[Federal Register Volume 62, Number 209 (Wednesday, October 29, 1997)]
[Notices]
[Pages 56171-56173]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-28663]


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ENVIRONMENTAL PROTECTION AGENCY

[PF-775; FRL-5752-2]


Notice of Filing of Pesticide Petitions

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 
certain pesticide chemicals in or on various food commodities.
DATES: Comments, identified by the docket control number PF-775, must 
be received on or before November 28, 1997.
ADDRESSES: By mail submit written comments to: Public Information and 
Records Integrity Branch (7502C), Information Resources and Services 
Division, Office of Pesticides Programs, Environmental Protection 
Agency, 401 M St., SW., Washington, DC 20460. In person bring comments 
to: Rm. 1132, CM #2, 1921 Jefferson Davis Highway, Arlington, VA.
    Comments and data may also be submitted electronically to: opp-
[email protected]. Follow the instructions under ``SUPPLEMENTARY 
INFORMATION.'' No confidential business information should be submitted 
through e-mail.
    Information submitted as a comment concerning this document may be 
claimed confidential by marking any part or all of that information as 
``Confidential Business Information'' (CBI). CBI should not be 
submitted through e-mail. Information marked as CBI will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2. A copy of the comment that does not contain CBI must be submitted 
for inclusion in the public record. Information not marked confidential 
may be disclosed publicly by EPA without prior notice. All written 
comments will be available for public inspection in Rm. 1132 at the 
address given above, from 8:30 a.m. to 4 p.m., Monday through Friday, 
excluding legal holidays.

FOR FURTHER INFORMATION CONTACT: By mail: Elizabeth Haeberer, 
Registration Division (7505C), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
Office location and telephone number: Rm. 250, CM #2, 1921 Jefferson 
Davis Highway, Arlington, VA 22202, (703) 308-2891; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions as 
follows proposing the establishment and/or amendment of regulations for 
residues of certain pesticide chemicals in or on various food 
commodities under section 408 of the Federal Food, Drug, and Comestic 
Act (FFDCA), 21 U.S.C. 346a. EPA has determined that these petitions 
contain data or information regarding the elements set forth in section 
408(d)(2); however, EPA has not fully evaluated the sufficiency of the 
submitted data at this time or whether the data supports granting of 
the petition. Additional data may be needed before EPA rules on the 
petition.
    The official record for this notice of filing, as well as the 
public version, has been established for this notice of filing under 
docket control number [PF-775] (including comments and data submitted 
electronically as described below). A public version of this record, 
including printed, paper versions of electronic comments, which does 
not include any information claimed as CBI, is available for inspection 
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal 
holidays. The official record is located at the address in 
``ADDRESSES'' at the beginning of this document.
    Electronic comments can be sent directly to EPA at:
    [email protected]


    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption. Comment and data 
will also be accepted on disks in Wordperfect 5.1 file format or ASCII 
file format. All comments and data in electronic form must be 
identified by the docket number [PF-775] and appropriate petition 
number. Electronic comments on this notice may be filed online at many 
Federal Depository Libraries.

List of Subjects

    Environmental protection, Agricultural commodities, Food additives, 
Feed additives, Pesticides and pests, Reporting and recordkeeping 
requirements.

    Dated: October 16, 1997.

James Jones,

Acting Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    Petitioner summaries of the pesticide petitions are printed below 
as required by section 408(d)(3) of the FFDCA. The summaries of the 
petitions were prepared by the petitioners and represent the views of 
the petitioners. EPA is publishing the petition summaries verbatim 
without editing them in any way. 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.

Gustafson, Inc.

PP 4F4415

    EPA has received a pesticide petition (PP 4F4415) from Gustafson, 
Inc., 1400 Preston Road, Suite 400, Plano, Texas 75093, proposing 
pursuant to section 408(d) of the Federal Food, Drug and

[[Page 56172]]

Cosmetic Act, 21 U.S.C. 346a(d), to amend 40 CFR Part 180 to make the 
time limited tolerances permanent by establishing a tolerance for 
residues of imidacloprid in or on the raw agricultural commodity 
sorghum grain 0.05 parts per million (ppm), forage 0.10 ppm, and stover 
0.10 ppm. The proposed analytical method involves homogenization, 
filtration, partition and cleanup with analysis by high performance 
liquid chromatography using UV detection'' for determining residues is 
a common moiety method for imidacloprid and its metabolites containing 
the 6-chloro-pyridinyl moiety using oxidation, derivatization, and 
analysis by capillary gas chromatography with a mass-selective 
detector. EPA has determined that the petition contains data or 
information regarding the elements set forth in section 408(d)(2) of 
the FFDCA; however, EPA has not fully evaluated the sufficiency of the 
submitted data at this time or whether the data supports granting of 
the petition. Additional data may be needed before EPA rules on the 
petition.

A. Residue Chemistry

    1. Plant metabolism. The metabolism of imidacloprid in plants is 
adequately understood for the purposes of these tolerances. The 
residues of concern are combined residues of imidacloprid and its 
metabolites containing the 6-chloro-pyridinyl moiety, all calculated as 
imidacloprid.
    2. Analytical method. The analytical method is a common moiety 
method for imidacloprid and its metabolites containing the 6-chloro-
pyridinyl moiety using a permanganate oxidation, silyl derivatization, 
and capillary 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 HPLC-UV which has been validated by the 
EPA as well. Imidacloprid and its metabolites are stable for at least 
24 months in the commodities when frozen.
    3. Magnitude of residues. Sorghum seed was treated with 
imidacloprid, formulated as Gaucho 480 FS at a rate of 8.0 oz. ai/cwt 
seed. Field trials were conducted at fifteen locations: Arkansas, 
California, Colorado (two locations), Kansas (two locations), 
Louisiana, Missouri, Nebraska (two locations), North Carolina, 
Oklahoma, South Dakota, and Texas (two locations). The sorghum seed was 
planted and the RACs were harvested at the appropriate growth stages. 
Residue levels in the sorghum grain were less than 0.05 ppm. Maximum 
residues were 0.058 ppm in the forage and 0.065 ppm in the stover. 
These residue data support tolerances of 0.05 ppm for sorghum grain, 
0.10 ppm for sorghum forage, and 0.10 ppm for sorghum stover. A 
processing study was submitted with this petition. No tolerances were 
required for processed fractions of sorghum grain since residues in the 
sorghum grain when treated at the 2X rate (which is higher than the 
maximum theoretical concentration factor of 1.6X) were less than the 
limit of quantitation (LOQ) of 0.05 ppm.

B. Toxicological Profile

    1. Acute toxicity. The acute oral LD50 values for 
imidacloprid technical ranged from 424 to 475 mg/kg bwt in the rat. The 
acute dermal LD50 was greater than 5,000 mg/kg in rats. The 
4-hour inhalation LC50 was less than 69 mg/m3 air 
(aerosol). Imidacloprid was not irritating to rabbit skin or eyes. 
Imidacloprid did not cause skin sensitization in guinea pigs.
    2. Genotoxicity. Extensive mutagenicity studies conducted to 
investigate point and gene mutations, DNA damage and chromosomal 
aberration, both using in vitro and in vivo test systems show 
imidacloprid to be non-genotoxic.
    3. Reproductive and developmental toxicity. A 2-generation rat 
reproduction study gave a no-observed-effect level (NOEL) of 100 ppm (8 
mg/kg/bwt). Rat and rabbit developmental toxicity studies were negative 
at doses up to 30 mg/kg/bwt and 24 mg/kg/bwt, respectively.
    4. Subchronic toxicity. Ninety-day feeding studies were conducted 
in rats and dogs. The NOELs for these tests were 14 mg/kg/bwt/day (150 
ppm) and 5 mg/kg/bwt/day (200 ppm), for the rat and dog studies, 
respectively.
    5. Chronic toxicity. A 2-year rat feeding/carcinogenicity study was 
negative for carcinogenic effects under the conditions of the study and 
had a NOEL of 100 ppm (5.7 mg/kg/bwt in males and 7.6 mg/kg/bwt in 
females for noncarcinogenic effects that included decreased body weight 
gain in females at 300 ppm and increased thyroid lesions in males at 
300 ppm and females at 900 ppm. A 1-year dog feeding study indicated a 
NOEL of 1,250 ppm (41 mg/kg/bwt). A 2-year mouse carcinogenicity study 
that was negative for carcinogenic effects under conditions of the 
study and that had a NOEL of 1,000 ppm (208 mg/kg/day).
    Imidacloprid has been classified under ``Group E'' (no evidence of 
carcinogenicity) by EPA's OPP/HED's Reference Dose (RfD) Committee. 
There is no cancer risk associated with exposure to this chemical. The 
reference dose (RfD) based on the 2-year rat feeding/carcinogenic study 
with a NOEL of 5.7 mg/kg/bwt and 100-fold uncertainty factor, is 
calculated to be 0.057 mg/kg/bwt. The theoretical maximum residue 
contribution (TMRC) from published uses is 0.008358 mg/kg/bwt/day 
utilizing 14.7% of the RfD.
    6. Animal metabolism. The nature of the imidacloprid residue in 
animals is adequately understood. The residues of concern are combined 
residues of imidacloprid and its metabolites containing the 6-
chloropyridinyl moiety, all calculated as imidacloprid.
    7. Metabolite toxicology. Metabolites, at the levels reported, are 
not toxicologically significant. No separate regulation of metabolites 
is warranted, and there is no scientific objection to the tolerance 
expression being for the combined residues of imidacloprid and its 
metabolites containing the 6-chloropyridinyl moiety.

C. Aggregate Exposure

    1. Dietary exposure. The EPA has determined that the reference dose 
(RfD) based on the 2-year rat feeding/carcinogenicity study with a NOEL 
of 5.7 mg/kg/bwt and 100-fold uncertainty factor, is calculated to be 
0.057 mg/kg/bwt. As published in the Federal Register June 12, 1996 (61 
FR 29674) (petition to establish tolerances on leafy green vegetables 
(PP 5F4522/R2237)), the theoretical maximum residue contribution (TMRC) 
from published uses is 0.008358 mg/kg/bwt utilizing 14.7% of the RfD 
for the general population. For the most highly exposed subgroup in the 
population, non-nursing infants (less than 1-year old), the TMRC for 
the published tolerances is 0.01547 mg/kg/day. This is equal to 27.1% 
of the RfD. The December 1, 1994 Federal Register (59 FR 61552) 
indicates that the tolerances for sorghum contribute 0.000001188 mg/kg/
bwt/day which represents 0.002% of the RfD which is included in the 
total values published in the June 12, 1996 Federal Register. 
Therefore, dietary exposure from the existing uses including the 
current temporary tolerances will not exceed the reference dose for any 
subpopulation (including infants and children).
    2. Food. Dietary exposure from the existing uses including the 
current temporary tolerances will not exceed the reference dose for any 
subpopulation (including infants and children).
    3. Drinking water. Although the various imidacloprid labels contain 
a

[[Page 56173]]

statement that this chemical demonstrates the properties associated 
with chemicals detected in groundwater, the Registrant is not aware of 
imidacloprid being detected in any wells, ponds, lakes, streams, etc. 
from its use in the United States. In studies conducted in 1995, 
imidacloprid was not detected in seventeen wells on potato farms in 
Quebec, Canada. In addition, groundwater monitoring studies are 
currently underway in California and Michigan. Therefore, contributions 
to the dietary burden from residues of imidacloprid in water would be 
inconsequential.
    4. Non-dietary exposure-- a. 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 g/cm2 and for 5 year old children from 5.1 - 33.3 g/
cm2. This compares with the average imidacloprid 
transferable residue level of 0.080 g/cm2 present 
immediately after the sprays have dried. These data indicate that 
children can safely contact. Bayer Corporation has conducted an 
exposure imidacloprid-treated turf as soon after application as the 
spray has dried.
    b. 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's Occupational and 
Residential Exposure Branch (OREB) and Bayer Corporation. Data indicate 
that the Margins of Safety for the worst case exposures for adults and 
infants occupying a treated building who are exposed continuously (24 
hours/day) are 8.0 x 107 and 2.4 x 108, 
respectively, and exposure can thus be considered negligible.
    c. 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 two percent 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 NOEL of 5.5 mg/m3, it is apparent that exposure 
to imidacloprid from smoking (direct and/or indirect exposure) would 
not be significant.
    d. Pet treatment. Human exposure from the use of imidacloprid to 
treat dogs and cats for fleas has been addressed by EPA's Occupational 
and Residential Exposure Branch (OREB) who have concluded 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

    No other chemicals having the same mechanism of toxicity are 
currently registered, therefore, there is no risk from cumulative 
effects from other substances with a common mechanism of toxicity.

E. Safety Determination

    1. U.S. population. Using the conservative exposure assumptions 
described above and based on the completeness and reliability of the 
toxicity data, it can be concluded that total aggregate exposure to 
imidacloprid from all current uses including those currently proposed 
will utilize little more than 15% of the RfD for the U.S. population. 
EPA generally has no concerns for exposures below 100% of the RfD, 
because the RfD represents the level at or below which daily aggregate 
exposure over a lifetime will not pose appreciable risks to human 
health. Thus, it can be concluded that there is a reasonable certainty 
that no harm will result from aggregate exposure to imidacloprid 
residues.
    2. Infants and children. In assessing the potential for additional 
sensitivity of infants and children to residues of imidacloprid, the 
data from developmental studies in both rat and rabbit and a 2-
generation reproduction study in the rat have been considered. The 
developmental toxicity studies evaluate potential adverse effects on 
the developing animal resulting from pesticide exposure of the mother 
during prenatal development. The reproduction study evaluates effects 
from exposure to the pesticide on the reproductive capability of mating 
animals through two generations, as well as any observed systemic 
toxicity.
    FFDCA Section 408 provides that the EPA may apply an additional 
safety factor for infants and children in the case of threshold effects 
to account for pre- and post-natal effects and the completeness of the 
toxicity database. Based on current toxicological data requirements, 
the toxicology database for imidacloprid relative to pre- and post-
natal effects is complete. Further for imidacloprid, the NOEL of 5.7 
mg/kg/bwt from the 2-year rat feeding/carcinogenic study, which was 
used to calculate the RfD (discussed above), is already lower than the 
NOELs from the developmental studies in rats and rabbits by a factor of 
4.2 to 17.5 times. Since a 100-fold uncertainty factor is already used 
to calculate the RfD, it is surmised that an additional uncertainty 
factor is not warranted and that the RfD at 0.057 mg/kg/bwt/day is 
appropriate for assessing aggregate risk to infants and children. Using 
the conservative exposure assumptions described above, EPA has 
concluded that the TMRC from use of imidacloprid from published uses is 
0.008358 mg/kg/bwt/day utilizing 14.7% of the RfD for the general 
population. For the most highly exposed subgroup in the population, 
non-nursing infants (less than 1 year old), the TMRC for the published 
tolerances is 0.01547 mg/kg/day. This is equal to 27.1% of the RfD. 
Therefore, dietary exposure from the existing uses including the 
currently proposed tolerances will not exceed the reference dose for 
any subpopulation (including infants and children).

F. International Tolerances

    No CODEX Maximum Residue Levels (MRLs) have been established for 
residues of imidacloprid on any crops at this time.
[FR Doc. 97-28663 Filed 10-28-97; 8:45 am]
BILLING CODE 6560-50-F