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Lambda-cyhalothrin (Zeneca). February 19, 1997. Pesticide Tolerance Petition. Federal Register.
http://www.epa.gov/docs/fedrgstr/EPA-PEST/1997/February/Day-19/p3932.htm
[Federal Register: February 19, 1997 (Volume 62, Number 33)]
[Notices]
[Page 7454-7456]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
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ENVIRONMENTAL PROTECTION AGENCY
[PF-699; FRL-5585-5]
Zeneca Ag Products; Pesticide Tolerance Petition Filing
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of filing.
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SUMMARY: This notice announces the filing of a pesticide petition
proposing the establishment of a regulation for residues of lambda-
cyhalothrin and its epimer in or on rice. The names for lambda-
cyhalothrin and its epimer are as follows: lambda-cyhalothrin, a 1:1
mixture of (S)-alpha-cyano-3-phenoxybenzyl-(Z)-(1R,3R)-3-(2-chloro-
3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate and
(R)-alpha-cyano-3-phenoxybenzyl-(Z)-(1S,3S)-3-(2-chloro-3,3,3-
trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate. Epimer of
lambda-cyhalothrin, a 1:1 mixture of (S)-alpha-cyano-3-phenoxybenzyl-
(Z)(1S,3S)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-
dimethylcyclopropanecarboxylate and (R)-alpha-cyano-3-phenoxybenzyl-
(Z)-(1R,3R)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-
dimethylcyclopropanecarboxylate. The summary was prepared by the
petitioner, Zeneca Ag Products.
DATES: Comments, identified by the docket control number [PF-699], must
be received on or before March 21, 1997.
ADDRESSES: By mail, submit written comments to: Public Response and
Program Resources Branch, Field Operations Division (7506C), Office of
Pesticide Programs, Environmental Protection Agency, 401 M St., SW.,
Washington, DC 20460. In person, bring comments to: Crystal Mall #2,
Room 1132, 1921 Jefferson Davis Highway, Arlington VA.
Comments and data may also be submitted electronically by sending
electronic mail (e-mail) to: opp-docket@epamail.epa.gov. Electronic
comments must be submitted as an ASCII file avoiding the use of special
characters and any form of encryption. Comments and data will also be
accepted on disks in WordPerfect in 5.1 file format or ASCII file
format. All comments and data in electronic form must be identified by
the docket control number [PF-699]. Electronic comments on this notice
may be filed online at many Federal Depository Libraries. Additional
information on electronic submissions can be found in Unit II. of this
document.
Information submitted as a comment concerning this notice 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 Room 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, George LaRocca, Product
Manager, (PM 13), Registration Division, Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
Office location, telephone number, and e-mail address: Crystal Mall #2,
1921 Jefferson Davis Highway, Arlington, VA, 703-305-6100, e-mail:
larocca.george@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: EPA has received a pesticide petition (PP-
6F4769) from Zeneca Ag Products, 1800 Concord Pike, P.O. Box 15458,
Wilmington, DE 19850-5458. The petition proposes, pursuant to section
408 of the Federal Food, Drug and Cosmetic Act (FFDCA), 21 U.S.C.
346a(d), to amend 40 CFR part 180 to establish tolerances for residues
of the insecticide lambda-cyhalothrin in or on the raw agricultural
commodities rice
[[Page 7455]]
grain at 1.0 parts per million (ppm), rice straw at 1.75 ppm, and in or
on the processed commodity rice hulls at 5.0 ppm. EPA has determined
that the petition contains data or information regarding the elements
set forth in section 408(d)(2) of the FFDCA; however, EPA has not fully
evaluated the sufficiency of the submitted data at this time or whether
the data supports granting of the petition. Additional data may be
needed before EPA rules on the petition. EPA has determined the
proposed analytical method is gas liquid chromatography with an
electron capture detector. As required by section 408(d) of the FFDCA,
as recently amended by the Food Quality Protection Act (FQPA) Pub. L.
104-170, Zeneca Ag Products (Zeneca) included in the petition a summary
of the petition and authorization for the summary to be published in
the Federal Register in a notice of receipt of the petition. The
summary represents the views of Zeneca; EPA as mentioned above, is in
the process of evaluating the petition. As required by section
408(d)(3) of the FFDCA, EPA is including the summary as a part of this
notice of filing. EPA may have made edits to the summary for the
purpose of clarity.
I. Petiton Summary
A. Residue Chemistry
1. Plant metabolism. The metabolism of lambda-cyhalothrin has been
studied in cotton, soybean, cabbage, and wheat plants. The studies show
that the metabolism generally follows that of other pyrethroid
insecticides. The ester linkage is cleaved to form
cyclopropanecarboxylic acids and the corresponding phenoxybenzyl
alcohol. Overall the studies show that unchanged lambda-cyhalothrin is
the principal constituent of the residue on edible portions of these
crops.
2. Analytical method. An adequate analytical method (gas liquid
chromatography with an electron capture detector) is available for
enforcement purposes.
3. Magnitude of residues. Sixteen field trials were carried out on
rice during 1995 in the United States. The trials were conducted in the
states of Arkansas, Louisiana, Missouri, Mississippi, Texas, and
California. These states account for 100% of the production acres of
rice in the United States. The number and geographical distribution of
the trials agrees with the recommendation given in the ``EPA Residue
Chemistry Guidance'' (1994). In these trials, the maximum combined
residues of lambda-cyhalothrin and epimer were 0.88 ppm in or on rice
grain and 1.62 ppm in or on rice straw. In addition, a single field
trial was conducted during 1995 in the States of Mississippi and
Arkansas for the purpose of determining if lambda-cyhalothrin residues
in rice, concentrate in or on processed rice fractions. Data from these
trials demonstrated that residues of lambda-cyhalothrin may concentrate
up to 6.1 times in or on rice hulls but do not concentrate in rice bran
or polished rice.
B. Toxicological Profile
The following toxicity studies have been conducted to support the
request for a regulation for residues of lambda-cyhalothrin in or on
rice.
1. Acute toxicity. Acute toxicity studies with the technical grade
of the active ingredient lambda-cyahothrin: oral LD50 in the rat
of 79 milligram/kilogram (mg/kg) (males) and 56 mg/kg (females), dermal
LD50 in the rat of 632 mg/kg (males) and 696 mg/kg females,
primary eye irritation study showed mild irritation, and primary dermal
irritation study showed no irritation.
2. Genotoxicity. The following genotoxicity tests were all
negative: a gene mutation assay (Ames), a mouse micronucleus assay, an
in vitro cytogenetics assay, and a gene mutation study in mouse
lymphoma cells.
3. Reproductive and developmental toxicity. i. A three-generation
reproduction study in rats fed diets containing 0, 10, 30, and 100 ppm
with no developmental toxicity observed at 100 ppm, the highest dose
tested. The maternal no observed effect level (NOEL) and lowest
observed effect level (LOEL) for the study are established at 30 (1.5
mg/kg/day) and 100 ppm (5 mg/kg/day), respectively, based upon
decreased parental body weight gain. The reproductive NOEL and LOEL are
established at 30 (1.5 mg/kg/day) and 100 ppm (5 mg/kg/day),
respectively, based on decreased pup weight gain during weaning.
ii. A developmental toxicity study in rats given gavage doses of 0,
5, 10, and 15 mg/kg/day with no developmental toxicity observed under
the conditions of the study. The developmental NOEL is greater than 15
mg/kg/day, the highest dose tested. The maternal NOEL and LOEL are
established at 10 and 15 mg/kg/day, respectively, based on reduced body
weight gain.
iii. A developmental toxicity study in rabbits given gavage doses
of 0, 3, 10, and 30 mg/kg/day with no developmental toxicity observed
under the conditions of the study. The maternal NOEL and LOEL are
established at 10 and 30 mg/kg/day, respectively, based on decreased
body weight gain. The developmental NOEL is greater than 30 mg/kg/day,
the highest dose tested.
4. Subchronic toxicity. i. A 90-day feeding study in rats fed doses
of 0, 10, 50, and 250 ppm with a NOEL of 50 ppm and a LOEL of 250 ppm
based on body weight gain reduction.
ii. A 21-day study in rabbits exposed dermally to doses of 0, 10,
100, and 1,000 mg/kg/day, 6 hours/day, 5 days/week with a systemic NOEL
>1,000 mg/kg/kg. There were no clinical signs of systemic toxicity at
any dose level tested.
5. Chronic toxicity. i. A 12-month feeding study in dogs fed dose
(by capsule) levels of 0, 0.1, 0.5, and 3.5 mg/kg/day with a NOEL of
0.1 mg/kg/day. The LOEL for this study is established at 0.5 mg/kg/day
based upon clinical signs of neurotoxicity.
ii. A 24-month chronic feeding/carcinogenicity study with rats fed
diets containing 0, 10, 50, and 250 ppm. The NOEL was established at 50
ppm and LOEL at 250 ppm based on reduced body weight gain. There were
no carcinogenic effects observed under the conditions of the study.
iii. A carcinogenicity study in mice fed dose levels of 0, 20, 100,
or 500 ppm (0, 3, 15, or 75 mg/kg/day) in the diet for 2 years. A
systemic NOEL was established at 100 ppm and systemic LOEL at 500 ppm
based on decreased body weight gain in males throughout the study at
500 ppm. The Agency has classified lambda-cyhalothrin as a Group D
carcinogen (not classifiable due to an equivocal finding in this
study). Zeneca concludes that no treatment-related carcinogenic effects
were observed under the conditions of the study.
6. Animal metabolism. Metabolism studies in rats demonstrated that
distribution patterns and excretion rates in multiple oral dose studies
are similar to single-dose studies. There is an accumulation of
unchanged compound in fat upon chronic administration with slow
elimination. Otherwise, lambda-cyhalothrin was rapidly metabolized and
excreted. The metabolism of lambda-cyhalothrin in livestock has been
studied in the goat, chicken, and cow. Unchanged lambda-cyhalothrin is
the major residue component of toxicological concern in meat and milk.
7. Metabolite toxicology. The Agency has previously determined that
the metabolites of lambda-cyhalothrin are not of toxicological concern
and need not be included in the tolerance expression. Given this
determination, Zeneca concludes that there is no need to discuss
metabolite toxicity.
[[Page 7456]]
C. Aggregate Exposure
1. Dietary exposure-- i. Food. For the purposes of assessing the
potential dietary exposure for all existing and pending tolerances for
lambda-cyhalothrin, Zeneca has utilized available information on
anticipated residues and percent crop treated. For all existing and
pending tolerances the anticipated residue contribution (ARC) is
estimated at 0.0002682 mg/kg/body weight (bwt)/day.
ii. Drinking water. Laboratory and field data have demonstrated
that lambda-cyhalothrin and its degradates are immobile in soil and
will not leach into groundwater. Other data show that lambda-
cyhalothrin is virtually insoluble in water and extremely lipophilic.
As a result, Zeneca concludes that residues reaching surface waters
from field runoff will quickly adsorb to sediment particles and be
partitioned from the water column. Zeneca concludes that together these
data indicate that residues are not expected in drinking water.
2. Non-dietary exposure. Other potential sources of exposure are
from non-occupational sources such as structural pest control and
ornamental plant and lawn use of lambda-cyhalothrin. Zeneca has no data
upon which to estimate exposure from these uses. However, given the
extremely low vapor pressure of lambda-cyhalothrin (1.5 x 10-9
millimeters (mm) of mercury (Hg)) and the low use rates, it is
anticipated that inhalation and dermal exposure from these uses Zeneca
concludes will be insignificant.
D. Cumulative Effects
At this time, Zeneca cannot make a determination based on available
and reliable information that lambda-cyhalothrin and other substances
that may have a common mechanism of toxicity would have cumulative
effects. Thus, Zeneca concludes that for purposes of this tolerance it
is appropriate only to consider the potential risks of lambda-
cyhalothrin in an aggregate exposure assessment.
E. Safety Determination
The acceptable reference dose (RfD) based on a NOEL of 0.1 mg/kg/
bwt/day from the chronic dog study and a safety factor of 100 is 0.001
mg/kg/bwt/day. A chronic dietary exposure/risk assessment has been
performed for lambda-cyhalothrin using the above RfD. Available
information on anticipated residues and percent crop treated was
incorporated into the analysis to estimate the ARC. The ARC is
generally considered a more realistic estimate than an estimate based
on tolerance level residues.
1. U.S. population. The ARC from established tolerances and the
current and pending actions are estimated to be 0.0002682 mg/kg/bwt/day
and utilize 26.82% of the RfD for the U.S. population.
2. Infants and children. The ARC for children, aged 1 to 6 years
old, and non-nursing infants (subgroups most highly exposed) utilizes
57% and 65% of the RfD, respectively. Generally speaking, the Agency
has no cause for concern if ARC for all published and proposed
tolerances is less than the RfD.
F. International Tolerances
There are no Codex maximum residue levels (MRL) established for
residues of lambda-cyhalothrin in or on rice.
II. Public Record
EPA invites interested persons to submit comments on this notice of
filing. Comments must bear a notification indicating the docket control
number [PF-699].
A record has been established for this notice under docket control
number [PF-699] (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
public record is located in Room 1132 of the Public Response and
Program Resources Branch, Environmental Protection Agency, Crystal Mall
#2, 1921 Jefferson Davis Highway, Arlington, VA.
Electronic comments can be sent directly to EPA at:
opp-docket@epamail.epa.gov.
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption. The official
record for this notice, as well as the public version, as described
above will be kept in paper form. Accordingly, EPA will transfer all
comments received electronically into printed, paper form as they are
received and will place the paper copies in the official record which
will also include all comments submitted directly in writing.
The official record is the paper record maintained at the address
in ``ADDRESSES'' at the beginning of this notice.
List of Subjects
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: February 6, 1997.
Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.
[FR Doc. 97-3932 Filed 2-18-97; 8:45 am]
BILLING CODE 6560-50-F