Document ID: EPA-HQ-OPP-2008-0345-0004
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-06-25T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

		June 9, 2008

	PC Code:  111401

	DP Barcode:  348152

	

MEMORANDUM

Subject:	Registration Review:  Data Call-In (DCI) Table for
Environmental Fate and Effects Data Gaps 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 a Data
Call-in (DCI) table for the profenofos environmental fate and effects
data gaps.  This DCI table is required to open the docket as part of the
registration review process for this chemical.  The attached DCI table,
which includes the guideline number and study title for required data,
also provides a rationale for requiring the data, an explanation of how
the data will be used, and a brief description of how the data could
impact the Agency’s future decision-making. 

Guideline Number:  835.1240 

Study Title:  adsorption/desorption

Rationale for Requiring the Data

Acceptable data have not been provided to quantify the
adsorption/desorption characteristics of profenofos in U.S. soils.
According to Code of Federal Regulations 40 (CFR40 2007) Part 158
Subpart D (data requirements for pesticides) adsorption/desorption data
are required for pesticides with terrestrial uses. Since profenofos use
on cotton is considered to be terrestrial, an acceptable study should be
submitted to fulfill OPPTS Guideline 835.1240. This study should define
Kd and KOC values of profenofos in U.S. soils. It is preferred that this
study be conducted using a batch equilibrium method.

Practical Utility of the Data

How will the data be used?

These data are used to estimate the transport of profenofos from
treatment sites to aquatic systems and ultimately to derive aquatic EECs
using PRZM/EXAMS. 

How could the data impact the Agency’s future decision-making?

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.

Guideline Number:  835.4300 

Study Title:  Aerobic Aquatic Metabolism

Rationale for Requiring the Data

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. 

Practical Utility of the Data

How will the data be used?

These data are used to estimate the degradation of profenofos in aquatic
systems and ultimately to derive aquatic EECs using PRZM/EXAMS. 

How could the data impact the Agency’s future decision-making?

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. For this
parameter, the input parameter guidance indicates that the value should
be 0.5X the aerobic soil metabolism half-life.

Guideline Number:  850.2100 

Study Title:  Avian Acute Oral Toxicity Test

Rationale for Requiring the Data

Acceptable acute avian oral toxicity data were submitted for exposures
of mallard duck to profenofos; however, data are not available for a
passerine species, which is now required under the 40 CFR Part 158 (CFR
40 2007) data requirements for conventional pesticides.  The new Part
158 data requirements specify that acute avian oral toxicity data be
submitted for either 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 the registration
review problem formulation, risks are expected for non-listed and listed
birds due to acute exposures to profenofos.  In addition, avian data for
other organophosphate (OP) insecticides, including dimethoate, show that
a passerine species, such as the red-winged blackbird, are one order of
magnitude more sensitive than other tested bird species to acute OP
insecticide exposure.   Therefore, an avian oral toxicity test is
required for passerine birds, as specified in 40 CFR Part 158.  A
passerine study protocol must be submitted for review by the Agency
prior to initiation of this study.

Practical Utility of the Data

How will the data be used?

Acute avian oral toxicity data for passerine species will be used to
refine the screening-level assessment by determining whether there are
differences in avian species sensitivity to profenofos between
passerines and upland game and waterfowl species.  Based on the
currently submitted acute avian data, profenofos is classified as
moderately toxic to birds on an acute oral basis and highly toxic on a
sub-acute dietary exposure basis. If oral acute toxicity data are not
submitted for passerines, risk will be assumed for all passerine
species.

How could the data impact the Agency’s future decision-making?

If future endangered species risk assessments are performed without
these data, the Agency would have to assume that profenofos “may
affect” birds directly (and listed species from other taxa
indirectly), and use of profenofos may need to be restricted in areas
where listed species could be exposed.  The lack of these data will
limit the flexibility the Agency and registrants have in coming into
compliance with the Endangered Species Act and could result in use
restrictions for profenofos which are unnecessarily severe.

Guideline Number:  850.1400

Study Title:   Fish Early Life Stage Toxicity Test

Rationale for Requiring the Data

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;
Pimephales promelas).  Based on the results of previous ecological risk
assessments for profenofos and derivation of preliminary aquatic RQs in
the registration review problem formulation, 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 is required in order to fulfill the data requirement.  

Practical Utility of the Data

How will the data be used?

The estuarine/marine early life stage fish data would allow the Agency
to refine its screening-level risk assessment by considering chronic
exposure and potential toxicity and risk to estuarine/marine fish.  In
addition, these data would allow the Agency to determine whether chronic
exposure to profenofos may potentially impact listed species in
estuarine/marine environments, either by direct effects on fish or by
indirect effects via reduction of prey.  By refining the assessment, the
Agency would be able to determine whether mitigation imposed as part of
the reregistration process was appropriate.  In the absence of chronic
toxicity data for estuarine and marine fish, EFED will assume chronic
risk to these taxa.

How could the data impact the Agency’s future decision-making?

If the data indicate that profenofos poses a significant chronic risk to
fish inhabiting estuarine/marine water bodies, the Agency may explore
additional decision options to minimize the risk of profenofos to
estuarine/marine fish.  If future endangered species risk assessments
are performed without these data, the Agency would have to assume that
profenofos “may affect” estuarine/marine fish directly (and listed
species from other taxa indirectly), and use of profenofos may need to
be restricted in areas where listed species could be exposed.  The lack
of these data will limit the flexibility the Agency and registrants have
in coming into compliance with the Endangered Species Act and could
result in use restrictions for profenofos which are unnecessary.  

Guideline Number:  850.4400 

Study Title:  Aquatic plant toxicity (Tier I)

Rationale for Requiring the Data

Profenofos 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, non-target
aquatic plant data for algae and vascular plants are required for
profenofos at the Tier I level.

Practical Utility of the Data

How will the data be used?

Data from Tier I aquatic plant toxicity studies will be used to estimate
potential risks to aquatic vascular and non-vascular plants associated
with the use of profenofos.  The data will reduce uncertainties
associated with the current risk assessment for aquatic plants and will
improve the Agency’s understanding of the potential effects of
profenofos on aquatic plants.  In the absence of Tier I data, risks for
both vascular and non-vascular aquatic plants will be presumed.

How could the data impact the Agency’s future decision-making?

Because aquatic vascular and non-vascular plants form the basis of the
food chain for aquatic habitats and significantly contribute to overall
water quality, a solid understanding of the potential risks to aquatic
plants is essential for sound environmental risk management
decision-making.  Without aquatic plant data for profenofos, the Agency
cannot determine if the current application rate of profenofos on cotton
may result in direct adverse effects to aquatic plants and/or indirect
effects resulting from reduction in the prey base and/or loss of
habitat/cover.  If future endangered species risk assessments are
performed without these data, the Agency would have to assume that
profenofos “may affect” aquatic plants directly (and listed species
from other taxa indirectly via reduction in prey base and/or habitat),
and use of profenofos may need to be restricted in areas where listed
species could be exposed.  The lack of these data will limit the
flexibility the Agency and registrants have in coming into compliance
with the Endangered Species Act and could result in use restrictions for
profenofos which are unnecessarily severe. 

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