[Federal Register Volume 62, Number 68 (Wednesday, April 9, 1997)]
[Rules and Regulations]
[Pages 17096-17100]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9091]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300471; FRL-5599-8]
RIN 2070-AB78
Imazapyr; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final Rule.
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SUMMARY: This document establishes tolerances for the residues of the
herbicide imazapyr, [2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-
1H-imidazol-2-yl]-3-pyridinecarboxylic acid], applied as the acid, in
or on field corn. American Cyanamid submitted a petition to EPA under
the Federal Food, Drug and Cosmetic Act as amended by the Food Quality
Protection Act of 1996 requesting the tolerances.
DATES: This rule becomes effective April 9, 1997. Written objections
must be submitted by June 9, 1997.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300471], may be submitted to: Hearing Clerk
(1900), Environmental Protection Agency, Rm. M3708, 401 M St., SW.,
Washington, DC 20460. 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 requests to: Rm. 1132,
CM #2, 1921 Jefferson Davis Highway, Arlington, VA 22202. Fees
accompanying objections and hearing requests shall be labeled
``Tolerance Petition Fees'' and forwarded to: EPA Headquarters
Accounting Operations Branch, OPP (Tolerance Fees), P.O. Box 360277M,
Pittsburgh, PA 15251.
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.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 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
[OPP-300471]. 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 in Unit IX of this document.
FOR FURTHER INFORMATION CONTACT: By Mail: Philip V. Errico, 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 Highway, Arlington, VA 22202. (703)
305-6027; e-mail: errico.philip@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: In the Federal Register of December 12, 1996
(61 FR 66658)(FRL-5576-9) EPA issued a notice announcing that American
Cyanamid, P.O. Box 400, Princeton, NJ 08543 had submitted pesticide
petition 6F4641 which requested that the Administrator, pursuant to
section 408 of the Federal Food, Drug and Cosmetic Act (FFDCA), and in
conformity with the Food Quality Protection Act (FQPA) of 1996, amend
40 CFR part 180 to establish tolerances for residues of imazapyr [2-
[4,5-dihydro-4-methyl-4(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-
pyridinecarboxylic acid], applied as the acid in or on field corn
grain, fodder, and forage at 0.05 ppm. The notice contained a summary
of the petition prepared by the petitioner, American Cyanamid,
including information and arguments to support their conclusion that
the petition complied with FQPA. It was stated in the notice that the
conclusions and arguments were not EPA's.
There were no comments received in response to the notices of
filing.
The data submitted in the petition and other relevant material have
been evaluated. The toxicological data listed below were considered in
support of these tolerances.
I. Toxicology Profile
1. A battery of acute toxicity studies placing technical imazapyr
in toxicity category I for eye irritation, category IV for oral
LD50 and primary dermal irritation, category III for dermal and
inhalation LD50.
2. A 90-day rat feeding study at doses of 0, 15,000, or 20,000 ppm
(males= 0, 1,248, or 1,695 milligrams per kilogram per day (mg/kg/day);
females 0, 1,423, or 1,784 mg/kg/day) with a no-observed-effect level
(NOEL) of 1,695 mg/kg/day the highest dose tested (HDT).
3. A 21-day rabbit dermal toxicity study at doses of 0, 100, 200,
or 400 mg/kg/day which showed occasional statistically significant
findings but these had no consistent pattern of toxicity. The NOEL was
determined to be 400 mg/kg/day HDT.
4. A 1-year dog chronic toxicity study at doses of 0, 25, 125, or
250 mg/kg/day. The NOEL was 250 mg/kg/day HDT.
5. A 2-year rat chronic/carcinogenicity study at doses of 0, 1,000,
5,000, or 10,000 ppm (males= 0, 49.9, 252.6, or 503 mg/kg/day; females=
0, 64.2, 317.6, or 638.6 mg/kg/day) with a NOEL of 503 mg/kg/day HDT.
6. An 18-month mouse carcinogenicity study at doses of 0, 1,000,
5,000, or 10,000 ppm (males= 0, 126, 674, or 1,301 mg/kg/day; females=
0, 151, 776, or 1,639 mg/kg/day) with a NOEL of 1,301 mg/kg/day HDT.
7. A rat developmental toxicity study at doses of 0, 100, 300, or
1,000 mg/kg/day. At 1,000 mg/kg/day, the only clinical sign of toxicity
in gravid dams was salivation. The NOEL for maternal toxicity is 300
mg/kg/day. There were no developmental findings in this study up to the
limit dose of 1,000 mg/kg/day HDT.
8. A rabbit developmental toxicity study at doses of 0, 25, 100, or
400 mg/kg/day with a maternal and developmental NOEL of 400 mg/kg/day
HDT.
9. A rat two--generation reproduction study at dietary
concentrations of 0,
[[Page 17097]]
1,000, 5,000, or 10,000 ppm (males= 0, 74.2, 380.5, or 738 mg/kg/day;
females= 0, 94.3, 471.2, or 933.3 mg/kg/day) with a NOEL of 10,000 ppm
HDT.
10. A metabolism study in rats indicated that imazapyr was rapidly
absorbed and excreted by 7 days post-dosing, with the majority of the
administered 14C-label (90%) eliminated in the urine within 48
hours. Metabolite characterization studies showed that essentially all
the test material was excreted unchanged. Two minor metabolites, CL
252,974 and CL 60,032, were detected in the urine or feces of treated
rats; however, their contribution combined was less than or equal to
0.5% of the administered dose. An additional 12 unidentified
metabolites were isolated, but they contributed less than 3% of the
total dose.
11. Acceptable studies on gene mutation and other genotoxic
effects: Ames Salmonella Assay; CHO/HGPRT Point Mutation Assay; In
vitro CHO cell chromosome aberration assay; Dominant lethal assay; and
Unscheduled DNA synthesis (UDS) yielded negative results.
II. Dose Response Assessment
1. Reference dose. The Reference Dose (RfD) represents the level at
or below which daily aggregate dietary exposure over a lifetime will
not pose appreciable risks to human health. The RfD is determined by
using the toxicological end-point or the NOEL for the most sensitive
mammalian toxicological study. To assure the adequacy of the RfD, the
Agency uses an uncertainty factor in deriving it. The factor is usually
100 to account for both interspecies extrapolation and intraspecies
variability represented by the toxicological data. The EPA has
established an RfD of 2.5 mg/kg/day based on a NOEL of 250 mg/kg/day
from a 1-year chronic dog feeding study.
2. Carcinogenicity classification. Using the Guidelines for
Carcinogenic Risk Assessment published September 24, 1986 (51 FR
33992), the EPA has classified imazapyr as Group ``E'', not a likely
human carcinogen.
3. Developmental toxicant determination. The acceptable
developmental studies (two-generation reproduction study in rats and
prenatal developmental toxicity studies in rats and rabbits) provided
no indication of increased sensitivity of rats or rabbits to in utero
and/or postnatal exposure to imazapyr.
III. Non-dietary (Residential and Occupational) Exposure Assessment
Imazapyr products marketed for residential use include total
vegetation control products that are used for plot treatments or bare
ground applications. These products are to be applied only where no
plant growth is desired and are not to be used on lawns. Therefore, for
these limited residential uses, the potential for exposure is minimal,
and is expected to be non-chronic. These products are in Toxicity
Categories II for eye irritation. Under the protective clothing
requirements of the Worker Protection Standards (WPS), handlers of
these products are expected to be adequately protected.
Imazapyr is also registered for use on non-food sites including
railroad, utility, pipeline, and highway rights-of-way, utility plant
sites, petroleum tank farms, pumping installations, fence rows, storage
areas, non-irrigation ditchbanks, under asphalt, under pond liners,
wildlife management areas, forestry site preparation, and other non-
crop areas. These low rate uses entail minimal exposure potential for
the general population. Use of protective clothing also reduces
exposure.
Since imazapyr is a group E chemical (evidence of non-
carcinogenicity for humans); the 21 day dermal study lacked any
significant observable effects at the limit dose, and no adverse
effects were observed in developmental toxicity studies in rats up to
1,000 mg/kg/day and rabbits up to 400 mg/kg/day, no toxicological
endpoints for non-chronic residential exposures were identified.
Therefore, non-chronic risk assessments are not required for
occupational or non-occupational residential uses.
IV. Dietary Exposure Assessment
Use of a agricultural pesticide may result, directly or indirectly,
in pesticide residues in food. Primary residues or indirect/inadvertent
residues in agricultural commodities are determined by chemical
analysis. To account for the diversity of growing conditions, cultural
practices, soil types, climates, crop varieties and methods of
application of the pesticide, data from studies that represent the
commodities are collected and evaluated to determine an appropriate
level of residue that would not be exceeded if the pesticide is used as
represented in the studies.
1. Plant/animal metabolism and magnitude of the residue. The nature
(metabolism) of imazapyr in plants and animals is adequately understood
for the purposes of these tolerances. There are no Codex maximum
residue levels established for residues of imazapyr on corn or the
rotational crops. In all the plant and animal (poultry and ruminants)
metabolism studies submitted, the residue of concern was the parent per
se, imazapyr.
2. Residue analytical methods. The analytical method proposed as an
enforcement method for field corn commodities is GS/MS Method M
2468.02. The method is suitable for detecting residues of the parent
compound, imazapyr, in field corn forage, silage, grain, fodder, meal
and oil. Tolerances for meat, milk, poultry, and eggs, are not required
for this petition, therefore, an analytical method for the enforcement
of animal tolerances is not needed.
V. Aggregate Exposure Assessment
In examining aggregate exposure, FQPA directs EPA to consider
available information concerning exposures from pesticide residue in
food, including water, and all other non-occupational exposures. The
aggregate sources of exposure the Agency looks at includes food,
drinking water or groundwater, and exposure from pesticide use in
gardens, lawns, or buildings (residential and other indoor uses).
1. Acute dietary. As part of the hazard assessment process, the
Agency reviews the available toxicology database to determine the
endpoints of concern. For imazapyr, the Agency does not have a concern
for an acute dietary assessment since the available data do not
indicate any evidence of significant toxicity from a 1 day or single
event exposure by the oral route. Therefore, an acute dietary risk
assessment was not required.
2. Chronic dietary. Using the Dietary Risk Evaluation System
(DRES), a chronic exposure analysis was performed using tolerance level
residues and 100 percent crop treated to estimate the Theoretical
Maximum Residue Contribution (TMRC) for the general population and 22
subgroups. This exposure analysis showed that exposure from residues
in/on corn for the U.S. population and all subgroups would be less than
1% of the RfD.
3. Drinking water. To determine the exposure from drinking water,
the Agency applied modeling procedures. Using the estimated chronic
drinking water values of 1 g/L for surface water and 3
g/L for ground water, the exposure to imazapyr from drinking
water was calculated to be 3 x 10-5 milligrams per kilogram of
body weight per day (mg/kg bw/day) for the U.S population (surface
water), 1 x 10-4 mg/kg bw/day for children (surface water), 7
x 10-5 mg/kg bw/day for U.S. population (ground water), and 3 x
10-4 mg/kg bw/day for children (ground water). The calculations
are included in the docket for this rulemaking.
[[Page 17098]]
4. Non-dietary (residential and non-occupational) exposure.
Imazapyr is registered for residential and non-occupational uses. As
part of the hazard assessment process, the Agency reviews the available
toxicological database to determine the endpoints of concern. For
imazapyr, the Agency does not have a concern for acute, short-term, or
intermediate-term occupational or residential risk assessment since the
available data do not indicate any evidence of significant toxicity by
the dermal or inhalation routes, or from a 1 day or single event
exposure by the oral route. Therefore, acute, short-term or
intermediate-term non-occupational or residential risk assessment was
not required.
As part of the hazard assessment process it was determined that a
chronic residential assessment was not necessary. The exposures which
would result from the use of imazapyr were determined to be of an
intermittent nature. The frequency and duration of these exposures do
not exhibit a chronic exposure pattern. The exposures do not occur
often enough to be considered a chronic exposure i.e., a continuous
exposure that occurs for at least several months. Therefore, chronic
residential exposures were not aggregated with dietary exposures in
estimating chronic risk.
5. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.'' The Agency believes that ``available
information'' in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may be helpful in
determining whether a pesticide shares a common mechanism of toxicity
with any other substances, EPA does not at this time have the
methodology to resolve the scientific issues concerning common
mechanism of toxicity in a meaningful way. EPA has begun a pilot
process to study this issue further through examination of particular
classes of pesticides. The Agency hopes that the results of this pilot
process will increase the Agency`s scientific understanding of this
question such that EPA will be able to develop and apply scientific
principles for better determining which chemicals have a common
mechanism of toxicity and evaluating the cumulative effects of such
chemicals. The Agency anticipates, however, that even as its
understanding of the science of common mechanisms increases, decisions
on specific classes of chemicals will be heavily dependent on chemical
specific data, much of which may not be presently available.
Although, at present, the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
the Agency can conclude that it is unlikely that a pesticide shares a
common mechanism of activity with other substances) and pesticides that
produce a common toxic metabolite (in which case common mechanism of
activity will be assumed).
EPA does not have, at this time, available data to determine
whether imazapyr has a common mechanism of toxicity with other
substances or how to include this pesticide in a cumulative risk
assessment. Unlike other pesticides for which EPA has followed a
cumulative risk approach, imazapyr does not appear to produce a toxic
metabolite produced by other substances. For the purposes of this
tolerance action, therefore, EPA has not assumed that imazapyr has a
common mechanism of toxicity with other substances. After EPA develops
methodologies for more fully applying common mechanism of toxicity
issues to risk assessments, the Agency will develop a process (either
as part of the periodic review of pesticides or otherwise) to reexamine
those tolerance decisions made earlier.
The registrant must submit, upon EPA's request and according to a
schedule determined by the Agency, such information as the Agency
directs to be submitted in order to evaluate issues related to whether
imazapyr shares a common mechanism of toxicity with any other substance
and, if so, whether any tolerance for imazapyr needs to be modified or
revoked.
VI. Determination of Safety for the U.S. Population and Non-Nursing
Infants
A. U.S. Population and Non-Nursing Infants
Using the Dietary Risks Evaluation System (DRES) a chronic analysis
was performed based on 100% of the crop treated and all residues at
tolerance levels. Based on the dietary/water risk assessment, the
proposed uses utilize less than 1% of the RfD for the U.S. population;
less than 1% of the RfD for nonnursing infants under 1 year old; less
than 1% for nursing infants under 1 year old; less than 1% for children
1 to 6 years old; and less than 1% for children 7 to 12 years old. The
Agency concluded that no harm will occur to non-nursing infants, or any
other members of the U.S. population from aggregate exposure to
imazapyr.
B. Infants and Children
Risk to infants and children was determined by the use of two
developmental toxicity studies in rats and rabbits and the two-
generation reproduction study in rats discussed below. The
developmental toxicity studies evaluates the potential for adverse
effects on the developing organism resulting from exposure during
prenatal development. The reproduction study provides information
relating to effects from exposure to the chemical on the reproductive
capability of both (mating) parents and on systemic toxicity.
The toxicological database for evaluating pre- and post-natal
toxicity for imazapyr is considered to be complete at this time. In the
rabbits, no evidence of maternal or developmental toxicity was observed
at doses up to 400 mg/kg/day, highest dose tested HDT. In the rat
developmental toxicity study, maternal (systemic) toxicity was noted
(indicated by salivation) at 1,000 mg/kg/day HDT.
In the rat two-generation reproduction study, no evidence of
toxicity was noted in either the adults or the offspring at dietary
levels at or close to the limit dose.
FFDCA section 408 provides that the EPA shall apply an additional
safety factor of 10 in the case of threshold effects for infants and
children to account for pre- and post-natal toxicity and the
completeness of the database unless EPA determines, based on reliable
data, that a different safety factor would be appropriate. The Agency
believes that an additional safety factor for infants and children is
not warranted. A complete set of developmental and reproductive studies
have been submitted and EPA has found them to be acceptable. The NOEL
used to calculate the RfD for the general U.S. population is 250 mg/kg
bw/day derived from the 1-year chronic toxicity study in dogs. That
NOEL is lower than the developmental NOELs for the teratology studies
in rabbits and rats (1.6 and 4x, respectively), as well as lower than
the
[[Page 17099]]
NOEL for the two-generation reproduction study in male and female rats
(3.2 to 3.9x). The Agency does not believe the effects seen in the
above studies are of such concern to require an additional safety
factor. Accordingly, the Agency believes the RfD has an adequate margin
of protection for infants and children. The percent RfD utilized by
imazapyr is less than 1% for nursing infants (less than 1 year old),
and for non-nursing infants and children 1 to 6 years old. EPA
concluded that there is reasonable certainty that no harm will occur to
infants and children from aggregate exposure to imazapyr.
VII. Other Considerations
1. Endocrine effects. No specific tests have been conducted with
imazapyr to determine whether the chemical may have an effect in humans
that is similar to an effect produced by a naturally occuring estrogen
or other endocrine effects. However, there were no significant findings
in other relative toxicity studies, i.e., teratology and multi-
generation reproductive studies, which would suggest that imazapyr
produces endocrine related effects.
2. Data Gap. Additional storage stability data are required to
support the 18 and 27 month storage stability tabulated data, including
storage temperature, analysis, raw data, representative chromatograms,
and quality assurance (good laboratory practices).
VIII. Objections and Hearing Requests
The new FFDCA section 408 (g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
the new section 408 (e) and (l)(6) as was provided in the old section
408 and section 409. However, the period for filing objections is 60
days rather than 30 days. EPA currently has procedural regulations
which governs the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by June 9, 1997 file written objections to any
aspect of this regulation and may also request a hearing with the
Hearing Clerk, at the address given below (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). Information submitted in connection with an objection or
hearing request may be claimed confidential by marking any part or all
of that information as ``Confidential Business Information'' (CBI),
Information marked as CBI will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2. A copy of the information
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.
IX. Public Docket
A record has been established for this rulemaking under the docket
number [OPP-300471] (including any comments and data submitted
electronically). 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 8:30 a.m.
to 4 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 22202.
Electronic comments can be sent directly to EPA at:
opp-docket@epamail.epa.gov
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 any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rule-making 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.
X. Regulatory Assessment Requirements
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is not a ``significant regulatory action'' and since this action
does not impose any information collection requirements subject to
approval under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., it
is not subject to review by the Office of Management and Budget. In
addition, this action does not impose any enforceable duty, or contain
any ``unfunded mandates'' as described in Title II of the Unfunded
Mandates Reform Act of 1995 Pub.L. 104-4), or require prior
consultation as specified by Executive Order 12875 (58 FR 58093,
October 28. 1993), or special considerations as required by Executive
Order 12898 (59 FR 7629), February 16, 1994).
Because tolerances established on the basis of a petition under
section 408(d) of FFDCA do not require issuance of a proposed rule, the
regulatory flexibility analysis requirements of the Regulatory
Flexibility Act (RFA), 5 U.S.C. 604(a), do not apply. Prior to the
recent amendment of the FFDCA, EPA had treated such rulemakings as
subject to the RFA; however, the amendments to the FFDCA clarify that
no proposal is required for such rulemakings and hence that the RFA is
inapplicable. Nonetheless, the Agency has previously assessed whether
establishing tolerances or exemptions from tolerance, raising tolerance
levels, or expanding exemptions adversely impact small entities and
concluded, as a generic matter, that there is no adverse impact. (46 FR
24950, May 4, 1981).
Under 5 U.S.C. 801(a)(1)(A) of the Administrative Procedure Act
(APA) as amended by the Small Business Regulatory Enforcement Fairness
Act of 1996 (Title II of Pub. L. 104-121, 110 Stat. 847), EPA submitted
a report containing this rule and other required information to the
U.S. Senate, the U.S. House of Representatives and the Comptroller
General of the General
[[Page 17100]]
Accounting Office prior to publication of the rule in today's Federal
Register. This rule is not a ``major rule'' as defined by 5 U.S.C.
804(2) of the APA, as amended.
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agriculatural commodities, Pesticides and pest, Reporting and
recordkeeping requirements.
Dated: March 31, 1997.
Daniel M. Barolo,
Director, Office of Pesticide Programs.
Therefore, 40 CFR part 180 is amended as follows:
1. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a. and 371.
2. By adding Sec. 180.500 to read as follows:
Sec. 180.500 Imazapyr; tolerances for residues.
Tolerances are being established for residues of the herbicide
imazapyr, [2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-
2-yl]-3-pyridinecarboxylic acid], applied as the acid or ammonium salt,
in or on the following raw agricultural commodities:
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
Corn, field, forage (silage)............................... 0.05
Corn, field, grain......................................... 0.05
Corn, field, stover........................................ 0.05
------------------------------------------------------------------------
[FR Doc. 97-9091 Filed 4-8-97; 8:45 am]
BILLING CODE 6560-50-F
