  SEQ CHAPTER \h \r 1 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES, AND

TOXIC SUBSTANCES

PC Code:  113961

DP Barcode:  324660

Decision #: 341716

	

MEMORANDUM								     November 6, 2006

SUBJECT:	Prothioconazole Section 3: Revised Environmental Fate and
Ecological Risk Assessment

TO:		Tony Kish, Product Manager

		Lana Coppolino, Product Manager

Registration Division (7505C)

FROM:	Christopher Salice, Biologist

		Roxolana Kashuba, Environmental Scientist

		Environmental Risk Branch IV		

Environmental Fate and Effects Division (7507C)

THROUGH:	Elizabeth Behl, Branch Chief

		Thomas Steeger, Senior Biologist

		R. David Jones, Senior Agronomist

		Environmental Risk Branch IV		

Environmental Fate and Effects Division (7507C)

Environmental Fate and Effects Division (EFED) has completed revisions
of its ecological risk assessment for the new fungicide prothioconazole
and its end-use product PROLINE® 480SC (41.0% a.i.).  The fungicide is
initially proposed for use on wheat, barley, oil seed (except sunflower
and safflower), dried shell pea and bean (except soybean), peanut, and
rice.  A total toxic residues approach (including prothioconazole and
two primary degradates: prothioconazole-desthio and
prothioconazole-S-methyl) was used to estimate ecological exposure
levels.  Combined residues of concern are expected to be persistent and
moderately mobile.  

The results of this revised screening-level assessment indicate that
there is a potential for direct adverse acute effects to non-target
fresh- and saltwater non-vascular plants, freshwater vascular plants,
and saltwater invertebrates other than mollusks at the proposed
application rates for some uses. The results also indicate a potential
for adverse effects associated with chronic exposures to mammals for all
proposed uses of prothioconazole.  For listed species, acute risk levels
of concern were exceeded for estuarine/marine invertebrates,
semi-aquatic plants, aquatic plants, and freshwater fish.  Listed
species chronic risk levels of concern were exceeded for mammals.  

Prothioconazole Recommended Label Language:

“Prothioconazole-desthio (a degradate of prothioconazole) is toxic to
shrimp.  Do not apply directly to water, or to areas where surface water
is present or to intertidal areas below the mean high water mark.  Do
not contaminate water when disposing of equipment washwater or rinsate."

	

"Prothioconazole-desthio (a degradate of prothioconazole) is known to
leach through soil into ground water under certain conditions as a
result of label use.  Use of this chemical in areas where soils are
permeable, particularly where the water table is shallow, may result in
ground-water contamination."

“This product may contaminate water through drift of spray in wind. 
This product has a high potential for runoff for several months or more
after application.  Poorly draining soils and soils with shallow
watertables are more prone to produce runoff that contains this product.
A level, well maintained vegetative buffer strip between areas to which
this product is applied and surface water features such as ponds,
streams, and springs will reduce the potential for contamination of
water from rainfall-runoff.  Runoff of this product will be reduced by
avoiding applications when rainfall is forecasted to occur within 48
hours.”

Status of Fate and Ecotoxicity Data for Prothioconazole:

Tables 1 and 2 list all of the available environmental fate and
ecological effect studies, respectively, and the acceptability of each
study.  The major uncertainties in characterizing the environmental fate
of prothioconazole involve non-rigorous soil extraction procedures, lack
of complete information on the fate of the 1,2,4-triazole degradate, and
inability to calculate parent adsorption coefficient and bioaccumulation
factor.  The major uncertainties in characterizing effects of
prothioconazole and/or prothioconazole-desthio are associated with the
toxicity of prothioconazole-desthio to estuarine/marine invertebrates,
the lack of an acceptable sediment toxicity test, and the lack of data
on the effects of the 1,2,4-triazole degradate.  However, in general,
all of the studies contained sufficient information on the fate and
effects of prothioconazole for EFED to complete an ecological risk
assessment of the chemical.  

Table 1.  Status of environmental fate data adequacy for
prothioconazole.

  SEQ CHAPTER \h \r 1 

Guideline	Description	MRID	Title	Substrate	Study Classification

161-1	  SEQ CHAPTER \h \r 1 835.212	Hydrolysis	46246505	Hydrolysis of
[Phenyl-UL-14C] JAU6476 in Sterile Aqueous Buffer Solutions.
Prothioconazole; phenyl label	Acceptable

161-1	  SEQ CHAPTER \h \r 1 835.212	Hydrolysis	46246506	SXX0665:
Hydrolysis in Buffers.	Prothioconazole-desthio;    phenyl label
Supplemental

161-2	  SEQ CHAPTER \h \r 1 835.224	Photolysis in Water	46246507
Photolysis of JAU6476 in Sterile Aqueous Buffer.	Prothioconazole; phenyl
and triazole labels	Supplemental

161-3	  SEQ CHAPTER \h \r 1 835.241	Photolysis on Soil	46246510
Photolysis of JAU6476 on Soil Surface.	Prothioconazole; phenyl label
Acceptable

161-4	  SEQ CHAPTER \h \r 1 835.237	Photolysis in Air	---	---

Not required

162-1	  SEQ CHAPTER \h \r 1 835.42	Aerobic Soil Metabolism	46246511
Proazolthion (proposed) [JAU6476]: Degradation and Metabolism of JAU6476
in Aerobic Soils.	prothioconazole	Acceptable

162-1	  SEQ CHAPTER \h \r 1 835.42	Aerobic Soil Metabolism	46246512
Aerobic Degradation of JAU6476 in Two Soils	prothioconazole	Acceptable

162-1	  SEQ CHAPTER \h \r 1 835.42	Aerobic Soil Metabolism	46246513
Degradation of JAU6476-desthio (SXX0665) in Four Soils under Aerobic
Conditions.	prothioconazole-desthio	Supplemental

162-1	  SEQ CHAPTER \h \r 1 835.42	Aerobic Soil Metabolism	46246514
Degradation of JAU6476-S-methyl (WAK7861) in Four Soils Under Aerobic
Conditions.	prothioconazole-S-methyl	Supplemental

162-2	  SEQ CHAPTER \h \r 1 835.42	Anaerobic Soil Metabolism	---	---

Not required

162-3	  SEQ CHAPTER \h \r 1 835.44	Anaerobic Aquatic Metabolism	46246516
Anaerobic Aquatic Metabolism of JAU6476.	prothioconazole	Acceptable

162-4	  SEQ CHAPTER \h \r 1 835.43	Aerobic Aquatic Metabolism	46246515
Aerobic Degradation and Metabolism of the Active Ingredient JAU6476 in
the Water/Sediment System	prothioconazole	Supplemental

163-1	  SEQ CHAPTER \h \r 1 835.1230

835.1240	Mobility	46246450	Adsorption/Desorption of [phenyl-UL-14C]
SXX0665 on Four Different Soils	prothioconazole-desthio	Acceptable

163-1	  SEQ CHAPTER \h \r 1 835.1230

835.1240	Mobility	46246501	Adsorption/Desorption of S-methyl-JAU6476 on
Four Different Soils.	prothioconazole-S-methyl	Acceptable

163-1	  SEQ CHAPTER \h \r 1 835.1230

835.1240	Mobility 	46246504	Aged Soil Column Leaching of JAU6476.
prothioconazole	Acceptable

163-1	  SEQ CHAPTER \h \r 1 835.1230

835.1240	Mobility	46246539	Leaching behaviour of JAU6476 formulated as
250 EC in soil (parent leaching).	prothioconazole (formulated product)
Supplemental

163-2	  SEQ CHAPTER \h \r 1 835.141	Laboratory Volatility	---	---

Not required

164-1	  SEQ CHAPTER \h \r 1 835.61	Terrestrial Field Dissipation
46246517

46246518

46246519	Terrestrial Field Dissipation of JAU6476 in California Soil,
1999.

Terrestrial Field Dissipation of JAU6476 in Georgia Soil, 1999.

Terrestrial Field Dissipation of JAU6476 in New York Soil, 1999.
prothioconazole (formulated product)	Supplemental

Supplemental

Supplemental

164-2	  SEQ CHAPTER \h \r 1 835.62	Aquatic Field Dissipation	46246522

46246523

46246524

	Aquatic Field Dissipation of JAU6476 in a California Rice Field, 2000.

Aquatic Field Dissipation of JAU6476 in an Arkansas Rice Field, 2000.

Aquatic Field Dissipation of JAU6476 in a cropped Arkansas Rice Field,
2000.	

prothioconazole (formulated product)	Supplemental

Supplemental

Supplemental

165-4	  SEQ CHAPTER \h \r 1 850.173	Accumulation in Laboratory Fish
46246034	(Carbon 14)-JAU6476-Bioconcentration and Biotransformation in
Bluegill (Lepomis macrochirus) Under Flow-Through Conditions.
prothioconazole 	Supplemental

165-4	  SEQ CHAPTER \h \r 1 850.173	Accumulation in Laboratory Fish
46246035	(Carbon 14)-JAU6476-Desthio - Bioconcentration and
Biotransformation in Bluegill (Lepomis macrochirus) Under Flow-Through
Conditions.	prothioconazole-desthio 	Acceptable



Table 2.  Status of ecological effects data adequacy for
prothioconazole.

Guideline	Description	MRID	Title	Substrate	Study Classification

71-1	

850.2100	Avian acute oral	462460-36

462460-37	Acute oral toxicity study with the Bobwhite	TGAI. 

SXX0665.  	Acceptable

Acceptable

71-2	OECD 205	Avian acute dietary	462460-38

462460-39	A dietary LC50 study with the Northern Bobwhite	TGAI. 

Desthio..	Acceptable

71-2	OECD 205	Avian acute dietary	462460-40	A dietary LC50 study with
the Mallard	TGAI. 	Acceptable

71-4a	--	Avian repro 	462460-42

462460-43	Avian reproduction study in Northern Bobwhite 	TGAI.  

Desthio.  No. 	Acceptable

Acceptable

71-4b	--	Avian repro	462460-44

462460-45	Avian reproduction study in Mallard	TGAI.  No. 

Desthio.  No.	Acceptable

Supplemental

72-1

Freshwater fish acute	462460-18

462460-19

462460-20

462460-21	An acute toxicity study with the Rainbow trout	TGAI.  No.

480SC 

SXX0665.  No.

S-methyl.  	Acceptable

Acceptable

Acceptable

Acceptable

72-1

Freshwater fish acute	462460-22

462460-23	Acute toxicity to Bluegill sunfish	TGAI. 

480SC 	Acceptable

Acceptable

Non-guideline	Non-guideline	Freshwater fish acute	462460-25	Acute
toxicity to common carp	TGAI. No.	Supplemental

72-1a

Freshwater fish acute	462460-26	Acute toxicity to Fathead minnow
Desthio.  	Acceptable

72-1a

Freshwater fish acute	462460-24	Acute toxicity to Golden orfe	SXX0665.  
Invalid

72-2	OECD 202	Freshwater invertebrate acute	462460-09

462460-10

462460-11

462460-12	An acute toxicity study with the daphnid	TGAI.  No.

480SC. 

SXX0665. 

S-methyl.  	Acceptable

Acceptable

Supplemental

Acceptable

Non-guideline	Non-guideline

462460-13	Acute toxicity study with crayfish	Desthio.  No	Invalid

72-3a

Estuarine/ marine fish acute	462460-27	Acute toxicity study with the
Sheepshead minnow	TGAI	Acceptable

72-3b



Oyster shell deposition	462460-14	Acute toxicity to Eastern Oyster	TGAI
Acceptable

72-3c



Estuarine/ marine invertebrate acute	462460-16

462460-17	Acute toxicity to Mysids

	TGAI.  No. 

Desthio.  No.	Acceptable

Acceptable

72-4a

Fish early life stage	462460-31

462460-32	Toxicity to the early life stages of the Rainbow trout	TGAI  

Desthio

	Invalid

Invalid

72-4b

Freshwater invertebrate life cycle	462460-28

462460-29	21-d chronic toxicity with the Daphnid	TGAI

Desthio	Acceptable

Acceptable

72-4c

Estuarine/ marine invertebrate life cycle	462460-30	Life cycle toxicity
test with the Mysid	Desthio. No. 	Acceptable

72-5

Estuarine/ marine fish life cycle	462460-33	Life-cycle toxicity test
with the Fathead minnow	Desthio	Supplemental

122-1

Non-target plants seedling emergence/vegetative vigor	462460-49	Tier I
seedling emergence/vegetative vigor	480SC 	Acceptable

123-2a

Non-target plants, Tier II seedling emergence	462460-50	Tier II seedling
emergence	480SC 	Acceptable

123-2



Non-target plants; aquatic vascular plant toxicity test	462461-01

462461-02

462461-04	Toxicity to duckweed	TGAI

480SC.

Desthio 	Acceptable

Acceptable

Acceptable

123-2

Non-target plants; freshwater non-vascular plant toxicity test	462461-09
Acute toxicity to the freshwater diatom	TGAI	Acceptable

123-2

Non-target plants; marine non-vascular plant toxicity test	462461-10
Growth inhibition test with the marine diatom	TGAI	Acceptable

123-2

Non-target plants; freshwater non-vascular plant toxicity test	462461-05

462461-07

462461-08	Growth inhibition test with freshwater blue-green alga	TGAI

S-methyl.  

SXX0665. No.	Acceptable

Supplemental

Acceptable

123-3

Non-target plants; freshwater non-vascular plant toxicity test	462461-03

462461-06	Toxicity to the freshwater green alga	TGAI

480SC 	Acceptable

Acceptable

141-1

Non-target insect contact toxicity test	462460-46

462460-48	Acute oral and contact toxicity tests with the honeybee	480SC 

TGAI	Acceptable

Acceptable

N/A

Sediment-dwelling invertebrate toxicity test	462461-31

462461-32	Development and emergence of Chironomus larvae	TGAI

SXX0665 	Supplemental

Supplemental











-  PAGE  1  of    NUMPAGES 6 - 

