency will use or consider in the assessment of cumulative 
toxicity.

V. Policies Not Rules

    The draft science policy document discussed in this notice is 
intended to provide guidance to EPA personnel and decision-makers, and 
to the public. As a guidance document and not a rule, the policy in 
this guidance is not binding on either EPA or any outside parties. 
Although this guidance provides a starting point for EPA pesticide risk 
assessments, EPA will depart from its policy where the facts or 
circumstances warrant. In such cases, EPA will explain why a different 
course was taken. Similarly, outside parties remain free to assert that 
a policy is not appropriate for a specific pesticide or that the 
circumstances surrounding a specific risk assessment demonstrate that a 
policy should be abandoned.
     The ``revised'' guidance is not an unalterable document. Once a 
``revised'' guidance document is issued, EPA will continue to treat it 
as guidance, not a rule. Accordingly, on a case-by-case basis EPA will 
decide whether it is appropriate to depart from the guidance or to 
modify the overall approach in the guidance.

VI. Contents of Docket

    Document that are referenced in this notice will be inserted in the 
docket under the docket control number OPP-00542. In addition, the 
documents referenced in the framework notice, which published in the 
Federal Register on October 29, 1998 (63 FR 58038) have also been 
inserted in the docket under docket control number OPP-00557.

List of Subjects

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, pesticides and pests.


[[Page 5799]]


    Dated: January 29, 1999.

Susan H. Wayland,
Acting Assistant Administrator for Prevention, Pesticides and Toxic 
Substances.

[FR Doc. 99-2781 Filed 2-4-99; 8:45 am]
BILLING CODE 6560-50-F