[Federal Register Volume 62, Number 48 (Wednesday, March 12, 1997)]
[Notices]
[Pages 11450-11453]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-6209]


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ENVIRONMENTAL PROTECTION AGENCY
[PF-721; FRL-5592-7]


BASF Corporation; Pesticide Tolerance Petition Filing

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of filing.

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SUMMARY: This notice announces the filing of pesticide petitions 
proposing the tolerances for residues of the pesticide pyridaben, [2-
tert-butyl-5-(4-ter-butylbenzylthio)-4-chloropyridazin-3(2H)-one] and 
its metabolites PB-7 (2-tert-butyl-5-[4-(1-carboxy-1-
methylethyl)benzylthio]-4-chloropyridazin-3(2H)-one) and PB-9 (2-tert-
butyl-4-chloro-5-[4-(1,1-dimethyl-2-hydroxyethyl)benzylthio]-
chloropyridazin-3(2H)-one). BASF is petitioning EPA for the 
establishment of tolerances for use of pyridaben to control certain 
pests on apples, pears, citrus, almonds, peaches (imported commodity), 
plums (imported commodity), and grapes (imported commodity). The 
proposed tolerances for pyridaben are: apples at 0.6 ppm, wet apple 
pomace at 1.0 ppm, pears at 0.75 ppm, citrus at 0.5 ppm, dried citrus 
pulp at 1.5 ppm, citrus oil at 10.0 ppm, almonds at 0.05 ppm, almond 
hulls at 4.0 ppm, peaches at 0.05 ppm, plums at 0.05 ppm, and grapes at 
0.75 ppm. The proposed tolerances for pyridaben and its metabolites 
are: milk at 0.01 ppm, meat at 0.05 ppm, meat by-products at 0.05 ppm, 
and fat at 0.05 ppm. This summary was prepared by the petitioner.

DATES: Comments, identified by the docket control number [PF-721], must 
be received on or before April 11, 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: Rm. 1132 CM #2, 
1921 Jefferson Davis Highway, Arlington, VA 22202. Comments and data 
may also be submitted electronically by sending electronic mail (e-
mail) to: [email protected]. 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 5.1 file format or in ASCII file format. All 
comments and data in electronic form must be identified by the docket 
control number [PF-721]. 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 comments concerning this notice may be 
claimed confidential by marking any part or all of that information as 
``Confidential Business Information'' (CBI). The 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: Richard Keigwin, Product Manager (PM) 
10, Registration Division (7505C), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
Office location, telephone number, and e-mail: Crystal Mall #2, Rm. 
210, 1921 Jefferson Davis Highway, Arlington, VA 22202, 703-305-6788, 
e-mail: [email protected].

SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions (PP) 
5F4543 (on citrus), 4E4370 (on imported commodities) and 6F4651 
(apples), 6F4741 (almonds), and 6F4721 (pears) from BASF Corporation, 
Agricultural Products, PO Box 13528, Research Triangle Park, NC 27709. 
The petition proposes, pursuant to section 408 of the Federal Food, 
Drug and Cosmetic Act (FFDCA), 21 U.S.C section 346a, to amend 40 CFR 
part 180 to establish tolerances for the pesticide pyridaben [2-tert-
butyl-5-(4-ter-butylbenzylthio)-4-chloropyridazin-3(2H)-one] in or on 
the raw agricultural commodities: apples, wet apple pomace, pears, 
citrus, dried citrus pulp, citrus oil, almonds, almond hulls, peaches, 
plums, and grapes, respectively. The petition also proposes to 
establish tolerances for pyridaben and its metabolites PB-7 (2-tert-
butyl-5-[4-(1-carboxy-1-methylethyl)benzylthio]-4-chloropyridazin-
3(2H)-one) and PB-9 (2-tert-butyl-4-chloro-5-[4-(1,1-dimethyl-2-
hydroxyethyl)benzylthio]-chloropyridazin-3(2H)-one) in or on the raw 
agricultural commodities: milk, meat, meat-by-products, and fat. 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 supports granting of this petition. Additional 
data may be needed before EPA rules on the petition.
    As required by section 408(d) of the FFDCA, as recently amended by 
the Food Quality Protection Act (FQPA), Pub. L. 104-170, BASF 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 BASF. EPA 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 the 
notice of filing. EPA may have made minor edits to the summary for the 
purpose of clarity.

I. Petition Summary

A. Plant and Animal Metabolism

    BASF Corporation notes that metabolism in plants and animals is 
understood.

B. Analytical Method

    The proposed analytical method involves extraction, partition, 
clean-up and detection of residues by gas chromatography/electron 
capture detector (gc/ecd).

C. Magnitude of the Residues

    Nine pear residue trials were conducted in six states. Residues of 
pyridaben were measured by gc/ecd. The method of detection had a limit 
of detection of 0.05 parts per million (ppm). Residues ranged from 0.07 
to 0.58 ppm.
    Twelve apple residue trials were conducted in six states. Residues 
of

[[Page 11451]]

pyridaben were measured by gc/ecd. The method of detection had a limit 
of detection of 0.05 ppm. Residues ranged from 0.08 to 0.44 ppm.
    Nineteen citrus residue trials were conducted in four states. 
Residues of pyridaben were measured by gc/ecd. The method of detection 
had a limit of detection of 0.05 ppm. Residues ranged from 0.05 to 0.42 
ppm.
    Eight almond residue trials were conducted in California. Residues 
of pyridaben were measured by gc/ecd. The method of detection had a 
limit of detection of 0.05 ppm. Residues were < 0.05 ppm in all trials.
    Eight peach residue trials were conducted in Chile. Residues of 
pyridaben were measured by gc/ecd. The method of detection had a limit 
of detection of 0.05 ppm. Residues were < 0.05 ppm in all trials.
    Six plum residue trials were conducted in Chile. Residues of 
pyridaben were measured by gc/ecd. The method of detection had a limit 
of detection of 0.05 ppm. Residues were < 0.05 ppm in all trials.
    Eight grape residue trials were conducted in Chile. Residues of 
pyridaben were measured by gc/ecd. The method of detection had a limit 
of detection of 0.05 ppm. Residues ranged from < 0.05 to 0.22 ppm.

D. Toxicological Profile

    1. Acute toxicity testing. a. Acute oral toxicity (rat): LD50 
= 1100 milligrams/kilogram (mg/kg) in males; 570 mg/kg in females. Tox 
Category: III
    b. Acute oral toxicity (mouse): LD50 = 424 mg/kg in males; 383 
mg/kg in females. Tox Category: II
    c. Acute dermal toxicity (rat): LD50 = > 2000 mg/kg in males 
and females. Tox Category: III
    d. Acute inhalation toxicity (rat): LC50 = 0.66 mg/l in males; 
0.62 mg/l in females. Tox Category: III
    e. Primary eye irritation (rabbit): Pyridaben is a slight ocular 
irritant. Tox Category: III
    f. Primary dermal irritation (rabbit): Pyridaben is not a dermal 
irritant. Tox Category: IV
    g. Dermal sensitization (guinea pig): Pyridaben is not a dermal 
sensitizer.
    2. Acute neurotoxicity (rat): Rats were dosed once with 0, 50, 100 
and 200 mg/kg. The no observed effect level (NOEL) for systemic 
toxicity was determined to be 50 mg/kg for both males and females. The 
lowest observed effect level (LOEL) for systemic effects was determined 
to be 100 mg/kg in both sexes based on decreased food consumption, 
decreased body weight gain and increased clinical signs. The LOEL for 
neurobehavioral effects was determined to be 200 mg/kg in males and 
>200 mg/kg in females.
    3. Subchronic toxicity testing. a. 21-Day dermal (rat): Rats were 
repeatedly dosed with pyridaben at 0, 30, 100, 300 and 1000 mg/kg/day 
for 21 days. The NOEL was determined to be 100 mg/kg/day and the LOEL 
300 mg/kg/day based on decreased body weight gain in females.
    b. 90-Day rodent (rat): CD rats were dosed with pyridaben at 0, 30, 
65, 155 and 350 ppm in the diet for 13 weeks. The NOEL was determined 
to be 65 ppm (4.94 mg/kg/day) for males and 30 ppm (2.64 mg/kg/day) in 
females. The LOEL for males was determined to be 155 ppm (11.55 mg/kg/
day) based on reduced body weight gain, reduced food consumption, 
reduced food efficiency, and altered clinical pathology parameters. The 
LOEL for females was determined to be 65 ppm (5.53 mg/kg/day) based on 
reduced body weight gain and reduced food efficiency.
    c. 90-Day non-rodent (dog): Beagle dogs were dosed with pyridaben 
at 0, 0.5, 1, 4, and 16 mg/kg/day in the diet for 13 weeks. The NOEL 
was determined to be 1 mg/kg/day and the LOEL determined to be 4 mg/kg/
day based on reduced body weight gain and an increase in clinical signs 
in both sexes.
    d. 90-Day neurotoxicity (rat): Rats were dosed with pyridaben at 0, 
30, 100, and 350 ppm in the diet for 13 weeks. The systemic NOEL was 
determined to be 100 ppm (equivalent to 8.5 mg/kg/day in males and 9.3 
mg/kg/day in females). The systemic LOEL was determined to be 350 ppm 
(equivalent to 28.8 mg/kg/day in males and 31.1 mg/kg/day in females) 
based on decreased body weight gain, decreased food consumption and 
decreased food efficiency. No neuropathological effects were noted in 
the study.
    4. Chronic toxicity testing. a. 1-Year non-rodent (dog): Two 
studies were run. In the first, beagle dogs were dosed with pyridaben 
at 0, 1, 4, 16 and 32 mg/kg/day in the diet for one year. In the 
second, beagle dogs were dosed with pyridaben at 0 and 0.5 mg/kg/day in 
the diet for 1 year. The NOEL was determined to be <0.5 ppm and LOEL 
determined to be 0.5 mg/kg/day based on increased clinical signs and 
decreased body weight gain in both sexes.
    b. Combined rodent chronic toxicity/carcinogenicity (rat): Wistar 
rats were fed 0, 4, 10, 28 and 80 ppm pyridaben in the diet to assess 
carcinogenicity and 0, 4, 10, 28 and 120 ppm in the diet to assess 
chronic toxicity for 104 weeks. The NOEL was determined to be 28 ppm in 
both sexes (equivalent to 1.13 mg/kg/day in males and 1.46 mg/kg/day in 
females). The LOEL was determined to be 120 ppm in both sexes 
(equivalent to 5.0 mg/kg/day in males and 6.52 mg/kg/day in females) 
based on decreased body weight gain in both sexes and decreased 
alanineamino transferase (ALT) levels in males. Pyridaben was not 
carcinogenic under the conditions of the test.
    c. Carcinogenicity in the rodent (mouse): CD-1 mice were fed 0, 
2.5, 8.0, 25 and 80 ppm pyridaben in the diet for 78 weeks. The NOEL 
was determined to be 25 ppm in both sexes (equivalent to 2.78 mg/kg/day 
in both sexes). The LOEL was determined to be 80 ppm in both sexes 
(equivalent to 8.88 mg/kg/day in males and 9.74 mg/kg/day in females) 
based on decreased body weight gain, decreased food efficiency and 
changes in organ weights and histopathology. Pyridaben was not 
carcinogenic under the conditions of the test.
    5. Developmental toxicity testing. a. Developmental toxicity (rat): 
Sprague-Dawley rats were dosed with 0, 2.5, 5.7, 13 and 30 mg/kg/day 
pyridaben in the diet from days 6 through 15 of gestation. The maternal 
NOEL was determined to be 4.7 mg/kg/day and the maternal LOEL was 
determined to be 13 mg/kg/day based on decreased body weight gain, and 
decreased food consumption during the dosing period. The developmental 
NOEL was determined to be 13 mg/kg/day and the developmental LOEL was 
determined to be 30 mg/kg/day based on decreased fetal body weight and 
an increase in incomplete ossification in selected bones.
    b. Developmental toxicity (rabbit): New Zealand white rabbits were 
dosed with 0, 1.5, 5, and 15 mg/kg/day pyridaben in the diet from days 
6 through 19 of gestation. The maternal NOEL was determined to be 5 mg/
kg/day and the maternal LOEL was determined to be 15 mg/kg/day based on 
decreased body weight gain, and decreased food consumption during the 
dosing period. The developmental NOEL was determined to be <15 mg/kg/
day and the developmental LOEL was determined to be <15 mg/kg/day.
    c. Developmental toxicity (rabbit): Himalayan rabbits were dosed, 
by dermal application, with 0, 70, 170 and 450 mg/kg/day pyridaben from 
days 6 through 19 of gestation. The maternal systemic NOEL was 
determined to be 70 mg/kg/day and the maternal LOEL was determined to 
be 170 mg/kg/day based on decreased body weight gain, and decreased 
food consumption during the dosing period. The developmental NOEL was 
determined to be 170 mg/kg/day and the LOEL determined to be 450

[[Page 11452]]

mg/kg/day based on decreased ossification of the skull.
    6. Reproductive toxicity testing. Multi-generation reproduction 
(rat): CD rats were dosed with 0, 10, 28 and 80 ppm pyridaben in the 
diet. The parental/systemic NOEL was determined to be 28 ppm in both 
sexes (equivalent to 2.20 mg/kg/day in males and 2.41 mg/kg/day in 
females). The parental/systemic LOEL was determined to be 80 ppm 
(equivalent to 6.31 mg/kg/day in males and 7.82 mg/kg/day in females) 
based on decreased body weight, decreased body weight gain and 
decreased food efficiency. The reproductive NOEL and LOEL were both 
determined to be >80 ppm in males and females.
    7. Mutagenicity testing. a. Ames Testing: Negative
    b. In vitro cytogenicity (Chinese hamster lung cells): Negative
    c. In vivo micronucleus assay (mouse): Negative
    d. DNA damage/repair (E. coli): Negative

E. Threshold Effects

    Based on the available chronic toxicity data, EPA has established 
the Reference Dose (RfD) for pyridaben at 0.005 mg/kg/day. The RfD for 
pyridaben is based on a 1-year feeding study in dogs with a threshold 
LOEL of 0.5 mg/kg/day based on increased clinical signs and decreased 
body weight gain in both sexes and an uncertainty factor of 100.

F. Non-Threshold Effects

    Using its Guidelines for Carcinogenic Risk Assessment, EPA has 
classified pyridaben as Group ``E '' for carcinogenicity (no evidence 
of carcinogenicity) based on the results of carcinogenicity studies in 
two species. There was no evidence of carcinogenicity in an 18-month 
feeding study in mice and a 2-year feeding study in rats at the dosage 
levels tested. The doses tested were adequate for identifying a cancer 
risk. Thus, a cancer risk assessment is not necessary.

G. Aggregate Exposure

    1. Dietary exposure. Since pyridaben is regulated based upon non-
carcinogenic chronic toxicity, BASF conducted a DRES analysis based on 
anticipated residue levels determined by EPA. The anticipated residue 
levels were derived from the average residue levels from field trials 
conducted at the maximum proposed use rate and minimum pre-harvest 
interval, and a correction factor of 2.3 to account for all 
organosoluble residues as determined by EPA. This analysis demonstrates 
that the exposure to non-nursing infants < 1 year, the most sensitive 
subpopulation is approximately 73.4 percent of the RfD and to the 
general population exposure is approximately 11.3 percent of the RfD.
    2. ``Other'' exposure. Other potential sources of exposure of the 
general population to residues of pesticides are residues in drinking 
water and exposure from non-occupational sources. Based on the studies 
submitted to EPA for assessment of environmental risk, BASF does not 
anticipate exposure to residues of pyridaben in drinking water. There 
is no established maximum concentration level for residues of pyridaben 
in drinking water under the Safe Drinking Water Act. BASF has not 
estimated non-occupational exposure for pyridaben since the current 
registration for pyridaben is limited to commercial greenhouse use for 
non-food ornamental plants and the only other domestic use will be for 
commercial apple, pear, citrus and almond production. The potential for 
non-occupational exposure to the general population is considered to be 
insignificant.
    3. Cumulative exposure. BASF also considered the potential for 
cumulative effects of pyridaben and other substances that have a common 
mechanism of toxicity. BASF has concluded that consideration of a 
common mechanism of toxicity is not appropriate at this time since 
there is no reliable information to indicate that toxic effects 
produced by pyridaben would be cumulative with those of any other 
chemical compounds.

H. Determination of Safety for U.S. Population

    Using the exposure assumptions described in Unit I.G. of this 
document, BASF concludes that aggregate exposure to pyridaben will 
utilize approximately 11.3 percent of the RfD for the U.S. population. 
EPA generally has no concern for exposures below 100 percent of the 
RfD. Therefore, based on the completeness and reliability of the 
toxicity data and the conservative exposure assessment, BASF concludes 
that there is a reasonable certanity that no harm will result from 
aggregate exposure to residues of pyridaben, including all anticipated 
dietary exposure and all other non-occupational exposures.

I. Determination of Safety for Infants and Children

    Developmental toxicity (delayed ossification) was observed in 
developmental toxicity studies using rats and rabbits. The NOEL's for 
developmental effects were established at 13 mg/kg/day in the rat study 
and 15 mg/kg/day in the rabbit study. The developmental effect observed 
in these studies is believed to be a secondary effect resulting from 
maternal stress (decreased body weight gain and food consumption).
    In a 2-generation reproduction study in rats, pups from the high 
dose group, which were fed diets containing 80 ppm (equivalent to 6.31 
and 7.82 mg/kg/day in male and females, respectively) gained less 
weight beginning on lactation day 14. Parental/systemic toxicity 
including decreased body weights, body weight gains and food efficiency 
in males, and slightly decreased body weights and body weight gains in 
females during lactation was also observed in the high dose group. The 
results of this study indicate that the loss in weight gain in pups 
from the high dose group was affected by nursing.
    No clear scientific consensus yet exists to determine the most 
appropriate endpoints for assessing risk in children. However, in 
consideration of the data that show both developmental and reproductive 
toxicity were effects secondary to parental toxicity, BASF believes 
that the established RfD of 0.005 mg/kg/day is the most conservative 
approach for assessing risk in children. Using the exposure assumptions 
described in Unit I.G. of this document, BASF has concluded that the 
percent of the RfD that will be utilized by aggregate exposure to 
residues of pyridaben from the proposed use in citrus, apples, pears, 
almonds, peaches, plums, and grapes is approximately 73.4 percent for 
non-nursing infants (<1 year), the most sensitive sub-population. Based 
on the completeness and reliability of the toxicity data and the 
conservative exposure assessment, BASF concludes that there is a 
reasonable certainty that no harm will result in infants and children 
from aggregate exposure to the residues of pyridaben, including all 
anticipated dietary exposure and all other non-occupational exposures.

J. Other Considerations

    The qualitative nature of the residues in plants and animals is 
adequately understood. Residues of the parent molecule, pyridaben are 
the only residues of concern. Residues of pyridaben do not concentrate 
in the processed commodities apple and citrus juice. There is a 
practical analytical method for detecting and measuring levels of 
pyridaben in or on food with a limit of detection that allows 
monitoring of food with residues at or above the levels set in these 
tolerances.

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K. International Tolerances

    A maximum residue level has not been established for pyridaben by 
the Codex Alimentarius Commission.

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-721]. All written comments filed in response to this 
petition will be available, in the Public Response and Program 
Resources Branch, at the address given above from 8:30 a.m. to 4 p.m., 
Monday through Friday, except legal holidays. A record has been 
established for this notice under docket control number [PF-721] 
(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 Rm. 1132 of the Public Response and Program Resources 
Branch, Field Operations Division (7506C), Office of Pesticide 
Programs, Environmental Protection Agency, Crystal Mall #2, 1921 
Jefferson Davis Highway, Arlington, VA.
    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. 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 document.

    Authority: 21 U.S.C. 346a.

List of Subjects

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: March 6, 1997.

Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.

[FR Doc. 97-6209 Filed 3-11-97; 8:45 am]
BILLING CODE 6560-50-F