[Federal Register: May 4, 2005 (Volume 70, Number 85)]
[Notices]
[Page 23162-23167]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04my05-66]
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ENVIRONMENTAL PROTECTION AGENCY
[OPP-2005-0111; FRL-7710-6]
Aminoethoxyvinylglycine hydrochloride (Aviglycine HCI); 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 identification (ID) number OPP-
2005-0111, must be received on or before June 3, 2005.
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: Denise Greenway, Biopesticides and
Pollution Prevention Division (7511C), Office of Pesticide Programs,
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460-0001; telephone number: (703) 308-8263; e-mail
address: greenway.denise@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)
Animal production (NAICS 112)
Food manufacturing (NAICS 311)
Pesticide 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 identification (ID) number OPP-2005-0111. 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,
1801 S. Bell St., 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
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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.1. 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-2005-0111. 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-2005-0111. 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 -2005-0111.
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, 1801 S. Bell St., Arlington, VA, Attention: Docket ID
number OPP-2005-0111. 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
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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: April 18, 2005.
Janet L. Anderson,
Director, Biopesticides and Pollution Prevention 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.
Valent BioSciences Corp.
PP 6F4632
EPA has received a pesticide petition 6F4632 from Valent
BioSciences Corp.,870 Technology Way, Libertyville, Il. 60048,
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 to
establish an exemption from the requirement of a tolerance for the
biochemical pesticide Aminoethoxyvinylglycine hydrochloride (Aviglycine
HCI or AVG) in or on walnut and cucumber.
Pursuant to section 408(d)(2)(A)(i) of the FFDCA, as amended,
Valent BioSciences Corp. has submitted the following summary of
information, data, and arguments in support of their pesticide
petition. This summary was prepared by Valent BioSciences Corp. and EPA
has not fully evaluated the merits of the pesticide petition. The
summary may have been edited by EPA if the terminology used was
unclear, the summary contained extraneous material, or the summary
unintentionally made the reader conclude that the findings reflected
EPA's position and not the position of the petitioner.
A. Product Name and Proposed Use Practices
Aviglycine HCl (AVG) is a plant growth regulator used in preventing
pistillate flower abortion (PFA) in walnuts, thereby increasing yield.
AVG is the active ingredient (ai) in ReTain Plant Growth Regulator (EPA
Reg. 73049-45) and ReTain Plant Growth Regulator for California (EPA
Reg. No. 73049-58). The proposed use is for a single application to
orchards when 5 to 10% of each of the trees is in bloom in order to
increase the fruit set in walnut cultivars that suffer a high incidence
of PFA. The proposed use rate for walnuts is 50 - 100 grams a.i./acre
(0.73 - 1.46 lbs of ReTain[reg] per acre targeting 125 parts per
million (ppm) AVG in the spray solution) in a spray volume of 100
gallons per acre for small trees, 200 gallons per acre for large trees.
Aviglycine HCl is a plant growth regulator effective in inducing
staminate (male) flowers on gynoecious (all female) breeding lines of
curcubits used in seed production. AVG is the ai in ReTain Plant Growth
Regulator (EPA Reg. 73049-45) and ReTain Plant Growth Regulator for
California (EPA Reg. No. 73049-58). The proposed use is for one to four
applications of ReTain to cucumber plants at early first leaf stage
through to the tenth leaf stage. The proposed use rate for cucumbers is
19 to 48 grams a.i./acre (0.28 - 0.7 lbs of ReTain[reg] per acre
targeting 250 to 500 ppm AVG in the spray solution) in a spray volume
of 10 to 25 gallons per acre to ensure good coverage.
B. Product Identity/Chemistry
1. Identity of the pesticide and corresponding residues. A study
designed to determine whether uptake, translocation and metabolism of
AVG occurs in apples identified seven minor metabolites in addition to
the primary metabolite, N-acetyl aviglycine HCl. The study was not
meant as a measure of the amount of AVG residues and metabolites found
in apples under normal field conditions. The only significant
incorporation of AVG in apple tissues, following brush-on application
at high rates, resulted from absorption from the peel rather than
translocation from the leaves. AVG is also metabolized in the tissues
to form N-acetyl aviglycine HCl and several other minor metabolites,
and is partially degraded on the apple surface to water-soluble
products that may be formed due to microbial and/or photodegradative
action.
2. Magnitude of residue at the time of harvest and method used to
determine the residue. It is improbable that the proposed early season
use of aviglycine HCl, as a means of preventing PFA, would result in
measurable residues in the meat of walnuts. The proposed timing of
application to walnut trees is early to mid-bloom. The use precludes
direct applications to walnut fruit which are not yet present on the
trees and are harvested 3-5 months after application. The edible
portion of the nut is further protected by the hull and shell
surrounding the nut. Translocation
[[Page 23165]]
of aviglycine HCl residues within treated plants was examined in
studies of AVG metabolism in apple trees. There is minimal
translocation of aviglycine HCl within plants. Residues of AVG will
degrade over time on and in treated plant tissue. As a result, the
potential for measurable residues of aviglycine HCl on the harvested
edible portion of walnuts following application of ReTain to control
PFA in walnuts is negligible.
The proposed use of aviglycine HCl on cucumbers is for seed
production only. The proposed use is for an early season application to
immature plants. There is minimal translocation of aviglycine HCl
within plants. Residues of AVG will degrade over time on and in treated
plant tissue. Therefore it is unlikely residual AVG will be present in
the fruit or seed at the time the seed is harvested. There are also two
generations between the seed production use of ReTain and generation of
a commercial edible plant product from that seed. Curcubit seed is
mechanically harvested with specialized equipment that destroys the
fruit to obtain the seed. As a result, the potential for measurable
residues of aviglycine HCl on the harvested edible portion of
commercially grown cucumbers following application of ReTain as a means
of inducing male flowers in seed production 2-generations before
commercial harvest is negligible. Analytical methods for the detection
of aviglycine HCl have been submitted to EPA in support of petitions
for tolerances on pome and stone fruit. An analytical method for
detection of aviglycine HCl residues in or on walnuts or cucumbers is
not required. There is negligible potential for measurable residues of
aviglycine HCl on walnuts or cucumbers as a result of the proposed use
of ReTain and an exemption from the requirements of a tolerance for
both walnuts and cucumbers is being sought.
3. A statement of why an analytical method for detecting and
measuring the levels of the pesticide residue are not needed. An
analytical method for detection of aviglycine HCl residues in walnuts
or cucumbers is not required. The proposed uses of aviglycine HCl on
walnuts is for a single season application of ReTain at a rate of 50 to
100 g a.i./acre, applied to walnut trees early to mid-bloom to control
pistillate flower abortion. It is highly unlikely that this early
season application at low rates would result in measurable residues in
the harvested meat of walnuts. Therefore, it should not be necessary to
establish a tolerance for this use. Residue studies, methods supporting
the analysis and methods of analysis for purpose of enforcement would
similarly not be required.
The proposed use of aviglycine HCl is one to four early season
applications of ReTain to breeding lines of cucumbers for seed
production. ReTain is not proposed for use on cucumbers destined for
commercial harvest and it is highly unlikely that application to
cucumbers grown for seed production could or would result in measurable
residues in the cucumbers grown commercially from progeny of that seed.
Therefore, it should not be necessary to establish a tolerance for this
use. Residue studies, methods supporting the analysis and methods of
analysis for purpose of enforcement would similarly not be required.
C. Mammalian Toxicological Profile
1. Acute toxicity. Aviglycine HCl has low acute oral, dermal, and
inhalation toxicity. The oral lethal dose (LD50) in rats is
>5,000 milligrams/kilogram (mg/kg), the dermal LD50 is
>2,000 mg/kg and the inhalation 4-hour lethal concentration
(LC50) is >5.00 milligrams/Liter (mg/L) air. AVG is not a
skin sensitizer in guinea pigs, and is not irritating to the skin and
eyes of rabbits. End-use formulations of AVG have similar low acute
toxicity profiles.
2. Genotoxicity. AVG does not induce gene mutations in bacterial
and mammalian cells, chromosome aberrations in mammalian cells or
deoxyribonucleic acid (DNA) damage in bacterial cells in in vitro test
systems. Similarly, it does not exhibit a clastogenic effect in vivo in
the rat micronucleus test. Therefore, there is no evidence to suggest a
genotoxic hazard at any of the three main levels of genetic
organization.
3. Reproductive and developmental toxicity. In the rabbit
developmental toxicity study with AVG, there was no evidence of
teratogenicity or other embryotoxic effects at the highest dose levels,
although maternal toxicity was evident. The rabbit maternal no
obvserved adverse effect level (NOAEL) was established at 0.4 mg a.i./
kg/day based on reduced body weight gains and food consumption, and
decreased defecation. Developmental NOAEL was established at 0.4 mg
a.i./kg/day based on fetal body weights. In the rat test the maternal
NOAEL was established at 1.77 mg a.i./kg/day based on inhibition of
body weight gain and reduced food consumption. The Developmental NOAEL
was found to be 1.77 mg a.i./kg/day based on decreased mean fetal body
weights and reduced ossification. The developmental and maternal LOELs
were established at 8.06 mg/kg/day.
AVG was evaluated in a rat 2-generation reproduction study
submitted by Abbott Laboratories. Based on reductions in body weight,
changes in organ weights and an increased incidence of microscopic
findings, the parental NOAEL was established at 0.8 mg a.i./kg/day. The
NOAEL for reproductive toxicity was established at 4.0 mg a.i./kg/day
and the neonatal toxicity NOAEL was established at 2.5 mg a.i./kg/day.
4. Subchronic toxicity. Subchronic (90-day) feeding studies were
conducted with rats, mice, and dogs. In a 90-day feeding study in rats,
the NOAEL was 0.4 mg a.i./kg bwt/day for males and females based on
increased incidence of periportal hepatocellular vacuolation in the
liver. In the 90-day feeding study in mice, the NOAEL was established
at 10 mg a.i./kg/day for males and females-based on decreased body
weight and histopathological changes in the liver (both sexes), in the
testis (males) and the adrenal (females) at 25 mg a.i./kg/day. For
dogs, the NOAEL was established at 0.6 mg a.i./kg/day based on
inappetence, low body weight gain and centrilobular histopathological
changes in the liver at 1.2 mg a.i./kg/day.
A 21 day repeat dose dermal toxicity study in rats was carried out
at 0, 100, 500, and 1,000 mg/kg/day. The no observed effect level
(NOEL) is 1,000 mg/kg/day; a lowest observed effect level (LOEL) was
not determined.
5. Chronic toxicity. Chronic studies with AVG were conducted on
rats to determine oncogenic potential and/or chronic toxicity of the
compound. The NOAEL for the 1 year chronic study was 0.7 mg/kg/day for
males and females based on decreases in body weights, food consumption,
testicular tubular and epithelial vacuolation, and pancreatic acinar
cell atrophy. The rat carcinogenicity study with AVG confirmed the
substance has no carcinogenic potential. There was no evidence of cell
necrosis that could be a preliminary stage before tumor genesis, and
time of death was similar to controls. During the 2 year
carcinogenicity study, the administration of AVG at 7 mg a.i/kg/day was
associated with body weight and food consumption reductions, increases
in the incidence of adrenal focal medullary cell hyperplasia,
testicular tubular atrophy and other associated findings in the testis
and epididymis, ocular cataracts, and pancreatic lobular/acinar cell
atrophy. The NOAEL was established at 0.7 mg/kg/day.
[[Page 23166]]
D. Aggregate Exposure
1. Dietary exposure--i. Food. There is no expected dietary exposure
to residues of aviglycine HCl from the proposed early to mid-bloom use
of ReTain on walnuts. No residues are expected on the commodity.
Additionally, the contribution of walnuts as a percent of total diet is
relatively small. It is estimated that walnuts contribute 0.009% of the
diet of the general population and 0.005% to the diet of non-nursing
infants. There is no expected dietary exposure to residues of
aviglycine HCl from the proposed use of ReTain on cucumbers for seed
production. No residues are expected on any cucumbers produced for
consumption from the proposed use. Expected dietary exposures from
residues of AVG would occur through apples, pears, peaches, nectarines,
plums, processed pome, and stone-fruits (excluding cherries). Acute and
chronic dietary exposure assessments were conducted using a Tier I
approach. This Tier I assessment incorporated tolerance level residues
for all commodities, assumption of 100% crop treated (CT) for all
crops, default processing factors and consumption data from the 1994
through 1998 United States Department of Agriculture (USDA) Continuing
Surveys of Food Intakes by Individuals (CSFII 1994, 1995, 1996, and
1998). Estimates of chronic and acute dietary exposure were calculated
using Dietary Exposure Evaluation Module Food Commodity Intake Database
(DEEMTM-FCIDTM) software (Novigen, 2001). The
database was used to determine chronic exposure estimates for the
overall U.S. population and 24 population subgroups and acute exposure
estimates for the overall U.S. population and 10 population subgroups.
The resulting exposures were compared to a chronic reference dose
(RfD) of 0.007 mg a.i./kg/day and an acute NOEL of 1.77 mg/kg bwt/day.
The RfD is based on the NOAEL of 0.7 mg a.i./kg/day from the rat
chronic toxicity study (52 week) and the rat carcinogenicity feeding
study (104-week) with a 100-fold uncertainty factor to account for
intra-species and inter-species variations. The acute NOEL is based on
the rat oral developmental toxicity study.
Chronic dietary exposure estimates for the overall U.S. population
and 24 population subgroups, including infants and children, are well
below the chronic RfD. Estimated daily exposures from tolerance level
residues and a 100% CT assumption for all crops were 15.9% of the RfD
or less for all populations examined. Acute dietary exposure was
estimated for the overall U.S. population and the population subgroups:
(i) all infants, (ii) nursing infants, (iii) non-nursing infants, (iv)
children 1 to 2 years of age, (viii) adults 20 to 49 years of age, (ix)
females 13 to 49 years of age and (x) adults 50 years and older.
Estimated daily exposures from tolerance level residues (at the
95th percentile) and a 100% CT assumption for all crops
resulted in MOEs (Margin of Exposure) greater than 430 for all
population groups examined.
The proposed agricultural uses of aviglycine HCl will not alter the
results of the chronic and acute dietary exposure analyses conducted
for pome fruit and stone fruit applications, which clearly demonstrated
a reasonable certainty that no harm will result from the agricultural
uses of AVG.
ii. Drinking water. AVG is highly unlikely to contaminate
groundwater resources due to its high soil sorption, and short soil and
water/sediment half-lives. Study results show that AVG is easily
adsorbed to soils, principally onto clay particles. Half-lives in soils
vary between 0.6 and 4.3 days. Water-sediment studies have shown that
AVG will be readily adsorbed to sediment where it is mineralized and
incorporated into the organic fraction of the sediment. Biodegradation
occurs in both systems. The half-life of AVG in the aqueous phase and
total water/sediment system was calculated to be approximately 1.2 and
2.3 days respectively. An AVG water concentration assessment was
conducted using the EPA first Tier screening models. FIRST was used for
surfacewater concentration assessment and forscreening concentration in
groundwater, SCI-GROW was used for groundwater assessment. There were
no estimated groundwater concentrations according to SCI-GROW. Peak
surfacewater concentrations estimated using FIRST were 1.283 and the
estimated annual average was 0.021 parts per billion (ppb), assuming
87% CT. The contribution of drinking water to aggregate risk is
considered to be negligible.
2. Non-dietary exposure. AVG has no product registrations for
residential non-food uses. Non-occupational, non-dietary exposure for
AVG has thus been estimated to be extremely small. Therefore, the
potential for non-dietary exposure is insignificant.
The exposure from the commercial use is expected to be dermal in
nature. A 21-day repeat dose dermal toxicity study resulted in no
significant treatment related effects at 1,000 milligrams/kilogram/day
(mg/kg/day), the highest dose tested (HDT).
E. Cumulative Exposure
Consideration of a common mechanism of toxicity is not necessary at
this time because there is no indication that toxic effects of AVG
would be cumulative with those of any other chemical compounds. AVG has
a novel mode of action compared to other currently registered active
ingredients. Therefore, Valent BioSciences Corp. believes it is
appropriate to consider only the potential risks of aviglycine HCl in
an aggregate risk assessment.
F. Safety Determination
1. U.S. population. Aviglycine HCl is an amino acid which has been
generated through a fermentation of a soil microorganism. The proposed
use of aviglycine HCL on walnuts prior to fruit development is not
expected to result in measurable residues on the walnuts harvested for
consumption approximately 4 months following application. Using the
chronic exposure assumptions for pome and stone fruit and the proposed
RfD described above, the dietary exposure to AVG for the U.S.
population was calculated to be 2.2% of the RfD.
Therefore, taking into account the proposed uses, it can be
concluded with reasonable certainty that residues of AVG in food and
drinking water will not result in unacceptable levels of human health
risk.
2. Infants and children. FFDCA section 407 provides that EPA shall
apply an additional safety factor for infants and children to account
for prenatal and postnatal toxicity and the lack of completeness of the
database. Only when there is no indication of increased sensitivity of
infants and children and when the data base is complete, may the extra
safety factor be removed. In the case of aviglycine HCl, the toxicology
database is complete. There is no indication of increased sensitivity
in the database overall, and specifically, there is no indication of
increased sensitivity in the developmental and multi-generation
reproductive toxicity studies. Therefore, Valent BioSciences Corp.
concludes that there is no need for an additional safety factor and a
safety factor of 100 be used for the assessment.
Using the chronic exposure assumptions and the proposed RfD
described above, the dietary exposure to AVG for non-nursing infants,
the most highly exposed population subgroup, was calculated to be
0.001110 mg/kg bwt/day or 15.9% of the reference dose. Daily exposure
for the overall U.S. population was estimated to be 0.000153 mg/kg bwt/
day. The proposed
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tolerances will utilize 2.2% of the RfD for the U.S. population.
G. Effects on the Immune and Endocrine Systems
Lifespan, and multigenerational studies on mammals, and acute and
subchronic studies on aquatic organisms and wildlife did not reveal any
definite immune or endocrine effects. An immunotoxicity study in rats
at 0, 1.25, 5 and 15 mg/kg/day with a NOAEL of 5 mg/kg/day based on
decreased primary antibody (igM) response to sheep red blood cells;
decreased absolute and relative thymus weights; decreased body weight,
food consumption and food efficiency at the high dose level. The LOEL
is 15 mg/kg/day.
Any endocrine related effects would have been detected in this
definitive array of required tests. The probability of any such effect
due to agricultural uses of AVG is considered negligible.
H. Existing Tolerances
Tolerances have been established for the residues of AVG in or on
the following food commodities:
----------------------------------------------------------------------------------------------------------------
Commodity Parts per million
----------------------------------------------------------------------------------------------------------------
Apples 0.08
----------------------------------------------------------------------------------------------------------------
Fruit, stone, group 12, (except cherry) 0.170
----------------------------------------------------------------------------------------------------------------
Pears 0.08
----------------------------------------------------------------------------------------------------------------
I. International Tolerances
There are no Codex maximum residue limits for use of aviglycine HCl
on apples or pears, or on any other crop.
[FR Doc. 05-8791 Filed 5-3-05; 8:45 am]
BILLING CODE 6560-50-S