[Federal Register Volume 61, Number 75 (Wednesday, April 17, 1996)]
[Proposed Rules]
[Pages 16745-16747]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-9474]




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DEPARTMENT OF TRANSPORTATION
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180

[PP 0E3835/P648; FRL-5356-5]

RIN 2070-AB18


Pesticide Tolerance for Diflubenzuron

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed Rule.

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SUMMARY: EPA proposes to establish a tolerance for residues of the 
insecticide diflubenzuron (N[[(4-chlorophenyl)amino]carbonyl]-2,6-
difluorobenzamide) in or on the raw agricultural commodity artichokes 
at 6.0 parts per million (ppm). The proposed regulation to establish a 
maximum permissible level for residues of the insecticide was requested 
in a petition submitted by the Interregional Research Project No. 4 
(IR-4).

DATES: Comments, identified by the document control number [PP 0E3835/
P648], must be received on or before May 17, 1996.

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 to OPP 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 ASCII file format. 
All comments and data in electronic form must be identified by the 
docket number [PP 0E3835/P648]. Electronic comments on this proposed 
rule may be filed online at many Federal Depository Libraries. 
Additional information on electronic submissions can be found in the 
SUPPLEMENTARY INFORMATION section of this document.

    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 
Virginia address given above, from 8 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays.

FOR FURTHER INFORMATION CONTACT: By mail: Hoyt L. Jamerson, 
Registration Division (7505W), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St. SW., Washington, DC 20460. 
Office location and telephone number: Sixth Floor, Crystal Station #1, 
2800 Jefferson Davis Highway, Arlington, VA 22202, 703-308-8783, e-mail 
address: [email protected].

SUPPLEMENTARY INFORMATION: The Interregional Research Project No. 4 
(IR-4), New Jersey Agricultural Experiment Station, P.O. Box 231, 
Rutgers University, New Brunswick, NJ 08903, has submitted pesticide 
petition (PP 0E3835) to EPA on behalf of the Agricultural Experiment 
Station of California. This petition requests that the Administrator, 
pursuant to section 408(e) of the Federal Food, Drug, and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(e), amend 40 CFR 180.377 by establishing a 
tolerance for residues of the insecticide diflubenzuron (N[[4-
chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide) in or on the raw 
agricultural commodity artichoke at 6.0 ppm.

    The scientific data submitted in the petition and other relevant 
material have been evaluated. The toxicological data considered in 
support of the proposed tolerance include:

    (1) A 1-year chronic feeding study with dogs administered 0, 2, 10, 
50 or 250 mg/kg/day with a no-observed-effect level (NOEL) established 
at 2 mg/kg/day. Statistically significant increases in methemoglobin 
and sulfhemoglobin in male and female dogs were observed at dose levels 
of 10 mg/kg/day and higher. Signs of hemolytic anemia, destruction of 
erythrocytes and of compensatory regeneration of erythrocytes were 
observed at dose levels of 50 mg/kg/day and higher.

    (2) A 2-year feeding/carcinogencity study with rats fed diets 
containing 0, 156, 625, 2,500, or 10,000 ppm (equivalent to 0, 7.8, 31, 
125, or 500 mg/kg/day) with statistically significant increases in 
methemoglobin and sulfhemoglobin observed at all treatment levels 
tested. Signs of hemolytic anemia and increased spleen and liver 
weights were observed in males and females at treatment levels of 2,500 
ppm and 10,000 ppm. Histological signs of erythrocyte destruction and 
compensatory regeneration were observed in males and females at dose 
levels of 156 ppm and higher. A no-observed-effect level was not 
established for this study, since effects were observed at the lowest 
dose tested. There were no carcinogenic effects observed under the 
conditions of this study.

    (3) A 91-week carcinogenicity study with mice fed diets containing 
0, 16, 80, 400, 2,000, or 10,000 ppm (equivalent to 0, 2.4, 12, 60, 
300, or 1,500 mg/kg/day). Increases in methemoglobin and sulfhemoglobin 
were consistently observed in male and female mice at dose levels of 80 
ppm and higher. Signs of hemolytic anemia, erythrocyte destruction and 
compensatory regeneration, and histopathological effects in the liver 
were observed at dose levels of 80 ppm and higher. No evidence of 
carcinogenicity was observed under the conditions of this study.

    (4) A 2-generation reproduction study with rats fed diets 
containing 0, 500, 5,000, or 50,000 ppm (equivalent to 0, 25, 250, or 
2,500 mg/kg/day). No effects on reproductive performance were observed 
in the parental adults. The NOEL for reproductive effects in the 
progeny is 250 mg/kg/day based on decreased body weight in the pups 
from birth to 21 days postpartum.

    (5) Developmental toxicity studies with rats and rabbits given 
technical grade diflubenzuron by gavage at dose levels of 0 or 1,000 
mg/kg/day with no maternal toxicity or toxicity to the developing fetus 
observed under the conditions of the study.

    (6) Mutagenicity studies using diflubenzuron as the test material 
were negative. These studies included a Salmonella/mammalian microsome

[[Page 16746]]

plate incorporation assay with and without metabolic activation, an in 
vitro chromosome damage assay using cultures of Chinese hamsters ovary 
cells with and without metabolic activation, and an unsheduled DNA 
synthesis assay using cultures of primary rat hepatocytes.
    The qualitative nature of the residue is adequately understood in 
plants based on data from citrus, mushroom, and soybean metabolism 
studies. Para-chloroaniline (PCA) and 4-chlorophenylurea (CPU) are 
metabolites of diflubenzuron that have been observed in mushrooms but 
not in citrus and soybeans. Diflubenzuron is also known to be 
metabolized to PCA and CPU in lactating goats, lactating cows, poultry, 
and rats.
    OPP's Health Effects Division Peer Review Committee has concluded 
that there is no evidence of carcinogenicity for diflubenzuron per se 
and has placed the chemical in Group E of EPA's classification system 
for carcinogens. The Committee also classified PCA as a Group B2 
carcinogen (a probable human carcinogen). The classification for PCA 
was based on the results of National Toxicology Program studies in 
which PCA was administered for 2 years by gavage to rats at doses of 0, 
2, 6, or 18 mg/kg/day and to mice at doses of 0, 3, 10, or 30 mg/kg/
day. Treatment-related increased incidences of uncommon sarcomas 
(fibrosarcomas, hemangiosarcomas and/or osteosarcomas) of the spleen 
were observed in male rats, and increased incidences of liver adenomas 
and carcinomas, and hemangiosarcomas in the spleen and/or liver were 
observed in male mice.
    The reference dose (RfD) for diflubenzuron is 0.02 mg/kg/day. The 
RfD is based on the NOEL of 2.0 mg/kg/day from the 1-year chronic 
feeding study in dogs and an uncertainty factor of 100. Available 
information relating to anticipated residues and percent of crop 
treated for established tolerances were used to calculate the 
Anticipated Residue Contribution (ARC) from residues of diflubenzuron 
in the human diet. The ARC from published tolerances is calculated at 
0.00008 mg/kg/day, which utilizes less than 1 percent of the RfD for 
the overall population. The ARC for children 1 to 6 years old, the 
population subgroup most highly exposed, utilizes 1 percent of the RfD. 
The Theoretical Maximum Residue Contribution from the proposed 
tolerance for artichokes would utilize an additional 0.1 percent of the 
RfD for the U.S. population and for children 1 to 6 years old. This 
dietary risk assessment indicates that there is no appreciable risk 
from the establishment of the proposed tolerance for artichokes.
    A quantitative cancer risk assessment was performed for PCA and 
CPU. Possible human exposure to PCA and CPU may occur as a result of 
the ingestion of PCA and CPU formed in animals which have consumed 
feeds containing diflubenzuron residues and from the metabolic 
conversion of diflubenzuron to PCA and CPU in the human body. For the 
purposes of this risk assessment, it was assumed that CPU has the same 
carcinogenic potential and potency as PCA. Although there is strong 
evidence supporting the carcinogenicty of PCA in rats and mice, the 
assumption that CPU also may be carcinogenic is not based on direct 
testing in animals, but rather on a comparison of the chemical 
structures of CPU and PCA. An assumption of a 2 percent conversion of 
diflubenzuron to PCA was used for the cancer risk assessment.
    The upper-bound cancer risk from dietary exposure to residues of 
PCA and CPU from existing uses of diflubenzuron is estimated at 1.3  x  
10-6. The additional cancer risk from the proposed tolerance for 
artichokes is estimated at 2  x  10-8. EPA concludes that the 
potential cancer risk from residues of PCA and CPU resulting from 
established tolerances and the proposed use on artichokes is 
negligible.
    An adequate analytical method, gas chromatography using an electron 
capture detector, is available for enforcement purposes. The analytical 
method for enforcing this tolerance has been published in the Pesticide 
Analytical Manual, Vol. II (PAM-II). There is no reasonable expectation 
that secondary residues will occur in milk, eggs, or meat and meat 
byproducts of livestock and poultry: there are no livestock feed items 
associated with artichokes.
    There are presently no actions pending against the continued 
registration of this chemical.
    Based on the information and data considered, the Agency has 
determined that the tolerance established by amending 40 CFR part 180 
would protect the public health. Therefore, it is proposed that the 
tolerance be established as set forth below.
    Any person who has registered or submitted an application for 
registration of a pesticide, under the Federal Insecticide, Fungicide, 
and Rodenticide Act (FIFRA) as amended, which contains any of the 
ingredients listed herein, may request within 30 days after publication 
of this notice in the Federal Register that this rulemaking proposal be 
referred to an Advisory Committee in accordance with section 408(e) of 
the FFDCA.
    A record has been established for this rulemaking under docket 
number [PP 0E3835/P648] (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 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The public record is located in Room 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:
    opp-D[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 rulemaking, 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 rulemaking record which will also include all comments 
submitted directly in writing. The official rulemaking record is the 
paper record maintained at the Virginia address in ``ADDRESSES'' at the 
beginning of this document.
    Under Executive Order 12866 (58 FR 51735, Oct. 4, 1993), the Agency 
must determine whether the regulatory action is ``significant'' and 
therefore subject to all the requirements of the Executive Order (i.e., 
Regulatory Impact Analysis, review by the Office of Management and 
Budget (OMB)). Under section 3(f), the order defines ``significant'' as 
those actions likely to lead to a rule (1) having an annual effect on 
the economy of $100 million or more, or adversely and materially 
affecting a sector of the economy, productivity, competition, jobs, the 
environment, public health or safety, or State, local or tribal 
governments or communities (also known as ``economically 
significant''); (2) creating serious inconsistency or otherwise 
interfering with an action taken or planned by another agency; (3) 
materially altering the budgetary impacts of entitlement, grants, user 
fees, or loan programs; or (4) raising novel legal or policy issues 
arising out of legal mandates, the President's priorities, or

[[Page 16747]]

the principles set forth in this Executive Order.
    Pursuant to the terms of this Executive Order, EPA has determined 
that this rule is not ``significant'' and is therefore not subject to 
OMB review.
    Pursuant to the requirements of the Regulatory Flexibility Act 
(Pub. L. 96-354, 94 Stat. 1164, 5 U.S.C. 601-612), the Administrator 
has determined that regulations establishing new tolerances or raising 
tolerance levels or establishing exemptions from tolerance requirements 
do not have a significant economic impact on a substantial number of 
small entities. A certification statement to this effect was published 
in the Federal Register of May 4, 1981 (46 FR 24950).

List of Subjects in 40 CFR Part 180

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

    Dated: April 3, 1996.

Susan Lewis,

Acting Director, Registration Division, Office of Pesticide Programs.

    Therefore, it is proposed that 40 CFR part 180 be amended as 
follows:

PART 180--[AMENDED]

    1. The authority citation for part 180 continues to read as 
follows:
    Authority: 21 U.S.C. 346a and 371.


    2. In Sec. 180.377, the table in paragraph (a) is amended by adding 
alphabetically the entry for artichoke to read as follows:


Sec. 180.377  Diflubenzuron; tolerances for residues.

    (a) *      *      *


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                                                              Parts per 
                        Commodities                            million  
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Artichoke..................................................          6.0
                                                                        
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[FR Doc. 96-9474 Filed 4-16-96; 8:45 am]
BILLING CODE 6560-50-F