[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 : [email protected]. 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: [email protected].

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:
    [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 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