[Federal Register Volume 59, Number 66 (Wednesday, April 6, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-8104]


[[Page Unknown]]

[Federal Register: April 6, 1994]


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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180

[PP3F4177/R2052; FRL-4772-1]

 

Pesticide Tolerances for Dimethenamid

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of the 
herbicide, dimethenamid, 2-chloro-N-[(1-methyl-2methoxy)ethyl]-N-(2,4-
dimethyl-thien-3-yl)-acetamide in or on the raw agricultural commodity 
(RAC) soybeans at 0.01 parts per million (ppm). This regulation to 
establish the maximum permissible level of residues of the herbicide in 
or on this commodity was requested in a petition submitted by Sandoz 
Agro Inc.

DATES: This regulation becomes effective on April 6, 1994.

ADDRESSES: Written objections and hearing requests, identified by the 
document control number, [PP3F4177/R2052], may be submitted to: Hearing 
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., 
SW., Washington, DC 20460. A copy of any objection and hearing request 
filed with the Hearing Clerk should be identified by the document 
control number and submitted to: Public Response and Program Resources 
Branch, Field Operations Division (7505C), Office of Pesticide 
Programs, Environmental Protection Agency, 401 M St., SW., Washington 
DC 20460. In Person, bring a copy of objections and hearing requests 
to: Rm 1132, CM #2, 1921 Jefferson Davis Highway, Arlington, VA 22202.
    Fees accompanying objections shall be labeled ``Tolerance Petition 
Fees'' and forwarded to: EPA Headquarters Accounting Operations Branch, 
OPP (Tolerance Fees), P.O. Box 360277M, Pittsburgh, PA 15251.

FOR FURTHER INFORMATION CONTACT: By mail: Cynthia Giles-Parker, Product 
Manager (PM) 22, Registration Division, Environmental Protection 
Agency, 401 M St., SW., Washington, DC 20460. Office location and 
telephone number: Rm. 229, CM #2, 1921 Jefferson Davis Highway, 
Arlington, VA 22202, (703-305-5540).

SUPPLEMENTARY INFORMATION: EPA issued a notice published in the Federal 
Register on October 21, 1993 (58 FR 54353) which announced that Sandoz 
Agro Inc., 1300 East Touhy Avenue, Des Plaines, IL 60018, had submitted 
a pesticide petition (PP 3F4177) to EPA requesting that the 
Administrator, pursuant to section 408(d) of the Federal Food, Drug, 
and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), establish tolerances for 
the residues of the herbicide, dimethenamid, 2-chloro-N-[(1-methyl-2-
methoxy)ethyl]-N-(2,4-dimethyl-thien-3-yl)-acetamide in or on the RAC 
soybean grain at 0.01 ppm. The Agency is editorially correcting the RAC 
to read soybeans. There were no comments or requests for referral to an 
advisory committee received in response to this notice of filing. The 
data submitted in the petitions and all other relevant material have 
been evaluated. The toxicology data considered in support of the 
tolerances include:
    1. A rat acute oral study with an LD50 of 2.14 grams (g)/kilogram 
(kg), males, 1.30 g/kg females and 1.57 g/kg combined.
    2. A 13-week rat feeding study with a no-observed effect level 
(NOEL) of 500 ppm (33.5 milligrams (mg)/kg/day for males and 40.1 mg/
kg/day for females).
    3. A 13-week dog feeding study with a NOEL of 100 ppm (2.5 mg/kg/
day).
    4. A 21 day rabbit dermal study with a NOEL of 50 mg/kg/day with 
mild irritant effect at all dose levels.
    5. A carcinogenicity study in mice with no carcinogenic effects 
observed at any dose level under the conditions of the study and a 
systemic NOEL of 300 ppm (40.8 mg/kg/day for males and 40.1 mg/kg/day 
for females, based on food consumption) and a systemic lowest effect 
level (LEL) of 1,500 ppm (205 mg/kg/day for males and 200 mg/kg/day for 
females based on food consumption) based on significantly elevated 
liver weights.
    6. A rat chronic feeding/carcinogenicity study with a systemic NOEL 
of 100 ppm (5 mg/kg/day) and a LEL of 700 ppm (35 mg/kg/day) due to 
decreased food efficiency and histopathology findings. Under the 
conditions of the study limited evidence of carcinogenicity was 
observed based on a statistically significant increasing trend for 
benign liver cell tumors in male rats and a statistically significant 
increasing trend for ovarian tubular adenomas in female rats. A re-
evaluation of the ovarian neoplasia data indicated that there was no 
statistically significant, dose-related, trend in the incidence of 
ovarian tumors in female rats. This study is discussed further below.
    7. A 1 year dog feeding study with a NOEL of 250 ppm (9.6 mg/kg/
day) and with a LEL = 1,250 ppm (49 mg/kg/day) based on clinical 
chemistry and histological changes in liver.
    8. A two generation reproduction study in rats with a parental and 
reproductive NOEL of 500 ppm (36 mg/kg/day for males and 40 mg/kg/day 
for females) and a parental and reproductive LEL of 2,000 ppm (150 mg/
kg/day for males and 160 mg/kg/day for females) based on reduction of 
body weight and of food consumption, and increases in liver weights 
(parental toxicity), and significant reductions in pup weight during 
lactation (reproductive toxicity).
    9. A rabbit developmental study with a maternal NOEL of 37.5 mg/kg/
day and a LEL of 75 mg/kg/day based on decreased body weight and food 
consumption, and with a developmental NOEL of 75 mg/kg/day and a LEL of 
150 mg/kg/day based on a low incidence of abortion/premature delivery 
and angulation of the hyoid alae.
    10. A rat developmental study with a maternal NOEL of 50 mg/kg/day 
and a LEL of 215 mg/kg/day based on excess salivation, increased liver 
weight and reduced body weight gain and food consumption, and with a 
developmental NOEL of 215 mg/kg/day and a LEL of 425 mg/kg/day based on 
increased resorptions.
    11. An Ames mutagenicity assay negative with and without 
activation, an in vitro chromosomal aberration using CHO cells positive 
with and without activation, an unscheduled DNA synthesis in rat 
hepatocytes unequivocally positive in one in vitro assay and negative 
in another in vitro assay. A Dominant Lethal Study to further evaluate 
the mutagenic mechanism is due March 5, 1995 (2 years after the date of 
the initial conditional registration of dimethenamid under the Federal 
Insecticide Fungicide and Rodenticide Act [FIFRA]).
    The Agency has concluded that the available data provide limited 
evidence of carcinogenicity for dimethenamid in rats and has classified 
the pesticide as a Category C carcinogen (possible human carcinogen 
with limited evidence of carcinogenicity in animals) in accordance with 
Agency guidelines, published in the Federal Register in 1986 (51 FR 
33992). Based on a review by the Health Effects Division Peer Review 
Committee for Carcinogenicity of the Office of Pesticide Programs, the 
Agency has determined that a quantitative risk assessment is not 
appropriate for the following reasons:
    1. The tumor response was primarily due to a significantly 
increasing trend for benign and/or malignant liver tumors in males and 
due to a significantly increasing trend for ovarian tubular adenomas in 
female rats. A re-evaluation of the ovarian neoplasia data indicated 
that there was not a statistically significant, dose-related, trend in 
the incidence of ovarian tumors in female rats.
    2. The chemical was not carcinogenic when administered in the diet 
to mice at dose levels ranging from 30 to 3,000 ppm.
    Based on this evidence, EPA concludes that dimethenamid poses at 
most a negligible cancer risk to humans and that for purposes of risk 
characterization the Reference Dose (RfD) approach should be used for 
quantification of human risk. Residues of dimethenamid will not 
concentrate in processed soybean commodities and a food or feed 
additive regulation is not required for dimethenamid.
    The standard risk assessment approach of using the RfD based on 
systemic toxicity was applied to dimethenamid. Using a hundredfold 
safety factor and the NOEL of 5 mg/kg bwt/day determined by the most 
sensitive species from the 2-year rat feeding study, the RfD is 0.05 
mg/kg/day. The Anticipated Residue Contribution (ARC) from the 
established tolerances is 0.000003 mg/kg bwt/day and utilizes 0.007 
percent of the RfD for the overall U. S. population. The proposed use 
on soybeans would contribute an additional 0.000068 mg/kg/day, raising 
the ARC to 0.000071 mg/kg bwt/day, or 0.14 percent of the RfD. The 
exposure of the most highly exposed subgroup in the population did not 
utilize a significantly greater amount of the RfD.
    Tolerances have been previously established for dimethenamid in 
corn grain, corn fodder and corn forage. The metabolism of dimethenamid 
in plants is adequately understood. There is no reasonable expectation 
of secondary residues occurring in meat, milk and eggs from the 
tolerance associated with this petition.
    An adequate analytical method, gas chromatography, is available for 
enforcement purposes. Because of the long lead time from establishing 
these tolerances to publication of the enforcement methodology in the 
Pesticide Analytical Manual, Vol. II, the analytical methodology is 
being made available in the interim to anyone interested in pesticide 
enforcement when requested from: Calvin Furlow, Public Information 
Branch, Field Operations Division (7506C), Office of Pesticide 
Programs, Environmental Protection Agency, 401 M St., SW., Washington, 
DC 20460. Office location and telephone number: Room 1130A, CM #2, 1921 
Jefferson Davis Highway, Arlington, VA 22202, (703-305-5937).
    The pesticide is considered useful for the purposes for which the 
tolerances are sought. Based on the information and data considered, 
the Agency concludes that the establishment of the tolerances will 
protect the public health. Therefore, the tolerances are established 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 and/or request a hearing 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 fees provided 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, and the requestor's 
contentions on each such issue, and a summary of the evidence relied 
upon by the objection (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).
    The Office of Management and Budget has exempted this rule from the 
requirements of section 2 of Executive Order 12866.
    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 28, 1994.

Douglas D. Campt,
Director, Office of Pesticide Programs.

    Therefore, chapter I of title 40 of the Code of Federal Regulations 
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. Section 180.464 is amended by revising the section heading to 
read as set forth below and by alphabetically inserting in the table 
the raw agricultural commodity, soybeans, to read as follows:


Sec. 180.464  Dimethenamid, 2-chloro-N-[(1-methyl-2methoxy)ethyl]-N-
(2,4-dimethyl-thien-3-yl)-acetamide; tolerances for residues.

* * * * *

------------------------------------------------------------------------
            Commodities                       Parts per million         
------------------------------------------------------------------------
                                                                        
                                  *****                                 
Soybeans...........................  0.01                               
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[FR Doc. 94-8104 Filed 4-5-94; 8:45 am]
BILLING CODE 6560-50-F