[Federal Register Volume 88, Number 222 (Monday, November 20, 2023)]
[Rules and Regulations]
[Pages 80582-80584]
[FR Doc No: 2023-25517]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1399; Project Identifier MCAI-2022-01533-E;
Amendment 39-22585; AD 2023-22-01]
RIN 2120-AA64

Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2020-15-07
for certain Rolls-Royce Deutschland Ltd & Co KG (RRD) (type certificate
previously held by Rolls-Royce plc) Model RB211-524G2-19, RB211-524G2-
T-19, RB211-524G3-19, RB211-524G3-T-19, RB211-524H2-19, RB211-524H2-T-
19, RB211-524H-36, and RB211-524H-T-36 engines. AD 2020-15-07 required
replacement of the low-pressure turbine (LPT) stage 1 disk with part
number (P/N) UL37606, UL37607, UL37608, UL37722, or UL37790, installed.
This AD was prompted by an updated analysis by the engine manufacturer,
which indicates certain part-numbered and serial-numbered LPT stage 1
disks that have undergone rework could fail before the current
published life limits. This AD retains the requirement to replace the
LPT stage 1 disk and includes additional LPT stage 1 disks, as
specified in a European Union Aviation Safety Agency (EASA) AD, which
is incorporated by reference. The FAA is issuing this AD to address the
unsafe condition on these products.

DATES: This AD is effective December 26, 2023.
    The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 26,
2023.

ADDRESSES:
    AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-1399; or in person at Docket Operations between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD
docket contains this final rule, the mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
address for Docket Operations is U.S. Department of Transportation,
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200
New Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:
     For service information identified in this final rule,
contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone:
+49 221 8999 000; email: [email protected]; website: easa.europa.eu.
You may find this material on the EASA website at ad.easa.europa.eu.
     You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 1200
District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call<PHONE_NUMBER>. It is
also available at regulations.gov under Docket No. FAA-2023-1399.

FOR FURTHER INFORMATION CONTACT: Sungmo Cho, Aviation Safety Engineer,
FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-
7241; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2020-15-07,

Amendment 39-21170 (85 FR 43682, July 20, 2020) (AD 2020-15-07). AD
2020-15-07 applied to RRD RB211-524G2-19, RB211-524G2-T-19, RB211-
524G3-19, RB211-524G3-T-19, RB211-524H2-19, RB211-524H2-T-19, RB211-
524H-36, and RB211-524H-T-36 model turbofan engines with LPT stage 1
disks, P/N UL37606, UL37607, UL37608, UL37722, or UL37790, installed.
AD 2020-15-07 required replacement of the LPT stage 1 disk before it
reaches its new Declared Safe Cycle Limit (DSCL) or within 25 flight
cycles after the effective date of the AD, whichever occurs later. The
FAA issued AD 2020-15-07 to prevent failure of the LPT stage 1 disk.
    The NPRM published in the Federal Register on July 12, 2023 (88 FR
44235). The NPRM was prompted by AD 2022-0237, dated December 2, 2022
(EASA AD 2022-0237) (also referred to as the MCAI), issued by EASA,
which is the Technical Agent for the Member States of the European
Union. The MCAI states that further investigation by the manufacturer
identified additional part-numbered LPT stage 1 disks affected by the
unsafe condition. As a result of this finding, RRD published revised
service information, which includes the additional affected LPT stage 1
disk P/Ns.
    You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-1399.
    In the NPRM, the FAA proposed to include additional LPT stage 1
disks and require accomplishing the actions specified in the MCAI
described previously, except for any differences identified as
exceptions in the regulatory text of the NPRM. The FAA is issuing this
AD to prevent failure of the LPT stage 1 disk, which if not addressed,
could result in uncontained release of high-energy debris from the
engine, in-flight shutdown of the engine, damage to the engine, and
damage to the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from the Air Line Pilots Association,
International (ALPA) and The Boeing Company who supported the NPRM
without change.

Conclusion

    These products have been approved by the aviation authority of
another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, it has notified the FAA of the unsafe condition described in
the MCAI referenced above. The FAA reviewed the relevant data and
determined that air safety requires adopting this AD as proposed.
Accordingly, the FAA is issuing this AD to address the unsafe condition
on these products. Except for minor editorial changes, this AD is
adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed EASA AD 2022-0237, which specifies procedures for
replacement of the LPT stage 1 disk and reducing the DSCL for LPT stage
1 disks.
    This material is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in ADDRESSES.

Costs of Compliance

    The FAA estimates that this AD affects 18 engines installed on
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
Remove and replace LPT stage 1 disk.  120 work-hours x $85            $30,000          $40,200         $723,600
                                       per hour = $10,200.
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    The FAA has determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive 2020-15-07, Amendment 39-21170 (85
FR 43682, July 20, 2020); and
0
b. Adding the following new airworthiness directive:

2023-22-01 Rolls-Royce Deutschland Ltd. & Co. KG: Amendment 39-
22585; Docket No. FAA-2023-1399; Project Identifier MCAI-2022-01533-
E.

(a) Effective Date

    This airworthiness directive (AD) is effective December 26,
2023.

(b) Affected ADs

    This AD replaces AD 2020-15-07, Amendment 39-21170 (85 FR 43682,
July 20, 2020).

(c) Applicability

    This AD applies to Rolls-Royce Deutschland Ltd & Co. KG (RRD)
Model RB211-524G2-19, RB211-524G2-T-19, RB211-524G3-19, RB211-524G3-
T-19, RB211-524H2-19, RB211-524H2-T-19, RB211-524H-36, and RB211-
524H-T-36 engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.

(e) Unsafe Condition

    This AD was prompted by an updated analysis by the engine
manufacturer, which indicates certain part-numbered and serial-
numbered low-pressure turbine (LPT) stage 1 disks that have
undergone rework could fail before the current published life
limits. The FAA is issuing this AD to prevent failure of the LPT
stage 1 disk. The unsafe condition, if not addressed, could result
in uncontained release of high-energy debris from the engine, in-
flight shutdown of the engine, damage to the engine, and damage to
the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified,
unless already done.

(g) Required Actions

    Except as specified in paragraph (h) of this AD: Perform all
required actions within the compliance times specified in, and in
accordance with, European Union Aviation Safety Agency (EASA) AD
2022-0237, dated December 2, 2022 (EASA AD 2022-0237).

(h) Exceptions to EASA AD 2022-0237

    (1) Where EASA AD 2022-0237 refers to its effective date, this
AD requires using the effective date of this AD.
    (2) This AD does not adopt the ``Remarks'' section of EASA AD
2022-0237.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, AIR-520, Continued Operational Safety Branch,
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. In accordance with 14
CFR 39.19, send your request to your principal inspector or local
Flight Standards District Office, as appropriate. If sending
information directly to the manager of the certification office,
send it to the attention of the person identified in paragraph (j)
of this AD and email to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.

(j) Additional Information

    For more information about this AD, contact Sungmo Cho, Aviation
Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198;
phone:<PHONE_NUMBER>; email: [email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the
incorporation by reference of the service information listed in this
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
    (i) European Union Aviation Safety Agency (EASA) AD 2022-0237,
dated December 2, 2022.
    (ii) [Reserved]
    (3) For EASA AD 2022-0237, contact EASA, Konrad-Adenauer-Ufer 3,
50668 Cologne, Germany; phone: +49 221 8999 000; email:
[email protected]; website:easa.europa.eu. You may find this EASA
AD on the EASA website at ad.easa.europa.eu.
    (4) You may view this service information at FAA, Airworthiness
Products Section, Operational Safety Branch, 1200 District Avenue,
Burlington, MA 01803. For information on the availability of this
material at the FAA, call<PHONE_NUMBER>.
    (5) You may view this material at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on October 25, 2023.
Caitlin Locke,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2023-25517 Filed 11-17-23; 8:45 am]
BILLING CODE 4910-13-P


[Federal Register: November 24, 2010 (Volume 75, Number 226)]
[Notices]
[Page 71719-71721]
[DOCID:fr24no10-112]

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DEPARTMENT OF HOMELAND SECURITY

Federal Emergency Management Agency

[Docket ID: FEMA-2010-0058]

Agency Information Collection Activities: Proposed Collection;
Comment Request, OMB No. 1660-0013; Exemption of State-Owned Properties
Under Self-Insurance

AGENCY: Federal Emergency Management Agency, DHS.

ACTION: Notice; 60-day notice and request for comments; extension,
without change, of a currently approved information collection; OMB No.
1660-0013; No Form.

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SUMMARY: The Federal Emergency Management Agency, as part of its
continuing effort to reduce paperwork and respondent burden, invites
the general public and other Federal agencies to take this opportunity
to comment on a proposed extension, without change, of a currently
approved information collection. In accordance with the Paperwork
Reduction Act of 1995, this notice seeks comments concerning the
collection of information necessary to allow States to request an
exemption from maintaining flood insurance on State-owned structures.

DATES: Comments must be submitted on or before January 24, 2011.

ADDRESSES: To avoid duplicate submissions to the docket, please use
only one of the following means to submit comments:
    (1) Online. Submit comments at http://www.regulations.gov under
Docket ID FEMA-2010-0058. Follow the instructions for submitting
comments.
    (2) Mail. Submit written comments to Docket Manager, Office of
Chief Counsel, DHS/FEMA, 500 C Street, SW., Room 835, Washington, DC
20472-3100.
    (3) Facsimile. Submit comments to<PHONE_NUMBER>.
    (4) E-mail. Submit comments to<EMAIL_ADDRESS>Include Docket
ID FEMA-2010-0058 in the subject line.
    All submissions received must include the agency name and Docket
ID. Regardless of the method used for submitting comments or material,
all submissions will be posted, without change, to the Federal
eRulemaking Portal at http://www.regulations.gov, and will include any
personal information you provide. Therefore, submitting this
information makes it public. You may wish to read the Privacy Act
notice that is available via the link in the footer of http://
www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Mary Ann Chang, Mitigation
Directorate, FEMA, at<PHONE_NUMBER>. You may contact the Records
Management Division for copies of the proposed collection of
information at facsimile number<PHONE_NUMBER> or e-mail address: FEM-
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: The Flood Disaster Protection Act of 1973,
as amended, 42 U.S.C. 4001 et seq., recognized that a reasonable method
of sharing the nation's risk of flooding at the national level was
required. The Act established a requirement to purchase flood insurance
for properties at risk from a flood. It also further provided an
exception to this requirement for State-owned properties that are
covered under an adequate State policy of self-insurance. When States
provide proof of this self-insurance, the designated property is not
required to be covered by flood insurance. Title 44 CFR Part 75
establishes the procedures by which a State may request exemption and
also establishes standards with respect to the Administrator's
determinations that a State's plan of self-insurance is adequate and
satisfactory for the purpose of exempting the State from the
requirement of purchasing flood insurance coverage, for State-owned
structures and their contents. This applies to areas identified by the
Administrator as A, AO, AH, A1-30, AE, AR, AR/A1-30, AR/AE, AR/AO, AR/
AH, AR/A, A99, M, V, VO, V1-30, VE, and E zones, in which the sale of
insurance has been made available.

Collection of Information

    Title: Exemption of State-Owned Properties Under Self-Insurance.
    Type of Information Collection: Extension, without change, of a
currently approved information collection.
    OMB Number: 1660-0013.
    Form Titles and Numbers: No Forms.
    Abstract: States can request an exemption to the requirement of
purchasing flood insurance on State-owned properties through the
submission of sufficient supporting documentation certifying that the
plan of self-insurance upon which the application for exemption is
based meets or exceed the standards of coverage required for flood and
flood-related hazards.
    Affected Public: State, local or Tribal Government.
    Estimated Total Annual Burden Hours: 100 Hours.

                                                       Estimated Annualized Burden Hours and Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Number of                    Average
                                      Form name/form      Number of     responses   Total number   burden per   Total annual     Average    Total annual
        Type of respondent                number         respondents       per      of responses  response (in   burden (in    hourly wage   respondent
                                                                       respondent                    hours)        hours)         rate          Cost
--------------------------------------------------------------------------------------------------------------------------------------------------------
 State, local or Tribal            Letter of                      20             1            20             5           100        $62.62        $6,262
 Government.                        Application and
                                    Supporting
                                    Documentation/No
                                    Form.
                                                       -------------------------------------------------------------------------------------------------
    Total........................  ...................            20  ............            20  ............           100  ............         6,262
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Estimated Cost: There are no record keeping, capital, start-up or
maintenance costs associated with this information collection.

Comments

    Comments may be submitted as indicated in the ADDRESSES caption
above. Comments are solicited to (a) Evaluate whether the proposed data
collection is necessary for the proper performance of the agency,
including whether the information shall have practical utility; (b)
evaluate the accuracy of the agency's estimate of the burden of the
proposed collection of information, including the validity of the
methodology and assumptions used; (c) enhance the quality, utility, and
clarity of the information to be collected; and (d) minimize the burden
of the collection of information on those who are to respond, including
through the use of appropriate automated, electronic, mechanical, or
other technological collection techniques or other forms of information
technology, e.g., permitting electronic submission of responses.

    Dated: November 16, 2010.
Lesia M. Banks,
Director, Records Management Division, Mission Support Bureau, Federal
Emergency Management Agency, Department of Homeland Security.
[FR Doc. 2010-29556 Filed 11-23-10; 8:45 am]
BILLING CODE 9110-11-P


Preliminary N Methyl Carbamate Cumulative Risk Assessment: Fact Sheet EPA has released its preliminary cumulative risk assessment for the N methyl carbamate pesticides. This assessment is based on evaluation of the potential for people to be exposed to more than one member of this group of pesticides at a time and considers exposures from food, drinking water, and residential sources. The assessment incorporates regional exposures from residential and drinking water sources, as the most appropriate way to account for the considerable variation in potential exposures across the country.

Because this is a preliminary assessment, it is too soon to draw firm conclusions about risks or consider risk management possibilities. EPA is still reviewing the results and seeking scientific peer review. EPA has submitted the preliminary risk assessment to the FIFRA Scientific Advisory Panel ( SAP), and will evaluate comments from the public and the SAP, and incorporate additional data received. EPA will modify this assessment as appropriate. The revised cumulative assessment will incorporate chemical specific Food Quality Protection Act ( FQPA) factors. As existing analyses are revised or new information becomes available, EPA will review this assessment and make further changes as appropriate.

Preliminary Assessment of N Methyl Carbamate Pesticides This assessment is preliminary and subject to refinement. The Agency cautions against premature conclusions based on this preliminary assessment, and against any use of information contained in these documents out of their full context. Risk mitigation measures have already been taken on some individual members of this group of pesticides, through interim reregistration decisions. The individual chemical assessments for other members of this group have not yet been completed. The Agency is reviewing the results of the assessment to determine if any issues may need to be addressed related to food commodities, drinking water, and residential uses. However, EPA has confidence in the overall safety of our food supply and emphasizes the importance of eating a varied diet rich in fruits and vegetables. At this point, no target Margin of Exposure ( MOE) has been established. Also, no FQPA safety factor has been incorporated into the assessment.

By evaluating the potential for combined exposures to two or more N methyl carbamate pesticides, the assessment moves beyond the already high level of protection of public health provided by the individual aggregate assessments. Looking at exposure over time helps take into account the potential effects of additional exposure before complete recovery from any given exposure. It also evaluates variation in exposure from drinking water and residential uses in different areas of the country.

Defining Cumulative Risk Assessment A cumulative risk assessment is the process of combining exposure ( the amount of a pesticide to which an individual is exposed) and hazard ( the health effects a pesticide could cause) from all substances that share a common mechanism of toxicity. The Food Quality Protection Act ( FQPA) directs EPA to consider the combined effects to human health that can result from exposure to such pesticides and other substances.

The potential risk presented by a pesticide depends on the toxicity of the pesticide and the amount of the pesticide to which a person is exposed. It is important to note that a pesticide having low toxicity but the potential for high exposure can present a risk similar to that of a pesticide having high toxicity but very little potential for exposure. Since people can be exposed to several pesticides that act the same way in the body at the same time through various foods, drinking water, and from uses in and around the home, school, or recreational areas, it is also necessary to assess the effects of cumulative exposure.

Potential Health Effects of the N Methyl Carbamate Pesticides The N methyl carbamate pesticides affect the nervous system by reducing the ability of cholinesterase, an enzyme, to function properly in regulating a neurotransmitter called acetylcholine. Acetylcholine helps transfer nerve impulses from a nerve cell to a muscle cell or another nerve cell. If acetylcholine is not properly controlled by cholinesterase, the nerve impulses or neurons remain active longer than they should, overstimulating the nerves and muscles and causing symptoms such as weakness or paralysis of the muscles.

There are other pesticides which are considered ' carbamate' pesticides. However, only the N methyl subclass of pesticides is considered in this cumulative risk assessment. The Nmethyl carbamates share the ability to inhibit cholinesterase through a specific pathway. Other ' carbamate' pesticides do not share the same common mechanism.

In general, cumulative risk assessments consider currently registered N methyl carbamates unless they:

  are being phased out according to specific legal agreements or   pose negligible, if any, potential for exposure, based on results of their individual risk assessments The full risk assessment provides details about the pesticides included and excluded.

( For more details, see the Federal Register Notice announcing availability of the carbamate cumulative assessment group: http:// www. epa. gov/ fedrgstr/ EPAPEST 2004/ February/ Day 04/ p2157. htm) EPA's Approach to Conducting Cumulative Risk Assessment EPA's approach to cumulative risk assessment relies on a careful review of the data on toxicity of individual pesticides and information on potential for exposure.

Before beginning the cumulative assessment process, EPA generally assesses risks associated with individual pesticides. For each individual pesticide, EPA performs an aggregate risk assessment ( considering all combined sources of exposure). In the aggregate assessment, EPA considers exposures to the individual pesticide from food, drinking water, and residential uses. At this stage, if risks exceed EPA's level of concern, the Agency would take steps to reduce risks associated with the chemical to acceptable levels. EPA's revised guidance on aggregate risk assessment (" General Principles for Performing Aggregate Exposure and Risk Assessment") is available on the web at www. epa. gov/ pesticides/ trac/ science.

The process generally follows these steps:

  Identify Pesticides with a Common Mechanism EPA identifies pesticides that have a common mechanism of toxicity. Once identified, these pesticides are called a " common mechanism group." Such a group consists of pesticides for which scientifically reliable data demonstrate that the same toxic effect occurs in or at the same organ or tissue by essentially the same sequence of major biochemical events. EPA guidance on the process for identifying whether pesticides have a common mechanism (" Guidance for Identifying Pesticides and Other Substances that Have a Common Mechanism of Toxicity") is available on the web at www. epa. gov/ pesticides/ trac/ science.

  Perform a Cumulative Assessment After establishing the common mechanism group, EPA performs the cumulative risk assessment in four steps:

1. Hazard Assessment and Characterization  This step identifies the potential health effects that can be caused by a pesticide. For the cumulative assessment, this includes the potential for health effects from exposure to multiple pesticides with a common mechanism of toxicity, including consideration of conditions that will allow the effects to cumulate and whether specific subgroups might have increased sensitivity to the common toxic effect.

2. Dose Response Assessment and Characterization  This step determines the relative toxic strength of each pesticide included in the assessment and establishes a dose that is used to estimate the potential combined risk. 3. Exposure Assessment and Characterization  This step assesses who is potentially exposed, how they might be exposed, and how much of the pesticide people could be exposed to through food, drinking water, and various non agricultural uses, such as use in and around the home. For the cumulative assessment, EPA will assess the potential for humans to be exposed to multiple members of the common mechanism group at the same time and whether there are regional or subpopulation concerns.

4. Risk Characterization  This step identifies the strengths and weaknesses of the analysis, potential sources of risk, and any subpopulations that are at increased risk. It describes the Agency's confidence in the results as well as assumptions used and uncertainties in the analysis.

The first two steps include use of a weight of the evidence approach to determine the harmful effect that occurs through a common mechanism of toxicity and to establish a common measure of toxic potency. A weight of the evidence approach involves reviewing all pertinent data and information, assessing the strengths and weaknesses of the data, and reaching conclusions based on the overall picture provided by the data, rather than based on any one specific study. One way of comparing toxic potency is by selecting one pesticide as the " index" pesticide ( generally the one for which the Agency has the best information on effects at a variety of doses) and comparing the other pesticides to it to determine their relative potency ( e. g., one might be half as toxic as the index pesticide, while another might be twice as toxic).

Steps 3 and 4 include estimating exposure and risks for the food, drinking water, and residential/ non occupational pathways. EPA combines these exposures using a calendarbased software modeling tool that allows the user to develop exposure estimates for a period of time, such as a day, a week, or a month.

EPA has published guidance on conducting cumulative risk assessments. This guidance has been reviewed by the FIFRA Scientific Advisory Panel. The revised guidance is available on EPA's Web site at http:// www. epa. gov/ pesticides/ trac/ science/ cumulative_ guidance. pdf ( PDF, 90 pp., 490 KB, about PDF).

Combining Results of the Food, Water, and Residential Assessments EPA is undertaking regional risk assessments for potential exposures from drinking water and residential pesticide uses. These regional assessments will allow the Agency to take into account the variation in uses of pesticides across the country, as well as the differences both in sources of drinking water and in the potential for presence of pesticide residues in water sources.

The Agency's food risk assessment for the N methyl carbamate pesticides is based primarily on residues reported in the U. S. Department of Agriculture's Pesticide Data Program. The estimate of food exposure is conducted on a national basis, since most food commodities are available in all areas of the country. EPA will combine this national food assessment with the regional drinking water and residential results.

Using the results of the cumulative risk assessment in making tolerance reassessment decisions FQPA requires EPA to consider the cumulative effects of substances that share a common mechanism of toxicity in making decisions about the safety of pesticide residues in food. The current risk assessment is a preliminary version; it will not be used in making risk management decisions. EPA's tolerance reassessment decisions for the Nmethyl carbamate pesticides will take into account the public comment and scientific consultation planned for the next few months. When the risk assessment is revised, EPA will require any unacceptable risks to be reduced to acceptable levels. In the meantime, EPA has already taken significant actions and continues to act on risks associated with individual pesticides, based on the risk assessments for those pesticides.

Data Sources Used for the Preliminary Assessment EPA has attempted to obtain the best available data to use in each component of this risk assessment. The sources of data vary for the food, water, and residential components of the risk assessment.

The sources of data for the food component include:

  USDA's Pesticide Data Program   USDA's Continuing Survey of Food Intake by Individuals   The Food and Drug Administration Center monitoring data For the water component of the assessment:

  USDA Agricultural Chemical Usage Reports for Field Crops, Fruits, and Vegetables   USDA Typical Planting and Harvesting Dates for Field Crops and Fresh Market and Processing Vegetables   Local sources for refinements   Monitoring studies from USGS and other sources For the residential/ non occupational component:

  Doane Golftrak   Outdoor Residential Exposure Task Force ( ORETF Survey)   Studies from scientific literature ( for more detail, refer to the preliminary assessment document available from the SAP meeting Web page.)   Exposure Factors Handbook   REJV Survey Key Steps Taken to Date to Develop the Methods Used in Cumulative Risk Assessment EPA used an open process in developing cumulative risk assessment methods and approaches, beginning shortly after the 1996 enactment of the Food Quality Protection Act. EPA held numerous public meetings on various components of the methods used in the risk assessment:

  More than 30 consultations with the FIFRA Scientific Advisory Panel on various issues related to scientific methods used in the assessment.   The International Life Sciences Institute ( ILSI) held workshops with EPA and other scientists on topics related to cumulative risk assessment.

In addition, EPA released for public comment 10 science policy papers related to the cumulative process over the past several years, including the draft guidance on cumulative risk assessment for comment on June 30, 2000.

For More Information   For information on assessing cumulative pesticide risk, visit: http:// www. epa. gov/ pesticides/ cumulative/.   The preliminary risk assessment is available from the SAP meeting Web page.   Information about the SAP meeting and related information are available at: http:// www. epa. gov/ oscpmont/ sap/# august.   Additional background documents will be posted as they become available.