Docket Number EPA-HQ-OPP-20 15-0381 

www.regulations.gov 

Thidiazuron Preliminary Work Plan 

Registration Review: Initial Docket 

Case Number 003 

Approved by: 

Date: 

June 2015 

CU-d--Y ~ Richard P. Keigwin, Jr. 

Director 

Pesticide Re-evaluation Division 

&,f .;)~ / a ot5 
Thidiazuron Preliminary Work Plan - Table of Contents 

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

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

STATUTORY AND REGULATORY AUTHORITY ...... ...... ................. ..... ............ ............. ... ..... 5 

CHEMICAL FACTS ...................................................................................................................... 5 

USE AND USAGE INFORMATION ............................................................................................ 6 

RECENT ACTIONS ........... ..... ............... ............. ............. ..................... ....... .... ... ..... ........ ... .... ....... 7 

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW ................................ 7 

TIMELINE .................................................................................................................. ........ .... ........ 9 

NEXT STEPS ...... ... ........ ....... .................. ................... .......................................... .. .. .... ..... ... .... .... 10 

Appendix - Additional Areas Considered in the Thidiazuron Registration Review ................ 11 

References: 

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

based on the following documents: 

1. Registration Review: A Joint Problem Formulation and Draft Risk Assessment of the 

Environmental Fate and Ecological Risk ofThidiazuron. Stephen Carey and William 

Eckel. June 16,2015. 

2. Thidiazuron: Human Health Combined Scoping Document and Draft Risk Assessment for 

Registration Review. Ronnie Bever, Ideliz Negron-Encarnacion, and Alexandra Gavelek. 

June 9, 2015. 

3. Thidiazuron: Tier I Review of Human Incidents. Shanna Recore and Elizabeth Evans. 

February 5, 2015. 

4. BEAD Chemical Profile (BCP)for Registration Review: Thidiazuron (10301). Sunil 

Ratnayake, Cynthia Doucoure, and Stephen Smearman. January 26, 2015. 

5. Thidiazuron Screening Level Usage Analysis (SLUA). September 22, 2014. 

6. EFED Master Label Report. September 29, 2014. 

7. HED Master Label Report. September 29, 2014. 

8. Thidiazuron: Drinking Water Exposure Assessment Memorandum for Preliminary Risk 

Assessment in Support ofThidiazuron Registration Review. Iwona Maher and William 

Eckel. May 13,2015. 

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

in the docket EPA-HQ-OPP-2015-038 1 at http://www.regulations.gov. 

2 
OVERVIEW 

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

registration review (docket number EPA-HQ-OPP-2015-0381). Thidiazuron is a phenylurea 

herbicide registered for use as a pre-harvest defoliant in cotton. Thidiazuron acts to reduce the 

foliage and immature fruiting structures which contribute to the staining of harvested cotton and 

also acts to facilitate cotton harvesting. Thidiazuron is not registered for any non-agricultural 

uses. 

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

knows about thidiazuron, 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 thidiazuron. This 

PWP also includes a summary of the draft human health and ecological risk assessments for 

thidiazuron registration review. The last comprehensive human health and ecological risk 

assessments for thidiazuron were completed in 2005 in support of the Reregistration Eligibility 

Decision (RED). Only minor updates to the RED risk assessments were required to meet current 

risk assessment standards, so EPA developed a combined scoping document/draft human health 

risk assessment and a combined problem formulation/draft ecological risk assessment. Both 

draft risk assessments and this PWP are now in the docket and the 60-day public comment period 

has commenced. 

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 thidiazuron and what types of new data or 

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

thidiazuron. The Agency encourages all interested stakeholders to review the PWP and 

Appendix and to provide comments and additional information that will help the Agency's 

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

wish to comment, there are some areas identified in the PWP and Appendix about which the 

Agency specifically seeks comments and information. Interested stakeholders could include: 

environmental non-profit or interest groups; pesticide manufacturers; agricultural labor or 

commodity groups; commercial, institutional, residential, and other users of pesticides; or the 

public at large. 

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

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

provides chemical facts, use and usage information, recent actions, conclusions ofthe completed 

human health and ecological risk assessments, and a projected registration review timeline for 

thidiazuron. Finally, the Appendix to this document includes identification and discussion of 

some areas that are considered generally in Registration Review along with some additional 

chemical case-specific information. 

3 
ANTICIPATED DATA NEEDS 

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

the anticipated data needs, see the Registration Review: A Joint Problem Formulation and Draft 

Risk Assessment of the Environmental Fate and Ecological Risk ofThidiazuron and Thidiazuron: 

Human Health Combined Scoping Document and Draft Risk Assessment for Registration 

Review. 

Table 1: Anticipated Data Needs for the Thidiazuron Registration Review 

Estimated 

Guideline Study Title1 

Timeframe 

Number1 Test Material (Months from 

receipt ofDCI) 

835.6100 Terrestrial field dissipation (storage stabi lity TEP 12 

portion only) 

850.2100 Avian acute oral toxicity (passeri ne species) TGA l 12 

850.3040 Field testing for poll inators (tier lll)2 TEP 24 

850.6100 Environmental chemistry method for water and TGA I 12 

associated independent laboratory va lidation 

850 .6100 Environmental chemistry method for soi l and TGAI 12 

associated independent laboratory va l idation3 

Non- Honeybee larval acute oral toxicity (tier f) TEP 12 

guideline 

Non- Honeybee adult I 0-day chronic oral toxicity (tier TEP 12 

guideline I) 

Non- Honeybee larval chronic oral toxicity (tier 1)

4 TEP 12 

guideline 

Non- Residues in pollen and nectar/fie ld residue TEP 24 

guideline analysis (tier I11 )

2 

Non- Semi-field toxicity testing for poll inators (tier ll)2 TEP 24 

guideline 

Non- Radio-validation for to lerance enforcement TEP 12 

guideline method TU-002-A06-0I (livestock commodities) 

TGAI = techmcal grade active mgredient; TEP =typical end-use product; 

1 On June 27,2012, EPA announced certain revisions in harmonized guideline series 850 - Ecological Effects Tests 

- including renumbering and other designations or changes for some guideline studies. See "Final Test 

Guidelines; OCSPP 850 Series; Notice of Availability" 77 FR 38282, June 27,2012. 

http://www .regulations.gov/#! documentDetail; D=EP A-HQ-OPPT -2009-0 154-0028 2 Tier II and tier Ill pollinator studies are required based on results of tier I pollinator studies. 3 An environmental chemistry method for soil has been submitted to EPA, but has not yet been reviewed. EPA will 

complete this review during registration review. 4 It is possible to conduct the larval chronic oral toxicity study in such a way as to derive both an LD50 (acute 

endpoint) and a NOAEC (chronic endpoint). If both an LD5o and NOAEC can be derived from a single study, then 

a separate acute larval toxicity study is not needed. 

4 
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 combined Final Work Plan (FWP) and Proposed 

Interim Registration Review Decision. 

CHEMICAL FACTS 

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

Table 2: Chemical Facts for Thidiazuron 

PC code 120301 

Case Number 003 

CAS Number 51707-55-2 

Year first registered 1982 

Pesticide Type Plant growth regulator 

Chemical class Phenyl urea 

Reregistration Eligibility A RED for thidiazuron was completed in September 2005. 

Decision (RED) 

Tolerance Reassessment Not applicable, tolerance reassessment was included in the RED. 

Eligibility Decision 

(TRED) 

5 http ://www.epa.gov/oppsrrd !/registration _revi ew/ 

5 
Table 2: Chemical Facts for Thidiazuron 

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

of a cumulative group that shares a common mechanism of 

toxicity. 

40 CFR Citation Tolerances for thidiazuron are established in 40 CFR § 180.403. 

Dual-use Thidiazuron is registered for conventional pesticidal uses only 

and has no registered antimicrobial or biopesticidal uses. 

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

Pesticide Re-evaluation Khue Nguyen, nguyen.khue@epa.gov, 703-347-0248 

Division, Chemical 

Review Manager 

Registration Division, Kathryn Montague, montague.kathryn@epa.gov, 703-305-1243 

Product Manager 

USE AND USAGE INFORMATION 

Table 3 summarizes the use and usage information for thidiazuron. Please see the BEAD 

Chemical Profile (BCP) for Registration Review: Thidiazuron (1 0301) in the registration review 

docket for more details. 

Table 3: Thidiazuron Use and Usage Information 

Summary of Use Thidiazuron is a phenylurea plant growth regulator registered for 

use as a cotton defoliant. It is applied as a pre-harvest treatment 

to reduce the fo liage and immature fruiting structures which 

contribute to the staining of harvested cotton. 

Use Sites Thidiazuron is only applied to cotton. There are no registered 

non-agricultural uses. 

Summary of Usage From 2008-20 12, an average of approximately 250,000 lbs of 

thidiazuron were applied annually to 3.8 million acres of cotton. 

The top states with the highest percentage of lbs thidiazuron 

applied were Georgia, Texas, Mississippi, and Arkansas. Georgia 

and Texas are the states with the highest use and together they 

account for nearly half of the cotton acreage treated with 

thidiazuron. 

Formulation Type(s) Wettablepowder, suspension or emulsifiable concentrate 

Application Method(s) Ground or aerial application equipment 

Technical Registrant(s) Bayer Cropscience LP; Loveland Products, Inc.; Nufarm Limited; 

Arysta Lifescience North America, LLC; and Adama Celsius 

Property B.V., Amsterdam (NL) 

No. of Registrations 24 Section 3 products6 

Restricted Use No 

6 Section 3 product labels can be obtained from the Pesticide Product Label System (PPLS) website 

(http:/ I oaspub.epa.gov /pest lab 1/pp Is. home). 

6 
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; 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. 

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

• Median and 90111 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. 

• Typical application interval (days). 

• State or local use restrictions. 

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

market. 

RECENT ACTIONS 

There are no recent actions for thidiazuron. 

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW 

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

2005 in preparation for the RED. The most recent ecological and environmental fate risk 

assessment was completed in 2005 for the same purpose. Findings and conclusions from these 

risk assessments are summarized in the Registration Review: A Joint Problem Formulation and 

Draft Risk Assessment of the Environmental Fate and Ecological Risk ofThidiazuron and 

Thidiazuron: Human Health Combined Scoping Document and Draft Risk Assessment for 

Registration Review. 

During registration review, the Agency anticipates the need to reassess risk for pollinators and 

complete an endangered species risk assessment for all uses ofthidiazuron. For human health, 

EPA anticipates the need to assess endocrine disruption risks for thidiazuron 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 wi ll be considered in the revised 

assessments, as well as any changes to the standard operating procedures or default exposure 

assumptions. 

Table 4 below summarizes the recently completed registration review human health and 

ecological risk assessments as detailed in the Registration Review: A Joint Problem Formulation 

and Draft Risk Assessment of the Environmental Fate and Ecological Risk ofThidiazuron and 

the Thidiazuron: Human Health Combined Scoping Document and Draft Risk Assessment for 

Registration Review. 

7 
Table 4: Summary of Preliminary Human Health and Ecological Risk Assessments for the 

Thidiazuron Registration Review 

Type of Risk Assessment Conducted? Notes 

Ecological and Environmental Fate 

Comprehensive ecological y The registration review risk assessment identified 

risk assessment potential drinking water risk to birds, terrestrial-phase 

amphibians, and reptiles foraging in treated fields, 

and risk to terrestrial plants. An endangered species 

assessment was not completed. The Agency 

anticipates a more in-depth evaluation in the future to 

determine the potential co-occurrence of listed species 

and the areas in which cotton is grown. 

Incidents Will check for There were 4 reported ecological incidents for 

updates thidiazuron. For a discussion of reported ecological 

incidents, see page 17 of the Problem Formulation. 

Human Health 

Dietary 

Food y The registration review human health risk assessment 

Drinking water y did not identify any dietary risks of concern. The 

highest exposed population subgroup was children 1-

2 years old at 9.3% ofthe cPAD. 

Occupational 

Handlers (mixers, loaders, y The occupational handler assessment did not identify 

applicators) any risks of concern. MOEs ranged from 30,000 to 

1,500,000. 

Post-application y A qualitative occupational post-application risk 

assessment was completed since only dermal 

exposure was expected and no dermal hazard was 

identified for thidiazuron. No post-application risks 

were identified. 

Residential 

Handlers N A residential handler assessment was not completed 

because thidiazuron is not registered for residential 

use. 

Post-application y Although thidiazuron is not registered for residential 

use, potential residential exposure could occur via 

spray drift. A residential post-application spray drift 

assessment was completed and did not identify any 

risks of concern. 

Other 

Aggregate y Evaluates the combined risk from dietary and 

residential exposures. The Agency only considered 

exposure from food and drinking water because 

thidiazuron is not registered for residential use. No 

aggregate risks were identified. 

8 
Cumulative N Thidiazuron is not currently a member of a 

cumulative group, therefore, no cumulative risk 

assessment was completed. 

Tolerances y The Agency is proposing to modify the tolerance 

expression for thidiazuron to be in line with current 

policy. The Agency is also proposing to modify 

tolerances for various cotton commodities based on 

recent residue data. 

Incidents Will check for Only 1 human incident of minor severity was reported 

updates for thidiazuron. For a discussion of reported human 

incidents for thidiazuron, see page 27 of the 

Thidiazuron: Human Health Combined Scoping 

Document and Draft Risk Assessment for Registration 

Review and the Thidiazuron: Tier I Review of Human 

Incidents. 

TIMELINE 

EPA has created the following estimated timeline for the completion of the thidiazuron 

registration review in Table 5 below. 

Table 5: Projected Thidiazuron Registration Review Timeline 

Activities Estimated Date 

Opening the Docket 

Open Docket and 60-day Public Comment Period for June 20 15--completed 

Preliminary Work Plan and Draft Risk Assessments7 

Close Public Comment August 2015 

Case Development 

Final Work Plan Not applicable 

Registration Review Decision 

60-day Public Comment Period for Proposed March 2016--May 2016 

Registration Review Decision 

Registration Review Decision and Begin Post-Decision September 2016 

Follow-up 

Issue DCI During post-interim decision followup 

Data Submission During post-interim decision followup 

Total (months) 15 months 

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. 

9 
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 Proposed Interim Registration Review 

Decision for the registration review ofthidiazuron. Subsequently, the Agency will hold a 60-day 

public comment period on the Proposed Interim Registration Review Decision, review and 

respond to comments, and issue the Interim Registration Review Decision for thidiazuron. 

EPA is undertaking a streamlined risk assessment process for the registration review of 

thidiazuron because of a number of factors: 

i) thidiazuron is only used on one crop in a geographically limited area of the 

United States, 

ii) the use pattern for thidiazuron has not changed since implementation of RED 

label changes, 

iii) the human health, ecotoxicology, and environmental fate databases for 

thidiazuron are mostly complete, 

iv) the existing honeybee data did not indicate immediate risks to pollinators, and 

v) only minor updates to the RED risk assessments were required to meet current 

risk assessment standards. 

Because of these reasons, the Agency did not see the need to issue a DCI for thidiazuron prior to 

risk assessment. The Agency anticipates issuing a DCI during post-Interim Registration Review 

Decision follow-up. 

10 
Appendix- Additional Areas Considered in the Thidiazuron 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 ofMRLs or disparities between U.S. 

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

the nature of the concern. 

Water Quality: 

Thidiazuron 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 thidiazuron. 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 ofthe OPP Standard Operating Procedure: Inclusion of Impaired 

Water Body and Other Water Quality Data in OPP 's Registration Review Risk Assessment and 

Management Process'' 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 thidiazuron 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 waters I 0/attai ns nation cy.cause detail 303d?p cause group id=885 9 http://iaspub.epa.gov/tmdl waters I 0/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/oppsrrd I /registration review/water quality sop.htm 

11 
ENDANGERED SPECIES: 

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

conducted for thidiazuron. The endangered species risk assessment planned during registration 

review will allow the Agency to determine whether use of thidiazuron 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 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 reregistration decision for thidiazuron, 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), thidiazuron 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 withE, A, or T hormonal systems will proceed to the next stage ofthe 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 theE, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list 

of chemicals identified for EDSP screening was published on June 14, 2013 12 and includes some 

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

chemicals. 

12 
pesticides scheduled for registration review and chemicals found in water. Neither of these lists 

should be construed as a list of known or likely endocrine disruptors. 

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 

HUMAN STUDIES: 

Occupational and Residential 

Past thidiazuron 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), 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. 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. 

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

13