2 Table of Contents

I. INTRODUCTION

................................ ................................ ................................ .................. 3
A. Summary of Propoxycarbazone

- sodium Registration Review

................................ ........ 4
B. Public Comments

................................ ................................ ................................ ............. 5

II. USE AND USAGE

................................ ................................ ................................ ................. 6
III. SCIENTIFIC ASSESSMENTS

................................ ................................ ........................... 7
A. Human Health Risk Assessment

................................ ................................ ...................... 7
1. Risk Conclusions

................................ ................................ ................................ .......... 7
2. Human Incidents

................................ ................................ ................................ ........... 7
3. Tolerances

................................ ................................ ................................ ..................... 7
B. Ecological Risk Assessment

................................ ................................ ............................. 8
1. Risk Conclusions

................................ ................................ ................................ .......... 8
2. Ecological Incidents

................................ ................................ ................................ ... 10
3. Characterization of Ecological Risk

................................ ................................ ........... 10
C. Benefits Assessment

................................ ................................ ................................ ....... 11
D. Endangered Species Assessment

................................ ................................ .................... 12
E. Endocrine Disruptor Screening Program

................................ ................................ ....... 13
IV. PROPOSED INTERIM REGISTRATION REVIEW DECISION

................................ ... 14
A. Risk Mitigation and Regulatory Rationale

................................ ................................ ..... 14
1. Spray Drift Reduction

................................ ................................ ................................ . 14
2. Herbicide Resistance Ma nagement

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

B. Tolerance Amendments

................................ ................................ ................................ .. 17
C. Proposed Interim Registration Review Decision

................................ ........................... 17
D. Data Requirements

................................ ................................ ................................ ......... 17
V. NEXT STEPS AND TIMELINE

................................ ................................ .......................... 18
A. Interim Registration Review Decision

................................ ................................ ........... 18
B. Implementation of Mitigation Measures

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

Appendix A: Summary of Proposed Actions Take n for Propoxycarbazone

- sodium1..............18 Appendix B: Propoxycarbazone

- sodium Label Tabl....................................................183 

### I. INTRODUCTION

This document is the Environmental Protection Agency’s (EPA or the Agency) Proposed Interim Registra tion Review Decision for propoxycarbazone

- sodium (case 7264, PC code 122019) and is being issued pursuant to 40 CFR Sections 155.56 and 155.58. A registration review decision is the Agency's determination whether a pesticide meets, or does not meet, the st andard for registration under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The Agency may issue, when it determines it to be appropriate, an Interim Registration Review Decision before completing a registration review. Among other thing s, the Interim Registration Review Decision may: 1) require new risk mitigation measures; 2) impose interim risk mitigation measures; 3) identify additional data or other information required to complete the review; and 4) include schedules for submitting the required data, conducting the new risk assessment, and completing the registration review. For further information on propoxycarbazone

- sodium, additional documents can be found in EPA’s public docket (EPA

- HQ

- OPP

- 2015

- 0095) at www.regulations.gov

.
FIFRA, as amended by the Food Quality Protection Act (FQPA) of 1996, mandated the continuous review of existing pesticides. All pesticides distributed or sold in the United States generally must be registered by the EPA based on scientific data showing that they will not cause unreasonable risks to human health or to the environment when used as directed on product labeling. The registration review program is intended to make sure that, as the ability to assess and r educe risk evolves and as policies and practices change, all registered pesticides continue to meet the statutory standard of no unreasonable adverse effects. Changes in science, public policy, and pesticide use practices will occur over time. Through the registration review program, the Agency periodically re

- evaluates pesticides to make sure that as these changes occur, products in the marketplace can continue to be used safely. Information on this program is provided at http://www.epa.gov/pesticide

- reevaluation/registration

- review

- process

.
In 2006, the Agency implemented the registration review program pursuant to FIFRA section 3(g) and will review each registered pes ticide every 15 years to determine whether it continues to meet the FIFRA standard for registration.

EPA is issuing a proposed interim registration review decision for propoxycarbazone

- sodium so that it can (1) move forward with aspects of the registrati on review that are complete and (2) implement interim risk mitigation. The Agency is currently working with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service to develop methodologies for conducting national endangered species as sessments for pesticides. Therefore, although EPA has not yet fully evaluated risks to threatened and endangered species, the Agency will complete its endangered species assessment and any necessary consultation with the Services for propoxycarbazone

- sodi um prior to completing the propoxycarbazone

- sodium registration review. Likewise, the Agency will complete endocrine screening for propoxycarbazone

- sodium, pursuant to the Federal Food, Drug, and Cosmetic Act (FFDCA) section 408(p), before completing this registration review. Lastly, EPA will determine whether additional pollinator exposure and effects data are necessary to make a final registration review decision for propoxycarbazone

- sodium and , if so, issue a data call

- in (DCI) to obtain any such data prior to completing the propoxycarbazone

- sodium registration review.4 Propoxycarbazone

- sodium is a selective, predominately post

- emergence herbicide belonging to the sulfonamide class of herbicides. It is formulated as a water dispersible granule, and is currently registered for use in control of certain grasses and broadleaf weeds in wheat, triticale, pastureland, rangeland, and the United States Department of Agriculture (USDA) Conservation Reserve Program lands. There are no registered residential uses. Application equipment and methods for propoxycarbazone

- sodium include ground application, aerial application, backpack, manually pressurized hand wand, and mechanically

- pressurized handgun. Because propoxycarbazone

- sodium was first registered in 2004, i t was not subject to reregistration.

A. Summary of Propoxycarbazone

- sodium Registration Review

Pursuant to 40 CFR S ection 155.50, EPA formally initiated registration review for propoxycarbazone

- sodium (case 7264 ) in March 2015. The following timeline hig hlights significant events that have occurred during the registration review of propoxycarbazone

sodium . Documentation of these events can be found in EPA ’ s propoxycarbazone public docket, EPA

- HQ

- OPP

- 2015

- 0095, accessed at www.regulations.gov :

• March 27

, 2015

– The EPA published for a 60

- day public comment period the Propoxycarbazone

- sodium: Combined Preliminary Work Plan and Summary of Draft Human Health and Environmental Risk Assessments ; Propoxycarbazone

- sodium Human Health Assessment Scoping Document and Preliminary Human Health Risk Assessment ; and the Preliminary Environmental Fate and Ecological Risk Assessment for the Registration Review of Propoxycarbazone

- sodium

.

• May 2015

– The Agency received two public comments on the Propoxycarbazone

sodium Combined Preliminary Work P lan and Summary of Risk Assessments and the Human Health and Ecological Risk Assessments

. These comments and the Agency’s responses are summarized in Section B. and in the Response to Comme nts on the Preliminary Environmental Fate and Ecol ogical Risk Assessment for the R egistration Review of Propoxycarbazone

- sodium document. The comments received by the Agency did not cause any substantive changes to the risk assessments or registration revi ew timeline.

• March 2016

– EPA is now publishing the Propoxycarbazone

- sodium Proposed Interim Registration Review Decision in the propoxycarbazone

- sodium registration review docket for a 60

- day public comment period. In addition to this document, the Agenc y is publishing the following supporting documents:

o Response to Comments on the Preliminary Environmental Fate and Ecol ogical Risk Assessment for the R egistration Review of Propoxycarbazone

- sodium

, August 17, 2015

o Propoxycarbazone : Usage on Wheat and Propo sed Herbicide Resistance Management Measures (PC #122019 ) , March 10, 20165 B. Public C omments

EPA received two public comments during the 60

- day comment period on the propoxycarbazone

- sodium Combined Preliminary Work Plan and Summary of Draft Human Health and Environmental Risk Assessments, which opened on March 27, 2015 and closed on May 26, 2015

. Comments were submitted by Bayer CropScience (Bayer), the technical registrant for propoxycarbazone

- sodium, and by t he Center for Biologic Diversity (CBD), an environmental public interest group. Comments from Bayer focused on various technical aspects of the Combined Work Plan, Preliminary Human Health and Preliminary Ecological and Environmental Fate Risk Assessments

. Comments from CBD focused on the EPA ’ s duty to consult with the U.S. Fish and Wildlife Services and the National Marine Fisheries Service on the registration review of propoxycarbazone

- sodium in accordance with the Endangered Species Act. The comments d id not affect the risk assessment conclusions. This Proposed Interim Decision document does not capture every comment submitted by Bayer nor all of the responses. C omments that are of a broader regulatory nature are summarized below

. Comments that are of technical nature on the Preliminary Ecological and Environmental Fate Risk Assessment and the Agency’s responses are addressed in the Response to Comments on the Preliminary Environmental Fate and Ecological Risk Assessment for the Registration Review of Propoxycarbazone

- sodium , August 17, 2015

. Public comments and the EPA Response to C omments document are located in the Registration Review Docket for propoxycarbazone

sodium (EPA

- HQ

- OPP

- 2015

- 0095)

C OMMENTS R ECEIVED FROM B AYER C ROP S CIENCE (EPA

- HQ

- OPP

- 2015

- 0095

- 0012)

Comment : Bayer commented that the schedule for propoxycarbazone

- sodium registration review is atypical and requested an opportunity to comment once the DCI data ha ve been submitted to the Agency.

EPA Response : The Agency acknowledges that the schedule for propoxycarbazone

- sodium registration review is atypical. The Agency determined that additional data were not required to complete the Preliminary Human Health and Ecological Risk Assessments and consequently proceeded to the risk assessme nt phase of Registration Review, expediting the process. The Agency notes that there will be no DCI issued for propoxycarbazone

- sodium at this time , but there is an opportunity for the public to comment on this Proposed Interim Registration Review Decision

.

Comment : Bayer provided clarification on propoxycarbazone

- sodium usage and use patterns listed in the Propoxycarbazone

- sodium (122019) EFED and HED Label Data Reports

.
EPA Response : The EPA thanks Bayer for clarification of the propoxycarbazone

- sodium usage and use patterns and has consider ed this information in this Registration Review Proposed Interim Decision.6 C OMMENTS R ECEIVED FROM THE C ENTER FOR B IOLOGIC D IVERSITY (EPA

- HQ

- OPP

- 2015

- 0095

- 0011)

Comment : The CBD comments focus on the EPA’s duty to c onsult with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (the Services) on the registration review of propoxycarbazone

- sodium in accordance with the Endangered Species Act (ESA). The CBD comments mention various aspects of the risk assessment process, including use of the best available data to develop threatened and endangered (listed) species risk assessments, and evaluation of effects on listed species and their designated critical habitat. CBD also expresses
concern reg arding the rigor of the Agency’s preliminary determinations regarding the effects of propoxycarbazone

- sodium on listed species and their designated critical habitat for the propoxycarbazone

- sodium registration review.

EPA Response : EPA has reviewed the comments from CBD and plans to address many of the concerns raised by CBD as part of the implementation plan for assessing the risks of pesticides to listed species based on the recommendations of the April 2013 National Academy of Sc iences (NAS) report. EPA will address concerns specific to propoxycarbazone

- sodium in connection with the development of its final registration review decision for this pesticide.

For further information on the registration review of propoxycarbazone

- sodium, including the Agency’s Response to Comment document, see the propoxycarbazone

- sodium public docket (EPA

- HQ

- OPP

- 2015

- 0095) at www.regul ations.gov

. 

### II. USE AND USAGE

Propoxycarbazone

- sodium is an herbicide registered for use to control certain post

- emergent grasses and broadleaf weeds including cheat grass, downy brome, jointed goatgrass, pigweed, and wild oat or mustard

. Propoxycarbazone

- sodium is registered for the following agricultural

uses: rangeland, pastures, Conservation Reserve Program lands, wheat , and triticale

. There are no residential use sites registered for propoxycarbazone

- sodium. Much of the propoxycarbazone

- sodium use is in the Northeastern United States. Propoxycarbazone

- sodium is formulated as a water dispersible granule and is applied via ground, aerial, and/or handheld equipment. The predominant use of propoxycarbazone sodium is on winter wheat with an average of 30,0 00 pounds a.i. applied to winter wheat on an annual basis between 2005 and 2012

.
For additional information on propoxycarbazone use and usage, see the October 22, 2014 BEAD Chemical Profile (BCP) for Registration Review: Propoxycarbazone

- sodium (122019) and the March 10 , 2016 Propoxycarbazone : Usage on Wheat and Proposed Herbicide Resistance Management Measures (PC #122019) in the propoxycarbazone

- sodium registration review docket (EPA

- HQ

- OPP

- 2015

- 0095).7 

### III. SCIENTIFIC ASSESSMENTS

A. Human Health Risk Assessment

A summary of the Agency’s human health risk assessment is presented below. The Agency used the most updated EPA science policies and risk assessment methodologies to prepare a quantitative risk assessment in support of propoxycarbazone

- sodium r egistration r eview. For more information, see Propoxycarbazone

- sodium. Human Health Assessment Scoping Document and Preliminary Human Health Risk Assessment in Support of Registration Review , February 25, 2015

, in the registration review docket (EPA

- HQ

- O PP

- 2015

- 0095) at www.regulations.gov.

1. Risk Conclusions

EPA has found no dietary risks of concern for propoxycarbazone

- sodium from exposure to residues in either food or drinking water. The Agency did not conduct a residential risk assessment because t here are no registered residential uses for propoxycarbazone

- sodium. Therefore, the aggregate exposure assessment is equivalent to the dietary assessment and not of

concern. EPA has not made a common mechanism of toxicity finding for propoxycarbazone

sod ium and any other substance for this assessment.

EPA has found no risks of concern for occupational handler or occupational post

- application exposure scenarios

. Since no dermal hazard was identified in the toxicological database, only inhalation exposure s were quantitatively assessed. In addition, EPA evaluated off

- target exposure of adults and children to spray drift and no risk estimates of concern were identified.

2. Human Incidents

On January 21, 2015, EPA completed a review of propoxycarbazone

- sodium incidents in the OPP Incident Data System (IDS) and Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health (CDC/NIOSH) Sentinel Event Notificat ion System for Occupational Risk

- Pesticides (SENSOR) databases

. Two incident cases were reported. One incident case was report ed as minor in the ID S (between the years 2009 and 2014) , and one case was identified in t he SENSOR/ NIOSH data base (between the years 1998

- 2010) , which involved multiple active ingredients. Based on the low frequency and low severity of incident cases reported, there does not appear to be a concern at this time that would warrant further investigation.

3. Tolerances

In order to be consistent with current Agency SOPs, the p ropoxycarbazone

- sodium tolerances on meat products will be updated to include the recommended number of significant figures as indicated below . In addition, the tolerance expression will be updated as recommended in Section 2.2.3 of the Propoxycarbazone

- sodium. Human Health Assessment Scoping Document and Preliminary Human Health Risk Assessment in Support of Registration Review

. No Codex8 maximum residue limits (MRLs) have been established fo r propoxycarbazone

- sodium except for wheat grain

. The Canadian MRL for residues of propoxycarbazone

- sodium and its metabolite in/on wheat grain (0.2 ppm) is equivalent to the U.S. tolerance expression level. Therefore, harmonization is not an issue at th is time.

Commodity Established Tolerance (ppm) Recommended Tolerance (ppm) Cattle, meat byproducts 0.3 0.30 Goat, meat byproducts 0.3 0.30 Horse, meat byproducts 0.3 0.30 Sheep, meat byproducts 0.3 0.30

B. Ecological Risk Assessment

A summary of the Agency’s ecological risk assessment is presented below. EPA used the most updated Agency science policies and risk assessment methodologies to prepare a quantitative ecological risk assessment in support of the registration review of prop oxycarbazone

- sodium. For a detailed discussion of the ecological risk assessment for propoxycarbazone

- sodium, see the Preliminary Environmental Fate and Ecological Risk Assessment for the Registration Review of Propoxycarbazone

- sodium

, dated March 3, 2015 in the propoxycarbazone

- sodium registration review docket EPA

- HQ

- OPP

- 2015

- 0095, which can be accessed at www.regulations.gov

.
EPA is currently working with its federal partners and other stakeholders to implemen t an interim approach for assessing potential risk to listed species and their designated critical habitats. Once the scientific methods necessary to complete risk assessments for listed species and their designated critical habitats are finalized, the Agency will complete its endangered species assessment for propoxycarbazone

- sodium. As such, the risk conclusio ns described below pertain to non

- listed species.

1. Risk Conclusions

The preliminary risk assessment showed that propoxycarbazone

- sodium is practically non

- toxic to all animal taxa including birds, mammals, terrestrial invertebrates, fish, and aquatic in ve rtebrates on an acute exposure basis. Consistent with the herbicidal mode of action, terrestrial plants are sensitive to propoxycarbazone

- sodium exposure. Propoxycarbazone

- sodium is very highly toxic to the vascular aquatic plant duckweed.

Aquatic Asse ssment

Fish, Amphibians, and Aquatic I nvertebrates

- Propoxycarbazone

- sodium was not found to be toxic to any fish or aquatic invertebrate species studied at tested concentrations. R isk quotients (RQs) did not exceed the Agency’s Level of Concern (LOC) for listed and

non

- listed species. Freshwater fish are assumed to be representative of aquatic

- phase amphibians in this assessment.9 Aquatic Plants

- Propoxycarbazone

- sodium is toxic to vascular and non

- vascular aquatic plants; however

, RQs (highest RQ = 0.74) do not exceed the LOC of 1 for listed or non

listed vascular or non

- vascular plants for any registered uses.

Terrestrial Assessment

Terrestrial Plants

- Consistent wit h its herbicidal mode of action propoxycarbazone

sodium is toxic to terrestrial plant species. The RQs for listed and non

- listed terrestrial plants exceed the LOC of 1 for almost all modeled scenarios with an RQ range of 0.8 1 to 5.8 for non

- listed species and 1.9

- 849 for listed species

. Non

- target terrestrial plants species in areas adjacent to treated fields could be impacted by exposure to propoxycarbazone

- sodium.

Birds and Mammals

- Propoxycarbazone

- sodium is practically non

- toxic to birds. Birds are assumed to be representative o f terrestrial

- phase amphibians and reptiles in this
assessment. Propoxycarbazone

- sodium was found to be non

- toxic to mammals. Acute RQ values were not calculated for birds or mammals due to non

- definitive toxicity endpoints, but even if the non

- definitiv e endpoint was conservatively equated to an LD 50 , the RQs would be below the Agency’s LOC of 0.1 for listed birds and mammals. Additionally, inhalation and spray drift are not exposure routes of concern for birds or mammals.

Terrestrial Invertebrates

- Honeybee a cute adult contact toxicity and acute adult oral toxicity data for propoxycarbazone

- sodium suggest that propoxycarbazone

- sodium is practically non

- toxic to honeybees on an acute exposure basis

. RQs were not calculated due to non

- definitive endpo ints, but even if EECs for honeybees were compared to the highest concentrations tested in the submitted honeybee acute contact an d oral studies, the RQs would not exceed the LOC of 0.4 for bees.

However, there is uncertainty regarding potential acute a nd chronic effects of propoxycarbazone

- sodium on honey bee larval development and survival. T herefore,

a dditional data on pollinators are required to understand the risk associated with propoxycarbazone

- sodium use to the developmental stages of honeybees because sensitivity may vary according to life

- stage and length (adult vs. larval and acute vs. chronic, respectively)

. EPA intends to issue a DCI to obtain these data. In the near future, EPA will provide further information and guidance on this effort. The pollinator studies that are anticipated to be required are listed in Table 1 below.10 Table 1. Potential Pollinator Data Requirements

Test Guideline (GLN) Number Study Type

850.3040** Field testing for pollinators Non

– GLN * (OECD 237) Honey bee larvae acute oral toxicity

Non

- GLN* Honey bee adult chronic oral toxicity Non

- GLN* Honey bee larvae chronic oral toxicity Non

- GLN ** Semi

- field testing for pollinators (tunnel or colony feeding studies) Non

- GLN** R esidues in pollen and nectar /field residue analysis

* Tier 1 (laboratory

- based studies)

** Tier 2 and 3 (Semi

- field and full field colony

- level studies). The need for a higher tier test for pollinators will be determined based upon lower

- tiered tests and/or other lines of data and the need for a refined pollinator risk assessment.

2. Ecological Incidents

A review of all available information in the following incident databases was completed in November 2014 : Ecologica l Incident Information System (E II S), Avian Monitoring Information System (AIMS), and OPP Aggregate Incident Data System (IDS)

. Based on a search of EIIS, the Agency has received 30 reports of adverse field effects to non

- target plants linked to
propoxyca rbazone

- sodium. A query of AIMS resulted in no records of incidents a ssociated with propoxycarbazone

- sodium. Based on a search of IDS, between 2005 and 2013, EPA received reports of 36 incidents involving propoxycarbazone

- sodium, all of which were associ ated with plant damage. For additional discussion of th e reported ecological incidents see Preliminary Environmental Fate and Ecological Risk Assessment for the Registration Review of Propoxycarbazone

- sodium

, March 3, 2015

.

3. Characterization of Ecologica l Risk

The preliminary risk assessment for propoxycarbazone

- sodium identified some RQs that exceeded EPA’s LOC for non

- target plant species

. The Agency uses the LOC as an indicator of potential adverse effects to non

- target organisms. LOC exceedances are only one line of evidence used by EPA to describe the risks posed by a pesticide to non

- target organisms. This risk characterization section describes other lines of evidence for propoxycarbazone

- sodium, puts the LOC exceedances into a broader context , and provides additional perspective on the exceedances

.

Terrestrial Plants

The preliminary risk assessment for propoxycarbazone

- sodium identified potential risk s of concerns for non

- target terrestrial plants (monocots and dicots) for almost all modele d exposure scenarios ( non

- listed terrestrial plant RQs range from 0.8 1

– 5.8 following exposure at labeled maximum application rates )

. Toxicity to terrestrial plant species is consistent with the herbicidal11 mode of action

. The Agency’s principal c oncern is off

- target spray drift resulting from aerial applications. T he droplet size distribution (DSD) was modeled for both fine to medium and medium to coarse DSD categories for aerial spray applications. Potential effects distances are significantly reduced using medium to coarse droplet size. Accordingly, the propoxycarbazone

sodium technical registrant ha s agreed to require the use of spray nozzles that limit product droplet size to coarse during applications. To further address concern of spray drift impact to

non

- target plants, the propoxycarbazone

- sodium registrant has also agreed to various label changes designed to reduce off

- target spray drift and extent of exposure to non

- target pla nt exposure.

Listed Species

Although the Agency is not making a complete endangered species finding at this time and the risk conclusions described in this document pertain to non

- listed species; the proposed label changes to address concern for and re duce sp ray drift impact to non

- target ( non

- listed ) terrestrial plants are also expected to reduce the extent of exposure and may reduce risk to the following listed taxa whose range and/or critical habitat co

- occur with the use of propoxycarbazone

sodium : terrestrial and semi

- aquatic plants ; terrestrial invertebrates ; birds; terrestrial and aquatic

phase amphibians ; reptiles ; mammals ; freshwater and marine/estuarine fish and invertebrates

.
EPA has not yet fully evaluated risks to listed species at this time. The Agency will complete its endangered species assessment and any necessary consultation with the Services for propoxycarbazone

- sodium prior to completing the propoxycarbazone

- sodium registration review.

C. Benefits Assessment

Prop oxycarbazone

- sodium inhibits acetolactate synthase (ALS), and is classified by the Weed Science Society of America (WSSA) as a Group 2 herbicide. It is a selective herbicide and is absorbed by leaves and roots and then translocated. Propoxycarbazone

- sodi um is characterized by a low rate of use and its efficacy is not affected by low air temperatures. In evaluating potential risk mitigation for propoxycarbazone

- sodium , EPA considered the risks, the benefits, and the use pattern of this compound. EPA believes that there is potential risk to non

- target plants from the use of propoxycarbazone

- sodium . However, these potential risks are outweighed by the ben efits associated with use of this compound. The major agricultural use of propoxycarbazone

- sodium is in wheat. It is applied post

- emergence to the weeds through ground or aerial application equipment. Data from 2010

- 2014 indicate that i t was applied on a verage to more than one million acres annually, approximately 2% of all wheat acres in the United States, with a higher percentage in certain regions such as Washington , which suggests that it is an important tool for controlling weeds regionally

. Propoxycarbazone

- sodium is one of the commonly used cheatgrass herbicides in winter wheat.

Alternatives to propoxycarbazone

- sodium in winter wheat include other ALS herbicides as well as synthetic auxins (WSSA Group 4). Alternatives for spring wheat are other ALS herbicides, as well as synthetic auxin, and inhibitors of acetyl CoA carboxylase ( ACCase ) (WSSA Group 1),12 and photosystem II inhibitors (WSSA Group 6). Most of these alternatives have been used mainly post

- emer gence, like propoxycarb azone

- sodium.

D. Endangered Species Assessment

In November 2013, the EPA, along with the Services and the USDA, released a summary of their joint Interim Approaches for assessing risks to endangered and threatened (listed) species fro m pesticides. The Interim Approaches were developed jointly by the agencies in response to the National Academy of Sciences’ (NAS) recommendations and reflect a common approach to risk assessment shared by the agencies as a way of addressing scientific dif ferences between the EPA and the Services. The NAS report 1 outlines recommendations on specific scientific and technical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obliga tions under the ESA and FIFRA.

The joint Interim Approaches were released prior to a stakeholder workshop held on November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 Pesticide Program Dialogue Committee (P PDC) and State

- FIFRA Issues Research and Evaluation Group (SFIREG) meetings. The agencies also held stakeholder workshops

— in April and October 2014, and in April 2015

— allowing additional opportunities for stakeholders to comment on the Interim Approach es. Additional workshops are planned to enhance stakeholder involvement. As part of a phased, iterative process for developing the Interim Approaches, the agencies will also consider public comments on the Interim Approaches in connection with the development of upcoming Registration Review decisions. The details of the joint Interim Approaches are contained in the white paper Interim Approaches for National

- Level Pesticide Endangered Species Act (ESA) Assessments Based on the Recommendations of the National A cademy of Sciences April 2013 Report 2 , dated November 1, 2013.

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 designated c ritical habitat, the ecological risk assessment supporting this Proposed Interim Decision for propoxycarbazone

- sodium does not contain a complete ESA analysis that includes effects determinations for specific listed species or designated critical habitat. Although EPA has not yet completed effects determinations for specific species or habitats, for this preliminary assessment EPA’s evaluation assumed, for all taxa of non

- target wildlife and plants, that listed species and designated critical habitats may be present in the vicinity of the application of propoxycarbazone

- sodium. 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 agen cies have been fully vetted. Once the agencies have fully developed and implemented the scientific methodology for evaluating risks for listed species and their designated critical habitats, these methods will be applied to subsequent analyses for
propoxy carbazone

- sodium as part of completing this registration review.

1 Assessin g Risks to Endangered and Threatened Species from Pesticides. Available at http://www.nap.edu/catalog.php?record_id=18344

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

- species/assessing

- pesticides

- under

- endangered

- species

- act#report13 E. Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these s tudies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and

c hronic studies that assess growth, developmental and reproductive effects in different taxonomic groups. As part of its most recent registration decision for propoxycarbazone

- sodium, EPA reviewed these data and selected the most sensitive endpoints for re levant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), propoxycarbazone

- sodium is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed t he EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrat or may designate.” The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the T ier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine

- related effects caused by the substance, and establish a dose

- response relationship between the dose and the E, A, or T effect.

Under FFDC A section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list of chemicals identified for EDSP screening was published on June 14, 2013 3 and includes some pesticides scheduled for Registration Review and chemicals found in water. Propoxycarbazone

sodium was not among the group of 58 pesticide active ingr edients on the initial list nor is it on the second list of chemicals to be screened under the EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data call

- ins for registration review chemicals, including propoxycarbazone

- sodium. For further information on the status of the EDSP, the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website.

3 See http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of chemicals.14 In this proposed interim decision, EPA is maki ng no human health or environmental safety findings associated with the EDSP screening of propoxycarbazone

- sodium. Before completing this Registration Review, the Agency will make an EDSP FFDCA section 408(p) determination.



### IV. PROPOSED INTERIM REGISTRATION REVIEW DECISION

A. Risk Mitigation and Regulatory Rationale

As discussed in the Ecological Risk Assessment Section of this document, propoxycarbazone

sodium poses a potential risk concern for non

- target terrestrial plants exposed to off

- target spray drift from aerial applications. I n evaluating potential risk mitig ation for propoxycarbazone

sodium, EPA considered the risks, the benefits, and the use pattern of this compound. EPA believes that there is potential risk to non

- target plants from the use of propoxycarbazone

sodium. However, these potential risks are outweighed by the benefits associated with use of this compound. To address the risks to non

- target plants, EPA is proposing the following risk mitigation measures.

1. Spray Drift Reduction

Current propoxycarbazone

- sodium labels are inconsistent with respect to droplet size (a major factor influencing spray drift). Additionally, some labels designate boom height and wind speed while others do not. To address spray drift concerns , the propoxycarbazone

- sodium technical registrant has agreed to undertake label language changes to achieve uniform spray drift parameters across all labels, including droplet size. EPA’s intention is to establish a baseline level of protect ion against spray drift that is consistent across all propoxycarbazone

- sodium products registered for use in agricultural settings.

These label changes are expected to reduce the extent of environmental exposure and risk to non

target plants and animals. Although the Agency is not making a complete listed s pecies safety finding at this time

, these label changes are also expected to reduce the extent of exposure and may reduce risk to listed species whose range and/or critical habitat co

- occur with the us e of propoxycarbazone

- sodium

.
The Agency is proposing the following label restrictions for propoxycarbazone

- sodium :

• Select nozzles and pressure that deliver coarser spray droplets as indicated in nozzle manufacturer’s catalogs and in accordance with ASA BE Standard S

- 572.

• Applicators may spray only when wind speed is between 3 and 10 mph

.

• For aerial applications, the release height must be no higher than 10 feet from the top of the crop canopy, unless a greater application height is required for pilot safety.

• For aerial applications, the distance of the outer most nozzles on the boom must not exceed three

- fourths of the length of the wingspan or rotor diameter. To further reduce drift, use one

- half of the length of the wingspan or rotor diamete r at the edge of a field.

• Applicators may not spray during temperature inversions

.15 • For ground applications, boom height must be no higher than 4 feet above the crop
canopy.

The Agency is encouraging the development of pesticide drift reduction technologie s (or DRTs;

see http://www.epa.gov/reducing

- pesticide

- drift/about

- drift

- reduction

- technology

- program ) that will help realize user, societal, and environmen tal benefits including:

• R educing the loss of pesticide from the application site ;

• Improving pest control;

• S lowing the advancement of herbicide

- resistant weed populations;

• R educing pesticide exposures to people, wildlife, and the environment ; and

• Reducing risks of damage and liabilities from off

- target deposition of drift.

Furthermore, EPA believes that the use of proven DRTs will provide users with a wider range of options for addressing drift concerns. Such DRTs could include specialized nozzles, spray shields, and drift

- reducing adjuvant chemicals. The Agency encourages users and producers of propoxycarbazone

- sodium to consider, test, and use these types of innovations as part of the risk management plan for pro po xycarbazone

- sodium. DRTs are expected to be useful in mitigating the risks drift poses to non

- target species, and particularly in addressing risks to listed species.

2. Herbicide Resistance Management

The development and spread of herbicide resistant weeds in agriculture is a widespread proble m that has the potential to fundamentally change production practices in US agriculture. While herbicide resistan t weeds have been known since the 1950s, the number of species and their geographical extent, has been increasing rapidly. Current ly there are 249 weed species worldwide with confirmed herbicide resistance, especially since the turn of the century. In the United States there are 155 weed species with confirmed resistance to one or more herbicides.

Management of herbicide resistant weeds, both in mitigating established herbicide resistant weeds and in slowing or preventing the development of new herbicide resistant weeds

, is a complex problem without a simple solution. Coordinated efforts of growers, agricultural extension, academi c researcher, scientific societies, pesticide registrants, and state and federal agencies are required to address this problem.

The EPA, Office of Pesticide Programs (OPP) is proposing measures for the pesticide registrants to provide growers and users wi th detailed information and recommendations to slow the development and spread of herbicide resistant weeds. This is part of a more holistic, proactive approach recommended by crop consultants, commodity organizations, professional/scientific societies, r esearchers, and the registrants themselves. OPP’s approach is measured, based on the inherent risk of weed resistance developing for a given herbicide, considering the target weeds and the agronomic practices of the registered crops. Situations with the least concern for the development of herbicide resistant weeds will have the fewest resistance management elements and the situations with the highest concern will have additional resistance management elements.16 Implementation Timeline and Opportunities for Public Comment on Herbicide Resistance Approach OPP is proposing to implement herbicide resistance measures for existing chemicals during registration review, and to implement herbicide resistance measures for new chemicals and new uses at the time of registration. In registration review, proposed herbicide resistance elements will be included in every herbicide proposed interim decision. Comments on these chemical specific measures are welcomed. The Agency will also soon issue a Pesticide Registrat ion Notice (PRN) that will provide additional guidance to registrants. All stakeholders are encouraged to comment.

Public comments received on both the propoxycarbazone

- sodium PID and the PRN will be considered prior to the final decision on this propoxy carbazone

- sodium registration review

.
Propoxycarbazone

- sodium Specific Herbicide Resistance Measures

Propoxycarbazone

- sodium acts to inhibit acetolactate synthase (ALS), a key enzyme in the biosynthesis of the branched

- chain amino acids in plants. This herbicide is c lassified by the Weed Science Society of America as belonging to mechanism of action Group 2. This mechanism of action ( MOA ) has a number of confirmed resistant weeds with over 150 confirmed cases of weed resistance worldwide and 48 cases of resistant weed species in the U.S. Of the 48 confirmed ALS resistant weeds in the US, approximately 15 have been identified and reported in wheat. Several target weeds in wheat have confirmed resistance to propoxycarbazone

- sodium

.

T he Group 2 h erbicides are of the highest concern for weed resistance development because th e mechanism of action already has a large number of confirmed herbicide resistant weed species in the U.S., is used on large acreage crop, wheat, with many reported resistant weeds, and Group 2 has seven commercialized herbicide resistant crops. Proposed herbicide resistance management elements for propoxycarbazone

- sodium include:

On the label 1. List Mechanism of Action (MOA) WSSA Group 2

. 2. List seasonal and annual maximum number of application s and rates for all crops. 3. List best management practices for Herbicide Resistance (as appropriate to crop)

. 4. State that user should scout before and a fter application. 5. List the definition of likely resistance on label

. 6. State that user should report lack of performance to registrant or their representative. 7. List confirmed resistant weeds in a separate table and list effective or recommended rates for th ese weeds with the table. 8. For products containing multiple MOA, identify the weeds controlled by each herbicide.

Reporting, Education, and Stewardship17 9. Registrant should report new cases of likely and confirmed resistance to EPA and users yearly. This will be in addition to any adverse effects reporting. 10. For sites/crops of high concern registrant should provide growers with:

• Resistance Management Plan

• Remedial Action Plan

• Educational materials on herbicide resistance management.

B. Tolerance Amendments

EPA has determined that there are no expected adverse human health effects from use of propoxycarbazone

- sodium. H owever, the Agency will pursue the following changes t o the propoxycarbazone

- sodium tolerances listed in 40 CFR S ection 180.650:

• The tolerances for cattle (meat byproducts), goat (meat byproducts), horse (meat byproducts), and sheep (meat byproducts ) will be changed from 0.3 ppm to 0.30 ppm to reflect the correct number of significant figures, in accordance with current policy.

• Update t he tolerance expression in accordance with current policy as recommended in Section 2.2.3 of the Propoxycarbazone

- sodium. Human Health Assessment Scoping Document and Preliminary Human Health Risk Assessment in Support of Registration Review

.

C. Proposed Interim Registration Review Decision

In accordance with 40 CFR Sections 155.56 and 155.58, the Agency is issuing this Proposed Interim Registration Review Decision. Except for the EDSP

, ESA and pollinator components of this case, the Agency has made the following Proposed Interim Registration Review Decision: (1) no additional data are required at this time; and (2) changes to the affected registrations or their labeling are needed at this time.

In this proposed interim registration review decision, EP A is making no human health or environmental safety findings associated with the EDSP screening of propoxycarbazone

- sodium, nor is it making a complete endangered species finding or a complete assessment of effects to pollinators

. Although the Agency is n ot making a complete endangered species finding at this time, the proposed mitigation described in this document is expected to reduce the extent of environmental exposure and may reduce risk to listed species whose range and/or critical habitat

co

- occur w ith the use of propoxycarbazone

- sodium. The Agency’s final registration review decision for propoxycarbazone

- sodium will be dependent upon the result of the Agency’s ESA assessment and any necessary consultation with the Services, an EDSP FFDCA section 40 8(p) determination, and an assessment of non

- target exposure to pollinators ( bees )

.

D. Data Requirements

No additional data are required as part of this proposed interim registration review decision. EPA will request the propoxycarbazone

- sodium registrant to submit pollinator data as a separate action.18 

### V. NEXT STEPS AND TIMELINE

A. Interim Registration Review Decision

In accordance with 40 CFR Sections 155.56 and 155.58, the Agency is issuing this Proposed Interim Registration Review Decision, and posting it i n the propoxycarbazone

- sodium registration review docket (EPA

- HQ

- OPP

- 2015

- 0095) for a 60

- day comment period. If there are no significant comments or additional information submitted to the docket during the comment period that leads the Agency to change i ts proposed decision, EPA will issue an Interim Registration Review Decision for propoxycarbazone

- sodium.

B. Implementation of Mitigation Measures

R egistrants are to submit amended lab els that include the label changes summarized in Appendix B to the Agency for approval within 60 days following issuance of the Interim Registration Review Decision in final form. A summary of the proposed mitigation measures are described in Appendices A and B.19 Appendix A: Summary of Proposed Actions Taken for Propoxycarbazone

- sodium

Appendix B: Prop oxycarbazone

- sodium label table Summary of Proposed Labeling Changes for Propoxycarbazone

- sodium Description Proposed Labeling Language for FPE Products Placement on Label SPRAY DRIFT Spray Drift Language • Select nozzles and pressure that deliver coarse (VMD 326

- 400) spray droplets as indicated in nozzle manufacturer’s catalogs and in accordance with ASABE Standard S

- 572.

• Applicators may spray only when wind speed is between 3 and 10 mph

.

• For aerial applications, the maximum release height must be no higher than 10 feet from the top of the crop canopy , unless a greater application height is required for pilot safety

.

• For ae rial applications, the distance of the outer most nozzles on the boom must not exceed three

- fourths of the length of the wingspan or rotor diameter. To further reduce drift, use

one

- half of the length of the wingspan or rotor diameter at the edge of a fie ld.

• Applicators may not spray during temperature inversions

.

• For ground applications, boom height must be no higher than 4 feet above the crop canopy. Directions for Use Registration Review Case#: 7264 PC Code: 122019 Chemical Type: herbicide Chemical Family: Sulfonylaminocarbonyltriazolinone Mechanism of Action: WSSA Group 2 Affected Population(s) Source of Exposure Route of Exposure Duration of Exposure Risk(s) of Concern Proposed Action(s) Taken

• Terrestrial Plants (monocots and dicots) • Aerial Application • Foliar and
root absorption • Acute • Acute toxicity • Require spray drift reduction language.

• Require herbicide resistance management language on label.20 Summary of Proposed Labeling Changes for Propoxycarbazone

- sodium Description Proposed Labeling Language for FPE Products Placement on Label HERBICIDE RESISTANCE MANAGEMENT

- Products Labeled for Agricultural Use
Herbicide Mechanism of Action “Group 2 HERBICIDE” Front Panel, upper right quadrant, surrounded by a black (or suitable color) rectangle Weed Resistance

Management • Listing of herbicide mechanism of action ( M O A ), and/or WSSA herbicide group number, at the top of the first page of each product l abel

.

• List seasonal and annual maximum number of applications and pounds

.

• Resistance management language from PR N otice 2001

- 5 and/or Best Management Practices (appropriate to crop) from Weed Science Society of Ameri ca (WSSA) & Herbicide Resistance Action Committee (HRAC), and/or HRAC proposed guidelines for herbicide labels.

• Users should s cout before and after application

.

• Include the d efinition of likely resistance

.

• List confirmed resistant weeds in separate table

a nd list effective or recommended rates for these weeds with the table

.
• For combination products with multiple M O As, list which herbicide is controlling which weed and minimum recommended rate

. Directions for Use, prior to directions for specific crops under the heading “WEED RESISTANCE MANAGEMENT”