2 

### Preliminary Work Plan

– Table of Contents

Overview 4

Anticipated Data Needs 5

Statutory and Regulatory Authority 7

Chemical Facts 7

Use and Usage Information 8

Recent Actions 12

Anticipated Risk Assessment s for Registration Review 12

Timeline 15

Next Steps 16

Appendix

– Additional Areas Considered in the Registration Review of Metam and MITC 17

References:

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

1. EFED and AD Registration Review Problem Formulation for Metam Sodium, Metam Potassium, and MITC. September 19, 2013

2. Metam Sodium, Metam Potassium, and MITC. Human Health Assessment Scoping Document in Support of Registration Review. September 4, 2013

3. Metam Sodium, Metam Potassium, MITC: Review of Human Incidents

. August 29, 2013

4. BEAD Chemical Profile (BCP) for R egistration Review: Methyldithiocarbamate Salts Chemical Case [Includes Metam

- sodium (039003) and Metam

- potassium (039002)]. July 15, 2013

5. BEAD Chemical Profile (BCP) for Registration Review: Methyl Isothiocyanate (MITC) (068103). February 19, 2013

6. Metam Sodium (039003) Screening Level Usage Analysis (SLUA). April 30, 20123 7. Metam Potassium (039002) Screening Level Usage Analysis (SLUA). April 30, 2012

8. PRD Label Data Report: Food/Feed & Non

- Food/Non

- Feed Uses Considered in Registration Review Work Planning. Metam Sodium (039003). December 21, 2012

9. PRD Label Data Report: Food/Feed & Non

- Food/Non

- Feed Uses Considered in Registration Review Work Planning. Metam Potassium (03900 2 ). March 07 , 2013

10. Amended Reregistration Eligibility Decision (RED) for the Methyldithiocarbamate Salts (Metam sodium, Metam potassium) and Methyl Isothiocyanate (MITC). May 2009

.

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

m ethyldithiocarbamate s alts docket EPA

- HQ

- OPP

- 2013

- 0140 and the methyl isothiocyanate

docket EPA

- HQ

- OPP

- 2013

- 0242 at http://www.regulations.gov

.4 OVERVIEW

The docket s for the methyldithiocarbamate salts (metam sodium, metam potassium) (docket

numbers EPA

- HQ

- OPP

- 2013

- 0140) and methyl isothiocyanate ( MITC) (docket number EPA

HQ

- OPP

- 2013

- 0242 ) are now open , initiating the first public comment period for th ese registration review s

. Th ese case s include the following active ingredients: metam sodium

, metam potassium

, MITC

. Metam sodium and metam potassium (hereafter referred collectively as “metam”) are n on

- selective fumigant biocides registered for use as pre

- plant soil fumigants for

use on a variety of food, feed

, fiber crops , forest trees, ornamentals and turf, including golf

courses, to kill soil dwelling pests (fungi, weeds, insects, and nematodes). There are several non

agricultural registered uses of metam , including antimicrobial uses and sewer root control use

. After application metam

- sodium and metam

- potassium break down quickly to the primary toxic degradate, MITC gas. MITC is highly volatile and is responsible for biocidal properties of these fumigants

. In addition to being a degradate of metam, MITC is also registered as an antimicrobial active ingredient for use in a variety of products

. There are no registered residential uses of metam or MITC products. MITC is also the primary degradate of the fumig ant active ingredient dazomet, which is addressed as a separate registration review case.

This Preliminary Work Plan (PWP) document explains what EPA's Office of Pesticide Programs

knows about metam and MITC

, highlighting anticipated data and assessment n eeds, 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 metam and

MITC

.

The registration review process was design ed to include a public participation component to solicit input from interested stakeholders. The Agency intends, b y sharing this information in the docket, to inform the public of what it knows about metam and MITC and what types of new

data or other info rmation would be helpful for the Agency to receive as it moves toward a

decision on metam and MITC. The Agency encourages all interested stakeholders to review the

PWP and Appendix and to provide comments and additional information that will help the Agenc y’s decision

- mak ing 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 s eeks comments and information. Interested stakeholders could

include: environmental non

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

The Preliminary Work Plan begins by listing the anticipated data needs for metam and MITC

. Next, it discusses the statutory and regulatory authority for R egistration R eview. Then the document provides chemical facts, use and usage information, recent actions, the anticipated r isk assessments, and a projected registration review timeline for metam and MITC

. 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 ch emical case

- specific

information.

ANTICIPATED DATA NEEDS5 Table 1 below summarizes anticipated data needs for metam and MITC. For additional discussion of the anticipated data needs, see the EFED and AD Registration Review Problem Formulation for Metam S od ium, Metam Potassium, and MITC, September 19, 2013

, and Metam Sodium, Metam Potassium, and MITC. Human Health Assessment Scoping Document in Support of Registration Review , September 4, 2013

.

Table 1: Anticipated Data Needs for the Metam and MITC Registration Review

Guideline

Number Study Title Test Material Estimated

Timeframe

(Months from receipt of DCI)

Anticipated Data Needs for All Uses of Metam and MITC

835.4300 Aerobic a quatic m etabolism MITC 24

850.4100 Terrestrial plant toxicity, seedling emergence MITC 12

850.6100 Environmental chemistry methods and associated independent laboratory v alidation s for air and

water MITC 12

Non

guideline Acute vapor exposure honey bee study MITC 12

Anticipated Data Needs for Soil Fumigant Uses of Metam

835.8100 Field v olatility

– shank bedded application M etam TEP 12

Outstanding Data Requirements from Post

- RED DCIs for All Uses 1

870.3 800 Reproduction and fertility effects MITC Due April 2014

870. 4200 Carcinogenicity MITC Due April 2014

835.8100 Field volatility from soil

– center pivot application M etam

– TEP

(metam soil fumigant product) Under review

850.1025 Oyster acute toxicity test (shell deposition) MITC Under review

850.1035 Mysid acute toxicity test MITC Under review

850.1075 Fish acute toxicity test, freshwater and marine MITC Under review

850.3020 Honey bee acute contact toxicity MITC Under review

850.4150 Vegetative v igor (Tier II) MITC Under review

850.4400 Aquatic p lant g rowth t oxicity (Tier II) MITC Under review

870.3700 Prenatal developmental toxicity study MITC Under review

870.6200 Neurotoxicity screening battery MITC Under review

Out standing Data Requirements from Post

- RED DCIs for Sewer Uses Only 2

1 The studies listed in this section were previously required through generic metam sodium (metam

- Na) and metam

potassium (metam

- K) data call

- in s (DCI) issued in March 2010 a nd are still outstanding . The DCI numbers are as follows: Soil Fumigant Registrants (Metam

- Na: GDCI

- 039003

- 28196, Metam

- K: GDCI

- 039002

- 28888); Antimicrobial Registrants (Metam

- Na: GDCI

- 039003

- 29028 , Metam

- K: GDCI

- 039002

- 29030 ); Sewer Use Registrants (Metam

- Na: GDCI

- 039003

- 29029 ); MITC registrants ( GDCI

- 068103

- 29026 ). These studies will not be included in the anticipated Registration Review DCI because they are already required through the earlier

DCI s

.6 Table 1: Anticipated Data Needs for the Metam and MITC Registration Review

Guideline

Number Study Title Test Material Estimated

Timeframe

(Months from receipt of DCI)

875.1300 Inhalation exposure

-- outdoor Metam

– TEP

(metam sewer root
control use product) Under review

875.1700 Product u se i nformation Metam

– TEP

(metam sewer root
control use product ) Under review

Out standing Data Requirements from Post

- RED DCIs for Soil Fumigant Uses Only 3

Non

guideline Ambient a ir m onitoring p rogram Metam

– TEP Due March

2014

Out standing Data Requirements from Post

- RED DCIs for Antimicrobial Uses Only 4

875.1200 Dermal exposure

-- i ndoor TEP Extension requested*

875.1400 Inhalation exposure

-- indoor TEP Extension requested*

875.1600 Application exposure monitoring data reporting TEP Extension requested*

875.1700 Product u se i nformation TEP Extension requested*

875.2500 Inhalation exposure TEP Extension requested*

875.2700 Product u se i nformation

– p ost

- application TEP Extension requested*

875.2800 Description of human activity TEP Extension requested*

875.2900 Data reporting and calculations TEP Extension requested*
TGAI = technical grade active ingredient; TEP = typical end

- use product ; * The recently submitted extension request will be reviewed prior to issuing the Final Work Plan.

2 The studies listed in this section were previously required through a generic metam sodium (metam

- Na) data call

in (DCI) issued in March 201 0 a nd are still outstanding . The DCI number is as follows: Metam

- Na: GDCI

- 039003

- 29029

. These studies will not be included in the anticipa ted Registration Review DCI because they are already required through the earlier DCI s

. 3 The studies listed in this section were previously required through generic metam sodium (metam

- Na) and metam potassium (metam

- K) data call

- in s (DCI) issued in March 201 1 a nd are still outstanding . The DCI numbers are as

follows: Metam

- Na: GDCI

- 039003

- 840 , Metam

- K: GDCI

- 039002

- 839

. These studies will not be included in the anticipated Registration Review DCI because they are already required through the earlier DCI s

. 4 The studies listed in this section were previously required through generic metam sodium (metam

- Na) and metam potassium (metam

- K) data call

- in s (DCI) issued in March 201 0 a nd are still outstanding . The DCI numbers are as

follows: Metam

- Na: GDCI

- 039003

- 290 28, Metam

- K: GDCI

- 039002

- 29030

. These studies will not be included in the anticipated Registration Review DCI because they are already required through the earlier DCI s

.7 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 Agency), based on scientific data showing that they will not cause unreasonable risks to human health or the envi ronment when used as directed on product labeling. The registration 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 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

. 5

The Agency is implementing the registration review program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, a nd 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 opened for each case

. The docket is the Agency’s opportunity to state what it knows about the pesticide and what addition al 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 metam and MITC.

CHEMICAL FACTS

Table 2 provides a summary of the chemical facts for metam and MITC.

Table 2: Chemical Facts for Metam and MITC

Metam Sodium Metam Potassium MITC

PC code 039003 039002 068013

Case Number 2390 2390 2405

CAS Number 137

- 42

- 8 137

- 41

- 7 556

- 61

- 6 Year first registered 1975 1973 1984 Pesticide Type Antimicrobial, f ungicid e , herbicid e , insecticid e
, nematicide

Chemical class Fumigant

R eregistration Eligibility Decision (R E D) 2008

– RED

2009

– Amended RED

5 http://www.epa.gov/oppsrrd1/registration_review/8 Table 2: Chemical Facts for Metam and MITC

Tolerance Reassessment Eligibility Decision (TRED) Not applicable

Cumulative group Not applicable

40 CFR Citation There are no established tolerances for metam or MITC. All registered food/feed uses are considered non

- food uses

. 6

Dual

- use Yes. Metam is registered for conventional and antimicrobial pesticidal uses . MITC is registered for antimicrobial uses only.

Non

- pesticidal uses There are no identified non

- pesticidal uses of metam or MITC.

Pesticide Re

- evaluation Division, Chemical Review Manager Jose Gayoso gayoso.jose@epa.gov (703) 347

- 8652
Antimicrobial Division,

Chemical Review Manager Wanda Henson

h enson.wanda@epa.gov ( 703 )

- 308

- 6345 Registration Division

, Product Manager Shaja Joyner joyner .shaja@epa.gov (703) 308

- 3194

USE AND USAGE INFORMATION

Table 3 and 4 summarize the use and usage information for metam and MITC. Please see the BEAD Chemical Profile (BCP) for Registration Review: Methyldithiocarbamate Salts Chemical

Case Includes Metam

- sodium (039003) and Metam

- potassium (039002)]. July 15, 2013 and the BEAD Chemical Profile (BCP) for Registration Review: Methyl Isothiocyanate (MITC)(068103). February 19, 2013

, in the registration review docket for more details on use and usage, as well as a summary of past alternatives and benefits assessments on metam soil fumigant uses

.

Table 3: Metam Sodium and Metam Potassium Product Use and Usage Information

Summary of Use and Sites Metam sodium and metam potassium are broad spectrum non

selective fumigants with fungicidal, herbicidal, insecticidal and nematicidal properties.

Conventional Uses Metam sodium and metam potassium are registered for pre

- plant soil fumigant use for: (1) ma ny food, feed, and fiber crops, (2) forest trees, (3) ornamentals, and (4) golf course turf.

Metam soil fumigant uses are meant to sterilize the soil prior to

6 Metam’s volatility in the environ ment and results of metabolism studies in plants assure that there is no reasonable expectation of finite residues to be incurred in/on any raw agricultural commodity when these products are applied according to label directions. Therefore, this fumigant d oes not require food tolerances and is not subject to the amendments to the FFDCA promulgated under the Food Quality Protection Act of 1996.

– Metam Sodium: Phase 5 Revised Chapter of the Reregistration Eligibility Decision Document (RED) . Smith, C. April 12, 2007.9 Table 3: Metam Sodium and Metam Potassium Product Use and Usage Information

planting a desired crop.

Metam sodium is also registered for use as a root control agent for

use in sewers and drains.

Antimicrobial Uses

Metam

- sodium is currently registered as an antimicrobial agent for: (1) wood poles/timbers, (2) leather processing (e.g., brine

- cured hides and skins), (3) sewage sludge/animal wastes.

Metam

- potassium is registered as an antimicrobial agent for: (1) pulp and paper production, (2) leather processing, (3) raw cane and beet sugar processing facilities, (4) coatings protective colloids, emulsion resins, and water

- thinned paints, (5) metal working cutting fluid s and oils, (6) petroleum operations, (7) water cooling tower systems, and (8) industrial water purification systems.

Some antimicrobial uses of metam were voluntarily canceled, effective February 17, 2009 (Federal Register Notice 73FR49196, August 20, 20 08). However, some canceled uses are still in the process of bei ng removed from product labels. 7

Therefore, t he remaining metam sodium uses that will be assessed during registration review are (1) wood poles/timbers, and (2) sewage sludge/animal wastes.

The remaining metam potassium uses that will be assessed during registration review are (1) pulp and paper production, (2) tanning drum leather processing, (3) recirculating water cooling tower systems, and (4) industrial water purification systems.

Summa ry of Usage Agricultural Usage Based on usage data from 2006

- 2011, metam

- sodium's annual agricultural usage averaged 42 million pounds of active ingredient (A. I.), treating an average of approximately 307 thousand acres, for an average application rate of 136 pounds active ingredient per acre. For the same time period, potatoes (57%) and carrots (17%) accounted for the largest percentages of usage in terms of total pounds of A. I. applied. Potatoes (55%) and carrots (14%)

7 The following metam sodium use has been canceled and will be removed from existing product label(s) during registration review : (1) leather processing (e.g., brine

- cured hides and skins).

The following metam potassium uses have been canceled a nd will be removed from existing product label(s): (1) leather processing (except for tanning drum leather), (2) raw cane and beet sugar processing facilities, (3) coatings protective colloids, emulsion resins, and water

- thinned paints, (4) metal working c utting fluids and oils, (5) petroleum operations, (6) once

- through water cooling systems, and (7) industrial water purification systems.10 Table 3: Metam Sodium and Metam Potassium Product Use and Usage Information

accounted for the largest percenta ges of total area treated (TAT).

For the same time period, metam

- potassium's annual agricultural usage averaged 12 million pounds of active ingredient , treating an average of approximately 77 thousand acres, for an average application rate of 150 pounds p er acre. Potatoes (56%) and tomatoes (14%) accounted for the largest percentages of usage in terms of total pounds of A. I. applied. Potatoes (51%) and tomatoes (16%) accounted for the largest percentages of total area treated.

Usage data is not available since label directions were changed as specified in the 2009 amended RED (e.g., buffer zones, restricted use classification, etc.).

Non

- Agricultural Usage

Non

- ag ricultural usage data for metam sodium and metam potassium are not available. Formulation Type(s) Both metam

- sodium and metam

- potassium are formulated as soluble concentrate, ready

- to

- use solution, and pressurized gas. Application Method(s) Soil fumigant Uses In agricultural settings, metam

- sodium and metam

- potassium are applied through chemigation or with tractor

- drawn e quipment. Chemigation methods include center pivot, lateral move, solid set sprinkler, drip irrigation, flood irrigation, border irrigation, and furrow irrigation. Tractor

- drawn applications are carried out with

v arious types of shank soil injection, rotary tiller, and spray blade injection equipment. Applications can either be tarped or untarped.

Sewer Uses In sewer use applications, metam

- sodium is applied using a foam applicator.

Antimicrobial Uses

The antimicrobial uses of metam sodium and metam potassium have a number of application methods, including open pour and manual application of pre

- filled tubes of solidified

- melt product for treatment of wood poles and pilings; metering pump for pulp and

paper , leather, cooling water towers, and industrial water purification; and metered injection for animal waste and sewage sludge treatment. Technical Registrant(s) Conventional and Antimicrobial: Amvac Chemical Corporation Conventional: Taminco, Tessenderlo K erley

Antimicrobial: Buckman11 Table 3: Metam Sodium and Metam Potassium Product Use and Usage Information

No. of Registrations Metam Sodium Section 3 products: 8 Conventional

– 20

Antimicrobial

– 8 Section 24(c) products: 11

Metam Potassium Section 3 products:

Conventional

– 5

Antimicrobial

– 7 Section 24(c) products: 2

Restricted Use Yes

– Soil fumigant and sewer uses

No

– Antimicrobial uses

Table 4 : MITC Product Use and Usage Information

Summary of Use and Sites MITC is registered as an antimicrobial agent for wood treatment. MITC is registered for use in large structural timbers (such as utility poles, pilling, and bridge timber). It is also registered for application to areas of timber where decay is suspected. Summary of Usage Usage data are not available for MITC products. Formulation Type(s) R eady

- to

- use s olution (impregnated material). Application Method(s) Manual application of pre

- filled tubes of solidified

- melt product for treatment of wood poles and pilings. Technical Registrant(s) MLPC International No. of Registrations Section 3 products: 1

Restricted Use No

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.

• Use/usage information on non

- agricultural (turf, sewer, ant imicrobial, etc.) use of metam

sodium and metam

- potasium would improve future assessments of the importance of these products.

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

.

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

.

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

– national, state, and county

.

• Typical a pplication timing (date of first application and application intervals)

– national, state, and county

.

8 Section 3 product labels can be obtained from the Pesticide Produ ct Label System (PPLS) website

( http://oaspub.epa.go v/pestlabl/ppls.home ).12 • Typical application interval (days)

.

• S tate or local use restrictions

.

• F oreign technical registrants not listed above who supply technical metam and MITC to
the US market

.

• Impact of post

- RED label changes on use/usage of metam products.

In addition, the Agency is interested in continuing the dialogue with stake holders on label issues that have evolved during the RED label implementation process

.

RECENT ACTIONS

Registration Act i o ns

In July and August 2013, three metam soil fumigant products were amended with reduced buffer zone distances for shank injection applications to bedded fields.

In April and May 2013 , the Agency received several FIFRA Section 24(c) Special Local Need regis trations for North Carolina and Virginia for soil fumigant pre

- plant application of metam to peanut fields . These registrations include buffer zone tables with application rates lower than what is available in the Section 3 metam soil fumigant labels.

Rer egistration

A Reregistration Eligibility Decision (RED) for metam and MITC was completed in 2008 and amended in 2009. As a result of the RED, a variety of risk mitigation measures were required to be implemented. For details on the mitigation measures, se e the Amended Reregistration Eligibility Decision (RED) for the Methyldithiocarbamate Salts (Metam sodium, Metam potassium) and Methyl Isothiocyanate (MITC ), dated May 2009 . Additionally, the Agency’s Soil Fumigant Toolbox website contains information on t hese and other soil fumigants: http://www.epa.gov/pesticides/reregistration/soil_fumigants/

. More information on the reregistration process can be found on the following website: http://www.epa.gov/pesticides/reregistration/index.htm

.

T he product reregistration process , which starts after completion of a RED, is still ongoing for

metam products

.

A dditionally , the Agency plans to work with stakeholders to determine if metam soil fumigant product labels should be reorganized or revised in order to clarify the Good Agricultural Practices and Buffer Zones that correspond to each of the various application methods.

ANT ICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

The most recent comprehensive human health risk assessment for metam and MITC was completed on August 30, 2009 as a third update on the human health risk assessment that was

conducted in preparation for the metam and MITC Reregistration Eligibility Decision (RED)

. The first version of the assessment was completed and released for public comment in 2004. Subsequent revisions were made to incorporate comments and new data. T he most recent13 ec ological and environmental fate risk assessment on metam and MITC was completed on December 29, 2010 to assess risk to the federally threatened California tiger salamander ( Ambystoma californiense )

, as part of the stipulated injunction ordered by the Federal District

Court for the Northern District of California in the case Center for Biological Diversity (CBD)

vs. EPA et al . (Case No. 07

- 2794

- JCS). The most recent comprehensive ecological and

environmental fate ri sk assessment for all uses of metam and MITC was completed in August

2004 in preparation for the metam and MITC RED. Antimicrobial risk was discussed in a May

2008 memo. Findings and conclusions from these risk assessments are summarized in EFED and AD Reg istration Review Problem Formulation for Metam Sodium, Metam Potassium, and MITC. September 19, 2013 and Metam Sodium, Metam Potassium, and MITC. Human Health Assessment Scoping Document in Support of Registration Review. September 4, 2013.

During registr ation review, t he Agency anticipates the need to conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses of metam
and MITC. For human health, EPA anticipates the need to conduct revised residential and

o ccupational risk assessment s during registration review

. If toxicological endpoints or points of departure are revised based on the data that are anticipated to be required for registration review

, they will be considered in the new assessment s
, as well as any changes to the standard operating

p rocedures or default exposure assumptions

.

T able 5 below summarizes the anticipated registration review risk assessments based on the

EFED Problem Formulation and HED Scoping Document

.

Table 5 : Anticipated Risk As sessments for the Registration Review of Metam and MITC

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 MITC will be considered the main stressor in the risk assessment. Due to the rapid conversion of metam to MITC, it is not expected that metam sodium and metam potassium will be bioavailable to terrestrial or aquatic organisms in any environmentally releva nt
concentration.

Incidents Will check for updates For a discussion of reported ecological incidents for metam and MITC, see page 28 of the Problem

Formulation.

Human Health Dietary

Food N There is no reasonable expectation of finite residues to be incurred in/on food and feed crops when metam sodium and metam potassium are used as preplant soil fumigants, so these uses are considered non

- food

uses, an d tolerances are not needed. There is also no

reaso nable expectation of finite residues in/on food

for the antimicrobial uses of metam sodium / potassium

and MITC

.14 Drinking water N Based on environmental fate data, the residual contents in soils, and monitoring data, the Agency does not expect MITC to adversely impact the drinking water sources such as surface water and ground water. However, a confirmatory updated drinking water assessment may be conducted in registration review. Occupational Handlers (m ixer s, loader s, applicators ) Y For soil fumigan t, sewer, and antimicrobial uses, updates to handler risk assessments are anticipated.

Post

- application Y An updated occupational post

- application risk assessment for some antimicrobial uses is anticipated.

N T he Agency does not anticipate conducting post

application risk assessments for soil fumigant and sewer use in registration review.

Residential

Handlers N There are no registered residential uses of

metam/MITC.

Post

- application N There are no registered residential uses of

metam/MITC. Bystander Y A revised residential risk assessment is anticipated in registration review to update risk to bystanders from inhalation exposure to MITC during and following soil fumigant uses of metam product s. Additionally, the Agency anticipates updating the fumigant factors document, which provides a discussion of values and parameters used as the basis

for buffer zone reduction credits as well as for establishing Good Agricultural Practices (GAPs) for

the soi l fumigants. Buffer zones and GAPs were required by the 2009 amended RED as measures to mitigate occupational and bystander risk.

Other Aggregate N E valuates the combined risk from dietary and residential exposures. No dietary risk is anticipated from metam and MITC uses. Therefore, and aggregate assessment is not anticipated.

Cumulative N Metam and MITC are not members of a cumulative group, so no cumulative risk assessment is planned.15 Tolerances N U ses are considered non

- food uses, so tolerances are

not needed.

Incidents Will check for updates For a discussion of reported human incidents for metam and MITC, see page 12 of the Scoping

Document and the Metam Sodium, Metam Potassium, MITC: Review of Hu man Incidents

. August 29, 2013.

Guidance for Commente rs: Additional ecological i nformation r equested for this registration r eview , and of particular interest to EPA, is described below.

• Ec ological incidents (non

- target plant damage and avian, fish, reptilian, amphibian and mammalian mortalities) not already reported to the Agency

.

• Water quality m onitoring data (see Appendix for further details)

.

• Wastewater treatment plant monitoring data following upstream uses of metam sodium sewer root control appl ications.

Guidance for Commenters: Additional human health information requested for this registration review, and of particular interest to EPA, is described below.

• Occupational or bystander exposure incidents as a result of soil fumigant applications.

• Uses of metam soil fumigant products that are not clearly associated with Good Agricultural Practices or Buffer Zones found on product labels.

TIMELINE

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

metam and MITC in Table 6 below

.

Table 6 : Projected Metam and MITC Registration Review Timeline

Activities Estimated Dat e Opening the Docket Open Docket and 60

- day Public Comment Period 2013

– September

Close Public Comment 2013

– November

Case Development

Final Work Plan 2014

– February

Issue DCI 2014 April

- June

Data Submission 2016 April

- June

6 0

- day Public Comment Period for Draft Risk

Assessments 9 2017 Oct.

– Dec.

Registration Review Decision

60

- day Public Comment Period for Proposed Registration Review Decision 2018 April

- June

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

of at least 30 calendar days for draft risk assessmen ts; 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

.16 Table 6 : Projected Metam and MITC Registration Review Timeline

Activities Estimated Dat e 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 metam and MITC.17 

### Appendix

– Additional Areas Considered in the Registration Review of

Metam and MITC

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. tolerances and MRLs in key export markets, providing as much specificity as possible regard ing

the nature of the concern. Since metam uses are pre

- plant and considered non

- food, and MITC is not registered for food/feed uses in the U.S., metam and MITC have no U.S. tolerances ; therefore, the Agency does not anticipate any trade irritant issues

.

Wat er Quality:

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

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

h ave been developed for MITC. More information on impaired water bodies and TMDLs can be

found at the Agency’s website

. 11 The Agency invites submission of water quality data for this pesticide in watersheds where soil fumigant use is prevalent

. 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 12 in order to ensure they can be used quantitatively or qualitatively in p esticide risk assessments.

Due to the large and rapid conversion of metam sodium and metam potassium to MITC (83 percent transformation and half life = 23 minutes), exposure to metam sodium and metam potassium in drinking water sources is not expected fro m pesticide applications.

In addition to the soil fumigant uses of metam sodium and metam potassium, there is a use in sanitary sewers to control tree roots. There is reportedly (Martyn, P., 2004) a contaminant (NDMA, nnitrosodimethylamine)in the product for which there is a National Recommended
Water Quality Criteria of 0.00069 

### : g/L (current/potential drinking water) and 3.0 

### : g/L (no potential for drinking water). The Agency also requests submission of NDMA and MITC

10 http://iaspub.epa.gov/tmdl_waters10/attains_ nation_cy.cause_detail_303d?p_cause_group_id=885

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

12 http://www.epa.gov/oppsrrd1/registration_revi ew/water_quality_sop.htm18 water quality data at the discharge poi nt in sewage treatment plants where MITC use in

sewers occurs

.

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 d evelopment, 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 population who, as a result of their location, cultural practices, or other factors, may have atypical, unusually high exposure to metam and/or MITC compared to the general population

. Please comment if you are aware of an y sub

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

ENDANGERED SPECIES :

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

conducted for metam and MITC. The ecologica l risk assessment planned during registration review will allow the Agency to determine whether use of metam and MITC has “no effect” or “may affect” federally listed threatened or endangered species (listed species) or their designated

critical habitats

. 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 appropriate.

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, including as sessments 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, organ w eights, 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 reproductive eff ects in different taxonomic groups. As part of its most recent registration decision for metam and MITC

, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p),

metam and MITC are 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 have 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 determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a

chemical substance to interact with the estro gen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have the potential to19 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 endocrine

- related effects caused by the substance, and

establish a dose

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

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 i ngredients. A second list of chemicals identified for EDSP screening was published on June 14, 2013 13 and includes some pesticides scheduled for Registration Review and chemicals found in water

. For further information on the status of the EDSP, the policie s and procedures, the list s of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website. 14

In the interim, EPA is making no human health or environmental safety findings associated with the EDSP screening of metam and MITC. Before completing this Registration Review, the Agency will make an EDSP FFDCA section 408(p) determination.

HUMAN STUDIES :

Occupationa l and Residentia l

Past metam and MITC risk assessments rely in part on data from studies in which adul t 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 E xposure Database (PHED), the Agricultural Reentry Task Force (ARTF) Database , and the Outdoor Residential Exposure Task Force (ORETF) 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 fundamentally 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 t he Protection of Human Subjects of Research (40 CFR Part 26) have been

satisfied , and t here is no regulatory barrier to continued reliance on these studies

.

Chemical

- specific Human Studies

Past metam and MITC risk assessments rely in part on one human st ud y which involved intentional exposure to MITC. A n intentional do s ing eye irritation and odor threshold study in human subjects (MRID no. 44400401) was used as the basi s for the acute MITC endpoint. The Human Studies Review Board (HSRB) reviewed this stud y at a May 2

- 3, 2006 meeting . The

HSRB concluded that a ll applicable requirements of EPA’s Rule for the Protection of Human Subjects of Research (40 CFR Part 26) were satisfied in the study and that there was no regulatory barr ier to continued reliance on this stud y

. In the course of registration review EPA

will reconsider th is stud y
, as well as any other research involving intentional exposure of human

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

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of

chemicals.

14 http://www.epa.gov/endo/20 subjects to metam and/or MITC brought to its attention. If EPA decides to rely on any of these studies, EPA will ensure that all applicable regulatory requirements are met, including

, but not

limited to

, the requirements for EPA ethics review and Human Studies Review Board review of certain research involving intentional exposure of human subjects.