2 

### Oxadiazon Preliminary Work Plan – Table of Contents

OVERVIEW ...................................................................................................................... ............. 3

ANTICIPATED DATA NEEDS .................................................................................................... 4

STATUTORY AND REGULATORY AUTHORITY ................................................................... 6

CHEMICAL FACTS ................................................................................................................ ...... 6

USE AND USAGE INFORMATION ............................................................................................ 7

RECENT ACTIONS ................................................................................................................ ....... 9

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW ................................ 9

TIMELINE ...................................................................................................................... .............. 12

NEXT STEPS .................................................................................................................... ........... 13

Appendix – Additional Areas Considered in the Oxadiazon Registration Review .................. 14

References:

This Preliminary Work Plan summarizes the En vironmental Protection Agency's current position based on the following documents:

1. EFED Registration Review Probl em Formulation for Oxadiazon

. Yingling, H.; Ruhman, M. December 5, 2014.

2. Oxadiazon. Human Health Scoping Docume nt in Support of Registration Review. Collantes, M.; Hansen, L.; Swartz, C. December 5, 2014.

3. Oxadiazon: Tier 1 Review of Human Incidents. Evans, E.; Recore, S. November 5, 2014.

4. BEAD Chemical Profile (BCP) for Re gistration Review: Oxadiazon (109001). Ratnayake, S.; Atwood, D.; Smearman, S. September 23, 2014.

5. 109001 Oxadiazon EFED Label Data Report. July 24, 2014.

6. 109001 Oxadiazon HED Master Label Report. July 24, 2014.

These and other supporting documents for the oxad iazon registration revi ew case may be found in the docket EPA-HQ-OPP-2014-0782 at http://www.regulations.gov

.3 OVERVIEW

The docket for oxadiazon is now open, initiati ng the first public comment period for this registration review (docket number EPA- HQ-OPP-2014-0782). Oxadiazon is a selective herbicide that is registered for use as pre- a nd early post-emergence treat ments for the control of many annual broadleaf and grass weeds. It was fi rst registered in the U.S. in 1978. Today, major use sites of oxadiazon are established or newly established bermudagrass, perennial ryegrass, fescue turf, and various orna mentals including landscape or namental beds. There are no registered food or feed uses for oxadiazon. This Preliminary Work Plan (PWP) document explains what EPA's Office of Pesticide Programs knows about oxadiazon, highlighting anticipated data and assessment needs, identify ing 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 oxadiazon.

The registration review process was designed to include a publi c participation component to solicit input from interested stak eholders. The Agency intends, by sharing this information in the docket, to inform the public of what it knows ab out oxadiazon and what types of new data or other information would be helpful for the Agen cy to receive as it moves toward a decision on oxadiazon. The Agency encourages all interested stakeholders to review the PWP and Appendix and to provide comments and additional inform ation 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; pe sticide manufacturers; agricultural labor or commodity groups; commercial, institutional, reside ntial, and other users of pesticides; or the public at large.

The Preliminary Work Plan begins by listing th e anticipated data need s for oxadiazon. Next, it discusses the statutory and regul atory authority for Registration Review. Then the document provides chemical facts, use and usage info rmation, recent actions, the anticipated risk assessments, and a projected registration review timeline for oxadiazon. Finally, the Appendix to

this document includes identification and discussion of some areas that ar e considered generally in Registration Review along with some a dditional chemical case-specific information.4 ANTICIPATED DATA NEEDS

Table 1 below summarizes anticipated data need s for oxadiazon. For additional discussion of the anticipated data needs, see the EFED Registration Review Probl em Formulation for Oxadiazon

and Oxadiazon. Human Health Scoping Docume nt in Support of Registration Review.

.

Table 1: Anticipated Data Needs for the Oxadiazon Registration Review

Guideline (GDLN)

Number 1 Study Title 1 Test Material Estimated

Timeframe

(Months from receipt of DCI)

or Status

835.4100 Aerobic soil metabolism TGAI 24 850.2100 Avian oral toxicity (passerine species) TGAI 12 850.4550 Cyanobacteria toxicity TEP 12 850.6100 Terrestrial field dissipation study (for turf) TEP 24

850.6100 Environmental chemistry methods and associated independent laboratory validations for the parent, oxadiazon, and three of its metabolites (methoxy, phenolic, and carboxylic) in soil/sediment and water TGAI and three

metabolites 12

Non-GDLN Special Study Acute oral toxicity to adult honey bees (OECD 213) TGAI 12

Non-GDLN Special Study Acute oral toxicity to larval honey bees (OECD 237) TGAI 12

Non-GDLN Special Study Chronic oral toxicity to adult honey bees TGAI 12

Non-GDLN Special Study Chronic oral toxicity to larval honey bees TGAI 12

Non-GDLN Special Study Pollinator feeding/semi-field/pollen and

nectar residue studies 2 TEP 24

850.3040 Field testing for pollinators 2 TEP 36 870.3465 28-day inhalation toxicity TGAI 12

875.2100 Dislodgeable foliar residue and turf

transferable residues TGAI 12

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

2 The need for this anticipated data requirement is contingent on results of the tier 1 bee studies (including acute oral toxicity to adult honey bees, acute oral toxicity to larval honey bees, chronic oral toxicity to adult honey bees, and chronic oral toxicity to larval honey bees).5 Outstanding Data Requirements from GDCI-109001-24733 3

835.4300 Aerobic aquatic metabolism (address unidentified/un-extracted residue) TGAI Supplemental (MRID 46594701)

850.1350 Mysid chronic toxicity test – life-cycle toxicity with Mysids ( America mysis, formerly Mysidopsis bahia ) TGAI In review (MRID 46473304)

850.1400 Freshwater fish early-life stage (raw data for the previously submitted study with rainbow trout) TGAI In review (MRID 41811601) 850.4100 Terrestrial plant toxicity, seedling emergence TEP Outstanding 850.4150 Terrestrial plant toxicity, vegetative vigor TEP Outstanding

850.1735 Whole sediment acute toxicity freshwater invertebrates: toxicity to freshwater amphipods ( Hyalella azteca ) during a 10-day sediment exposure TGAI In review (MRID 46473303)

850.1740 Whole sediment acute toxicity freshwater invertebrates: toxicity to midge ( Chironomus riparius ) during a 10-day sediment exposure TGAI In review (MRID 46487301)

Non-GDLN Special Study Freshwater fish early life-stage toxicity test with fathead minnow ( Pimephales promelas ) under high light conditions TGAI In review (MRID 48759101)
TGAI = technical grade active ingred ient; TEP = typical end-use product

3 The studies listed in this section were previously require d through a generic data call-in issued in November 2004

and are still outstanding, or in review. These studies will not be included in the anticipated Registration Review DCI because they are already re quired through the earlier DCI.6 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 Stat es (U.S.) generally must be registered by the Environmental Protection Agency (EPA or the Ag ency), based on scientific data showing that they will not cause unreasonable ri sks to human health or the environment when used as directed on product labeling. The registration re view 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 unreasonabl e 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 prog ram, the Agency periodically r eevaluates pesticides to make sure that as change occurs, products in the mark etplace can be used safely. Information on this program is provided on EPA’s website. 4

The Agency is implementing the registration revi ew program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), a nd will review each registered pesticide every 15 years to determine whether it continues to meet th e FIFRA standard for registration. The regulations governing registra tion 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 registrati on review decision. After reviewing and responding to comments and data received in the docke t during this initial comment period, the Agency will develop a Final Work Plan (FWP) and anticipated schedule for the registration review of oxadiazon.

CHEMICAL FACTS

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

Table 2: Chemical Facts for Oxadiazon

PC code 109001

Case Number 2485

CAS Number 19666-30-9 Year first registered 1978 Pesticide Type Light-dependent peroxidizing herbicide (LDPH)

Chemical class Oxadiazolone Reregistration Eligibility Decision (RED) 2003

Tolerance Reassessment Eligibility Decision (TRED) Not applicable; tolerance reassessment was included in the RED.

Cumulative group Not applicable; oxadiazon ha s not been identifie d as a member of a cumulative group that shares a common mechanism of toxicity.

4 http://www.epa.gov/oppsrrd1/registration_review/7 Table 2: Chemical Facts for Oxadiazon

40 CFR Citation There are no estab lished tolerances for oxadiazon. Dual-use Oxadiazon is registered for conventional pesticid al uses only and has no registered antimicrobi al or biopesticidal uses. Non-pesticidal uses There are no identified non-pesticidal uses.

Pesticide Re-evaluation Division, Chemical Review Manager Katherine St. Clair, stclai r.katherine@epa.gov, 703-247-8778

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 oxadiazon. Please see the BEAD Chemical Profile (BCP) for Regi stration Review: Oxadiazon (109001) in the registration review

docket for more details.

Table 3: Oxadiazon Use and Usage Information

Summary of Use Oxadiazon is a selective herb icide that is registered for use as preand early post-emergence treatm ents for the control of many annual broadleaf and grass weeds. Specific target weeds include crabgrass, goosegrass, annual bluegrass, and annual sedge. Use Sites Agricultural use sites: Ox adiazon is not registered for use on agricultural use sites, an d there are no registered food or feed uses or anticipated food or feed uses for oxadiazon. The registered use sites for oxadiazon are considered non-agricultural.

Non-agricultural use sites: Major use sites of oxadiazon are established or newly establis hed bermudagrass, perennial ryegrass, fescue turf, and vari ous ornamentals including landscape ornamental beds. Oxadiazon is registered for commercial use on turf grown in golf courses and in areas such as apartment/condominium complexes, parks, athletic fields, playgrounds, and cemeteries. In addition, oxadiazon is used on

sod farms and on conifer nurseries and landscapes (i.e. industrial sites, ornamental, roadside pl antings, woody, ornamental shrubs, vines and trees, and he rbaceous ornamentals). Summary of Usage EPA has very limited us age data for oxadiazon due to its nonagricultural use pattern. Da ta for oxadiazon use on nonagricultural sites is limited to proprietary data. Based on 2012 data, the usage of oxadiazon on non- agricultural use sites totaled approximately 273,000 pounds of active ingredient and the primary non-agricultural use site was golf courses with approximately 78% of oxadiazon use, followed by landscape sites8 Table 3: Oxadiazon Use and Usage Information

(7%), institutional turf (6%), and turf (5%). Data for earlier or more recent years were not available. Formulation Type(s) Oxadiazon can be form ulated as a granular product, wettable powder, emulsifiable concentrate, water soluble packets, or can be
mixed with fertilizer. Application Method(s) Products can be applied by ground using spreader/granular applicator or calibrated sprayer. Technical Registrant(s) Bayer Enviro nmental Science; Nufarm Limited. No. of Registrations 62 Section 3 registra tions (2 technical products, 2 manufacturing use products, 58 end-use products) 5

Restricted Use No

Guidance for Commenters: Additional areas of use and usage related information requested for this registration review, and of part icular interest to EPA, are described below.

 EPA requests that the registrant provide the name, toxicity, struct ure, and CAS number for each of the degradates listed in Sec tion 5 of the EFED Problem Formulation.

 EPA requests that the registrants confirm th eir intentions regarding oxadiazon turf and lawn uses. If the registrants’ intentions are to restrict th e use of oxadiazo n on residential or home lawns/turf, then a resi dential handler exposure asse ssment is not required during registration review for these uses. However, if a site is restricted, then neither ‘residential’ nor ‘occupational’ /’commercial’ handlers may apply the specified product to the site. If the registrant intends to al low occupational/commercial handlers to apply oxadiazon to residential turf and lawns, then they cannot restrict th e use on residential lawns by homeowners, and a residential handle r assessment for turf/lawn will need to be

conducted.

 Certain oxadiazon labels are unclear with respect to application parameters. Without further information, EPA expects to use cons ervative assumptions to approximate these parameters in order to conduct a quantitative risk assessment. However, the Agency will work with registrants to clarify informa tion on oxadiazon product labels, especially the maximum annual application rates for non-agricu ltural uses including golf courses, turf,
and ornamental lawns.

 Confirmation of the following label information: sites of application; formulations; application methods and equipment; maxi mum application rates; frequency of application, application intervals, and maxi mum number of applica tions per season; and geographic limitations on use.

 Use distribution ( e.g. , acreage and geographical distri bution of relevant use sites).

 Median and 90 th percentile reported use rates (lbs a i/A) from usage data – national, state, and county.

 Typical application timing (date of first applic ation and application in tervals) – national, state, and county.

5 Section 3 product labels can be obtained from th e Pesticide Product Label System (PPLS) website

(http://oaspub.epa.gov/pestlabl/ppls.home).9  The following usage/use information for non-agri cultural uses: total pounds a.i. applied; percent crop/site treated; application rate s (typical and maximum); frequency of application by region of the country; methods of application; targ et or niche pests; efficacy in formation/product performance.

 Typical application interval (days).

 State or local use restrictions.

 Foreign technical registrants not listed above who supply tech nical oxadiazon to the US
market.

RECENT ACTIONS

The RED for oxadiazon was completed in 2003, a nd the product reregistration process was completed in 2009.

ANTICIPATED RISK ASSESSMENT S FOR REGISTRATION REVIEW

The most recent comprehensive human health ri sk assessment for oxadiazon was completed in 2007 for a new use on residential landscape or namentals by professional landscape personnel. The most recent ecological and environmental fate risk assessment was completed in 2001 for the oxadiazon Reregistration Eligibility Decisi on. Findings and conclusions from these risk

assessments are summarized in the EFED Registration Review Problem Formulation for
Oxadiazon and Oxadiazon. Human Health Scoping Document in Support of Registration Review.

During registration review, the Agency antici pates the need to conduct a comprehensive ecological risk assessment, including an enda ngered species assessment, for all uses of oxadiazon. For human health, EPA anticipates th e need to conduct revised dietary (drinking water only), residential, and o ccupational risk assessments duri ng registration review; EPA also anticipates re-evaluating the need for an aggr egate (combined drinking water and residential) assessment based on currently available informa tion and science/risk as sessment policies. If toxicological endpoints or points of departure are revised based on th e data that are anticipated to be required for registration review, they will be considered in the new assessments, as will any changes to the standard operating proce dures or default exposure assumptions.

Table 4 below summarizes the anticipated regi stration review risk assessments based on the

EFED Problem Formulation and HED Scoping Document.10 Table 4: Anticipated Risk Assessments for the Oxadiazon 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 Yes EPA anticipates conducting an updated comprehensive ecological risk assessment during registration review. The new assessment will incorporate the most up-to-date modeling methodologies, updated toxico logical endpoints, and

data submitted under the anticipated registration
review data call-in.

Incidents Will check for updates For a discussion of reporte d ecological incidents for oxadiazon, see page 14 of the Problem Formulation.

Human Health Dietary Food No There are no register ed food uses for oxadiazon. EPA does not anticipate conduc ting an updated dietary assessment for registration review unless there are significant changes to the drinking water estimated

concentrations or if there are significant changes to the points of departure, uncer tainty factors, or safety

factors. Drinking water Yes EPA anticipates conducting an updated drinking water assessment during registration review to incorporate updated estimated drinking water

concentrations. Occupational Handlers (mixers, loaders, applicators) Yes The most recent occupational exposure assessment
was conducted for the 2007 human health risk assessment. EPA anticipates conducting an updated occupational handler asse ssment during registration
review. Post-application Yes The most recent occupational exposure assessment
was conducted for the 2007 human health risk assessment. EPA anticipates conducting an updated occupational post-application assessment during registration review.

Residential11 Handlers Yes A residential handler assessment has not been performed. EPA anticipates conducting a residential

handler risk assessment duri ng registration review if the registrants intend to support use of oxadiazon on residential property.

In the 2007 human health assessment for ornamentals and landscape use, it was assumed that there would be no residential handler exposure since the product could only be applied by professional landscape personnel (in accordance with the label). However,

since the oxadiazon labels do not identify the end-use products as restricted use, a residential handler exposure assessment is now required to be protective of potential homeowners who apply oxadiazon to

ornamentals.

Regarding lawn/turf use of oxadiazon, EPA requests that the registrants confirm their intentions for these uses. If the registrants’ inte ntions are to restrict the use of oxadiazon on residential or home lawns/turf, then a residential handler exposure assessment is not required during registration review for lawn and turf uses. However, if a site is restricted, then neither ‘residential’ nor ‘occupationa l’/’commercial’ handlers may apply the specified product to the site. If the registrant intends to allow occupational/commercial handlers to apply oxadiazon to residential turf and lawns, then they cannot rest rict the use on residential lawns by homeowners, and a residential handler
assessment for turf/lawn w ill need to be conducted. Post-application Yes The most recent residential post-application exposure
assessment was conducted for the 2007 human health risk assessment. EPA anticipates conducting an updated residential post-application assessment during registration review.

Other Aggregate No An aggregate assessment evaluates the combined risk from dietary and residential exposures. Due to the lack the of food uses, an aggregate assessment is not appropriate for oxadiazon. However, the Agency will determine if it is appropriat e to consider the combined exposure from drinking water and residential sources. Cumulative No Not applicable; oxadiazon has not been identified as a member of a cumulative group that shares a common mechanism of toxicity.12 Tolerances No Not applicable; there are no established tolerances for

oxadiazon.

Incidents Will check for updates For a discussion of reported human incidents for oxadiazon, see page 15 of the Scoping Document and

the Oxadiazon: Tier 1 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 alr eady reported to the Agency.

 Water quality monitoring data (s ee Appendix for further details).

 The name, toxicity, structure, and CAS numb er for each of the degradates listed in
Section 5 of the EFED Problem Formulation

TIMELINE

EPA has created the following estimated timeline for the completion of the oxadiazon registration review in Table 5 below.

Table 5: Projected Oxadiazon Registration Review Timeline

Activity Estimated Date Opening the Docket Open Docket and 60-day Public Comment Period 2014 – December Close Public Comment Period 2015 – February Case Development Issue Final Work Plan 2015 – May Issue DCI 2015 July – Sept. Data Submission 2018 July – Sept. Open 60-day Public Comment Period for Draft Risk

Assessments 6 2020 Jan. - March

Registration Review Decision Open 60-day Public Comment Period for Proposed Registration Review Decision 2020 Oct. – Dec.

Issue Registration Review Decision and Begin PostDecision Follow-up 2021

Total (years) 7

6 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.13 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 i ssue a Final Work Plan for the registration
review of oxadiazon.14 Appendix – Additional Areas Considered in the Oxadiazon Registration Review

PUBLIC COMMENTS AND FEEDBACK:

Guidance for Commenters: The areas below highlight topics of special interest to the Agency where your comments, data submi ssions, or reference to sources of additional information could be of particular use.

Trade Irritants:

Through the registration review process, the Ag ency intends to solicit information on trade irritants and, to the extent feas ible, 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, provi ding as much specificity as possible regarding

the nature of the concern. Because oxadiazon 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:

Oxadiazon is not identified as a cause of impa irment for any water bodies listed as impaired under section 303(d) of the Clean Water Act. 7 In addition, no Total Maximum Daily Loads (TMDL) have been developed for oxadiazon. 8 More information on impaired water bodies and TMDLs can be found at the Agency’s website. 9 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 Procedur e: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Regist ration Review Risk Assessment and Management Process 10 in order to ensure they can be us ed quantitatively or qualitatively in pesticide risk assessments.

Environmental Justice:

EPA seeks to achieve environmenta l justice, the fair tr eatment and meaningful involvement of all people, regardless of race, color, national origi n, or income, in the deve lopment, implementation, and enforcement of environmental laws, regulati ons, 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 thei r location, cultural practices, or other factors, may have atypical, unusually high exposure to oxadi azon 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.

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

8 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl _pollutant_detail?p_pollutant_group_id=885&p_pollutant_

group_name=PESTICIDES

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

10 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm15 ENDANGERED SPECIES:

A risk assessment that supports a complete endangered species determination has not been conducted for oxadiazon. The ecologi cal risk assessment planned dur ing registration review will allow the Agency to determine whether use of oxadiazon has “no effect” or “may affect” federally listed threatened or endangered specie s (listed species) or their designated critical habitats. When an assessment concludes that a pes ticide’s use “may affect” a listed species or its designated critical habitat, the Agency will c onsult with the U.S. Fish and Wildlife Service
and/or National Marine Fisheries Service (the Se rvices), as appropriate.

ENDOCRINE DISRUPTOR SCREENING PROGRAM:

As required by FIFRA and FFDCA, EPA reviews num erous studies to asse ss potential adverse outcomes from exposure to chemicals. Collectiv ely, these studies includ e acute, subchronic and chronic toxicity, including asse ssments of carcinogenicity, ne urotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include e ndpoints which may be susceptible to endocrine influe nce, including effects on endocri ne target organ histopathology, organ weights, estrus cyclicity, sexual maturatio n, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess gr owth, developmental and reprod uctive effects in different taxonomic groups. As part of its most recent re gistration decision for oxadiazon, EPA reviewed these data and selected the most sensitive endpoint s for relevant risk assessment scenarios from the existing hazard database. However, as re quired by FFDCA section 408(p), oxadiazon is subject to the endocrine screeni ng part of the Endocrine Disrup tor Screening Program (EDSP).

EPA has developed the EDSP to determine whet her 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 ot her such endocrine effect s as the Administrator may designate.” The EDSP employs a two-tiered approach to making th e 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 estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine-related eff ects 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 pest icide active ingredients and 9 inert ingredients. A second list of
chemicals identified for EDSP scr eening was published on June 14, 2013 11 and includes some pesticides scheduled for registration review and chemicals found in water

. Neither of these lists
should be construed as a list of know n or likely endocri ne disruptors.

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

chemicals.16 For further information on the status of the ED SP, the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening ba ttery, please visit our
website. 12

HUMAN STUDIES:

Occupational and Residential

Past oxadiazon risk assessments rely in part on da ta from studies in which adult human subjects were intentionally exposed to a pesticide to determine their dermal and inhalation exposure. Many such studies, involving exposur e to many different pesticides, comprise generic pesticide exposure databases such as the Pesticide Handl ers Exposure Database (PHED), the Agricultural Reentry Task Force (ARTF) Database, and th e Outdoor Residential Exposure Task Force (ORETF) Database. EPA has reviewed all the st udies supporting these multi-pesticide generic exposure databases, and has found no clear and c onvincing evidence that the conduct of any of them was either fundamentally unethical or si gnificantly deficient relative to the ethical standards prevailing at the time the research was conducted. All applicab le requirements of EPA’s Rule for the Protection of Human Subject s of Research (40 CFR Part 26) have been satisfied, and there is no regulatory barri er to continued reliance on these studies.

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