### Page 1 of 33 

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460

PC Code: 073301

DP Barcode: 429 645

MEMORANDUM March 1 0

, 2016

Subject: Inorganic Chlorates (Sodium Chlorate) Problem Formulation for Registration

Review

To: Brittany Pruitt

, Chemical Review Manager Tracy Perry, Team Leader Kelly Sherman

, Branch Chief Risk Management and Implementation Branch 3

Pesticide Re

- Evaluation Division (7508P)

Sandra O’Neill, Chemical Review Manager Rose Kyprianou, Team Leader Lance Wormell, Branch Chief Regulatory Management Branch 2 Antimicrobials Division (7510P)

From: Stephen Carey, Biologist Andrew Shelby

, Physical Scientist

Environmental Risk Branch 6 Environmental Fate and Effects Division ( 7507P)

Diana Hsieh, Biologist

D avid Bay s, Biologist Siroos Mostaghimi, PhD, Senior Scientist Risk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)

Through: Mark Corbin, Branch Chief Monica Wait, RAPL

Environmental Risk Branch 6

Environmental Fate a nd Effects Division (7507P)

Laura Parsons, Associate Branch Chief Risk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)

### Page 2 of 33 

### The Environmental Fate and Effects Division (EFED) and the Antimicrobials Division (AD)

have comple ted the problem formulation (PF) for the environmental fate and ecological risk assessments to be conducted as part of the registration review of the inorganic salt sodium

chlorate (PC Code 073301 ). The inorganic chlorates registration review case consist s of multiple pesticidal active ingredients , including sodium chlorate, calcium chlorate, potassium chlorate, and magnesium chlorate. However

, sodium chlorate is the only chemical that has active pesticidal product registrations

, and thus it will be the f ocus of this registration review problem

formulation. Sodium chlorate is registered for both conventional (herbicide and plant desiccant)

uses and antimicrobial uses.

Sodium chlorate is registered for use on a wide variety of agricultural and non

- agricul tural uses

nationwide . The agricultural uses include beans, corn, cotton, flax, guar, peas, peppers, potato, rice, safflower, sorghum, soybeans, sunflower, and wheat

. According to the Screening Level Usage analysis (BEAD, 7/1/15), cotton, rice, and potato es make up the bulk of the agricultural usage with an annual average of 700,000 lbs, 500,000 lbs, and 10,000 lbs of a.i. applied respectively. The non

- agricultural uses of sodium chlorate include fallow land , ornamentals, and

uncultivated land

.

Sodium chlorate is also registered for antimicrobial uses including : pulp/paper mill water systems, recirculating and once

- through cooling water towers, drinking water treatment, textile mill water systems, sewage and wastewater systems, gas and oil fracturing fl uid systems, disinfectants and sanitizers, ballast water treatments, and impounded lakes

.

As the first stage of the risk assessment process for Registration Review, this problem formulation provides an overview of what is currently known about the environ mental fate and ecological effects associated with sodium chlorate . It also describes the preliminary ecological risk hypothesis and analysis plan for evaluating and characterizing risk to non

- target species and the environment in support of Registration Review.

Data Gaps

The ecological effects and environmental fate database is largely complete for sodium chlorate except for the following required studies under 40 CFR Part 158:

Environmental Fate

Conventional Use s :

• 

### Terrestrial Field Dissipation (Gu ideline 835.6100) has never been waived. There is uncertainty on how long sodium chlorate (formulated) may remain active in the field. Of particular concern is persistence in use sites in semi

- arid areas. Additional information and/or

actual field studies are needed. The open literature information previously submitted by the registrant i s not sufficient to decrease the uncertainty on field persistence of sodium chlorate products.

### Page 3 of 33 

### • Environmental chemistry method (ECM) in water and a corresponding Independen t Laboratory Validation (ILV) (Guideline 850.6100)

• Environmental chemistry method (ECM) in soil and a corresponding Independent Laboratory Validation (ILV) (Guideline 850.6100)

Antimicrobial Uses :

Sodium chlorate is used as a chlorine dioxide generator for its antimicrobial uses

. No additional

environmental fate data are necessary for the antimicrobial uses of sodium chlorate

.

Ecological Effects

Conventional Uses :

• Agricultural and non

- agricultural outdoor applications of s odium chlorate may cause

exposure to pollinators visiting off

- site plants that are con taminated by spray drift. A complete set of honey bee toxicity data for adults and larvae have not been submitted for

sodium chlorate

, and these data are needed to fulfill the Agency ’s recent policy on pollinator protection. A Tier I study on the toxicity of residues on foliage (OCSPP 850.3030) is not needed since results of the honey bee acute contact LD 50 

### is >25 μg a.i./bee, above the 11 μg a.i./bee trigger criterion. To be consistent with the honey bee risk assessment framework, the following six Tier I , II and III honey bee studies, yet to be submitted for sodium chlorate, are required:

o Honey bee larval acute oral toxicity study (following OECD 237, Tier I)

o H oney bee larval chronic oral toxicity study, special study, Tier I)

o Honey bee adult chronic or al (special study; Tier I)

o Semi

- field testing for pollinators (special study, Tier II).

o Field testing for pollinators (OCSPP 850.3040, Tier III)

o Field trial of residues in pollen and nectar (special study, Tier III)

For pollinator studies without finalize d OECD guidelines, protocols should be submitted for EPA review and comment prior to study initiation. The need for higher Tier semi

- field and full field pollinator studies for sodium chlorate will be determined after review of the Tier I

studies.

• Accept able avian acute oral toxicity data were not submitted for a passerine species exposed to sodium chlorate, which is now required under the 40 CFR Part 158 data requirements (Guideline 850.2100). Though the available bobwhite quail and mallard duck studies indicate sodium chlorate has low toxicity to bird species, it is uncertain whether passerines may be more or less sensitive to this chemical as a result of their higher metabolic rate and differing metabolic pathways. An avian oral toxicity study is needed for a passerine species.

• A complete set of toxicity data for aquatic plants is not available. Guidelines 850.4400,

850.4500

, and 850.4550 require one aquatic vascular plant species and four aquatic

### Page 4 of 33 

### nonvascular plant species. Only the Lemna minor (an aqu atic vascular plant) and Selenastrum capricornutum (one of the four aquatic nonvascular plants) plant species were submitted to satisfy the 850 guidelines for toxicity testing with aquatic plants. A marine diatom, a cyanobacteria , and a fr eshwater diatom have not been submitted, which are generally required for herbicide and some antimicrobial uses

. A dditional data under

Guidelines 850.4500 and 850.4550 will be needed to address the uncertainty in the aquatic

risk assessment for herbicides

. However, t hese studies will not be required for the antimicrobial uses of this chemical, because the antimicrobial sodium chlorate products are all chlorine dioxide generators . Therefore, chlorine dioxide is t he compound to which aquatic plants would po tentially be exposed from the antimicrobial uses. T h e Agency has

these studies on chlorine dioxide

, which can be used in a risk assessment.

Conventional and Antimicrobial Uses :

• Currently, acceptable chronic studies for aquatic organisms

, except the daphnid

, are not
available. EFED and AD currently ha ve data gaps for the Fish Early Life

- Stage studies with freshwater and estuarine/marine fish species (Guide line 850.1400 ) and for a Life Cycle study

with estuarine/marine invertebrates (Guideline 850.1350 ) to obtain a chronic toxicity value in

order to assess the risks of sodium chlorate to these aquatic organisms.

While the current uses trigger the 40 CFR Part 158 criteri a for requiring the se chronic aquatic

studies

, the studie s are not needed at this time based on the low chronic toxicity observed in

the available information and the anticipated environmental exposure

. A comparison of the highest estimated envi ronmental exposure ( EEC ) of 0.9 mg/L for agricultural uses (obtained from the RED) and the daphnid No Observed Adverse Effect C oncentration ( NOAEC ) of 500 mg/L (MRID 46731301) indicates a chronic toxicity value would have to be 555 times

more sensitive th an the daphnid NOAEC (the only data available to assess the potential risk to aquatic organisms from chronic exposure) in order to result in a n level of concern ( LOC ) exceedance, which is unlikely. Also, the NOAEC of 500 mg/L in the daphnid chronic study was at the highest treatment level tested with no effects observed

. , . In the absence of data, conservative assumptions may be used in the registration review risk assessment, if needed.

### Page 5 of 33 

# Problem Formulation of the Environmental Fate and Ecological Risk in Support of t he Registration Review

of Inorganic Chlorates ( Sodium Chlorate )

Sodium Chlorate CAS Registry No.: 7775

- 09

- 9

PC Code: 07 3 301

Prepared by: Environmental Fate and Effects Division:

Environmental Risk Branch VI Stephen Carey, Biologist Andrew Shelby, Phy si cal Scientist U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division

Environmental Risk Branch VI 1200 Pennsylvania Ave., NW

Mail Code 7507P Washington, DC 20460

Antimicrobials Divi sion: Risk Assessment and Science Support

Branch Diana Hsieh, Biologist

D avid Bays

, Ph

. D. Biologist Siroos Mostaghimi, Ph.D. , Senior Scientist

Reviewed by: Laura Parsons, Associate Branch Chief Reviewed by:

Monica Wait

, RAPL Mark Corbin, ERB6 Branch Chie f



### M arch 10 , 201 6 

## Office of Chemical Safety

and Pollution Prevention

### Page 6 of 33 

## Contents

1. Introduction

................................ ................................ ................................ .............................. 7

2. Use Characterization

................................ ................................ ................................ ................ 7

3. Conclusions from Previous Assessments

................................ ................................ ............... 10

3.1. Previous Ecological Risk Assessments

................................ ................................ .......... 10

3.2 Previous Drinking Water Exposure Assessment

................................ ............................ 10

3.3. Clean Water Act and Safe Drinking Water Act Programs

................................ ............. 11

4. Environmental Fate and Transport

................................ ................................ ......................... 11

4.1. Transformation Products

................................ ................................ ................................ . 13

5. Receptors

................................ ................................ ................................ ................................ 13

5.1. Effects to Aquatic Organisms

................................ ................................ ......................... 13

5.2. Effects to Terrestrial Organisms

................................ ................................ ..................... 14

5.3. Ecological Incidents

................................ ................................ ................................ ........ 15

6. Exposure Pathways of Concern

................................ ................................ ............................. 16 7. Analysis Plan

................................ ................................ ................................ ........................... 16

7.1. Stressors of Concern

................................ ................................ ................................ ....... 16

7.2. Measures of Exposure

................................ ................................ ................................ .... 16

7.3. Measures of Effect

................................ ................................ ................................ .......... 17

7.4. Endangered Species Assessments

................................ ................................ ................... 17

7.5. Endocrine Disruptor Screening Program

................................ ................................ ........ 18

8. Environmental Fate and Ecological Effects Data

................................ ................................ . 18

8.1. Environmental Fate

................................ ................................ ................................ ............ 18

8.2. Effects

................................ ................................ ................................ ................................ 20

9. References

................................ ................................ ................................ ................................ 24 Appendix 1. STIR

................................ ................................ ................................ ..................... 32 Appendix 2. SIP

................................ ................................ ................................ ........................ 33

### Page 7 of 33 

# 1. Introduction

EFED and AD evaluated the most recent ecological risk assessments for sodium chlorate in association with the updated toxicity, exposure, and usage information to determine if sufficient

data are available and if fur ther updates are needed to support registration review. EFED and AD will use application scenarios that result in upper bound exposure scenarios for the registered

uses of sodium chlorate for the risk assessment.

Sodium chlorate is a strong oxidizer and may be reduced to a variety of chemical species depending on the environmental conditions. As a consequence of its reaction as an oxidant, sodium chlorate generates reduced chloro species (i. e., chlorine in lower oxidation states than chlorate), such as c hlorite and hypochlorite

.

In addition to its registered use as a pesticide active ingredient, s odium chlorate is approved as an inert ingredient in pesticide formulations, is listed as an i m purity in some pesticide formulations

, and has non

- pesticidal u ses as a bleaching agent particularly in paper production. The registration review ecological assessment will not address the inert and non

- pesticidal uses of sodium chlorate, but they will be included in the water monitoring data obtained from the EPA

O ffice of Water.

Some trade names for conventional products containing sodium chlorate include Purate ®



### , Drexel

Defol ®



### , Weed and Grass Killer ®



### , Ureabor ®



### , Monobor

- Chlorate ®



### , Cotton Defoliant Concentrate ®



### , EKA SC BC 47

, Ercocide ®



### , Pramitol ®



### , Drew ®



### , and Purema x ®

. 

### End

- use products are formulated

as flowable concentrates, granulars, impregnated materials, pelleted/tableted, ready

- to

- use solutions, and soluble concentrates

.

Some trade names for antimicrobial products containing sodium chlorate include Purate ®



### , EKA

, Ercocide

, and PureMax

. End

- use products are formulated as aqueous solutions and soluble

concentrates.



# 2. Use Characterization

Sodium chl orate is currently registered for use on a wide range of agricultural crops, fallow or

uncultivated land, and indus trial uses. Crop and land uses range from pre

- emergence to pre

harvest in the timing of application. Table 1 details the registered uses of sodium chlorate

.

Table 1

. Sodium Chlorate Application Rates for the Various Agricultural and Non

agricultural Con ventional and Antimicrobial Uses.

Crop Maximum Single Application

Rate (lb a.i./A) Number of Applications Maximum Application

Rate (Annual or crop cycle) Re

applicati

on Interval Method of Application

AGRICULTURAL DRAINAGE

SYSTEMS NDC NS NS NS Water

trea tment.

AGRICULTURAL 6 NS NS NS Spray.

### Page 8 of 33 

### Table 1

. Sodium Chlorate Application Rates for the Various Agricultural and Non

agricultural Con ventional and Antimicrobial Uses.

Crop Maximum Single Application

Rate (lb a.i./A) Number of Applications Maximum Application

Rate (Annual or crop cycle) Re

applicati

on Interval Method of Application

FALLOW/IDLELAND /

CONSERVATION RESERVE

AGRICULTURAL

FALLOW/IDLELAND /

CONSERVATION RESERVE 6 NS NS NS Spray.
BEANS, DRIED

- TYPE 6 NS NS NS Spray.

COMMERCIAL/INDUSTRIAL

WATER COOLING SYSTEMS NDC NS NS NS Water treatm ent CORN (ALL OR UNSPECIFIED) 6 NS NS NS Spray.

COTTON (UNSPECIFIED) 6 2 NS NS Foliar

treatment.

FLAX 6 NS NS NS Spray.

DRINKING WATER

TREATMENT NDC NS NS NS Water treatment

GUAR 6 NS NS NS Spray.

INDUSTRIAL PROCESSING

WATER NDC NS NS NS Water

treat ment.

LAKES/PONDS/RESERVOIRS (WITHOUT HUMAN OR WILDLIFE USE) NDC NS NS NS Water

treatment.

NONAGRICULTURAL

UNCULTIVATED

AREAS/SOILS 0.9* NS NS NS Prepaving

treatment.

NONAGRICULTURAL

UNCULTIVATED

AREAS/SOILS 143.3 1 NS NS Broadcast

ORNAMENTALS (UNSPECI FIED) 6 NS NS NS Spray.

PASTEURIZER/WARMER/CA

NNERY COOLING WATER

SYSTEMS NDC NS NS NS Water

treatment. PEAS, SOUTHERN 6 NS NS NS Spray. PEPPER (CHILI TYPE) 7.5 NS NS NS Spray. POTATO, WHITE/IRISH (OR UNSPECIFIED) 6 NS NS NS Spray.

PULP/PAPER MILL WATE R

SYSTEMS NDC NS NS NS Preservative

treatment.

PULP/PAPER MILL WATER

SYSTEMS NDC NS NS NS Water

treatment.

RICE 6 NS NS NS Spray. SAFFLOWER (UNSPECIFIED) 6 NS NS NS Spray.

SECONDARY OIL

RECOVERY INJECTION

WATER NDC NS NS NS Water

treatment.

SEWAGE SYS TEMS NDC NS NS NS Water

treatment.

### Page 9 of 33 

### Table 1

. Sodium Chlorate Application Rates for the Various Agricultural and Non

agricultural Con ventional and Antimicrobial Uses.

Crop Maximum Single Application

Rate (lb a.i./A) Number of Applications Maximum Application

Rate (Annual or crop cycle) Re

applicati

on Interval Method of Application

SORGHUM 6 NS NS NS Spray. SOYBEANS (UNSPECIFIED) 6 NS NS NS Spray.

SUNFLOWER 6 NS NS NS Spray.

WHEAT 6 NS NS NS Spray.

NDC

– No dosage conversion

NS

– Not specified



### BEAD’s screening level usage analysis (SLUA , 7/1/ 2015 ) characterizes agricultural usage of sodium chlorate from 2004 through 2013. The SLUA does not include usage of sodium chlorate as an antimicrobial pesticide or for industrial or non

- agricultural uses. The largest use patterns in agriculture are cot ton and rice. A verage annual agricultural usage from 2004 through 2013 was more than one million pounds per year . See Table 2 for details on usage below.

Table 2

. Screening Level Estimates of Agricultural Uses of Sodium Chlorate

Annual Average Percent Crop Treated

Crop Lbs. A.I. Average Maximum

Corn 1,000 <2.5 <2.5

Cotton 700,000 <2.5 10

Peppers 1,000 <1 <2.5

Potatoes 10,000 <1 <2.5

Pumpkins + <500 <1 <2.5

Rice 500,000 5 5

Sorghum 2,000 <2.5 5

Squash + <500 <2.5 <2.5

Watermelons + <500 <1 <2.5

All numbers are rounded. <500: less than 500 pounds of active ingredients.

<2.5: less than 2.5 percent of crop is treated. <1: less than 1 percent of crop is treated. + : Removal of the cuburbit sites from the labels occurred before and during the tim eframe of the

SLUA.

SLUA data sources include:

USDA

- NASS (United States Department of Agriculture's National Agricultural Statistics Service)

Private Pesticide Market Research California DPR (Department of Pesticide Regulation)

These results reflect ama lgamated data developed by the Agency an d are releasable to the public.

### Page 10 of 33 

# 3

. Conclusions from Previous Assessments

**3 .1.**  **Previous Ecological Risk Assessments** 

The Agency has previously conducted ecological risk assessments for inorganic chlorate s that

se rve as a basis fo r this problem formulation

. These assessments are briefly summarized below. The sodium chlorate reregistration ecological risk assessment was conducted in 2006 (DP 303884, 6/1/2006)

. The major ecological conclusions pre sented in previous risk assessment s for inorganic chlorate use s were as follows:

Summary of Risk Concerns Identified for Sodium Chlorates in the Previous Assessment (RED)

Taxa with

Acute LOC

Exceedances Taxa with

Chronic LOC

Exceedances Taxa with

No LOC

Exceedances BCF Pe rsistence Degradates of

Concern

Terrestrial plants, Birds 1



### , Mammals 2



### , Aquatic vascular plants Birds, Mammals Aquatic organisms and Aquatic

nonvascular plants 3 

### No No Not an ecological

concern

1 Acute risk to birds cannot be precluded for non

- ag uses . No mortality occurred in the studies at the highest concentration tested; however, EECs on several food items for some of the non

- ag uses are significantly higher than 5620 mg/kg

- diet.

2 Acute risk to mammals cannot be precluded for non

- ag uses even though c hlorate is of low toxicity to mammals (10% mortality occurred at 5000 mg/kg

- bw). Some of the non

- ag uses could result in ingestion of chlorate at levels that are significantly higher than 5000 mg/kg

- bw for some food items.

3 LOCs for algae (aquatic nonvasc ular plants) were not exceeded; however, aquatic nonvascular plant toxicity data in several required species have not been submitted. Thus, potential risk to aquatic nonvascular plants may have been underestimated. Also, open literature data suggest that b rown algae may be considerably more sensitive than green algae.



## 3.2 **Previous D**  **rinking Water Exposure Assessment**

The most recent drinking water assessment (DWA) for sodium chlorate was for the Reregistration Eligibility Decision (RED) (D303556, January 5, 2005). An addendum to this DWA was issued on February 23, 2005 (D303568).

The modeled drinking water assessment conducted for the RED utilized FIRST for Estimated Drinking Water Concentrations ( EDWCs ) from surface water and SCI

- GROW for EDWCs from groundwater. However, the predicted chlorate concentrations were believed to be theoretical maximums because the chemical speciation of chlorate could not be considered in modeling. The highest EDWC for chlorate was 784 ppb for th e 12.5 lbs a.i./A use on potatoes and chili peppers. There are no longer registered uses on potatoes and chili peppers with application rates as high as the previously assessed rate s . H owever, broadcast use on non

- agricultural uncultivated areas has a

ma ximum application rate of 143.3 lbs a.i./A and was not considered in the estimation of RED

EDWCs. The DWA addendum explains the conservatism of EDWCs presented in the original assessment as each estimate of chlorate, chlorite, and hypochlorite assumes all sodium chlorate reduces to the given single reduced species. Due to the conservative nature of the modeled EDWCs, the revised RED drinking water assessment used finished (i.e., from the tap) drinking

### Page 11 of 33 

### water monitoring data from the EPA Office of Water to estimate chlorate concentrations in drinking

water.



## 3 **.3. Clean Water Act**  **and Safe Drinking**  **Water Act Programs** 

Chlorates are not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act. H owever, impairment is noted in one case for one transformation product of sodium chlorate, chlorine dioxide. The impairment is in the Upper San Antonio River within San Antonio, TX.

No Total Maximum Daily Load (TMDL) criteria have been developed for so dium chlorate or its transformation products

. Aquatic life benchmarks have not been developed for sodium chlorate

or its transformation products.

Chlorate is monitored under the Unregulated Contaminant Monitoring Rule (UCMR) for

consideration under the S afe Drinking Water Act. Under the rule, public water systems are sampled within the drinking water distribution system. Results for UCMR 3 (published i n October 2015) are summarized with respect to chlorate’s minimum reporting level (20 μ g/L) and

refere nce concentration (210 μ g/L). Of 55,990 water samples taken in connection with the required monitoring , 55% were above the minimum reporting level and 15% were above the reference concentration. 4,749 public water systems reported results for UCMR 3 (USE PA, 2015).



# 4

. Environmental Fate and Transport

Chlorate is fu lly ionized in water, and is expected to dissociate immediately when added to moist soil. The very low vapor pressure and very high solubility of chlorate in water suggest that

volatilization of chlorate from soil and water is an unlikely transpo rt route. In addition, the very

low octanol

- water partition coefficient indicates that it is not a lip ophilic chemical and therefore, has low potential to bioaccumulate in fish or other aquatic organisms.

As an anion, chlorate is not likely to adsorb to soil/sediment particulates. Therefore, on this basis alone, chlorate has a high leaching and run

- off potential, particularly when heavy rainfall occurs immediately after application, whe n it can be washed off of the application site. These general routes of dissipation assume that chlorate remains as "chlorate". That is, potential redox reactions

of chlorate are not taken into account.

The pesticide active species in sodium chlorate is the chlorate anion ( ClO 3 - 

### ). Sodium c hlorate is a strong oxidizer (electron acceptor)

, and its mode of action as a defoliant/desiccant is linked to its oxidizing properties. As an oxidizer (electron acceptor), the reactions of sodium chlorate in the

environment are dominated b y natural electron donor chemical species (reductants).

A selection of sodium chlorate environmental fate and transport properties are summarized in

Table 3 below.

### Page 12 of 33 

### Table 3

. Physical Chemical and Environmental Fate Properties of Sodium Chlorate

.

Param eter Value Source /Comment Selected Physical/Chemical Parameters

Chemical

Structure Sodium Chlorate RED

Empirical

Formula NaClO 3 Sodium Chlorate RED

IUAPC Name Sodium chlorate Sodium Chlorate RED

CAS No. 7775

- 09

- 9 Sodium Chlorate RED

PC Code No. 073301 Sodium Chlorate RED SMILES string: [Cl](=O)(=O)O.[Na] Sodium Chlorate RED

Molecular Weight 106.5 g/mol Sodium Chlorate RED

Physical state Crystalline Solid Sodium Chlorate RED Vapor pressure 7.3 x 10

- 1 6 (torr) Sodium Chlorat e RED Aqueous solubility 1 x 10 6 mg/L at 25 deg C Sodium Chlorate RED

Henry’s Law

Constant 1.0 x 10

- 22 atm

- m 3 /mole Sodium Chlorate RED

log Kow

- 7.08 Sodium Chlorate RED

Persistence Hydrolysis half

life (pH 5, 7, 9) Stable The chlorate anion is not e xpected to react with

water Aqueous photolysis half

life Stable The chlorate anion does not absorb energy in the wavelength range of sunlight. Therefore, it lacks the necessary condition for a chemical to undergo direct photolysis.

Aerobic soil

metaboli sm half

life (range in days) Stable Persistence in soil is highly dependent on type of soil, pH, other chemical species present in soil, soil moisture temperature, precipitation ( i e., high spatial and temporal variability). A registrant submitted open li terature study indicates effects to sawa millet (a bioassay) 8 to 22 weeks after application to soil (MRID 05016686). The reference study reflects dissipation as chlorate is a soil sterilant and

cannot be metabolized.

Anaerobic aquatic

metabolism half

li fe Stable See “Aerobic soil metabolism”

Aerobic aquatic

metabolism half

life (total system) Stable See “Aerobic soil metabolism”

### Page 13 of 33 

### Table 3

. Physical Chemical and Environmental Fate Properties of Sodium Chlorate

.

Param eter Value Source /Comment
Mobility Adsorption/ desorption Miscible in water Chlorate is an anion. Thus, it is expected to be highly mobile in soils (high leaching and runoff potential). In addition, it has a very low potential to volatilize from soils and water (very low vapor pressure and extremely high solubility in water).



## 4

.1. Transformation Products

The major transformation products of so dium chlorate are chlorite (ClO 2 - 

### ) , hypochlorite (ClO

- 

### )

, chlorous acid (HClO 2 

### ) , chlorine dioxide (ClO 2 

### ), chlorine (Cl 2 

### ), and chloride (Cl

- 

### )

. Chemical transformation from chlorate to the oxyanions and chlorine gases is dependent on redox

conditions in the environment and transformation from chlora t e to another oxyanion does not preclude transformation back to chlorate in differing redox conditions. The primary use of sodium chlorate as an antimicrobial pesticide is as a chlorine dioxide generator which is formed by mixing sodium chlorate with strong acids. Chlorate may also be oxidized to form perchlorate ; however this requires high pressure, electrical charge, heat, or high pH, and therefore the formation of perchlorate is considered unlikely under stand ard pesticidal use conditions.



# 5

. Receptors

Tables 4 and 5 provide summaries of the most sensitive endpoints for the aquatic and terrestrial taxonomic groups, respectively, and most sensitive surrogate species tested to characterize the potential acute an d chronic ecological effects of sodium chlorate

. In addition, the tables provide a preliminary overview of the potential acute toxicity of sodium chlorate by providing the acute toxicity classifications. Additional details are provided below

.



## 5 .1. Effect s to Aquatic Organisms

Table 4 . Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for

Sodium chlorate

Taxonomic

Group Study Type Surrogate Species Toxicity Value (m g a.i./L) Acute Toxicity

Classification or

Adverse Effect

Observed So urce (Study classification)

Freshwater fish 1 Acute Rainbow trout LC 50 >1,000 Practically non

toxic 41887203 (Supplemental)

Chronic N/A N/A N/A No data

Freshwater

invertebrates Acute

Water flea EC 50 = 920 Practically non

toxic 4374801 (Supplemental)

Chronic NOAEC = 500 (no effects at highest level) -- 46731301 (Acceptable)

### Page 14 of 33 

### Table 4 . Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for

Sodium chlorate

Taxonomic

Group Study Type Surrogate Species Toxicity Value (m g a.i./L) Acute Toxicity

Classification or

Adverse Effect

Observed So urce (Study classification)

Estuarine/marine

fish Acute Sheepshead

minnow LC 50 >1,000 Practically non

toxic 41887207 (Supplemental)

Chronic N/A

-- No data 2

Estuarine/marine

invertebrates Acute Mysid sh rimp EC 50 >1,000 Practically non

toxic 41887206 (Supplemental)

Chronic N/A

-- No data 2

Whole sediment;

saltwater

invertebrates Chronic Saltwater amphipod N/A

-- No data 3

Whole sediment;

freshwater

invertebrates Chronic Freshwater amphipod N/A

-- No da ta 3

Whole sediment;

freshwater

invertebrates Chronic Freshwater midge N/A

-- No data 3

Aquatic plants and algae Vascular Lemna minor EC 50 = 133

NOAEC = 62.5 -- 46687601 (Acceptable)

Non

vascular Freshwater algae ( Selenastrum capri cornutum ) EC 50 = 43

NOAEC = 3.1 -- 41887201 (Acceptable)

1 Freshwater fish are surrogates for aquatic

- phase amphibians.

2 The acute

- to

- chronic ratio (ACR) could not be employed since acceptable chronic studies were not available for

calculations. C onserv ative assumptions will be made in absence of data.

3 Not triggered per 40 CFR Part 158 based on chemical characteristics

.



## 5 .2. Effects to Terrestrial Organisms

Table 5 . Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for

Sodium chlorate

Taxonomic

Group Study Type Surrogate Species Toxicity Value Acute Toxicity

Classification or

Chronic Effects

Observed Source (Study classification)

Passerine Acute oral N/A No data N/A No data

Birds 1 Acute oral Mallard

duck LD 50 >2,510 mg a .i./kg

bw Practically non

- toxic 42149401 (Supplemental)

Subacute Dietary

Bobwhite quail LC 50 >5,620 mg a.i./kg

diet Practically non

- toxic 41819908 (Acceptable)

Chronic NOAEC = 271 mg a.i./kg

diet Affected Endpoint: At 964 mg a.i./kg

- diet,

effects wer e observed on egg production and thickness, embryonic survival, and hatchling body weight. 46729701 (Acceptable)

### Page 15 of 33 

### Table 5 . Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for

Sodium chlorate

Taxonomic

Group Study Type Surrogate Species Toxicity Value Acute Toxicity

Classification or

Chronic Effects

Observed Source (Study classification)

Mammals Acute Oral
Laboratory

rat LD 50 >5,000 mg a.i./kg

bw Practically non

- toxic 41819901 (Accep table)

Chronic NOAEL = 500 mg a.i./kg

diet Affected Endpoint:

None 46524001 (Acceptable)

Terrestrial

Invertebrates Acute

Contact

- Adults

Honey bee LD 50 >116 μg a.i./bee Practically non

- toxic 47216001 (A cceptable)

Acute Oral

- Adults LC 50 >75 μg a.i./bee

Acute Oral

- Larval No data N/A No data

Chronic

Oral

– Adults No data N/A No data

Chronic

Oral

- Larval No data N/A No data

Terrestrial plants Seedling Emergence Dic ot (Lettuce) EC 25 >15.7 lb a.i./A

NOAEC = 1.72 lb a.i./A -- 47882301 (Supplemental) Monocot (All) EC 25 >15.4 lb a.i./A

NOAEC = 15.4 lb a.i./A --

Vegetative Vigor Dicot (Soybean) EC 25 = 3.68 lb a.i./A

NOAEC = 0.557 lb a.i./A -- 47882302 (Supplemental ) Monocot (Onion) EC 25 = 7.28 lb a.i./A

NOAEC = 0.177 lb a.i./A --

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.



## 5 .3. Ecological Incidents

The ecological incident information system (EIIS) is an OPP database that house s ecological incidents that have been reported to the Agency. When available, EIIS includes date and location of an incident, type and magnitude of effects observed in various species, use(s) of pesticides known or suspected of contributing to the inciden t, and results of any chemical residue analysis or other analyses conducted during incident investigation. EIIS incidents are categorized according to the certainty that the incident resulted from pesticide exposure. The Avian Monitoring System (AIMS) is a database administered by the American Bird Conservancy that contains publicly available data on reported avian incidents involving pesticides. Many of

the incidents listed in this database are also in the EIIS.

As of December 10, 2015, no incidents for sodium chlorate ha ve been found in the databases. The absence of reported incidents should not be construed as the absence of incidents. Incident reports for non

- target organisms typically provide information only on mortality events and plant damage. Sublethal effects in organisms such as abnormal behavior, reduced growth and/or

### Page 16 of 33 

### impaired reproduction are rarely reported, except for some phytotoxic effects in terrestrial plants. EPA's changes in the registrant reporting requirements for incidents in 199 8 may also account for a reduced number of reported incidents.



# 6

. Exposure Pathways of Concern

The environmental fate and toxicity profile for sodium chlorate suggests that direct spray, spray drift, leaching and runoff represent the likely exposure pathw ays for terrestrial and aquatic non

target organisms. Surface water and inhalation exposure pathways for ecological ris k were also

screened during development of this Problem Formulation using the SIP (Screening Imbibition Program) and STIR (Screening Too l for Inhalation Risk) screening methods to determine if they are potential pathways of concern or support requesting data

. The result s of the screening are not meant to provide a definitive analysis about any potential concern. STIR indicates the exposure pathway via inhalation is of low concern for terrestrial vertebrates since volatilization of chlorate from soil and water is an unlikely transport route and chlorate is practically nontoxic to terrestrial vertebrates. SIP, on the other hand, indicates th e exposure pathway via drinking water is of a potential concern for chronic effects to terrestrial vertebrates but not a concern on an acute exposure basis. This pathway will be explored further with the development of SIP v.2.0 in a future Ecological Risk Assessment

. SIP and STIR are described in detail on EPA’s websit e 1



### , and the modeling can be found in Appendices 1 and 2

.



# 7 . Analysis Plan

7

.1. Stressors of Concern

Ecological Risk Assessment

Based on available ecological toxicity data, it appears that the stressor of ecological concern for terrestrial and aquatic organisms is parent sodium chlorate only

.



## 7

.2. Measures of Expos ure

For conventional uses, EFED will use standard available models to evaluate potential exposures to aquatic and terrestrial organisms and/or exposure routes as described at

h t t p : / / www2. epa.gov/pesticide

- science

- and0assessing

- pesticide

- risks/models

- pesticide

- risk

assessment

.

For the antimicrobial uses, the active sodium chlorate labels result in five a ntimicrobial major

use patterns : industrial processes and water systems, agricultural premises and equipment, commercial, institutional and industrial premises and equipment, antifouling coating and ballast water treatments, and aquatic areas

. Specifically

, sodium chlorate is used as a chlorine dioxide

generator in : pulp/paper mill water systems, pasteurizer/cannery/retort water systems, recirculating and once

- through cooling water towers, drinking water treatment systems, textile

1 http://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/models

- pesticide

- risk

- assessment#terrestria l

### Page 17 of 33 

### mill water systems, sewage and wastewater systems, gas and oil recovery injection water systems, gas and oil fracturing fluid systems, ultrasonic tank water, photo processing wash water, leather processing water, animal drinking water, disinfectants and sanitizers for use in

commer cial, institutional, and industrial settings, ballast water treatments, and impounded lake, pond and reservoir water (including industrial wastewater). The chlorine dioxide F inal W ork

P lan (docket number EPA

- HQ

- OPP

- 2015

- 0267

- 0005) states that EPA intend s to conduct a down

- the

- drain assessment for chlorine dioxide used in once through cooling towers and it will

be modeled for the revised risk assessment at that time. Therefore, no chlorine dioxide

assessment will be done here.

Chemicals that are released down

- the

- drain can typically take from a few to several hours to

reach wastewater treatment p lant ( WWTP ) intakes following their discharge ; and from several hours to roughly a day following their discharge down

- the

- drain to subsequently be discharged

from WWTP to surface water. Data on WWTP dissipation have not been submitted for sodium chlorate, however sodium chlorate is completely ionized in water, thus producing sodium (Na + 

### ) and the chlorate (ClO

3 - 

### ) anion. Anions do not bind readily to soil or sediment particulates and, therefore, are expected to be very mobile. If c hlorate d id not undergo any redox reactions, it

would be expected to be very mobile and to partition predominantly into the water. However, extensive redox reactions are expected to occur in the environment that will reduce the

concentration of chlorate in the water column

.

The Agenc y has created conceptual models for potential routes of environmental exposure which are included in “Conceptual Models for Environmental Exposure Pathways of Antimicrobial Pesticides,” (EPA

- HQ

- OPP

- 2014

- 0638

- 0002), found in the docket at www.regulations.gov

. C onceptual models for the uses listed above for sodium chlorate may be found at that docket.



## 7

.3. Measures of Effect

Toxicity data presented in Section 5 of this problem formulation will be used to ca lculate risk quotients. Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk assessment also will be considered. The open literature studies are identified using EPA’s ECOTOXicology database ( ECOTOX) (USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The publically available database is available at http://www2.epa.gov/chemical

research/ecotoxicology

- database

. The evaluation of both sources of data can also provide insight into the direct and indirect effects of pesticides on biotic communities from loss of species that

are s ensitive to the chemicals and from changes in structure and functional characteristics of the

affected communities.



## 7

.4

. Endangered Species Assessments

Consistent with EPA’s responsibility under the Endangered Species Act (ESA), the Agency will

evaluat e risks to federally listed threatened and endangered (listed) species from registered uses of pesticides in accordance with the Joint Interim Approaches developed to implement the recommendations of the April 2013 National Academy of Sciences (NAS) report

, Assessing

### Page 18 of 33 

### Risks to Endangered and Threatened Species from Pesticides

. The NAS report outlines recommendations on specific scientific and technical issues related to the development of pestic ide risk assessments that EPA and the Services must conduct in connection with their obligations under the ESA and FIFRA. EPA will address concerns specific to sodium chlorate in connection with the development of its final registration review decision fo r sodium chlorate

.

In November 2013, EPA, the U.S. Fish and Wildlife Service, National Marine Fisheries (the Services), and USDA released a white paper containing a summary of their joint Interim Approaches for assessing risks to listed species from pest icides. These Interim Approaches were developed jointly by the agencies in response to the NAS recommendations, and reflect a common approach to risk assessment shared by the agencies as a way of addressing scientific

differences between the EPA and the S ervices. Details of the joint Interim Approaches are contained in the November 1, 2013 white paper 2



### , Interim Approaches for National

- Level Pesticide Endangered Species Act Assessments Based on the Reco mmendations of the National Academy of Sciences April 2013 Report.

Given that the agencies are continuing to develop and work toward implementation of the Interim Approaches to assess the potential risks of pesticides to listed species and their designat ed critical habitat, this ecological problem formulation supporting the Preliminary Work

Plan for sodium chlorate does not describe the specific ESA analysis, including effects determinations for specific listed species or designated critical habitat, to b e conducted during registration review. While the agencies continue to develop a common method for ESA analysis, the planned risk assessment for the registration review of sodium chlorate will describe the level of ESA analysis completed for this particul ar registration review case. This assessment will allow EPA to focus its future evaluations on the types of species where the potential for effects exists, once the scientific methods being developed by the agencies have been fully vetted. Once the agencie s have fully developed and implemented the scientific methods necessary to complete risk assessments for listed species and their designated critical habitats, these methods will be applied to subsequent analyses of sodium chlorate as part of completing th is registration review

.



## 7

.5

. Endocrine Disruptor Screening Program

Sodium chlorate was not included in the first group of chemicals issued an order to conduct Tier 1 EDSP testing. For additional information the EDSP program, visit http://www2.epa.gov/endocrine

- disruption/endocrine

- disruptor

- screening

- program

- edsp

overview

.



# 8

. Environmental Fate and Ecological Effects Data

8 .1. Environmental Fate

2 http://www2.epa.gov/endangered

- species/interim

- approaches

- pesticide

- endangered

- species

- act

- assessments

- based

nas

- report

### Page 19 of 33 

### Table 6 identifies environmental fate studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assess ment.

Table 6. Submitted Environmental Fate Studies and Data Needs for Sodium Chlorate

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to

conduct risk

assessment? Justification and Assumptions

EPA will Make

in Absence of

Data

835.2120 Hydrolysis 47116303 Waived No

835.2240 Aqueous photolysis 47116303 Waived No

835.2410 Soil photolysis 47116303 Waived No

850.3300 Activated Sludge Respiration Inhibition Test (ASRI) No data N/A No No exposure to

sodium chlorate expected for AD

uses , therefore data

are not needed. 835.3110

835.3220

835.3240

835.3280 Biodegradability or Simulation Test No data N/A No

835.4100 Aerobic soil

metabolism 47623303 Waived No

835.4300 Aerobic aquatic

metabolism 47623303 Waived No

835.4400 Anaerobic aquatic

metabolism 47623303 Waived No

835.1230

835.1240 Adsorption/ desorption and leaching 47623303 Waived No

835.6100 Terrestrial field dissipation 140486

5016686 Not Accept able Yes (conventional uses) EPA needs

terrestrial field dissipation data

because our usual

models are not

sufficient for estimating exposure to inorganic compounds reliant on redox chemistry for dissipation.

850.1730 Fish bioconcentration 47623303 Waived No

Environmental

Chemistry

Method: Water

& its ILV

850.6100 Analytical method in

water - - Yes (conventional uses)

### Page 20 of 33 

### Table 6. Submitted Environmental Fate Studies and Data Needs for Sodium Chlorate

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to

conduct risk

assessment? Justification and Assumptions

EPA will Make

in Absence of

Data

Environmental

Chemistry

Method: Soil &

its ILV

850.6100 Analytical method in

soil - - Yes (conventional uses)



## 8 .2. Effects

Tables 7 an d 8 identify ecological effects studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment. Only technical grade active ingredient (TGAI) sodium chlorate data needs are discussed; studies with sodium chlorate formulated products and/or sodium chlorate transformation products are not being requested at this time. Rationales for the additional data requested are presented below.

Table 7 . Sub mitted Aquatic Ecological Effects Studies and Data Needs for Sodium

C hlorate

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are data needed for

assessment? Justification

and Assumptions

EPA will

Make in

Absence of

Data

8 50.1010 Freshwater

invertebrate acute toxicity 41887204 Supplemental No

--

850.1025

850.1035 Estuarine/Marine

invertebrate acute toxicity 41887205

41887206 Supplemental Supplemental No

--

850.1075 Freshwater fish acute toxicity 41887202

41887203 Supple mental Supplemental No

--

850.1075 Estuarine/Marine

fish acute toxicity 41887207 Supplemental No

--

850.1300 Freshwater

invertebrate life cycle 46731301 Acceptable No

--

850.1350 Estuarine/Marine

invertebrates life cycle No data N/A No Triggered per 40 CFR Part

158 based on

### Page 21 of 33 

### Table 7 . Sub mitted Aquatic Ecological Effects Studies and Data Needs for Sodium

C hlorate

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are data needed for

assessment? Justification

and Assumptions

EPA will

Make in

Absence of

Data

850.1400 Estuarine/Marine

f ish early

- life

stage No data N/A No use pattern but

not needed

based on low chronic toxicity

observed in the

available

information and the anticipated

environmental

exposure. However, it is a data gap. 850.1400 Freshwater fish early

- life stage No data N/A No

850.1500 Fish life cycle (None) (N/A) No Not triggered per 40 CFR Part

158 based on

results of acute

studies

850.1735 Whole sediment;

acute
invertebrate:

f reshwater (None) (N/A) No Not triggered per 40 CFR Part

158 based on

chemical

characteristics 850.1740 Whole sediment;

acute
invertebrate:

marine (None) (N/A) No

850.4400 Aquatic plant growth: Vascular plants 46687601 Acceptable No

--

850.4500 Aquatic Plant Growth: Algal 41887201 Acceptable Yes (conventional uses ) 1 Studies with

the freshwater

and marine

diatoms and Cyanobacteria

are necessary

### Page 22 of 33 

### Table 7 . Sub mitted Aquatic Ecological Effects Studies and Data Needs for Sodium

C hlorate

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are data needed for

assessment? Justification

and Assumptions

EPA will

Make in

Absence of

Data

850.4550 Aquatic Plant

Growth: Cyanobacteria No data N/A Yes (conventional uses ) 1 to satisfy

standard data requirement

for herbicides

. Without data,

risk would be presumed for aquatic non

vascular plants, including listed species.

1. These data are needed for conventional but not fo r antimicrobial uses since the antimicrobial uses are chlorine dioxide generators. The Agency has data for chlorine dioxide.



### Table 8 . Submitted Terrestrial Ecological Effects Studies and Data Needs for

Sodium C hlorate *

OCSPP

Guideline Data Requireme nt Submitted

Studies (MRID) Study

Classifications Are data

needed for

assessment? Current Additional

Data Need

850.2100 Avian oral toxicity 42149401 Supplemental Yes (conventional uses) A passerine bird study is needed to satisfy standard data requiremen t for

outdoor uses. Without data, risk would be presumed for passerines, including

listed small

- sized bird species.

850.2200 Avian dietary toxicity 41819907

41819908 Acceptable Acceptable No

--

850.2300 Avian reproduction 46729701

48097301 Acceptable

Acc eptable No

--

Non

guideline Avian

inhalation (None) (N/A) No The STIR model indicates exposure through inhalation is

not a concern for birds.

### Page 23 of 33 

### Table 8 . Submitted Terrestrial Ecological Effects Studies and Data Needs for

Sodium C hlorate *

OCSPP

Guideline Data Requireme nt Submitted

Studies (MRID) Study

Classifications Are data

needed for

assessment? Current Additional

Data Need

850.3020 Adult honey

bee acute

contact toxicity 47216001 Acceptable No

--

SS Adult honey

bee acute oral

toxic ity 47216001 Acceptable No

--

850.3030 Honey bee

residue on

foliage No data No data No No data is available; however, EFED is not asking for the toxicity of residue on foliage

since the bee contact

LD 50 was >25 μg a.i./bee, which is above the 11 μg a.i./b ee criterion that triggers the study. AD will not require toxicity of

residue data because

sodium chlorate is not expected to be applied

to wood used to construct honey bee

enclosures.

850.3040 Field testing for pollinators No data No data Yes (convention al uses)

Pollinator Tier I, II

and III studies with the honeybees are necessary to satisfy

standard data requirement. Without data, risk would be presumed for pollinators, including listed species. SS Larval honey

bee chronic oral toxicity No data No data Yes (conventional uses)

SS Adult honey

bee chronic oral toxicity No data No data Yes (conventional uses)

SS Larval honey

bee acute oral toxicity No data No data Yes (conventional uses)

SS Field testing of

residues in pollen and

nectar No data No d ata Yes (conventional uses)

SS Semi

- field testing for pollinators No data No data Yes (conventional uses)

### Page 24 of 33 

### Table 8 . Submitted Terrestrial Ecological Effects Studies and Data Needs for

Sodium C hlorate *

OCSPP

Guideline Data Requireme nt Submitted

Studies (MRID) Study

Classifications Are data

needed for

assessment? Current Additional

Data Need

850.4100 Tier I or II seedling

emergence 47882301 Supplemental No

--

850.4150 Tier I or II vegetative

vigor 47882302 Supplemental No

* No terre strial assessment is considered necessary for the antimicrobial use patterns.



# 9 . References

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

USEPA. 1998. Guidelines for Ecological Risk Assessment. Risk Assessment Forum, Offic e of Research and Development, Washington, D.C. EPA/630/R

- 95/002F. April 1998.

USEPA 2006. Environmental Fate and Effects Division RED for the Reregistration of Inorganic Organics . Dated July 2006.

U.S. EPA, Office of Pesticide Programs, Antimicrobial Division, Risk Assessment and Science Support Branch. August 4, 2014

. Conceptual Models for Environmental Exposure Pathways of Antimicrobial Pesticides. EPA

- HQ

- OPP

- 2014

- 0638. htt p://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPP

- 2014

- 0638

- 0002

USEPA 2015. The Third Unregulated Contaminant Monitoring Rule (UCMR 3): Data Summary.

Office of Water. October 2015. EPA 815

- S

- 15

- 003

### Page 25 of 33 

# Environmental Fate Bibliography

161

- 1 Hydrolysis

MRID Citation Reference

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 161

- 2 Photodegradation

- water

MRID Citation Reference

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 161

- 3 Photodegradation

- soi l

MRID Citation Reference

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 162

- 3 Anaerobic aquatic metab.

MRID Citation Reference

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 164

- 1 Terrestrial field dissipati on

MRID Citation Reference

136388 Interregional Research Project No. 4 (1979) Results of Tests Concerning the Amount of Sodium Chlorate Residue Remaining in or on Guar Including a Description of the Analytical Method Used. (Compilation; unpublishe d study received Jun 15, 1979 under 9E2220; CDL:098331

- A)

140486 Interregional Research Project No. 4 (1976) The Results of Tests on the Amount of Sodium Chlorate Residue Remaining on or in Rice and Rice Straw Including a Description of the Analytical M ethod Used. (Compilation; unpublished study received Apr 6, 1976 under 6E1996; CDL:097358

- A)

### Page 26 of 33 5016686 Konnai, M.; Takeuchi, Y.; Takematsu, T. (1974) Ringyoyo josozai no dojochu niokeru zanryu oyobi ido nikansuru kisoteki kenkyu_ ?Basic studies on the

res idues and movements of forestry herbicides in soil_| Utsunomiya Daigaku Nogakubu Gakujutsu Hokoku. ?Bulletin of the College of Agriculture, Utsunomiya University.| 9(1):95

- 112.



## 164

- 2 Aquatic field dissipation

MRID Citation Reference

476233 03 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 165

- 4 Bioaccumulation in fish

MRID Citation Reference

47623303 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.1230 Sediment and soil absorption/desorption for parent and degradates

MRI D Citation Reference

47324203 Rice, C. (2008) Ecological Effects and Environmental Fate: Waiver Requests: Purate BWT. Unpublished study prepared by Ecochlor, Inc. 29 p.

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmenta l Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.1240 Soil column leaching

MRID Citation Reference

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental F ate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.2120 Hydrolysis of parent and degradates as a function of pH
at 25 C

MRID Citation Reference

### Page 27 of 33 47116303 Rice, C. (2007) Application fo r Pesticide Registration Amendment Purate: Ecological Effects and Environmental Fate Waiver Requests. Unpublished study prepared by Keller and Heckman LLP and Eka Chemicals Inc. 19 p.

47324203 Rice, C. (2008) Ecological Effects and Environmental Fate: Wa iver Requests: Purate BWT. Unpublished study prepared by Ecochlor, Inc. 29 p.

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and

Heckman LLP. 29 p.



## 835.2240 Direct photolysis rate of parent and degradates in water

MRID Citation Reference

47116303 Rice, C. (2007) Application for Pesticide Registration Amendment Purate: Ecological Effects and Environmental Fate Waiver Requests. Un published study prepared by Keller and Heckman LLP and Eka Chemicals Inc. 19 p.

47324203 Rice, C. (2008) Ecological Effects and Environmental Fate: Waiver Requests: Purate BWT. Unpublished study prepared by Ecochlor, Inc. 29 p.

47623303 4023 Rice, C. (2 008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.2410 Photodegradation of parent and degradates in soil

MRID Citation Reference

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.4100 Aerobic soil metabolism

MRID Citation Reference

47116303 4023 Rice, C. (2007) Application for Pesticide Registration Amendment Purate: Ecological Effects and Environmental Fate Waiver Requests. Unpublished study prepared by Keller and Heckman LLP and Eka Chemicals Inc. 19 p.

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.4300 Aerobic aquatic metabolism

MRID Citation Reference

### Page 28 of 33 47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.4400 Anaerobic aquatic metabolism

MRID Citation Reference

47623303 4035 R ice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## 835.6200 Aquatic field dissipation

MRID Citation Reference

47623303 4023 Rice, C. (2008) Purate BWT: Ecological Effects and Environmental Fate Waiver Requests. Project Number: 4023. Unpublished study prepared by Keller and Heckman LLP. 29 p.



## Eco logical Effects Bibliography (Acceptable or Supplemental studies only)

850.1010 Daphnid acute toxicity test

MRID Citation Reference

41887204 Ward, T.; Boeri, R. (1991) Acute Flow

- through Toxicity of Sodium Chlorate to the Daphnid, Daphnia magna: Lab Project Number: 90144

- AW. Unpublished study prepared by Resource Analy sts, Inc. 23 p.



## 850.1025 Oyster acute toxicity test (shell deposition)

MRID Citation Reference

41887205 Ward, T.; Boeri, R. (1991) Acute Fl ow

- through Mollusc Shell Deposi tion Test of Sodium Chlorate: Lab Project Number: 90116

- DE. Unpub lished study prepared by Resource Analysts, Inc. 23 p.



## 850.1035 Mysid acute toxicity test

MRID Citation Reference

### Page 29 of 33 41887206 Ward, T.; Boeri, R. (1991) Acute Flow

- through Toxicity of Sodium Chlorate to the Mysid, Mysidopsis bahia: Lab Proje ct Number: 90117

- DE. Unpublished study prepared by Resource Analysts, Inc. 23 p.



## 850.1075 Fish acute toxicity test, freshwater and marine

MRID Citation Reference

41887202 Ward, T.; Boeri, R. (1991) Acute Flow

- through Toxicity of Sodium Ch lorate to the Bluegill Sunfish, Lepomis macrochirus: Lab Proj ect Number: 90142

- AW. Unpublished study prepared by Resource Analysts, Inc. 23 p.

41887203 Ward, T.; Boeri, R. (1991) Acute Flow

- through Toxicity of Sodium Chlorate to the Rainbow Trout, Oncor hynchus mykiss: Lab Project Number: 90143

- AW. Unpublished study prepared by Resource Analysts, Inc. 23 p.

41887207 Ward, T.; Boeri, R. (1991) Acute Flow

- through Toxicity of Sodium Chlorate to the Sheepshead Minnow, Cyprinodon variegatus: Lab Project Num ber: 90115

- DE. Unpublished study prepared by Resource Analysts, Inc. 23 p.



## 850.1300 Daphnid chronic toxicity test

MRID Citation Reference

46731301 Thomas, P (200 4 ) Chronic toxicity of Sodium Chlorate to Daphnia magna Under
Semi

- Static Con ditions in a 21 Day Reproduction Test. Lab Project No. ICS

- 103 Final Research Report; CER F03043 T 02006 ODC. Unpublished study prepared by Akzo Nobel Chemicals Research Environmental Chemistry Department, Arnhem, the Netherlands

.



## 850.2100 Avian a cute oral toxicity test

MRID Citation Reference

42149401 Fink, R. (1990) Acute Oral LD50

- Mallard Duck: [Sodium Chlorate]: Final Report: Project Nos. 176

- 101; WI

- 704. Unpublished study prepared by Wildlife International. 18 p.

43412301 Harrison, E. (1980) Addendum to MRID #42149401: Acute Oral LD50

- Mallard Duck: (Sodium Chlorate). Unpublished study prepared by Kerr

- McGee Chemical Co. 5 p.



## 850.2200 Avian dietary toxicity test

MRID Citation Reference

41819907 Long, R.; Beavers, J. ; Smith, G. (1991) Sodium Chlorate: A Dietary LC50 Study with the Northern Bobwhite: Lab Project Number: 311

- 101. Unpublished study prepared by Wildlife International Ltd. 19 p.

### Page 30 of 33 41819908 Long, R.; Beavers, J.; Smith, G. (1991) Sodium Chlorate: A Dietary LC50 Study with the Mallard: Lab Project Number: 311

- 102. Un

- published study prepared by Wildlife International Ltd. 19 p.



## 850.2300 Avian reproduction test

MRID Citation Reference

48097301 Davidson, M. (2010) Sodium Chlorate: Avian Repr oduction Study with the Mallard (Anas platyrhynchos): Final Report. Project Number: 09001. Unpublished study prepared by Genesis Laboratories, Inc. 229 p.

46729701 Arch, A. (2004) Sodium Chlorate: Assessment to Determine the Effects on Reproduction in th e Bobwhite Quail (Colinus virginianus): Final Report. Project Number: K3AK1008. Unpublished study prepared by Central Science Laboratory. 171 p.



## 850.3020 Honey bee acute contact toxicity

MRID Citation Reference

47216001 Wilkins, P. (2003) Acute Contact and Oral Toxicity of Sodium Chlorate to Honey Bees (Apis mellifera L.). Project Number: K3AK1001. Unpublished study prepared by Central Science Laboratory. 40 p.



## 850.4100 Seedling emergence, Tier II

MRID Citation Reference

4788 2301 Porch, J.; Krueger, H.; Kendall, T. (2009) Sodium Chlorate: A Toxicity Test to Determine the Effects of the Test Substance on Seedling Emergence of Ten Species of Plants: Final Report. Project Number: 680/101. Unpublished study prepared by Wildlife I nternational, Ltd. 97 p.



## 850.4150 Vegetative vigor, Tier II

MRID Citation Reference

47882302 Porch, J.; Krueger, H.; Kendall, T. (2009) Sodium Chlorate: A Toxicity Test to Determine the Effects of the Test Substance on Vegetative Vigor of Ten Species of Plants: Final Report. Project Number: 680/102. Unpublished study prepared by Wildlife International, Ltd. 136 p.



## 850.4400 Aquatic plant toxicity test using Lemna spp. Tiers I and II

MRID Citation Reference

### Page 31 of 33 46687601 Scheerbau m, D . (200 3 ) Sodium Chlorate Aquatic Plant Toxicity Test, Lemna

minor , Static, 7 days

. Lab Project No. 030724AT/TLA93762. Unpublished study prepared by Dr. U. Noack Laboratorien, Sarstedt, Deutschland

.



## 850.4500 Algal toxicity, Tiers 1 and II

MRID Citation Reference

41887201 Ward, T.; Boeri, R. (1991) Static Acute Toxicity of Sodium Chlorate to the Freshwater Alga, Selenastrum capricornutum: Lab Project Number: 90161

- AW. Unpublished study prepared by Resource Analysts, Inc. 23 p.

### Page 32 of 33 

# Appendi **x 1**

**. STIR** 

Input

Application and Chemical Information

Enter Chemical Name Inorganic
Chlorates

Enter Chemical Use All Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) air

Enter Chemical Molecular We ight (g/mole) 106.5 Enter Chemical Vapor Pressure (mmHg) 7.30E

- 16 Enter Application Rate (lb a.i./acre) 12.5

Toxicity Properties

**Bird**

Enter Lowest Bird Oral LD 50 (mg/kg bw) >2510 Enter Mineau Scaling Factor 1.15

Enter Tested Bird Weight (kg) 1.58

**Mammal**

Enter Lowest Rat Oral LD 50 (mg/kg bw) >5000

Enter Lowest Rat Inhalation LC 50 (mg/L) >3.9 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



# Output

Results Avian (0.020 kg )

Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.18E

- 12

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 5.26E

- 13

Adjusted Inhalation LD 50 > 7.87E+00

Ratio of Vapor Dose to Adjusted Inhalation LD 50 < 6.68E

- 14 Exposure not Likely Significan t

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 1.20E+00 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 < 1.53E

- 01 Exposure not Likely Significant



### Results Mammalian (0.015 kg )

Maximum Vapor Concentration in Air at Sat uration (mg/m 3 ) 4.18E

- 12

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 6.61E

- 13

Adjusted Inhalation LD 50 > 2.32E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 < 2.85E

- 15 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 1.51E+00 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 < 6.50E

- 03 Exposure not Likely Significant

### Page 33 of 33 

# A **ppendix 2**  **. SIP**

Table 1. Inputs

Parameter Value

Chemical name Sodium Chlorate
Solubility (in water at 25 o C; mg/L) 1.00E+06

Mammalian LD 50 (mg/kg

- bw) >5000 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 25 Mammalian test species laboratory rat Body weight (g) of "other" mam malian species

Avian LD 50 (mg/kg

- bw) >2510
Avian test species mallard duck Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) 300 Bobwhite quail NOAEC (mg/kg

- diet) 271

NOAEC (mg/kg

- diet) for other bird species Body weight (g) of other avian species NOAEC (mg/kg

- diet) for 2nd other bird species Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic
Upper b ound exposure (mg/kg

- bw) 172000.0000 172000.0000 Adjusted toxicity value (mg/kg

- bw) >3845.8028 19.2290 Ratio of exposure to toxicity <44.7241 8944.8163

Conclusion* D rinking water alone is

NOT a potential concern
for mammals Exposure through drinking

wat er alone is a potential

concern for mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 810000.0000 810000.0000 Adjusted toxicity value (mg/kg

- bw) >2884.2971 14.8838 Ratio of exposure to acute toxicity <0. 0042 54421.6999

Conclusion* D rinking water alone is

NOT a potential concern
for mammals Exposure through drinking water alone is a potential
concern for birds

*Conclusion is for Surface water exposure alone. This does not combine all routes of ex posure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through Surface water may contribute to a total exposure that has potential for effects to non

- target animals.