58074 Federal Register / Vol. 65, No. 188 / Wednesday, September 27, 2000 / Notices

Users of these products who desire

continued use on crops or sites being

deleted should contact the applicable

registrant before March 26, 2001 unless

indicated otherwise, to discuss

withdrawal of the application for

amendment. This 180–day period will

also permit interested members of the

public to intercede with registrants prior

to the Agency’s approval of the deletion.

The following Table 2 includes the

names and addresses of record for all

registrants of the products in Table 1, in

sequence by EPA company number.

TABLE 2. — REGISTRANTS REQUESTING AMENDMENTS TO DELETE USES

IN CERTAIN PESTICIDE REGISTRATIONS

EPA Company No. Company Name

and Address

000862 Sun Company,

Inc., P.O. Box

1135, Marcus

Hook, PA

19061.

002724 Wellmark International, 1000

Tower Lane,

Bensenville, IL

60106.

011556 Bayer Corporation,

P.O. Box 390,

Shawnee Mission, KS 66201.

068292 EDM Corporation,

P.O. Box 8552,

Porterville, CA

93258.

III. What is the Agency Authority for

Taking This Action?

Section 6(f)(1) of FIFRA provides that

a registrant of a pesticide product may

at any time request that any of its

pesticide registrations be amended to

delete one or more uses. The Act further

provides that, before acting on the

request, EPA must publish a notice of

receipt of any such request in

theFederal Register. Thereafter, the

Administrator may approve such a

request.

IV. How and to Whom Do I Submit

Withdrawal Requests?

1. By mail: Registrants who choose to

withdraw a request for use deletion

must submit such withdrawal in writing

to James A. Hollins, at the address given

above, postmarked March 26, 2001.

2. In Person or by courier: Deliver

your withdrawal request to: Document

Processing Desk (DPD), Information

Services Branch, Office of Pesticide

Programs (OPP), Environmental

Protection Agency, Rm. 266A, Crystal

Mall 2, 1921 Jefferson Davis Highway,

Arlington, VA. The DPD is open from

8:00 a.m. to 4:30 p.m., Monday through

Friday, excluding legal holidays. The

DPD telephone number is (703) 305–

5263.

3. Electronically. You may submit

your withdrawal request electronically

by e-mail to: hollins.james@gov. Do not

submit any information electronically

that you consider to be CBI. Avoid the

use of special characters and any form

of encryption. Electronic submissions

will be accepted in WordPerfect 6.1/8.0

or ASCII file format.

V. Provisions for Disposition of Existing

Stocks

The Agency has authorized the

registrants to sell or distribute product

under the previously approved labeling

for a period of 18 months after approval

of the revision, unless other restrictions

have been imposed, as in special review

actions.

List of Subjects

Environmental protection,

Agricultural commodities, Pesticides

and pests.

Dated: September 18, 2000.

Richard D. Schmitt,

Acting Associate Director, Information

Resources Services Division,Office of

Pesticide Programs.

[FR Doc. 00–24779 Filed 9–26–00; 8:45 a.m.]

BILLING CODE 6560–50–S

ENVIRONMENTAL PROTECTION

AGENCY

[PF–976; FRL–6744–6]

Notice of Filing a Pesticide Petition to

Establish a Tolerance for a Certain

Pesticide Chemical in or on Food

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice.

SUMMARY: This notice announces the

initial filing of a pesticide petition

proposing the establishment of

regulations for residues of a certain

pesticide chemical in or on various food

commodities.

DATES: Comments, identified by docket

control number PF–976, must be

received on or before October 27, 2000.

ADDRESSES: Comments may be

submitted by mail, electronically, or in

person. Please follow the detailed

instructions for each method as

provided in Unit I.C. of the

SUPPLEMENTARY INFORMATION. To ensure

proper receipt by EPA, it is imperative

that you identify docket control number

PF–976 in the subject line on the first

page of your response.

FOR FURTHER INFORMATION CONTACT: By

mail: James Tompkins, Registration

Division (7505W), Office of Pesticide

Programs, Environmental Protection

Agency, 1200 Pennsylvania Ave., NW.,

Washington, DC 20460; telephone

number: (703) 305–5697; e-mail address:

tompkins.jim@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be affected by this action if

you are an agricultural producer, food

manufacturer or pesticide manufacturer.

Potentially affected categories and

entities may include, but are not limited

to:

Categories NAICS

codes

Examples of potentially affected

entities

Industry 111 Crop production

112 Animal production

311 Food manufacturing

32532 Pesticide manufacturing

This listing is not intended to be

exhaustive, but rather provides a guide

for readers regarding entities likely to be

affected by this action. Other types of

entities not listed in the table could also

be affected. The North American

Industrial Classification System

(NAICS) codes have been provided to

assist you and others in determining

whether or not this action might apply

to certain entities. If you have questions

regarding the applicability of this action

to a particular entity, consult the person

listed under FOR FURTHER INFORMATION

CONTACT.

B. How Can I Get Additional

Information, Including Copies of this

Document and Other Related

Documents?

1. Electronically. You may obtain

electronic copies of this document, and

certain other related documents that

might be available electronically, from

the EPA Internet Home Page at http://

www.epa.gov/. To access this

document, on the Home Page select

‘‘Laws and Regulations,’’ ‘‘Regulations

and Proposed Rules,’’ and then look up

the entry for this document under the

‘‘Federal Register—Environmental

Documents.’’ You can also go directly to

the Federal Register listings at http://

www.epa.gov/fedrgstr/.

2. In person. The Agency has

established an official record for this

action under docket control number PF–

976. The official record consists of the

Federal Register / Vol. 65, No. 188 / Wednesday, September 27, 2000 / Notices 58075

documents specifically referenced in

this action, any public comments

received during an applicable comment

period, and other information related to

this action, including any information

claimed as confidential business

information (CBI). This official record

includes the documents that are

physically located in the docket, as well

as the documents that are referenced in

those documents. The public version of

the official record does not include any

information claimed as CBI. The public

version of the official record, which

includes printed, paper versions of any

electronic comments submitted during

an applicable comment period, is

available for inspection in the Public

Information and Records Integrity

Branch (PIRIB), Rm. 119, Crystal Mall

#2, 1921 Jefferson Davis Highway,

Arlington, VA, from 8:30 a.m. to 4 p.m.,

Monday through Friday, excluding legal

holidays. The PIRIB telephone number

is (703) 305–5805.

C. How and to Whom Do I Submit

Comments?

You may submit comments through

the mail, in person, or electronically. To

ensure proper receipt by EPA, it is

imperative that you identify docket

control number PF–976 in the subject

line on the first page of your response.

1. By mail. Submit your comments to:

Public Information and Records

Integrity Branch (PIRIB), Information

Resources and Services Division

(7502C), Office of Pesticide Programs

(OPP), Environmental Protection

Agency, 1200 Pennsylvania Ave., NW.,

Washington, DC 20460.

2. In person or by courier. Deliver

your comments to: Public Information

and Records Integrity Branch (PIRIB),

Information Resources and Services

Division (7502C), Office of Pesticide

Programs (OPP), Environmental

Protection Agency, Rm. 119, Crystal

Mall #2, 1921 Jefferson Davis Highway,

Arlington, VA. The PIRIB is open from

8:30 a.m. to 4 p.m., Monday through

Friday, excluding legal holidays. The

PIRIB telephone number is (703) 305–

5805.

3. Electronically. You may submit

your comments electronically by e-mail

to: opp-docket@epa.gov, or you can

submit a computer disk as described

above. Do not submit any information

electronically that you consider to be

CBI. Avoid the use of special characters

and any form of encryption. Electronic

submissions will be accepted in

Wordperfect 6.1/8.0 or ASCII file

format. All comments in electronic form

must be identified by docket control

number PF–976. Electronic comments

may also be filed online at many Federal

Depository Libraries.

D. How Should I Handle CBI That I

Want to Submit to the Agency?

Do not submit any information

electronically that you consider to be

CBI. You may claim information that

you submit to EPA in response to this

document as CBI by marking any part or

all of that information as CBI.

Information so marked will not be

disclosed except in accordance with

procedures set forth in 40 CFR part 2.

In addition to one complete version of

the comment that includes any

information claimed as CBI, a copy of

the comment that does not contain the

information claimed as CBI must be

submitted for inclusion in the public

version of the official record.

Information not marked confidential

will be included in the public version

of the official record without prior

notice. If you have any questions about

CBI or the procedures for claiming CBI,

please consult the person identified

under FOR FURTHER INFORMATION

CONTACT.

E. What Should I Consider as I Prepare

My Comments for EPA?

You may find the following

suggestions helpful for preparing your

comments:

1. Explain your views as clearly as

possible.

2. Describe any assumptions that you

used.

3. Provide copies of any technical

information and/or data you used that

support your views.

4. If you estimate potential burden or

costs, explain how you arrived at the

estimate that you provide.

5. Provide specific examples to

illustrate your concerns.

6. Make sure to submit your

comments by the deadline in this

notice.

7. To ensure proper receipt by EPA,

be sure to identify the docket control

number assigned to this action in the

subject line on the first page of your

response. You may also provide the

name, date, and Federal Register

citation.

II. What Action is the Agency Taking?

EPA has received a pesticide petition

as follows proposing the establishment

and/or amendment of regulations for

residues of a certain pesticide chemical

in or on various food commodities

under section 408 of the Federal Food,

Drug, and Comestic Act (FFDCA), 21

U.S.C. 346a. EPA has determined that

this petition contains data or

information regarding the elements set

forth in section 408(d)(2); however, EPA

has not fully evaluated the sufficiency

of the submitted data at this time or

whether the data support granting of the

petition. Additional data may be needed

before EPA rules on the petition.

List of Subjects

Environmental protection,

Agricultural commodities, Feed

additives, Food additives, Pesticides

and pests, Reporting and recordkeeping

requirements.

Dated: September 19, 2000.

James Jones,

Director, Registration Division, Office of

Pesticide Programs.

Summary of Petition

The petitioner summary of the

pesticide petition is printed below as

required by section 408(d)(3) of the

FFDCA. The summary of the petition

was prepared by the petitioner and

represent the view of the petitioner.

EPA is publishing the petition summary

verbatim without editing it in any way.

The petition summary announces the

availability of a description of the

analytical methods available to EPA for

the detection and measurement of the

pesticide chemical residues or an

explanation of why no such method is

needed.

American Cyanamid Company

0F6186

EPA has received a pesticide petition

(0F6186) from American Cyanamid

Company, P.O. Box 400, Princeton, NJ.

08543–0400 proposing, pursuant to

section 408(d) of the FFDCA, 21 U.S.C.

346a(d), to amend 40 CFR part 180 by

establishing a tolerance for residues of

herbicide imazethapyr, 2-[4,5-dihydro4-methyl-4-(1-methylethyl)-5-oxo-1Himidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid) as its free acid or its

ammonium salt (calculated as the acid),

and its metabolite 2-[4,5-dihydro-4-

methyl-4-(1- methylethyl-5- oxo-1Himidazol-2-yl]-5-(1-hydroxyethyl)-3-

pyridinecarboxylic acid both free and

conjugated in or on the raw agricultural

commodities(RAC) rice grain at 0.5 parts

per million (ppm) and rice straw at 0.3

ppm and in or on crayfish at 0.1 ppm.

EPA has determined that the petition

contains data or information regarding

the elements set forth in section

408(d)(2) of the FFDCA; however, EPA

has not fully evaluated the sufficiency

of the submitted data at this time or

whether the data support granting of the

petition. Additional data may be needed

before EPA rules on the petition.

58076 Federal Register / Vol. 65, No. 188 / Wednesday, September 27, 2000 / Notices

A. Residue Chemistry

1. Plant metabolism. The qualitative

nature of the residues of imazethapyr in

rice is adequately understood. Based on

studies conducted on soybean, edible

forage legumes, and corn, parent

imazethapyr, and common metabolites

CL 288511 and CL 182704 are the only

residues of concern for tolerance setting

purposes.

2. Analytical method. Practical

analytical methods for detecting and

measuring imazethapyr residues of

concern in rice, its processed

commodities, and crayfish are

submitted to EPA with this petition. The

analytical method for rice commodities,

grain, and straw is based on capillary

electrophoresis with limits of

quantitation (LOQ) of 0.05 ppm.

Measurement of imazethapyr residues

in polished rice, hull, and bran are

accomplished by liquid

chromatography/atmospheric pressure

ionization-electrospray (API/ES) mass

spectrometry (LC/MS). The validated

LOQ of the method is 0.025 ppm. A

CZE-methodology is also submitted for

the determination of imazethapyr in

crayfish with limits of quantitation of 50

parts per billion (ppb). These

independently validated methods are

appropriate for the enforcement

purposes of this petition.

3. Magnitude of residues. A total of

nineteen field trials were conducted

with imazethapyr and its metabolites on

rice in 1997 and 1998 at several

different use rates and timing intervals

to represent the use patterns which

would result in the highest residue. In

these trials, residues of parent

compound AC 263499 in grain and

straw were less than the limit of

quantitation (0.05 ppm). The hydroxy

metabolite, CL 288511 was detected in

grain samples at a maximum value of

0.085 ppm. All straw samples analyzed

for CL 288511 residues were less than

the limit of quantitation (0.05 ppm). The

glucose conjugate, CL 182704 was

detected at a maximum value of 0.11

ppm in grain. All straw samples

analyzed for CL 182704 residues were

less than the limit of quantitation (0.05

ppm). The RAC samples were also

processed into polished rice, hull, and

bran. Results from these studies support

the proposed tolerances of 0.5 ppm for

rice grain and 0.3 ppm for rice straw.

Based on the chemical nature of

imazethapyr, results from a fish

bioaccumulation study and further

studies conducted on a surrogate

chemical, imazapyr (CL 243997), there

is no reasonable expectation of finite

residues of imazethapyr in crayfish.

However, the registrant is proposing a

tolerance in or on crayfish at 0.1 ppm.

B. Toxicological Profile

A complete, valid and reliable data

base of mammalian and genetic

toxicology studies support the proposed

tolerances for imazethapyr. This data

base was previously reviewed by the

EPA in support of the tolerance petition

and registration of imazethapyr on

soybeans, legume vegetables, corn,

alfalfa, and peanuts.

1. Acute toxicity. Imazethapyr

technical is considered to be nontoxic

(toxicity category IV) to the rat by the

oral route of exposure. In an acute oral

toxicity study in rats, the LD50 value of

imazethapyr technical was greater than

5,000 milligrams/kilograms (mg/kg) bwt

for males and females. The results from

an acute dermal toxicity study in rabbits

indicate that imazethapyr is slightly

toxic (toxicity category III) to rabbits by

the dermal route of exposure. The

dermal LD50 value of imazethapyr

technical was greater than 2,000 mg/kg

bwt for both male and female rabbits.

Imazethapyr technical is considered to

be non-toxic (toxicity category IV) to the

rat by the respiratory route of exposure.

The 4–hour LC50 value was greater than

3.27 mg/L (analytical) and greater than

4.21 mg/L (gravimetric) for both males

and females. Imazethapyr technical was

shown to be non-irritating to rabbit skin

(toxicity category IV) and mildly

irritating to the rabbit eye (toxicity

category III). Based on the results of a

dermal sensitization study (Buehler),

imazethapyr technical is not considered

a sensitizer in guinea pigs.

2. Genotoxicty. Imazethapyr technical

was tested in a battery of four in vitro

and one in vivo genotoxicity assays

measuring several different endpoints of

potential genotoxicity. Collective results

from these studies indicate that

imazethapyr does not pose a mutagenic

or genotoxic risk.

3. Reproductive and developmental

toxicity. The developmental toxicity

study in Sprague Dawley rats conducted

with imazethapyr technical showed no

evidence of developmental toxicity or

teratogenic effects in fetuses. Thus,

imazethapyr is neither a developmental

toxicant nor a teratogen in the rat. The

no observed adverse effect level

(NOAEL) for maternal toxicity was 375

mg/kg bwt/day, based on clinical signs

of toxicity in the dams (e.g. excessive

salivation) at 1,125 mg/kg bwt/day.

Imazethapyr technical did not exhibit

developmental toxicity or teratogenic

effects at maternal dosages up to and

including 1,125 mg/kg bwt/day, the

highest dose tested (HDT). Results from

a developmental toxicity study in New

Zealand white rabbits with imazethapyr

technical also indicated no evidence of

developmental toxicity or teratogenicity.

Thus, imazethapyr technical is neither a

developmental toxicant nor a teratogen

in the rabbit. The NOAEL for maternal

toxicity was 300 mg/kg bwt/day, based

on decreased food consumption and bwt

gain, abortion, gastric ulceration, and

death at 1,000 mg/kg bwt/day, the next

HDT. The NOAEL for developmental

toxicity and teratogenic effects was

determined to be >1,000 mg/kg bwt/day

based on no developmental toxicity or

fetal malformations associated with the

administration of all doses. The results

from the 2–generation reproduction

toxicity study in rats with imazethapyr

technical support a NOAEL for

reproductive toxicity of 10,000 ppm

(equivalent to 800 mg/kg bwt/day). The

NOAEL for non-reproductive

parameters (i.e. decreased weanling

bwts) is 5,000 ppm.

4. Subchronic toxicity. A short-term

(21–day) dermal toxicity study in

rabbits was conducted with imazethapyr

technical. No dermal irritation or

abnormal clinical signs were observed at

dose levels up to and including 1,000

mg/kg bwt/day ( HDT), supporting a

NOAEL for dermal irritation and

systemic toxicity of 1,000 mg/kg bwt/

day. In a subchronic (13–week) dietary

toxicity study in rats with imazethapyr

technical, no signs of systemic toxicity

were noted, supporting a NOAEL of

10,000 ppm the highest concentration

tested (HCT) (equivalent to 820 mg/kg

bwt/day). In a subchronic (13–week)

dietary toxicity study in dogs with

imazethapyr technical, no signs of

systemic toxicity were noted,

supporting a NOAEL of 10,000 ppm

(equivalent to 250 mg/kg bwt/day), the

HCT.

5. Chronic toxicity. A 1–year dietary

toxicity study was conducted with

imazethapyr technical in Beagle dogs at

dietary concentrations of 0, 1,000, 5,000,

and 10,000 ppm. In this study, the

NOAEL for systemic toxicity was 1,000

ppm (equivalent to 25 mg/kg bwt/day),

based on slight anemia, i.e., decreased

red cell parameters observed at 5,000

and 10,000 ppm concentrations. No

treatment-related histopathological

lesions were observed at any dietary

concentration, including the HCT

(10,000 ppm).

In a 2–year chronic dietary

oncogenicity and toxicity study in rats

conducted with imazethapyr technical,

the NOAEL for oncogenicity, and

chronic systemic toxicity was 10,000

ppm (equivalent to 500 mg/kg bwt/day),

the HCT. An 1–month chronic dietary

oncogenicity and toxicity study in mice

with imazethapyr technical support, a

Federal Register / Vol. 65, No. 188 / Wednesday, September 27, 2000 / Notices 58077

NOAEL for oncogenicity of 10,000 ppm,

the HCT (equivalent to 1,500 mg/kg

bwt/day), and a NOAEL for chronic

systemic toxicity of 5,000 ppm

(equivalent to 750 mg/kg bwt/day),

based on decreased bwt gain in both

sexes). The EPA has classified

imazethapyr as a Group E carcinogen

(evidence of non-carcinogenicity for

humans) based on the absence of

treatment-related tumors in acceptable

carcinogenicity studies in both rats, and

mice.

6. Animal metabolism. The rat, goat,

and hen metabolism studies indicate

that the qualitative nature of the

residues of imazethapyr in animals is

adequately understood. In 3 rat

metabolism studies conducted with

radio-labeled imazethapyr technical the

major route of elimination of the

herbicide was through rapid excretion

in urine and to a much lesser extent in

feces. In the first study, almost 100% of

the administered material was recovered

in excreta within 96 hours (89–95% in

urine, 6–11% in feces). The major

residue in urine and feces was parent

compound. Approximately 2% of the

dose was metabolized and excreted as

the α-hydroxyethyl derivative of

imazethapyr. In the second study, the

test material was rapidly and

completely eliminated unchanged in the

urine within 72 hours of dosing. After

24 hours, 92.1% of radio-activity was

excreted in the urine with 4.67% in the

feces. There was no significant

bioaccumulation of radio-activity in the

tissues from this rat metabolism study (<

0.01 ppm after 24 hours). In the third

study, 4 groups treated with radiolabeled imazethapyr readily excreted

>95% of the test material in the urine

and feces within 48 hours. A high

percentage (97–99%) of the test material

was excreted in the urine as unchanged

parent, the remainder as the αhydroxyethyl derivative of imazethapyr.

For all 3 studies, the major route of

elimination of the herbicide in rats was

through rapid excretion of unchanged

parent compound in urine. It is clear

that imazethapyr and its related

residues do not accumulate in tissues

and organs.

In the goat metabolism study, parent 14C-imazethapyr was dosed to lactating

goats at 0.25 ppm and 1.25 ppm. Results

showed 14C-residues of <0.01 ppm in

milk, and <0.05 ppm in leg muscle, loin

muscle, blood, fat, liver, and kidney.

Laying hens dosed at 0.5 ppm and 2.5

ppm with 14C-imazethapyr showed 14Cresidues of <0.05 ppm in eggs and all

tissues (blood, muscle, skin/fat, liver,

and kidney).

Additional animal metabolism studies

have been conducted with CL 288511

(main metabolite in treated crops fed to

livestock) in both laying hens and

lactating goats. These studies have been

repeated to support subsequent use

extensions on crops used as livestock

feed items which would theoretically

result in a higher dosing of imazethapyrderived residues to livestock ( i.e., corn,

alfalfa). In these studies, lactating goats

dosed at 42 ppm of 14C-CL 288511

showed 14C-residues of <0.01 ppm in

milk, leg muscle, loin muscle, and

omental fat. 14C-residues in blood were

mostly <0.01 ppm but reached 0.01 ppm

on 2 of the treatment days. 14C-residue

levels in the liver, and kidney were 0.02

and 0.09 ppm, respectively. Laying hens

dosed at 10.2 ppm of 14C-imazethapyr

showed 14C-residues of <0.01 ppm in

eggs and all tissues (blood, muscle,

skin/fat, liver, and kidney). 14Cimazethapyr or 14C-CL 288511 ingested

by either laying hens or lactating goats

was excreted within 48 hours of dosing.

These studies indicate that parent

imazethapyr and CL 288511-related

residues do not accumulate in milk or

edible tissues of the ruminant.

7. Metabolite toxicology. Metabolism

studies in soybean, peanut, corn, and

alfalfa indicate that the only significant

metabolites are the α-hydroxyethyl

derivative of imazethapyr, CL 288511

and its glucose conjugate CL 182704.

The α-hydroxyethyl metabolite has also

been identified in minor quantities in

the previously submitted rat metabolism

studies and in goat and hen metabolism

studies. No additional toxicologically

significant metabolites were detected in

any of the plant or animal metabolism

studies.

8. Endocrine disruption. Collective

organ weight data and histopathological

findings from the 2–generation rat

reproductive study, as well as from the

subchronic and chronic toxicity studies

in 3 different animal species

demonstrate no apparent estrogenic

effects or treatment-related effects of

imazethapyr on the endocrine system.

C. Aggregate Exposure

1. Dietary exposure. The potential

dietary exposure to imazethapyr has

been calculated from the proposed

tolerance for use on rice and previously

established tolerances for peanuts,

legume vegetables, soybeans, alfalfa,

endive, lettuce, and corn. This very

conservative chronic dietary exposure

estimate used the proposed tolerance of

0.5 ppm for rice, and tolerance values of

0.1 ppm for peanuts, 0.1 ppm for

legume vegetables, 0.1 ppm for

soybeans, 3.0 ppm for alfalfa, 0.1 ppm

for endive (escarole), 0.1 ppm for

lettuce, and 0.1 ppm for corn. In

addition, these estimates assume that

100% of these crops contain

imazethapyr residues.

i. Food. Potential exposure to residues

of imazethapyr in food will be restricted

to intake of rice, peanuts, legume

vegetables, soybeans, alfalfa (sprouts),

endive, lettuce, and corn. Using the

assumptions discussed above, the

theoretical maximum residue

concentration (TMRC) values of

imazethapyr were calculated for the

U.S. general population and subgroups.

Based on the tolerances given above, the

TMRC values for each group are:

• 0.000419 mg/kg bwt/day for the

general U.S. population.

• 0.001104 mg/kg bwt/day for all

infants (<1–year).

• 0.001298 mg/kg bwt/day for nonnursing infants.

• 0.000870 mg/kg bwt/day for

children 1 to 6 years of age.

• 0.000610 mg/kg bwt/day for

children 7 to 12 years of age.

The TMRC values indicate that nonnursing infants are the most highly

exposed population subgroup.

ii. Drinking water. As a screeninglevel assessment for aggregate exposure,

the U.S. EPA evaluates a drinking water

level of comparison (DWLOC), which is

the maximum concentration of a

chemical in drinking water that would

be acceptable in light of total aggregate

exposure to that chemical. In 1990, the

EPA set the reference dose (RfD) for

imazethapyr at 0.25 mg/kg bwt/day,

based on the NOAEL from the 1–year

dietary toxicity study in dogs of 25 mg/

kg bwt/day and a 100–fold uncertainty

factor. Based on the chronic RfD of 0.25

mg/kg bwt/day and the EPA’s default

factors for bwt and drinking water

consumption, the DWLOCs have been

calculated to assess the potential dietary

exposure from residues of imazethapyr

in water. For the adult population the

chronic DWLOC was 8,735 ppb and for

children the DWLOC was estimated to

be 2,491 ppb.

Chronic drinking water exposure

analyses were calculated for

imazethapyr using EPA screening

models screening concentration in

ground water ((SCI-GROW) for ground

water and (generic expected

environmental concentration) (GENEEC)

for surface water). The SCI-GROW value

is 16.54 ppb and the calculated peak

GENEEC value is 5.96 ppb by aerial

application. For the U.S. adult

population, the estimated exposures of

imazethapyr residues in groundwater

and surface water are approximately

0.19% and 0.07%, respectively, of the

DWLOC. The estimated exposures of

children to imazethapyr residues in

ground water and surface water are

approximately 0.66%, and 0.24%,

58078 Federal Register / Vol. 65, No. 188 / Wednesday, September 27, 2000 / Notices

respectively, of the DWLOC. Therefore,

the exposures to drinking water from

imazethapyr use are negligible.

2. Non-dietary exposure. Imazethapyr

products are notcurrently registered or

requested to be registered for residential

use; therefore the estimate of residential

exposure is not relevant to this tolerance

petition.

D. Cumulative Effects

Imazethapyr is a member of the

imidazolinone class of herbicides. Other

compounds of this class are registered

for use in the United States. However,

the herbicidal activity of the

imidazolinones is due to the inhibition

of acetohydroxyacid synthase (AHAS),

an enzyme only found in plants. AHAS

is part of the biosynthetic pathway

leading to the formation of branched

chain amino acids. Animals lack AHAS

and this biosynthetic pathway. This lack

of AHAS contributes to the low toxicity

of the imidazolinone compounds in

animals. We are aware of no information

to indicate or suggest that imazethapyr

has any toxic effects on mammals that

would be cumulative with those of any

other chemical. Therefore, for the

purposes of this tolerance petition no

assumption has been made with regard

to cumulative exposure with other

compounds having a common mode of

action.

E. Safety Determination

1. U.S. population. The RfD

represents the level at or below which

daily aggregate exposure over a lifetime

will not pose appreciable risks to

human health. In 990, the EPA set the

RfD for imazethapyr at 0.25 mg/kg bwt/

day, based on the NOAEL from the 1–

year dietary toxicity study in dogs of 25

mg/kg bwt/day and a 100–fold

uncertainty factor. The chronic dietary

exposure of 0.000419 mg/kg bwt/day for

the general U.S. population will utilize

only 0.2% of the RfD of 0.25 mg/kg bwt/

day. EPA generally has no concern for

exposures below 100% of the RfD. Due

to the low toxicity of imazethapyr, an

acute exposure dietary risk assessment

is not warranted. The complete and

reliable toxicity data base, the low

toxicity of the active ingredient, and the

results of the chronic dietary exposure

risk assessment, support the conclusion

that there is a ‘‘reasonable certainty of

no harm’’ from the proposed use of

imazethapyr on imidazolinone tolerant

rice. Furthermore, these factors support

the proposed tolerance on rice.

2. Infants and children. The

conservative dietary exposure estimates

of all registered uses including the

proposed tolerance for rice show

exposures of 0.001104, 0.000440,

0.000870, and 0.000610 mg/kg bwt/day

which will utilize 0.4, 0.2, 0.3, and

0.2% of the RfD for all infants (<1 year),

nursing infants, children 1-6 years, and

children 7-12 years, respectively. The

chronic dietary exposures for nonnursing infants, the most highly

exposed subgroup, will utilize only

0.5% of the RfD. Results from the 2–

generation reproduction study in rats

and the developmental toxicity studies

in rabbits and rats indicate no increased

sensitivity to developing offspring when

compared to parental toxicity. These

results also indicate that imazethapyr is

neither a developmental toxicant nor a

teratogen in either the rat or rabbit.

Therefore, an additional safety factor is

not warranted, and the RfD of 0.25 mg/

kg bwt/day, which utilizes a 100–fold

safety factor is appropriate to ensure a

reasonable certainty of no harm to

infants and children.

F. International Tolerances

There are no Codex maximum residue

levels established or proposed for

residues of imazethapyr on rice.

[FR Doc. 00–24680 Filed 9–26–00; 8:45 am]

BILLING CODE 6560–50–S

ENVIRONMENTAL PROTECTION

AGENCY

[PF–972; FRL–6742–4]

Notice of Filing a Pesticide Petition to

Establish a Tolerance for a Certain

Pesticide Chemical in or on Food

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice.

SUMMARY: This notice announces the

initial filing of a pesticide petition

proposing the establishment of

regulations for residues of a certain

pesticide chemical in or on various food

commodities.

DATES: Comments, identified by docket

control number PF–972, must be

received on or before October 27, 2000.

ADDRESSES: Comments may be

submitted by mail, electronically, or in

person. Please follow the detailed

instructions for each method as

provided in Unit I.C. of the

SUPPLEMENTARY INFORMATION. To ensure

proper receipt by EPA, it is imperative

that you identify docket control number

PF–972 in the subject line on the first

page of your response.

FOR FURTHER INFORMATION CONTACT: By

mail: Bipin Gandhi, Registration

Division (7505C), Office of Pesticide

Programs, Environmental Protection

Agency, 1200 Pennsylvania Ave., NW.,

Washington, DC 20460; telephone

number: (703) 308–8380; e-mail address:

gandhi.bipin@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be affected by this action if

you are an agricultural producer, food

manufacturer or pesticide manufacturer.

Potentially affected categories and

entities may include, but are not limited

to:

Categories NAICS

Examples of potentially affected

entities

Industry 111 Crop production

112 Animal production

311 Food manufacturing

32532 Pesticide manufacturing

This listing is not intended to be

exhaustive, but rather provides a guide

for readers regarding entities likely to be

affected by this action. Other types of

entities not listed in the table could also

be affected. The North American

Industrial Classification System

(NAICS) codes have been provided to

assist you and others in determining

whether or not this action might apply

to certain entities. If you have questions

regarding the applicability of this action

to a particular entity, consult the person

listed under FOR FURTHER INFORMATION

CONTACT.

B. How Can I Get Additional

Information, Including Copies of this

Document and Other Related

Documents?

1. Electronically. You may obtain

electronic copies of this document, and

certain other related documents that

might be available electronically, from

the EPA Internet Home Page at http://

www.epa.gov/. To access this

document, on the Home Page select

‘‘Laws and Regulations,’’ ‘‘Regulations

and Proposed Rules,’’ and then look up

the entry for this document under the

‘‘Federal Register—Environmental

Documents.’’ You can also go directly to

the Federal Register listings at http://

www.epa.gov/fedrgstr/.

2. In person. The Agency has

established an official record for this

action under docket control number PF–

972. The official record consists of the

documents specifically referenced in

this action, any public comments

received during an applicable comment

period, and other information related to

this action, including any information

claimed as confidential business

information (CBI). This official record