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acifluorfen (Tackle) Proposed Tolerance 4/96

[Federal Register: April 17, 1996 (Volume 61, Number 75)] [Notices]
[Page 16781-16782]
>From the Federal Register Online via GPO Access []
40 CFR Part 180
[PP 0E3821/P649; FRL-5356-6]
RIN 2070-AB18
Sodium Salt of Acifluorfen; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed Rule.
SUMMARY: EPA proposes to establish a tolerance for combined residues of the 
herbicide sodium salt of acifluorfen (also referred to in this document as 
acifluorfen) in or on the raw agricultural commodity strawberry. The proposed 
regulation to establish a maximum permissible level for residues of the 
herbicide was requested in a petition submitted by the Interregional Research 
Project No. 4 (IR-4).
DATES: Comments, identified by the document control number [PP 0E3821/P649], 
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: 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 0E3821/P649]. 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.
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) 0E3821 to EPA 
on behalf of the Agricultural Experiment Stations of Alabama, Arkansas, 
California, Connecticut, Florida, Indiana, Maryland, Michigan, New York, North 
Carolina, Oklahoma, Oregon, Tennessee, Virginia, and Washington. This petition 
requested that the Administrator, pursuant to section 408(e) of the Federal 
Food, Drug, and Cosmetic Act (21 U.S.C. 346a(e)) propose the establishment of 
a tolerance for combined residues of the sodium salt of acifluorfen (sodium 5-
[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid) and its metabolites 
(the corresponding acid, methyl ester and amino analogues) in or on the raw 
agricultural commodity strawberry at 0.05 part per million (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 2-year feeding study in dogs fed diets containing 0, 50, 300, or 
1,800 ppm with a no-observed-effect-level (NOEL) of 50 ppm (equivalent to 1.25 
mg/kg/day). Blood coagulation was observed in test animals at the 300 ppm dose 
    2. A 2-generation reproduction study in rats fed diets containing 0, 25, 
500 or 2,500 ppm with no adverse effect on adult reproductive performance 
observed under the conditions of the study. The NOEL was established at 25 ppm 
(equivalent to 1.25 mg/kg of body weight/day) based on decreased viability and 
increased incidence of kidney lesions in high dose offspring.
    3. A developmental toxicity study in rabbits given oral gavage doses of 0, 
3, 12, or 36 mg/kg/day with no developmental toxicity observed at any of the 
dose levels tested.
    4. A developmental toxicity study in rats given oral gavage doses of 0, 
20, 90, or 180 mg/kg/day with a NOEL for developmental toxicity (reduced mean 
fetal weight) of 20 mg/kg/day. The NOEL for maternal toxicity was established 
at 90 mg/kg/day based on reduced body weight at the highest dose tested.
    5. A 2-year carcinogenicity study in rats fed diets containing 0, 25, 150, 
500, 2,500, or 5,000 ppm with a NOEL of 500 ppm (equivalent to 25 mg/kg/day). 
The lowest-observed-effect level was established at 2,500 ppm (equivalent to 
125 mg/kg/day) based on increased liver enzyme changes in male and female rats 
and renal changes (nephritis) in male rats.
    6. Acifluorfen produced positive results for gene mutation in a mitotic 
recombination assay in yeast cells and a dominant lethal assay in fruit fly. 
The chemical was negative in a structural chromosome aberration test in bone 
marrow cells and an unscheduled DNA synthesis test in rat hepatocytes.    7. A 
metabolism study in mice shows that acifluorfen is excreted primarily as the 
parent compound within 4 days of ingestion.
    8. An 18-month carcinogenicity study in B6C3F1 mice fed diets containing 
0, 625, 1,250, or 2,500 ppm with statistically significant positive trends for 
liver tumors (adenomas, carcinomas, and adenomas/carcinomas combined) and 
stomach tumors (papillomas) in both male and in female mice. These tumor types 
were significantly increased at the highest dose level tested (2,500 ppm) in 
male and female mice, and liver tumors were also significantly increased at 
the lowest dose level tested (625 ppm) in male mice.
    9. A 2-year carcinogenicity study in CD-1 mice fed diets containing 0, 
7.5, 45, or 270 ppm with a statistically significant increase in the total 
number of liver tumors (primarily adenomas) in high dose (270 ppm) female 
mice. No significant increase in liver tumors were observed in male mice at 
any feeding level tested. The highest dose tested (270 ppm) did not 
approximate a maximum tolerated dose in male and female mice.
    Based on a weight-of-evidence determination, OPP's Health Effects 
Division, Carcinogenicity Peer Review Committee (CPRC) has classified 
acifluorfen as Group B2 carcinogen (probable human carcinogen). This decision, 
which is in accordance with proposed Agency guidelines published in the 
Federal Register of November 23, 1984 (49 FR 46294), was based primarily on 
evidence of an increased number of malignant, or combined benign and 
malignant, liver tumors in multiple experiments involving two different 
strains of mice. Acifluorfen also produced uncommon stomach tumors in male and 
female B6C3F1 mice. Other structurally related diethyl-ether pesticides have 
been shown to produce liver tumors in mice. In addition, mutagenicity studies 
show evidence of mutagenic activity, but not in mammalian cell systems.
    The upper-bound carcinogenic risk from dietary exposure to acifluorfen was 
calculated using a potency factor (Q<SUP>*) of 0.107 (mg/kg/day)<SUP>-1 and 
dietary exposure as estimated by the Anticipated Residue Contribution (ARC) 
for existing tolerances and the proposed tolerance for strawberry. The upper-
bound carcinogenic risk from established and proposed uses is calculated at 
5.6  x  10<SUP>-7. The proposed use on strawberry accounts for 1.9  x  
10<SUP>-8 of the total cancer risk, which is a negligible increase in risk.
    The RfD for acifluorfen is established at 0.013 mg/kg of body weight/day, 
based on a NOEL of 1.25 mg/kg body weight/day and an uncertainty factor of 
100. The NOEL is taken from the 2-generation rat reproduction study in which 
decreased survival and increased incidence of kidney lesions were observed in 
the offspring of rats fed higher dose levels. The ARC for the overall U.S. 
population from established tolerances and the proposed use on strawberry 
utilizes less than 1 percent of the RfD. In addition, less than 1 percent of 
the RfD is utilized for all population subgroups for which EPA has dietary 
consumption data. EPA generally has no cause for concern for exposures below 
100 percent of the RfD.
    The nature of the residue is adequately understood for the purpose of the 
proposed tolerance and an adequate analytical method, gas chromatography, is 
available for enforcement purposes. An analytical method for enforcing this 
tolerance has been published in the Pesticide Analytical Manual (PAM), Vol. 
II. No secondary residues in meat, milk, poultry, or eggs are expected since 
strawberry are not considered a livestock feed commodity. 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 0E3821/P649] (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:
    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 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 
    Dated: April 3, 1996.
Susan Lewis, Acting Director, Registration Division, Office of Pesticide 
    Therefore, it is proposed that 40 CFR part 180 be amended as follows:
    1. The authority citation for part 180 continues to read as follows:
    Authority: 21 U.S.C. 346a and 371.
    2. In Sec. 180.383, the table is amended by adding alphabetically the 
commodity strawberry, to read as follows:
Sec. 180.383  Sodium salt of acifluorfen; tolerances for residues.
*      *      *
                          Commodities                              per  
                  *        *        *        *        *                 
                         Strawberry.....              ........    0.05