Document ID: EPA-HQ-OPP-2007-0437-0003
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-08-29T04:00Z

Fenoxaprop-p-ethyl Summary Document

Registration Review: Initial Docket

August 29, 2007

	

								

Approved By:

								

___________________

								Steven Bradbury, Ph.D

								Director, Special Review and

		       				Reregistration Division 

TABLE OF CONTENTS

									               	Page #

Preliminary Work Plan (PWP)					3

Fact Sheet								7

Ecological Risk Assessment Problem Formulation		11                      
                                                               

Human Health Effects Scoping Document			54

Glossary of Terms and Abbreviations				63

I. PRELIMINARY WORK PLAN

Introduction:

 The Food Quality Protection Act of 1996 amendments to the Federal
Fungicide Insecticide and Rodenticide Act (FIFRA) mandated a new
program:  registration review.  All pesticides distributed or sold in
the United States generally must be registered by the United States
Environmental Protection Agency (the Agency) based on scientific data
showing that they will not cause unreasonable risks to human health,
workers, or the environment when used as directed on product labeling. 
The new registration review program is intended to make sure that, as
the ability to assess and reduce risk evolves and as policies and
practices change, all registered pesticides continue to meet the
statutory standard of no unreasonable adverse effects.  Changes in
science, public policy, and pesticide use practices will occur over
time.  Through the new registration review program, the Agency
periodically reevaluates pesticides to make sure that as change occurs,
products in the marketplace can continue to be used safely.  
Information on this program is provided at:
http://www.epa.gov/oppsrrd1/registration_review/. 

This document opens the first reevaluation of fenoxaprop-p-ethyl under
Registration Review.  The Agency plans to review each registered
pesticide every 15 years to determine whether it continues to meet the
FIFRA standard for registration.  The public phase of registration
review begins when the initial docket is opened for each case.  The
docket is the Agency’s opportunity to state clearly what it knows
about the pesticide and what additional risk analyses and data or
information it believes are needed to make a registration review
decision.  After reviewing and responding to comments and data received
in the docket during this initial comment period, the Agency will
develop and commit to a final work plan and schedule for the
registration review of fenoxaprop-p-ethyl (FPE).

Anticipated Risk Assessment and Data Needs:

The Agency anticipates updating and revising the ecological risk
assessment for FPE (including an endangered species risk assessment),
and updating and revising the human health risk assessment.  Additional
data that the Agency may need to complete these assessments are
specified below.

Ecological Risk:

The Agency has determined that a revised risk assessment is necessary
for FPE under registration review, to bring the assessment in line with
current standards, policies, and registered use patterns.  This will
include an assessment of potential risk to endangered and threatened
species (referred to as listed species).  Please refer to Section III of
this document, Ecological Risk Assessment Problem Formulation, for a
detailed discussion of the anticipated ecological risk assessment needs.
 A summary follows:

  

There are data gaps in the toxicity database for FPE.  However,
available data for racemic fenoxaprop-ethyl will be used for acute
toxicity aquatic organism studies because available toxicity data
indicate that fenoxaprop-ethyl and FPE have similar acute toxicity to
aquatic organisms.

The technical registrant has recently submitted 23 mammalian toxicology
studies conducted with FPE with the intent to show equivalent toxicity
with fenoxaprop-ethyl.  These studies are being reviewed.  If review of
these studies indicates that fenoxaprop-ethyl and FPE are not similarly
toxic to mammals, additional FPE studies for mammals will be required by
DCI for the human health risk and ecological risk assessments.  In
addition, if the mammalian data do not show similar toxicity between the
two active ingredients, chronic avian toxicity studies will also be
required for the ecological risk assessment.

The planned ecological risk assessment will allow the Agency to
determine whether use of FPE has "no effect" or "may affect" federally
listed threatened or endangered species (listed species) or their
designated critical habitats.  If the assessment indicates that FPE "may
affect" a listed species or its designated critical habitat, the
assessment will be refined.  The refined assessment will allow the
Agency to determine whether use of FPE is “likely to adversely
affect” the species or critical habitat or "not likely to adversely
affect" the species or critical habitat.  When an assessment concludes
that a pesticide's use "may affect" a listed species or its designated
critical habitat, the Agency will consult with the U.S. Fish and
Wildlife Service and National Marine Fisheries Service (the Services),
as appropriate.

  

Human Health Risk:

The Agency has determined that a revised risk assessment is necessary
for FPE under registration review, to bring the assessment in line with
current standards, policies, and registered use patterns.  This revised
assessment will include 1) an assessment of the similarity of the
toxicities of fenoxaprop-ethyl and FPE and 2) an assessment of whether
the potential carcinogenicity of FPE should be assessed by the linear or
threshhold /margin of exposure (MOE) method.  Please refer to Section
IV, the Human Health Effects Scoping Document for a detailed discussion
of the anticipated risk assessment and/or data needs for human health. 
A summary follows:

The Agency plans to review the newly received FPE developmental toxicity
studies and any other studies deemed relevant, and compare these studies
to the analogous studies conducted on fenoxaprop-ethyl.  The Agency will
make a decision as to whether the entire fenoxaprop-ethyl database,
notably the chronic, cancer, and reproductive toxicity studies, may be
bridged to FPE.  If complete bridging is agreed on, then no FPE toxicity
data are likely to be required.  If partial or no bridging is permitted,
then the FPE toxicity studies that must be required will be identified.

The Agency will schedule an evaluation of the carcinogenic potential of
fenoxaprop-ethyl/FPE by the Agency’s HED Cancer Assessment Review
Committee (CARC).  The CARC will determine whether a mechanism and
threshold effect/MOE  approach is more appropriate for the
carcinogenicity assessment for FPE than the low dose extrapolation
method (Q1*).  If the MOE approach is not appropriate, the CARC will
recalculate the Q1* based on current data and methods.  If the
carcinogenicity assessment changes from the previous assessment, cancer
risk estimates for dietary and occupational exposure will be revised.

The Agency will prepare an updated human health risk assessment
including-

New risk assessments which aggregate food, drinking water and
residential exposures.

Occupational handler inhalation assessments for cotton, soybeans, rice,
or peanuts, and for various turf uses (sod farms, commercial and
residential turf), ornamentals, and rights-of-way.

Timeline:

The timeline below reflects the time that will be needed for
registration review of FPE if additional data are deemed necessary for
the human health and ecological effects risk assessments.  If review of
the  FPE mammalian toxicity studies indicate that bridging between
fenoxaprop-ethyl and FPE toxicity studies is appropriate, additional
data will not need to be called in, and the overall risk assessment
timeline will shorten to three years. 

Activities	Estimated Month/Year

(Example - quarters are calendar year)

Open docket	Aug. 2007

Public comment	Nov. 2007

Final Work Plan	1st Quarter 2008

Issue DCI	4th Quarter 2008

Data Submission	4th Quarter 2010

Preliminary Risk Assessment	2nd Quarter 2012

Public Comment Period	3rd Quarter 2012

Proposed Registration Review Decision	4th Quarter 2012

Public Comment Period	1st Quarter 2013

Final Registration Review Decision & Begin Post-Decision Follow-up	2013

Total (years)	6

Guidance for Commenters:

The public is invited to comment on EPA’s preliminary registration
review work plan and rationale.  The Agency will carefully consider all
comments as well as any additional information or data provided prior to
issuing a final work plan for the FPE case.

Through the registration review process, the Agency intends to solicit
information on trade irritants and, to the extent feasible, take steps
toward facilitating irritant resolution.  Growers and other stakeholders
are asked to comment on any trade irritant issues resulting from lack of
Maximum Residue Levels (MRLs) or disparities between U.S. tolerances and
MRLs in key export markets, providing as much specificity as possible
regarding the nature of the concern.

Stakeholders are also specifically asked to provide information and data
in the following areas:

Confirmation on the following label information.

sites of application

formulations

application methods and equipment

maximum application rates

frequency of application, application intervals, and maximum number of
applications per season and per year

geographic limitations on use

Use or potential use distribution (e.g., acreage and geographical
distribution of relevant uses).

Use history.

Median and 90th percentile reported use rates (lbs. a.i./acre) from
usage data – national, state and county.

Application timing (date of first application and application intervals)
by use – national, state, and county.

6.   Sub-county crop location data.

7.	Usage/use information for non-agricultural uses (e.g., golf courses,
athletic fields, ornamentals).

8 . 	Directly acquired county-level usage data (not derived from state
level data).

maximum reported use rate (lbs. a.i./acre) from usage data – county

percent crop treated – county

median and 90th percentile number of applications – county

total pounds per year – county

the year the pesticide was last used in the county/sub-county area

the years in which the pesticide was applied in the county/sub-county
area

9. 	Typical application interval (days).

10. State or local use restrictions.

11. Ecological incidents specific to FPE (non-target plant damage and
avian, fish, reptilian, amphibian and mammalian mortalities) not already
reported to the Agency.

12. Monitoring data.

13. FPE is not identified as a cause of impairment for any water body
listed as impaired under section 303(d) of the Clean Water Act, based on
information provided at   HYPERLINK
"http://oaspub.epa.gov/tmdl/waters_list.impairments?p_impid=3" 
http://oaspub.epa.gov/tmdl/waters_list.impairments?p_impid=3 .  However,
the Agency invites submission of any other existing water quality data. 
To the extent possible, data elements outlined in Appendix A of the
“OPP Standard Operating Procedure: Inclusion of Water Quality &
Impaired Water Body Data in OPP’s Registration Review Risk Assessment
& Management Process,” should be provided.  To ensure the data can be
used quantitatively or qualitatively in pesticide risk assessments, see 
 HYPERLINK
"http://www.epa.gov/oppsrrd1/reregistration_review/water_quality.htm" 
http://www.epa.gov/oppsrrd1/reregistration_review/water_quality.htm .

Next Steps:

After the comment period closes in November 2007 and the comments are
reviewed, the Agency will prepare a Final Work Plan for this pesticide. 

Top of Form

Bottom of Form

II. FACT SHEET

                         

Background

FPE (case number: 7209) is undergoing registration review.  FPE is the
r-isomer enriched (95%) formulation of fenoxaprop-ethyl, which is the
racemic mixture of the r- and s- isomers (ratio 50:50).

Technical registrant: Bayer CropScience

FPE: PC Code 129092, CAS # 71283-80-2

Fenoxaprop-ethyl: PC Code 128701, CAS # 66441-23-4 

Fenoxaprop-ethyl no longer has any registered products.

A Reregistration Eligibilty Decision (RED) was not conducted for FPE
because the pesticide was registered after 1984 and was, therefore, not
subject to reregistration.

There are 16 FIFRA Section 3 active registrations and several FIFRA 24
(c) Special Local Needs registrations.

 Ecological risk and exposure assessments that serve as the basis for
the ecological risk assessment problem formulation include the
following:

FIFRA Section 3 new use  risk assessment of proposed uses on wheat,
soybeans, cotton, peanuts, and conservation reserves (DP barcode 164986;
Feb. 14, 1996)

Four FIFRA Section 18 risk assessments for uses on barley and rice from
1997 to 2001;

One FIFRA Section 18 risk assessment (DP barcode 338410) for use on
grass grown for seed in 2007.

A drinking water assessment (DP barcode 239618; Oct. 3, 1997)

Chemical Review Manager: Kylie Rothwell 

Product Managers: Eugene Wilson and Joanne Miller 

Use and Usage 

FPE is a selective postemergence herbicide of the aryloxyphenoxy
propionate group that controls annual and perennial grass weeds.

FPE is used on rice, barley, soybeans, cotton, peanuts, and wheat.  It
is also used for sod farms, commercial and residential turf, highway
rights of way, acreage conservation reserve (set-aside) and ornamentals.
 There are also consumer use products.

FPE is formulated as an emulsifiable concentrate, a soluble
concentrate/liquid, and as a liquid ready-to-use product.

Screening-level estimates indicate that approximately 700,000 pounds of
active ingredient are used annually.

The estimates of current usage indicate minimal usage on cotton and
rice, with approximately 5% of the crop treated for soybeans,
approximately 25% for wheat, and less than 1% for cotton. 

Use information, such as application rates and number of applications
specified on product labels, is found in Appendix A in the docket. 

Recent Actions

Four FIFRA Section 18 risk assessments for uses on barley and rice were
performed from 1997 to 2001.

The concentration of the r- isomer was increased from 89% to 95% in the
MP compound  in 2002.  

Risk assessments were performed for an emergency exemption which was
requested for use of FPE on grass seed in Oregon in March 2007.

Ecological Risk Assessment Status

To meet current standards, a new ecological risk assessment (including 
listed species) is needed for all registered outdoor uses.  However,
based on the results of previous risk assessments, and screening model
results presented in the attached Ecological Risk Assessment Problem
Formulation:

Risk quotients for labeled uses of FPE are unlikely to exceed the acute
levels-of-concern (LOCs) for birds, mammals and aquatic plants.

Risk quotients for labeled uses of FPE may exceed the acute LOC for
estuarine/marine invertebrates and terrestrial monocot plants; the
chronic LOC for birds, mammals, and freshwater and estuarine/marine fish
and invertebrates; and the endangered species LOC for birds, mammals,
terrestrial monocot plants, and freshwater and estuarine/marine fish and
invertebrates.

78 reports of adverse field effects to non-target plants have been
received.  The Agency considers the cause to be uncertain in 39 cases in
which several herbicides were used.  There are no incident reports
involving contamination of ground or surface water.  

Human Health Risk Assessment Status

To meet current standards, and to incorporate data not considered in the
most recent risk assessment (1998), new human health risk assessments
are needed.  The conceptual model of risk to human health will also be
revisited, both by considering the appropriateness of bridging between
toxicity data for fenoxaprop-ethyl and FPE and by evaluating whether the
cancer risk assessment should be conducted using the linear Q1* or the
MOA approach.  Please refer to Section IV of this document, Human Health
Effects Scoping Document, for a detailed discussion of the anticipated
risk assessment needs for human health.  Below is a summary of the
findings:

Dietary (Food and Drinking Water):

There are no dietary risks that exceed the Agency’s level of concern
(LOC). 

Residential

A homeowner “handler” risk assessment has not yet been conducted.  

There are currently several registered homeowner products containing
FPE.  To assess risks to homeowners, a short-term residential handler
inhalation assessment should be conducted for lawn and ornamental use
based on inhalation exposure only; dermal exposure would not be assessed
because of the negative results of the dermal toxicity studies. 

Also, by current standards, children’s “incidental” oral exposure
(to treated turf) would be assessed based on an existing oral toxicity
study of the appropriate exposure duration.

Occupational

Occupational handler risk assessment was completed for the 1997 and 1998
barley and wheat tolerance petitions based on inhalation exposure, only.
 

Dermal exposure was not assessed based on the negative results of the
dermal toxicity studies. 

Occupational handler inhalation assessments have not been conducted for
cotton, soybeans, rice, or peanuts, or for various turf uses (sod farms,
commercial and residential turf), ornamentals, and rights-of-way.

Carcinogenic risk estimates were completed for workers based on their
specific function (such as aerial applicator and ground applicator). 
The highest carcinogenic risk estimated was 10-6 and was based on the
mixer/loader function for aerial applications.  

Carcinogenicity Assessments

The most recent assessment in 1998 used an interim Q1* of 9.1 x 10-2,
which was based on increases in adrenal tumors in male mice.

The upper-bound (food only) carcinogenic risk estimate was 9.1 x 10-7.

Data Call-In (DCI) Status

No DCIs were issued for fenoxaprop-ethyl or FPE.

Tolerances:

Permanent tolerances were established for the combined residues of
fenoxaprop-ethyl and its metabolites, 40 CFR Section 180.430(a). 
Because fenoxaprop-ethyl and FPE are chemically similar, the tolerances
established for fenoxaprop-ethyl are used for FPE.  Tolerances for
fenoxaprop-ethyl were reassessed in 1998 under the Food Quality
Protection Act in conjunction with a risk assessment for new use on
barley.  If the Agency determines that fenoxaprop-ethyl and FPE are
toxicologically equivalent, the tolerance expression will remain the
same.  The fenoxaprop-ethyl tolerances for barley, wheat, rice,
cottonseed and soybean have been set at 0.05 ppm.  

The Codex Alimentarius has not established maximum residue levels (MRLs)
for fenoxaprop-ethyl and FPE.  However, the Pest Management Regulatory
Association (Canada) has an MRL of 0.03 ppm for fenoxaprop-ethyl in
milk.  There are FPE MRLs for rice (0.05 ppm), barley (0.05 ppm), and
wheat (0.05 ppm) in Mexico.

Fenoxaprop-p-ethyl Registrations:

Table 1. Current FPE Section 3 product labels.

Product Name	Company	Registration # 	Uses

Fusion Herbicide	Syngenta Crop Protection	100-1059	cotton,
rights-of-way, soybeans

Whip 360 Herbicide	Bayer CropScience	264-647	conservation reserves,
rice, soybeans

Silverado Herbicide	Bayer CropScience	264-650               
conservation reserves, cotton, peanuts, soybeans, wheat

Fenoxaprop-p-ethyl technical	Bayer CropScience	264-653            

	Puma 1EC Herbicide	Bayer CropScience	264-666	barley, wheat

Ricestar Herbicide	Bayer CropScience	264-682	rice

Acclaim Extra Herbicide	Bayer Environmental Science	432-950	ornamentals,
rights-of-way, turf

Preclaim EW Herbicide	Bayer Environmental Science	432-957              
ornamentals, rights-of-way, turf

Preclaim Crabgrass Killer & Weed Preventer	Bayer Environmental Science
432-958              	ornamentals (residential), turf (residential)

Preclaim Herbicide	Bayer Environmental Science	432-959              
ornamentals, rights-of-way, turf

Triway + Phenoxaprop Ready-to-Spray Herbicide	Bayer Advanced	72155-62
turf (residential)

Triway + Fenoxaprop Concentrate Herbicide	Bayer Advanced	72155-63	turf
(residential)

Triway + Phenoxaprop Ready-to-Use Herbicide	Bayer Advanced	72155-66	turf
(residential)

Crabgrass Killer R-T-S Herbicide	Bayer Advanced	72155-74	ornamentals
(residential), turf (residential)

Bayer Advanced Lawn Herbicide 3F Concentrate	Bayer Advanced	72155-77
turf (residential)

Bayer Advanced Lawn Herbicide 3F RTU	Bayer Advanced	72155-78	turf
(residential)

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

		July 30, 2007

	PC Code:  129092

	DP Barcode:  338163

MEMORANDUM

Subject:	Registration Review – REVISED Preliminary Problem Formulation
for the Ecological Risk Assessment of Fenoxaprop-p-ethyl

To:		Kylie Rothwell, Chemical Review Manager 

		Kevin Costello, Team Leader

		Reregistration Branch 

		Special Review and Reregistration Division

		Office of Pesticide Programs

From:		Kristina Garber, Biologist

		Greg Orrick, Environmental Scientist

		Environmental Risk Branch 4

		Environmental Fate and Effects Division

		Office of Pesticide Programs

Through:	Elizabeth Behl, Chief

		Environmental Risk Branch 4

		Environmental Fate and Effects Division

		Office of Pesticide Programs

Attached is the revised preliminary problem formulation for the
ecological risk assessment to be conducted as part of the Registration
Review of the herbicide fenoxaprop-p-ethyl (FPE).



REGISTRATION REVIEW

ECOLOGICAL RISK ASSESSMENT PROBLEM FORMULATION FOR:

Fenoxaprop-p-ethyl

(+)-Ethyl 2-(4-((6-chloro-2-benzoxazolyl)oxy)phenoxy)propanoate

CAS Registry Number: 71283-80-2

PC Code: 129092

Prepared by:

	Kristina Garber, Biologist

Greg Orrick, Environmental Scientist	U. S. Environmental Protection
Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch IV

1200 Pennsylvania Ave., NW

Mail Code 7507P

Washington, DC 20460

Reviewed by:

R. David Jones, Senior Agronomist

Brian Kiernan, Biologist

Elizabeth Behl, Branch Chief

	1. STRESSOR SOURCE AND DISTRIBUTION

Fenoxaprop-p-ethyl [FPE; (+)-ethyl
2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoate] is a selective
aryloxyphenoxypropionate herbicide used to control grass plants after
emergence.  Aryloxyphenoxypropionate herbicides are mobile in the phloem
and work by inhibiting acetyl coenzyme A carboxylase, which effectively
inhibits lipid synthesis in target plants (Martin, 2000).  FPE is the
R-enantiomer (or d-isomer) of the racemate fenoxaprop-ethyl (PC Code
128701).  The racemate is no longer registered by EPA, as FPE appears to
be more efficacious than the S-enantiomer (l-isomer).  Submitted studies
contain enriched isomeric mixtures of 85:15 d:l, 89:11 d:l, or 97:3 d:l
and currently registered products contain FPE at the 97:3 d:l mixture. 
Submitted studies and existing labels loosely refer to these enriched
mixtures as FPE regardless of the purity.

There are 18 Section 3 product registrations that currently contain FPE
(Table 1), which include agricultural and non-agricultural uses. 
Agricultural uses include barley, cotton, peanuts, rice, soybeans, and
wheat.  Non-agricultural uses include conservation reserves,
ornamentals, rights-of-way, and turf.  Applications of FPE to
ornamentals and to turf can be in residential and commercial settings. 
FPE products are flowable and are applied by ground or aerial methods;
applications by chemigation are prohibited.  For more details on the use
information of FPE, including application rates, methods and timing, see
Appendix A.

As of 7/18/07, EFED was notified that registrations 264-649 and 264-654
were cancelled. Therefore, these labels were not considered in this
problem formulation.

Table 1. Current FPE Section 3 product labels.

Product Name	Registration # 	Uses

Fusion Herbicide	100-1059	cotton, rights-of-way, soybeans

Whip 360 Herbicide	264-647	conservation reserves, rice, soybeans

Silverado Herbicide	264-650               	conservation reserves,
cotton, peanuts, soybeans, wheat

Puma 1EC Herbicide	264-666	barley, wheat

Ricestar Herbicide	264-682	rice

Acclaim Extra Herbicide	432-950	ornamentals, rights-of-way, turf

Preclaim EW Herbicide	432-957              	ornamentals, rights-of-way,
turf

Preclaim Crabgrass Killer & Weed Preventer	432-958              
ornamentals (residential), turf (residential)

Preclaim Herbicide	432-959              	ornamentals, rights-of-way,
turf

Triway + Phenoxaprop Ready-to-Spray Herbicide	72155-62	turf
(residential)

Triway + Fenoxaprop Concentrate Herbicide	72155-63	turf (residential)

Triway + Phenoxaprop Ready-to-Use Herbicide	72155-66	turf (residential)

Crabgrass Killer R-T-S Herbicide	72155-74	ornamentals (residential),
turf (residential)

Bayer Advanced Lawn Herbicide 3F Concentrate	72155-77	turf (residential)

Bayer Advanced Lawn Herbicide 3F Ready-to-Use	72155-78	turf
(residential)

2. INTEGRATION OF AVAILABLE INFORMATION

The risk assessments that serve as the basis for this problem
formulation include the following (for details, see Appendix B):

1 Section 3 New Use (S3NU) Risk Assessment of proposed uses on wheat,
soybeans, cotton, peanuts, and conservation reserves (DP barcode 164986;
Feb. 14, 1996)

1 Drinking Water Assessment (DP barcode 239618; Oct. 3, 1997)

4 Section 18 Risk Assessments for uses on barley and rice from 1997 to
2001

1 Section 18 Risk Assessment (DP barcode 338410+) for use on grass grown
for seed in 2007

3. ECOLOGICAL EFFECTS

Registrant submitted data for exposures of aquatic and terrestrial
organisms to FPE are available.  At this time, several data gaps exist
for the toxicity of FPE to aquatic and terrestrial organisms. In order
to fill these data gaps, available data for fenoxaprop-ethyl will be
used in this ecological risk assessment.  Available toxicity data for
fenoxaprop-ethyl indicate that the racemic mixture has similar acute
toxicity to aquatic organisms when compared to FPE (Appendix C).  In
this assessment, it will be assumed that the R- and S-enantiomers are of
equivalent toxicities.  In cases where toxicity data are available for
both FPE and fenoxaprop-ethyl, the most conservative endpoint (i.e. the
lowest toxicity value) will be used, regardless of whether or not it
relates to FPE or fenoxaprop-ethyl, for deriving RQs for FPE.  Toxicity
data for aquatic and terrestrial organisms that will be used in deriving
RQs are defined below.  The full set of available ecological effects
data for FPE and fenoxaprop-ethyl, including data from additional
studies, is described in Appendix D.  In some cases, only draft DERs are
available for ecotoxicity studies.  These data are considered
provisional at this time.  Data are also available for exposures of
organisms to formulated products containing FPE or fenoxaprop-ethyl. 
These data will not be considered quantitatively in this assessment.

The ECOTOXicology database (ECOTOX), was searched in order to provide
additional ecological effects data.  No data were located in ECOTOX for
FPE.  For fenoxaprop-ethyl, toxicity data are available for aquatic (30
records) and terrestrial (107 records) organisms.  These data will be
evaluated at a later time for their possible value added to this risk
assessment.

3.1. Effects to aquatic organisms

On an acute exposure basis, FPE is considered very highly toxic (LC50
<0.1 mg/L) to estuarine/marine invertebrates, highly toxic (LC50 0.1-1
mg/L) to freshwater fish, and moderately toxic (LC50 >1-10 mg/L) to
freshwater invertebrates and estuarine/marine fish.  Provisional chronic
toxicity data for rainbow trout indicate a NOEC of 0.022 mg/L. 
Available chronic toxicity data for mysid shrimp indicate a NOEC of
0.01095 mg/L.  FPE is moderately toxic (LC50 >1-10 mg/L) to aquatic
vascular plants and highly toxic (EC50>0.1-1 mg/L) to aquatic
non-vascular plants.  Summaries of the most sensitive data from
submitted aquatic toxicity data for FPE are located in Table 2.  

Table 2.  Summary of most sensitive endpoints of submitted toxicity
studies for aquatic organisms exposed to FPE.  All data are relevant to
exposures of organisms to FPE, unless otherwise noted (by “**”).

Species

(common name)	Taxa Represented	End-point	Duration

(hours)	 Mean concentration (mg a.i./L)	Study Classification	Ref. (MRID)

Lepomis macrochirus

(Bluegill Sunfish)	Freshwater fish and amphibians	LC50	96	  0.31**	
Acceptable	00130337

Oncorhynchus mykiss

(Rainbow Trout)

NOEC	91 (days)	0.022*	Provisional	44786801

LOEC

0.036*

Daphnia  magna

(Water Flea)	Freshwater Invertebrates 	EC50	48	 >1.058 	 Supplemental
44664002

Cyprinodon variegatus

(Sheepshead minnow)	Estuarine/ Marine Fish	LC50	96	>1.0**	 Supplemental 
00163779

Mysidopsis bahia

(Mysid shrimp)	Estuarine/ Marine Invertebrates	LC50	96	0.098** 
Acceptable	00163777

NOEC	28 (days)	0.01095	Provisional	44786802

LOEC

0.03265

Lemna gibba

(duckweed)	Aquatic vascular plants  	EC50	14 (days)

 	 >3.00 	

 Supplemental	44664003

NOEC

3.00 

Selenastrum capricornutum (Green algae)	Aquatic non-vascular plants	EC50
120	0.43	

Supplemental	42009609

NOEC

0.027

* Based on nominal concentrations.

**Based on exposures of organisms to fenoxaprop-ethyl

No data are available to characterize chronic exposures of freshwater
invertebrates or estuarine/marine fish to either FPE or
fenoxaprop-ethyl.  In light of these data gaps, the Acute to Chronic
Ratio (ACR) approach will be used to estimate the chronic toxicity of
FPE to these organisms.  Available toxicity data for mysid shrimp
exposed to FPE include a 96-h LC50 of 0.107 mg/L and a 28 day NOEC of
0.01095 mg/L.  The result is an ACR of 9.77 for invertebrates. 
Application of this ratio to available acute toxicity data for daphnia
(>1.058 mg/L), results in an estimated chronic NOEC value of 0.108 mg/L.
 Available toxicity data for rainbow trout exposed to FPE include a 96-h
LC50 of 0.46 mg/L and a 91 day NOEC of 0.022 mg/L.  The result is an ACR
of 20.9 for fish.  Application of this ratio to available acute toxicity
data for sheepshead minnow (>1.0 mg/L), results in an estimated chronic
NOEC value of 0.0478 mg/L.  Given that the available acute toxicity
values for freshwater invertebrates and estuarine/marine fish are
indiscreet, there is uncertainty associated with the estimated NOAEC
values defining the effects of chronic exposures to these organisms.

3.2. Effects to terrestrial organisms

Data are available to assess the toxicity of FPE to terrestrial plants. 
A tier 1 seedling emergence test with dicot species (carrot, soybean,
cabbage, lettuce, tomato and cucumber) yielded an EC25 >0.1 lb a.i./A. 
As expected based on the target organisms (i.e. grasses) of this
herbicide, FPE was more toxic to monocots in a seedling emergence test. 
Corn was the most sensitive of the tested monocots, with an EC25 and
NOEC of 0.002 and <0.0006 lbs a.i./A, respectively.  No toxicity data
were submitted to assess the effects of FPE to the vegetative vigor of
dicots.  Available vegetative vigor toxicity data for monocots indicated
corn as the most sensitive monocot species tested, with EC25 and NOEC of
0.0025 and <0.0006 lbs a.i./A, respectively.  These data are summarized
in Table 3.

Table 3.  Summary of submitted toxicity studies for terrestrial
organisms exposed to FPE.

Species 

(common name)	Measure of effect	End-point	Mean Concentration	Test
Substance (% a.i.)	Study Classification	Reference (MRID)

Dicot	Seedling Emergence

(Tier 1)	EC25	>0.1 lb a.i./a	7.2 (D-isomer)	Acceptable	41276904

Corn	Seedling Emergence (Tier 2)	EC25	0.002 lbs a.i./A	7.2 (D-isomer)
Acceptable	41276905

NOEC	<0.0006 lbs a.i./A

	Corn	Vegetative vigor    (Tier 2)	EC25	0.0025 lbs a.i./A	7.2	

Acceptable	41276907

NOEC	<0.0006 lbs a.i./A

	

No data are available at this time to characterize the effects of
exposures of FPE to birds, mammals or to terrestrial invertebrates;
however, these data are available for fenoxaprop-ethyl.  Therefore,
available data for fenoxaprop-ethyl are used to fill these data gaps. 
Equivalent toxicities of FPE and fenoxaprop-ethyl are presumed for both
mammals and birds.

Fenoxaprop-ethyl (and thus, FPE) is classified practically nontoxic to
mammals (LD50 >2000 ppm), birds (LD50 >2000 mg/kg, LC50 >5000 mg/kg),
and terrestrial insects (LD50 >11µg/bee) on an acute exposure basis. 
Chronic exposures to rats in a reproduction study indicate a NOAEL for
reproduction and parental effects of 5 ppm (0.25 mg/kg/day).  Chronic
exposures to bobwhite quail in reproduction studies indicate effects to
hatching, with a NOAEC of 30 ppm.  No data are available to assess the
toxicity of exposures of fenoxaprop-ethyl to terrestrial plants. 
Summaries of the most sensitive data from submitted terrestrial toxicity
data for fenoxaprop-ethyl are located in Table 4.  

Table 4.  Summary of submitted toxicity studies for terrestrial
organisms exposed to fenoxaprop-ethyl.  Since it is assumed that FPE and
fenoxaprop-ethyl are of equivalent toxicities to these organisms, these
values are utilized for estimating the toxicities of FPE.

Species 

(common name)	Taxa Represented	End-point	Mean Concentration	Test
Substance (% a.i.)	Study Classification	Reference (MRID)

Rattus norvegicus (laboratory rat)	Terrestrial mammals	LD50	2357 mg/kg
(males)

2500 mg/kg (females)	Technical	Acceptable	00130010

00130011

NOAEL	5 ppm 

(0.25 mg/kg/day)	97.2	Acceptable	0014847

LOAEC	30 ppm*

(1.5 mg/kg/day)

	Anas platyrhynchos

(Mallard Duck)	Birds, terrestrial phase amphibians and reptiles 

 

 

 	LC50	>5620 ppm	96.6±0.9	Acceptable	00130333

Colinus virginianus

(Northern Bobwhite Quail)

LD50	>2510 mg/kg	96.6±0.9	Acceptable	00130330

LC50	>5620	96.6±0.9	Acceptable	00130334

NOAEC	30 ppm	95.5	Acceptable	00155304

LOAEC	180 ppm**

	Apis mellifera

(Honey Bee)	Terrestrial invertebrates	LD50	>100 µg/bee	Technical
Acceptable	00130641

*Based on decreased blood lipids in parent, and reduced pup body
weights.

**Based on effects to hatching.

4. INCIDENT REPORTS

The Agency has received 78 reports of adverse field effects to
non-target plants that have been linked to the use of FPE.  All of these
incidents involved damage to a grain crop (barley, corn, rice, or
wheat).  The Agency considered the cause to be uncertain in 39 cases
because more than one herbicide was applied to the crop.  In the
remaining 36 cases, the Agency considers FPE to be the probable cause. 
Most of the incidents were reports of crop damage that occurred
following application of the herbicide directly to the crop, although
three incidents occurred from carryover effects of applications made to
another crop in a previous growing season.  None of the incidents
involved damage to crops or other plants outside the treatment site.  

The Agency has received one report linking FPE to adverse field effects
to wild animals.  In 1998, Approximately 200 fish died in a pond in
White County, Illinois  following application of FPE, along with two
other herbicides (fluazifop-p-butyl and fomesafen sodium), on a nearby
soybean field.  Because FPE is highly toxic to fish and was applied in
close proximity to the pond, the Agency believes that exposure to this
herbicide was a probable cause or contributing factor to the fish
mortality.

The Agency has received no report of adverse field effects to non-target
animals or plants that have been attributed to the use of
fenoxaprop-ethyl.  The Agency also has no incident report from pesticide
registrants concerning fenoxaprop-ethyl contamination of ground or
surface water.

A lack of reported incidents does not necessarily mean that such
incidents have not occurred.  In addition, incident reports for
non-target plants and animals typically provide information on mortality
events only.  Reports for other adverse effects, such as reduced growth
or impaired reproduction, are rarely received.

5. EXPOSURE CHARACTERISTICS

FPE residues bioconcentrate in fish and can be moderately mobile in
soil.  The majority of the environmental fate and transport data
submitted for FPE are provisional and currently in review.  The
submitted data indicate that, as an ester, FPE rapidly de-esterifies
(t1/2 range = 1-3 days) to fenoxaprop-p acid (AE F088406,
(D+)-2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy] propanoate), which is
also biologically active (USEPA, 1997).  The environmental fate and
transport data set submitted for fenoxaprop-p acid is poor, consisting
of a hydrolysis study conducted at 50-65°C with extrapolated values for
environmental temperatures (MRID 44659603) and a batch equilibrium study
(MRID 44768101), both of which are in review.  

For current assessments, exposure is assessed in terms of the residues
of concern of fenoxaprop-p-ethyl, which include the parent (AE F046360),
fenoxaprop-p acid (AE F088406), and the hydrolytic product AE F054014
(USEPA, 2007).  FPE residues of concern are expected to degrade slowly,
as they are stable to photolysis, hydrolyze with a half-life of 269 to
717 days, and biodegrade with a half-life of 4-9 months under a range of
conditions.  However, a provisional rice paddy dissipation study
indicated that residues of FPE dissipated with a half-life of 3.6 days
before the paddy was reflooded.

Environmental fate-related data submitted in support of the no longer
supported racemic mixture, fenoxaprop-ethyl (PC code 128701), will not
be used in current assessments because the environmental fate
characteristics of the two mixtures have not been bridged.  Chemical
properties of FPE and environmental fate parameters of FPE and its
residues of concern are listed in Table 5.



Table 5.  General chemical properties and environmental fate parameters
of fenoxaprop-p-ethyl (based on provisional sources).

Chemical/Fate Parameter	Value	Source

Chemical name
(D+)-ethyl-2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]propanoate	MRID
44676401 (provisional)

Molecular mass	361.8 g/mol	MRID 44676401 (provisional)

Vapor pressure (20(C)	1.4 x 10-8 torr	Acc. # 412-03-0113

Water solubility  (pH 5.8; 20(C)	0.7 mg/L	MRID 44676401 (provisional)

Octanol-water partition coefficient (KOW)	38,000	MRID 44659601

Fish Bioconcentration Factor	129 (edible)

1021 (non-edible)

510 (whole fish)	MRID 41567707

Soil-water distribution coefficient (Kd) 1; Organic carbon partitioning
coefficient (KOC)1	12.6 L/kg; 5420 L/kgOC

176 L/kg; 6670 L/kgOC

213 L/kg; 26200 L/kgOC

443 L/kg; 17400 L/kgOC	MRID 42915001 (provisional)

Total residues Freundlich soil-water distribution coefficient (KF) 2;
Total residues Freundlich organic carbon partitioning coefficient (KFOC)
2	4.10 (1/n=1.00); 1770L/kgOC

5.91 (1/n=1.00); 223 L/kgOC

6.55 (1/n=1.00); 807 L/kgOC

9.77 (1/n=1.00); 383 L/kgOC	MRID 42915001 (provisional)

Hydrolysis half-life; Total residues half-life

(pH 5, 25(C)	37.5 d; 269 d	MRID44659602 (provisional)

Hydrolysis half-life; Total residues half-life

(pH 7, 25(C)	75.1 d; 717 d

	Hydrolysis half-life; Total residues half-life

(pH 9, 25(C)	5.64 d; 649 d

	Aqueous photolysis half-life	No evidence of degradation	MRID 44676401
(provisional)

Aerobic soil metabolism half-life;

Total residues half-life	2.5 d; 188 d	MRID 43400602 (provisional)

Anaerobic aquatic metabolism half-life;

Total residues half-life	0.44 d, <1 d; 

116 d, 267 d	MRID 45081601 (provisional)

Terrestrial field dissipation half-life;

Total residues half-life	<1 d; 3.6 d	MRID 43066404 (provisional)

1 Point estimates at 0.35 ppm dosing concentration.

2 1/n is the Freundlich exponent that describes curvilinearity.

5.1 Transport and mobility

FPE is partially soluble in water, dissolving at 0.7 mg/L at 20(C and pH
5.8 (MRID 44676401).  The compound is not expected to volatilize
significantly due to its low vapor pressure of 1.4 x 10-8 torr (20(C;
Acc. # 412-03-0113).  The octanol-water partition coefficient of FPE is
38,000 (MRID 44659601), which is indicative of the relatively high
bioconcentration factor (BCF) observed in fish viscera (1021x) relative
to the BCF observed in edible fish portions (129x; MRID 41567707).  The
BCF for whole fish portions was 510x, which does not exceed reporting
thresholds for concern for bioconcentration (64 FR 58665, Oct. 29,
1999).

FPE is slightly to hardly mobile (Kd of 12.6 to 443); however, its
degradates fenoxaprop-p acid and AE F054014 are mobile (Kd of 1.8 to 25
and 2.0 to 3.8, respectively), according to a provisional batch
equilibrium study (MRID 42915001).  Therefore, FPE total residues of
concern (TRC), which include FPE and these two degradates, are
moderately mobile overall.  The mobility of the FPE combined residues of
concern is of interest relative to that of FPE alone due to the rapid
degradation of FPE; Freundlich soil-water partitioning coefficients (KF)
for the combined residues calculated within the same provisional batch
equilibrium study range from 4.10 (1/n=1.00) to 9.77 (1/n=1.00) (MRID
42915001).  Mobility of the total residues is not well explained by
affinity to organic matter, as the coefficient of variation (CV) across
four soils for KFOC (87%) is greater than that for KF (36%).  In
general, compounds, such as fenoxaprop-p acid and HOE 054014, with KF
values less than five are mobile enough to potentially present a ground
water concern in some soils.

A provisional study specifically on fenoxaprop-p acid appears to confirm
that it has greater mobility than FPE (KF range = 1.17 (1/n=0.88) to
8.76 (1/n=0.73); MRID 44768101).

5.2 Degradation

FPE is hydrolyzed moderately in acidic conditions (t½ = 37.5 d at pH
5), slowly in neutral conditions (t½ = 75.1 d at pH 7), and quickly in
alkaline conditions (t½ = 5.64 d at pH 9; MRID 44659602).  Three major
hydrolysis degradates were identified: fenoxaprop-p acid, AE F054014
(6-chloro-2,3-dihydro-benzoxazol-2-one), and AE F096918
(2-(4-hydroxyphenoxy)propanoate).  Fenoxaprop-p acid is the primary
degradate at up to 63.6% of applied radioactivity in the hydrolysis
study (14 days after treatment (DAT); MRID 44659602); both FPE and
fenoxaprop-p acid may hydrolyze to AE F054014, which was observed in the
hydrolysis study at up to 35.8% of the applied (21 DAT); fenoxaprop-p
acid moderately hydrolyzes to both AE F054014 and AE F096918 at equal
molar amounts; AE F096918 was observed at up to 42.0% of the applied (64
DAT) in the anaerobic aquatic metabolism study (MRID 45081601).  There
is no evidence of degradation of FPE by photolysis (MRID 44676401).

FPE was quickly biodegraded in aerobic soils (t½ = 2.5 d; MRID
43400602) and in anaerobic aquatic systems (t½ < 1 d; MRID 45081601). 
The four major degradates observed in the these two metabolism studies
were fenoxaprop-p acid at up to 65.8% and 100.8% of the applied (2-3
DAT), AE F096918 at up to 42.0% of the applied (64 DAT) in the anaerobic
aquatic metabolism study, M3 (an unidentified degradate in the aerobic
soil metabolism study) at up to 10.2% of the applied (59 DAT), and
carbon dioxide at up to 14.5% (98 DAT) and 29.9% (238 DAT) of the
applied, in the aerobic soil metabolism and anaerobic aquatic metabolism
studies, respectively.

5.3 Field studies

A terrestrial and aquatic field dissipation study of FPE was conducted
with the end use product Whip® (HOE 46360 75 EW; MRID 43066404). 
Whip® was broadcast at 0.41 lbs a.i./A onto subplots of clay loam soil
in a drained rice patty in California with rice seedlings grown to the
1- to 4-leaf stage.  At 4 DAT, the paddy was flooded with 6 inches of
canal water and flood irrigated through 60 DAT.  Soil samples (0-12 inch
depth) were collected through 60 DAT.  The limit of quantitation for
residues of FPE was 10 ppb (10 µg/kg); samples containing ≥50 ppb of
FPE residues were analyzed for individual compounds.  FPE residues of
concern (FPE, fenoxaprop-p acid, and AE F054014) dissipated in the
drained soil (0-3 inch depth) with a half-life of 3.6 days.  This
dissipation rate is faster than expected regarding the degradation rates
in the submitted fate and transport studies; therefore, there is some
uncertainty as to whether the major routes of dissipation for this
compound have been well characterized.

FPE residues were detected at a maximum concentration of 350 ppb (15% of
the applied concentration; 0-3 inch depth, 0.04 DAT) and at a maximum
depth of 6 inches.  FPE residues were not detected above the limit of
quantitation in flood water.  FPE parent was detected at a maximum
concentration of 60 ppb (0-3 inch depth; 1-2 DAT); fenoxaprop-p acid was
detected at a maximum concentration of 270 ppb (0-3 inch depth; 0.4
DAT); AE F054014 was detected at a maximum concentration of 70 ppb (0-3
inch depth; 4 DAT).  Maximum depths of FPE parent, fenoxaprop-p acid,
and AE F054014 were not reported.

5.4 Degradates

Major degradates of FPE include fenoxaprop-p acid, AE F054014, AE
F096918, M3 (an unidentified compound), and carbon dioxide (chemical
names and structures are tabulated in Appendix E).  One minor degradate
has been identified, AE F040356 (4-(6-chloro-2-benzoxazolyloxy)phenol). 
FPE and its major degradates containing the 6-chloro-2-benzoxazol moiety
(fenoxaprop-p acid and AE F054014) are residues of concern for dietary
risk assessment and, therefore, for mammals (USEPA, 2007).  Toxicity
data specific to the two degradates of concern are unavailable.  In the
absence of data, the FPE degradates of concern are assumed to have
similar toxicity to FPE parent.  Therefore, a total residues of concern
(TRC) approach will be used for current drinking water exposure
assessment and aquatic ecological risk assessment to evaluate the
potential exposure of humans and aquatic taxa to the residues of risk
concern, i.e., FPE, fenoxaprop-p acid, and AE F054014.

6. CHARACTERISTICS OF ECOSYSTEMS POTENTIALLY AT RISK

For FPE and pesticides in general, the ecosystems at greatest risk are
those in close proximity to the use areas.  These would include
agricultural fields growing barley, cotton, peanuts, rice, soybeans and
wheat, as well as conservation reserves, rights-of-way, container- and
field-grown ornamentals, golf courses, sod farms, other turf areas
(e.g., athletic fields), residential areas and water bodies directly
adjacent to use sites that may receive chemical residues via drift,
runoff, and/or discharged ground water.  Within water bodies, the water
column, sediments, and pore water are all compartments of concern. 
Organisms of concern include birds, mammals, reptiles, fish, amphibians,
terrestrial and aquatic invertebrates, and plants.  The assessment
endpoints are intended to reflect population sustainability and
community structure within ecosystems and hence relate back to
ecosystems at risk.  If risks are expected for given species/taxa based
on the screening-level assessment, then risks might be expected to
translate to higher levels of biological organization.

7. ASSESSMENT ENDPOINTS

Assessment endpoints are defined as “explicit expressions of the
actual environmental value that is to be protected.”  Defining an
assessment endpoint involves two steps: 1) identifying the valued
attributes of the environment that are considered to be at risk; and 2)
operationally defining the assessment endpoint in terms of an ecological
entity (i.e., a community of fish and aquatic invertebrates) and its
attributes (i.e., survival and reproduction).  Therefore, selection of
the assessment endpoints is based on valued entities (i.e., ecological
receptors), the ecosystems potentially at risk, the migration pathways
of pesticides, and the routes by which ecological receptors are exposed
to pesticide-related contamination.  The selection of clearly defined
assessment endpoints is important because they provide direction and
boundaries in the risk assessment for addressing risk management issues
of concern.  Changes to assessment endpoints are typically estimated
from the available toxicity studies, which are used as the measures of
effects to characterize potential ecological risks associated with
exposure to a pesticide, such as FPE.

To estimate exposure concentrations, an ecological risk assessment
considers application(s) at the maximum application rate to use sites
that have vulnerable soils.  The most sensitive toxicity endpoints are
used from surrogate test species to estimate treatment-related direct
effects on acute mortality and chronic reproductive, growth and survival
assessment endpoints.  Guideline toxicity tests are intended to
determine effects of pesticide exposure on birds, mammals, fish,
terrestrial and aquatic invertebrates, and plants.  The toxicity studies
are used to evaluate the potential of a pesticide to cause adverse
effects, to determine whether further testing is required, and to
determine the need for precautionary label statements to minimize the
potential adverse effects to non-target animals and plants.  

8. CONCEPTUAL MODEL

The conceptual model used to depict the potential ecological risk
associated with FPE assumes that FPE is capable of affecting aquatic and
terrestrial organisms provided environmental concentrations are
sufficiently elevated as a result of proposed label uses.  However,
through a preliminary iterative process of examining fate and effects
data, the conceptual model, i.e., the risk hypothesis, has been refined
to reflect the exposure pathways and the organisms for which risk is
most likely.  Based on a preliminary risk screening and past assessments
indicating that FPE is highly toxic to freshwater fish on an acute
exposure basis and causes potential effects in mammals and birds when
chronically exposed, the hypothesis for the risks of FPE to non-target
animals (depicted in Figure 1) focuses on both aquatic and terrestrial
environments.  Therefore, exposure as a result of direct spray, spray
drift, granules, and runoff will be considered.  Risk to aquatic plants
is also considered in this screening-level assessment.  For terrestrial
animals, the major route of exposure considered is the dietary route;
consumption of food items such as plant leaves or insects that have FPE
residues as a result of spraying and drift.  For aquatic animal species,
the major routes of exposure are considered to be via the respiratory
surface (gills) or the integument.  Aquatic plants may be exposed via
direct uptake and adsorption.

Estimated exposure concentrations (EEC) for all organisms are obtained
through the use of several Agency exposure models.  EECs modeled for the
preliminary risk screen and the 2007 Section 18 risk assessment used
degradation half-lives calculated for the collective residues of risk
concern in the submitted environmental fate studies.  As shown in Table
5, hydrolysis half-lives increased from short—moderate values for FPE
alone to relatively persistent values counting TRC and aerobic soil
metabolism and anaerobic aqueous metabolism half-lives increased from
rapid values for FPE alone to approaching persistent values counting
TRC.

8.1. Risk Hypothesis

Risk hypotheses are specific assumptions about potential adverse effects
(i.e., changes in assessment endpoints) and may be evaluated on theory
and logic, empirical data, mathematical models, or probability models
(USEPA, 2004).  For this assessment, the risk is stressor-initiated,
where the stressor is the release of FPE to the environment.  The
following risk hypothesis is presumed for this screening level
assessment:

Based on the application methods, mode of action, and the sensitivity of
non-target aquatic and terrestrial species, FPE has the potential to
reduce survival, reproduction, and/or growth in terrestrial and aquatic
organisms.

In order for a chemical to pose an ecological risk, its residues of
concern must reach non-target organisms at concentrations found to cause
adverse effects.  The exposure pathway is the way by which a pesticide
moves in the environment from the application site to non-target
organisms.  The assessment of ecological exposure in this assessment
includes an examination of the source and potential migration pathways
for FPE residues of concern, and the determination of potential exposure
routes to non-target species.

8.2. Diagram  tc "2.  Diagram " \l 3 

Application methods for the use of FPE involve spray using ground or
aerial equipment.  Ecological receptors that may potentially be exposed
to FPE include terrestrial and semi-aquatic wildlife (i.e., mammals,
birds, amphibians, terrestrial invertebrates, reptiles and plants).  In
addition, aquatic receptors (e.g., freshwater and estuarine/marine fish
and invertebrates, amphibians, and aquatic plants) may also be exposed
as a result of potential migration of FPE via spray drift and/or runoff
from the site of application to various aquatic environments.  These
data form the basis for identifying potential endpoints, stressors, and
ecological effects associated with FPE use (Figure 1).

 

Figure 1.  Conceptual model of the transport and effects of FPE in the
environment.  Dotted lines indicate exposure routes that were considered
and not thought to contribute significantly to the fate and transport of
FPE.

9. ANALYSIS PLAN OPTIONS

In Registration Review, pesticide ecological risk assessments will
follow the Agency’s Guidelines for Ecological Risk Assessment, will be
in compliance with the paper titled “Overview of the Ecological Risk
Assessment Process in the Office of Pesticide Programs, U.S.
Environmental Protection Agency” (“Overview Document”; USEPA,
2004), and will be done in accordance with Section 7 of the Endangered
Species Act.

A review of previously completed screening level risk assessments
indicate that screening level assessments of acute and chronic risk to
non-target organisms has not been completed for all uses.  Based on
toxicity data and Risk Quotients (RQs) described in the Section 18
assessment for grass grown for seed in Oregon (the most recent
ecological assessment available), there are potential effects to mammals
and birds from chronic exposures to FPE in terrestrial habitats, when
applied at the proposed label rates.  The proposed application rate for
grass grown for seed (0.0825 lbs a.i./A/year) is lower than or similar
to the maximum application rates on the current labels for all other
uses (see Table 6).  Furthermore, due to a lack of toxicity data,
potential risks to aquatic organisms, birds, and beneficial insects have
not previously been assessed by the Agency.  Appendix B shows the
current status of risk assessments for registered uses of FPE.

9.1. Discussion of Assumptions and Uncertainties

In addition to conducting screening level assessments (and refined
assessments, if necessary) for all FPE uses, other uncertainties and
potential paths forward are described below.

Maximum yearly application rates could not be determined based on
information provided on product labels for all uses.  In the absence of
label clarifications, assumptions will be made in the ecological risk
assessments according to the information in Table 6.

Table 6.  Assumptions related to maximum rates per application, number
of applications per year, intervals between applications, and maximum
number of seasons per year for FPE.

Use	Max Application Rate per Application (lbs a.i./A)	Max # of
Applications Per Season 	Min application Interval (days)	 Max # of
Seasons Per Year

 Barley	 0.0825	 1	NA	 1

 Conservation Reserve	 0.126	 NS	NS	 26*

 Cotton	 0.126	1 	NA	1 

 Ornamental	 0.092	 NS	NS	26*

Peanuts	0.126	1	NA	1

Rice	0.0713	2	14	2

Right-of-Way	0.178	3	14	2

Soybeans	0.128	1	NA	1

Turf	0.178	3	14	2

Wheat	0.084	1	NA	2

NS = not specified

NA = not applicable

* It is assumed that it is possible to apply every 14 days.

Available product labels identified maximum application rates per
season, not per year.  Table 6 also includes assumptions related to the
maximum number of seasons per year.

Since multiple crops to which FPE can be applied can be rotated on the
same field within the same year (e.g. barley and wheat; peanuts and
cotton), it is possible to have multiple season applications of FPE.

The following amendments are recommended for improving label clarity:

All labels should be amended to define the maximum rate per application
for each use, as well as the maximum number of applications per year in
accordance with CFR 156.10 (i)(2). 

Several labels indicate “recommended” application rates.  This
language should be altered to read “maximum application rates.”

On several labels, including 72155-62, 72155-63, 72155-66, 72155-74,
72155-77 and 72155-78, the density of FPE per product (e.g. lbs FPE per
gallon) should be cited. 

See Appendix A for label specific details. 

It will be assumed that aerial and ground methods of application can be
employed for all uses, excluding residential uses.

No data are available for assessing the responses of an estuarine/marine
fish species to exposures to FPE.  In the absence of these data,
available data for the exposures of fenoxaprop-ethyl to sheepshead
minnow (MRID 00163779) will be used.

No acute, sub-acute or chronic toxicity data are available for exposures
birds to FPE.  In the absence of these data, available data for the
exposures of fenoxaprop-ethyl to mallards and quail (MRIDs 00130333,
00155305, 00130330, 00130334 and 00155304) will be used.

No acute or chronic toxicity data are available for exposures of mammals
to FPE.  In the absence of these data, available data for the exposures
of fenoxaprop-ethyl to laboratory rats (MRIDs 00130010, 00130011,
0014847) will be used.

No data are available for assessing the responses of beneficial
terrestrial insects to exposures to FPE.  In the absence of these data,
available data for fenoxaprop-ethyl exposures to the honey bee (MRID
00130641) will be used.

Several toxicity studies have been submitted in relation to the effects
of FPE to aquatic organisms.  At this time, only draft DERs are
available.  Therefore, there is uncertainty in which data will be used
for risk estimation.

No data are available for assessing the responses of freshwater
invertebrates and estuarine/marine fish to chronic exposures of FPE.  In
the absence of these data, the ACR method will be used to estimate NOEC
values for these taxa.

9.2. Preliminary Assessment of Exposure and Risks

Preliminary estimated environmental concentrations (EECs) were
calculated for aquatic habitats using the GENEEC2 Model.  EECs relevant
to terrestrial animals and plants were calculated using T-REX (v. 1.3.1)
and TerrPlant (v.1.2.2), respectively (see APPENDICES F and G for
details).  

Based on preliminary aquatic EECs and the assumptions discussed above,
acute and chronic risks at the highest labeled application rate are
expected for non-listed and listed aquatic animals.  Risks are also
expected for non-listed and listed birds and terrestrial mammals due to
chronic dietary based or dose based exposures to FPE.  Risks are
expected as well for non-listed and listed species of monocots
inhabiting semi-aquatic and dry areas based on exposures of FPE
originating from the maximum application rate.  Because of the potential
risk from direct effects to the listed and non-listed taxa described
above, should exposure occur, listed species in all taxa may potentially
be affected indirectly due to alterations in their habitat (e.g., food
sources, shelter, and areas to reproduce).

If the planned ecological risk assessment continues to indicate that FPE
may potentially impact, either directly or indirectly, listed species or
critical habitat, and therefore does not support a “no effect”
determination, further refinements will be made.  This will involve
determining whether use of FPE is “likely to adversely affect” the
species, or in the case of designated critical habitat, whether use of
the pesticide may destroy or adversely modify any principle constituent
elements for the critical habitat, and if so, whether the expected
impacts are “likely to adversely affect” the critical habitat.  The
first step in the process is to improve the exposure estimates based on
refining the geographic proximity of FPE’s use and the listed species
and/or critical habitat.  If there is no geographic proximity, this
information would support a determination that FPE use will have no
effect on the species or critical habitat.  If after conducting the
first step of this analysis the Agency determines that geographic
proximity exists, both potential direct effects and any potential
indirect effects of the pesticide use will be examined.  This process is
consistent with the Agency's Overview Document.  The Agency will consult
as necessary with the U.S. Fish and Wildlife Service and National Marine
Fisheries Service (collectively ‘the Services’), consistent with the
Services' regulations.

If the screening level risk assessment identifies potential concerns for
indirect effects on listed species, the next step for EPA and the
Services would be to identify which listed species and critical habitat
are potentially implicated.  Analytically, the identification of such
species and critical habitat can occur in either of two ways.  First,
the agencies could determine whether the action area overlaps critical
habitat or the occupied range of any listed species.  If so, EPA would
examine whether FPE’s potential impacts on non-endangered species
would affect the listed species indirectly or directly affect a
constituent element of the critical habitat.  Alternatively, the
agencies could determine which listed species depend on biological
resources, or have constituent elements that fall into, the taxa that
may be directly or indirectly impacted by FPE.  Then EPA would determine
whether the use of FPE overlaps the critical habitat or the occupied
range of those listed species.

9.3. Anticipated Data Needs

EFED is awaiting review of the majority of submitted environmental fate
studies for FPE before recommending the request of any additional
environmental fate data.

As stated above, there is uncertainty associated with the use of
toxicity studies involving fenoxaprop-ethyl to represent effects of
organisms to FPE.  Although there is evidence to suggest that FPE and
fenoxaprop-ethyl are of similar acute toxicities to aquatic organisms,
there are currently no data to compare effects of FPE and
fenoxaprop-ethyl to terrestrial animals.  When this assessment is
conducted, if there is a lack of data for exposures of mammals and birds
FPE, available data for fenoxaprop-ethyl will be used.  However,
availability of toxicity data for mammals and birds exposed to FPE would
decrease uncertainties associated with assuming that the two isomers are
of equivalent toxicities to these organisms.  EFED recommends requiring
acceptable toxicity studies of mammals and birds exposed to FPE.  EFED
is particularly interested in data related to chronic exposures
(reproductive toxicity studies), since effects were observed in studies
where mammals and birds were exposed to fenoxaprop-ethyl (MRIDs 00014847
and 00155304).

 

The Agency will also conduct a search of the open literature to ensure
that the best available science is utilized.  The Agency uses the ECOTOX
(www.epa.gov/ecotox) database as its mechanism for searching the open
literature for ecological effects information.  ECOTOX integrates three
previously independent databases - AQUIRE, PHYTOTOX, and TERRETOX - into
a system which includes toxicity data derived predominately from the
peer-reviewed literature, for aquatic life, terrestrial plants, and
terrestrial wildlife, respectively.  ECOTOX utilizes specific screening
criteria to ensure consistent data quality for OPP risk assessment
purposes.

9.4. Other Information Needs

There is specific information that will assist the Agency in refining
the ecological risk assessment, including any species-specific effects
determinations.  The Agency is interested in obtaining the following
information:

confirmation on the following label information

sites of application

formulations

maximum application rates

frequency of application, application intervals, and maximum number of
applications per season

geographic limitations on use

use or potential use distribution (e.g., acreage and geographical
distribution of relevant uses)

use history

median and 90th percentile reported use rates (lbs. a.i./acre) from
usage data – national, state, and county

application timing (date of first application and application intervals)
by use – national, state, and county

sub-county crop location data

usage/use information for non-agricultural uses (e.g., golf courses,
athletic fields, ornamentals)

directly acquired county-level usage data (not derived from state level
data)

maximum reported use rate (lbs. a.i./acre) from usage data – county

percent crop treated – county

median and 90th percentile number of applications – county

total pounds per year – county

The analysis plan will be revisited and may be revised depending upon
the data available in the open literature and the information submitted
by the public in response to the opening of the Registration Review
docket.

10. REFERENCES

Martin, H. 2000. Herbicide mode of action categories. Ontario Ministry
of Agriculture, Food and Rural Affairs. ISSN 1198-712X. Available online
at: http://www.omafra.gov.on.ca/english/crops/facts/00-061.htm#lipid.

USEPA. 1997. Section 18 for the Use of Fenoxaprop-p-ethyl (Tiller EC) on
Barley in North Dakota. DP barcode 236605, 236606. U.S. Environmental
Protection Agency, Office of Pesticide Programs. EFED memorandum to RD.
Jul. 10, 1997.

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the
Office of Pesticide Programs. U.S. Environmental Protection Agency,
Office of Prevention, Pesticides and Toxic Substances, Office of
Pesticide Programs, Washington DC. January 23, 2004.

USEPA. 2007. Personal email communication with Michael Doherty, Health
Effects Division.  May 23, 2007.

Submitted Studies

Acc. # 412-03-0113.  Moraski, R.  1983.  EAB Review of 8340 – EUP –
T.  HED memorandum, Nov. 3, 1983.  HED Records Center Series 361 Science
Reviews – File R038903.  52 p.

MRID 130010. Hollander; Weigand (1982) Acute Oral Toxicity of HOE 33171
O H AT203 (Active Ingredient Techn.) to the Male Rat: Report No. 576/79;
A24696. (Translation; unpublished study received Aug 4, 1983 under
8340-EX-7; prepared by Hoechst AG, W. Ger., submitted by American
Hoechst Corp., Somerville, NJ; CDL:071787-B)

MRID 130011. Hollander, Weigand (1982) Acute Oral Toxicity of HOE 33171
O H AT203 (Active Ingredient Techn.) to the Female Rat: Report No.
577/79; A24698. (Translation; unpublished study received Aug 4, 1983
under 8340-EX-7; prepared by Hoechst AG, W. Ger., submitted by American
Hoechst Corp., Somerville, NJ; CDL: 071787-C)

MRID 130330. Fink, R.; Beavers, J. (1982) Acute Oral LD50: Bobwhite
Quail: HOE-33171 OH AT 203: Project No. 125-129. Final rept. (Un-
published study received Aug 4, 1983 under 8340-EX-7; prepared by
Wildlife International, Ltd., submitted by American Hoechst Corp.,
Somerville, NJ; CDL:071796-C)

MRID 130333. Fink, R.; Beavers, J. (1982) Eight-day Dietary LC50:
Mallard Duck: HOE-33171 OH AT 203: Project No. 125-128. Final rept. (Un-
published study received Aug 4, 1983 under 8340-EX-7; prepared by
Wildlife International, Ltd., submitted by American Hoechst Corp.,
Somerville, NJ; CDL:071796-F)

MRID 130334. Fink, R.; Beavers, J. (1982) Eight-day Dietary LC50:
Bobwhite Quail HOE-33171 OH AT 203: Project No. 125-127. Final rept.
(Unpublished study received Aug 4, 1983 under 8340-EX-7; pre- pared by
Wildlife International, Ltd., submitted by American Hoechst Corp.,
Somerville, NJ; CDL:071796-G)

MRID 130641. Atkins, E. (1982) Bee Adult Toxicity Dusting Test Summary:
Summary Sheet No. 729. (Unpublished study received Aug 4, 1983 under
8340-EX-7; prepared by Univ. of Calif. Riverside, Dept. of Entomology,
submitted by American Hoechst Corp., Somerville, NJ; CDL:071796-Q)

MRID 148474. Tesh, J.; Willoughby, C.; Whitney, J. (1985) Effects Upon
Reproduc- tive Performance of Rats Treated Continuously Throughout Two
Successive Generations: Vols I, II, and III: Report No. 84/HAG087/636.
Unpublished study prepared by Life Science Research. 1552 p.

MRID 155304. Roberts, N.; Phillips, C.; Anderson, A.; et al. (1985) The
Effects of Dietary Inclusion of Hoe 033171--Active Ingredient Technical
(Code: HOE 033171 OH ZD96 0001) on Reproduction in the Bobwhite Quail:
HRC Report No. HST 243/85162. Unpublished Hoechst report A31296 prepared
by Huntingdon Research Centre plc. 221 p.

MRID 163779. McAllister, W.; Swigert, J.; Bowman, J. (1986) Acute
Toxicity of HOE 33171 Technical Substance to Sheepshead Minnows
(Cyprinodon variegatus): Amended Static Acute Toxicity Rept. #33977. Un-
published study prepared by Analytical Bio-Chemistry Laborato- ries,
Inc. 60 p.

MRID 41276904. Chetram, R. (1989) Tier 1: Seed Germination/Seedling
Emergence: Nontarget Phytotoxicity Study: HOE-046360: Lab Project
Number: LR88/110B. Unpublished study prepared by Pan-Agricultural
Laboratories, Inc. 155 p.

MRID 41276905. Chetram, R. (1989) Tier 2: Seed Germination/Seedling
Emergence Nontarget Phytotoxicity Study: HOE-046360: Lab Project Number:
LR89/14B. Unpublished study prepared by Pan-Agricultural Laboratories,
Inc. 134 p.

MRID 41276907. Chetram, R. (1989) Tier 2: Vegetative Vigor Nontarget
Phytotoxicity Study: HOE-046360: Lab Project Number: LR89/14A.
Unpublished study prepared by Pan-Agricultural Laboratories, Inc. 13 p.

MRID 42009604. Fischer, R. (1986) The Effect of HOE 046360: Substance,
Technical ... Salmo gairdneri (Rainbow Trout) in a Static Acute Toxicity
Test (Sg347/a, Method EPA): Lab Project Number: A33683: OEK 86- 092E.
Unpublished study prepared by Hoechst AG. 20 p.

MRID 42009607. Murphy, D.; Peters, G. (1991) Technical
Fenoxaprop-p-Ethyl (...): A 96-Hour Flow-ThroughAcute Toxicity Test with
the Saltwater Mysid (Mysidopsis bahia): Lab Project Number: 125A-101A.
Unpub- lished study prepared by Wildlife International Ltd. 66 p.

MRID 42009609. Heusel, R. (1991) Fenoxaprop-P-Ethyl: Substance,
Technical (...): Effect to Selenastrum capricornutum (Green Alga) in an
Algal Assay Bottle Test (Method EPA): Lab Project Number: A45608:
A46010. Unpublished study prepared by Hoechst AG. 55 p.

MRID 42915001. Reynolds, J.  1992.  Adsorption and Desorption of
14C-Fenoxaprop-p-ethyl in Four Soils.  Lab. project # 91063. 
Unpublished study performed by XenoBiotic Laboratories, Inc., Princeton,
NJ; submitted by Hoechst Celanese Corporation, Somerville, NJ.  Sep. 17,
1992 (revised Aug. 15, 1993).  144 p.

MRID 43066404.  Carringer, R. and J. O’Grodnick.  Aquatic Dissipation
of HOE 46360 75EW [Whip® 360 Herbicide] (Fenoxaprop-p-ethyl) Applied to
Rice in California.  Lab. Study # 91-0028 (AASI), 91-0016 (EAL). 
Unpublished study performed by American Agricultural Services, Inc.,
Cary, NC and EN-CAS Analytical Laboratories, Winston-Salem, NC;
submitted by Hoechst Celanese Corporation, Somerville, NJ.  Dec. 8,
1993.  300 p.

MRID 43400602.  Buttner, B.  1992.  HOE 046360-chlorophenyl-U-14C:
Aerobic Soil Metabolism Study at 11 and 21 °C.  Lab. study # CB91/017. 
Unpublished study performed by Hoechst Aktiengesellschaft, Frankfurt am
Main, Germany; submitted by AgrEvo USA Company, Wilmington, DE.  Jan.
23, 1992.  79 p.

MRID 44659601.  Schollmeier, M., U. Eyrich, and A. Uhl.  1992.  HOE
046360, (Fenoxaprop-p-ethyl); Determination of the Partition Coefficient
n-Octanol/Water.  Lab. study # CP92/131.  Unpublished study performed by
Hoechst AG, Frankfurt am Main, Germany; submitted by AgrEvo USA Company,
Wilmington, DE.  Nov. 11, 1992.  22 p.

MRID 44659602.  Reynolds, J.  1993.  HOE 046360 (Fenoxaprop-p-ethyl):
Hydrolysis of [14C] Fenoxaprop-p-ethyl in Water at pH 5, 7, and 9.  Lab.
study # 93091.  Unpublished study performed by XenoBiotic Laboratories,
Inc., Plainsboro, NJ; submitted by AgrEvo USA Company, Wilmington, DE. 
May 25, 1993.  122 p.

MRID 44659603.  Schollmeier, M. and U. Eyrich.  1993.  Free Acid
Metabolite of HOE 046360 (Fenoxaprop-p-ethyl): Determination of the
Abiotic Hydrolysis as a Function of pH.  Lab. study # CP93/009. 
Unpublished study performed by Hoechst Schering AgrEvo GmbH, Frankfurt
am Main, Germany; submitted by AgrEvo USA Company, Wilmington, DE.  Aug.
11, 1993.  99 p.

MRID 44664002. Stachura, B.; Ruff, D. (1998) Fenoxaprop-p-ethyl
Technical 88.1% w/w: Code: AE F04636000 1C97 0002: The 48 Hour Acute
Toxicity to Daphnia magna, in a Static Renewal System:Lab Project
Number: BMM98W514: A67511: AZ 06135. Unpublished study prepared by
AgrEvo USA Company. 48 p.

MRID 44664003. Christ, M.; Ruff, D. (1997) Fenoxaprop-p-ethyl Technical
88.1% w/w: Code: AE F046360 00 1C97 0002: The Toxicity to Duckweed
(Lemna gibba), in a Static Renewal System: Lab Project Number: BM9W502:
A57845: AZ 07051. Unpublished study prepared by AgrEvo USA Company. 56
p.

MRID 44676401.  Schwab, W.  1993.  HOE 046360-14C, Photodegradation of
Fenoxaprop-p-ethyl in Surface Water, Sterile Water, and Distilled Water.
 Lab. study # CP91/035.  Unpublished study performed by Hoechst
Aktiengesellschaft, Frankfurt am Main, Germany; submitted by AgrEvo USA
Company, Wilmington, DE.  Sep. 28, 1993.  151 p.

MRID 44768101.  1999.  Rupprecht, J.  The Adsorption/Desorption of [14C]
AE F088406 on Six Soils and One Sediment.  Lab. study # BM98E501. 
Unpublished study performed by AgrEvo USA Company, Pikeville, NC;
submitted by AgrEvo USA Company, Wilmington, DE.  Feb. 22, 1999.  70 p.

MRID 415677077.  Wink, O. and R. Fischer.  1987.  HOE 046360-14C:
Flow-through Bioaccumulation and Metabolism Study with Bluegill Sunfish,
(Lepomis macrochirus).  Lab. study # CM010/87 & Lm27/a.  Unpublished
study performed by Hoechst AG, Frankfurt am Main, Germany; submitted by
Hoechst Celanese Corporation, Somerville, NJ.  Oct. 30, 1987.  83 p.

MRID 44786801. Stachura, B.; Ruff, D. (1999) Fenoxaprop-p-ethyl
Technical: Effects on Early Life Stages of Rainbow Trout, Oncorhynchus
mykiss: Lab Project Number: BM98W513: C002144.Unpublished study prepared
by AgrEvo Research Center. 168 p.

MRID 44786802. Boeri, R.; Magazu, J.; Ward, T. (1999) Fenoxaprop-p-ethyl
Technical: The 28 Day Chronic Toxicity to the Mysid, Mysidopsis bahia in
a Flow Through System: Lab Project Number: C002140: 1656-AG: BM98W519.
Unpublished study prepared by T.R. Wilbury Laboratories, Inc. 85 p.

MRID 45081601.  Volkel, W.  2000.  14C-AE F046360/14C-AE F033171:
Degradation and Metabolism in an Anaerobic Aquatic System.  Lab. project
# 725040.  Unpublished study performed by RCC Ltd., Itingen,
Switzerland; submitted by Hoechst Schering AgrEvo GmbH, Frankfurt am
Main, Germany.  Mar. 2, 2000.  114 p.

APPENDIX A:  Current FPE Registrations and Uses, Including Maximum
Application Rates and Application Timing.

Use	Label	Application Method	Application timing	Application Interval
(days)	Maximum Application Rate/Ap (lbs a.i./A)	Max # aps/year	Comments

Barley	264-666	ground, aerial	from emergence to 5 leaf stage	NA	0.0825
1*	 

Conservation Reserve (set aside)	264-647	ground, aerial	Not specified
Not specified	0.07125	Not specified	 

Conservation Reserve (set aside)	264-650               	ground, aerial
Not specified	Not specified	0.126	Not specified	 

Cotton	264-650               	ground, aerial	Not specified	NA	0.126	1*
Label states that the user can make 2 applications per season for a
maximum of 1.5 pints product per season. The maximum single application
rate allowed by the label corresponds to 1.5 pints product per season. 

Cotton	100-1059	ground, aerial	"before, during or after planting or
after harvest of soybeans or cotton"	NA	0.105	1*	Applications allowed
in: AL, AR, FL, GA, LA, MS, MO, NC, NM, OK, SC, TN, TX, VA

Ornamental - residential	432-958              	ground***	to young,
actively growing weeds	Not specified	0.092	Not specified	 

Ornamental	432-957              	ground, aerial**	preemergence to 3
tiller	NA	0.09	1*	 

Ornamental	432-959              	ground, aerial**	to young, actively
growing weeds	NA	0.09	1*	 

Ornamental	432-950	ground, aerial**	when weeds emerge	14	0.089	6*	 

Ornamental - residential	72155-74	ground***	Not specified	Not specified
0.075	Not specified	Application rate determined using product density
defined on MSDS.

Peanuts	264-650               	ground, aerial	Not specified	NA	0.126	1*
Label states that the user can make 2 applications per season for a
maximum of 1.5 pints product per season. The maximum single application
rate allowed by the label corresponds to 1.5 pints product per season. 

Rice	264-647	ground, aerial	see label	14	0.07125	2*	 

Rice	264-682	ground, aerial	can be applied to rice from 2 leaf stage to
late tillering stage	14	0.068	2*	Maximum single application rate is not
specified. 2 applications per season are permitted for a total of 0.136
lbs a.i./a.

Right-of Way	432-950	ground, aerial**	when weeds emerge	14	0.178	3*
Label gives recommended single application rates, with a maximum of 39
oz.  Maximum single application rate in this table is relevant to 40 oz
application. The total application per season is 120 oz (0.534 lbs
a.i./A), which could conservatively be the maximum single application
rate. 

Right-of Way	432-957              	ground, aerial**	preemergence to 3
tiller	NA	0.09	1*	 

Right-of Way	432-959              	ground, aerial**	to young, actively
growing weeds	NA	0.09	1*	 

Right-of Way	100-1059	ground, aerial	Not specified	Not specified	0.039
Not specified	 

Soybeans	264-647	ground, aerial	see label	NA	0.128	1*	 

Soybeans	264-650               	ground, aerial	Not specified	NA	0.126	1*
Label states that the user can make 2 applications per season for a
maximum of 1.5 pints product per season. The maximum single application
rate allowed by the label corresponds to 1.5 pints product per season. 

Soybeans	100-1059	ground, aerial	"before, during or after planting or
after harvest of soybeans or cotton"	NA	0.105	1*	Applications allowed
in: AL, AR, CT,DE, FL, GA,ID, IL, In, IA, KS, KY, LA, ME, MD, MA, MI,
MN, MS, MO, MT, NE, NH, NJ, NY, NC, ND, OH, KO, OR, PA, RI, SC, SD, TN,
TX, VT, VA, WA, WV, WI, WY

Turf	432-950	ground, aerial**	when weeds emerge	14	0.178	3*	Label gives
recommended single application rates, with a maximum of 39 oz.  Maximum
single application rate in this table is relevant to 40 oz application.
The total application per season is 120 oz (0.534 lbs a.i./A), which
could conservatively be the maximum seasonal application rate. 

Turf	432-957              	ground, aerial**	preemergence to 3 tiller	NA
0.09	1*	 

Turf	432-959              	ground, aerial**	to young, actively growing
weeds	NA	0.09	1*	 

Turf - residential	432-958              	ground***	to young, actively
growing weeds	Not specified	0.092	Not specified	 

Turf - residential	72155-74	ground***	Not specified	Not specified	0.075
Not specified	Application rate determined using product density defined
on MSDS.

Turf - residential	72155-62	ground***	Not specified	Not specified	Not
specified	Not specified	 

Turf - residential	72155-63	ground***	Not specified	Not specified	Not
specified	Not specified	 

Turf - residential	72155-66	ground***	Not specified	Not specified	Not
specified	Not specified	 

Turf - residential	72155-77	ground***	Not specified	Not specified	Not
specified	Not specified	 

Turf - residential	72155-78	ground***	Not specified	Not specified	Not
specified	Not specified	 

Wheat	264-650               	ground, aerial	3 leaf to tillering stage in
wheat	NA	0.084	1*	For use in TX and OK only. 

Wheat	264-666	ground, aerial	from emergence to 70 days from harvest	NA
0.0825	1*	 

Wheat	264-655             	ground, aerial	3 leaf to 6 leaf stage in
wheat	NA	0.0388	1*	 

*Maximum number of applications of maximum application rate per SEASON.

**Application method is not defined.	 	 	 	 	 	 

***It is assumed that since this product is intended for residential
uses (including small volume applications), applications will be made by
ground methods.

APPENDIX B:  Past Ecological Risk Assessments for FPE.

DATE	COMPOUND	TYPE OF ACTION	USE(S)	POTENTIAL RISK IDENTIFIED	SUMMARIZED
ECOLOGICAL CONCLUSIONS

2-14-1996	FPE	S3NU	Wheat, soybeans, cotton, peanuts, conservation
reserve	Yes	Potential risk to terrestrial plants, including 10 listed
plants.

7-10-1997	FPE	§18	Barley in North Dakota	Yes	Minimal risk to animals;
risk to terrestrial plants.  Insufficient data on aquatic plants.

10-3-1997	FPE	DWA	All	N/A	N/A

4-28-1998	FPE’s safener	§18	Barley in North Dakota	Yes	Low risk to
mammals, birds, fish, aquatic invertebrates and aquatic plants from
safener.  No expected unacceptable risk to listed species.

3-25-1999	FPE	§18	Rice in Arkansas	Yes	Risk only to terrestrial plants.
 No endangered species concerns.

2-2-2001	FPE & its safener	§18	Rice in Arkansas and Louisiana	Yes
Little risk to non-target animals.  Potential risk to terrestrial
plants, including 3 listed dicots in AR.

6-25-2007	FPE	§18	Grass for seed in Oregon	Yes	Chronic risk to mammals;
no listed mammals identified.  Risk to semi-aquatic monocots and listed
terrestrial monocots; 1 listed monocot identified.

APPENDIX C:  Comparison of available ecotoxicity data for FPE and
fenoxaprop-ethyl.

Data are available for 4 aquatic species for comparison of the effects
of FPE and fenoxaprop-ethyl exposure to the same species.  Acute
exposures of aquatic organisms to FPE and fenoxaprop-ethyl result in
similar EC50 values, generally being on the same order of magnitude
(Table C.1).  When considering all acute exposure toxicity data for
aquatic animals (fish and invertebrates), FPE and fenoxaprop-ethyl are
classified highly to moderately toxic to these organisms (Figure C.1). 
References for these toxicity data are identified in Appendix D.

TABLE C.1.  Comparison of available aquatic toxicity data for FPE and
fenoxaprop-ethyl.  Units in mg a.i./L.

Species

(common name)	End-point	Duration

(hours)	FPE	Fenoxaprop-ethyl

Lepomis macrochirus

(Bluegill Sunfish)	LC50	96	0.58	0.31

Daphnia magna      (waterflea)	EC50	48	>1.058	3.18

Mysidopsis bahia

(Mysid shrimp)	LC50	96	0.107-0.109	0.098

Selenastrum capricornutum (Green algae)	EC50	120	0.43	0.65

	

Figure C.1.  Acute toxicity data (EC50s) for aquatic animals exposed to
FPE or fenoxaprop-ethyl. 

*freshwater fish; **freshwater invertebrates; ***estuarine/marine fish;
****estuarine/marine invertebrates

APPENDIX D:  Registrant submitted effects data for TGAI FPE and
Fenoxaprop-ethyl.

Available aquatic toxicity data for FPE and fenoxaprop-ethyl are
presented in Tables D.1 and D.3, respectively.  Available terrestrial
toxicity data for FPE and fenoxaprop-ethyl are presented in Tables D.2
and D.4, respectively. 

TABLE D.1.  Summary of submitted toxicity studies for aquatic organisms
exposed to FPE (PC 129092). Endpoints are based on measured test
concentrations, except where noted.

Species

(common name)	Measure of Effect	End-point	Duration

(hours)	Mean conc, units in       mg a.i./L

(95% c.i.)	Test substance

(% a.i.)	Study Classification	Ref. (MRID)

Freshwater Fish

Lepomis macrochirus

(Bluegill Sunfish)	Mortality	LC50	96	0.58**	95.6	Acceptable	42009603

Oncorhyncus mykiss

(Rainbow Trout)	Mortality	LC50	96	0.46**	95.6	Acceptable	42009604

	Mortality	LC50	96	0.58**	95.6	Supplemental	42009605

	Length and wet weight	NOEC	91 (days)	0.022**	88.1	Draft DER	44786801

LOEC

0.036**

	Freshwater Invertebrates

Daphnia  magna

(Water Flea)	Immobility	EC50	48	>1.058	88.1	Supplemental	44664002

	Immobility	EC50	48	2.7**	95.6	Invalid	42009606

Estuarine/Marine Invertebrates

Mysidopsis bahia

(Mysid shrimp)	Mortality	LC50	96	0.107	89.5	Acceptable	42009607

	Dry Weight	NOEC	28 (days)	0.01095	88.1	Draft DER	44786802

LOEC

0.03265

	Aquatic Plants

Lemna gibba

(duckweed)	Frond number

	EC50	14 (days)

	>3.00	88.1	

Supplemental	44664003

NOEC

3.00

	Navicula pelliculosa

(Freshwater diatom)	% Inhibition	EC50	96	2.5	88.1	Draft DER	44768105

NOEC

1.6

	Skeletonema costatum        (Marine diatom)	% Inhibition	EC50	96	>0.8
88.1	Draft DER	44768104

NOEC

0.38

	Anabaena flos-aquae

(Blue-green algae)	% Inhibition	EC50	96	>0.78	88.1	Draft DER	44768103

NOEC

	Selenastrum capricornutum (Green algae)	% Inhibition	EC50	120	0.43	97.4
Supplemental	42009609

NOEC

0.027

	** Based on nominal concentrations.

TABLE D.2.  Summary of submitted toxicity studies for terrestrial plants
exposed to FPE (PC 129092).

Species

(common name)	Measure of effect	End-point	Mean Concentration

(C.I.)	Test Substance (% a.i.)	Study Classification	Reference (MRID)

Carrot, soybean, cabbage, lettuce, tomato, cucumber	Seedling Emergence

(Tier 1)	EC25	>0.1 lb a.i./A	7.2 (D-isomer)	Acceptable	41276904

Corn, oat, ryegrass, onion	Seedling Emergence (Tier 1)	EC25	<0.1 lb
a.i./A	7.2 (D-isomer)	Acceptable	41276904

Corn	Seedling Emergence (Tier 2)	EC25	0.002 lbs a.i./A	7.2 (D-isomer)
Acceptable	41276905

NOEC	<0.0006 lbs a.i./A

	Oat	Seedling Emergence (Tier 2)	EC25	0.0096 lbs a.i./A	7.2 (D-isomer)
Acceptable	41276905

NOEC	<0.0006 lbs a.i./A

	Ryegrass	Seedling Emergence (Tier 2)	EC25	0.0578 lbs a.i./A	7.2
(D-isomer)	Acceptable	41276905

NOEC	<0.0240 lbs a.i./A

	Onion	Seedling Emergence (Tier 2)	EC25	N/A	7.2 (D-isomer)	Acceptable
41276905

NOEC	>0.0960 lbs a.i./A

	Corn	Vegetative vigor    (Tier 2)	EC25	0.0025 lbs a.i./A	7.2	Acceptable
41276907

NOEC	<0.0006 lbs a.i./A

	Oat	Vegetative vigor    (Tier 2)	EC25	0.0779 lbs a.i./A	7.2	Acceptable
41276907

NOEC	N/A

	Ryegrass	Vegetative vigor    (Tier 2)	EC25	0.0817 lbs a.i./A	7.2
Acceptable	41276907

NOEC	<0.0480 lbs a.i./A

	

TABLE D.3.  Summary of submitted toxicity studies for aquatic organisms
exposed to fenoxaprop-ethyl (PC 128701).

Species

(common name)	Measure of Effect	End-point	Duration

(hours)	 Mean conc, units in       mg a.i./L

(95% c.i.)	% a.i.	Study Classification	Ref. (MRID)

Freshwater Fish

Lepomis macrochirus

(Bluegill Sunfish)	Mortality	LC50	96	0.31      (0.26-0.35)	95.8
Acceptable	00130337

Lepomis gibbosus

(pumpkinseed Sunfish)	Mortality	LC50	96	0.36      (0.32-0.41)	96.0
Acceptable	00130338

Salmo trutta    (brown trout)	Mortality	LC50	96	0.48      (0.45-0.52)
96.0	Acceptable	00130335

Idus melanotus (golden orfe)	Mortality	LC50	96	>0.8	Technical	Invalid
00130340

Freshwater Invertebrates

Daphnia  magna

(Water Flea)	Immobility 	EC50	48	3.18      (1.79-7.36) 	  96.0 
Acceptable  	00130342

Procambarus simulans      (crayfish)	Mortality	LC50	96	1.1       
(0.74-1.5)	96.5	Supplemental	00154343

Estuarine/Marine Fish

Cyprinodon variegatus

(Sheepshead minnow)	Mortality	LC50	96	>1.0 	  96.5 	 Supplemental 
00163779

Estuarine/Marine Invertebrates

Mysidopsis bahia

(Mysid shrimp)	Mortality 	LC50	96	0.098 

(0.068-0.15)	 96.5   	Acceptable  	00163777

Mysidopsis bahia

(Mysid shrimp)	Mortality 	LC50	96	 0.107 	96.8   	Acceptable 	42009608

Crassostrea virginica       (Eastern oyster)	Immobility	EC50	48	0.25

(0.15-0.38)	96.5	Supplemental	00163775

Mercenaria mercenaria    (Quahog clam)	Immobility	EC50	48	0.20     
(0.11-0.35)	96.5	Acceptable	ACC: 40404702

Aquatic Plants

Selenastrum capricornutum (Green algae)	% Inhibition	EC50	7 (days)	731.9

(227.7-6093.2)  	 96.5	

  Acceptable	  Acc: 40404704

	% Inhibition	EC50	5 (days)	0.65  	 96.8	

  Acceptable	42009610

NOEC

 0.104

	* Draft DER available.

** Based on nominal concentrations.

*** Not listed in OPPIN under this PC code.



TABLE D.4.  Summary of submitted toxicity studies for terrestrial
organisms exposed to fenoxaprop-ethyl (PC 128701).

Species 

(common name)	Measure of effect	End-point	Mean Concentration

(C.I.)	Test Substance (% a.i.)	Study Classification	Reference (MRID)

Mammals

Rattus norvegicus (laboratory rat)	Mortality	LD50	2357 mg/kg (males)

2500 mg/kg (females)	Technical	Acceptable	00130010

00130011

	Reproduction	NOAEL	5 ppm 

(0.25 mg/kg/day)	97.2	Acceptable	0014847

LOAEL	30 ppm

(1.5 mg/kg/day)

	Birds

Anas platyrhynchos

(Mallard Duck)	Mortality	LD50	>2510 mg/kg	96.6±0.9	Invalid	00130329

	Mortality	LC50	>5620 ppm	96.6±0.9	Acceptable	00130333

	Reproduction	NOAEC	180 ppm              (highest test conc.)	95.5

	Acceptable

	00155305

LOAEC	>180 ppm

	Japanese Quail (male)	Mortality	LD50	>5000 mg/kg	Technical	Supplemental
00130331

Japanese Quail (female)	Mortality	LD50	>5000 mg/kg	Technical
Supplemental	00130332

Colinus virginianus

(Northern Bobwhite Quail)	Mortality	LD50	>2510 mg/kg	96.6±0.9
Acceptable	00130330

	Mortality	LC50	>5620	96.6±0.9	Acceptable	00130334

	hatching	NOEC	30 ppm	95.5	Acceptable	00155304

LOEC	180 ppm

	Terrestrial Invertebrates

Apis mellifera

(Honey Bee)	Mortality	LD50	>100 µg/bee	Technical	Acceptable	00130641

APPENDIX E:  Chemical Names, Structures, and Maximum Reported Amounts
of Fenoxaprop-p-ethyl and its Degradates.

Table E.1.    SEQ CHAPTER \h \r 1 Maximum Reported Amounts of
Fenoxaprop-p-ethyl Degradation Products.

  SEQ CHAPTER \h \r 1 Degradate	  SEQ CHAPTER \h \r 1 Maximum % of
Applied	Study Type	MRID

AE F088406	63.6 (14 d)

65.8 (3 d)

100.8 (2 d)	Hydrolysis

Aerobic soil metabolism

Anaerobic aquatic metabolism	MRID 44659602

MRID 43400602

MRID 45081601

AE F0540141	35.8 (21 d)

8.2 (168 d)

2.8 (27 d)	Hydrolysis

Aqueous photolysis

Anaerobic aquatic metabolism	MRID 44659602

MRID 44676401

MRID 45081601

AE F040356	4.9 (168 d)

6.8 (14 d)

5.5 (97 d)	Aqueous photolysis

Aerobic soil metabolism

Anaerobic aquatic metabolism	MRID 44676401

MRID 43400602

MRID 45081601

AE F096918	42.0 (64 d)	Anaerobic aquatic metabolism	MRID 45081601

M1 (multiple compounds)	12.4 (168 d)	Aqueous photolysis	MRID 44676401

M2 (unidentified)	6.4 (168 d)	Aqueous photolysis	MRID 44676401

M3 (unidentified)	10.2 (59 d)	Aerobic soil metabolism	MRID 43400602

M4 (unidentified)	3.3 (7 d)	Aerobic soil metabolism	MRID 43400602

M5 (unidentified)	4.9 (168 d)	Aqueous photolysis	MRID 44676401

CO2	14.5 (98 d)

29.9 (238 d)	Aerobic soil metabolism

Anaerobic aquatic metabolism	MRID 43400602

MRID 45081601

Unextracted residues	60.3 (98 d)

58.5 (163 d)	Aerobic soil metabolism

Anaerobic aquatic metabolism	MRID 43400602

MRID 45081601

1 AE F054014 accounted for up to 20.7% of the applied in unextracted
residues during the aerobic soil metabolism study (MRID 43400602).



Table E.2.  Chemical Names and Structures of Fenoxaprop-p-ethyl and its
Degradates.

Chemical Name	Structure

AE F046360

(D+)-ethyl-2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]propanoate

Fenoxaprop-p-ethyl	

AE F088406

(D+)-2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]propanoate

Fenoxaprop-p	

AE F054014

6-chloro-2,3-dihydro-benzoxazol-2-one	

AE F040356

4-(6-chloro-2-benzoxazolyloxy)phenol	

AE F096918

2-(4-hydroxyphenoxy)propanoate	

APPENDIX F:  Preliminary EECs for aquatic habitats and RQs for aquatic
organisms.

Table F.1.  Agency Levels of Concern (LOCs).

Risk Presumption	Taxa	LOC

Acute Risk	Birds, mammals, aquatic animals	0.5

	Plants	1

Acute Restricted Use	Birds, mammals	0.2

	Aquatic animals	0.1

Acute Endangered Species	Birds, mammals	0.1

	Aquatic animals	0.05

	Plants	1

Chronic Risk	Birds, mammals, aquatic animals	1

Input parameters, justifications, and source references for the GENEEC2
(Mar. 9, 2006) model appear in Table F.2 for the maximum use patterns of
FPE listed in Table F.3.

Table F.2.  GENEEC2 Input Parameters for Maximum Use Patterns of FPE.

Input Parameter	Value	Justification	Source

Kd (mL/g)	4.10	Represents the lowest total residue Kd for a non-sand
soil.	MRID 42915001 (provisional)

Aerobic soil metabolism half-life (days)	564	Represents 3 times a single
total residue half-life.	MRID 43400602 (provisional)

Wetted in?	No	Label directions	Current labels

Application method	Aerial	Label directions	Current labels

Solubility in water (ppm)	0.7	Represents the measured water solubility
value for FPE.	MRID 44676401 (provisional)

Aerobic aquatic metabolism

half-life (days)	1128	Represents 2 times the aerobic soil metabolism
half-life input value in the absence of data and with near stability of
total residues to hydrolysis.	N/A

Aqueous photolysis half-life (days)	Stable	Represents the single
environmental phototransformation half-life for total residues.	MRID
44676401 (provisional)

Table F.3.  Preliminary Tier I Aquatic Estimated Environmental
Concentrations (EEC) of FPE Residues of Concern, Reported in µg/L
(Calculated using GENEEC2).

Use pattern	Max. Annual App. Rate (lbs a.i./acre)	Peak EEC	Max. 4-day
Mean EEC	Max. 21-day Mean EEC	Max. 60-day Mean EEC	Max. 90-day Mean EEC

Barley	0.0825	3.33            	3.32     	3.28   	3.18	3.11

Conservation Reserve	3.276 

(assuming 26 app/yr)	111	110	109	106	103

Conservation Reserve	0.378 

(assuming 3 app/yr) 	15.2	15.2	15.0	14.5	14.2

Cotton, Peanuts	0.126	5.08	5.07	5.00	4.86	4.75

Ornamental	2.392 (assuming 26 app/yr)	80.7	80.5	79.5	77.2	75.5

Rice	0.1426 (assuming 2 app/yr)	83.9	83.9	83.9	83.9	83.9

Right-of-Way	1.068 (assuming 6 app/yr)	41.5	41.4	40.9	39.7	38.8

Soybeans	0.128	5.16	5.15	5.08	4.93	4.83

Turf	1.068 (assuming 6 app/yr)	39.8	39.8	39.2	38.1	37.2

Wheat	0.168 (assuming 2 app/yr)	6.47	6.45	6.37	6.18	6.04

At the Tier I screening level, preliminary acute RQs exceed the listed
LOC for freshwater fish from use on conservation reserves, ornamentals,
rice, rights-of-way, and turf; for freshwater invertebrates and
estuarine/marine fish from use on conservation reserves, ornamentals,
and rice; and for listed estuarine/marine invertebrates from all labeled
uses other than barley (Table F.4).

Table F.4.  Preliminary RQs for acute exposures of aquatic organisms to
FPE (exceedances in bold).1

Use pattern	 FW Fish	FW Invertebrates	 EM Fish	EM Invertebrates 

Barley	0.0107	0.00315	0.00333	0.0340

Conservation Reserve (26 app)	0.358	0.105	0.111	1.13

Conservation Reserve (3 app)	0.0490	0.0144	0.0152	0.155

Cotton	0.0164	0.00480	0.00508	0.0518

Ornamental	0.260	0.0763	0.0807	0.823

Peanuts	0.0164	0.00480	0.00508	0.0518

Rice	0.271	0.0793	0.0839	0.856

Right-of-Way	0.134	0.0392	0.0415	0.423

Soybeans	0.0166	0.00488	0.00516	0.0526

Turf	0.128	0.0376	0.0398	0.406

Wheat	0.0209	0.00612	0.00647	0.0660

1 EECs were based on peak values reported in Table F.3; toxicity values
were reported in Table 2.

At the Tier I screening level, preliminary chronic RQs exceed the LOC
for all aquatic animals at the highest labeled annual application rate
of FPE (0.126 lbs a.i./A @ 26 applications per year on conservation
reserves) (Table F.5).  Preliminary chronic RQs exceed the LOC for
freshwater fish and estuarine/marine invertebrates from use on
conservation reserves, ornamentals, rice, rights-of-way, and turf; for
freshwater invertebrates from use on conservation reserves; and for
estuarine/marine fish from use on conservation reserves, ornamentals,
and rice.

Table F.5.  Preliminary RQs for chronic exposures of aquatic organisms
to FPE (exceedances in bold).1

Use pattern	 FW Fish	 FW Invertebrates	 EM Fish	EM Invertebrates 

Barley	0.145	0.0304	0.0665	0.300

Conservation Reserve (26 app)	4.82	1.01	2.22	9.95

Conservation Reserve (3 app)	0.659	0.139	0.303	1.37

Cotton	0.221	0.0463	0.102	0.457

Ornamental	3.51	0.736	1.62	7.26

Peanuts	0.221	0.0463	0.102	0.457

Rice	3.81	0.777	1.76	7.66

Right-of-Way	1.80	0.379	0.831	3.74

Soybeans	0.224	0.0470	0.103	0.464

Turf	1.73	0.363	0.797	3.58

Wheat	0.281	0.0590	0.129	0.582

1 For fish, EECs were based on 60-day values reported in Table F.3.  For
invertebrates, EECs were based on 21-day values reported in Table F.3. 
Toxicity values were reported in Table 2.  As discussed in the effects
section, the ACR method was used to derive toxicity value.

APPENDIX G:  Preliminary EECs for terrestrial habitats and RQs for
terrestrial organisms.

G.1. Terrestrial animals

T-REX is used to calculate dietary and dose-based EECs of FPE for
mammals and birds.  Input values for T-REX are located in Table G.1. 
Upper-bound Kenega nomogram values are utilized to derive EECs for
triticonazole exposures to terrestrial mammals and birds based on
dietary- and dose-based exposures (Table G.2).  The maximum exposure
scenario allowed by the labels, which applies to uses on turf, is used
to characterize exposures to mammals and birds.  A 1-year time period is
simulated.  Because label rates indicate a maximum use scenario (i.e. 3
applications of 0.178 lbs a.i./A) per season, not per year, only one
season is modeled.  Because multiple seasons of turf are possible, EECs
and RQs resulting from this modeling approach would result in an
underestimation of exposure of terrestrial mammals and birds to FPE.
Consideration is given to different types of feeding strategies for
mammals and birds, including herbivores, insectivores and granivores. 
For dose-based exposures, three weight classes of mammals (15, 35 and
1000 g) and birds (20, 100, and 1000 g) are considered.  Toxicity values
used to define effects to mammals and birds from acute and chronic
exposures are described in the effects characterization section of this
document.  Due to a lack of data specific to FPE, effects data for
fenoxaprop-ethyl are used for derivation of RQs. 

Table G.1.  Input parameters for deriving terrestrial EECs for FPE using
T-REX.

      Parameter Description 	Value

FPE maximum Application Rate (lbs a.i./A)	0.178

Half-life (days)	351

Application Interval (days)	14 

Number of Applications	32

1 default value

2Only one season is modeled.

Table G.2.  T-REX calculated EECs of FPE on food residues.

Food Type	Dietary Based 

(ppm)

(mammals and birds)	Dose Based 

(mg/kg-bw)

(mammals)	Dose Based 

(mg/kg-bw)

(birds)

	All Size Classes	Small 

(15 g)	Medium 

(35 g)	Large 

(1000 g)	Small 

(15 g)	Medium 

(35 g)	Large 

(1000 g)

Short Grass 	99.6	95.0	65.7	15.2	113	64.7	29.0

Tall Grass	45.7	43.5	30.1	6.98	52.0	29.7	13.3

Broadleaf plants/sm insects	56.0	53.4	36.9	8.56	63.8	36.4	16.3

Fruits/pods/lg insects	6.23	5.94	4.10	0.95	7.09	4.04	1.81

Seeds (granivore)	6.23	1.32	0.91	0.21	7.09	4.04	1.81

Acute dose-based RQs are derived using the reported LD50 2357 mg/kg. 
The LOC is not exceeded for acute, dose-based exposures of mammals to
FPE (Table G.3).  Chronic dietary-based RQs are derived using the
reported NOAEC of 5 ppm (mg/kg-diet).  Chronic dose-based RQs are
calculated using the NOAEL of 0.25 mg/kg-bw/day.  For chronic
dietary-based and dose-based exposures, the LOC for non-listed and
listed species is exceeded for all mammal size classes and all mammal
feeding categories (Table G.4). 

Table G.3.  Acute RQs for mammals of different size and feeding classes.

Food Type	Dose Based

	Small (15 g)	Medium (35 g)	Large (1000 g)

Short Grass 	0.02	0.02	0.01

Tall Grass	0.01	0.01	<0.01

Broadleaf plants/sm insects	0.01	0.01	<0.01

Fruits/pods/lg insects	<0.01	<0.01	<0.01

Seeds (granivore)	<0.01	<0.01	<0.01

Table G.4.  Chronic RQs for mammals of different size and feeding
classes. 

Food Type	Dietary Based	Dose Based

	All Size Classes	Small (15 g)	Medium (35 g)	Large (1000 g)

Short Grass 	19.91	1731	1481	79.21

Tall Grass	9.131	79.21	67.71	36.31

Broadleaf plants/sm insects	11.21	97.31	83.11	44.51

Fruits/pods/lg insects	1.251	10.81	9.231	4.951

Seeds (granivore)	1.251	2.401	2.051	1.101

1 Exceeds LOC (1) for chronic exposures to non-listed and listed
terrestrial mammals.

Acute dose-based RQ values are calculated using the value available for
the bobwhite quail (LD50>2510 mg a.i./kg-bw).  The acute risk listed
species LOC is not exceeded for non-listed birds.  The acute risk LOC
for non-listed species is potentially exceeded only for listed, small
birds consuming short grass (Table G.5).

Table G.5.  Dose-based RQ values for acute exposures to birds.

Food Type	20 g	100 g	1000 g

Short Grass 	<0.06	<0.03	<0.01

Tall Grass	<0.03	<0.01	<0.01

Broadleaf plants/sm insects	<0.04	<0.02	<0.01

Fruits/pods/seeds/lg insects	<0.01	<0.01	<0.01

1Potentially exceeds the acute LOC for birds (0.5).

2Potentially exceeds the acute listed species LOC for birds (0.1).

Acute dietary-based RQ values are calculated using the LC50for bobwhite
quail (>5620 mg/kg-diet).  The acute risk LOC is not exceeded for birds.
 Chronic dietary-based RQ values are calculated using the bobwhite quail
NOAEC (30 mg/kg-diet).  The chronic risk LOC is exceeded for birds
feeding on short grasses, tall grasses, broadleaf plants and small
insects (Table G.6). 

Table G.6.  Acute and chronic, dietary-based RQ s for birds by food
type.

Food Type	Acute RQ

 	Chronic RQ 

 

Short Grass 	<0.02	3.321

Tall Grass	<0.01	1.521

Broadleaf plants/small insects	<0.01	1.871

Fruits/pods/seeds/large insects	<0.01	0.21

1LOC (1) exceeded for chronic exposures to non-listed and listed birds.

Based on the information above, chronic exposures are potentially of
significant concern.  If the lowest annual maximum use is modeled in
T-REX, LOCs for non-listed and listed mammals are still exceeded (Table
G.7).  This use rate, 0.0825 lb a.i./A per year, applies to barley
(Table 6).  

Table G.7.  Chronic RQs for mammals and birds exposed to FPE due to use
on barley.

Food Type	Dietary Based  (mammals)	Dietary Based  (birds)	Dose Based 

 (mammals)

	All Size Classes	All Size Classes	Small 

(15 g)	Medium 

(35 g)	Large 

(1000 g)

Short Grass 	3.961	0.66	34.41	29.41	15.71

Tall Grass	1.821	0.30	15.81	13.51	7.211

Broadleaf plants/sm insects	2.231	0.37	19.31	16.51	8.851

Fruits/pods/lg insects	0.25	0.04	2.151	1.831	0.98

Seeds (granivore)	0.25	0.04	0.48	0.41	0.22

1LOC (1) exceeded for chronic exposures to non-listed and listed mammals
or birds.

G.2. Terrestrial Plants

TerrPlant is used to calculate EECs for non-target plant species
inhabiting dry and semi-aquatic areas (Table G.8).  Selected model
parameters include: an application rate of 0.178 lbs a.i./A to represent
the maximum single application rate of FPE (Table 6); and a runoff value
of 0.01 (selected based on FPE solubility, which is classified by
TerrPlant as <10 mg/L).  EECs for these crops correspond to aerial
application methods categorized as which assumes 5 % spray drift.  EECs
relevant to terrestrial plants consider pesticide concentrations in
drift and in runoff.  Since EECs do not consider multiple applications,
exposures could be underestimated in cases where plants are exposed
through multiple applications of FPE.  Based on the single maximum
application rate of FPE applied by air, the LOC is exceeded for
non-listed and listed species of monocots inhabiting dry and
semi-aquatic areas.  The LOC for non-listed and listed dicots is not
exceeded (Table G.9). 

Table G.8.  EECs (lbs a.i./A) generated by TERRPLANT (v. 1.2.2) for
evaluation of exposure of dry and semi-aquatic area plants to FPE.

Use Pattern	Loading to adjacent areas	Loading to semi-aquatic areas
Drift 

  Turf	  0.00178	0.0178 	0.0089 

Table G.9.  RQ values for plants in dry and semi-aquatic areas exposed
to FPE through runoff and/or spray drift.*

Plant Type	Listed Status	Dry 	Semi-Aquatic	Spray Drift

Monocot	non-listed	5.34	13.35	4.45

Monocot	listed	17.8	44.5	14.8

Dicot	non-listed	0.11	0.27	<0.1

Dicot	listed 	0.11	0.27	<0.1

*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to
that plant group.

IV. HUMAN HEALTH EFFECTS SCOPING DOCUMENT

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

7/19/07

				

MEMORANDUM

					

SUBJECT:	Fenoxaprop-P-ethyl.  Registration Review Scoping Document for
Human Health Assessments.

PC Code:	129092

		CFR:		40 CFR 180.430 

DP Barcode:	D338172

Registrant:	Bayer CropScience

FROM:	Richard Griffin, Risk Assessor 

Shanna Recore, Occupational/Residential Assessor 

Elissa Reaves, Ph.D., Toxicologist

		Donald Wilbur, Chemist

		Reregistration Branch 2

Health Effects Division (7509P)

THROUGH:	Alan Nielsen, Branch Senior Scientist

		William Hazel, Ph.D., Branch Chief

		Reregistration Branch 2

Health Effects Division (7509P)

			

TO:		Kylie Rothwell, Chemical Review Manager 

		Reregistration Branch 3

		Special Review and Reregistration Division (7508P)

This is the Registration Review scoping document for the human health
assessments of the herbicide fenoxaprop-P-ethyl.  HED has considered the
available fenoxaprop-P-ethyl risk assessments, updates to toxicity and
exposure databases, changes in use directions, changes in manufacturing
process, open literature data, and current science policy in the
preparation of this scoping document.  The primary purposes of this
scoping document are to determine the:

adequacy of previous assessments and their applicability to current
standards, policies, registered use patterns, etc.;

need for additional or revised human health risk assessments;

need for additional data to support the continued registration of
pesticide products containing fenoxaprop-P-ethyl.

This scoping document and other documents will be made available to the
public via an electronic docket to which relevant information and data
may be submitted during a public comment period.  The “public”
includes all stakeholders such as government agencies, grower groups,
pesticide producers or registrants, private citizens, etc.  Upon
consideration of any public input, a final determination of needed data
and risk assessments will be made by the Agency.

Overview

Fenoxaprop-P-ethyl is a postemergent herbicide of the aryloxyphenoxy
propionate group (formerly the oxyphenoxy acid ester group).  Other
herbicides in this group are fluazifop-butyl, diclofop methyl,
quizalofop-ethyl, and haloxyfop-methyl.  This group is known for high
herbicidal activity against grasses and can be sprayed over the top of
broadleaf crops, including cotton and soybean, without significant
injury to the crop.  Fenoxaprop-P-ethyl is also registered for use in
the culture of small grains and peanut as well as on turf and around
ornamentals, including golf courses, sod farms, and residential lawns.

In 1987, fenoxaprop-ethyl (P.C. Code 128701) was first registered.  It
was a racemic mixture (i.e., a 50:50 blend) of the d- and l-isomers;
this document refers to this active ingredient as the racemic mixture,
or simply FE.  The manufacturing-use product (MP) was first registered
under FIFRA to Hoechst Celanese Corp. (EPA Reg. No. 8340-43).

An application to amend the registration of the Hoechst MP by enriching
it for the herbicidally-active isomer was received 9/18/91; an upper
case “P” was introduced in the chemical name denoting
“positive,” i.e., the direction the enantiomer rotates polarized
light.  Fenoxaprop-P-ethyl (P.C. Code 129092) was synthesized using a
new manufacturing process to produce a new “formulation” of 8340-43
containing the active enantiomer at 89% which was registered on 2/10/94.
 

A new registrant, Aventis Crop Sciences, USA, LP, under EPA Reg. No.
264-653, further enriched the composition of the former Hoechst MP in
2002 by increasing the concentration of the active or d-isomer from 89%
to 95%.  All end-use products are currently formulated using this MP
(label accepted 5/15/02).

The active ingredient, Fenoxaprop-P-ethyl or FPE, is the subject of the
Registration Review being initiated by this document.  However, although
no longer a registered active ingredient in the U.S., most available
toxicology and exposure data involved testing of the racemic mixture. 
It has recently come to the Agency’s attention that certain studies
testing FPE have been conducted for the purposes of “bridging” from
the FE database to FPE.  There are 23 studies that have been conducted
with FPE.  The Agency has performed a preliminary review of these
studies and intends to conduct a full evaluation of the relevant studies
during the public comment period to determine whether the available
combined FE and FPE toxicology and residue chemistry data are adequate
to provide confidence that the existing and/or forthcoming risk
assessments are/will be protective of human health.  The Agency will
also ascertain whether the laboratory-generated test substances used in
the bridging toxicity studies (88-99% FPE) are appropriate to represent
the currently-marketed 95%.  This will necessitate, at a minimum, a
comparison of isomer percentages and ratio and the impurity profiles
associated with the FPE toxicity study test substances and the current
95% MP.

Tolerances are established under 40 CFR §180.430(a) for the combined
residues of the parent compound, fenoxaprop-ethyl
[(±)-ethyl-2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoate], and
its metabolites 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoic
acid (the free acid) and 6-chloro-2,3-dihydrobenzoxazol-2-one, expressed
as fenoxaprop-ethyl equivalents, in or on barley grain, cottonseed,
peanuts, peanut hulls, rice grain, soybeans, and wheat grain at 0.05
ppm; barley straw at 0.1 ppm; and wheat straw at 0.5 ppm.  Tolerances
for the same residues in livestock commodities have also been
established as follows:  0.02 ppm in milk and 0.05 ppm in the fat, meat,
and meat byproducts of cattle, goats, hogs, horses, and sheep.  The
tolerances are currently expressed in terms of combined residues of both
the active and inactive isomers.  If the hazard bridging assessment
determines that FE and FPE are toxicologically equivalent, the tolerance
expression need not change. 

FPE is available as an emulsifiable concentrate (EC), a liquid
ready-to-use (RTU), and as a soluble concentrate/liquid (SC/L).  Methods
of application include band treatment, broadcast, high/low volume spray,
and spot treatment.  These treatments can be made by aircraft,
backpack/hose-end/tank-type sprayers, band sprayers, and boom sprayers. 
 

  

A Screening-level Usage Analysis (SLUA) was performed by the Biological
and Economic Analysis Division (10/17/06) indicating that less than 1
million pounds of FPE are used annually in the U.S.  Approximately 5% of
the U.S. soybean crop and 25% of the U.S. wheat crop are treated.  There
is minimal usage of FPE on barley, cotton, peanut, and rice (<1% crop
treated).  Usage estimates for turf and ornamentals are not available.

Human Incident Data

Human incidents resulting from exposure to FPE (FE before 1994) have
been summarized for this Registration Review by M. Hawkins and H.
Allender (4/10/07, D338156).  Incident data covering the 13-year period
from 1993 to 2005 are stored in the Toxic Exposure Surveillance System
(TESS) maintained by the Association of Poison Control Centers.  Of five
occupationally exposed adults, three had minor symptoms and two had
none.  Of 14 nonoccupationally exposed adults, four displayed symptoms;
of these four showing symptoms, two were moderate and one was major in
severity.  Of four exposed children reported to PCCs from 1993 to 2005,
none were symptomatic or were taken to a Health Care Facility (HCF).

Three cases of potential adult exposure were reported in OPP’s
Incident Data System from 1999 to present.  One was shown to be
unrelated to FPE exposure and there was insufficient follow-up of the
other two to determine if symptoms resulted.

Of 5,899 cases reported to the National Institute of Occupational Safety
and Health/Sentinel Event Notification System for Occupational Risks
(NIOSH/SENSOR) from 1998 to 2003, none involved exposure to FPE.

Based on the available human incident data, OPP suggests that no
mitigation action be taken on FPE at this time.

Toxicology Data/Endpoints

The hazard database of FE was peer reviewed by HED’s Hazard
Identification Assessment Review Committee (HIARC) on 9/18/97 and by
HED’s Risk Assessment Review Committee (RARC) on 10/16/97.  The
toxicity database for FE was judged at that time to be adequate for all
aspects of FQPA-based risk assessment including selection of endpoints
for the conduct of acute and chronic aggregate risk assessments and
endpoints for occupational risk assessment.  

Acute RfD = 0.32 mg/kg/day.  The hazard component of acute risk was
based on a rat developmental toxicity study (MRID 00152156) in which
fetal malformations (diaphragmatic and umbilical hernia, split sternum,
scoliosis, and innominate artery), decreased fetal weight and increased
total visceral and skeletal anomalies occurred at the LOAEL of 100
mg/kg/day.  The NOAEL and dose level for acute risk assessment was 32
mg/kg/day, the interspecies x intraspecies (10 x 10) Uncertainty Factor
was 100, and the FQPA Safety Factor was 1.  The FQPA Safety Factor was
reduced to 1 since the fetal effects only occurred at maternally toxic
doses.  The population of concern was women of childbearing age. 
Maternal effects seen at the LOAEL were increased incidence of
salivation, increased water consumption, decreased body weight gain and
increased liver weights.

Chronic RfD = 0.0025 mg/kg/day.  The hazard component of chronic risk
was the NOAEL of 0.25 mg/kg/day based on decreased total blood
lipids/cholesterol at the LOAEL of 1.5 mg/kg/day in a rat reproductive
toxicity study (MRID 00263030).  Furthermore, the highest dose of 9
mg/kg/day also produced increased absolute and relative brain and kidney
weights with increased incidence of nephrocalcinosis reported in a
previous study. The reproductive LOAEL of 1.5 mg/kg/day was based on
reduced pup body weights (F1a).  The interspecies x intraspecies (10 x
10) Uncertainty Factor was 100, and the FQPA Safety Factor was 1.  The
FQPA Safety Factor was reduced to 1 since developmental toxicity studies
showed no increased sensitivity; fetal malformations in the rat
developmental study were only at maternally toxic doses; and a
multi-generation reproduction rat study showed no increased sensitivity
to pups as compared to adults.   

Short-/Intermediate-/Long-Term Dermal.  FE was found not to be toxic via
the dermal route as neither dermal nor systemic toxicity was seen at the
limit dose (1,000 mg/kg/day) in a rat dermal developmental toxicity
study.  Also, no dermal or systemic toxicity was observed at the highest
dose tested (20 mg/kg/day) in a 21-day dermal toxicity study in rats. 
Therefore, dermal exposure and risk assessments for pesticide workers as
well as adults and children in residential settings were not required
based on these studies.

Short-/Intermediate-/Long-Term Inhalation.  Inhalation risk estimates
(for any time interval) were based on a 6-week rat inhalation toxicity
study that demonstrated decreased total lipid and adverse kidney/liver
effects at the study LOAEL of 0.075 mg/kg/day.  The NOAEL and dose level
for risk assessment was 0.015 mg/L with a standard MOE requirement of
100. 

Carcinogenic Risk.  A second mouse cancer study required as a condition
of registration was received in 1996.  At the 9/18/97 HIARC meeting, it
was recommended that, until a Cancer Assessment Review Committee (CARC)
meeting could take place, an interim, protective risk assessment should
be carried out using the linear low dose extrapolation method (Q1*)
based on the increases in adrenal tumors in male mice.  The Q1* of 9.1 x
10-2 was calculated for adrenal tumors and was recommended to calculate
lifetime carcinogenic risk.  The Agency intends to hold this CARC
meeting to determine the cancer classification and potency before final
decisions are made as to data and risk assessment needs.

Adequacy of the Toxicity Database

The hazard database is considered to be complete and adequate for the
racemic mixture as a food use pesticide including the relatively
recently submitted second mouse carcinogenicity study.  Note that, upon
comparison with FPE bridging studies and detailed evaluation by the CARC
to occur in the near future, it is possible that some shortcomings may
be discovered in the existing studies.

At the time of the proposed change in composition of the MP from the
racemic mixture to an 85:15 d/l enrichment (9/18/91), it was considered
to be registration of an alternate formulation of the same registered
product (EPA Reg. No. 8340-43).  Apparently typical in such situations
at that time was that only the battery of six acute mammalian toxicity
studies would be required; these, testing FPE, were submitted in 1991. 
The Agency did not require additional toxicity studies for the purpose
of bridging FE to FPE.  Note that, although the 85:15 ratio form of FPE
was used for limited toxicity testing, it was apparently never marketed
in a registered pesticide product.  Instead, by 2/10/94, Hoechst was
capable of achieving 89% FPE on a commercial scale.

HED typically considers more than acute toxicity studies necessary to
bridge from one toxicity database to another.  Generally, the same
studies (listed below) necessary to support registration of a nonfood
pesticide are needed to permit bridging from an enriched isomer to a
racemic mixture of two enantiomers of a pesticide: 

acute toxicity battery

90-day repeated dose study (oral or dermal-rat)

one developmental toxicity study (rat)

mutagenicity test battery  

The Agency became aware that a number of such studies had been conducted
on FPE for submission to the European Union.  At the Agency’s request,
Bayer CropScience has recently submitted (4/23/07) 23 toxicology studies
conducted with FPE that had not been previously submitted to the Agency.
 These included acute (all routes), subchronic (all routes), metabolism,
developmental (rodent and non-rodent) studies and a mutagenicity
battery.  The Agency is currently conducting detailed reviews (DERs) of
relevant FPE toxicity data.  Final conclusions regarding the adequacy of
the combined FE and FPE hazard databases for human health risk
assessment purposes will be made upon the completion of DERs of FPE
studies, the bridging decision, the endpoint selection, and the cancer
classification.

Adequacy of Dietary Exposure Data/Risk Estimates

Residue chemistry data are adequate to support the registered food uses
and tolerances for FE/FPE tolerances including plant, ruminant, and
poultry metabolism, analytical methods, storage stability, processing,
and field trials.  Tolerances for FE/FPE residues are below the level of
detection in the grain/seed portion of each crop (barley, wheat, rice,
cottonseed, and soybean), as reflected in the tolerances of 0.05 ppm
(the method Limit of Quantification, or LOQ).  Both acute and chronic
dietary risk assessments are conservative, being based on
tolerance-level residue for all foods although livestock feed items were
corrected by percent crop treated.  

Adequacy of Drinking Water Exposure Data/Risk Estimates

In the 2/3/98 human health assessment, EFED used the “GENEEC”
drinking water model which generates upper-bound (or Tier 1) estimates
of surface water runoff.   Since dietary and drinking water risk
estimates (as seen in the DWLOCs) were negligible based on upper-bound
assumptions, an updated drinking water assessment would not likely be
useful unless EFED is aware of some significant policy or use pattern
change expected to affect estimated drinking water concentrations.

 

  

Adequacy of Residential Exposure Data/Risk Estimates

According to the registrant, in 1998, all residential treatments were
done by professional applicators.  Appropriately, a homeowner
“handler” risk assessment was never conducted.  However, there are
currently several registered homeowner products containing FPE.   To
assess risks to homeowners, a short-term residential handler inhalation
assessment should be done for lawn and ornamental use based on
inhalation exposure only; dermal exposure would not be assessed because
the dermal route of exposure is not of concern for risk assessment. 

Also, by current standards, children’s “incidental” oral exposure
(to treated turf) would be assessed based on an existing
(to-be-determined) oral toxicity study of the appropriate exposure
duration.    

Adequacy of Occupational Exposure Data/Risk Estimates

Occupational handler risk assessment was completed for the 1997 and 1998
barley and wheat tolerance petitions based on inhalation exposure, only.
 Dermal exposure was not assessed based on the negative results of the
dermal toxicity studies. Carcinogenic risk estimates were completed for
workers based on their specific function (aerial applicator, ground
applicator, etc.).  The highest carcinogenic risk estimated was 10-6 and
was based on the mixer/loader function for aerial applications.  

Postapplication dermal exposure does not need to be assessed for FPE
since no systemic dermal effects of concern were identified in toxicity
studies involving dosing via the dermal route.  Postapplication
inhalation exposure is not a concern.  Restricted Entry Intervals (REIs)
are determined according to the Worker Protection Standard (WPS) where
applicable. 

It does not appear that occupational handler inhalation assessments have
been done for cotton, soybeans, rice, or peanuts, or for various turf
uses (sod farms, commercial and residential turf), ornamentals, and
rights-of-way.

Available Risk Assessment/Risk Estimates

A quantitative human health risk assessment has not been conducted on
FPE.  The most complete human health risk assessment was conducted on FE
(S. Knizner, et al., 2/3/98, D242374).   Aggregate acute and chronic
exposure estimates were found not to exceed HED's level of concern. 
More specifically, the acute dietary risk estimate for women (<13 yr)
was well below (<1%) the acute RfD of 0.32 mg/kg/day.  Chronic dietary
risk estimates for all population groups were less than 1% of the
chronic RfD.  At that time, the drinking water component of aggregate
exposure was addressed by using the “Drinking Water Level of
Concern” (DWLOC) approach.  Potential FE residues in drinking water
were found not to be greater than HED's level of concern for acute
aggregate (women <13 yr) or for chronic aggregate risk.  Use of DWLOCs
in aggregate risk has now been replaced by direct incorporation of
drinking water consumption and contamination estimates into the DEEM (or
other) exposure model.  Based on the estimated U.S. population’s
chronic dietary (food-only) exposure and an “interim” Q1* of 9.1 x
10-2, the upper-bound (food-only) carcinogenic risk estimate was 9.1 x
10-7.   Since the carcinogenic risk DWLOC exceeded the average lifetime
contamination estimate, there is negligible cancer risk from chronic
exposures to FE in drinking water and food.

The 2/3/98 human health risk assessment quantified occupational risks
associated with inhalation exposure during mixing, loading, and applying
FE (Tiller EC Herbicide) to barley.  Exposure via the dermal route is
not of concern as neither dermal nor systemic effects were observed at
the limit dose in a dermal developmental toxicity study in rats and
rabbits or in a 21-day rat dermal toxicity study.  The Margins of
Exposure (MOEs) were 4,500 for aerial mixer/loaders to 80,000 for aerial
applicators (well above the level of concern of 100).  Carcinogenic risk
estimates for pesticide workers did not exceed HED’s level of concern.
 

The 2/3/98 risk assessment did not quantify risks to residential
applicators (homeowners) because the registrant attested that, at that
time, only professional applicators treated residential turf and
ornamentals with FE.  In terms of postapplication exposure, dermal
toxicity was not considered of concern and neither adults nor children
were considered to have significant inhalation exposure.  

Recommendations

Agency Action Items

Conduct full reviews (DERs) on the newly received FPE developmental
toxicity studies and any other studies deemed relevant.  Compare these
studies to the analogous studies conducted on FE.  Make a decision as to
whether the entire FE database, notably the chronic, cancer, and
reproductive toxicity studies, may be bridged to FPE.  If complete
bridging is agreed upon, then no FPE toxicity data are likely to be
required.  If partial or no bridging is permitted, identify the FPE
toxicity studies that must be required.

Schedule an evaluation of the carcinogenic potential of FE/FPE by the
HED Cancer Assessment Review Committee.  Quantified carcinogenic risk
estimates may not be appropriate.

Prepare an updated human health risk assessment including

Risk estimates for oral exposure to children on treated turf.

Inhalation risk estimates for adult homeowners applying FPE to
residential turf.  

Estimates of FPE concentrations in drinking water directly input to the
“DEEM” or other aggregate exposure model.

V. GLOSSARY OF TERMS AND ABBREVIATIONS

ai		Active Ingredient

AR		Anticipated Residue

CFR		Code of Federal Regulations

cPAD		Chronic Population Adjusted Dose

CSF		Confidential Statement of Formula

CSFII		USDA Continuing Surveys for Food Intake by Individuals

DCI		Data Call-In

DEEM		Dietary Exposure Evaluation Model

DFR		Dislodgeable Foliar Residue

DNT		Developmental Neurotoxicity

DWLOC		Drinking Water Level of Comparison

EC		Emulsifiable Concentrate Formulation

EDWC		Estimated Drinking Water Concentration

EEC		Estimated Environmental Concentration

EPA			Environmental Protection Agency

EUP		End-Use Product

FDA		Food and Drug Administration

FIFRA		Federal Insecticide, Fungicide, and Rodenticide Act

FFDCA		Federal Food, Drug, and Cosmetic Act

FQPA		Food Quality Protection Act

FOB		Functional Observation Battery

GENEEC		Tier I Surface Water Computer Model

IR		Index Reservoir

LC50	Median Lethal Concentration.  A statistically derived concentration
of a substance that can be expected to cause death in 50% of test
animals.  It is usually expressed as the weight of substance per weight
or volume of water, air or feed, e.g., mg/l, mg/kg or ppm.

LD50	Median Lethal Dose.  A statistically derived single dose that can
be expected to cause death in 50% of the test animals when administered
by the route indicated (oral, dermal, inhalation).  It is expressed as a
weight of substance per unit weight of animal, e.g., mg/kg.

LOC		Level of Concern

LOAEL		Lowest Observed Adverse Effect Level

µg/g		Micrograms Per Gram

µg/L		Micrograms Per Liter

mg/kg/day		Milligram Per Kilogram Per Day

mg/L		Milligrams Per Liter

MOE		Margin of Exposure 

MRID	Master Record Identification (number).  EPA's system of recording
and tracking submitted studies.

MUP		Manufacturing-Use Product

NA		Not Applicable

NAWQA		USGS National Ambient Water Quality Assessment

NPDES		National Pollutant Discharge Elimination System

NR		Not Required

NOAEL		No Observed Adverse Effect Level

OPP		EPA Office of Pesticide Programs

OPPTS		EPA Office of Prevention, Pesticides and Toxic Substances

PAD		Population Adjusted Dose

PCA		Percent Crop Area

PDP		USDA Pesticide Data Program

PHED		Pesticide Handler's Exposure Data 

PHI		               Preharvest Interval

ppb		Parts Per Billion

PPE		Personal Protective Equipment

ppm		Parts Per Million

PRZM/EXAMS		Tier II Surface Water Computer Model  

Q1*	The Carcinogenic Potential of a Compound, Quantified by the EPA's
Cancer Risk Model

RAC		Raw Agriculture Commodity

RED		Reregistration Eligibility Decision

REI		Restricted Entry Interval

RfD		Reference Dose

RQ		Risk Quotient

SCI-GROW		Tier I Ground Water Computer Model

SAP		Science Advisory Panel

SF		Safety Factor

SLN		Special Local Need  (Registrations Under Section 24©) of FIFRA)

TGAI		Technical Grade Active Ingredient

USDA		United States Department of Agriculture

UF		Uncertainty Factor

WPS		Worker Protection Standard

 PAGE   

 PAGE   35 

Docket Number: EPA-HQ-OPP-2007-0437

  HYPERLINK "http://www.regulations.gov"  www.regulations.gov 

Docket Number: EPA-HQ-OPP-2007-0437

  HYPERLINK "http://www.regulations.gov"  www.regulations.gov 

  PAGE  54 

Docket Number: HQ-OPP-2007-0437

www.regulations.gov

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