### -2 of 69- 

# Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Exposure Assessments in Support of the Registration Review of Oryzalin

CAS Registry Number: 19044-88-3
PC Code: 104201

Prepared by: Anita Ullagaddi, Biologist Christopher M. Koper, Chemist Reviewed by: James Lin, Environmental Engineer Sujatha Sankula, Risk Assessment Process Leader Nancy Andrews, Branch Chief U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division
Environmental Risk Branch I 1200 Pennsylvania Ave., NW
Mail Code 7507P Washington, DC 20460

December 9, 2010

### -3 of 69- Table of Contents

1. Purpose........................................................................................................................... 4
2. Problem Fo rm ulation ..................................................................................................... 4 2.1. Nature of Regulatory Action................................................................................... 4
2.2. Previous Assessments ............................................................................................. 4 2.2.1. Ecological Risk Assessments........................................................................... 4 2.2.2. Drinking Water Exposure Assessments........................................................... 5
3. Stressor Source and Distribution ................................................................................... 6
3.1. Mode of Action....................................................................................................... 6 3.2. Overview of Pesticide Use and Usage.................................................................... 6 3.3. Environmental Fate and Transport........................................................................ 12 4. Receptors...................................................................................................................... 17 4.1. Effects to Aquatic Organisms ............................................................................... 18 4.2. Effects to Terrestrial Organisms ........................................................................... 19
4.3. Incident Databases Review................................................................................... 20 4.4. Ecosystems Potentially at Risk ............................................................................. 22 5. Assessment Endpoints ................................................................................................. 22 6. Conceptual Model........................................................................................................ 22 6.1. Risk Hypothesis .................................................................................................... 23 6.2. Conceptual Diagram ............................................................................................. 23 7. Analysis Plan .............................................................................................................. . 25
7.1. Stressors of Concern ............................................................................................. 25 7.2. Measures of Exposure........................................................................................... 26
7.3. Measures of Effect ................................................................................................ 27 7.4. Integration of Exposure and Effects ..................................................................... 28
7.5. Deterministic and Probabilistic Assessment Methods.......................................... 29 7.6. Endangered Species Assessment .......................................................................... 29 7.7. Drinking Water Assessment ................................................................................. 30 7.8. Preliminary Identification of Data Gaps............................................................... 30 7.8.1. Fate Data Gaps............................................................................................... 30 7.8.2. Effects Data Gaps .......................................................................................... 32
8. References.................................................................................................................... 36 Appendix A. Toxicity Data for Oryzalin ......................................................................... 48 Appendix B. Data Call-In Tables..................................................................................... 53 Appendix C. Oryzalin Formulations C ontaining Multip le Active Ingredients................. 61 Appendix D. Oryzalin Incidents ....................................................................................... 63 Appendix E. ECOSAR Analysis for the UN-2 Degradate

............................................... 66

### -4 of 69- 1. Purpose

The purpose of this problem formulation is to provide the status of the environmental fate and ecological effects of oryzalin, considering it s currently registered uses. Oryzalin is a
dinitroaniline herbicide that is registered nationally for the control of annual grasses and
certain broadleaf weeds in fruit and nut cr ops, vineyards, Christmas tree plantations, ornamentals, turf, and several other non-crop sites. This document will provide a plan for analyzing data relevant to oryzalin and for conducting environmental fate, ecological risk, endangered species, and drinking water ex posure assessments for its registered uses. Additionally, this problem form ulation is intended to identify data gaps, uncertainties, and potential assumptions used to address th ose uncertainties relative to characterizing the ecological risk associated with th e registered uses of oryzalin.

2. Problem Formulation

2.1. Nature of Regulatory Action

Under the F ederal Insecticide, Fungicide, and Rodenticide Act (FIFRA), all pesticides
distributed or sold in the Un ited States generally must be registered by the Environmental Protection Agency (EPA). In determining wh ether a pesticide can be registered in the United States, EPA evaluates its safety to non-target species based on a wide range of
environmental and health effects studies. In 1996, FIFRA was amended by the Food Quality Protection Act, and the Agency was mandated to implement a new program for the periodic review of pesticides, i

. e ., registration review ( http://www.epa.gov/oppsrr d1/registration_review/ ). The Registration Review program is intended to ensure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides co ntinue to meet the st atutory standard of no
unreasonable adverse effects to human health an d the environment. Changes in science, public policy, and pesticide use practices will occur over time. Through the new Registration Review program, the Agency peri odically reevaluates pesticides to make sure that as change occurs, products in the marketplace can be used safely.

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

2.2. Previous Assessments

2.2.1. Ecological Risk Assessments

Oryzalin was first registered in the United States in 1974 as a pre-em ergence herbicide for use on weeds growing in fruit and nut orchar ds, vineyards, forestry, ornamentals, turf,

### -5 of 69- rights-of-ways, and other non-ag ricultural sites. A Registration Standard was issued in 1987 (NTIS# PB89-102396) that evaluated the studi es submitted on oryzalin to that date.
Prior to the issuance of the Re gistration Standard, several agri cultural crops were deleted. The only agricultural crop groups remaining on oryzalin labels are berries, vine and orchard crops ( i.e., citrus fruits, pome fruits, stone fruits, tree nuts, and a few tropical fruits). In addition, oryzalin has many non-agricultural uses including ornamentals, Christmas trees, and established warm season turf and rights-of-ways. A Data Call-In was issued in 1991 requiring additional phytotoxicity data, plant and animal analytical methods, and non-dietary exposure data. EPA is sued the Registration Eligibility Decision (RED) for oryzalin in September of 1994 by de termining that all of the then registered oryzalin products were eligib le for re-registration except fo r products labeled for use on residential lawns and turf. The results of the Agency’s 1994 ecological risk assessment for oryzalin, which was conducted as part of the RED, suggest the potential for adverse acute effects to non-target aquatic animals in shallow waters (6 inches deep) and terrestrial and aquatic plants. No acute or sub- lethal chronic effects to birds were reported due to exposure to oryzalin.

The Agency also completed an effects determination for the threatened and endangered
Pacific anadromous salmon and steelhead in 2003 based on oryzalin uses in grapes and almonds in the Pacific Northwest as part of the settlement for the petition filed against EPA by Washington Toxics Coalition (filed N ovember 26, 2002). The results of this endangered species risk assessment showed that oryzalin may affect but is not likely to adversely affect 17 ESUs (Evolutionarily Significant Units) and will have no effect on
nine ESUs. These determinations were ba sed on possible indire ct effects to listed salmonids from loss of aquatic plant c over in spawning and rearing habitats.

In 2008, the potential for oryzalin to adve rsely affect the California Red Legged Frog (CRLF) was evaluated. An assessment was completed in September 2010 that determined the potential for oryzalin to a dversely affect the Calif ornia Tiger Salamander (CTS). The 2008 CRLF assessment and the 2010 CTS assessment concluded that oryzalin is Likely to Adversely Affect th e CRLF and the CTS, respectively, from direct effects and indirect effects via impacts to a quatic and terrestrial pl ants and may modify the critical habitat of both species.

2.2.2. Drinking Water Exposure Assessments

The m ost recent comprehensive drinking water assessment was conducted in 2003 in support of the oryzalin Tole rance Reassessment Progress an d Risk Management Decision (TRED; D209537). The TRED, dated May 26, 2004, determined that the lawn and turf uses for oryzalin are eligible for re-registration based on the submitted new studies on exposure monitoring on residential lawns and turf. However, the estimates were derived using older versions of the PRZM 3.12/EXAMS 2.975 models.

### -6 of 69- 3. Stressor Source and Distribution

Oryzalin, ap plied to the soil su rface prior to the emergence of weeds, is a herbicide used to control seedling grasses and some annual br oadleaf weeds in a vari ety of agricultural crops such as avocado, fig, olives, berries, ci trus fruits, pome fruits, tree nuts, tropical fruits, stone fruits, and vineyards. Othe r labeled non-agricultural uses for oryzalin include ornamentals, Christmas tree plantations , warm season turf grass, residential and non-croplands such as rights-of-w ays, forest trees, industria l areas, and non-agricultural areas. Several degradates have been iden tified for oryzalin. However, only one degradate has been identified as a major (>10%) degradate (UN-2; 2-ethyl-7-nitro-1- propyl-5-sulfonylaminobenzimidazole 3-oxide), which has been shown to form at 14% in an aquatic photodegradation study . The degradates of oryzal in were not found to be of concern for human health (US EPA, 2003). The toxicity of UN-2 is uncertain due to lack of submitted data; however, estimates of aqua tic toxicity were conducted using structure activity relationships (ECOSAR, v. 1.0.0). This analysis suggests that UN-2 is estimated to be considerably less toxic to aquatic organisms than the parent chemical ( Appendix
E ).

3.1. Mode of Action

Oryzalin is a broad spectrum herbicide that is used to control seedling grasses and some
annual broadleaf weeds in both agricultural and non-agricult ural settings. Depending on the formulation, the registered products of oryz alin are applied to the soil surface prior to the emergence of weeds as broadcast spray or band treatment for liquid formulations (using low pressure ground equipment) or soil broadcast for granular formulations (using spreaders). To facilitate activation and move ment of the chemical to the weed seed germination zone, a single 1⁄2 to 1 inch of rainfall or sprinkler ir rigation is required. Depending on the rate of application, the soil residual activity of or yzalin ranges between
4 and 10 months.

Oryzalin is mainly absorbed by roots, ha s little or no foliar activity, and is not translocated to the stem and leafy parts of the plant. Thus the primary effect of oryzalin is on root development. Roots of affected plan ts are relatively few in number, short, thick, and club shaped. The inhibited root growth cause s the stem and leafy parts of plants to be stunted and become dark green.

Oryzalin, similar to the other members of the dinitroaniline chemical family, acts by disrupting the assembly of microtubules. As a result, mitosis or cel l division of plants, ranging from single-celled alg ae to higher plants, is inhi bited. Oryzalin, however, is ineffective against vertebrate and fungal microtubules.

3.2. Overview of Pesticide Use and Usage

Oryzalin is a dinitroaniline herbicide that is registered nationally for control of annual grasses and certain broadleaf weeds in fru it and nut crops, vineyards, Christm as tree plantations, ornamentals, turf, and several othe r non-crop sites. Oryza lin is formulated as

### -7 of 69- granules (0.4 to 1% a.i.), wettable powder (75% a.i.), water disp ersible granules (60 - 85% a.i.), emulsifiable con centrate (2.84 to 40.4% a.i.), flowable concentrate (40.4% a.i.), and formulation intermediate/liquid (40.4% a.i.). Depending on the formulation, oryzalin is typically applie d using low pressure ground equipment or spreaders. The labels for oryzalin caution not to apply this herbicide to Douglas fi r, slender deutzia, Techny arborvitae, eastern hemlock, begonia, and coleus due to phytotoxicity on the above species.

All current labeled uses for or yzalin will be re-evaluated unde r registration review; these uses are agricultural uncultivated areas, almond, apple, apricot, avocado, blackberry, blueberry, boysenberry, caneberries, cashew, ch estnut, cherry, chinquapin, citron, citrus, citrus hybrids, crabapple, currant, dewberry, elderberry, fig, filbert (hazelnut), forest trees, golf course turf, gooseberry, gr apefruit, grapes, guava, hickory nut, household/domestic dwellings outdoor premises , industrial areas (outdoor), kiwi fruit, kumquat, lemon, lime, loganberry, loquat, macadamia nut (bushnut), mayhaw (hawthorn), nectarine, non-agricultural ou tdoor buildings/structu res, non-agricultural rights-of-way/fencerows/hedgerows, non-agricu ltural uncultivated areas/soils, nursery stock, olive, orange, ornamental and/or shade trees, ornamental ground cover, ornamental herbaceous plants, ornamental lawns a nd turf, ornamental nonflowering plants, ornamental woody shrubs and vines, papaya , peach, pear, pecan, pistachio, plum, pome fruits, pomegranate, prune, pummelo (sha ddock), quince, raspberry (black, red), recreation area lawns, residentia l lawns, small fruits, stone fr uits, tangerines, tree nuts, and walnut (English/black). There are no new pe nding uses for oryzalin that are active at
this time. Table 3.1 summarizes the oryzalin products that are curren tly registered in the
United States. Table 3.2 presents the uses and correspondi ng application rates (single and maximum), application interval, and methods of application that will be considered in the registration review assessment.

Table 3.1. Summary of Oryzalin Products Registered in the United States

Product Name EPA Reg. No. Percent Active Ingredient Formulation

Double O E-Pro Herbicide 000228-00632 1 G

ET-029 000228-00698 40.4 L

F8426 HERBICIDE FL05000400 40.4 EC

Harrier WDG 081943-00008 85 DF

HELENA XL2G 005905-00556 1 G

LEBANON FERTILIZER WITH
SURFLAN 000961-00352 1 G

LILLY/MILLER HOSE 'N GO WEED
& GRASS PREVENTER 000802-00565 2.84 L

NATIONS AG II ORYZALIN 4 066222-00138 41 EC

NATIONS AG II ORYZALIN 4 PRO 066222-00207 41 EC

ORYZA AG 070506-00096 40.4 EC

ORYZA T&O 070506-00097 40.4 EC
Oryzalin 2G 053883-00220 1 G

### -8 of 69- Table 3.1. Summary of Oryzalin Products Registered in the United States

Product Name EPA Reg. No. Percent Active Ingredient Formulation

ORYZALIN COATED GRANULES 034704-00823 1.67 G

ORYZALIN LIQUID 034704-00865 40.4 EC

ORYZALIN PRO 4 053883-00168 41 EC

ORYZALIN T&O 034704-00882 40.4 EC

ROUT ORNAMENTAL HERBICIDE 058185-00027 1 G

SNAPSHOT 80 DF 070506-00053 60 DF

SURFLAN 0.25 A.S. 070506-00047 3 EC

SURFLAN 75W 070506-00040 75 WP

SURFLAN 75W WATER SOLUBLE
PACKAGES 070506-00042 75 WP

SURFLAN 85DF 070506-00050 85 DF

SURFLAN A. S. 070506-00044 40.4 EC

SURFLAN A.S. 070506-00043 40.4 EC

SURFLAN DRY FLOWABLE
HERBICIDE 070506-00046 85 DF

TURF FERTILIZER CONTAINS
GALLEY PLUS SURFLAN 070506-00055 0.86 G

TURF FERTILIZER CONTAINS
SURFLAN 0.75% 070506-00052 0.75 G

TURF FERTILIZER CONTAINS
SURFLAN 1% 070506-00051 1 G

VERTAGREEN FERTILIZER FOR
PROFESSIONAL TURF WITH
SURFLAN 008660-00150 1 G

WEED STOPPER 054705-00005 40.4 EC

WEED STOPPER HOSE'EM 054705-00011 3 L

XL 2G 070506-00045 1 G

XL 2GR 070506-00056 1 G

XL2G 038167-00030 1 G

070506-00095 98 TGAI

083558-00024 41 MP

070506-00041 98.3 TGAI

070506-00054 75 MP

083558-00022 95.6 TGAI Technical and Manufacturing Product
Labels

070506-00048 40.4 MP
G=granular; L=liquid; EC=emulsifiable concentrate; DF=d ry flowable; WP=wettable powder; TGAI=technical grade active ingredient; MP=manufacturing product

### -9 of 69- Table 3.2. Maximum Labeled App lication Rates for Oryzalin

Use Formulation
Code 1 Application
Method Maximum Single Application
Rate (lb a.i./A) Maximum
Number of Applications

per Year (#) Maximum
Seasonal Application
Rate (lb a.i./A) Application
Interval

(days)

EC/DF Low pressure ground sprayer/ Sprinkler irrigation
/Broadcast/ Chemigation/
Soil broadcast

treatment

6 2 12 75 Berries Blackberry, blueberries, boysenberry, caneberries, currant, dewberry, elderberry,

gooseberry, loganberry and raspberry

Citrus Fruits Grapefruit, kumquat, kiwi,

lime, lemon, mandarin, tangerine, orange, pummelo, nectarine, orange

Pome Fruits Apple, apricot, crabapple, fig, loquat, mayhaw, pomegranate, and quince

Tree Nuts Almonds, cashew, chestnut chinquapin, filbert, hickory nut, macadamia nut, pecan, pistachio walnut

Stone Fruits Avocado, cherry, nectarine,

olive, peach, pear, plum,

prune

Vineyards Wine and table grapes

Tropical Fruits Guava, papaya G Granules by Spreader/
Broadcast 4 4 15 60

EC/DF/WP/L Low pressure ground sprayer/ Sprinkler irrigation
/Broadcast/ Chemigation/
Soil broadcast

treatment 4 3 12 90 Non-bearing Trees/Vineyards

Granular Granule applicator Spreader,
/Broadcast 4 4 15 60

### -10 of 69- Table 3.2. Maximum Labeled App lication Rates for Oryzalin

Use Formulation
Code 1 Application
Method Maximum Single Application
Rate (lb a.i./A) Maximum
Number of Applications

per Year (#) Maximum
Seasonal Application
Rate (lb a.i./A) Application
Interval

(days)

EC/DF/WP/L Low pressure ground sprayer/ Sprinkler irrigation
/Broadcast/ Chemigation/
Soil broadcast

treatment 4 3 12 90 Ornamentals 2

G Granule applicator Spreader,
/Broadcast 4 4 15 60

EC/DF/L/WP Low pressure ground sprayer/ Sprayer/ Spreader
/Broadcast/

Directed

spray/
Soil broadcast

treatment 4 2 8 60

G Granule applicator Spreader,
/Broadcast 4 2 8 60 Christmas Tree Plantation

G Granule applicator Spreader,
/Broadcast 3.34 5 15 90

EC/L Low pressure ground sprayer/ Sprayer 1.5 2 2.25 90 Ornamental Bulbs

G Granule applicator Spreader,
/Broadcast 1.5 2 2.25 90

EC/L Low pressure ground sprayer/ Sprayer 2 3 6 90 Turf

G Granule applicator Spreader,
/Broadcast 1.5 4 6 90

### -11 of 69- Table 3.2. Maximum Labeled App lication Rates for Oryzalin

Use Formulation
Code 1 Application
Method Maximum Single Application
Rate (lb a.i./A) Maximum
Number of Applications

per Year (#) Maximum
Seasonal Application
Rate (lb a.i./A) Application
Interval

(days)

EC/L/WP Low pressure ground sprayer/ Sprayer 6 2 12 180 Non-agricultural Areas Rights-of-way, fencerows, hedgerows, buildings/structures, outdoor
industrial areas

G Granule applicator Spreader,
/Broadcast 6 2 12 240

Residential Areas
G Granule applicator Spreader 2 3 6 56

Agricultural Uncultivated
Areas DF Low pressure ground sprayer 3 3 9 120

1 Formulation codes: DF- Water Dispersible Granules (Dry Flowable); EC-Emulsifiable Concentrate; G-Granular; L-Liquid; WPWettable Powder

2 Use in landscape gardens, container and field grown ornamentals, drainage areas under shadehouse benches, ground covers/perennials



### According to the United States Geological Surv ey’s (USGS) national pesticide usage data (based on information from 1999 to 2004), an av erage of 358,151 lb per year of oryzalin are applied nationally to agricu lture in the United States (see Figure 3.1 ). As of 2002, over 93% of total agricultural uses fo r oryzalin are in the crops listed in Figure 3.1 . The highest poundage (142,601 lbs) of oryzalin wa s applied to citrus fruits. Grapes (74,753 lbs) and apples (39,855 lbs) represented th e second and third hi ghest total pounds of oryzalin applied, respectively. Based on a Screening Level Usage Analysis (SLUA) conducted by EPA (January 21, 2010), using data from 2001 to 2007, there is an estimated ~1,212,000 lb of oryzalin used per year [most of which is used on almonds (400,000 lb), grapes (400,000 lb), and pist achios (100,000 lb)]. Estimates of nonagricultural usage of oryzalin are not availabl e. Reasons for the difference in the amount of oryzalin reportedly app lied between the USGS data and the SLUA is unknown; however, the 2002 data may not be representa tive of the 2001 to 2007, which is covered by the SLUA.

### -12 of 69- Figure 3.1. Estimated, Annual, Nation al, Agricultural Oryzalin Usage. (from http://water.usgs.gov/nawqa/pnsp/usage/ maps/show_map.php?year=02&map=m1873) [ The pesticide use maps available from this site show the average annual pesticide use intensity expressed as average weight (in pounds) of a pe sticide applied to each square mile of agricultural land in a county. The area of each map is based on state-level estimates of pesticide use rates for individual crops that were compiled by the CropLife Foundation, Crop Protection Research Institute 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.].



### 3.3. Environmental Fate and Transport

Best-available data defining th e physical, chem ical, fate a nd transport characteristics associated with oryzalin are summarized in Table 3.3 . It should be noted that several studies are currently under review, as noted in Table 3.3 , and the values presented for these studies are based solely on a cursory re view of the data; upon completion of review, it is possible that the fate profile for oryzalin may change. The major routes of oryzalin dissipation are aqueous photolysis, photode gradation on soil surface, and degradation under anaerobic conditions. Oryzalin appears to degrade slowly under aerobic soil conditions and is stable to hydr olysis. Under field conditions oryzalin appeared to be

### -13 of 69- moderately persistent, with a half-life of about two m onths. Based on its low vapor pressure (1.0 x 10 -7 

### mm Hg at 25 ° C) and Henry's Law Constant (1.8 x 10 -8 

### atm

⋅ m 3 

### /mol), volatilization loss of oryzalin from soil and water systems is expected to be insignificant compared to dissipation by abiotic and biotic degradation.

Table 3.3. Summary of Oryzalin Environmental Physicochemical and Fate Properties

Parameter Value Major Degradates Minor Degradates Source/

MRID # Study Status

Common name Oryzalin --- USEPA, 1994 ---
Chemical name 3,5-dinitro-N 4 ,N 4

- dipropylsulfanilamide --- USEPA, 1994 ---
Chemical family Dinitroaniline --- USEPA, 1994 ---
CAS Number 19044-88-3 --- USEPA, 1994 --- Empirical formula C 12 H 18 N 4 O 6 S --- USEPA, 1994 ---

Structure --- USEPA, 1994 ---

Molecular mass 346.35 --- USEPA, 1994 Water solubility (20 ° C) 2.5 mg/L
--- USEPA, 1994 --

Vapor pressure (25 ° C) 1.0 x 10 -7 mm Hg at 25°C
--- MRID 40454801 Acceptable

Henry’s Law
Constant 1.82 x 10 -8 atm m 3 /mol --- Calculated 1



### ---

Octanol/water partition coefficient (Log K

ow ) 3.73 at pH 7 --- USEPA, 1994 

### ---

Hydrolysis Stable (pH 5, 7, 9)
--- MRID 41378401 Under review*

Direct Aqueous Photolysis 0.06 days UN-2, 14.0% OR-3, 5.7%, OR-5, 4.0% OR-X, 2.9% MRID 41278701 Supplemental 2

Soil Photolysis 3.8 days OR-3, 2.6%, OR-15, 3.2% OR-21, 4.6%. MRID 41050001 Under review*

Aerobic Soil
Metabolism 63 days OR-20 4.7 %, UN-1, UN-2,OR-2, OR-4, OR-9, OR-13, OR-15 and OR-41,

< 2.4% MRID 41322801 Under review*

Anaerobic Soil
Metabolism 10 Days OR-20, <0.2% OR-15, <0.2% UN-1, <0.2% OR-2, <0.2% MRID 41322802 Under review*

Aerobic Aquatic data gap
--- --- Call in data

### -14 of 69- Table 3.3. Summary of Oryzalin Environmental Physicochemical and Fate Properties

Parameter Value Major Degradates Minor Degradates Source/

MRID # Study Status

Metabolism
Anaerobic Aquatic
Metabolism data gap
--- --- Call in data

Soil Partition
Coefficient
(K

oc: L kg o.c. -1 ) 3 722, 602, 803 and 1109 (average = 809)
--- MRID 41479802 Under review*

Terrestrial Field Dissipation FL: 68 days
MI: 77-138 days
CA: 58-146 days --- MRID 42138001 Supplemental 4

Fish
Bioconcentration Factor (BCF) 32x (edible) 105x (non-edible) 66x (whole fish) --- MRID 40787501 Acceptable

*Values presented for studies that are currently under review are based on a cursory review of the data and are subject to change.

1 Henry’s Law (atm-m 3 /mole) = (VAPR/760)/(SOL/MWT), where VAPR is vapor pressure in torr, MWT is molecular weight in g/mol, and SOL is the solubility in water in mg/L.

2 The supplemental information submitted in addition to the study (MRID 41278701) completely satisfies the data requirement (EFED Search Document 2002465). The OR-X degradate is identified as 3-nitro-5-aminosulfanilamide.

3 Koc was calculated from Kd and % o.m. from raw data using the formulas % o.c. = % o.m./1.72 and Koc = (Kd/% o.c.) x 100

4 Study is upgradeable pending submission and review of analytical method and independent laboratory validation.



### Laboratory studies i ndicate that oryzalin is stable to hydrolysis at pHs 5, 7 and 9. (MRID 41378401) but exhibits susceptibility to rapi d direct aqueous photolysis; the aqueous photolytic half-life is 1.4 hours (MRID 41278701) . The degradates of aqueous photolysis are OR-5 (2.9%), OR-3 (5.7%), and UN- 2 (14%). The chemical also readily photodegrades on the soil surface with an estimated half-life of 3.8 days, and the degradates are OR-3 (2.6%), OR-15 (3.2%) and OR-21 (4.6%) (MRID 41050001).

Oryzalin degrades aerobically with a half-life of 63 days in sandy loam soil (MRID 41322801). Nine degradates were identified, each accounting for < 2.4% of the applied radioactivity ( Table 3.3 ) except for 4-hydroxy-3,5-dinitr obenzenesulfonamide (OR-20),
which accounted for a maximum of 4.7% of radi oactivity at 1 month post treatment in the soil aerobic metabolism study. The benzenesulfona mide ring remained intact in all of the identified metabolites. By the end of the experiment at 6.1 months, 63.1% of the applied radioactivity was nonextr actable and 5.7% had been mineralized to CO 2 

### . Under anaerobic conditions oryzalin nitro groups undergo re duction to amines, dealkylation, and ring formation to produce benzimidazoles, with a half-life of 10 days (MRID 41322802).
Anaerobic metabolites that accounted for < 0.2% are UN-1, OR-2, OR-15, and OR-20.
Table 3.4 provides names, structures and the occu rrence of various degradates detected
in environmental fate studies.

### -15 of 69- In the field, oryzalin appears to dissipate sl owly with a half-life of 68 days in Florida sand soil and a first phase half -life of 58 days in Californi a loam soil and 77 days in Michigan silty clay loam soil. The second pha se half-lives were 146 days in California loam soil and 138 days in Michigan silty clay lo am soil. Parent oryzalin did not appear to be mobile under field conditions. The parent was undetectable and always less than detection limits (i.e., 0.01 ppm; MRID 42138001) below 12 inches of soil depth. Oryzalin degradates were not monitored in the field dissipation studies submitted. Although oryzalin does not appear to be mobile under field conditions, the soil partition coefficients (K
oc 

### = 602 to 1109 L Kg -1 

### ; MRID 41479802 ) indicate that chemical mobility will vary from moderately mobile to slight ly mobile according to FAO Classification Scheme (FAO, 2000) depending on soil type and organic matter content.

Oryzalin has potential to contaminate surface water via spray drift and runoff. Substantial quantities of oryzalin could be available for runoff for a few days to months postapplication depending on the degree of expos ure to sunlight (phot odegradation on soil half-life of 3.8 days; aerobic soil half-life of 63 days; terrestrial field dissipation half-lives of 77-138 and 58-146 days). The soil partitioning coefficients of oryzalin indicates that fractions of oryzalin could be transpor ted via both dissolution in runoff water and adsorption to eroding soil in the event of signi ficant rainfall occurring after application prior to soil incorporation. Based upon its K
oc 

### , significant fractions of the oryzalin in receiving surface waters should exist both dissolved in the wa ter column and adsorbed to suspended sediment. The susceptibility of oryzal in to direct photolysis in water (half-life = 1.4 hours) should limit its pe rsistence in clear shallow waters with low light attenuation. However, its resistance to abioti c hydrolysis coupled with only a moderate susceptibility to aerobic biodegradation indicate that it will be somewhat more persistent in receiving surface waters that are deeper, have high light attenuation, low microbiological activities and long hydrological resident times.

Oryzalin is less likely to c ontaminate ground water resources due to reduction in the anaerobic soil layer. Howeve r, in sandy soils under some environmental conditions, such as excess precipitation, or where soil prefer ential flow conditions exist and exposure to sunlight is minimal, oryzalin residues ma y leach into ground water and undergo reduction to more polar compounds.

Based on a laboratory bioaccumulation study (MRID 40787501), oryzalin did not significantly bioconcentrate in bluegill sunfish. The BCFs we re 32X in edible tissue, 105X in nonedible tissue, and 66X in whol e fish. Depuration ranged from 79.2 to 80.8% after 24 hours and 88.7 to 95.1% after 14 days.

Nine degradates have been identified for oryzalin in the soil aerobic metabolism study. Three other degradates were also id entified in various fate studies ( Table 3.4 ). 4- Hydroxy-3,5-dinitrobenzenesulfonamide (OR- 20) accounted for a maximum of 4.7% of radioactivity at 1 month post-treatment in the soil aerobic metabolism study. Eight other degradates were isolat ed, but each comprised < 2.4% of the applie d radioactivity. The available data on degradates of oryzalin are insufficient to assess their runoff characteristics or persistence in su rface waters. The registrant conducted a

### -16 of 69- mobility/adsorption/desorption study to dete rmine the mobility of nine oryzalin degradates and whether or not degradate leach ing is a major route of dissipation. Out of nine metabolites formed, three (OR-20, UN-2, and the unidentified compound UN-3; MRID 43433202) appeared to be very mobile.

Table 3.4 Oryzalin Degradates Identified in Environmental Fate Studies

Code Structure IUPAC Name Percent Formation
/Reference

OR-2 3,5-dinitro-4-(propylamino) benzenesulfonamide (< 2.4%) MRID 41322801 1

(<0.2 %) MRID 41322802 2

OR-3 3,5-dinitro-4-aminobenzenesulfonamide (5.7%) MRID 41278701 3

(2.6%) MRID 41050001 4

OR-4 3-amino-4-(dipropylamino)-
5-nitrobenzenesulfonamide (< 2.4%) MRID 41322801 1

MRID 41322802 2

OR-5 3-amino-4-propylamino)- 5-
nitrobenzenesulfonamide (4.0%) MRID 41278701 3

OR-9 3,4,5-triaminobenzenesulfonamide (< 2.4%) MRID 41322801 1

OR-13 2-ethyl-7-nitro-1-propyl1H-benzimidazole-5-
sulfonamide (< 2.4%) MRID 41322801 1

MRID 41322802 2

OR-15 2-ethyl-7-nitro-1Hbenzimidazole-5-
sulfonamide (< 2.4%) MRID 41322801 1

(< 0.2%) MRID 41322802 2

(3.2%) MRID 41050001 4

OR-20 4-hydroxy-3,5-dinitrobenzenesulfonamide (4.7%) MRID 41322801 1

(< 0.2%) MRID 41322802 2

### -17 of 69- Table 3.4 Oryzalin Degradates Identified in Environmental Fate Studies

Code Structure IUPAC Name Percent Formation
/Reference

OR-21 3,4-dinitro-4- dipropylamineo-sulfanalic
acid (4.6%) MRID 41050001 4

OR-41 4-[(2-hydroxypropyamino)]-3,5-dinitrobenzenesulfonamide (< 2.4%) MRID 41322801 1

UN-1 3,3’-azoxybis[(4- propylamino]-5-nitro]-

benzenesulfonamide (< 2.4%) MRID 41322801 1

(< 0.2%) MRID 41322802 2

UN-2 2-ethyl-7-nitro-1-propyl1H-benzimidazole-5-
sulfonamide-3-oxide (< 2.4%) MRID 41322801 1

MRID 41322802 2

(14%) MRID 41278701 3

1 Aerobic soil metabolism; 2 Anaerobic soil metabolism; 3 Aquatic photolysis; 4 Soil photolysis



### 4. Receptors

Consistent with the process described in the Overview Docum ent (USEPA, 2004), the risk assessment for oryzalin will rely on a su rrogate species approach. Toxicological data generated from surrogate test species, which are intended to be representative of broad taxonomic groups, are used to extrapolate th e potential effects on a variety of species (receptors) included under these taxonomi c groupings. Only one degradate may potentially form at amounts greater than 10% of the applied parent compound (UN-2, 14%); however, none of the degradates of or yzalin were found to be of toxicological concern for mammalian species (MARC memo D289755 dated 5 June 2003). Toxicity estimates based on structure activity relationships suggest that UN-2 is less toxic than the parent compound to terrestrial and aquatic species. Theref ore, only the toxicity and potential exposure to non-target organisms to the parent oryzalin wi ll be quantified. The most sensitive endpoints from the available to xicity data for oryzalin will be used to quantify risk.

Acute and chronic toxicity da ta from studies submitted by pesticide registrants along with the available open literature are used to evaluate the potential direct and indirect effects of oryzalin to aquatic and te rrestrial receptors. This incl udes toxicity on the technical grade active ingredient, degradates, and when available, formulated products ( e.g. , “SixPack” studies). The open literature studies are identified through EPA’s ECOTOXicology (ECOTOX) database, which em ploys a literature search engine for

### -18 of 69- locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data may also pr ovide insight into the direct and indirect effects of oryzalin on biotic communities fr om loss of species that are sensitive to the chemical and from changes in structure and functional characterist ics of the affected communities. A preliminary review of ope n literature data from ECOTOX (collected March 2010) on oryzalin was conducted as part of this Problem Formulation to help identify data gaps. A more complete review of the data from ECOTOX will be conducted for evaluation for possible quantitative and/or qualitative incl usion in this risk

assessment.

A summary of the most sensitive data re presenting non-target organisms exposed to oryzalin in aquatic and terrestri al habitats is provided in Sections 4.1 and 4.2

, respectively. A summary of ecological in cidents associated w ith oryzalin and a description of ecosystems potentia lly at risk are provided in Sections 4.3 and 4.4

, respectively.

4.1. Effects to Aquatic Organisms

A summary of the most sensit ive aquatic toxicity data fo r oryzalin from registrantsubmitted studies is provided in Table 4.1 . A summary of all submitted ecotoxicity data for oryzalin is provided in Appendix A . Oryzalin is classified as moderately toxic to freshwater fish, moderately toxic to estuarine/ marine fish, moderately toxic to freshwater invertebrates, and highly toxi c to estuarine/marine invert ebrates on an acute exposure
basis. The EC 50 

### for the most sensitive non-vascular aquatic plants (Green algae, Selenastrum capricornutum ) is 52 μg a.i./L, with a NOAEC of 13.8 μg a.i./L based on cell density (MRID 431369-01). However, two non- vascular aquatic plant studies were classified as invalid; these species could yield potentially mo re sensitive endpoints. The
EC 50 

### for vascular aquatic plants (Duckweed, Lemna gibba ) is 13 μg a.i./L, with a NOAEC of 3.28 μg a.i./L based on frond count (MRID 431369-05).

Regarding chronic effects, the only data cu rrently available for oryzalin and aquatic organisms are for freshwater fish and freshwater invertebrates ( i.e ., there are currently no
chronic data available for estuarine/marine fish or invertebrates). For freshwater fish, the most sensitive NOAEC is 0.22 mg a.i./L for the fathead minnow ( Pimephales promelas )
based on a reduction in mean larval wei ghts (MRID 00126841). The only chronic toxicity
data available for freshwater invertebrates is for daphnids ( Daphnia magna ) (MRID 439869-01). This study resulted in a NOAEC of 0.358 mg a.i. /L based on reduction in dry weight of the first generation daphnids (LOAEC = 0.608 mg a.i./L).

Table 4.1. Summary of the Most Sensitive Endpoi nts from Submitted Aquatic Toxicity Studies for Oryzalin Study Type Species Toxicity Value Toxicity Classification MRID & Status

Acute –
Freshwater Fish Bluegill sunfish ( Lepomis
macrochirus ) 96-hr LC 50 : 2.88 mg/L NOAEC: 1 mg/L Slope: 9.3 Moderately toxic 00072595 Acceptable

### -19 of 69- Table 4.1. Summary of the Most Sensitive Endpoi nts from Submitted Aquatic Toxicity Studies for Oryzalin Study Type Species Toxicity Value Toxicity Classification MRID & Status

Chronic –
Freshwater Fish Fathead minnow ( Pimephales promelas ) NOAEC: 0.22 mg/L LOAEC: 0.43 mg/L (based on mean larval weights) NA 00126841 Acceptable

Acute –
Estuarine/Marine
Fish Sheepshead minnow ( Cyprinodon variegatus ) 96-hr LC 50 : >3.04 mg/L NOAEC: 3.04 mg/L Moderately toxic 438877-01 Acceptable

Acute –
Freshwater
Invertebrate Water flea ( Daphnia magna ) 48-hr EC 50 : 1.5 mg/L NOAEC: 0.62 mg/L (based on hypoactivity, prostration, and immobility) Slope: 9.5 Moderately toxic 00072596 Acceptable

Chronic –
Freshwater
Invertebrate Water flea ( Daphnia magna ) NOAEC: 0.358 mg/L LOAEC: 0.608 mg/L (based on dry weight of first generation daphnids) NA 439869-01 Acceptable

Acute –
Estuarine/Marine
Invertebrate Eastern oyster ( Crassostrea

virginica ) 96-hr EC 50 : 0.285 mg/L NOAEC: 0.0994 mg/L (based on shell deposition) Highly toxic 438877-02 Acceptable

Aquatic – Nonvascular Plants Green algae ( Selenastrum capricornutum ) 5-day EC 50 : 52 μg a.i./L NOAEC: 13.8 μg a.i./L (based on cell density) NA 431369-01 Supplemental

Aquatic –
Vascular Plants Duckweed ( Lemna gibba ) 14-day EC 50 : 13 μg/L NOAEC: 3.28 μg/L (based on frond count) NA 431369-05 Supplemental



### 4.2. Effects to Terrestrial Organisms

Table 4.2 summarizes th e most sensitive terrestria l toxicity endpoints for oryzalin based
on an evaluation of submitted stud ies. Oryzalin is classified as slightly toxic to birds on an acute oral basis and practical ly non-toxic to birds on an acute dietary basis. Oryzalin is classified as practically non-toxic to ma mmals and honey bees on an acute basis. The Tier II terrestrial plant studies were classified as supplemen tal because the studies utilize a technical grade active ingredient (TGAI) inst ead of the required t ypical end-use product (TEP). The lack of Tier II terrestrial plant studies conducte d with a TEP is considered a data gap (see Section 7.8.2 ).

For chronic effects, the NOAEC for birds is 132 mg/kg-diet ba sed on a reduction of female body weight in bobwhite quail ( Colinus virginianus ) (MRID 441622-01). For mammals, the chronic toxicity value is a NOAEL of 13.82 mg/kg-bw/day based on numerous endpoints in the laboratory rat ( Rattus norvegicus ) (MRID 00026779, 00044332, 00070569).

### -20 of 69- Table 4.2. Summary of the Most Sensitive En dpoints from Submitted Terrestrial Toxicity Studies for Oryzalin Study Type Species Toxicity Value Toxicity Classification MRID & Status
Acute – Avian
Oral Bobwhite quail (Colinus virginianus ) LD 50 : 506.7 mg/kg-bw/day Slope: 4.5 Slightly toxic 00098462 Acceptable

Acute – Avian Dietary Bobwhite quail ( Colinus virginianus ) LC 50 : >5,000 mg/kg-diet NOAEC: <625 mg/kg-diet

(based on reduced food consumption and body weight gain) Practically non-toxic 00072593 Acceptable

Chronic – Avian

Reproduction Bobwhite quail ( Colinus virginianus ) NOAEC: 132 mg/kg-diet LOAEC: 311 mg/kg-diet

(based on female body weight) NA 441622-01 Acceptable

Acute –
Mammalian Oral Rat ( Rattus norvegicus ) LD 50 : 10,000 mg/kg-bw Practically non-toxic 00026592 Acceptable
Chronic –
Mammalian Reproduction Rat ( Rattus norvegicus ) NOAEL: 13.82 mg/kgbw/dayLOAEL: 42.9 mg/kgbw/day (based on numerous endpoints) NA 00026779
00044332
00070569 Acceptable

Acute – Contact Toxicity Honey bee ( Apis mellifera ) LC 50 : >11 μg/bee Practically non-toxic 00066220 Acceptable
Terrestrial Plant
– Tier II Seedling Emergence Oat, Corn, Ryegrass, Onion, Cabbage, Cucumber, Lettuce, Tomato, Soybean,
Radish EC 25 : 0.014 lb a.i./acre (monocot: ryegrass shoot length)
EC 25 : 0.050 lb a.i./acre (dicot: tomato shoot length) NA 426024-01 Supplemental (used TGAI)

Terrestrial Plant
– Tier II Vegetative Vigor Corn, Oat, Ryegrass, Onion, Lettuce, Tomato, Cabbage, Cucumber, Radish, Soybean EC 25 : 0.080 lb a.i./acre (monocot: corn dry weight)

EC 25 : 0.030 lb a.i./acre (dicot: tomato dry weight) NA 426024-01 Supplemental (used TGAI)



### 4.3. Incident Databases Review

Prelim inary reviews of the Ecological Incide nt Information System (EIIS, version 2.1) and the Avian Incident Monitoring System (AIMS) 1 

### were conducted on August 2, 2010. There were no avian incidents reported in th e AIMS database. There were five plant
incidents and one fish incide nt involving oryzalin reported in the EIIS database. The reported incidents occurred between 1989 and 2002. The certainty in which these incidents were a result of oryzalin use was described as unlikely in one incident, possible in four incidents, and probable in one incide nt. Two of the incidents were the results of registered uses, one was an accidental misuse, one was an intentional misuse, and the causes of two incidents were unknown. Specifi c details of the incidents are described below (more detailed information can be found in Appendix C ).

1 http://www.abcbirds.org/abcprograms/ policy/pesticides/aims/aims/index.cfm

### -21 of 69- Terrestrial Incidents

Five incidents were reported in the EIIS data base that involved orname ntal or crop plants. In 1989 in Washington state, Douglas fir trees , which were treated directly, experienced damage (I001734-001). The magnitude of the in jury is unknown, and the incident was
classified as an intentional misuse. It was probable that oryzalin caused this injury. Another incident involving Douglas fir tree s (I001485-027) occurred when the trees were treated directly, causing death. It is possible that oryzalin ca used this mortality. In 1992 in Benton, Washington, an unspecified type of tree experienced damage (I014409-062). It is possible that oryzalin caused this damage . In 1998, thirteen acres of grapes in Grant, Washington were damaged when they were tr eated directly with oryzalin (I013884-027). The incident was classified as a registered use and it was unlikely that oryzalin caused the damage. In 2002 in Washington, Oregon six acres of tulips were damaged when they were treated directly with oryzalin (I013636- 027). The incident was classified as a registered use, and it was possible th at oryzalin caused this damage.

Aquatic Incidents

In 2001, about 450 to 500 bluegill sunfish a nd largemouth bass were found dead in a three-acre pond in Georgia (I011444-011). Small numbers began dying around April 6 - 7, 2001, and heavier numbers began dying aroun d April 12 and 13. SURFLAN had been sprayed on March 31 at a time when 35-40 mph winds were blowing, and the application site was within 50-60 feet of the pond in an uphill direction. It is possible that the pond was contaminated by either spray drift or runoff because rain fell on April 4. The fisheries biologist, who reporte d the incident to the chemi cal company, believed that the fish most likely died of a bacterial inf ection. The report contained no mention of analytical data in this case. The incident wa s classified as an inte ntional misuse, and it is possible that oryzalin contributed to this fish kill.

In addition to the incidents recorded in E IIS and AIMS, additional incidents have been reported to the Agency in an aggregated format . Pesticide registrant s report certain types of incidents to the Agency as aggregate counts of incidents occurring per product per quarter. Ecological incidents reported in a ggregate reports include those categorized as ‘minor fish and wildlife’ (W-B), ‘minor plant’ (P-B), and ‘other non-target’ (ONT) incidents. ‘Other non-target’ incidents include reports of ad verse effects to insects and
other terrestrial invertebrates. Two minor aggregate incide nt reports involving plants have been submitted to the Agency for oryzalin.

Due to limitations with data in the EIIS, a low number or lack of reported incidents in the
database cannot be used as evidence that addi tional incidents have not occurred. Incident reports for non-target plants and animals typically provide info rmation on mortality events only. Reports for other adverse eff ects, such as reduced growth or impaired reproduction, are rarely received. EPA’s cha nges in the registrant reporting requirements of incidents may also account for the reduced number of reported inci dents. Registrants are now only required to submit detailed in formation on ‘major’ incidents. Minor

### -22 of 69- incidents are generally reporte d aggregately and are not incl uded in EIIS. In addition, there have been changes in state monitori ng efforts due to lack of resources.

4.4. Ecosystems Potentially at Risk

The ecosystem s at risk are often extensive in scope; therefore, it may not be possible to identify specific ecosystems during the deve lopment of a nation-wide ecological risk assessment. However, in general terms, te rrestrial ecosystems poten tially at risk could
include the treated field and im mediately adjacent areas that ma y receive drift or runoff. Areas adjacent to the treate d field could include cultiv ated fields, fencerows and hedgerows, meadows, fallow fields or grassla nds, woodlands, riparian habitats and other
uncultivated areas.

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

5. Assessment Endpoints

Assessm ent endpoints represent the actual enviro nmental value that is to be protected, defined by an ecological entity (species, comm unity, or other entity) and its attribute or characteristics (USEPA, 1998). For oryzali n, the ecological entities may include the following: birds, mammals, terrestrial-phase amphibians, reptiles, freshwater fish and invertebrates, aquatic-phase amphibians, es tuarine/marine fish and invertebrates, terrestrial plants, terres trial invertebrates, and aquatic pl ants. The attributes for each of
these entities include surviv al, growth, and reproduction.

6. Conceptual Model

For a pesticide to pose an ecological risk, it m ust 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.

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

### -23 of 69- 6.1. Risk Hypothesis

A risk hypothesis describes the predicted re lationship am ong the stre ssor, exposure, and assessment endpoint response along with the rati onale for their selection. For oryzalin, the following ecological risk hypothesis is being employed for th is ecological risk

assessment:

Based on the application methods, mode of action, fate and transport, and the sensitivity of non-target aquatic and terrestri al species, oryzalin has the potential to reduce survival, reproduction, and/or growth in non-target terrestrial and aquatic organisms when used in accordan ce with the current labels. These nontarget organisms include Federally-lis ted threatened and endangered species as well as non-listed species.

6.2. Conceptual Diagram

The environmental fate properties of oryzalin indicate that runoff, spray drift and direct spray represent potential transport mechanisms of oryzalin to aquatic and terrestrial habitats where non-target organisms may be exposed. These transport mechanisms ( i.e

., sources) are depicted in the conceptual models below ( Figures 6.1 and 6.2 ) along with the receptors of concern and the potential at tribute changes in the receptors due to exposure to oryzalin.

### -24 of 69- Figure 6.1. Conceptual Model for Oryza lin Exposure and Effects to Aquatic Organisms. Dotted Lines Indicate Exposure Pathways that Have a Low Likelihood of Contributing to Ecological Risk. 

### Stressor

Source

Receptors

Attribute Change Oryzalin applied to use site

Spray drift

Fish/aquatic-phase amphibians Eggs
Larvae
Juveniles / Adults

Individual organisms
Reduced survival Reduced growth Reduced reproduction Food chain Reduction in algae Reduction in prey Habitat integrity Reduction in primary productivity
Reduced cover Community change Surface water/

Sediment Runoff

Aquatic Animals
Invertebrates
Vertebrates 

### Exposure
Media

Uptake/gills or integument

Ingestion Ingestion Soil Groundwater

Uptake/gills or integument

Aquatic Plants

N on-vascular
Vascular Uptake/cell, roots, leaves Riparian plant
terrestrial

exposure pathways see

Figure 6.2

### -25 of 69- Figure 6.2. Conceptual Model for Oryza lin Exposure and Eff ects to Terrestrial Organisms.

7. Analysis Plan

In order to address the ri sk hypothesis, the potential for adverse effects on the
environm ent will be estimated. The use, environmental fate, and ecological effects of oryzalin will be characterized and integrated to assess the risks. Risk quotients (RQs) will be derived for oryzalin by dividing estimated environmental concentrations (EEC) by the most sensitive endpoint from the releva nt, available toxicity data for oryzalin.

This analysis plan will be revisited and may be revise d depending upon a full review of the data available in the ope n literature and the information submitted by the public in response to the opening of the Registration Review docket.

7.1. Stressors of Concern

One degradate has been identified as a majo r (>10%) degradate (UN-2, 2-ethyl-7-nitro-1- propyl-5-sulfonylaminobenzimidazole 3-oxide), which has been shown to form at 14% in 

### Stressor

Sou rce

Receptors

Attribute Change Oryzalin applied to use site

Direct application Spray drift

Birds / Terrestrialphase amphibians / reptiles /
mammals Terrestrial

insects

Individual organisms
Reduced survival Reduced growth Reduced reproduction Food chain Reduction in prey Habitat integrity Reduction in primary productivity
Reduced cover Community change Terrestrial/riparian plants grasses/forbs, fruit, seeds (trees, shrubs) Runoff

Mammals 

### Exposure
Media Soil

Ingestion Ingestion

Ingestion Ingestion Dermal uptake/Ingestion

Root uptake

Birds /

Am p hibians Ingestion

### -26 of 69- an aquatic photodegradation study . The degradates of oryzal in were not found to be of concern for human health (US EPA, 2003). The toxicity of UN-2 is uncertain due to lack of submitted data; however, estimates of aqua tic toxicity were conducted using structure activity relationships (ECOSAR, v. 1.0.0). This analysis suggests that UN-2 is estimated to be considerably less toxic to aquatic organisms than the parent chemical ( Appendix
E ).

The Agency does not routinely include, in its risk assessments, an evaluation of mixtures of active ingredients, either those mixtur es of multiple active ingredients in product formulations or those in the applicator’s ta nk. In the case of the product formulations of multiple active ingredients (that is, a regist ered product containing more than one active ingredient), each active ingredient is subj ect to an individual risk assessment for regulatory decision regarding the active ingredient on a particular use site. If effects data are available for a formulated product contai ning more than one active ingredient, they may be used qualitatively or quantitatively in accordance with the Agency’s Overview
Document and the Services’ Evaluation Memorandum (U.S., EPA 2004; USFWS/NMFS 2004).

There are ten registered products that contain oryzalin and one or more additional active ingredients ( Appendix D ). Based on a review of the available studies on oryzalin mixtures, it appears that the information pres ented in the papers pertain to efficacy and phytotoxicity of the mixtures for weed cont rol. No information is available on the toxicity of indivi dual components of or yzalin mixtures ( Appendix D ).

7.2. Measures of Exposure

In order to estimate risks of oryzalin exposures in aquatic and terres trial environments, all exposure modeling and resulting risk conclu sions will be based on registered labels including maximum application rates and methods cited in Table 3.2 for each use of oryzalin. Measures of exposur e are based on aquatic and terr estrial models that predict estimated environmental concentrations (EECs) of oryzalin. The models used to predict aquatic EECs are the Pesticid e Root Zone Model coupled with the Exposure Analysis Model System (PRZM/EXAMS). The model us ed to predict terrestrial EECs on food
items is T-REX. The model used to deri ve EECs relevant to terrestrial and wetland plants is TerrPlant. These models ar e parameterized using relevant reviewed environmental fate data from registrant subm issions and the literature; model input values will be consistent with the most recent version of the input parameter guidance (Version 2.1; EFED 2009).

PRZM (v3.12.2, May 2005) and EXAMS (v2.98.4.6, Ap ril 2005) are simulation models coupled with the input shell pe5.pl (Nove mber 2006). The models generate daily exposures and calculate 1-in-10 year EECs of oryzalin that may occur in surface water bodies adjacent to applicati on sites receiving oryzalin thr ough runoff and spray drift. PRZM simulates pesticide application, moveme nt, and transformation on an agricultural field and the resultant pesticide loadings to a receiving water body via runoff, erosion and spray drift. EXAMS simulates the fate of the pesticide in the water body and estimates

### -27 of 69- resulting concentrations. The standard scenarios used for ecological pesticide assessments assume application to a 10-hectar e agricultural field that drains into 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 screeni ng-level exposure of aquatic organisms to oryzalin. The measure of exposure for aquatic species is the 1-in-10 year return peak or rolling mean concentration. The 1-in-10 year peak is used for estimating acute exposures of direct effects to aquatic organisms. The 1- in-10-year 60-day mean is used for assessing chronic exposure to fish and aquatic-phase amphibians. The 1-in-10-year 21-day mean is used for assessing chronic exposure to aquatic invertebrates.

In addition to modeling estimates, available monitoring data will be evaluated. Monitoring data will include those collected/reported by stat es as well as other federal departments/agencies (e.g., USGS Nati onal Water Quality Assessment (NAQWA; http://water.usgs.gov/nawqa) ).

Exposure estim ates for terrestrial animals assumed to be in the target area or in an area exposed to spray drift are derived using the T-REX model (version 1.4.1, October 2008). This model incorporates the Kenaga nomograph, as modified by Fletcher et al . (1994), which is based on a large set of field residue data. The upper limit values from the nomograph represent the 95 th 

### percentile of residue values from actual field measurements (Hoerger and Kenega 1972). The Fletcher et al . (1994) modifications to the Kenaga nomograph are based on measured field re sidues from 249 published research papers, including information on 118 species of plants, 121 pesticides, and 17 chemical classes. EECs for terrestrial plants inhabiting dry a nd wetland areas are derived using TerrPlant (version 1.2.2, December 2006). This model uses estimates of pesticides in runoff and in spray drift to calculate EECs. EECs are based upon solubility, application rate and minimum incorporation depth in addition to type of formulation and method of application.

Two spray drift models, AGDisp and AgDRIFT ar e used to assess expos ures of terrestrial plants to oryzalin deposited in terrestrial ha bitats by spray drift. AGDisp (version 8.13; December 2004) is used to simulate aerial and ground applications. AgDrift (version 2.01; May 2001) is used to simulate spra y blast applications to orchard crops.

7.3. Measures of Effect

Ecological effects data are used as measures of direct and indirect effects to biological receptors. Data are obtained from registrant-submitted studies or from literature studies identified by ECOTOX. The ECOTOX database 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 da ta for aquatic life, terrestrial plants, and wildlife. ECOTOX wa s created and is maintained by EPA, Office of Research and Development, and the Na tional Health and Environmental Effects Research Laboratory's Mid- Continent Ecology Division.

### -28 of 69- Information on the potential effects of oryzalin on non-target animals is also collected from the Ecological Incident Info rmation System (EIIS; USEPA, 2007 c ). The EIIS is a database containing adverse effect (typically mortality) reports on non-target organisms
where such effects have been associated with the use of pesticides. Incidents reported in the aggregate incident reports and the Avia n Incident Monitoring System (AIMS) will
also be searched. AIMS is a database ad ministered by the American Bird Conservancy (partially funded by EPA). It contains public ly available data on re ported avian incidents involving pesticides (http://www.abcbirds.org/abcprograms/po licy/pesticides/aims/aims/index.cfm).

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.

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

The acute measures of effect used 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.

7.4. Integration of Exposure and Effects

Risk characterization is the integration of exposure and ecological e ffects characterization to determine the potential ecolo gical risk from the use of oryzalin 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 sp ecies. For the assessment of oryzalin risks, the risk quotient (RQ) method is used to compare expos ure 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 (LOC) (U SEPA, 2004). These criteria are used to

### -29 of 69- indicate when oryzalin’s use, as directed on the labels, has the poten tial to cause adverse
direct or indirect effects to non-target organisms. In addition, incident data from EIIS, aggregate incident reports, and AIMS 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 assessment. Depending on the risk manager’s need for additional information re garding risk, an effort will be made to further describe risk using probabilistic tools that 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 deem ed as appropriate means of refining assessments where deterministic approaches have identified risks.

7.6. Endangered Species Assessment

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 oryzali n. 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 asso ciated with the registration of oryzalin is based on an
action area. The action area is considered to be the area directly or indirectly affected by the federal action, as indicated by the 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 Document (USEPA, 2004) considers the results of the risk assessment process to es tablish boundaries for that action area with the understanding that exposures below the Agency’s defined LOCs constitute a no-effect threshold. For the purposes of this assessment, attention will be focused on the footprint of the action ( i.e ., the area where oryzalin application occurs), plus all areas where offsite transport ( i.e ., spray drift, runoff, etc .) may result in potential exposure that exceeds the Agency’s LOCs. Specific measures of ecologi cal effect that define the action area for listed species include any direct and indirect effects and/or potential modification of its critical habitat, including reduction in surv ival, growth, and reproduction as well as the
full suite of sub-lethal effects available in th e effects literature. Th erefore, the action area extends to a point where environmental exposur es are below any meas ured lethal or sublethal effect threshold for any biological en tity at the whole organism, organ, tissue, and cellular level of organi zation. In situations where it is not possible to determine the threshold for an observed effect, the action area will be assumed to encompass the entire
United States.

### -30 of 69- 7.7. Drinking Water Assessment

The m ost recent comprehensive drinking water assessment was conducted in 2003 in support of the oryzalin TRED. However, the estimates were derived using older versions of the PRZM/EXAMS models. As such, a dr inking water assessment will be conducted to support future human health risk assessm ents of oryzalin. The drinking water assessment will incorporate model estimates of the parent oryzalin in surface and ground
waters. Concentrations of the residue in surface waters will be estimated using PRZM/EXAMS (see description above). The PRZM model simulates pesticide
movement and transformation on and across th e agricultural field resulting from crop applications. The EXAMS model simulates pesticide loading via runoff, erosion, and spray drift assuming a standard watershed of 172.8 ha that drains into an adjacent standard drinking water index reservoir of 5.26 ha and an average depth of 2.74 m. Percent Cropped Areas (PCA) that account fo r the maximum area within a watershed that may be planted with the modeled crop will be applied to adjust predicted concentrations by PRZM/EXAMS. Ground water estimates of oryzalin concentrations will be established using SCI-GROW. The SCI-GROW model was developed by fitting a linear model to ground water concentrations with the Relative Index of Leaching Potential (RILP) as the independent variable. Ground water concentrations were taken from 90- day average high concentrations from Prospective Ground Water studies. The RILP is a
function of aerobic soil metabolis m and the soil-water partition coefficient. The drinking water assessment will also include available surface and ground water monitoring data.

7.8. Preliminary Identification of Data Gaps

Oryzalin use is defined as having terrestria l agricultural and non-agricultural uses. According to the Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirem ents for pesticides) environmental fate and non-target organism effects data are required for oryzalin based on its terrestrial use. Available studies submitted to fulfill environmental fate and ecological effects guid eline requirements, as well as outstanding data gaps for oryzalin, are defined in Sections 7.8.1 and 7.8.2

.

Further information on data required to fulf ill the Agency’s guideline requirements for oryzalin and its formulated products is pr esented as the Data Call-in (DCI) table in Appendix B . In addition to providing the guide line number and study title for required data, the DCI table provides a rationale for requiring the data , an explanation of how the data will be used, and a brie f description of the how the da ta could impact the Agency’s future decision-making.

7.8.1. Fate Data Gaps

The environm ental fate data requirements for oryzalin are partially fulfilled, and some data gaps still remain ( Table 7.1 ).

### -31 of 69- Table 7.1. Status of Available Environmenta l Fate Data and Remaining Data Gaps

Guideline Description MRID Classification Data Gap? Additional MRIDs a Comments

835.2120
161-1 Hydrolysis 41378401 Currently Under
Review See
Comment 66193, 106697, 131990 The study is currently under review, and it has not yet been
determined whether guideline requirements will be
satisfied.

835.2240
161-2 Photodegradation in Water 41278701 Acceptable b No 155491 --

835.2410
161-3 Photodegradation in Soil 41050001 Currently Under
Review See
Comment 38892, 41576, 106695, 106697, 106698,
45716303 The study is currently under review, and it has not yet been
determined whether guideline requirements will be
satisfied.

835.4100
162-1 Aerobic Soil Metabolism 41322801 Currently Under
Review See
Comment 131992 The study is currently under review, and it has not yet been
determined whether guideline requirements will be
satisfied.

835.4200
162-2 Anaerobic Soil Metabolism 41322802 Currently Under
Review See
Comment -- The study is currently under review, and it has not yet been
determined whether guideline requirements will be
satisfied.

835.4300
162-3 Aerobic Aquatic Metabolism -- -- Yes -- Call-In Data

835.4400
162-4 Anaerobic Aquatic Metabolism -- -- Yes -- Call-In Data

835.1230
835.1240
163-1 Leaching Adsorption/Desorption 41479801
41479802 Currently Under
Review See
Comment 2803, 2804, 38888, 38889, 106699, 106700, 106732, 160842, 5001264, 43433201,
43433202 These studies are currently under review, and it has not yet been determined whether guideline requirements will be
satisfied.

835.6100
164-1 Terrestrial Field Dissi pation 42138001 Supplemental c Yes 24857, 38890, 38891, 106687, 106696, 106701, 106704, 106705, 106709, 106710, 106717, 106724, 106725, 106732, 131991, 5001077, 5001264,
41859701 Mobility on degradates received.
See MRIDs
43433201 and
43433202.

Call-In Data for analytical method and independent laboratory
validation.

### -32 of 69- Table 7.1. Status of Available Environmenta l Fate Data and Remaining Data Gaps

Guideline Description MRID Classification Data Gap? Additional MRIDs a Comments

835.6200
164-2 Aquatic Field Dissipation -- -- Yes -- Call-In Data for analytical method and independent laboratory
validation.

850.1730
165-4 Bioaccumulation in Fish (BCF) 40787501 Acceptable d No -- --

a Additional studies submitted to the Agency to support the data re quirement. See reference section for the bibliographies of su bmitted fate studies.

b The supplemental information submitted in addition to the st udy (MRID 41278701) completely satisfies the data requirement.

c The study is upgradeable pending submission and review of the analytical method and indepe ndent laboratory validation.

d The supplemental information submitted in addition to the st udy (MRID 40787501) completely satisfies the data requirement.



### 7.8.2. Effects Data Gaps

Although many subm issions have been made to pr ovide data on the effects of oryzalin to aquatic and terrestrial organisms, data gaps still exist and are included in Tables 7.2 to 7.4 , below.

Table 7.2. Available Ecological Effects Data fo r Terrestrial Animals Exposed to Oryzalin and Remaining Data Gaps

Guideline Description MRID/
Accession Classification Data Gap? Comments

850.2100 Avian oral toxi city 00098462 Acceptable Yes 1

00072593 Acceptable 850.2200 Avian dietary toxicity

00072594 Acceptable No

441622-01 Acceptable No 850.2300 Avian reproduction

441622-02 Supplemental Yes 2

850.3020 Honeybee acute contact toxicity 00066220 Acceptable No 1 Acceptable avian data was
submitted for the bobwhite quail. However, avian acute oral toxicity data are not available for passerines, which are required under 40 CFR
Part 158.

2 Acceptable avian data are required for mallard duck.

### -33 of 69- Table 7.3. Available Ecological Effects Data for Aquatic Animals Exposed to Oryzalin and Remaining Data Gaps

Guideline Description MRID/
Accession Classification Data Gap? Comments

TN 1078 Acceptable

00072595 Acceptable 850.1075 Freshwater fish – Acute toxicity 00072595 Acceptable No

850.1075 Estuarine/marine fish – Acute toxicity 438877-01 Acceptable No

850.1010 Freshwater
invertebrates – Acute toxicity 00072596 Acceptable No

438877-01 Acceptable 850.1025
850.1035 Estuarine/marine
invertebrates – Acute toxicity 438877-02 Acceptable No

00126842 Acceptable 850.1400 Freshwater fish – early life stage test 00126841 Acceptable No

850.1400 Estuarine/marine fish – early life stage test Not
submitted - Yes 1

850.1300 Freshwater
invertebrate – life cycle test 439869-01 Acceptable No

850.1350 Estuarine/marine
invertebrates – life cycle test Not
submitted - Yes 2

850.1735 Freshwater
invertebrate – Acute

whole sediment Not
submitted - Yes 3

850.1740 Estuarine/marine
invertebrate – Acute

whole sediment Not
submitted - Yes 3

Other A Freshwater and
estuarine/marine
invertebrate – Chronic
whole sediment Not
submitted - Yes 3 1 An estuarine/marine fish early life stage test is required because oryzalin may enter
this environment due to its use and mobility patterns. It is also expected to be persistent
in water under some
conditions.

2 An estuarine/marine invertebrate life cycle test is required because oryzalin may
enter this environment due to its use and mobility patterns. It is also expected to be persistent in water under some
conditions.

3 This data is required. However, it is currently
uncertain if an acute or a chronic study is required. Oryzalin’s chemical properties trigger the requirement for sediment toxicity studies (the Kd >50, the log Kow is >3, and a Koc is >1000). Acute studies are required if the persistence in sediment is ≤ 10 days, and chronic studies are required if the persistence in sediment is expected to be >10 days. The requested aquatic metabolism study will allow
EFED to determine if an acute or a chronic study is required.

### -34 of 69- Table 7.3. Available Ecological Effects Data for Aquatic Animals Exposed to Oryzalin and Remaining Data Gaps

Guideline Description MRID/
Accession Classification Data Gap? Comments

A Three species required using the following study guidance: 1) EPA 600/R-99/064 Test Method 100.4: Hyalella

azteca 42-d Test for Measuring the Effects of Sediment Associated Contaminants on Survival, Growth, andReproduction; 2) EPA 600/R-99/064 Test Method 100.5: Life-cycle Test for Measuring the Effects of Sedimentassociated Contaminants on Chironomus dilutus or C. tentans in USEPA 2000 Methods for Measuring the Toxicity and Bioaccumulation of Sedi ment-associated Contaminants with Freshwater Invertebrates; 3) Leptocheirus plumulosus in USEPA 2001 Method for Assessing the Chronic Toxicity of Marine and Estuarine Sediment-associated Contaminants with the Amphipod Leptocheirus plumulosus EPA 600/R-01/020.

Protocols should be submitted for approval prior to tes ting for chronic studies. Th e preferred sediment is formulated; guidance for the formulated sediment can be found in OECD 218 Sediment-Water Chironomid Toxicity Test using Spiked Sediment. Based on test variability for the endpoints of concern and the need to establish a NOAEC/LOAEC, the following number of replicates and test animals are recommended: for the midge test with C. dilutus: 16 replicates containing 12 test organisms each (12 replicates at test initiation; 4 added at 10 days for auxiliary males); for the freshwater amphipod test with H. azteca : 12 replicates per treatment (4 for 28-d survival and growth and 8 for the remainder of the test) with 10 neonates per replicate; and for the L. plumulosus: 10 replicates per treatment with 20 neonates per replicate. For alternative test designs, the protocol should discuss the power of the test.



### Table 7.4. Available Ecological Effects Data for Plants Exposed to Oryzalin and Remaining Data Gaps

Guideline Description MRID Classification Data Gap? Comments

850.4225 Terrestrial Plant toxicity: Tier II seedling emergence 426024-01 Supplemental Yes 1

850.4250 Terrestrial Plant toxicity: Tier II vegetative vigor 426024-01 Supplemental Yes 1

431369-01 Supplemental

431369-02 Invalid

431369-03 Invalid 850.5400 Aquatic Plant Growth: algae

431369-04 Supplemental Yes 2

850.4400 Aquatic Plant Growth: vascular plants 431369-05 Supplemental Yes 2 1 The submitted study
utilizes the technical grade active ingredient (TGAI). The data requirements specify the use of a typical end-use product (TEP).

2 Acceptable data are required for non-vascular and vascular plants.



### Avian Acute Oral Toxicity

Acceptable acute avian oral toxicity data we re submitted for exposures of bobwhite quail to oryzalin; however, data are not available for passeri nes, which are required under 40 CFR Part 158 (October 26, 2007) data requireme nts for conventional pesticides (72 FR 60934; USEPA, 2007 d ). The Part 158 data requirements specify that acute avian oral toxicity data be submitted for either a ma llard duck or bobwhite quail and a passerine species. Therefore, an avian oral toxici ty test (OCSPP Guideline 850.2100) is required

### -35 of 69- for passerine birds. A passerine study pr otocol should be submitted for review by EPA prior to initiation of this study. If oral acute toxicity data are not submitted for passerines, EFED will assume acute risk for passerine species.

Avian Chronic Reproduction Toxicity

Acceptable chronic avian repr oduction toxicity data were submitted for exposures of bobwhite quail for oryzalin. However, th e 40 CFR Part 158 data requirements for conventional pesticides require acceptable to be submitted for the mallard duck as well. A mallard duck study was submitted but was cl assified as supplemental because the prelaying exposure period was not of sufficient length.

Chronic Toxicity Studies with Est uarine/Marine Fish and Invertebrates

Chronic toxicity data for or yzalin are not available for estuarine/marine fish or invertebrates. Because the registered use patterns permit oryzalin to enter estuarine/marine environments, these data are required. Therefore, an estuarine/marine invertebrate life cycle toxici ty test (OCSPP Guideline 850.1350) and an estuarine/marine fish early life stage toxicity test (O CSPP Guideline 850.1400) are required. Chronic studies are important for oryzalin because it is stable to hyd rolysis and may, therefore, be persistent in water under some conditions. In the absence of chronic oryzalin toxicity data for estuarine/marine invertebrates and fish, the Agency will assume risks to estuarine/marine animals from the uses of oryzalin.

Acute and Chronic Toxicity Studies with Fr eshwater and Estuarine/Marine Sedimentdwelling Invertebrates

Oryzalin’s chemical properties trigger the requi rement for sediment toxicity studies (the Kd >50, the log Kow is >3, and a Koc is >1000). Acute studies (OCSPP 850.1735, 850.1740) are required if the pers istence in sediment is ≤ 10 days, and chronic studies 2 

### are required if the persistence in sediment is expected to be >10 days. The requested aquatic metabolism study will allow EFED to de termine if acute or chronic studies are required. If chronic studies are required, protocols should be submitted prior to test
initiation.

Terrestrial and Aqua tic Plant Studies

Aquatic (both vascular and non-vascular species) and terrestrial plant toxicity studies and associated risk analysis of plants are requi red for registration of pesticides with outdoor

2 Three species required using the following study guidance: 1) EPA 600/R-99/064 Test Method 100.4: Hyalella azteca 42-d Test for Measuring the Effects of Sedi ment Associated Contam inants on Survival, Growth, and Reproduction; 2) EPA 600/R-99/064 Test Method 100.5: Life-cycle Test for Measuring the
Effects of Sediment-associated Contaminants on Chironomus dilutus or C. tentans in USEPA 2000 Methods for Measuring the Toxicity and Bioaccumula tion of Sediment-associat ed Contaminants with Freshwater Invertebrates; 3) Leptocheirus plumulosus in USEPA 2001 Method for Assessing the Chronic Toxicity of Marine and Estuarine Sediment-associated Contaminants with the Amphipod Leptocheirus plumulosus EPA 600/R-01/020.

### -36 of 69- uses (CFR Part 158). For te rrestrial plants, Tier II st udies (OCSPP Guidelines 850.4225 and 850.4250) are required when poten tial concerns are triggered ( i.e ., when there is some indication that there may be significant toxicity to plants). For oryzalin, these
indicators include the herbicidal mode of action and st atements on the label indicating toxicity to plants.

The submitted terrestrial plant toxicity studies utilized the technical grade active ingredient (TGAI) and were classified as s upplemental. The data requirements specify theuse of a typical end-use product (TEP). The submitted aquatic (vascular and nonvascular) plant studies were classified as supplemental or invalid due to numerous problems with the study designs. The scientific soundne ss of the studies is in question, as the conducting laboratory may not have had a ppropriate QA/QC methods in place. The
two studies that were classifi ed as invalid showed statis tically significant differences, which were also biologically relevant, between the solven t control and the negative
control.

Degradate Toxicity

No toxicity data were submitted for the de gradate UN-2. UN-2 is a major degradate of oryzalin that forms primarily via aqueous photolysis. However, ECOSAR analysis ( Appendix E ) predicted the UN-2 would be less toxi c than the parent , and considering the amount at which UN-2 forms (14%), submissi on of degradate toxicity data is unlikely to add value or change the outcome of the risk assessment. Therefore, no degradate
studies are recommended for request at this time.

8. References

Food and Agriculture Organization of the United Nations (FAO). 2000. Appendix 2. Parameters of pesticides that influence processes in the soil. In FAO Information Division Editorial Group (Ed.), Pesticide Disposal Series 8. Assessing Soil Contamination: A Reference Manual. Rome: Food & Agriculture Organization of the United Nations. http://www.fao.org/DOCREP/003/X2570E/X2570E06.htm

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

Hoerger, F. and E. E. Kenaga. 1972. Pesticide Resi dues on Plants: Correlation of Representative Data as a Basis for Estimation of their Magnitude in the Environment. In F. Coulston and F. Korte, eds., Environmental Quality and Safety: Chem istry, Toxicology, and Technology, Georg Thieme Publ., Stuttgart, West Germany, pp. 9-28.

U.S. Department of Agriculture (USDA). 2007. Na tional Agricultural Statistics Service. United States Department of Agriculture. http://www.nass.usda.gov/

U.S. EPA. 1994. Oryzalin: Reregistration Eligibility Decision (RED). Office of Prevention, Pesticides, and Toxic Substances. Office of Pesticide Programs. Washington, D.C. September 1994. http://www.epa.gov/oppsrrd1/REDs/0186.pdf

### -37 of 69- USEPA. 1998. Guidelines for Ecological Risk Assessment. Risk Assessment Forum, Office of Research and Development, Washington, D.C. EPA/630/R-95/002F. April 1998. http://cfpub.epa.gov/ncea/cfm/ recordisplay.cfm ?deid=30759

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

.

USEPA. 200 3. Oryzalin; Health Effects Division (HED) Metabo lism Assessment Review Committee (MARC) Decision Document. U.S. Environmenta l Protection Agency, Office of Prevention,
Pesticides and Toxic Substan ces, Office of Pesticide Progra ms, Health Effects Division, Memorandum. June 5, 2003.

USEPA. 2004. Overview of the Ecological Risk As sessment Process in the Office of Pesticide Programs. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC. January 23, 2004.

USEPA. 2006 a . Standardized Soil Mobility Classification Guidance. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division, Memorandum. April 21, 2006.

USEPA. 2007 c . Ecological Incident Information System. http://www.epa.gov/espp/consultation/ecoriskove rview.pdf

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

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

.

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

Worthing, C. R and R. J. Hance, editors. 1991. The Pesticide Manual: A World Compendium (9th edition). British Crop Protection C ouncil, Surrey, UK. June, 1991.

SUBMITTED ENVIRONMEN TAL FATE STUDIES:

Guideline 161-1 Hydrolysis:

MRID 38892 Day, E.W.; Mosier, J.W.; Saunders, D.G. (1972) Studies on the Rate of Degradation of EL-119 by Sunlight. (Unpublished study received Dec 29, 1972 under 3F1347; subm itted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL 093605-J)

MRID 66193 Day, E.W.; Sullivan, W.L.; Decker, O.D. (1976) A Hy drolysis Study of the Herbicides Oryzalin and Metribuzin. (Unpublished study received Sep 16, 1977 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Inc.; CDL 231825-D)

MRID 106697

### -38 of 69- Day, E.; Mosier, J.; Saunders, D. (1972) Studies on the Rate of Degradation of EL-119 by Sunlight. (Unpublished study received Dec 22, 197 2 under 3F1347; submitted by Elan co Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-B)

MRID 131990 Elanco Products Co. (1983) Oryzalin Technical, Surflan 75W/AS Product Chemistry. (Compilation; unpublished study received Oct 6, 1983 under 1471-96; CDL 251445-A)

MRID 41378401 Saxena, A. (1990) Hydrolysis of Oryzalin in Buffered Aqueous Solutions Final Report Lab Project Number HLA 6313-100. Unpublished study prepared by Hazleton Laboratories America, Inc. 52 p.

Guideline 161-2 Photodegradation in Water:

MRID 155491 Gray, J.; Moiser, J.; Saunders, D. (1980) Photolysis of Oryzalin in Aqueous Solution. Unpublished study prepared by Lilly Research Laboratories. 30 p.

MRID 41278701 Gohdes, M. (1989) Artificial Sunli ght Photodegradation of ?Carbon 14|-Oryzalin in a Buffered Aqueous Solution Lab Project Number HLA/6237/103. Unpublished study prepared by Hazleton Laboratories America, Inc. 115 p.

Guideline 161-3 Photodegradation in Soil:

MRID 38892 Day, E.W.; Mosier, J.W.; Saunders, D.G. (1972) Studies on the Rate of Degradation of EL-119 by Sunlight. (Unpublished study received Dec 29, 1972 under 3F1347; subm itted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL 093605-J)

MRID 41576 Elanco Products Company (1968?) Photodecomposition. (Unpublished study received Apr 30, 1970 under 0F0968; CDL 091661-AB, 091660)

MRID 106695 Elanco Products Co. (1972) Radiochemical Procedure for the Determination of the Photochemical Degradation of Oryzalin. (Unpublished study received on unknown date under 1471-9 6; CDL 101596-C)

MRID 106697 Day, E.; Mosier, J.; Saunders, D. (1972) Studies on the Rate of Degradation of EL-119 by Sunlight. (Unpublished study received Dec 22, 197 2 under 3F1347; submitted by Elan co Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-B)

MRID 106698
Elanco Products Co. Photodecom position of 14C Oryzalin. (Unpublis hed study received Dec 22, 1972 under 3F1347; CDL 092131-C)

MRID 41050001 Gohdes, M. (1989) Artificial Sunlight Photodegradation of ?carbon 14|-Oryzalin on Soil Amendment No. 1 to the Final Report Project ID HLA 6237-102. Unpublished study prepared by Hazleton Laboratories America, Inc. 111 p.

MRID 45716303

### -39 of 69- Saunders, D.; Emery, K.; Powers, F. (1989) Photolysis of Fenarimol, Tebuthiuron, and Oryzalin on Soil at pH 5.7 and 7.7 Lab Project Number AAC8922 3316 0. Unpublished study prepared by Lilly Research Laboratories. 135 p.

Guideline 162-1 Aerobic Soil Metabolism :

MRID 131992 Sassic, K.; Golab, T.; Wooten, H.; et al. (1982) 14C Oryzalin Anaerobic Soil Degradation Study Experiment No. ABC-0110. (Un- published study received Oct 6, 1983 unde r 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly a nd Co., Indianapolis, IN; CDL 251446-C)

MRID 41322801 Graper, L.; Rainey, D. (1989) Aerobic Metabolism of Carbon 14| Oryzalin in Sandy Loam Soil Lab Project Number ABC/0434. Unpublished study prepared by DowElanco 33 p.

Guideline 162-2 Anaerobic Soil Metabolism :

MRID 41322802 Graper, L.; Rainey, D. (1989) Anaerobic Metabolism of Carbon 14| Oryzalin in Sandy Loam Soil Lab Project Number ABC/0435. Unpublished study prepared by DowElanco 26 p.

Guideline 163-1 Leaching and Adsorption/Desorption:

MRID 2803 Barrentine, J. L. (1969) Experiment No. JLB9-1 Soil Leaching Data|. (Unpublished study received Apr 30, 1970 under 0F 0968; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL 091661-O)

MRID 2804 Barrentine, J.L. (1969) Experiment No. JLB9-2 Soil l eaching Data|. (Unpublished study received Apr 30, 1970 under 0F0968 ; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL 091661-P)

MRID 38888 Holzer, F.J. (1972) EL-119--Leaching study. (Unpublished study received Dec 29, 1972 under 3F1347; prepared in cooperation with Purdue Univ., Agronomy Dept., Soil Testing Laboratory, submitted by Elanco Products Co., Div. of Eli L illy and Co., Indianapolis, Ind.; CDL 093605-F)

MRID 38889 Elanco Products Company (1972) EL-119 Leaching Study on Degradat ion Products. (Unpublished study received Dec 29, 1972 under 3F1347; prepared in cooperation with Purdue Univ., Dept. of Agronomy, Plant and Soil Analysis Laboratory; CDL 093605-G)

MRID 106699 Holzer, F. (1972) EL-119 Leaching Study Refere nce 450-AD-64-111. (Unpublished study received Dec 22, 1972 under 3F1347; prepared in cooperation with Purdue Univ., Agronomy Dept., Soil Testing Laboratory, submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-E)

MRID 106700 Elanco Products Co. (1972) EL-119 Leaching Study on Degradation Products Reference 450-AD-64-71. (Compilation; unpublished study received D ec 22, 1971 under 3F 1347; CDL 092131-F)

MRID 106732

### -40 of 69- Golab, T.; Ward, N.; Donoho, A.; et al. (1971) Oryza lin As a Pre- emergence Surface-applied Herbicide for Soybeans. (Unpublished study received Sep 27, 1971 under 1471-EX-36 ; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 210006-B)

MRID 160842 Jacques, G.; Harvey, R. (1979) Ad sorption and diffusion of dinitroaniline herbicides in soils. Weed Science 27(4) 450-455.

MRID 5001264 Harvey, R.G. (1974) Soil adsorption and volatility of dinitroaniline herbicides. Weed Science 22(2) 120-

124.

MRID 41479801 Saunders, D. (1990) Oryzalin Aged Soil Leaching Study Lab Project Number AAC8923. Unpublished study prepared by DowElanco, Plant Science Chemical Development. 57 p.

MRID 41479802 Saunders, D.; Powers, F. (1987) Adsorption and Desorption of Oryzalin on Soil Lab Project I.D. EWD8726. Unpublished study prepared by Lilly Research Laboratories. 66 p.

MRID 43433201 Cook, W. (1994) Adsorption and Desorption of OR-20 on Soil Lab Project Number ENV93117. Unpublished study prepared by DowElanco. 76 p.

MRID 43433202 Merritt, D.; Patterson, V. (1994) Ag ed Desorption of Oryzalin and Metabolites on Four Soils Lab Project Number ENV93102. Unpublished study prepared by DowElanco. 156 p.

Guideline 164-1 Terrestrial Field Dissipation:

MRID 24857 Kennedy, J.M.; Talbert, R.E.; Fischer, B. (1974) Din itroaniline Herbicides Their Persistence on the Soil Surface, Residual Activity, and Re lative Crop Tolerance|. (Unpub lished study received 1975 under 2G1285; prepared by Univ. of Arkansas, Agricultural Experiment Station, submitted by Union Carbide Agricultural Products Co., Ambler, Pa.; CDL 095154-E)

MRID 38890 Elanco Products Company (1 971) Introduction. (Unpublished stud y received Dec 29, 19 72 under 3F1347; CDL 093605-H)

MRID 38891 Massey, G.D.; Webster, H.L.; Watson, J.H.; et al. (1972) Degradation Study--Oryzalin|. (Unpublished study including experiment nos. GDM1-26, HLW1-8, JHW1-14..., receiv ed Dec 29, 1972 under 3F1347; submitted by Elanco Products Co., Div. of Eli L illy and Co., Indianapolis, Ind.; CDL 093605-I)

MRID 106687 Elanco Products Co. (1976) Summary Environmental Chemistry Surflan|. (Compilation; unpublished study received Sep 1, 1976 under 1471-96; CDL 095261-A)

MRID 106696 Elanco Products Co. (1972) Analyses for Residues of Surflan 75W in Beans and Other Crops|. (Compilation; unpublished study received D ec 22, 1972 under 3F 1347; CDL 092131-A)

### -41 of 69- MRID 106701 Elanco Products Co. (1971) Determination of Residues of EL-119 and Dieldrin in Water and Soil|. (Unpublished study received Dec 22, 1 972 under 3F1347; CDL 092131-G)

MRID 106704 Massey, G. (1971) EL-119 Environmental Study Experiment No. GDMO-18. (Unpublished study received Dec 22, 1972 under 3F1347; submitted by El anco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN

MRID 106705 Shoop, G. (1971) EL-119 Environmental Study Experiment No. GJSO- 21. (Unpublished study received Dec 22, 1972 under 3F1347; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-L)

MRID 106709 Webster, H. (1972) General Summary EL-119 Experiment No. HLWO- 7. (Unpublished study received Dec 22, 1972 under 3F1347; sub- mitted by Elanco Produ cts Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-P)

MRID 106710 Webster, H. (1972) EL-119 Environmental Study| Experiment No. HLW1-8. (Unpublished study received Dec 22, 1972 under 3F1347; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-Q)

MRID 106717 Keaton, J. (1972) General Summary EL-119| Experiment No. JAKO- 37. (Unpublished study received Dec 22, 1972 under 3F1347; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-X)

MRID 106724 Warner, L. (1971) EL-119 Environmental Study Experiment No. LCWO -17. (Unpublished study received Dec 22, 1972 under 3F1347; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-AE)

MRID 106725 Ascheman, R. (1971) EL-119 Environmental Study Experiment No. REAO-13. (Unpublished study received Dec 22, 1972 under 3F1347; submitted by El anco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 092131-AF)

MRID 106732 Golab, T.; Ward, N.; Donoho, A.; et al. (1971) Oryza lin As a Pre- emergence Surface-applied Herbicide for Soybeans. (Unpublished study received Sep 27, 1971 under 1471-EX-36 ; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 210006-B)

MRID 131991 Golab, T.; Sherman, W.; Wooten, H.; et al. (1980) Radiochemical Studies with 14C Oryzalin in Soil, Soybean (Primary Crop) and Various Rotational Crop Plants. (Unpublished study received Oct 6, 1983 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL 251446-A)

MRID 5001077 Parochetti, J.V.; Dec, G.W., Jr.; Burt, G.W. (1976) Volatility of eleven dinitroaniline herbicides. Weed Science 24(6) 529-532.

### -42 of 69- MRID 5001264 Harvey, R.G. (1974) Soil adsorption and volatility of dinitroaniline herbicides. Weed Science 22(2) 120-

124.

MRID 41859701 Day, E.; Griggs, R.; Decker, O. (1990) Oryzalin Terre strial Field Dissipation Study-An Interim Report Lab Project No AAC8914. Unpublished study prepared by DowElanco, Formulation and Chemistry Lab. 48 p.

MRID 42138001 Decker, O. (1991) Oryzalin Terre strial Field Dissipation Study Lab Project Number AAC8914. Unpublished study prepared by DowElanco, North American Environ. Chem. Lab. 349 p.

Guideline 164-2 Aquatic Field Dissipation:

MRID 22059 Day, E.W.; Decker, O.D.; Rodewald, K.J.; et al. (1977) A Laboratory Hydrolysis Study on the Herbicide Oryzalin. (Unpublished study receive d Mar 9, 1978 under 1471-96; su bmitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL 233020-B)

MRID 38890 Elanco Products Company (1 971) Introduction. (Unpublished stud y received Dec 29, 19 72 under 3F1347; CDL 093605-H)

Guideline 165-4 Bioaccumulation in Fish:

MRID 40787501 Magnussen, J. (1988) Laboratory Studies of Carbon 14| Oryzalin Accumulation in Fish Laboratory Project ID's ABC-0393 ABC-0394. Unpub lished study prepared by Lilly Research Laboratories, Inc. 59 p.

SUBMITTED EFFECTS STUDIES:

71-1 Avian Single Dose Oral Toxicity

MRID SAN
Document

Number Citation Reference

26763 See 106728 West, H.C.; Kehr, C.C.; Hoffman, D.G.; et al. (1972) The Acute Oral Toxicity of Technical EL-119 in Bobwhite Quail and Mallard Ducks. (Unpublished study received Dec 12, 1979 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind., CDL:241537-I)

38670 See 106728 West, H.C.; Kehr, C.C.; Hoffman, D.G.; et al. (1972) The Acute Oral Toxicity of Technical EL-119 in Bobwhite Quail and Mallard Ducks. (Unpublished study r eceived on unknown date under 1471- 96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:242443-H)

98462 2002391 Cochrane, R.L.; Kehr, C.C.; Jordan, W.H.; et al. (1982) The Toxicity of Oryzalin (EL-119, Compound 67019) to Bobwhite in a 14- day Acute

### -43 of 69- Oral Study: Study A02980. (Unpublished study received Apr 8, 1982 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:247229-B)

98464 2002392 Cochrane, R.L.; Kehr, C.C.; Jordan, W.H.; et al. (1982) The Toxicity of Oryzalin (EL-119, Compound 67019) to Bobwhite in a 14-day Acute Oral Study: Study A03580. (Unpublished study received Apr 8, 1982 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:247229-D)

106728 2002393
2045653 West, H.; Kehr, C.; Hoffman, D.; et al. (1972) The Acute Oral Toxicity of Technical EL-119 in Bobwhite Quail and Mallard Ducks. (Unpublished study received Dec 22, 1972 under 3F1347; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:092131-AL)

71-2 Avian Dietary Toxicity

MRID SAN
Document

Number Citation Reference

72593 2002386 Carter, J.L.; Negilski, D.S.; Kehr, C.C.; et al. (1980) The Toxicity of Compound 67019 (Oryzalin) to Bobwhite Quail in a Five- day Dietary Study: Study No. A010-79. Includes undated method ATY. (Unpublished study received May 7, 1981 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:245053-A)

72594 2002387
2045657 Carter, J.L.; Negilski, D.S.; Kehr, C. C.; et al. (1980) The Toxicity of Compound 67019 (Oryzalin) to Malla rd Ducks in a Five- day Dietary Study: Study No. 7005-79. Includes undated method ATY. (Unpublished study received May 7, 1981 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:245054-A)

71-4 Avian Reproduction

MRID SAN
Document

Number Citation Reference

126843
LE00RY01 on
the DER 2002382 Cochrane, R.; Jordan, W.; Brannon , D.; et al. (1982) The Toxicity of Oryzalin (EL-119, Compound 67019) in a One-generation Study with Mallards: Study A00482. (Unpublished study r eceived Apr 14, 1983 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:071521-C)

129050 2002383 Cochrane, R.; Jordan, W.; Brannon, D.; et al. (1983) The Toxicity of Oryzalin (EL-119, Compound 67019) in a One-generation Reproduction Study with Bobwhite: Study A01282. (U npublished study received Jun 3, 1983; Jun 8, 1983 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:250589-A)

44162201 2023890 Gallagher, S.; Beavers, J.; Jaber, M. (1996) Oryzalin: A Reproduction

### -44 of 69- Study with the Northern Bobwhite (Colinus virginianus): Lab Project Number: 103-415: ES-3084. Unpublished study prepared by Wildlife International Ltd. 177 p.

44162202 2023891 Gallagher, S.; Beavers, J.; Jaber, M. (1996) Oryzalin: A Reproduction Study with the Mallard (Anas platyrhynchos): Lab Project Number: 103- 416: ES-3085. Unpublished study prepared by Wildlife International Ltd. 174 p.

72-1 Acute Toxicity to Freshwater Fish

MRID SAN
Document

Number Citation Reference

72595 2002388 = BG
2002389 =

RBT Sleight, B.H., III (1971) Acute Toxicity of EL-119 to Bluegill (Lepomis macrochirus) and Rainbow Trout (Salmo gairdneri). (Unpublished study received May 7, 1981 under 1471- 96; prepared by Bionomics, Inc., submitted by Elanco Products Co., Div. of Eli Lilly & Co., Indianapolis, Ind.; CDL:245055-A)

TN1078 2002431 USEPA Beltsville Animal Biology Lab with Rainbow trout and 95% active ingredient

106663 2002395
2045652 Elanco Products Co. (1968) Environmental Bioassay, Fish: Oryzalin. (Unpublished study received Jun 18 , 1972 under 2G1 201; CDL:091019- F)

106729 2002394
2045654 Elanco Products Co. (1968) Environmental Exposure of Oryzalin to Goldfish: Acute Toxicity. (Unpublis hed study received Dec 22, 1972 under 3F1347; CDL:092131-AO)

26758 See 106729 Elanco Products Company. Acute Toxicity: Environmental Expo- sure of Goldfish to Oryzalin. (Unpub lished study received Dec 12, 1979 under 1471-96; CDL:241537-B)

72-2 Acute Toxicity to Freshwater Invertebrates

MRID SAN
Document

Number Citation Reference

72596 2002390
2045656 Carter, J.L.; Karnak, R.E.; Kehr, C. C.; et al. (1980) The Toxicity of Compound 67019 (Oryzalin) to Daphnia magna in a 48-hour Static Test: Study Nos. 5005-79 and 50 12-79. (Unpublishe d study received May 7, 1981 under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly & Co., Indianapolis, Ind.; CDL:245056-A)

72-3 Acute Toxicity to Estuarine/Marine Organisms

MRID SAN
Document

Number Citation Reference

### -45 of 69- 43887701 2002375 Ward, T.; Kowalski, P.; Boeri, R. (1995) Oryzalin: Acute Toxicity to the Sheepshead Minnow, Cyprinodon variegatus: Lab Project Number: 654-DO: ES-2956. Unpublished study prepared by T.R. Wilbury Labs, Inc. 24 p.

43887702 2002376 Boeri, R.; Kowalski, P.; Ward, T. (1995) Oryzalin: Acute FlowThrough Mollusc Shell Deposition Test: (Crassostrea virginica): Lab Project Number: 653-DO: DECO-ES-2955. Unpublished study prepared by T.R. Wilbury Labs, Inc. 25 p.

43887703 2002377 Boeri, R.; Kowalski, P.; Wa rd, T. (1995) Oryzalin: Acute Toxicity to the Grass Shrimp, Palaemonetes p ugio: Lab Project Number: 652-DO: DECO-ES-2954. Unpublished study prepared by T.R. Wilbury Labs, Inc. 24 p.

72-4 Fish Early Life Stage/ Aquatic Invertebrate Life Cycle Study

MRID SAN
Document

Number Citation Reference

106665 2002396
2045655 Worth, H. (1971) Effect of a Season-long Exposure to Oryzalin on
Fathead Minnow Produc tion. (Unpublished study received Jun 18, 1972 under 2G1201; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:091019-H)

126841
LE00RY03 on

DER 2042384 Sauter, S.; Meyerhoff, R.; Jordan, W.; et al. (1983) The Toxicity of Oryzalin (EL-119, Compound 67019) in Water to Fathead Minnows ... in a 34-day Early Life-stage Study: Study F11482. (Unpublished study received Apr 14, 1983 under 1471-9 6; submitted by El anco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:071521-A)

126842
LE00RY04 on

DER 2002385 Meyerhoff, R.; Sauter, S.; Jordan, W.; et al. (1983) The Toxicity of Oryzalin (EL-119, Compound 67019) in Water to Rainbow Trout ... in a 66-day Early Life-stage Study: Study F11382. (Unpublished study received Apr 14, 1983 under 1471-9 6; submitted by El anco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:071521-B)

43986901 2002374 Kirk, H.; Hugo, J.; Miller, K.; et al. (1996) Evaluation of the ChronicToxicity of Oryzalin Herbicide (3,5-Dinitro-N4,N4-di(Npropyl)sulfanilamide) to the Daphnia magna Straus: Lab Project Number: DECO-ES-2995. Unpublished study prepared by The Dow Chemical Co. 84 p.

122-1 Seed Germination/Seedling Emergence and Vegetative Vigor

MRID SAN
Document

Number Citation Reference

42602401 Feutz, E. (1992) Evaluating the Effects of Oryzalin on the Germination, Emergence, and Vegetative Vigor of Non-target Terrestrial Plants: Lab Project Number: 40292. Unpublished study prepared by ABC Labs, Inc. 155 p.

### -46 of 69- 123-1 Seed Germination/Seedling Emergence and Vegetative Vigor

MRID SAN
Document

Number Citation Reference

42602401 Feutz, E. (1992) Evaluating the Effects of Oryzalin on the Germination, Emergence, and Vegetative Vigor of Non-target Terrestrial Plants: Lab Project Number: 40292. Unpublished study prepared by ABC Labs, Inc. 155 p.

123-2 Aquatic Plant Growth

MRID SAN
Document

Number Citation Reference

43136901 2082507 Hughes, J.; Williams, T. (1994) The Toxicity of Oryzalin toSelanastrum capricornutum: Lab Project Number: B460-155-1: DR0320-8068: ES-2693. Unpublished study prepared by Malcolm Pirnie, Inc. 37 p.

43136902 2082508 Hughes, J.; Williams, T. (1994 ) The Toxicity of Oryzalin to Anabaenaflos-aquae: Lab Project Number: B460-155-2: DR-0320-8068: ES2691. Unpublished study prepared by Malcolm Pirnie, Inc. 37 p.

43136903 2082509 Hughes, J.; Williams, T. (1994 ) The Toxicity of Oryzalin to Navicula pelliculosa: Lab Project Number : B460-155-3: DR-0320-8068: ES2694. Unpublished study prepared by Malcolm Pirnie, Inc. 34 p.

43136904 2082510 Hughes, J.; Williams, T. (1994) The Toxicity of Oryzalin to Skeletonema costatum: Lab Project Number: B460-155-4: DR-0320- 8068: ES-2695. Unpublished study prepared by Malcolm Pirnie, Inc. 37

p.

43136905 2082511 Hughes, J.; Williams, T. (1994) The Toxicity of Oryzalin to Lemna gibba G3: Lab Project Number: B460-155-5: DR-0320-8068: ES-2692. Unpublished study prepared by Malcolm Pirnie, Inc. 35 p.

141-1 Honeybee Acute Toxicity

MRID SAN
Document

Number Citation Reference

00066220 2002379 ATKINS, E.L., L.D. ANDERSON, D. KELLUM, and K. W. NEUMA. (1976) PROTECTING HONEY BEES FROM PESTICIDES. University of California, Division of Agricultural Science, Leaflet 2883.

Non Guideline

MRID Type of
Document Citation Reference

47164601 Registrant Moore, D.; Breton, R.; Rodney, S.; et al. (2007) Generic Problem

### -47 of 69- assessment Formulation for California Red-Legged Frog. Project Number: 89320, 05232007. Unpublished study prepared by Cantox Environmental Inc. 87

p.

47164602 Registrant

assessment Holmes, C.; Vamshi, R. (2007) Data and Methodology Used for Spatial Analysis of California Red Legged Frog Observations and Proximate Land Cover Characteristics. Project Number: 3152007, WEI/252/03. Unpublished study prepared by Waterborne Environmental, Inc. (WEI). 19 p.

38668 Summary Worth, H.M.; Anderson, R.C., eds. (1971) The Safety Evaluation of Oryzalin, EL 119. (Unpublished study received on unknown date under 1471-96; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:242443-A)

38671 Summary Elanco Products Company (1971) Toxicology Studies with Oryzalin 75WP. (Unpublished study received on unknown date under 1471- 96; CDL:242443-I)

106658 Summary Elanco Products Co. Toxicology Studies with Oryzalin 75WP. Summary of studies 091019-B through 091019-H. (Unpublished study received Jun 18, 1972 unde r 2G1201; CDL:091019-A)

38671 Summary Elanco Products Company (1971) Toxicology Studies with Oryzalin
75WP . (Unpublished study received on unknown date under 1471- 96; CDL:242443-I)

106658 Summary Elanco Products Co. Toxicology Studies with Oryzalin 75WP. Summary of studies 091019-B through 091019-H. (Unpublished study received Jun 18, 1972 unde r 2G1201; CDL:091019-A)

106666 Summary Elanco Products Co. Th e Safety Evaluation of Oryzalin, EL119. (Unpublished study received Jun 18 , 1972 under 2G1 201; CDL:091019- I)

106667 Summary Elanco Products Co. (1968) Single Exposure Effects: ?Oryzalin|. (Unpublished study received Jun 18, 1972 under 2G1201 ; CDL: 091019- J)

2002432 Summary of Mammalian laboratory toxicity data

27401 DER not
located - Efficacy study Christensen, C.; Rogers, W.; Colbert, F.; et al. (1976) Sward 50W for Preemergence Control of Annual Gra sses and Some Broad- leaf Weeds in Mature Turfgrasses. (Unpublished study received Aug 12, 1976 under 1471-106; prepared in cooperation with Univ. of Florida, submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:224918-A)

### -48 of 69- Appendix A. Toxicity Data for Oryzalin

Table A-1. Summary of Guideline Aqua tic Organisms’ Acute Toxicity Data

Species LC 50 /EC 5

0 (mg/L) Slope 95% C.I. (mg/L) MRID Toxicity Category Study
Classification Notes

Freshwater Fish 3.45 - 3.0 – 3.9 TN 1078 Moderately
toxic Acceptable - Rainbow trout (Onchorhynchus mykiss) 3.26 - 2.9 – 3.7 00072595 Moderately
toxic Acceptable 96 hr test with cold water fish; reported NOAEC = 3.2 ppm Bluegill sunfish (Lepomis macrochirus) 2.88 9.3 2.23 – 3.7 00072595 Moderately
toxic Acceptable 96 hr study with warm water fish; reported NOAEC = 1 ppm
Marine/Estuarine Fish Sheepshead

minnow (Cyprinodon variegatus) > 3.04 - - 43887701 Moderately
toxic Acceptable 96 hr test;
NOAEC =

highest
concentration tested (3.04 ppm)

Freshwater Invertebrates
Water flea (Daphnia magna) 1.5 9.5 1.4 – 1.6 00072596 Moderately
toxic Acceptable 48-hour test; hypoactivity, prostration, and immobility were
the effects noted
at concentrations greater than 1.6 ppm; NOAEC = 0.62 ppm
Marine/Estuarine Invertebrates Grass shrimp ( Palaemonetes pugio ) >3.11 - - 43887701 Moderately
toxic to practically
non-toxic Acceptable 96 hr test; only 20% mortality at the highest dose tested (3.1 ppm);
NOAEC = 1.95

ppm Eastern oyster ( Crassostrea

virginica ) 0.285 - 0.2 – 0.5 4388 7702 Highly toxic Accep table 96 hour oyster shell deposition study; NOAEC = 0.0994 ppm

### -49 of 69- Table A-2. Summary of Guideline Aqua tic Organisms’ Chronic Toxicity Data

Species LOAEC (mg/L) NOAEC (mg/L) MRID Study
Classification Notes

Freshwater Fish
Rainbow trout (Onchorhynchus mykiss) >0. 46 >0.46 00126842 Acceptable 66 day early life-stage study; no adverse effects at any concentration tested; based on

MRID 00072595, NOAEC could range between 0.46 to 3.2

ppm Fathead minnow

(Pimephales

promelas) 0.43 0.22 00126841 Accepta ble 34 day early life-stage study; no
adverse effects at all concentrations tested; however, mean larval weights were significantly lower than solvent

control with the highest dose
tested

Freshwater Invertebrates
Water flea (Daphnia magna) 0.608 0.358 4398 6901 Acceptable Life cycle test; dry weight of first generation daphnids is the most sensitive endpoint



### Table A-3. Summary of Aquatic Plant Data

Species EC 50 Slope 95% C.I. (ppb) MRID &
Classification Notes

Aquatic non-vascular plants Green algae (Selenastrum capricornutum) 52 ppb - 17.1 – 98.7 43136901 Supplemental Endpoint affected = cell density; 5-day study duration; NOAEC = 13.8 ppb

Blue-green algae (Anabaena flos-aquae) NA - NA 43136902

Invalid NA

Freshwater diatom ( Navicula pelliculosa ) NA - NA 43136903

Invalid NA

Marine diatom ( Skeletonema costatum ) Not
Determined - NA 43136904 Supplemental Endpoint affected = cell density; 5-day study duration; NOAEC = 30.6 ppb Aquatic vascular plants
Duckweed ( Lemna gibba) 13 ppb - 9.7 – 19 43136905 Supplemental Endpoint affected = frond count; 14-day study duration; NOAEC = 3.28 ppb

### -50 of 69- Table A-4. Summary of Guideline Acute Avian Data

Species LD 50 /LC 50 (mg/kg ai) Slope 95%
C.I. MRID Toxicity Category Study
Classification Notes

Avian Acute Oral Bobwhite quail ( Colinus virginianus ) 506.7 (combined
male and female) 4.5 391 -
656 00098462 Slightly
toxic Acceptable Effects noted include lethargy, ataxia, ruffled

appearance, emaciation, and yellow

colored loose feces

within 5 hours following treatment;
dose-related decline in food consumption (3 to 7 days after treatment) and body weight loss
were also noted Avian Sub-acute Dietary Bobwhite quail ( Colinus virginianus ) >5000 - - 0007259 3 Acceptable The 10% mortality noted in the highest
dose is not treatmentrelated
Mallard duck ( Anas platyrhynchos ) >5000 - - 00072594 Practically
non-toxic

Acceptable No mortality at highest doses; food consumption is greater
in the treatments compared to controls



### Table A-5. Summary of Guideline Chroni c Avian (Reproductive Effects) Data

Species LOAEC mg/kg ai NOAEC mg/kg ai MRID Endpoints
Affected Study
Classification Notes

Bobwhite quail ( Colinus virginianus ) > 1000 1000 00129050 No effects at highest dose on any endpoints
tested Supplemental High bird mortality in
controls due to head injuries led to supplemental
classification of the study
Mallard duck ( Anas platyrhynchos ) > 1000 1000 00126843 No effects at highest dose on any endpoints
tested Supplemental The initial Core
classification of

the study was

changed to Supplemental in oryzalin RED due
to a 4-fold
increase in oryzalin use rates

since the study
was first
classified in 1982 Bobwhite quail ( Colinus virginianus ) 311 132 44162201 Female body weight Acceptable -

Mallard duck >311 311 44162202 No effects at Supplemental Reduction in

### -51 of 69- Table A-5. Summary of Guideline Chroni c Avian (Reproductive Effects) Data

Species LOAEC mg/kg ai NOAEC mg/kg ai MRID Endpoints
Affected Study
Classification Notes

( Anas platyrhynchos ) highest dose on any endpoints
tested hatchling body weight at the
lowest dose tested

was not treatment-related



### Table A-6. Summary of Mammalian Data

Species Endpoint MRID Toxicity Category Study
Classification Notes

Rat ( Rattus norvegicus ) LD 50 = 10,0000 mg/kg ai 00026592 Practically
non-toxic Acceptable No mortality at highest dose
tested

Mammalian Chronic Dietary

Rat ( Rattus norvegicus ) NOAEL =
13.82 mg/kg/day;
LOAEL =
42.9 mg/kg/day 00026779
00044332
00070569 - Acceptable Females were more sensitive than males; LOAEL values are based on decreased body weight

gain, decreased hematology parameters, increased microscopic findings in the thyroid in females and decreased survival; increased thyroid weight, increased incidence of

skin lesions; follicular cell thyroid tumors in both sexes, skin tumors in both sexes, and

mammary gland tumors in
females



### Table A-7. Summary of Terrestrial Non-Target Insect Toxicity Data

Species LC 50 μg/bee Toxicity Category MRID # Notes

Honey bee ( Apis mellifera ) > 11 Practically
non-toxic 00066220 Acute contact toxicity at 48 hours

### -52 of 69- Table A-8. Summary of Terrestrial Plant Data

Crop Type of Study Species NOAEC (lb ai/A) EC 25 (lb ai/A)

Seedling Emergence

Oats 0.0740 0.16

Corn 0.667 ND
Ryegrass 0.008 0.014 Monocots

Onion 0.222 0.12
Cabbage 0.222 0.52

Cucumber 0.667 0.78

Lettuce 0.222 0.088

Tomato <0.0056* 0.050
Soybean 6.00 >6.00 Dicots

Radish 2.00 >6.00
Vegetative Vigor

Corn 0.0740 0.080

Oats 0.222 0.22
Ryegrass 0.0253 0.097 Monocots

Onion 2.00 >6.00

Lettuce 0.0253 0.040

Tomato 0.0253 0.030
Cabbage 0.222 3.0

Cucumber 0.222 1.5

Radish 0.222 >6.00 Dicots

Soybean 2.00 3.1

ND = not determined MRID 426024-01 classified as supplemental
*NOAEC could not be determined. EC 05 was determined to be 0.0056 lb a.i./acre, but this value is outside the tested concentration range.

### -53 of 69- Appendix B. Data Call-In Tables.

The Environm ental Fate and Effects Division (EFED) has completed a Data Call-In (DCI) table for the oryzalin environmental fate and effects data gaps identified in registration review. The attached DCI table, which includes the guideline number and study title for required data, also provides a rationale for requiring the data, an explanation of how the data will be used, a nd a brief description of how the data could impact the Agency’s future decision-making.

Environmental Fate Data:

Pending completion of review of fate studies (MRID 41050001, 41378401, 41322801, 41322802, 41479801, 41479802; see Table 7.1 for details), additional data gaps may be
identified.

Guideline Number: 835.4300 Study Title: Aerobic Aquatic Metabolism Study Rationale for Requiring the Data An aerobic aquatic metabolism study has not been submitted to support the registration review of oryzalin. Per 40 CFR 158, Subpart N, this study is part of the required
environmental fate data. Practical Utility of the Data
How will the data be used? The aerobic aquatic metabolism study would facilit ate a better understanding of oryzalin’s degradation in the water column or se diment under oxygen-rich conditions in the laboratory. In order to reliably estimate aquatic expos ure, aerobic aquatic metabolism data are necessary inputs to the EXAMS model. The data will identify any transformation products that may occur. In addition, this study will also help determine if sediment toxicology studies are required for oryzalin.

How could the data change the Agency’s d ecision or impact the Agency’s future decision-making? If data indicate that oryzalin persists in aerobic aquatic environments, additional use precautions and/or restrictions may be necessar y. In addition, the lack of these data will limit the flexibility the Agency and registrant s have in coming into compliance with the Endangered Species Act and could result in use restrictions for oryzalin which are unnecessarily severe.

Guideline Number: 835.4400 Study Title: Anaerobic Aquatic Metabolism Study Rationale for Requiring the Data An anaerobic aquatic metabolism study has not been submitted to support the registration review of oryzalin. Per 40 CFR 158, Subpart N, this study is part of the required
environmental fate data.

### -54 of 69- Practical Utility of the Data
How will the data be used? The anaerobic aquatic metabolism study w ould facilitate a better understanding of oryzalin’s degradation in the water column or sediment under oxygen-poor conditions in the laboratory. In order to reliably estimate aquatic expos ure, anaerobic aquatic metabolism data are necessary inputs to the EXAMS model. The data will identify any transformation products that may occur. In addition, this study will also help determine if sediment toxicology studies are required for oryzalin.

How could the data change the Agency’s d ecision or impact the Agency’s future decision-making? If data indicate that oryzalin persists in anaerobic aquatic environments, additional use precautions and/or restrictions may be necessar y. In addition, the lack of these data will limit the flexibility the Agency and registrant s have in coming into compliance with the Endangered Species Act and could result in use restrictions for oryzalin which are unnecessarily severe.

Guideline Number: 835.6100 and 835.6200 Study Title: Environmental Chemistry Methods Rationale for Requiring the Data Independently validated analytical methods for residues in soil and in water (environmental chemistry methods) submitted by the registrant are used to evaluate analyses described in submitted environmental fate and ecological effects studies. Submitted analytical methods are also used by various Federal, State, Tribal, and local agencies to detect and monitor residues that are or are suspected to be in environmental compartments due to outdoor uses and accident al releases. The availability of these analytical methods is necessary to ensure the safety of those in proximity to releases of oryzalin residues in the environment. Independent laboratory validations for submitted analytical methods are necessary to confir m the levels of detection and quantitation reported in registrant -prepared validations.

Use of oryzalin may contaminate surface water due to spray drift and runoff of residues. There is also the potential fo r ground water contamination in sandy soils or where soil preferential flow conditions exist and exposure to sunlight is minimal. Additionally, based upon its K
oc 

### , significant fractions of the oryzalin in receiving surface waters may adsorb to suspended sediment. Given its resistance to abiotic hydrolysis coupled with only a moderate susceptibility to aerobic biodegrada tion, oryzalin will be more persistent in receiving deeper surfac e waters, resulting in potential sediment cont amination. Therefore, outside agencies may request analytical me thods with which to monitor for oryzalin
residues in water and in soil or sediment. Practical Utility of the Data

How will the data be used? In the absence of independently validate d environmental chemistry methods, submitted environmental fate and ecological effects data may not be reviewable and entities outside

### -55 of 69- the Agency may lack chemical-specific methods for analyses in environmental compartments. Independently validated environmental chemistry methods will be used to evaluate the submitted environmental fate and ecological effects data and will be made available to the public to support mo nitoring for oryzalin residues.

How could the data change the Agency’s d ecision, or impact the Agency’s future decision-making?
Risk assessment conclusions could be altered if they are not supported by either study data or environmental monitoring detections th at are based on independently validated environmental chemistry methods. Furthermor e, while not directly related to Agency decision-making, independently validated envi ronmental chemistry methods are necessary to ensure the safety of those in proximity to releases of oryzalin residues in the
environment.

Environmental Effects Data:

Guideline Number: 850.2100 Study Title: Avian Acute Oral Toxicity Test Rationale for Requiring the Data Acceptable acute avian oral toxicity data we re submitted for exposures of bobwhite quail to oryzalin; however, da ta are not available for a passerine species, which is now required under the 40 CFR Part 158 (Oct. 26, 2007) data requirements for conventional pesticides. The Part 158 data requirements specify that acute avian oral toxicity data be submitted for either mallard duck or bobwhite quail and a passe rine species. Therefore, an avian oral toxicity test is required for passerine birds, as spec ified in 40 CFR Part 158 (OCSPP Guideline 850.2100). A passerine study protocol must be submitted for review by the Agency prior to initia tion of this study. Practical Utility of the Data
How will the data be used? Acute avian oral toxicity data for passerine species will be used to refine the screeninglevel assessment by determining whether there are differences in avian species sensitivity to oryzalin between passerines and upland game species. If oral acute toxicity data are not submitted for passerines, risk will be assumed for all passerine species.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessmen ts are performed wit hout these data, the Agency would have to assume that oryzalin “may affect” listed passe rine birds directly (and listed species from other taxa indirectly), an d use of oryzalin and its formulated products may need to be restricted in areas where listed species coul d be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act an d could result in use restrictions for oryzalin use that ar e unnecessarily severe.

### -56 of 69- Guideline Number: 850.2300 Study Title: Avian Chronic Reproduction Toxicity Test Rationale for Requiring the Data Acceptable reproduction toxicity data were submitted for exposures of bobwhite quail to oryzalin; however, the submitted mallard duck study was classified as supplemental due to the pre-laying exposure period being of insufficient length. The Part 158 data requirements specify that acceptable reproductio n toxicity data be submitted for both the mallard duck and the bobwhite quail. Practical Utility of the Data
How will the data be used? Chronic avian reproduction toxicity data for the mallard duck will be used to refine the screening-level assessment by determining whet her there are differences in avian species sensitivity to oryzalin between waterfowl a nd upland game species. If acceptable data are not submitted for mallard ducks, risk will be assumed for all waterfowl species.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessmen ts are performed wit hout these data, the Agency would have to assume that oryzalin “may affect” listed wate rfowl birds directly (and listed species from other taxa indirectly), an d use of oryzalin and its formulated products may need to be restricted in areas where listed species coul d be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act an d could result in use restrictions for oryzalin use that ar e unnecessarily severe.

Guideline Number: 850.1350 Study Title: Estuarine/Marine Inv ertebrate Life Cycle Toxicity Test Rationale for Requiring the Data Chronic toxicity data for ory zalin are not available for estu arine/marine invertebrates. Since the current use patterns permit oryzalin to enter estuar ine/marine environments, these data are required under the 40 CFR Part 158 (Oct. 26, 2007). In addition, under some conditions, oryzalin may be persistent in water. Therefore, an estuarine/marine invertebrate life cycle to xicity test (OCSPP Guideline 850.1350) is required. Practical Utility of the Data
How will the data be used? Chronic toxicity data for estuarine/marine inve rtebrate species will be used to refine the screening-level assessment by determining whether there are potential risks to invertebrates inhabiting estuarine/ marine environments from the use of oryzalin. If chronic toxicity data are not submitted for estuarine/marine invertebrates, risk will be assumed for
all invertebrates in estuarine/marine envi ronments potentially exposed to oryzalin.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessmen ts are performed wit hout these data, the Agency would have to assume that oryza lin “may affect” liste d estuarine/marine invertebrate species directly (and listed speci es from other taxa indirectly), and use of oryzalin and its formulated products may need to be restricted in areas where listed species

### -57 of 69- could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for oryza lin use that are unnecessarily severe.

Guideline Number: 850.1400 Study Title: Estuarine/Marine Fish Early Life Stage Toxicity Test Rationale for Requiring the Data Chronic toxicity data for ory zalin are not available for estu arine/marine fish. Since the current use patterns permit oryzalin to enter es tuarine/marine environments, these data are required under the 40 CFR Part 158 (Oct. 26, 2007). In addition, under some conditions, oryzalin may be persistent in water. Therefor e, an estuarine/marine fish early life stage toxicity test (OCSPP Guidel ine 850.1400) is required. Practical Utility of the Data
How will the data be used? Chronic toxicity data for estuarine/marine fish species will be used to refine the screeninglevel assessment by determining whether th ere are potential risks to fish inhabiting
estuarine/marine environments from the use of oryzalin. If chronic toxicity data are not submitted for estuarine/marine fish, risk will be assumed for all fish potentially exposed to oryzalin in estuarine/marine environments.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessmen ts are performed wit hout these data, the Agency would have to assume that oryzalin “may affect” listed es tuarine/marine fish species directly (and listed species from other ta xa indirectly), and use of oryzalin and its formulated products may need to be restrict ed in areas where listed species could be exposed. The lack of these data will limit the fl exibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for oryzalin use that are unnecessarily severe.

Guideline Number: 850.1735, 850.1740, Other 1 

### Study Title: Freshwater and Estuarine/ Marine Invertebrate Acute and Chronic Whole Sediment Toxicity Tests Rationale for Requiring the Data Acute and chronic toxicity data for oryzal in are not available for freshwater and
estuarine/marine invertebrates. Since the cu rrent use patterns permit oryzalin to enter aquatic environments, these data are requi red under the 40 CFR Part 158 (Oct. 26, 2007). In addition, under some conditions, oryzalin ma y be persistent in water. Oryzalin’s chemical properties trigger the requirement for sediment toxicity studies (the Kd >50, the log Kow is >3, and a Koc is >1000). Acute st udies are required if the persistence in
sediment is ≤ 10 days, and chronic studies are require d if the persistence in sediment is expected to be >10 days. The requested aquatic metabolism study will allow EFED to determine if an acute or a chronic study is required. Practical Utility of the Data
How will the data be used? Sediment toxicity data for freshwater and es tuarine/marine invertebrate species will be

### -58 of 69- used to refine the screening-level assessmen t by determining whethe r there are potential risks to sediment-dwelling invertebrates i nhabiting freshwater and estuarine/marine environments from the use of oryzalin. If sediment toxicity data are not submitted forfreshwater and estuarine/marine invertebrates, risk will be assumed for all sedimentdwelling invertebrates in freshwater and es tuarine/marine environments potentially exposed to oryzalin.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessmen ts are performed wit hout these data, the Agency would have to assume that ory zalin “may affect” lis ted freshwater and estuarine/marine invertebrate species dire ctly (and listed species from other taxa indirectly), and use of oryzalin and its formulated products ma y need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants ha ve in coming into compliance with the Endangered Species
Act and could result in use restrictions fo r oryzalin use that are unnecessarily severe.

1 Three species required for chronic test using the fo llowing study guidance: 1) EPA 600/R-99/064 Test
Method 100.4: Hyalella azteca 42-d Test for Measuring the Effects of Sediment Associated Contaminants on Survival, Growth, and Reproduction; 2) EPA 600/R-99/064 Test Method 100.5: Life-cycle Test for Measuring the Effects of Sedime nt-associated Contaminants on Chironomus dilutus or C. tentans in USEPA 2000 Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates; 3) Leptocheirus plumulosus in USEPA 2001 Method for Assessing the Chronic Toxicity of Marine and Estuarine Sediment-associated Contaminants with the Amphipod Leptocheirus plumulosus EPA 600/R-01/020.

Protocols should be submitted for approval prior to tes ting for chronic studies. Th e preferred sediment is formulated; guidance for the formulated sediment can be found in OECD 218 Sediment-Water Chironomid Toxicity Test using Spiked Sediment. Based on test variability for the endpoints of concern and the need to establish a NOAEC/LOAEC, the following number of replicates and test animals are recommended: for the midge test with C. dilutus: 16 replicates containing 12 test organisms each (12 replicates at test initiation; 4 added at 10 days for auxiliary males); for the freshwater amphipod test with H. azteca : 12 replicates per treatment (4 for 28-d survival and growth and 8 for the remainder of the test) with 10 neonates per replicate;
and for the L. plumulosus: 10 replicates per treatment with 20 neon ates per replicate. For alternative test designs, the protocol should discuss the power of the test.



### Guideline Numbers: 850.4225 and 850.4250 Study Title: Terrestrial Plant Toxicity Tests (Tier II) Rationale for Requiring the Data Terrestrial plant toxicity studi es and associated risk analys is of plants are required for registration of pesticid es with outdoor uses (CFR Part 158) . For terrestrial plants, Tier II studies are required when potenti al concerns are triggered ( i.e ., when there is some indication that there may be si gnificant toxicity to plants). These indicators may be an
herbicidal mode of action or statements on the label indicating toxicity to plants.

The submitted studies utilize the technical grad e active ingredient (TGAI) rather than a typical end-use product (TEP). A formulated product may contain adjuvants or other inert ingredients that may increase risks to non-targ et terrestrial plants. Therefore, Tier II seedling emergence and vegetative vigor studies (OCSPP Gu idelines 850.4225 and 850.4250) that utilize a TEP are requir ed. In the absence of such data, risks to terrestrial

### -59 of 69- plants from the use of oryzalin will be assumed in the risk assessment. Practical Utility of the Data
How will the data be used? Tier II vegetative vigor and seedling emergence data for terrestrial pl ants will be used to determine the potential for oryzalin to affect non-target plant species in the terrestrial environment. In the absence of data specific fo r these plants, risk to terrestrial plants will
be assumed.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessmen ts are performed wit hout these data, the Agency would have to presume risk to non-targ et terrestrial plants from use of oryzalin. Therefore, use of oryzalin and its formulated products may need to be restricted in areas where listed species could be exposed. The lack of these data will lim it the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act
and could result in use restrictions for oryzalin that are unnecessarily severe.

Guideline Number: 850.4400 Aquatic Plant Growth Tier II Study (Vascular Aquatic Plant) Rationale for Requiring the Data Aquatic (both vascular and non-vascular specie s) toxicity studies and associated risk analysis of plants are required for registration of pesticides with outdoor uses (CFR Part 158). The data submitted for oryzalin are classified as supplemental because of problems with the study design; in additi on, the reliability of the study is in question. Therefore, an acceptable aquatic vascular plant study is required as specified in 40 CFR Part 158 (OCSPP Guideline 850.4400). Practical Utility of the Data
How will the data be used? Data from Tier II aquatic plan t toxicity studies will be used to estimate potential risks to aquatic plants associated with uses of or yzalin. The data will reduce uncertainties
associated with the current risk assessment for plants and will improve understanding of the potential risks of oryzalin on aquatic plants . Because plants form the basis of most habitats and significantly cont ribute to overall environmenta l quality, a so lid understanding of the potential risks to aquatic plants is essential for sound environmental management. The data will also be used in determining whether a “may affect” to Federally-listed threatened and endangered species is lik ely under the Endangered Species Act.

Additionally, the need for labe ling language to mitigate effect s on non-target aquatic plant species is unknown. Results of this study woul d be used to determine if surface water exposure concentrations, due to run-off, are below levels of concern at the current label rates and to identify what, if any, label langu age is needed to mitigate identified risks.

How could the data impact the Agency’s future decision-making? Without acceptable aquatic plant growth data for oryzalin, the Agency cannot determine the levels of oryzalin that result in effects to vascular aquatic plants. The lack of these data will limit the flexibility the Ag ency and registrants have in coming into compliance with the Endangered Species Act, a nd could result in use restrict ions for oryzalin which may

### -60 of 69- otherwise be avoided, or whic h are unnecessarily severe.

Guideline Number: 850.5400 Aquatic Plant Growth Tier II Study (Non-vascular Aquatic Plant) Rationale for Requiring the Data Aquatic (both vascular and non-vascular specie s) toxicity studies and associated risk analysis of plants are required for registration of pesticides with outdoor uses (CFR Part 158). The data submitted for oryzalin are classified as supplemental because of problems with the study design or invalid due to si gnificant differences between the solvent and negative controls. Therefore, acceptable aquatic non-vascular plant studies are required as specified in 40 CFR Part 158 (OCSPP Guideline 850.4400). Practical Utility of the Data
How will the data be used? Data from Tier II aquatic plan t toxicity studies will be used to estimate potential risks to aquatic plants associated with uses of or yzalin. The data will reduce uncertainties
associated with the current risk assessment for plants and will improve understanding of the potential risks of oryzalin on aquatic plants . Because plants form the basis of most habitats and significantly cont ribute to overall environmenta l quality, a so lid understanding of the potential risks to aquatic plants is essential for sound environmental management. The data will also be used in determining whether a “may affect” to Federally-listed threatened and endangered species is lik ely under the Endangered Species Act.

Additionally, the need for labe ling language to mitigate effect s on non-target aquatic plant species is unknown. Results of this study woul d be used to determine if surface water exposure concentrations, due to run-off, are below levels of concern at the current label rates and to identify what, if any, label langu age is needed to mitigate identified risks.

How could the data impact the Agency’s future decision-making? Without acceptable aquatic plant growth data for oryzalin, the Agency cannot determine the levels of oryzalin that result in effects to non-vascular aquatic plants. The lack of these data will limit the flexibility the Agency a nd registrants have in coming into compliance with the Endangered Species Act, and could re sult in use restrictions for oryzalin which may otherwise be avoided, or which are unnecessarily severe.

### -61 of 69- Appendix C. Oryzalin Formulations Cont aining Multiple Active Ingredients

The Agency does not routinely include, in its risk assessm ents, an evaluation of mixtures of active ingredients, either those mixtur es of multiple active ingredients in product formulations or those in the applicator’s ta nk. In the case of the product formulations of active ingredients (that is, a registered product containing mo re than one active ingredient), each active ingredient is subj ect to an individual risk assessment for regulatory decision regarding the active ingredient on a particular use site. If effects data are available for a formulated product contai ning more than one active ingredient, they may be used qualitatively or quantitatively 3, 4



### .
There are no product LD 50 

### values, with associated 95% Confidence Intervals (CIs) available for oryzalin. As discussed in USEPA (2000) a quantitative component-based evaluation of mixture toxicity requires data of ap propriate quality for each component of a mixture. In this mixture evaluation, an LD 50 

### with associated 95% CI is needed for the formulated product. The same quality of data is also required for each component of the
mixture. Given that the formulated products for oryzalin do not have LD 50 

### data available it is not possible to undertake a quantitat ive or qualitative analysis for potential interactive effects. However, because the active ingredients are not expected to have similar mechanisms of action, metabolites, or toxicokinetic behavior , it is reasonable to conclude that an assumption of dose-addition would be inappropriate. Consequently, an assessment based on the toxicity of oryzalin is the only reasonable approach that employs the available data to address the poten tial acute risks of the formulated products

.

3 Overview of the Ecological Risk Assessment Proces s in the Office of Pesticid e Programs, Environmental Protection Agency (January 2004) (Overview Document).

4 Memorandum to Office of Preventio n, Pesticides and Toxic Substance, US EPA conveying an evaluation by the U.S. Fish and Wildlife Service and National Mari ne Fisheries Service of an approach to assessing the ecological risks of pesticide products (January 2004).-62 of 69-Pesticide Products Formulated with Oryzalin and Other Active Ingredients5,6PRODUCTADJUSTED FOR ACTIVEINGREDIENTPRODUCT/TRADE NAMEEPA Reg.No.% OryzalinLD50(mg/kg) CI (mg/kg) LD50(mg/kg) CI (mg/kg)HELENA XL2G00590500556 1>5000NALimit DoseNALimit DoseNALimit DoseXL2G 038167000301>5000NALimit DoseNALimit DoseNALimit DoseORYZALIN 2G05388300220 1>5000NALimit DoseNALimit DoseNALimit DoseROUT ORNAMENTALHERBICIDE 05818500027 1 >5000NALimit DoseNALimit DoseNALimit DoseXL 2G07050600045 1>5000NALimit DoseNALimit DoseNALimit DoseTURF AND ORNAMENTALFERTILIZER CONTAINSBALAN 0.575% +SURFLAN 0.575% 07050600049 0.575 4444 No Data No CI Data No CI DataUP-SHOT DF HERBICIDE 07050600053 60>5000NALimit DoseNALimit DoseNALimit DoseTURF FERTILIZERCONTAINS GALLEY PLUSSURFLAN 07050600055 0.86 >5000NALimit DoseNALimit DoseNALimit DoseXL 2GR07050600056 1>5000NALimit DoseNALimit DoseNALimit DoseDOUBLE O G-PROHERBICIDE07967600020 1 >5000NALimit DoseNALimit DoseNALimit Dose5From registrant submitted data to support registration. Compiled by the Office of Pesticide Programs Registration Division.6Oryzalin LD50= >10000 mg/kg

### -63 of 69- Appendix D. Oryzalin Incidents

A search for ecological incidents related to or yzalin use, conducted on August 2, 2010, yielded six incidents. Of these, one inci dent pertained to aqua tic organism s where as five incidents were on terrestrial plants. The summary of the six incidents reported for oryzalin is provided below.

Aquatic Incidents

Approximately 450 bluegill sunfish and largemou th bass were killed between April 6 and 13, 2001 in Georgia, following the application of a formulated product of oryzalin (Surflan) on March 31. Rain fell on 4 April and it is possible that the pond was contaminated by either spray drift or runoff. The legality of use for this incident was listed as “misuse”. Residues in fish tissue were not measured. The certainty index fo r this incident (I011 444-011) is POSSIBLE.

Terrestrial Incidents

The Washington Department of Agri culture reported that 13 acres of merlot wine grapes in Grant County were damaged on April 3, 1998 due to direct application of oryzalin. The legality of use for this incident was listed as “registered us e”. The certainty index for this incident (I013884- 027) is UNLIKELY as oryzalin is a registered pe sticide in grape. The damage to grapes is possibly due to the application of norflurazon, the legality of which was listed as “misuse”.

A plant incident (7/3/1992) that resulted in damage to trees a nd shrubs (specific plants not reported) was reported from Bent on County, Washington in 1992. The incident resulted due to applicator error of mixing oryzal in with bromacil/diuron. The lega lity of this use was reported as “undetermined”. The certainty index for th is incident (I014409-062) is POSSIBLE.

A nursery in the Washington county of Oregon re ported on February 2, 2002 that six acres of tulips were damaged by exhibiting twisting of le aves. The certainty index for this incident (I013636-027) is POSSIBLE. The legality of this use was reported as “registered use”. The report mentions that isoxaben was used al ong with glyphosate, diclofop-methyl, fenhexamid, iprodione, and oryzalin and that diclofop-methyl was used previously used in the sprayer.

Dow Elanco reported an incident in 1994 th at 676,000 Douglas fir seedlings treated with Snapshot herbicide (isoxaben + oryzalin) had to be discarded as they turned chlorotic and swollen. The certainty index for this incident (I001485-001) is “ undetermined” and the legality was reported as POSSIBLE. The incident report noted that little information was provided to determine which herbicide in the mixture caused the damage.

An acre of Idaho strain fir trees experienced loss of turgidity, necrosis, stem brittleness, fissures, and death in Washington stat e in 1989/90. Pesticide applica tion history indicated use of oxyfluorfen at planting, napropamide one month after planting, oxyfluorfen five months after planting, and oryzalin eleven months after plan ting. The legality of use for this incident was
listed as “intentional misuse” as the label for Su rflan (oryzalin) clearly st ates “do not apply to Douglas fir”. The certainty index for th is incident (I001734-001) is PROBABLE.

### -64 of 69- Uncertainties Related to the Use of Incident Information from the Ecological Incident Information System

Incident data are used in risk assessments to pr ovide evidence that the risk predictions from the screening level assessment are s upported by actual effects in the field. Incident reports submitted to EPA since approximately 1994 have been tracked by assignment of incident numbers in an Incident Data System (IDS), micr ofiched, and then entered to a second database, the Ecological Incident Information System (EIIS). Additionally, there is an on-going effort to
enter information to EIIS on incide nt reports received prior to estab lishment of current databases. Incident reports are not receive d in a consistent format ( e.g ., states and various labs usually have their own formats), may involve multiple incident s involving multiple chemicals in one report, and may report on only part of a given incident investigation ( e.g ., residues).

Incidents entered into EIIS are categorized into one of several certainty levels regarding the likelihood that a particular pestic ide is associated with the inci dent: highly probable, probable, possible, unlikely, or unrelated. In brief, “h ighly probable” incidents usually require carcass
residues and/or clear circumstan ces regarding the exposure. “P robable” incidents include those
where residues were not available and/or ci rcumstances were less clear than for “highly probable.” “Possible” incidents include those where multiple chemicals may have been involved
and it is not clear what the cont ribution was of a given chemical . The “unlikely” category is used, for example, where a given chemical is pr actically nontoxic to the category of organism
killed and/or the chemical was tested for but not detected in samples. “Unrelated” incidents are those that have been confirmed to be not pesticide-related.

Incidents entered into the EIIS are also categorized as to us e/misuse. Unless specifically confirmed by a state or federal agency to be mi suse, or there was very clear misuse such as intentional baiting to kill wildlife, incide nts are not typically c onsidered misuse.

The number of documented kills in EIIS is believed to be a small fraction of total mortality caused by pesticides. Mortality incidents must be seen, reported, investigated, and have investigation reports submitted to EPA to have the potential for entry into the database. Incidents often are not seen, due to scavenger removal of carcasses, decay in the field, or simply because carcasses may be hard to see on many sites and/or few people are systematically looking. Poisoned animals may also move off-s ite to less conspicuous areas before dying. Incidents may not get reported to appropriate authorities capable of investigating the incident for a variety of reasons including the finder may not know of the importance of reporting incidents, may not know who to call, may not feel they have th e time or desire to call, or may hesitate to
call because of their own involvement in the kill. Incidents reported may not get investigated if resources are limited or may not get investigated thoroughly, with residue analyses, for example. Also, if kills are not reported and investigat ed promptly, there will be little chance of documenting the cause, since tissues and residu es may deteriorate quickly. Reports of investigated incidents often do not get submitted to EPA, since reporting by states is voluntary.

### -65 of 69- Furthermore, the database relies heavily on registrant-submitted incident reports, and registrants are currently only required to submit detailed information on ‘major’ ecological incidents, while ‘minor’ incidents are reported aggregately. Based on the 40 CFR (§159.184 Toxic or adverse effect incident reports), an ecological incident is considered ‘major’ if any of the following criteria are met:

Fish or wildlife :

(A) Involves any incident caused by a pest icide currently in Formal Review for ecological concerns.

(B) Fish: Affected 1,000 or more individua ls of a schooling species or 50 or more individuals of a non-schooling species.

(C) Birds: Affected 200 or more individuals of a flocking species, or 50 or more individuals of a songbird species, or 5 or more individuals of a predatory species.

(D) Mammals, reptiles, amphibians: Affected 50 or more individuals of a relatively common or herding species or 5 or more indi viduals of a rare or solitary species.

(E) Involves effects to, or illegal pesticide tr eatment (misuse) of a substantial tract of habitat (greater than or equal to 10 acres, terrestrial or aquatic).

Plants :

(A) The effect is alleged to have occurre d on more than 45 percent of the acreage exposed to the pesticide.

All other ecological incide nts are considered ‘minor’ and only need to be aggregately reported. ‘Minor’ incidents reported by the registrants are not included in th e EIIS database. Therefore, for example, an incident coul d affect 900 fish, 150 birds, 45 ma mmals, and 40% of an exposed crop and not be included in th e EIIS database [unless is it reported by a non-registrant ( e.g ., an incident submitted by a state agency – which are not systematically collected)]. Therefore,
because the number of documented kills in EIIS is believed to be a small fraction of total mortality caused by pesticides, absence of reports does not necessarily provide evidence of an
absence of incidents.

### -66 of 69- Appendix E. ECOSAR Analysis

UN-2 Degradate

SMILES : CCCN2c1c(N(=O)(=O))cc(S(N)(=O)=O)cc1N(=O)N2CC CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C11 H16 N5 O5 S1 MOL WT : 330.34 Log Kow: -2.33 (KowWin estimate) Melt Pt: Wat Sol: 3.257E+005 mg/L (WskowWin estimate)

ECOSAR v1.00a Class(es) Found

------------------------------ Hydrazines Amides Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ======

========== Hydrazines : Fish 96-hr LC50 125.736 Hydrazines : Daphnid 48-hr LC50 39.927 Hydrazines : Green Algae 72-hr EC50 6.19e-005 Hydrazines : Fish ChV 15.102 ! Hydrazines : Daphnid ChV 21.599 ! Hydrazines : Green Algae ChV 1.55e-005 !

Amides : Fish 96-hr LC50 1.14e+005 Amides : Daphnid 48-hr LC50 14346.239 Amides : Green Algae 96-hr EC50 11.699 Amides : Fish ChV 672.586 Amides : Daphnid ChV 189.251 ! Amides : Green Algae ChV 0.552

=========================== ================== ======== ======

========== Neutral Organic SAR : Fish 96-hr LC50 1.18e+006 * (Baseline Toxicity) : Daphnid 48-hr LC50 4.04e+005 * : Green Algae 96-hr EC50 29421.822 : Fish ChV 1.23e+005 : Daphnid ChV 17337.098 : Green Algae ChV 4826.486

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Hydrazines:

---------- For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

### -67 of 69- For Green Algae Acute Toxicity Values: If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For All Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

-----------------------------------------------------------------------------



### Parent Oryzalin

SMILES : CCCN(CCC)c1c(cc(cc1N(=O)(=O))S(N)(=O)=O)N(=O)(=O) CHEM : Oryzalin CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C12 H18 N4 O6 S1 MOL WT : 346.36 Log Kow: 2.73 (KowWin estimate) Melt Pt: Wat Sol: 2.5 mg/L (experimental database)

ECOSAR v1.00a Class(es) Found

------------------------------ Dinitrobenzenes Amides Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ======

========== Dinitrobenzenes : Fish 96-hr LC50 3.477 *

### -68 of 69- Dinitrobenzenes : Daphnid 48-hr LC50 24.885 * Dinitrobenzenes : Green Algae 96-hr EC50 0.817 Dinitrobenzenes : Fish ChV 0.040 Dinitrobenzenes : Daphnid ChV 0.294 Dinitrobenzenes : Green Algae ChV 0.103 Dinitrobenzenes : Fish (SW) 96-hr LC50 3.075 * Dinitrobenzenes : Fish (SW) ChV 0.298 !

Amides : Fish 96-hr LC50 11.902 * Amides : Daphnid 48-hr LC50 8.612 * Amides : Green Algae 96-hr EC50 0.478 Amides : Fish ChV 0.070 Amides : Daphnid ChV 0.114 ! Amides : Green Algae ChV 0.579

=========================== ================== ======== ======

========== Neutral Organic SAR : Fish 96-hr LC50 64.922 * (Baseline Toxicity) : Daphnid 48-hr LC50 40.896 * : Green Algae 96-hr EC50 23.743 * : Fish ChV 6.065 * : Daphnid ChV 4.294 * : Green Algae ChV 9.810 *

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Dinitrobenzenes:

--------------- For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For Green Algae Acute Toxicity Values: If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For All Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50)

### -69 of 69- Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

-----------------------------------------------------------------------------