2 INTRODUCTION

This is the Environmental Protection Agency’s (E PA or the Agency) Final Work Plan (FWP) for the registration review of clopyralid. This wo rk plan addresses public comments received concerning the Preliminary Work Plan (PWP), which was posted in the clopyralid registration review docket (EPA-HQ-OPP-2014-0167). Clopyralid (3,6-dichloropyridin e-2-carboxylic acid) is a pyridine herbicide. This case includes th e clopyralid parent al ong with its potassium, triethylamine, and monoethanolamine salts. Pyri dine herbicides are a uxin growth regulators, which mimic naturally-occurring plant hormones, thereby disrupting growth processes and causing abnormal growth patterns in plants. Clop yralid is registered for use on a variety of agricultural crops, and n on-crop use sites, including tree and s od farms, forests, pastures and rangelands, ornamental landscapes and nurseries, golf courses and recreational areas. Clopyralid may be applied as a broadcast foliar or soil-d irected spray via aircraft , ground- and hand-held sprayers, granular spreader or via tree injection.

The Agency is implementing the registration revi ew program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and will review each registered pesticide every 15 years to determine whether it continues to meet th e FIFRA standard for registration. Changes in scienc e, public policy, and pesticide us e practices occur over time. The registration review program is intended to make su re that, as the ability to assess risk evolves and as policies and practices change, al l registered pesticides continue to meet the statutory standard. The public phase of registration review begins wh en the initial 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 wa s issued. Next is a summary of substantive comments received during the public comment peri od 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 comme nts. This section is followed by registration review planned data needs, risk assessments expected to be conducted, and the projected registration review timeline for clopyralid. La stly, there is a discus sion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

On June 23, 2014, EPA, Health Canada’s Pest Management Regulatory Agency, and the California Department of Pesticide Regulation issued Guidance for Assessing Pesticide Risks to

Bees . This guidance describes a tiered risk assessment process, and associated data requirements, for any pesticides with registered us es resulting in non-target exposure to bees. In accordance with this guidance, EPA has ame nded the ecological problem formulation for clopyralid to add the following three honey bee toxicity studies. For deta ils, please see the September 8, 2014 memo, Addendum to the EFED Registration Review Problem Formulation for Clopyralid Regarding Tier I Honey Bee Toxicity Testing

.

- Pollinator Chronic Oral Toxicity – honeybee adult

- Pollinator Acute Oral Toxicity – honeybee larvae

- Pollinator Chronic Oral Toxicity – honeybee larvae

1 http://www.epa.gov/oppsrrd1/registration_review/3 Clopyralid uses include aerial applications to multiple agricultural cr ops, pastures, rangeland, agricultural fallow/idleland/conservation reserve, forest trees, and nonagricultural uncultivated areas/soils where spray drift ma y land on blooming non-target plants and could result in residues in pollen and nectar. The residues in pollen and nectar could then be transported to hives by adult forager bees and potentially affect larval honeyb ees. Given this potential exposure scenario and clopyralid’s highly persistent na ture, as with other members of the picolinic acid family, the Agency plans to require the afor ementioned studies for clopyralid.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on th e Clopyralid Preliminary Work Plan, which opened on March 28, 2014 and closed on May 28, 2014, the Agency received 10 public comments. Comments were submitted by Dow Agro Sciences, a technical registrant, and various stakeholders including: West Marin Compost Coaliti on, Florida Fruit & Vegetable Association, National Alfalfa & Forage Alliance, Chittenden So lid Waste District, Southern Minnesota Beet Sugar Cooperative, a certified crop advisor, FIFR A Endangered Species Task Force, and the Center for Biological Diversity. The comments do not address the timeline described in the PWP, but they do address the planned ecological and human health risk assessments and data needs. In the PWP, EPA also solicited comments on the specific topics of environmental justice, water quality concerns, and trade irritants, but no comments or information were received on

those issues.

This section does not capture every comment made about the PWP nor all of the Agency’s responses. Summarized below ar e public comments that resulted in changes to the anticipated registration review data needs, risk assessments, or timeline, or are of a broader regulatory nature. Public comments and EPA responses in their entirety are locat ed in the docket, EPAHQ-OPP-2014-0167.

Comments submitted by Dow AgroScie nces’ (Dow) in EPA-HQ-OPP-2014-0167-0015.

1. Comment: Dow provided use information on s everal clopyralid uses including key pests/uses. They also provided typical applic ation rates for certain uses as well as information to better understand risk from residues in groundwate r used as irrigation water.

Dow also states that several use sites lis ted in supporting docume nts are not currently registered uses on clopyralid labels. These us es are as follows: alfalfa, almonds, beans, chestnuts, filberts, lentils, macadamia nuts, peas , pecans, pistachio nuts, potatoes, safflower, sorghum, soybeans, sunflowers, and walnuts. Dow also noted that no tole rances exist for the following crops: soybeans, tree nuts, lentils, alfalfa, beans, peas, potatoes, safflower, sorghum or sunflower. Additionally, Dow commen ted that it is initia ting label amendments to better define non-spec ific use sites on labels.

Response: The Agency thanks Dow for the in formation provided, which will be used during the registration review of clopyr alid. The Agency also concurs with Dow’s comment that the crops listed by Dow are not regist ered for clopyralid and that no tolerances exist for the crops noted above. In regard to non-specific use site s on labels, the EPA will work with Dow to amend labels to better define non-specific use si tes prior to the prelim inary risk assessment.4 2. Comment: Dow states the CAS number is corr ect for clopyralid TEA (119308-91-7). However the definition of the form as clopyralid triethanolamine salt is incorrect and should read “triethylamine salt.”

Response: The Agency agrees that triethylam ine salt is the correct nomenclature and will be

used in future documents.

3. Comment: Dow currently has only one registered end use product containing the clopyralid acid, Curtail M (62719-86). It is Dow’s opinion that a restricted entry interval (REI) based on the toxicity package for the integrated sy stem (i.e., salt, not acid) is appropriate and protective of workers handling these formulati ons. If necessary, Dow is willing to add label language instructing workers to allow the spray to dry before reentry for liquid products containing the acid.

Response: The Agency concurs that the form, as applied, should be the form that dictates the REI. With regard to Dow’s opinion that an REI of 12 hours is adequate for the clopyralid product Curtail M (62719-86), further information is required to maintain the current REI of

12 hours.

4. Comment: Dow states that there are no residential use patterns or a use pattern that would allow professional application to residential turf or ornamentals. Therefore, home owners should not be exposed to clopyra lid applications at their home.

Response: Unless a product is classified as a re stricted-use pesticide, EPA assumes that the general public may apply the product. Under this assumption, the Agency conducts risk assessments as necessary based on the use patterns and hazard profile.

5. Comment: Concerning the seedling emergence (GDLN 850.4100) and vegetative vigor (GDLN 850.4150) data requirements, Dow proposed to continue to rely on existing data from MRID 40081401 and supplement it with data for formulation EF-24 3. Where no typical end use products exist for the clopyralid salts, Dow does not propose to conduct these

studies.

Response: The Agency has classified MRID 40081401 as supplemental due to a number of methodological limitations detailed in the data review (DP398834). This study does not fulfill the guideline requirement for tier 2 vegetative vigor and seedling emergence data for clopyralid. These studies are needed to assess risk to non- target terrestrial plants. EPA does agree that for the clopyralid triethylamine (TEA) salt (PC 117404) and the potassium salt (PC 117423) there are currently no active registrations for single active ingredient products (i.e., not co-formulated); therefore these studies s hould be conducted with the technical active ingredient. The Agency welcomes any additiona l information that Dow believes will address this uncertainty.5 Comments submitted by West Marin Compos t Coalition (WMCC), Chittenden Solid Waste District (CSWD), in EPA-HQ-OPP-2014-0167-0013/0018.

1. Comment: WMCC and CSWD expressed their opposition toward the continued registration of clopyralid, due to clopyralid’s persisten ce and presence in compost and the need for revised formulations that can reduce clopy ralid’s presence in compost. WMCC also expressed an interest in EPA expanding a produc t stewardship program for the picolinic

acids. Both stakeholders noted the economic co st of persistent herbic ide contamination in compost. CSWD also pointed out that compost holding times would not be adequate mitigation due to the burden it puts on composters.

Response: The Agency thanks WMCC and CSWD for their comm ents regarding the picolinic acid herbicides and their persisten ce in compost. The agency is aware of these issues and will seek additional compost industry input during the registration review process.

Comments submitted by Joe Hastings (a certifie d crop advisor), National Alfalfa & Forage Alliance (NAFA), Florida Fruit & Vegetable A ssociation (FFVA), and Southern Minnesota Beet Sugar Cooperative (SMBSC) in EPA-HQ-OPP-2014-0167-0011/0012/0019/0020.

1. Comment: Joe Hastings, NAFA, FFVA, and SMBSC expre ssed their support of the clopyralid registration noting its effectiveness as an herb icidal tool. FFVA also stressed the importance of maintaining the current post-harvest inte rval (PHI) of 1 day as strawberries are repeatedly harvested throughout the growi ng season. EPA’s Scoping Document currently states the need for an increase in PHI to 2 days for worker protection.

Response: EPA thanks Joe Ha stings, NAFA, FFVA, and SMBSC for their comments, which will be considered during registration review. EPA is working with Dow and FFVA to resolve the PHI early in registration review.

Comments submitted by Center for Biologi cal Diversity (CBD), in EPA-HQ-OPP-2014-

0167-0017.

1. Comment: The Center for Biological Diversity’s (CBD) comments focus on the EPA’s duty to

consult with the U.S. Fish and Wildlife Service and the Natio nal Marine Fisheries Service (the Services) on the registration review of clopyralid in accor dance with the Endangered Species Act (ESA). The CBD comments menti on various aspects of the risk assessment process, including use of the best available data to develop endangered species risk assessments, and evaluation of effects on endangered and threatened species and their designated critical habitat. CBD also expresses concern regarding the rigor of the Agency’s preliminary determina tions regarding the effects of cl opyralid on endangered and threatened (listed) species and their designated critical habitat for the clopyralid registration review.

Response: EPA has reviewed the comments fr om CBD on the registration review docket opening for clopyralid 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 Acad emy of Sciences (NAS) report. EPA will6 address concerns specific to clopyralid in connection with the development of its final registration review deci sion for this pesticide.

In November 2013, the EPA, along with the Serv ices and the USDA, released a summary of their joint Interim Approaches for assessing ri sks to endangered and threatened (listed) species from pesticides. The Interim Approaches were developed jointly by the agencies in response to the NAS recommendations and refl ect a common approach to risk assessment shared by the agencies as a way of addressing scientific differences between the EPA and the

Services. The NAS report 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 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 presen ted the joint Interim Approaches at the December 2013 Pesticide Program Dialogue Co mmittee (PPDC) and State-FIFRA Issues Research and Evaluation Group (SFIREG) meetings. The agencies also held a stakeholder workshop in April 2014, allowing additional oppor tunities for stakeholders to comment on the Interim Approaches. Additional works hops are planned to enhance stakeholder involvement; the next workshop is scheduled for October 2014. As part of a phased, iterative process for developing the Interim Approaches , the agencies will also consider public comments on the Interim Approaches in conn ection with the development of upcoming registration review decisions. The details of the joint Interi m Approaches are contained in

the white paper

, Interim Approaches for National-Level Pesticide Endangered Species Act Assessments Based on the Recommendations of the National Academy of Sciences April 2013 Report , dated November 1, 2013.

Given that the agencies are continuing to de velop and work toward implementation of the Interim Approaches to assess the potential risk s of pesticides to listed species and their designated critical habitat, the ecological problem formulation supporting this Final Work Plan for clopyralid does not describe the specific ESA analysis, including effects determinations for specific listed species or designated critical ha bitat, to be conducted during registration review. In the ecologica l problem formulation document for clopyralid, EPA described the screening-level risk assessment to determine the potential effects of clopyralid on all taxa of non-target wildlife a nd plants, which will assume that listed species and their designated critical hab itats may be present in the vi cinity of the application of clopyralid. This screening-le vel assessment will allow EPA to focus its future evaluations on the types of species where th e potential for effects exists on ce the scientific methods being developed by the agencies have been fully vett ed. While the agencies continue to develop a common method for ESA analysis, the planned screening-level risk assessment for the registration review of clopyralid will describe the level of ES A analysis completed for this particular registration review case. Once the ag encies have fully developed and implemented the scientific methods necessary to complete risk assessments for endangered and threatened (listed) species and their desi gnated critical habitats, these methods will be applied to subsequent analyses for clopyralid as part of completing this registration review.7 Comments submitted by FIFRA Endangered Species Task Force (FESTF), in EPA-HQOPP-2014-0167-0016.

1. Comment: The technical registrants for clopyralid, as identified on the fact sheet included in the PWP, are Albaugh, Inc., and Dow AgroSciences LLC, which are FESTF members and are entitled to rely on FESTF data.

Response: EPA appreciates FESTF’s comments and will consider this information during registration review. EPA also notes that the fa ct sheet included in the PWP identified United Phosphorus Inc. as a technical re gistrant for clopyralid in addition to those mentioned in the

comment.8 PLANNED DATA NEEDS

Table 1 below summarizes the data needs for clopyralid based on the EFED Registration Review Problem Formulation for Clopyralid

, Addendum to the EFED Regi stration Review Problem Formulation for Clopyralid Regarding Tier I Honey Bee Toxicity Testing and Clopyralid. Human Health Assessment Scoping Docu ment in Support of Registration Review . The table has been updated since the PWP to reflect updated guidance for assessing risk to bees, which resulted in the addition of three pollinato r toxicity studies to the data needs.

Table 1: Planned Data Needs for the Clopyralid Registration Review

Guideline

Number 2 Study Title 2 Test Material Estimated

Timeframe

(Months from receipt of DCI)

835.4100 Aerobic soil metabolism (3 additional soils) TGAI 24

835.4300 Aerobic aquatic metabolism (2 sediments) TGAI 24

850.1300 Chronic freshwater invertebrate TGAI 12

850.1400 Freshwater fish early-life stage TGAI 12

850.2100 3 Avian oral toxicity (passerine species) TGAI 12

850.2300 Avian reproduction (upland game species) TGAI 24

850.4100 4 Terrestrial plant toxicity, seedling emergence TEP 12

850.4150 4 Terrestrial plant toxicity, vegetative vigor TEP 12

850.4400 Aquatic vascular plant growth TEP 12

850.4500 Aquatic non-vascular plant growth (2 additional species) TEP 12

850.4550 Cyanobacteria Toxicity TEP 12

850.6100 Environmental chemistry methods and associated independent laboratory validations for soil, water, and compost Compost

sourced from

material treated

with TEP 12

NonGuideline 3 Dissipation Study in Compost Compost

sourced from

material treated

with TEP 12

2 On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850 – Ecological Effects Tests

– including renumbering and other designations or changes for some guideline studies. See “Final Test Guidelines; OCSPP 850 Series; Notice of Av ailability” 77 FR 38282 , June 27, 2012. http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPPT-2009-0154-0028

3 A protocol must be submitted to the Agency within 90 days of receipt of the DCI.

4 Data are required for four typical end use products, one each containing clopyralid, clopyralid monoethanolamine salt, clopyralid triethylamine salt, and clopyralid potassi um. Where no appropriate formulations exist for this purpose (i.e. for triethylamine salt, 117404 and potassium salt, 117423) studies should be conducted with the technical products.9 Table 1: Planned Data Needs for the Clopyralid Registration Review

Guideline

Number 2 Study Title 2 Test Material Estimated

Timeframe

(Months from receipt of DCI)

NonGuideline 3 Pollinator Chronic Oral Toxicity – honeybee

adult TGAI 12

NonGuideline 3 Pollinator Acute Oral Toxicity – honeybee larvae TGAI 12

NonGuideline 3 Pollinator Chronic Oral Toxicity – honeybee

larvae TGAI 12

Anticipated Data Needs for Clopyralid End-Use Products Co-formulated with other Herbicides

850.4150 5 Terrestrial plant toxicity, vegetative vigor TEP 12
TGAI = technical grade active ingredie nt; TEP = typical end-use product;

RISK ASSESSMENTS FOR REGISTRATION REVIEW

During registration review, the Agency will conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses of cl opyralid. For human health, EPA will conduct revised dietary and aggregate risk assessments during registration review. If toxicological endpoints or points of departure are revised based on the data that are required for registration review, they will be considered in th e new assessments, as well as any changes to the standard operating procedures or default exposure assumptions.

Table 2 below summarizes the planned registrati on review risk assessments based on the EFED Problem Formulation, Addendum to the EFED Re gistration Review Problem Formulation for Clopyralid Regarding Tier I Honey Bee Toxici ty Testing and HED Scoping Document. The planned assessments have been updated since the PWP to reflect updated Agency guidance, which resulted in the addition of a pollinator risk assessment.

5 Data are required for representative TEPs co-formulated with other herbicid es for the most sensitive crops from prior clopyralid studies (i.e., onion, snap bean, soybean, sunflower, tomato, and wheat).10 Table 2: Planned Risk Assessments for the Clopyralid Registration Review

Type of Risk Assessment Conduct? Notes

Ecological and Environmental Fate Comprehensive ecological (species to be assessed include terrestrial and aquatic organisms), pollinator, including endangered species Y Given current clopyralid us e patterns and anticipated pollinator exposure, a pollinator risk assessment will be conducted following recently completed guidance.

Incidents Will check for updates For a discussion of reported ecological incidents for clopyralid, see page 15 of the Problem Formulation.

Human Health Dietary Food Y The Agency plans to conduct an updated dietary assessment to incorporate new estimated drinking

water concentrations. Drinking water Y Occupational Handlers (mixers, loaders, applicators) N The need for a spray drift and volatilization risk assessment for clopyralid will be examined during registration review. Post-application N

Residential Handlers N The need for a spray drift and volatilization risk assessment for clopyralid will be examined during registration review.

Post-application N

Other Aggregate Y Evaluates the combined risk from dietary and residential/public recr eational exposures. Cumulative N/A Clopyralid has not b een identified as a member of a cumulative group that shares a common mechanism of toxicity. Tolerances Y The Agency anticipates working to harmonize tolerances/MRLs, where possible, during registration

review.11 Incidents Will check for updates For a discussion of reported human incidents for clopyralid, see page 10 of the Clopyralid. Human Health Assessment Scoping Document in Support of Registration Review . Due to the low frequency and generally low severity of in cident cases reported for clopyralid there does not app ear to be a concern at this time that would warrant further investigation.

TIMELINE

EPA has created the following estimated timeline for the completion of the clopyralid registration review in Table 3 below. The projected timeline has not changed since the PWP.

Table 3: Registration Review for Clopyralid – Projected Registration Review Timeline

Activities Estimated Date Opening the Docket Open Docket and 60-day Public Comment Period 2014 – March Close Public Comment 2014 – May Case Development Final Work Plan 2014 – September

Issue DCI 2014 Oct. – Dec.

Data Submission 2016 Oct. – Dec. 60-day Public Comment Period for Draft Risk Assessments [1] 2018 April - June Registration Review Decision 60-day Public Comment Period fo r Proposed Registration Review

Decision 2019 Jan. - March

Registration Review Decision and Begin Post-Decision Follow-up 2020 Total (years) 6

NEXT STEPS

As noted previously, the Agency plans to requir e several environmental fa te, ecological effects, and human health studies for clopyralid through a Da ta Call-In Notice, expect ed to be issued in

2014.

[1] The regulations governing Registration Review generally require the Agency to provide a public comment period

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 assessments.