[Federal Register: August 20, 2003 (Volume 68, Number 161)]
[Notices]
[Page 50138-50143]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20au03-48]
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ENVIRONMENTAL PROTECTION AGENCY
[OPP-2003-0262; FRL-7321-7]
Dimethomorph; Notice of Filing Pesticide Petitions to Establish
Tolerances for Certain Pesticide Chemical in or on Food
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice announces the initial filing of pesticide
petitions proposing the establishment of regulations for residues of a
certain pesticide chemical in or on various food commodities.
DATES: Comments, identified by docket ID number OPP-2003-0262, must be
received on or before September 19, 2003.
ADDRESSES: Comments may be submitted electronically, by mail, or
through hand delivery/courier. Follow the detailed instructions as
provided in Unit I. of the SUPPLEMENTARY INFORMATION.
FOR FURTHER INFORMATION CONTACT: Shaja R. Brothers, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 308-3194; e-mail address:
brothers.shaja@epa.gov.
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
Potentially affected entities may include, but are not limited to:
[sbull] Industry (NAICS 111)
[sbull] Crop production (NAICS 112)
[sbull] Animal production (NAICS 311)
[sbull] Food manufacturing (NAICS 32532)
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 in this unit could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether this action might apply to 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 Copies of this Document and Other Related Information?
1. Docket. EPA has established an official public docket for this
action under docket ID number OPP-2003-0262. The official public docket
consists of the documents specifically referenced in this action, any
public comments received, and other information related to this action.
Although, a part of the official docket, the public docket does not
include Confidential Business Information (CBI) or other information
whose disclosure is restricted by statute. The official public docket
is the collection of materials that is available for public viewing at
the Public Information and Records Integrity Branch (PIRIB), Rm. 119,
Crystal Mall 2, 1921 Jefferson Davis Hwy., Arlington, VA. This
docket facility is open from 8:30 a.m. to 4 p.m., Monday through
Friday, excluding legal holidays. The docket telephone number is (703)
305-5805.
2. Electronic access. You may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr/.
An electronic version of the public docket is available through
EPA's electronic public docket and comment system, EPA Dockets. You may
use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public
comments, access the index listing of the contents of the official
public docket, and to access those documents in the public docket that
are available electronically. Although, not all docket materials may be
available electronically, you may still access any of the publicly
available docket materials through the docket facility identified in
Unit I.B.1. Once in the system, select ``search,'' then key in the
appropriate docket ID number.
Certain types of information will not be placed in EPA Dockets.
Information claimed as CBI and other information whose disclosure is
restricted by statute, which is not included in the official public
docket, will not be available for public viewing in EPA's electronic
public docket. EPA's policy is that copyrighted material will not be
placed in EPA's electronic public docket but will be available only in
printed, paper form in the official public docket. To the extent
feasible, publicly available docket materials will be made available in
EPA's electronic public docket. When a document is selected from the
index list in EPA dockets, the system will identify whether the
document is available for viewing in EPA's electronic public docket.
Although, not all docket materials may be available electronically, you
may still access any of the publicly available docket materials through
the docket facility identified in Unit I.B. EPA intends to work towards
providing electronic access to all of the publicly available docket
materials through EPA's electronic public docket.
For public commenters, it is important to note that EPA's policy
is that public comments, whether submitted electronically or on paper,
will be made available for public viewing in EPA's electronic public
docket as EPA receives them and without change, unless the comment
contains copyrighted material, CBI, or other information whose
disclosure is restricted by statute. When EPA identifies a comment
containing copyrighted material, EPA will provide a reference to that
material in the version of the comment that is placed in EPA's
electronic public docket. The entire printed comment, including the
copyrighted material, will be available in the public docket.
Public comments submitted on computer disks that are mailed or
delivered to the docket will be transferred to EPA's electronic public
docket. Public comments that are mailed or delivered to the docket will
be scanned and placed in EPA's electronic public docket. Where
practical, physical objects will be photographed, and the photograph
will be placed in EPA's electronic public docket along with a brief
description written by the docket staff.
C. How and to Whom Do I Submit Comments?
You may submit comments electronically, by mail, or through hand
delivery/courier. To ensure proper receipt by EPA, identify the
appropriate docket ID number in the subject line on the first page of
your comment. Please ensure that your comments are submitted within the
specified comment period. Comments received after the close of the
comment period will be marked ``late.'' EPA is not required to consider
these late comments. If you wish to submit CBI or information that is
otherwise protected by statute, please follow the instructions in Unit
I.D. Do not use EPA Dockets or e-mail to submit CBI or information
protected by statute.
1. Electronically. If you submit an electronic comment as
prescribed in this unit, EPA recommends that you include your name,
mailing address, and an e-mail address or other contact information in
the body of your comment. Also, include this contact information on the
outside of any disk
[[Page 50139]]
or CD ROM you submit, and in any cover letter accompanying the disk or
CD ROM. This ensures that you can be identified as the submitter of the
comment and allows EPA to contact you in case EPA cannot read your
comment due to technical difficulties or needs further information on
the substance of your comment. EPA's policy is that EPA will not edit
your comment, and any identifying or contact information provided in
the body of a comment will be included as part of the comment that is
placed in the official public docket, and made available in EPA's
electronic public docket. If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA
may not be able to consider your comment.
i. EPA Dockets. Your use of EPA's electronic public docket to
submit comments to EPA electronically is EPA's preferred method for
receiving comments. Go directly to EPA Dockets at http://www.epa.gov/edocket
, and follow the online instructions for submitting comments.
Once in the system, select ``search,'' and then key in docket ID number
OPP-2003-0262. The system is an `` anonymous access'' system, which
means EPA will not know your identity, e-mail address, or other contact
information unless you provide it in the body of your comment.
ii. E-mail. Comments may be sent by e-mail to opp-docket@epa.gov,
Attention: Docket ID number OPP-2003-0262. In contrast to EPA's
electronic public docket, EPA's e-mail system is not an ``anonymous
access'' system. If you send an e-mail comment directly to the docket
without going through EPA's electronic public docket, EPA's e-mail
system automatically captures your e-mail address. E-mail addresses
that are automatically captured by EPA's e-mail system are included as
part of the comment that is placed in the official public docket, and
made available in EPA's electronic public docket.
iii. Disk or CD ROM. You may submit comments on a disk or CD ROM
that you mail to the mailing address identified in Unit I.C.2. These
electronic submissions will be accepted in WordPerfect or ASCII file
format. Avoid the use of special characters and any form of encryption.
2. By mail. Send your comments to: Public Information and Records
Integrity Branch (PIRIB) (7502C), Office of Pesticide Programs (OPP),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460-0001, Attention: Docket ID number OPP-2003-0262.
3. By hand delivery or courier. Deliver your comments to: Public
Information and Records Integrity Branch (PIRIB), Office of Pesticide
Programs (OPP), Environmental Protection Agency, Rm. 119, Crystal Mall
2, 1921 Jefferson Davis Hwy., Arlington, VA, Attention: Docket
ID number OPP-2003-0262. Such deliveries are only accepted during the
docket's normal hours of operation as identified in Unit I.B.1.
D. How Should I Submit CBI to the Agency?
Do not submit information that you consider to be CBI
electronically through EPA's electronic public docket or by e-mail. You
may claim information that you submit to EPA as CBI by marking any part
or all of that information as CBI (if you submit CBI on disk or CD ROM,
mark the outside of the disk or CD ROM as CBI and then identify
electronically within the disk or CD ROM the specific information that
is CBI). Information so marked will not be disclosed except in
accordance with procedures set forth in 40 CFR part 2.
In addition to one complete version of the comment that includes
any information claimed as CBI, a copy of the comment that does not
contain the information claimed as CBI must be submitted for inclusion
in the public docket and EPA's electronic public docket. If you submit
the copy that does not contain CBI on disk or CD ROM, mark the outside
of the disk or CD ROM clearly that it does not contain CBI. Information
not marked as CBI will be included in the public docket and EPA's
electronic public docket without prior notice. If you have any
questions about CBI or the procedures for claiming CBI, please consult
the person listed under FOR FURTHER INFORMATION CONTACT.
E. What Should I Consider as I Prepare My Comments for EPA?
You may find the following suggestions helpful for preparing your
comments:
1. Explain your views as clearly as possible.
2. Describe any assumptions that you used.
3. Provide copies of any technical information and/or data you used
that support your views.
4. If you estimate potential burden or costs, explain how you
arrived at the estimate that you provide.
5. Provide specific examples to illustrate your concerns.
6. Make sure to submit your comments by the deadline in this
notice.
7. To ensure proper receipt by EPA, be sure to identify the docket
ID number assigned to this action in the subject line on the first page
of your response. You may also provide the name, date, and Federal
Register citation.
II. What Action is the Agency Taking?
EPA has received pesticide petitions proposing the establishment
and/or amendment of regulations for residues of a certain pesticide
chemical in or on various food commodities under section 408 of the
Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a. EPA has
determined that this petition contains data or information regarding
the elements set forth in FFDCA section 408(d)(2); however, EPA has not
fully evaluated the sufficiency of the submitted data at this time or
whether the data support granting of the petition. Additional data may
be needed before EPA rules on the petition.
List of Subjects
Environmental protection, Agricultural commodities, Feed additives,
Food additives, Pesticides and pests, Reporting and recordkeeping
requirements.
Dated: August 11, 2003.
Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.
Summary of Petitions
The petitioner's summary of the pesticide petitions are printed
below as required by FFDCA section 408(d)(3). The summary of the
petitions were prepared by BASF Corporation and represents the view of
BASF Corporation. The petition summary announces the availability of a
description of the analytical methods available to EPA for the
detection and measurement of the pesticide chemical residues or an
explanation of why no such method is needed.
Interregional Research Project Number 4 (IR-4)
PP 2E6483 and PP 3E6558
EPA has received pesticide petitions (2E6483 and 3E6558) from
Interregional Research Project Number 4 (IR-4), 681 U.S. Highway
1 South, North Brunswick, NJ 08902-3390 proposing, pursuant to
section 408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21
U.S.C. 346a(d), to amend 40 CFR part 180.493 by establishing tolerances
for residues of dimethomorph, (E,Z)4-[3-(4-chlorophenyl)-3-(3,4-
dimethoxyphenyl)-1-oxo-2-propenyl morpholine in or on the following raw
agricultural commodities: Vegetable, fruiting, group 8 at 2.0 parts per
million (ppm) (2E6483), brassica, leafy, greens,
[[Page 50140]]
(subgroup 5B), and turnip, tops at 20 ppm (PP 3E6558), taro, leaves at
6.0 ppm (3E6558), and taro, roots at 0.5 ppm (3E6558). IR-4 also
proposes to delete the existing tolerance for tomato, fruit at 0.5 ppm.
Tomato is included in the proposed tolerance for the fruiting vegetable
group 8 at 2.0 ppm. EPA has determined that the petitions contain data
or information regarding the elements set forth in section 408(d)(2) of
the FFDCA; however, EPA has not fully evaluated the sufficiency of the
submitted data at this time or whether the data support granting of the
petitions. Additional data may be needed before EPA rules on the
petitions. This summary has been prepared by BASF Corporation, Research
Triangle Park, NC 27709.
A. Residue Chemistry
1. Plant metabolism. Based upon the results of metabolism studies
conducted on potato, grape, and lettuce, the nature of the residues in
plants is considered to be understood.
2. Analytical method. A reliable method for the determination of
dimethomorph residues in fruiting vegetables (except cucurbits) (crop
group 8), leafy brassica greens (subgroup 5B), turnip greens, taro
leaves and roots exists; this method is the FDA Multi-Residue Method,
Protocol D, as published in the Pesticide Analytical Manual I.
3. Magnitude of residues. The magnitude of residues for the
proposed tolerances are adequately understood.
B. Toxicological Profile
1. Acute toxicity--i. Oral lethal dose LD50 studies were
conducted on dimethomorph technical:
a. An acute oral toxicity study in the Sprague-Dawley rat for
dimethomorph technical with a LD50 of 4,300 milligrams/
kilogram body weight (mg/kg bwt) for males and 3,500 mg/kg bwt for
females. Based upon EPA toxicity criteria, the acute oral toxicity
category for dimethomorph technical is Category III or slightly toxic.
b. An acute toxicity study in the CD-1 mouse for dimethomorph
technical with a LD50 of greater than 5,000 mg/kg bwt for
males and 3,699 mg/kg/bwt for females. Based on the EPA toxicity
category criteria, the acute oral toxicity category for dimethomorph
technical is Category III or slightly toxic.
ii. Oral LD50 studies were conducted on the two isomers
(E and Z) alone:
a. An acute oral toxicity study in the Wistar rat for the E-isomer
with a LD50 greater than 5,000 mg/kg bwt for males and
approximately 5,000 mg/kg bwt for females.
b. An acute oral toxicity study in the Wistar rat for the Z-isomer
with a LD50 greater than 5,000 mg/kg bwt for both males and
females.
iii. An acute dermal toxicity study in the Wistar rat for
dimethomorph technical with a dermal LD50 greater than 5,000
mg/kg bwt for both males and females. Based on the EPA toxicity
category criteria, the acute dermal toxicity category for dimethomorph
is Category IV or relatively non-toxic.
iv. A 4-hour inhalation study in Wistar rats for dimethomorph
technical with a lethal concentration LC50 greater than 4.2
milligram per liter (mg/L) for both males and females. Based on the EPA
toxicity category criteria, the acute inhalation toxicity category for
dimethomorph technical is Category IV or relatively non-toxic.
v. A skin irritation study was performed using New Zealand White
rabbits. Based on EPA's toxicity criteria, the skin irritation toxicity
category for dimethomorph technical in this study is Category IV or
non-to-slightly irritating.
vi. An eye irritation study using New Zealand white rabbits
demonstrated dimethomorph technical produced moderate conjunctival
redness, slight to moderate chemosis and slight discharge 3 hours after
treatment. Based on EPA's toxicity criteria, the eye toxicity category
for dimethomorph technical is Category III (slightly to moderately
irritating).
2. Genotoxicity.--i. Salmonella reverse gene mutation assays (2
studies) were negative up to a limit dose of 5,000 g/plate. Chinese
hamster lung V79 cells were negative for mutations at the HGPRT locus
at up to toxic doses in two studies.
ii. Two Chinese hamster lung (V79 cells) structural chromosomal
studies were reportedly positive for chromosomal aberrations at the
highest dose tested (HDT) (160 g/ml/-S9; 170 g/ml/+S9). However,
dimethomorph induced only a weak response in increasing chromosome
aberrations in this test system. In addition, these results were not
confirmed in two micronucleus tests under in vivo conditions.
iii. Structural chromosomal aberration studies were weakly positive
in human lymphocytic cultures, but only in S9 activated cultures
treated at 422 g/mL, the HDT, which was strongly cytotoxic. No increase
in chromosomal aberrations was observed in the absence of S9 activation
at all doses. Furthermore, the positive clastogenic response observed
under the in vitro conditions was not confirmed in two in vivo
micronucleus assays.
iv. Micronucleus assay (2 studies) indicated that dimethomorph was
negative for inducing micronuclei in bone marrow cells of mice
following i.p. administration of doses up to 200 mg/kg or oral doses up
to the limit dose of 5,000 mg/kg. Thus, dimethomorph was found to be
negative in these studies for causing cytogenic damage in vivo.
v. Dimethomorph was negative for inducing unscheduled DNA
synthesis, in cultured rat liver cells, at doses up to 250 grams per
milliliter (g/ml), a weakly cytotoxic level.
vi. Dimethomorph was negative for transformation in Syrian hamster
embryo cells treated, in the presence and absence of activation, up to
cytotoxic concentrations (265 g/mL/+S9; 50 g/mL/-S9).
3. Reproductive and developmental toxicity--i. A rat developmental
toxicity study with a lowest observed adverse effect level (LOAEL) for
maternal toxicity of 160 mg/kg/day and a NOAEL for maternal toxicity of
60 mg/kg/day. The NOAEL for developmental toxicity is 60 mg/kg/day.
Dimethomorph is not teratogenic in the Sprague-Dawley rat.
ii. A rabbit development toxicity study with a LOAEL for maternal
toxicity of 650 mg/kg/day and a NOAEL for maternal toxicity of 300 mg/
kg/day. The NOAEL for developmental toxicity is 650 mg/kg/day, the HDT.
Dimethomorph is not teratogenic in the New Zealand white rabbit.
iii. A two-generation rat reproduction study with a LOAEL for
parental systemic toxicity of 1,000 ppm, or approximately 80 mg/kg/day,
and a NOAEL for parental systemic toxicity of 300 ppm, or approximately
24 mg/kg/day. The NOAEL for fertility and reproductive function was
1,000 ppm, the highest concentration tested (HCT), or approximately 80
mg/kg bwt/day.
4. Subchronic toxicity--i. A 90-day dietary study in Sprague-Dawley
rats with a NOAEL of greater than or equal to 1,000 ppm, the HCT
tested, or approximately 73 mg/kg/day for males and 82 mg/kg/day for
females.
ii. A 90-day dog dietary study with a NOAEL of 450 ppm, or
approximately 15 mg/kg/day, and a LOAEL of 1,350 ppm, or approximately
43 mg/kg/day.
5. Chronic toxicity-i. A 2-year chronic toxicity study in Sprague-
Dawley rats with a NOAEL of 200 ppm or approximately 9 mg/kg/day for
males and 12 mg/kg/day for females. The LOAEL for systemic toxicity is
750 ppm, or approximately 36 mg/kg/day for males and 58 mg/kg/day for
females.
ii. A 1-year chronic toxicity study in dogs with a NOAEL of 450
ppm, or approximately 14.7 mg/kg/day and a
[[Page 50141]]
LOAEL of 1,350, or approximately 44.6 mg/kg/day.
iii. A 2-year oncogenicity study in Sprague-Dawley rats with a
NOAEL for systemic toxicity of 200 ppm, or approximately 9 mg/kg/day
for males and 11 mg/kg/day for females. The LOAEL for systemic toxicity
was 750 ppm, or approximately 34 mg/kg/day for males and 46 mg/kg/day
for females. There was no evidence of increased incidence of neoplastic
lesions in treated animals. The NOAEL for oncogenicity is 2,000 ppm,
the Highest Concentration Tested (HCT), or approximately 95 mg/kg/day
for males and 132 mg/kg/day for females.
iv. A 2-year oncogenicity study in CD-1 mice with a NOAEL for
systemic toxicity of 100 mg/kg/day and a LOAEL of 1,000 mg/kg/day.
There was no evidence of increased incidence of neoplastic lesions in
treated animals. The NOAEL for oncogenicity is 1,000 mg/kg/day, the
HDT.
6. Animal metabolism. Results from the livestock and rat metabolism
studies show that orally administered dimethomorph was rapidly excreted
by the animals. The principal route of elimination is the feces.
7. Metabolite toxicology. There were no metabolites identified in
plant or animal commodities which require regulation.
8. Endocrine disruption. Collective organ weights and
histopathological findings from the two-generation reproduction study
in rats, as well as from the subchronic and chronic toxicity studies in
two or more animal species, demonstrate no apparent estrogenic effects
or effects on the endocrine system. There is no information available
which suggests that dimethomorph technical would be associated with
endocrine effects.
C. Aggregate Exposure
1. Dietary exposure. The CARES 1.1 model with the CSFII/FCID
consumption data were used to calculate chronic and acute exposure
estimates. Result exposure estimates 99.9th percentile were
compared against the dimethomorph reference dose (RfD) and chronic
population adjusted dose (cPAD).
i. Food. The dietary assessment analysis followed an initial tier
approach with only one minor refinement. Tolerance values, default
processing factors, and 100% crop treated (CT) values were assumed in
the assessment. The only minor refinement was including percent crop
treated values for potatoes (2.2%), tomatoes (0.1%), cucumbers (2.9%),
and pumpkin (13.6%). Vegetables (fruiting, bulb, cucurbit), lettuce
(leaf, head), grapes (including raisins), potatoes, hops, grain,
brassica (leafy greens), leaves of root and tuber vegetables, and taro
roots as the target crops were also considered for this analysis.
a. Chronic. Results of the chronic dietary exposure assessment for
dimethomorph (BAS 550 F) are listed in Table 1. The estimated chronic
dietary exposure for all current and pending commodities ranged from
7.5% to 15.2% of the %cPAD (0.1 mg/kg bwt/day) for all subpopulations.
Table 1.-Chronic Dietary Exposure Assessment for Dimethomorph (BAS 550 F)
----------------------------------------------------------------------------------------------------------------
Exposure Estimate (mg/kg bwt/
Population day) %cRfD %cPAD
----------------------------------------------------------------------------------------------------------------
Birth to 1-year 0.007972 7.97 7.97
----------------------------------------------------------------------------------------------------------------
1-2 years 0.01513 15.13 15.13
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3-5 years 0.01331 13.31 13.31
----------------------------------------------------------------------------------------------------------------
1-6 years 0.01512 15.12 15.12
----------------------------------------------------------------------------------------------------------------
6-12 years 0.007794 7.79 7.79
----------------------------------------------------------------------------------------------------------------
Teens 13-19 years 0.007482 7.48 7.48
----------------------------------------------------------------------------------------------------------------
Females 13-49 years 0.007771 7.77 7.77
----------------------------------------------------------------------------------------------------------------
Males 20-49 years 0.006853 6.85 6.85
----------------------------------------------------------------------------------------------------------------
Adults 50+ years 0.007548 7.55 7.55
----------------------------------------------------------------------------------------------------------------
b. Acute. Exposure estimates for the dimethomorph acute dietary
assessment ranged from 0.064 to 0.174 mg/kg bwt/day for all
subpopulations (Table 2). The %aRfd and %aPAD were not applicable for
the acute dietary assessment since toxicology studies have shown that
dimethomorph poses no acute dietary risk.
Table 2.--Acute Dietary Exposure Assessment for dimethomorph (BAS 550 F)
----------------------------------------------------------------------------------------------------------------
Exposure Estimate (mg/kg bwt/
Population day) %aRfD %aPAD
----------------------------------------------------------------------------------------------------------------
Birth to 1-year 0.1736 NA NA
----------------------------------------------------------------------------------------------------------------
1-2 years 0.1742 NA NA
----------------------------------------------------------------------------------------------------------------
3-5 years 0.1584 NA NA
----------------------------------------------------------------------------------------------------------------
1-6 years 0.1654 NA NA
----------------------------------------------------------------------------------------------------------------
6-12 years 0.09621 NA NA
----------------------------------------------------------------------------------------------------------------
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Teens 13-19 years 0.07855 NA NA
----------------------------------------------------------------------------------------------------------------
Females 13-49 years 0.07306 NA NA
----------------------------------------------------------------------------------------------------------------
Males 20-49 years 0.06386 NA NA
----------------------------------------------------------------------------------------------------------------
Adults 50 + years 0.07058 NA NA
----------------------------------------------------------------------------------------------------------------
Results of the chronic and acute dietary exposure analysis
demonstrate a reasonable certainty that no harm to the general U.S.
population or any subpopulation would results from the use of
dimethomorph on vegetables (fruiting, bulb, cucurbit), lettuce (leaf,
head), grapes (including raisins), potatoes, hops, grain, brassica
(leafy greens), leaves of root and tuber vegetables, and taro root.
ii. Drinking water. EPA's Pesticide Root Zone Model/Exposed
Analysis Modeling System (PRZM/EXAMS) and Screening Concentration in
Groundwater (SCI-GROW) models were used to estimate the maximum
dimethomorph concentrations in surface water and ground water,
respectively. Results for the chronic drinking water assessment are
listed in Table 3.
Table 3.--Chronic Drinking Water Assessment for Dimethomorph
----------------------------------------------------------------------------------------------------------------
Children birth to
DWLOC chronic Adult males 20-49 Adult females 13-49 Children 1-6 1
----------------------------------------------------------------------------------years-------------------------
No effect level 9 9 9 9
-----------------------------------------------------------------------------------------------
Safety factor 100 100 100 100
-----------------------------------------------------------------------------------------------
RfD= 0.09 0.09 0.09 0.09
-----------------------------------------------------------------------------------------------
cPAD 0.09 0.09 0.09 0.09
-----------------------------------------------------------------------------------------------
A) Chronic food (mg/kg/day) 0.006853 0.007771 0.01512 0.007972
-----------------------------------------------------------------------------------------------
B) Residential (mg/kg/day) 0 0 0 0
-----------------------------------------------------------------------------------------------
water cPAD-(A+B) 0.08314700 0.10222900 0.07488000 0.08202800
-----------------------------------------------------------------------------------------------
DWLOC chronic [mu]g/L 2910 3067 749 820
-----------------------------------------------------------------------------------------------
DEC's
----------------------------------------------------------------------------------------------------------------
PRZM/EXAMS (EFED) surface 12.65 12.65 12.65 12.65
water ([mu]g/L)
-------------------------------
Sci-Grow (EFED) ground water 0.26 0.26 0.26 0.26
----------------------------------------------------------------------------------------------------------------
2. Aggregate exposure (diet + water). The aggregate exposure of
dimethomorph residues for food and drinking water is summarized in
Table 4 below. Currently dimethomorph (BAS 550 F) is not considered for
residential use and therefore residential exposure was not included in
the aggregate exposure assessment.
Table 4.--Aggregate Exposure of Dimethomorph (BAS 550 F)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Exposure Infants (0-1 years) Children (1-6 years) Males (20-49 years) Females (13-49 years)
--------------------------------------------------------------------------------------------------------------------------------------------------------
FOOD
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acute exposure (mg/kg bwt/day) 0.1736 0.1654 0.06386 0.07306
-----------------------------------------------------
Chronic exposure (mg/kg bwt/day) 0.007972 0.01512 0.006853 0.007771
-----------------------------------------------------
%aRfD and %aPAD NA NA NA NA
-----------------------------------------------------
%cRfD and %cPAD 7.97 15.12 6.85 7.77
-----------------------------------------------------
WATER
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acute exposure (mg/kg/bwt) 0.001265 0.000843 0.000361 0.000402
-----------------------------------------------------
[[Page 50143]]
Chronic exposure (mg/kg bwt/day) 0.001265 0.000843 0.000361 0.000402
-----------------------------------------------------
%aRfD and %aPAD NA NA NA NA
-----------------------------------------------------
%cRfD and %cPAD 25.30 16.87 7.23 8.03
-----------------------------------------------------
AGGREGATE
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acute exposure (mg/kg bwt/day) 0.174865 0.166243 0.064221 0.073462
-----------------------------------------------------
Chronic exposure (mg/kg bwt/day) 0.009237 0.015963 0.007214 0.008173
-----------------------------------------------------
%aRfD and %aPAD NA NA NA NA
-----------------------------------------------------
%cRfD and %cPAD 33.27 31.99 14.08 15.80
--------------------------------------------------------------------------------------------------------------------------------------------------------
These results indicate the aggregate exposure of dimethomorph (BAS
550 F), from potential residues in food and drinking water, will not
exceed EPA's level of concern (100% of RfD). Overall, considering a
``worst-case'' scenario, we can conclude with reasonable certainty that
no harm will occur from either acute or chronic aggregate exposure of
dimethomorph residues in the current and pending commodities.
3. Non-dietary exposure. Currently, there are no registered
residential uses for dimethomorph in the United States. Thus, an
assessment of non-dietary exposure is not relevant to this petition.
D. Cumulative Effects
There is no information to indicate that any toxic effects
produced by dimethomorph would be cumulative with those of any other
chemical. The fungicidal mode of action of dimethomorph is unique;
dimethomorph inhibits cell wall formation only in Oomycete fungi. The
result is lysis of the cell wall that kills growing cells and inhibits
spore formation in mature hyphae. This unique mode of action and
limited pest spectrum suggest that there is little or no potential for
cumulative toxic effects in mammals. In addition, the toxicity studies
submitted to support this petition do not indicate that dimethomorph is
a particularly toxic compound. No toxic end-points of potential concern
were identified.
E. Safety Determination
1. U.S. population. Based on the acute toxicity data, BASF believes
that dimethomorph does not pose any acute dietary risks. Therefore, a
calculation of an acute RfD is not needed. The cPAD is 0.1 mg/kg bwt/
day, based on a NOAEL of approximately 10 mg/kg bwt/day (200 ppm) from
a 2-year dietary toxicity study in rats that demonstrated decreased
body weight and liver foci in females at 750 ppm. The cPAD is
calculated using an uncertainty factor of 100. The theoretical maximum
residue concentration (TMRC) for all commodities covered in this
petition is estimated at 0.003 mg/kg bwt/day for the general
population. This represents a dietary exposure to the general
population of the United States that is 3.0% of the cPAD. The combined
TMRC for all current and pending dimethomorph tolerances in potatoes,
tomatoes, grapes, hops, cereal grain commodities, lettuce (head and
leaf), endive (escarole), radichio, cucurbit vegetables (crop group 9),
bulb vegetables (crop group 3), and fruiting vegetables (except
cucurbits) (crop group 8) will utilize less than 10% of the cPAD for
the general U.S. population. Since EPA generally has no concern for
exposures below 100 percent of the cPAD, EPA should conclude that there
is a reasonable certainty that no harm will result from aggregate
exposure to dimethomorph residues in or on commodities of the cited
crops.
2. Infants and children. The TMRC for all commodities covered in
this petition is minimal. The consumption of residues of dimethomorph
on commodities associated with this request will use approximately 7.0%
of the cPAD for children ages 1-6. Moreover, the combined TMRC values
for all current and pending dimethomorph tolerances will utilize less
than 10% of the cPAD for each of the subgroups. The results of the
studies submitted to support this package provide no evidence that
dimethomorph caused reproductive, developmental or fetotoxic effects.
No such effects were noted at dose levels that were not maternally
toxic. The NOAELs observed in the developmental and reproductive
studies were 6 to 65 times higher than the NOAEL used to establish the
cPAD. There is no evidence to indicate that children or infants would
be more sensitive than adults to toxic effects caused by exposure to
dimethomorph. Therefore, the registrant believes that the results of
the toxicology and metabolism studies support both the safety of
dimethomorph to humans based on the intended use as a fungicide on
domestically produced fruiting vegetables (except cucurbits) (crop
group 8) and the granting of the requested tolerances.
F. International Tolerances.
There are no Canadian, Mexican, or Codex maximum residue levels
established for dimethomorph for the commodities associated with this
request; consequently, a discussion of international harmonization is
not relevant.
[FR Doc. 03-20899 Filed 8-19-03; 8:45 am]
BILLING CODE 6560-50-S