Introduction

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP) for the registration review of bentazon. The Final Work Plan includes the expected registration review timeline. The FWP also a ddresses public comments received concerning the Preliminary Work Plan (PWP) in the Summary Document which was posted in the bentazon registration review docket (E PA-HQ-OPP-2010-0117) and any ot her comments concerning the initial docket postings. The Summary Document provided information on what EPA knows about the pesticide and what additional risk analyses and data or information the Agency

believes are needed to make a registration review decision.

The Agency is implementing the registra tion review program and will review each registered pesticide every 15 years to determin e whether it continues to meet the Federal Insecticide, Fungicide, and Rode nticide Act (FIFRA) standard for registration. Changes in science, public policy, and pestic ide use practices occur over time. The registration review program is intended to make sure that, as the ab ility to assess risk evolves and as policies and practices change, all registered pesticides contin ue to meet that statutory standard. The public phase of registration review begins when the ini tial docket is opened for e ach case. Information on this program is provided at http://www.epa.gov/oppsrrd1/registration_review/

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Bentazon is a benzothiadiazole herbicide registered to c ontrol post-emergent broadleaf weeds and sedges in numerous agricultural fiel d crops, and around trees and vines in various fruit and nut crops. Bentazon is also registered for use to control weeds in residential and

recreational lawns around ornament al plants. The Reregistration Eligibility Decision (RED) for bentazon was completed in September 1994 (available at: http://www.epa.gov/oppsrrd1/REDs/0182.pdf) . In 2000, EPA reassessed tolerances of bentazon in compliance with the Food Qua lity Protection Act (FQPA) (65 Fed. Reg. 12122, March 8, 2000).

This document makes final the work plan for the bentazon registrati on review processes.

Actions since Publication of PWP

In 2005, EPA received new use applications fo r bentazon for peaches and nectarines from Interregional Research Project No. 4 (IR-4). A dietary risk assessment was completed in 2006 that evaluated the proposed new uses and updated drinking water exposure estimates for registered uses of bentazon. This risk assessm ent showed that the existing uses of bentazon result in chronic dietary risk estimates of concern for infants. Most of the dietary bentazon exposure to infants is from dri nking water. IR-4 subsequently withdrew the new use requests. To address the dietary risks of concern for the ex isting uses of bentazon, th e technical registrant (BASF) has voluntarily requested to amend their product registrati on label to clarify that the maximum annual application rate is 2 lbs of bent azon active ingredient (ai) from all sources per acre per calendar year and not 3 lb s ai/Acre/year. This rate reduc tion mitigates the dietary risks of concern identified in the 2006 dietary risk assessment. On September 21, 2010 BASF sent a formal correspondence to EPA, committing to subm it a label amendment re quest to clarify the lower maximum annual application rate.In May 2010, BASF submitted a letter voluntarily requesting the cancellation of the following five bentazon Section 3 produc t registrations: 7969-78, 7969-122, 51036-363, 51036- 415, and 51036-421. On September 22, 2010, a Federa l Register Notice (FRN) announcing the receipt of the registrants request to voluntarily cancel certain be ntazon pesticide registrations was published. This notice initiated a 30-day commen t period. These requests will not terminate any use sites of bentazon. EPA intends to grant thes e requests at the close of the comment period for this announcement unless the Agency receives s ubstantive comments within the comment period that would merit its further review of the reque sts, or unless the registrants withdraw their requests within this period.

Comments Received on Preliminary Work Plan

On March 31, 2010 EPA opened a 60-day pub lic comment period for the registration review of bentazon. The comment period ende d on June 1, 2010. The Preliminary Work Plan document can be located in the bentazon regi stration review docket (EPA-HQ-OPP-2010-0117)

at www.regulations.gov

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In the PWP, EPA solicited comments on three specific topics: environmental justice, water body impairment and trade irritants. No comments or information were received during the public comment period concerning these issues.

During the public comment period, the Agency received several comments, as described and discussed below, from two parties (BASF and the Physicians Committee for Responsible Medicine). The comments receiv ed do not change the data and risk assessment needs or the

timeline detailed in the bentazon PWP.

In their comments, the technical registrant id entified several applica tion use patterns and crop uses which they claim are not supported by BASF and asked the Agency to “adjust their assessments to eliminate these from the work pla n.” The Agency thanks the registrant for their comments and will consider this information when conducting the risk assessments.

BASF also commented that “EPA has misinter preted the label dir ections and use rates specified on the Rezult ® Herbicide Label (E PA Reg. No. 7969-194) as 3.2 pints/A (2 lb ai/Acre), when the corre ct use rate is 1.6 pints /Acre of the bentazon component of Rezult, resulting in a bentazon use rate of only 1.0 lb ai/Acre from Rezult appl ication.” The Agency thanks BASF for their comment; however EPA believes that the current label indicates a maximum annual application rate of 3 lbs ai/Acre. In response, the registrant has voluntarily requested to amend their product registration label to clarify that the maximum annual application rate is 2 lbs ai/Acre and not 3 lbs ai/Acre. This rate reduction label amendment mitigates the dietary risks of concern identified in the 2006 dietary risk assessment.

The Agency also received several commen ts from BASF and the Physicians Committee for Responsible Medicine (PCRM) regarding th e technical informati on presented in the Registration Review – Preliminary Problem Form ulation for Ecological Risk and Environmental Fate, Endangered Species, and Drinking Wa ter Assessments for Sodium Bentazon document, dated February 5, 2010. A detail ed description of the commen ts received and the Agency’sresponse to these comments is available in a separate response memoranda from the Agency’s

Environmental Fate and Effect s Division (EFED), which can be located in the bentazon registration review docke t (EPA-HQ-OPP-2010-0117) at www.regulations.gov

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Anticipated Risk Assessment and Data Needs

The Agency anticipates conducting a comp rehensive ecological risk assessment, including an endangered species risk assessment, for all uses of bentazon. The Agency also anticipates revising dietary, reside ntial, aggregate, and occupationa l risk assessments for all uses

of bentazon.

Ecological Risk:

• The most recent ecological risk assessment was completed in 2005 to support the proposed

new use of bentazon to control weed s in peach and nectarine orchards.

• In a refined risk assessment for the 1994 RED, EPA concluded that registered uses of bentazon would “not likely a dversely affect” threatened and endangered mammals and birds. However, this assessment was not conducted pursuant to current policies. Accordingly, the Agency has not conducted a risk assessment that supports a complete endangered species determination. The eco logical risk assessment planned during registration review will allow the Agency to determine whether bentazon’s use has “no effect” or “may affect” federally listed threaten ed or endangered spec ies (listed species) or their designated critical habita ts. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critic al habitat, the Agency will consult with the

U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Services), as appropriate.

• The Agency needs the following data in or der to conduct a comple te ecological risk assessment, including an endangered species assessment, for bentazon:

o GDLN 850.1300 – Aquatic Invertebra te Life Cycle (freshwater)

o GDLN 850.1400 – Fish Early Life-Stage (freshwater)

o GDLN 850.2100 – Avian Acute Or al Toxicity, Passerine

o GDLN 850.5400 – Aquatic Plant Gr owth (algal) (Tier II)

o GDLN 835.6100 (7) – Environmental Chemistry Methods – soil

o GDLN 835.6200 (7) – Environmental Chemistry Methods – sediment

• For a detailed discussion of the ecological risk assessment and data needs refer to the Registration Review – Preliminary Probl em Formulation for Ecological Risk and Environmental Fate, Endangered Species, and Drinking water Assessments for Sodium Bentazon (PC Code 103901) (February 5, 2010), which is available in the docket.Human Health Risk:

• The most recent human health risk assessm ent for bentazon was completed in 2006 to support the proposed new use of bentazon to control weeds in peach and nectarine

orchards.

• The bentazon toxicity database is not complete. EPA needs the following guideline studies to reevaluate toxicological endpoints for bentazon:

o GDLN 870.7800 – Immunotoxicity

o GDLN 870.6200 – Acute Neurotoxicity – Rat

o GDLN 870.6200 – 90-day Neurotoxicity – Rat

• The bentazon residue chemistry database is sufficient to support all current bentazon registrations.

• The Agency anticipates conducting a complete dietary risk assessment, which includes a refined drinking water assessment, in registra tion review to incorpor ate updated estimated drinking water concentrations , updated percent crop treated information, and potential changes to toxicological e ndpoints and safety factors.

• The Agency anticipates revising the bentazon residential risk assessment in registration review. A higher applicati on rate (application by comme rcial applicators only) is registered for use on residential lawns and has not been assessed for post-application exposure. In addition, updated transfer coeffi cients are available for the post-application dermal assessment. Lastly, a golfer post-app lication assessment will need to be conducted as part of registration review.

• The Agency anticipates revisi ng the aggregate risk assessmen t in registration review to incorporate revised residential and dietary a ssessments as well as any new toxicological endpoints and safety factors.

• The Agency anticipates revising the occupationa l risk assessment in registration review to incorporate revised toxicological endpoints and several handler and post-application exposure scenarios that have not been previously assessed.

• For a detailed discussion of the human health risk assessment and data needs refer to the Bentazon. Human Health Assessment Scoping Do cument in Support of Registration Review (March 17, 2010), which is av ailable in the docket.

Other Data Needs:

• GLDN 830.7050 UV/Visible Li ght Absorption – this study is a new data requirement under 40 CFR part 158 (Product Chemistry Data Requi rements) for registration of a pesticide (food and non-food uses). The Agency antici pates requiring this study to obtain basicinformation about the compound’s identity/com position and the wavelengths at which the compound may be susceptible to photochemical degradation.

Endocrine Disruptor Screening Program

As required under FFDCA section 408(p), EP A has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substances (inc luding pesticide active and other ingredients) may have an effect in humans or wildlife si milar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two-tiered ap proach 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 estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine related eff ects caused by the substance, and establish a quantitative relationship betw een the dose and the E, A, or T effect.

Between October 2009 and February 2010, EPA issu ed test orders/data call-ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. This list of chemicals was sele cted based on the potenti al for human exposure through pathways such as food and water, resi dential activity, and cer tain post-application agricultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Bentazon is not among the group of 58 pesticide active ingredients on th e initial list to be

screened under the EDSP. Under FFDCA sec. 408(p) the Agency must screen all pesticide chemicals. Accordingly, EPA anticipates i ssuing future EDSP orders/data call-ins for all Registration Review cases, including those for which EPA has already opened a Registration Review docket for a pestic ide active ingredient.

For further information on the status of the ED SP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery, plea se visit our website: http://www.epa.gov/endo/

.Timeline

The Agency has created the following estimated timeline for the completion of the bentazon registration review.

Registration Review for Bentazon– Proj ected Registration Review Timeline

Activities Estimated Date Opening the docket Open Docket and Public Comment Period 2010 – March

Close Public Comment 2010 – May Case Development

Final Work Plan 2010 – September

Issue DCI 2011 – April – June

Data Submission 2013 – April – June Open Public Comment Period for Preliminary Risk Assessments 2014 – Oct. – Dec.

Close Public Comment Period 2015 – Jan. – March Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision 2015 – April - June

Close Public Comment Period 2015 – July – Sept. Final Registration Review Decision and Begin Post-Decision Follow-up 2016 Total (years) 6

Next Steps

The Agency plans to issue a Data Call-In (D CI) for bentazon in 2011. This new data will

be used to conduct the risk assessments out lined in this FWP for all bentazon uses.