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Spiromesifen; Notice of Filing a Pesticide Petition to Establish a Tolerance for a Certain Pesticide Chemical in or on Food

 
[Federal Register: July 28, 2004 (Volume 69, Number 144)]
[Notices]
[Page 45047-45051]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28jy04-70]

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ENVIRONMENTAL PROTECTION AGENCY
[OPP-2004-0197; FRL-7366-2]
 
Spiromesifen; Notice of Filing a Pesticide Petition to Establish 
a Tolerance for a 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 a pesticide 
petition 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-2004-0197, must be 
received on or before August 27, 2004.

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: Thomas C. Harris, Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 308-9423; e-mail address: 
harris.thomas@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:
    ? Crop production (NAICS 111), e.g., agricultural workers; 
greenhouse, nursery, and floriculture workers; farmers.
    ? Animal production (NAICS 112), e.g., cattle ranchers and 
farmers, dairy cattle farmers, livestock farmers.
    ? Food processing (NAICS 311), e.g., agricultural workers; 
farmers; greenhouse, nursery, and floriculture workers; ranchers; 
pesticide applicators.
    ? Pesticide manufacturers (NAICS 32532), e.g., agricultural 
workers; commercial applicators; farmers; greenhouse, nursery, and 
floriculture workers; residential users.
    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 identification (ID) number OPP-2004-0197. 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. Note: Due to renumbering of 
buildings in area, the street address will change to 1801 South Bell 
Street as of June 26, 2004. 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.regulations.gov/ 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

[[Page 45048]]

facility identified in Unit I.B.1. Once in the system, select 
``search,'' then key in the appropriate docket ID number.
    Certain types of information will not be placed in the EPA Dockets. 
Information claimed as CBI and other information whose disclosure is 
restricted by statute, which is not included in the official public 
docket, will not be available for public viewing in EPA's electronic 
public docket. EPA's policy is that copyrighted material will not be 
placed in EPA's electronic public docket but will be available only in 
printed, paper form in the official public docket. To the extent 
feasible, publicly available docket materials will be made available in 
EPA's electronic public docket. When a document is selected from the 
index list in EPA Dockets, the system will identify whether the 
document is available for viewing in EPA's electronic public docket. 
Although not all docket materials may be available electronically, you 
may still access any of the publicly available docket materials through 
the docket facility identified in Unit I.B. EPA intends to work towards 
providing electronic access to all of the publicly available docket 
materials through EPA's electronic public docket.
    For public commenters, it is important to note that EPA's policy is 
that public comments, whether submitted electronically or in paper, 
will be made available for public viewing in EPA's electronic public 
docket as EPA receives them and without change, unless the comment 
contains copyrighted material, CBI, or other information whose 
disclosure is restricted by statute. When EPA identifies a comment 
containing copyrighted material, EPA will provide a reference to that 
material in the version of the comment that is placed in EPA's 
electronic public docket. The entire printed comment, including the 
copyrighted material, will be available in the public docket.
    Public comments submitted on computer disks that are mailed or 
delivered to the docket will be transferred to EPA's electronic public 
docket. Public comments that are mailed or delivered to the docket will 
be scanned and placed in EPA's electronic public docket. Where 
practical, physical objects will be photographed, and the photograph 
will be placed in EPA's electronic public docket along with a brief 
description written by the docket staff.

C. How and to Whom Do I Submit Comments?

    You may submit comments electronically, by mail, or through hand 
delivery/courier. To ensure proper receipt by EPA, identify the 
appropriate docket ID number in the subject line on the first page of 
your comment. Please ensure that your comments are submitted within the 
specified comment period. Comments received after the close of the 
comment period will be marked ``late.'' EPA is not required to consider 
these late comments. If you wish to submit CBI or information that is 
otherwise protected by statute, please follow the instructions in Unit 
I.D. Do not use EPA Dockets or e-mail to submit CBI or information 
protected by statute.
    1. Electronically. If you submit an electronic comment as 
prescribed in this unit, EPA recommends that you include your name, 
mailing address, and an e-mail address or other contact information in 
the body of your comment. Also include this contact information on the 
outside of any disk or CD ROM you submit, and in any cover letter 
accompanying the disk or CD ROM. This ensures that you can be 
identified as the submitter of the comment and allows EPA to contact 
you in case EPA cannot read your comment due to technical difficulties 
or needs further information on the substance of your comment. EPA's 
policy is that EPA will not edit your comment, and any identifying or 
contact information provided in the body of a comment will be included 
as part of the comment that is placed in the official public docket, 
and made available in EPA's electronic public docket. If EPA cannot 
read your comment due to technical difficulties and cannot contact you 
for clarification, EPA may not be able to consider your comment.
    i. EPA Dockets. Your use of EPA's electronic public docket to 
submit comments to EPA electronically is EPA's preferred method for 
receiving comments. Go directly to EPA Dockets at http://www.epa.gov/
edocket/, and follow the online instructions for submitting comments. 
Once in the system, select ``search,'' and then key in docket ID number 
OPP-2004-0197. 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-2004-0197. 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-2004-0197.
    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-2004-0197. Note: Due to renumbering of buildings in area, 
the street address will change to 1801 South Bell Street as of June 26, 
2004. 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,

[[Page 45049]]

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 a pesticide petition as follows 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: July 9, 2004.
Betty Shackleford,
Acting Director, Registration Division, Office of Pesticide Programs.

Summary of Petition

    The petitioner summary of the pesticide petition is printed below 
as required by FFDCA section 408(d)(3). The summary of the petition was 
prepared by the petitioner and represents the view of the petitioner. 
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.

I. Bayer Corporation

PP 3F6537

    EPA has received a pesticide petition (3F6537) from Bayer 
CropScience, 2 T.W. Alexander Drive, Research Triangle Park, NC 27709 
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 by 
establishing tolerances for the following residues:
    1. Spiromesifen; butanoic acid, 3,3-dimethyl-, 2-oxo-3-(2,4,6-
trimethylphenyl)-1-oxaspiro[4.4]non-3-en-4-yl ester, and its enol 
metabolite; 4-hydroxy- 3-(2,4,6-trimethylphenyl)-1-oxaspiro[4.4]
non-3-en-2-one in or on the raw agricultural commodities strawberry at 
2.0 parts per million (ppm); vegetable, tuberous and corm, crop subgroup 
1C at 0.01 ppm; vegetable, leafy greens (except Brassica), crop subgroup 
4A at 10 ppm; vegetable, Brassica, head and stem, crop subgroup 5A at 
2.0 ppm; vegetable, Brassica, leafy, crop subgroup 5B at 12 ppm; 
vegetable, fruiting, crop group 8 at 0.30 ppm; tomato, paste at 0.60 
ppm; vegetable, Cucurbit, crop group 9 at 0.10 ppm; corn, field, grain 
at 0.01 ppm; corn, field, forage at 3.0 ppm; corn, field, stover at 5.0 
ppm; cotton at 0.50 ppm; and cotton, gin byproducts at 15 ppm.
    2. Spiromesifen; butanoic acid, 3,3-dimethyl-, 2-oxo-3-(2,4,6-
trimethylphenyl)-1-oxaspiro[4.4]non-3-en-4-yl ester, its enol 
metabolite; 4-hydroxy-3-(2,4,6-trimethylphenyl)-1-oxaspiro[4.4]non- 3-
en-2-one, and its metabolites containing the 4-hydroxymethyl moiety; 4- 
hydroxy-3-[4- (hydroxymethyl)- 2,6-dimethylphenyl]- 1-oxaspiro[4.4]
non-3-en-2-one, moieties in or on the rotational crop commodities 
alfalfa, forage at 1.5 ppm; alfalfa, hay at 3.0 ppm; wheat, grain at 
0.01 ppm; wheat, forage at 0.20 ppm; wheat, hay at 0.15 ppm; wheat, 
straw at 0.25 ppm; wheat, bran at 0.05 ppm; wheat, shorts at 0.03 ppm; 
barley, grain at 0.02 ppm; barley, hay at 0.25 ppm; barley, straw at 
0.25 ppm; beet, sugar, tops at 0.20 ppm; beet, sugar, roots at 0.02 
ppm; and beet, sugar, molasses at 0.05 ppm.
    3. Spiromesifen; butanoic acid, 3,3-dimethyl-, 2-oxo-3-(2,4,6-
trimethylphenyl)-1-oxaspiro[4.4]non-3-en-4-yl ester, and its 
metabolites containing the enol; 4-hydroxy- 3-(2,4,6-trimethylphenyl)-
1-oxaspiro[4.4] non-3-en-2-one, or 4-hydroxymethyl; 4- hydroxy-3-[4-
(hydroxymethyl)-2,6-dimethylphenyl]- 1-oxaspiro[4.4] non-3-en-2-one, 
moieties in or on the raw agricultural commodities cattle, fat at 0.05 
ppm; cattle, meat byproducts at 0.05 ppm; milk at 0.01 ppm; and milk, 
fat at 0.03 ppm.
    EPA has determined that the petition contains 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 supports granting of the 
petition. Additional data may be needed before EPA rules on the 
petition.

A. Residue Chemistry

    1. Plant metabolism. The metabolism of spiromesifen in plants is 
adequately understood. Studies have been conducted to delineate the 
metabolism of radiolabeled spiromesifen in various crops, all showing 
similar results. The residue of concern is spiromesifen and its enol 
metabolite.
    2. Analytical method. Adequate analytical methodology using LC/MS/
MS detection is available for enforcement purposes.
    3. Magnitude of residues. Complete residue data exists for 
spiromesifen on these crops and crop groupings. The data support the 
requested tolerances.

B. Toxicological Profile

    1. Acute toxicity. Oral and dermal LD50 values were 
>2,000 mg/kg bw. Inhalation LC50 values were >4,873 mg/
m3 air. Spiromesifen was not irritating to rabbit skin or 
eyes but did cause skin sensitization in the Magnusson/Kligman 
maximization test in guinea pigs. Acute toxicity studies for 
spiromesifen support an overall toxicity Category III.
    2. Genotoxicity. Several genotoxicity tests were conducted to test 
for point-mutagenic activity, chromosome aberration in vitro and in 
vivo, and for DNA repair. All tests conducted were negative, indicating 
no evidence of mutagenic or genotoxic potential.
    3. Reproductive and developmental toxicity. An oral developmental 
toxicity study in rat did not reveal any evidence of teratogenic 
potential. The maternal and developmental no observed adverse effect 
levels (NOAELs) were 10 mg/kg bw/day. An oral developmental toxicity 
study in rabbits demonstrated a maternal NOAEL of 5 mg/kg bw/day, a 
developmental NOAEL of 35 mg/kg bw/day and did not reveal any 
teratogenic potential. A 2-generation study in rats, with a parental 
toxicity NOAEL of 2.2 mg/kg bw/day for males and 3.8 mg/kg bw/day for 
females, did not reveal evidence of a primary reproductive

[[Page 45050]]

toxicity potential. The reproductive NOAEL was 36.6 mg/kg bw/day for 
males and 14.2 mg/kg bw/day in females.
    4. Subchronic toxicity. A subchronic toxicity feeding study with 
rats over 90 days demonstrated a NOAEL of 6.3 and 7.7 mg/kg bw/day for 
males and females, respectively, based on reduced body weights, effects 
on the lipid metabolism (decrease of triglycerides and cholesterol) and 
thyroid effects (colloidal alteration, hypertrophy) at the higher dose 
levels. A subchronic feeding study in mice over 14 weeks demonstrated a 
NOAEL of 3.2 and 5.1 mg/kg bw/day based on effects on lipid metabolism 
(decrease of cholesterol) and adrenal effects (cytoplasmic 
eosinophilia). A 14-week feeding study in dogs demonstrated a NOAEL of 
9.2 and 9.3 mg/kg bw/day based on liver effects (enzyme induction, 
increased liver weights and cytoplasmic change) and thyroid effects 
(decreased T4).
    5. Chronic toxicity. A 12-month chronic feeding study in rats 
demonstrated a NOAEL of 6.5 and 19.3 mg/kg bw/day for males and 
females, respectively. A 24-month oncogenicity study in rats 
demonstrated a NOAEL of 6.1 and 19.5 mg/kg bw/day for males and 
females, respectively. An oncogenicity study in the mouse revealed a 
NOAEL of 3.3 and 3.8 mg/kg bw/day for males and females, respectively 
based on macroscopic and microscopic adrenal effects. There was no 
indication in the rat or mouse for an oncogenic effect of spiromesifen. 
A 1-year feeding study with dogs demonstrated a NOAEL of 11.5 and 10.8 
mg/kg bw day for males and females, respectively based on decreased 
body weights, liver effects (increased liver weight, hepatocellular 
cytoplasmic change, vacuoles) adrenal effects (increased incidence of 
small cell types).
    6. Animal metabolism. Metabolism and pharmacokinetic studies in the 
rat demonstrate that spiromesifen residues are rapidly absorbed, 
metabolized and eliminated. There was no evidence of accumulation of 
residues in any tissues or organs. The primary metabolites are the 
enol, which is formed by cleavage of the alkyl ester group, and the 4-
hydroxymethyl metabolite. However, several other metabolites are also 
formed.
    7. Metabolite toxicology. The residues of concern are spiromesifen, 
its enol metabolite and BSN 4-hydroxymethyl, which are products of 
metabolism in mammalian systems, as well as in the environment. Since 
both products are major metabolites following the oral administration 
of spiromesifen to rats, toxicology data for these metabolites are 
completely supported by data obtained for spiromesifen.
    8. Endocrine disruption. There is no evidence to suggest that 
spiromesifen has any primary endocrine disruptive potential. 
Reproductive and developmental findings provided no evidence of an 
enhanced sensitivity of the young. All prospective endocrine and 
endocrine-related changes which were noted were considered a function 
of the chemical's biological mode of action, the degree of exposure, a 
response secondary to other changes (e.g, enhanced liver metabolism), 
an aging or strain-specific phenomenon, or some combination of these 
factors.

C. Aggregate Exposure

    1. Dietary exposure. For the acute dietary analysis, the acute 
reference dose (aRfD) of 2.0 mg/kg/day was derived from a NOAEL of 200 
mg/kg based on an acute neurotoxicity study in rats and the application 
of an uncertainty factor (UF) of 100 to account for inter-species 
extrapolation and intra-species variability. For the chronic dietary 
analysis, the chronic reference dose (cRfD), of 0.022 mg/kg/day was 
derived from a NOAEL of 2.2 mg/kg/day based on a 2-generation 
reproduction toxicity study in rats and the application of an UF of 
100. Based on the moderate, exposure-driven, non-primary, and/or animal 
specific nature of the endocrine and neurological changes attributed to 
exposure to spiromesifen as well as the lack of evidence to support a 
primary embryotoxic or teratogenic potential for spiromesifen, an FQPA 
safety factor of 1 was applied to the acute and chronic toxicology 
values, resulting in an acute population adjusted dose (aPAD) of 2.0 
mg/kg/day and a chronic population adjusted dose (cPAD) of 0.022 mg/kg/
day. As a conservative measure, the aPAD and cPAD values were used for 
all population sub-groups when conducting the assessments.
    i. Food. Assessments were conducted to evaluate the potential risks 
due to acute and chronic dietary exposure of the entire U.S. population 
and selected population subgroups to residues of spiromesifen. These 
assessments cover the proposed use of spiromesifen on brassica (head 
and stem, broccoli and cabbage; leafy, mustard greens), corn (field), 
cotton, cucurbits (cantaloupe, cucumbers, and summer squash), fruiting 
vegetables (peppers and tomatoes), leafy greens (head and leaf lettuce 
and spinach), potatoes, strawberries, and the rotational crops of 
alfalfa, barley, sugarbeets, and wheat. For the acute assessment, the 
most highly exposed population subgroup was children 1-6 years with an 
exposure equal to 0.4% of the acute reference dose (aPAD) at the 95th 
percentile. Acute exposure of the overall US population was equivalent 
to 0.3% of the aPAD. For the chronic dietary assessment, the most 
highly exposed population subgroup was children 1-6 years, with an 
exposure equal to 1.2% of the chronic reference dose (cPAD). Chronic 
exposure for the overall U.S. population equated to 0.4% of the cPAD. 
These Tier 2 acute and chronic dietary exposure estimates are well 
below EPA's level of concern for the overall U.S. population as well as 
the various population subgroups.
    ii. Drinking water. Spiromesifen is immobile in soil and therefore 
will not leach into groundwater. Additionally, due to insolubility in 
water and a highly lipophilic nature, any residues in surface water 
will rapidly bind to soil particles and remain with sediment where it 
is quickly degraded, and therefore not contribute to potential dietary 
exposure from drinking water. Estimated environmental concentrations 
(EECs) of spiromesifen and its enol metabolite in surface water (Tier 
I) were determined using EPA's FIRST screening model (FIFRA Index 
Reservoir Screening Tool). EEC predictions of spiromesifen its enol 
metabolite in groundwater (Tier I) were made using SCI-GROW (Screening 
Concentration in Ground Water). Tier II EEC predictions in surface 
drinking water were made using the Pesticide Root Zone Model, PRZM3, in 
combination with the Exposure Analysis Modeling System, EXAMS II, and 
EPA's Index Reservoir (IR) scenario. Use of spiromesifen (Tier II) on 
strawberries and vegetables was simulated in Florida, potatoes in 
Minnesota and cotton in Texas and California. Applications of 
spiromesifen to field corn were also evaluated in Texas.
    The highest predicted Tier I surface water EECs for spiromesifen 
were from use on strawberries, with peak (acute) and annual average 
(chronic) concentrations of 7.41 and 0.18 ppb, respectively. 
Corresponding surface water EECs for the enol metabolite were 37.5 and 
19.4 ppb. Strawberries produced the highest EECs under the Tier I 
scenario due to the conservative runoff assumptions built into the 
model. The highest predicted EECs in ground water were 0.000 ppb for 
spiromesifen and 1.09 ppb for the enol, also from the strawberry use 
scenario. Tier II EECs were predicted to be highest for strawberries 
and vegetables. The highest peak, 4-day, 21-day, 60-day, 90-day, yearly 
upper 90th percentile (of the

[[Page 45051]]

annual maximums) and annual average concentrations across all use 
scenarios were 1.30 and 1.07 ppb for FL strawberries and 0.66, 0.35, 
0.24, 0.07 and 0.05 ppb for Florida vegetables, respectively. EECs of 
spiromesifen enol were highest for Florida strawberries, with 
corresponding concentrations of 32, 30, 26, 17, 11, 3.9, and 1.7 ppb, 
respectively.
    The highest acute and chronic concentrations (spiromesifen and enol 
in surface water combined) across all use scenarios were used to assess 
human health risk from drinking water. Potential risk was estimated by 
comparing estimated drinking water concentrations to the acute and 
chronic Population Adjusted Dose (PAD) values, while accounting for 
differences in body weight and drinking water consumption between 
adults and children. These calculations result in risk estimates in the 
form of percentages of the acute and chronic PAD values. Tier I acute 
risk for adults and children were estimated at 0.06 and 0.23%, 
respectively, while Tier II acute estimates were 0.05 and 0.17%, 
respectively. Maximum Tier I chronic risk was estimated at 2.5% for 
adults and 8.9% for children. Corresponding Tier II chronic risk was 
estimated at 0.52% for adults and 1.8% for children (0.81% for children 
using the mean of the annual average concentrations over the simulation 
period).
    2. Non-dietary exposure. Exposure assessments were prepared for 
both mixer/loader-applicators and reentry workers based on use of 
spiromesifen on various field crops, vegetables and strawberries. 
Agricultural worker margins of exposure (MOE) estimates were 
conservatively based on a no-observable-effect level (NOEL) of 1.06 mg/
kg/day, maximum label rates, and a dermal absorption value of 2.25%. An 
occupational exposure uncertainty factor of 100 was used in the 
assessment. All margins of exposure (total) exceeded 100, indicating 
that these uses of spiromesifen pose no significant risk to workers who 
mix, load and apply this product, or to those who reenter treated areas 
to perform post-application activities. These data support the use of a 
single layer of clothing for mixer/loaders and applicators, gloves for 
mixer/loaders, and a 12-hour REI for reentry workers.
    Exposure assessments were also conducted for both applicators and 
reentry based on use of spiromesifen for ornamentals, greenhouse and 
nursery applications. There are no indoor residential uses for 
spiromesifen, and therefore no assessments were performed for indoor 
residential use. All margins of exposure (total) exceeded 100, 
indicating that these uses of spiromesifen pose no significant risk to 
workers who mix, load and apply this product, or to those who reenter 
treated areas to perform post-application activities. These data 
support the use of a single layer of clothing for mixer/loaders and 
applicators, gloves for mixer/loaders, and reentry activities to be 
performed immediately after the application spray dries.

D. Cumulative Effects

    Spiromesifen represents a new class of chemistry, ketoenoles. There 
are no known registered chemicals within this class. Bayer will submit 
information, if necessary, for EPA to consider concerning potential 
cumulative effects of spiromesifen consistent with the schedule 
established by EPA at 62 FR 42020 (Aug. 4, 1997) (FRL-5734-6) and other 
EPA publications pursuant to the Food Quality Protection Act.

E. Safety Determination

    1. U.S. population. Based on the exposure assessments described 
above and on the completeness and reliability of the toxicity data, it 
can be concluded that total aggregate exposure to spiromesifen from all 
label uses will utilize less than 10 percent of the RfD for chronic 
dietary exposures and that margins of exposure in excess of 100 exist 
for aggregate exposure to spiromesifen for non-occupational exposure. 
EPA generally has no concerns for exposures below 100 percent of the 
RfD, because the RfD represents the level at or below which daily 
aggregate exposure over a lifetime will not pose appreciable risks to 
human health. Margins of exposure of 100 or more also indicate an 
adequate degree of safety. Thus, it can be concluded that there is a 
reasonable certainty that no harm will result from aggregate exposure 
to spiromesifen residues.
    2. Infants and children. In assessing the potential for increased 
sensitivity of infants and children, data from developmental studies in 
both rat and rabbit and a 2-generation reproduction study in the rat 
can be considered. The developmental toxicity studies evaluate any 
potential adverse effects on the developing animal resulting from 
pesticide exposure of the mother during prenatal development. The 
reproduction study evaluates any effects from exposure to the pesticide 
on the reproductive capability of mating animals through two 
generations, as well as any observed systemic toxicity. None of these 
studies conducted with spiromesifen indicated developmental or 
reproductive effects. The toxicology data which support these uses of 
spiromesifen include the following: An oral developmental toxicity 
study in rat that did not reveal any evidence of teratogenic potential. 
Maternal and developmental NOAELs were 10 mg/kg bw/day. An oral 
developmental toxicity study in rabbits demonstrated a maternal NOAEL 
of 5 mg/kg bw/day, a developmental NOAEL of 35 mg/kg bw/day and did not 
reveal any teratogenic potential. A two-generation study in rats, with 
a parental toxicity NOAEL of 2.2 mg/kg bw/day, did not reveal evidence 
of a primary reproductive toxicity potential. The reproductive NOAEL 
was 14.2 mg/kg bw/day. FFDCA Section 408 provides that EPA may apply an 
additional safety factor for infants and children. The additional 
safety factor may be used when prenatal and postnatal threshold effects 
were observed in studies or to account for incompleteness of the 
toxicity database. Based on the toxicological data requirements, the 
data relative to prenatal and postnatal effects in children is 
complete. No indication of increased susceptibility of younger animals 
was observed in any of the above studies. For the population with the 
highest exposure, children 1-6 years old, the acute dietary exposure at 
the 95th percentile was 0.4% of the aPAD, equivalent to an MOE of 
24845. Acute exposure of the overall US population was equivalent to 
0.3% of the aPAD. For the chronic dietary analysis, the most highly 
exposed population subgroup was children 1-6 years old, with an 
exposure equal to 1.2% of the cPAD. Chronic exposure for the overall 
U.S. population equated to 0.4% of the cPAD.

F. International Tolerances

    Codex maximum residue levels (MRLs) are not yet established for 
spiromesifen.

[FR Doc. 04-16720 Filed 7-27-04; 8:45 am]
BILLING CODE 6560-50-S 

 
 


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