Docket Number EPA-HQ-OPP-2009-0160 www.regulations.gov

Fluridone Final Work Plan for Registration Review

March 2010

Case Number 7200

Approved by: ___________________________ Richard P. Keigwin, Jr. Director, Pesticide Re-evaluation Division

Date: ___________________________2 Introduction:

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP) for the registration review of fluridone. The Fi nal Work Plan includes the expected registration

review timeline. The FWP also addresse s public comments received concerning the Preliminary

Work Plan (PWP) in the Summary Document which was posted in th e fluridone registration review docket (EPA-HQ-OPP-2009-0160) 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 registration re view program and will review each registered pesticide every 15 years to determine whether it continues to meet the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) standard for registration. Changes in science, public policy, and pesticide use practices occur over time. The registra tion review program is intended to make sure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides continue to meet that st atutory standard. The pub lic phase of registration review begins when the initial docket is opened for each case. Information on this program is provided at http://www.epa.gov/oppsrr d1/registration_review/

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Fluridone is a systemic aquatic herbicide us ed to manage aquatic weeds in ponds, lakes, reservoirs, irrigation canals, drai nage canals, and rivers. It ha s two degradates of concern: Nmethyl formamide (NMF) and 3-trifluoromethyl benzoic acid. Fluridone is registered for residential use on ponds. It is par ticularly useful for the control of hydrilla in the southern states

and Eurasian milfoil in the northern states. Fluridone was the subject of a September 2004 “Report of the Food Quality Protection Act (FQP A) Tolerance Reassessment Progress and Risk Management Decision (TRED),” (available at http://www.epa.gov/oppsrrd1/REDs/fluridone_tred.pdf). Since fluridone was first registered in 1986, it was not subject to a Reregistration Eligibi lity Decision, but a tolerance reassessment was required under the 1996 Food Qualit y Protection Act (FQPA).

On September 23, 2009, EPA opened a 60-day public comment period for the registration review of fluridone. The Agency received comments from 30 parties, which included community groups, registrants, state and local governments, and commercial applicators. After reviewing acceptable studies that were submitted after the PWP’s publication, the Agency no longer anticipates requesting four studies for the fluridone technical grad e active ingredient (TGAI): an environmental chemistry method in soil (Guide line 835.6100), a freshwater early-life stage study (Guideline 850.1400), a freshwater fish life cycle study (Guideline 850.1500), and an acute toxicity study for freshwater fish (Guideline 850.1075). Howeve r, the Agency has not altered the six-year timeline detailed in the fluridone PWP.

In addition, the registrants may submit waiver requ ests for the required acute freshwater aquatic toxicity studies (Guidelines 850.1075 and 850.1010) for the fluridone ty pical end-use product (TEP) if the end-use product(s) tested in previous studies (MRIDs 000103297 & 000103309) are still representative of use. The registrants should submit these waiver requests in their 90-day3 response to the fluridone data call -in (DCI). The Agency will re view these waiver requests at

that time.

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

An overview of comments is presented in the “Summary of Comments Received during Docket Opening” section of this document. A more de tailed description of th e comments received and the Agency’s response to these comments are av ailable in the separate response memoranda from the Agency’s Environmental Fate and Eff ects Division (EFED) and Health Effects Division (HED) located in the fluridone registra tion review docket (E PA-HQ-OPP-2009-0160).

Summary of Comments Receive d During Docket Opening:

During the public comment period, the Agency r eceived comments from various stakeholders, which included commercial applicators who a pply fluridone, state and county agencies, the FIFRA Endangered Species Task Force, the W ithlacoochee Area Residents, Inc., and the registrants – SePRO Corporation and Tessenderlo KERLEY, Inc.

Commercial applicators and stat e and county government parties commented that fluridone is a highly valued tool for reducing dense populations of aquatic weeds as part of integrated longterm pest management. In addition, these parties noted that fluridone is selective and does not impair non-target, desirable aquatic plants. State and county commente rs included Lee County, Florida Hyacinth Control District, Washingt on State Department of Ecology, Louisiana Department of Wildlife and Fisheries, Southw est Florida Water Management District, Lake County Mosquito/Aquatic Plant Management Di vision, Seminole County, Florida, California Department of Boating and Waterways, Fl orida Fish and Conservation Commission, and California Department of Food and Agriculture. The Agency will consider these comments and fluridone’s benefits, pursuant to FIFRA, as appropriate, through registration review.

The FIFRA Endangered Task Force (FESTF) comme nted that SePRO Corporation and Kerley Trading, Inc, the registrants for fluridone, are no t FESTF members, and therefore must offer to pay FESTF to rely on FESTF submitted data or develop substantially similar data on their own.

Withlacoochee Area Residents Inc. described some of the environmental and ecological

deleterious effects it witnessed after fluridone application and urged EPA to fully consider effects to estuarine ecosystems during registration review.

Some specific comments and Agency responses are addressed below. Comments relevant to human health have been addressed by the Health Effects Division’s document, Fluridone, Response to Comments on the Preliminary Work Pl an for the Registration Review of Fluridone (2/22/2010). Comments rega rding the ecological fate or effects of fluridone have been addressed by the Response to Comments on Registration R eview – Problem Formulation for the4 Environmental Fate, Ecological Risk, and Endange red Species Assessment in Support of the Registration Review of Fluridone (2/24/2010).

The Agency has also revised the following registration review supporting documents for

fluridone: Registration Review: Pre liminary Problem Formula tion for Ecological Risk, Environmental Fate, and Endangered Species A ssessment for Fluridone, California Department of Pesticide Regulation Usage Data, and Appendix A: Food/Feed & Non-Food/Non-Feed Uses Considered in Registration Revi ew Work Planning (Appendix A) to reflect changes identified in OPP’s responses. These supporting documents, public comments, and data evaluation records completed after publication of the PWP ar e available in docket EPA-HQ-OPP-2009-0160 at www.regulations.gov.

SePRO Corporation

Comment 1:

SePro notes that the PWP states that ther e are tablet and emulsifiable concentrate (EC) formulations of fluridone current ly registered. However, SePRO clarified that there are no tablet or EC forms of fluridone currently regi stered, only pellets if in a solid state and aqueous suspension or soluble concen trate if in a liquid state.

Response: EPA thanks SePRO for clarifying the current formul ations of fluridone regi stered for use and has revised Appendix A to more accurately reflect registered formulations.

Comment 2: SePRO commented that other than applications that are made to dewatered aquatic sites (2 lbs/Acre) or recommended rates for static canals (40 lbs/Surface Acre), it is not possible to calculate a maximum application rate for formulated fluridone (i.e., Sonar®) in pounds/acre or gallons/acre. In EPA’s Appendix A: Food/Feed & Non-Food/Non-Feed Uses Considered in Registration Review Work Planning (Appendix A) , it is unclear how the maximum application rates were calculated for individual applic ations (e.g., 1.22 gal/A, 0.865 lb/A, or 0.2085 gal/A) and for the total maximum application rate al lowed per one growing season (e.g., 1 ppb/yr, 8.34 ppb/yr, or 16.68 ppb/yr). For example, in Appendix A, some of the liste d maximum application rates per application are greater than the maximum rate that can be applied per growing season. Fluridone (Sonar®) is applied to a 3-dimensi onal environment, and the water depth must be considered when determining how much product to apply per acre. Unless an assumption is made on the average depth used in this com parison, the amount of product applied will vary across sites depending on the water depth, even wh en the in-water concentration will be the same. For example, to apply 90 ppb in a pond with an average depth of 3 feet would require 0.18 gallons of Sonar A.S. (67690-4), while applying 90 ppb in a pond with an average depth of 5 feet would require approximately 0.3 gallons. In other words, 1 pound of fluridone in 3 acre feet of water is approximately 124 ppb, but in 5 feet of water that 1 pound of fluridone would result in approximately 74 ppb.5 Response: The Agency thanks SePRO for its comment and ha s revised Appendix A to reference applicable

concentrations instead of application rates.

Comment 3 : According to SePRO, there are no minimum retr eatment intervals (MRIs) listed on any of the registered labels. Appendix A lists 45 days for so me of the Use Sites. Retreatment intervals are determined by the need to maintain the active ingredient level in water at a predetermined concentration. This interval can vary depending on many conditions, but dilution of the treated water is the main determining factor.

Response: The Agency thanks SePRO for its comment. There are no MRIs for any fluridone products; Appendix A has been revised accordingly.

Comment 4: SePRO notes that in Appendix A, for the “Hum an Drinking Water Systems” use site, the EC and liquid formulations are allowed in New York due to the 24(c) that is activ e in the state for these formulations. SePRO also noted that the Sec tion 3 label in Georgia includes the “Aquatic Areas/Water” use site. Finally SePRO noted that under the “Streams/R ivers/Channeled Water” use site, for the EC formulation for fluridone , the Geographic Restriction column in the spreadsheet should indicate that th is use is allowed for Georgia due to the 24(c) that is active in

the state.

Response: EPA thanks SePRO for clarifying geographic restrictions for fl uridone use patterns and has revised appendix A accordingly.

Comment 5: SePRO queried usage data from the California Department of Pesticide Regulation Pesticide Information Portal (PIP), and noted the follow ing differences between its query results and EPA’s document entitled, “Fluridon e (112900), California Departmen t of Pesticide Regulation Usage Data” :

- For year 2007, the value of 40.95 pounds active ingredient applie d for the commodity “unknown” did not appear.

- For year 2005, the following data were available:

Commodity 2005 Pound Applied

Landscape Maintenance 586.43

Regulatory Pest Control 1677.83

Rights of Way 186.76

Structural Pest Control 207.54

Unknown 25.97

Water Area 858.85

Recreational Areas, Tennis Courts, Parks, etc 0.99866 Response: EPA thanks SePRO for identifying this usage data . This data was not available on January 9, 2009 when it was first queried by the Agency. Fluridone (112900), California Department of Pesticide Regulation Usage Data has been revised to incorpor ate this updated information.

Tessenderlo KERLEY

Comment 6 : According to Tessenderlo KERLEY, there were s everal errors and incorrect assumptions in the application rates specified Appendi x A. Fluridone is applied to obtain a desired concentration, not a specific application rate per Acre. The actual application rate per Acre can vary tremendously depending on the depth of the water body being treated, the desired concentration of fluridone, and the flow rate of the water body being treated. Therefore, it would be virtually impossible to determine the maximum rate per Ac re being treated withou t a hypothetical water body with specific dimensions. It would be mo re appropriate to specify the maximum single application rate of 90 or 150 ppb, depending on th e water body being treated, and a maximum rate per annual growth cycle (i.e. sum of all applications) of 90 or 150 ppb, depending on the water body being treated. In addition, the maximum application rate of 4.88 lb ai/A identified for EC products for certain water bodies is calculat ed from 156.2 fl. oz. of a 4 lb SC product per Acre. However, the rate of 156.2 fl. oz. is based on treating a water body with an average depth of 20 feet at 90 ppb, not at the allowed maximum of 150 ppb.

Response: Please see EPA’s response to comment 2 above.

Comment 7: Tessenderlo KERLEY notes that in Appendix A, the MRI for several use sites is listed as 45 days.

This is incorrect. There is no minimum retreatmen t interval specified on the labeling.

Response: Please see EPA’s response to comment 3 above.

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 27 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 issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pesticid e active ingredients and 9 inert ingredients.

This list of chemicals was selected based on th e potential for human exposure through pathways such as food and water, residen tial activity, and certain post-applic ation agricultural scenarios.

This list should not be construed as a lis t of known or likely endocrine disruptors.

Fluridone is not among the group of 58 pesticide active ingredie nts on the initia l 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, pleas e visit our website: http://www.epa.gov/endo/.

Risk Assessment and Data Needs:

The Agency anticipates conducting a comprehens ive ecological risk assessment, including an endangered species risk assessment, for all uses of fluridone. The Agency also anticipates conducting an occupational handler assessment for all fluridone products. In addition, once new hazard data is received (neuroto xicity and immunotoxicity), the Agency may reexamine points of departure and safety factors for fluridone and revise the human health risk assessment if necessary. Additional data that the Agency anticipates needing to complete these assessments

are included below.

Ecological Risk:

• The Agency has not conducted a risk asse ssment that supports a complete endangered species determination for the current use a nd usage of fluridone. The ecological risk assessment planned during registration revi ew will allow the Agency to reexamine

whether fluridone’s current use has “no effect” or “may affect ” federally listed threatened or endangered species (listed species) or their designated cr itical habitats. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical habitat, the Agency will consult w ith the FWS and/or National Marine Fisheries Service (the Services ), as appropriate.

• The Agency anticipates needing the followi ng data in order to conduct a complete ecological risk assessment, including an enda ngered species assessment, for fluridone and its metabolites: N-methyl formamide (NMF ) and 3-trifluoromet hyl benzoic acid:8 Fluridone Technical Grade Active Ingredient (TGAI)

o GDLN 850.1025 Acute toxicity estuarine/mari ne organisms: oyster shell deposition

o GLDN 850.1075 – Acute toxicity estuarine/marine fish

o GDLN 850.1300 – Aquatic inverteb rate life-cycle: daphnid

o GDLN 850.1500 – Fish life-cycl e: estuarine/marine

o GDLN 850.2100 – Avian oral toxi city: Passerine species

o GDLN 850.2300 – Avian reproduction: upland game bird and waterfowl species

o GDLN 850.3020 – Honeybee acute contact toxicity

o GDLNs 850.4400 and 850.5400 – Aquatic plant growt h, tier II aquatic plant growth (TGAI

or TEP)

o Special Study – whole sediment ch ronic freshwater invertebrate

Fluridone Typical End-Use Product (TEP)

o GDLN 850.1010 – Acute toxicity freshwater invertebrates 1

o GDLN 850.1025 Acute toxicity estuarine/mari ne organisms: oyster shell deposition

o GLDN 850.1075 – Acute toxicity estuarine/marine fish

o GLDN 850.1075– Acute toxicity freshwater fi sh: coldwater and warmwater species, preferably walleye and minnow 2

o GDLNs 850.4100, 850.4150 – Terrestrial plant toxici ty test, tier II seedling emergence and vegetative vigor

o GDLNs 850.4400 and 850.5400 – Aquatic plant growt h, tier II aquatic plant growth (TGAI

or TEP)

N-methyl formamide (NMF)

o GDLN 850.1010 – Acute toxicity freshwater invertebrates

o GLDN 850.1075– Acute toxicity freshwater fi sh: coldwater and wa rmwater species, preferably walleye and minnow

o GDLN 850.1300 – Aquatic inverteb rate life-cycle: daphnid

o GDLN 850.1400 – Freshwater fish early-life stage

o GDLN 850.2100 – Avian oral toxi city: Passerine species

o GDLN 850.2300 – Avian reproduction: upland game bird and waterfowl species

3-trifluoromethyl benzoic acid

o GDLN 850.2100 – Avian oral toxi city: Passerine species

o GDLN 850.2300 – Avian reproduction: upland game bird and waterfowl species

Please refer to the document, Registration Review: Preliminary Problem Formulation for Ecological Risk, Environmental Fate, and Endangere d Species Assessment for Fluridone, August 20, 2009 for a detailed discussion of the Agency’s an ticipated ecological risk and environmental

fate assessment needs.

1 The study submitted to fu lfill this guideline (MRID 000103 297) is acceptable. Therefore, the registrants may request a waiver for this data requirem ent if the end-use product used in the submitted study is still representative of current end use products.

2 The study submitted to fu lfill this guideline (MRID 000103 297) is acceptable. Therefore, the registrants may request a waiver for this data requirem ent if the end-use product used in the submitted study is still representative of current end use products.9 Human Health Risk:

• The Agency does not expect to conduct a dr inking water assessment (DWA) as part of registration review for fluri done because maximum applica tion rates to waters near drinking water inputs have not increased since the 2004 TRED.

• The dietary exposure database for fluridone is complete, and EPA does not anticipate conducting additional dietary asse ssments for the registration review of fluridone unless endpoints or safety factors change as a result of new toxicity data.

• Residue chemistry data are adequate to s upport all tolerances; how ever, the tolerance expression in 40 CFR § 180.420 should be revise d during registration review to ensure that it appropriately addresses the metabolites and degradates of fl uridone. The proposed revisions are to the chemical description rather than the individual tolerance levels. (See

the “Tolerances and International Harmonizati on” section of the Fact Sheet for more detail).

• Residential application exposur es from all fluridone products have been assessed, and no risks of concern have been identified; therefore, EPA does not anticipate conducting additional residential exposure assessments in registration review unless endpoints or safety factors change as a re sult of new toxicity data.

• The Agency estimated aggregate exposure and risk from dietary exposure (food and water) and exposures from swimming in tr eated water bodies in 2004. However, after 2004, EPA issued the first fluri done registration with a reside ntial use. Nevertheless, EPA does not anticipate conducting a new aggregat e assessment, unless endpoints or safety factors change as a result of new toxicity data, because the mo st recent aggregate assessment showed risks considerably be low the level of concern, and the new registration would not result in sign ificantly different exposures.

• Most fluridone products have not been asse ssed for occupational exposure; therefore, EPA anticipates completing an occupational ha ndler assessment in re gistration review. Post-application exposure to workers from prev iously treated water bodies is negligible; therefore, the Agency doe s not anticipate conducting a post-application exposure

assessment.

• The fluridone toxicity database is largely complete except for new studies required under the revised 40 CFR part 158. EPA anticipat es requiring the following guideline studies:

o GDLN 870.6200 Neurotoxicity Battery (acu te and subchronic neurotoxicity)

o GDLN 870.7800 Immunotoxicity Study10 • Please refer to Fluridone. Human Health Assessment Scoping Document in Support of Registration Review, July 16, 2009, available in the docket, for a detailed discussion of the anticipated risk assessment and data needs for completing the human health risk

assessment.

Other Data Needs:

• GLDN 830.750 UV/Visible Light Ab sorption – this study is a new data requirement under 40 CFR part 158 (Product Chemistry Data Requirements) for registration of a pesticide (food and non-food uses). The Agency anticipates requiring this study to obtain basic information about the compound’s id entity/composition and the wavelengths at which the compound may be suscepti ble to photochemical degradation.

Timeline:

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

Registration Review for Fluridone – Pr ojected Registration Review Timeline

Activities Estimated

Year/Month Opening the Docket Open Docket and Public Comment Period September 2009

Close Public Comment November 2009 Case Development
Issue Final Work Plan (FWP) March 2010 Issue Data Call-in (DCI) October – December

2010

Data Submission October – December

2012 Open Public Comment Period for Preliminary Risk Assessments April – June 2014 Close Public Comment Period July – September

2014 Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision October – December

2014 Close Public Comment Period January – March

2015

Final Registration Review D ecision & Begin Post-Decision Follow-up 2015

Total (years) 611 Next Steps:

As noted previously, the Agency anticipates requiring several ecologi cal effects and human health studies through a Data Call-In Notice, expected to be issued in 2010. This new

information will be used to conduct the risk asse ssments outlined in this FWP for all fluridone

uses.