[Federal Register Volume 61, Number 60 (Wednesday, March 27, 1996)]
[Proposed Rules]
[Pages 13474-13476]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7445]



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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[PP 4E4365 and 4E4376/P645; FRL-5348-1]
RIN 2070-AB18


Diquat; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This document proposes to establish a tolerance for the plant 
growth regulator diquat [6,7-dihydrodipyrido (1,2-a:2',1'-c) 
pyrazinediium] derived from application of the dibromide salt and 
calculated as the cation in or on the imported raw agricultural 
commodities bananas and coffee at 0.05 part per million (ppm). Zeneca, 
Inc., petitioned for this proposed regulation to establish a maximum 
permissible level for the residues of the plant growth regulator.

DATES: Comments identified by the docket number, (PP 4E4365 and 4E4376/
P645), must be received on or before April 26, 1996.

ADDRESSES:  Submit written comments by mail 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: Public Docket, Rm. 
1132, Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
    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 in 5.1 file format or ASCII file 
format. All comments and data in electronic form must be identified by 
the docket number (PP 4E4365 and 4E4376/P645). No Confidential Business 
Information (CBI) should be submitted through e-mail. Electronic 
comments on this proposed rule may be filed online at many Federal 
Depository Libraries. Additional information on electronic submissions 
can be found below in this document.
    Information submitted as a comment concerning this document may be 
claimed confidential by marking any part or all of that information as 
CBI. Information so marked will not be disclosed except in accordance 
with procedures as 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 will be included in the 
public docket by EPA without prior notice. The public docket is 
available for public inspection in Rm. 1132 at the above address, from 
8 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays.

FOR FURTHER INFORMATION CONTACT:  By mail: Joanne I. Miller, Product 
Manager (PM-23), Registration Division (7505C), Office of Pesticide 
Programs, Environmental Protection Agency, 401 M St., SW., Washington, 
DC 20460. Office location, telephone number, and e-mail address: Rm. 
237, CM #2, 1921 Jefferson Davis Highway, Arlington, VA, (703)-305-
6224; e-mail: [email protected].

SUPPLEMENTARY INFORMATION: Zeneca, Inc., P.O. Box 15458, Wilmington, DE 
19850, has submitted pesticide petition (PP 4E4365 and 4E4376) to EPA. 
This petition requested that the Administrator, pursuant to the Federal 
Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e), establish a 
tolerance for residues of the plant growth regulator diquat [6,7-
dihydrodipyrido (1,2-a:2',1'-c) pyrazinediium derived from application 
of the dibromide salt and calculated as the cation in or on the raw 
agricultural commodity bananas at 0.02 ppm and coffee at 0.05 ppm. The 
petition for bananas was subsequently amended to raise the tolerance 
level to 0.05 ppm.
    The data submitted in the petition and other relevant material have 
been evaluated. The toxicological data considered in support of the 
tolerances include the following:
    1. A 2-year chronic toxicity/carcinogenicity study in rats resulted 
in a systemic lowest-observed-effect level (LOEL) of 2.91 mg/kg/day in 
males and 3.64 mg/kg/day in females (expressed as diquat cation), and a 
systemic no-observed effect level (NOEL) of 0.58 mg/

[[Page 13475]]
kg/day in males and 0.72 mg/kg/day in females (expressed as diquat 
cation).
    2. A 1-year feeding study in dogs resulted in a systemic LOEL of 
2.5 mg/kg/day and a systemic NOEL of 0.5 mg/kg/day in both sexes 
(expressed as diquat cation).
    3. A 2-year feeding study in mice resulted in a systemic LOEL of 
11.96 mg/kg/day in males and 16.03 mg/kg/day in females (expressed as 
diquat cation), and a systemic NOEL of 3.56 mg/kg/day in males and 4.78 
mg/kg/day in females (expressed as diquat cation).
    4. A developmental toxicity study in rats resulted in a maternal 
toxicity LOEL of 32 to 56 mg/kg/day and a maternal toxicity NOEL of 8 
to 14 mg/kg/day (expressed as diquat cation), and a developmental 
toxicity LOEL of 32 to 56 mg/kg/day and a developmental toxicity NOEL 
of 8 to 14 mg/kg/day (expressed as diquat cation).
    5. A developmental toxicity study in rabbits resulted in a maternal 
toxicity LOEL of 5.0 mg/kg/day and a maternal toxicity NOEL of 2.5 mg/
kg/day (expressed as diquat cation). The developmental toxicity was not 
clearly established.
    6. A recently submitted developmental toxicity study in rabbits 
resulted in a maternal toxicity LOEL of 3 mg/kg/day and a maternal 
toxicity NOEL of 1 mg/kg/day (expressed as diquat cation), and a 
developmental toxicity LOEL of 10 mg/kg/day and a developmental 
toxicity NOEL of 3 mg/kg/day (expressed as diquat cation).
    7. A developmental toxicity study in mice resulted in a maternal 
toxicity LOEL of 2 mg/kg/day and a maternal toxicity NOEL of 1 mg/kg/
day (expressed as diquat cation), and a developmental toxicity LOEL of 
4 mg/kg/day and a developmental toxicity NOEL of 2 mg/kg/day (expressed 
as diquat cation).
    8. A two-generation reproduction study on rats resulted in a 
systemic toxicity LOEL of 4 mg/kg/day and a systemic toxicity NOEL of 
0.8 mg/kg/day (expressed as diquat cation), and a reproductive toxicity 
LOEL of 12 to 20 mg/kg/day and a reproductive toxicity NOEL of 4 mg/kg/
day (expressed as diquat cation).
    9. Diquat showed nonmutagenicity in one gene mutation test (Ames), 
two structural chromosome aberration tests (mouse micronucleus and 
dominant lethal in mice), and one test for other genotoxic effects 
(unscheduled DNA synthesis in rat hepatocytes in vitro). Positive 
results were seen in one gene mutation test (mouse lymphoma cell assay) 
and in one chromosome aberration test (human blood lymphocytes, 
depending on the concentration of diquat and the presence of the 
metabolic activation system).
    10. Metabolism studies showed about 90% of the administered dose 
being eliminated in feces, indicating that diquat was poorly absorbed 
from the gastrointestinal tract. Following a subcutaneous injection to 
circumvent the intestine, nearly all of the administered dose was 
recovered in the urine within 2 days.
    The Office of Pesticide Program's Health Effects Division's 
Carcinogenicity Peer Review Committee (CPRC) has classified diquat as a 
Group E carcinogen (no evidence of carcinogenicity) under the Agency's 
Guidelines for Carcinogen Risk Assessment, published in the Federal 
Register of September 24, 1986 (51 FR 33992). In its evaluation, CPRC 
gave consideration to body weight changes in a 2-year feeding study in 
mice and histopathological changes in the eyes in a 2-year chronic 
feeding/carcinogenicity study in rats.
    The Reference Dose (RfD) is established at 0.005 mg/kg/day, based 
on a NOEL of 0.5 mg/kg/day from the chronic toxicity study in dogs and 
an uncertainty factor of 100. The Anticipated Residue Concentration 
(ARC) from the current actions is estimated at 0.00074 mg/kg/day of 
body weight/day for the general population and utilizes 15% of the RfD 
for the U.S. population. The ARC for the most exposed subgroup is 
0.0024 mg/kg/day of body weight/day for nonnursing infants (less than 
1-year old) and utilizes 48% of the RfD. Therefore, no appreciable risk 
is expected from the chronic dietary intake since the RfD is not 
exceeded for either the general population or any subgroup.
    The nature of the residue is adequately understood for the purposes 
of the tolerances. An adequate analytical method, extraction with 
sulfuric acid with spectrometric detection, is available for 
enforcement purposes. The analytical method for enforcing these 
tolerances have been published in the Pesticide Analytical Manual, Vol. 
II (PAM II).
    The pesticide is considered useful for the purposes for which it is 
sought, and the tolerances are capable of achieving the intended 
physical or technical effect. There are currently no actions pending 
against the registration of this chemical.
    Based on the information and data considered, the Agency concludes 
that the proposed tolerances will protect the public health. Therefore, 
it is proposed that the tolerances 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 the ingredient 
listed herein, may request within 30 days after the publication of this 
document in the Federal Register that this proposal be referred to an 
Advisory Committee in accordance with section 408(e) of the FFDCA.
    Interested persons are invited to submit written comments on the 
proposed regulation. Comments must bear a notation indicating the 
document control number, [PP 4E4365 and 4E4376/P645). All written 
comments filed in response to this petition will be available in the 
Public Response and Program Resources Branch at the above address from 
8 a.m. to 4:30 p.m., Monday through Friday, except legal holidays.
    A record has been established for this proposal under docket number 
(PP 4E4365 and 4E4376/P645) (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:
    [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 proposal, 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 address in ``ADDRESSES'' at the 
beginning of this document.
    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether the regulatory

[[Page 13476]]
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 the principles set forth in this Executive Order.
    Pursuant to the terms of this Executive Order, EPA has determined 
that this proposed 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: March 20, 1996.
Stephen L. Johnson,
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. 180.226, by adding new paragraph (c) to read as follows:


Sec. 180.226   Diquat; tolerances for residues.

    *    *    *    *    *
    (c) Tolerances are established for the plant growth regulator 
diquat [6,7-dihydrodipyrido (1,2-a:2',1'-c) pyrazinediium] derived from 
application of the dibromide salt and calculated as the cation in or on 
the following raw agricultural commodities:

                                                                        
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                      Commodity                        Parts per million
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Bananas..............................................               0.05
Coffee...............................................               0.05
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There are no U.S. registrations as of December 6, 1995.

[FR Doc. 96-7445 Filed 3-26-96; 8:45 am]
BILLING CODE 6560-50-F