[Federal Register Volume 70, Number 85 (Wednesday, May 4, 2005)]
[Notices]
[Pages 23162-23167]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-8791]


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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: [email protected].

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 [email protected], 
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

[[Page 23167]]

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