40644 Federal Register / Vol. 65, No. 127 / Friday, June 30, 2000 / Notices

Administrative Law Judge, or court, the

facility’s monitoring reports, and EPA,

state, or local inspection reports. EPA

should encourage the defendant to agree

to share information with the

community, within parameters

discussed above. This should help EPA

and the defendant establish a positive

relationship with the community and

enable the community to participate in

the SEP process more effectively.

VII. Conclusion

EPA is committed to involving

communities in the consideration of

SEPs in appropriate cases. This

guidance is intended to facilitate

community involvement in SEP

consideration and helps effectuate the

best possible SEPs in settlement of

enforcement cases in a manner that

promotes mutual trust and confidence,

and builds positive relationships

between the community and the

Agency.

This document is guidance intended

for the use of EPA personnel and does

not create any right or benefit,

substantive or procedural, enforceable at

law by a party against the United States,

its agencies, its officers, or any person.

This guidance is not intended to

supercede any statutory or regulatory

requirements, or EPA policy. Any

inconsistencies between this guidance

and any statute, regulation, or policy

should be resolved in favor of the

statutory or regulatory requirement, or

policy document, at issue.

Appendix A—Resources for Identifying

Communities

Below are some suggested resources within

and outside of EPA that may be useful in

targeting community outreach efforts.

Suggested Internal Sources

1. Community involvement coordinators at

OERR’s Community Involvement and

Outreach Center;

2. Headquarters offices, including: Office of

Environmental Justice, American Indian

Environmental Office, Federal Facilities

Enforcement Office;

3. Colleagues in other media programs or

regions;

4. Regional offices or coordinators who

handle community involvement,

environmental justice, tribal issues, or

Community-Based Environmental Protection

(CBEP);

5. ‘‘Model Plan for Public Participation’’

(November, 1996), developed by the Public

Participation and Accountability

Subcommittee of the National Environmental

Justice Advisory Council (available at NEJAC

website: www.epa.gov/oeca/oej/nejac).

Suggested External Sources

1. State, local, or tribal governments;

2. Educational or spiritual organizations;

3. Other federal agencies;

4. Neighborhood organizations or groups,

and individuals in neighborhoods closest to

the defendant’s facility;

5. Community activists;

6. Environmental and environmental

justice organizations and groups;

7. Local unions, business groups, and civic

groups;

8. The defendant or other members of the

regulated community (i.e., trade

associations);

9. Local newspapers, radio, television,

local Internet sites.

Appendix B—Community Outreach

Techniques

*This list is intended to provide a library

of options available for use in conducting

community outreach, and is not intended to

suggest that all of these techniques be used

in any given case.

1. Interview: Face-to-face or telephone

discussions with community members

provide information about local concerns and

issues. A significant time commitment may

be required to gather feedback representative

of the community.

2. Small Group Meeting: Convening

community members in a local meeting place

stimulates dialogue, generates information,

and may build rapport among participants.

3. Focus Group Meeting: Focus group

participants are convened by a trained

facilitator to provide answers to specific

questions. This direct approach is an efficient

information-gathering tool if participants

represent a cross-section of the community.

4. Public Meeting: Public meetings are

useful for hearing what people have to say

about current issues and engaging

community members in the process. At

public meetings, EPA should focus on active

listening and learning from the public.

5. Public Availability Session/Open House:

A public availability session is a less

structured alternative to a public meeting

that provides everyone an opportunity to ask

questions, express concerns, react to what is

being proposed, and make suggestions.

Typically, a public official announces she or

he will be available at a convenient time and

place where community members can talk

informally.

6. Public Notice: Public notices in the print

media or on radio and television are a

relatively inexpensive way to publicize

community participation opportunities. In

addition to the mainstream media, minority

publications, church bulletins and other such

vehicles offered by local organizations can

reach a more diverse audience.

7. Workshop: Workshops are participatory

seminars to educate small groups of citizens

on particular site issues. Workshops involve

and empower participants; but they, too, can

be time-intensive.

8. Site Tour: Site tours can familiarize

citizens, the media and local officials with

the nature of environmental concerns

affecting a community near a specific site.

Tours may result in better communication

among the community, facility, and Agency,

however, they are frequently resourceintensive to arrange and conduct.

9. Information Repository: An information

repository is a project file containing timely

information on site-specific activities and

accurate detailed and current data about a

site or enforcement action. Project files are

typically kept at convenient public locations,

e.g., libraries, and publicized through various

media.

[FR Doc. 00–16632 Filed 6–29–00; 8:45 am]

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION

AGENCY

[OPP–00658; FRL–6556–4]

Pesticides; Policy Issues Related to

the Food Quality Protection Act

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice of availability.

SUMMARY: To assure that EPA’s policies

related to implementing the Food

Quality Protection Act are transparent

and open to public participation, EPA is

soliciting comments on the pesticide

draft science policy paper entitled

‘‘Proposed Guidance on Cumulative

Risk Assessment of Pesticide Chemicals

That Have a Common Mechanism of

Toxicity.’’ This document is the

eighteenth in a series concerning

science policy papers related to the

Food Quality Protection Act and the

Tolerance Reassessment Advisory

Committee.

DATES: Comments for the draft science

policy paper, identified by docket

control number OPP–00658, must be

received on or before August 28, 2000.

ADDRESSES: Comments may be

submitted by mail, electronically, or in

person. Please follow the detailed

instructions for each method as

provided in Unit I.C. of the

‘‘SUPPLEMENTARY INFORMATION.’’

To ensure proper receipt by EPA, it is

imperative that you identify docket

control number OPP–00658 in the

subject line on the first page of your

response.

FOR FURTHER INFORMATION CONTACT:

Kathleen Martin, Environmental

Protection Agency (7509C), 1200

Pennsylvania, Ave., NW., Washington,

DC 20460; telephone number: (703)

308–2857; fax: (703) 305–5147; e-mail:

martin.kathleen@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be potentially affected by

this action if you manufacture or

formulate pesticides. Potentially

affected categories and entities may

include, but are not limited to:

Federal Register / Vol. 65, No. 127 / Friday, June 30, 2000 / Notices 40645

Categories NAICS

Examples

of potentially affected entities

Pesticide

Producers

32532 Pesticide

manufacturers

Pesticide

formulators

This listing is not intended to be

exhaustive, but rather provides a guide

for readers regarding entities likely to be

affected by this action. Other types of

entities not listed could also be affected.

The North American Industrial

Classification System (NAICS) codes

have been provided to assist you and

others in determining whether or not

this action affects certain entities. If you

have any questions regarding the

applicability of this action to a

particular entity, consult the person

listed under ‘‘FOR FURTHER

INFORMATION CONTACT.’’

B. How Can I Get Additional

Information, Including Copies of this

Document or Other Related Documents?

1. Electronically. You may obtain

electronic copies of this document, the

draft science policy paper, and certain

other related documents that might be

available from the Office of Pesticide

Programs’ Home Page at http://

www.epa.gov/pesticides. On the Office

of Pesticide Programs’ Home Page select

‘‘FQPA’’ and then look up the entry for

this document under ‘‘Science

Policies.’’ You can also go directly to the

listings at the EPA Home Page at http:/

/www.epa.gov. On the Home Page select

‘‘Laws and Regulations’’ and then look

up the entry for this document under

‘‘Federal Register—Environmental

Documents.’’ You can go directly to the

Federal Register listings http://

www.epa.gov/fedrgstr.

2. Fax-on-demand. You may request a

faxed copy of the draft science policy

paper, as well as supporting

information, by using a faxphone to call

(202) 401–0527. Select item 6049 for the

paper entitled ‘‘Proposed Guidance on

Cumulative Risk Assessment of

Pesticide Chemicals That Have a

Common Mechanism of Toxicity.’’ You

may also follow the automated menu.

3. In person. The Agency has

established an official record for this

action under docket control number

OPP–00658. In addition, the documents

referenced in the framework notice,

which published in the Federal Register

on October 29, 1998 (63 FR 58038)

(FRL–6041–5) have also been inserted in

the docket under docket control number

OPP–00658. The official record consists

of the documents specifically referenced

in this action, and other information

related to this action, including any

information claimed as Confidential

Business Information (CBI). This official

record includes the documents that are

physically located in the docket, as well

as the documents that are referenced in

those documents. The public version of

the official record does not include any

information claimed as CBI. The public

version of the official record, which

includes printed, paper versions of any

electronic comments submitted during

an applicable comment period is

available for inspection in the Public

Information and Records Integrity

Branch (PIRIB), Rm. 119, Crystal Mall

#2, 1921 Jefferson Davis Hwy.,

Arlington, VA, from 8:30 a.m. to 4 p.m.,

Monday through Friday, excluding legal

holidays. The PIRIB telephone number

is (703) 305–5805.

C. How and to Whom Do I Submit

Comments?

You may submit comments through

the mail, in person, or electronically. To

ensure proper receipt by EPA, it is

imperative that you identify docket

control number OPP–00658 in the

subject line on the first page of your

response.

1. By mail. Submit your comments to:

Public Information and Records

Integrity Branch (PIRIB), Information

Resources and Services Division

(7502C), Office of Pesticide Programs

(OPP), Environmental Protection

Agency, 1200 Pennsylvania, Ave., NW.,

Washington, DC 20460.

2. In person or by courier. Deliver

your comments to: Public Information

and Records Integrity Branch (PIRIB),

Information Resources and Services

Division (7502C), Office of Pesticide

Programs (OPP), Environmental

Protection Agency, Rm. 119, Crystal

Mall #2, 1921 Jefferson Davis Highway,

Arlington, VA. The PIRIB is open from

8 a.m. to 4 p.m., Monday through

Friday, excluding legal holidays. The

PIRIB telephone number is (703) 305–

5805.

3. Electronically. You may submit

your comments electronically by e-mail

to: opp-docket@epa.gov, or you can

submit a computer disk as described

above. Do not submit any information

electronically that you consider to be

CBI. Avoid the use of special characters

and any form of encryption. Electronic

submissions will be accepted in

WordPerfect 6.1/8.0 or ASCII file

format. All comments in electronic form

must be identified by docket control

number OPP–00658. Electronic

comments may also be filed online at

many Federal Depository Libraries.

D. How Should I Handle CBI that I Want

to Submit to the Agency?

Do not submit any information

electronically that you consider to be

CBI. You may claim information that

you submit to EPA in response to this

document as CBI by marking any part or

all of that information as 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

version of the official record.

Information not marked confidential

will be included in the public version

of the official record without prior

notice. If you have any questions about

CBI or the procedures for claiming CBI,

please consult the person identified

under ‘‘FOR FURTHER INFORMATION

CONTACT.’’

E. What Should I Consider as I Prepare

My Comments for EPA?

EPA invites you to provide your

views on the various draft science

policy papers, new approaches we have

not considered, the potential impacts of

the various options (including possible

unintended consequences), and any

data or information that you would like

the Agency to consider. 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 solid technical information

and/or data to support your views.

4. If you estimate potential burden or

costs, explain how you arrived at the

estimate.

5. Indicate what you support, as well

as what you disagree with.

6. Provide specific examples to

illustrate your concerns.

7. Make sure to submit your

comments by the deadline in this

document.

8. To ensure proper receipt by EPA,

be sure to identify docket control

number OPP–00658 in the subject line

on the first page of your response. You

may also provide the name, date, and

Federal Register citation.

40646 Federal Register / Vol. 65, No. 127 / Friday, June 30, 2000 / Notices

II. Background Information About the

Tolerance Reassessment Advisory

Committee

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 reevaluation 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 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 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

comprises more than 50 representatives

of affected user, producer, consumer,

public health, environmental, states and

other interested groups. The TRAC has

met six times as a full committee from

May 27, 1998 through April 29, 1999.

The Agency worked 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 and related

policies would benefit from initiating

notice and comment on the major

science policy issues.

The TRAC identified nine science

policy issue areas they believed 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

accordance with the framework

described in a separate document

published in the Federal Register of

October 29, 1998 (63 FR 58038), EPA

has been issuing a series of draft papers

concerning nine science policy issues

identified by the TRAC related to the

implementation of FQPA. This

document announces the availability of

the draft science policy paper(s) as

identified in the ‘‘SUMMARY.’’

III. Summary of ‘‘Proposed Guidance

on Cumulative Risk Assessment of

Pesticide Chemicals That Have a

Common Mechanism of Toxicity’’

The Food Quality Protection Act of

1996 requires EPA to consider the

cumulative effects to human health that

can result from exposure to pesticides

and other substances that have a

common mechanism of toxicity. This

document describes the process that

OPP is developing for performing

cumulative risk assessments. Such

assessments will play a significant role

in the evaluation of risks posed by

pesticides, and will enable OPP to make

regulatory decisions that fully protect

public health and sensitive

subpopulations, including infants and

children.

The cumulative assessment of risk

posed by exposure to multiple

chemicals by multiple pathways

(including food, drinking water, as well

as from residential/non-occupational

exposure to air, soil, grass, and indoor

surfaces) presents a formidable

challenge for OPP. Given that

cumulative risk assessment is at an early

phase of development, and will

continue to evolve with experience and

improved toxicological and exposure

databases, the goal of this draft science

policy paper is to describe the first

generation of methods and approaches

to the cumulative risk assessment

process. Thus, this guidance for

cumulative assessment should be

viewed as a work in progress.

Before undertaking a cumulative risk

assessment for a set of chemicals that

have a common mechanism of toxicity,

OPP will follow its procedures for

identifying the chemicals that belong in

that group (see ‘‘Guidance for

Identifying Pesticide Chemicals and

Other Substances that Have a Common

Mechanism of Toxicity,’’ 64 FR 5796,

February 5, 1999 (FRL–6060–7); also see

OPP’s Home Page at http://

www.epa.gov/pesticides). This process

involves the use of a weight-of-theevidence approach to identify a list of

candidate chemicals, a ‘‘Common

Mechanism Group’’ (CMG), for which

scientifically reliable data demonstrate a

common toxic effect by a common

mechanism of action.

Also before conducting a cumulative

assessment, OPP will perform an

aggregate risk assessment for each

chemical in a CMG. OPP will follow the

guidance described in the draft science

policy paper entitled, ‘‘Guidance for

Performing Aggregate Exposure and

Risk Assessments,’’ which was issued

for public comment on November 10,

1999 (64 FR 61343) (FRL–6388–8); also

see OPP’s Home Page at http://

www.epa.gov/pesticides). Using this

guidance, OPP will simultaneously

consider the exposures from dietary

(food), drinking water, and residential/

non-occupational uses of each pesticide.

If the combined exposure from these

sources exceeds the level of concern,

then OPP would take appropriate

regulatory action.

When the aggregate risk assessments

for individual chemicals in a CMG are

completed, OPP will perform the

cumulative risk assessment in the four

steps summarized below: (1) Hazard

assessment and characterization; (2)

Dose response assessment and

characterization; (3) Exposure

assessment and characterization; and (4)

Risk characterization. OPP will carry

out steps 1 and 2 by using a weight-ofthe-evidence approach to determine the

toxic endpoint that occurs through a

common mechanism for the chemicals

in the CMG, and by establishing a

common measure of toxic potency

(‘‘common point-of-departure’’) on

which the cumulative risk assessment is

based. For steps 3 and 4, OPP will

estimate exposure and risks for the

dietary (food), residential/nonoccupational and drinking water

pathways. However, due to limitations

Federal Register / Vol. 65, No. 127 / Friday, June 30, 2000 / Notices 40647

in currently available data and

assessment methodologies, OPP will

usually not be able to simply add

exposures across these pathways. While

OPP has extensive data for dietary

(food) exposures, the data for

residential/non-occupational and

drinking water exposure are

comparatively less. OPP is working to

improve its ability to develop better

estimates of exposure both through

drinking water and from residential use.

For example, OPP is exploring the use

of surrogate/bridging data for pesticides

with similar use patterns that can be

used to estimate residential exposures

that are similarly descriptive as the

dietary exposure assessment. This

approach is comparable to the approach

currently used for worker exposure

assessments using the Pesticide

Handlers’ Exposure Database (PHED)

where data from different pesticides

with similar use patterns are used to

estimate likely exposures to other

pesticides. In fact, OPP is currently

developing a pilot cumulative

assessment on a set of organophosphates

(OPs). OPP plans to present this

assessment to the SAP for review/

comment when completed. The

assessment will provide tangible

examples of how surrogate/bridging

data may be used in such an assessment.

Lessons learned from this use of

surrogate data will be used to update

this guidance in the future.

When data on and methods for

estimating exposure by different

pathways—food, drinking water,

residential use—are of appropriate

quality, OPP will combine exposure

estimates for a quantitative, cumulative

risk assessment. In other circumstances,

however, OPP can perform

sophisticated, refined probabilistic

exposure and risk assessments for food

exposure, but may only be able to

conduct single-point (‘‘deterministic’’)

exposure and risk assessments for nonoccupational exposures, and screening

level modeling estimates for potential

drinking water exposures. Hence, OPP

does not believe that it is scientifically

appropriate in most cases to add

exposures across these pathways to

obtain a cumulative total. Nevertheless,

OPP will consider the exposures and

risks from all pathways ‘‘in parallel’’

and at a minimum will develop

comparative qualitative assessments in

order to complete the cumulative

assessment and to help inform what

regulatory action may be necessary to

assure the full protection of human

health.

It is OPP’s goal to be able to combine

exposures across all pathways as soon

as scientifically reliable data and

methodologies are available to do so.

Toward this end, the Agency is making

a concerted effort to develop or obtain

new data and more sophisticated

exposure and risk assessment

methodologies. EPA’s Office of Research

and Development is planning and

conducting new studies concerning

exposure to infants and children related

to non-occupational routes of exposure.

OPP has also called in data from

registrants for several non-dietary routes

of exposure including dermal contact

and hand/object-to-mouth contact with

contaminated surfaces and toys. OPP is

also working collaboratively with the

U.S. Geological Survey to develop new

regression-based, predictive modeling

tools which OPP expects will allow for

improved estimates of pesticide

concentrations in finished drinking

water. And many registrants are

conducting studies on their own

initiative that are generating additional

exposure data for food, drinking water,

and residential/non-occupational

sources. Moreover, OPP is continuously

developing and proposing through its

science policies better methods for

assessing exposure and risk. Finally,

through publication of this draft science

policy paper and others, OPP is seeking

ideas, feedback, and recommendations

from the SAP and the general public.

The guidance in this draft science

policy paper lays down the following

approaches and steps:

1. Hazard assessment and

characterization. Hazard assessment

and characterization emphasizes the

analysis and integration of all relevant

biological information in selecting the

toxicological endpoint upon which to

base the accumulation of the common

hazard across multiple chemicals

sharing a common mechanism of

toxicity.

(a) Weight-of-the-evidence. A weightof-the-evidence narrative should be

included in the hazard characterization

that clearly lays out a summary of the

key evidence, describes the robustness

of the data for characterizing the

common mechanism of toxicity for each

chemical member, characterizes the

conditions under which the cumulative

hazard may be expressed by route,

pattern, duration and magnitude of

exposure, and recommend the

appropriate common toxicological

endpoint(s) for dose-response

assessment. Significant strengths,

weaknesses, and uncertainties of the

evidence are highlighted.

(b) Common mechanism group. A

common mechanism group (CMG) is a

group of pesticides determined to cause

adverse effects by a common

mechanism of toxicity. The CMG is

defined using the previously released

‘‘Guidance for Identifying Pesticide

Chemicals and Other Substances that

Have a Common Mechanism of

Toxicity’’ (64 FR 5796, February 5,

1999). Not all members of a CMG will

necessarily be incorporated in the

cumulative risk assessment.

2. Dose-response assessment and

characterization. Dose-response

assessment and characterization should

provide a common and uniform basis

for reliably determining each chemical

member’s relative toxic strength and

contribution to the cumulative risk. For

the common toxic endpoint, all doseresponse assessments should include

consideration of their relevance to

assessing children’s health risks by

addressing whether key studies

reflected dosing of adult age animals

only.

(a) Common point of departure. A

common point of departure (POD) on

each chemical’s dose-response curve is

identified to determine its toxic potency

relative to the other chemical members.

This point of departure should be based

on a common endpoint which is derived

from studies using the same species/

strain/sex and duration of exposure for

each chemical member in the group.

Thus, previous chemical-specific

assessments and resulting reference

doses may be inappropriate because

they may be based on a different

endpoint, strain, or duration of

exposure.

(b) Benchmark response or effective

dose. A common benchmark response or

effective dose (ED) is the preferred point

of departure to represent cumulative

risk of the chemical group. Despite its

limitations, the no-observed-adverseeffect-levels (NOAEL) will generally be

used in the near term in many situations

until the toxicological databases

improve and permit reliable benchmark

analysis.

(c) Benchmark response or NOAEL.

After a benchmark response or NOAEL

is designated for an individual chemical

member, there may be chemical specific

adjustments needed to normalize the

response data across the chemical group

to ensure a more nearly uniform point

of departure.

(d) Dose addition approaches. Dose

addition approaches are most

appropriate to use for summing the

cumulative hazard given that

cumulative risk assessment will be

based on chemicals sharing a common

toxic effect that arises by a common

mechanism of toxicity. Dose addition

assumes that the chemicals of interest

act on similar biological systems,

behave similarly in terms of the primary

physiologic processes (absorption,

40648 Federal Register / Vol. 65, No. 127 / Friday, June 30, 2000 / Notices

metabolism, distribution, elimination),

and elicit a common response. Thus, the

cumulative margin of exposure

approach or the relative potency factor

approach are appropriate risk metric

methods for normalizing exposure by

accounting for the different relative

toxic potencies of the group.

3. Exposure assessment and

characterization. Exposure assessment

and characterization for the cumulative

risk assessment will, to the extent data

permit, maintain the temporal and

spatial linkages for the many factors

defining a possible individual exposure.

The assessment will be designed in

cooperation with the risk manager to

assure that all necessary questions

regarding potential risk are answered,

but that the assessment performed is

consistent with the data available.

(a) Aggregate assessment. An

aggregate assessment will be performed

on each chemical that may be included

in the cumulative risk assessment before

the final assessment is designed. This

step will ensure that the available data

have been carefully evaluated with

regard to their ability to describe the

potential exposure of the population of

interest to each chemical.

(b) Focus on the major contributors to

risk. The cumulative assessment will

focus on the major contributors to risk,

permitting resources and risk mitigation

activities to be developed that will most

efficiently address likely risk

reductions.

(c) Data and exposure assessment

methods’ availability and quality. Data

and exposure assessment methods’

availability and quality will also

influence how comprehensive and

refined an assessment can be performed.

Data that lend themselves to

distributional analyses should be used

accordingly. Data that are less

descriptive of the full range of potential

exposures may be used in less

comprehensive analyses. Where the

quality of available data about exposure

by different pathways varies greatly,

cumulative assessments for individual

pathways should be performed, but the

exposure estimates for different

pathways should not be combined

quantitatively unless bridging data

(surrogate data) are available. At a

minimum, a qualitative assessment

should be developed which covers

topics such as comparative pathway

analysis, high end exposure, variability,

and uncertainty.

4. Risk characterization. The risk

characterization contains the primary

conclusions regarding the character and

potential magnitude of the cumulative

risk. Included in the characterization is

a discussion of how well the data

support the conclusions as well as

identification of key uncertainties and

uses of assumptions. The major

chemical contributors to the cumulative

risk, the scenarios of concern, and

subpopulations of special concern

including children, are also identified.

(a) A cumulative assessment group

(CAG) is a subset of the CMG. The CAG

is that group of pesticides selected for

inclusion in the cumulative risk

assessment. The chemicals in the CAG

are judged to have a hazard and

exposure potential that could result in

the expression of a cumulative risk.

Consideration of concurrent exposure is

much greater for acute or short-term

toxic effects because of the greater

potential for more rapid onset of and

recovery from the toxic effect. For

chronic and cancer effects mediated

through reversible precursor events,

overlapping exposure should also be

considered. For other chronic and

cancer endpoints for which long-term

exposure is necessary to cause the

effect, concurrent exposures are not

required for the chemicals to act by a

common mechanism. Because of EPA’s

commitment to addressing those risks

eliciting the greatest concern first,

pesticides with essentially no exposure

(as indicated by the single pesticide

aggregate assessment) will be deferred

from the CAG.

(b) The outcome of a cumulative risk

assessment is viewed as important

information that will help inform risk

management decisions regarding

possible mitigation options across all

members of the CAG.

(c) There will not be one outcome but

varying risk values for differing

proportions of populations exposed to

chances of adverse health effects

resulting from different time scales of

exposures.

(d) A composite group uncertainty

factor is applied after estimating

cumulative risk to account for interspecies and intra-species differences as

well as uncertainties that are common

and inherent to the chemical group.

In September 1999, EPA presented a

preliminary draft of the hazard and dose

response components of the draft

science policy paper for review by the

FIFRA SAP. The purpose of that review

was to seek early comment from the

SAP on the hazard and dose response

analyses needed when accumulating

risk from exposure to two or more

chemicals that share a common

mechanism of toxicity (i.e., guidance

contained in chapters 3 and 5 of the

draft science policy paper). The issues

covered at the September SAP meeting

included selection of chemicals,

common end pont, and a point of

departure; methods for estimating the

cumulative effect of a common

mechanism; and how to deal with

uncertainty. Additionally, a preliminary

case study was presented on

organophosphorus pesticides

illustrating the hazard and doseresponse guidance. In November 1999,

the SAP provided EPA comments on the

September draft. A draft of chapters 4

and 6 of the draft science policy paper

was also taken to the SAP in December

1999, for discussion of exposure and

risk characterization components of this

guidance document. The SAP’s

comments on the December draft were

completed in February 2000. After the

SAP comments and the public

comments on the draft science policy

paper are received and reviewed by the

Agency, it will be reissued in a revised

form for use within and outside of OPP.

The draft science policy paper

discussed in this document 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 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.

IV. Questions/Issues

OPP invites public comment on the

following issues and questions:

A. Issue 1. Selection of Chemicals for a

Cumulative Risk Assessment

Chapter 3 of the draft science policy

paper emphasizes that all chemicals

which have been initially grouped by a

common mechanism of toxicity are not

necessarily appropriate for inclusion in

a final cumulative risk assessment.

There are both hazard and exposure

considerations.

Question 1: Does chapter 3 clearly

present additional hazard

considerations that are needed to

determine those chemical members

which should be included in the final

cumulative risk assessment?

B. Issue 2. Selection, Normalization,

and Adjustment of the Point of

Departure (PoD) for Cumulating the

Common Toxicity

As discussed in chapter 5.1-5.2, a

point of departure (i.e., a dose or

Federal Register / Vol. 65, No. 127 / Friday, June 30, 2000 / Notices 40649

exposure metric corresponding to some

fixed marker of toxicity) should be

selected to sum the combined exposure

for the chemical group. To the extent

possible, the PoDs should reflect a

uniform measure of the common toxic

effect, which is produced by a common

mechanism of toxicity, across the

chemical members. A benchmark dose

approach is preferred to derive the PoDs

for each chemical member.

Question 2: In single chemical

assessments, the Agency uses the upper

bound estimates (i.e., the lower

confidence limit on dose) for both

cancer (called LED) and noncancer

benchmark dose assessment. The

concern has been raised, however, that

summing upper bounds of multiple

compounds may result in a exaggerated

risk. Do you agree that it is more

appropriate to sum the central estimates

(i.e., ED) rather than combining upper

bounds in the cumulative risk

assessment of multiple chemicals? If

not, why not?

C. Issue 3. Incorporation of Group

Uncertainty Factors

As discussed in chapter 5.3,

traditionally one or more of the

uncertainty factors (UF) are used to

derive a Reference Dose (RfD) for a

single chemical. There are five

uncertainty factors that are considered

to account for the following

extrapolations: LOAEL to NOAEL

(UFL), subchronic NOAEL to chronic

NOAEL (UFS), experimental animal to

humans (UFA), interhuman variation

(UFH), and incomplete database to

complete database (UFD). It is proposed

that the extrapolations of LOAELs to

NOAELs or subchronic NOAELs to

chronic NOAELs be applied as

adjustments of a chemical’s PoD before

estimating the cumulative risk. These

adjustments are meant to be based on

some scientific data that permits a

reasonable extrapolation or

interpolation rather than applied solely

as a science policy default decision.

EPA further proposes that other

traditional uncertainty factors be treated

as a composite ‘‘group uncertainty

factor’’ that pertains to the chemical

members as a whole. Thus, the intraspecies and inter-species UFs and the

database completeness UF are applied

as a composite group factor after

cumulative risk is estimated (i.e., not

before on each chemical’s PoD). The

rationale of the group UF is based on the

premise that these factors should be

viewed for the group as a whole given

that all the chemicals are anchored by

a common toxic effect produced by a

common mechanism. Additionally, one

is not simply evaluating risk in the

context of a single chemical data base

but the database for all the chemicals in

the assessment. The advantage of a

group uncertainty factor is that it allows

one to separate the resulting risk that is

based on scientific adjustments from

judgmental policy decisions to account

for uncertainty. Finally, EPA proposes

that an FQPA safety factor decision be

applied for the group rather than on

individual pesticides.

Question 3: Do you agree with this

approach, and does the draft science

policy paper clearly describe the

rationale and guidance for the

implementation of chemical specific

adjustment factors and of a group UF for

the cumulative risk assessment? Has the

draft guidance clearly presented the

limitations and strengths of the group

UF approach?

D. Issue 4. Methods for Estimating the

Cumulative Toxicity

As discussed in chapter 5.6, one of

the steps in the cumulative risk

assessment process will be to select a

method to cumulate dose or exposures.

This method will serve to normalize

differences in the toxic potencies among

the chemicals in the cumulative

assessment. Precedence in the Agency’s

1986 and revised 1999 ‘‘Guidance for

Conducting Health Risk Assessment of

Chemical Mixtures’’ (http://

www.epa.gov/ncea/pdfs/mixtures.pdf)

describes several techniques for

estimating risk to multiple chemicals.

The cumulative guidance focuses on the

component-based dose addition

methods used in the EPA’s chemical

mixture assessment guidance document.

Two methods, a margin-of-exposure

approach and an approach using

relative potency factors, are presented.

Question 4a: Do you agree that both

methods are valid to consider for

estimating cumulative risk associated

with exposures to chemical that cause a

common toxic effect by a common

mechanism? Has the draft document

clearly described these two approaches

and their strengths and limitations? Are

there other methods that OPP should

consider?

Question 4b: EPA anticipates that

most mechanisms of toxicity

encountered currently will be nonlinear

dose-response relationships.

Nevertheless, for mechanisms of toxicity

consistent with linear dose-response

relationships, do you agree that using

the relative potency factor approach by

summing the slopes of the doseresponse curves is an appropriate

method? If not, what methods would

you recommend for low-dose linear

extrapolations of risk?

E. Issue 5. Case Study

In Appendix A of the draft science

policy paper is a case study on

organophosphorus pesticides.

Question 5: Does this case study

provide a clear example of the

application of the hazard and doseresponse elements of the draft guidance?

F. Issue 6. Input Parameters

There are several types of data

available for pesticide exposure

assessment (e.g., field trial data,

monitoring data, percent crop treated,

label usage). For the food pathway,

monitoring data are available from the

USDA Pesticide Data Program (PDP).

OPP conducts the majority of its

drinking water assessments by

calculating a screening level value.

Similarly, residential assessments are

conducted using the draft residential

Standard Operating Procedures (SOPs)

which also provide a screening level

assessment. Thus, given PDP, the

assessment of the food pathway will, in

many cases, be based on higher quality

data than for the residential and

drinking water pathways where usually

only screening values are available.

Because of the different quality of data

that will be encountered when

conducting a cumulative exposure

assessment, the concern is raised that

the value and benefit of high quality

monitoring data will be lost if combined

with extrapolated exposure values from

screening models.

Question 6.1: Please comment on how

this concern could be addressed. For

instance, should OPP at this time

conduct separate pathway assessments

for food, drinking water, and residential

exposures so as to avoid combining

higher quality monitoring data with

more limited screening level data?

Question 6.2: Please comment on

whether there are other means of

dealing with existing data to reduce the

uncertainties about exposure values

derived from screening approaches.

Question 6.3: Please comment on

whether and how OPP could

incorporate quantitative uncertainty

analyses in the overal cumulative risk

assessment when OPP uses data of

varying quality.

Question 6.4: Is it appropriate to

extrapolate food exposure from residue

field trials and use/usage information if

food monitoring data such as USDA’s

PDP data are not available?

G. Issue 7. Deferral Criteria

OPP is proposing that deferral criteria

be applied to ‘‘negligible’’ sources of

risk in a full cumulative risk

assessment. OPP believes that this

40650 Federal Register / Vol. 65, No. 127 / Friday, June 30, 2000 / Notices

approach will permit a better focus on

the more important sources of risk. It

will also assist the risk manager in

understanding and evaluating sources of

risk that may provide the greatest

benefit with risk mitigation activities.

Question 7.1: Please comment on

whether the deferral criteria discussed

in chapters 4 and 6 appear to be

reasonable. Are there other exclusionary

criteria that should be considered?

Question 7.2: Should OPP establish

more specific criteria, for example, not

only the magnitude of the exposure

resulting from a particular chemical, use

pattern or pathway, but also the size of

the exposed population group?

H. Issue 8: National and Regional

Exposures

The potential for people to encounter

overlapping exposures to different

pesticides will be influenced by many

factors. One important consideration is

the geographic effects and seasonal uses

of pesticides. Thus, a framework is

proposed for assessing different

pathways of exposure that are

essentially driven by these

considerations. OPP believes that the

food pathway should be approached on

both a national and regional scale to

account for both national and regional

distribution of treated commodities.

However, the OPP believes that

residential and drinking water pathways

are more appropriately dealt with on a

regional or multi-state basis, since there

is no single, national source of drinking

water; and residential exposures may be

driven by regional use patterns.

Question 8.1: Please comment on

whether the concept of developing a

series of cumulative assessments on a

geographic scale for different pathways

is reasonable.

I. Issue 9: Case Study

Cumulative risk assessment is at an

early stage of development.

Furthermore, there is very limited

experience in conducting such

assessments. Thus, the development of

case studies using actual data are

critical to refining useful and practical

guidance, and to identifying future

research and testing needs. OPP is

taking a step wise approach to the

development of such case studies by

starting with simple examples and

moving toward more complex

situations.

Attached is a case study that uses

actual food residue data on three

pesticides and evaluates only a single

pathway/route/duration of exposure.

Certain assumptions were made in the

case study. In single chemical exposure

assessment, for example, nondetects are

assumed to be one half the level of

detection and composite samples are

decomposited. In this case study, for

illustrative purposes, nondetects were

assumed to be zero, the samples were

not decomposited, and surrogate data

were not used.

Question 9.1: Given that an important

goal of the cumulative assessment is to

reliably determine sources of concern

from a multi-chemical exposure, please

comment on to what extent is it

appropriate to apply standard practices

and assumptions used in single

chemical assessments.

V. Policies Not Rules

The draft science policy paper

discussed in this document 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 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.

EPA has stated in this document that

it will make available revised guidance

after consideration of public comment.

Public comment is not being solicited

for the purpose of converting any policy

document into a binding rule. EPA will

not be codifying this policy in the Code

of Federal Regulations. EPA is soliciting

public comment so that it can make

fully informed decisions regarding the

content of each guidance document.

The ‘‘revised’’ guidance will not be

unalterable. 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. In the course of inviting

comment on each guidance document,

EPA would welcome comments that

specifically address how a guidance

document can be structured so that it

provides meaningful guidance without

imposing binding requirements.

List of Subjects

Environmental protection,

Administrative practice and procedure,

Agricultural commodities, Pesticides

and pests.

Dated: June 22, 2000.

Susan H. Wayland,

Acting Assistant Administrator for

Prevention, Pesticides and Toxic Substances.

[FR Doc. 00–16634 Filed 6–29–00; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

[FRL–6727–5]

Draft NPDES General Permits for Water

Treatment Facility Discharges in the

States of Maine, Massachusetts, and

New Hampshire

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notices of Draft NPDES General

Permits—MEG640000, MAG640000,

and NHG640000.

SUMMARY: The Director of the Office of

Ecosystem Protection, EPA—New

England, is issuing Notice of Draft

National Pollutant Discharge

Elimination System (NPDES) general

permits for water treatment facility

discharges to certain waters of the States

of Maine, Massachusetts, and New

Hampshire for the purpose of reissuing

the current permit which expired on

January 9, 2000. These general NPDES

permits establish notice of intent (NOI)

requirements, effluent limitations,

standards, prohibitions and

management practices for the water

treatment facility discharges. Owners

and/or operators of facilities discharging

effluent from water treatment facilities

including those currently authorized to

discharge under the expired general

permit will be required to submit to

EPA—New England, a notice of intent to

be covered by the appropriate general

permit and will receive a written

notification from EPA of permit

coverage and authorization to discharge

under one of the general permits. The

eligibility requirements are discussed in

detail under section D.2.b and the

reader is strongly urged to go to that

section before reading further. This

general permit does not cover new

sources as defined under 40 CFR 122.2.

DATES: For comment period: interested

persons may submit comments on the

draft general permits as part of the

administrative record to the

Environmental Protection Agency, New

England Region, at the address given

below no later than July 31, 2000. The

general permit shall be effective on the

date specified in the final general permit

published in the Federal Register and

will expire five years from the final

publication date of the Federal Register.