2 INTRODUCTION

This is the Environmental Protection Agency’s (E PA or the Agency) Final Work Plan (FWP) for the registration review of DMDS. This work plan addresses public comments received concerning the Preliminary Work Plan (PWP), which was posted in the DMDS registration review docket (EPA-HQ-OPP-2013-0488). DMDS is a broad-spectrum pre-pl ant soil fumigant currently registered for use to control or suppr ess nematodes, various soil borne pathogens, and weeds on the following crops: strawberry, tomat o, pepper, eggplant, cucumber, squash (all varieties), melons (all varieties) , blueberry, forest nursery crop s and field grown ornamentals. The registered uses of DMDS as a pre-plant soil fumigant are considered non-food because DMDS quickly degrades or is metabolized into non-toxic degradates in the soil. The strong odor of DMDS is described as the smell of garlic or rotting/decaying matter; however the odor threshold is orders of magnitude below the le vel where nasal irritation is identified and may serve as a warning that the chemi cal is being used in the area.

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 DMDS. Las tly, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

There are no additional updates on DMDS since the PWP.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the DMDS Preliminary Work Plan, which opened on December 20, 2013 and closed on February 18, 2014, the Agency received one public comment, from the Center for Biological Divers ity. EPA’s response to th is comment is included

in this section. The comment addresses the time line described in the PWP as well as the planned ecological risk assessment with re gard to threatened and endangered species. 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.

1 http://www.epa.gov/oppsrrd1/registration_review/3 The public comment did not result in changes to the anticipated re gistration review data needs, risk assessments, or timeline.

Comments submitted by the Center for Biol ogical Diversity located at EPA-HQ-OPP-2013-

0488-0009.

Comment : The Center for Biological Diversity ’s (CBD) comments focus on the EPA’s independent duty under the Endangered Species Ac t (ESA) to consult with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (the Services) on the registration review of DMDS.

Response : EPA has reviewed the comments from CBD on the registration review docket opening for DMDS and plans to address many of the conc erns 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 will address concerns specific to DMDS in connection with the developm ent of its registration review

decision for DMDS.

At this time, EPA has not fully developed its ri sk assessment process for listed species. In November 2013, the EPA, along with the Services and the U.S. Department of Agriculture (USDA) released a summary of their joint Inte rim Approaches for assessing risks to listed species from pesticides. The Interim Approaches were developed jointly by the Agencies in response to the National Academy of Sciences ’ (NAS) recommendations and reflect a common approach to risk assessment shared by the Agencies as a way of a ddressing scientific differences between the EPA and the Services. The NAS report, available at http://www.nap.edu/cata log.php?record_id=18344 , outlines recommendations on specific

scientific and technical issues related to the de velopment of pesticide risk assessments that EPA

and the Services must conduct in connection wi th their obligations unde r the ESA and FIFRA. The joint Interim Approaches were released prio r to a stakeholder workshop held on November 15, 2013. In addition, the EPA presented the jo int Interim Approaches at the December 2013 Pesticide Program Dialogue Committee (PPDC) and State-FIFRA Issues Research and Evaluation Group (SFIREG) meeti ngs, allowing additional opport unities for stakeholders to comment on the Interim Approaches. 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 deve lopment of upcoming Registration Review decisions. The details of the jo int Interim Approaches are cont ained in the white paper “Interim Approaches for National-Level Pesticide Enda ngered Species Act Assessments Based on the Recommendations of the National Academy of Sciences April 2013 Report,” dated November 1, 2013, available at http://www.epa.gov/espp/2013/nas.html

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PLANNED DATA NEEDS

Table 1 below summarizes the planne d data needs for DMDS based on the EFED Registration Review Problem Formulation for Dimethyl Disulfide and the Dimethyl Disulfide Human-Health Assessment Scoping Document in Support of Registration Review . The planned data needs have not changed from what was included in the PWP.4 Table 1: Anticipated Data Needs for the DMDS Registration Review

Guideline

Number 2 Study Title 2 Test

Material Estimated

Timeframe

(Months from receipt of DCI)

NonGuideline Acute Honey Bee Vapor Exposure TGAI 24

Outstanding Data Requirements from Conditional Registration 3

875.1300 Inhalation Exposure, out door (broadcast shank injection with a high barrier tarp) TEP Due September 1,

2014

875.1300 Inhalation Exposure, outdoor (raised bed shank injection with a high barrier tarp) TEP Due September 1,

2014

875.1300 Inhalation Exposure, outdoor (raised bed drip irrigation with a high barrier tarp) TEP Due September 1,

2014

835.8100 Field volatility (broadcast shank injection with a high barrier tarp) TEP Due September 1,

2014

835.8100 Field volatility (raised bed shank injection with a high barrier tarp) TEP Due September 1,

2014

835.8100 Field volatility (raised bed drip irrigation with a high barrier tarp) TEP Due September 1,

2014
850.4150 Terrestrial plant toxicity, vegetative vigor tier II TEP In Review
TGAI = technical grade active ingredie nt; TEP = typical end-use product;

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 Availability” 77 FR 38282, June 27, 2012. http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPPT-2009-0154-0028

3 The studies listed in this section were previously requi red as conditions of registration [July 9, 2010] and were

outstanding at the time of the PWP. These studies will not be included in the anticipated Registration Review DCI because they are already required and have been submitted as conditions of registration. http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPP-2007-0092-00295 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 DMDS. For human health, EPA will conduct revised occupational and residential ( bystander) risk assessmen ts during registration review. If toxicological endpoints or points of departure are revised base d on the data that are required for registration review, they will be cons idered in the new assessments, as well as any changes to the standard operating proce dures or default exposure assumptions.

Table 2 below summarizes the planned registrati on review risk assessments based on the EFED Problem Formulation and HED Scoping Document . The planned assessments have not changed

from what was included in the PWP.

Table 2: Planned Risk Assessments for the DMDS Registration Review

Type of Risk Assessment Conduct? Notes

Ecological and Environmental Fate Comprehensive ecological (species to be assessed include terrestrial and aquatic organisms), including endangered species Y

Incidents Will check for updates For a discussion of reporte d ecological incidents for DMDS, see page 23 of the Problem Formulation. No incidents have been reported for DMDS.

Human Health Dietary Food N Registered uses of DM DS are considered non-food; dietary exposure is not expected. Drinking water N Based on environmen tal fate data in water, the Agency does not expect DMDS to adversely impact drinking water sources. Occupational Handlers (mixers, loaders, applicators) Y Revised occupational risk assessments may be necessary based on submission of the conditionally required worker exposure and field volatility data

listed in Table 1. Post-application Y

Residential Handlers N There are currently no re gistered residential uses of

DMDS. Post-application N There are currently no registered residential uses of

DMDS. Bystander Y Additional or revi sed residential bystander risk assessments may be necessary based submission of the conditionally required wo rker exposure and field volatility data listed in Table 1.6 Other Aggregate N Evaluates the comb ined risk from dietary and residential exposures.

Cumulative N DMDS has not been identified as a member of a cumulative group that shares a common mechanism of toxicity. Tolerances N The currently register ed uses of DMDS as a pre-plant soil fumigant are considered non-food and do not require food tolerances.

Incidents Will check for updates For a discussion of reported human incidents for DMDS see page 9 of the Scoping Document and Dimethyl Disulfide (DMDS): Tier 1 Review of Human

Incidents

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TIMELINE

EPA has created the following estimated timelin e for the completion of the DMDS registration review in Table 3 below. The projected timeline has not change d since the PWP.

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

Activities Estimated Date Opening the Docket Open Docket and 60-day Public Comment Period Dec. 2013 – Completed Close Public Comment Feb. 2014 – Completed Case Development Final Work Plan May 2014 –Completed Issue DCI 2014 – July-September Data Submission 2016 – July-September 60-day Public Comment Period for Draft Risk Assessments 4 2018 – January-March Registration Review Decision 60-day Public Comment Period fo r Proposed Registration Review

Decision 2018 – July-September

Registration Review Decision and Begin Post-Decision Follow-up 2019 Total (years) 6

NEXT STEPS

As noted previously, the Agency plans to requ ire an ecological effects study for DMDS through a Data Call-In Notice, expected to be issued in 2014.

4 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.