# Environmental Fate and Ecological Risk
Assessment Problem Formulation in

Support of Registration Review for
Deltamethrin

March 23, 2010



# Environmental Fate and Effects Division Office of Pesticide Programs US Environmental Protection AgencyPrepared by: Amanda Solliday, Biologist José L. Meléndez, Chemist

Reviewed by: Keith Sappington, Senior Scientist Mah Shamim, Ph.D., Branch Chief

Approved by: Mah Shamim, Ph.D., Branch Chief

Environmental Risk Branch V

23 Table of Contents

1. Purpose

............................................................................................................................... ..... 4
2. Problem Formulation .............................................................................................................. 4 2.1 Nature of Regulatory Action ................................................................................................ 4
2.2. Previous Risk Assessments.................................................................................................. 5

3. Stressor Source and Distribution ............................................................................................ 7
3.1. Mechanism of Action .......................................................................................................... 5 3.2. Overview of Pesticide Usage ............................................................................................ 10 3.3. Environmental Fate and Transport .................................................................................... 14
4. Receptors ............................................................................................................................... 22 4.1. Aquatic and Terrestrial Effects ......................................................................................... 22
4.2. Incident Database Review

................................................................................................. 25 4.3. Ecosystems Potentially at Risk ......................................................................................... 27 6. Conceptual Model .............................................................................................................. 29 6.1. Risk Hypothesis ............................................................................................................... 29 6.2. Conceptual Diagram ........................................................................................................ 29 7. Analysis Plan ..................................................................................................................... 31
7.1. Stressors of Concern ......................................................................................................... 32 7.2. Measures of Exposure ....................................................................................................... 32
7.3. Measures of Effect ............................................................................................................ 34 7.4. Integration of Exposure and Effects ................................................................................. 35
7.5. Deterministic and Probabilistic Assessment Methods ...................................................... 35 7.6. Endangered Species Assessments ..................................................................................... 35 7.7. Drinking Water Assessment ............................................................................................. 36 7.8. Preliminary Identification of Data Gaps ........................................................................... 36
7.8.1. Fate ............................................................................................................................. 36
7.8.2 Effects ......................................................................................................................... 39
8. References

............................................................................................................................... . 44 Appendix A. SRRD data request justification tables.................................................................. 471. Purpose

The purpose of this problem formulation is to provide the foundation for the ecological risk assessment being conducted for the regist ered uses of deltamethrin. As such, it articulates the purpose and objectiv es of the risk assessment, evaluates the nature of the problem, and provides a plan for analyzing the data and characterizing the ecological risk (EPA, 1998). Additionally, this problem formula tion is intended to identify data gaps, uncertainties and potential assumptions need ed to address those uncertainties in characterizing the ecological risk associated with the registered uses of deltamethrin.

Deltamethrin is a synthetic pyrethroid insecticide that is registered for a variety of agricultural and residential us es, including (but not limited to) globe artichokes, canola, crambe, rapeseed, field corn, popcorn, sweet corn, cotton, cucurbits, eggplant, groundcherry, pepinos, peppers, tomatillo, tomato, garlic, leeks, onion, shallots, apple, crabapple, loquat, mayhaw, pear, oriental p ear, quince, carrot, celeriac, turnip-rooted chervil , chicory, edible burdock, garden b eet, ginseng, horseradish, parsley (turniprooted), parsnip, radish, orient al radish, rutabaga, salsify, bl ack salsify, Spanish salsify, skirret, turnip, potato, sweet potato, arracach a, arrowroot, Chinese artichoke, Jerusalem artichoke, edible canna, bitter and sweet cassa va, chayote (root), chufa, dasheen, ginger, leren, tanier, tumeric, yam bean, true yam, sorghum, soybeans, sunflowers, tree nuts domestic dwellings, ornamental lawns and turf, ornamental woody shrubs and vines, paths/patios, paved areas (pri vate roads/sidewalks), pet liv ing/sleeping quarters, garbage cans, residential lawns, bathroom premises , cadavers, caskets (and also morgues and mortuaries), carpets, commercial transporta tion facilities, commercial/ institutional/ industrial premises (indoors), diaries and cheese processing plant premises, dogs/ canines (collars) (and also pet living quarters), drai nage systems, eating establishments, feed mills/ feed processing plants, food processi ng plant premises, food stores/ markets/ supermarket premises, greenhouses, hospital/ medical institutions premises, household/ domestic dwellings, human bedding/ mattresse s, public building/ structures, sewage systems, ships and boats, and zoos.

2. Problem Formulation

2.1. Nature of Regulatory Action

The Food Quality Protection Act of 1996 mandated the EPA to implement a new

program, i.e ., registration review ( http://www.epa.gov/oppsrrd1/registration_review/ ). All pesticides distributed or sold in the United St ates generally must be registered by EPA. The decision to register a pesticide is base d on the consideration of scientific data and other factors showing that it will not cause unr easonable risks to human health, workers,
or the environment when used as directed on product labeling. The registration review program is intended to ensure that, as the abili ty to assess risk evolves and as policies and practices change, all registered pesticides co ntinue to meet the st atutory standard of no

4unreasonable 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 reevaluate s pesticides to make sure that as change occurs, products in th e 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 to determin e whether deltamethrin continues to meet the FIFRA standard for regist ration. This problem formulati on for the environmental fate and ecological risk assessment chapter in suppo rt of the registration review is intended for the initial docket opening the pub lic phase of the review process.

2.2. Mechanism of Action

Deltamethrin is classified as a Type II pyrethroid, with a cyano group at the alpha -carbon position, or the alcohol moiety. The primary bi ological effects of deltamethrin, and other pyrethroids, on insects and vert ebrates reflect an inhibiti on of the correct firing of neurotransmitter deliver signals from one cell to another via nerve membrane inhibition of the voltage-gated Ca 2+ channels (calcium ion channe ls) coupled with a stimulatory effect on the voltage-gated Na + channels (sodium ion channels ). The insecticidal effect of pyrethroids is characterized by a rapid “ knock down,” or paralysis, of insects. In insects, the type II pyrethroids predominantly cause ataxia and uncoordinated movement. All pyrethroids act as axonic poisons, affec ting both the peripheral and central nervous systems, and share similar modes of acti on. Pyrethroids, including deltamethrin, stimulate repetitive action in the nervous system by binding to voltage-gated Na + channels, prolonging the Na + ion permeability during the excitatory phase of the action potential. This action leads to spontaneous depolarizations, augmented neurotransmitter secretion rate and neuromuscular block, whic h ultimately results in paralysis of the
insect.

2.3. Previous Risk Assessments

The previous risk assessments conducted on deltamethrin indicated risk concerns for organisms living in fresh and estuarine/ marine bodies of water. In addition, there were risk concerns for aquatic or ganisms living in the benthos.

In 2007, EFED conducted an environmental fa te and ecological risk assessment for deltamethrin use on flax, and concluded that the chemical is highly toxic to exposed aquatic organisms and to nontarget beneficial insects. Also, the assessment concluded that proposed use patterns prescribed for deltamethrin on flax have the potential for chronic exposure and harm to fish and aquati c invertebrates, includ ing those living in or near the benthos, since deltamethrin is accumulate d in the sediment. It was indicated that many use areas are expected to be located adja cent to some types of aquatic habitats, and

5that drift may be harmful to both beneficial insects and aquatic organisms. Based on the environmental fate properties for deltameth rin it appeared to be immobile, relatively persistent in the environment, stable to hydrolysis and photolysis, and very lipophilic.

Prior to the 2007 assessment on flax, an risk assessment was issued in 2002 for the use of the chemical on field corn, sorghum, soybean s, sunflowers, bulb vegetables, cucurbit vegetables, leafy vegetables, fruiting vegetables, carrots, pot atoes, radishes, artichokes, cauliflower, broccoli, cabbage, mustard greens, tree nuts, stone fruits and pome fruits. Findings from the 2002 ecological risk assessmen t were similar to those described above for flax. In 1994, EFED issued an assessment for the use of the chemical on cotton. The
conclusions were as follows:

“Based on the available information EEB concludes that the proposed use poses serious risk to exposed, aquatic organisms or nontarget beneficial insects. Many cotton production sites are expected to be located adj acent to some type of aquatic habitat. Without further precautions against drift contamination (such as application only when/wind di rection is away from nont arget aquatic habitats), EEB cannot dismiss the possibility of hazar d to aquatic species located in waters adjacent to application sites. The effects of drift to populations of pollinating beneficial insects may also be extreme unless applications are made at times of low activity (foraging) for these sp ecies. Endangered species concerns must be addressed on a site by site basis in relati on to the ecological risk factor involved with that particular site location (i .e. proximity to critical habitat).”

1999 Scientific Advisory Panel on Sediment Toxicity and Fate of Synthetic Pyrethroids
A Scientific Advisory Panel (SAP) in 1999 examined the sediment toxicity and fate of synthetic pyrethroids. In response to a quest ion regarding whether se diment toxicity data on one pyrethroid (cypermethrin) could be us ed to predict sediment toxicity to all pyrethroids, the panel generally supporte d the method of using data from a few pyrethroids to extrapolate information on t oxicity to other pyret hroids. The panel recommended testing cypermethrin, “bifenth rin (relatively non-toxic to freshwater aquatic organisms, very insoluble in water, large bioconcentration factor) and possibly trefluthrin (highly toxic to fr eshwater aquatic organisms, stable in water, intermediate solubility in water to cypermethrin an d bifenthrin)” (USEPA , 1999). Although this agreement was made in 1999, the new CFR Pa rt 158 requirements include sediment toxicity tests and these studies are considered particularly important for ecological risk
assessment of deltamethrin.

The SAP commented on the use of K d or K OC to estimate concentrations of synthetic pyrethroids in sediments, recommen ding that the Agency reconsider K OC as a measure of the binding potential of synthe tic pyrethroids to sediment and soil because the use of K d alone limits extrapolation to experimental conditions while K OC “allows one to estimate partitioning across a wide variety of soil/se diment types” (USEPA, 1999). The Panel expressed concern that standard methods used to measure sorption may not be applicable to highly hydrophobic compounds due to high solid s to water ratio, consideration of the

6character of the organic matter, presen ce of dissolved organic carbon, use of nonrepresentative soils and sedi ments as sorbents, and improper methods used to measure organic carbon.

While the biota-sediment-accum ulation-factor is a widely accepted method of assessment of bioaccumulation in sediments, the Panel indicated that the bioconcentration data for Daphnia and Hyalella should be sufficient to predict bioconcentration of pyrethroids. Finally, the Panel indicated that use of a so lid phase microextraction (SMPE) method to
determine the dissolved concentration in wate r could be used to a ccount for sorption of pyrethroids to organic car bon and colloids present in the water column in the
measurement of bioconcentration factors.

In 2003 and in response to the comments from the SAP on pyrethroids, EFED requested the following studies on esfenvalerate, cypermet hrin, bifenthrin and cyfluthrin (Rexrode and Melendez, 2003).

850.1735: Acute Sediment (freshwater) - Test organism: Hyalella azteca and Chironomus tentans - Duration: 10 days, endpoint is survival.

EPA/600/R01/020: Chronic Estuarin e/Marine Sediment Testing

- 28 day test on Leptocheirus plumulosus

, - Percentage of neonates that survive as adults.
- Growth rate. - Reproduction (#eggs/female, etc .).
- Behavior.

A chronic 65-day freshwater test was also requested for cypermethrin only.



### EPA/600/R-991064: Chronic Freshwater Sediment Testing

- 

### 65 day test on Chironomus tentans

- Survival.

- Growth rate.

- Reproduction (# eggsffemale, time to oviposition, proportion of females ovipositing, % hatch).

3. Stressor Source and Distribution

Deltamethrin is a synthetic pyrethroid insecticide. Its structure has three rings, two phenyl rings attached to each other by an oxygen atom, and a cyclopropyl ring. It is cyano-substituted in the alpha position. The chemistry of deltamethrin may be dictated by its ester moiety; this is substantiated by the hydrolysis study, in which the chemical is labile at the highest pH of 9. The structure of the molecule has three chiral centers that could result in a total of 8 stereoisomers. Chemically, it is the [1R, cis ; alpha S]-isomer

7[alternatively (1S)-alcohol (1 R)-cis-acid] out of eight st ereoisomeric esters of the dibromo analogue of chrysanthemic acid. Deltamethrin has a 2,2-dibromoethenyl substitution in the cyclopropyl ring.

A summary of physicochemical propertie s of deltamethrin is included in Table 3.1

.

Table 3.1. Summary of physicochemic al properties of deltamethrin.

PARAMETER VALUE(S) (units) SOURCE

CAS Chemical Name ( S )-cyano (3-phenoxyphenyl) methyl (1 R ,3 R )-3-(2,2- dibromoethenyl)-2,2-dimeth ylcyclopropanecarboxylate

IUPAC Chemical Name ( S )- α -cyano-3-phenoxybenzyl (1 R ,3 R )-3-(2,2- dibromovinyl)-2,2-dimethylcyclopropanecarboxylate

or ( S )- α -cyano-3-phenoxybenzyl (1 R )- cis -3-(2,2- dibromovinyl)-2,2-dimethylcyclopropanecarboxylate Deltamethrin data sheet: http://www.alanwood.net/pe

sticides/deltamethrin.html
accessed 06/23/09

PC Code 097805 OPP Databases

Chemical Structure (from chemical’s data sheet)

CAS Reg. No. 52918-63-5 Deltamethrin data sheet

Molecular Weight 505.2 Laskowski, 2002

Solubility ( 20 o C) 0.000200 mg/L or 2.00x10 -4 ppm or 0.200 ppb Laskowski, 2002

Vapor Pressure (25 o C) 9.32 x 10 -11 mmHg Laskowski, 2002

Henry’s Law Constant 3.1 x 10 -7 atm-m 3 /mol (from vapor pressure and water solubility) Laskowski, 2002

Octanol-Water Partition Coefficient (20 o C) (log K OW and K OW ) 4.53 and 3.42 x 10 4 Laskowski, 2002

Octanol-Air Partition
Coefficient

(log K OA and K OA ) 9.89 and 7.76 x 10 9 EPISuite v.4.0 Estimate

Biomagnification
Potential Presumption*: If log K OA > 5, log K OW >2 and the rate of chemical transformation is low, the chemical may biomagnify in terrestrial food chains.*

For deltamethrin, log K OA =9.89, log K OW =4.53 & rate of transformation is relatively low; it appears that deltamethrin has a potential to biomagnify in terrestrial
food chains. *Gobas et al. 2003 and Armitage & Gobas, 2007 support this presumption utilized here only as a broad
reference to determine the potential for biomagnification.

Deltamethrin has a very high molecular weight of 505.2 g/mol. With a very small solubility (only 0.200 ppb) and a high oc tanol/ water partition coefficient (K OW = 34,200),

8it appears that deltamethrin has the potentia l to bioaccumulate/ bioconcentrate. With a small vapor pressure (9.32 x 10 -11 mmHg), a relatively small Henry’s Law Constant (3.1

x 10 -7 atm-m 3 /mol), and despite its low solubilit y, deltamethrin does not appear to volatilize substantially from wet surfaces.

For deltamethrin, the log K OA is 9.89 and the log K OW is 4.53. For chemicals that are not readily metabolized in vivo, a log K OA and log K OW in this range (K OA > 5, log K OW >2) have been associated with biomagnificati on in terrestrial-based food webs based on information presented in articles by Gobas et al. and Armitage & Gobas (2003 and 2007, respectively). However, pyrethroids, su ch as deltamethrin, undergo substantial
biotransformation in vivo . Even though the EFED has not ad opted an official reference to distinguish chemicals that biomagnify, their pr esumption was utilized here as a general or broad reference to detect the biomagnificat ion potential in terr estrial food chains.

Even though various degradates were observed in the laboratory studies ( e.g. 3-PBA and tetramethrinic acid), it was found that they we re the result of the rupture of the ester bond of the parent molecule. It is believed that the resulting molecules are not as toxic as the parent because they presumably have lost the neurotoxic mode of action. Table 3.2
shows the chemical structures of deltamethr in’s major degradation products. At this time, except for alpha -R-deltamethrin, they are no t considered stressors.

Another potential source of de ltamethrin is tralomethrin. Tralomethrin is another synthetic pyrethroid that, upon degradati on, yields deltamethrin as its major transformation product. In the risk assessmen t, the exposure to deltamethrin due to the use of tralomethrin will be addressed quali tatively. (For additional information about tralomethrin, please, re fer to DP Barcode 365550.)

Table 3.2. Major Transformation Products of Deltamethrin

Common

Name Chemical Name Structure

alpha -Rdeltamethrin ( R )- α -cyano-3-phenoxybenzyl

(1 R ,3 R )-3-(2,2-dibromovinyl)-2,2-

dimethylcyclopropane-carboxylate ( R )-alcohol (1 R )-cis acid of deltamethrin
(structure not provided)

m-PBA or

mPBAc or

3-PBA
(CAS No.
3739-38-6) 3-phenoxybenzoic acid O

OH O

3-
PBAldehyde

(CAS No.
39515-51-0) 3-phenoxybenzaldehyde O

H O

9Table 3.2. Major Transformation Products of Deltamethrin

Common

Name Chemical Name Structure

Decamethrinic

Acid or cisBr 2 CA (CAS

No. 53179-78-
5) (lR-cis)-3(2,2-dibromoethyl)-2,2-

dimethylcyclopropanecarboxylic acid Br

Br OH O

3.1. Overview of Pesticide Usage

A summary of all agricult ural use patterns for deltamethrin is shown in Table 3.3

.

Table 3.3. Summary use information for deltamethrin, based on LUIS Report Table A2, dated 06/24/09, and evaluation of two labels (EPA Reg. Nos. 264-1007 and 264-1011).

USE SINGLE APP. RATE (lb.

a.i./A) NUMBER
OF APPS. SEASONAL
APP. RATE

(lb. a.i./A) INTERVAL

BETWEEN APPS. (days) APP. METHOD PHI (days)

Globe artichoke 0.028 5 0.14 3 Aerial, Ground Spray

or Dust 3

Canola, crambe, rapeseed 0.009 2 0.018 7 Aerial or Ground Spray 7

Corn, field 0.022 5 0.095 21 Aerial or Ground Spray 21

Corn, pop 0.022 5 0.095 21 Aerial, Ground Spray

or Dust 21

Corn, sweet 0.028 16 0.45 1 Aerial, Ground Spray

or Dust 1

Cotton 0.030 10 0.3 5 Aerial or Ground Spray 21

Cucurbit crop group 9
(cantaloupe, chayote, Chinese waxgourd, citron melon, cucumber, gherkin, gourds,
Momordica species, muskmelon, pumpkin, squash, watermelon) 0.028 6 0.168 3 Aerial, Ground Spray

or Dust 3

Fruiting vegetables crop group 8 (eggplant, groundcherry, pepinos, peppers, tomatillo, tomato) 0.028 6 0.168 5 Aerial, Ground Spray

or Dust 1

10Table 3.3. Summary use information for deltamethrin, based on LUIS Report Table A2, dated 06/24/09, and evaluation of two labels (EPA Reg. Nos. 264-1007 and 264-1011).

SINGLE APP. SEASONAL INTERVAL

NUMBER
USE RATE (lb. a.i./A) OF APPS. APP. RATE BETWEEN (lb. a.i./A) APPS. (days) APP. METHOD PHI (days)

Tomato 0.011 NS NS 7 Dust,
Shaker Can NS

Bulb vegetables crop group 3 (garlic, leeks, onion, shallots) 0.028 4 0.112 5 Aerial, Ground Spray

or Dust 1

Pome fruits crop group 11
(apple, crabapple, loquat, mayhaw, pear, oriental pear, quince) 0.022 1-2 0.042 7 Aerial or Ground Spray 21

Root vegetables crop subgroup 1B (except sugarbeet) (carrot, celeriac, turnip-rooted cher vil , chicory, edible burdock, garden beet, ginseng, horseradish, parsley (turnip-rooted), parsnip, radish, oriental radish, rutabaga, salsify, black salsify, Sp anish salsify, skirret, turnip) 0.028 5 0.14 3 Aerial, Ground Spray

or Dust 3

Tuberous and corm vegetables crop subgroup

1C (potato, sweet potato, arracacha, arrowroot, Chinese artichoke, Jerusalem artichoke, edible canna, bitter and sweet cassava, chayote (root), chufa, dasheen, ginger, leren, tanier, tumeric, yam bean, true yam) 0.028 5 0.14 3 Aerial, Ground Spray

or Dust 3

Sorghum 0.022 2 0.045 Not Specified Aerial or Ground Spray 14

Soybeans 0.028 4-5 0.1 Not specified Aerial or Ground Spray 21

Sunflowers 0.018 2-3 0.045 Not specified Aerial or Ground Spray 21

Tree nuts crop group 14 (almond, beech nut, Brazil nut, butternut, cashew, chestnut, chinquapin, filbert, hickory nut, macadamia nut, pecan, pistachio, walnut) 0.033 5 0.165 7 Aerial or Ground Spray
(foliar or dormant) 21

The Label Use Information System (LUIS report) & Usage/Label Use Reports for Deltamethrin (provided by BEAD) was based on a partial listing of labels, due to the large number of labels available for review; us e data is not based on an exhaustive review of the entire population of labe ls. Section 3 labels or major producers labels, along with

11all State and Local Needs (SLNs) labels, are included in the LUIS report. These data represent the major uses of this chemical.

Potential application methods include ground and aerial spray, chemigation spray, sprinkler irrigation (apparently no ULV), and dust application.

The labels for deltamethrin require a buffer z one of 10 ft around certain bodies of water, such as lakes, reservoirs, rivers, permanent streams, marshes or natural ponds, estuaries and commercial fish farm ponds, so as to a llow growth of a maintained vegetative filter strip. The agricultural products should not be applied by ground equipment within 25 ft or by aerial equipment within 150 ft of freshwat er or estuarine/ marine bodies of water.

Inspection of the use information for tralomethrin and deltamethrin found one product that contains both active ingredients. Deltame thrin is the major degradate of tralomethrin in the environment. The product, HR 20900 (EPA Reg. No. 34147-10), is for use on cotton via ground or aerial applications (no ULV). The product contains 1 lb a.i./gallon (0.5 lb of tralomethrin and 0.5 lb of deltamethrin/gallon) and the maximum seasonal total application rate is 0.20 lb a.i./A/growing season.

Available toxicity data for environmental mixt ures of deltamethrin with other pesticides will be presented as part of the ecological risk assessment. It is expected that the toxic effect of deltamethrin, in combination with ot her pesticides used in the environment, is likely to be a function of many factors includ ing but not necessarily limited to: (1) the exposed species, (2) the co-cont aminants in the mixture, (3) the ratio of deltamethrin and co-contaminant concentrations, (4) differences in the patt ern and duration of exposure among contaminants, and (5) the different ial effects of othe r physical/chemical characteristics of the receiving waters ( e.g. organic matter present in sediment and suspended water). Quantitatively predicting th e combined effects of all these variables on mixture toxicity to any gi ven 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 regarding the confidence of risk assessment conclusions will be addressed as part of the uncertainty analysis.

Piperonyl butoxide and MGK ar e commonly used in formulations with pyrethroids. For deltamethrin, one active product registration ex ists for a ready-to-u se solution (Reg. # 73049-389). Another currently active registration exists for the formul ation intermediate of the ready-to-use solution (Reg. # 73049-210). Piperonyl butoxide acts as a potentiator in both mammals and insects because the pyret hroid is not metabolized and excreted as quickly (Barile, 2004; Hodgson and Smart, 2001). Exposure to pyrethroids along with piperonyl butoxicide increases the toxicity of the pyre throids (Weston & Lydy, 2010). MGK-264, another potentiator/s ynergist used with pyrethroi ds, has similar effects as those observed for piperonyl butoxide (Hodgson and Smart, 2001). No current deltamethrin registrations exist for a product with MGK-264.

The Agency routinely assesse s potential exposure to form ulations by examining acute exposure to spray drift. Acute toxicity data on the formulation is compared to potential

12exposure to spray drift. The sole active delt amethrin registration th at contains piperonyl butoxide is a residential spray can use. The sp ray drift associated with this use will be minimal. Therefore, a quantitative assessmen t of the potential aquatic exposure to the formulation containing piperony l butoxide is not necessary. Ho wever, piperonyl butoxide and/or MGK from other pyrethroid applications could interact with tralomethrin in the environment or the additives could be app lied co-currently as a tank mix. Therefore, potential interactions will be discussed qualitatively in the risk assessment.

A summary from the Screening Level Usage Analysis (SLUA) for deltamethrin is provided in Table 3.4

.

Table 3.4. Summary of Screening-Level Estimates of Agricultural Uses of Deltamethrin (SLUA, dated 03/16/09). Percent (%) Crop Treated Crop lb a.i. Average Maximum
Almonds <500 <1 <2.5

Apples <500 <1 <2.5
Artichokes <500 15 20

Corn <500 <1 <2.5

Cotton 6,000 <2.5 <2.5
Onions <500 <1 <2.5

Pears <500 5 5

Potatoes <500 <1 <2.5 Sorghum 1,000 <1 <2.5 Soybeans <500 <1 <2.5
Sunflowers <500 <1 <2.5

Sweet Corn <500 <1 <2.5

Walnuts <500 <1 <2.5

All numbers are rounded. '<500' indicates less than 50 0 pounds of active ingredient. '<2.5' indicates less than 2.5 percent of crop is treated. '<1' indicates less than 1 percent of crop is treated.
The sources of the SLUA include the USDA-NASS, Private Pesticide Market Research, the National Pesticide Use Database (NPUD 2002) of the CropLife America Founda tion and California Department of Pesticide Regulation (CDPR) data. The information reflects amalgamated data developed by the Agency
and are in a releasable format.

The U.S. Geological Survey (USGS) pesticide use maps ( Fig. 3.1 ) show regional scale patterns in use intensity within the United St ates. The USGS pesticide maps are based on State level estimates of pesticide use ra tes for individual crops, which have been compiled by the National Center for Food and Agricultural Policy (NCFAP) for 1999 through 2004, and on the 2002 Census of Agriculture for county crop acreage crop.

The only use for deltamethrin included in the map at the time (through 2002) was cotton, constituting 100% of the use and with 9,448 lb applied mostly th rough a belt including the states of VA, NC, SC and GA. Multiple uses have been added to the chemical as
indicated above.

13Fig. 3.1. Estimated Use of Deltamethrin in 2002

Note of Caution: The pesticide use maps available from the web ( http://water.usgs.gov/nawqa/pnsp/usage/maps/compound_listing.php?year=02 ) show the average annual pesticide use intensity expressed as average weight (in pounds) of a pesticide applied to each square mile of agricultural land in a county. The area of each map is based on statelevel estimates of pesticide use rates for individual crops that were compiled by the CropLife Foundation, Crop Protection Rese arch Institute during based on information collected during 1999 through 2004 and on 2002 Census of Agriculture county crop acreage. The maps do not represent a specific year, but rather show typical use patterns over the five year period 1999 through 2004. Use intensity rate s are expressed as the pounds applied per square mile of mapped agricultural land in a county. The area of mapped agricultural land for each count y was obtained from an enhanced version of the 1992 USGS National Land Cover Data (NLCD). The key limitations of the data used to produce thes e maps include the following: (1) state use coefficients represent an average for the entire state and consequently do not reflect the local variability of pesticide management practices found within states and counties, (2) pesticide use estimates are not for a specific year, but r epresent typical use patterns for the five year period, (3) state pesticide use coefficients may not have been available for all states where a pest icide may have been applied to agricultural land, and therefore, are not displayed on the maps, (4) the county crop acreage is based on the 2002 Ce nsus of Agriculture and may not represent all crop acreage because of Census nondisclosure rules, and (5) agricultural land area used t o calculate the pesticide use intensity and display the data was derived from 30-meter satellite remote sensing data that may over estimate or underestimate the actual agricultural land area. The maps are not intended for making local-scale estimates of pesticide use, such as estimates a t the county level.
Please refer to Method for Estimating Pesticide Use for a detailed discussion of how the pesticide use data were developed.

In addition to the classical agricultural use sites, deltamethrin has multiple other uses.
These uses include food/feed use sites and non-food/ non-feed use sites. Deltamethrin may be used in multiple urban environments. Many of these uses are classified as
outdoor residential such as household/ domes tic dwellings, ornamental lawns and turf, ornamental woody shrubs and vines, paths/patio s, paved areas (private roads/sidewalks),

14pet living/sleeping quarters, garbag e cans, and residential lawns. Table 3.5 provides a summary of the terrestrial nonagricultural use sites for deltamethrin. Uses such as spot
treatment or crack and crevice are include d, and application methods vary. Many of these uses could involve substantive exposure to wildlife, specificall y, aquatic organisms, and they will be assessed accordingly ( e.g. , turf, golf course turf, household premises, rights of way, ornamentals/ shade trees, recreational areas, urban areas and residential lawns).

Table 3.5. Uses Classified as Terrestri al Nonagricultural for Deltamethrin

Use Max. App. Rate/
units Max. No. Apps./ Year Max. App. Rate per

Year Min. App. Int./ days animal kennels/sleeping quarters (commercia l) 1 application NS NS 7, 14, 30, NS automobiles, taxis, limousines, recreational vehicles, & tires 1 a pplication NS NS 7, 14, 30, NS barley 5.0x10 -5 lb cwt NS NS NS barns/barnyards/auction barns 2 sec NS NS NS commercial storages/warehouses premises 1 application NS NS 7, 14, 30, NS

commercial/industrial lawns 0.131 lb/A and others NS NS 7 commercial/institutional/industrial premises/equipm ent (outdoor) 1 application NS NS 30, NS compost/compost piles 1 application NS NS NS corn (unspecified) and corn, pop 2.8x10 -5 lb cwt NS NS NS eating establishments 1 application NS NS 7, NS fencerows/hedgerows 1 application NS NS NS

golf course turf 0.131 lb/A, 0.0034 lb 1K sq.ft, 0.0097

lb/mound NS NS 7

household/domestic dwellings outdoor premises Various NS NS 7, 21, 28, 30, AN, NS industrial areas (outdoor) 1 application NS NS 30 nonagricultural outdoor buildings/structures 0.0034 lb 1K sq.ft and
others NS NS 7, NS nonagricultural rights-of-way/fencerows/hedgerows 0.0026 lb 1K sq.ft,
0.0039 lb/mound NS NS 7, NS

oats 2.6x10 -5 lb cwt NS NS NS

ornamental and/or shade trees 0.0050 lb 1K sq.ft and
others NS NS 7, 21, NS ornamental grasses 0.0016 lb 1K sq ft NS NS 7, NS

ornamental herbaceous plants 0.0050 lb 1K sq.ft and
others NS NS 7, 21, 28, NS,

AN

ornamental lawns and turf 0.131 lb/A, 0.0034 lb 1K sq.ft and others NS NS 7, 21, 28, NS

ornamental nonflowering plants 0.0050 lb 1K sq.ft and
others NS NS 7, 21, 28, NS

ornamental sod farm (turf) 0.131 lb/A, 0.0034 lb 1K sq.ft, 0.0097
lb/mound & others NS NS 7

ornamental woody shrubs and vines 0.0050 lb 1K sq.ft,

2.6x10 -5 lb/mound &
others NS NS 7, 21, 28, NS

paths/patios 0.0050 lb 1K sq.ft, 0.0050 lb/mound,

6.2x10 -4 lb/sq ft NS NS 7, 21, 28, 30, AN, NS

paved areas (private roads/sidewalks) 0.0026 lb 1K sq.ft,
0.0039 lb/mound NS NS 7, 30, NS

pet living/sleeping quarters 0.0050 lb 1K sq.ft and
others NS NS 7, 14, 21, 30,
NS

recreation area lawns 0.131 lb/A, 0.0034 lb 1K sq.ft, 0.0097

lb/mound NS NS 7
recreational areas 1 application NS NS 7, 30, NS

refuse/solid waste containers (garbage cans) 0.0026 lb 1K sq ft,
others NS NS 7, 14, 30, NS refuse/solid waste sites (outdoor) 0.0050 lb 1K sq.ft, NS NS 7, 21, 30, NS

15Table 3.5. Uses Classified as Terrestri al Nonagricultural for Deltamethrin

Use Max. App. Rate/
units Max. App.

Max. No. Apps./ Year Rate per Min. App.

Year Int./ days

0.0050 lb/mound

residential lawns 0.131 lb/A, 0.0034 lb 1K sq.ft, 0.0097

lb/mound NS NS 7, NS rice, rye, sorghum 5.0x10 -5 lb cwt NS NS NS specialized animals various NS NS 7, 14

urban areas 0.0050 lb 1K sq.ft, 0.0050 lb/mound,
others NS NS 21

wheat 3.0E-5 lb bu NS NS NS wide area/general outdoor treatment (public health use) 1 application NS NS NS NS = Not Specified; AN = As Needed. Data obtained from LUIS Report, Table 1.

In addition, there are numerous other i ndoor non-food use sites like for example, bathroom premises, cadavers, caskets (and also morgues and mortuaries), carpets, commercial transportation fac ilities, commercial/ instituti onal/ industrial premises (indoors), diaries and cheese pr ocessing plant premises, dogs/ canines (collars) (and also pet living quarters), drainage systems, eating establishments, feed mills/ feed processing plants, food processing plant premises, food stores/ markets/ supermarket premises, greenhouses, hospital/ medical institutions premises, household/ domestic dwellings, human bedding/ mattresses, public building/ stru ctures, sewage systems, ships and boats, and zoos. These labeled uses will be assessed only qualitatively in the ecological risk assessment, as they present minimal chan ce for exposure to nontarget organisms in aquatic or terrestrial environments.

In a recent study (Stout II, et al. 2009), conducted by the US Department of Housing and Urban Development, in collaboration with th e Agency, several chemicals were surveyed on floors of occupied homes. The survey included several synthetic pyrethroids like
deltamethrin. Deltamethrin was detected with a frequency of 27%, il lustrating that this chemical is commonly applied in homes. Weston et al. 2005, studied the presence of synthetic pyrethroids in Rose ville, CA, selected as a ty pical suburban development. Sediments from creeks that drain subdivisions of single-family homes were found to be
toxic to Hyalella azteca . The synthetic pyrethroids were considered to be the primary cause of the toxicity. Amweg et al. 2006 also studied synthetic pyrethroids in urban
areas of CA and TN. Deltamethrin was found to be a contributor to the toxicity of sediments sampled. These are just a few examples that illustrate the high use of synthetic pyrethroids in urban se ttings and potential ecological repercussions.

Deltamethrin is not among the constituents monitored by the National Water Quality Assessment (NAWQA), maintained by the U.S. Geological Survey. However, multiple articles from the literature document the pres ence of synthetic pyret hroids in both urban and agricultural sediments. For example, Weston et al. 2005 (see also above), reported
that there were detectable amounts of deltameth rin at up to 46 ng/g in sediments of creeks and tributaries in Roseville, CA (Placer Count y). Out of 24 sampling sites, deltamethrin was detected in 14 sites (reporting limit <1 ng/ g). Generally bifenthrin was the synthetic pyrethroid most detected and at highest concentrations. Th e authors indicate that the presence of synthetic pyrethro ids was not likely to be due to agricultural uses. In Placer

16County, the use of synthetic py rethroids for agricultural purpo ses was reported to amount to around 1%, with no agricultural use of the chemical deltamethrin. Budd et al. 2007 sampled sediments in mixed land (urban and agricultural) in the San Diego Creek in Newport Bay Watershed in southern Califor nia. Bifenthrin a nd fenpropathrin were among the most frequently detected synthetic pyrethroids. The researchers found that the concentration of synthetic pyrethroids was ge nerally lower in residential or commercial areas as opposed to agricultural sites. Als o, the frequency of detections of pyrethroids was higher during the wet season ( e.g. for deltamethrin 28% during the wet season vs. 11% during the dry season). Trimble et al. 2009 screened a previously referenced database of 24 pesticides and 94 urban sedi ment samples (with minimal agricultural or industrial contribution) collected from creeks and streams throughout central and northern California. The synthetic pyrethro ids and chlorpyrifos were the pesticides detected more frequently. After normalizing the chemical concentrations for organic carbon “to provide better estimates of the biol ogically available chemical fractions,” all the seven pyrethroids monitored had levels exceeding the established level of interest, LOI (defined as 0.005 toxic units, TU) for at least one sample. Deltamethrin exceeded 0.5TU in greater than 5% of the samples (so did bifenthrin, cypermethrin, cyfluthrin and lambda-cyhalothrin). Deltamethrin’s frequenc y of occurrence was 49% . It was detected in a large number of samples, but it decreased in relevance when the level of exceedance was established at 0.5TU. Therefore, it was considered of “moderate concern” because it did not contribute frequently or substantially to the overall TU values in the samples. In a study by Weston et al. 2009, bifenthrin was the most fr equently detected pyrethroid
from runoff waters from Roseville and Elk Grove urban sites. Cyfluthrin and permethrin were also frequently detected. Deltamet hrin was observed only on occasion and at relatively low concentrations (<3 ng/L); how ever, one sample from Elk Grove, obtained during a November rainfall, had the highest concentration of deltamethrin of any pyrethroid (with 252 ng/L). During the dry s eason, deltamethrin was not detected in either site, while during the wet season, it was found with a frequency of detection of 25% (in both sites). Amweg et al. 2004 found that the averag e sediment 10-day LC50 for deltamethrin was 0.79 μg/g OC

.

Weston 2007 says that, “Contrary to popular perception, non-agricultural use of pyrethroids far exceeds agricultural use, at least in California, one of the few areas where data are available. A similar situation is likely elsewhere where there is substantial urban development. Whereas agricultural use of pyrethroids in California is about 300,000 lb/yr, non-agricultural commercial use (mostly applications done by professional pest control firms) is currently about 700,000 lb/yr. Retail sales to homeowners are not included in this non-agricultural figure, but are probably about another 100,000 lb/yr. Some of the major urban uses of pyrethroids include cypermethrin and permethrin for termite control, permethrin to maintain landscaping, and bifent hrin and cyfluthrin for a variety of pests
around homes.”

Another potential source of deltamethrin is tralomethrin. Tralomethrin is another synthetic pyrethroid that, upon degradation, yields deltamethrin as its major transformation product. In the risk assessment, the exposure to deltamethrin due to the use of tralomethrin will be dealt with qualitatively.

173.2. Environmental Fate and Transport

A summary of environmental fa te/transport properties of deltamethrin is included in
Table 3.6

.

Table 3.6. Summary of Environmental Fate and Transport Properties of Deltamethrin

PARAMETER VALUE(S) (units) SOURCE

Hydrolysis Half-life

pH 5, 7, 9; (25 o C) Stable at pH 5 and 7. Half -life of 2.5 days at pH 9.

BR 2 CA and m-PB Aldehyde MRID 41651038, Supplemental

Aqueous Photolysis - Halflife (pH 5) 64 and 84 days for benzyl and gem labels, respectively or considered relatively stable. cis -BR 2 CA MRID 42114818,

Acceptable

Soil Photolysis - Half-life The half life was 9 days, but, at the end of the 30 day study, both the irradiated and dark control samples had around the

same amount of parent materi al. Considered relatively stable to photodegradation on soil. MRID 42114819,

Acceptable

Aerobic Soil Metabolism
Half-life Dubbs fine SL and Memphis Si L (soil pHs 5.8-5.9) were tested at two application rates and with two radiolabels, first order half-lives as follows (hal f-lives provided for cyano and

phenoxy labels, respectively: SL : at 0.02 lb/A: 52.5, 54.6 days, at 0.20 lb/A 50.2, 55.0 da ys; for the SiL: at 0.02 lb/A 46.2, 50.2 days, at 0.20 lb/A 45 .6, 52.5 days. It appeared that the application rate did not affect the rate of reaction.

Additional study conducted with Dubbs fine SL at 10-40oC,
the half-lives obtained at 25 oC were 19.7 and 24.6 days for the cyano and vinyl labels, respectively.

Alkaline Arizona SL (pH 8.1) half-lives 22 and 26 days MRID 41677404, 41677405,

42114820

Acceptable

Anaerobic Soil
Metabolism - Half-life Alkaline SL half-lives 32, 36 days for the benzyl and gem labels, respectively. BR 2 CA max. 52%.

[Additional study performed with deltamethrin: SL system –In the study deltamethrin was a major degradate, with halflives of 42.9-46.7 days. Also 3-PBA (20.6%) and BR 2 CA (40.6-57.0%)] MRID 42114821

Acceptable

[Additional study performed on deltamethrin: 44814505]

Anaerobic Aquatic
Metabolism - Half-life Not Available Not Available

Aerobic Aquatic
Metabolism - Half-life Both systems from the Netherlands: System I, L: 25.9 days; System II, SL: 120 days – half-lives include deltamethrin plus α -R-deltamethrin.

Major – α -R-deltamethrin (21-24% at 7-14 d) and unidentified volatiles (possibly CO 2 ) – minor 3-PB Acid ( ≤ 7%) & RU 53605. Systems fr om the Netherlands. Halflives based on the sum of deltamethrin plus the alpha -Risomer of deltamethrin. MRID 44977005

Supplemental

Organic Carbon Partition
Coefficient for Parent (K OC ) 392000, 577000, 204000, 460000 mL/g OC , for AK SiL, GA SiL, TX SL, and MS SiClL. Immobile (FAO 2000)

Soil Partition Coefficient for Parent (K d ) 3000, 4750, 960, 3740 mL/g,

for AK SiL, GA SiL, TX SL, and MS SiClL MRID 41651039, 42976501

Acceptable, Partial (the

additional mobility information is provided in
Table 3.8 ).

18Table 3.6. Summary of Environmental Fate and Transport Properties of Deltamethrin

PARAMETER VALUE(S) (units) SOURCE

Terrestrial Field Dissipation

Half-life Louisiana cotton 231 days, long half-life observed, both for the bareground and the cropped plot; this soil had a lower organic matter content and it was postulated that it was the reason for the longer half-lives. California cotton 37 d for bareground plot, and 40 d for cropped plot. Minnesota corn 69 d for bareground plot, and 14 days for the cropped plot. Studies provide limited information about th e degradates. MRID 42137505, 42773903,

42114822 Acceptable

Biaccumulation in Fish (BCF) 698X whole body, 189X edible portion, depuration was moderately slow (50% between 3-7 days, and 70-75% after 2 weeks) MRID 41651040, 43072701,
43072702

Acceptable

When applied to the field, deltame thrin is likely to partition to the soil and organi c matter in the crops; deltamethrin appears to bind strongly to soil and organic matter, though binding is not instantaneous or immediate (K OW = 34,200 and K OC »100,000; immobile, FAO 2000). It is not expected to leach into subsurfaces. It may reach aquatic enviro nments via spray drift
or in runoff events acc ompanied by erosion. Deltamethr in appears to be moderately to highly persistent in terrestrial environments (aerobic soil metabolism 20-55 days; terrestrial field dissipation 14-231 days). It has the potential to persist in aquatic environments, where it may partition with the sediment and has the po tential to affect be nthic and epibenthic organisms (aerobic aquatic metabolism 26-1 20 days; anaerobic soil metabolism 32-47 days). Due to its low vapor pressure (9.32 x 10 -11 mmHg) and Henry’s Law Constant (3.1x10 -7 atm-m 3 /mol), deltamethrin is unlikel y to volatilize s ubstantially.

Deltamethrin is relatively stable at pH 5 and 7. However, it rapidly degraded (half-life of 2.5 days) at an alkaline pH of 9 to form (lR-cis)-3-(2,2-dibromoethyl)-2,2-dimethylcyclopropanecarboxylic acid (Br 2 CA, <0.l5 μg/L) and 3-ph enoxybenzaldehyde (3- PBaldehyde, 3.42 μg/L). It does not appear to photodegr ade substantially in aqueous solutions (half-lives 64 & 84 days). Although the soil photolysis study gave a half-life of 9 days, considerable degradation was occu rring in the dark controls as well.

Based on acceptable aerobic soil metabolism data , deltamethrin in Dubb s fine sandy loam and Memphis silt loam soil, tested at two application rates and with two radiolabels, degraded at moderate rates (first order hal f-lives 19.7-55.0 days) to form DBVA (or Br 2 CA) (<10%) and CO 2 . Over the l28 day in cubation period, 62-77% and 52-60% of the 14 Ccyano- and the 14 C-phenoxy-labelled parent evolved as 14 CO 2 . The proposed routes of degradation are ester hydrolysis and mi crobial-mediated mi neralization to CO 2 . An
additional aerobic soil metabol ism study was submitted for an alkaline Arizona sandy loam (pH 8.l), which yielded somewhat lower half-liv es of 22 and 26 days . For the gem label study, Br 2 CA was formed, which peaked at 23-26% on day 30 and 14, respectively. Given the fact that the pH of the latter study was high er, the half-lives were lower, which is what was expected from th e hydrolysis study.

In an anaerobic soil metabolis m study, deltamethrin degraded in an Arizona sandy loam (pH 8.l) with a half-life of 32-36 days for the benz yl and gem labels, respectively. For the gem label experiment, on ly l metabolite, Br 2 CA or decamethrinic acid, was found at 49% of the

19applied radioactivity by day 30 and remained at about this level on days 59 (52%) and 90 (48%). For the benzyl label, the only metabolite id entified was m-PB Ac id, which was only detected in a day 30 sample, ac counting for only 3% of the app lied radioactivity. This study is not representative of a neutral or acidic pH soil, which is expected to yield higher halflives.

In aerobic aquatic metabolism stud y, consisting of a loam or a sandy loam test systems from the Netherlands, the half lives for the whole systems were 26 and 120 days, respectively. The major transformation product was the α -R-isomer of deltamethrin, at up to 24% in the SL. A new anaerobic aquatic metabolism study should provide additional valuable information on a test system that is comp letely aerobic. No anaerobic aquatic metabolism study is available for review.

In batch equilibrium studies, deltamet hrin was found to be immobile (K OC >100,000, FAO classification, FAO 2000) and had Freundlich K d 's of 3,790 for a Mi ssissippi SiClL, 3000 for an Arkansas SiL, 4750 for a Georgia SiL, and 960 for a Texas SL. K OC 's ranged from

204000 to 577000 . Although deltamethrin is tightly bo und, adsorption wa s not immediate, because equilibrium times were 4-24 hours.

In three terrestrial field dissi pation studies parent appeared not to be mobile in soil and degraded in l-2 months, except the Louisian a study, where the ha lf-life was almost 8 months. The longer half-life c ould fall within the range of normal fiel d variability and the
Louisiana soil was the lowest in organic matter, which could re sult in the lowest amount of soil binding and soil microbial degradation. No clear pattern of degradate formation and decline was seen, possibly beca use the low application rate and 6" sampling intervals
resulted in soil dilu tion, so degradates were not detected.

In fish bioconcentration study, deltamethrin had bioconcentra tion factors of 189x and 3630x
in edible and visceral fish tissues, respectively. The whole body BCF of 698x was
calculated from edible and viscer al fish tissue results (as opposed to a direct measurement of whole body). The majo rity of the radioactive residue fo und in fish was parent, accounting
for 78 and 83% of the total ra dioactive residue in edible and visceral fish tissues, respectively. No depuration study was done; however, the depuration rate (about 50% between days 3-7 and 70-75% after 2 weeks of depuration) from a previously submitted study was considered (MRID# 416510-40, similar BCF's).

Table 3.7 provides a summary of the various degradation products formed by each process in the studies re viewed for deltamethrin.

Table 3.7. Summary of degradate formatio n from degradation of deltamethrin.

DEGRADATE and MAXIMUM CONCENTRATION

STUDY TYPE cis- Br 2 CA (% applied) Deltamethrin Isomers (% applied) m-PBAc or m-PBald (% applied) SOURCE

Hydrolysis <0.15 μg/L ( vs. app. rate 10.0 μg/L) _ m-PBald: 3.37 μg/L at 30 days ( vs. app. rate 10.0 μg/L) MRID 41651038

20Table 3.7. Summary of degradate formatio n from degradation of deltamethrin.

DEGRADATE and MAXIMUM CONCENTRATION

STUDY TYPE cis- Br 2 CA Deltamethrin Isomers m-PBAc or (% applied) (% applied) m-PBald SOURCE (% applied)

Aqueous Photolysis 3% at day 21 m-PBAc 11% at day

21 MRID 42114818

Soil Photolysis 40% at 21 days (samples contained

more cis - than trans

Br 2 CA; it was present also in dark control) R-S epimerization was reported, but no

trans -deltamethrin
observed m-PBAc 11% at 14 days in preliminary study MRID 42114819

Aerobic Soil Metabolism 23-26% at 14-30 days _ _ MRID 41677404, 41677407,
42114820

Anaerobic Soil Metabolism 49% by day 30, and
remained at that level through day 90 (48-52% during the period) _ m-PBAc 3% at 30 days MRID 42114821

Aerobic Aquatic
Metabolism _ 24% at day 14 m-PBAc ( ≤ 7%) MRID 44977005

Terrestrial Field Dissipation Detected in one study. 2-4 ppb detectedsporadically. transdeltamethrin
detected in one study. Not monitored MRID 42114822, 42137505,
42773903

It appears that m-PB-Acid and m-PB-aldehyde are not very pers istent in the environment. However, Br 2 CA appears to persist much more th an the former comp ounds. It was observed in laboratory studies and in the field. These degradat es are the result of the ester rupture in the parent molecule . Another transformation pr oduct that was monitored in various of the studies (soil photolysis and aerobic aquatic metabolism) was the α -Rdeltamethrin, an isomer of deltamethrin. It ap pears that it was not measured or could not be distinguished from the parent in other laboratory studies.

Table 3.8 provides a summary of batch equilibriu m data for 3-PB-acid and decamethrinic acid ( cis -Br 2 CA).

Table 3.8. Summary of mobility data for deltamethrin degradates

PARAMETER VALUE(S) (units) SOURCE

Organic Carbon Partition Coefficient, 3-PB-Ac (K OC ) 288, 190, 105, 50.7 mL/g OC (for Cl, SiClL, SL & ClL)

Soil Partition Coefficient, 3-PB-Ac (K d ) 0.668, 1.54, 2.68, 1.34 mL/g (for Cl, SiClL, SL & ClL) MRID 44977006, Acceptable, Partial (additional mobility
information in Table 3.6 )

( m -Phenoxybenzoic Acid,

m -PBA or 3-PBA)

21Table 3.8. Summary of mobility data for deltamethrin degradates

PARAMETER VALUE(S) (units) SOURCE

Organic Carbon Partition Coefficient, cis -Br 2 CA, (K OC ) 38.2, 46.8, 43.7, 23.0, 10.1 mL/g OC for AZ SL#2, AZ SL#3, SiClL, SL, ClL

Soil Partition Coefficient,
cis -Br 2 CA (K d ) 0.09, 0.11, 0.36, 0.59, 0.27 mL/g

for AZ SL#2, AZ SL#3, SiClL, SL, ClL MRID 42475908, Acceptable, Partial

(Decamethrinic acid,

RU 23441 or cis -Br 2 CA)

A major degradate of deltamethrin, cis -Br 2 CA or decamethrinic acid, appeared to be mobile in 5 soils (Freundlich K d s <l, and K OC ‘s=10.1-46.8, FAO mobili ty classification, FAO 2000). In additio n, for the degrad ate m-PB-Acid, K d ’s were in the range of 0.7-2.7 while the

K OC ’s were in the range of 51-288 (mobile to moderately mobile acco rding to FAO mobility classification, FAO 2000). Of these degradates, Br 2 CA has the potential to leach to subsurfaces, or to reach adjacent bodies of water via runoff even ts, most likely dissolved in
the water.

4. Receptors

4.1. Aquatic and Terrestrial Effects

The receptor is the biological entity th at is exposed to the stressor (EPA, 1998). Due to the outdoor uses of deltamethrin, the types of receptors that may be exposed include both aquatic and terrestrial receptors, such as birds, reptiles, mammals, amphibians, freshwater and estuarine/ marine fish, non-target terrestr ial & aquatic invertebra tes and terr estrial & aquatic plants. This list may not be compre hensive. Spray drift and runoff exposures are expected for both ground and aerial applicati ons of deltamethrin. Consistent with the process described in the Overview Document (EPA, 2004), this risk assessment uses a surrogate species approach in its evaluation of deltamet hrin. Toxicological 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.

Tables 4.1 and 4.2 provide a summary of the taxonomi c groups and the surrogate species tested to help understand potential acute eco logical effects of pesticides to these nontarget taxonomic groups. In addition, the ta bles provide a preliminary overview of the potential acute toxicity of deltamethrin by pr oviding the acute toxicity classifications.

Terrestrial Species

The available toxicity data suggests that delt amethrin appears to be practically nontoxic on an acute basis to avian species based on a bobwhite quail ( Colinus virginianus ) single
dose LD 50 > 2250 mg/kg bw (MRID 00158273) and an 8-day dietary LC 50 > 4640 mg/kg diet for the mallard duck ( Anas platyrynchos ) (MRID 00060723). Deltamethrin showed no adverse effects to reproduction at the hi ghest concentration tested (NOAEC = 450 mg/kg diet) in the two one-generation chr onic studies conducted on the bobwhite quail and mallard duck (MRIDs 42114808 and 42114809).

22For mammalian toxicity, EFED will coordinate with HED to determine the most sensitive endpoints for acute and chronic studies.

As expected for a registered insecticide, deltamethrin is highl y toxic to nontarget
terrestrial invertebrates. An acute contact study on honeybees ( Apis mellifera ) for deltamethrin technical produced an LD 50 = 0.0015 μg/bee (MRID 42114815). In a foliage residual study conducted with de ltamethrin EC (2.5% a.i.), 100% mortality occurred in honey bees exposed to direct contact at 0.01 – 0.015 lbs EC/A (0.00025 lbs a.i./A – 0.000375 lbs a.i./A) and significant adverse effect s (78% mortality) we re still occurring when bees were exposed to alfalfa foliage 34 hours after treatment at the 0.015 lbs EC/A level (0.000375 lbs a.i./A) (MRID 42475905). In another foliage residual test, the RT 25 at 0.02 lbs a.i./A was estimated to be somewh ere between 2 and 8 hours after treatment (MRID 42773902).

Table 4.1 Summary of most sensitive endpoints from subm itted terrestrial toxicity studies for deltamethrin.

Species

(common

name) Taxa Represented Endpoint Mean Concentration Test
Substance

(% a.i.) Citation

MRID Acute Toxicity
Classification

Colinus virginianus (Bobwhite

quail) LD 50 > 2250 mg/kg bw 99.3 00158273 Practically
nontoxic

Anas platyrynchos (Mallard duck) LC 50 > 4640 mg/kg diet 98 00060723

NOAEC 450 mg/kg diet Colinus virginianus (Bobwhite

quail)

and

Anas platyrynchos (Mallard duck) Birds, terrestrialphase amphibians, and reptiles

LOAEC NA 99.4% 42114808 and

42114809 Practically
nontoxic

Apis mellifera

(Honey bee) Terrestrial
invertebrates LD 50 0.0015 μg/bee 99.7 42114815 Highly toxic

1 Based on percent of normal hatchlings from three-week embryos.

Aquatic Species

Freshwater

23Deltamethrin technical is very highly t oxic to freshwater fish, with a 96-hour LC 50 = 0.58 μg a.i./L in the most sensitive acute test conducted on Lepomis gibbosus (Pumpkinseed sunfish) (MRID 00060721). In other tests with deltamethrin technical, the 96-hour LC 50 = 0.91 μg a.i./L for coldwater rainbow trout ( Oncorhynchus mykiss) and the 96-hour LC 50 = 0.91 μg a.i./L for warmwater bluegill sunfish ( Lepomis macrochirus) (MRIDs 00158274 and 00158275)

. Deltamethrin EC is also consider ed to be highly toxic to the rainbow trout ( Oncorhynchus mykiss) on an acute basis, with an LC 50 = 0.25 μg a.i./L (MRID 41651013). A chronic freshwater life cycl e fish study for deltamethrin technical resulted in a 28-day NOAEC=0.017 μg a.i./L and LOAEC = 0.035 μg a.i./L for fathead minnow ( Pimephales promelas ) based on reduced growth of females (MRID 42786802. An early life stage study with fathead mi nnow resulted in a NOAEC=0.022 μg a.i./L and a LOEC = 0.036 μg a.i./L for a 36-day test with larval growth as the most sensitive endpoint effected (MRID 42114814).

Daphnia magna is used as the test species for fres hwater invertebrates for both acute and chronic effects. Acute toxicity values for daphnids suggest th at deltamethrin technical is highly toxic to freshwater inve rtebrates, with a 48-hour EC 50 range from 0.57 μg a.i./L to 3.5 μg a.i./L (MRIDs 44928701 and 00158276). In an acute toxicity test with deltamethrin EC (2.54% a.i.), the 48-hour EC 50 = 0.11 μg a.i./L (MRID 41651014). Chronic toxicity to invertebrates is represented through Daphnia magna life cycle studies. In a daphnid chronic life-cycle te st with deltamethrin, the NOAEC = 0.0041 μg/L and the LOAEC = 0.0089 μg/L based on advers e effects to growth and reproductive success at mean-measured concentrations (MRID 42114813).

Estuarine/Marine Estuarine/marine fish are repres ented by the sheepshead minnow ( Cyprinodon variegatues ). Acute toxicity studies indicates that deltamethrin is highly toxic to estuarine/marine fish, with an LC 50 = 0.58 μg a.i./L for the technical material and an LC 50 = 0.36 μg a.i./L for the EC (25.4% a.i.) (MRIDs 41651015 and 42114811).

Estuarine/marine aquatic invertebrates are represented by the mysid shrimp ( Mysidopsis
bahia ) and eastern oyster ( Crassostrea virginica ) with toxicity studies indicating deltamethrin is very highly toxic to both. In an acute study with mysid shrimp, the 96-
hour LC 50 = 0.0037 μg a.i./L for deltamethrin technical, based on mean-measured concentrations (MRID 42114810). For the deltame thrin formulated product, an acute toxicity study with the mysid shrimp resulted in 96-hour LC 50 = 0.0017 μg a.i./L (MRID 42114812). In studies with the eastern oyster, the 96-hour EC 50 = 12.0 μg a.i./L for
deltamethrin technical and the 96-hour EC 50 = 17.9 μg a.i./L for deltamethrin EC (2.48% a.i.), based on effects to shell deposition (MRIDs 41651016 and 41651017). No chronic estuarine/marine study with estuarine/mari ne invertebrates has been submitted for
deltamethrin.

Aquatic Studies with Deltamethrin and Tralomethrin Co-formulation
Six studies were submitted for the tralomet hrin/deltamethrin co-formulated product, HR2900 or Striker EC (12.4% a.i. of tralomethrin and deltamethrin in approximately

24equal proportions). For freshwater fis h, this co-formulated product has a 96-hour

LC 50 =1.5 μg a.i./L for bluegill sunfish (MRID 43073903) and a 96-hour LC 50 =0.39 μg a.i./L for rainbow trout (MRID 43073904). The tralomethrin/deltamethrin co-formulation
has a 48-hour EC 50 of 0.18 for freshwater inve rtebrates, represented by Daphnia magna (MRID 43073905). For estuarine/marine fish represented by the sheepshead minnow, the
acute 96-hour LC 50 =0.49 μg a.i./L (MRID 43073906). Acute estuarine/marine invertebrate toxicity tests w ith mysids resulted in an LC 50 =0.021 μg a.i./L (MRID 43073908) and LC 50 <110 μg a.i./L for eastern oysters (no endpoint was established because greater than a 50% reduction occurr ed at the lowest dose tested) (MRID 43073907).

For these studies on the tralomethrin and de ltamethrin co-formulation, some uncertainty exists regarding the degree of the effect that can be attributed to the formulation (inerts and ingredients other than the active) and wh ich are a result of the combining the two active ingredients. It is impor tant to note that these studies give lower acute toxicity endpoints than either technical active ingredient or single ac tive ingredient formulation
alone for freshwater fish.

Table 4.2. Summary of most sensitive endpoints from submitted aquatic toxicity studies
for deltamethrin.

Species

(common name) Taxa Represented Endpoint Duration (hours) Mean
concentration

(μg a.i./L) Citation

MRID Acute Toxicity
Classification

Lepomis gibbosus

(Pumpkinseed sunfish) LC 50 96 0.58 00060721

NOAEC 0.017 Pimephales promelas

(Fathead Minnow) Freshwater fishand aquaticphase amphibians

LOAEC 28 (days) 0.035 42786802 Very highly
toxic

EC 50 48 0.11 41651014

NOAEC 0.0041 Daphnia magna

(Water Flea) Freshwater
Invertebrates

LOAEC 21 (days) 0.0089 42114813 Very highly
toxic

Cyprinodon variegatus (Sheepshead

minnow) Estuarine/
Marine Fish LC 50 96 0.36 42114811 Very highly
toxic

LC 50 96 0.0017 42114812 Very highly
toxic

NOAEC NA Mysidopsis bahia

(Mysid shrimp) Estuarine/
Marine
Invertebrates

LOAEC 28 (days) NA NA NA

25Plants

One study has been submitted for effects of deltamethrin on terrestrial plants. This study was conducted on 55 species of nursery plants, and does not satisfy any non-target plant phytotoxicity data requirements, as no e ndpoints were established. Deltamethrin was applied in dust form, with products contai ning 4.8% and 0.05% active ingredient. No treatment-related phytotoxic e ffects were observed (MRID 43519101).

No aquatic plant data is available to the Agency for deltamethrin.

Available open literature will be used to evaluate the potential direct effects of deltamethrin to the terrestrial receptors identif ied in this section. This includes toxicity data on the technical grade active ingredient , and when available, formulated products (e.g. “Six-Pack” studies).

At this time, a full and complete ECOTOX search has not been performed, but will be conducted prior to issuance of any Data Call-i n. The open literature studies will be identified through EPA’s ECOTOX database ( http://cfpub.epa.gov/ecotox/ ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluati on of data can also pr ovide insight into the direct and indirect effects of deltamethrin on biotic communities from loss of species that
are sensitive to the chemical and from cha nges in structure and f unctional characteristics of the affected communities. Open literature t oxicity data for other ‘target’ insect species (not including bees, butterflies, beetles, and non-insect invertebrates including soil arthropods and worms), which include efficacy studies, are not currently considered in deriving the most sensitive e ndpoint for terrestrial insects. Efficacy studies do not typically provide endpoint values that are useful for risk assessment ( e.g. , NOAEC, EC50, etc.), but rather are intended to identi fy a dose that maximizes a particular effect ( e.g. , EC100). Therefore, efficacy data and non-e fficacy toxicological target insect data will not be included in the ECOTOX open literature search.

Incident Database Review

A preliminary review on August 11, 2009 of the Ecological Incident Information System (EIIS, version 2.1), which is maintained by th e Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy, indicates one repo rted ecological incide nt associated with
the use of deltamethrin. These incidents are summarized in Table 4.3. This total excludes
incidents classified as ‘un likely’ and only includes thos e incidents with certainty categories of ‘highly probable’, and ‘probable’ and ‘possible’ (for EIIS) and ‘certain’, ‘highly likely’, ‘likely’, ‘proba ble’, and ‘possible’ (for AIMS). In the EIIS and AIMS databases, the “unlikely” category is used when a chemical is not lik ely to be responsible for the incident. For example, an ‘unlikely’ classification might be applied in situations where a given chemical is pract ically nontoxic to the category of organism killed and/ or there is evidence that another pesticide or stressor likely caused the incident. Incidents classified as ‘unlikely’ for deltamethrin will not be included in this Problem Formulation

26or the ecological risk assessment conducted for Registration Review.

In a single incident reported for deltamethrin (Deltaguard GC 5SC), two other chemicals were also involved, imidacloprid and thiopha nate-methyl. These chemicals were applied to a golf course, and runoff caused a fish kill of approximately 350 bullhead fish ( Ameirurus sp). Deltamethrin was considered the probable cause of the incident, as it is
much more toxic to fish than either im idacloprid and thiophanate-methyl. Residues of
deltamethrin were detected in water collected at the inci dent site at 0.13 ppb. This
incident was classified as a misuse (EIIS I015407-001). See Table 4.3 for summary.

Table 4.3. Wildlife Incidents Associated with Deltamethrin

Chemical

Name Incident

Number (Source) Taxa
Involved Magnitude Year Location (County,

State) Use Legality
of Use Certainty Category 1 Residue

s Other
Chemicals

Involved

Deltamethrin EIIS

I015407-

001 Fish ( Ameriuru

s sp.) 350
individuals 2004 Allen, OH Golf

Course Misuse Probable 0.13 ppb
in
affected

water Imidacloprid
and Thiophanate

-methyl

1 Incidents classified as ‘unlikely’ are excluded.

Although only a total of one incident for delta methrin has been reported to the Agency, the absence of reported incident s should not be construed as the absence of incidents. Incident reports for non-target organisms t ypically provide information only on mortality events and plant damage incidents. Except for phytotoxic effects in terrestrial plants, sublethal effects for organisms such as re duced growth or impaired reproduction are rarely reported. EPA’s changes in the registrant reporting re quirements for incidents in 1998 may account for a reduced number of reporte d incidents. Registrants are now only required to submit detailed information on ‘maj or’ fish, wildlife, and plant incidents. Minor fish, wildlife, and plant incidents, as well as all other nont arget incidents, are generally reported aggregately a nd are not included in EIIS. In addition, there have been changes in state monitoring efforts due to lack of resources.

In the risk assessment, the incident will be fu rther evaluated to determine if it represents current patterns of use for deltamethrin. Examples of additional considerations are mitigation ( e.g ., reduced application rates), product cancellations, and changes in use patterns that have occurred since th e date of the reported incidents.

As it has been indicated earli er, deltamethrin is not among the constituents monitored by the National Water Quality Assessment Data Warehouse, (NAWQA) maintained by the U.S. Geological Survey; however, multiple ar ticles from the literature document the presence of synthetic pyre throids like deltamethrin inboth urban and agricultural sediments (refer to Section 3.2 ).

4.3. Ecosystems Potentially at Risk

27Deltamethrin may be applied on a variety of food crops, including corn, cotton, soybeans, cucurbits, fruiting vegetables, bulb vegetables, pome fruits, tuberous and corm vegetables and tree nuts. Thus, the ecosystems at risk may be extensive in sc ope, and as a result it may not be possible to identify specific ecosy stems during the development of a baseline risk assessment. In general terms, terrestria l ecosystems potentially at risk due to the use of deltamethrin, could include the treated fi eld and areas immediately adjacent to the treated field that may receive drift or runoff. Areas adjacen t to the treated field could include cultivated fields, fencerows a nd hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats and other uncultivated areas. Due to the persistence of deltamethrin, it is expected to drift and/ or ru noff due to application to food crops, resulting in possible exposure to aquatic ecosystems. Aquatic ecosystems potentially at risk due to the use of deltamethrin include water bodies adjacent to, or down stream from, the treated field and mi ght include impounded bodies such as ponds, lakes and reservoirs, or flowi ng waterways such as streams or rivers. For uses in coastal areas, aquatic habitat also includes mari ne ecosystems, including estuaries.

5. Assessment Endpoints

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

To estimate exposure concentra tions, the ecological risk as sessment considers a single application at the maximum application rate to fields that have vul nerable soils. The most sensitive toxicity endpoints are used from surrogate test species to estimate
treatment-related direct eff ects on acute mortality and chr onic reproductive, growth and survival assessment endpoints. Toxicity te sts are intended to determine effects of pesticide exposure on birds, mammals, fish, te rrestrial and aquatic invertebrates, and plants. These tests include short-term acu te, sub-acute, and repr oduction studies and are typically arranged in a hierarchical or tiered system that progresse s from basic laboratory tests to applied field studies. The toxicity st udies are used to evaluate the potential of a pesticide to cause adverse effects, to determ ine whether further tes ting is required, and to determine the need for precautionary label st atements to minimize the potential adverse effects to non-target animals and plants.

28An open literature search will be conducted to determine any relevant endpoints. The search will focus on survival, growth and repr oductive effects for a quatic and terrestrial effects of deltamethrin. More sensitive endpoints from acceptable open literature studies
will be included in this risk assessment.

6. Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological receptors in biologically significant concen trations. 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.

A conceptual model provides a written desc ription and visual re presentation of the predicted relationships between deltamethr in, 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 (EPA, 1998).

6.1. Risk Hypothesis

Risk hypotheses are specific assumptions about potential adverse effects ( i.e. , changes in assessment endpoints) and may be based on theory and logic, empirical data, mathematical models, or probability models (E PA 1998). For this assessment, the risk is stressor-initiated, where the stressor is the re lease of deltamethrin into the environment. The following risk hypothesis is presumed for this screening-level assessment:

Deltamethrin, when used in accordance with registered labels, will likely lead to off-site movement of the compound via runoff, spray drift, and eroded soil leading to exposure of nontarget plants and animals Based on information on environmental fate, mode of action, direct toxicity and potential indirect effects, EFED assumes that registered uses of de ltamethrin have the potential to cause reduced survival, growth, and reproducti on to non-target terrestrial and/or aquatic animals and plants.

Note that another potential source of delta methrin is tralomethrin. Tralomethrin is another synthetic pyrethroid that, upon degr adation, yields deltamethrin as its major transformation product. In the risk assessmen t, the exposure to deltamethrin due to the use of tralomethrin will be addressed qualitatively.

The conceptual model is a generic graphic de piction of the risk hypothesis. It includes the potential pesticide or stressor (deltame thrin), the source of the pesticide and/or transport pathways, exposure media, exposur e point, biological receptor types, and attribute changes.

6.2. Conceptual Diagram

29The conceptual site model is a generic gr aphic depiction of the risk hypothesis, and assumes that the insecticide deltamethrin, having outdoor uses, is capable of affecting aquatic and terrestrial animals provided that environmental concentrations are sufficiently elevated as a result of proposed label us es. Based on an examination of the physicochemical properties of deltamethrin, the fate and disposition in the environment, and mode of application, a concep tual model was developed th at represents the possible relationships between the stressors, ecologica l receptors, and the assessment endpoints. Through a preliminary iterative process of examining available data, the conceptual model ( i.e ., the representation of the risk hypothesis) may be refined to reflect the likely exposure pathways and the organisms that ar e most relevant and applicable to this assessment (see Figure 6.1 , below). It includes the potential pesticide or stressor (deltamethrin), the sources and/ or transpor t pathways, exposure media, exposure points, biological receptor types and at tribute changes. The conceptual model depicted in Fig.
6.1 is similarly applicable to the urban outdoor uses of deltamethrin.

In order for a chemical to pose an ecologica l risk, it must reach ecological receptors in biologically significant concen trations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological receptor. For an ecological exposure pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecologi cal receptors, and a feasible route of exposure. In addition, the potential m echanisms of degradation/ transformation ( i.e. , which degradation/ transformation products may form in the environment, in which media, and how much ) must be understood, especially if for the chemical, its metabolites/ tran sformation products are of gr eater toxicological concern than the parent compound. The assessment of ecological exposure pathways, therefore, includes an examination of the source and pot ential migration pathways for constituents, and the determination of potential exposure routes.

Under the possible uses of deltamethrin, the sources and mechanisms of release of the compound are from ground or aerial spray applic ations. Surface runoff from the areas of application is assumed to depend on factors such as topography, irrigation, and rainfall events. Direct deposition may result in contamination of food items that may be consumed by terrestrial organisms. Spray drift results in contaminated adjacent areas, including bodies of water.

For aquatic receptors, the major point of expos ure is through direct contact with the water column, sediment, and pore water (gill/ integum ent) contaminated with spray drift (from spray application) and/ or runoff from treated areas. Indirect effects to aquatic organisms (especially fish) can also o ccur through impact to various food chains and through bioaccumulation. The representative aquati c receptors are certain freshwater and estuarine/ marine fish, invert ebrates, and, in certain cases , aquatic plants. The major point of exposure for terrestrial animals is consumption of food contaminated with residues such as grass, foliage, and small ins ects. For plants, the point of exposure is direct contact or root uptake. The representa tive terrestrial receptors are mammals, birds, and, in certain cases, terrestria l plants. The attribute cha nges used to assess risk to terrestrial receptors depe nd on the type of test ( e.g. , reduced survival, growth, or

30reproduction for animals and seedling emergen ce and vegetative vigor for plants). It should be noted, that these species do not cove r all the possible species in the animal and plant kingdoms; certain taxa are considered as surrogates for other taxa. For example, fish are considered surrogates for aquatic phase amphibians.

Note: This simplified conceptual model does not show details about biomagnification for a chemical (though it shows bioaccumulati on). Deltamethrin has a very high K OW and according to its physicochemical and fate properties, there is a potential for bioaccumulation/ bioconcentration in aqua tic organisms, and biomagnification in terrestrial organisms. The potential for bioacc umulation/ biomagnifica tion is not stressed in this conceptual model, but will be ex amined in the risk assessment. See Section 7.2 Measures of Exposure.

7. Analysis Plan

In order to address the ri sk hypothesis, the potential for adverse effects on the environment is estimated. Usage, environm ental fate and trans port, and ecological
effects of deltamethrin 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

31of adverse ecological effects, the risk quotient-based approach does not provide a quantitative estimate of likeli hood and/or magnitude of an adverse effect. However, as outlined in the Overview Document (USE PA 2004), the likelihood of effects to individual organisms from par ticular uses of a chemical 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 de pending on 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

The focus of this assessment is on the pare nt material, deltamet hrin. However, the Agency will review open literature to identi fy degradate(s) of potential toxicological concern. Various degradates of deltamethr in, such as m-phenoxybenzoic acid (3-PB Ac) and decamethrinic acid (or cis -Br 2 CA), exist; however, they ar e not structurally related to the parent since they have lost the backbone st ructure of the parent after ester cleavage. They are believed to be less toxic than the parent. Deltamethrin also undergoes epimerization under certain circum stances. The half-lives calc ulated for deltamethrin, are based on the sum of the parent and its isomers.

Toxicity data for environmental mixtures of deltamethrin with other pesticides (those mixtures occurring in the environment followi ng application), if available, may be presented as part of the ecological risk assessmen t. It is expected th at the toxic effect of deltamethrin, in combination with other pesticides used in the environment ( e.g. tralomethrin, a source of deltamethrin), is likely to be a func tion of many factors including, but not necessarily limited to: (1) the exposed species, (2 ) the co-contaminants in the mixture, (3) the ratio of deltamethrin and co-cont aminant concentrations, (4) differences in the pattern and duration of exposure among contaminants, and (5) the differential effects of other phys ical/ chemical characteristic s of the receiving waters ( e.g. organic matter present in sediment and susp ended 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 av ailable data and methodologies. However, a qualitative discussion of imp lications of the available pesticide mixture effects data on
the confidence of risk assessment conclusions wi ll be addressed as part of the uncertainty analysis.

7.2. Measures of Exposure

In order to estimate risks of deltamethri n exposures in aquatic and terrestrial environments, all exposure modeling and resul ting risk conclusions will be made based on maximum application rates fo r the current use patterns. Measures of exposure are based on aquatic and terrestrial models that predict estimated environmental concentrations of deltamethrin using maximu m labeled application rates and methods, as

32well as any mitigation measures specifically in dicated on the label. 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 exposure is T-REX. The model used to deri ve EECs relevant to terrestrial and wetland plants is TerrPlant. The pot ential for bioaccumulation for the chemical is assessed using the KABAM model, as well the results from BCF studies. These models are parameterized using relevant reviewed registrant-submitted environmental fate and transport data.

PRZM (v.3.12.2, May 2005) and EXAMS (v.2.98.4.6, April 2005) are screening simulation models coupled with the input sh ell PE5.pl (August, 2007) to generate daily exposures and 1-in-10 year EECs of deltameth rin, that may occur from spray drift and runoff to surface water bodies adjacent to app lication sites. PRZM simulates pesticide application, movement and transformation on an agricultural fiel d and the resultant pesticide loadings to a recei ving water body via runoff, erosion and spray drift. The EXAMS model simulates the fate of the pesticide and resulting concentrations in the water body. The standard scenario used fo r ecological pesticide assessments assumes application to a 10-hectare agri cultural field that drains in to an adjacent 1-hectare water body that is 2 meters deep (20,000 m 3 volume) with no outlet. PRZM/ EXAMS is used to estimate screening-level exposure of aqua tic organisms to deltamethrin and/ or its transformation products, should they be of c oncern. The measure of exposure for aquatic species is the 1-in-10 year re turn peak or rolling mean c oncentration. 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 assessi ng chronic exposure to fi sh and aquatic-phase amphibians. The 1-in-10-year 21-day mean is used for assessing aquatic invertebrate chronic exposure.

Given the aquatic toxicity of deltamethrin and its likelihood to occur in sediment, the Agency will also consider the potential exposures resulting fro m benthic/ sediment concentrations (EECs). Pore water concentrations are commonly used to predict toxicity
of non-ionic substances in sediments and ch aracterize exposure to organisms that spend time in or near sediments (Di Toro et al. 1991; US EPA 2002). PRZM/ EXAMS estimates 1-in-10-year peak and 21-day mean EECs for pore water.

Exposure estimates for terrestrial animals assumed to be in the targ et area are derived using the T-REX model (version 1.3.1, 12/07/200 6). For pesticides such deltamethrin, which can be applied as a dust, this includes the amount of pesticide per square foot, used
in LD 50 per square foot risk assessment calcu lations. EECs for terrestrial plants inhabiting dry and wetland ar eas are derived using TerrPla nt (version 1.2.2, 12/26/2006). This model uses estimates of pesticides in runoff and in spray drift (assumed to be 0% for granulars) to calculate EECs. EECs are ba sed upon solubility, a pplication rate and minimum incorporation depth.

As indicated in Table 3.1 , deltamethrin appears to have a potential to bioconcentrate/ biomagnify. The potential for bioaccumulation of deltamethrin will also be examined in
the risk assessment. Because de ltamethrin has a fairly high K OW (34,200) and the

33chemical is persistent in sediments, there is a potential fo r bioaccumulation. The depuration rate is moderately slow (about 50% between days 3-7 and 70-75% after 2 weeks of depuration, MRID 41651040. Bio accumulation will be assessed using the results from BCF studies, as well as the KABAM model (K OW (based) Aquatic BioAccumulation Model, version 1.0, 2009), adjusting for biotransformation rates.

7.3. Measures of Effect

Ecological effects data are used as measures of direct and indirect effects to biological receptors. Data are typically obtained from registrant-submitted studies or from literature studies identified by ECOTOX. The ECOTOX da tabase 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 chemi cal mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX wa s created and is maintained by the USEPA,
Office of Research and Devel opment, and the National Health and Environmental Effects Research Laboratory's Mid- Continent Ecology Division.

The acute measures of effect used fo r animals in this assessment are the LD 50 , LC 50 and

EC 50 . LD stands for "Lethal Dose", and LD 50 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 LC 50 is the concentration of a chemical that is estimated to kill 50% of the test organisms. EC stands for “Effective Concentration” and the EC 50 is
the concentration of a chemical that is estim ated 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 ObservedAdverse-Effect-Level” and refers to the highest tested dose of a subs tance that has been reported to have no harmful (adverse) e ffects on test organisms. The NOAEC ( i.e. , “NoObserved-Adverse-Effect-Concentration”) is the highest test concentr ation at which none of the observed effects were statistically diffe rent from the control. The NOEC is the NoObserved-Effects-Concentration. For non-li sted plants, only acute exposures are assessed ( i.e. , EC 25 for terrestrial plants and EC 50 for aquatic plants); for listed plants
either the NOAEC or EC 05 is used.

Information on the potential effects of de ltamethrin on non-target animals is also collected from the Ecological Incident Informa tion System (EIIS). The EIIS is a database containing adverse effect (typ ically mortality) reports on non-target organisms where
such effects have been associated with th e use of pesticides. Information on incidents involving avian species are also provided through the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy.

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

34toxicity studies conducted w ith the Typical End-Use Product (TEP) may be used to
assess effects as a result of e xposure to spray drift only and only reflect potential effects from a brief exposure to the formulation.

The assessment of risk for direct effects to non-target organisms makes the assumption that the toxicity of deltamethrin to birds is similar to terrestrial-phase amphibians and reptiles. The same assumption is made for fish data, which is used to infer toxicity to aquatic-phase amphibians.

7.4. Integration of Exposure and Effects

Risk characterization is the integration of exposure and ecological e ffects characterization to determine the potential ecologi cal risk from the use of pe sticides 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 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 will be used to
indicate when deltamethrin’s us es, as directed on the label, have the potential to cause
adverse direct or indirect eff ects 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 pointestimate based approach described in the risk a ssessment. An effort may also be made to further qualitatively describe ri sk using probabilistic tools th at the Agency has developed. These tools have been reviewed by FIFRA Scientific Advisory Panels ( http://www.epa.gov/sc ipoly/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 deltamethrin. This assessment will be conducted in accordance with the Overview Document (USE PA 2004), provisions of the ESA, and the
Services’ Endangered Species C onsultation Handbook (USFWS/NMFS, 1998).

The assessment of effects associ ated with the registration of deltamethrin is based on an
action area. The action area is considered to be the area directly or indirectly affected by

35the federal action, as indicated by the exceedan ce 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 Do cument (USEPA 2004) considers the results of the risk assessment process to estab lish 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 assessmen t, attention will be focused on the footprint of the action ( i.e. , the area where deltamethrin applica tion occurs), plus all areas where offsite transport may result in potential e xposure that exceeds the Agency’s LOCs. Specific measures of ecological effect that de fine the action area for listed species include any direct and indirect effects and/ or pot ential 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 sub-lethal effect threshold for any biological entity at the whol e organism, organ, tissue, and/ or cellular level of organization. In situa tions where it is not possible to determine the threshold for an observed effect, the action ar ea is not spatially limited and is assumed to be the entire
United States.

7.7. Drinking Water Assessment

A drinking water assessment will be conducte d to support future human health risk
assessments of deltamethrin should it be required by HED. The drinking water assessment will incorporate model estimates of deltamethrin in surface and ground
waters. Concentrations in surface waters wi ll be estimated using FQPA Index Reservoir Screening Tool (FIRST, v.1.1.1, 12/18/07) (or su bsequently using PRZM/ EXAMS, with the Index Reservoir - see description above , if refinements are required). Ground water
estimates of concentrations will be estimat ed 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 availabl e surface and ground water monitoring data.

7.8. Preliminary Identification of Data Gaps

7.8.1. Fate

The environmental fate database for deltamethrin is largely complete. For registration review, the following are the data gaps for the chemical:

835.4300. Aerobic Aquatic Metabolism – A study is required in one water/sediment system, which is preferably domestic since th e supplemental data available is from two foreign water/ sediment systems (from the Neatherlands). The percent organic matter was very high in both sediments (3.0 and 12.4%), and furthermore, the pH of the water in both systems was above 8 (the range for two sy stems, measured at the initial and final intervals was 8.0 to 8.7). Deltamethrin is known to be susceptible to hydrolysis at higher pHs. The new test system should have a near neutral or slightly ac idic pH. Also, other deficiencies included that the system was not completely aerobi c or anaerobic, the

36analytical method could not distingui sh deltamethrin from its primary α -R-isomer or trans-deltamethrin, 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 a ccount for that fact, as indicated in the study Data Evaluation Record (DER).

835.4400. Anaerobic Aquatic Metabolism – No study has been submitted. The study is required.

Environmental Chemistry Methods (ECMs), and Independent Laboratory Validations (ILVs), for Soil, Water and Sediment . ECMs associated with the Terrestrial Field Dissipation study (Field dissipation §158.1300; OPPTS guidelines 835.6100, 835.6200, and 835.6300), along with successful confirmatory method trials (validation) by an inde pendent laboratory ( i.e. ILVs), are required. If there is risk concern for a given taxon, ECMs should be av ailable for the environmental media in which organisms of the taxon reside. These ECMs should have limits of quantization for
the residues of concern that are lower than the relevant toxico logical levels of concern. All previous reviews on deltame thrin indicate that there is high concern for acute and chronic aquatic toxicity. Certain scenarios may have triggered acut e and chronic levels
of concern for freshwater and/ or estuarine/ marine aquatic in vertebrates and/ or for fish. In addition, the latter risk assessments conduc ted on deltamethrin, indicated risk concerns for organisms living in the benthos. Th erefore, ECMs for water and sediment are required in addition to the ECM for soil. The ECMs should include parent and those residues found in the laboratory studies that exceeded 10% of the applied. The following appear to be the residues of concern for each media: Soil – parent, its epimers, alpha -R-deltamethrin, trans -deltamethrin, Br 2 CA, 3-PBAc Water – parent, its epimers, alpha -R-deltamethrin, Br 2 CA, 3-PBAc, 3-PBAldehyde Sediment – parent, its epimers, alpha -R-deltamethrin Br2CA, 3-PBAc and 3- PBAldehyde The registrant is encouraged to submit stat e-of-the-art environmental chemistry methods; further, multi-residue methods (MRMs) for so il, water and sediment are preferred. The registrant submitted one method for soil (MRID 42773903, LOQ 2 ppb, published in the Agency’s ECM website) 1 is available, that could quantify deltamethrin, transdeltamethrin and decamethrinic acid (Br 2 CA) in soil; the method is not useful to quantify 3-PBAc, which was up to 11% in the soil phot odegradation study. A full description of the method validation procedures performed by an independent laboratory should be submitted. It should include the following information: (a) Recovery level(s) of the test compound(s) from the soil, water and sediment (substrates) at various relevant fortification level(s) using the residue analytical met hodology; (b) a validated method sensitivity level; (c) results of the study and statistical test applied, including a stepwise presentation of the procedure for calculating percent recovery from the raw data; (d) all the data/ information necessary to independent ly verify the results; (e) summary of the results; and, (f) discussion a nd conclusions of the results.

Table 7.1 lists the status of the environmental fate data requirements for deltamethrin.

1 Available at url: http://www.epa.gov/oppbead1/methods/ecmindex.htm

37Table 7.1. Summary of Environmental Fate Data Requirements for Deltamethrin

Study Identification Use
Pattern 1 Does EPA Have Data To Satisfy This Requirement? Bibliographic
Citation Must Additional
Data Be Submitted
Under FIFRA

3(c)(2)(B)?

§158.1300 ENVIRONMENTAL FATE

Degradation Studies-Lab :

835.2120 Hydrolysis 1,2 Yes 41651038 No

835.2240 Photodegradation in

Water 1,2 Yes 42114818 No

835.2410 Photodegradation
on Soil 1,2 Yes 42114819 No

835.2370 Photodegradation in
Air 1,2 No Not Available Waived 2

Metabolism Studies-Lab :

835.4100 Aerobic Soil 1,2 Yes 41677404, 41677407,
42114820 No

835.4200 Anaerobic Soil 1,2 Yes 42114821,

44814505 No

835.4400 Anaerobic Aquatic 1,2 No Not Available Yes

835.4300 Aerobic Aquatic 1,2 Partially 44977005 Yes 3

Mobility Studies :

835.1230 Leaching – Adsorption/ Desorption 1,2 Yes 41651039, 42475908, 42976501,
44977006 No

835.1410 Volatility (Lab) 1,2 No Not Available Waived 2

835.8100 Volatility (Field) 1,2 No Not Available Waived 2

Dissipation Studies-Field :

835.6100 Terrestrial Field Dissipation 1,2 Yes 42114822, 42137505,
42773903 No

835.6200 Aquatic Field Dissipation 1,2 No N/A Reserved

835.6300 Forestry Dissipation 1,2 No N/A N/A

Ground Water Monitoring Studies :

38Table 7.1. Summary of Environmental Fate Data Requirements for Deltamethrin

Must Additional
Data Be Submitted Does EPA Have

Study Identification Use Bibliographic Under FIFRA Data To Satisfy Pattern 1 This Requirement? Citation 3(c)(2)(B)?

835.7100 Ground Water Monitoring 1,2 No NA Reserved

§158.1100 SPRAY DRIFT

201-1 Droplet Size Spectrum 1,2 No 2 NA No 4

202-1 Drift Field Evaluation 1,2 No 2 NA No 4

Other Studies :

ECM and ILV 1,2 Partially 42773903 Yes 5

1. Use Patterns: 1=Terrestrial/Food; 2=Terrestrial/Feed. 2. Deltamethrin has low vapor pressure and Henry’s Law Constant, data requirement was waived. 3. One study is required in only one wa ter/sediment system. The system should be domestic, have a near neutral pH, and should address deficiencies listed in the previous study. 4. Datarequirement covered by submission of the Spray Drift Task Force. 5. The registrant is encouraged to submit stateof-the-art environmental chemistry met hods; further, multi-residue methods (MRMs) for soil, water and sediment are preferred.

7.8.2 Effects

For registration review, the follo wing studies are being requeste d to fulfill any data gaps:

Guideline Number: 850-2100 Study Title: Passerine Acute Avian Oral Although an acute avian oral study was rece ived for the bobwhite quail, the Agency updated its data requirements in 40 CFR Part 158 (October 26, 2007) to include an acute oral toxicity study for both a pa sserine species and either a waterfowl or an upland game species. Prior to starting toxicity testing, a pr otocol will need to be provided for review. Many passerine species utili ze agricultural fields, fore sts, residential areas and surrounding areas, and, therefore, have the potential to be exposed to pesticides used in agricultural, forest, and residential settings. It is likely that, for most pesticide use patterns, passerines are more likely to be e xposed to pesticides than upland game species
and waterfowl. Passerines are smaller and ha ve faster metabolisms than the waterfowl and upland game bird species tr aditionally used in avian toxi city tests which could impact their sensitivity to chemicals.

Guideline Number: 850.1400 Study Title: Fish Early Life Stage (saltwater)
Guideline Number: 850.1500 Study Title: Fish Life Cycle (saltwater) Deltamethrin has the potential to enter estuarine/marine water bodies based on current usage patterns that include coastal areas. Expos ure to aquatic organism s is also evidenced by studies from Weston et al (2005) and Amweg et al (2006). Furthermore, the acute

39LC 50 = 0.36 μg a.i./L for estuarine/marine fish, indicating that deltamethrin is very highly
toxic on an acute basis to sh eepshead minnow and demonstrati ng potential chronic risk to this taxon (MRID 42114811). Available ecological studies also show that low-level chronic exposure to deltamethrin has the pot ential to cause adverse reproductive effects in freshwater fish (NOAEC = 0.017 μg a. i./L, MRID 42786802). Without this study, the Agency would have to presume chronic risk to listed and non-listed es tuarine/marine fish, but would not be able to quantify the risk.

Guideline Number: 850.1350 Study Title: Aquatic Invert ebrate Life-Cycle (saltwater) The acute toxicity of deltamethrin to estuarin e/marine invertebrates indicates the potential
for chronic risk to animals in this taxon, and the potential for chronic exposure exists. Deltamethrin has the potential to enter estuarine/marine water bodies based on current usage patterns that include coastal areas. W ithout this study, the Agency would have to presume chronic risk to listed and non-listed estuarine/mari ne invertebrates, but would not be able to quantify the risk. The Agency had conditionally required aquatic invertebrate life-cycle studies (Guidelines 850.1300, 850.1350, and 850.1400) for terrestrial food and nonfood, aquatic food and nonfood, forestry, and domestic outdoor

uses.

Guideline Number: 850-1790 Study Title: Whole sediment: chroni c invertebrates freshwater and marine No chronic sediment toxicity tests for fres hwater or marine invertebrates have been submitted to satisfy the Agency’s updated data requirements for outdoor uses in 40 CFR Part 158 (October 26, 2007). Benthic organisms inhabit sediment environments that may be exposed to run-off or spray drift from de ltamethrin applications used in agricultural, forest, and residential settings. Previous studi es have identified a pot ential adverse effect for freshwater and estuarine/marine aquatic organisms based on water column toxicity values. Therefore, there is uncertainty associ ated with that estimate that can be reduced using data from a toxicity test with benthic or ganisms. There is the potential for persistent exposure from deltamethrin in sediment indicated by the fate properties and open literature studies on pyr ethroids (Stout II, et al. 2009, Weston et al. 2005, and Amweg et al. 2006). For sediment studies i nvolving pyrethroids, tests on Hyalella azteca

, Chironomus tentans , and Leptocheirus plumulosus are requested. Although both are freshwater species, Hyalella and Chironomus differ substantially in their ecological niche (i.e., epibenthic vs. infaunal specie s), physiology, and there is some evidence suggesting Hyalella is among the more sensitive invert ebrates to some pyrethroids based on water column tests (Anderson et al. 2006).

Guideline Numbers: 850.4150 and 850.4250 Study Title: Vegetative vigor and Seedling emergence, Tier I/ Tier II No acceptable toxicity data are currently ava ilable to assess the risk of deltamethrin to non-target terrestrial plants. Since deltamethrin has reside ntial outdoor uses, vegetative vigor and seedling emergence studies are requi red. These phytotoxicity data are needed to evaluate the level of pesticide exposure to non-target terrestrial and aquatic plants and to assess the impact of pesticides on endangered and threatened plants.

40Guideline Number: 850.4400 Study Title: Aquatic Vascular Plant Growth- Lemna spp. Tiers I/II No acceptable studies for deltamethrin have been submitted for vascular aquatic plants. The Agency has finalized its update to the data requirements in 40 CFR Part 158. In these updated data requirements, which were promulgated on October 26, 2007, vascular plant testing is required for pesticides such as deltamethrin with outdoor uses.

Guideline Number: 850.5400 Study Title: Algal toxicity test

, Tier I/II No toxicity data are currently available to assess the risk of de ltamethrin to aquatic nonvascular plants. Since deltamethrin has re sidential outdoor uses, Tier I/II aquatic nonvascular plant studies are re quired. These phytotoxicity data are needed to evaluate the level of pesticide exposure to non-target aquatic plants and to assess the impact of pesticides on endangered a nd threatened plants.

For mammalian toxicity, EFED will coordinate with HED to determine the most sensitive endpoints for acute and chronic studies.

Testing on Typical e nd-use products (TEP)

A Typical End-Use Product is defined in the Pesticide Assessment Guidelines Subdivision J Hazard Evaluation: Nontarget plants on Part 120-2(1) on Page 18 as “a pesticide product that is representati ve of a major formulation category ( e.g ., emulsifiable concentrate, granular product, we ttable powder) and pesticide group ( e.g ., herbicide, fungicide, insecticide etc .) and contains the active ingredie nt of the applicant’s product.” (Holst and Ellwanger, 1982)

Page 5 of the Pesticide Assessment Guidelines S ubdivision J Hazard Evaluation: Nontarget plants provides additional information on what TEP data should be tested for toxicity testing in the following excerpt.

“The Agency seeks to avoid imposi ng a burden of dupli cative testing on applicants for registration. Therefore, where 40 CFR Part 158 specifies that the test substance should be a representa tive end-use product, testing may be performed using the formulation in questi on (end-use product be ing registered) or similar, yet representative, end-use product. It is not necessary to repeat the test using other similar products.” (Holst and Ellwanger, 1982).

When TEP data are requested data should be submitted for the different formulations,

e.g ., wettable powder, emulsifiable concentrate, granular, along with a rationale as to why the TEP is representative of other similar e nd-use products. Acute aqua tic toxicity studies conducted with the Typical End-Use Product (TEP ) may be used to assess effects as a result of exposure to spray dr ift only and reflect potential e ffects from a brief exposure to the formulation. Therefore, appropriate TEPs s hould be selected from formulations that are registered for agricultur al uses, not residential.

41Table 7.2 lists the status of the ecological e ffects data requirements for deltamethrin.

Table 7.2. Ecological Effects Data Requirements for Deltamethrin

Data Requirement Use
Pattern 1 Does EPA Have Data To Satisfy
This Requirement?

(Yes, No, or

Partially) Bibliographic
Citation Must
Additional

Data Be
Submitted
Under FIFRA

3(c)(2)(B)?

§158.490 TERRESTRIAL ORGANISMS

71-1(a) Acute Avian Oral, Quail/Duck 1,2 Partially 00158273 Yes 2

71-2(a) Acute Avian Diet, Quail 1,2 No NA Waived 3

71-2(b) Acute Avian Diet, Duck 1,2 Yes 00060723 No

71-3 Wild Mammal Toxicity 1,2 NA

71-4(a) Avian Reproduction Quail 1,2 Yes 42114808 No

71-4(b) Avian Reproduction Duck 1,2 Yes 42114809 No

71-5(a) Simulated Terrestrial Field Study 1,2 NA

71-5(b) Actual Terrestrial Field Study 1,2 NA

§158.630 AQUATIC ORGANISMS TESTING

72-1(a) Acute Fish Toxicity Bluegill 1,2 Yes 00158275 No

72-1(b) Acute Fish Toxicity (TEP) 1,2 Yes 41651013 No 4

72-1(c) Acute Fish Toxicity Rainbow

Trout 1,2 Yes 00158274 No

72-2(a) Acute Aquatic Invertebrate 1,2 Yes 44928701 No

72-2(b) Acute Aquatic Invertebrate (TEP) 1,2 Yes 41651014 No

72-3(a) Acute Est/Mar Toxicity Fish 1,2 Yes 41651015 No

72-3(b) Acute Est/Mar Toxicity Mollusk 1,2 Yes 41651016 No

72-3(c) Acute Est/Mar Toxicity Shrimp 1,2 Yes 42114810 No

72-3(d) Acute Est/Mar Toxicity Fish (TEP) 1,2 Yes 42114811 No

72-3(e) Acute Est/Mar Toxicity Mollusk (TEP) 1,2 Yes 41651017 No

72-3(f) Acute Est/Mar Toxicity Shrimp (TEP) 1,2 Yes 42114812 No

72-4(a) Early Life Stage Fish 1,2 Partially 42114814 Yes 5

42Table 7.2. Ecological Effects Data Requirements for Deltamethrin

Does EPA Have Must

Data Requirement Use
Pattern 1 Data To Satisfy Additional
This Data Be Requirement? Submitted

(Yes, No, or

Partially) Bibliographic Under FIFRA
Citation 3(c)(2)(B)?

72-4(b) Life Cycle Aquatic Invertebrate (freshwater) 1,2 Yes 42114813 No

850.1350 Life Cycle Aquatic Invertebrate (saltwater) 1,2 No NA Yes

72-5 Life Cycle Fish 1,2 Partially 42786802 Yes 5

72-6 Aquatic Organism Accumulation 1,2 NA

72-7(1) Simulated Aquatic Field Study 1,2 NA

72-7(b) Actual Aquatic Field Study 1,2 NA

850.1730 Bioaccumulation in Fi sh 1,2 Yes 4165 1040, 4 3072701,
43072702 No

850.1735 Whole sedimen t: acute freshwater
invertebrates 1, 2 No NA Waived

850.1740 Whole sediment: acute marine
invertebrates 1, 2 No NA Waived

Whole sediment: chronic invertebrates
freshwater & marine 1, 2 No NA Yes

§158.540 PLANT PROTECTION

122-1(a) Seed Germ, Seedling Emergence 1,2 No NA Yes

122-1(b) Vegetative Vigor 1,2 No NA Yes

122-2 Aquatic Plant Growth 1,2 No NA Yes 6

123-1(a) Seed Germ./Seedling Emerg. 1,2 NA NA No 7

123-1(b) Vegetative Vigor 1,2 NA NA No 7

123-2 Aquatic Plant Growth 1,2 NA NA No 8

124-1 Terrestrial Field Study 1,2 NA

124-2 Aquatic Field Study 1,2 NA

§158.490 NONTARGET INSECT TESTING

141-1 Honey Bee Acute Contact 1,2 Yes 42114815 No

141-2 Honey Bee Residue on Foliage 1,2 Yes 42475905 and

42773902 No

141-5 Field Test for Pollinators 1,2 NA

43Table 7.2. Ecological Effects Data Requirements for Deltamethrin

Does EPA Have Must

Data Requirement Use
Pattern 1 Data To Satisfy Additional
This Data Be Requirement? Submitted

(Yes, No, or

Partially) Bibliographic Under FIFRA
Citation 3(c)(2)(B)?

1 Use Patterns: 1=Terrestrial/Food; 2=Terrestrial/Feed.

2 Data are required for one passerine species and either on waterfowl or one upland ga me bird species. At this time, only an acute oral test for a game bird species has been submitted.

3 Because none of the previously submitted studies show any acute oral, dietary or chronic t oxic effects to waterfowl and upland game bird species, no dietary study is required for the mallard duck.

4 Part 158 data requirements state that the freshwater fish test species for the TEP testing should be the most sensitive of the species tested with th e TGAI. The 96-hour LC 50 = 0.91 μg a.i./L for coldwater rainbow trout ( Oncorhynchus mykiss) and warmwater bluegill sunfish ( Lepomis macrochirus) (MRIDs 00158274 and 00158275) were equivalent for deltamethrin technical. The most sensitive species tested for deltamethrin technical acute toxicity was Lepomis gibbosus (Pumpkinseed sunfish) (MRID 00060721). However Lepomis gibbosus is not a guideline species. Therefore, the rainbow trout acute toxicity test for the formulated product satisfies the guideline requirement.

5 Data are required for saltwater/marine fi sh species. With current registered use patterns, deltamethrin can potentially enter water bodies, based on the available environmental fate data. Exposure to aquatic organisms is also evidenced by studies
from Weston et al (2005) and Amweg et al (2006). Furthermore, the acute LC 50 = 0.36 μg a.i./L for estuarine/marine fish, indicating that deltamethrin is very highly toxic on an acute basis to sheepshead minnow (MRID 42114811). Available ecological studies also show th at low-level chronic exposure to deltamethrin has the potential to cause adverse reproductive effects in freshwater fish (NOAEC = 0.017 μg a.i./L, MRID 42786802).

6 Aquatic toxicity tests are required for both algal and aquatic vascular species.

7 Required if a tested terrestrial species exhibits a 25 pe rcent or greater detrimental e ffect in the Tier I study.

8 Required if a tested aquatic species exhibits a 50 per cent or greater detrimental e ffect in a Tier I study.

8. References

Amweg, E.L. D.P. Weston, J. You and M.J. Lydy. 2006. Pyrethroid Insecticides and Sediment Toxicity in Urban Creek s from California and Tennessee. Environ. Sci.
Technol.

, 2006

, 40 (5), pp 1700–1706.

Amweg, E.L., D.P. Weston and N.M. Ureda. 2004. Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environ Toxicol & Chem, 24 (4), pp.

966–972.

Armitage, J.M., & Gobas, F.A.P.C. 2007. A te rrestrial food-chain bi oaccumulation model
for POPs. Environmental Scien ce and Technology, 41 , 4019-4025.

Barile, F. A. 2004. Clinical Toxicology: Principles and Mechanisms . Boca Raton, FL:
CRC Press.

44Budd, R, S. Bondarenko, D. Haver, J. Kabashima, and J. Gan. 2007. Occurrence and Bioavailability of Pyrethroids in a Mixed Land Use Watershed. J. Environ. Qual. 36: 1006–1012 (2007).

Di Toro, DM, Zarba CS, Hansen DJ, Berry WJ, Swartz RC, Cowan CE, Pavlou SP, Allen HE, Thomas NA, Paquin PR. 1991. Technical basis for establishing sediment quality criteria for nonionic organic chemicals usi ng equilibrium partitioning. Environ. Toxicol.
Chem. 10:1541-1583.

Gobas, F.A.P.C., B.C. Kelly and J.A. Arnot. 2003. Quantitative structure activity relationships for predicting the bioaccumulati on of POPs in terrestrial food webs. QSAR
Comb. Sci. 22:329-336.

Hodgson, E., & Smart, R. C. (Eds.). (2001). Introduction to Biochemical Toxicology (Third ed.). New York: Wiley-Interscience.

Holst, R. W., & Ellwanger, T. C. 1982. Pesticide Assessment Guidelines. Subdivision J. Hazard Evaluation: Nontarget Plants . EPA-540/09-82-020. Octobe r 1982. Office of Pesticide Programs. Office of Pesticides and Toxic Substances. United States Environmental Protection Agency.

Laskowski, D.A., 2002. Physical and chemical properties of pyrethroids. Rev. Environ. Contam. Toxicol. 2002; 174:49-170.

Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil Contaminatio n: A Reference Manual. Appendix 2. Parameters of pesticides th at influence processes in th e soil. Editorial Group, FAO Information Division: Rome, 2000. http://www.fao.org/DOCREP/003/X2570E/X2570E00.htm

Stout II, D.M., K Bradham, P.P. Egeghy, P. Jones, C.W. Croghan, P.A. Ashley, E. Pinzer, W. Friedman, M.C. Brinkman, M.G. Nishioka and D.C. Cox. 2009. American Healthy Homes Survey: A National Study of Resi dential Pesticides Me asured from Floor Wipes. Environ. Sci. Technol., 2009
, 43, 4294–4300.

Trimble, A.J, D.P. Weston, J.B. Belde n, and M.J. Lydy. 2009. Identification and Evaluation of Pyrethroid Insecticide Mixtures in Urban Sediments. Environ Toxicol & Chem 26 (8) pp. 1687–1695 (from ET&C paper in press).

U.S. Environmental Protection Agency. 1998. Guidelines for Ecological Risk Assessment. Risk Assessment Forum, Office of Research and Development, Washington, D.C. EPA/630/R-95/002F. April 1998.

U.S. Environmental Protection Agency. 2000. Risk Characterization Handbook. Science Policy Council, U.S. Environmenta l Protection Agency, Washington, D.C.
20460. EPA 100-B-00-002. December 2000.

45U.S. Environmental Protection Agency. 2002. Technical Basis for the derivation of Equilibrium Partitioning Sediment Guidelin es (ESGs) for the Protection of Benthic Organisms: Nonionic Organics [Draft]. EPA Document No. 822R02041. October 2002.

U.S. Environmental Protection Agency. 2004. Overview of the Ecological Risk
Assessment Process in the Office of Pesticid e Programs, U.S. Environmental Protection Agency. Endangered and Threatened Speci es Effects Determinations. Office of Prevention, Pesticides and Toxic Substances , Office of Pesticide Programs, Washington, D.C. January 23, 2004.

U.S. Environmental Protection Agency. 1999. FIFRA Scientific Advisory Panel Meeting, February 23, 1999 held at the Holida y Inn Hotel, Arlington, Virginia. S. R. N. 99-03A. March 25, 1999. Office of Pesticide Programs.
Available at http://www.epa.gov/scipoly/sap/m eetings/1999/022399_mtg.htm#materials (Accessed December 14, 2009).

U.S. Environmental Protection Agency. 2005. Generic Format and Guidance for the Level I Screening Ecological Risk Assessm ents Conducted in the Environmental Fate
and Effects Division. Office of Pesticide Programs, Washington, D.C. January 24, 2005.

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

Weston, D.P., R.W. Holmes, J. You and M.J. Lydy. 2005. Aquatic Toxicity Due to Residential Use of Pyrethroid Insecticides. Environ. Sci. Technol.

, 2005

, 39 (24), pp

9778–9784.

Weston, D. 2007. Impacts of Pyrethroid Pesticides on Water Quality from Urban and Agricultural Sectors. Conference Proceedings; California Plant and Soil Conference: Opportunities for California Agriculture. Ca lifornia Chapter of the American Society of Agronomy, pp. 35-37.

Weston, D.P., R.W. Holmes, and M.J. Lydy. 2009. Residential runoff as a source of pyrethroid pesticides to urban creeks. Environmental Pollution 157, 287–294.

Weston, D.P. and M.J. Lydy. 2010. Urban and Agricultural Sources of Pyrethroid
Insecticides to the Sacramento-S an Joaquin Delta of California. Environ. Sci. Technol. 2010, 44, 1833–1840.

46Appendix A. SRRD data re quest justification tables

The following proposed Data Call-in tables include rationales for requiring the data requested in this problem formulation, expl anations of the util ity of the data, and explanations for how the data might impact risk assessment, following the format provided by SRRD.

Guideline Number: 835.4300 Study Title: Aerobic Aquatic Metabolism

Guideline Number: 835.4400 Study Title: Anaerobic Aquatic Metabolism Rationale for Requiring the Data According to 40 CFR Part 158, Subpart N (Environmental Fate) §158.1300 (Environmental fate data requirements table), these data are re quired for all terrestrial use patterns.

An aerobic aquatic metabolism study is required in one water/sediment system, which is preferably domestic since the supplemental data available is from two foreign water/ sediment systems. The percent organic matter was very high in both sediments (3.0 and 12.4%), and furthermore, the pH of the water in both system s was above 8 (range for two systems, measured at the initial and final intervals was pH of 8.0 to 8.7). Deltamethrin is known to be susceptible to hydrolysis at higher pHs. The new test system should have a near neutral pH. Also, other deficiencies listed in the study Data Ev aluation Record (DER) should be addressed.

There is no anaerobic aquatic metabolism study. Practical Utility of the Data How did the Agency make its registr ation decision without these data? The previous assessments were based on supplem ental aerobic aquatic metabolism data and the anaerobic soil metabolism study.

How will the data be used? Deltamethrin is a synthetic pyrethroid with high toxicity towards aquatic organisms, including those living in the benthos. Knowledge of its pe rsistence in aquatic envi ronments is important. The results of this study will be used in the e nvironmental fate assessment, and later on, in the ecological risk characterization.

In addition, the data will be used to derive the ra te of reaction input parameter to be used in the aquatic models GENEEC2, PRZM/ EXAMS and FIR ST. The results from these models are used for ecological risk estimation and in drinking water exposure assessments.

How could the data impact the Agency’s future decision-making? Without these data, the Agency would have to make certain conservative assumptions ( e.g. use a two times the aerobic soil metabolism half-life i nput for the aerobic aquatic metabolism or two
times the anaerobic soil metabolism half-life for the anaerobic aquatic metabolism in the aquatic models). These conservative assumptions could lead to higher predicted concentrations (EECs), according to the models, and consequently, higher risk quotients. Also, there would be a higher degree of uncertainty in the environmental fa te assessment. Knowledge of these dissipation pathways in detail is essential to perform a be tter and accurate environmental fate assessment and
risk assessment.

47The lack of these data will limit the flexibility th e Agency and registrants have in coming into compliance with the Endangered Species Act and c ould result in use restrictions for deltamethrin that may be unnecessary.

48Guideline Number: None Study Title: Environmental Chemistry Methods (ECM) and Independent Laboratory Validation (ILV) for Soil, Water and Sediment Rationale for Requiring the Data According to the data requirements in 40 CFR Pa rt 158, ECMs are currently required along with successful confirmatory method trials (va lidation) by an independent laboratory ( i.e. ILVs). In addition to the method for soil, at this time, methods are required for water and sediment. Acceptable ECMs for the residues of concern (p arent and its transformation products) should have levels of quantization that are adequate to address risk concerns or that are at levels below the toxicological endpoints for the relevant a quatic organisms. The results of previous
assessments indicate that there is risk for freshwa ter and estuarine/ marine fish, invertebrates and benthic organisms. Therefore, ECMs for water and sediment are required in addition to the ECM for soil. The ECMs should include parent and those residues found in the laboratory studies that exceeded 10% of the applied. The registrant is encouraged to submit state-of-the-art environmental chemistry methods; further, multi -residue methods (MRMs) for soil, water and sediment are preferred. Practical Utility of the Data How did the Agency make its registr ation decision without these data? Instead of monitoring data, models we re utilized to calculate the exposure ( i.e. Estimated Environmental Concentrations, EECs), using availa ble environmental fate data. Currently, there is a published method for soils, but the method is not useful to quantify 3-PBAc, which was up to 11% in the soil photodegradation study.

How will the data be used? The data will be used to verify the suitability of the methods. Subsequently the methods could be used by states or other enforcement agencies, de partments or entities, to monitor concentrations of the residues of concern. Validated analytical methods in environmental media ( a.k.a. , ECMs) are useful for conducting and evaluating submitted environmental fate and toxicity field and monitoring studies and for addressing potential risk s to the environment posed by the use and/or accidental release of pesticides.

How could the data impact the Agency’s future decision-making? If monitoring of the chemical is required or performed, the Agency could be able to determine if the chemical is present in the environment at concentrations that are threatening to wildlife (or to humans, in the case of drinking waters), according to the levels of concern (LOCs). If that is the case, measures to prevent these concentrations to o ccur could be taken. The data could also be used by enforcement entities like the states or gove rnment agencies or departments. Without these data, the potential for the determination of residues of deltamethrin and its epimers and degradates in soil, water and sediment is rest ricted. 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 restricti ons for deltamethrin which may otherwise be avoided, or which are unnecessarily severe.

49Guideline Number: 850-2100 Study Title: Passerine Acute Avian Oral Rationale for Requiring the Data Although an acute avian oral study was received for the bobwhite quail, the Agency updated its data requirements in 40 CFR Part 158 (October 26, 2007) to include an acute oral toxicity study for both a passerine species and either a waterfowl or an upland game species. Prior to starting toxicity testing, a protocol will need to be provided for review.

o Many passerine species utili ze agricultural fields, fo rests, residential areas and surrounding areas, and, therefore, ha ve the potential to be exposed to pesticides used in agricultural, forest, and residential settings

 It is likely that, for most pesticid e use patterns, passerines are more likely to be exposed to pesticid es than upland game species and
waterfowl

o Passerines are smaller and have faster metabolisms than the waterfowl and upland game bird species traditionally used in avian toxicity tests which could impact their sensitivity to chemicals.

Practical Utility of the Data How did the Agency make its registr ation decision without these data? Since this is a new requirement, EPA was using th e results from the toxicity tests for the upland gamebird species (Note: A study on a waterfowl species was never submitted).

How will the data be used? Data from passerine toxicity studies will be used to estimate potential risks to birds associated
with uses of deltamethrin. The data will redu ce uncertainties associated with the current risk assessment for passerine species and will improve our understanding of the potential effects of
deltamethrin.

How could the data impact the Agency’s future decision-making? Because birds significantly contribute to overall environmental quality, a solid understanding of the potential risks to birds, including passerine species, is essential for sound environmental management. Without acceptable data for deltameth rin, the Agency cannot determine the levels of deltamethrin that result in effects to passerin e species. If the data indicates that registered tralomethrin usage may pose a risk of adverse effe cts to non-target birds above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk. The lack of these data will limit the flexibility the Agency and registra nts have in coming into compliance with the Endangered Species Act, and could result in u se restrictions for deltamethrin which may otherwise be avoided, or which are unnecessarily severe.

50Guideline Number: 850.1400 Study Title: Fish Early Life Stage (saltwater)
Guideline Number: 850.1500 Study Title: Fish Life Cycle (saltwater) Rationale for Requiring the Data

Deltamethrin has the potential to enter estuarine/marine water bodies based on current usuage patterns that include coastal areas. Exposure to aquatic organisms is also evidenced by studies from Weston et al (2005) and Amweg et al (2006). Furthermore, the acute LC 50 = 0.36 μg a.i./L for estuarine/marine fish, indicating that deltamethrin is very highly toxic on an acute basis to sheepshead minnow and demonstrating potential chronic risk to this taxon (MRID 42114811). Available ecological studies also show that low-level chronic exposure to deltamethrin has the potential to cause adverse reproductive effects in freshwater fish (NOAEC = 0.017 μg a.i./L, MRID 42786802).

Practical Utility of the Data How did the Agency make its re-registrat ion decision without this data? To address potential risks, the Agen cy imposed mitigation, as an inte rim measure, which included reduced use rates and application restrictions.

How will the data be used? The estuarine/marine fish early life stage and fish life-cycle study would allow the Agency to analyze chronic effects, including effects on reproductive success and growth, to estuarine/marine fish. The effects
data would be used to determine the likelihood th at the chronic risks can potentially impact aquatic communities, either by direct effects on fish or by i ndirect effects via invertebrates by reducing their food sources. By refining the assessment, the Agency woul d be able to determine whether the mitigation imposed as part of the reregistration process was appropria te due to toxicity concerns with deltamethrin.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessments are perfo rmed without these data, the Agency would have to assume that deltamethrin "may affect" endangered invertebrates directly (and endangered species from other taxa indirectly), and use of deltamethrin might need to be restricted in areas where endangered 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 Speci es Act and could result in use restrictions for deltamethrin which are unnecessarily severe.

51Guideline Number: 850.1350 Study Title: Aquatic Invertebrate Life-Cycle (saltwater) Rationale for Requiring the Data

The acute toxicity of deltamethrin to estuarine/marine invertebrates indicates the potential for chronic risk to animals in this taxon, and the potential for chr onic exposure exists. Deltamethrin has the potential to enter estuarine/marine water bodies based on current usuage patterns that include coastal areas. The parent compound tralomethrin exhibits chronic toxicity effect s to estuarine/marine invertebrates. Without this study, the Agency would have to presume chroni c risk to listed and non-listed estuarine/marine invertebrates, but would not be able to quantify the risk.

The Agency had conditionally required aquatic i nvertebrate life-cycle studies (Guidelines 850.1300, 850.1350, and 850.1400) for terrestrial food and nonfood, aquatic food and nonfood, forestry, and
domestic outdoor uses.

Practical Utility of the Data How did the Agency make its re-registrat ion decision without this data? To address potential risks, the Agen cy imposed mitigation, as an inte rim measure, which included reduced use rates and application restrictions.

How will the data be used? The aquatic invertebrate life-cycle study would allow the Agency to analyze chronic effects, including effects on reproductive success and growth, to saltwater inve rtebrates. The effects data would be used to determine the likelihood that the chronic risks can poten tially impact aquatic communities, either by direct effects on invertebrates or by indirect effects on fish by reducing their food sources. By refining the assessment, the Agency would be able to determin e whether the mitigation imposed as part of the reregistration process was appropriate due to toxicity concerns with deltamethrin.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessments are perfo rmed without these data, the Agency would have to assume that deltamethrin "may affect" endangered invertebrates directly (and endangered species from other taxa indirectly), and use of deltamethrin might need to be restricted in areas where endangered 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 Speci es Act and could result in use restrictions for deltamethrin which are unnecessarily severe.

52Guideline Number: None Study Title: Whole sediment: Chronic invertebrates freshwater and marine Rationale for Requiring the Data No chronic sediment toxicity tests for freshwater or marine invertebrates have been submitted to satisfy the Agency’s updated da ta requirements for outdoor uses in 40 CFR Part 158 (October 26, 2007). For sediment studies involving pyrethroids, tests on Hyalella azteca

, Chironomus tentans

, and Leptocheirus plumulosus are requested. Although both are freshwater species, Hyalella and
Chironomus differ substantially in their ecological niche (i.e., epibenthic vs. infaunal species), physiology, and there is some evidence suggesting Hyalella is among the more sensitive invertebrates to some pyrethroids based on water column tests (Anderson et al. 2006).

o Benthic organisms inhabit sediment e nvironments that may be exposed to run-off or spray drift from deltamethri n applications used in agricultural, forest, and residential settings

o Previous studies have identified a pote ntial adverse effect for freshwater and estuarine/marine aquatic organism s based on water column toxicity values. Therefore, there is uncertainty associated with that estimate that can be reduced using data from a toxici ty test with benthic organisms.

o There is the potential for persiste nt exposure from deltamethrin in sediment indicated by the fate proper ties and open literature studies on pyrethroids (Stout II, et al. 2009, Weston et al. 2005, and Amweg et al. 2006).

Practical Utility of the Data How did the Agency make its registr ation decision without these data? Surface waters EECs were estimated, while the benthic zone of the bodies of water could not be estimated at the time. The possibility of accumula tion of the chemical in sediments was stressed
in all the reviews. It was noted that LOCs for aquatic organisms were exceeded using a variety of methods to calculate EECs. Recently, the Agen cy has used the pore water EECs, generated by PRZM/ EXAMS, for other synthetic pyrethroids with similar aquatic toxicity and level of binding to soils/ sediments than deltamethrin. Using th e equilibrium partitioning theory (EqP), the RQs were estimated for other pyrethroids. It has been found that the RQs ex ceeded the LOCs for these chemicals. A similar finding is expected for deltamethrin.

How will the data be used? Data from sediment toxicity studies will be used to estimate potential risks to benthic organisms
associated with uses of deltamethrin. The da ta will reduce uncertainti es associated with the current risk assessment for benthic species and will improve our understanding of the potential
effects of deltamethrin.

How could the data impact the Agency’s future decision-making? Although there was uncertainty in estimating the effect of deltamethrin on benthic organisms in the previous assessment, there was a potential risk associated with adverse effects identified for estuarine/marine acute and chronic organisms. Acceptable data for benthic organisms will reduce the uncertainty from the previous assessment If th e data indicates that registered deltamethrin usage may pose a risk of adverse effects to non- target benthic organisms above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk. The lack of these data

53will limit the flexibility the Agency and registra nts have in coming into compliance with the Endangered Species Act, and could result in u se restrictions for deltamethrin which may otherwise be avoided, or which are unnecessarily severe.

54Guideline Numbers: 850.4150 and 850.4250 Study Title: Vegetative vigor and Seedling emergence, Tier I/ Tier II

Rationale for Requiring the Data

No acceptable toxicity data are currently available to assess the risk of deltamethrin to terrestrial plants.

Since deltamethrin has residential outdoor uses, vegetative vigor and seedling emergence studies are required. These phytotoxicity data are needed to evaluate the level of pesticide exposure to non-target terrestrial and aquatic plants and to assess the impact of pesticides on endangered and threatened plants. Practical Utility of the Data

How did the Agency make its re-regis tration decision without these data? Since EPA was unable to evaluate the potential ri sks to terrestrial plants associated with the proposed uses of deltamethrin, risks were not precluded for vegetative vigor and seedling emergence endpoints for terrestrial plants.

How will the data be used? Data from terrestrial plant toxicity studies will be used to estimate potential risks to plants
associated with uses of deltamethrin. The da ta will reduce uncertainti es associated with the current risk assessment for terrestrial plants a nd will improve our understanding of the potential effects of deltamethrin on plants.

How could the data impact the Agency’s future decision-making? Because plants form the basis of most habitats and significantly contribute to overall environmental quality, a solid understanding of the potential risks to terrestrial plants is essential for sound environmental management. Without accep table plant growth data for deltamethrin, the Agency cannot determine the levels of deltamethrin th at result in effects to terrestrial plants. If the data indicates that registered deltamethrin usage may pose a risk of adverse effects to non-target terrestrial plants plants above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk. 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 deltamethrin which may ot herwise be avoided, or which are unnecessarily

severe.

55Guideline Number: 850.4400 Study Title: Aquatic Vascular Plant Growth- Lemna spp. Tiers I/II

Rationale for Requiring the Data

No acceptable studies for deltamethrin have been submitted for vascular aquatic plants. The Agency has finalized its update to the data requirements in 40 CFR Part 158. In these updated data requirements, which were promulgated on October 26, 2007, vascular plant testing is required for pesticides such as de ltamethrin with outdoor uses.

Practical Utility of the Data

How did the Agency make its re-regis tration decision without these data? Since EPA was unable to evaluate the potential ri sks to aquatic vascular plants associated with the use of deltamethrin, risks were pr esumed for vascular aquatic plants.

How will the data be used? Data from aquatic plant toxicity studies will be used to estimate potential risks to plants
associated with uses of deltamethrin. The da ta will reduce uncertainti es associated with the current risk assessment for aquatic plants and will improve our unders tanding of the potential effects of tralomethrin on vascular aquatic plants.

How could the data change the Agency’s decision, or impact the Agency’s future decisionmaking? Because plants form the basis of most habitats and significantly contribute to overall environmental quality, a solid un derstanding of the potential risks to aquatic plants is essential for sound environmental management. Without pl ant growth data for deltamethrin, the Agency
cannot determine the levels of deltamethrin that r esult in effects to vascular aquatic plants. If the data indicates that registered deltamethrin usage may pose a risk of adverse effects to nontarget aquatic vascular plants above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk.

If future endangered species risk assessments are performed without these data, the Agency would have to assume that deltamethrin "may a ffect" endangered plants and use of deltamethrin might need to be restricted in areas where e ndangered species could be exposed. The lack of these data will limit the flexibility the Agency an d registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for deltamethrin that may be unnecessarily severe.

5657 Guideline Number: 850.5400 Study Title: Algal toxicity test

, Tier I/II Rationale for Requiring the Data

No toxicity data are currently available to assess the risk of tralomethrin and the degradate deltamethrin to aquatic nonvascular plants. Since tralomethrin has residential outdoor uses, Tier I/II aquatic nonvascular plant studies are required. These phytotoxicity data are needed to evaluate the level of pesticide exposure to non-ta rget aquatic plants and to assess the impact of pesticides on endangered and threatened plants. Practical Utility of the Data

How did the Agency make its re-regis tration decision without these data? Since EPA was unable to evaluate the potential risk s to aquatic nonvascular plants associated with the proposed uses of tralomethrin, risks were presumed for aquatic plants.

How will the data be used? Data from Tier I/II nonvascular aquatic plant toxi city studies will be used to estimate potential risks to plants associated with uses of tralomet hrin. The data will redu ce uncertainties associated
with the current risk assessment for nonvascu lar aquatic plants and will improve our understanding of the potential effects of tral omethrin and the degradate deltamethrin.

How could the data impact the Agency’s future decision-making? Because plants form the basis of most habitats and significantly contribute to overall environmental quality, a solid unde rstanding of the potential risks to nonvascular aquatic plants is essential for sound environmental management. Wit hout plant growth data for tralomethrin and the degradate deltamethrin, the Agency cannot determ ine the levels of tralomethrin that result in effects to aquatic plants. If the data indicates that registered tralomethrin usage may pose a risk of adverse effects to non-target aquatic nonvascular plants above the Agency Level of Concern, the Agency may explore decision options to mitigate th is risk. 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 fo r tralomethrin which may otherwise be avoided, or which are unnecessarily severe.