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Imidacloprid; Notice of Filing Pesticide Petitions to Establish Tolerances for a Certain Pesticide Chemical in or on Food

Note: EPA no longer updates this information, but it may be useful as a reference or resource.


 
[Federal Register: February 5, 2003 (Volume 68, Number 24)]
[Notices]
[Page 5880-5885]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05fe03-54]

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ENVIRONMENTAL PROTECTION AGENCY
[OPP-2002-0081; FRL-7287-5]
 
Imidacloprid; Notice of Filing Pesticide Petitions to Establish 
Tolerances 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 pesticide 
petitions proposing the establishment of regulations for residues of a 
certain pesticide chemical in or on various food commodities.

DATES: Comments, identified by docket ID number OPP-2002-0081, must be 
received on or before March 7, 2003.

ADDRESSES: Comments may be submitted electronically, by mail, or 
through hand delivery/courier. Follow the detailed instructions as 
provided in Unit I. of the SUPPLEMENTARY INFORMATION.

FOR FURTHER INFORMATION CONTACT: 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. 
Potentially affected categories and 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. To determine 
whether you or your business may be affected by this action, you should 
carefully examine the applicability provisions in OPP-2002-0081. 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-2002-0081. The 
official public docket consists of the documents specifically 
referenced in this action, any public comments received, and other 
information related to this action. Although a part of the official 
docket, the public docket does not include Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. The official public docket is the collection of materials 
that is available for public viewing at the Public Information and 
Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2, 
1921 Jefferson Davis Hwy., Arlington, VA. This docket facility is open 
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal 
holidays. The docket telephone number is (703) 305-5805.
    2. Electronic access. You may access this Federal Register document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr/.
    An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA Dockets. You may 
use EPA Dockets at http://www.regulations.gov/ to submit or view public 
comments, access the index listing of the contents of the official 
public docket, and to access those documents in the public docket that 
are available electronically. Although not all docket materials may be 
available electronically, you may still access any of the publicly 
available docket materials through the docket facility identified in 
Unit I. B.1. Once in the system, select ``search,'' then key in the 
appropriate docket ID number.
    Certain types of information will not be placed in the EPA Dockets. 
Information claimed as CBI and other information whose disclosure is 
restricted by statute, which is not included in the official public 
docket, will not be available for public viewing in EPA's electronic 
public docket. EPA's policy is that copyrighted material will not be 
placed in EPA's electronic public docket but will be available only in 
printed, paper form in the official public docket. To the extent 
feasible, publicly available docket materials will be made available in 
EPA's electronic public docket. When a document is selected from the 
index list in EPA Dockets, the system will identify whether the 
document is available for viewing in EPA's electronic public docket. 
Although not all docket materials may be available electronically, you 
may still access any of the publicly available docket materials through 
the docket facility identified in Unit I.B. EPA intends to work towards 
providing electronic access to all of the publicly available docket 
materials through EPA's electronic public docket.
    For public commenters, it is important to note that EPA's policy is 
that public comments, whether submitted electronically or in paper, 
will be made available for public viewing in EPA's electronic public 
docket as EPA receives them and without change, unless the comment 
contains copyrighted material, CBI, or other information whose 
disclosure is restricted by statute. When EPA identifies a comment 
containing copyrighted material, EPA will provide a reference to that 
material in the version of the comment that is placed in EPA's 
electronic public docket. The entire printed comment, including the 
copyrighted material, will be available in the public docket.
    Public comments submitted on computer disks that are mailed or 
delivered to the docket will be transferred to EPA's electronic public 
docket. Public comments that are mailed or delivered to the docket will 
be scanned and placed in EPA's electronic public docket. Where 
practical, physical objects will be photographed, and the photograph 
will be placed in EPA's electronic public docket along with a brief 
description written by the docket staff.

C. How and To Whom Do I Submit Comments?

    You may submit comments electronically, by mail, or through hand 
delivery/courier. To ensure proper receipt by EPA, identify the 
appropriate docket ID number in the subject line on the first page of 
your comment. Please ensure that your comments are submitted within the 
specified comment period. Comments received after the close of the 
comment period will be marked ``late.'' EPA is not required to consider 
these late comments. If you wish to submit CBI or information that

[[Page 5881]]

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-2002-0081. 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-2002-0081. 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-2002-0081.
    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-2002-0081. Such deliveries are only accepted during the 
docket's normal hours of operation as identified in Unit I.B.1.

D. How Should I Submit CBI to the Agency?

    Do not submit information that you consider to be CBI 
electronically through EPA's electronic public docket or by e-mail. You 
may claim information that you submit to EPA as CBI by marking any part 
or all of that information as CBI (if you submit CBI on disk or CD ROM, 
mark the outside of the disk or CD ROM as CBI and then identify 
electronically within the disk or CD ROM the specific information that 
is CBI). Information so marked will not be disclosed except in 
accordance with procedures set forth in 40 CFR part 2.
    In addition to one complete version of the comment that includes 
any information claimed as CBI, a copy of the comment that does not 
contain the information claimed as CBI must be submitted for inclusion 
in the public docket and EPA's electronic public docket. If you submit 
the copy that does not contain CBI on disk or CD ROM, mark the outside 
of the disk or CD ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and EPA's 
electronic public docket without prior notice. If you have any 
questions about CBI or the procedures for claiming CBI, please consult 
the person listed under FOR FURTHER INFORMATION CONTACT.

E. What Should I Consider as I Prepare My Comments for EPA?

    You may find the following suggestions helpful for preparing your 
comments:
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide copies of any technical information and/or data you used 
that support your views.
    4. If you estimate potential burden or costs, explain how you 
arrived at the estimate that you provide.
    5. Provide specific examples to illustrate your concerns.
    6. Offer alternative ways to improve the notice or collection 
activity.
    7. Make sure to submit your comments by the deadline in this 
notice.
    8. To ensure proper receipt by EPA, be sure to identify the docket 
ID number assigned to this action in the subject line on the first page 
of your response. You may also provide the name, date, and Federal 
Register citation.

II. What Action is the Agency Taking?

    EPA has received pesticide petitions as follows proposing the 
establishment and/or amendment of regulations for residues of 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 these petitions contain 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: January 24, 2003.
 Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    The petitioner's summaries of the pesticide petitions are printed 
below as required by FFDCA section 408(d)(3). The summaries of the 
petitions were prepared by Bayer Corporation and represents the view of 
the company. The petitions summaries announce 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. The Interregional Research 
Project No. 4 (IR-4) assembled and submitted the petitions to EPA on 
behave of the Bayer Corporation.

[[Page 5882]]

Interregional Research Project Number 4 and Bayer Corporation

PP 1E6268, PP 1E6254, PP 1E6237, PP 1E6225, PP 0E6203, PP 2E6403, PP 
2E6406, PP 2E6409, PP 2E6417, PP 2E6421, PP 2E6435, PP 2E6414, PP 
2E6458, and PP 2E6506

    EPA has received pesticide petitions from the Interregional 
Research Project Number 4 (IR-4), Technology Centre and Rutgers State 
University of New Jersey, 681 U.S. Highway #1 South, North 
Brunswick, NJ 08902-3390 proposing, pursuant to section 408(d) of the 
Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to 
amend 40 CFR part 180.472 by establishing tolerances for the combined 
residues of imidacloprid, 1-(6-chloro-3-pyridinyl)methyl-N-nitro-2-
imidazolidinimine, and its metabolites containing the 6-chloropyridinyl 
moiety, all expressed as imidacloprid in or on the raw agricultural 
commodities as follows:
    1. PP 1E6268 proposes tolerances for bushberry subgroup 13B and 
lingonberry, juneberry, and salal at 3.5 parts per million (ppm).
    2. PP 1E6254 proposes a tolerance for okra at 1.0 ppm.
    3. PP 1E6237 proposes a tolerance for watercress at 3.5 ppm.
    4. PP 1E6225 proposes a tolerance for artichoke at 2.5 ppm.
    5. PP 0E6203 proposes a tolerance for cranberry at 0.05 ppm.
    6. PP 2E6403 proposes a tolerance for vegetable, legume, except 
soybean, group 6 at 4.0 ppm.
    7. PP 2E6406 proposes tolerances for avocado, papaya, star apple, 
black sapote, mango, sapodilla, canistel, and mamey sapote at 1.0 ppm, 
and lychee, longan, Spanish lime, rambutan, pulasan, and persimmon at 
3.0 ppm.
    8. PP 2E6409 proposes a tolerance for vegetable, leaves of root and 
tuber, group 2 at 4.0 ppm.
    9. PP 2E6417 proposes a tolerance for strawberry at 0.5 ppm.
    10. PP 2E6421 proposes a tolerance for fruit, stone, group 12 at 
3.0 ppm.
    11. PP 2E6435 proposes tolerances for guava, feijoa, jaboticaba, 
wax jambu, starfruit, passionfruit, and acerola at 1.0 ppm.
    12. PP 2E6414 proposes tolerances for corn, pop, grain at 0.05 ppm 
and corn, pop, stover at 0.2 ppm.
    13. PP 2E6458 proposes a tolerance for mustard seed at 0.05 ppm.
    14. PP 2E6506 proposes a tolerance for vegetable, root, and tuber, 
except sugar beet, group 1 at 0.4 ppm.
    EPA has determined that the petitions contain data or information 
regarding the elements set forth in section 408(d)(2) of the FFDCA; 
however, EPA has not fully evaluated the sufficiency of the submitted 
data at this time or whether the data support granting of the 
petitions. Additional data may be needed before EPA rules on the 
petitions. Bayer Corporation, Crop Protection, Kansas City, MO 64120-
0013 produces the imidacloprid product(s) of concern for these pending 
tolerances.

A. Residue Chemistry

    1. Plant metabolism. The nature of the imidacloprid residue in 
plants and livestock is adequately understood. The residues of concern 
are combined residues of imidacloprid and it metabolites containing the 
6-chloropyridinyl moiety, all calculated as imidacloprid.
    2. Analytical method. The analytical method is a common moiety 
method for imidacloprid and its metabolites containing the 6-
chloropyridinyl moiety using a permanganate oxidation, silyl 
derivatization, and capillary gas chromatography/mass spectrometry (GC/
MS) selective ion monitoring. This method has successfully passed a 
petition method validation in EPA labs. There is a confirmatory method 
specifically for imidacloprid and several metabolites utilizing GC/MS 
and high performance liquid chromotography/using ultra-violet detection 
(HPLC/UV) which has been validated by EPA as well. Imidacloprid and its 
metabolites are stable for at least 24 months in the commodities when 
frozen.
    3. Magnitude of residues. Bushberry subgroup, lingonberry, 
juneberry, and salal. IR-4 has received requests from Maine for 
imidacloprid use on lowbush blueberries and from New Jersey, Delaware, 
Michigan, and South Carolina for use on high bush blueberries. Two 
field trials were performed on lowbush blueberries and nine trials on 
highbush blueberries to support the requested tolerance of 3.5 ppm.
    ? Okra. No data was submitted in support of this tolerance 
petition; rather, IR-4 proposes that EPA, utilizes the registrant's 
fruiting vegetable data (peppers and tomatoes). IR-4 believes this 
approach is justified based upon the similarities of okra to members of 
the fruiting vegetable crop group. It is noteworthy that okra is 
classified as a fruiting vegetable under CODEX.
    ? Watercress. IR-4 received a request from the Florida 
Agricultural Experiment Station for the registration of imidacloprid on 
watercress. No watercress data were presented in support of this 
petition; rather, IR-4 requests that EPA utilizes the registrant's head 
and leaf lettuce data to support the proposed watercress tolerance of 
3.5 ppm.
    ? Artichoke. IR-4 has received requests from California for 
the use of imidacloprid on artichoke. To support this request and the 
proposed tolerance of 2.5 ppm, magnitude of residue data were collected 
from three field trials in California.
    ? Cranberry. IR-4 received a request from Massachusetts for 
the use of imidacloprid on cranberries. To support this request and the 
proposed tolerance for strawberry at 0.05 ppm. IR-4 conducted five 
field trials in the states of Massachusetts, New Jersey, Wisconsin, and 
Oregon.
    ? Peas. IR-4 received a request from Washington, Oregon, and 
Delaware for the use of imidacloprid on peas. In support of this 
request, field trials were conducted in Wisconsin, Ohio, Washington, 
Maryland, New Jersey, and California.
    ? Mamey sapote. IR-4 received a request from Florida for the 
use of imidacloprid on mamey sapote. In support of this request, two 
field trials were conducted in southern Florida.
    ? Leaves of root and tuber crop group. IR-4 received a 
request from Oregon and California for the use of imidacloprid on 
beets. In support of this request, magnitude of residue data were 
collected from field trials conducted in Texas, Ohio, New Jersey, 
Oregon, and Indiana. Data from beet tops were combined with the 
previously submitted petition for turnip tops to support a tolerance 
for leaves of root and tuber vegetables.
    ? Stone fruit. IR-4 received requests from Utah, Washington, 
Michigan, and Oregon for the use of imidacloprid on cherries, Michigan 
and Washington for the use of imidacloprid on peaches, and Michigan for 
the use of imidacloprid on plums. Magnitude of residue data were 
collected on these crops to support a stone fruit crop group tolerance.
    ? Strawberry. IR-4 received requests from Oregon, 
Mississippi, Michigan, Wisconsin, and North Carolina for the use of 
imidacloprid on strawberries. In support of this requested tolerance, 
magnitude of residue trials were conducted in Florida, California, New 
Jersey, Wisconsin, and Oregon.
    ? Dry beans. IR-4 received requests from New York, 
Washington, Wisconsin, Georgia, California, and Idaho for the use of 
imidacloprid on dry beans. In support of this request, magnitude of 
residue trials were conducted in Washington, North Dakota, New York, 
Wisconsin, and California.
    ? Guava and related crops (feijoa, jaboticaba, wax jambu, 
starfruit,

[[Page 5883]]

passion fruit, and acerola). IR-4 received a request from Florida for 
the use of imidacloprid on guava. Magnitude of the residue data were 
collected from Florida on guava to support a tolerance on guava and 
related crops.
    ? Corn, pop. No crop-specific data were submitted with the 
petition proposing imidacloprid tolerances on popcorn. IR-4 proposes 
that EPA translates residue data from field corn to popcorn in order to 
establish the requested tolerances.
    ? Mustard seed. No crop-specific data are being submitted 
with this petition proposing an imidacloprid tolerance on mustard seed. 
IR-4 proposes that EPA translates residue data from canola to mustard 
seed in order to establish the tolerance based upon the botanical and 
cultural similarities of the crops. Additionally, Canada has a crop 
group for oil seeds (crop group 20) which contains mustard seed and has 
canola as one of the representative commodities.

B. Toxicological Profile

    EPA has evaluated the available imidacloprid toxicity data and 
considered its validity, completeness, and reliability as well as the 
relationship of the results of the studies to human risk. EPA has also 
considered available information concerning the reliability of the 
sensitivities of major identifiable subgroups of consumers, including 
infants and children. The nature of the toxic effects caused by 
imidacloprid is discussed in Unit II.A. of the final rule on 
imidacloprid pesticide tolerances published in the Federal Register of 
September 18, 1998 (63 FR 49837) (FRL-6027-1). Please refer to this 
document should you desire detailed toxicological information on 
imidacloprid.
    1. Animal metabolism. The metabolism of NTN 33893 (imidacloprid) in 
rats was reported in seven studies. The data show that imidacloprid was 
rapidly absorbed and eliminated in the excreta (90% of the dose within 
24 hours), demonstrating no biologically significant differences 
between sexes, dose levels, or route of administration. Elimination was 
mainly renal (70-80% of the dose) and fecal (17-25%). The major part of 
the fecal activity originated in the bile. Total body accumulation 
after 48 hours consisted of 0.5% of the radioactivity with the liver, 
kidney, lung, skin, and plasma being the major sites of accumulation. 
Therefore, bioaccumulation of imidacloprid is low in rats. Maximum 
plasma concentration was reached between 1.1 and 2.5 hours. Two major 
routes of biotransformation were proposed for imidacloprid. The first 
route included an oxidative cleavage of the parent compound rendering 
6-chloronicotinic acid and its glycine conjugate. Dechlorination of 
this metabolite formed the 6-hydroxynicotinic acid and its mercapturic 
acid derivative. The second route included the hydroxylation followed 
by elimination of water of the parent compound rendering NTN 35884. A 
comparison between [methylene-\14\C-]imidacloprid and [imidazolidine-
4,5-\14\C]imidacloprid showed that while the rate of excretion was 
similar, the renal portion was higher with the imidazolidine-labeled 
compound. In addition, accumulation in tissues was generally higher 
with the imidazolidine-labeled compound.
    A comparison between imidacloprid and one of its metabolites, WAK 
3839, showed that the total elimination was the same for both 
compounds. The proposed metabolic pathways for these two compounds were 
different. WAK 3839 was formed following pretreatment (repeated dosing) 
of imidacloprid.
    2. Endocrine disruption. The toxicology data base for imidacloprid 
is current and complete. Studies in this data base include evaluation 
of the potential effects on reproduction and development, and an 
evaluation of the pathology of the endocrine organs following short- or 
long-term exposure. These studies revealed no primary endocrine effects 
due to imidacloprid.

C. Aggregate Exposure

    1. Dietary exposure. Assessments were conducted to evaluate 
potential risks due to chronic and acute dietary exposure of the U.S. 
population and selected population subgroups to residues of 
imidacloprid. These analyses cover all registered crops including 
rotational crops; uses pending with EPA Registration Division's 2002 
work plan including dry beans, peas, bushberries, lingonberry, 
juneberries, salal, carrots, turnips, okra, cranberries, artichoke 
(globe), watercress, beet roots, leaves of root and tuber vegetables, 
stone fruit, mamey sapote, guava, feijoa, jaboticaba, wax jambu, 
starfruit, passion fruit, acerola, strawberry, cucumber (greenhouse), 
and tomato (greenhouse), and an import tolerance petition on bananas, 
active and proposed section 18 uses on blueberries, cranberries, table 
beets, strawberries and turnips.
    Novigen sciences, Inc.'s Dietary Exposure Evaluation Model 
(DEEM\TM\), which is licensed to Bayer Corporation, was used to 
estimate the chronic and acute dietary exposure. This software uses the 
food consumption data from the 1994-1998 United States Department of 
Agriculture (USDA) Continuing Surveys of Food Intake by Individuals 
(CSFII).
    The endpoint for acute dietary risk assessments is based on 
neurotoxicity characterized by decreases in motor or locomotor activity 
in female rats at 42 milligrams/kilogram body weight/day (mg/kg bwt/
day) (the lowest observed adverse effect level (LOAEL) from an acute 
neurotoxicity study). Based on an uncertainty factor (UF) of 10x for 
interspecies and 10x for intraspecies, the acute reference dose (RfD) = 
0.42 mg/kg bwt/day. EPA has determined that an additional UF for FQPA 
(reduced to 3x) applies to all population subgroups for acute risk. 
Application of the additional 3x safety factor results in an acute 
population adjusted dose (aPAD) 0.14 mg/kg bwt/day or a margin of 
exposure (MOE) of 300.
    For chronic dietary analyses, EPA has established the RfD for 
imidacloprid at 0.057 mg/kg/day based on a no-observed adverse effect 
level (NOAEL) of 5.7 mg/kg bwt/day from a rat chronic toxicity 
carcinogenicity study and UF of 10x for interspecies and 10x for 
intraspecies. EPA has determined that an additional UF for FQPA 
(reduced to 3x) applies to all population subgroups for chronic risk. 
Application of the additional 3x safety factor results in a chronic 
population adjusted dose (cPAD) of 0.019 mg/kg bwt/day.
    The registrant believes that results from the acute and chronic 
dietary exposure analyses described below demonstrate a reasonable 
certainty that no harm to the overall U.S. population or any population 
subgroup will result from the use of imidacloprid on currently 
registered and pending uses.
    i. Food. Acute and chronic (Tier 3) risk assessments were made 
using the results of field trials conducted at maximum label 
application rates and the shortest pre-harvest intervals. For some of 
the vegetable crops, the residue data were collected at 1.5x or greater 
than the maximum label rate of 0.5 lb active ingredient/acre per 
season. In addition, no adjustments were made to account for 
dissipation of residues during storage, transportation from the field 
to the consumer, washing or peeling. Therefore, the actual dietary 
exposure will be less than that presented here.
    For the chronic analysis, mean field trial residues were 
calculated. For the acute Monte Carlo analysis, the entire distribution 
of residue field trial data were used for the ``non-blended'' and 
``partially blended'' foods as determined by EPA's standard operating 
procedure (SOP) 99.6. For the foods considered as

[[Page 5884]]

``blended'' by EPA's Health Effects Division (HED) SOP 99.6, mean field 
trial residue data were used. As allowed in EPA's draft guidance for 
submission of probabilistic human health exposure assessments one half 
limit of detection limit of detection (LOD) limit of quantitation (LOQ) 
values were used for all non-detected values (values below the 
sensitivity of the method).
    ii. Acute. Bayer Corporation's acute Monte Carlo dietary exposure 
assessment estimated percent of the aPAD and corresponding MOE for the 
overall U.S. population (all seasons) and various subpopulations. In 
this analysis, the exposure for the total U.S. population was equal to 
7.73% of the aPAD at the 99.9\th\ percentile. The most highly exposed 
population subgroup, children (1 to 6 yrs), had an exposure equal to 
16.42% of the aPAD at the 99.9\th\ percentile. Therefore, the acute 
dietary exposure estimates are below EPA's level of concern (LOC) for 
the overall U.S. population as well as the various subpopulations.
    iii. Chronic. The Bayer Corporation chronic dietary exposure 
estimated the percent of the cPAD for the overall U.S. population (all 
seasons) and various subpopulations. In this analysis, the exposure for 
the total U.S. population was equal to 1.4% of the cPAD. The most 
highly exposed population subgroup, children (1 to 6 yrs), had an 
exposure equal to 3.0% of the cPAD. Therefore, the chronic exposure 
estimates are below EPA's LOC for the overall U.S. population as well 
as the various subpopulations.
    iv. Drinking water. EPA, as published in the Federal Register of 
April 10, 2001 (69 FR 18554) (FRL-6777-6), calculated acute and chronic 
drinking water levels of concern (DWLOC) and compared them with the 
estimated environmental concentrations (EECs) for surface water and 
ground water. Based on this comparison, they determined that acute 
exposure and chronic exposure would not be expected to exceed the aPAD 
and cPAD, respectively. It is not expected that the additional exposure 
from the minor crops pending in EPA's 2002 work plan would 
significantly change EPA's water assessment.
    2. Non-dietary exposure--i. Residential turf. Bayer Corporation has 
conducted an exposure study to address the potential exposures of 
adults and children from contact with imidacloprid treated turf. The 
population considered to have the greatest potential exposure from 
contact with pesticide treated turf soon after pesticides are applied 
are young children. Margins of safety (MOS) of 7,587-41,546 for 10-year 
old children and 6,859-45,249 for 5-year old children were estimated by 
comparing dermal exposure doses to the imidacloprid no-observable 
effect level of 1,000 mg/kg/day established in a 15-day dermal toxicity 
study in rabbits. The estimated safe residue levels of imidacloprid on 
treated turf for 10-year old children ranged from 5.6 - 38.2 grams/
centimeters (g/cm\2\) and for 5-year old children from 5.1 - 33.5 g/
cm\2\. This compares with the average imidacloprid transferable residue 
level of 0.080 g/cm\2\ present immediately after the sprays have dried. 
The data indicate that children can safely contact imidacloprid-treated 
turf as soon after application as the spray has dried.
    ii.  Termiticide. Imidacloprid is registered as a termiticide. Due 
to the nature of the treatment for termites, exposure would be limited 
to that from inhalation and was evaluated by EPA and the Bayer 
Corporation. Data indicate that the MOS for the worst case exposures 
for adults and infants occupying a treated building who are exposed 
continuously (24 hours/day) are 8.0 x 10\7\ and 2.4 x 10\8\, 
respectively - and exposure can thus be considered negligible.
    iii. Tobacco smoke. Studies have been conducted to determine 
residues in tobacco and the resulting smoke following treatment. 
Residues of imidacloprid in cured tobacco following treatment were a 
maximum of 31 ppm (7 ppm in fresh leaves). When this tobacco was burned 
in a pyrolysis study only 2% of the initial residue was recovered in 
the resulting smoke (main stream plus side stream). This would result 
in an inhalation exposure to imidacloprid from smoking of approximately 
0.0005 mg per cigarette. Using the measured subacute rat inhalation 
NOAEL of 5.5 milligrams/meters (mg/m\3\), it is apparent that exposure 
to imidacloprid from smoking (direct exposure and/or indirect exposure) 
would not be significant.
    iv. Pet treatment. Human exposure from the use of imidacloprid to 
treat dogs and cats for fleas has been addressed by EPA. Bayer 
Corporation believes, that due to the fact that imidacloprid is not an 
inhalation or dermal toxicant and that while dermal absorption data are 
not available, imidacloprid is not considered to present a hazard via 
the dermal route.

D. Cumulative Effects

    Imidacloprid is a chloronicotinyl insecticide. At this time, EPA 
has not made a determination that imidacloprid and other substances 
that may have a common mechanism of toxicity would have cumulative 
effects. Therefore, for these tolerance petitions, Bayer Corporation 
assumes that imidacloprid does not have a common mechanism of toxicity 
with other substances and only the potential risks of imidacloprid in 
its aggregate exposure are considered.

E. Safety Determination

    1. U.S. population. EPA has considered data from developmental 
toxicity studies in the rat and rabbit and a 2-generation reproduction 
study in the rat. These studies are discussed in the toxicological 
profile section of Unit II. of the Federal Register dated September 18, 
1998 (63 FR 49837). The developmental toxicity data demonstrated no 
increased sensitivity of rats or rabbits to in utero exposure to 
imidacloprid. In addition, the multi-generation reproductive toxicity 
study did not identify any increased sensitivity of rats to in utero or 
postnatal exposure. Parental NOAELs were lower or equivalent to 
developmental or offspring NOAELs. The developmental toxicity studies 
are designed to evaluate adverse effects on the developing organism 
resulting from maternal pesticide exposure during gestation. 
Reproduction studies provide information relating to effects from 
exposure to the pesticide on the reproductive capability of mating 
animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional ten-
fold margin of safety for infants and children in the case of threshold 
effects to account for prenatal and postnatal toxicity and the 
completeness of the data base unless EPA determines that a different 
margin of safety will be safe for infants and children. Margin of 
safety are incorporated into EPA risk assessments either directly 
through use of a MOE analysis or through using uncertainty (safety) 
factors in calculating a dose level that poses no appreciable risk to 
humans. EPA believes that reliable data support using the standard UF 
(usually 100 for combined interspecies and intraspecies variability) 
and not the additional ten-fold MOE/UF when EPA has a complete data 
base under existing guidelines and when the severity of the effect in 
infants or children or the potency or unusual toxic properties of a 
compound do not raise concerns regarding the adequacy of the standard 
MOE/SF.
    Although developmental toxicity studies showed no increased 
sensitivity in fetuses as compared to maternal animals following in 
utero exposures in rats and rabbits, no increased sensitivity in pups 
as compared to adults was seen in the 2-generation reproduction 
toxicity study in rats, and the toxicology data base is complete as to 
core

[[Page 5885]]

requirements, EPA has determined that the additional SF for the 
protection of infants and children will be retained but reduced to 3x 
based on the following weight-of-the-evidence considerations relating 
to potential sensitivity and completeness of the data:
    ? There is concern for structure activity relationship. 
Imidacloprid, a chloronicotinyl compound, is an analog to nicotine and 
studies in the published literature suggest that nicotine, when 
administered causes developmental toxicity, including functional 
deficits, in animals and/or humans that are exposed in utero.
    ? There is evidence that imidacloprid administration causes 
neurotoxicity following a single oral dose in the acute study and 
alterations in brain weight in rats in the 2-year carcinogenicity 
study.
    ? The concern for structure activity relationship along with 
the evidence of neurotoxicity dictates the need of a developmental 
neurotoxicity study for assessment of potential alterations on 
functional development.
    Because a developmental neurotoxicity study potentially relates to 
both acute and chronic effects in both the mother and the fetus, EPA 
has applied the additional UF for FQPA for all population subgroups, 
and in both acute and chronic risk assessments.
    Based on the exposure assessments described above and on the 
completeness and reliability of the toxicity data, Bayer Corporation 
has concluded that the dietary exposure estimates from all label and 
pending uses of imidacloprid are 7.73% of the aPAD at the 99.9\th\ 
percentile and 1.4% of the cPAD for the U.S. population. Thus, Bayer 
Corporation has concluded that there is a reasonable certainty that no 
harm will result from aggregate exposure to imidacloprid residues.
    2. Infants and children. Based on the exposure assessments 
described above for the safety determination of the U.S. population and 
on the completeness and reliability of the toxicity data, Bayer 
Corporation has concluded that the dietary exposure estimates from all 
label and pending uses of imidacloprid are 16.42% of the aPAD at the 
99.9\th\ percentile and 3.0% of the cPAD for the most sensitive 
population subgroup, children 1 to 6 years. Thus, Bayer Corportion has 
concluded that there is a reasonable certainty that no harm will result 
from aggregate exposure to imidacloprid residues.

F. International Tolerances

    No Codex maximum residue levels have been established for residues 
of imidacloprid on any crops currently pending at EPA.
FR Doc. 03-2773 Filed 2-4-03; 8:45 a m]
BILLING CODE 6560-50-S 

 
 


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