[Federal Register Volume 68, Number 93 (Wednesday, May 14, 2003)]
[Notices]
[Pages 25883-25888]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-11759]


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ENVIRONMENTAL PROTECTION AGENCY

[OPP-2003-0118; FRL-7301-3]


Fluroxypyr; 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.

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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 ID number OPP- 2003-0118, must be 
received on or before June 13, 2003.

ADDRESSES: Comments may be submitted electronically, by mail, or 
through hand delivery/courier. Follow the detailed instructions as 
provided in Unit I. of the SUPPLEMENTARY INFORMATION.

FOR FURTHER INFORMATION CONTACT: Joanne I. Miller, Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 305-6224; e-mail address: 
[email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does This Action Apply to Me?

     You may be potentially affected by this action if you an 
agricultural producer, food manufacturer or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
    [sbull] Crop production (NAICS Code 111)
    [sbull] Animal production (NAICS Code 112)
    [sbull] Food manufacturing (NAICS Code 311)
    [sbull] Pesticide manufacturing (NAICS Code 32532)
     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 this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
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 Copies of This Document and Other Related Information?

    1. EPA Docket. EPA has established an official public docket for 
this action under docket ID number OPP-2003-0118. The official public 
docket consists of the documents specifically referenced in this 
action, any public comments received, and other information related to 
this action. Although, a part of the official docket, the public docket 
does not include Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. The official 
public docket is the collection of materials that is available for 
public viewing at the Public Information and Records Integrity Branch 
(PIRIB), Rm. 119, Crystal Mall 2, 1921 Jefferson Davis Hwy., 
Arlington, VA. This docket facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The docket telephone 
number is (703) 305-5805.
    2. Electronic access. You may access this Federal Register document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr/.
     An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA dockets. You may 
use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public 
comments, access the index listing of the contents of the official 
public docket, and to access those documents in the public docket that 
are available electronically. Although, not all docket materials may be 
available electronically, you may still access any of the publicly 
available docket materials through the docket facility identified in 
Unit I.B.1. Once in the system, select ``search,'' then key in the 
appropriate docket ID number.
     Certain types of information will not be placed in the EPA 
dockets. Information claimed as CBI and other information whose 
disclosure is restricted by statute, which is not included in the 
official public docket, will not be available for public viewing in 
EPA's electronic public docket. EPA's policy is that copyrighted 
material will not be placed in EPA's electronic public docket but will 
be available only on printed, paper form in the official public docket. 
To the extent feasible, publicly available docket materials will be 
made available in EPA's electronic public docket. When a document is 
selected from the index list in EPA dockets, the system will identify 
whether the document is available for viewing in EPA's electronic 
public docket. Although, not all docket materials may be available 
electronically, you may still access any of the publicly available 
docket materials through the docket facility identified in Unit I.B. 
EPA intends to work towards providing electronic access to all of the 
publicly available docket materials through EPA's electronic public 
docket.
     For public commenters, it is important to note that EPA's policy 
is that public comments, whether submitted electronically or on paper, 
will be made available for public viewing in EPA's electronic public 
docket as EPA receives them and without change, unless the comment 
contains copyrighted material, CBI, or other information whose 
disclosure is restricted by statute. When EPA identifies a comment 
containing copyrighted material, EPA will provide a reference to that 
material in the version of the comment that is placed in EPA's 
electronic public docket. The entire printed comment, including the 
copyrighted material, will be available in the public docket.
     Public comments submitted on computer disks that are mailed or 
delivered to the docket will be transferred to EPA's electronic public 
docket. Public comments that are mailed or delivered to the docket will 
be scanned and placed in EPA's electronic public docket. Where 
practical, physical objects will be photographed, and the photograph 
will be placed in EPA's electronic public docket along with a brief 
description written by the docket staff.

C. How and to Whom Do I Submit Comments?

     You may submit comments electronically, by mail, or through hand 
delivery/courier. To ensure proper receipt by EPA, identify the 
appropriate docket ID number in the subject line on

[[Page 25884]]

the first page of your comment. Please ensure that your comments are 
submitted within the specified comment period. Comments received after 
the close of the comment period will be marked ``late.'' EPA is not 
required to consider these late comments. If you wish to submit CBI or 
information that is otherwise protected by statute, please follow the 
instructions in Unit I.D. Do not use EPA dockets or e-mail to submit 
CBI or information protected by statute.
    1. Electronically. If you submit an electronic comment as 
prescribed in this unit, EPA recommends that you include your name, 
mailing address, and an e-mail address or other contact information in 
the body of your comment. Also, include this contact information on the 
outside of any disk or CD ROM you submit, and in any cover letter 
accompanying the disk or CD ROM. This ensures that you can be 
identified as the submitter of the comment, and allows EPA to contact 
you in case EPA cannot read your comment due to technical difficulties 
or needs further information on the substance of your comment. EPA's 
policy is that EPA will not edit your comment, and any identifying or 
contact information provided in the body of a comment will be included 
as part of the comment that is placed in the official public docket, 
and made available in EPA's electronic public docket. If EPA cannot 
read your comment due to technical difficulties and cannot contact you 
for clarification, EPA may not be able to consider your comment.
    i. EPA Dockets. Your use of EPA's electronic public docket to 
submit comments to EPA electronically is EPA's preferred method for 
receiving comments. Go directly to EPA dockets at http://www.epa.gov/edocket, and follow the online instructions for submitting comments. 
Once in the system, select ``search,'' and then key in docket ID number 
OPP-2003-0118. The system is an ``anonymous access'' system, which 
means EPA will not know your identity, e-mail address, or other contact 
information unless you provide it in the body of your comment.
    ii. E-mail. Comments may be sent by e-mail to [email protected], 
Attention: Docket ID number OPP-2003-0118. In contrast to EPA's 
electronic public docket, EPA's e-mail system is not an ``anonymous 
access'' system. If you send an e-mail comment directly to the docket 
without going through EPA's electronic public docket, EPA's e-mail 
system automatically captures your e-mail address. E-mail addresses 
that are automatically captured by EPA's e-mail system are included as 
part of the comment that is placed in the official public docket, and 
made available in EPA's electronic public docket.
    iii. Disk or CD ROM. You may submit comments on a disk or CD ROM 
that you mail to the mailing address identified in Unit I.C.2. These 
electronic submissions will be accepted in WordPerfect or ASCII file 
format. Avoid the use of special characters and any form of encryption.
    2. By mail. Send your comments to: Public Information and Records 
Integrity Branch (PIRIB) (7502C), Office of Pesticide Programs (OPP), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001, Attention: Docket ID Number OPP-2003-0118.
    3. By hand delivery or courier. Deliver your comments to: Public 
Information and Records Integrity Branch (PIRIB), Office of Pesticide 
Programs (OPP), Environmental Protection Agency, Rm. 119, Crystal Mall 
2, 1921 Jefferson Davis Hwy., Arlington, VA, Attention: Docket 
ID Number OPP-2003-0118. Such deliveries are only accepted during the 
docket's normal hours of operation as identified in Unit I.B.1.

D. How Should I Submit CBI to the Agency?

     Do not submit information that you consider to be CBI 
electronically through EPA's electronic public docket or by e-mail. You 
may claim information that you submit to EPA as CBI by marking any part 
or all of that information as CBI (if you submit CBI on disk or CD ROM, 
mark the outside of the disk or CD ROM as CBI and then identify 
electronically within the disk or CD ROM the specific information that 
is 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 docket and EPA's electronic public docket. If you submit 
the copy that does not contain CBI on disk or CD ROM, mark the outside 
of the disk or CD ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and EPA's 
electronic public docket without prior notice. If you have any 
questions about CBI or the procedures for claiming CBI, please consult 
the person listed 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 
ID 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 Cosmetic Act (FFDCA), 21 U.S.C. 346a. 
EPA has determined that this petition contains data or information 
regarding the elements set forth in FFDCA 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: April 30, 2003.
Debra Edwards,
Director, Registration Division, Office of Pesticide Programs.

Summary of Petition

    The petitioner's summary of the pesticide petition is printed below 
as required by FFDCA section 408(d)(3). The summary of the petition was 
prepared by Dow AgroSciences and represents the view of the petitioner. 
The petition summary announces the availability of a description of the 
analytical methods available to EPA for the detection and measurement 
of the

[[Page 25885]]

pesticide chemical residues or an explanation of why no such method is 
needed.

Dow AgroSciences

PP 9F6050

     EPA has received a pesticide petition (9F6050) from Dow 
AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268 proposing, 
pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180 by establishing 
tolerances for residues of fluroxypyr in or on the raw agricultural 
commodities as follows: tolerances for residues of fluroxypyr 1-
methylheptyl ester (MHE) in or on sweet corn are being proposed in 
support of this registration as follows: 0.02 parts per million (ppm) 
for kernels plus cob with husk removed, and 1.0 ppm for forage. 
Tolerances for residues of fluroxypyr MHE in or on field corn are being 
proposed in support of this registration as follows: 0.02 ppm for 
grain; 1.0 ppm for forage; and 0.5 ppm for stover. Tolerances for 
residues of fluroxypyr MHE in or on sorghum are being proposed as 
follows: Sorghum grain, 0.02 ppm; sorghum forage, 2.0 ppm; sorghum 
stover, 4.0 ppm. Tolerances for residues of fluroxypyr MHE in or on 
grasses are proposed as follows: grass forage, 120 ppm; grass hay, 160 
ppm; and grass silage, 100 ppm. Based on the above tolerances and an 
animal feeding study, increased tolerances are also proposed for 
fluroxypyr MHE and fluroxypyr, expressed as combined residues of total 
fluroxypyr, in or on the following animal commodities: milk of cattle, 
goats, hogs, horses and sheep, 0.3 ppm; and kidney of cattle, goats, 
hogs, horses and sheep, 1.5 ppm. EPA previously received a pesticide 
petition (9F6050) for fluroxypyr and the Notice of Filing was published 
in the Federal Register on January 15, 2003. The notice of filing 
erroneously omitted tolerances proposed for residues of fluroxypyr on 
corn. Thus, this notice will supercede the previously published notice 
of filing.

A. Residue Chemistry

    1. Plant metabolism. Fluroxypyr is a systemic herbicide that is 
readily translocated and rapidly converts to the acid form following 
absorption. Fluroxypyr moves readily throughout the plant via the 
phloem (nutrient transporting) system and to a lesser extent through 
the xylem (water transporting). Fluroxypyr is distributed throughout 
the entire plant, including the meristems and other developing plant 
parts.
    2. Analytical method. There is a practical method gas 
chromatography (GC) with mass spectrometry detection (MSD) for 
measuring levels of fluroxypyr MHE in or on food with a limit of 
detection that allows monitoring of food with residues at or above the 
levels set for the proposed tolerances. Fluroxypyr has been tested 
through the Food and Drug Administration's (FDA's) Multi residue 
Methodology, Protocols C, D, and E. The results have been published in 
the FDA Pesticide Analytical Manual, Volume I.
    3. Magnitude of residues. The metabolism of fluroxypyr MHE in 
plants and animals (goats and poultry) is adequately understood for the 
purposes of these tolerances. Magnitudes of residue studies were 
conducted for field corn, sweet corn, sorghum and grasses. A process 
products study was not conducted in field corn since residues of 
fluroxypyr MHE were not detected in corn grain at 5X the application 
rate. In addition, processing of sorghum was not conducted since 
residue data for flour are not required at this time, because sorghum 
flour is used exclusively in the United States as a component for 
drywall, and not as either a human food or a feedstuff. No residues of 
fluroxypyr are expected in root or leafy vegetable crops grown in 
rotation to fluroxypyr-treated field corn, sweet corn, sorghum, and 
grasses, after a 30-day plant-back interval at the maximum allowable 
label rate of 8 oz. active ingredient/Acre (a.i./A). Field corn, sweet 
corn, sorghum and grasses grown in rotation may contain low levels of 
fluroxypyr residues; however, the tolerance values proposed for these 
crops will adequately assure compliance with the labeled use patterns.

B. Toxicological Profile

    1. Acute toxicity. Fluroxypyr MHE has low acute toxicity. The rat 
oral LD50 is >5,000 milligrams/kilogram (mg/kg), the rabbit 
dermal LD50 is >2,000 mg/kg, and the rat inhalation 
LC50 is > 1.0 milligrams/per liter (mg/l) 1,000 mg/cubic 
meter. In addition, fluroxypyr MHE is not a skin sensitizer in guinea 
pigs, has no dermal irritation in rabbits, and shows mild ocular 
irritation in rabbits. The end use formulation of fluroxypyr MHE has a 
similar low acute toxicity profile.
    2. Genotoxicty. Short term assays for genotoxicity consisting of a 
bacterial reverse mutation assay (Ames test), an in vitro assay for 
cytogenetic damage using the Chinese hamster ovary cells, an in vitro 
chromosomal aberration assay using rat lymphocytes, and an in vivo 
cytogenetic assay in the mouse bone marrow (micronucleus test) have 
been conducted with fluroxypyr MHE. These studies show a lack of 
genotoxicity. In addition, short term assays for genotoxicity 
consisting of an Ames metabolic activation test, possible induction of 
point mutations at the hypoxanthine guanine phophoribosyl transferase 
(HGPRT)-Locus of Chinese hamster ovary cells, in vivo and in vitro 
chromosomal aberrations in the Chinese hamster ovary cells, unscheduled 
DNA synthesis in human embryonic cells, and an assay in mouse lymphoma 
cells have been conducted with fluroxypyr. These studies also show a 
lack of genotoxicity.
    3. Reproductive and developmental toxicity. Developmental studies 
in rats and rabbits were conducted with both fluroxypyr MHE and 
fluroxypyr. Studies with fluroxypyr MHE showed maternal and fetal no 
observed adverse effect levels (NOAELs) of 300 mg/kg/day (rat) and 500 
mg/kg/day (rabbit). Studies with fluroxypyr showed NOAELs in the rat of 
250 mg/kg/day for maternal effects and 500 mg/kg/day for fetal effects 
and a NOAEL in the rabbit of 250 mg/kg/day for both maternal and fetal 
effects. These studies show that fluroxypyr and fluroxypyr MHE are not 
teratogenic nor will they interfere with in utero development. Two 
multi-generation reproduction studies were conducted with fluroxypyr in 
rats. The first in Wistar rats showed no effect on fertility or 
reproductive performance and had a NOAEL of 500 mg/kg/day (highest dose 
tested). The second study in Sprague-Dawley rats showed a parental 
NOAEL for systemic effects of 100 mg/kg/day in male rats and 500 mg/kg/
day in female rats. The NOAEL for reproductive effects was 750 mg/kg/
day for males and 1,000 mg/kg/day for females (highest dose tested). 
The NOAEL for neonatal effects was 500 mg/kg/day.
    4. Subchronic toxicity. Fluroxypyr MHE showed a NOAEL of 1,000 mg/
kg/day in a 90-day rat dietary study and a 21-day rabbit dermal study. 
Ninety day feeding studies with fluroxypyr showed NOAELs of 80 mg/kg/
day (Wistar rats), 700 mg/kg/day (Fischer 344 rats), 1,342 mg/kg/day 
(male mice), and 1,748 mg/kg/day (female mice). In a 4-week dietary, 
range finding study with fluroxypyr in dogs the NOAEL found was > 50 
mg/kg/day.
    5. Chronic toxicity. Based on chronic testing with fluroxypyr in 
the mouse, dog, and rat (two studies), a reference dose (RfD) of 0.8 
mg/kg/day is proposed for fluroxypyr and fluroxypyr MHE. The RfD has 
incorporated a 100-fold safety factor to the NOAEL found in the rat 
chronic test. NOAELs found in the chronic dietary studies are as 
follows: 150 mg/kg/day (dog), 300 mg/kg/day

[[Page 25886]]

(mouse), 80 mg/kg/day (Wistar rats), 100 mg/kg/day (male Fischer 344 
rats), and 500 mg/kg/day (female Fischer 344 rats).
    6. Animal metabolism. Both fluroxypyr and fluroxypyr MHE have been 
evaluated in rat metabolism studies. In summary, these studies show 
that fluroxypyr MHE is rapidly hydrolyzed and the fate of the 
hydrolysis products, fluroxypyr and 1-methylheptanol, are independent 
of whether they were given as the ester or the acid. Fluroxypyr, per 
se, was extensively absorbed and rapidly excreted principally unchanged 
in the urine; 1-methylheptanol also was rapidly absorbed and rapidly 
eliminated. Repeated administration of fluroxypyr MHE was not 
associated with accumulation in tissues. Also, the metabolism and 
pharmacokinetics of 1-methylheptanol are comparable to that of the 
methylheptyl portion of fluroxypyr MHE.
    7. Metabolite toxicology. Administration of fluroxypyr, as the acid 
or methylheptyl ester in a variety of toxicological studies, has 
produced similar effects. The principal response to sufficiently high 
dosages, whether administered over the short-term or, in some cases, 
over a lifetime, was nephrosis. Fluroxypyr is an organic acid that is 
actively excreted into the urine by the kidney. Thus, the target organ 
and dose response relationship for fluroxypyr toxicity is entirely 
consistent with the data on the toxicokinetics of fluroxypyr. 
Metabolism studies have shown that fluroxypyr MHE is rapidly and 
completely hydrolyzed to fluroxypyr acid and methylheptanol.
    8. Endocrine disruption. There is no evidence to suggest that 
fluroxypyr and fluroxypyr MHE have an effect on any endocrine system.

C. Aggregate Exposure

    1. Dietary exposure--i. Food. Tier I dietary risk assessments were 
conducted for acute, short-term, and chronic exposures. Very 
conservative assumptions were made in these risk assessments. The 
dietary exposure assessments were based on all commodities with 
tolerances for fluroxypyr established at 40 CFR 180.535 together with 
proposed tolerances for field corn, sweet corn, grain sorghum, and 
forage grass and hay, including revised tolerances for milk and meat. 
It was assumed that fluroxypyr residues were present at tolerance or 
proposed tolerance levels and that 100% of the crops were treated. 
Potential dietary exposure and risk was estimated using 
DEEMTM software (Dietary Exposure Evaluation Model, Version 
7.075, Novigen Sciences, Inc., Washington, DC).
     Developmental toxicity was not observed in the absence of maternal 
toxicity and there was no indication of increased susceptibility in 
young animals to prenatal or postnatal exposure to fluroxypyr in the 
toxicology studies. Therefore, an additional Food Quality Protection 
Act (FQPA) safety factor for infants and children was not included in 
this assessment. Acute dietary risk was assessed using an acute RfD of 
1.25 mg/kg/day, based on a maternal NOAEL of 125 mg/kg/day from a rat 
developmental toxicity study and an uncertainty factor of 100 (10X for 
interspecies extrapolation and 10X for intraspecies variation). EPA 
previously established the maternal NOAEL for this study at 125 mg/kg/
day and it was used here for a very conservative assessment of 
potential developmental toxicity. Pregnant females are estimated to 
have acute dietary exposure of 0.006582 mg/kg/day, which occupies only 
0.53% of the acute RfD. Adverse effects are not expected for exposures 
occupying 100% or less of the RfD. Therefore, acute dietary exposure 
and risk are well within acceptable levels.
     Chronic dietary exposure estimates along with a short-term oral 
NOAEL were used to assess short-term dietary exposure and risk. The 
assessment of chronic dietary exposure and risk is discussed below. The 
chronic exposure values reported for the total U.S. population and for 
children 1-6 years old was used to estimate dietary exposure for adults 
and toddlers, respectively. A 90-day dietary study in rats with a NOAEL 
of 80 mg/kg/day was selected for establishing a short-term oral 
toxicity endpoint. A 90-day subchronic study was selected for 
evaluating risk from short-term oral exposure since the 90-day exposure 
interval is more appropriate than chronic exposure for assessing short-
term risk. Of the 90-day subchronic studies conducted with fluroxypyr, 
the one selected provided the lowest NOAEL. The short-term oral NOAEL 
(80 mg/kg/day) was divided by the estimated dietary exposure for adults 
and toddlers to calculate the respective short-term margins of exposure 
(MOEs). A conservative Tier I estimate of chronic dietary exposure to 
fluroxypyr estimated exposure at 0.003160 mg/kg/day and 0.010321 mg/kg/
day for the total U.S. population and for children 1-6 years old, 
respectively. A short-term dietary (food) MOE was calculated by 
dividing the short-term oral NOAEL (80 mg/kg/day) by the estimated 
exposure (0.003160 mg/kg/day). The resulting food MOE for adults and 
toddlers was calculated to be 25,316 and 7,751, respectively. Since the 
MOE is substantially greater than 100, risk is estimated to be well 
within acceptable levels.
     Tolerances for fluroxypyr exist for several raw agricultural 
commodities and as discussed previously, tolerances for additional 
commodities have been proposed. Chronic dietary exposure to fluroxypyr 
is possible due to the potential presence of fluroxypyr residue in 
certain foods. Therefore, a chronic dietary risk assessment was 
conducted. The assessment used a chronic RfD of 0.8 mg/kg/day based on 
a NOAEL of 80 mg/kg/day from a combined chronic toxicity and 
carcinogenicity study in rats and an uncertainty factor of 100 (10X for 
interspecies extrapolation and 10X for intraspecies variation). A Tier 
I chronic dietary exposure and risk assessment was conducted. It was 
assumed that fluroxypyr residues were present at tolerance or proposed 
tolerance levels and that 100% of the crops were treated. 
DEEMTM estimates dietary exposure and the percent of the 
chronic RfD that is occupied by the input residue values for several 
population subgroups in the United States. Chronic dietary exposure for 
the general U.S. population was estimated to be 0.003160 mg/kg/day, 
which occupies 0.4% of the RfD. Children 1-6 years old comprise the 
population subgroup predicted to have the highest potential level of 
dietary exposure. Children 1-6 years old are estimated to have a 
chronic dietary exposure of 0.010321 mg/kg/day, which occupies 1.3% of 
the RfD. Adverse effects are not expected for exposures occupying 100% 
or less of the RfD. Therefore, chronic dietary exposure and risk for 
both the general U.S. population and children 1-6 years old are well 
within acceptable levels.
    ii. Drinking water. There are no established maximum contaminant 
levels for residues of fluroxypyr in drinking water and health advisory 
levels for fluroxypyr in drinking water have not been established. 
Guidance from EPA has indicated that Tier I screening level models, 
such as GENEEC and SCI-GROW, may be used to estimate upper-bound 
pesticide residues in surface water and ground water when assessing 
potential exposure through drinking water. Estimated concentrations of 
a pesticide in surface water or ground water are then compared to a 
drinking water level of comparison (DWLOC) as a surrogate estimate of 
exposure and risk. The DWLOC is the concentration of a pesticide in 
drinking water that would be acceptable as an upper limit in light

[[Page 25887]]

of total aggregate exposure to that pesticide. Potential drinking water 
concentrations of fluroxypyr were estimated in ground water and surface 
water using the screening concentration in ground water (SCI-GROW) and 
the generic expected environmental concentration (GENEEC) models, 
respectively. Both SCI-GROW are Tier I screening level models that use 
conservative assumptions.
     The estimated concentration of fluroxypyr in ground water 
according to SCI-GROW is 0.16 mg/L. EPA has indicated that peak 
concentrations of a pesticide in surface water should be used in an 
acute assessment for comparison with DWLOC values. The estimated peak 
concentration of fluroxypyr in surface water using GENEEC is 20.88 mg/
L. The upperbound estimated fluroxypyr concentrations in ground water 
(0.16 mg/L) and surface water (20.88 mg/L) are substantially below the 
acute DWLOC of 37,303 mg/L for pregnant females. Therefore, even with 
the numerous conservative assumptions included in this assessment, 
aggregated acute fluroxypyr exposure for pregnant females resulting 
from dietary exposure and upper-bound drinking water exposure is well 
within acceptable limits of exposure and risk.
     As indicated above, the estimated concentration of fluroxypyr in 
ground water according to SCI-GROW is 0.16 mg/L. EPA has indicated that 
the 56-day value from GENEEC should be divided by 3 for comparison to 
short-term, intermediate-term and chronic DWLOC values. The estimated 
56-day concentration of fluroxypyr in surface water using GENEEC is 
7.08 mg/L. Therefore, the surface water concentration used in this 
assessment is 2.36 mg/L (7.08 mg/L / 3). Potential residential exposure 
resulting from fluroxypyr use on turf was included along with potential 
dietary exposure when calculating the short-term DWLOC for adults and 
toddlers. The short-term DWLOC for toddlers and the general population 
of adults was calculated to be 7,843 mg/L and 27,450 mg/L, 
respectively. The DWLOCs are substantially greater than high-end 
estimated exposure from surface water or ground water, indicating risk 
from potential drinking water exposure is well within acceptable 
levels.
     As indicated above with short-term exposure, Tier I screening 
level estimates of potential fluroxypyr concentrations in ground water 
and surface water are 0.16 mg/L and 2.36 mg/L, respectively. Chronic 
DWLOCs for children 1-6 years old and for the general population of 
adults are 7,896 mg/L and 27,889 mg/L, respectively. Since the chronic 
DWLOCs are substantially greater than potential exposure through ground 
water or surface water, risk from potential chronic exposure through 
drinking water is well within acceptable levels.
    2. Non-dietary exposure. The proposed use of fluroxypyr on 
residential turf presents the potential for short-term residential 
exposure. Homeowners may have dermal and inhalation exposure to 
fluroxypyr during application to turf and also may have dermal exposure 
due to post-application activity on the treated turf. Toddlers may have 
dermal and oral exposure to fluroxypyr due to post-application activity 
on treated turf. Transferable residue of fluroxypyr from turf was found 
to range from 0.03 to 0.74% (used as a high end stimate) of the 
fluroxypyr applied and to dissipate with a half-life ranging from 1.4 
to 2.5 days. Exposure was estimated based on equations and default 
values given in the Standard Operating Procedures (SOPs) for 
Residential Exposure Assessment. Risk from short-term dermal exposure 
was assessed using a NOAEL of 1,000 mg/kg/day from a 21-day rabbit 
dermal study. Short-term oral and inhalation exposure was assessed 
using a NOAEL of 80 mg/kg/day from a 90-day rat feeding study.
     A high-end estimate of exposure for adults was developed by 
combining dermal exposure from application of fluroxypyr to turf with 
post-application dermal exposure also on the day of treatment (day 0). 
Homeowner exposure during the application of fluroxypyr to turf 
includes both dermal and inhalation exposure. Surrogate dermal and 
inhalation exposure data from Pesticide Handlers Exposure Data base 
(PHED V1.1) was used in estimating applicator exposure. The PHED 
surrogate data used to estimate exposure assumes residential applicator 
attire to include short pants, shortsleeve shirt, and no gloves. The 
applicator exposure estimate was based on a broadcast application using 
a garden hose end sprayer. Margin of exposure (MOE) values for dermal 
and inhalation exposures were calculated using the toxicity endpoints 
previously described. Based on these Tier I screening-level estimates, 
the general population of adults was estimated to have potential dermal 
and inhalation exposures resulting in MOE values of 8,635 and 
2,666,667, respectively. These MOEs are substantially greater than 100, 
indicating that risk from these potential exposures is well within 
acceptable levels.
     Toddlers may have exposure to fluroxypyr due to post-application 
activity on treated turf. When a pesticide in liquid formulation is 
applied to turfgrass toddlers may experience post-application exposure 
through dermal exposure and also, through oral exposure due to hand-to-
mouth transfer of pesticide residue and ingestion of treated turfgrass 
from treated areas. Based on Tier I screening-level estimates, the MOE 
values for dermal exposure and oral exposures are 34,722 and 26,667, 
respectively. Even with conservative Tier I estimates the MOEs are well 
above 100, indicating that risk from these potential exposures is well 
within acceptable levels.

D. Cumulative Effects

     The potential for cumulative effects of fluroxypyr MHE and 
fluroxypyr and other substances that have a common mechanism of 
toxicity is also considered. There is no reliable information to 
indicate that toxic effects produced by fluroxypyr MHE and fluroxypyr 
would be cumulative with those of any other pesticide chemical. Thus, 
it is appropriate to consider only the potential risks of fluroxypyr 
MHE and fluroxypyr in an aggregate exposure assessment.

E. Safety Determination

    1. U.S. population. Acute dietary exposure for pregnant females to 
residues of fluroxypyr from current and proposed uses was estimated to 
occupy only 0.53% of the acute RfD, which is well below levels expected 
to pose any appreciable risk to human health. Additionally, the acute 
DWLOC was calculated to be over 1,700-fold greater than potential 
fluroxypyr residue in drinking water predicted by conservative 
screening level models. Thus, aggregated acute exposure to fluroxypyr 
resulting from current and proposed uses is well within acceptable 
levels of risk.
     Use of fluroxypyr on turf results in potential short-term 
residential exposure for adults. Potential short-term dietary and 
residential exposures were combined into an aggregate MOE. Potential 
exposure through drinking water was not included in the aggregate MOE, 
but was evaluated in aggregate through use of a DWLOC calculated for 
short-term exposure. The short-term aggregate MOE for the general 
population of adults was calculated to be 6,423. Additionally, the 
short-term DWLOC for the general population of adults was over 10,000-
fold greater than potential fluroxypyr residues in drinking water 
predicted by conservative screening level models.

[[Page 25888]]

Therefore, aggregate short-term exposure and risk for adults is 
expected to be well within acceptable levels.
     Using conservative exposure assumptions previously described, 
chronic dietary exposure to residues of fluroxypyr from current and 
proposed uses was estimated to occupy only 0.4% of the RfD for the 
general U.S. population. The chronic DWLOC for adults was calculated to 
be over 10,000 fold greater than potential fluroxypyr residue in 
drinking water predicted by conservative screening-level models.
     Thus, based on the completeness and reliability of the toxicity 
data and the conservative exposure assessment it is concluded that 
there is a reasonable certainty that no harm will result to the general 
U.S. population, pregnant females, or developing young from acute, 
short-term, or chronic aggregate exposures to fluroxypyr residues from 
current and proposed uses.
    2. Infants and children. FFDCA Section 408 provides that EPA may 
apply an additional safety factor for infants and children in the case 
of threshold effects to account for prenatal and postnatal toxicity and 
the completeness of the data base. Based on the current toxicological 
data requirements, the data base for fluroxypyr MHE relative to 
prenatal and postnatal effects for children is complete. There were no 
indications of neurotoxicity and developmental toxicity was not 
observed in the absence of maternal toxicity. It is concluded that 
there is no indication of increased sensitivity of infants and children 
relative to adults and that an additional FQPA safety factor is not 
required.
     The acute and short-term exposures were assessed for pregnant 
females to evaluate the risk for developmental toxicity and it was 
concluded that, there was reasonable certainty of no harm from 
aggregate exposures resulting from current and proposed uses of 
fluroxypyr.
     Toddlers may experience short-term dermal and oral exposure to 
fluroxypyr as a result of postapplication activities on treated 
residential turf. Additionally, there is the potential for exposure to 
fluroxypyr through residue in food and drinking water. Tier I 
assessments were conducted to develop very conservative estimates of 
potential short-term exposure through residential, dietary and drinking 
water pathways. Potential dietary and residential exposures were 
combined into an aggregate MOE value. The aggregate MOE was 5,120, well 
above 100, indicating risk is well within acceptable levels. 
Additionally, the short-term DWLOC for toddlers was greater than 
potential fluroxypyr residue in drinking water predicted by 
conservative screening level models.
     Based on a conservative Tier I assessment, chronic dietary 
exposure to residues of fluroxypyr from current and proposed uses was 
estimated to occupy only 1.3% of the RfD for children 1-6 years old, 
the population subgroup predicted to be most highly exposed. 
Additionally, the DWLOC was calculated to be over 3,000-fold greater 
than potential fluroxypyr residue in drinking water predicted by 
conservative screening level models.
     Thus, based on the completeness and reliability of the toxicity 
data and the conservative exposure assessment it is concluded, that 
there is a reasonable certainty that no harm will result to infants and 
children from acute, short term, and chronic aggregate exposures to 
fluroxypyr residues from current and proposed uses.

F. International Tolerances

     There are no Codex maximum residue levels established for residues 
of fluroxypyr MHE and fluroxypyr on any food or feed crop.
[FR Doc. 03-11759 Filed 5-13-03; 8:45 am]
BILLING CODE 6560-50-S