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sethoxydim (Poast) Pesticide Tolerance 2/96

[Federal Register: February 29, 1996 (Volume 61, Number 41)]
[Rules and Regulations]               
[Page 7732-7734]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[PP 4F4344/R2207; FRL-5350-7]
RIN 2070-AB78
Sethoxydim; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This document establishes a pesticide tolerance for the combined 
residues of the herbicide sethoxydim; 2-[1-(ethoxyimino)butyl]-5-[2-
(ethylthio)propyl]-3-hydroxy-2-cyclohexene-1-one) and its metabolites 
containing the 2-cyclohexene-1-one moiety (calculated as the herbicide) in or 
on the raw agricultural commodities (RACs) corn, field, grain at 0.5 parts per 
million (ppm); corn, fodder at 2.5 ppm; and corn forage at 2.0 ppm. These 
tolerances replace current entries for field corn, grain; corn, fodder; and 
corn, forage. BASF Corporation requested these tolerances in a petition 
submitted to EPA pursuant to Federal Food, Drug, and Cosmetic Act (FFDCA).
EFFECTIVE DATE: February 29, 1996.
ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [PP 4F4344/R2207], may be submitted to: Hearing 
Clerk (1900), Environmental Protection Agency, Rm M3708, 401 M St., 
SW., Washington, DC 20460. Fees accompanying objections shall be 
labeled "Tolerance Petition Fees" and forwarded to EPA Headquarters 
Accounting Office Branch, OPP (Tolerance Fees), P.O. Box 360277M, 
Pittsburgh, PA 15251. A copy of any objections and hearing requests 
filed with the Hearing Clerk should be identified by the docket control 
number and submitted 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 copy of objections and hearing request to: Rm 1132, CM 
#2, 1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: opp-docket@epamail.gov. Copies of objections and hearing 
request must submitted as an ACSII file avoiding the use of special 
characters and any firm of encryption. Copies of objections and hearing 
requests will also be accepted on disks in Word Perfect in 5.1 file 
format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket number 
[4F4344/R2207]. No Confidential Business Information (CBI) should be 
submitted through e-mail. Electronic copies of objections and hearing 
requests on this rule may be filed online at many Federal Depository 
Libraries. Additional information on electronic submissions can be 
found below in this document.
FOR FURTHER INFORMATION CONTACT: By mail, Robert J. Taylor, Product Manager 
(PM 25), 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. 241, CM #2, 1921 Jefferson 
Davis Hwy., Arlington, VA, (703) 305-6027; e-mail:
                  taylor.robert@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: On August 17, 1995 (60 FR 42884), EPA issued 
a notice in the Federal Register announcing that BASF Corporation, P.O. 
Box 13528, Research Triangle Park, NC 27709-3528, had submitted a 
pesticide petition (PP 4F4344) to EPA proposing to amend 40 CFR part 
180 pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic 
Act (FFDCA), 21 U.S.C. 346a(d), establishing regulations to permit the 
combined residues of the herbicide sethoxydim; 2-[1-(ethoxyimino)butyl]-5-[2-
(ethylthio)propyl]-3-hydroxy-2-cyclohexene-1-one) and its metabolites 
containing the 2-cyclohexene-1-one moiety (calculated as the herbicide) in or 
on the raw agricultural commodities (RACs) corn, grain at 0.5 part per million 
(ppm); corn, fodder at 2.5 ppm; corn, forage at 2.0 ppm, and corn, silage at 
2.0 ppm.
    No comments were received in response to this notice of filing.
    The petitioner subsequently amended the petition by submitting a 
revised section F deleting the proposed tolerance for corn silage. 
Because this is a deletion of a previously proposed tolerance, no 
longer in Table 2 of the Residue Chemistry Guidelines, there is no 
potential risk to humans. Therefore an additional period of public 
comment is not necessary.
    The scientific data submitted in the petitions and other relevant 
material have been evaluated. The toxicological data considered in 
support of the proposed tolerances include:
    1. Several acute toxicology studies place technical sethoxydim in 
acute toxicity category IV for primary eye and dermal irritation and 
acute toxicity category III for acute oral, dermal, and inhalation. The 
dermal sensitization - guinea pig study was waived because no 
sensitization was seen in guinea pigs dosed with the end-use product 
Poast (18% a.i.).
    2. A 21-day dermal study with rabbits fed dosages of 0, 40, 200, 
and 1,000 mg/kg/day with a NOEL (no-observed adverse effect level) of 
greater than 1,000 mg/kg/day (limit dose).
    3. A 1-year feeding study with dogs fed dosages (based on 
consumption) of 0, 8.86/9.41, 17.5/19.9, and 110/129 mg/kg/day (males/
females) with a NOEL (no-observed effect level) of 8.86/9.41 mg/kg/day 
(males/ females) based on equivocal anemia in males and females at 
17.5/19.9 mg/kg/day, respectively.
    4. A 2-year chronic feeding/carcinogenicity study with mice fed 
dosages of 0, 6, 18, 54, and 162 mg/kg/day with no carcinogenic effects 
observed under the conditions of the study at dose levels up to and 
including 162 mg/kg/day (highest dose tested (HDT)) and a systemic NOEL 
of 18 mg/kg/day. A maximum tolerated dose (MTD) was not achieved for 
females in this study. A determination of the need for an additional 
study will be made once the replacement chronic feeding/carcinogenicity 
study in rats is evaluated.
    5. A 2-year chronic feeding/carcinogenic study with rats fed 
dosages of 0, 2, 6, and 18 mg/kg/day (HDT) with no carcinogenic effects 
observed under the conditions of the study at dosage levels up to and 
including 18 mg/kg/day (HDT) and a systemic NOEL greater than or equal 
to 18 mg/kg/day (HDT). This study was reviewed under current guidelines 
and was found to be unacceptable because the doses used were 
insufficient to induce a toxic response and a maximum tolerated dose 
(MTD) was not achieved. This study must be repeated.
    6. A chronic feeding/carcinogenic study with rats was submitted to 
supplement the above study. Rats in this study were fed dosages of 0, 
18.2/23.0, and 55.9/71.8 mg/kg/day (males/females) with no carcinogenic 
effects observed under the conditions of the study at dose levels up to 
and including 55.9/71.8 mg/kg/day (HDT) (males/females) and a systemic 
NOEL greater than or equal to 55.9/71.8 mg/kg/day (males/females). The 
doses used were insufficient to induce a toxic response and failed to 
achieve an MTD or define a Lowest Effect Level (LEL). Slight decreases 
in body weights in the final quarter of the study, although not biologically 
significant, can support a free standing NOEL of 55.9/71.8 mg/kg/day 
(males/females). A new study is necessary to replace both this study and the 
one discussed above.
    7. A developmental toxicity study in rats fed dosages of 0, 50, 
180, 650, and 1,000 11mg/kg/day with a maternal NOEL of 180 mg/kg/day 
and a maternal LEL of 650 mg/kg/day (irregular gait, decreased 
activity, excessive salivation, and anogenital staining); and a 
developmental NOEL of 180 mg/kg/day and a developmental LEL of 650 mg/
kg/day (21-22% decrease in fetal weights, filamentous tail and lack of 
tail due to the absence of sacral and/or caudal vertebrae, and delayed 
ossification in the hyoids, vertebral centrum and/or transverse 
processes, sternebrae and/or metatarsals, and pubes).
    8. A developmental toxicity study in rabbits fed doses of 0, 80, 
160, 320, and 400 mg/kg/day with a maternal NOEL of 320 mg/kg/day and a 
maternal lowest observable effect level (LOEL) of 400 mg/kg/day (37% 
reduction in body weight gain without significant differences in group 
mean body weights, and decreased food consumption during dosing); and a 
developmental NOEL greater than 400 mg/kg/day (HDT).
    9. A 2-generation reproduction study with rats fed dosage levels of 
0, 150, 600, and 3,000 ppm (approximately 0, 7.5, 30, and 150 mg/kg/
day) with no reproductive effects observed at 3,000 ppm (approximately 
150 mg/kg/day) (HDT). However, the Agency considers this study usable 
for regulatory purposes and has established a free-standing NOEL of 
3,000 ppm (approximately 150 mg/kg/ day).
    10. Mutagenicity studies included: Ames Assays which were negative 
for Salmonella typhimurium strains TA98, TA100, TA1535, and TA 1537, 
with and without metabolic activity; sethoxydim did not cause 
structural chromosomal aberrations at doses up to 5,000 mg/kg in 
Chinese hamster bone marrow cells in vivo; a Host Mediated Assay 
(mouse) with S. typhimurium was negative at 2.5 grams/kg/day of 
chemical, and recombinant assays and forward mutations in Bacillus 
subtilis, Escherichia coli, and S. typhimurium were all negative at 
concentrations of greater than or equal to 100%; an in vitro 
Unscheduled DNA Synthesis Assay in Primary Rat Hepatocytes had a 
negative response for DNA repair (UDS) in primary rat hepatocyte 
cultures exposed up to insoluble (>101 ug/ml) and cytotoxic (507 ug/ml) 
doses.
    11. In a rat metabolism study, excretion was extremely rapid and 
tissue accumulation was negligible, assuming DMSO vehicle does not 
affect excretion or storage of NP-55 (78% excreted into urine and 20.1% 
in feces).
    The reference dose (RFD) based on a NOEL of 8.86 mg/kg bwt/day in 
the 1-year feeding study in dogs, and an uncertainty factor of 100 was 
calculated to be 0.09 mg/kg bwt/day. The theoretical maximum residue 
contribution (TMRC) for existing tolerances for the overall U. S. 
population is 0.032767 mg/kg bwt/day or 35% of the RfD. The current 
action will increase the TMRC by 0.000134 mg/kg bwt/day. These 
tolerances and previously established tolerances utilize a total of 37 
percent of the RfD for the overall U.S. population. For U.S. subgroup 
populations, nonnursing infants and children aged 1 to 6, the current 
action and previously established tolerances utilize, respectively, a 
total of 63.5% and 74% of the ADI, assuming that residue levels are at 
the established tolerances and that 100% of the crop is treated. [These 
studies are also referenced in an EPA proposed rule on sethoxydim 
published elsewhere in this issue of the Federal Register.]
    Desirable data lacking based on review of data under current 
guidelines include a repeat of the chronic feeding/carcinogenicity 
study in rats. Once the rat study is evaluated, a repeat of the mouse 
carcinogenicity study may be needed. Because the current studies, 
although unacceptable by current guidelines, provide useful information 
and these tolerances utilize less than 1% of the RfD, the Agency 
believes there is little risk from establishment of these tolerances. 
Any additional tolerance proposals will be considered on a case-by-case 
basis.
    The pesticide is useful for the purposes for which these tolerances 
are sought and capable of achieving the intended physical or technical 
effect. The nature of the residue is adequately understood, and 
adequate analytical methods (gas chromatography using sulfur-specific 
flame photometric detection) are available for enforcement purposes. 
Previously approved versions of the analytical method are listed in the 
Pesticide Analytical Manual, Volume II (PAM II), as Method I. The 
analytical methods for corn grain, fodder, and forage are revisions of 
the above method. Because of the long lead time from establishing these 
tolerances until publication, the enforcement methodology for corn 
grain, fodder, and forage are being made available in the interim to 
anyone interested in pesticide enforcement when requested by mail from: 
Calvin Furlow, Public Response Resources Branch, Field Operations 
Division (7506C), Office of Pesticide Programs, Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. Office 
location and telephone number; Rm 1130 A, CM #2, 1921 Jefferson Davis 
Hwy., Arlington, VA, (703) 305-6027.
    There are currently no actions pending against the registration of 
this chemical. Any expectation of residues occurring in eggs, milk, 
meat, fat or meat by-products of cattle, goats, hogs, horses, and sheep 
or poultry will be covered by existing tolerances.
    Based on the information and data considered, the Agency has 
determined that the tolerances established by amending 40 CFR part 180 
would protect the public health. Therefore, EPA is establishing the 
tolerances as set forth below.
    Any person adversely affected by this regulation may, within 30 
days after publication of this document in the Federal Register, file 
written objections with the Hearing Clerk, at the address given above 
(40 CFR 178.20). A copy of the objections and/or hearing requests filed 
with the Hearing Clerk should be submitted to the OPP docket for this 
rulemaking. The objections submitted must specify the provisions of the 
regulation deemed objectionable and the grounds for the objections (40 
CFR 178.25). Each objection must be accompanied by the fee prescribed 
by 40 CFR 180.33(i). If a hearing is requested, the objections must 
include a statement of the factual issue(s) on which a hearing is 
requested, the requestor's contentions on each such issue, and a 
summary of any evidence relied upon by the objector (40 CFR 178.27). A 
request for a hearing will be granted if the Administrator determines 
that the material submitted shows the following: There is a genuine and 
substantial issue of fact; there is a reasonable possibility that 
available evidence identified by the requestor would, if established, 
resolve one or more of such issues in favor of the requestor, taking 
into account uncontested claims or facts to the contrary; and 
resolution of the factual issue(s) in the manner sought by the 
requestor would be adequate to justify the action requested (40 CFR 
178.32).
    A record has been established for this rulemaking under docket 
number [PP 4F4344/R2207] (including objections and hearing requests 
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 pm., 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.
    Written objections and hearing requests, identified by the docket 
control number [PP 4F4344/R2207], may be submitted to the Hearing Clerk 
(1900), Environmental Protection Agency, Rm 3708, 401 M St., SW., 
Washington, DC 20460.
    A copy of electronic objections and hearing requests filed with the 
Hearing Clerk can be sent directly to EPA at:
                    opp-docket@epamail.epa.gov
    A copy of electronic objections and hearing requests filed with the 
Hearing Clerk 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 any objections and hearing requests 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 objections and hearing requests submitted directly in 
writing. The official rulemaking record is a 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 action is "significant" 
and therefore subject to review by the Office of Management and Budget 
(OMB) and the requirements of the Executive Order. Under section 3(f), 
the order defines a "significant regulatory action" as an action that 
is likely to result in 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 referred to 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 the rights and obligation of recipients 
thereof; 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 the 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, Food additive, Pesticides and pests, Reporting and 
recordkeeping requirements.
    Dated: February 20, 1996.
Stephen L. Johnson,
Director, Registration Division, Office of Pesticide Programs.
    Therefore, 40 CFR part 180 is 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. 180.412(a), by revising the entries for corn, field, grain; 
corn fodder; and corn forage to read as follows.
Sec. 180.412   2-[1-Ethoxyimino)butyl]-5-(2-ethylthio)propyl]-3-hydroxy-2-
cyclohexen-1-one; tolerances for residues.
    (a)  *    *    *
                                                                        
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                   Commodity                        Parts per million   
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                  *        *        *        *        *       
corn, field, grain.............................            0.5
corn fodder....................................            2.5
corn forage....................................            2.0
                                                              
                  *        *        *        *        *       
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    *      *      *      *      *