2 

### DMDS Preliminary Work Plan

– Table of Contents

OVERVIEW

................................ ................................ ................................ ................................ ......... 4

ANTICIPATED DATA NEEDS

................................ ................................ ................................ ......... 5

STATUTORY AND REGULATORY AUTHORITY

................................ ................................ ...... 6

CHEMICAL FACTS

................................ ................................ ................................ ............................ 6

USE AND USAGE INFORMATION

................................ ................................ ................................ 7

RECENT ACTIONS

................................ ................................ ................................ ............................ 8

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

................................ .. 8

TIMELINE

................................ ................................ ................................ ................................ .......... 10

NEXT STEPS

................................ ................................ ................................ ................................ ..... 10

Appendix

– Additional Areas Considered in the DMDS Registration Review

.......................... 11

References:

This Preliminary Work Plan summarize s the Environmental Protection Agency's current position based on the following documents:

1. Dimethyl Disulfide Human

- Health Assessment Scoping Document in Support of Registration Review

. Charles Smith, Shalu Shelat, Nancy McCarroll

. D412525

. November 27, 2013

.

2. EFED Registration Review Problem Formulation for Dimethyl Disu l fide

. Gabe Rothman,

Jo e Dec ant

. D412524

. D ecember 3, 2013

.

3. Dimethyl Disulfide (DMDS): Tier 1 Review of Human Incident s. Elizabeth Evans, Shanna

Recore. D413869

. August 20, 2013

.

4. BEAD Chemical Profile (BCP) for Registration Review of Dimethyl Disulfide (029088)

. Leonard Yourman, Jihad Alsadek, Derek Berwald. June 24, 2013

.

5. EFED Label Data Report : Dimethyl Disulfide (029088)

. April 19, 20133 6. HED Master Label Data Report : Dimethyl Disulfide (029088). April 19, 2013

These and other supporting documents for the DMDS registration review case may be found in

the docket EPA

- HQ

- OPP

- 2013

- 0488 at http://www.regulations.gov

.4 OVERVIEW

The docket for DMDS is now open , initiating the first public comment period for this registration

review (docket number EPA

- HQ

- OPP

- 2013

- 0488 )

. DMDS is a broad

- spectrum pre

- plant soil fumigant currently registered for use to control or suppre ss nematodes, various soil borne pathogens, and weeds o n the following crops: strawberry, tomato, pepper, eggplant, cucumber

, squash (all varieties) , melons (all varieties ), blueberry, forest nurser y crops and field grown

ornamental s

. The registered uses of DMDS as a pre

- plant soil fumigant are con sidered 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 level where nasal irritation is identified and may serve as a warning that the chemical is being used in the area

. This Preliminary Work Plan (PWP) document e xplains what EPA's Office of Pesticide Programs knows about DMDS, highlighting anticipated data and assessment needs, identifying the types of information that would be especially useful to the Agency in conducting the review , and providing an anticipated timeline for completing the registration review for DMDS.

The registration review process was designed to include a public participation component to solicit input from interested stakeholders. The Agency intends, b y sharing this information in the

doc ket, to inform the public of what it knows about DMDS and what types of new data or other information would be helpful for the Agency to receive as it moves toward a decision on DMDS

. The Agency encourages all interested stakeholders to review the PWP and Appendix and to provide comments and additional information that will help the Agency’s decision

- making process for this chemical. In addition to general areas on which persons may wish to comment,

there are some areas identified in the PWP and Appendix about which the Agency specifically

seeks comments and information. Interested stakeholders could include: environmental non

profit or interest groups; pesticide manufacturers; agricultural labor or commodity groups; commercial, institutional, residentia l, and other users of pesticides; or the public at large.

The Preliminary Work Plan begins by listing the anticipated data needs for DMDS

. Next, it discusses the statutory and regulatory authority for R egistration R eview. Then the document provides chem ical facts, use and usage information, recent actions, the anticipated risk assessments, and a projected registration review timeline for DMDS

. Finally, the Appendix to

this document includes identification and discussion of some areas that are considered generally

in R egistration R eview along with some additional chemical case

- specific information.5 ANTICIPATED DATA NEEDS

Table 1 below summarizes anticipated data needs for DMDS . For additional discussion of the anticipated data needs, see the EFED Registration Review Problem Formulation for Dimethyl

Disu l fide and Dimethyl Disulfide Human

- Health Assessment Scoping Document in Support of Registration Review

.

Table 1: Anticipated Data Needs for the DMDS Registration Review

Guideline

Number 1 Study Title 1 Test Material Estimated

Timeframe

(Months from receipt of DCI)

Non

Guideline Acute Honey Bee Vapor Exposure TGAI 24

Outstanding Data Requirements from Conditional Registration 2

87 5.1300 Inhalation Exposure, outdoor (broadcast shank injection with a high barrier tarp) TEP Due 4/ 1/201 4

875.1300 Inhalation Exposure, outdoor (raised bed shank injection with a high barrier tarp) TEP Due 4/1/2014

875.1300 Inhalation Exposure, outdoor ( raised bed drip irrigation with a high barrier tarp) TEP Due 4/1/2014

835. 8100 Field volatility (broadcast shank injection with a high barrier tarp) TEP Due 4/1/2014

835. 8100 Field volatility (raised bed shank injection with a high barrier tarp) TEP Due 4/1/2014

835. 8100 Field volatility ( raised bed drip irrigation with a high barrier tarp) TEP Due 4/1/2014

850.4150 Terrestrial plant toxicity, vegetative vigor tier II TEP Due 5/14/2 014 TGAI = technical grade active ingredient; TEP = typical end

- use product ;

1 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 A vailability” 77 FR 38282, June 27, 2012. http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0154

- 0028

2 The studies listed in this section were previo usly required as conditions of registration [July 9, 2010] and are still

outstanding. These studies will not be included in the anticipated Registration Review DCI because they are already required as conditions of registration. http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPP

2007

- 0092

- 00296 STATUTORY AND REGULATORY AUTHORITY

The Food Quality Protection Act (FQPA) of 1996 mandated a registration review program

. All pesticides distributed or sold in the United States (U.S.) generally must be registered by the Environmental Protection Agency (EPA or the Age ncy), based on scientific data showing that they will not cause unreasonable risks to human health or the environment when used as directed on product labeling. The registration review program is intended to make sure that, as the ability

to assess risk e volves and as policies and practices change, all registered pesticides continue to meet the statutory standard of no unreasonable adverse effects to human health or the

environment. Changes in science, public policy, and pesticide use practices will occur over time. Through the registration review program, the Agency periodically reevaluates pesticides to make sure that as change occurs, products in the marketplace can be used safely. Informatio n on this program is provided on EPA’s website

. 3

The Agency is implementing the registration review 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 the FIFRA standard for registration. The regulations governing registration review begin at 40 CFR 155.40

. T he Agency will consider benefits information and data as required by FIFRA. The public phase of registration review begins when the initial docket is opene d for each case. The docket is the Agency’s opportunity to state what it knows about the pesticide and what additional risk analyses and data or information it believes are needed to make a registration review decision. After reviewing and responding to comments and data received in the docket during this initial comment period, the Agency will develop a F inal W ork P lan (FWP) and anticipated schedule for the registration review of DMDS

.

CHEMICAL FACTS

Table 2 provides a summary of the chemical facts for DMDS

.

Table 2: Chemical Facts for DMDS

PC code 029088

Case Number 7454

CAS Number 624

- 92

- 0

Date first registered July 9, 2010 Pesticide Type Soil f umigant

Chemical class Reduced o rganosulfur c ompound

R eregistration Eligibility Decision (R E D) Because it was registered after November 1984, DMDS was not subject to reregistration.

Tolerance Reassessment Eligibility Decision (TRED) N ot applicable. DMDS does not require the es tablishment of food tolerances, because the currently registered uses of DMDS as a pre

plant soil fumigant are considered non

- food

. Cumulative group Not applicable . DMDS has not been identified as a member of a cumulative group that shares a common mechanism of toxicity.

3 http://www.epa.gov/oppsrrd1/registration_review/7 Table 2: Chemical Facts for DMDS

40 CFR Citation There are no established tolerances fo r DMDS. The currently registered uses of DMDS as a pre

- plant soil fumigant are considered non

- food and do not require food tolerances

. Dual

- use DMDS is registered for conventional pesticidal uses only and has no registered antimicrobial or biopesticidal uses

. Non

- pesticidal uses DMDS has industrial uses, primarily in the refining and petrochemical industries . I t is also used to dissolve elemental sulfur in order to unplug natural gas wells, as an additive to prevent metal dusting during the manufacture of ‘sponge iron

, ’ and as a thiomethylating agent in organic synthesis.

Pesticide Re

- evaluation Division, Chemical Review Manager Garland Waleko, waleko.garland@epa.gov , 703

- 308

- 8049

Registration Division

, Product Manager Tony Kish, kish.tony@eps.gov

, 703

- 308

- 9443

USE AND USAGE INFORMATION

Table 3 summarizes the use and usage information for DMDS

. Please see the BEAD Chemical Profile (BCP) for Registration Review of Dimethyl Disulfide (029088 ) in the registration review

docket for more details

.

Table 3 : DMDS Use and Usage Information

Summary of Use Dimethyl disulfide (DMDS) i s a broad

- spectrum pre

- pl ant soil fumigant registered for use to control or suppress nematodes, various soil borne pathogens, and weed s on the following crops: strawberry, tomato, pepper, eggplant, cucumber , squash (all varieties) , melons (all varieties ), blueberry, forest nursery crops and field grown ornamental s.

DMDS may be co

- applied with either chloropicrin , metam sodium, or 1,3

- dichloropropene; these combination s are expected to be methyl bromide replacement fumigants.

Use Sites P re

- plant soil fumigant on the following crops: strawberry, tomato, pepper, eggplant, cucumber , squash (all varieties) , melons (all

varieties ), blueberry, forest nursery crops and field grown

ornamental s. Summary of Usage EPA has no usage data for DMDS because it was first registered for

use in 2010. Formulation Type(s) Soluble concentrate, emulsifiable concentrate Application Method(s) Applied to the soil prior to planting via shank injection (broadcast or raised bed) or drip irrigation equipment. Labels require treated areas to be covered by high

- barrier, virtually impermeable film (VIF) tarps to redu ce emissions

.8 Table 3 : DMDS Use and Usage Information

Technical Registrant (s) Arkema, Inc. No. of Registrations 4 Section 3 products 4

. No Section 24c or Section 18 registrations

. Restricted Use Yes

Guidance for Commente rs: Additi onal areas of use and usage related information requested for this registration r eview , and of particular interest to EPA, are described below.

• C onfirmation of the following label information : sites of application ; formulations ; application methods and equipment ; maximum application rates ; frequency of application, and geographic limitations on use

.

• U se distribution ( e.g. , acreage and geographical distribution of relevant use sites )

.

• M edian and 90 th percentile reported use rates (lbs ai/ A ) from usage data

– national, state, and county

.

• Typical a pplication timing

– national, state, and county

.

• S tate or local use restrictions

.

• F oreign technical registrants not listed above who supply technical DMDS to the US

market

.

RECENT ACTIONS

DMDS was first re gistered for its current uses on July 9, 2010. Th ere are no other recent actions

for DMDS.

Most registration review dockets for active ingredients considered to be fumigant pesticides opened in September 2013; a lthough the DMDS docket is opening in December 20 13 it is still part of this group.

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

The most recent comprehensive human health risk assessment for DMDS was completed in April 2010 when DMDS was initially registered with EPA. T he most recent ecological and

environmental fate risk assessment was also completed April 2010 for the same purpose

. Findings and conclusions from these risk assessments are summarized in the EFED Registration Review Problem Formulation for Dimethyl Disu l fide and Dimethyl Disulfide Human

- Health Assessment Scoping Document in Support of Registration Revie w.

During registration review, t he Agency anticipates the need to conduct a comprehensive ecological risk assessment, including an endangered species asse ssment, for all uses of DMDS

. For human health, EPA anticipates the need to conduct revised occupational and residential (bystander) risk assessment s during registration review

. If toxicological endpoints or points of departure are revised based on the data that are anticipated to be submitted during registration

review (already required though conditional registration)

, they will be considered in the new

4 Section 3 product labels can be obtained f rom the Pesticide Produ ct Label System (PPLS) website ( http://oaspub.epa.gov/pestlabl/ppls.home ).9 assessment s
, as well as any changes to the standard operating p rocedures or default exposure
assumpt ions

.

T able 4 below summarizes the anticipated registration review risk assessments based on the

EFED Problem Formulation and HED Scoping Document

.

Table 4: Anticipated Risk Assessments for the DMDS Registration Review

Type of Risk Assessment Conduct ? Notes

Eco logical 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 reported ecological incidents for

DMDS , see page 23 of the Problem Formulation. No incidents have been reported for DMDS.

Human Health Dietary

Food N R egistered uses of DMDS are considered non

- foo d; dietary exposure is not expected. Drinking water N Ba sed on environmental 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 registered residential uses of

DMDS.

Post

- application N There are currently no registered residential uses of

DMDS. Bystander Y Additional or revised residential bystander risk assessments may be necessary based submission of the conditionally required worker exposure and field volatility data listed in Table 1.

Other Aggregate N E valuates the combined 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.10 Tolerances N The currently registered 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 Revie w of Human

Incidents

.

TIMELINE

EPA has created the following estimated timeline for the completion of the DMDS registration

review in Table 5 below

.

Table 5: Projected DMDS Registration Review Timeline

Activities Estimated Dat e Opening the Docket Open Docket and 60

- day Public Comment Period 2013

– December

Close Public Comment 2014

– February Case Development

Final Work Plan 2014

– May

Issue DCI 2014

– July

- September

Data Submission 2016

– July

- September

6 0

- day Public Comment Period for Draft Risk

Assessments 5 2018

– January

- March

Registration Review Decision

60

- day Public Comment Period for Proposed Registration Review Decision 2018

– July

- September

Registration Review Decision and Begin Post

- Decision

Follow

- up 2019

Total (years) 6

NEXT STEPS

After the 6 0

- day public comment period closes, the Agency will review and respond to any comments received in a timely manner and then issue a Final Work Plan for the registration

review of DMDS

.

5 The regulations governing Registration Review generally require the Agency to provide a public comment period

of at least 30 calendar days for draft risk as sessments; see 40 CFR Part 155.53(c). For conventional pesticides, t he Agency plans to provide a 60 calendar day public comment period generally for draft risk assessment s

.11 

### Appendix

– Additional Areas Considered in the DMDS Registration Review

PUBLIC COMMENTS AND FEEDBACK :

Guidance for C ommenters: The areas below highlight topics of special interest to the Agency where your comments, data submissions, or reference to sou rces of additional information c ould

be of particular use.

Trade Irritants:

Through the registration review process, the Agency intends to solicit information on trade irritants and, to the extent feasible, take steps toward facilitating irritant resolution. The Agency

will work to harmonize tolerances and international maximum residue limits (MRL s ) and may modify tolerance levels to do so, when possible

. Growers and other stakeholders are asked to

comment on any trade irritant issues resulting from lack of MRLs or disparities between U.S.

to lerances and MRLs in key export markets, providing as much specificity as possible regarding

the nature of the concern. Because DMDS is not registered for food/feed uses in the U.S., it has

no U.S. tolerances ; therefore, the Agency does not anticipate an y trade irritant issues for it.

Water Quality:

DMDS is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act

. 6 In addition, n o Total Maximum Daily Load s (TMDL)

have been developed for DMDS

. 7 More information on impaired water bodies and TMDLs can

be found at the Agency’s website

. 8 The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix

A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management Process 9
in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessments.

Environmental Justice:

EPA seeks to achieve environmental justice, the fair treatment and meaningful involvement of all people, regardless of race, color, national origin, or income, in the development, implementation, and enforcement of environmental laws, regulations, and policies. To help address potential environmental justice issues, the Agency seeks information on any groups or segments of the popula tion who, as a result of their location, cultural practices, or other factors, may have atypical, unusually high exposure to DMDS compared to the general population. Please comment if you are aware of any sub

- populations that may have atypical, unusually high exposure compared to the general population.

6 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

7 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_

group_name=PESTICIDES

8 http://www.epa.gov/owow/tmdl/

9 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm12 ENDANGERED SPECIES :

A risk assessment that supports a complete endangered species determination has not been

conducted for DMDS

. The ecological risk assessment planned during registration review will allow the Agency to determine whether use of DMDS has “no effect” or “may affect” federally listed threatened or endangered species (listed species) or their designated critical habit ats. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Services), as appropri ate.

ENDOCRINE DISRUPTOR SCREENING PROGRAM :

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and chronic toxicity, includi ng assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology,

or gan weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproducti ve effects in different taxonomic groups. As part of its recent registration decision for DMDS

, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as requir ed by FFDCA section 408(p), DMDS is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingredients) may hav e an effect in humans or wildlife similar 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 approach to making the statutorily required

determinatio ns. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have t he potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse e ndocrine

- related effects caused by the substance, and

establish a dose

- response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list of chemicals identified for EDSP screening was published on June 14, 2013 10 and includes some pesticides scheduled for registration r eview and chemicals found in water

. Neither of these lists should be construed as a list of known or likely endocrine disruptors.

10 See http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of

chemicals.13 For further information on the status of the EDSP, the policies a nd procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our

website. 11

HUMAN STUDIES :

Occupational

Past DMDS risk assessments rely in part on data from studies in which adult human subjects were intentionally exposed to a pesticide to determine their dermal and inhalation exposure. Many such studies, involving exposure to many different pesticides, comprise generic pesticide exposure databases such as the Pesticide Ha ndlers Exposure Database (PHED) and the Agricultural Reentry Task Force (ARTF) Database

. EPA has reviewed all the studies supporting

these multi

- pesticide generic exposure databases, and has found no clear and convincing evidence that the conduct of any of them was either fundam entally unethical or significantly deficient relative to the ethical standards prevailing at the time the research was conducted. A ll applicable requirements of EPA’s Rule for the Protection of Human Subjects of Research (40 CFR Part 26) have been satisfi ed , and t here is no regulatory barrier to continued reliance on

these studies

.

11 http://www.e pa.gov/endo/