UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE  OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES

	

September 27, 2007

PC Code 097805 

DP Barcode: D335623, D335624 and D273473

MEMORANDUM

SUBJECT:	EFED Section 3 Registration of Deltamethrin for use on Flax and
Results from the Submission of a 6A2 Adverse Effects Daphnid Study (MRID
449287-01).

FROM:	N.E. Federoff, Wildlife Biologist

	José L. Meléndez, Chemist

Environmental Risk Branch V

Environmental Fate and Effects Division (PY1 S-7507)

THROUGH:	Mah T. Shamim, Ph.D., Chief

Environmental Risk Branch V

Environmental Fate and Effects Division (PY1 S-7507)

TO:	Olga Odiott, Risk Manager Reviewer

George Larocca, Risk Manager 13

Registration Division (PY1 S-7219)

EFED has completed the assessment for the use of Deltamethrin to be used
on flax. Deltamethrin is utilized as an active ingredient in DECIS 0.2EC
(264-1007) and in DECIS 1.5EC (EPA Reg. No. 264-1011).  Risks for the
currently proposed deltamethrin use on flax will be based on a previous
assessment on pome fruit (attached) with the same rate of 0.04 lbs
ai/A/season.  The endangered species listing for flax is also attached. 


Deltamethrin is highly toxic to exposed aquatic organisms or nontarget
beneficial insects.  The prescribed use patterns have the potential for
chronic exposure and harm to fish and aquatic invertebrates, specially
those living in or near the benthos (since deltamethrin is accumulated
in the sediment).  Many use areas are expected to be located adjacent to
some types of aquatic habitats.  Drift may be harmful to both beneficial
insects and aquatic impact.   Deltamethrin appears to be immobile,
relatively persistent in the environment, stable to hydrolysis and
photolysis, and very lipophilic.

Results from the submitted acute daphnid study (MRID 449287-01):

The 48 hour toxicity of deltamethrin to Daphnia magna was studied under
flow-through conditions. The 48 hour LC50 was 0.57 ug ai/L (probit
slope=2.93). The 48 hour NOAEC was <0.11 ug ai/L based on
immobilization.  Sublethal effects included lethargic daphnids and
daphnids present on the bottom of the exposure vessels.  Based on the
results of this study, deltamethrin would be classified as highly toxic
to Daphnia manga.  This study is classified as Supplemental because a
NOAEC was not established. 

Endangered Species Listing for Use of Deltamethrin on Flax:

	Species Listing by State with Use Criteria

	No species were excluded

	Minimum of 1 Acre.

	All Medium Types Reported

	Amphibian, Fish, Crustacean, Bivalve, Gastropod, Arachnid, Insect

	flax

	Idaho	( 7) species:	Taxa	Critical Habitat

	Salmon, Chinook (Snake River Fall Run)	Threatened	Fish	No

	(Oncorhynchus (=Salmo) tshawytscha)	Freshwater, Saltwater, Brackish

	Salmon, Chinook (Snake River spring/summer)	Threatened	Fish	Yes

	(Oncorhynchus (=Salmo) tshawytscha)	Brackish, Saltwater, Freshwater

	Salmon, Sockeye (Snake River population)	Endangered	Fish	No

	(Oncorhynchus (=Salmo) nerka)	Brackish, Saltwater, Freshwater

	Steelhead, (Snake River Basin population)	Threatened	Fish	Yes

	(Oncorhynchus (=Salmo) mykiss)	Freshwater, Brackish, Saltwater

	Trout, Bull	Threatened	Fish	No

	(Salvelinus confluentus)	Freshwater

	Trout, Bull (Columbia River population)	Threatened	Fish	Yes

	(Salvelinus confluentus)	Freshwater

	Trout, Bull (Klamath River population)	Threatened	Fish	Yes

	(Salvelinus confluentus)	Freshwater

	Minnesota	( 1) species:	Taxa	Critical Habitat

	Shiner, Topeka	Endangered	Fish	Yes

	(Notropis topeka (=tristis))	Freshwater

	Montana	( 1) species:	Taxa	Critical Habitat

	Sturgeon, Pallid	Endangered	Fish	No

	(Scaphirhynchus albus)	Freshwater

	North Dakota	( 1) species:	Taxa	Critical Habitat

	Sturgeon, Pallid	Endangered	Fish	No

	(Scaphirhynchus albus)	Freshwater

	South Carolina	( 1) species:	Taxa	Critical Habitat

	Sturgeon, Shortnose	Endangered	Fish	No

	(Acipenser brevirostrum)	Saltwater, Freshwater

	South Dakota	( 3) species:	Taxa	Critical Habitat

	Shiner, Topeka	Endangered	Fish	Yes

	(Notropis topeka (=tristis))	Freshwater

	Sturgeon, Pallid	Endangered	Fish	No

	(Scaphirhynchus albus)	Freshwater

	Beetle, American Burying	Endangered	Insect	No

	(Nicrophorus americanus)	Terrestrial

	Washington	( 9) species:	Taxa	Critical Habitat

	Salmon, Chinook (Snake River Fall Run)	Threatened	Fish	No

	(Oncorhynchus (=Salmo) tshawytscha)	Freshwater, Saltwater, Brackish

	Salmon, Chinook (Snake River spring/summer)	Threatened	Fish	Yes

	(Oncorhynchus (=Salmo) tshawytscha)	Brackish, Saltwater, Freshwater

	Salmon, Chinook (Upper Columbia River Spring)	Endangered	Fish	Yes

	(Oncorhynchus (=Salmo) tshawytscha)	Freshwater, Saltwater, Brackish

	Salmon, Sockeye (Snake River population)	Endangered	Fish	No

	(Oncorhynchus (=Salmo) nerka)	Brackish, Saltwater, Freshwater

	Steelhead, (Snake River Basin population)	Threatened	Fish	Yes

	(Oncorhynchus (=Salmo) mykiss)	Freshwater, Brackish, Saltwater

	Steelhead, (Upper Columbia River population)	Threatened	Fish	Yes

	(Oncorhynchus (=Salmo) mykiss)	Brackish, Saltwater, Freshwater

	Trout, Bull	Threatened	Fish	No

	(Salvelinus confluentus)	Freshwater

	Trout, Bull (Columbia River population)	Threatened	Fish	Yes

	(Salvelinus confluentus)	Freshwater

	Trout, Bull (Klamath River population)	Threatened	Fish	Yes

	(Salvelinus confluentus)	Freshwater

	No species were selected for exclusion.

  SEQ CHAPTER \h \r 1 

	August 6, 2002

MEMORANDUM

SUBJECT:	Tolerance Petition for Uses of Deltamethrin (PC Code 097805) on
Field Corn, Sorghum, Soybeans, Sunflowers, Bulb Vegetables, Cucurbit
Vegetables, Leafy Vegetables, Fruiting Vegetables, Carrots, Potatoes,
Radishes, Artichokes, Cauliflower, Broccoli, Cabbage, Mustard Greens,
Tree Nuts, Stone Fruits, and Pome Fruits (DP Barcode D262498)
Incremental Ecological Effects Risk Assessment Due to the New Uses
Review of an Aquatic Metabolism Study of Deltamethrin, and a Batch
Equilibrium Study of m-Phenoxybenzoic Acid, a Major Degradate of
Deltamethrin.

FROM:	Miachel Rexrode, Ph.D., Senior Aquatic Biologist

		José Luis Meléndez, Chemist

		ERB V/Environmental Fate and Effects Division (7507C)

THROUGH:	Mah T. Shamim, Ph.D., Chief

		Environmental Risk Branch V

		Environmental Fate and Effects Division (7507C)

TO:		George LaRocca, PM,

		William Sprout, PM Team Reviewer

		Registration Division (7505C)

This memo presents an incremental Ecological Effects Risk Assessment for
the use of deltamethrin.  The registrant seeks to establish tolerances
for the use of the chemical on field corn, sorghum, soybeans,
sunflowers, bulb vegetables, cucurbit vegetables, leafy vegetables,
fruiting vegetables, carrots, potatoes, radishes, artichokes,
cauliflower, broccoli, cabbage, mustard greens, tree nuts, stone fruits,
and pome fruits.

In addition, this memo presents the review of two laboratory studies
submitted by the registrant: an Aquatic Metabolism study for
deltamethrin, and a Batch Equilibrium study for m-phenoxybenzoic acid, a
major degradate of deltamethrin.

RESULTS:

Incremental Ecological Effects Risk Assessment for the New Uses of
Deltamethrin

Deltamethrin is highly toxic to exposed aquatic organisms or nontarget
beneficial insects.  The prescribed use patterns have the potential for
chronic exposure and harm to fish and aquatic invertebrates, specially
those living in or near the benthos (since deltamethrin is accumulated
in the sediment).  Many use areas are expected to be located adjacent to
some types of aquatic habitats.  Drift may be harmful to both beneficial
insects and aquatic impact.  The problem of endangered species should be
addressed on a site by site basis.  Deltamethrin appears to be immobile,
relatively persistent in the environment, stable to hydrolysis and
photolysis, and very lipophilic.

EFED conducted previously a Risk Assessment for the use of deltamethrin
on Cotton (DP Barcode D188115, 01/17/94).  The proposed application rate
for cotton was 0.020 lb a.i./A to a maximum of 0.2 lb a.i./season.  The
worst case scenario, including the new uses in the application of
deltamethrin on broccoli, coliflower, cabbage, and mustard, where the
proposed application rate is 0.028 lb a.i./A applied up to 8 times or
0.22 lb a.i./A.  EFED believes that the ecological risk posed by the new
uses of deltamethrin is similar to the use on cotton, previously
assessed.  A new full scale assessment will not be conducted until such
time that the EFED can fully revise new ecological effects data.  In the
meantime, the Division will rely on the previously released Risk
Assessment.

Review of the Two Studies Submitted by the Registrant

162-3/4  Aerobic/Anaerobic Metabolism of Deltamethrin (MRID# 44977005)

could not distinguish deltamethrin from its primary α-R-isomer, there
is an unexplained steady decline in the material balance to 80-87% at
the last test interval, and radioactive material may have been adhered
to the walls of the vessels and the methodology could not account for
that fact.

163.1	Adsorption and Desorption of  14C-m-Phenoxybenzoic Acid in Four
Soils (MRID# 44977006)

This study may be considered acceptable and it provides partial
information towards the fulfillment of the mobility data requirement for
deltamethrin.  The study provides information about the mobility of a
major degradate of deltamethrin, m-phenoxybenzoic acid.  Some details of
the study are not clear and the registrant is required to submit
additional information to clarify the validity of the results.

Tier I Estimated Environmental Concentrations for Use in the Human
Health Risk Assessment

For surface water, the acute (peak) value is 200 ppt and the annual
average value is 67 ppt.  The groundwater screening concentration is 6
ppt.  These values generally represent upper-bound estimates of the
concentrations that might be found in surface water and groundwater due
to the use of deltamethrin on broccoli, considering the possibility of
concurrent applications of tralomethrin, which appears to represent the
worst case scenario.  A separate memorandum addressing the estimated
Drinking Waters Concentrations summarizes the approach taken for the
calculation and more detailed results.

Summary of Laboratory Studies Reviewed by EFED

162-3/4  Aerobic/Anaerobic Metabolism of Deltamethrin (MRID# 44977005)

This study provides marginal supplemental information about the aquatic
metabolism of deltamethrin in an aerobic water and anaerobic sediment
system.  There were various deficiencies found in the system (as
described below).



The system was not completely aerobic nor anaerobic.  The study does not
fulfill data requirements 162-3 nor 162-4.  Although the water was kept
aerobic, the sediment was undisturbed and was anaerobic at the
beg湩楮杮漠⁦桴⁥瑳摵⹹

The primary analytical method used for quantitation of compounds could
not separate parent deltamethrin from its α-R-isomer.

The material balance declined steadily throughout the study, and was
only an average 80-87% of the applied at the final sampling interval.

Radioactive material may have been adhered to the walls of the vessels,
steel supports, scintillation vials of the carbon dioxide traps, etc..

er content, and the other was a sandy loam with a much lower organic
matter content.  The pH in both systems was ≥8.0.  The waters and the
sediments were obtained from locations in the Neatherlands. 
Deltamethrin  was applied at the rate of 0.14 mg a.i./L water, and was
incubated for 84 days in darkness at 20°C.  Based on the data
available, results can be summarized as follows:

The following half-lives are based on total deltamethrin plus its
α-R-isomer

	Water-loam sediment from a ditch, Delft, Netherlands,

System I	Water-sandy loam sediment from Kromme Rijn river, Odijk,
Netherlands, System II

Half-life of water	6.0 days

(r2 = 0.806; 0-14 days)	<1 day

(observed)

Half-life in sediment	62.2 days

(r2 = 0.880; 2-84 days)	132 days

(r2 = 0.914; 1-84 days)

Half-life in entire system	25.9 days

(r2 = 0.902; 0-28 days)	120 days

α-R-isomer of deltamethrin =
[1R-[1-α-(R*),3-α-]]-3-(2,2-Dibromovinyl)-2,2-dimethyl-cyclopropanecar
boxylic acid, cyano (3-phenoxyphenyl)methyl ester,

volatile compounds, most likely CO2

Minor transformation prods.	3-PBA = 3-phenoxybenzoic acid

RU 53605 = [1R-[1-α-(S*),3-α-]]-3-(2,2-Dibromovinyl)-2,2
dimethyl-cyclopropanecarboxylic acid, cyano[3-(4-hydroxyphenoxy)
phenyl]-methyl ester



Aerobic conditions were maintained in the water layer of the
water-sediment systems throughout  the study; anaerobic conditions
existed in the sediment just prior to treatment and were not measured
thereafter.  Deltamethrin was initially associated to the water, and to
the sediment at later intervals.

formation product was α-R-isomer of deltamethrin (maximums of 21% at 7
days in loam sediment and 24% at 14 days in sandy loam sediment), water
layers were not analyzed for the α-R-isomer.

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ajor transformation product totaling 26.5-31.2% of applied in water-loam
sediment systems and 19.7-21.8% in water-sandy loam sediment systems
after 84 days.

udes isomerization at the α-carbon to yield the α-R-isomer; ester
cleavage coupled with oxidation of the phenoxy moiety to yield
3-phenoxybenzoic acid; 4'-hydroxylation of the phenoxy moiety to yield
RU 53605 with subsequent ester cleavage to yield
4'-hydroxyphenoxybenzoic acid; ultimately, mineralization to volatile
compounds occurs.

163.1	Adsorption and Desorption of  14C-m-Phenoxybenzoic Acid in Four
Soils (MRID# 44977006)

This study provides partial information towards the fulfillment of the
mobility data requirement for deltamethrin.  The study provides
information about the mobility of a major degradate of deltamethrin,
m-phenoxybenzoic acid.  Some details of the study are not clear and the
registrant is required to submit additional information to clarify the
validity of the results. The missing parameters are described in the
following section and in the section of comments.

The adsorption/desorption characteristics of [benzylic
14C]m-phenoxybenzoic acid, was studied in clay soil [pH 7.6, organic
matter=0.4%], silty clay loam soil [pH 6.5, organic matter=1.4%], sandy
loam soil [pH 6.4, organic matter=4.40%], and clay loam soil [pH 6.8,
organic matter= 4.56%], each from the U.S. in a batch equilibrium
experiment.  The adsorption phase of the study was carried out by
equilibrating soil with [14C]m-phenoxybenzoic acid at nominal
concentrations of 0.25, 0.5, 2.5 and 5.0 mg a.i./kg at ambient
temperatures for 48 hours (actual temperatures and lighting conditions
not reported).  Based on the results obtained, the mobility of
m-phenoxybenzoic acid can be classified as moderate to very high.  A
summary of results is as follows:

Soil Adsorption and Desorption Characteristics for m-phenoxybenzoic acid

Soil	Adsorption	Desorption

	Kads	1/N	Koc	Mobility Classif.	Kdes	1/N	Koc

Clay	0.6677	0.9898	287.76	Moderate	0.8694	1.0280	374.73

Silty clay loam	1.5421	1.0068	189.90	Moderate	2.9957	1.1039	368.90

Sandy loam	2.6806	0.9386	105.03	High	4.2138	0.9570	165.10

Clay loam	1.3397	0.9218	50.65	Very high	1.8536	0.9331	70.08

Kads - Freundlich adsorption coefficients; 1/N - Slope of Freundlich
adsorption isotherms.

Koc - Coefficient adsorption per organic carbon (Kd or K x 100/% organic
carbon).

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ported.  The complete mean mass balance (adsorption and one desorption
phase) was 100.54%, 100.13%, 97.39%, and 101.53% of the applied for the
clay, silty clay loam, sandy loam and clay loam soils, respectively. 

 

 

