2

Dazomet Preliminary Work Plan – Table of Contents

Overview 4

Anticipated Data Needs 5

Statutory and Regulatory Authority 8

Chemical Facts 8

Use and Usage Information 9

Recent Actions 11

Anticipated Risk Assessments for Registration Review 11

Timeline 14

Next Steps 14

Appendix – Additional Areas Considered in the Dazomet Registration Review 15

References:

This Preliminary Work Plan summarizes the Environmental Protection Agency's current position 

based on the following documents:

1. Problem Formulation for the Ecological Risk and Drinking Water Exposure Assessments to 

be Conducted in Support of the Registration Review of Dazomet. Panger, M. August 27, 

2013.

2. Dazomet Human-Health Assessment Scoping Document in Support of Registration Review. 

Shelat, S, C. Smith and N. Mottl. September 4, 2013. 

3. Dazomet: Review of Human Incidents. Recore, S. and E. Evans. August 29, 2013.

4. BEAD Chemical Profile for Registration Review: Dazomet (035602). Yourman, L., S. 

Haddad, and D. Berwald. May 14, 2012.

5. Dazomet (035602) Screening Level Usage Analysis (SLUA). March 19, 2012.

6. PRD Label Data Report. February 13, 2012.
3

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

the docket EPA-HQ-OPP-2013-0080 at http://www.regulations.gov.

In addition, the following documents may be found in the docket EPA- HQ-OPP-2005-0128 at 

http://www.regulations.gov.

7. Amended Reregistration Eligibility Decision for Dazomet. May 2009.

8. Dazomet: Updated Final Revised HED Chapter of the Reregistration Eligibility Decision 

Document (RED). Shelat, S. and C. Smith. April 2009.
4

OVERVIEW

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

registration review (docket number EPA-HQ-OPP-2013-0080). Dazomet is a non-selective soil 

fumigant with fungicidal, herbicidal, and nematicidal properties used as a pre-plant soil fumigant 

for strawberries and tomatoes in California only, and nationally for non-bearing crops, and for 

golf course turf. Dazomet is also an active ingredient in a variety of antimicrobial products. 

After application dazomet breaks down quickly to the primary toxic degradate, methyl 

isothiocyanate (MITC) gas. MITC is highly volatile and is responsible for the biocidal properties 

of this fumigant. The MITC case is addressed in a separate Preliminary Work Plan, located in 

the MITC docket (EPA-HQ-OPP-2013-0242).

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

knows about dazomet, 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 dazomet.

The registration review process was designed to include a public participation component to 

solicit input from interested stakeholders. The Agency intends, by sharing this information in the 

docket, to inform the public of what it knows about dazomet and what types of new data or other 

information would be helpful for the Agency to receive as it moves toward a decision on 

dazomet. 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 decisionmaking 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, residential, and other users of pesticides; or the 

public at large.

The Preliminary Work Plan begins by listing the anticipated data needs for dazomet. Next, it 

discusses the statutory and regulatory authority for Registration Review. Then the document 

provides dazomet facts, use and usage information, recent actions, the anticipated risk 

assessments, and a projected registration review timeline for dazomet. Finally, the Appendix to 

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

in Registration Review along with some additional dazomet case-specific information.
5

ANTICIPATED DATA NEEDS

Table 1 below summarizes anticipated data needs for dazomet. For additional discussion of the 

anticipated data needs, see the Problem Formulation for the Ecological Risk and Drinking Water 

Exposure Assessments to be Conducted in Support of the Registration Review of Dazomet and 

Dazomet Human-Health Assessment Scoping Document in Support of Registration Review. 

Table 1: Anticipated Data Needs for the Dazomet Registration Review

Guideline 

Number1 Study Title1

Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

Anticipated Data Needs for the Parent Dazomet (for conventional uses of dazomet)

835.1230 Adsorption/ desorption and leaching TGAI 12

835.1240 Adsorption/ desorption and leaching TGAI 12

850.2100 Avian oral toxicity (passerine) TGAI 12

Anticipated Data Needs for the Parent Dazomet (for antimicrobial uses only)

875.1700 Product use information TEP 12

875.1200

Dermal exposure for open pour 

mixing/loading paint (occupational) and 

applying paint (airless sprayer and 

brush/roller; occupational and residential)

TEP 24

875.2400 Post-application dazomet dermal exposure for 

finger painting TEP 24

Anticipated Data Needs for the Degradate MITC (for conventional uses of dazomet)

850.6100

Environmental chemistry methods and associated 

independent laboratory validations for air, soil, and 

water

MITC 12

835.4300 Aerobic aquatic metabolism MITC 24

NonguidelineHoneybee vapor exposure MITC 24

850.1400 Freshwater fish 

early-life stage MITC 12

Anticipated Data Needs for the Degradate MITC (for antimicrobial uses of dazomet only)

875.1400 Inhalation exposure for open pour 

mixing/loading paint (occupational) and 

applying paint (airless sprayer and 

brush/roller; occupational and residential)

MITC 24

 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 Availability” 77 FR 38282, June 27, 2012. 

http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0154-0028
6

Table 1: Anticipated Data Needs for the Dazomet Registration Review

Guideline 

Number1 Study Title1

Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

875.2400 Post-application dermal exposure (for painted 

rooms) MITC 24

835.3110

835.3220

835.3280

835.3240

Ready biodegradability test or one of three 

biodegradation in activated sludge simulation tests MITC 12

Outstanding Data Requirements from GDCI-035602-288502 (2010 Soil Fumigant Dazomet DCI)

835.8100 Field volatility from soil TEP In review

850.1025 Oyster acute toxicity (shell deposition) MITC In review

850.1035 Mysid acute toxicity MITC In review

850.1075 Fish acute toxicity, freshwater and marine MITC In review

850.2300 Avian reproduction test TGAI In review

850.3020 Honey bee acute toxicity MITC Due April 2014

850.4100 Seedling emergence (Tier II) MITC In review

850.4150 Vegetative vigor (Tier II) MITC In review

850.4400 Aquatic plant growth toxicity (Tier II) MITC In review

870.4200 Carcinogenicity MITC Due April 2014

870.3700 Prenatal developmental toxicity study MITC In review

870.3800 Reproduction and fertility effects MITC Due April 2014

870.6200 Neurotoxicity screening battery MITC In review

 2 The studies listed in this section were previously required through a generic data call-in issued in March 2010 and 

are still outstanding. These studies will not be included in the anticipated Registration Review DCI because they 

are already required through the earlier DCI.
7

Table 1: Anticipated Data Needs for the Dazomet Registration Review

Guideline 

Number1 Study Title1

Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

Nonguideline 

(numbered 

as SS-2 on 

the 

dazomet 

DCI)

Avian acute inhalation

MITC In review

Outstanding Data Requirements from GDCI-035602-290243(2010 Antimicrobial Dazomet DCI4)

875.1200 Dermal Exposure - Indoor TEP In review

875.1400 Inhalation Exposure - Indoor MITC Extension 

requested*

875.1600 Application exposure monitoring data reporting TEP Extension 

requested*

875.1700 Product Use Information TEP Extension 

requested*

875.2500 Inhalation Exposure MITC In review

875.2700 Product Use Information TEP Extension 

requested*

875.2800 Description of human activity TEP Extension 

requested*

875.2900 Data reporting and calculations TEP Extension 

requested*

850.1025 Oyster acute toxicity (shell deposition) MITC In review

850.1035 Mysid acute toxicity MITC In review

850.1075 Fish acute toxicity, freshwater and marine MITC In review

860.1520 Processed Food/Feed (paper manufacturing 

processes

TEP In review

870.3700 Prenatal developmental toxicity study MITC In review

 3 The studies listed in this section were previously required through a generic data call-in issued in March 2010 and 

are still outstanding. These studies will not be included in the anticipated Registration Review DCI because they 

are already required through the earlier DCI.

4 The exposure and air concentration monitoring data required by the 2010 antimicrobial dazomet DCI is to support 

the following dazomet uses identified by the 2009 Amended Dazomet RED. These uses include: 1) a treatment 

during the production of pulp and paper; 2) a materials preservative treatment for paper coatings, non-food 

adhesives, epoxy flooring compounds, slurries, and high viscous suspensions; 3) a biocide treatment during 

petroleum operations; 4) a biocide treatment in recirculating cooling water systems; and 5) a remedial wood 

treatment to utility poles. 
8

Table 1: Anticipated Data Needs for the Dazomet Registration Review

Guideline 

Number1 Study Title1

Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

870.3800 Reproduction and fertility effects MITC Due March 

2014

870.5395 Mammalian erythrocyte micronucleus test MITC In review

870.4200 Carcinogenicity MITC Due March 

2014

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.

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 environment 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. Information 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, 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. The 

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 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 Final Work Plan (FWP) and anticipated schedule for 

the registration review of dazomet.

CHEMICAL FACTS

Table 2 provides a summary of the chemical facts for dazomet.

 5 http://www.epa.gov/oppsrrd1/registration_review/
9

Table 2: Chemical Facts for Dazomet

PC code 035602

Case Number 2135

CAS Number 533-744-4

Year first registered 1967

Pesticide Type Nematicide, herbicide, fungicide, insecticide, and slimicide

Dazomet class Dithiocarbamate

Reregistration Eligibility 

Decision (RED)

July 2008; Amended RED date May 2009

Tolerance Reassessment 

Eligibility Decision 

(TRED)

Not applicable. 

Cumulative group Not applicable. Dazomet has not been identified as a member of a 

cumulative group that shares a common mechanism of toxicity. 

40 CFR Citation There are no tolerances established for dazomet. All registered food 

uses are pre-plant.6

Dual-use Yes. Dazomet is registered for conventional and antimicrobial 

uses.

Non-pesticidal uses There are no identified non-pesticidal uses of dazomet.

Pesticide Re-evaluation 

Division, Dazomet

Review Manager

Dana Friedman, friedman.dana@epa.gov, (703) 347-8827

Antimicrobials Division, 

Dazomet Review Manager

Wanda Henson, henson.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 summarizes the use and usage information for dazomet. Please see the BEAD Chemical 

Profile for Registration Review: Dazomet (035602) in the registration review docket for more 

details.

Table 3: Dazomet Use and Usage Information

Summary of Use Dazomet is a non-selective soil fumigant with fungicidal, 

herbicidal, and nematicidal properties. Dazomet is also an active 

ingredient in a variety of antimicrobial products. The primary 

degradate of dazomet is methyl isothiocyanate (MITC). The MITC 

 6 Dazomet’s volatility in the environment 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 does not require food tolerances and is not 

subject to the amendments to the FFDCA promulgated under the Food Quality Protection Act of 1996. Dazomet: 

Updated Final Revised HED Chapter of the Reregistration Eligibility Decision Document (RED). Shelat, S. and C. 

Smith. April 2009.
10

Table 3: Dazomet Use and Usage Information

case is addressed in a separate Preliminary Work Plan, located in 

the MITC docket (EPA-HQ-OPP-2013-0242).

Use Sites Conventional Uses

The conventional uses of dazomet include applications to 

strawberries (California only), tomatoes (California only), golf 

greens/tees, nonbearing crops, turf sites (establishing or 

renovating), ornamental sites (establishing or renovating), field 

nurseries (establishing or renovating), compost piles and potting 

soils. 

Antimicrobial Uses

The antimicrobial uses of dazomet include treatment during the 

production of pulp and paper; a material preservative treatment for 

paper coatings, non-food adhesives, epoxy flooring compounds, 

slurries, and high viscous suspensions; a biocide treatment during 

petroleum operations and in recirculating cooling water systems; 

and a remedial wood treatment to utility poles. There are also

antimicrobial uses of dazomet in paint and finger paint.

Summary of Usage The Agency has limited data on the use of dazomet. According to the 

Nursery and Floriculture Summary of the USDA, approximately 

15,000 pounds of dazomet was used as a soil fumigant in 2003.

Use information for dazomet is available for golf courses in 2002 

(15,500 lbs. a.i.) and 2006 (approximately 6,000 lbs. a.i.). In 2010 in 

California, 55,511 pounds of dazomet were used on rights-of-way; 

however, there was no information available on use of dazomet for 

rights-of-ways in other states.

Formulation Type(s) Conventional Use

The sole end-use formulation is granular.

Antimicrobial Use

Formulations are pelleted/tableted, liquid (soluble concentrate and 

flowable concentrate) solutions, water soluble

packaged solids, and ready to use solutions.

Application Method(s) Conventional Use

It is applied as a dry granule and incorporated into the soil or applied 

to the soil surface and watered into the soil to activate it.

Antimicrobial Use

It can be applied by open pour, metering pump, and water-soluble 

packaged solid.

Technical Registrant(s) Conventional Use

AMVAC Chemical Corporation

Antimicrobial Use
11

Table 3: Dazomet Use and Usage Information

Buckman Laboratories, Inc., Kemira Chemicals, Inc., Lanxess 

Corporation

No. of Registrations Conventional Use

Section 3 products: 2

Antimicrobial Use

Section 3 products: 17

Restricted Use Conventional Use

Yes

Antimicrobial Use

No

Guidance for Commenters: Additional areas of use and usage related information

requested for this registration review, and of particular interest to EPA, are described below.

• Confirmation of the following label information: sites of application; application 

methods and equipment; maximum application rates; frequency of application, and 

maximum number of applications per season; and geographic limitations on use.

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

• Median and 90th percentile reported use rates (lbs ai/A) from usage data – national, state, 

and county.

• Typical application timing (date of first application and application intervals) – national, 

state, and county.

• Usage/use information for non-agricultural uses.

• State or local use restrictions.

• Foreign technical registrants not listed above who supply technical dazomet to the US 

market.

In addition, the Agency will continue the dialogue with stakeholders on label issues that have 

evolved during the RED label implementation process.

RECENT ACTIONS

A Reregistration Eligibility Decision (RED) was completed for dazomet in July 2008 and 

amended in May 2009. The Agency determined that dazomet products were eligible for 

reregistration provided a number of risk mitigation measures are adopted and label amendments 

are made to reflect these measures. For details on the mitigation measures, see the Amended 

Reregistration Eligibility Decision (RED) for Dazomet, dated May 2009. Additionally, the 

Agency’s Soil Fumigant Toolbox website contains information on these 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.

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

dazomet products.
12

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

The most recent comprehensive human health risk assessment for dazomet was completed in 

2008 in preparation for the RED, and updated in April 2009 for the Amended RED. The most 

recent ecological and environmental fate risk assessment was completed in April 2008 for the 

RED. Findings and conclusions from these risk assessments are summarized in the Problem 

Formulation for the Ecological Risk and Drinking Water Exposure Assessments to be Conducted 

in Support of the Registration Review of Dazomet and Dazomet Human-Health Assessment 

Scoping Document in Support of Registration Review.

During registration review, the Agency anticipates the need to conduct a comprehensive

ecological risk assessment, including an endangered species assessment, for all uses of dazomet.

For human health, EPA anticipates the need to conduct revised occupational and bystander risk 

assessments during registration review for conventional uses, and occupational and residential 

assessments for antimicrobial uses. 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 assessments, as well as any changes to the standard operating procedures 

or default exposure assumptions.

Table 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 Dazomet 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 Since dazomet rapidly hydrolyzes to MITC, potential 

exposure to aquatic receptors is primarily to MITC

via surface runoff; consequently, the toxicity data for 

MITC will be used to assess risk to fish, aquatic 

invertebrates, and aquatic plants. Terrestrial exposure 

to birds, mammals, invertebrates can occur through 

consumption of dazomet granules and/or by

inhalation of MITC. 

Incidents Will check for 

updates

For a discussion of reported ecological incidents for 

dazomet, see page 16 of the Problem Formulation.

Human Health

Dietary

Food N The uses of dazomet on strawberries and tomatoes 

(California only) are considered non-food uses, since 

there is no reasonable expectation of finite residues 

in/on food crops when dazomet is used as a pre-plant 

fumigant. An assessment is not anticipated in 

registration review.
13

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, so an assessment is not anticipated in 

registration review.

Occupational

Handlers (mixers, loaders, 

applicators)

Y For soil fumigant 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 Based on re-entry restrictions specified by the 2009 

amended RED for the conventional uses of dazomet, 

the Agency does not expect risk to re-entry workers to 

exceed the Agency’s level of concern.

Residential

Handlers Y For antimicrobial uses only, additional residential

handler dermal and inhalation exposure data are 

required and will be reviewed and incorporated in the 

risk assessment in registration review.

Post-application Y For antimicrobial uses only, additional postapplication dermal exposure data are required and 

will be reviewed and incorporated in the risk 

assessment in registration review.

Bystander Y For soil uses, there is the potential for residential 

bystander (anyone not involved in the application) 

inhalation exposure to MITC after a soil fumigation 

application of dazomet. A revised residential risk 

assessment is anticipated in registration review to 

update risk to bystanders during and following soil 

fumigant uses of dazomet products.

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 fumigants. Buffer zones and GAPs were specified

by the 2009 amended RED as measures to mitigate 

occupational and bystander risk.

Other
14

Aggregate N Evaluates the combined risk from dietary and 

residential exposures. No dietary risk is anticipated 

from dazomet. Therefore, an aggregate assessment is 

not anticipated.

Cumulative N Dazomet is not a member of a cumulative group, so 

no cumulative risk assessment is planned

Tolerances N Dazomet is a pre-plant soil fumigant so there are no 

tolerances established for this chemical.

Incidents Will check for 

updates

For a discussion of reported human incidents for 

dazomet, see page 8 of the Scoping Document and 

Dazomet: Review of Human Incidents.

Guidance for Commenters: Additional ecological information requested for this 

registration review, and of particular interest to EPA, is described below.

• Ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian and 

mammalian mortalities) not already reported to the Agency.

• Water quality monitoring data (see Appendix for further details).

TIMELINE

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

review in Table 5 below.

Table 5: Projected Dazomet Registration Review Timeline

Activities Estimated Date

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

60-day Public Comment Period for Draft Risk 

Assessments7

2017 Oct. – Dec.

Registration Review Decision

60-day Public Comment Period for Proposed 

Registration Review Decision

2018 April - June

Registration Review Decision and Begin Post-Decision 

Follow-up

2019

 7 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.
15

Table 5: Projected Dazomet Registration Review Timeline

Activities Estimated Date

Total (years) 6

NEXT STEPS

After the 60-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 dazomet.
16

Appendix – Additional Areas Considered in the Dazomet Registration Review

PUBLIC COMMENTS AND FEEDBACK:

Guidance for Commenters: The areas below highlight topics of special interest to the Agency 

where your comments, data submissions, or reference to sources of additional information could 

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 (MRLs) 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 regarding 

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

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

Water Quality:

Dazomet is not identified as a cause of impairment for any water bodies listed as impaired under 

section 303(d) of the Clean Water Act.

8

 In addition, no Total Maximum Daily Loads (TMDL) 

have been developed for dazomet.

9

 More information on impaired water bodies and TMDLs can 

be found at the Agency’s website.

10 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 Process11

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 

population who, as a result of their location, cultural practices, or other factors, may have 

atypical, unusually high exposure to dazomet 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.

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

9

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

group_name=PESTICIDES

10 http://www.epa.gov/owow/tmdl/ 11 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm
17

ENDANGERED SPECIES:

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

conducted for dazomet. The ecological risk assessment planned during registration review will 

allow the Agency to determine whether use of dazomet 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.

On June 5, 2013, the Center for Biological Diversity and the Pesticide Action Network North 

America filed an amended complaint in its lawsuit in the United States District Court for the 

Northern District of California, against the Environmental Protection Agency (EPA) for 

allegedly failing to undergo consultation with the United States Fish and Wildlife Service and the 

National Marine Fisheries Service regarding the effects of 50 pesticides, including dazomet, on 

over 100 endangered and threatened species throughout the United States (Center for Biological 

Diversity, et al. v. EPA, et al., No. C 11-00293 (N.D.Cal.).

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 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, 

organ 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 reproductive effects in different 

taxonomic groups. As part of its most recent registration decision for dazomet, 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), dazomet 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 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 estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the 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 endocrine-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 
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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, 201312 and includes some 

pesticides scheduled for Registration Review and chemicals found in water. For further 

information on the status of the EDSP, the policies and procedures, the lists of chemicals, future 

lists, the test guidelines and the Tier 1 screening battery, please visit our website.13

In the interim, EPA is making no human health or environmental safety findings associated with 

the EDSP screening of dazomet. Before completing this Registration Review, the Agency will 

make an EDSP FFDCA section 408(p) determination.

HUMAN STUDIES:

Occupational and Residential

Past dazomet 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 Handlers Exposure Database (PHED) 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. All applicable requirements of EPA’s Rule for the Protection of Human Subjects of 

Research (40 CFR Part 26) have been satisfied, and there is no regulatory barrier to continued 

reliance on these studies.

Dazomet-specific Human Studies

Past dazomet risk assessments have relied in part on human studies which involved intentional 

exposure to the dazomet degradate MITC In the course of registration review EPA will 

reconsider these studies, as well as any other research involving intentional exposure of human 

subjects to dazomet and its degradates 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.

 12 See http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0477-0074 for the final second list of 

chemicals.

13 http://www.epa.gov/endo/