Docket Number EPA-HQ-OPP

-2012-0896 www .regul ations.gov



## Bromoxynil Final Work Plan Registration Review

Case Number 2070
September 2013

Approved by:

## ~¥:0"·~ p

## ~~~.~. Richard P. Keigwin,

## ~ Director Pesticide Re-evaluation Division

Date:INTRODUCTION This is the Environmental Protection Agency ' s (EPA or the Agency) Final Work Plan (FWP) fl r the registration review of bromoxynil. This case includes the active ingredients bromoxynil phenol, bromoxynil octanoate, and bromoxynil heptanoate. The octanoate and the heptanoate active ingredients are esters of the phenol active in gred ient. These three active ingredients (collectively, "bromoxynil " ) are postemergence broadleafweed herbicides that are registered fl r use in grass c rops and some to lerant broadleaf crops , as well as non-crop sites. Bromoxynil products are registered for use in both agricultural and commercial/industrial settings. A third ester ofbromoxyni l pheno l , bromoxynil butyrate (PC 035303), was previously registered with the Agency but currently has no active registrations and is therefore not addressed in this Registration Review. Th i s work plan addresses public comments received concerning the Preliminary Work Plan (PWP), which was po ste d in the bromoxynil registration review docket (EPA-HQ

- OPP-20 12-0896). The Agency is implementi!lg the registration review program pursuant to Sect ion 3(g) of t h e Federal Insecticide , Fungicide , and Rodenticide Act (FIFRA) , and will review each regi stered pesticide every 15 years to determine whether it continues to meet the FIFRA standard for

. registration

. Changes in science, public policy, and pesticide use practices occur over time

. Th registration review program is intended to make sure that, as the ability to assess rjsk evolves d as policies and practices change, all regis tered pesticides continue to meet the statutory s tandar The public phase of registration review begins when the init ial docket is opened for each case. Information on this program is provided on the Agency's website. 1
The FWP begins with any updates since the PWP was issued. Next is a summary of substantiv comments rec e ived during the public comment period for the PWP concerning anticipated data needs , expected risk assessments, or the estimated timeline identified in the PWP, and a summary of the Agency ' s responses to those comments. This section is followed by registratio review planned data needs , risk assessments expected to be conducted , and the projected registration review timeline for bromoxynil. Lastly, there is a discussion of next steps. UPDATES SINCE THE PWP WAS ISSUED The projected timeline has been updated since the PWP to reflect impacts of recent Agency actions shortening the timeframe between FWP and Data Call

- In (D CI) issuance and adding a quarter in between posting of preliminary risk assessments (PRAs) and proposed decisions. Since the PWP, an immunotoxicity study has been submitted to the Agency and is currently in review. The immunotoxic ity data requirement has been added to the li st ofplanned data needs for data compensation purposes. SUMMARY OF COMMENTS AND AGENCY RESPONSES During the 60-day public comment period on the Bromoxynil Preliminary Work Plan , which opened on March 27 , 2013 and closed on May 28 , 2013 , the Agency received three public

1 http: //www .epa.gov /op p srrd 1 /registration

_review / 2comments
. The three parties who submitted comments were the FIFRA E ndangered Species Task Force (FESTF) , the Washington State Pest Management Resource Serv ice at Washington State University Tri-Cities , and the techn ical product registrant Bayer CropScience. The co mment s do not address the timeline or th e planned ecologi cal and human health risk assessments describ ed in the PWP, but th ey do address the anticipated data requirements. General u se and u sage data are als o provided in these comments. In the PWP , EPA also solicit d comments on the specific topics of environmenta l justice , water quality concerns , and trade irritants , but no comments o r information were received on those issues. Summarized public comments and Agency responses related to the anticipated eco lo gical risk

. assessment or data needs can be found in the July 17 , 2013 document EFED Response to Publi Comments Submitted in Response to the Bromoxynil Registration Review Problem Formulatio PWP in the docket, EPA-HQ -OPP -20 12 -0896. The Agency thanks all commenters for their comments and will consider the information s uppli ed by them as EPA conducts the reg istratio review and makes its registration review decision.



### 3PLANNED DATA NEE DS
Table 1 below summarizes the planned data needs for bromoxyni l b ased on the EFED Respons to Public Comm ents Submitted in Response to the Bromoxynil Reg istration Review Problem Formulation PWP. Since the PWP , an immunotoxicity study has been submitted to the Agenc and is currently in review. T h e immunotoxicity data requirement has been added to the list of planned data needs for data compensation purpose s.
Table 1: Planned Data Needs for the Registration Review of Bromoxynil 1 Estimated Guideline Study Title Timeframe Number Test (Months from Material 2 receipt ofDCI) Bromoxynil (phenol)

- PC Code 035301 835.2240 Photodegradation in water 12 835.4100 Aerobic soil metabolism TGAI o r 24 PAIRA 835.4300 Aerobic aquatic metabolism 24 850.6100 Env ironmental Chemistry Methods and Associated TGAI 12 lndepen

. dent Laboratory Validation 3 850.2300 Avi an reproduction 4 TGAI 24 850.4400 Aquatic p lant growth (aquatic vascular plant) 12 T GA I 850.4500 Aquatic p lant growth (algal p lant) 12 870.7800 lmmun otoxicity ) TGAI 12 875.2100 Di slodgeable foliar residue and turf transferable T EP 24 residues Bro moxyn il octanoate- PC Code 035302 835.4100 Aerobic soil metabolism TGAl or PAIRA 24 850.6100 Environmen tal Chemi stry Methods and Associated Independent Laboratory Validati on 3 TGAI 12 850.2100 A vi an oral toxicity 6 TGAI 12 875. 2 100 Dislodgeable foliar residue; turf transferable TEP 24 Residues Bromoxynil heptanoate 7

- PC Code 128920 83 5

. 1230 Adsorpti on/Desorption (Batch Equilibrium) 12 835.2120 Hydro l ysis 12 835

.2240 Photodegradation in water 12 835.2410 Soil ph otolysis TGAI o r 12 835.4100 Aerobic soi l metabo l ism PAIRA 24 835.4300 Aerobic aquatic metabolism 24 835.4400 Anaerobic aquatic metabolism 24 850.6100 Env ironmental Chemistry Methods and Associated TGAI 12 Independent Laboratory Validation 3 875.2100 Dislodgeable foliar residue and turf transferable TEP 24 re si dues
41 On June 27,2012, EPA announced certain revisions in harmonized guideline series 850

- Ecological Effects Tess

- including renumbering and other designations or changes for some guideline studies. See " Final Test Gu ideline ; OCSPP 850 Series ; Notic e of Availability" 77 FR 38282, June 27 , 2012. http ://www.regulation s. gov /# ! documentDetail ;D= EPA-HO-O P PT-2009

- 0 154-002 8 2 TGAI = technical grade active ingredient; TEP = typical end-use product; PAIRA = pure active ingredient, radio labe led 3 This ECM/ ILV anticipated data need is for methods in water
. 4 An avian reproduction s tud y with bromoxynil (phenol) is an anticipated data requirement. In absence of these d a if the y are required , the available endpoi nts for bromox y nil octanoate will be used for risk assessme nt. 5 Bromoxynil (p henol) , bromoxynil heptanoate and bromoxynil octanoate have been determined by the Agency to e toxicologically equivalent on a molar basis (03 74609- Br om oxy nil: Human Health Ri sk Assessment for Amende Uses on Grass Grown for Seed, Conservation Reserv e Pr og

ram Areas, and Grain Sorghum, C. Walls, 04/20 1 2011

. As such, data from an acceptable immunotoxicity study for one of th e three bromoxynil forms data will bridge to e other forms and be sufficient for sati sfy ing the immunotoxicity anticipated data need for this registration review case. 6 For thi s anticipated data requireme nt , the study expected to be requeste d would be for a passerine species. The anticipa ted Data Call-In Notic e will require that a protocol for the study be submitted to EPA for approval before he study begins. 7 The Agency will review where it is appropriate to bridge the re sults of environmental fa te stud ies conducted wit bromoxyni l octanoate to bromoxynil heptanoate

. If bridging is determined to be an acceptab le strategy, aqueous photolysis , aerobic aquatic metabolism , anaerobic aquatic metabolism , so il photol ysis , and ad sorp tion/desorption s tudies using bromoxyn i l heptanoate likely would not be required.

RISK ASSESSMENTS FOR REGISTRATION REVIEW During registration review , the Agency anticipate s the need to conduct a comprehensive ecological risk assessment , including an endangered species assessment , for a ll uses of bromoxynil. For human health , EPA anticipates the need to conduct an occupational risk assessment during registration review. If drinking water estimates do not need revision, a revised dietary assessment for bromoxynil may not be required for the purpose of registration review. If toxicological endpoints or points of departure are revised bas ed on the data that are anticipated to be required for registration review, they will be considered in the new assessmen s, as well as any changes to the standard operating procedures or d efault expos ure assumptions. Table 2 below summarizes the planned registration review risk assessments based on the EFE Problem Formulation and HED Scoping Docume nt. The planned assessments have not change fro m what was i ncl uded in the PWP.



### 5Table 2: Planned Risk Assessments for the Bromoxynil Registration Review Type of Risk Assessment Conduct? Notes 

### Ecolotdeal and 

### Environmental Fate Comprehensive ecological Yes (spec ies to be assessed include terrestrial and aquatic organisms), including endangered species Incidents Yes For a discussion ofbromoxynil ' s reported ecolo r. ical incidents, see page 17 of the Problem Forrnulati < n. 

### Human Health Dietary Food No A new dietary risk assessment may not be**neede ~**  because changes in the Agency ' s assessment me hods s ince the most recently conducted risk assessme tare not ant ic ip ated to affect the risk concl u sion

. If drinking water estimates do not need revision, a revised dietary assessment for bromoxynil may ot be required for the purpose of registration review. Drinking water Yes Occupational H andlers (mixers , loaders , Yes applicators) Post-application Yes Residential H andlers No There are no residential uses of bromoxynil. Post

- application No Other Aggregate Yes Evaluate s the combined risk from food and drinl< ing water exposures. Cumulative No Bromoxynil is not a member of a cumulative grc up and no cumulative risk asses s ment is planned. Tolerances Yes Tolerances for bromoxynil are listed in 40 CFR§ 180. 324. Incidents No There is not a concern at this time that would w arrant further investigation. The Agency will continue 0 monitor the incident information and, if a concer**s** triggered, additional analysis will be included in he risk assessment. For a discussion ofbromoxynil s reported human incidents, see page 1 0 of the Sc< ping Document.



### 6TIME LINE EPA has created the following estima ted timeline fo r the completion of the bromoxynil registratio n review in Table 3 below. The projected timeline has been updated since the PWP 

### p reflect impacts of recent Agency actions shortening the timeframe between FWP and DCI issuance and add ing a quarter in between posting of PRAs and propos ed decisions.

Table 3: Registration Review f or Bromoxynil - Proje cted Registratio n Rev iew Timeli n4 Activities Estimated Date Opening the Docket Open Docket and 60

- day Public Comment Period March 20 13

- Complet! d Close Public Comment May 2013 -Co mp leted Cas e Developmen t Fin al Work Plan August 2013

- Comp let**d** Iss u e D CI 2014: Jan.

- March Data Submission 20 16: Jan. -March 60

- day Pub lic Comment Period for D raft Risk Assessments ' 20 1 7 : July

- Sept. Regi stratio n Rev iew D ec i sio n 60-da y Pub li c Comment Period fo r Prop osed Regis trati on Review 2018: Jan. -March D ec i sion Registration Review Decision and B egin Post-Decision Follow-up 2019 Total (years) 6

NEXT STEPS As noted previously , the Agency plans to require several environmenta l fate , ecological effects and human health stud ies for bromoxynil through a Data Call-In Notice, expected to be issued**~** January- Marc h of20 14.

7 The regulations governing Registrati on Review generally require the Agency to prov ide a public comment perio

of at least 30 calendar days for draft risk assessments; see 40 CFR Part 155.53(c). For conventional pesticides , tt e Agency plan s to provide a 60 calendar day public comment period generally for draft risk assessments. 7