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# Imazaquin Final Work Plan Registration Review

Case Number 7204

March 2015

Appro v ed by:



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Date: Richard P. Keigwin , Jr. Director P es ticide Re

- evaluation Division 

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**jcflOI~**INTRODUCTION This is the Enviro nme ntal Protection Age ncy ; s (E PA or the Agency) Final Work Plan (FWP) fo r the reg i stration rev iew of imazaquin. This wor k p l an addresses public comments received concerning th e Preliminary Work Plan (PWP), which was posted in the imazaquin registra ti on review docket (EPA-HQ

- O PP -2014

- 0224). Unless ot h erwise specified , ref erences to im azaquin througho ut this document include im azaquin and its ammonium salt. Imaza quin is an imidazo linone herbicide that is formulat ed as an acid or ammonium sa lt. It is registered for uses as a pre -plant , pre-emergence and early post-emergence on soybeans. It is al so registered for p re and post-emergence weed contro l on orname n tals and warm season turfgrass in both residential (lawns) and non-residential (go lf-cour ses) settin gs. The Agency i s implementing the registration review pro gram pur s ua nt to Section 3(g) of the Federal Inse ctic ide, Fungicide , and Ro denti c ide Act (FIFRA), and wi ll revi ew each registered pestic ide every 15 yea r s to determine w hether it co nt inues to meet the FIFRA standard for registration. Ch anges in scie nce, publi c po licy, and pest icide use practices occur over time. The re gi strat ion review program i s intended t o make sure that, as the abi lity to assess risk e volves and as policies and practices change, all regi stered pesticides continue to me et the statutory stand ard. The public phase of registration review begins when the initial docket is opened for each case. Informat i on on this program is prov ided on the Agenc y's website. 1 The FWP begins with any updates since the PWP was i ss ued. Nex t i s a summary of substantive comme nts receive d during the public comment period for the PWP concerning an ticipated data n eeds , expected risk assessments , or the estimat ed timeline identified in the P WP, and a summary of the Agency's responses to those comme nts. Thi s section is followed by registration review planned data needs , risk assessments expected to be conducted, and the projected registration rev iew timeline fo r imaza quin. Lastly , th ere is a dis c u ss io n of next st eps. UPDATES SINCE THE PWP WAS I SSUED The Agency approved a pro cess for impl ementing th e new pollina to r data requ ests cons i ste nt with OPP's 2014 Guidancefor Assessing Pesticide Risks to Bees 2

. The plann ed data needs for imazaquin include the current bee-related data requirements that are in cluded in 40 CFR Part 158 and addition a l studies which are consistent with the new Guidance for Assessin g Pesticide Ri sks to Bees (se e Tab le 1 for the new pollinator data re quiremen ts). SUMMARY OF COMMENTS AND AGENCY RESPONSES During the 60-day public comment period o n the Im azaqui n Pr e liminary Work Plan , which opened on September 24 , 2014 and clo sed on Novemb e r 24 , 2014 , the Agency rece i ved three public comments. Comments we re submi tted by th e Center for Bi o logic al Di ve rsity (CBD) , FIFRA Endangered Special Task Fo rce (FES TF), and from Pr oject Apis m. (PAm).

1 http :// www .epa .gov / opp s rrd l/regi s tration

_ re view/ 2 http :// www . epa.gov/ pesticides/ science / efed/policy guidance / team authors/terrestrial biology tech team/Guidance AssessingPesticides R isk2Bees.pdf

.

2The comments from CBD focused on the EPA's duty to consult with the U.S

. Fish and Wildlife Service and the National Marine Service (t he Services) on the registration review of imazaquin 

### in accordance with the Endangered Species Act (ESA). The comment from FESTF identified BAS F Corporation as a FESTF member, which i s entitled to rely on FESTF data. Project Apis m. (PAm) is a non-profit honey bee re search funding organization in the U.S. Their comments focu sed on the development of a federal s trategy to prot ect honey bees and other pollinators, and their wi llin gness to as sis t with, coordinate, or manage new federal initiatives. The se public comments are located in t he docket , EPA-HQ-OPP

- 20 1 4-0224. The co mment s do not address the timeline described in the PWP , or the planned eco logical and human health risk a ssessments and data requirements. In the PWP , EPA also solicited comments on the specific top ic s of environmental justice, water quality concerns , and trade irritants, but no comments or information were received on those issues. Comments submitted by FESTF in EPA-HQ-OPP
- 2014-0224--0012. 1. Comment: BASF Corporation , the imazaquin technical registrant , is a FESTF member and is e ntitled to rely on the FESTF data

. Respon se: The Agency thanks FES T F for its comment, and will consider the FESTF data during the imazaquin registration review. Comments submitted by CBD in EPA-HQ-OPP-2014 -0 224-0013. 2. Comment: The Center for Biological Diversity's (CBD) co mment sfocus on the EPA's duty to consult with the US. Fish and Wildlife Service and the National Marine Fisheries Service (the Services) on the registration review of imazaquin in accordance with the Endangered Species Act (ESA). The CBD comments mention various aspects of the risk assessmentprocess, including use of the best available data to develop endangered species risk assessments, and evaluation of effects on endangered and threatened species and their desi gnated critical habitat. CBD also exp ress es concern regarding the rigor of the Agency 's preliminary determinations regarding the effects of imazaquin on endangered and threatened (listed) species and their designated critical habitat for the imazaquin registration review. Resp onse: EPA has reviewed the comments from CBD on the registration review docket opening for imazaquin and plan s to address many of the concerns raised by CBD as part ofthe implementation plan for assessing the risks of pesticides to li sted species based on the recommendations of the Ap ril2013 National Academy of Sciences (NAS) report. EPA wi 11 addre ss concerns specific to imazaquin in connection with the development of its final registration review decision for this pe stic ide. In November 20 13 , the E PA , along with the Services and the USDA, released a summary of the ir joint Interim Approaches for assessing ·risks to endangered and threatened (listed) species from pesticides. The Interim Approaches were developed jointly by the agencies in response to the NA S recommendations an d reflect a common approach to risk assessment s hared by the agencies as a way of addressing scientifi c differences between
3the EPA and the Services. The NAS report outlines recommendations on specific sc ientific and technical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obligations 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 (PPDC) and State

- FIFRA Issues Research and Evaluation Group (SFIREG) meetings. The agencies also held a stakeholder workshop in April and October 2014 , allowing additional opportunit ie s for stakeho lders to comment on the Interim Approaches. 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

**.** Interim Approaches for National-Level Pesticide Endangered Sp e cies Act Assessments Based on the Recomm endations of the National Academy of Sciences April 2013 Report, dated November 1, 2013. Given that the agencies are continuing to develop and work toward impleq1entation of the Interim Approaches to assess the potential risks of pesticides to listed species and their designated critical habitat , the ecological problem formulation supporting this Final Work Plan for imazaquin does not describe the specific ESA analysis, including effects determinations for specific listed species or designated critical habitat , to be conducted during registration review. In the ecological problem formulation document for imazaquin, EPA described the screening-level risk assessment to determine the potential effects of imazaquin on all taxa of non-target wildlife and plants, which will assume that li sted species and th eir designated critical habitats may be present in the vicinity of the application of imazaquin. This screening-level assessment will allow EPA to focus its future evaluations on the types of species where th e potential for effects exists once the scientific methods being developed by the agencies have been fully vetted. While the agencies continue to develop a common method for ESA analysis, the planned screeningl eve l risk assessment for the regi stration review of imazaquin will describe the level of ESA analysis completed for this particular registration review case. Once the agencies have fully developed and implemented the scientific methods necessary to complete risk assessments for endangered and threatened (listed) species and their designated critical habitats, these methods will be applied to subsequent analyses for imazaquin as part of completing this registration review. Comments submitted by Project Apis m. in (PAm) EPA-HQ-OPP-2014-0224--0014. 3. Comment: The comments from PAm focus on the development of a

federal strategy to protect honey bees and otherpollinators. PAm comments indicated that they are the largest non-governmental, non-profit honey bee research funding organization in the US ., and that they earned the respect of the nation ' s commercial beekeepers and the top be e scientists in the country. PAm also indicated that they are the ' go-to ' organization at the interface of honey bees and pollinated crops. PAm derives its name from Apis
4mellifera, the

**scient~fic** name for the Eu rop e an hon ey bee. They expressed th ei r willingness to coor dina te new hon ey bee h ealth programs and would be p l ease d to assist with, coordinat e

, o r mange new federal initiatives

. R esponse: The Agency thanks PAm for its comment and w ill consider this information as it co nducts the registratio n review of imazaquin

. PLANNED DATA NEEDS Table 1 be low su mm arizes the planned data needs fo r imazaquin based on the Registr ation Review: Preliminary Problem Formulation for Environm ental Fate, Ecological Risk, Endangered Species, and Human Health Drinking Water Expos ure Assessments fo r Imazaquin and th e Ammo nium Salt of lm azaquin and lmazaquin: Huma n Health Risk Assessment Scoping Docum ent in Supp ort of R eg istration Review. The planned data ne e ds have changed from what w a s includ ed in the PWP

. The planned data needs fo r imazaquin includ e the new pollinator data requirements.
Table 1: Planned Data Needs for the Imazaquin Registration Review Estimated Guideline Number-1 Study Title3 Timeframe Test (Months from Material receipt of DCI) Anticipated Data Needs for the Parent Imazaquin 875.2100 T urfTransf erabl e Res idue TEP 12 835

. 1230 Batch equi librium TG AI 12 ad s orption/desorptio n 835.24 10 Photo degradatio n on so il TGAI 12 835.224 0 Photodegr adatio n in wate r TG AI 12 8 35.41 00 Aerob ic s oil m etabo li s m (three TGA I 24 additional so il s) 835.4300 Aerob i c aquatic m etabo lism TGAI 24 835.4400 Anaerob ic aquatic metabo li sm TG AI 24 Environme ntal Chemistry Method 850.6100 (ECM) and Assoc ia te d Independent TGAI 12 Labo ratory Validations (ILV) for resid ues in water 850. 1025 or 850

. 1055 Acute toxicity estuarine and marine TGAl 12 org anisms (m ollusk) 850 .1035 or 850.1045 Acute toxicity estuari n e and marine TGA1 12 organi s ms (invertebrate)

3 On June 27, 2 0 12 , EPA announced certain revi sions in harmonized guidel ine series 850

- Eco logic al Effects Tests

- including renumbering and o th er designation s or changes fo r some g uideline studies. See " Final Test Guidel i ne s; OCSPP 850 Serie s; Notice ofAvailabilit y" 77 FR 38282 , June 27,2012. http ://www .regulation s.gov / #! documentDetai I;D= EP A

- HO-OPPT -2009-0 154-0028 

### 5Table 1: Planned Data Needs for the Imazaquin Registration Review Estimated Guideline Nnmbe.-1 Study Titlel Timeframe Test (Months from Material receipt of DCI) 850

. 1075 Sa ltwater fish acute toxicity TGAI 12 850

. 1300 Fre s hwater invertebrate s life-c ycle TGAI 12 850.1350 Sa ltwater invert eb rate s life-cycle TGAI 12 8 50. 1400 Freshwater fish earl y -life stage TGAI 12 850.1400 Saltwater fish early-life stage TGAI 12 850.2300 Avian reproduction ( upland species and TGAI 24 waterfowl) 850.4400 Aquatic plant growth (Tier II vascular TGAI 12 plant s) 850.4500 Aquatic plant growth (Tier II algae (3 TGAI 12 s pecies) 850.4550 Aquatic plan t growth (Cyanobacteria) TGAI 12 850.3020 (Tier 1)4 Honey bee adult acute contact toxicity TGAI 12 850 .3030 (T i er 1) 4 Honey bee toxici ty of res idue s on TEP 12 foliage 850.3040 (Tier 2 or 3t Field testing for pollinators TEP 12 Non-guideline, OECD Honey bee larval acute oral toxicity TGAI 12 TG 237 5 • 6 No n-guideline 5 • 6 • 7 Honey bee larval chronic oral toxicity TGAI 24 Non-guideli ne, OECD Honey bee adult acute oral toxicity T GAI 12 TG 213 6 No n-guideline 6 • 7 Honey bee adult chronic oral toxicity TGAI 24 Non-guideline (Tier 2) 6 Semi-field testing for pollinators TEP 12 (tunnel or colony feed in g studies) Non-guideline (T ier 2) 6 Field trial of residues in pollen and TEP 12 nectar TGAI = techmcal grade acttve mgredtent ; TEP = typtcal end-use produ ct;

4 Toxicity Testing Requirements for Bees as Specified in 40 CFR Part I 58. 5 A 21-day larval toxicity study may be suf ficient to assess both acute and chronic toxicity to d eveloping brood

. 6 Additional Recommendations for Bee Testing. 7 A protocol sho uld be submitted to the Agency for review and approval prior to study initiation. 

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### RISK ASSESSMENTS FOR REGISTRATION REVIEW During regi stration review , the Agency will conduct a comprehensive ecological risk assessment , including an e ndangered spec ies assessment , for all u ses of imazaquin

. For h u man health , E PA w ill conduct revised dietary, residential , and occupational risk assessments during registration review. If toxicological endpoints or points of departure are revised bas ed on the data that are required for registration review, they will be cons idered in the new asses sm e nt s , as w ell as any change s t o the standard operating procedures or default exposure assumptions. T abl e 2 below summarizes the planned registration rev i ew risk assessments based on the Registration Review: Preliminary Problem Formulation for Environmental Fate, Ecological Ri sk, Endangered Specie s, and Human Health Drinking Water Exposure Assessme nt sfor Imazaquin and the Ammonium Sa lt of Imazaquin and Jmazaquin: Human Health Risk Assessment Scoping Document in Support of Registration Review. Th e planned assessments have not changed from w hat was included in the PWP. 

### Table 2: Planned Risk Ass essments for the Imazaquin Registration Review Type of Risk C on duct? Notes Assessment Ecololdcal and Environmental Fate Compreh e n si ve y ecological (species t o be assessed include terre stri a l and aq ua tic organi sms), including endangered spec i es Incidents Wi ll chec k for For a d i scussion of reported ecological incidents for updates imazaqu in , see page 1 1 ofthe Problem Formulation. 

### Human Health Dietary Fo od N The dietary exposure database is a dequa te
. At thi s time , a revised dietary risk asses sment i s not anticipated for imazaquin , provided there are no signi ficant changes to the toxicological points of departure (POD ) , uncertainty factors , and no sig nificant chan ges to the estimated drinking water concentration s (EDWCs)

. Drinking water 

### y The Agency anticipates updating the dri nking water assess ment under

**re~stration** review. Occupational Handlers ( mixers, 

### y Occ upational h and ler and po st-a ppli cation exposure loader s, applicato rs) assess ments will be p erformed und er reg i stration Post-appli catio n 

### y review usin g current policies. Any c hanges to the toxicological POD or uncertainty factors will also be incorpo rated. Residential

7Handl e rs 

### y A rev i sed resi d entia l exposure assessment using the Post-appli cation 

### y 2012 Re si den tial SOPs will be n eeded during registration review. Any revision s to toxicological POD or uncertainty factors will be incorporated. The need for a vo lati li za tion risk assessment will be examined during registration review

. Other Aggregate 

### y Eva luates the

. comb ined risk from dietary and resident ial exposures. Revised aggregate risk assessments will be performed for imazaquin if there are any changes to toxico logical POD or uncertainty factors, or if there are any significant change s to the revised res id ential exposures or s i gn ificant chan ges to the EDWC s. Cumulative N EPA has not made a determination of whether imazaquin has a common mechani sm of toxicity with other substances. Therefore, a cumu lative risk assessment h as not been performed for imazaquin. T oleran ces 

### y During registration review, the Agency anticipates modify ing t he U.S. tole rance definition for imazaquin. There are curre ntl y no internatio nal maximum residue limits (MRLs) for imazaquin ; th erefore, there are no harmonization i ss ues with Codex, C anada, or Mexico

. Incidents Wi ll check for For a discussion of repo rted hum an incidents for updates im azaquin , see page 10 of the Scoping Document and the Imazaquin: Tier I Review of Human Incidents. 

### TIME LINE EPA has crea ted t he following estimated tim elin e for t he comp l etio n of the imazaquin registration review in T ab le 3 bel o w . The projected timeline has not changed s ince the PWP. Table 3: Projected Imazaquin Registrati o n Review Timeline Activities Estimated Date Openin g the Docket Op en Docket and 60-day Public Comment Period Sept. 2014

- Comp l eted Close Public Comment Nov. 2014

- Completed Case Development Fina l Work Plan March 20 15

- Co mpleted I ss ue DCI 2015 April

- June Data Submi ss io n 2017 April

- June



### 8Table 3: Projected Imazaquin Registration Review Timeline Activities Estimated Date 60-day Public Comment Period for Draft Risk 2018 Oct.

- Dec. Assessments 8 Registration Review Decision 60 -d ay Public Comment Period fo r Proposed 2019 July- September Registration Review Decision Registration Review Decision and Begin Po st-Decision 2020 Follow-up Tota l (years) 6 As noted prev ious ly , the Agency plans to require severa l environmental fate, ecological effects , and human health studies for imazaquin through a Data Call -In Notice, expected to be issued in June 2015.

8 The regulations governing Registration Review ge nerall y require the Agency to provide a public comment p eriod

of at least 30 calendar days for draft risk assessments ; see 40 CFR Part 155.53(c). For conventional pesticides , the Agency plans to provide a 60 calendar day public comment period generally for draft risk assessme nts.



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