Document ID: EPA-HQ-OPP-2008-0345-0003
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-06-25T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

		March 31, 2008

	PC Code:  111401

	DP Barcode:  348151

	

MEMORANDUM

Subject:	Registration Review:  Preliminary Problem Formulation for
Ecological Risk, Environmental Fate, Endangered Species, and Drinking
Water Assessments for Profenofos

To:		Christina Scheltema, Chemical Review Manager

Kevin Costello, Team Leader

Reregistration Branch

Special Review and Reregistration Division

Office of Pesticide Programs

From:		Kristina Garber, Biologist

Anita Pease, Senior Biologist

		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

The Environmental Fate and Effects Division (EFED) has completed the
preliminary problem formulation (attached) for the ecological risk,
environmental fate, endangered species, and drinking water assessments
to be conducted as part of the Registration Review of the
organophosphate insecticide/miticide, profenofos (PC Code 111401). 
Functioning as the first stage of the risk assessment process for
registration review, this problem formulation provides an overview of
what is currently known about the environmental fate and ecological
effects associated with profenofos and its degradates.  It also
describes the preliminary ecological risk hypothesis and analysis plan
for evaluating and characterizing risk to non-target species and the
environment in support of the registration of profenofos. 

  SEQ CHAPTER \h \r 1 

				

Problem Formulation for the 

Environmental Fate, Ecological Risk, Endangered Species, and Drinking
Water Assessments 

in Support of the Registration Review of Profenofos

Profenofos (CAS 41198-08-7)

Prepared by:

Kristina Garber, Biologist

Anita Pease, Senior Biologist	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:

Thomas Steeger, Senior Biologist

R. David Jones, Senior Agronomist

Elizabeth Behl, Branch Chief

	

March 31, 2008

Table of Contents

  TOC \o "1-3" \h \z \u    HYPERLINK \l "_Toc194397455"  1.  Purpose	 
PAGEREF _Toc194397455 \h  4  

  HYPERLINK \l "_Toc194397456"  2.  Problem Formulation	  PAGEREF
_Toc194397456 \h  4  

  HYPERLINK \l "_Toc194397457"  2.1. Nature of Regulatory Action	 
PAGEREF _Toc194397457 \h  4  

  HYPERLINK \l "_Toc194397458"  2.2. Previous Risk Assessments	  PAGEREF
_Toc194397458 \h  4  

  HYPERLINK \l "_Toc194397459"  3. Stressor Source and Distribution	 
PAGEREF _Toc194397459 \h  6  

  HYPERLINK \l "_Toc194397460"  3.1. Mechanism of Action	  PAGEREF
_Toc194397460 \h  6  

  HYPERLINK \l "_Toc194397461"  3.2. Overview of Pesticide Usage	 
PAGEREF _Toc194397461 \h  6  

  HYPERLINK \l "_Toc194397462"  3.3. Environmental Fate and Transport	 
PAGEREF _Toc194397462 \h  7  

  HYPERLINK \l "_Toc194397463"  3.3.1. Degradation	  PAGEREF
_Toc194397463 \h  8  

  HYPERLINK \l "_Toc194397464"  3.3.2. Transport	  PAGEREF _Toc194397464
\h  9  

  HYPERLINK \l "_Toc194397465"  3.3.3. Terrestrial Field Dissipation	 
PAGEREF _Toc194397465 \h  9  

  HYPERLINK \l "_Toc194397466"  3.3.4. Bioaccumulation	  PAGEREF
_Toc194397466 \h  9  

  HYPERLINK \l "_Toc194397467"  4.  Receptors	  PAGEREF _Toc194397467 \h
 10  

  HYPERLINK \l "_Toc194397468"  4.1. Effects to Aquatic Organisms	 
PAGEREF _Toc194397468 \h  10  

  HYPERLINK \l "_Toc194397469"  4.2. Effects to Terrestrial Organisms	 
PAGEREF _Toc194397469 \h  11  

  HYPERLINK \l "_Toc194397470"  4.3. Incident Database Review	  PAGEREF
_Toc194397470 \h  13  

  HYPERLINK \l "_Toc194397471"  4.4. Ecosystems Potentially at Risk	 
PAGEREF _Toc194397471 \h  14  

  HYPERLINK \l "_Toc194397472"  5. Assessment Endpoints	  PAGEREF
_Toc194397472 \h  14  

  HYPERLINK \l "_Toc194397473"  6.  Conceptual Model	  PAGEREF
_Toc194397473 \h  15  

  HYPERLINK \l "_Toc194397474"  6.1.  Risk Hypothesis	  PAGEREF
_Toc194397474 \h  15  

  HYPERLINK \l "_Toc194397475"  6.2.  Conceptual Diagram	  PAGEREF
_Toc194397475 \h  16  

  HYPERLINK \l "_Toc194397476"  7.  Analysis Plan	  PAGEREF
_Toc194397476 \h  17  

  HYPERLINK \l "_Toc194397477"  7.1.  Stressors of Concern	  PAGEREF
_Toc194397477 \h  18  

  HYPERLINK \l "_Toc194397478"  7.2.  Measures of Exposure	  PAGEREF
_Toc194397478 \h  18  

  HYPERLINK \l "_Toc194397479"  7.3.  Measures of Effect	  PAGEREF
_Toc194397479 \h  19  

  HYPERLINK \l "_Toc194397480"  7.4. Integration of Exposure and Effects
  PAGEREF _Toc194397480 \h  20  

  HYPERLINK \l "_Toc194397481"  7.5. Deterministic and Probabilistic
Assessment Methods	  PAGEREF _Toc194397481 \h  21  

  HYPERLINK \l "_Toc194397482"  7.6. Endangered Species Assessments	 
PAGEREF _Toc194397482 \h  21  

  HYPERLINK \l "_Toc194397483"  7.7. Drinking Water Assessment	  PAGEREF
_Toc194397483 \h  22  

  HYPERLINK \l "_Toc194397484"  7.8. Preliminary Identification of Data
Gaps	  PAGEREF _Toc194397484 \h  22  

  HYPERLINK \l "_Toc194397485"  7.8.1. Fate	  PAGEREF _Toc194397485 \h 
22  

  HYPERLINK \l "_Toc194397486"  7.8.2. Effects	  PAGEREF _Toc194397486
\h  23  

  HYPERLINK \l "_Toc194397487"  8.  References	  PAGEREF _Toc194397487
\h  27  

  HYPERLINK \l "_Toc194397488"  APPENDIX A:  Preliminary EECs for
aquatic habitats and RQs for aquatic organisms.	  PAGEREF _Toc194397488
\h  32  

  HYPERLINK \l "_Toc194397489"  APPENDIX B:  Preliminary EECs and
associated RQs for terrestrial mammals and birds	  PAGEREF _Toc194397489
\h  36  

  HYPERLINK \l "_Toc194397490"  APPENDIX C:  Preliminary EECs and
associated RQs for terrestrial and riparian plants	  PAGEREF
_Toc194397490 \h  39  

 1.  Purpose

The purpose of this problem formulation is to provide an understanding
of what is known about the environmental fate and ecological effects of
the registered uses of profenofos.  Profenofos is an organophosphate
used as an insecticide and miticide on cotton.  This document will
provide a plan for analyzing data relevant to profenofos and for
conducting environmental fate, ecological risk, endangered species and
drinking water assessments for its registered uses.  Additionally, this
problem formulation is intended to identify data gaps, uncertainties,
and potential assumptions used to address those uncertainties relative
to characterizing the ecological risk associated with the registered
uses of profenofos.  

2.  Problem Formulation

2.1. Nature of Regulatory Action

Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA),
all pesticides distributed or sold in the United States generally must
be registered by EPA.  In determining whether a pesticide can be
registered in the U.S., EPA evaluates its safety to non-target species
based on a wide range of environmental and health effects studies.   In
1996, FIFRA was amended by the Food Quality Protection Act, and EPA was
mandated to implement a new program for the periodic review of
pesticides, i.e., registration review (  HYPERLINK
"http://www.epa.gov/oppsrrd1/registration_review/" 
http://www.epa.gov/oppsrrd1/registration_review/ ).  The registration
review program is intended to ensure that, as the ability to assess risk
evolves and as policies and practices change, all registered pesticides
continue to meet the statutory standard of no unreasonable adverse
effects to human health and the environment. 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 be used safely. 

As part of the implementation of the new Registration Review program
pursuant to Section 3(g) of the Federal Insecticide, Fungicide and
Rodenticide Act (FIFRA), the Agency is beginning its evaluation of
profenofos to determine whether it continues to meet the FIFRA standard
for registration. This problem formulation for the environmental fate,
ecological risk, endangered species, and drinking water assessment
chapter in support of the registration review will be posted in the
initial docket opening the public phase of the review process.

2.2. Previous Risk Assessments

A national-level ecological risk assessment was completed as part of the
interim reregistration eligibility decision (IRED) for profenofos in
August 2000 (USEPA 2000).  The IRED was finalized in July 2006 after the
cumulative human health risk assessment of the organophosphate (OP)
class of pesticides was completed (USEPA 2006).  The ecological risk
assessment included in the profenofos IRED was based on laboratory fate
and ecotoxicological data submitted by the registrant in support of
reregistration and from data in publicly available literature, and
incident reports of adverse effects on non-target organisms associated
with the use of profenofos.  The primary environmental concerns
identified in the 2000 environmental fate and ecological risk assessment
were associated with risks to freshwater and estuarine/marine fish and
invertebrates (USEPA 2000).  Estimated risks to aquatic invertebrates,
which are not typically captured in incident reports, were higher than
those expected for fish, based on modeled exposure concentrations.  The
Agency’s levels of concern (LOCs) were exceeded for these aquatic
animals.  Fish kill incidents received under FIFRA 6(a)(2) and
summarized in the Agency’s Ecological Incident Information System
(EIIS) provide further evidence that profenofos poses a hazard to fish
when used under typical use conditions on cotton.  For non-target
terrestrial organisms, the risk from profenofos exceeded acute and
chronic levels of concern for birds; acute levels of concern for small
mammals; and triggered risk concerns for endangered species.  In
addition, profenofos was reported as highly toxic to honeybees.

Based on the results of the IRED, a number of mitigation measures were
implemented to address ecological risks for profenofos.  The profenofos
label was modified to: (1) reduce the seasonal maximum application rate
from 6 to 5 lb a.i./A/season; (2) limit the 1 lb a.i./A rate to only
lepidopteran pests up to twice per season; (3) reduce the maximum
application rate under all other conditions to 0.75 lb a.i./A; (4)
require 300-ft spray drift and 100-ft run-off buffer zones around water
bodies for aerial and ground applications, respectively; (5) prohibit
use in Reeves County, Texas, and within one mile of the Dexter National
Fish Hatchery in New Mexico; and (6) prohibit application or drift of
profenofos to crops or weeds on which bees are foraging.  

An emergency exemption petition (Section 18) risk assessment for use of
profenofos on rice (in Texas) was also completed in 2007 (USEPA 2007a). 
The results of the Section 18 assessment indicated that the proposed use
of profenofos on rice for seed in Texas may result in acute and chronic
risk for terrestrial and aquatic animals.  Potential risks to
terrestrial invertebrates and terrestrial and aquatic plants were
identified as well.  

Final Biological Opinion on Profenofos in Response to Request for
Consultation

EPA reinitiated a formal consultation with the U. S. Fish and Wildlife
Service (USFWS) in 1989 regarding profenofos impacts on endangered
species.  This consultation was on selected portions of five previous
“cluster” biological opinions evaluating pesticides for certain
crops (corn, cotton, soybeans, sorghum, wheat, barley, oats and rye),
forestry use pesticides, mosquito larvicides, and rangeland and
pastureland pesticides.  As a result, the USFWS issued a formal
Biological Opinion (USFWS 1989), which identified reasonable and prudent
measures and alternatives to mitigate potential effects on
Federally-listed threatened/endangered species from the use of
profenofos.  The opinion identified 6 amphibians, 77 fish, 38 freshwater
mussels, and 10 arthropods potentially affected by the use of
profenofos.  Of the 131 species identified, 21 (16%) were classified as
“in jeopardy”.

3. Stressor Source and Distribution

3.1. Mechanism of Action

 

Profenofos, O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl
phosphorothioate, is an insecticide/miticide belonging to the
organophosphate class of pesticides.  Organophosphate toxicity is based
on the inhibition of the enzyme acetylcholinesterase, which cleaves the
neurotransmitter acetylcholine.  Inhibition of acetylcholinesterase by
organophosphate insecticides interferes with proper neurotransmission in
cholinergic neurosynapses and neuromuscular junctions.

3.2. Overview of Pesticide Usage

Profenofos was originally registered for use in the United States in
1982.  It is used to control cotton pests including aphids, lygus bugs
(Lygus spp.), and cotton bollworm (Helicoverpa zea).  Currently, labeled
use of profenofos includes only applications to cotton. There is one
active Section 3 product containing profenofos (registration # 100-669).
 According to this product label, profenofos can be applied to cotton by
aerial or ground methods. For general use, the maximum single
application rate is 0.75 lb a.i./A.  Additional applications can be made
up to 5 lbs a.i/A/season (this is equivalent to 6 applications of 0.75
lb a.i./A plus 1 application of 0.5 lb a.i./A).  For lepidopteran pests,
the maximum single application rate per season is 1 lb a.i./A with 2
applications per season for a total of 2 lbs a.i./A/ season.  

As of 2002, an estimated 153,000 pounds of profenofos were applied
annually in the United States (Figure 1).  According to National
Agricultural Statistics Services data from 2000-2007, cotton was planted
in Alabama, Arizona, Arkansas, California, Florida, Georgia, Kansas,
Louisiana, Mississippi, Missouri, New Mexico, North Carolina, Oklahoma,
South Carolina, Tennessee, Texas and Virginia (USDA 2007). Therefore,
potential application sites of profenofos are expected to include these
states.

 

Figure   SEQ Figure \* ARABIC  1 . Historical Extent (2002) of
profenofos usage.

(Source
http://ca.water.usgs.gov/pnsp/pesticide_use_maps/show_map.php?year=02&ma
p=m6084 ).

3.3. Environmental Fate and Transport

Registrant-submitted data defining the physical, chemical, fate and
transport characteristics associated with profenofos are summarized in
Table 1.  As part of registration review, available fate studies for
profenofos have been reevaluated. The fate and transport of profenofos
in the environment is briefly discussed below.



Table 1.  General chemical and environmental fate properties of
profenofos.

Chemical/Fate parameter	Value	Source (MRID)

Molecular Weight (g/mol)	373.63	Product chemistry 

Vapor Pressure (torr)	3.46 E-06	41905001

Octanol-water Partition Coefficient (Log KOW)	4.83 (25 °C)	EFGWB
Science Chapter (USEPA 1996)

Octanol-air Partition Coefficient (Log KOA)	10.7	EPIsuite, v.3.20

Water Solubility (mg/L; at 25 °C)	20	IRED (USEPA 2000)

Henry's Law Constant (atm-m3 mol-1)	2.38 x 10-7	EFGWB Science Chapter
(USEPA 1996)

Hydrolysis  half lives (days)

                    	104 - 108 (pH 5)

24 - 62 (pH 7)

0.3 (pH 9)	416276309,

41939001

Aqueous photolysis half-life	stable	41879901, 41939002

Soil Photolysis half-life (days)1	9.5	44683901

Aerobic Soil Metabolism half-life (days)	3	42334302

Anaerobic Soil Metabolism half-life (days)	12.4	42334303

Anaerobic Aquatic Metabolism half-life (days)	4	42218101

Organic carbon normalized partition coefficients (KOC) 	185 2	EPIsuite,
v.3.20

Fish Bioconcentration Factor (BCF)	29x (body)

45x (head)

682x (viscera)	00085952, 

92148059

1Represents environmental soil photolysis half-life (12 h light, 12 h
dark).

2Estimated value.

3.3.1. Degradation

Available laboratory studies indicate that profenofos degrades by
microbial metabolism as well as the abiotic process of hydrolysis. 
Aerobic and anaerobic soil metabolism half-lives are similar, ranging 3
to 12.4 days. Degradation due to hydrolysis varies with pH, with
half-life values of 104-108 days for acidic (pH 5) waters, 24-62 days
for neutral waters (pH 7) and 0.3 days for alkaline waters (pH 9). 
Under anaerobic aquatic conditions, the half-life of profenofos due to
metabolism is 4 days. In water, under sterile conditions, profenofos is
stable to photolysis; however, in soil, under non-sterile conditions,
profenofos has a photolysis half-life of 9.5 days.

The predominant degradate of profenofos observed in laboratory studies
(including hydrolysis, photolysis and metabolism) was
4-bromo-2-chlorophenol, which was formed by hydrolysis of the
organophosphate group from the phenyl ring of profenofos. Also formed in
equimolar parts with this degradate is O-ethyl-S-propyl phosphorthioate.

3.3.2. Transport  PRIVATE   tc  \l 2 "Mobility" 

No scientifically valid studies are available to define the mobility of
profenofos or its degradates in soil. The estimated organic carbon
partition coefficient (Koc) of 185 (EPIsuite, v.3.20) suggests that
profenofos may be moderately mobile in soil.

Laboratory studies show that some profenofos residues may be released to
the atmosphere through volatilization.  Over 30 days, volatility of
profenofos residues averaged 6.13 x 10-3 µg/cm2/hr and the vapor
pressure averaged 3.46 x 10-6 torr (MRID: 419050-01).  In this study,
4-bromo-2-chlorophenol was the major volatile residue.  

3.3.3. Terrestrial  PRIVATE  Field Dissipation tc  \l 2 "Field
Dissipation" 

The submitted field studies do not provide adequate information for more
than a rough qualitative assessment of profenofos dissipation in the
field, in large part because profenofos degraded during storage.  Both
profenofos and its degradate, 4-bromo-2-chlorophenol, dissipated from
the surface to 6 inches in cotton and bare-ground plots in California
and Texas with a half-life of several days (MRIDs: 428513-01,
429009-01).  Neither profenofos, nor 4-bromo-2-chlorophenol was detected
below 12 inches in either study (minimum detection limit of 10 ppb). 
Because the studies were conducted in soil and weather conditions that
resulted in a moisture deficit there was little or no excess water
available for downward movement through the soil. 

		3.3.4.  PRIVATE  Bioaccumulation tc  \l 2 "Accumulation" 

In a bioconcentration study with bluegill sunfish, profenofos residues
concentrated in fish tissues at a factor of 29X for whole fish. The
dominant chemical identified in the viscera is 4-bromo-2-chlorophenol
(33-48% of the recovered radioactivity). Once fish were moved to water
not containing profenofos, depuration was rapid, with 96% of profenofos
residues eliminated from fish tissues within 8 days (MRIDs 00085952 and
summarized in 92148059).  

The octanol-water partition coefficient (Log KOW = 4.83) indicates that
profenofos has the potential to bioaccumulate in aquatic ecosystems;
however, bioaccumulation may be limited by metabolism of profenofos to
4-bromo-2-chlorophenol and other degradates.

The estimated log octanol-air partition coefficient (Log KOA) of 10.7
(EPIsuite, v.3.20) suggests that bioaccumulation of profenofos in
terrestrial food chains is possible (Kelly et al. 2007).  

Potential bioaccumulation of profenofos will be considered in future
risk assessments.

4.  Receptors

Consistent with the process described in the Overview Document (USEPA
2004), the risk assessment for profenofos relies on a surrogate species
approach.  T  SEQ CHAPTER \h \r 1 oxicological data generated from
surrogate test species, which are intended to be representative of broad
taxonomic groups, are used to extrapolate to potential effects on a
variety of species (receptors) included under these taxonomic groupings.
 Based on previous assessments (e.g., see the IRED, USEPA 2000), no
major degradates of toxicological concern were identified; therefore,
the focus of the assessment is parent profenofos.

Acute and chronic toxicity data from studies submitted by pesticide
registrants along with the available open literature are used to
evaluate the potential direct and indirect effects of profenofos to
aquatic and terrestrial receptors. This includes toxicity on the
technical grade active ingredient, degradates, and when available,
formulated products (e.g., “Six-Pack” studies).  The open literature
studies are identified through EPA’s ECOTOXicology (ECOTOX) database
(USEPA 2007d), which employs a literature search engine for locating
chemical toxicity data for aquatic life, terrestrial plants, and
wildlife.  The evaluation of both sources of data may also provide
insight into the direct and indirect effects of profenofos on biotic
communities from loss of species that are sensitive to the chemical and
from changes in structure and functional characteristics of the affected
communities.  Open literature data from ECOTOX on profenofos will be
available in September 2008, and subsequently evaluated for possible
quantitative and/or qualitative inclusion in this risk assessment.    

A summary of the aquatic and terrestrial toxicity data used to derive a
preliminary evaluation of risk for profenofos is provided in Sections
4.1 and 4.2, respectively.  In addition, a summary of ecological
incidents associated with profenofos and a description of ecosystems
potentially at risk are provided in Sections 4.3 and 4.4, respectively.

4.1. Effects to Aquatic Organisms

A summary of the most sensitive aquatic toxicity data from
registrant-submitted studies is provided in Table 2. Profenofos is
classified as very highly toxic to freshwater and estuarine/marine fish
and invertebrates on an acute exposure basis.  Chronic effects in
freshwater fish and invertebrates and estuarine/marine invertebrates
include diminished survival and growth.  No chronic data are available
for estuarine/marine fish.  Toxicity data for aquatic plants are also
not available for profenofos. 

 



Table 2.  Summary of most sensitive endpoints from submitted aquatic
toxicity studies for profenofos.  

Species

(common name)	Taxa Represented	End-point	Duration

(hours)	 Mean concentration (µg a.i./L)	Citation 

MRID 	Acute Toxicity Classification

Lepomis macrochirus

(Bluegill Sunfish)	Freshwater fish and aquatic-phase amphibians	LC50	96	
14.1*	4009801-01

(Mayer and Ellersieck 1986)	Very highly toxic

Pimephales promelas

(Fathead Minnow)

NOAEC	31 (days)	2.0	000859-58

(LeBlanc et al. 1979)	NA

LOAEC

4.4

Daphnia  magna

(Water Flea)	Freshwater Invertebrates 	EC50	48	 0.93*	416273-04

(Bellantoni 1990)	Very highly toxic

NOAEC	 42 (days)	0.2	000859-64

(LeBlanc and Surprenant 1980)	NA

LOAEC

0.33

Lagodon rhomboids (Pinfish)	Estuarine/ Marine Fish	LC50	96	7.7*
000859-60

(Heitmuller 1980)	Very highly toxic

Mysidopsis bahia

(Mysid shrimp)	Estuarine/ Marine Invertebrates	LC50	96	2.4	000859-63

(Hollister 1980)	Very highly toxic

NOAEC	28 (days)	0.22	000859-63

(Hollister 1980)	NA

LOAEC

0.35

* Based on nominal concentrations.

4.2. Effects to Terrestrial Organisms

Available data on the toxicity of profenofos to terrestrial plants and
animals are summarized in Tables 3 and 4, respectively.

Tier II seedling emergence and vegetative vigor data are available to
assess the toxicity of profenofos to terrestrial plants.  In the Tier II
seedling emergence test, the dicotyledonous (dicot) cucumber (Cucumis
sativus) was the most sensitive species, based on plant dry weight. 
Effect concentrations for 25% of the plants (EC25) could not be
established for any of the other dicots tested, although lettuce
(Lactuca sativa) and cabbage (Brassica oleracea) dry weight were also
affected at concentrations below the maximum application rate.  No
adverse effects were observed in monocotyledonous plants (monocots) at
the highest test concentration in the Tier II seedling emergence test. 
In Tier II vegetative vigor studies, there were no adverse effects for
any of the tested monocots or dicots at the highest treatment level (1.0
lb a.i./A). 

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

Species 

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

(lbs a.i./A)	Test Substance (% a.i.)	Study Classification	Citation MRID

Cucumber (dicot)	Seedling Emergence

(Tier 2)

(dry weight)	EC25	0.13	90.4	Acceptable	416273-07

(Chetram 1990)

NOAEC	0.11

	All tested monocots	Seedling Emergence 

(Tier 2)	NOAEC	>1.0	90.4	Acceptable	416273-07

(Chetram 1990)

All tested monocots and dicots	Vegetative Vigor 

(Tier 2)	NOAEC	>1.0	90.4	Acceptable	416273-05

(Chetram 1990)

Profenofos is classified as moderately toxic to mammals and birds on an
acute oral basis, and highly toxic to birds on a sub-acute dietary
exposure basis.  Body weight was reduced in parents and offspring in the
rat (Ratus norvegicus) 2-generation reproduction study.  Avian
reproduction studies indicate that profenofos causes reproductive
impairment (i.e., reduction in egg production) to Northern bobwhite
quail (Colinus virginianus).  Profenofos is highly toxic to honey bees
(Apis mellifera) on an acute contact exposure basis.



Table 4.  Summary of most sensitive endpoints from submitted terrestrial
toxicity studies for profenofos.  

Species 

(common name)	Taxa Represented	End-point	Mean Concentration	Test
Substance (% a.i.)	Citation 

MRID 

	Acute Toxicity Classification

Mouse 	Mammals	LD50	298 mg/kg-bw	Tech.	001052-26

	Moderately toxic

Rattus norvegicus

(Laboratory Rat)

NOAEL	7.3 mg/kg-bw	89	432133-08

432133-09	NA

LOAEL	29 mg/kg-bw*

	Anas platyrhynchos

(Mallard Duck)	Birds, terrestrial- phase amphibians, and reptiles 

 

 

 	LD50	55 mg/kg-bw	89.4	416273-01

(Pedersen 1990)	Moderately toxic

Colinus virginianus

(Northern Bobwhite Quail) 

LC50	

57 mg/kg-diet

	Tech.	431073-01 

(Brewer and Taliaferro 1994)	Highly toxic

NOAEC	

<1 mg/kg-diet	90.6	000866-61

(Fink and Beavers 1978)	NA

LOAEC	

1 mg/kg-diet**

	Apis mellifera

(Honey Bee)	Terrestrial invertebrates	LD50	0.0953 µg/bee	90.4	416273-08

(Winter 1990)	Highly toxic

*Based on reduction in body weight.

**Based on reproductive impairment.

4.3. Incident Database Review

A preliminary review of the Ecological Incident Information System
(EIIS) maintained by the Agency’s Office of Pesticide Programs (OPP)
indicates a total of 26 reported ecological incidents associated with
the use of profenofos.  All reported incidents involved mortalities to
aquatic animals and occurred between 1989 and 1999 in Alabama, Georgia,
Louisiana, and Mississippi.  Although past and current registrations for
profenofos have been limited to use on cotton, 17 of the 26 incidents
were reported for cotton uses, while two of the areas were defined as
agricultural areas, and the remaining five areas were undefined. Two of
the profenofos uses associated with the incidents were accidental
misuses of the chemical, 12 incidents were associated with registered
uses, and the remaining 12 incidents were undetermined. The certainty
that the incidents were associated with profenofos exposure was
considered unlikely (3 incidents), possible (7 incidents), probable (10
incidents) and highly probable (6 incidents).  No incidents associated
with adverse field effects of profenofos to non-target terrestrial
animals or plants have been reported in the EIIS.

Although the number of reported incidents has dropped considerably since
mitigation measures were implemented following the 2000 IRED, the
absence of reported incidents from 2000 to the present should not be
construed as the absence of incidents.  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.  EPA’s changes in the
registrant reporting requirements of incidents may also account for the
reduced number of reported incidents.  Registrants are now only required
to submit detailed information on ‘major’ incidents.  Minor
incidents are generally reported aggregately and are not included in
EIIS.  In addition, there have been changes in state monitoring efforts
due to lack of resources.  However, the incident data that are available
indicate that exposure pathways are complete and that exposure levels
are sufficient to result in field-observable effects.  It is also
important to note that the incident data indicate that the potential
risks to aquatic animals discussed in the ecological risk assessment in
support of the reregistration eligibility decision were supported by
actual incidents occurring in the field.

4.4. Ecosystems Potentially at Risk

The ecosystems at risk are often extensive in scope; therefore, it may
not be possible to identify specific ecosystems during the development
of a nation-wide ecological risk assessment.  However, in general terms,
terrestrial ecosystems potentially at risk could include the treated
field and immediately adjacent areas that may receive drift or runoff. 
Areas adjacent to the treated field could include cultivated fields,
fencerows and hedgerows, meadows, fallow fields or grasslands,
woodlands, riparian habitats and other uncultivated areas.  

Aquatic ecosystems potentially at risk include water bodies adjacent to,
or down stream from, the treated field and could include impounded
bodies such as ponds, lakes and reservoirs, or flowing waterways such as
streams or rivers.  For uses in coastal areas, aquatic habitat also
includes marine ecosystems, including estuaries.  

5. Assessment Endpoints

Assessment endpoints represent the actual environmental value that is to
be protected, defined by an ecological entity (species, community, or
other entity) and its attribute or characteristics (USEPA 1998).    For
profenofos, the ecological entities may include the following:  birds,
mammals, terrestrial-phase amphibians, reptiles, freshwater fish and
invertebrates, aquatic-phase amphibians, estuarine/marine fish and
invertebrates, terrestrial plants, insects, and aquatic plants and
algae. The attributes for each of these entities may include growth,
reproduction, and survival.  

6.  Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological
receptors in biologically significant concentrations.  An exposure
pathway is the means by which a pesticide moves in the environment from
a source to an ecological receptor.  For an ecological pathway to be
complete, it must have a source, a release mechanism, an environmental
transport medium, a point of exposure for ecological receptors, and a
feasible route of exposure.

The conceptual model for profenofos provides a written description and
visual representation of the predicted relationships between profenofos,
potential routes of exposure, and the predicted effects for the
assessment endpoint. A conceptual model consists of two major
components: risk hypothesis and a conceptual diagram (USEPA 1998).

Based on preliminary estimated environmental concentrations (EECs) and
effects data, preliminary risk quotients (RQs) were calculated for
aquatic animals (Appendix A) and terrestrial animals and plants
(Appendices B and C).  Based on maximum application rates and available
fate data for profenofos, estimated acute and chronic RQ values are
sufficient to exceed levels of concern (LOCs) for Federally-listed
threatened/endangered (listed) and non-listed fish and invertebrates. 
Risks are also expected for non-listed and listed birds and mammals due
to acute and chronic exposures to profenofos.  Risks are expected as
well for non-listed and listed species of dicots inhabiting semi-aquatic
areas based on exposures of profenofos originating from the maximum
application rate.  Because of the potential risk from direct effects to
the listed and non-listed taxa described above, listed species in all
taxa may potentially be affected indirectly due to alterations in their
habitat and prey items (e.g., food sources, shelter, and areas to
reproduce). These preliminary conclusions are used to derive the risk
hypothesis and conceptual diagram discussed below. 

6.1.  Risk Hypothesis

A risk hypothesis describes the predicted relationship among the
stressor, exposure, and assessment endpoint response along with the
rationale for their selection.  For profenofos, the following ecological
risk hypothesis is being employed for this ecological risk assessment:

Based on the application methods, mode of action, fate and transport,
and the sensitivity of non-target aquatic and terrestrial species,
profenofos has the potential to reduce survival, reproduction, and/or
growth in non-target terrestrial and aquatic organisms when used in
accordance with the current label.  These non-target organisms include
Federally listed threatened and endangered species as well as non-listed
species.

	6.2.  Conceptual Diagram

The environmental fate properties of profenofos indicate that runoff,
spray drift, volatilization and direct spray represent potential
transport mechanisms of profenofos to aquatic and terrestrial habitats
where non-target organism may be exposed.  These transport mechanisms
(i.e., sources) are depicted in the conceptual models below (Figures 2
and 3) along with the receptors of concern and the potential attribute
changes in the receptors due to exposures of profenofos.  

 tc "2.  Diagram " \l 3 

 

Figure 2.  Conceptual model for profenofos effects on aquatic organisms.
 Dotted lines indicate exposure pathways that have a low likelihood of
contributing to ecological risk.

 

Figure 3.  Conceptual model for profenofos effects on terrestrial
organisms.  

7.  Analysis Plan

In order to address the risk hypothesis, the potential for adverse
effects on the environment is estimated.  The use, environmental fate,
and ecological effects of profenofos are characterized and integrated to
assess the risks.  This is accomplished using a risk quotient (ratio of
exposure concentration to effects concentration) approach.  Although
risk is often defined as the likelihood and magnitude of adverse
ecological effects, the risk quotient-based approach does not provide a
quantitative estimate of likelihood and/or magnitude of an adverse
effect.  However, as outlined in the Overview Document (USEPA 2004), the
likelihood of effects to individual organisms from particular uses of
profenofos is estimated using the probit dose-response slope and either
the level of concern (discussed below) or the actual calculated risk
quotient value.  

This 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.

	7.1.  Stressors of Concern

As discussed above, profenofos degrades into 4-bromo-2-chlorophenol and
O-ethyl-S-propyl phosphorthioate.  Based on previous assessments (e.g.,
see the IRED, USEPA 2000), no major degradates of toxicological concern
were identified.  Therefore, the focus of this assessment is expected to
be the parent, profenofos.  However, the Agency will review all
available current degradate ecotoxicity data to identify any additional
stressors of concern for this assessment.

In its ecological risk assessments, the Agency does not routinely
include an evaluation of mixtures of active ingredients, either those
mixtures of multiple active ingredients in product formulations or those
in the applicator’s tank. In the case of the product formulations of
active ingredients (that is, a registered product containing more than
one active ingredient), each active ingredient is subject to an
individual risk assessment for regulatory decision regarding the active
ingredient on a particular use site.  If effects data are available for
a formulated product containing more than one active ingredient, the
data may be used qualitatively or quantitatively in accordance with the
Agency’s Overview Document and the Services’ Evaluation Memorandum
(USEPA 2004; USFWS/NMFS 2004).     

Available toxicity data for environmental mixtures of profenofos with
other pesticides will be presented as part of the ecological risk
assessment.  It is expected that the toxic effect of profenofos, in
combination with other pesticides used in the environment, is likely to
be a function of many factors including but not necessarily limited to:
(1) the exposed species, (2) the co-contaminants in the mixture, (3) the
ratio of profenofos and co-contaminant concentrations, (4) differences
in the pattern and duration of exposure among contaminants, and (5) the
differential effects of other physical/chemical characteristics of the
receiving waters (e.g. organic matter present in sediment and suspended
water).  Quantitatively predicting the combined effects of all these
variables on mixture toxicity to any given taxa with confidence is
beyond the capabilities of the available data and methodologies. 
However, a qualitative discussion of implications of the available
pesticide mixture effects data on the confidence of risk assessment
conclusions will be addressed as part of the uncertainty analysis.

	7.2.  Measures of Exposure

In order to estimate risks of profenofos exposures in aquatic and
terrestrial environments, all exposure modeling and resulting risk
conclusions will be made based on maximum application rates for cotton
discussed in Section 5.  Measures of exposure are based on aquatic and
terrestrial models that predict estimated environmental concentrations
of profenofos using maximum labeled application rates and methods, as
well as any mitigation measures specifically indicated on the label
(e.g. spray drift buffers).  The models used to predict aquatic EECs are
the Pesticide Root Zone Model coupled with the Exposure Analysis Model
System (PRZM/EXAMS).  The model used to predict terrestrial EECs on food
items is T-REX.  The model used to derive EECs relevant to terrestrial
and wetland plants is TerrPlant.  These models are parameterized using
relevant reviewed registrant-submitted environmental fate data.

PRZM (v3.12.2, May 2005) and EXAMS (v2.98.4.6, April 2005) are screening
simulation models coupled with the input shell pe5.pl (Aug 2007) to
generate daily exposures and 1-in-10 year EECs of profenofos that may
occur in surface water bodies adjacent to application sites receiving
profenofos through runoff and spray drift.   PRZM simulates pesticide
application, movement and transformation on an agricultural field and
the resultant pesticide loadings to a receiving water body via runoff,
erosion and spray drift.  EXAMS simulates the fate of the pesticide and
resulting concentrations in the water body.  The standard scenario used
for ecological pesticide assessments assumes application to a 10-hectare
agricultural field that drains into an adjacent 1-hectare water body
that is 2 meters deep (20,000 m3 volume) with no outlet.  PRZM/EXAMS is
used to estimate screening-level exposure of aquatic organisms to
profenofos.  The measure of exposure for aquatic species is the 1-in-10
year return peak or rolling mean concentration.  The 1-in-10 year peak
is used for estimating acute exposures of direct effects to aquatic
organisms. The 1-in-10-year 60-day mean is used for assessing chronic
exposure to fish and aquatic-phase amphibians. The 1-in-10-year 21-day
mean is used for assessing aquatic invertebrate chronic exposure.

Exposure estimates for terrestrial animals assumed to be in the target
area or in an area exposed to spray drift are derived using the T-REX
model (version 1.3.1, 12/07/2006).    SEQ CHAPTER \h \r 1 This model
incorporates the Kenega nomograph, as modified by Fletcher et al.
(1994), which is based on a large set of actual field residue data. The
upper limit values from the nomograph represent the 95th percentile of
residue values from actual field measurements (Hoerger and Kenega,
1972).  The Fletcher et al. (1994) modifications to the Kenega nomograph
are based on measured field residues from 249 published research papers,
including information on 118 species of plants, 121 pesticides, and 17
chemical classes.  EECs for terrestrial plants inhabiting dry and
wetland areas are derived using TerrPlant (version 1.2.2, 12/26/2006). 
This model uses estimates of pesticides in runoff and in spray drift to
calculate EECs.  EECs are based upon solubility, application rate and
minimum incorporation depth.  

The AgDRIFT spray drift model (version 2.01; dated 5/24/2001) is used to
assess exposures of terrestrial plants to profenofos deposited on
terrestrial habitats by spray drift. AgDRIFT will also be used to
determine the appropriate PRZM/EXAMS parameter values for modeling the
percent drift corresponding to the buffers indicated on the label. 

	7.3.  Measures of Effect

 

Ecological effects data are used as measures of direct and indirect
effects to biological receptors.  Data are obtained from
registrant-submitted studies or from literature studies identified by
ECOTOX.  The ECOTOX database (USEPA 2007d) provides more ecological
effects data in an attempt to bridge existing data gaps.  ECOTOX is a
source for locating single chemical toxicity data and potential chemical
mixture toxicity data for aquatic life, terrestrial plants, and
wildlife.  ECOTOX was created and is maintained by the USEPA, Office of
Research and Development, and the National Health and Environmental
Effects Research Laboratory's Mid-Continent Ecology Division.

Information on the potential effects of profenofos on non-target animals
is also collected from the Ecological Incident Information System (EIIS;
USEPA 2007b).  The EIIS is a database containing adverse effect
(typically mortality) reports on non-target organisms   where such
effects have been associated with the use of pesticides.   

Where available, sublethal effects observed in both registrant-submitted
and open literature studies will be evaluated qualitatively.  Such
effects may include behavioral changes (e.g., lethargy and changes in
coloration).  Quantitative assessments of risks, though, are limited to
those endpoints that can be directly linked to the Agency’s assessment
endpoints of impaired survival, growth and reproduction.

  SEQ CHAPTER \h \r 1 The assessment of risk for direct effects to
non-target organisms makes the assumption that toxicity of profenofos to
birds is similar to terrestrial-phase amphibians and reptiles.  The same
assumption is made for fish and aquatic-phase amphibians. 

The acute measures of effect used for animals in this assessment are the
LD50, LC50 and EC50.  LD stands for "Lethal Dose", and LD50 is the
amount of a material, given all at once, that is estimated to cause the
death of 50% of the test organisms.  LC stands for “Lethal
Concentration” and LC50 is the concentration of a chemical that is
estimated to kill 50% of the test organisms.  EC stands for “Effective
Concentration” and the EC50 is the concentration of a chemical that is
estimated to produce a specific effect in 50% of the test organisms. 
Endpoints for chronic measures of exposure for listed and non-listed
animals are the NOAEL/NOAEC and NOEC.  NOAEL stands for “No
Observed-Adverse-Effect-Level” and refers to the highest tested dose
of a substance that has been reported to have no harmful (adverse)
effects on test organisms.  The NOAEC (i.e.,
“No-Observed-Adverse-Effect-Concentration”) is the highest test
concentration at which none of the observed effects were statistically
different from the control.  The NOEC is the
No-Observed-Effects-Concentration.  For non-listed plants, only acute
exposures are assessed (i.e., EC25 for terrestrial plants and EC50 for
aquatic plants); for listed plants either the NOAEC or EC05 is used.  

 

	7.4. Integration of Exposure and Effects

Risk characterization is the integration of exposure and ecological
effects characterization to determine the potential ecological risk from
the use of profenofos on cotton and the likelihood of direct and
indirect effects to non-target organisms in aquatic and terrestrial
habitats.  The exposure and toxicity effects data are integrated in
order to evaluate the risks of adverse ecological effects on non-target
species.  For the assessment of profenofos risks, the risk quotient (RQ)
method is used to compare exposure and measured toxicity values.  EECs
are divided by acute and chronic toxicity values.  The resulting RQs are
then compared to the Agency’s Levels of Concern (LOCs) (USEPA 2004). 
These criteria are used to indicate when profenofos’s uses, as
directed on the label, have the potential to cause adverse direct or
indirect effects to non-target organisms.  In addition, incident data
from the EIIS will be considered as part of the risk characterization.  

                  

	7.5. Deterministic and Probabilistic Assessment Methods

The quantitative assessment of risk will primarily depend on the
deterministic point-estimate based approach described in the risk
assessment.  An effort will be made to further qualitatively describe
risk using probabilistic tools that the Agency has developed.  These
tools have been reviewed by FIFRA Scientific Advisory Panels ( 
HYPERLINK "http://www.epa.gov/scipoly/sap/index.htm" 
http://www.epa.gov/scipoly/sap/index.htm ) and have been deemed as
appropriate means of refining assessments where deterministic approaches
have identified risks.

	7.6. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered
Species Act (ESA), the Agency will evaluate risks to Federally-listed
threatened and/or endangered (listed) species from registered uses of
profenofos.  This assessment will be conducted in accordance with the
Overview Document (USEPA 2004), provisions of the ESA, and the
Services’ Endangered Species Consultation Handbook (USFWS/NMFS, 1998).

The assessment of effects associated with the registration of profenofos
is based on an action area.  The action area is considered to be the
area directly or indirectly affected by the federal action, as indicated
by the exceedance of Agency Levels of Concern (LOCs) used to evaluate
direct or indirect effects.  The Agency’s approach to defining the
action area under the provisions of the Overview Document (USEPA 2004)
considers the results of the risk assessment process to establish
boundaries for that action area with the understanding that exposures
below the Agency’s defined LOCs constitute a no-effect threshold.  
For the purposes of this assessment, attention will be focused on the
footprint of the action (i.e., the area where profenofos application
occurs), plus all areas where offsite transport (i.e., spray drift,
runoff, etc.) may result in potential exposure that exceeds the
Agency’s LOCs.  Specific measures of ecological effect that define the
action area for listed species include any direct and indirect effects
and/or potential modification of its critical habitat, including
reduction in survival, growth, and reproduction as well as the full
suite of sublethal effects available in the effects literature. 
Therefore, the action area extends to a point where environmental
exposures are below any measured lethal or sublethal effect threshold
for any biological entity at the whole organism, organ, tissue, and
cellular level of organization.  In situations where it is not possible
to determine the threshold for an observed effect, the action area is
not spatially limited and is assumed to be the entire United States.

7.7. Drinking Water Assessment

A drinking water assessment will be conducted to support future human
health risk assessments of profenofos. The drinking water assessment
will incorporate model estimates of profenofos in surface and ground
waters.  Concentrations of profenofos in surface waters will be
estimated using PRZM/EXAMS (see description above). Ground water
estimates of profenofos concentrations will be estimated using the
Screening Concentration in Ground Water (SCI-GROW) model (v.2.3, July
2003).  The drinking water assessment will also include a summary of
available surface and ground water monitoring data.  

7.8. Preliminary Identification of Data Gaps

		7.8.1. Fate

The environmental fate data requirements for profenofos are partially
fulfilled with some data gaps still remaining (Table 5).  Data gaps
include: an aerobic aquatic metabolism half-life and quantification of
leaching and adsorption/desorption of profenofos on various U.S. soils. 
The data gaps are discussed below. 

Table 5. Available environmental fate data for profenofos and remaining
data gaps.

Guideline	Description	MRID	Classification	Data Gap?	comments

835.2120	Hydrolysis	41627309	Acceptable	No	

*MRID 44683901 is under review. This review will be completed as part of
registration review.

**MRID 41627311 was originally classified as “acceptable” and was
used to fulfill this guideline requirement.  Reevaluation of this study
indicates that it is invalid since test soils were autoclaved prior to
treatment with profenofos.

41939001	Acceptable

835.2240	Photodegradation in water	41879901	Acceptable	No

	41939002	Acceptable

835.2410	Photodegradation in soil	41627310	Supplemental	No

	44683901	Undetermined at this time*

835.2370	Photodegradation in air	42030401	Supplemental	No

	835.4100	Aerobic soil metabolism	42334302	Acceptable	No

	835.4200	Anaerobic soil metabolism	42334303	Acceptable	No

	835.4300	Aerobic Aquatic Metabolism	none	none	Yes

	835.4400	Anaerobic Aquatic Metabolism	42218101	Acceptable	No

	835.1230

835.1240	 Leaching and adsorption/

desorption	none**	none	Yes

	835.1410	Laboratory Volatility	41905001	Supplemental	No

	835.6100	Terrestrial Field Dissipation	42851301	Supplemental	No

	42900901	Supplemental

165-4	Bioaccumulation in Fish	85952	Supplemental	No

	92148059

	

Aquatic Metabolism

Acceptable data have not been provided to quantify the metabolism of
profenofos under aerobic aquatic conditions. According to Code of
Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data
requirements for pesticides) aerobic aquatic metabolism are required for
pesticides with terrestrial uses. Since profenofos use on cotton is
considered to be terrestrial, aerobic aquatic metabolism data for
profenofos should be submitted to fulfill OPPTS Guideline 835.4300.
These data are used to estimate the degradation of profenofos in aquatic
systems and ultimately to derive aquatic EECs using PRZM/EXAMS. In the
case that these data are unavailable at the time risk assessments are
conducted, PRZM/EXAMS input parameter guidance default values will be
employed to account for aerobic aquatic metabolism (See Table A.1. of
Appendix A).

Leaching and Adsorption/Desorption

At this time, there are no acceptable studies to quantify the adsorption
and desorption characteristics of profenofos in U.S. soils.  EFED
recommends that the Special Review and Reregistration Division (SRRD)
request the submission of an acceptable study under OPPTS Guideline
835.1230 to define Kd and KOC values of profenofos in U.S. soils. In the
absence of these data, EFED will assume that there is no sorption of
profenofos to soils or organic matter on the treatment site.  In order
to implement this in derivation of aquatic EECs, a KOC value of 0 will
be used to parameterize PRZM/EXAMS.  Input of a KOC value >0 is expected
to result in lower aquatic EECs. If acceptable data are provided, the
uncertainties associated with this assumption will be reduced.

7.8.2. Effects

Although many submissions have been made to provide data on the effects
of profenofos to aquatic and terrestrial organisms, several data gaps
still exist (Tables 6 – 8).  Data gaps include the following: avian
acute oral toxicity, early-life stage estuarine/marine fish toxicity,
and aquatic plant growth studies. The data gaps are discussed below. 

Table 6. Available ecological effects data for terrestrial animals
exposed to profenofos and remaining data gaps.

Guideline	Description	MRID/

Accession	Classification	Data Gap?	Comments

850.2100	Avian oral toxicity	41627301*	Acceptable	Yes*	*Avian acute oral
toxicity data are not available for passerines, which are required under
the new 40 CFR Part 158.  An acute oral toxicity study using passerines
must be submitted to fulfill this data requirement.

00099113	Supplemental

850.2200	Avian dietary toxicity 	00099114	Supplemental	No

	43107302	Acceptable

43107301	Acceptable

00099115	Acceptable

850.2300	Avian reproduction	00072150	Supplemental	No

	00083076	Acceptable

00086661	Acceptable

850.3020	Honeybee acute contact toxicity	41627308	Acceptable	No

	



Table 7. Available ecological effects data for aquatic animals exposed
to profenofos and remaining data gaps.

Guideline	Description	MRID/ Accession	Classification	Data Gap?	comments

850.1075	Freshwater fish – 

Acute toxicity 	400980101	Supplemental	No	

*A saltwater fish early-life stage test (850.1400) is required for
profenofos because the acute toxicity value for saltwater fish is < 1
mg/L.

**A freshwater fish full life-cycle test (835.1500) was requested for
profenofos based on the 2006 IRED; however, a waiver was granted for
this request, given that an acceptable early life stage freshwater fish
study is available.

TN 2399	Supplemental

00083075	Acceptable

00085953	Supplemental

00072148	Acceptable

00085958	Supplemental

00072149	Acceptable

TN 2400	Acceptable

850.1075	Saltwater fish – 

Acute toxicity 	00085960	Acceptable	No

	850.1010	Freshwater invertebrates –

Acute toxicity	41627304	Acceptable	No

	00085964	Supplemental

00108015	Supplemental

252706	Supplemental

850.1025

850.1035

850.1045

850.1055	Saltwater invertebrates –

Acute toxicity 	00085963	Acceptable	No

	00085961	Acceptable

00085959	Acceptable

00085962	Acceptable

850.1300	Freshwater  invertebrate –

 life cycle test	00085964	Acceptable	No

	850.1350	Saltwater invertebrates – 

life cycle test	00085963	Acceptable	No

	850.1400	Freshwater fish – 

early life stage test	00085958	Acceptable	No

	850.1400	Saltwater fish – 

early life stage test	None	Not Applicable	Yes*

	850.1500	Fish – 

life cycle test	None	Not Applicable	No**

	



Table 8. Available ecological effects data for plants exposed to
profenofos and remaining data gaps.

Guideline	Description	MRID	Classification	Data Gap?	comments

850.4100	Terrestrial Plant toxicity: Tier I seedling emergence	None	Not
applicable	No	

*Non-target aquatic plant data are required for profenofos at the Tier 1
level.

850.4225	Terrestrial Plant toxicity: Tier 2 seedling emergence	41627307
Acceptable	No

	850.4150	Terrestrial Plant toxicity: Tier I vegetative vigor	None	Not
applicable	No

	850.4150	Terrestrial Plant toxicity: Tier 2 vegetative vigor	41627305
Acceptable	No

	850.4400	Aquatic Plant Growth: algae	None	Not applicable	Yes*

	850.4400	Aquatic Plant Growth: vascular plants	None	Not applicable	Yes*

	

Avian Acute Oral Toxicity 

Acceptable acute avian oral toxicity data were submitted for exposures
of mallard duck to profenofos; however, data are not available for
passerines, which are required under the new 40 CFR Part 158 (CFR 40
2007) data requirements for conventional pesticides (72 FR 60934; USEPA
2007c).  The new Part 158 data requirements specify that acute avian
oral toxicity data be submitted for either a mallard duck or bobwhite
quail AND a passerine species.  Based on the results of previous
ecological risk assessments for profenofos and derivation of preliminary
RQs in this problem formulation (Section 6 and Appendix B), risks are
expected for non-listed and listed birds due to acute exposures to
profenofos.  Therefore, an avian oral toxicity test (OPPTS Guideline
850.2100;
http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological
_Effects_Test_Guidelines/Drafts/850-2100.pdf) is required for passerine
birds, as specified in 40 CFR Part 158 (CFR40 2007).  EFED suggests that
SRRD request submission of a passerine study protocol for review by the
Agency prior to initiation of this study.  If oral acute toxicity data
are not submitted for passerines, EFED will assume acute risk for
passerine species.

Chronic Toxicity Studies with Estuarine and Marine Fish

Chronic toxicity data are not available for estuarine and marine fish. 
In the absence of these data, an acute-to-chronic ratio (ACR) would
normally be derived; and the chronic toxicity to estuarine and marine
fish would be estimated based on the ACR for freshwater fish.  However,
an ACR cannot be derived because the freshwater fish data necessary for
calculating the ACR are not available. Chronic data are not available
for the most acutely sensitive freshwater species (bluegill sunfish;
Lepomis macrochirus), and definitive acute data are not available for
the most chronically sensitive freshwater species (fathead minnow). 
Based on the results of previous ecological risk assessments for
profenofos and derivation of preliminary aquatic RQs in this problem
formulation (Section 6 and Appendix A), risks are expected for
non-listed and listed fish due to chronic exposures to profenofos in
aquatic habitats.  In addition, the majority of reported ecological
incidents associated with the use of profenofos have involved fish
kills.  Therefore, an estuarine/marine fish early life-stage toxicity
test (OPPTS Guideline 850.1400;
http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological
_Effects_Test_Guidelines/Drafts/850-1400.pdf) is required in order to
fulfill the data requirement.  In the absence of chronic toxicity data
for estuarine and marine fish, EFED will assume chronic risk to these
taxa.

Aquatic Plant Studies 

Toxicity data for vascular and non-vascular aquatic plants are not
available.  Based on the 40 CFR Part 158 data requirements, Tier I level
non-target aquatic plant data are required for all insecticides.  In
addition, available data for non-target terrestrial plants show impacts
to cucumber seedling emergence at a concentration less than the maximum
single application rate for profenofos.  Therefore, this data gap must
be filled, and non-target aquatic plant data for algae and vascular
plants (OPPTS Guideline 850.4400;
http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological
_Effects_Test_Guidelines/Drafts/850-4400.pdf) are required for
profenofos at the Tier 1 level.  In the absence of Tier I data, EFED
will assume risk to both vascular and non-vascular aquatic plants.

8.  References

CFR 40.  2007.  Code of Federal Regulations 40 Parts 150 to 189. 
Protection of the Environment.  U.S. Government Printing Office.

Fletcher, J.S., J.E. Nellessen, and T.G. Pfleeger.  1994.  Literature
review and evaluation of the EPA food-chain (Kenaga) nomogram, an
instrument for estimating pesticide residues on plants.  Environ. Tox.
Chem. 13:1383-1391.

  SEQ CHAPTER \h \r 1 Hoerger, F. and E. E. Kenaga, 1972. Pesticide
Residues on Plants: Correlation of Representative Data as a Basis for
Estimation of their Magnitude in the Environment. In F. Coulston and F.
Korte, eds., Environmental Quality and Safety: Chemistry, Toxicology,
and Technology, Georg Thieme Publ., Stuttgart, West Germany, pp. 9-28.

Mayer, F.; Ellersieck, M.  1986.  Manual of Acute Toxicity: 
Interpretation and Data Base 410 Chemicals and 66 Species of Fresh-Water
Animals.  US Fish & Wildlife Service; Resource Publication (160):  579
p.

U.S.Department of Agriculture (USDA). 2007. National Agricultural
Statistics Service. United States Department of Agriculture. Available
online at:   HYPERLINK "http://www.nass.usda.gov/" 
http://www.nass.usda.gov/ .

U.S. Environmental Protection Agency (USEPA).  1998.  Guidelines for
Ecological Risk Assessment.  Risk Assessment Forum, Office of Research
and Development,  Washington, D.C.  EPA/630/R-95/002F.  April 1998.  
HYPERLINK "http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=30759" 
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=30759  

USEPA.  2000.   Interim Registration Eligibility Decision (IRED):
Profenofos.  U.S. Environmental Protection Agency, Office of Pesticide
Programs, Washington, DC.  August, 2000.  

USEPA. 2002. Guidance for Selecting Input Parameters in Modeling the
Environmental Fate and Transport of Pesticides, Version II. US
Environmental Protection Agency, Washington DC. Online at:
http://www.epa.gov/oppefed1/models water/input_guidance2_28_02.htm.

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.  2006.   Reregistration Eligibility Decision (IRED): Profenofos. 
U.S. Environmental Protection Agency, Office of Pesticide Programs,
Washington, DC.  July, 2006.  

USEPA.  2007a.   Profenofos: transmittal of section 18 for profenofos to
control rice panicle mite on rice in Texas.  U.S. Environmental
Protection Agency, Office of Pesticide Programs, Washington, DC. 
September 2007. 

USEPA.  2007b.  Ecological Incident Information System.   HYPERLINK
"http://www.epa.gov/espp/consultation/ecorisk-overview.pdf" 
http://www.epa.gov/espp/consultation/ecorisk-overview.pdf 

USEPA. 2007c.  40 CFR Part 158.  Pesticides; Data Requirements for
Conventional Chemicals: Final Rule. 72 FR 60934.  October 26, 2007.

USEPA. 2007d.  ECOTOXicology Database.  Office of Research and
Development National Health and Environmental Effects Research
Laboratory’s (NHEERL’s) Mid-Continent Ecology Division (MED).  
HYPERLINK "http://cfpub.epa.gov/ecotox/"  http://cfpub.epa.gov/ecotox/  

U.S. Fish and Wildlife Service (USFWS) and National Marine Fisheries
Service (NMFS).  1998.  Endangered Species Consultation Handbook: 
Procedures for Conducting Consultation and Conference Activities Under
Section 7 of the Endangered Species Act.  Final Draft.  March 1998.

 

SUBMITTED FATE STUDIES:

MRID		

000859-52 	Cargile, N.L., and J.E. Cassidy.  1977.  The metabolism of
o-14C-CGA-15324 in bluegill sunfish.  Report No. ABR-77076.  Unpublished
study performed and submitted by Ciba-Geigy Corporation, Greensboro, NC.
 

416273-09	Ziegler, D.A., and S.A. Hallenbeck.  1988.  Hydrolysis of
profenofos in aqueous solutions.  Laboratory Project ID 1091A. 
Unpublished study performed by Analytical Development Corporation,
Colorado Springs, CO, and submitted by Ciba-Geigy Corporation,
Greensboro, NC.

416273-10	Das, Y.T.  1989a.  Photodegradation of
[phenyl(U)14C]profenofos on soil under artificial sunlight.  Laboratory
Project Number ISSI No. 89131.  Unpublished study performed by
Innovative Scientific Services, Inc., Piscataway, NJ, and submitted by
Ciba-Geigy Corporation, Greensboro, NC.

416273-11	Yu, W.C.  1987.  Determination of adsorption/desorption
constants of profenofos.  Laboratory Project Study Number 14300. 
Unpublished study performed by Cambridge Analytical Associates, Inc.,
Boston, MA and submitted by Ciba-Geigy Corporation, Greensboro, NC. 

418799-01	Das, Y.T.  1989b.  Photodegradation of
[phenyl(U)-14C]profenofos in aqueous solution buffered at pH 5 under
artificial sunlight.  Laboratory Project No. 89132.  Unpublished study
performed by Innovative Scientific Services, Inc., Piscataway, NJ, and
submitted by Ciba-Geigy Corporation, Greensboro, NC.

419050-01	Carpenter, M.  1991.  Laboratory volatility of 14C-profenofos.
 ABC Laboratories' No. 39119.  Ciba-Geigy Protocol No. 141-90. 
Unpublished study performed by ABC Laboratories, Columbia, MO; submitted
by Ciba-Geigy Corporation, Greensboro, NC.

419390-01	Das, Y.T.  1990a.  Hydrolysis of [phenyl(U)-14C]profenofos in
aqueous solutions buffered at pH 5, 7, and 9.  Laboratory Project No.
90122.    Ciba-Geigy Protocol No. 146-90.  Unpublished study performed
by Innovative Scientific Services, Inc., Piscataway, NJ, and submitted
by Ciba-Geigy Corporation, Greensboro, NC.

419390-02	Das, Y.T.  1990b.  Photodegradation of
[phenyl(U)-14C]profenofos in aqueous solution buffered at pH 5 under
artificial sunlight.  Laboratory Project No. 90121.  Ciba-Geigy Protocol
No. 147-90.  Unpublished study performed by Innovative Scientific
Services, Inc., Piscataway, NJ, and submitted by Ciba-Geigy Corporation,
Greensboro, NC.

420304-01	Kieatiwong, S.  1991.  Photodegradation of [14C]-profenofos in
the vapor phase by natural sunlight.  Laboratory Project ID:  PTRL
Project No. 310W.  Ciba-Geigy Protocol No. 12-91.  Unpublished study
performed by Pharmacology and Toxicology Research Laboratory, Richmond,
CA, and submitted by Ciba-Geigy Corporation, Greensboro, NC.

422181-01	Das, Y. T.  1992a.  Metabolism of [phenyl(U)-14C]profenofos
under anaerobic aquatic soil conditions.  ISSI No. 90123, Ciba-Geigy
Study No. 156-90.  Unpublished study performed by Innovative Scientific
Services, Inc., Piscataway, NJ, and submitted by Ciba-Geigy Corporation,
Greensboro, NC.

423343-02	Das, Y.T.  1992b.  Metabolism of [phenyl(U)-14C]profenofos
under aerobic soil conditions.  ISSI No. 91030; Ciba-Geigy Study No.
18-91.  Unpublished study performed by Innovative Scientific Services,
Inc., Piscataway, NJ, and submitted by Ciba-Geigy Corporation,
Greensboro, NC.

423343-03	Das, Y. T.  1991.  Metabolism of [phenyl(U)-14C]profenofos
under anaerobic soil conditions.  ISSI No. 91031, Ciba-Geigy Study No.
19-91.  Unpublished study performed by Innovative Scientific Services,
Inc., Piscataway, NJ, and submitted by Ciba-Geigy Corporation,
Greensboro, NC.

428513-01	Selman, F., and Larson, M.  1993a.  Terrestrial Dissipation of
Profenofos (Curacron 8E) on Bareground and Cotton in California. 
Unpublished study performed by Pan-Agricultural Laboratories, Inc.,
Madera, CA and Agricultural & Priority Pollutants Laboratories, Inc.,
Fresno, CA; submitted by Ciba Plant Protection, Greensboro, NC.

429009-01	Selman, F., and Larson, M.  1993b.  Terrestrial Dissipation of
Profenofos (Curacron 8E) on Bareground and Cotton in Texas.  An
unpublished study performed by Pan-Agricultural Laboratories, Inc. 
Madera, CA and Enseco-Cal Labs, West Sacramento, CA and submitted by
Ciba Plant Protection, Greensboro, NC.

921480-59	Swidersky, P.  1990.  Phase 3 summary of MRID 00085952: The
metabolism of 0-14C-CGA-15324 in bluegill sunfish: Project MI2-130-4F. 
Report No. ABR-77076.  Unpublished study performed by Ciba-Geigy
Corporation, Greensboro, NC and EG & G Bionomics, Wareham, MA.

SUBMITTED EFFECTS STUDIES:

000721-46	Ciba-Geigy Corporation (1978) Commentary and Reports of
Investigations Made with Respect to the Environmental Safety of Curacron
(CGA-15324, Profenfos) to Wildlife. Summary of studies 237826-B through
237826-H. (Unpublished study received Mar 20, 1979 under 100-598;
CDL:237826-A). 

000859-58	LeBlanc, G.A.; Hoberg, J.R.; Dean, J.W. (1979) The Toxicity of
CGA- 15324 to Fathead Minnow (Pimephales promelas) Eggs and Fry: Report
#BW-79-6-490. (Unpublished study received Nov 6, 1981 under 100-598;
prepared by EG & G, Bionomics, submitted by Ciba- Geigy Corp.,
Greensboro, N.C.; CDL:246216-L).

000859-60	Heitmuller, T. (1980) Acute Toxicity of Profenofos to Pinfish
(Lagodon rhomboides): Report No. BP-80-2-35. (Unpublished study received
Nov 6, 1981 under 100-598; prepared by EG & G, Bionomics, submitted by
Ciba-Geigy Corp., Greensboro, N.C.; CDL: 246216-N).

000859-63	Hollister, T.A. (1980) Acute and Chronic Toxicity of
Profenofos to Mysid Shrimp (Mysidopsis bahia): Report No. BP-80-2-40.
(Unpublished study received Nov 6, 1981 under 100-598; prepared by EG &
G, Bionomics, submitted by Ciba-Geigy Corp., Greensboro, N.C.;
CDL:246216-Q).

000859-64	LeBlanc, G.A.; Surprenant, D.C. (1980) The Chronic Toxicity of
CGA- 15234 to the Water Flea (Daphnia magna): Report #BW-80-2- 611.
(Unpublished study received Nov 6, 1981 under 100-598; prepared by EG &
G, Bionomics, submitted by Ciba-Geigy Corp., Greensboro, N.C.;
CDL:246216-R).

000866-61	Fink, R.; Beavers, J.B. (1978) Final Report: One-generation
Repro- duction Study--Bobwhite Quail: CGA-15324 Technical: Project No.
108-151. (Unpublished study received Nov 6, 1981 under 100- 598;
prepared by Wildlife International, Ltd., submitted by Ciba-Geigy Corp.,
Greensboro, N.C.; CDL:246218-AB)

001052-26	Bathe, R. (1974) Acute Oral LD50 of Technical CGA-15324 in the
Mouse: Project No. Siss 3647. (Unpublished study received Feb 14, 1979
under 100-598; prepared by Ciba-Geigy, Ltd., Switz., submitted by
Ciba-Geigy Corp., Greensboro, NC; CDL:097794-F).

001052-42	Ciba-Geigy Corp. (1979) Follow-up to EPA Meeting of November
13, 1978, on Curacron Potential For Chronic Exposure to Aquatic
Organisms: Report No. ABR-79026. (Compilation; unpublished study
received Mar 20, 1979 under 100-598; CDL:237827.

416273-01	Pedersen, C. (1990) Profenofos Technical: 21-Day Acute Oral
LD50 Study in Mallard Ducks: Lab Project Number: 89 DD 75. Unpub- lished
study prepared by Bio-Life Associates, Ltd. 40 p.

416273-04	Bellantoni, D. (1990) Profenofos Technical: A 48-Hour Static
Acute Toxicity Test with the Cladoceran (Daphnia magna): Lab Project
Number: 108A. Unpublished study prepared by Wildlife Interna- tional
Ltd. 20 p.

416273-05	Chetram, R. (1990) Profenofos: Tier 2 Vegetative Vigor
Nontarget Phytotoxicity Study using Profenofos Technical (Curacron): Lab
Project Number: LR90-408. Unpublished study prepared by Pan-
Agricultural Laboratories, Inc. 133 p.

416273-07	Chetram, R. (1990) Profenofos: Tier 2 Seedling Emergence
Notarget Phytotoxicity Study using Profenofos Technical (Curacron): Lab
Project Number: LR90-410. Unpublished study prepared by Pan-
Agricultural Laboratories, Inc. 135 p. 

416273-08	Winter, P. (1990) Profenofos: An Acute Contact Toxicity Study
with the Honey Bee: Lab Project Number: 108-321. Unpublished study
prepared by Wildlife International Ltd. 17 p. 

431073-01	Brewer, L.; Taliaferro, L. (1994) Profenofos Technical: CGA
15324: Eight-Day Dietary LC50 Study in Northern Bobwhite: Lab Project
Number: 019301. Unpublished study prepared by Ecotoxicity and Biosystems
Associates, Inc. 108 p.

431073-02	Taliaferro, L. (1994) Profenofos Technical: CGA 15324:
Eight-Day Dietary LC50 Study in the Mallard Duck: Lab Project Number:
019302. Unpublished study prepared by Ecotoxicity and Biosystems
Associates, Inc. 110 p. 

432133-08	Minor, J.; Richter, A. (1994) A Two-Generation Reproduction
Study in Rats with CGA-15324 Technical: Final Report: Lab Project
Number: F-00102. Unpublished study prepared by Ciba-Geigy Corp.,
Environmental Health Center. 822 p. 

432133-09	Gilles, P. (1994) A Two-Generation Reproduction Study in Rats
with CGA-15324 Technical: Amendment 1 to Final Report: Lab Project
Number: F-00102. Unpublished study prepared by Ciba-Geigy Corp.,
Environmental Health Center. 9 p.

 

921480-04	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00085810. One Generation Reproduction Study of Profenofos (CGA-15324) in
Bobwhite Quail: Report No. 108-173. Prepared by WILDLIFE INTERNATIONAL
LTD. 24 p.

921480-06	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00072150. One Generation Reproduction Study of Profenofos (CGA-15324) in
Mallard Duck: Report No. 108-153. Prepared by WILDLIFE INTERNATIONAL
LTD. 21 p. 

921480-08	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00083075. Acute Toxicity of Profenofos (CGH 15324) Technical to Bluegill
(Lepomis macrochirus): Report No. BW-78-12-371. Prepared by EG &G
Bionomics. 16 p. 

921480-09	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00072149. Acute Toxicity of Profenofos (CGA-15324) Technical to Rainbow
Trout (Salmo gairdneri): Report No. BW-79-1-382. Prepared by EG &G
Bionomics. 18 p. 

921480-10	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00085960. Acute Toxicity of Profenofos (CGA-15324) to Pinfish (Lagodon
rhomboides): Report No. BP-80-2-35. Prepared by EG & G Bionomics Marine
Research Lab. 17 p. 

921480-11	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00085962. Acute Toxicity of Profenofos to Eastern Oysters (Crassostrea
virginica): Report No. BP-80-2-37. Prepared by EG & G Bionomics Marine
Research Lab. 18 p.

921480-12	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00085961. Acute Toxicity of Profenofos to Pink Shrimp (Penaeous
duorarum): Report No. BP-80-2-36. Prepared by EG & G Bionomics Marine
Research Lab. 17 p. 

921480-13	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00085964. Chronic Toxicity of Profenofos Technical to Daphnia magna
under Flow-through Conditions: Report No. BW-80-2-611. Prepared by EG&G
Bionomics. 20 p. 

921480-14	Plautz, J. (1990) Ciba-Geigy Corp. Phase 3 Summary of MRID
00085958. Toxicity of Profenofos (CGA-15324) Technical to Fathead Minnow
(Pimephales promelas): Report No. BW-79-6-490. Prepared by EG&G
Bionomics. 17 p. 

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

PRZM (v3.12.2, May 2005) and EXAMS (v2.98.4.6, April 2005) are
simulation models.  These models are run using the input shell pe5.pl
(Aug 2007) to generate daily exposures and 1-in-10 year estimated
environmental concentrations (EECs) for profenofos.  The conceptual
model for exposure represents surface water bodies adjacent to
application sites receiving profenofos through runoff and spray drift. 
PRZM simulates pesticide application, movement and transformation on an
agricultural field and the resultant pesticide loadings to a receiving
water body via runoff, erosion and spray drift.  EXAMS simulates the
fate of the pesticide and resulting concentrations in the water body. 
The standard scenario used for ecological pesticide assessments assumes
application to a 10-hectare agricultural field that drains into an
adjacent 1-hectare water body, 2-meters deep (20,000 m3 volume) with no
outlet.  PRZM/EXAMS was used to estimate screening-level exposure of
aquatic organisms to profenofos.  The measure of exposure for aquatic
species is the 1-in-10 year return peak or rolling mean concentration. 
The 1-in-10 year peak is used for estimating acute exposures of direct
effects to the CRLF, as well as indirect effects to the CRLF through
effects to potential prey items, including: algae, aquatic
invertebrates, fish and frogs. The 1-in-10-year 60-day mean is used for
assessing chronic exposure to the CRLF and fish and frogs serving as
prey items; the 1-in-10-year 21-day mean is used for assessing chronic
exposure for aquatic invertebrates, which are also potential prey items.
Input parameters for PRZM/EXAMS and the resulting EECs are in Tables A.1
and A.2, respectively.



Table A.1. PRZM/EXAMS input parameters.

Input Parameter	Value	Justification

Chemical specific

Molecular Wt. (g/mol)	373.63	Product chemistry data

Solubility in water  (mg/L at 25oC)	200	10X solubility1

Vapor pressure (torr)	3.46x10-6	Product chemistry data

Henry’s Law Constant (atm-m3/mol)	2.38 x 10-7	Product chemistry data

Koc  (mL/goc)	0	Since no acceptable data are available, Koc is assumed
to be 0.

Aerobic Soil Metabolism Half-life (days)	9	3X available value (3d) 1

Aerobic Aquatic Metabolism Half-life (days)	4.5	0.5X aerobic soil
metabolism half-life  parameter value (9 d) 1

Anaerobic Aquatic Metabolism Half-life (days)	12	3X available value (4d)
1

Hydrolysis Half-life (days)	62	Longest hydrolysis rate available for pH
7

Aqueous Photolysis Half-life (days) 	0	Assume stable1

Use specific

Chemical application method (CAM)	2	Foliar applications

Application rate (kg/ha)	1.12

0.84	(for 2 applications per season)

(for 6 applications per season, plus one application at 0.56 kg/ha)

Application efficiency	0.95	Aerial application

Spray drift fraction	0.024	For aerial applications, the label indicates
that applications cannot be made within 300 ft of any body of water.
This reduces estimates of spray drift to 2.4% (according to Tier I
modeling with AgDRIFT).

Application interval (days)	5	Label instructions 

(registration 100-669)

Initial application date	July 1	Within the crop growing period for all 4
PRZM cotton scenarios. 

1According to input parameter guidance for PRZM/EXAMS (USEPA 2002).

Table A.2. Preliminary aquatic EECs for aerial applications of
profenofos to cotton.

PRZM scenario	Peak EEC

(1-in-10 year)	21-day EEC

(1-in-10 year)	60-day EEC

(1-in-10 year)

2 aerial applications per year at 1 lb a.i./A (1.12 kg/ha)

CA cotton STD	4.61	1.68	0.790

MS cotton STD	35.1	9.04	3.31

NC cotton STD	13.6	6.12	2.59

TX cotton OP	41.6	36.2	28.4

6 aerial applications per year at 0.75 lb a.i./A (0.84 kg/ha) plus one
application at 0.5 lb a.i./A (0.56 kg/ha)

CA cotton STD	13.4	4.96	2.34

MS cotton STD	42.4	15.8	7.97

NC cotton STD	26.4	11.2	5.26

TX cotton OP	67.4	18.9	7.11

Table A.3.  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

Table A.4. Preliminary RQs for freshwater fish and invertebrates.

Scenario	Acute Fish1	Chronic Fish 2	Acute Invert 3	Chronic Invert 4

2 aerial applications per year at 1 lb a.i./A (1.12 kg/ha)

CA cotton STD	0.327	0.395	5.0	8.4

MS cotton STD	2.489	1.655	37.7	45.2

NC cotton STD	0.965	1.295	14.6	30.6

TX cotton OP	2.950	14.2	44.7	181

6 aerial applications per year at 0.75 lb a.i./A (0.84 kg/ha) plus one
application at 0.5 lb a.i./A (0.56 kg/ha)

CA cotton STD	0.950	1.17	14.4	24.8

MS cotton STD	3.007	3.985	45.6	79

NC cotton STD	1.872	2.63	28.4	56

TX cotton OP	4.780	3.555	72.5	94.5

1 Based on LC50 = 14.1 ug/L for bluegill sunfish.	 	 

2 Based on NOAEC = 2.0 ug/L for fathead minnow.	 	 

3 Based on EC50 = 0.93 ug/L for waterflea.	 	 

4 Based on NOAEC = 0.2 ug/L for waterflea.	 	 

Table A.5. Preliminary RQs for estuarine/marine fish and invertebrates.

Scenario	Acute Fish1	Chronic Fish 2	Acute Invert 3	Chronic Invert 4

2 aerial applications per year at 1 lb a.i./A (1.12 kg/ha)

CA cotton STD	0.599	NA	1.9	7.64

MS cotton STD	4.558	NA	14.6	41.1

NC cotton STD	1.766	NA	5.7	27.8

TX cotton OP	5.403	NA	17.3	164.5

6 aerial applications per year at 0.75 lb a.i./A (0.84 kg/ha) plus one
application at 0.5 lb a.i./A (0.56 kg/ha)

CA cotton STD	1.740	NA	5.6	22.5

MS cotton STD	5.506	NA	17.7	71.8

NC cotton STD	3.429	NA	11.0	50.9

TX cotton OP	8.753	NA	28.1	85.9

1 Based on LC50 = 7.7 ug/L for pinfish.	 	 

2 Chronic toxicity data are not available for estuarine/marine fish.	 
 

3 Based on EC50 = 2.4 ug/L for mysid shrimp.	 	 

4 Based on NOAEC = 0.22 ug/L for mysid shrimp.	 	 

APPENDIX B:  Preliminary EECs and associated RQs for terrestrial
mammals and birds

B.1. Terrestrial animals

The T-REX model (version 1.3.1) is used to calculate dietary and
dose-based EECs of profenofos for mammals and birds.  Exposure to
mammals and birds is based on the maximum application rate and minimum
interval between applications, according to the registered profenofos
label for cotton.  Input values for T-REX are located in Table B.1. 
Upper-bound Kenega nomogram values are utilized to derive EECs for
profenofos exposures to terrestrial mammals and birds based on dietary-
and dose-based exposures (Table B.2).  A 1-year time period is
simulated. 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.  

Table B.1.  Input parameters for deriving terrestrial EECs for
profenofos using T-REX.

      Parameter Description 	Value

Application Rate (lbs a.i./A)	1a

Foliar Half-life (days)	1.3b

Application Interval (days)	5

Number of Applications	2a

a Based on 2 applications @ 1.0 lb a.i./A.

b 1.3-day foliar half-life (based on the 90th percentile of the foliar
dissipation half-lives for profenofos in Willis and McDowell (1986).

Table B.2.  T-REX calculated EECs of profenofos 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 

(20 g)	Medium 

(100 g)	Large 

(1000 g)

Short Grass 	256.69	244.73	169.14	39.22	292.34	166.71	74.64

Tall Grass	117.65	112.17	77.52	17.97	133.99	76.41	34.21

Broadleaf plants/sm insects	144.39	137.66	95.14	22.06	164.44	93.77	41.98

Fruits/pods/lg insects	16.04	15.30	10.57	2.45	18.27	10.42	4.66

Seeds (granivore)	16.04	3.40	2.35	0.54	18.27	10.42	4.66

Acute dose-based RQs for mammals are derived using the reported LD50 298
mg/kg.  The acute listed species LOC of 0.1 is exceeded for small and
medium-sized mammals (< 35 g) that feed on short and tall grass,
broadleaf plants, fruits, pods, and small insects, as well as large
mammals (1000 g) that feed on short grass, broadleaf plants and small
insects, based on acute, dose-based exposures of mammals to profenofos
(Table B.3).  Chronic dietary-based RQs for mammals are derived using
the reported NOAEC of 100 ppm (mg/kg-diet).  Chronic dose-based RQs are
calculated using the NOAEL of 7.3 mg/kg-bw/day.  For chronic dietary-
and dose-based exposures, the chronic LOC is exceeded for all mammal
size classes that feed on short and tall grass, broadleaf plants, and
small insects (Table B.4). 

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

Food Type	Dose-Based RQs

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

Short Grass 	0.37a	0.32a	0.17

Tall Grass	0.17	0.15	<0.10

Broadleaf plants/sm insects	0.21a	0.18	0.10

Fruits/pods/lg insects	<0.10	<0.10	<0.10

Seeds (granivore)	<0.10	<0.10	<0.10

Bolded RQs values > acute endangered species LOC of 0.1.

a  RQ value > acute restricted use LOC of 0.2.

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

Food Type	Dietary-Based RQs	Dose-Based RQs

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

Short Grass 	2.57	15.25	13.03	6.98

Tall Grass	1.18	6.99	5.97	3.20

Broadleaf plants/sm insects	1.44	8.58	7.33	3.93

Fruits/pods/lg insects	0.16	0.95	0.81	0.44

Seeds (granivore)	0.16	0.21	0.18	0.10

Bolded values > chronic LOC of 1.0.

Acute dose-based RQ values are calculated using the value available for
the mallard duck (LD50 = 55 mg a.i./kg-bw).  The acute endangered
species LOC of 0.1 is exceeded for all size classes and feeding types of
birds, with the exception of large birds that eat fruits, pods, seeds,
and large insects.  In addition, the acute risk LOC of 0.5 is exceeded
for all feeding types for the small 20 g bird and for medium and large
sized birds (100 to 1000 g) that consume short and tall grass, broadleaf
plants, and small insects. (Table B.5).

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

Food Type	20 g	100 g	1000 g

Short Grass 	10.24a,b	4.59a,b	1.45a,b

Tall Grass	4.69a,b	2.10a,b	0.67a,b

Broadleaf plants/sm insects	5.76a,b	2.58a,b	0.82a,b

Fruits/pods/seeds/lg insects	0.64a,b	0.29a	0.09

Bolded RQs values > acute endangered species LOC of 0.1.

a  RQ value > acute restricted use LOC of 0.2.

b  RQ value > acute risk LOC of 0.5.

Acute dietary-based RQ values, which are calculated using the LC50 for
bobwhite quail (57 mg/kg-diet), exceed the acute endangered species LOC
for all feeding types and the acute risk LOC for birds that feed on
short and tall grass, broadleaf plants, and small insects.  Chronic
dietary-based RQ values are calculated using the bobwhite quail NOAEC
(<1 mg/kg-diet).  Although definitive chronic avian RQs could not be
derived, the chronic risk LOC is exceeded birds consuming all types of
food items (Table B.6). 

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

Food Type	Acute RQ

 	Chronic RQ 

 

Short Grass 	4.50a,b	>256.69

Tall Grass	2.06a,b	>117.65

Broadleaf plants/small insects	2.53a,b	>144.39

Fruits/pods/seeds/large insects	0.28a	>16.04

Bolded acute RQ values >  endangered species LOC of 0.1; bolded chronic
RQ values >  chronic LOC of 1.0.

a  Acute RQ value > acute restricted use LOC of 0.2.

b  Acute RQ value > acute risk LOC of 0.5.

APPENDIX C:  Preliminary EECs and associated RQs for terrestrial and
riparian plants 

The TerrPlant model (version 1.2.2) is used to calculate EECs for
non-target plant species inhabiting dry and semi-aquatic areas (Table
C.1).  Selected model parameters include: an application rate of 1.0 lbs
a.i./A to represent the maximum single application rate of profenofos;
and a runoff value of 0.02 (selected based on profenofos solubility,
which is 20 mg/L).  EECs for these crops correspond to aerial and ground
application methods, which assume 5% and 1% spray drift, respectively. 
EECs relevant to terrestrial plants consider pesticide concentrations in
drift and in runoff.  Since TerrPlant does not consider multiple
applications, exposures could be underestimated in cases where plants
are exposed through multiple applications of profenofos.  Based on the
single maximum aerial or ground application rate of profenofos, the LOC
is exceeded for non-listed and listed species of dicots inhabiting
semi-aquatic areas (Table C.2).  No adverse effects were observed in any
of the four tested monocots at the highest test concentration (1.0 lb
a.i./A) of profenofos in the seedling emergence and vegetative vigor
plant studies; therefore, risks are not expected for terrestrial monocot
plant species. 

Table C.1.  EECs (lbs a.i./A) generated by TERRPLANT (v. 1.2.2) for
evaluation of exposure of dry and semi-aquatic area plants to
profenofos.

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

  Cotton (aerial)	0.07	0.25	0.05

Cotton (ground)	0.03	0.21	0.01

Table C.2.  RQ values for plants in dry and semi-aquatic areas exposed
to profenofos through runoff and/or spray drift.*

Plant Type	Listed Status	Dry 	Semi-Aquatic	Spray Drift

Dicot	non-listed	0.23	1.62*	<0.1

Dicot	listed 	0.27	1.91*	<0.1

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

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Ingestion

Birds / Amphibians

Wet/dry deposition

Root uptake

Long range atmospheric transport

Dermal uptake/Ingestion

Ingestion

Ingestion

Ingestion

Ingestion

Soil

Exposure

Media

Mammals

Runoff

Terrestrial/riparian plants

grasses/forbs, fruit, seeds (trees, shrubs)

Habitat integrity

Reduction in primary productivity

Reduced cover

Community change

Food chain

Reduction in prey

Individual organisms

Reduced survival

Reduced growth

Reduced reproduction

Terrestrial 

insects

Birds / Terrestrial-phase amphibians / reptiles / mammals

Juvenile

Adult

Spray drift

Direct

application

Pesticide applied to use site

Attribute

Change

Receptors

Source

Stressor

Riparian plant terrestrial exposure pathways see Figure 3

Uptake/cell, 

roots, leaves

Aquatic Plants

Non-vascular

Vascular

Uptake/gills 

or integument

Ground water

Soil

Wet/dry deposition

Long range atmospheric transport

Ingestion

Ingestion

Uptake/gills 

or integument

Exposure

Media

Aquatic Animals

Invertebrates

Vertebrates

Runoff

Surface water/

Sediment

Habitat integrity

Reduction in primary productivity

Reduced cover

Community change

Food chain

Reduction in algae

Reduction in prey

Individual organisms

Reduced survival

Reduced growth

Reduced reproduction

Fish/aquatic-phase amphibians

Eggs     

Larvae 

Juveniles / Adults

Spray drift

Profenofos applied to use site (cotton)

Attribute

Change

Receptors

Source

Stressor