[Federal Register: June 9, 2004 (Volume 69, Number 111)]
[Notices]
[Page 32346-32351]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09jn04-65]
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ENVIRONMENTAL PROTECTION AGENCY
[OPP-2004-0148; FRL-7360-2]
Pymetrozine; 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-2004-0148, must be
received on or before July 9, 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: Sidney Jackson, Registration Division
(7505C), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: (703) 305-7610; e-mail address: jackson.sidney@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.
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. Potentially affected entities
may include, but are not limited to:
Crop production (NAICS code 111)
Animal production (NAICS code 112)
Food manufacturing (NAICS code 311)
Pesticide manufacturing (NAICS code 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. 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-2004-0148. 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
[[Page 32347]]
electronic public docket and 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 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 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 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-2004-0148. 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-2004-0148. 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-2004-0148.
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-2004-0148. 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
[[Page 32348]]
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 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:May 24, 2004.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.
Summary of Petition
The petitioner's summary of the pesticide petition is printed below
as required by FFDCA section 408(d)(3). The summary of the petition was
prepared by Syngento Crop Protection, the pesticide's registrant, and
submitted by the Interregional Research Project Number 4 (IR-4) 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.
Interregional Research Project Number 4
PP 2E6467
EPA has received a pesticide petition (PP 2E6467) from the IR-4
Project, Project Centre for Minor Crop Pest Management, Rutgers, The
State University of New Jersey, 681 U.S. Highway 1 South,
North Brunswick, NJ 8920-3390 proposing, pursuant to section 408(d) of
FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part 180, by establishing a
tolerance for residues of the insecticide pymetrozine (1,2,4-triazin-
3(2H)-one,4,5-dihydro-6-methyl-4-(3-pyridinylmethylene)amino in or on
the raw agricultural commodity asparagus at 0.02 parts per million
(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 support granting of the
petition. Additional data may be needed before EPA rules on the
petition.
A. Residue Chemistry
1. Plant metabolism. The metabolism of pymetrozine in plants is
understood for the purposes of the proposed tolerances. Studies in
rice, tomatoes, cotton and potatoes gave similar results. The metabolic
pathways have demonstrated that pymetrozine, per se, is the residue of
concern for tolerance setting purposes.
2. Analytical method. Syngenta has submitted an analytical method
(AG-643) for the determination of pymetrozine in crop substrates. The
limit of detection (LOD) for the analytical method is 1.0 ng and the
limit of quantification (LOQ) is 0.02 ppm. Samples are extracted,
purified with solid-phase and liquid-liquid partitions and analyzed by
high performance liquid chromotography (HPLC). Analytical method has
undergone independent laboratory validation. The pymetrozine Analytical
Method AG-643 is proposed as the tolerance enforcement method. Syngenta
has also submitted an analytical method (AG-647) for the determination
of the major crop metabolite of pymetrozine, GS-23199. GS-23199 is
considered a marker for metabolite residues. This metabolite is not
proposed as part of the tolerance expression. Samples are extracted,
purified with solid-phase and/or liquid-liquid partitions and analyzed
by HPLC.
3. Magnitude of residues. Residue data were generated for
pymetrozine for tolerance setting and dietary exposure estimates. Data
were also generated for a major metabolite, GS-23199. Adequate residue
trials were performed for pymetrozine on the uses proposed in this
notice of filing.
B. Toxicological Profile
1. Acute toxicity. In general, pymetrozine has low acute toxicity
being classified as Toxicity Category III for acute dermal and primary
eye irritation studies and Toxicity Category IV for acute oral, acute
inhalation and primary dermal studies. The oral lethal dose
(LD)50 in rats is >5,820 milligrams/kilogram (mg/kg) for
males and females, combined. The rat dermal LD50 is>2,000
mg/kg and the rat inhalation lethal concentration (LC)50 is
> 1.8 milligrams/liter (mg/L) air. Pymetrozine is a slight sensitizer
in guinea pigs. End-use water-dispersible granule formulations of
pymetrozine have similar low acute toxicity profiles.
2. Genotoxicity. Pymetrozine did not induce point mutations in
bacteria (Ames assay in Salmonella typhimurium and Escherichia coli) or
in cultured mammalian cells (Chinese hamster V79) and was not genotoxic
in an in vitro unscheduled DNA synthesis assay in rat hepatocytes.
Chromosome aberrations were not observed in an in vitro test using
Chinese hamster ovary cells and there were no clastogenic or aneugenic
effects on mouse bone marrow cells in an in vivo mouse micronucleus
test. These studies show that pymetrozine is not mutagenic or
genotoxic.
3. Reproductive and developmental toxicity. In a teratology study
in rats, pymetrozine caused decreased body weights and food consumption
in females given 100 and 300 mg/kg/day during gestation. This maternal
toxicity was accompanied by fetal skeletal anomalies and variations
consistent
[[Page 32349]]
with delayed ossification. The no observed adverse effect level (NOAEL)
for maternal and fetal effects in rats was 30 mg/kg/day. In a rabbit
teratology study, maternal death, reduced body weight gain and food
consumption were observed at 125 mg/kg/day (highest dose tested).
Embryo and feto toxicity (abortion in one female and total resorptions
in two females) accompanied maternal toxicity. Body weight and food
consumption decreases, early resorptions and postimplantation losses
were also observed in maternal rabbits given 75 mg/kg/day. There was an
increased incidence of fetal skeletal anomalies and variations at these
maternally toxic doses. The NOAEL for maternal and fetal effects in
rabbits was 10 mg/kg/day. Pymetrozine is not teratogenic in rats or
rabbits. In a 2-generation reproduction study in rats, parental body
weights and food consumption were decreased, liver and spleen weights
were reduced and histopathological changes in liver, spleen and
pituitary were observed at approximately 110-440 mg/kg/day (highest
dose tested). Liver hypertrophy was observed in a few parental males at
approximately 10-40 mg/kg/day. Reproductive parameters were not
affected by treatment with pymetrozine. The NOAEL for reproductive
toxicity is approximately 110-440 mg/kg/day. The NOAEL for toxicity to
adults and pups is approximately 1-4 mg/kg/day.
4. Subchronic toxicity. Pymetrozine was evaluated in 13-week
subchronic toxicity studies in rats, dogs and mice. Liver, kidneys,
thymus and spleen were identified as target organs. The NOAEL was 33
mg/kg/day in rats and 3 mg/kg/day in dogs. In mice, increased liver
weights and microscopical changes in the liver were observed at all
doses tested. The NOAEL in mice was < 198 mg/kg/day. No dermal
irritation or systemic toxicity occurred in a 28-day repeated dose
dermal toxicity study with pymetrozine in rats given 1,000 mg/kg/day.
Minimum direct dermal absorption (1.1%) of pymetrozine was detected in
rats over a 21-hour period of dermal exposure. Maximum radioactivity
left on or in the skin at the application site and considered for
potential absorption was 11.9%.
5. Chronic toxicity. Based on chronic toxicity studies in the dog
and rat, a reference dose (RfD) of 0.0057 mg/kg/day is proposed for
pymetrozine. This RfD is based on a NOAEL of 0.57 mg/kg/day established
in the chronic dog study and an uncertainty factor of 100 to account
for interspecies extrapolation and interspecies variability. Minor
changes in blood chemistry parameters, including higher plasma
cholesterol and phospholipid levels, were observed in the dog at the
lowest observed adverse effect level (LOAEL) of 5.3 mg/kg/day. The
NOAEL established in the rat chronic toxicity study was 3.7 mg/kg/day
and was based on reduced body weight gain and food consumption,
hematology and blood chemistry changes, liver pathology and biliary
cysts.
The carcinogenic potential of pymetrozine has been evaluated in
rats and mice. A liver tumor response was observed in male and female
mice and female rats at high doses exceeding the maximum tolerated
dose. These liver tumors correlated with reversible biochemical
(induction of liver metabolizing enzymes) and morphological (hepatocyte
and smooth endoplasmic reticulum proliferation) changes and a
reversible saturation of metabolic processes. EPA has assigned a cancer
classification of ``likely'' to pymetrozine and calculated a Q1* value.
However, Syngenta believes that the mechanism of action leading to
liver tumors at maximum tolerated doses is a non-genotoxic threshold
event and should be regulated as such.
6. Animal metabolism. The metabolism of pymetrozine in the rat is
well understood. Metabolism involves oxidation of substituent groups of
the triazine ring yielding ketones and carboxylic acids. Hydrolysis of
the enamino bridge between rings results in products that are further
metabolized. The metabolic pathways in animals and plants are similar.
7. Metabolite toxicology. The residue of concern for tolerance
setting purposes is the parent compound. Metabolites of pymetrozine are
considered to be of equal or lesser toxicity than the parent.
8. Endocrine disruption. Pymetrozine does not belong to a class of
chemicals known or suspected of having adverse effects on the endocrine
system. There is no evidence that pymetrozine has any effect on
endocrine function in developmental and reproduction studies.
Furthermore, histological investigation of endocrine organs in chronic
dog, rat and mouse studies did not indicate that the endocrine system
is targeted by pymetrozine.
C. Aggregate Exposure
1. Dietary exposure. Tier III acute, chronic and lifetime dietary
exposure evaluations were made using the Dietary Exposure Evaluation
Model (DEEMTM), version 7.81 from Exponent. Empirically
derived processing studies for cotton oil (0.62X), potato chips
(1.00X), tomato paste (0.57X) and tomato puree (0.21X) were used in
these assessments. All consumption data for these assessments was taken
from the USDA's Continuing Survey of Food Intake by Individuals (CSFII)
with the 1994-1996 consumption database and the Supplemental CSFII
children's survey (1998) consumption database. These exposure
assessments included all registered uses on cotton, pecans, hops,
cucurbits, tuberous and corm vegetables, Brassica (cole) leafy
vegetables, leafy vegetables, fruiting vegetables, and a pending new
use on asparagus. Secondary residues in animal commodities were not
included in the exposure assessment since no tolerance values exist for
residues in meat and milk and a three-level dairy feeding study in
lactating livestock showed no residues at any of the feeding levels.
Additionally, the highest feeding level (10 ppm) used in this study was
at least 10-fold higher than what would be expected in treated feed.
a. Food. For the purposes of assessing the potential dietary
exposure, Syngenta Crop Protection has estimated aggregate exposure
from all crops for which tolerances are established or proposed. These
assessments utilized residue data from field trials where pymetrozine
was applied at the maximum intended use rate and samples were harvested
at the minimum pre-harvest interval (PHI) to obtain maximum residues.
Percent of crop treated values were values were taken from the
Biological and Economic Analysis Division's (BEAD's) latest pymetrozine
estimate compiled on August 15, 2001.
i. Chronic exposure. The chronic reference dose (RfD) of
pymetrozine is 0.0038 mg/kg bwt/day and is based on a NOAEL of 0.38 mg/
kg bwt/day from a chronic feeding study in rats and a 100X uncertainty
factor. No additional FQPA safety factor was applied. The pymetrozine
Tier III chronic dietary exposure assessment was based upon field trial
residue results. For the purpose of aggregate risk assessment, the
exposure values were expressed in terms of margin of exposure (MOE),
which was calculated by dividing the NOAEL by the exposure for each
population subgroup. In addition, exposure was expressed as a percent
of the chronic reference dose (%RfD). Chronic exposure to the most
exposed sub-population (children 1-2 years old) resulted in a MOE of
1,203 (1.1% of the chronic RfD of 0.0038 mg/kg bwt/day). Since the
benchmark MOE for this assessment was 100 and the EPA generally has no
concern for exposures below 100% of the RfD, Syngenta believes that
there is a reasonable
[[Page 32350]]
certainty that no harm will result from dietary (food) exposure to
residues arising from the current and proposed uses of pymetrozine.
ii. Acute exposure. The aRfD for pymetrozine for all populations
except females (13+ years old) is 0.42 mg/kg-bw/day and is based on a
lowest observable adverse effect level (LOAEL) of 125 mg/kg/day from an
acute neurotoxicity study in rats and a 300X uncertainty factor. The
acute population adjusted-dose (aPAD) for females (13+ years old) is
0.10 mg/kg bwt/day and is based on a NOAEL of 10 mg/kg bwt/day from a
rabbit developmental toxicity study and a 100X uncertainty factor. A
Tier III probabilistic acute dietary analysis was conducted with a full
distribution of residues for all registered commodities and asparagus.
Each residue distribution was adjusted for percent of crop treated by
adding zeroes to the distribution to account for the percent of crop
not treated. Acute exposure to females (13-50 years old) resulted in a
MOE of 19,881 (0.5% of the acute population adjusted dose (aPAD) of
0.10 mg/kg bwt/day). Acute exposure to the most exposed sub-population
children 1-2 years old resulted in a MOE of 123,640 (0.2% of the acute
RfD of 0.0038 mg/kg bwt/day). Since the benchmark MOE for this
assessment was 300 and since EPA generally has no concern for exposures
below 100% of the RfD, Syngenta believes that there is a reasonable
certainty that no harm will result from dietary (food) exposure to
residues arising from the current and proposed uses of pymetrozine.
iii. Lifetime exposure. Lifetime risk to pymetrozine was evaluated
by comparing exposure to a Q* value of 0.0119 (mg/kg bwt/
day)-1 based on male mouse liver benign hepotomas and/or
carcinomas combined. Lifetime risk for the U.S. population was 3.49 x
10-7. Since this value is below the EPA's lifetime risk
limit of 1.00 x 10-6, these results indicate that there is a
reasonable certainty of no harm resulting from lifetime exposures
through the consumption of pymetrozine-treated commodities.
b. Drinking water. Drinking water exposure to pymetrozine was
evaluated based on the crop uses above with EPA's surface water Tier I
model (Generic Expected Environmental Concentration (GENEEC)). Hops,
with three applications at 0.1875 lb a.i./acre, gave the highest total
application and this rate was; therefore, used in GENEEC to estimate
the chronic, acute and lifetime estimated environmental concentrations
(EECs) for drinking water.
1. Acute exposure--i. The acute EEC for pymetrozine was 4.27 ppb
and the chronic EEC was 0.31 parts per billion (ppb.) The calculated
acute DWLOC for the most sensitive sub-population children 1-2 years
old was 4,190 ppb. Since acute EEC value of 4.27 ppb is less than the
calculated acute DWLOC, these results indicate that there is a
reasonable certainty of no harm resulting from acute drinking water
exposures.
ii. Chronic exposure. The chronic EEC for pymetrozine was 0.031
ppb. The calculated chronic DWLOC for the most sensitive sub-population
children 1-2 years old was 38 ppb. Since the chronic EEC of 0.31 ppb is
below this value, these results indicate that there is a reasonable
certainty of no harm resulting from chronic drinking water exposures.
iii. Lifetime exposure. Using a Q* value of 0.0119 mg/kg bwt/
day-1 and a chronic EEC of 0.31 ppb, the risk to a typical
70 kg adult drinking 2 liters of water per day would be at 1.05 x 10-
7.
2. Non-dietary exposure. Pymetrozine is registered on ornamentals
and exposure could occur through post-application re-entry to treated
plants. Syngenta believes that risks due to short-term, intermediate-
term or chronic exposure are either not applicable or insignificant.
D. Cumulative Effects
EPA is also required to consider the potential for cumulative
effects of pymetrozine and other substances that have a common
mechanism of toxicity. Pymetrozine belongs to a chemical class known as
pyridine azomethines and exhibits a unique mode of action. EPA
consideration of a common mechanism of toxicity is not appropriate at
this time since EPA does not have information to indicate that toxic
effects produced by pymetrozine would be cumulative with those of any
other chemical compounds; thus only the potential risks of pymetrozine
are considered in this exposure assessment.
E. Safety Determination
1. Acute risk. Exposure to pymetrozine residues in food will occupy
no more than 0.2% of the RfD of 0.42 mg/kg bwt/day for the most
sensitive population subgroup children 1-2 years old. Residue values
used for these dietary risk assessments were from field trials and
incorporated percent of crop treated information in the residue
distributions. Acute dietary exposure estimates were determined at the
99.9th percentile of acute exposure. Estimated
concentrations of pymetrozine residues in surface water and ground
water were below the calculated acute drinking water level of
comparison (DWLOC). Therefore, Syngenta does not expect acute aggregate
risk to pymetrozine residues from food and water sources to exceed the
level of concern for acute dietary exposure.
2. Chronic risk. Chronic dietary exposure to pymetrozine residues
in food for the most sensitive population subgroup (children 1-2 years
old) occupied 1.1% of the chronic RfD of 0.0038 mg/kg bwt/day. Residue
values used for these dietary risk assessments were from field trials
and incorporated percent of crop treated information, as indicated
above. Estimated concentrations of pymetrozine residues in surface
water and ground water were below the calculated chronic drinking water
level of comparison (DWLOC). Syngenta believes that the chronic
aggregate risk from pymetrozine residues in food and drinking water
would therefore not be expected to exceed the EPA's level of concern.
3. Lifetime risk. The chronic lifetime dietary risk to pymetrozine
residues in food for the U.S. population was 3.49 x 10-7,
which is below EPA's level of concern (1.0 x 10-6). Residue
values used for this lifetime risk assessment were from field trials
and incorporated percent of crop treated information, as indicated
above. The estimated concentrations of pymetrozine residues in surface
water and ground water are lower than the calculated lifetime DWLOC.
Therefore, Syngenta concludes that the aggregate lifetime risk from
pymetrozine residues in food and drinking water sources would therefore
not be expected to exceed EPA's level of concern for lifetime dietary
exposure.
Syngenta has considered the potential aggregate exposure from food,
water and non-occupational exposure routes and concluded that aggregate
exposure is not expected to exceed 100% of the acute, chronic and
lifetime reference doses. Therefore, Syngenta believes there is a
reasonable certainty that no harm will result to infants and children
from the aggregate exposures to pymetrozine.
F. International Tolerances
There are no established European Codex, Canadian, or Mexican
maximum residue limits for pymetrozine. There are provisional MRLs in
Germany for hops 10 ppm and potatoes 0.02 ppm. The European Union is
currently evaluating a proposed tolerance of 5 ppm on hops. At this
time, international
[[Page 32351]]
harmonization of residue levels is not an issue.
[FR Doc. 04-12703 Filed 6-8-04; 8:45 am]
BILLING CODE 6560-50-S