738R04003
United States Prevention, Pesticides
Environmental Protection and Toxic Substances November 2004
^^^r^- Agency (7508C)
\^tijrr
Reregistration
Eligibility Decision for
Oxadiazon
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738R04003
vvEPA
United States Prevention, Pesticides
Environmental Protection and Toxic Substances November 2004
Agency (7508C)
Reregistration
Eligibility Decision for
Oxadiazon
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United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508C)
EPA-738-F-04-003
November 2004
SEFft R.E.D. FACTS
Pesticide
Reregistration
Oxadiazon
All pesticides sold or distributed in the United States must be registered by
EPA, based on scientific studies showing that they can be used without posing
unreasonable risks to humans or the environment. Because of advances in scientific
knowledge, the law requires that pesticides which were first registered before
November 1, 1984, be reregistered to ensure that they meet today's more stringent
standards.
In evaluating pesticides for reregistration, EPA obtains and reviews a complete
set of studies from pesticide producers, describing the human health and
environmental effects of each pesticide. To implement provisions of the Food Quality
Protection Act of 1996, EPA considers the special sensitivity of infants and children
to pesticides, as well as aggregate exposure of the public to pesticide residues from
all sources, and the cumulative effects of pesticides and other compounds with
common mechanisms of toxicity. The Agency develops any mitigation measures or
regulatory controls needed to effectively reduce each pesticide's risks. EPA then
reregisters pesticides that meet the safety standard of the FQPA and can be used
without posing unreasonable risks to human health or the environment.
When a pesticide is eligible for reregistration, EPA explains the basis for its
decision in a Reregistration Eligibility Decision (RED) document. This fact sheet
summarizes the information in the RED document for oxadiazon (Chemical Code No.
109001; Case No. 2485).
Use Profile Oxadiazon is a pre-emergent or early post-emergent oxadiazole herbicide
registered for commercial use on turf grown on golf courses (~77% of total use)
and in apartment/condominium complexes, parks, athletic fields, playgrounds, and
cemeteries (~12% of total use). In addition, oxadiazon is used on sod farms and
on conifer nurseries and landscapes (i.e. industrial sites, ornamental, roadside
plantings, woody, ornamental shrubs, vines and trees, and herbaceous
ornamentals). Annual usage is approximately 249,000 pounds on 52,000 acres.
Regulatory
Oxadiazon was registered in 1978. A Phase Four generic data call-in (DCI)
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History was issued in May of 1991. Due to additional data required under FIFRA as
amended in 1988, the oxadiazon registrant decided to no longer support food uses
of oxadiazon. On June 3, 2002, the Agency considered the FQPA safety finding to
be met and counted the oxadiazon tolerances as reassessed. There are no
CODEX, Canadian, or Mexican tolerances for oxadiazon residues.
Human Health Toxicity
Assessment In humans, acute exposure to oxadiazon can cause irritation to the skin, eyes
and mucous membranes. In both subchronic and chronic studies, effects on the
liver were consistent among the species tested (rat, dog, mouse). Oxadiazon is
classified as "likely to be carcinogenic to humans" based on studies that showed an
increase in the incidence of liver tumors in two species (mice and rats) following
chronic exposure to oxadiazon.
Dietary Risks
There are no food or feed, or anticipated food or feed uses for oxadiazon.
The Registrant is not supporting any tolerances for oxadiazon in the United States.
Existing tolerances have been revoked. Likewise, there are no Canadian or
Mexican tolerances for oxadiazon.
Worker Risks
Cancer risks for occupational handlers of wettable-powder formulations of
oxadiazon are of concern. Exposure scenarios of concern include
mixing/loading/applying wettable powder formulations. To reduce these risks, the
wettable powder formulations will be packaged in water-soluble packaging (WSP)
only.
Residential and Other Nonoccupational Risks
The oxadiazon label indicates that the purchase, storage and application of
this pesticide is limited to commercial nursery, turf and landscape personnel, and the
product is not available to homeowners. Post-application residential exposure
scenarios include apartment complexes, golf courses, and playgrounds. The
Agency has concluded that residential exposure to oxadiazon is not of concern.
FQPA Considerations
Given that there are no remaining food/feed uses for oxadiazon, and given
that all food tolerances have been revoked, this pesticide no longer falls under the
scope of FQPA. As such, no quantitative aggregate assessment of risk from
dietary and residential was conducted. EPA has qualitatively evaluated the
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likelihood of concurrent exposures from different sources of oxadiazon for the
general population, including children. Because of the relatively low volume of
oxadiazon use on sites other than golf courses, its specialized use pattern, and its
relatively high cost, concurrent exposures are not expected.
In addition, oxadiazon was not assessed for the cumulative effects of
pesticides having a common mechanism of toxicity. The Agency does not have
sufficient information at this time concerning common mechanism issues to determine
whether or not oxadiazon shares a common mechanism of toxicity with other
substances, including other oxadiazoles. Therefore, for the purposes of this risk
assessment, the Agency has assumed that oxadiazon does not share a common
mechanism of toxicity with any other chemicals.
Environmental
Assessment
Summary
Ecological Risks
Environmental fate studies indicate that oxadiazon persists in the environment
bound to organic matter. In clear, shallow bodies of water, oxadiazon not bound to
organic matter may be degraded by sunlight. Alternatively, oxadiazon is defined as
a light-dependent peroxidizing herbicide (LDPH), which suggests that toxicity is
greater in the presence of light. Studies indicate that after application to soil,
oxadiazon remains near the surface, and can be transported via runoff to nearby
surface water bodies. Leaching from surface soils to groundwater is expected to
be low or negligible, unless the soil is very porous. Since this stable compound can
bind to particulate and organic matter, oxadiazon residues can accumulate in
sediments at the bottom of bodies of water.
To mitigate ecological risks the technical registrants has agreed to label
amendments which include reductions in application rates. In addition, the Agency
is requiring that the registrant submit data related to fish and invertebrate toxicity,
as well as data from toxicity studies with aquatic plants and sediment.
This Fact Sheet explains the Agency's decision regarding the reregistration
eligibility of the registered uses of oxadiazon. The Agency has found that the current
uses of oxadiazon are eligible for reregistration, provided the changes specified in the
RED are made to the packaging and labels.
Additional Data
Required
EPA is requiring the following confirmatory data requirements for oxadiazon:
870.3465: 28-day inhalation toxicity
850.1300: Early-Life Stage in Freshwater and Estuarine/Marine Fish
850.1350: Life Cycle in Freshwater and Estuarine/Marine Invertebrates
850.4100: Seedling Emergence (Tier 1)
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850.4150: Vegetative Vigor (Tier 1)
850.4225: Seedling Germination/Emergence
850.4250: Vegetative Vigor (Tier 2)
835.4300: Aerobic Aquatic Metabolism
Aquatic Phototoxicity Studies (Fathead minnow)
Acute and Chronic Sediment Toxicity Testing
Water Monitoring Study
Product Labelinq AH oxadiazon end-use products must comply with EPA's current pesticide
Chanaes Reailired product labeling requirements. For a comprehensive list of labeling requirements,
please see Section V of the oxadiazon RED document.
Regulatory EPA has determined that all products containing oxadiazon as the active
Conclusion ingredient are eligible for reregistration, provided changes specified in the oxadiazon
RED are incorporated into the label and additional data identified in Section V of the
RED confirm this conclusion.
For More
Information
EPA is requesting public comments on the Reregistration Eligibility Decision
(RED) document for oxadiazon during a 60-day time period, as announced in a
Notice of Availability published in the Federal Register. To obtain a copy of the
oxadiazon RED document, please contact the OPP Public Docket (7502C), US EPA,
Ariel Rios Building, 1200 Pennsylvania Avenue, NW, Washington, DC 20460-0001,
telephone: (703) 305-5805. Electronic copies of the oxadiazon RED and all
supporting documents are also available on the Agency's website at
http://www. cfpub. epa. gov/oppref/rereg/status. cfm ?show=rereg.
For more information about EPA's pesticide reregistration program or the
oxadiazon RED, please contact the U.S. EPA, OPP, Special Review and
Reregistration Division (7508C), Washington, DC 20460-0001, telephone: (703) 308-
8000.
For more information about the health effects of pesticides, or for assistance in
recognizing and managing pesticide poisoning symptoms, please contact the National
Pesticide Information Center (NPIC). Call toll-free (800) 858-7378, from 6:30 am to
4:30 pm Pacific Time, or 9:30 am to 7:30 pm Eastern Standard Time, seven days a
week. Their internet address is htto://www. noic. orst. edu.
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ISB
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
PREVENTION, PESTICIDES AND
TOXIC SUBSTANCES
CERTIFIED MAIL .'.'.*
Dear Registrant:
This is to inform you that the Environmental Protection Agency (hereafter referred to as
EPA or the Agency) has completed its review of the available data and public comments received
related to the risk assessment for the oxadiazole pesticide, oxadiazon (Ronstarฎ). Based on its
review, EPA has identified risk mitigation measures that the Agency believes are necessary to
address the human health and environmental risks associated with the current use of oxadiazon.
The EPA is now publishing its reregistration eligibility and risk management decisions for the
current uses of oxadiazon, and its associated human health and environmental risks. The enclosed
"Reregistration Eligibility Decision for Oxadiazon," which was approved on September 15, 2003,
contains the Agency's decision on the individual chemical oxadiazon.
A Notice of Availability for this Reregistration Eligibility Decision (RED) for oxadiazon is
published in the Federal Register. To obtain a copy of the RED document, please contact the
OPP Public Regulatory Docket (7502C), US EPA, Ariel Rios Building, 1200 Pennsylvania
Avenue NW, Washington, DC 20460, telephone (703) 305-5805. Electronic copies of the RED
and all supporting documents are available on the Internet. See http://www.epa.gov/pesticides.
This document and the process used to develop it are the result of a pilot process to
facilitate greater public involvement and participation in the reregistration and/or tolerance
reassessment decisions for pesticides. As part of the Agency's effort to involve the public in the
implementation of the Food Quality Protection Act of 1996 (FQPA), the Agency is undertaking a
special effort to maintain open public dockets and to engage the public in the reregistration and
tolerance reassessment processes for these chemicals. The human health and environmental risk
assessments were placed in the public docket and an invitation for public comment was
announced in the Federal Register on February 19, 2003.
Please note that the oxadiazon risk assessments and the attached RED concern only this
particular chemical. Oxadiazon is a member of the oxadiazole class of herbicides. While current
data are limited, EPA has evidence that compounds within a class may share a common
mechanism of toxicity. At this time, the Agency does not have sufficient data concerning
common mechanism issues to determine whether or not oxadiazon shares a common mechanism
Recycled/Recyclable . Printed with Vegetable Oil Based Inks on 100% Recycled Paper (40% Postconsumer)
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of toxicrty with other substances, including other oxadiazoles or other probable human
carcinogens. Therefore, for the purposes of this risk assessment, the Agency has assumed that
oxadiazon does not share a common mechanism of toxicity with any other chemicals.
Product labels should be revised by the manufacturer to adopt the changes set forth in
Section V of this document. Instructions for registrants on submitting revised labeling and the
time frame established to do so can be found in Section V of this document.
If you have questions on this document or the proposed label changes, please contact the
Special Review and Reregistration Division representative, Mark Seaton, at (703) 306-0469. For
questions about product reregistratkm and/or the Product DCI that accompanies this document,
please contact Bentley Gregg at (703) 308-8178.
Betty Shackleford, Acting Director
Special Review and
Reregistration Division
Attachment
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Reregistration Eligibility Decision
for
Oxadiazon
ListB
Case 2485
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Table of Contents
Glossary of Terms and Abbreviations iv
Oxadiazon Reregistration Eligibility Decision Team vii
Executive Summary viii
I. Introduction 1
n. Chemical Overview 3
A. Chemical Identification 3
B. Use Profile 4
C. Estimated Usage of Pesticide 4
D. Regulatory History 5
III. Summary of Oxadiazon Risk Assessment 6
A. Human Health Risk Assessment 6
1. Toxicity of Oxadiazon 6
2. Dose Response Assessment and Toxicity Endpoints 8
3. FQPA Considerations 9
4. Dietary Risk from Drinking Water 10
5. Residential and Other Non-occupational Post-application Risks 13
6. Occupational Risk 14
7. Incident Data 21
B. Environmental Risk Assessment 21
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1. Environmental Fate and Transport 22
2. Water Resources 22
3. Ecological Risk 23
4. Endangered Species Risk Assessment 32
IV. Risk Management, Reregistration and Tolerance Reassessment Decision 33
A. Determination of Reregistration Eligibility 33
B. Tolerance Reassessment 33
C. Regulatory Position 34
1. FQPA and Aggregate Risk 34
2. Endocrine Disrupter Effects 34
3. Cumulative Risks 35
4. Benefits Assessment 35
D. Tolerance Summary 35
E. Human Health Risk Mitigation 35
1. Dietary (Drinking Water) Risk Mitigation 35
2. Non-occupational Post-application Risk Mitigation 37
3. Occupational Risk Mitigation 39
4. Inhalation Toxicity and Exposure Uncertainties 41
F. Environmental Risk Mitigation 41
1. Terrestrial Organism Risk Mitigation 41
2. Aquatic Organism Risk Mitigation 42
G. Other Labeling Requirements 43
1. Endangered Species Statement 43
2. Spray Drift Management 44
V. Actions Required of Registrants 44
A. Manufacturing Use Products 46
1. Additional Generic Data Requirements 46
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2. Labeling for Manufacturing Use Products 47
B. End-Use Products 47
1. Additional Product-Specific Data Requirements 47
2. Labeling for End-Use Products 47
C. Labeling Requirements Summary Table 48
D. Existing Stocks 53
VI. Appendices.
Appendix A. Table of Oxadiazon Use Patterns Eligible for Reregistration 55
Appendix B. Table of Generic Data Requirements and Studies Used to Make the Reregistration
Decision 61
Appendix C. Technical Support Documents 65
Appendix D. Citations Considered to be Part of the Database Supporting the Reregistration
Decision (Bibliography) 69
Appendix E. Generic Data Call-in 81
Appendix F. Product-specific Data Call-in 89
Appendix G. EPA's Batching of Oxadiazon Products for Meeting Acute Toxicity Data
Requirements for Reregistration 99
Appendix H. List of Registrants Sent this Data Call-in 105
Appendix I. List of Available Related Documents andElectronically Available Forms 107
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Glossary of Terms and Abbreviations
AGDCI Agricultural Data Call-In
ai Active Ingredient
aPAD Acute Population Adjusted Dose
AR Anticipated Residue
BCF Bioconcentration Factor
CFR Code of Federal Regulations
cPAD Chronic Population Adjusted Dose
CSF Confidential Statement of Formula
CSFII USDA Continuing Surveys for Food Intake by Individuals
DCI Data Call-In
DEEM Dietary Exposure Evaluation Model
DFR Dislodgeable Foliar Residue
DWLOC Drinking Water Level of Comparison.
EC Emulsifiable Concentrate Formulation
EEC Estimated Environmental Concentration.
EP End-Use Product
EPA Environmental Protection Agency
FDA Food and Drug Administration
FIFRA Federal Insecticide, Fungicide, and Rodenticide Act
FFDCA Federal Food, Drug, and Cosmetic Act
FQPA Food Quality Protection Act
FOB Functional Observation Battery
G Granular Formulation
GENEEC Tier I Surface Water Computer Model
GLN Guideline Number
HAFT Highest Average Field Trial
IR Index Reservoir
LCj0 Median Lethal Concentration. A statistically derived concentration of a substance that can be expected to
cause death in 50% of test animals. It is usually expressed as the weight of substance per weight or volume of
water, air or feed, e.g., mg/1, mg/kg or ppm.
LD50 Median Lethal Dose. A statistically derived single dose that can be expected to cause death in 50% of the test
animals when administered by the route indicated (oral, dermal, inhalation). It is expressed as a weight of
substance per unit weight of animal, e.g., mg/kg.
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LOG Level of Concern
LOD Limit of Detection
LOAEL Lowest Observed Adverse Effect Level
M ATC Maximum Acceptable Toxicant Concentration
ug/g Micrograms Per Gram
ug/L Micrograms Per Liter
mg/kg/day Milligram Per Kilogram Per Day
mg/L Milligrams Per Liter
MOE Margin of Exposure
MUP Manufacturing-Use Product
MRID Master Record Identification (number). EPA's system of recording and tracking studies submitted.
NA Not Applicable
NAWQA USGS National Water Quality Assessment
NPDES National Pollutant Discharge Elimination System
NR Not Required
NOAEL No Observed Adverse Effect Level
OP Organophosphate
OPP EPA Office of Pesticide Programs
OPPTS EPA Office of Prevention, Pesticides and Toxic Substances
PCA Percent Crop Area
PAD Population Adjusted Dose
PDF USDA Pesticide Data Program
PHED Pesticide Handler's Exposure Data
PHI Preharvest Interval
ppb Parts Per Billion
PPE Personal Protective Equipment
ppm Parts Per Million
PRZM/
EXAMS Tier II Surface Water Computer Model
Q,* The Carcinogenic Potential of a Compound, Quantified by the EPA's Cancer Risk Model
RAC Raw Agriculture Commodity
RED Reregistration Eligibility Decision
REI Restricted Entry Interval
RiD Reference Dose
RQ Risk Quotient
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SCI-GROW Tier I Ground Water Computer Model
SAP Science Advisory Panel
SF Safety Factor
SLC Single Layer Clothing .
SLN Special Local Need (Registrations Under Section 24(c) of FIFRA)
TGAI Technical Grade Active Ingredient
TRR Total Radioactive Residue
USD A United States Department of Agriculture
USGS United States Geological Survey
UF Uncertainty Factor
UV Ultraviolet
WPS Worker Protection Standard
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Oxadiazon Reregistration Eligibility Decision Team
Office of Pesticide Programs:
Biological and Economic Analysis Division
Stephen Smeaiman Economic Analysis Branch
William Chism Herbicide and Insecticide Branch
Environmental Fate and Effects Division
Mike Rexrode Environmental Risk Branch 5
Jose Melendez Environmental Risk Branch 4
Faraque Khan Environmental Risk Branch 4
Health Effects Division
Nancy McCarroll
Sheila Piper
Seyed (Nader) Tadayon
Ken Dockter
Toxicology Branch 1
Chemistry and Exposure Branch 1
Chemistry and Exposure Branch 1
Reregistration Branch 2
Registration Division
Joanne Miller
Gene Wilson
Herbicide Branch
Herbicide Branch
Special Review and Reregistration Division
Mark Seaton Reregistration Branch 2
Tom Myers Reregistration Branch 2
Vll
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Executive Summary
This document presents the Environmental Protection Agency's (the Agency) decision regarding the
reregistration eligibility of the registered uses of oxadiazon. The Agency made its reregistration eligibility
determination based on the data required for reregistration, the current guidelines for conducting acceptable
studies to generate such data, and published scientific literature. The Agency has found that currently
registered uses of oxadiazon are eligible for reregistration, provided specified changes are made to the label.
Oxadiazon is a herbicide registered for use on golf course and commercial turf, and on ornamental plants
and shrubs by horticultural nurseries. There are no registered homeowner uses. EPA estimates that
approximately 250,000 pounds of active ingredient are used annually, about 80% of which is applied to golf
course turf.
Overall Risk Summary
EPA's human health risk assessment for oxadiazon suggests dietary (drinking water) and occupational
risks of concern. Risk estimates based on refined (Tier II) models indicate a chronic cancer risk of concern
from exposure to drinking water from surface water sources. To further assess the risk from drinking water
exposure, the Agency is requiring the registrant to submit three years of drinking water monitoring data
collected from sites determined by the Agency to be likely to result in upper-bound exposures.
In addition, there is a cancer risk of concern for handlers who mix/load/apply wettable powder
formulations. To mitigate the cancer risk to handlers, the Agency is requiring changes to packaging, as well as
changes to the required personal protective equipment for handlers who mix/load/apply wettable powder
formulations.
The ecological risk assessment suggests potential chronic risks of concern to aquatic organisms from
application of oxadiazon at the maximum application rate of 8 Ibs ai/A/year to golf courses. In order to further
assess the risk to fish and invertebrates from oxadiazon exposure, the Agency is requiring that the registrant
submit additional early stage fish toxicity data and invertebrate life cycle toxicity data.
Dietary Risk
Acute, chronic and cancer dietary risk from food are not of concern since there are no food tolerances
and no registered food uses. Acute and chronic (non-cancer) risks from oxadiazon in groundwater and
surface water are also not of concern. Cancer risks from surface water are potentially of concern for the
general population based on modeled estimates of environmental concentrations of oxadiazon in surface water
from use on golf courses. To address potential drinking water risks associated with estimated surface water
concentrations resulting from the use of oxadiazon on golf course turf, the registrant has agreed to reduce the
maximum annual application rate at 6 Ibs ai/A, with the exception that areas heavily infested with weeds may
be treated with up to 8 Ibs ai/A. The registrant has agreed to provide additional water monitoring data to
refine exposure estimates.
Occupational Risks
Risks for occupational handlers of oxadiazon are of concern. Exposures of concern include
mixing/loading/applying wettable powder formulations. To mitigate the cancer risk to handlers, the registrant
has agreed that wettable powder formulations of oxadiazon be packaged in water-soluble packaging. In
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addition, wettable-powder product labels will require that handlers wear chemical-resistant gloves in addition
to long pants and a long-sleeved shirt during mixing/loading/applying activities.
Occupational post-application scenarios assessed for oxadiazon include golf course and sod farm
workers engaged in turf maintenance. There are no risks of concern from occupational post-application
exposure scenarios.
Residential Risk
There were no exposure scenarios of concern for residential risk.
Ecological Risks
Oxidiazon use on golf course turf is of concern given the maximum application rates for turf and the
likelihood of golf course runoff to move toward surface water. Acute risks for birds, mammals, fish, aquatic
invertebrates and aquatic plants at the typical application rates for golf course turf are not of concern. Chronic
risks are not a concern for birds or mammals, but are potentially of concern for aquatic organisms at the
maximum application rate of 6 Ibs ai/A/year for turf. In order to further assess the risk to fish and invertebrates
from oxadiazon exposure, the Agency is requiring that the registrant submit additional toxicity data including
early-stage estuarine fish studies and life cycle estuarine/marine invertebrate studies. Also, enhanced toxicity
through exposure to high levels of solar radiation may increase risk to aquatic organisms that inhabit small,
shallow water bodies. Therefore, EPA is requiring a study on the phototoxicity of oxadiazon in fathead
minnows.
Reregistration Eligibility Decision
As required under Section 4(g)(2)(A) of FIFRA, the Agency has completed its review of oxadiazon-
specific data, and has determined that the data are sufficient to support reregistration of all products containing
oxadiazon provided that certain data gaps are addressed, the risk reduction measures outlined in this
document are adopted and labels are amended to implement these measures. The reviewed data were
sufficient to allow the Agency to determine that oxadiazon can be used without resulting in unreasonable
adverse effects to humans and the environment. The Agency, therefore, finds that all products containing
oxadiazon as the active ingredient are eligible for reregistration, provided specified changes are made to the
label. Actions needed to reregister particular products are addressed in Section V of this document The
Agency concludes that these label changes address the current risk estimates and reflect the use of all
acceptable data available at this time together with uncertainty factors where data gaps exist.
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I. Introduction
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was amended in 1988 to accelerate
the reregistration of products with active ingredients registered prior to November 1,1984. The amended Act
calls for the development and submission of data to support the reregistration of an active ingredient, as well as
a review of all submitted data by the U.S. Environmental Protection Agency (referred ito as EPA or "the
Agency"). Reregistration involves a thorough review of the scientific database underlying a pesticide's
registration. The purpose of the Agency's review is to reassess the potential hazards arising from the currently
registered uses of the pesticide; to determine the need for additional data on health and environmental effects;
and to determine whether or not the pesticide meets the "no unreasonable adverse effects" criteria of FIFRA.
On August 3,1996, the Food Quality Protection Act (FQPA) was signed into law. This Act amends
FIFRA to require tolerance reassessment during reregistration. It also requires that by 2006, EPA must
review all tolerances in effect on the day before the date of the enactment. FQPA also amends the Federal
Food, Drug, and Cosmetic Act (FFDCA) to require a safety finding in tolerance reassessment based on
factors including an assessment of cumulative effects of chemicals with a common mechanism of toxicity.
With respect to tolerances for oxadiazon, there have been no active food-use registrations since 1991.
The tolerance for rice straw was revoked as of the July 1, 2001 revision to 40 CFR 180.346. In a
confirmatory letter to EPA, dated January 24,2001, the registrant maintained its previous position that it
would not support the sixteen remaining oxadiazon tolerances. Therefore, effective April 24,2003, EPA
revoked all the tolerances in 40 CFR 180.346 for the combined residues of the herbicide oxadiazon and its
metabolites in the following commodities: in or on milk; cattle, fat; cattle, meat; cattle, meat byproducts; goats,
fat; goats, meat; goats, meat byproducts; hogs, fat; hogs, meat; hogs, meat byproducts; horses, fat; horses,
meat; horses, meat byproducts; sheep, fat; sheep, meat; and sheep, meat byproducts. In addition, because
EPA determined on April 21,2002 that there is no reasonable expectation of finite residues of oxadiazon and
its metabolites in or on meat, milk, poultry, and egg commodities, the sixteen associated tolerances for
livestock commodities were considered by the Agency to no longer be needed under 40 CFR 180.6(a)(3).
Therefore, on June 3,2002, the Agency considered the FQPA safety finding to be met and counted the
sixteen oxadiazon livestock tolerances as reassessed.
Given that all tolerances for oxadiazon have been revoked, this pesticide no longer falls under the scope
of FQPA. As such, no quantitative aggregate assessment of risk from dietary and residential exposures was
completed as part of the reregistration process. EPA has evaluated the likelihood of concurrent exposures to
oxadiazon for the general population, including children. Because of the relatively low volume of use of
oxadiazon on sites other than golf courses, its specialized use pattern, and its relatively high cost, concurrent
exposures are not likely.
At this time, the Agency has not made a decision as to whether oxadiazon shares a common mechanism
of toxicity with other oxadiazoles, or any other pesticide. A careful evaluation of all the available data is still
needed, as well as peer review by the FIFRA Scientific Advisory Panel, before a formal decision is made.
Therefore, for the purposes of this risk assessment, the Agency has assumed that oxadiazon does not share a
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common mechanism of toxicity with other pesticides. After a decision is made regarding common mechanism
of toxicity, and if the Agency has determined that a cumulative assessment is necessary, the Agency will
address any outstanding risk concerns at that time.
This document presents the Agency s decision regarding the reregistration eligibility of the registered uses
of oxadiazon, including the consideration of risk to infants, children and adults for any potential food, drinking
water, dermal, inhalation or oral exposures. In an effort to simplify the RED, the information presented herein
is summarized. More detailed information can be found in the technical supporting documents for oxadiazon
referenced in this RED. The revised risk assessments and related addenda are not included in this document,
but are available on the Agency's web page at www.epa.gov/pesticides, and in the Public Docket.
This document consists of six sections. Section I is the introduction. Section n provides a profile of the
use and usage of oxadiazon, and its regulatory history. Section HI gives an overview of the human health and
environmental assessments, based on the data available to the Agency. Section IV presents the reregistration
eligibility and risk management decisions. Section V summarizes the necessary label changes based on the risk
mitigation measures outlined in Section IV. Finally, the Appendices list all related documents and how to
access them, and Data Call-In (DCI) information.
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II. Chemical Overview
A. Chemical Identification
rVr
"
\
y.-l 3
Common name:
Chemical name:
Empirical formula:
CAS Registry No.:
Case number:
OPP Chemical Code:
Molecular weight:
Trade name:
Oxadiazon
[2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl) -2-1,3,4-
oxadiazoline-5-one]
C15H18C12N203
19666-30-9
2485
109001
345.2
Ronstar
Basic manufacturer: Bayer Environmental Science
Technical oxadiazon is a white, crystalline powder with a melting point of 90 ฐC. Oxadiazon is stable for
30 days at 55 ฐC, and is stable in the presence of aluminum, iron and tin powders (but not ferric chloride).
The water solubility of oxadiazon is 0.7 mg/L at 20 ฐC. Oxadiazon has a vapor pressure of 7.76 x 10~7 mm
Hg.
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B. Use Profile
Oxadiazon is labeled for professional use only. The label indicates that the purchase, storage and
application of this pesticide are limited to commercial nursery, turf and landscape personnel. The product is
not available to homeowners. The following is information on the currently registered uses of oxadiazon. A
detailed table of the uses of oxadiazon eligible for reregistration is contained in Appendix A.
Type of Pesticide and Target Pests: Oxadiazon is a pre-emergent or early post-emergent
oxadiazole herbicide used to control grassy weeds (e.g., goosegrass and crabgrass) and broadleaf
weeds in turf and ornamentals. Oxadiazon works by interfering with the pathway for chlorophyll
production, and results in a breakdown of plant tissue on exposure to light.
Use Sites: Oxadiazon is registered for commercial use on residential turf (i.e.,
apartment/condominium complexes, parks, athletic fields, playgrounds, and cemeteries) and on
golf courses (predominant use). In addition, oxadiazon is used on sod farms and on conifer
nurseries and landscapes (i.e., industrial sites, ornamental, roadside plantings, woody, ornamental
shrubs, vines and trees, and herbaceous ornamentals). Oxadiazon use sites are classified as non-
food sites (i.e., primarily golf course fairways), residential outdoor use, roadsides and nurseries.
Formulation Types Registered; Oxadiazon is formulated as a granular (predominant
formulation, -90% of total use) and wettable powder.
Method and Rates of Application
Equipment: Granular formulas are applied using mechanical spreaders, manual spreaders
(i.e., belly grinder, push type spreader) or tractor-drawn spreaders. Methods of
application associated with the other formulation and use-patterns of oxadiazon
include: groundboom, rights-of-way sprayer, handgun sprayer, backpack
sprayer, low pressure handwand, high pressure handwand, and lawn handgun.
Rates: The frequency of application ranges from 1 to 3 applications per season.
Oxadiazon can be applied at a minimum single application rate of 2.0 pounds
active ingredient per acre (ai/A) up to a maximum single application rate of 4.0
pounds ai/A to turf and ornamentals. The annual maximum application rate is 8
Ibs ai/A/year.
Use Classification: Not classified.
C. Estimated Usage of Pesticide
Approximately 250,000 pounds of oxadiazon are applied to approximately 50,000 acres annually.
Oxadiazon is used primarily in southern states and predominantly on golf courses. Table 1 summarizes the
EPA's best available estimates for the pesticide uses of oxadiazon. These estimates are derived from a variety
of published and proprietary sources available to the Agency.
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Table 1. Oxadiazon Usage Summary
Crop
Lbs. Active
Ingredient Applied
(Wtd. Avg.)1
Percent Crop
Treated
(Likely Maximum)
Percent Crop Treated
(Wtd. Avg.)1
Turf:
Golf Courses
Landscape,
Rights-of-way,
Parks
Horticultural
Nurseries
160,000
28,000
56,000
6%
...
3%
'Wtd Avg (weighted average): the most recent years and more reliable data are weighted more heavily.
: missing information or lack of confidence in the data.
D. Regulatory History
Oxadiazon was registered in 1978. A Phase Four generic data call-in (DCI) was issued in May of
1991. Due to additional data required under FIFRA as amended in 1988, the oxadiazon registrant decided to
no longer support food uses of oxadiazon. With respect to tolerances for oxadiazon, there have been no
active food-use registrations since 1991. The tolerance for rice straw was revoked as of the July 1,2001
revision to 40 CFR 180.346. In a confirmatory letter to EPA, dated January 24,2001, the registrant
maintained its previous position that it would not support the sixteen remaining oxadiazon tolerances.
Therefore, effective April 24,2003, EPA revoked all the tolerances in 40 CFR 180.346 for the combined
residues of the herbicide oxadiazon and its metabolites in the following commodities: in or on milk; cattle, fat;
cattle, meat; cattle, meat byproducts; goats, fat; goats, meat; goats, meat byproducts; hogs, fat; hogs, meat;
hogs, meat byproducts; horses, fat; horses, meat; horses, meat byproducts; sheep, fat; sheep, meat; and
sheep, meat byproducts. In addition, because EPA determined on April 21,2002 that there is no reasonable
expectation of finite residues of oxadiazon and its metabolites in or on meat, milk, poultry, and egg
commodities, the sixteen associated tolerances for livestock commodities were considered by the Agency to
no longer be needed under 40 CFR 180.6(a)(3). Therefore, on June 3,2002, the Agency considered the
FQPA safety finding to be met and counted the sixteen oxadiazon livestock tolerances as reassessed. There
are no CODEX, Canadian, or Mexican tolerances for oxadiazon residues.
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III. Summary of Oxadiazon Risk Assessments
A. Human Health Risk Assessment
1. Toxicity of Oxadiazon
Details of the hazard assessment of oxadiazon can be found in the revised Human Health Risk
Assessment for Oxadiazon, dated June 6,2003 (McCarroll, 2003). Major features of the toxicology profile
are presented below. In acute studies, oxadiazon was only slightly toxic to rats and rabbits. In rabbits,
oxadiazon was mildly irritating to ocular tissue and negligibly irritating to the skin, and in guinea pig studies,
oxadiazon was not a dermal sensitizer (Table 2).
Table 2. Acute Toxicity Data on Oxadiazon
Guideline No./ Study Type
870.1100
Acute oral toxicity (rat)
870.1200
Acute dermal toxicity (rabbit)
870.1300
Acute inhalation toxicity (rat)
870.2400
Acute eye irritation (rabbit)
870.2500
Acute dermal irritation (rabbit)
870.2600
Skin sensitization (guinea pig)
MRID No.
41866501
(97.5% a.i.)
41866502
(97.5% a.i.)
41866503
(93.7% a.i.)
41866504
(97.5% a.i.)
41866505
(97.5% a.i.)
41230401
(93.7% a.i.)
Results
LD50>5000mg/kg cT, ? combined
LD50 >2000 mg/kg, cf, ? combined
LC50 >1.94 mg/L cf, ? combined
Mild irritant to ocular tissues
Negligibly irritating to skin
Not a dermal sensitizer (Buehler test)
Toxicity
Category
IV
III
III
III
III
In both subchronic and chronic studies, the major target organ of oxadiazon toxicity was the liver.
Effects were consistent among the species tested (rat, dog, mouse) and typically included enlarged livers along
with increases in serum clinical chemistry parameters associated with hepatotoxicity such as alkaline
phosphatase and serum aspartate or alanine aminotransferase.
Following long-term dietary administration, oxadiazon caused an increased incidence of hepatocellular
adenoma and carcinoma in rats and mice. Consistent findings were reported in a total of four acceptable
studies in two species (two mouse and two rat studies). A third mouse study was unacceptable, although
-------
increased hepatocellular tumors were also observed in mice of both sexes. A classification of "likely to be
carcinogenic to humans" was assigned by the Cancer Assessment Review Committee (CARC). A quantitative
risk (Qi*) of 7.11 x 10"2 (mg/kg/day)"1 was calculated as the most potent unit risk, based on the incidence of
male mouse liver adenoma and/or carcinoma combined tumor rates in the ICR-JCL mouse.
hi a special submitted mechanistic study in rats and a published study in rats, mice and dogs, oxadiazon
induced peroxisomal proliferation (based on liver enlargement, peroxisomal enzyme induction and electron
microscopy) after a 14-day dietary administration. Some peroxisomal proliferator compounds are known to
be liver carcinogens, but the Health Effects Division Mechanism of Toxicity Assessment Review Committee
(MTARC) concluded that there is insufficient evidence to support peroxisome proliferation as a mechanism of
carcinogenicity for oxadiazon due to insufficient data showing hepatocellular proliferation, lack of concordance
between the enzyme induction dose-response and tumor formation, and an unexplained decrease in catalase,
which is normally significantly increased by peroxisomal proliferator compounds.
Oxadiazon did not show mutagenic potential in any in vitro assays with bacteria (S. typhimurium and
E. coli) or mammalian cells (TK +/-mouse lymphoma cells), did not show clastogenic potential in Ihe in vitro
Chinese hamster ovary cell chromosomal aberration assays and did not induce unscheduled DNA synthesis in
cultured primary rat hepatocytes. However, a dose-related increase in transformation frequencies was
observed in an in vitro Syrian hamster kidney BHK21 C13/HRC1 cell transformation assay.
Significant fetal toxicity (fetal loss due to resorptions and post-implantation loss, decreased fetal weight,
skeletal variations) was observed in developmental toxicity studies in both rats and rabbits. These fetal effects
occurred at the same dose levels at which slight maternal toxicity (decreased weight gain/weight loss) were
observed. Offspring survival effects were also observed in the rat two-generation reproduction study. No
toxicity was reported at the lowest dose tested; however, in the range-finding phase of the reproduction study
at higher dose levels, fetal and neonatal survival were also sharply reduced. The decreased neonatal survival
was due at least in part to effects on lactation, based on findings of inactive mammary glands in the dams at
necropsy. Neonatal loss may have resulted from starvation and would, therefore, be an effect of direct
maternal toxicity. Inactivity of the mammary tissue as a possible effect of endocrine disruption was considered
by the Hazard Identification Assessment Review Committee (HIARC) but was not found to be likely since
there was no evidence from any other study in the database suggesting endocrine disruption. No fetal
malformations were observed in the rat or rabbit developmental toxicity studies; however, some skeletal
variations (delayed ossification, asymmetric pelvis) were reported. The above findings indicate that there is no
quantitative evidence of increased susceptibility of rats or rabbits following in utero or postnatal exposure to
oxadiazoa
Neurotoxicity studies are not required for oxadiazon because no clinical signs of toxicity suggestive of
neurobehavioral alterations nor evidence of neuropathological effects were observed in any of the available
toxicity studies. There was no evidence of neurotoxicity of oxadiazon in the rat and rabbit developmental
toxicity studies, nor in the rat two-generation reproduction toxicity study.
Based on the available data, the Metabolism Assessment Review Committee (MARC) concluded that
the only residue of concern is the parent compound, oxadiazon, because major degradation products would
only be minor components in the environment and are not likely to be significantly more toxic than the parent.
The only toxicity data gap that has been identified at this time is a 28-day inhalation study (OPPTS No.
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870.3465). This study is being required by the Agency because some currently registered products of
oxadiazon include spray formulations which could result in exposure via the inhalation route.
2. Dose Response Assessment and Toxicity Endpoints
The HIARC concluded that neither an acute nor a chronic reference dose (RfD) was required for
oxadiazon because there are no food or feed uses. A short-term oral endpoint was selected for incidental oral
exposure in children, using a No Observed Adverse Effect Level (NOAEL) of 12 mg/kg/day based on a
statistically significant decrease in maternal body weight gains at 40 mg/kg/day (LOAEL) in a developmental
study in rats (Table 3). The same endpoint was selected for short-term and intermediate dermal exposure.
In the absence of food or feed uses, HIARC did not select an acute RfD for oxadiazon. In order to
estimate acute drinking water risk, EPA has used the same study and endpoint described above for short-term
incidental exposure. 'For the acute drinking water assessment an uncertainty factor of 100 was applied, based
on a 1 OX for intraspecies variation and a 10X for interspecies extrapolation. Therefore, the "theoretical acute
RfD" would be 0.12 mg/kg/day. When maternal toxicity can be attributed to a single dose (e.g, body weight
loss in the early dosing period), the developmental studies can be selected for the acute RfD, the short-term
(1-7 days) incidental oral exposure and/or the intermediate (7 days to several months) because the critical
effect (in the case of oxadiazon, body weight loss at days 16-20 which was possibly due to resorption of
fetuses) occurred during the treatment period which encompasses both exposure periods of concern. It is
reasonable to assume that effects were possibly manifested by exposure to a single dose and the resulting
body weight loss did not become apparent until after 7 days.
A chronic RfD was not selected by HIARC because the lack of food or feed uses. However, for the
purpose of assessing potential risks from drinking water, EPA has used the chronic/oncogenicity feeding study.
For the chronic drinking water assessment, an uncertainty factor of 100 was applied based on a 1 Ox factor for
intraspecies variation and a lOx factor for interspecies extrapolation. This chronic oral endpoint was based on
increased incidence of swollen cells in the central lobe of the livers of male rats observed at the LOAEL of 3.5
mg/kg/day. The NOAEL in this study was 0.36 mg/kg/day. Therefore, the "theoretical chronic RfD" would
be 0.0036 mg/kg/day. For long-term dermal exposure, this same endpoint was selected. The HIARC
recommended that a dermal absorption factor of 9% be used in the calculations, based on a dermal
penetration study.
Due to a lack of inhalation studies, the HIARC selected an endpoint from oral studies for inhalation risk
assessments. For short and intermediate-term inhalation exposure, the same oral study was chosen as for
dermal exposure of these durations, with a NOAEL of 12 mg/kg/day. The same chronic/oncogenicity feeding
study in rats chosen for dermal exposure of this duration was selected for the long-term inhalation exposure,
with a NOAEL of 0.36 mg/kg/day. An absorption factor of 100% was applied for inhalation exposures.
A level of concern, referred to as a Margin Of Exposure or MOE, of 100 for occupational and
residential exposure scenarios was calculated using a lOx factor for intraspecies variation and a lOx factor for
interspecies extrapolation. Because the effects from dermal and inhalation exposure are the same, the doses
for these routes and duration were combined. Dermal and incidental oral exposures for toddlers were also
combined to reflect a total exposure burden.
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Table 3: End
EXPOSURE
SCENARIO
Incidental Oral,
Short-Tenn and
Intermediate
Term
Dermal, Short-
Term and
Intermediate-
Term
Dermal, Long-
Term
Inhalation,
Short- Term and
Intermediate-
Term
Dietary, Long-
term
Inhalation,
Long-Term
Cancer
points for Oxadiazon Risk Assessment
DOSE
(mg/kg/day)
NOAEL= 12
Maternal
effects
NOAEL= 12
Maternal
effects'
Development
al effects
NOAEL=0.36
NOAEL= 12
Maternal
effects'
Development
al effects
NOAEL=0.36
NOAEL=
0.36
Q,*of7.11 x .
10-'
(mg/kg/day)"'
ENDPOINT
Reduced body weight/body weight gain at 40 mg/kg/day
(LOAEL).
Reduced body weight/body weight gain at 40 mg/kg/day
(LOAEL) / Increased fetal resorptions/postimplantation
loss, increased incidence of incomplete ossification at 40
mg/kg/day
(LOAEL). For this risk assessment, the dermal
absorption rate of 9% is applied.
Increased centrilobular swelling in male livers at 3.5
mg/kg/day (LOAEL). For this risk assessment, the
dermal absorption rate of 9% is applied.
Reduced body weight/body weight gain at 40 mg/kg/day
(LOAEL) / Increased fetal resorptions/postimplantation
loss, increased incidence of incomplete ossification at 40
mg/kg/day
(LOAEL). For this risk assessment, a 100%
absorption rate is applied
Increased centrilobular swelling in male livers at 3.5
mg/kg/day (LOAEL).
Increased centrilobular swelling in male livers at 3.5
mg/kg/day (LOAEL). A 100% absorption rate applied.
Significant increase (pair-wise and trend, p<0,01) in liver
adenomas and/or carcinomas combined in males at k9.3
mg/kg/day).
STUDY
Developmental Toxicity -
Rat
MRID No. 40470202
Developmental Toxicity -
Rat
MRID No. 40470202
Combined Chronic Feeding/
Oncogenicity - Rat
MRID Nos. 40993401,
00149003/00157780
Developmental Toxicity -
Rat
MRID No. 40470202
Combined Chronic Feeding/
Oncogenicity - Rat
MRID Nos. 40993401,
00149003/00157780
Combined Chronic Feeding/
Oncogenicity - Rat
MRID Nos. 40993401,
00149003/00157780
Combined Chronic Feeding/
Carcinogenicity - Mouse
MRID Nos. 40993301
3. FQPA Considerations
On August 3,1996, the Food Quality Protection Act of 1996 (FQPA) was signed into law. This Act
amends FIFRA to require tolerance reassessment during reregistration. With respect to tolerances for
oxadiazon, there have been no active food-use registrations since 1991. Effective April 24,2003, EPA
revoked all the tolerances in 40 CFR 180.346 for the combined residues of the herbicide oxadiazon and its
-------
metabolites. In addition, the Agency considered the FQPA safety finding to be met and counted the sixteen
oxadiazon livestock tolerances as reassessed.
Given that there are no remaining food/feed uses for oxadiazon, and given that all food tolerances have
been revoked, this pesticide no longer falls under the scope of FQPA. As such, no quantitative aggregate
assessment of risk from dietary and residential was conducted. EPA has qualitatively evaluated the likelihood
of concurrent exposures from different sources of oxadiazon for the general population, including children.
Because of the relatively low volume of oxadiazon use on sites other than golf courses, its specialized use
pattern, and its relatively high cost, concurrent exposures are not expected.
Only 15% (or about 28,000 pounds) of the oxadiazon that is applied each year is used on parks,
landscapes, rights-of-way, etc., and this use is distributed across five or more states. An even smaller portion
of the 28,000 pounds is used on sites where people, including children could be exposed, such as parks.
Because of its comparatively high cost, oxadiazon is not routinely used in residential lawn care. Furthermore,
the exposure assumption in both the residential and drinking water assessments are sufficiently protective to
account for the unlikely event of exposure from more than one source.
With respect to sensitivity in children, there is no evidence of either a qualitative or quantitative increase
in susceptibility of rats or rabbits to in utero and/or postnatal oxadiazon exposure. Although significant fetal
toxicity was observed in developmental toxicity studies in both rats and rabbits (i.e., fetal loss due to
resorptions and post-implantation loss) and in a two-generation reproduction study (i.e., reduced neonatal
survival), these fetal/neonatal effects occurred at the same doses that caused maternal toxicity. It is also likely
that neonatal losses resulted from starvation and could, thus, be a possible direct maternal toxic effect.
Inactivity of the mammary tissue as a possible endocrine disruption effect was considered but was found to be
unlikely since there was no evidence from any other study in the database suggesting endocrine disruption.
4. Dietary Risk from Drinking Water
Since there are no food/feed uses of oxadiazon and no tolerances exist, dietary risk from oxadiazon can
only result through exposure in drinking water. Drinking water exposure to pesticides can occur through
ground and surface water contamination. EPA considers acute, chronic non-cancer, and chronic cancer
drinking water risks and uses modeling and monitoring data, if available, to estimate those risks. To determine
the maximum contribution from water allowed in the diet, EPA first looks at how much of the overall allowable
risk is contributed by food and then determines a "drinking water level of comparison" (DWLOC) to ascertain
whether or not modeled or monitored concentrations exceed this level. In the case of oxadiazon, there is no
contribution from food. Estimated environmental concentrations (EECs) that are above the corresponding
DWLOC exceed the Agency's level of concern.
Based on its review of submitted studies, the EPA has concluded that oxadiazon would be stable and
persistent under typical terrestrial environmental conditions. In the absence of measured environmental
concentrations of oxadiazon from monitoring studies, and based on environmental fate characteristics, potential
oxadiazon concentrations in unfinished drinking water were estimated using Tier 2 PRZM/EXAMS (surface
water) and Tier 1 SCIGROW (ground water) models. The PRZM/EXAMS model as used here is a standard
turf scenario that includes a two-centimeter layer of thatch, and is referred to as the Florida Turf Scenario.
10
-------
The combined ("linked") PRZM/EXAMS model is typically used by EPA in estimating pesticide
concentrations in surface waters. The PRZM model estimates the amount of pesticide that reaches a body of
surface water as a result of runoff. The EXAMS model estimates pesticide concentrations by taking into
account different mechanisms for dissipation, weather patterns, and periodic application of pesticide, for
several years. The PRZM/EXAMS model generates concentration estimates of acute (one in ten year peak
concentration), non-cancer chronic (one in ten year mean concentration) and chronic cancer (36-year mean
concentration).
As used here, the PRZM/EXAMS estimates of pesticide concentrations in surface water generated by
this linked model can be considered to be upper-bound estimates. Several conservative parameter values
have been incorporated into the mathematical formulas, including a calculated factor for the half-life of
oxadiazon in water. The Florida Turf Scenario introduces a two-inch thatch layer as an intercept to
incorporation of oxadiazon with soil particles. As typically applied, oxadiazon granules are watered into the
soil surface, thereby mediating the potential effects of the thatch layer. Also, an assumption in the current
model is that oxadiazon is applied as a wettable powder formulation (i.e., applied as a spray), and therefore
the model includes a value for spray drift into water bodies.
An additional conservative parameter incorporated into the model is the value for percent crop area
(PCA). The term PCA refers to the area of land around a watershed that is planted with crops to which a
specific pesticide will be applied. In the example of oxadiazon, the primary application site is golf course turf.
In the present model, a PCA value of 94% was used to account for the land area of a typical golf course that
is greens, tees, fairway (27%) and rough (67%). The EPA makes the protective assumption that 94% of land
area around a particular watershed might possibly be made up of golf course, and that 100% of the golf
courses in the watershed apply oxadiazon at the maximum application rate and frequency. Registrants have
submitted a GIS analysis suggesting that the upper-bound limit of PCA for turf (including golf courses and
other recreational turf) in south Florida is substantially less than 94%. Model-derived surface water EECs and
DWLOCs are summarized in Table 4.
The SCIGROW model is typically used for Tier 1 screening purposes for pesticides applied to soils. The
SCIGROW model is based on leaching studies conducted in sandy soils above shallow aquifers, and estimates
likely groundwater concentration. In areas with those characteristics, groundwater is particularly vulnerable to
contamination. The SCIGROW model estimated environmental concentration for oxadiazon in groundwater is
0.59 ppb.
Table 4. Surface Water DWLOC and EEC Comparisons
Infants (<1 year)
Children (1-6 years)
Females (13-50
years)
Acute
DWLOC
(PI*)
1200
1200
3600
Acute
EEC
(PPb)
181
Chronic (non-
cancer)
DWLOC (ppb)
36
36
108
Chronic
(non-
cancer)
EEC (ppb)
65
Chronic
(cancer)
DWLOC
(ppb)
049
Chronic (cancer)
EEC
(PPb)
56
11
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Table 4. Surface Water DWLOC and EEC Comparisons
U.S. population
4200
126
I
Ground Water DWLOC and EEC Comparisons
Infants (<1 year)
Children (1-6 years)
Females (13-50
years)
U.S. population
1200
1200
3600
4200
0.59
36
36
108
126
0.59
0.49
0.59
a. Acute Drinking Water Risk
Acute DWLOCs were calculated for oxadiazon based on results of a developmental toxicity study. The
No Observable Adverse Effect Level (NOAEL) was 12 mg/kg/day, with the toxicity endpoint being a
reduction in maternal body weight gain at the Lowest Observable Adverse Effect Level (LOAEL) of 40
mg/kg/day. The rationale for selection of this endpoint is provided in the "Dose Response and Toxicity
Endpoint" section of this document. Based on a comparison of DWLOCs to the corresponding
PRZM/EXAMS (surface water) and SCIGROW (groundwater) estimates (EECs), the EECs for surface
water (181 ppb) and groundwater (0.59 ppb) were less than the DWLOCs calculated for all populations
(1200 - 4200 ppb) and, thus, the Agency concludes that acute exposure to residues of oxadiazon in surface
and groundwater-sourced drinking water is not of concern.
b. Chronic Drinking Water Risk
Chronic DWLOCs were calculated based on a chronic toxicity/carcinogenicity study. The NOAEL was
0.36 mg/kg/day, based on the endpoint of centrilobular swelling in male rats, observed at the LOAEL of 3.5
mg/kg/day. The rationale for selection of this endpoint is provided in the "Dose Response and Toxicity
Endpoint" section of this document. Using the PRZM/EXAMS model estimates, the EECs for surface water
(65 ppb) were higher than the DWLOCs calculated for infants and children (36 ppb) (Table 4) and thus,
potentially of concern. The chronic ground water EEC of 0.59 ppb was less than the chronic (noncancer)
DWLOC of 36 for the most sensitive subpopulations (children less than 1, and children 1-6 years) and is not a
concern.
c. Cancer Drinking Water Risk
For the cancer exposure calculations, the Agency used multi-year mean water concentration values. The
DWLOCcance,. is the concentration in drinking water that results in a negligible cancer risk of one in a milion (1.0
x 10'6). The cancer ground water EEC of 0.59 ppb slightly exceeds the DWLOC of 0.49. However, given
the protective exposure assumptions, this slight exceedence is not of concern. The cancer EEC for surface
water (56 ppb) exceeds the cancer DWLOC (0.49 ppb) (Table 4) and thus, is potentially of concern.
12
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5. Residential and Other Non-occupational Post-application Risks
Since oxadiazon is only available to professional turf, landscape, and nursery personnel, there are no
residential handler scenarios. Although oxadiazon is not available for homeowner use, the Agency has
determined that there are potentiat postapplication exposures to residents entering oxadiazon treated turf and
lawns. A complete discussion of potential residential exposures, including the sources of exposure data and
toxicity information is found in the document "Revised Occupational and Residential Exposure Assessment and
Recommendations for the Reregistration Eligibility Decision Document for Oxadiazon" dated June 7,2003
(Tadayon, 2003) on the Agency's web page at www.epa.gov/pesticides, and in the Public Docket.
The scenarios likely to result in postapplication exposures in non-occupational situations are presented
below. The duration of postapplication dermal exposure is expected to be either short-term or intermediate-
term, based on oxadiazon turf residue dissipation data. Oxadiazon has a half-life on turf of up to 1.4 days
(irrigated) and 1.7 days (non- irrigated) after spraying, requiring several days to dissipate to non detectable
levels of transferable residues (MRID # 435178-01). Because the label prohibits application more than 3
times per year, and even with the slow dissipation rates, it is not expected that individual residential exposure
duration would exceed 30 days in duration. Exposure on a residential lawn would diminish continuously with
time, while exposure through recreation turf contact would more likely be random intermittent events of varying
doses, all less than the dose predicted in this assessment. Residential postapplication exposure assessments
assume that residents wear the following attire: short sleeved shirt, short pants, shoes and socks, and no gloves
or respirator. The scenarios likely to result in postapplication exposures are as follows:
dermal postapplication risks to adults and toddlers when entering oxadiazon treated turf and lawns;
oral postapplication risks to toddlers from "hand-to-mouth" (i.e., ingestion of grass, soil, granular pellets,
or hand-to-mouth contact) exposure when reentering lawns treated with granular and wettable powder
formulations.
Representative turf reentry activities include, but are not limited to:
Adults involved in a low exposure activity, such as golfing or walking on treated turf.
Toddlers involved in a low exposure activity, such as walking on treated turf.
Adults mowing or other moderate contact activity, for 1-2 hours.
Adults involved in a high exposure activity, such as heavy yard work (doses similar to occupational
scenarios for cutting and harvesting sod).
Toddlers involved in high exposure activities on turf.
For risk assessment purposes, Margins of Exposure (MOEs) compare the estimated exposure
concentration to a No Observed Adverse Effect Level (NOAEL) from an animal study. In the case of
oxadiazon, the Agency's level of concern for residential post-application risk is exceeded if MOEs fall below
100. The target MOE of 100 for non-occupational exposure scenarios was selected based on the uncertainty
factors of lOx for intraspecies variation and lOx for interspecies extrapolation.
The registrant submitted a study on turf-transferable residues (TTR) in response to an
occupational/residential exposure Data Call-in, and in support of oxadiazon re-registration requirements.
13
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Ronstarฎ 50 WP a wettable powder product containing ~ 50 % oxadiazon, was applied to turf in North
Carolina. The study was conducted in order to quantify the dermal exposure associated with re-entry onto
oxadiazon treated turf. Ronstarฎ 50 WP which is labeled for use on dormant, Bermuda grass, St. Augustine
grass and Zoisia turf in areas such as fairways, parks, and lawns was used at a maximum label rate of 3 .0 Ib
ai/A. Two different exposure scenarios were monitored:
- Application at the maximum label rate followed by re-entry as soon as the turf was dry.
- Application followed within 30 minutes by sprinkler irrigation of 1/10 inch of water with re-entry occurring as
soon as the turf is dry.
Utilizing the transferable residue data and revised residential SOPs, all of the non-cancer risk scenarios
developed for adults and children had short-term and intermediate-term dermal MOEs greater than 100. The
cancer risks for all adult, non-occupational, dermal, post-application exposures ranged from 6 x 10~6 to 8 x 10"7
. Although the estimated cancer risk slightly exceeds the Agency's level of concern (1.0 x 10"6), that estimate is
conservative given that the risk assessment was performed with a spray application, whereas approximately
90% of oxadiazon is applied as a granular formulation. The granule size for a typical end-use product, Ronstar
G, is 20/50 Mesh, or 300-850 microns. In all instances, the granules are designed to fall below the grass
canopy and into the thatch layer. If used according to label directions, it is unlikely that oxadiazon granules
would be accessible to a child or adult. According to the registrant, for best results oxadiazon granules should
be watered-in as soon as is practical following application. Watering-in the granules will carry them further into
the thatch layer, and will further decrease the likelihood of dermal exposure.
Estimated incidental oral short-term exposures ("hand-to-mouth") for children had an MOE of 100
using the TTR default values from the residential SOP; when the TTR data from a submitted oxadiazon study
were used, the MOEs were 240 and 90 for irrigated and non-irrigated turf, respectively.
MOEs were not calculated for the incidental ingestion of oxadiazon granules because, as discussed
above, the very small granules would not be available on the lawn surface and thus not accessible to children.
It is thought, therefore, that the incidental ingestion of granules is not likely to be a cause for concern.
6. Occupational Risk
a. Occupational Toxicity
For risk assessment purposes, Margins of Exposure (MOEs) compare the estimated exposure
concentration to a No Observed Adverse Effect Level (NOAEL) from an animal study. In the case of
oxadiazon, the Agency's level of concern for occupational risk is exceeded if MOEs fall below 100. The
target MOE of 100 for occupational exposure scenarios was selected based on the uncertainty factors of lOx
for intraspecies variation and lOx for interspecies extrapolation. The short-term and intermediate-term MOEs
for occupational risk were calculated based on a NOAEL of 12 mg/kg/day from a rat developmental toxicity
study. The LOAEL in this study was 40 mg/kg/day; the endpoint is reduced bodyweight gain.
14
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The short-term and intermediate-term MOEs for dermal and inhalation exposures were calculated using
an oral NOAEL of 12 mg/kg/day for both exposure durations (see Human Health Risk Assessment Section
3.3 Dose Response Assessment). The Agency also used route-to-route extrapolations to convert this oral
dose to dermal and inhalation doses. A dermal absorption rate of 9% was applied to the dermal exposure
assessments and an inhalation absorption rate of 100% was applied to the inhalation exposure assessments.
Since the effects from dermal and inhalation exposure are based on the same oral study (i.e. rat developmental
toxicity study), the exposures for these routes and durations were combined.
b. Occupational Handler Exposure
Occupational exposure to oxadiazon via the dermal and inhalation routes may occur during mixing,
loading and applying through the use of ground spray, granular and other turf application methods. Based on
the use patterns, 14 major occupational exposure scenarios were identified for oxadiazon:
(la) mixing/loading wettable powders for chemigation application;
(Ib) mixing/loading wettable powders for groundboom application;
(Ic) mixing/loading wettable powders for rights-of-way sprayer,
(2) loading granular formulations;
(3) applying sprays with a groundboom;
(4) applying sprays with a rights-of-way sprayer;
(5) applying wettable powder sprays with handgun sprayer;
(6) applying granules with a tractor drawn spreader;
(7) mixing/loading/applying sprays with a backpack sprayer;
(8) mixing/loading/applying sprays with a low pressure handwand (wettable powder formulations);
(9) mixing/loading/applying sprays with a high pressure-handwand (wettable powder formulations);
(10) mixing/ loading/ applying sprays with a lawn handgun (wettable powder formulations);
(11) mixing/ loading/ applying granules with a push type spreader; and,
(12) mixing/loading/applying granules with a bellygrinder.
Maximum single application rates for oxadiazon range from 3 to 4 Ib. ai/acre, with the higher rate being applied
to golf courses, roadside turf, lawns, parks, recreational areas and woody ornamentals.
The exposure scenarios are of short-term (1-30 days) and intermediate-term (30 days to several
months). Since the use patterns for oxadiazon do not suggest any long term use, exposure scenarios of a
longer duration were not considered. The estimated exposures considered:
- baseline protection (long pants, long shirts and no gloves - dermal; no respirator - inhalation),
15
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-additional PPE (long pants, long shirts and chemical resistant gloves and/or double layer of clothing - dermal;
plus 80% protection from dust/mist respirator - inhalation), and
-engineering controls (use of water soluble packages for wettable powder formulations).
EPA completed handler exposure assessments first assuming the baseline level of protection and, if
required, increasing levels of risk mitigation (PPE and engineering controls) to achieve an MOE of 100 or
more for non-cancer risks. The Agency's assumptions for specific categories of handlers and equipment are
as follows:
all occupational handlers are wearing footwear (socks plus shoes or boots)
occupational mixers and loaders using open mixing techniques are wearing long-sleeved shirts and
long pants and gloves; this represents minimum PPE
occupational mixers and loaders using open mixing techniques are wearing long-sleeved shirts and
long pants, coveralls and gloves; this represents maximum PPE
occupational applicators who use open cab tractor-driven application equipment are wearing long-
sleeved shirts and long pants and gloves; this represents minimum PPE.
Also, if necessary, dust/mist respirator represented by 5-fold protection factor or an organic vapor
respirator represented by a 10-fold protection factor are added to mitigate the risks.
Engineering control assumptions are as follows:
engineering controls are not available for occupational handlers (mixers, loaders, and applicators)
who use hand-held application equipment.
occupational mixers and loaders handling liquid formulations using a closed system are wearing
chemical-resistant gloves plus long-sleeved shirts and long pants.
occupational mixers and loaders handling wettable powders using a closed system (water-soluble
packages) are wearing long-sleeved shirts and long pants, and chemical-resistant gloves.
occupational applicators who use tractor-driven application equipment are located in enclosed
cabs are wearing long-sleeved shirts and long pants, and no gloves.
Chemical-specific data for assessing human exposures during pesticide handling activities were not
submitted to the Agency in support of the reregistration of oxadiazon. In such instances, it is the policy of the
EPA to use data from the Pesticide Handlers Exposure Database (PHED) Version 1.1 to assess handler
exposures for regulatory actions when chemical-specific monitoring data are not available. EPA's level of
confidence in these data are explained in detail in the "Revised Occupational and Residential Exposure
Assessment and Recommendations for the Reregistration Eligibility Decision Document for Oxadiazon" dated
June 7,2003 (Tadayon, 2003).
16
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c. Occupational Risk (noncancer)
The results of the short- and intermediate-term handler assessments are presented in Table 5 and
indicate that potential non-cancer exposure scenarios have MOE(s) greater than or equal to 100 at either the
baseline (i.e., long pants, long sleeved shirts, no gloves), PPE (i.e., long pants, long sleeved shirts, and
chemical resistant gloves while using open systems) or using engineering controls (i.e., water-soluble
packages). The only exception, for which engineering controls are not feasible, is scenario 8 (low pressure
handwand-wettable powder formulations), with a total MOE of 46 with maximum PPE. The low-pressure
hand wand applicator is likely to be used in non-turf areas of golf courses, such as landscaping.
Table 5: Exposure Variables (Noncancer) and MOEs for Uses of Oxadiazon
Exposure Scenario
(Scenario**)
Crop
Type
App Rates
(Ib ai/acre)
Daily
Acres
Treated
Total MOEs
Base
line
PPE
Eng.
Control
Mixer/Loader
Mixing/Loading Wettable
Powders for Chemigation
Application (la)
Mixing/Loading Wettable
Powders for Groundboom
Application (Ib)
Mixing/Loading Wettable
Powders for Rights-of-Way
Sprayer (Ic)
Loading Granular formulations
(2)
sod farms
conifer nurseries, woody
ornamentals
herbaceous ornamentals
sod farms
golf courses
roadside turf,
ornamentals
sod farms, conifers
forest
golf course turf, parks,
recreational areas
woody ornamentals
3
4
3
3
4
4
4
4
4
350
40
40
80
40
40
80
40
40
2
12
16
8
12
12
920
1800
1800
35
220
300
150
220
220
NA
NA
NA
610
NA
NA
NA
NA
NA
NA
NA
NA
Applicator
Applying with a Groundboom
(3)
Applying with a
Rights-of-Way Sprayer (4)
sod farms
herbaceous ornamentals
golf courses
conifer nurseries, woody
ornamentals
roadsides
3
3
4
4
4
80
40
40
40
40
1500
3000
2300
2300
37
NA
NA
NA
NA
120
NA
NA
NA
NA
NA
17
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Table 5: Exposure Variables (Noncancer) and MOEs for Uses of Oxadiazon
Exposure Scenario
(Scenario #)
Applying Wettable-Powders
for Handgun Applicators
(ORETF) (5)
Applying Granular with a
Tractor Drawn Spreader (6)
Crop
Type
lawns, parks,
recreational areas
sod farms
golf courses
App Rates
(Ib ai/acre)
4
4
4
Daily
Acres
Treated
5
80
40
Total MOEs
Base
line
See
PPE
1100
2200
PPE
540
NA
NA
Mixer/Loader/Applicator
Backpack Sprayer (LCD) (7)
Low Pressure Handwand -
Wettable Powder Formulations
(LCO) (8)
High Pressure Handwand
(Wettable Powder
Formulations) (9)
Lawn Handgun (Wettable
Powder Formulations)
(ORETF) (10)
Granulars with a Push Type
Spreader (ORETF) (11)
Granulars with a Bellygrinder
(LCO) (12)
lawns, golf courses,
ornamentals nurseries
lawns, golf courses,
nursery stock
woody ornamentals,
conifer nurseries.
ornamentals, lawns,
parks rec areas
lawns, golf courses,
parks, recreational
areas, ornamentals
golf courses, parks, rec
areas.
4
4
4
4
4
4
5
5
5
5
5
1
See
PPE
10
See
PPE
280
1100
190
140
46
100
NA
NA
NA
Eng.
Control
NA
NA
NA
NA
NF
NA
NA
NA
NA
Baseline dermal unit exposure scenarios includes long pants, long shirts and no gloves.
Baseline inhalation unit exposure represents no respirator
PPE dermal unit exposure includes long pants, long shins and gloves for scenarios 5, 7, and 9.
PPE dermal unit exposure includes long pants, long shirts gloves and double layer (50% protection) for scenarios la, Ib, Ic, and 8.
PPE inhalation unit exposure represents dust/ mist respirator (80 % protection) for scenarios la, Ib, Ic, and 8.
Engineering Control dermal unit exposure scenarios includes long pants, long shirts, gloves and water soluble packages for scenario la.
Engineering inhalation unit exposure represents no respirator.
NA = Not applicable.
NF - Not Feasible. No engineering controls are available to mitigate risk.
18
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d. Occupational Handler Risk (cancer)
The cancer risk assessments for handlers used baseline PPE and, as needed, increasing levels of risk
mitigation (PPE and engineering controls) to achieve cancer risks below EPA's level of concern. As noted
previously, the Agency's level of concern for cancer risks for occupational exposure to pesticides ranges from
1.0 x 10"4 to 1.0 x 10~6, depending on the feasibility, availability, and cost of various mitigation options.
Potential cancer risks to handlers were assessed using the following assumptions:
an average typical adult body weight of 70kg;
typical working lifetime of 35 years;
70 year lifetime;
dermal absorption of 9% and inhalation absorption of 100% of the oral dose.
Based on the scenarios identified above, the Agency estimates that cancer risks from occupational
dermal and inhalation exposures to oxadiazon range from 1.7 x 10"2 to 4.7 x 10"7 during "baseline".conditions
(i.e. long pants, long-sleeves, no gloves). Cancer risk ranges from 1.0 x 10"3 to 1.4 x 10'7 when PPE was
used. The Agency estimates that cancer risk decreases to a range of 5 x 10"5 to 1 x 10"8 with engineering
controls. Engineering controls included the use of chemical-resistant gloves along with water soluble
packaging for wettable powder formulations. Overall these estimates suggest that when PPE and/or
engineering controls are used, none of the evaluated scenarios have cancer risks that exceed 1.0 xlO^ , but
most are in the range where further consideration is warranted.
e. Occupational Exposure and Risk, Post-application (non-cancer)
EPA uses the term "post-application" to describe those individuals who can be exposed to pesticides
after entering areas previously treated with pesticides and performing certain tasks or activities (also often
referred to as reentry exposure). Most of the oxadiazon used is applied either pre-plant or when the crops are
quite small (early post-emergence). This fact, and the degree of mechanization, minimizes the post-application
contact of workers with oxadiazon. However, the Agency has determined that there are potential post-
application exposures to individuals re-entering oxadiazon treated areas for the purpose of:
Roadsides: mowing
Bermuda grass rights-of-way: mowing
Sod farms: mowing and harvesting
Golf-course turf: mowing
Based on usage information provided by the registrants for reregistration, the most common post-
application exposures for oxadiazon will occur for workers on turf. Based on label restrictions and pattern of
19
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use, oxadiazon is applied early in the season, either pre-plant or before weeds emerge (pre-emergence).
Mowing would be a common post-application activity after either spraying method. Treated turf or grasses
will routinely require reentry activities, such as mowing and watering, and eventually harvesting in the case of
sod farms.
Because oxadiazon has a low vapor pressure (1.0 x 10"6mm Hg) and is only used outdoors, the
inhalation component of post-application exposure is anticipated to be negligible. Therefore, all calculations of
post-application risk estimates have been done for dermal exposure only.
For short-and intermediate-term non-cancer risks, mowing (e.g., golf courses, roadsides, and sod farms)
and harvesting (e.g., sod farms) scenarios were considered. Transfer coefficients of 500 and 16,500 crrrVhr
were used, based on the Agricultural Re-entry Task Force data (refer to EPA Exposure SAC Policy guidance
3.1, 8/00). Occupational post-application activities had MOEs of 30-1000 at day 0. This information is
summarized below in Table 6.
f. Occupational Risk, Post-application (cancer)
Cancer risks for occupational post-application scenarios were estimated not to exceed EPA's level of
concern (i.e. <; 1.0 x 10"4; Table 6).
Table 6: Occupational Short- and Intermediate-Term Postapplication Risks for Oxadiazon at Day 0
Crop/Use
Pattern
Golf
Course
Turf
Sod Farms
Bermuda
Grass
Rights of
Wav
Applicatio
nRate
(Ib ai/acre)
4
4
4
Postapplication Activity
Mow, seed, scout,
mechanical weed, aerate,
fertilize, prune
Transplant, hand weed
Mow, scout, mechanical
weed, irrigate
Transplant, hand weed,
harvest (hand or
mechanical)
Mow, seed, scout,
mechanical weed, aerate,
fertilize
Transfer Coefficient1
500
16,500
500
16,500
500
MOE"
1000
30
1000
30
1000
Cancer Risk
LADD-
mg/kg/day
4.23e-5
139e-3
4.23e-5
1.39e-3
4.23e-5
Risk-
3.01e-6
9.92e-S
S.Ole-6
9.92e-5
3.01e-6
Transfer coefficient from Science Advisory Council for Exposure: Policy Memo # 003 .1 "Agricultural Transfer Coefficients,"
Revised - August 7, 2000.
"MOE = Short-term NOAEL (12 mg/kg/day; based on a dermal study) / dermal dose where absorbed dose = TTR (ug/cm2) x TC
(cmVhr) x conversion factor (1 mg/1,000 ug) x exposure time(8hrs/day)x dermal absorption (9 %) / body weight (60 kg; adult).
20
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cAbsorbed dermal dose where absorbed dose = TTR (ng/cm!) x TC (cnWhr) x conversion factor (1 mg/1,000 ng) x exposure time
(8 hrs/day) x dermal absorption (9 %) / body weight (70 kg) x (Number of days (3) exposure per year applicator) /365 days per
year) x 35 years worked/70 year lifetime
'Cancer Risk = LADD (mg/kg/day) x (Q,*), where Q,* = 7.1 le'! (mg/kg/day)'.
7. Incident Data
Oxadiazon has not been reported to cause life-threatening illness or death in humans. On the
list of the top 200 chemicals for which National Pesticide Information Center (NPIC, formerly
National Pesticide Telecommunications Network) received calls from 1984-1991 inclusively,
oxadiazon was ranked 192nd with 12 incidents in humans reported and five incidents in animals
(mostly pets). Most of the cases appear to be related to irritation to the skin, eyes and mucous
membranes.
B. Environmental Risk Assessment
A summary of the Agency's environmental fate and effects risk assessment is presented below.
More detailed information on the environmental and ecological risks associated with the use of
oxadiazon may be found in the "EFED Revised Risk Assessment for the Reregistration Eligibility
Decision of Oxadiazon," dated June 11,2003. Since that document was completed, the Agency
made changes to refine its assessment of the chronic surface water concentrations of oxadiazon
associated with the use on turf. Specifically, the Tier 1 model simulations were refined using the Tier
2 PRZM/EXAMS model simulation with a turf scenario. The linked PRZM/EXAMS models are
typically used by EPA in estimating pesticide concentrations in surface waters. The PRZM model
estimates the amount of pesticide that reaches a body of surface water as a result of runoff. The
EXAMS model estimates pesticide concentrations by taking into account different mechanisms for
dissipation, weather patterns, and periodic application of pesticide, for several years. The complete
environmental fate and effects risk assessment and related addenda are not included in this document,
but are available on the Agency's web page at www.epa.gov/pesticides, and in the Public Docket.
21
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1. Environmental Fate and Transport
Based on the fate studies reviewed, oxadiazon would be stable and persistent under typical
terrestrial environment conditions. Soil photolysis and hydrolysis under acidic and basic conditions
do not appear to be an important dissipation mechanism. However, direct aqueous photolysis half-
life of about three days (summer sunlight conditions in Florida) suggests that in clear and shallow
surface water bodies where sunlight penetration can be significant, photolytic degradation of
oxadiazon is possible. The photolytic effect may substantially diminish in turbid and deeper water
bodies.
Microbial metabolism in soil and aquatic environments under either aerobic and anaerobic
conditions is not expected to cause any significant transformation of oxadiazon, although a number of
degradates have been reported from the different chemical and biological fate studies.
Studies on equilibrium sorption and aged/unaged oxadiazon indicate that the pesticide has low
environmental mobility (Kj's ranged from 8.17 to 22.83; K^'s ranged from 1409 to 3268). Thus,
oxadiazon is likely to be transported, via surface runoff, bound to credible soil particles, to nearby
surface water bodies. Leaching from surficial soils to groundwater is expected to be low or
negligible, unless the soil is very porous or has some cracks that favor preferential flow. Oxadiazon
exhibited slow dissipation in two terrestrial field studies conducted in California and North Carolina.
2. Water Resources
The potential impact to water quality from the use of oxadiazon on turf is essentially due to the
parent (as opposed to possible degradates). Oxadiazon appears to be persistent under most
environmental conditions making the chemical available for surface runoff. The remaining factor
which affects the impact of oxadiazon on water quality is mobility in soils. A soil column leaching
study, and supplemental batch equilibrium studies, indicate that oxadiazon has low mobility in the
various soils tested. Ordinarily this would mean that the chemical would remain soil bound and would
be transported to a water body on eroded soil. Turf scenarios, however, offer different challenges
than typical agricultural crops. The turf itself offers a vegetative interception layer (including thatch)
that prevents rapid deposition of the oxadiazon on the surface of the soil. Both liquid and granular
formulation labels of oxadiazon recommend mowing the grass prior to application. Also, both liquid
and granular formulation labels of oxadiazon specify that the chemical's effectiveness is improved if it
is wetted in after application. Oxadiazon is more likely to bind to soil particles if the turf is watered
after application of the pesticide.
The models used for the Tier 1 determination of the water exposures were FIRST, GENEEC
2.0 for surface waters, and SCIGROW for ground waters. The models are screening tools designed
22
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to provide upper-bound estimates of the concentrations that might be found due to the use of
oxadiazon. For drinking water, a Tier II refinement was performed, using PRZM/EXAMS. In the
Tier n refinement, a scenario that incorporates three applications (1 @ 4 Ib a.i./A and 2 @ 2 Ib ai/A)
was used. Surface water monitoring data for oxadiazon is limited and has not been used to represent
possible concentrations of oxadiazon in surface waters. The chemical is not included in the NAWQA
monitoring studies. The STORET database contained only two samples taken from the same location
within an interval of only four days. The estimated recommended acute and long term drinking water
concentrations are detailed in Chapter 6 of the document "EFED Revised Risk Assessment for the
Reregistration Eligibility Decision of Oxadiazon," dated June 11,2003.
3. Ecological Risk
Risk characterization integrates the results of the exposure and ecotoxicity data to evaluate the
likelihood of adverse ecological effects. The Agency calculates risk quotients (RQs) by dividing
exposure estimates by acute and chronic ecotoxicity values:
RQ = EXPOSUREfTOXICITY
RQs are then compared to OPP's levels of concern (LOCs). These LOCs are criteria used
by EPA to indicate potential risk to nontarget organisms. The criteria indicate that a pesticide used as
directed has the potential to cause adverse effects on nontarget organisms. The exposure and effects
inputs to a screening-level assessment are by design assumed to overestimate likely exposures and
effects of pesticides. Exceedence of an LOG indicates that risks of concern are possible, but the
likelihood, magnitude, and/or severity of the risk cannot be quantified. Risk presumptions, along with
the corresponding LOCs, are given in Table 7 below.
Table 7. Risk Presumptions for Terrestrial and Aquatic Animals
Risk Presumption
Acute Risk-there is potential for acute risk; mitigation may be warranted
in addition to restricted use classification,
Acute Restricted Use -there is potential for acute risk, but may be
mitigated through restricted use classification,
Acute Endangered Species -endangered species may be adversely
affected,
LOG
terrestrial animals
0.5
0.2
0.1
LOG
aquatic animals
0.5
0.1
0.05
23
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Table 7. Risk Presumptions for Terrestrial and Aquatic Animals
Chronic Risk -there is potential for chronic risk; regulatory action may
be warranted.
1
1
Aquatic and terrestrial risk assessments were conducted by using standard ecotoxicity
endpoints (i.e., LD50 and LC50 values, and NOAEC values). The toxicity endpoints chosen for use in
the ecological risk assessment are summarized below in Table 8.
Table 8. Tnxicnlopical Endnninrs Used to Determine Risk Quotients (ROs)
Type Of Toxicity
Oral Acute
Dietary
Chronic
Oral Acute
Chronic
Acute
Chronic
Acute
Chronic
Acute
Chronic
Acute
Chronic
Acute
Organism
Bird
Mammal
Freshwater Fish
Freshwater
Invertebrates
Estuarine Fish
Estuarine
Invertebrates
Aquatic Plants
(vascular)
(Nonvascular)
Species
Mallard
Bobwhite/Mallard
Bobwhite
Rat
Rat
Rainbow trout/Bluegill
Rainbow trout
Daphnid
Daphnid
Sheepshead Minnow
Sheepshead Minnow
Mysid
Mysid
duckweed
marine diatom
Toxicological Endpoint
1040ms/ke
>5000 ppm
500 ppm '
>5000 mg/kg
200 ppm2
0.88 ppm
0.88 ppb 3
2. 18 ppm
0.03 ppm
1 .5 ppm
0.00 15 ppm4
0.27 ppm
0.003 7ppm4
EC50=41ppb
NOAEC = <8 ppb
EC50=5.2ppb
1 No effects on any reproductive parameter or viability of F, offspring at the highest dose tested, 1000 ppm;
however due to excessive mortality (33%) of adult female birds in that dose level, a NOAEC for chronic effects
was set at 500 ppm.
24
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2 LOAEL of >38 mg/kg/ day for inactive mammary tissue and fetal/pup death observed in the one year range-
finding test of a rat reproduction study. NOAEC >200 ppm.
3 Rainbow trout was more sensitive than the fathead minnow (fathead minnow NOAEC= 33 ppb).
4 Extrapolation from acute/chronic ratio.
a.
Risks to Birds
Table 9 provides avian acute and chronic RQs from exposure to multiple applications of
oxadiazon EC to turf for the maximum three application rates (4.0,3.0 and 2.0 Ibs ai/A) and two split
applications (1.0 Ib ai/A, 4 times/6 months; 1.3 Ibs ai/A, 3 times/6 months). The maximum three
applications have the potential for chronic exposure to birds that feed on plants and grass (e.g.,
ducks, geese) and may result in risk to these birds (RQ = 1.0 - 2.0). The split application appears to
lower this chronic exposure and risk (RQ = <_!). The EC formulation was evaluated because it
presents an upper-bound estimate of risk. The majority of oxadiazon is applied as a granular
formulation. Exposure from the granular formulation was evaluated because birds may be exposed to
granular pesticides through ingestion when foraging for food or grit. RQ values were calculated for
three weight classes of birds (lOOOg waterfowl, 180g upland game bird, and 20g songbird). All
scenarios for the granular resulted in no acute risk to birds (RQ < 0.5). However, the potential
chronic concern noted for non-endangered birds suggest that oxadiazon may present a risk to
endangered species (RQ > 0.1).
Pesticide dissipation from foliar surfaces is primarily due to degradation or dissipation by one
or more processes including photolysis, hydrolysis, microbial degradation and volatilization. Since
adequate foliar dissipation data are not available for oxadiazon, a default half-life of 35 days was used
in the EEC calculations.
Table 9. Avian Acute and Chronic Risk Quotients *
Site Application
Rate Ibs ai/A
(#appl)
Turf (EC)
4.0(2)
Food Item
Short grass
Tall grass
Broadleaf
plants/insects
Seeds
Maximum EECs
(Ppm)
984.1
451.1
553.6
61.5
Acute RQ
(EEC/LC50)
<0.2
<0.1
<0.1
<0.0
Chronic RQ
(Max.
EEC/NOAEQ
2.0
1.0
0.1
0.1
25
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Table 9. Avian Acute and Chronic Risk Quotients "
Turf (EC) '
3.0(2)
Turf (EC)
2.0(2)
Turf (EC)
1.0 (split 4
applications/ 6
months)
Turf (EC)
1.3 (split 3
applications/ 6
months)
Short grass
Tall grass
Broadleaf
plants/insects
Seeds
Short grass
Tall grass
Broadleaf
plants/insects
Seeds
Short grass
Tall grass
Broadleaf
plants/insects
Seeds
Short grass
Tall grass
Broadleaf
plants/insects
Seeds
739.6
339.0
416.0
46.2
493.1
226.0
277.3
30.8
424.4
194.5
238.7
26.5
257.0
117.8
144.6
16.1
<0.1
0.0
<0.1
0.0
<0.1
0.0
0.0
0.0
<0.1
0.0
0.0
0.0
<0.1
0.0
0.0
0.0
1.5
1.0
1.0
0.1
1.0
0.4
0.5
0.1
1.0
0.4
0.5
0.1
1.0
0.4
0.5
0.1
"Avian acute and chronic risk quotients (RQ's) as generated through ELL-FATE for broadcast ground spray
applications for oxadiazon. RQ's are based on mallard duck LC50 > 5,000 ppm and NOAEC = 500 ppm. The EEC
reflects the turf use with the three highest use rate (4.0, 3.0 and 2.0 Ibs ai/A, 2 applications) and two split
applications (1.0 Ib ai/A, 4 times/6 months; 1.3 Ibs ai/A, 3 times/6 months).
b.
Risks to Mammals
The Agency has concluded that for the EC formulation of oxadiazon the assessed single
applicaton rates (4.0, 3.0 and 2.0 Ibs ai/A), as well as the split use rates (1.0 and 1.3 Ibs ai/A) should
not result in acute risk to mammals (RQ < 0.2). However, these application scenarios can result in
chronic exposure and risk to mammalian herbivores and insectivores (15g, 35g, and lOOOg) with RQ
values ranging from 0.1 to 4.9 (Table 10). This chronic risk to non-endangered mammalian species
also suggests the potential for impact to endangered species.
26
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Table 10. Mammalian Chronic Risk Quotients'
Crop
Application Rate Ibs ai/A
( # of applications)
Turf (EC)
4.0(2)
Turf (EC)
3.0(2)
Turf (EC)
2.0(2)
Turf (EC)
1.0 (split 4
applications/
6 months)
Turf (EC)
1.3 (split 3
applications/
6 months)
Food Items
Short Grass
Tall Grass
Broadleaf plant/ Insects
Seeds
Short Grass
Tall Grass
Broadleaf plant/ Insects
Seeds
Short Grass
Tall Grass
Broadleaf plant/ Insects
Seeds
Short Grass
Tall Grass
Broadleaf plant/ Insects
Seeds
Short Grass
Tall Grass
Broadleaf plant/ Insects
Seeds
Max.
EEC
(ppm)
986.1
452.0
554.7
61.6
739.6
339.0
416.0
46.2
493.1
226.0
227.3
30.8
424.4
194.5
238.7
26.5
257.0
117.8
144.6
16.1
Chronic RQ
(Max. EEC/NOAEQ"
4.9
2.3
2.8
0.3
3.7
1.7
2.1
0.2
2.4
1.1
1.4
0.1
2.4
1.1
1.3
0.1
1.6
1.0
1.0
0.1
"Mammalian chronic risk quotients as generated through ELL-FATE for ground application of an emulsifiable
concentrate of oxadiazon are based on rat (Rattus norvegicus) NOAEC = 200 ppm. The EEC reflects the three
highest assessed application rates (4.0,3.0 and 2.0 Ibs ai/A, 2 applications) and two split applications (1.0 Ib ai/A, 4
times/6 months; 1.3 Ibs ai/A, 3 times/6 months).
b Chronic risk (LOC_> 1)
c. Risks to Fish and Aquatic Invertebrates
Tables 11 and 12 provide acute and chronic RQ values for oxadiazon exposure to freshwater
and estuarine/marine species for turf use patterns (apph'cation rates for EC at 2.0 - 4.0 Ibs ai/A and
4.0 Ibs ai/A for granular). Although our assessment suggests that oxadiazon acute exposure may
result in low acute risk to fish (RQ = 0.1 - 0.2) and invertebrates (RQ = 0.3 - 0.5), there is
27
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uncertainty regarding the potential for enhanced risk that may occur through phototoxicity. Since
oxadiazon is a light-dependent peroxidizing herbicide (LDPH), enhanced toxicity through exposure to
high levels of solar radiation is a possible concern regarding aquatic organisms that inhabit small,
shallow water bodies.
EPA's Tier I (GENEEC) risk assessment suggests that chronic exposure to this compound
can result in risk to freshwater and estuarine/marine fish (RQ = 39.3 -131.8) and aquatic
invertebrates (RQ = 3.9 - 36.7). Endangered species concerns are also suggested, as acute RQs
exceeded the level of concern (0.1). Also, enhanced toxicity through exposure to high levels of solar
radiation may increase toxic risk to aquatic organisms that inhabit small, shallow water bodies.
Therefore, EPA is requiring a study on the phototoxicity of oxadiazon in fathead minnows.
The Tier I GENEEC model 60-day EEC for oxadiazon in surface water following 2-4 Ib
applications of granular oxadiazon was 142 ppb. However, the conservative Tier I model does not
account for the effect of established golf course turf on reducing sediment run-off. Tier n
PRZM/EXAMS estimates of EECs for drinking water, although not directly applicable to the risk
assessment for aquatic organisms, suggest that the golf course scenario greatly reduces run-off. Tier
n estimates of oxadiazon concentrations in surface-sourced drinking water were approximately six-
fold lower than the Tier I GENEEC estimate described above. It is reasonable to assume that Tier II
EECs for a pond scenario would likewise be reduced.
Table 11. Acute and Chronic RQ's for Oxadiazon Exposure to Fish*
CropApp.
Rate (Ibs
ai/A;#
App.)
Turf (EC)
4.0 (2)
Turf (EC)
3(2)
Turf (EC)
2(2)
Organism
Freshwater
Estuarine/
Marine
Freshwater
Estuarine/
Marine
Freshwater
Estuarine/
Marine
Acute
(LC*
ppm)
0.88
1.5
0.88
1.5
0.88
1.5
Chronic
(NOAEC,
ppm)
0.00088
0.0015"
0.00088
0.0015"
0.00088
0.0015 "
EEC
Peak
(ppm)
0.143
0.143
0.130
0.130
0.088
0.088
EEC
60-Day
Avg.
(ppm)
0.116
0.116
0.122
0.122
0.083
0.083
Acute RQ
(EEC/LCso)
0.2'
0.1 c
0.1 c
0.1 '
0.1 c
0.0
Chronic
RQ"
(EEC/NOAEQ
131.8
77.3
139.0
813
943
553
28
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Table 11. Acute and Chronic RQ's for Oxadiazon Exposure to Fish*
Turf
(Granular)
4.0 (2)
Freshwater
Estuarine/
Marine
0.88
1.5
0.00088
0.0015"
0.122
0.122
0.099
0.099
0.1 c
0.1 c
112.5
66.0
"Acute and chronic RQ's for evaluating toxic risk of oxadiazon exposure to fish (freshwater and estuarine/marine).
RQ's are based on the bluegill (Lepomis macrochirus) LC50 = 0.88 ppm, rainbow trout (Oncorhynchus mykiss)
NOAEC = 0.00088 ppm and sheepshead minnow (Cyprinodon variegatus) LC50 = 1.5 ppm., NOAEC = 0.0015 ppm1.
EEC values are generated from GENEEC and reflect three of the highest assessed EC application rates, and the
maximum assessed granular use rate (4.0, 3.0, and 2.0 Ibs ai/A, 2 applications each; 4.0 Ibs ai/A, 2 applications,
respectively) for turf use.
b Extrapolated chronic value using acute/chronic freshwater toxicity ratio
c Acute restricted use (> 0.1), acute species
d Chronic concern (> 1.0)
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Table 12. Acute and Chronic Risk Quotients for Aquatic Invertebrates"
Crop App.
Rate (Ibs
ai/A)#
App. (days)
Turf (EC)
4.0 (2)
Turf (EC)
3.0(2)
Turf (EC)
2.0 (2)
Turf
(Granular)
4.0(2)
Organism
Freshwater
Estuarine/
Marine
Freshwater
Estuarine/
Marine
Freshwater
Estuarine/
Marine
Freshwater
Estuarine/
Marine
Acute
(EC*,,
ppm)
2.18
0.27
2.18
0.27
2.18
0.27
2.18
0.27
Chronic
(NOAEC,
ppm)
0.03
0.0037
0.03
0.0037
0.03
0.0037
0.03
0.0037
EEC
Peak
(ppm)
0.143
0.143
0.130
0.130
0.088
0.088
0.122
0.122
EEC
21-Day
Ave.
(ppm)
0.136
0.136
0.127
0.127
0.086
0.086
0.116
0.116
Acute RQ
(EEC/
LCso)
0.12
0.52
0.52
0.52
0.0
0.32
0.0
0.42
Chronic
RQ
(EEC/NOAEQ
4.51
36.71
4.21
34J3
2.9s
23.23
3.91
31.3'
a Acute and chronic risk RQ's for evaluating toxic risk of oxadiazon exposure to aquatic invertebrates (freshwater
and estuarine / marine). RQ's are based on Daphnia (Daphnia magna) EC50 = 2.18 ppm, NOAEC = 0.03 ppm and
the Mysid shrimp (Americamysis bahia) EC50 = 0.27 ppm, NOAEC = 0.0037 ppm1' EEC values are generated from
GENEEC and reflect three of the highest proposed EC application rates, and the maximum granular use rate (4.0,
3.0, and 2.0 Ibs ai/A, 2 applications each; 4.0 Ibs ai/A, 2 applications, respectively) for turf use.
1 Extrapolated chronic value using acute/chronic freshwater toxicity ratio
2 Acute restricted use (> 0.1)
3 Chronic concern (> 1.0)
30
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d. Risk to Benthic Organisms
Oxadiazon residues can accumulate in sediments and may increase the risk from chronic
exposure of benthic and epibenthic organismsaquatic organisms that live in or on the sediment. In
order to better understand this potential risk, EPA is requiring appropriate acute and chronic
sediment toxicity testing on this compound.
e. Risks to Aquatic Plants
Exposure to non-target aquatic plants may occur through runoff or spray drift from adjacent
treated sites. An aquatic plant acute risk assessment is usually made for aquatic vascular plants from
the surrogate duckweed Lemna gibba. Non-vascular acute aquatic plant risk assessments are
performed using either algae or a diatom, whichever is the most sensitive species. Runoff and drift
exposure are computed from GENEEC2 and the risk quotient is determined by dividing the
pesticide's initial or peak concentration in water by the plant EC50 value. Acute risk quotients for
vascular and non-vascular plants are tabulated in Table 13.
Aquatic plant acute risk levels of concern are exceeded (Table 13) for both vascular and
nonvascular plants. TheRQs range from 1.1 to 4.2 for vascular plants and from 8.5-33 for non-
vascular plants. The acute plant risk level of concern is exceeded for vascular plants with RQs
ranging of 5.5 -22. Currently, EPA does not perform assessments for chronic risk to aquatic plants.
The Tier IGENEEC model 60-day EEC of oxadiazon in surface water following 2-4 Ib
applications of granular oxadiazon was 142 ppb. However, the conservative Tier I model does not
account for the effect of established golf course turf on reducing sediment run-off. Tier n
PRZM/EXAMS estimates of EECs for drinking water, although not directly applicable to the risk
assessment for aquatic organisms, suggest that the golf course scenario greatly reduces run-off. Tier
n estimates of oxadiazon concentrations in surface-sourced drinking water were approximately six-
fold lower than the Tier I GENEEC estimate described above. It is reasonable to believe that Tier n
EECs for a pond scenario would likewise be reduced.
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Table 13. Acute Risk Quotients for Aquatic Plants '
Turf/ Rate of Application
in Ibs ai/A (Number of Applications).
4(2)
4(1)
3(1)
2(1)
4(2)
4(1)
3(1)
2(1)
Species
duckweed
"
"
t<
diatom
u
"
EC50
(ppm)
0.041
0.041
0.041
0.041
0.0052
0.0052
0.0052
0.0052
EEC
(ppm)
0.173
0.089
0.067
0.044
0.173
0.089
0.067
0.044
Non-target
plant RQ
(EEC/EC,n)
4.2
2.2
1.6
1.1
33.3
17.1
12.9
8.5
"Acute risk quotients for aquatic plants are based upon a duckweed (Lemna gibba) EC50 of 41 ppb and a
nonvascular plant (marine diatom) EC50 of 5.2 ppb.
4. Endangered Species Risk Assessment
Endangered species LOCs for liquid and granular formulations of oxadiazon are exceeded for
acute risks to birds, mammals, freshwater and estuarine fish and invertebrates and aquatic vascular
plants. Although the terrestrial plant data are outstanding, it is assumed that endangered terrestrial
plants are at risk since oxadiazon is an herbicide. Although the endangered species LOG for
estuarine invertebrates has been exceeded, there are no listed species in this group.
The Agency is currently engaged in a Proactive Conservation Review with the Fish and
Wildlife Service (FWS) and the National Marine Fisheries Service under section 7(a)(l) of the
Endangered Species Act. The objective of this review is to clarify and develop consistent processes
for endangered species risk assessments and consultations. Subsequent to the completion of this
process, the Agency will reassess the potential effects of oxadiazon use to federally listed threatened
and endangered species. At that time the Agency will also consider any regulatory changes
recommended in the RED that are being implemented. Until such time as this analysis is completed,
the overall environmental effects mitigation strategy articulated in this document and any County
Specific Pamphlets described in section IV of the RED which address oxadiazon, will serve as interim
protection measures to reduce the likelihood that endangered and threatened species may be
exposed to oxadiazon at levels of concern.
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IV. Risk Management, Reregistration and Tolerance Reassessment Decision
A. Determination of Reregistration Eligibility
Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submission of relevant
data concerning an active ingredient, whether or not products containing the active ingredient are
eligible for reregistration. The Agency has previously identified and required the submission of the
generic (i.e., active ingredient-specific) data required to support reregistration of products containing
oxadiazon as an active ingredient. The Agency has completed its review of these generic data, and
has determined that the data are sufficient to support reregistration of all products containing
oxadiazon provided that certain data gaps are addressed, the risk reduction measures outlined in this
document are adopted and labels are amended to implement these measures. Appendix B identifies
the generic data requirements that the Agency reviewed as part of its determination of reregistration
eligibility of oxadiazon.
These data were sufficient to allow the Agency to determine that oxadiazon can be used
without resulting in unreasonable adverse effects to humans and the environment The Agency,
therefore, finds that all products containing oxadiazon as the active ingredient are eligible for
reregistration, provided specified changes are made to the label. Actions needed to reregister
particular products are addressed in Section V of this document. Those actions are the result of risk
management steps summarized in Chapter 4. The Agency concludes that these label changes address
the current risk estimates and reflect the use of all acceptable data available at this time together with
uncertainty factors where data gaps exist.
The Agency may take appropriate regulatory action if new information comes to the Agency's
attention regarding the reregistration of oxadiazon. The Agency may also require the submission of
additional data (1) to support the registration of products containing oxadiazon, (2) if the data
requirements for registration change, or (3) if the guidelines for generating such data change.
B. Tolerance Reassessment
With respect to tolerances for oxadiazon, there have been no active food-use registrations
since 1991. The tolerance for rice straw was revoked as of the July 1, 2001 revision to 40 CFR
180.346. In a confirmatory letter to EPA, dated January 24,2001, the registrant maintained its
previous position that it would not support the sixteen remaining oxadiazon tolerances. Therefore,
effective April 24,2003, EPA revoked all the tolerances in 40 CFR 180.346 for the combined
residues of the herbicide oxadiazon and its metabolites in the following commodities: in or on milk;
cattle, fat; cattle, meat; cattle, meat byproducts; goats, fat; goats, meat; goats, meat byproducts; hogs,
fat; hogs, meat; hogs, meat byproducts; horses, fat; horses, meat; horses, meat byproducts; sheep,
fat; sheep, meat; and sheep, meat byproducts. In addition, because EPA determined on April 21,
2002 that there is no reasonable expectation of finite residues of oxadiazon and its metabolites in or
33
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on meat, milk, poultry, and egg commodities, the sixteen associated tolerances for livestock
commodities were considered by the Agency to no longer be needed under 40 CFR 180.6(a)(3).
Therefore, on June 3,2002, the Agency considered the FQPA safety finding to be met and counted
the sixteen oxadiazon livestock tolerances as reassessed. There are no CODEX, Canadian, or
Mexican tolerances for oxadiazon residues.
C. Regulatory Position
1. FQPA and Aggregate Risk
Given that all tolerances for oxadiazon have been revoked, this pesticide no longer falls under
the scope of FQPA. As such, no quantitative aggregate assessment of risk from dietary and
residential exposures was completed as part of the reregistration process. EPA has qualitatively
evaluated the likelihood of combined exposures for the general population, including children.
Because of the relatively low volume of use of oxadiazon on sites other than golf courses, its
specialized use pattern, and its relatively high cost, neither concurrent nor aggregate exposures from
different sources of oxadiazon are likely. If EPA receives a petition for food/feed uses and/or
tolerances, EPA will perform an FQPA evaluation at that time.
2. Endocrine Disrupter Effects
EPA is required under the FFDCA, as amended by FQPA, to develop a screening program
to determine whether certain substances (including all pesticide active and other ingredients) "may
have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or
other such endocrine effects as the Administrator may designate." Following recommendations of its
Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC), EPA determined that
there was scientific basis for including, as part of the program, the androgen and thyroid hormone
systems, in addition to the estrogen hormone system. EPA also adopted EDSTAC's
recommendation that EPA include evaluations of potential effects in wildlife. For pesticides, EPA will
use FIFRA and, to the extent that effects in wildlife may help determine whether a substance may
have an effect in humans, FFDCA authority to require the wildlife evaluations. As the science
develops and resources allow, screening of additional hormone systems may be added to the
Endocrine Disruptor Screening Program (EDSP).
When the appropriate screening and/or testing protocols being considered under the EDSP
have been developed, oxadiazon may be subject to additional screening and/or testing to better
characterize effects related to endocrine disruption.
34
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3. Cumulative Risks
For the purposes of this risk assessment, the Agency has assumed that oxadiazon does not
share a common mechanism of toxicity with other oxadiazoles or carcinogenic chemicals.
4. Benefits Assessment
The EPA has concluded that there are no suitable selective pre-emergence alternatives to
oxadiazon currently available. Oxadiazon is expensive in comparison to other goosegrass controls,
but those controls are not as selective, as they kill non-target plants as well. Because oxadiazon is
expensive (estimated $100 - $200 per acre in 2003), it is expected that mainly high-end golf courses
are going to use the herbicide.
D. Tolerance Summary
All tolerances for oxadiazon have been revoked. No maximum residue limits for oxadiazon
have been established by Codex for any agricultural commodities. Therefore, there are no issues
regarding compatibility with respect to U.S. tolerances.
E. Human Health Risk Mitigation
1. Dietary (Drinking Water) Risk Mitigation
Screening-level estimates (EECs) of potential drinking water exposure from ground water
sources do not exceed the acute or chronic (non-cancer and cancer) DWLOC values, and therefore,
are not of concern. However, exposure from surface water sources after application to golf courses
is potentially of concern for chronic non-cancer and chronic cancer dietary risk.
The Tier n modeled estimate of average concentrations in surface water associated with the
use of oxadiazon on golf courses is 56 ppb. That value exceeds the Agency's level of concern by
100-fold. However, it should be noted that this estimate was derived using an assumption that
oxadiazon is applied as a wettable powder formulation (i.e., applied as a spray), and therefore
includes a value for spray drift into water bodies. However, the predominant formulation for
oxadiazon applied to golf course turf is granular, and typically the herbicide is encapsulated in a
granular fertilizer.
Additionally, the Tier n assessment of EECs used an annual application rate of 8 Ibs ai/A.
Discussions with the oxadiazon registrant and golf course personnel indicate that the cost of
oxadiazon limits the frequency of use of the 8 Ibs ai/A annual rate to areas with heavy weed
35
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infestation, as might be encountered during the first year during which golf course turf is being
established. Following the first year at the 8 Ibs ai/A rate, more typical rates of 2-6 Ibs ai/A/yr are
used on established turf. The registrant has agreed to set the maximum application rate at 6 Ibs
a.i./A/yr (typically applied in multiple applications) except in areas of heavy weed infestation. In areas
with heavy weed infestation, the maximum application rate will be 8 Ibs a.i./A/yr. The maximum
single application rate is 4 Ibs ai/A.
When the typical annual maximum application rate (6 Ibs ai/A) and the impact of a granular
formulation versus a wettable-powder formulation are considered, the surface water EEC decreases
to approximately 25 ppb. This value is below the level of concern for chronic non-cancer risk, but is
still 50-fold greater than the chronic cancer DWLOC.
Limited water monitoring data from three states indicate that oxadiazon, though detected in
surface water bodies, is present at concentrations below the Agency's level of concern. Additionally,
preliminary data from a study designed to measure pesticide concentrations in golf course runoff, and
performed under an EPA grant, suggest that oxadiazon concentrations in surface-sourced drinking
water will not exceed the Agency's level of concern (DWLOC = 0.49 ppb).
One factor that may be contributing to the apparent discrepancy between model estimates
and measured concentrations is the percent crop area (PCA) value. This value is used in the
PRZM/EXAMS models as the percentage of land area, within a specific watershed, that is made up
of the crop of interest, in this case golf course turf. In characterizing oxadiazon, the Agency has used
a PCA value of 94% to account for the land area of a typical golf course that is tees and greens
(4%), fairway (23%) and rough (67%). Using the 94% PCA value results in an upper-bound
estimate of the potential environmental concentrations of oxadiazon if 94% of a watershed was golf
course turf, and on each golf course 100% of available turf was treated with oxadiazon at the
maximum application rate.
The registrant has submitted Geographic Information System (GIS) data that localizes golf
courses in Florida, along with watershed boundary information. That data suggests that the upper
bound PCA for golf course turf in Florida is substantially less than 94%. The Agency took that
information into account when it concluded that although oxadiazon is eligible for reregistration, water
monitoring studies are required.
As noted above, the currently supported maximum rate of 8 Ibs ai/A/year might be applied to
turf with heavy weed infestation during the first year in which a golf course is being established.
Thereafter, because of the expense of treating with oxadiazon, typical application rates of 2-6 Ibs ai/A
would be used, depending on location. For most locations, a single 2-4 Ib ai application per year is
sufficient to control goosegrass. However, in the extreme southern locations (e.g., south Florida)
where the growing season is continuous, two applications of 3 Ibs ai/A are typical. Similarly,
economic factors limit the use of oxadiazon on golf course roughs. Since roughs make up
approximately 67% of golf course turf area, the limited use on roughs can have a great impact on the
total pounds applied.
36
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The estimated EECs in surface water were derived using the high-end values discussed
above, in addition to others that, when combined, lead to an upper-bound estimate of risk. For
example, when estimating the chronic cancer risk, the assumption is made that an individual drinks
from the same water source every day for a 70-year lifetime. After characterizing the assumptions
used to derive the estimates of oxadiazon concentrations in drinking water, the Agency has concluded
that the actual concentrations of oxadiazon in drinking water are likely to be below the Agency's level
of concern. To confirm the absence of chronic exposure to oxadiazon in drinking water at
concentrations that exceed the Agency's cancer level of concern, the Agency is requiring the
registrant to submit three years of drinking water monitoring data collected from sites determined by
the Agency to be likely to result in upper-bound exposures, with interim reporting after the first
season. In addition to providing real-world measures of oxadiazon concentrations in drinking water,
the monitoring data may prove to be useful in on-going efforts to validate a refined PCA value for
turf. In the event that interim data indicate concentrations of oxadiazon in drinking water do exceed
the Agency's level of concern, registrants have agreed to consider further mitigation measures, such
as, further rate reductions and limitations on the areas of golf courses that can be treated. Regardless
of the outcome of the water monitoring study, the registrant has agreed to establish a 15 foot "no
apply" zone around bodies of water that may serve as sources of drinking water.
2. Non-occupational Post-application Risk Mitigation
a. Non-cancer risk mitigation
Because oxadiazon is not available for sale to homeowners, residential handler scenarios do
not exist. All of the non-cancer post-application risk scenarios for adults and toddlers had short-term
and intermediate-term dermal MOEs greater than 100. Therefore, no mitigation measures are
needed.
Estimated incidental, oral short-term exposures ("hand-to-mouth") for children had an MOE
of 100 using the TTR default values from the residential SOP. When the TTR data from the
submitted oxadiazon study were used, the MOEs were 90 and 240 for non-irrigated and irrigated
dormant grass, respectively. The MOE of 90 for non-irrigated grass does not meet or exceed the
target value of 100, and is therefore potentially of concern. However, the risk estimate can be
considered to be an upper-bound for several reasons: 1) the submitted TTR study data were
obtained using the wettable powder formulation, whereas the formulation more likely to be used on
residential turf is granular oxadiazon. The granule size for a typical end-use product, Ronstar G, is
20/50 Mesh, or 300-850 microns. In all products, the formulated granules are designed to fall below
the grass canopy into the thatch layer. If used according to label directions, it is unlikely that
oxadiazon granules would be accessible to a child. According to the registrant, for best results
oxadiazon granules should be watered-in as soon as is practical following application. Watering-in
the granules will carry them further into the thatch layer, and will further decrease the likelihood for
exposure. When compared to values for granular formulations, TTR values are generally 10-100 fold
37
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greater for liquid formulations; 2) the highest mean residues from the Jazzercize study described
above were used to estimate exposures between zero and one days after treatment, and the hand-to
mouth risk estimates were generated at those high-end exposure levels; and 3) the risk estimates
were generated assuming 20 hand-to mouth events per hour for a two hour duration. That value was
taken from observations of children in an indoors setting, and is likely an overestimate when
considering an outdoor scenario.
Given that the estimate of risk from incidental, oral short-term exposures ("hand-to-mouth")
for children resulted from the combined use of these high-end exposure assumptions, the EPA
concludes that the risk estimate that results in an MOE of 90 for non-irrigated dormant grass is likely
to be an overestimate and not a cause for concern. No mitigation measures are required to address
the non-cancer chronic risk from non-occupational post-application exposure.
MOEs were not calculated for the incidental ingestion of oxadiazon granules because, as
discussed above, the very small granules would not be available on the lawn surface and thus not
accessible to children. It is thought, therefore, that the incidental ingestion of granules is not likely to
be a cause for concern.
b. Cancer risk mitigation
The cancer risks for all adult post-application exposures were between 6.22 x 10"6 and 7.51
x 10"7. Exposure scenarios ranged from adults involved in low exposure activities on turf such as
mowing with a push mower (Transfer Coefficient = 500 cm2/hour; cancer risk = 7.51 x 10"7) and
golfing (Transfer Coefficient = 500 cnf/hour; cancer risk = 1.50 x 10"6) to adults involved in high
exposure activities on turf such as heavy yard work (Transfer Coefficient = 14,500 crrrVhr; cancer
risk = 6.22 x 10"6 on non-irrigated turf). The cancer risk estimates were based on several upper-
bound assumptions, including: 1) the maximum application rate of 4 Ibs ai/A; 2) an exposure
concentration based on the residue concentration at day 0-1 after treatment with a wettable powder
formulation; and 3) three exposures to oxadiazon-treated turf per year for 35 years.
Those assumptions are thought to be upper-bound, since: 1) although the maximum single
application rate is 4 Ibs ai/A, the typical application rate for residential and golf course turf is 2-3 Ibs
ai/A; 2) based on residue data, the dissipation half-life for oxadiazon on turf is approximately 1.5
days. As such, it is unlikely that an individual would golf or perform heavy yard work, and thereby be
exposed to the maximum residue concentration, each time oxadiazon is applied over a 35 year
period; and 3) typically oxadiazon is applied once per year to residential turf, and twice per year to
golf course turf in areas with extended growing seasons (e.g. south Florida).
Given the combination of upper-bound assumptions, as described above, the Agency
concludes that the cancer risk equation, as used in the assessment of cancer risk from post-
application, non-occupational exposure to oxadiazon, is likely to result in an overestimate of risk. No
mitigation measures are required to address the risk of cancer from post-application, non-
occupational exposure to oxadiazon.
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3. Occupational Risk Mitigation
a. Handlers
(1.) Non-cancer risk mitigation
The results of the short and intermediate-term handler assessments are presented in Table 5
and indicate that all, but one, potential non-cancer exposure scenarios provide at least one application
rate with a total MOE(s) greater than or equal to 100 at either the baseline (i.e., long pants, long
sleeved shirts, no gloves) using open systems, PPE (i.e., long pants, long sleeved shirts, and chemical
resistant gloves while using open systems), or using engineering controls (i.e., closed systems). The
only exception, with the feasible level of mitigation, is application of wettable powder formulations
with a low pressure handwand, with an MOE of 46.
This scenario assumes that a worker would treat five acres per day using a low-pressure
hand wand. The highest volume use of a low-pressure hand wand applicator is likely to be on non-
turf areas of golf courses (e.g., in areas under and around trees, shrubs, and ornamentals). According
to golf course personnel, a typical worker would likely cover a maximum of one acre a day when
applying oxadiazon with a low-pressure hand wand. The total area on a golf course likely to be
treated with a low-pressure handwand is approximately two acres. Using a conservative assumption
that in a worst-case scenario a worker might treat three acres in a day, and considering PPE, the
MOE for this scenario would increase to the target MOE of 100. The Agency concludes that the
non-cancer risk does not exceed the Agency's level of concern, therefore, no mitigation is required to
address the non-cancer risks from occupational handler exposures to oxadiazon.
(2.) Cancer risk mitigation
The cancer risk assessments for handlers used baseline exposure scenarios and, as needed,
increasing levels of risk mitigation (PPE and engineering controls) to achieve cancer risks that would
be considered of no concern. According to Agency policy, the level of concern for cancer risks from
occupational exposure to pesticides ranges from 1.0 x 10"4 to 1.0 x Iff6, depending on the feasibility,
availability, and cost of various mitigation options.
Based on the scenarios identified previously, the Agency estimates that the risk of developing
cancer from occupational dermal and inhalation exposures to oxadiazon ranges from 1.7 x 10"2 to 4.7
x 10"7 during "baseline" conditions (i.e., long pants, long-sleeves, no gloves). Cancer risk ranges
from 1 x 10"3 to 1 x 10'7 when personal protective equipment (PPE) (i.e., long pants, long-sleeved
shirt, and chemical-resistant gloves) was used. The Agency estimates that cancer risk decreases to a
range of 5 x 10~5 to 1 x 10"8 with engineering controls. Engineering controls included the use of
chemical-resistant gloves along with water-soluble packaging for wettable powder formulations.
Overall these data suggest that when PPE and engineering controls are used, none of the evaluated
39
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scenarios have cancer risks that exceed 1.0 x 10"4 . Therefore, the Agency is requiring that wettable
powder formulations of oxadiazon be packaged in water-soluble packaging. In addition, wettable-
powder product labels will require that handlers wear chemical-resistant gloves in addition to long
pants and a long-sleeved shirt during mixing/loading/applying scenarios.
b. Post-application
The Agency uses the term "post-application" to describe those individuals who can be
exposed to pesticides when entering areas previously treated with pesticides and performing certain
jobs, tasks or activities. This is also often referred to as reentry exposure. The Agency has
determined that there are potential post-application exposures to individuals re-entering oxadiazon
treated areas for the purpose of:
Roadsides: mowing
Bermuda grass rights-of-way: mowing
Sod farms: mowing, hand-weeding, and harvesting
Golf-course turfgrass: mowing and hand-weeding
For short-and intermediate-term non-cancer risks, mowing (e.g., golf courses, roadsides, and
sod farms) and harvesting (e.g., sod farms) scenarios were considered for post-application
occupational exposure. Calculations for mowing activities resulted in MOEs of 1000.
Calculations for hand-weeding and harvesting activities on golf courses and sod farms
resulted in MOEs of 30, less than the target MOE of 100 for post-application occupational
exposures. However, the values used to calculate the hand-weeding and harvesting MOEs likely
result in an over-estimate of risk. For example, the calculation for hand-weeding on golf courses
assumes that a worker would perform that activity for 8 hours/day on the day following application of
oxadiazon at the maximum application rate. Based on the quality of turf present on high-end golf
courses most likely to apply oxadiazon, it is unlikely that golf course personnel would spend more
than one or two hours per day performing hand-weeding activities. The Agency concludes that the
risk from post-application hand-weeding of golf courses does not exceed the level of concern. No
mitigation measures will be required.
With respect to risk concerns from post-application activities on sod farms, while the
oxadiazon label does not prohibit its use, the cost of treating with oxadiazon is prohibitive. Due to its
cost, less than 20% of sod farmers are using oxadiazon. Those sod farmers that are using oxadiazon
apply it as a wettable powder formulation at 2-3 Ibs ai/A immediately after planting (aka sprigging) to
control weeds during sod establishment. Harvesting activities occur six to nine months following
application, depending on the variety of grass being grown. As noted above, the scenario with
respect to hand-weeding assumes an 8-hour workday, which is unlikely. The foliar dissipation half
life for oxadiazon (approximately 1.5 days) is such that after three days post-application, the MOE
would rise above 100. Therefore, the Agency concludes that the risk from post-application
40
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harvesting on sod farms does not exceed the level of concern. No mitigation measures will be
required.
Cancer risks for occupational postapplication scenarios were estimated not to exceed EPA's
level of concern.
4. Inhalation Toxicity and Exposure Uncertainties
The Agency is concerned about potential inhalation risk to applicators using wettable powder
formulations.
The following confirmatory data are required:
870.3465 28-day inhalation toxicity study
F. Environmental Risk Mitigation
1. Terrestrial Organism Risk Mitigation
Using the EC formulation, at application rates of 2.0 - 4.0 Ibs ai/A (2 applications/6 months)
and two split applications (1.0 Ibs ai/A applied 4 times/6 months and 1.3 Ibs ai/A applied 3 times/6
months), model estimates indicate that oxadiazon may pose a chronic risk to mammals that eat plants
and insects. RQs range from 1 to 5.
The Agency does not currently perform screening-level assessments of chronic risk to birds
and mammals from granular formulations. Here, the emulsifiable concentrate (EC) formulation was
used to estimate chronic risk to birds and mammals. The emulsifiable concentrate formulation likely
represents an upper-bound scenario in terms of oxadiazon exposure to birds and mammals that might
feed on grasses and insects on golf course turf. Approximately 90% of oxadiazon is applied as a
granular formula. Unlike the residue that would remain on grass and foliage following a spray
application, granules of oxadiazon would settle to the thatch or soil layer. This is especially true when
the turf is watered following application, as many end-product labels currently recommend. The
granule size for a typical end-use product, Ronstar G, is 20/50 Mesh, or 300-850 microns. In all
products, the formulated granules are designed to fall below the grass canopy. If used according to
label directions, it is unlikely that oxadiazon granules would be accessible to birds and mammals that
feed on grasses. According to the registrant, for best results oxadiazon granules should be watered-
in as soon as is practical following application. Watering-in the granules will carry them further into
the thatch layer, and will further decrease the likelihood for exposure. As such, the amount of
oxadiazon available for ingestion by birds and mammals is likely to be less than was used in
calculating the RQ values, and it is likely that the actual exposures would result in RQ values
significantly less than the range of 1 to 5 obtained by assessing the emulsifiable concentrate
41
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formulation. The Agency concludes that the chronic risk to terrestrial organisms from exposure to
oxadiazon does not exceed the level of concern. No mitigation measures will be required.
2. Aquatic Organism Risk Mitigation
a. Fish and Invertebrates
Tier 1 model estimates of oxadiazon concentrations in water suggest that acute exposures
pose low risk to fish (RQ = 0.1-0.2) and invertebrates (RQ^ 0.3 - 0.5); however, there is some
uncertainty about the role of sunlight on oxadiazon toxicity in clear, shallow bodies of water.
GENEEC model outputs suggest that chronic exposure to oxadiazon may result in risk to freshwater
and estuarine/marine fish. RQs range from 94 to 139 (freshwater) and 55 to 81 (estuarine/marine),
depending on application rate and formulation. Likewise, model estimates indicate that chronic
exposure to oxadiazon may result in chronic risk to freshwater and estuarine/marine invertebrates.
RQs range from 2.9 to 4.5 (freshwater) and 23 to 37 (estuarine/marine), depending on application
rate and formulation.
The Tier I GENEEC model 60-day EEC of oxadiazon in surface water following two four-
pound applications of granular oxadiazon was 142 ppb. However, the conservative Tier I model
does not account for the effect of established golf course turf on reducing run-off. Tier n
PRZM/EXAMS estimates of EECs for drinking water, although not directly applicable to the risk
assessment for aquatic organisms, suggest that the golf course scenario greatly reduces run-off. Tier
II estimates of oxadiazon concentrations in surface-sourced drinking water were approximately six-
fold lower than the Tier I GENEEC estimate described above. It is reasonable to believe that Tier n
EECs for a pond scenario would likewise be reduced.
In order to further assess the risk to fish and invertebrates from oxadiazon exposure, the
Agency is requiring that the registrant submit toxicity data from early-stage estuarine fish studies and
life cycle estuarine/marine invertebrate studies. Also, enhanced toxicity through exposure to high
levels of solar radiation may increase toxic risk to aquatic organisms that inhabit small, shallow water
bodies. Therefore, EPA is requiring a study on the phototoxicity of oxadiazon in fathead minnows.
b. Benthic Organisms
Oxadiazon residues can accumulate in sediments and may increase the risk from chronic
exposure of benthic and epibenthic organisms (aquatic organisms that live in or on the sediment) to
the pesticide. In order to better understand this potential risk, EPA is requiring appropriate sediment
toxicity testing, both acute and chronic, on this compound.
42
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c. Aquatic Plants
For aquatic plants, RQs for acute exposure are relatively high, ranging from 1.1 to 4.2 for
duckweed, and 8.5 to 33 for diatoms, depending on application rates and formulation.
The Tier IGENEEC model 60-day EEC of oxadiazon in surface water following two four-
pound applications of granular oxadiazon was 142 ppb. However, the conservative Tier I model
does not account for the effect of established golf course turf on reducing sediment run-off. Tier n
PRZM/EXAMS estimates of EECs for drinking water, although not directly applicable to the risk
assessment for aquatic organisms, suggest that the golf course scenario greatly reduces run-off. Tier
n estimates of oxadiazon concentrations in surface-sourced drinking water were approximately six-
fold lower than the Tier I GENEEC estimate described above. It is reasonable to assume that Tier
II EECs for a pond scenario would likewise be reduced.
Currently, the Agency does not have sufficient data with respect to the toxic effects of
oxadiazon on aquatic organisms on which to base an effective risk management strategy. To help
clarify the risks to aquatic plant species, the Agency is requiring that the registrant submit the following
studies: aerobic aquatic metabolism, seedling gerrnination/emergence, vegetative vigor, and aquatic
phototoxicity.
G. Other Labeling Requirements
1. Endangered Species Statement
The Agency has developed the Endangered Species Protection Program to identify pesticides
whose use may cause adverse impacts on endangered and threatened species, and to implement
mitigation measures that address these impacts. The Endangered Species Act requires federal
agencies to ensure that their actions are not likely to jeopardize listed species or adversely modify
designated critical habitat. To analyze the potential of registered pesticide uses to affect any particular
species, EPA puts basic toxicity and exposure data developed for REDs into context for individual
listed species and their locations by evaluating important ecological parameters, pesticide use
information, the geographic relationship between specific pesticide uses and species locations, and
biological requirements and behavioral aspects of the particular species. This analysis will take into
consideration any regulatory changes recommended in this RED that are being implemented at this
time. A determination that there is a likelihood of potential impact to a listed species may result in
limitations on use of the pesticide, other measures to mitigate any potential impact, or consultations
with the Fish and Wildlife Service and/or the National Marine Fisheries Service as necessary.
The Endangered Species Protection Program as described in a Federal Register notice (54
FR 27984-28008, July 3,1989) is currently being implemented on an interim basis. As part of the
interim program, the Agency has developed County Specific Pamphlets that articulate many of the
43
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specific measures outlined in the Biological Opinions issued to date. The Pamphlets are available for
voluntary use by pesticide applicators on EPA's website at www.epa.gov/espp. A final Endangered
Species Protection Program, which may be altered from the interim program, has been proposed for
public comment in the Federal Register (67 FR #231, December 2, 2002; edocket OPP-2002-
0311.)
2. Spray Drift Management
Approximately 90% of oxadiazon is applied as a granular formulation, for which spray drift is
not a concern. The approximately 10% of oxadiazon that is applied as a spray using a wettable
powder formulation is applied to nursery stock and non-turf areas of golf courses using handheld
sprayers and to sod farms using tractor-drawn boom sprayers. The wettable powder formulation is
not typically used around bodies of water, so that the risk of contamination of water with oxadiazon
as a result of spray drift is not of concern. No label language is required to address ecological or
drinking water concerns that arise from off-target drift from spray applications of oxadiazon.
To address the risk to human health associated with off-target drift from spray applications,
the following label language is required for oxadiazon wettable-powder products: "Do not apply this
product in a way that will contact workers or other persons either directly or through drift."
The Agency is currently working with stakeholders to develop appropriate generic label
statements to address off-target drift risk. Once this process has been completed, oxadiazon
products may need to be revised to include this additional language.
V. Actions Required of Registrants
In order to be eligible for reregistration, registrants need to implement the risk mitigation
measures outlined in Section IV, which include, among other things, submission of the following:
For oxadiazon technical grade active ingredient products, registrants need
to submit the following items.
Within 90 days from receipt of the generic data call-in (DCI):
(1) completed response forms to the generic DCI (i.e., DCI response form and
requirements status and registrant's response form); and
(2) submit any time extension and/or waiver requests with a full written
justification.
Within the time limit specified in the generic DCI:
44
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(1) Cite any existing generic data which address data requirements or submit
new generic data responding to the DCI.
Please contact Mark Seaton at 703/306-0469 with questions regarding generic reregistration
and/or the DCI. All materials submitted in response to the generic DCI should be addressed:
By US mail:
Document Processing Desk (DCI/SRRD)
Mark Seaton
US EPA (7508C)
1200 Pennsylvania Ave., NW
Washington, DC 20460
By express or courier service:
Document Processing Desk (DCI/SRRD)
Mark Seaton
Office of Pesticide Programs (7508C)
Room 266A, Crystal Mall 2
1921 Jefferson Davis Highway
Arlington, VA 22202
For products containing the active ingredient oxadiazon, registrants need to
submit the following items for each product.
Within 90 days from the receipt of the product-specific data call-in (PDCI):
(1) Complete response forms to the PDCI (i.e., PDCI response form and
requirements status and registrant's response form); and
(2) Submit any time extension or waiver requests with a full written
justification.
Within eight months from the receipt of the PDCI:
(1) Two copies of the confidential statement of formula (EPA Form 8570-4);
(2) A completed original application for reregistration (EPA Form 8570-1).
Indicate on the form that it is an "application for reregistration";
(3) Five copies of the draft label incorporating all label amendments outlined
in Table 15 of this document;
(4) A completed form certifying compliance with data compensation
requirements (EPA Form 8570-34);
(5) If applicable, a completed form certifying compliance with cost share offer
requirements (EPA Form 8570-32); and
(6) The product-specific data responding to the PDCI.
45
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Please contact Bonnie Adler at (703) 308-8523 with questions regarding product
reregistration and/or the PDCI. All materials submitted in response to the PDCI should be
addressed:
By US mail:
Document Processing Desk (PDCI/PRB)
Bonnie Adler
US EPA (7508C)
1200 Pennsylvania Ave., NW
Washington, DC 20460
By express or courier service only:
Document Processing Desk (PDCI/PRB)
Bonnie Adler
Office of Pesticide Programs (7508C)
Room 266A, Crystal Mall 2
1921 Jefferson Davis Highway
Arlington, VA 22202
A. Manufacturing Use Products
1. Additional Generic Data Requirements
The generic database supporting the reregistration of oxadiazon for the eligible uses has been
reviewed and determined to be substantially complete. The following confirmatory data are required:
Guideline Test Name
28-day inhalation toxicity
Aerobic Aquatic Metabolism
Early-stage Estuarine Fish
Life Cycle Estuarine/Marine Invertebrate
Seedling Germination/Emergence
Vegetative Vigor
Seedling Germination/Emergence
Vegetative Vigor
Aquatic Phototoxicity Studies (Fathead minnow)
Acute and Chronic Sediment Toxicity Testing
Water Monitoring Study
OPPTS
Guideline No.
870.3465
835.4300
850.1400
850.1300
850.1350
850.4100
850.4150
850.4225
850.4250
-
Old Guideline
No.
82-4
162-4
72-4(a)
72-4(b)
122-1 (a)
122-l(b)
123-1 (a)
123- l(b)
70-1
70-1
70-1
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2. Labeling for Manufacturing Use Products
To remain in compliance with FIFRA, manufacturing use product (MUP) labeling should be
revised to comply with all current EPA regulations, PR Notices and applicable policies. The MUP
labeling should bear the labeling contained in the table at the end of this section. The MUP label will
explicitly prohibit use of products that do not conform to Section V.B.2 of this document.
B. End-Use Products
1. Additional Product-Specific Data Requirements
Section 4(g)(2XB) of FIFRA calls for the Agency to obtain any needed product-specific data
regarding the pesticide after a determination of eligibility has been made. Registrants must review
previous data submissions to ensure that they meet current EPA acceptance criteria and if not,
commit to conduct new studies. If a registrant believes that previously submitted data meet current
testing standards, then the study MRID numbers should be cited according to the instructions in the
Requirement Status and Registrants Response Form provided for each product.
2. Labeling for End-Use Products
Labeling changes are necessary to implement measures outlined in Section V above. Specific
language to implement these changes is specified in Table 14 at the end of this section. To remain in
compliance with FIFRA, end-use product (EUP) labeling should be revised to comply with all current
EPA regulations, PR Notices and applicable policies.
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C. Labeling Changes Summary Table
In order to be eligible for reregistration, amend all product labels to incorporate the risk mitigation measures outlined in Section
IV. The following table describes how language on the labels should be amended.
Table 14: Summary of Labeling Changes for Oxadiazon
Description
Amended Labeling Language
Placement on
Label
Manufacturing Use Products
One of these statements
may be added to a label
to allow reformulation of
the product for a specific
use or all additional uses
supported by a
formulator or user group
Packaging statement
required by the RED for
wettable-powder
formulations
"Only for formulation into an herbicide for the following use(s) [fill blank only with those uses that are
being supported by MP registrant]. This product may not be formulated into products intended for
residential consumer use. "
"This product may be used to formulate products for specific use(s) not listed on the MP label if the
formulator, user group, or grower has complied with U.S. EPA submission requirements regarding
support of such use(s)."
"This product may be used to formulate products for any additional use(s) not listed on the MP label if
the formulator, user group, or grower has complied with U.S. EPA submission requirements regarding
support of such use(s)."
"All wettable-powder formulations must be packaged in water-soluble packaging."
Directions for Use
Directions for Use
Directions for Use
48
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Description
Amended Labeling Language
Placement on
Label
Environmental Hazards
Statements Required by
the RED and Agency
Label Policies
"Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or other
waters unless in accordance with the requirements of a National Pollution Discharge Elimination System
(NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not
discharge effluent containing this product to sewer systems without previously notifying the local
sewage treatment plant authority. For guidance contact your State Water Board or Regional Office of
the EPA."
"Do not apply this product within 15 feet of bodies of water that may serve as sources of drinking
water."
Directions for Use
End Use Products
Front Panel Statement for
Granular and Wettable
Powder Products
"For sale to and use by professional applicators only. Not for sale to or use by homeowners/consumers.'
Insert in a
prominent
position
associated with the
Brand name on the
front panel of the
pesticide label
49
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Description
Amended Labeling Language
Placement on
Label
PPE Requirements
Established by the RED
for wettable powders
formulations
"Personal Protective Equipment (PPE)"
"Some materials that are chemical-resistant to this product are" (registrant inserts correct chemical-
resistant material). "If you want more options, follow the instructions for category" [registrant inserts
A,B,C,D,E,F,G,or H] "on an EPA chemical-resistance category selection chart."
"Mixers, loaders, applicators, and other handlers must wear:
-Long-sleeved shirt and long pants,
-Shoes plus socks, and
-Chemical resistant gloves, such as (registrant insert correct chemical-resistant materials),
In addition, mixers and loaders must wear a chemical-resistant apron.
See engineering controls for additional requirements."
Immediately
following/below
Precautionary
Statements:
Hazards to
Humans and
Domestic Animals
PPE Requirements
Established by the RED
for granular formulations
"Personal Protective Equipment (PPE)
Loaders, applicators, and other handlers must wear:
- Long-sleeved shirt and long pants, and
- Shoes plus socks."
Immediately
following/below
Precautionary
Statements:
Hazards to
Humans and
Domestic Animals
User Safety Requirements
for Wettable Powder
Formulations and
Granular Formulations
"Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables
exist, use detergent and hot water. Keep and wash PPE separately from other laundry."
Precautionary
Statements:
Hazards to
Humans and
Domestic Animals
immediately
following the PPE
requirements
50
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Description
Amended Labeling Language
Placement on
Label
Engineering Controls for
Wettable Powder
Formulations
(Wettable powders
products must be
contained in water
soluble packaging to be
eligible for reregistration)
"Water-soluble packets when used correctly qualify as a closed mixing/loading system under the
Worker Protection Standard for Agricultural Pesticides [40 CFR 170.240(d)(4)]. Mixers and loaders
using water-soluble packets must:
- wear the personal protective equipment required above for mixers/ loaders, and
- be provided and have immediately available for use in an emergency, such as a broken package, spill,
or equipment breakdown: chemical-resistant footwear and a NIOSH-approved dust mist filtering
respirator with MSHA/NIOSH approval number prefix TC-21C or a NIOSH-approved respirator with any
N, R, P, or HE filter."
Precautionary
Statements:
Hazards to
Humans and
Domestic Animals
(Immediately
following PPE and
User Safety
Requirements.)
User Safety
Recommendations
"User Safety Recommendations
Users should wash hands before eating, drinking, chewing gum, using tobacco, or using the toilet.
Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put
on clean clothing.
Users should remove PPE immediately after handling this product. Wash the outside of gloves before
removing. As soon as possible, wash thoroughly and change into clean clothing."
Precautionary
Statements under:
Hazards to
Humans and
Domestic Animals
immediately
following
Engineering
Controls
(Must be placed in
a box.)
Restricted-Entry Interval
for WPS uses
"Do not enter or allow worker entry into treated areas during the restricted entry interval (REI) of 12
hours."
Directions for Use,
Agricultural Use
Requirements Box
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Description
Amended Labeling Language
Placement on
Label
Early Entry Personal
Protective Equipment
established by the RED.
"PPE required for early entry to treated areas that is permitted under the Worker Protection Standard and
that involves contact with anything that has been treated, such as plants, soil, or water, is:
- coveralls,
- shoes plus socks, and
- chemical-resistant gloves made of any waterproof material."
General Application
Restrictions
"Do not apply this product in a way that will contact workers or other persons, either directly or through
drift. Only protected handlers may be in the area during application."
Place in the
Directions for Use
directly above the
Agricultural Use
Box.
Application Restrictions
for Granular and
Wettable Powder
Formulations
The label must be revised to specify a maximum application rate of xxx {registrant to provide value}
pounds of product per acre per year (equivalent to 6 pounds ai/A/year), except in areas where there is
heavy weed infestation. In areas of heavy weed infestation, the maximum application rate is xxx
{registrant to provide value} pounds of product per acre per year (equivalent to 8 pounds ai/A/year).
The label must be revised to specify a maximum single application rate of xxx {registrant to provide
value} pounds of product per acre (equivalent to 4 pounds ai/A)
The label must be revised to read "Not for use on home lawns."
Directions For Use
under General
Precautions and
Restrictions
Application Restrictions
for Granular
Formulations
"The label must be revised to read "For best results, water-in the product as soon as practical after
application."
1 PPE that is established on the basis of Acute Toxicity of the end-use product must be compared to the active ingredient PPE in this document. The more
protective PPE must be placed in the product labeling. For guidance on which PPE is considered more protective, see PR Notice 93-7.
2 If the product contains oil or bears instructions that will allow application with an oil-containing material, the "N" designation must be dropped.
Instructions in the Labeling section appearing in quotations represent the exact language that should appear on the label.
Instructions in the Labeling section not in quotes represents actions that the registrant should take to amend their labels or product registrations.
52
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D. Existing Stocks
Registrants may generally distribute and sell products bearing old labels/labeling for 26 months
from the date of the issuance of this Reregjstration Eligibility Decision (RED). Persons other than the
registrant may generally distribute or sell such products for 50 months from the date of the issuance of
this RED. Refer to "Existing Stocks of Pesticide Products; Statement of Policy"; Federal Register,
Volume 56, No. 123, June 26,1991.
53
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54
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Appendix A. Table of Oxadiazon Use Patterns Eligible for Reregistration
55
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Appendix A
OXADIAZON (CASE 2485) USE PATTERNS ELIGIBLE FOR REREGISTRATION
Site
Application Equipment
Formulation
Maximum
Single
Application
Rate
Max No
of
Appl
per/y
Restrictions
Turf: golf course, ornamental
Groundboom Application,
Handgun Application,
Tractor Drawn Spreader,
Backpack Sprayer,
Low Pressure Handwand,
Push Type Spreader,
Bellygrinder.
Granular
Water-soluble powder
4 Ib ai/acre
3
Maximum 6 Ibs ai/A/yr except in
cases of heavy weed infestation (8 Ib
ai/A/yr)
Do not apply through any type of
irrigation system.
Do not contaminate water by
cleaning of equipment or disposal of
equipment wash waters.
Do not contaminate water, food, or
feed by storage or disposal.
Do not store or use in or around the
home or home garden.
Do not graze livestock in treated
areas.
Turf: sod farms
Chemigation Application
Groundboom Application
Granular
Water-soluble powder
4 Ib ai/acre
3
Maximum 6 Ibs ai/A/yr except in
cases of heavy weed infestation (8
56
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Site
Application Equipment
Formulation
Maximum
Single
Application
Rate
Max No
of
Appl
per/y
Restrictions
Ib ai/A/yr)
Do not apply through any type of
irrigation system.
Do not contaminate water by
cleaning of equipment or disposal
of equipment wash waters.
Do not contaminate water, food, or
feed by storage or disposal.
Do not store or use in or around the
home or home garden.
Do not graze livestock in treated
areas.
Nursery: woody ornamental
shrubs, vines and trees
Groundboom Application
Handgun Applicators
Tractor Drawn Spreader
Backpack Sprayer
Low Pressure Handwand
Push Type Spreader
Bellygrinder
Granular
Water-soluble powder
4 Ib ai/acre
Maximum 6 Ibs ai/A/yr except in
cases of heavy weed infestation (8 Ib
ai/A/yr)
Do not apply through any type of
irrigation system.
Do not contaminate water by
cleaning of equipment or disposal of
57
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Site
Application Equipment
Formulation
Maximum
Single
Application
Rate
Max No
of
Appl
per/y
Restrictions
equipment wash waters.
Do not contaminate water, food, or
feed by storage or disposal.
Do not store or use in or around the
home or home garden.
Do not graze livestock in treated
areas.
Roadsides, rights-of-way
Rights-of-way sprayer
Granular
Water-soluble powder
4 Ib ai/acre
Maximum 6 Ibs ai/A/yr except in
cases of heavy weed infestation (8 Ib
ai/A/yr)
Do not apply through any type of
irrigation system.
Do not contaminate water by
cleaning of equipment or disposal of
equipment wash waters.
Do not contaminate water, food, or
feed by storage or disposal.
Do not store or use in or around the
home or home garden.
58
-------
Site
Application Equipment
Formulation
Maximum
Single
Application
Rate
Max No
of
Appl
per/y
Restrictions
Do not graze livestock in treated
areas.
59
-------
60
-------
Appendix B. Table of Generic Data Requirements and Studies Used
to Make the Reregistration Decision
61
-------
APPENDIX B
Data Supporting Guideline Requirements for the Reregistration of
Oxadiazon
REQUIREMENT
PRODUCT
New
Guideline
Number
830.1550
830.1600
830.1670
830.1700
830.1750
830.1800
830.6302
830.6303
830.6304
830.7050
830.7200
830.7300
830.7840
830.7860
830.7950
830.7550
830.6313
Old
Guideline
Number
61-1
6 1-2 A
61-2B
62-1
62-2
62-3
63-2
63-3
63-4
None
63-5
63-7
63-8
63-9
63-11
63-13
CHEMISTRY
Product Identity and Composition
Start. Mat. & Mnfg. Process
Formation of Impurities
Preliminary Analysis
Certification of limits
Analytical Method
Color
Physical State
Odor
UV/Visible Absorption
Melting Point
Density
Solubility
Vapor Pressure
Octanol/Water Partition Coefficient
Stability
USF
PATTERN CITATION(S)
All
All
All
All
All
All
All
All
All
All
All
All
All
All
All
All
40968001
40968001
40968001
41863601
41863601
41863601
41842801
41842801
41842801
Data gap
41842801
41565701
41474201
41230301
41230302
41877601
ECOLOGICAL EFFECTS
850.2100
850.2200
850.2300
850.1075
850.1010
850.1075
850.1025
850.1035
850.1045
71-1
71-2
71-4
72-1 A
72-2
72-3(a)
72-3(b)
72-3(c)
Avian Acute Oral Toxicity
Avian Dietary Toxicity
Avian Reproduction
Fish Toxicity
Freshwater Invertebrate Toxicity
Estuarine/Marine Toxicity - Fish
Estuarine/Marine Toxicity - Mollusk
Estuarine/Marine Toxicity - Shrimp
C
C
C
C
C
C
C
C
41610101
41610102
41610103
41993201
41993202
42330401
42350601
42331801
42615801
42570301
42615802
62
-------
Data Supporting Guideline Requirements for the Reregistration of
Oxadiazon
REQUIREMENT
850.1400
850.1300
850.1350
850.4100
850.4150
850.4400
850.4225
850.4250
850.4400
850.3020
72-4(a)
72^{b)
122-1 (a)
122-l(b)
122-2
123-1 (a)
123-l(b)
123-2
141-1
70-1
70-1
70-1
Estuarine Fish- Early Life Stage
Estuarine/Marine Invertebrate Life Cycle
Seed Germ./ Seedling Emergence Tier I
Vegetative Vigor Tier I
Aquatic Plant Growth
Seed Germ./ Seedling Emergence Tier II
Vegetative Vigor Tier II
Aquatic Plant Growth
Honey Bee Acute
Aquatic Phototoxicity Studies (Fathead minnow)
Acute and Chronic Sediment Toxicity Testing
Water Monitoring Study
ป JCl?
PATTERN CITATION(S)
C
C
C
C
C
C
C
C
C
C
C
C
Data gap
Data gap
Data gap
Data gap
41610105
41610106
41610107
41610108
42659001
Data gap
Data gap
41610105-41610108
42468301
Data gap
Data gap
Data gap
TOXICOLOGY
870.1100
870.1200
870.1300
870.2400
870.2500
870.2600
870.3100
870.3150
870.3200
870.3465
870.3700a
870.3700b
870.3800
870.4100a
870.4 lOOb
870.4200
81-1
81-2
81-3
81-4
81-5
81-6
82-1 A
82-1B
82-2
82-4
83-3A
83-3B
83-4
83-1A
83-1B
83-2B
Acute Oral Toxicity-Rat
Acute Dermal Toxicity-Rabbit
Acute Inhalation Toxicity-Rat
Primary Eye Irritation-Rabbit
Primary Skin Irritation
Dermal Sensitization
90-Day Feeding - Rodent
90-Day Feeding - Dog
21 -Day Dermal - Rabbit
28-day inhalation toxicity
Prenatal development ( rat)
Prenatal development (rabbit)
Reproduction and fertility effects (rat)
Chronic Feeding Toxicity - Rodent
Chronic Feeding Toxicity - Dog
Oncogenicity - Mouse
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
41866501
41866502
41866503
41866504
41866505
41230401
00111804
00111805
41863602
Data gap
40470202
40470201
41239801
see 870.4300
41326401
00115733
40993301
63
-------
Data Supporting Guideline Requirements for the Reregistration of
Oxadiazon
REQUIREMENT
870.4300
870.5100-
870.5500
870.5375
870.5550
870.7485
870.7600
83-5
84-2A-84-2B
84-4
85-1
Special
Study
Combined Chronic Toxicity/ Carcinogenicity-Rat
Gene mutation studies
Cytogenetics In vitro mammalian cell chromosomal
aberration assay
Other Effects
General Metabolism
Dermal penetration-Rat
PA CITATION(S)
c
c
c
c
c
c
00149003
00157780
40993401
00069893
41871701
00115726
00115729
00115728
00115730
00115723
00115727
00115703
42324701
42663601
44588101
42310001
OCCUPATIONAL/RESIDENTIAL EXPOSURE
875.2100
132-1A
Transferable Residue Dissipation: Lawn and Turf
c
43517801
ENVIRONMENTAL FATE
835.2120
835.2240
835.2410
835.4100
835.4400
835.4300
835.1230
835.1240
835.6100
None
161-1
161-2
161-3
162-1
162-3
162-4
163-1
164-1
165-4
Hydrolysis
Photodegradation - Water
Photodegradation - Soil
Aerobic Soil Metabolism
Anaerobic Aquatic Metabolism
Aerobic Aquatic Metabolism
Leaching/ Adsorption/Desorption
Terrestrial Field Dissipation
Bioaccumulation in Fish
c
c
c
c
c
c
c
c
c
41863603
41897201
41898201
42772801
42773802
Data gap
41898202
41889601
41767401
42226701
64
-------
Appendix C. Technical Support Documents
65
-------
Appendix C.TECHNICAL SUPPORT DOCUMENTS
Additional documentation in support of this RED is maintained in the OPP docket, located in
Room 119, Crystal Mall #2,1921 Jefferson Davis Highway, Arlington, VA. It is open Monday through
Friday, excluding legal holidays, from 8:30 am to 4 pm.
The docket initially contained preliminary risk assessments and related documents as of
February 19,2003. Sixty days later the first public comment period closed.
All documents, in hard copy form, may be viewed in the OPP docket room or downloaded or
viewed via the Internet at the following site:
http://www.epa.gov/edocket/
These documents include:
HEP Documents:
L OXADIAZON: Response to the 30-day Error Only Comments on the HED
Chapter of the Reregistration Eligibility Decision Document (RED). PC Code:
109001, Case #819425, Submission No. S610158, DP Barcode: D280876
[49 pages]
2. Revised Occupational and Residential Exposure Assessment and
Recommendations for the Reregistration Eligibility Decision Document for
Oxadiazon. DP Barcode: D276360 [62 pages]
3. Oxadiazon. Reregistration Case No. 2680. Toxicology Chapter for the
Reregistration Eligibility Decision (RED) Document for Oxadiazon. DP Barcode:
D266361 [45 pages]
4. Oxadiazon-Report of the Hazard Identification Assessment Review Committee.
(HED Doc. No. 014469) [30 pages]
5. Cancer Assessment Document Evaluation of the Carcinogenic Potential of
Oxadiazon (Third Review) (HED Doc. No. 014555) [28 pages]
6. Oxadiazon: Assessment of Mode of Action on Liver Carcinogenicity. DP
Barcode: D266361 [15 pages]
7. Revised Oxadiazon Quantitative Risk Assessment (Q1 *) Based On ICR-JCL
Mouse and SPF Wistar Rat Dietary Studies With 3/4's Interspecies Scaling
Factor (HED Doc. No. 014465) [3 pages]
66
-------
8. Oxadiazon. (List B, Case No. 2485) The Outcome of the HED Metabolism
Assessment Review Committee Meeting Held on 1/30/01. DP Barcode
272425. Chemical 109001. [4 pages]
9. Oxadiazon. List B Reregistration Case 2485. PC Code 109001. Product
Chemistry and Residue Chemistry Chapter for the Reregistration Eligibility
Decision [RED] Document. DP Barcode D273740. [3 pages]
10. Oxadiazon. List B Reregistration Case 2485. PC Code 109001. Product
Chemistry and Residue Chemistry Chapter for the Reregistration Eligibility
Decision [RED] Document. DP Barcode D273740. [12 pages]
EFED Documents:
1. EFED Risk Assessment for the Reregistration Eligibility Decision of Oxadiazon.
DP Barcode: D280320 [83 pages]
2. Tier I Estimated Environmental Concentration of Oxadiazon. DP Barcode:
D273599 [4 pages]
3. Tier II Estimated Drinking Water Concentrations (EDWCs) for Human Health
Risk for oxadiazon on Florida Golf Course (PC Code 1090001, DP Code:
D281176) [7 pages]
67
-------
68
-------
Appendix D. Citations Considered to be Part of the Database Supporting the Reregistration
Decision (Bibliography)
69
-------
GUIDE TO APPENDIX D
1. CONTENTS OF BIBLIOGRAPHY. This bibliography contains citations of all studies
considered relevant by EPA in arriving at the positions and conclusions stated elsewhere in the
Reregistration Eligibility Document. Primary sources for studies in this bibliography have been
the body of data submitted to EPA and its predecessor agencies in support of past regulatory
decisions. Selections from other sources including the published literature, in those instances
where they have been considered, are included.
2. UNITS OF ENTRY. The unit of entry in this bibliography is called a "study". In the case of
published materials, this corresponds closely to an article. In the case of unpublished materials
submitted to the Agency, the Agency has sought to identify documents at a level parallel to the
published article from within the typically larger volumes in which they were submitted. The
resulting "studies" generally have a distinct title (or at least a single subject), can stand alone for
purposes of review and can be described with a conventional bibliographic citation. The
Agency has also attempted to unite basic documents and commentaries upon them, treating them
as a single study.
3. IDENTIFICATION OF ENTRIES. The entries in this bibliography are sorted numerically by
Master Record Identifier, or "MRID" number. This number is unique to the citation, and should
be used whenever a specific reference is required. It is not related to the six-digit "Accession
Number" which has been used to identity volumes of submitted studies (see paragraph 4(d)(4)
below for further explanation). In a few cases, entries added to the bibliography late in the
review may be preceded by a nine character temporary identifier. These entries are listed after
all MRID entries. This temporary identifying number is also to be used whenever specific
reference is needed.
4. FORM OF ENTRY. In addition to the Master Record Identifier (MRID), each entry consists
of a citation containing standard elements followed, in the case of material submitted to EPA, by
a description of the earliest known submission. Bibliographic conventions used reflect the
standard of the American National Standards Institute (ANSI), expanded to provide for certain
special needs.
a Author. Whenever the author could confidently be identified, the Agency has chosen to
show a personal author. When no individual was identified, the Agency has shown an
identifiable laboratory or testing facility as the author. When no author or laboratory
could be identified, the Agency has shown the first submitter as the author.
70
-------
b. Document date. The date of the study is taken directly from the document. When the
date is followed by a question mark, the bibliographer has deduced the date from the
evidence contained in the document. When the date appears as (1999), the Agency
was unable to determine or estimate the date of the document.
c. Title. In some cases, it has been necessary for the Agency bibliographers to create or
enhance a document title. Any such editorial insertions are contained between square
brackets.
d. Trailing parentheses. For studies submitted to the Agency in the past, the trailing
parentheses include (in addition to any self-explanatory text) the following elements
describing the earliest known submission:
(1) Submission date. The date of the earliest known submission appears
immediately following the word "received."
(2) Administrative number. The next element immediately following the word
"under" is the registration number, experimental use permit number, petition
number, or other administrative number associated with the earliest known
submission.
(3) Submitter. The third element is the submitter. When authorship is defaulted to
the submitter, this element is omitted.
(4) Volume Identification (Accession Numbers). The final element in the trailing
parentheses identifies the EPA accession number of the volume in which the
original submission of the study appears. The six-digit accession number follows
the symbol "CDL," which stands for "Company Data Library." This accession
number is in turn followed by an alphabetic suffix which shows the relative
position of the study within the volume.
71
-------
PRODUCT CHEMISTRY
40968001 Brocahard, M. (1988) Oxadiazon Manufacturing Process and Discussion of
Formation of Impurities. Unpublished compilation prepared by Rhone-Poulen
Sante. 54 p.
41230301
Citation: Hoffman, M. (1989) Vapor Pressure Determination of Oxadiazon:
Final Report: HLA 6001-372. Unpublished study prepared by Hazleton
Laboratories Americas, Inc. 71 p.
41230302
Seymour, R., Hall, L. (1988) Octanol/Water Partition Coefficient Determination
for Oxadiazon. Unpublished study prepared by Rhone-Poulenc Ag Co. 12 p.
41474201
Pruitt, P. (1987) Solubility of Oxadiazon (R. P.-17623) in Selected Solvents:
Lab Project Number 40207. Unpublished study prepared by Rhone-Poulenc
AgCo. 8 p.
41565701
Chabassol, Y. (1990) Oxadiazon-Specific Gravity and Density at 20 (degree)
C: Lab Project Number: 89-15. Unpublished study prepared by Rhone-
Poulenc Secteur Agro. 16 p.
41842801
Chabassol, Y. (1991) Oxadiazon Technical Grade Physical Properties: Lab
Project Number: 90-26. Unpublished study prepared by Rhone- Poulenc
Secteur Agro. 40 p.
41863601
Chabossol, Y.; Chabert, M.; Hunt, G. et al. (1991) Oxadiazon Technical Grade:
Analysis and Certification of Product Ingredients. Lab Project Number: 90-12:
9115221. Unpublished study prepared by Rhone- Poulenc, Secteur Agro. 462
P-
41877601
Sanders, J. (1991) Oxadiazon, Technical: Determination of Stability: Lab
Project Number: 4053-91-0061-AS. Unpublished study prepared by Ricerca,
Inc. 102 p.
ECOLOGICAL EFFECTS
41610101 Pedersen, C. (1990) Oxadiazon Technical: 21-Day Acute Oral LD50 Study in
bobwhite Quail: Lab Project Number: BLAL/NO/89 QD 139. Unpublished
study prepared by Bio-Life Associates, Ltd. 35 p.
72
-------
41610102
Pedersen, C. (1990) Oxadiazon Technical: 8-Day Acute Dietary LC50 Study in
bobwhite Quail: Lab Project Number. BLAL/NO/89 QC 141.Unpublished
study prepared by Bio-Life Associates, Ltd. 82 p.
41610103
Pedersen, C. (1990) Oxadiazon Technical: 8-Day Acute Dietary LC50 Study in
Mallard Ducklings: Lab Project Number. BLAL/NO/89 DC 137. Unpublished
study prepared by Bio-Life Associates, Ltd. 80 p.
41610105
Giddings, J. (1990) Oxadiazon Technical-Toxicity to the Marine Diatom
Skeletonema costatum: Lab Project Number: 90-7-3384: 10566-
1089-6137-450. Unpublished study prepared by Springborn Laboratories, Inc.
55 p.
41610106
Giddings, J. (1990) Oxadiazinon Technical-Toxicity to the Freshwater Diatom
Navicula pelliculosa: Lab Project Number:90-8-3423; 10566-1089-6137-440.
Unpublished study prepared by Springborn Laboratories, Inc. 52 p.
41610107
41610108
41784301
Giddings, J. (1990) Oxadiazon Technical-Toxicity to the Duckweed Lemma
gibba G3: Final Report: Lab Project Number: 90-7-3389;
10566.1089.6137.410. Unpublished study prepared by Springborn
Laboratories, Inc. 48 p.
Giddings, J. (1990) Oxadiazon Technical-Toxicity to the Freshwater Green Alga
Selenastrum capricomutum: Amended Report: Lab Project Number:
90-8-3422; 10566.1089.6137.437. Unpublished study prepared by
Springborn Laboratories, Inc. 52 p.
Blakemore, G.; Burgess, D. (1991) Chronic Toxicity of Oxadiazon Technical to
Daphnia magna under Flow-thru Conditions: Final Report: Lab Project Number
38369. Unpublished study prepared by Analytical Bio-Chemistry Labs., Inc.
349 p.
41993201
Fletcher, D.; Pedersen, C. (1991) Oxadiazon Technical: Toxicity and
Reproduction Study in Mallard Ducks: Lab Project Number: 89 DR 35.
Unpublished study prepared by Bio-Life Associates, Ltd.138 p.
41993202
Fletcher, D.; Pedersen, C. (1991) Oxadiazon Technical: Toxicity and
Reproduction Study in bobwhite Quail: Lab Project Number: 89 QR 39.
Unpublished study prepared by Bio-Life Associates, Ltd. 145 p.
73
-------
42330401
Sword, M.; Northup, R. (1992) Acute Flow-Through Toxicity of Oxadiazon to
Rainbow Trout (Oncorhynchus mykiss): Lab Project Number: 39729.
Unpublished study prepared by ABC Laboratories, Inc. 211 p.
42331801
Blasberg, J.; Bowman, J. (1992) Acute Toxicity of Oxadiazon to Daphnia
magna under Flow-through Conditions: Amended Final Report: Lab Project
Number: 39730. Unpublished study prepared by ABC Labs, Inc. 254 p.
42350601
Sword, M.; Northup, R, (1992) Acute Flow-through Toxicity of Oxadiazon to
Bluegill (Lepomis rnacrochirus): Final Report: Lab Project Number: 39728.
Unpublished study prepared by ABC Labs., Inc. 194 p.
42468301
Beevers, M. (1992) Acute Contact Toxicity of Oxadiazon Technical to Honey
Bees (Apis mellifera L.): Lab Project Number: CAR 160-92. Unpublished study
prepared by California Agricultural Research, Inc. 14 p.
42570301
Dionne, E. (1992) Oxadiazon TechnicalAcute Toxicity to Eastern Oyster
(Crassostrea virginica) under Flow-through Conditions: Final Report: Lab
Project Number: 92-7-4329: 10566. 0392.6238.504. Unpublished study
prepared by Springborn Labs, Inc. 63 p.
42615801
Machado, M. (1992) Oxadiazon Technical-Acute Toxicity to Sheepshead
Minnow (Cyprinodon variegatus) under Flow-through Conditions: Final Report:
Lab Project Number: 92-8-4383 10566.0392.6237.505. Unpublished study
prepared by Springbom Labs, Inc. 66 p.
42615802
Machado, M. (1992) Oxadiazon Technical-Acute Toxicity to Mysid Shrimp
(Mysidopsis bahia) under Flow-through Conditions: Final Report: Lab Project
Number: 92-7-4348: 10566.0392.6236.515. Unpublished study prepared by
Springborn Labs, Inc. 65 p.
42659001
Mihaich, E. (1993) Response to EPA Review of Oxadiazon Anabaena
flos-aquae Study (MRID 41610104) and Selenastrum caprocornutum (sic)
Study (MRID 41610108): Lab Project No. NS/EMM-93-03. Unpublished
study prepared by Rhone-Poulenc Ag Co. and Springbom Labs., Inc. 10 p.
74
-------
TOXICOLOGY
00069893
Shirasu, Y., Moriya, M. and Kato, K. (1976) Microbial Mutagenic Study on
Oxadiazon. Institute of Environmental Toxicology, Nissan Chemical Industries,
Ltd., Japan. No study/report no. provided. Report dated June 4,1976.
Unpublished study.
00111804
Weatherholtz, W. and Voelker, R. (1970) 13-week Dietary
Administration--Rats: RP 17623. TRW, Inc., Vienna, VA. Study No.
656-114. May 28,1970. Unpublished study.
00111805
Weatherholtz, W. and Voelker, R. (1970) 13-week Oral Administration-Dogs:
RP 17623. TRW, Inc., Vienna, VA. Project No. 656-115. May 22,1970.
Unpublished study.
00115703
Hossack, D.J.N. and Daniel, M.R. (1982) Oxadiazon Lot CA 76 204 and
Recrystallized Oxadiazon 17 623 RP Cell Transformation Test for
Carcinogenicity. Huntingdon Research Centre, England. Laboratory report
number RNP 152A/79368, July 29,1982. Unpublished study.
00115723
Myhr, B.C. and McKeon, M. (1982) Evaluation of Oxadiazon Recristallise in
the Primary Rat Hepatocyte Unscheduled DNA Synthesis Assay. Litton
Bionetics, Inc., Kensington, MD. LBI Project No. 20991. June, 1982.
Unpublished study.
00115726
Cifone, M.A and Balinas, V. (1982) Mutagenicity Evaluation of Oxadiazon in
the Mouse Lymphoma Forward Mutation Assay. Litton Bionetics, Inc.,
Kensington, MD. LBI Project No. 20999. Unpublished study.
00115727
Myhr, B.; McKeon, M. (1982) Evaluation of Oxadiazon (Lot MAG 405) in the
Primary Rat Hepatocyte Unscheduled DNA Synthesis Assay. Litton Bionetics,
Inc., Kensington, MD. LBI Project No. 21001. June, 1980. Unpublished
study.
00115728
Galloway, S. and Lebowitz, H. (1982) Mutagenicity Evaluation of Oxadiazon
Recristallise, Lot BOS 2 385 in an in vitro Cytogenetic Assay Measuring
Chromosome Aberration Frequencies in Chinese Hamster Ovary (CHO) Cells.
75
-------
Litton Bionetics, Inc., Kensington, MD. LBI Project No. 21000. July, 1982.
Unpublished study.
00115729
Cifone, M. and Balinas, V. (1982) Mutagenicity Evaluation of Oxadiazon
Recristallise in the Mouse Lymphoma Forward Mutation Assay. Litton
Bionetics, Inc., Kensington, MD. LBI Project No. 20999. April, 1982.
Unpublished study.
00115730
Galloway, S. and Lebowitz, H. (1982) Mutagenicity Evaluation of Oxadiazon,
Lot MAG 405 in an in vitro Cytogenetic Assay Measuring Chromosome
Aberration Frequencies in Chinese Hamster Ovary (CHO) Cells. Litton
Bionetics, Inc., Kensington, MD. LBI Project No. 21000. July, 1982.
Unpublished study.
00115733
Oxadiazon: Oncogenicity in Dietary Administration to Mice for a Period of 105
Weeks: Project No. 82/RHOOOH/245. Prepared by Life Science Research. 10
P-
00149003
Kudo, S., Takeuchi, T., Hayashi, K. et al. (1981) Twenty-four Month Chronic
Toxicity Study of Oxiadiazon in Rats. Nippon Institute for Biological Science
and Institute of Environmental Toxicology. No study/report no. July, 1981.
Unpublished study.
00157780
Nippon Institute for Biological Science (1986) Twenty-four Month Chronic
Toxicity Study of Oxadiazon in Rats: Revised Data Tables per EPA Request.
Unpublished data.
40470201
Tesh, J.; Ross, F.; Bailey, G.; et al. (1987) Oxadiazon: Teratology Study in the
Rabbit: Laboratory Project ID 87/RHA095/534. Unpublished study performed
by Life Science Research, England. 92 p.
40470202
Tesh, J.; McAnulty, P.; Wightman, B; et al. (1987) Oxadiazon: Teratology
Study in the Rat: Laboratory Project ID 87/RHA093/356 . .Unpublished study
performed by Life Science Research, England. 145 p.
76
-------
40993301
Shirasu, Y. (1987) Oxadiazon-23 Month Oral Chronic Toxicity and
Oncogenicity Study in Mice. Institute of Environmental Toxicology, Tokyo,
Japan. Study No. not listed. February, 1987. Unpublished study.
40993401
Y. Shirasu (1987). Oxadiazon - 24 Month Chronic Toxicity and Oncogenicity
Study in Rats. Institute of Environmental Toxicology, Tokyo, Japan; Study No.
not listed. February 1987. Unpublished study.
40993401
Y. Shirasu (1987). Oxadiazon - 24 Month Chronic Toxicity and Oncogenicity
Study in Rats. Institute of Environmental Toxicology, Tokyo, Japan; Study No.
not listed. February 1987. Unpublished study.
41230401
Siglin, J. (1988) Delayed contact hypersensitivity study in guinea pigs with
oxadiazon (EPA). Springborn Life Sciences, Inc., Spencerville, OH.
Laboratory Study No. 3147.26. December 20,1988. Unpublished study.
41239801
Tesh, J.; McAnulty, P.; Higgins, C. (1988) Oxadiazon: Effects of Dietary
Administartion Upon Reproductive Performance of Rats Treated Continuously
Throughout Two Successive Generations: Pro-ject ID 88/RHA097/366. 863
P-
41326401
Chapman, E. (1989) Oxadiazon: Toxicity Study by Oral (Capsule)
Administration to Beagle Dogs for 52 Weeks: Lab Project Number: 88/0763.
Unpublished study prepared by Life Science Research, Ltd. 560 p.
41863602
Siglin, J.C. (1991) 21-Day Dermal Toxicity Study in Rabbits with Oxadiazon
Technical. Springborn Labs, Inc., Spencerville, OH. Lab Project Number:
3147.86. March 20,1991. Unpublished study.
41866501
Rush, R. (1990) Acute Oral Toxicity Study in Rats with Oxadiazon: Final
Report: Lab Project Number: 3147.84. Unpublished study prepared by
Springborn Laboratories, Inc. 26 p.
41866502
Rush, R. (1990) Acute Dermal Toxicity Study in Rabbits with Oxadia- zon:
Final Report: Lab Project Number: 3147.85. Unpublished Study prepared by
Springborn Laboratories, Inc. 24 p.
77
-------
41866503
Michlewicz, K. (1988) Acute Inhalation Toxicity Study of Oxadiazon in Rats-
Limit Test: Lab Project Number: 3147.24. Unpublished Study prepared by
Springborn Laboratories, Inc. 32 p.
41866504
Rush, R. (1991) Primary Eye Irritation Study in Rabbits with Oxadiazon: Final
Report: Lab Project Number: 3147.110. Unpublished Study prepared by
Springborn Laboratories, Inc. 30 p.
41866505
Rush, R. (1991) Primary Skin Irritation Study in Rabbits with Oxadiazon: Final
Report: Lab Project Number: 3147.111. Unpublished Study prepared by
Springborn Laboratories, Inc. 22 p.
41871701
L.F. Stankowski, Jr, (1991). Ames Salmonella Plate Incorporation Assay on
Oxadiazon. Pharmalon Research International Inc., Waverly, PA. Study No.
PH301-RP-001-91. April 30,1991. Unpublished study.
42324701
Powles, P. (1992) (14C>Oxadiazon: Absorption, Distribution, Metabolism, and
Excretion in the Rat: [Final Report]. Hazleton UK, England. Study No.
7120-68/118. May 11,1992. Unpublished study.
42663601
Powles, P. (1993): (14C)-Oxadiazon: Absorption, Distribution Metabolism and
Excretion in the Rat. [Amendment to Final Report MRID No. 42324701]
Hazleton UK, England. Study No. 7120-68/118. February 9,1993.
Unpublished study.
44588101
Cheng, T. (1996) Dermal Absorption of 14C- Oxadiazon in Male Rats
(Preliminary and Definitive Phases) Coming Hazleton, Vienna, VA. Lab Project
Number: CHW 6224-224.
OCCUPATIONAL/RESIDENTIAL EXPOSURE
43517801
Rosenheck, L.; Sanchez, S. (1995) Evaluation of Turf Re-entry Exposure to a
Broadcast Application of Ronstar 50WP: Lab Project Number: 93293.
Unpublished study prepared by Pan-Agricultural Labs, Inc. 300 p.
78
-------
ENVIRONMENTAL FATE
41767401
41863603
41897201
41898201
Norris, F.A. 1991. A terrestrial field soil dissipation study with oxadiazon.
Study No. EC/P-89-0014. File No. 40642. Unpublished study performed and
submitted by Rhone-Poulenc Ag Company, Research Triangle Park, NC
Corgier, M.M.C., and Robin, J.M. 1991. 14C-Oxadiazon Hydrolysis at 25ฐC.
Unpublished study performed by Rhone-Poulenc, Lyon, France, and submitted
by Rhone-Poulenc, Research Triangle Park, NC
Corgier, M.M.C., and A.P. Plewa. 1991. 14C-oxadiazon photodegradation in
aqueous solution. Study No. 90-29. Filing Reference
AG/CRLD/AN/9115609. Unpublished study performed by Rhone-Poulenc
Secteur Agro, Lyon, France, and submitted by Rhone-Poulenc Ag Company,
Research Triangle Park, NC
Das,Y.T. 1991. Photodegradation of [Phenyl(U)-14C] Oxadiazon on Soil
under Artificial Sunlight. Unpublished study performed by Innovative Scientific
Services, Inc. Piscataway, N.J., and sponsored and submitted by Rhone-
Poulenc Ag Company, Research Triangle Park, NC
41898202 Dykes, J. 1991. Soil Adsorption/Desorption with 14C- Oxadiazon. An
unpublished study performed by Analytical Bio-Chemistry Laboratories, Inc.,
Columbia, MO, nad submitted by Rhone Poulenc Ag Company, Research
Triangle Park,NC
42226701 Armstrong, K., B.D. Cameron, S.A. Chapleo, B.E. Hall, and A.Haswell. 1991.
Oxadiazon: Bioaccumulation test in bluegill sunfish. IRI Project No. 381195;
Report No. 8385. Unpublished study performed by Inversk Research
International, Tranent, Scotland, and submitted by Rhone-Poulenc Ag
Company, Research Triangle Park, NC
Manley, J.D., I.A.J. Hardy, and E.A. Savage. 1992. Herbicides: Oxadiazon spectroscopic
investigation of metabolites from a [14C]-oxadiazon bioaccumulation test in bluegill sunfish. IRI Project
No. 381195. Unpublished study performed by Rhone-Poulenc Agriculture Limited, Ongar, United
Kingdom, and submitted by Rhone-Poulenc Ag Company, Research Triangle Park, NC (No Study ID)
42772801 Waring, A.R. 1993a. [14C]Oxadiazon: Aerobic soil metabolism. HUK Study
No. 68/111; Report No. 7218. Unpublished study performed by Hazleton UK,
Harrogate, North Yorkshire, England, and submitted by Rhone-Poulenc
Agriculture Company, Research Triangle Park, NC
42773802 Waring, A.R 1993b. [14C]Oxadiazon: Anaerobic aquatic metabolism. HUK
Study No. 68/112; Report No. 7214. Unpublished study performed by
79
-------
Hazleton UK, Harrogate, North Yorkshire, England, and submitted by Rhone-
Poulenc Agriculture Company, Research Triangle Park, NC
80
-------
Appendix E. Generic Data Call-in
81
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DRAFT COPY
Page 1 of 1
United States Environmental Protection OMB Approval 2070-010?
Agency Washington, D.C. 20460 OMB Approval 2070-0057
DATA CALL-IN RESPONSE
INSTRUCTIONS: Please type or print in ink. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1 . Company Name and Address 2. Case # and Name 3. Date and Type of DCI and Number
SAMPLE COMPANY 2485 Oxadiazon DD-MMM-YYYY
NO STREET ADDRESS Chemical # and Name 109001 GENERIC
NOC,TY,XX 00000 Oxadiazon |D# QDCM09001.NNNNN
4. EPA
Product
Registration
NNNNNN-NNNNN
5. 1 wish to
cancel this
product regis-
tration volun-
tarily
6. Generic Data
6a. 1 am claiming a Generic
Data Exemption because 1
obtain the active ingredient
from the source EPA regis-
tration number listed below.
6b. 1 agree to satisfy Generic
Data requirements as indicated
on the attached form entitled
"Requirements Status and
Registrant's Response."
7. Product Specific Data
7a. My product is an MUP and
1 agree to satisfy the MUP
requirements on the attached
form entitled "Requirements
Status and Registrant's
Response."
N.A.
7b. My product is an EUP and
1 agree to satisfy the EUP
requirements on the attached
form entitled "Requirements
Status and Registrant's
Response."
N.A.
8. Certification I certify that the statements made on this form and all attachments are true, accurate, and complete. I acknowledge that any g pate
knowingly false or misleading statement may be punishable by fine, imprisonment or both under applicable law.
Signature and Title of Company's Authorized Representative
in Klnmn ซซ Onซซ__.. . . _. ...
-------
United States Environmental Protection OMB Approval 2070-0107
Agency Washington, D.C. 20460 OMB Approval 2070-0057
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
INSTRUCTIONS: Please type or print in ink. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1 . Company Name and Address
SAMPLE COMPANY
NO STREET ADDRESS
NO CITY, XX 00000
4. Guideline
Requirement
Number
835.4300
, ..
5. Study Title
2. Case # and Name 3. Date and Type of DCI and Number
2485 Oxadiazon DD-MMM-YYYY
Chemical # and Name 109001 GENERIC
Oxadiazon ,D# QDCI-109001-NNNNN
Environmental Fate Dab Requirement* (Conventional
Chemical)
Aerobic aquatic metabolism
4. . . . - w ..<;. - - - -. -
: ,,'.-,:-_,, ii-iuiiuiroqi. i-tam rrmrcuoii ua\a rtequirgreqms ivonvenoonai
850.4100
850.4150 :
850.4225
8S04250 ' '' -:
850.1300
850.1350
8S0.1400 x
Terrestrial plant toxicity, Tier 1 (seeding emergence) (1 ,2 ,3)
Termstriaifi lant toxictty. Tier 1 (vegetative vigor) (4 ,5 $;
3
6. Use
Pattern
C, K
^.-,. -.
x-?$\':\
C, K
CK /-'-//
, fx -^; '*&'$
^ ., ' ' ' *:';?
C, K
C,K ;;.- ; '-.-..v,-;:V>-
".'- ' - -~H , -;ซ;.''%:
C, K
^'^'~:*r&t
7. Test .
Substance
S*SV
TGAI or PAIRA
... .... ;,.- . t>
TEP
TEP . % . -_^:"'-
TEP
jJiTA.y-i--.-I ' - \ i -1
JW/-.; / :/.. >
TGAI
', ' , ' .
TGAI
'','-
8. Time
Frame
(Months)
24
12
12 ..- __:.;
12
12
12
12
9. Registrant
Response
.*
'" ', - ';S-
ฃ .
%.Mi.;
1 0. Certification I certify that the statements made on this form and all attachments are true, accurate, and complete. I acknowledge that any 11. Date
knowingly false or misleading statement may be punishable by fine, imprisonment or both under applicable law
Signature and Title of Company's Authorized Representative
12. Name of Company
13. Phone Number
-------
DRAFT COPY
Page 2 of 2
United States Environmental Protection
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
OMB Approval 2070-0107
OMB Approval 2070-0057
INSTRUCTIONS: Please type or print in ink. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1 . Company Name and Address
SAMPLE COMPANY
NO STREET ADDRESS
NO CITY, XX 00000
4. Guideline
Requirement
Number
870.3465
161-frf S
V'i
70-1 -SS
5. Study Title
90-day inhalation toxlcfty
Surface Water Monitoring Study
2. Case # and Name
2485 Oxadiazon
Chemical # and Name 1 09001
Oxadiazon
<[23,24)
' /^t4% '%
' ./,-, %**;/ - ,>
Aquatic Phototoxicity Study (Fathead minnow) (32)
Aquatic Sediment Toxicity Testing
p
R
0
T
0
C
O
L
Progress
Reports
1
^
2
%'
3
8'
6. Use
Pattern
C,K
CMC- /;ซ
C, K
. '^- " ?^
3. Date and Type of DCI and Number
DD-MMM-YYYY
GENERIC
ID# GDCI-109001-NNNNN
;' .-J
m
Initial to indicate certification as to information on this page
It. .11 1 L -t ป;*?-.ป'.
7. Test
Substance
ISM ' . -;,^r
lT/SAI'// /f. r"f ^ ^-'' '/~, i~'y.
TGAI
8. Time
Frame
(Months)
2'
36
24
9. Registrant
Response
1 ~'.':' -
Date
-------
united oiaies nnvironmemai rroiecuon
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUKEMENTS
Case # and Name: 2485 Oxadiazon
DCI Number: GDCI-109001 -NNNNN
Key: TCP = Typical End Use Product [TCP]; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAIRA = Technical Grade of the Active Ingredient or Active Ingredient, Radio-Labelled
Use Categories Key:
C - Terrestrial nonfood crop
K- Residential
Footnotes: FJhe following notes are referenced in column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANTS RESPONSE form.]
1 Not required for contained pesticide treatments such as bait boxes and pheromone traps unless adverse effects reports are received by the Agency.
2 Required for all outdoor pesticide uses except for known phytotoxicants such as herbicides, desiccants, defoliants, and plant growth regulators.
3 Reserved for aquatic residential uses.
4 Not required for contained pesticide treatments such as bait boxes and pheromone traps unless adverse effects reports are received by the Agency.
5 Required for all outdoor pesticide uses except for known phytotoxicants such as herbicides, desiccants, defoliants, and plant growth regulators.
Q Reserved for aquatic residential uses.
7 Generally not required for granular formulations. May be requested on a case-by-case basis.
8 Not required for contained pesticide treatments such as bait boxes and pheromone traps unless adverse effects reports are received by the Agency.
g Reserved for aquatic residential uses.
10 Required if a terrestrial species exhibits a 25 percent or greater detrimental effect in Tier 1.
11 Required for known phytotoxicants such as herbicides, desiccants, defoliants, and plant growth regulators.
12 Not required for contained pesticide treatments such as bait boxes and pheromone traps unless adverse effects reports are received by the Agency.
13 Reserved for aquatic residential uses.
14 Generally not required for granular formulations. May be requested on a case-by-case basis.
15 Required if a terrestrial species exhibits a 25 percent or greater detrimental effect in Tier 1.
-------
DRAFT COPY Page2of3
United States Environmental Protection
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 2485 Oxadiazon
DCI Number: GDCI-109001 -NNNNN
Key: TEP = Typical End Use Product [TEP]; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAIRA = Technical Grade of the Active Ingredient or Active Ingredient, Radio-Labelled
Use Categories Key:
C - Terrestrial nonfood crop
K - Residential
Footnotes: [The following notes are referenced in column two (S. Study File) of the REQUIREMENTS STATUS AND REGISTRANTS RESPONSE form.]
16 Required for known phytotoxicants such as herbicides, desiccants, defoliants, and plant growth regulators.
17 Data using the TGAI are required to support all outdoor end-use product uses including turf. Data are generally not required to support end use products in the form of a gas, a highly volatile
liquid, a highly reactive solid, or a highly corrosive material.
18 Data are preferred on Daphnia magna.
19 Data are generally not required for other, non-turf, outdoor residential uses, i.e., gardens and ornamentals.
20 Data are generally not required for other, non-turf, outdoor residential uses, i.e., gardens and ornamentals.
21 Data are required on estuarine species if the product is: (i) intended for direct application to the estuarine or marine environment; (ii) expected to enter this environment in significant
concentrations because of its expected use or mobility patterns, and (iii) if the acute LC50 or EC50 < 1 mg/l; or (iv) if the estimated environmental concentration in water is equal to or greater
than 0.01 of the acute EC50 or LC50 and any of the following conditions exist: (a) studies of other organisms indicate the reproductive physiology of fish and/or invertebrates may be affected;
(b) physicochemical properties indicate bioaccumulation of the pesticide; (c) the pesticide is persistent in water (e.g., half-life in water greater than 4 days).
22 Data are preferred on oppossum shrimp (America mysis) formerly (Mysidopsis bahia).
23 Required if there is the likelihood of significant repeated inhalation exposure to the pesticide as a gas, vapor, or aerosol.
24 Based on estimates of the magnitude and duration of human exposure, studies of shorter duration, e.g., 21 or 28-days, may be sufficient to satisfy this requirement. Registrants should consult
with the Agency to determine whether studies of shorter duration would meet this requirement.
25 Data using the TGAI are required to support all outdoor end-use product uses including turf. Data are generally not required to support end use products in the form of a gas, a highly volatile
liquid, a highly reactive solid, or a highly corrosive material.
26 Data are generally not required for other, non-turf, outdoor residential uses, i.e., gardens and ornamentals.
27 Data are generally not required for other, non-turf, outdoor residential uses, i.e., gardens and ornamentals.
28 Data are preferred on rainbow trout. If fathead minnow (Pimephales promelus) is used, a 96 hour LC50 on that species must also be provided.
-------
uinu/u kjiaivo i_vii v 11 uiui
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 2485 Oxadiazon
DCI Number: GDCI-109001 -NNNNN
Key: TEP = Typical End Use Product [TEP]; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAIRA = Technical Grade of the Active Ingredient or Active Ingredient, Radio-Labelled
Use Categories Key:
C - Terrestrial nonfood crop
K - Residential
Footnotes: [The following notes are referenced in column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE form.]
29 Data are required on estuarine species if the product is: (i) intended for direct application to the estuarine or marine environment; (ii) expected to enter this environment in significant
concentrations because of its expected use or mobility patterns, and (iii) if the acute LC50 or EC50 < 1 mg/l; or (iv) if the estimated environmental concentration in water is equal to or greater
than 0.01 of the acute EC50 or LC50 and any of the following conditions exist: (a) studies of other organisms indicate the reproductive physiology of fish and/or invertebrates may be affected;
(b) physicochemical properties indicate bioaccumulation of the pesticide; (c) the pesticide is persistent in water (e.g., half-life in water greater than 4 days).
30 Data are preferred on sheepshead minnow (Cypinodon variegatus).
31 The Agency is requesting a three-year water monitoring study to characterize the concentration of oxadiazon in drinking water that draws from surface water sources. The Agency expects that
this data will confirm that the concentration of oxadiazon does not exceed the level-of-concern.
32 Enhanced toxicity through exposure to high levels of solar radiation may increase toxic risk to aquatic organisms that inhabit small, shallow bodies of water. In order to better estimate the
potential risk, EPA is requiring a study on the phototoxicity of oxadiazon in fathead minnows. Please submit protocol prior to study initiation.
33 Oxadiazon residues can accumulate in sediments and may increase the risk from chronic exposure of benthic and epibenthic organisms to the pesticide. In order to better understand this
potential risk, EPA is requiring appropriate sediment toxicity testing, both acute and chronic, on this compound. Please submit protocol prior to study initiation.
-------
-------
Appendix F. Product-specific Data Call-in
89
-------
DRAFT COPY
Page 1 of 1
United States Environmental Protection OMB Approval 2070-010?
Agency Washington, D.C. 20460 OMB Approval 2070-0057
DATA CALL-IN RESPONSE
INSTRUCTIONS: Please type or print in ink. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1 . Company Name and Address 2. Case # and Name 3. Date and Type of DCI and Number
SAMPLE COMPANY 2485 Oxadiazon DD-MMM-YYYY
NO STREET ADDRESS Chemical # and Name 109001 PRODUCT SPECIFIC
NO CITY. XX 00000 Oxadiazon |D# pDCM09001.NNNN
4. EPA
Product
Registration
NNNNNN-NNNNN
5. 1 wish to
cancel this
product regis-
tration volun-
tarily
6. Generic Data
6a. 1 am claiming a Generic
Data Exemption because 1
obtain the active ingredient
from the source EPA regis-
tration number listed below.
N.A.
6b. 1 agree to satisfy Generic
Data requirements as indicated
on the attached form entitled
"Requirements Status and
Registrant's Response."
N.A.
7. Product Specific Data
7a. My product is an MUP and
1 agree to satisfy the MUP
requirements on the attached
form entitled "Requirements
Status and Registrant's
Response."
7b. My product is an EUP and
1 agree to satisfy the EUP
requirements on the attached
form entitled "Requirements
Status and Registrant's
Response."
8. Certification I certify that the statements made on this form and all attachments are true, accurate, and complete. I acknowledge that any g Date
knowingly false or misleading statement may be punishable by fine, imprisonment or both under applicable law.
Signature and Title of Company's Authorized Representative
-- A M. . 1
-------
Agency Washington, D.C. 20460 OMB Approval 2070-0057
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
INSTRUCTIONS: Please type or print in ink. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1 . Company Name and Address
SAMPLE COMPANY
NO STREET ADDRESS
NO CITY, XX 00000
4. Guideline
Requirement
Number
* " "'' f '?' ' ' ' X
830.1550
830.1600
830.1620
83W660-, "^ _,
830.1670
830.1700 - - :iV- ,;<-); -
v-r:-, ."--,*.
830.1750
830.1800
830.6302
830.6303 ;
830.6304
5. Study Title
2. Case # and Name 3. Date and Type of DCI and Number
2485 Oxadiazon DD-MMM-YYYY
PRODUCT SPECIFIC
EPA Reg. No. NNNNNN-NNNNN ID # C,-109001-NNNN
Product Chemistiv Data RBauirementsfCoHvenflonal
Chemical)
Product Identity and composition
(D
Description of materials used to produce the product (2)
, s .-- ; ^ _"_.-,-.,
Description of production process
Description of formulation process
Discussion of formation of impurities
Preliminary analysis
Certified limits
Enforcement analytical method
Color
PittsicaJ state ;*',. ,.-, , ,
' ^ --' , ,
Odor
*
(3)
V,,.,^\;,V.Vf
(5)
(6,7,8)
(9,10)
, . - <ซ> y*^
(12)
;. (13) "'-^
(14)
P
R
0
T
O
C
L
':
i \
Progress
Reports
1
^,
2
4s
3
:-"'
'
..
\
'$ .
6. Use
Pattern
' .; ;. ' -f ':
~ '' ' ' ' :':''', ''*""
A, B, C, D, E, F, G, H, I,
J, K, L, M, N, O
A{ &,->;%, F,
-------
DRAFT COPY
Page 2 of 4
United States Environmental Protection OMB Approval 2070-0107
Agency Washington, D.C. 20460 OMB Approval 2070-0057
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
INSTRUCTIONS: Please type or print in ink. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1 . Company Name and Address 2. Case # and Name 3. Date and Type of DCI and Number
SAMPLE COMPANY 2485 Oxadiazon DD-MMM-YYYY
NO STREET ADDRESS PRODUCT SPECIFIC
NO CITY, XX 00000 ID# PDCI-109001-NNNN
EPA Reg. No. NNNNNN-NNNNN
4. Guideline
Requirement
Number
830:6313
830.6314
830.6315 Vx
830.6316
ฃ**v ^-r..:>
830.6319
830.6321
830.7000
830.7050
830,7100
830.7200
5. Study Title
StelJility to sunligj^,jซrmal and elevated . (15,16)
Oxidizing or reducing action (17)
RammabHjty \ ,. (18)
Explodability (19)
^jtf^ftttrt ,-^: . |?p^v;:
Miscibility (21)
Corrosion characteristics .,._/. ,-.-;: >(22)' '
Dielectric breakdown voltage (23)
pMrf^ter^lu^^sosi^tonit ,,;-..; , ^ J24^|^ >,
UV/Visible absorption
wscofcs?- ปv--- -;; : }$$,^^"
Melting point/melting range (27 ,28)
P
R
O
T
O
C
O
L
Progress
Reports
1
2
:F>
,. -
-' ,*
3
i*<>;
yi/4.
6. Use
Pattern
A, B, C, D, E, F, G, H, I,
J, K, L, M, N, O
J&i&'Oi B, E F, G, Wk 4
4"Krfi
A, B, C, D, E, F, G, H, I,
J, K, L, M, N, O
7. Test
Substance
MP/EP
Mfc/PP*
MP/EP
,;; v;'" VT
A, B, C, D, E, F, G, H, I,
J, K, L, M, N, O
i ii^*-t\V*>ซjrf ki y% * ' * > ;
A, B, C, D, E, F, G, H, I,
J, K, L, M, N, O
PffW'ffS-8*^
A, B, C, D, E, F, G, H, I,
J, K, L, M, N, 0
A, B, C, D, E, F, G, H, I,
J, K, L, M, N, O
MP/EP
ซpปr ' i"->-."
6x?;. :
MP/EP
|^^/EP. -
TGAI/PAI
TGAI
8. Time
Frame
(Months)
8
B-
8
8k; ' v
8
8 ' : ;
8
B
8
8 > ~
8
9. Registrant
Response
;;^! ";;..;,
ป'; .,;,>,-;--.-;
Initial to indicate certification as to information on this page I Date
-------
Agency Washington, D.C. 20460 OMB Approval 2070-0057
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
INSTRUCTIONS: Please type or print in ink. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1. Company Name and Address 2. Case* and Name 3. Date and Type of DCI and Number
SAMPLE COMPANY 2485 Oxadiazon DD-MMM-YYYY
NO STREET ADDRESS PRODUCT SPECIFIC
NO CITY, XX 00000 ID# PDCI-109001-NNNN
EPA Reg. No. NNNNNN-NNNNN
4. Guideline
Requirement
Number
830.7220 ' , = /->-;
830.7300
83&7370
830.7550
830.7840
030.7800
830.7950
870.1100
S7&12QD
870.1300
5. Study Title
Boiling point/boiling range ป,v (2S^|K}>; \,,
Density/relative density (31 ,32)
0^^<^^^^^:^' ,V, <33|P ,
Partition coefficient (n-octanol/water), shake flask (35)
method
Partitioncosfficient(n-octanol/water), estimation by (36)
liquid chromatography
Water solubility: Column elution method, shake flask (37)
method
Water solubility, generator column method (38)
Vapor pressure (39 ,40)
Toxicotoav Data Reauirements {Conventional CHenilcan : :
Acute Oral Toxicity (41 ,42)
Acute dermal toxicity %; , . *<< ^ , ,i:.j. (43!j4A ,45)
Acute inhalation toxicity (46)
P
R
0
T
O
C
L
:'5'
Progress
Reports
1
' V
2
:r
,7.
3
; 4i
'$
]:.M>
w
6. Use
Pattern
ff'Mfo^1
A, B, C, D, E, F, G, H, 1,
J, K, L, M, N, O
IIK^Io^1'
A, B, C, D, E, F, G, H, 1,
J, K, L, M, N, O
A, B, C, D, E, F, G, H, 1,
J, K, L, M, N, O
A, B, C, D, E, F, G, H, 1,
J, K, L, M, N, O
V/ vs s. , 4 %
A, B, C, D, E, F, G, H, 1,
J, K, L, M, N, 0
fcBป.-:C, 0; E, Fซ Gซ-'HMป.
A, B, C, D, E, F, G, H, 1,
J, K, L, M, N, O
Initial to indicate certification as to information on this page
(full text of certification is on page one).
7. Test
Substance
V/: V-itJK ' -""'''i'' ' ;
TGAI/MP/EP
^BdrPAl.=!> ,-=- '
TGAI/PAI
TGAI or PAI
jfiQ&ar PAI
TGAI or PAI
TGAI.EP.dilute EP?
rc^Mi^B*: ,- -
TGAI/MP/EP
8. Time
Frame
(Months)
8 >.;>
8
B ,-" ';:"
8
8
B ;- --
8
8
'; ".--
8
9. Registrant
Response
:- .
\; _,;' '
Date
-------
DRAFT COPY
Page 4 of 4
United States Environmental Protection
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
OMB Approval 2070-0107
OMB Approval 2070-0057
INSTRUCTIONS: Please type or print in inK. Please read carefully the attached instructions and supply the information requested on this form.
Use additional sheet(s) if necessary.
1 . Company Name and Address
SAMPLE COMPANY
NO STREET ADDRESS
NO CITY, XX 00000
4. Guideline
Requirement
Number
870.2400
870.2500
870.26(H* ;
5. Study Title
Ai**ซhk &ifi^ jฃri4t*44>Mit < ฐ jJ/'"' " ' *
Hcuie eye irfttaifon ^ -Vil^* -;
Acute dermal irritation
Skin sensftization , ,
2. Case # and Name
2485 Oxadiazon
EPA Reg. No. NNNNNN-NNNNN
; - t47)
(48 ,49)
P
R
0
T
0
C
O
L
Progress
Reports
1
2
3
^ ~?
6. Use
Pattern
A, 9) C, P, 6, P, 0,
3. Date and Type of DCI and Number
DD-MMM-YYYY
PRODUCT SPECIFIC
ID# PDCI-1 09001 -NNNN
Hit
A, B, C, D, E, F, G, H. I.
J, K, L, M, N, O
4'k't.Wti.V '
Initial to indicate certification as to information on this page
7. Test
Substance
rjd^^P/EP
TGAI/MP/EP
8. Time
Frame
(Months)
a
B
B
9. Registrant
Response
Date
-------
unnea siaies nnviroiuneiiuu
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUD31EMENTS
Case # and Name: 2485 Oxadiazon
DCI Number: PDCI-109001 -NNNN
Key: MP/EP = Manufacturing-Use Product, Pure Active Ingredient; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAI = Technical Grade of the Active Ingredient or Pure Active Ingredient;
TGAI.EP.dilute EP? = Technical Grade of the Active Ingredient, End Use Product, and possibly diluted End Use Product; TGAI/MP/EP = Manufacturing-Use Product, Pure Active Ingredient and
Technical Grade Active Ingredient; TGAI/PAI = Technical Grade Active Ingredient, Pure Active Ingredient
Use Categories Key:
A - Terrestrial food crop
B - Terrestrial feed crop
C - Terrestrial nonfood crop
D - Aquatic food crop G -
E - Aquatic nonfood outdoor use H -
F - Aquatic nonfood industrial use I -
Aquatic non-food residential J - Forestry use
Greenhouse food crop K - Residential
Greenhouse nonfood crop L - Indoor food use
M - Indoor nonfood use
N - Indoor medical use
O - Residential Indoor use
Footnotes: [The following notes are referenced in column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANTS RESPONSE form.]
1 Data must be provided in accordance with the "Product Composition" Section.(158.155)
2
3
4
5
6
7
8
9
10
11
12
13
14
it is formulated into salts or esters,
Data must be provided in accordance with the "Description of Materials used to Produce the Product" Section.(158.160)
Data must be provided in accordance with the "Description of Production Process" Section.(158.162)
Data must be provided in accordance with the "Description of Formulation Process" Section.(158.165)
Data must be provided in accordance with the "Description of Formation of Impurities" Section(158.167)
Data must be provided in accordance with the "Preliminary Analysis" Section.(158.170)
Required for TGAIs and products produced by an integrated system.
If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
Data must be provided in accordance with the "Certified Limits" Section(158.175)
If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
Data must be provided in accordance with the "Enforcement Analytical Method" Section.(158.180)
If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
-------
DRAFT COPY Page2of4
United States Environmental Protection
Agency Washington, B.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 2485 Oxadiazon
DCI Number: PDCI-109001 -NNNN
Key: MP/EP = Manufacturing-Use Product, Pure Active Ingredient; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAI = Technical Grade of the Active Ingredient or Pure Active Ingredient;
TGAI.EP.dilute EP? = Technical Grade of the Active Ingredient, End Use Product, and possibly diluted End Use Product; TGAI/MP/EP = Manufacturing-Use Product, Pure Active Ingredient and
Technical Grade Active Ingredient; TGAI/PAI = Technical Grade Active Ingredient, Pure Active Ingredient
Use Categories Key:
A - Terrestrial food crop D - Aquatic food crop G - Aquatic non-food residential J - Forestry use M - Indoor nonfood use
B - Terrestrial feed crop E - Aquatic nonfood outdoor use H - Greenhouse food crop K - Residential N - Indoor medical use
C- Terrestrial nonfood crop F- Aquatic nonfood industrial use I- Greenhouse nonfood crop L- Indoor food use O- Residential Indoor use
Footnotes: [The following notes are referenced in column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE form.]
15 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
16 Data on the stability to metals and metal ions is required only if the active ingredient is expected to come in contact with either material during storage.
17 Required if the product contains an oxidizing or reducing agent
1 s Required when the product contains combustible liquids.
19 Required when the product is potentially explosive.
20
Product Specific Data Call-Ins issued under the Reregistration Eligibility Decision (RED)/lnterim Reregistration Eligibility Decision (IRED) Documents."
21 Required if the product is an emulsifiable liquid and is to be diluted with petroleum solvents.
22
Product Specific Data Call-Ins issued under the Reregistration Eligibility Decision (RED)/lnterim Reregistration Eligibility Decision (IRED) Documents."
23 Required if the end-use product is a liquid and is to be used around electrical equipment.
24 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
25 Required if the product is dispersible with water.
26 Required if the product is a liquid.
27 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
28 Required when the TGAI is solid at room temperature.
-------
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 2485 Oxadiazon
DCI Number: PDCI-109001 -NNNN
Key: MP/EP = Manufacturing-Use Product, Pure Active Ingredient; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAI = Technical Grade of the Active Ingredient or Pure Active Ingredient;
TGAI.EP.dilute EP? = Technical Grade of the Active Ingredient, End Use Product, and possibly diluted End Use Product; TGAI/MP/EP = Manufacturing-Use Product, Pure Active Ingredient and
Technical Grade Active Ingredient; TGAI/PAI = Technical Grade Active Ingredient, Pure Active Ingredient
Use Categories Key:
A - Terrestrial food crop D - Aquatic food crop G - Aquatic non-food residential J - Forestry use M - Indoor nonfood use
B - Terrestrial feed crop E - Aquatic nonfood outdoor use H - Greenhouse food crop K - Residential N - Indoor medical use
C - Terrestrial nonfood crop F - Aquatic nonfood industrial use I - Greenhouse nonfood crop L - Indoor food use O - Residential Indoor use
Footnotes: [The following notes are referenced in column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANTS RESPONSE form.]
29 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
30 Required if the TGAI is liquid at room temperature.
31 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
32 True density or specific density are required for all test substances. Data on bulk density is required for MPs that are solid at room temperature.
33 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
34 Required when the test substance contains an acid or base functionality (organic or inorganic) or an alcoholic functionality (organic).
35 Required if the TGAI or PAI is organic and non-polar.
36 Required if the TGAI or PAI is organic and non-polar.
37 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
38 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
39 If the TGAI cannot be isolated, data are required on the practical equivalent of the TGAI (i.e., if the active ingredient is either an acid, base or ionic form, and it is formulated into salts or esters,
the concentration of the active ingredient in these products must be expressed in acid equivalent or active equivalent).
40 Not required for salts.
41 Diluted EP testing is required to support the end product registration if results using the EP meet the criteria for restricted use classification under Section 152.170(b) or special review
consideration under Section 154.7(a)(1).
42 Not required if test material is a gas or a highly volatile liquid.
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DRAFT COPY Page4of4
United States Environmental Protection
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 2485 Oxadiazon
DCI Number: PDCI-109001 -NNNN
Key: MP/EP = Manufacturing-Use Product, Pure Active Ingredient; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAI = Technical Grade of the Active Ingredient or Pure Active Ingredient;
TGAI.EP.dilute EP? = Technical Grade of the Active Ingredient, End Use Product, and possibly diluted End Use Product; TGAI/MP/EP = Manufacturing-Use Product, Pure Active Ingredient and
Technical Grade Active Ingredient; TGAI/PAI = Technical Grade Active Ingredient, Pure Active Ingredient
Use Categories Key:
A - Terrestrial food crop D - Aquatic food crop G - Aquatic non-food residential J - Forestry use M - Indoor nonfood use
B - Terrestrial feed crop E - Aquatic nonfood outdoor use H - Greenhouse food crop K - Residential N - Indoor medical use
C - Terrestrial nonfood crop F - Aquatic nonfood industrial use I - Greenhouse nonfood crop L - Indoor food use O - Residential Indoor use
Footnotes: [The following notes are referenced in column two (S. Study File) of the REQUIREMENTS STATUS AND REGISTRANTS RESPONSE form.]
43 Diluted EP testing is required to support the end product registration if results using the EP meet the criteria for restricted use classification under Section 152.170(b) or special review
consideration under Section 154.7(a)(1).
44 Not required if test material is a gas or a highly volatile liquid.
45 Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
46 Required if the product consists of, or under conditions of use will result in, a respirable material (e.g., gas, vapor, aerosol, or participate).
47 Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
48 Not required if test material is a gas or a highly volatile liquid.
49 Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
50 Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
51 Required if repeated dermal exposure is likely to occur under conditions of use.
-------
Appendix G. EPA's Batching of Oxadiazon Products for
Meeting Acute Toxicity Data Requirements for Reregistration
99
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EPA'S BATCHING OF OXADIAZON PRODUCTS FOR MEETING ACUTE
TOXICITY DATA REQUIREMENTS FOR REREGISTRATION
In an effort to reduce the time, resources and number of animals needed to fulfill the acute
toxicity data requirements for reregistration of products containing Oxadiazon the primary active
ingredient, the Agency has batched products which can be considered similar for purposes of acute
toxicity. Factors considered in the sorting process include each product's active and inert ingredients
(identity, percent composition and biological activity), type of formulation (e.g., emulsifiable
concentrate, aerosol, wettable powder, granular, etc.), and labeling (e.g., signal word, use
classification, precautionary labeling, etc.). Note the Agency is not describing batched products as
"substantially similar" since some products with in a batch may not be considered chemically similar or
have identical use patterns.
Using available information, batching has been accomplished by the process described in the
preceding paragraph. Notwithstanding the batching process, the Agency reserves the right to require,
at any time, acute toxicity data for an individual product should need arise.
Registrants of products within a batch may choose to cooperatively generate, submit or cite a
single battery of six acute toxicological studies to represent all the products within that batch. It is the
registrants' option to participate in the process with all other registrants, only some of the other
registrants, or only their own products within in a batch, or to generate all the required acute
toxicological studies for each of their own products. If the registrant chooses to generate the data for
a batch, he/she must use one of the products within the batch as the test material. If the registrant
chooses to rely upon previously submitted acute toxicity data, he/she may do so provided that the
data base is complete and valid by to-days standards (see acceptance criteria attached), the
formulation tested is considered by EPA to be similar for acute toxicity, and the formulation has not
been significantly altered since submission and acceptance of the acute toxicity data. Regardless of
whether new data is generated or existing data is referenced, the registrants must clearly identify the
test material by EPA Registration Number. If more than one confidential statement of formula (CSF)
exists for a product, the registrant must indicate the formulation actually tested by identifying the
corresponding CSF.
In deciding how to meet the product specific data requirements, registrants must follow the
directions given in the Data Call-In Notice and its attachments appended to the RED. The DCI
Notice contains two response forms which are to be completed and submitted to the Agency within
90 days of receipt. The first form, "Data Call-in Response," asks whether the registrant will meet the
100
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data requirements for each product. The second form, "Requirements Status and Registrant's
Response," lists the product specific data required for each product, including the standard six acute
toxicity tests. A registrant who wishes to participate in a batch must decide whether he/she will
provide the data or depend on someone else to do so. If the registrant supplies the data to support a
batch of products, he/she must select the one of the following options: Developing data (Option 1),
Submitting an existing Study (Option 4), Upgrading an existing Study (Option 5), or Citing an Existing
Study (Option). If a registrant depends on another's data, he/she must choose among: Cost sharing
(Option 2), Offers to Cost Share (Option
3) or Citing an Existing Study (Option 6). If a registrant does not want to participate in a batch, the
choices are Options 1,4, 5 or 6. However, a registrant should know that choosing not to participate
in a batch does not preclude other registrants in the batch from citing his/her studies and offering to
cost share (Option 3) those studies.
Forty six products were found which contain Oxadiazon as the active ingredient. These
products have been placed into five batches and a No batch in accordance with the active and
inert ingredients and type of formulation.
Batch 1
EPA Reg. No.
264-502
432-887
432-893
Percent active ingredient
50.0
50.0
50.0
Formulation Type
Solid
Solid
Solid
Batch 2
EPA Reg. No.
8660-36
35512-44
Percent active ingredient
1.0
1.0
Formulation Type
Solid
Solid
101
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Batch 3
EPA Reg. No.
961-379
8378-61
8660-17
10404-63
34704-833
52287-1
52287-14
67508-1
Percent active ingredient
1.0
1.0
1.0
1.0
1.0
0.95
1.20
1.0
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Batch 4
EPA Reg. No.
52287-10
52267-11
52287-12
Percent active ingredient
Oxadiazon - 0.500 Benefin
- 0.375 Trifluralin -
0.375
Oxadiazon - 0.75 Benefin
- 0.25 Trifluralin - 0.25
Oxadiazon- 1.00
Benefin - 0.25
Trifluralin- 0.25
Formulation Type
Solid
Solid
Solid
Batch 5
EPA Reg. No.
961-371
961-382
Percent active ingredient
Oxadiazon - 0.50
Oxadiazon - 0.69
Formulation Type
Solid
Solid
102
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10404-93
34704-834
52287-3
52287-9
Oxadiazon - 0.63
Oxadiazon - 0.67
Oxadiazon - 0.67
Oxadiazon - 0.75
Solid
Solid
Solid
Solid
No Batch
EPA Reg. No.
264-450
432-886
432-898
538-146
538-147
538-164
538-257
961-340
961-380
8378-62
9198-75
9198-154
9198-155
Percent active ingredient
94.0
2.0
2.0
4.0
8.0
Oxadiazon- 1.31 Bensulide
- 5.25
Oxadiazon - 2.0
Pendimethalin - 0.62
1.73
1.50
1.50
1.38
Oxadiazon- 1.0
Dithiopyr -0.125
Oxadiazon- 1.0
Dithiopyr -0.1875
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
103
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9198-176
9198-185
9198-203
10404-97
34704-771
35512-43
48234-1
48234-2
48234-10
48234-14
48234-15
Oxadiazon - 1.31 Bensulide
- 5.25
2.75
1.5
Oxadiazon- 1.0
Dithiopyr- 0.15
Oxadiazon - 2.0
Napropamide - 4.0
2.0
Oxadiazon- 1.0
Balfin-0.5
2.0
Oxadiazon- 1.0
Oxyfluorfen - 2.0
1.0
Oxadiazon - 1 .0 Prodiamine
-0.2
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
104
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Appendix H. List of Registrants Sent this Data Call-in
105
-------
United States Environmental Protection
Agency Washington, D.C. 20460
LIST OF ALL REGISTRANTS SENT THIS DATA CALL-IN NOTICE
Co. Nr.
432
538
961
1381
5905
7001
7138
8378
8660
9198
10404
32802
34704
35512
48234
52287
67508
Case # and Name: 2485,Oxadiazon
Company Name Agent For
BAYER ENVIRONMENTAL
SCIENCE
SCOTTS COMPANY, THE
LEBANON SEABOARD
CORPORATION
AGRILIANCE, LLC
HELENA CHEMICAL CO
J.R. SIMPLOT CO
SOUTHERN STATES
COOPERATIVE, INC.
KNOX FERTILIZER CO INC
SYLORR PLANT CORP.
THE ANDERSONS LAWN
FERTILIZER DIVISION, INC.
LESCO INC
HOWARD JOHNSON'S
ENTERPRISES INC
LOVELAND PRODUCTS, INC.
HOWARD FERTILIZER & REGISTRATIONS BY DESIGN INC.
CHEMICAL CO., INC
REGAL CHEMICAL CO.
HARRELL'S INC TOTALTURF CONSULTING LLC
MEADOWBROOK GOLF GROUP, H.R. MCLANE INC
Address
95 CHESTNUT RIDGE ROAD
14111 SCOTTSLAWNRD
1600 EAST CUMBERLAND STREET
PO Box 64089
225 SCHILLING BOULEVARD, SUITE 300
PO Box 198
6606 WEST BROAD STREET
PO Box 248 W. CULVER ROAD
PO Box 142642
PO Box 119
1 5885 SPRAGUE ROAD
700 W. VIRGINIA ST STE 222
PO Box 1286
1 18 1/2 E MAIN STREET, SUITE 1
600 BRANCH DR
PO Box 7928
7210 RED RD, SUITE 206
City & State
MONTVALE
MARYSVILLE
LEBANON
ST. PAUL
COLLIERVILLE
LATHROP
RICHMOND
KNOX
ST. LOUIS
MAUMEE
STRONGSVILLE
MILWAUKEE
GREELEY
SALEM
ALPHARETTA
HILTON HEAD
ISLAND
MIAMI
Zip
NJ 07645
OH 43041
PA 17042
MN 551640089
TN 38017
CA 95330
VA 23230
IN 46534
MO 631 140642
OH 43537
OH 44136
Wl 532041548
CO 80632
VA 24153
GA 30004
SC 29938
FL 33143
INC.
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Appendix I. List of Available Related Documents and
Electronically Available Forms
107
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Pesticide Registration Forms are available at the following EPA internet
site:
http://www.epa. gov/opprdOO I/forms/
Pesticide Registration Forms (These forms are in PDF format and require the Acrobat reader)
Instructions
1. Print out and complete the forms. (Note: Form numbers that are bolded can be filled
out on your computer then printed.)
2. The completed form(s) should be submitted in hardcopy in accord with the existing
policy.
3. Mail the forms, along with any additional documents necessary to comply with EPA
regulations covering your request, to the address below for the Document Processing
Desk.
DO NOT fax or e-mail any form containing 'Confidential Business Information' or 'Sensitive
Information.'
If you have any problems accessing these forms, please contact Nicole Williams at (703) 308-5551 or
by e-mail at williams.nicole@epa.gov.
The following Agency Pesticide Registration Forms are currently available via the internet:
at the following locations:
8570-1
8570-4
Application for Pesticide
Registration/Amendment
Confidential Statement of Formula
http://www.epa.gov/opprd001/forms/8570-l.pdf
http://www.epa.gov/opprd001/forms/8570-4.Ddf
108
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8570-5
8570-17
8570-25
8570-27
8570-28
8570-30
8570-32
8570-34
8570-35
8570-36
8570-37
Notice of Supplemental Registration
of Distribution of a Registered
Pesticide Product.
Application for an Experimental Use
Permit
Application for/Notification of State
Registration of a Pesticide To Meet a
Special Local Need
Formulator's Exemption Statement
Certification of Compliance with Data
Gap Procedures
Pesticide Registration Maintenance
Fee Filing.
Certification of Attempt to Enter into
an Agreement with other Registrants
for Development of Data
Certification with Respect to Citations
of Data (PR Notice 98-5)
Data Matrix (PR Notice 98-5)
Summary of the Physical/Chemical
Properties (PR Notice 98-1)
Self-Certification Statement for the
Physical/Chemical Properties (PR
Notice 98-1)
http://www.epa.gov/opprd001/forms/8570-5.pdf
http://www.epa.gov/opprd001/forms/8570-17.pdf
http://www.epa.gov/opprd001/forms/8570-25.pdf
http://www.epa.gov/opprd001/forms/8570-27.pdf
_ _
http://www.epa.gov/opprd001/forms/8570-28.pdf
http://www.epa.gov/opprd001/forms/8570-30.pdf
http://www.epa.gov/opprd001/forms/8570-32.pdf
http://www.epa.gov/opppmsdl/PR Notices/pr98-
5.pdf
http://www.epa.gov/opppmsdl/PR Notices/pr98-
5.pdf
http://www.epa.gov/opppmsdl/PR Notices/pr98-
l.pdf
http://www.epa.gov/opppmsdl/PR Notices/pr98-
l.pdf
Pesticide Registration Kit
www.eDa.gov/pesticides/registrationkit/
Dear Registrant:
For your convenience, we have assembled an online registration kit which contains the following
pertinent forms and information needed to register a pesticide product with the U.S. Environmental
Protection Agency's Office of Pesticide Programs (OPP):
109
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1. The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food,
Drug and Cosmetic Act (FFDCA) as Amended by the Food Quality Protection Act
(FQPA)ofl996.
2. Pesticide Registration (PR) Notices
a. 83-3 Label Improvement Program-Storage and Disposal Statements
b. 84-1 Clarification of Label Improvement Program
c. 86-5 Standard Format for Data Submitted under FIFRA
d. 87-1 Label Improvement Program for Pesticides Applied through Irrigation
Systems (Chemigation)
e. 87-6 Inert Ingredients in Pesticide Products Policy Statement
f 90-1 Inert Ingredients in Pesticide Products; Revised Policy Statement
g. 95-2 Notifications, Non-notifications, and Minor Formulation Amendments
h. 98-1 Self Certification of Product Chemistry Data with Attachments (This
document is in PDF format and requires the Acrobat reader.)
Other PR Notices can be found at http://www.epa.gov/opppmsd l/PR_Notices
3. Pesticide Product Registration Application Forms (These forms are in PDF format and will
require the Acrobat reader).
a. EPA Form No. 8570-1, Application for Pesticide Registration/Amendment
b. EPA Form No. 8570-4, Confidential Statement of Formula
c. EPA Form No. 8570-27, Formulator's Exemption Statement
d. EPA Form No. 8570-34, Certification with Respect to Citations of Data
e. EPA Form No. 8570-35, Data Matrix
4. General Pesticide Information (Some of these forms are in PDF format and will require the
Acrobat reader).
a. Registration Division Personnel Contact List
b. Biopesticides and Pollution Prevention Division (BPPD) Contacts
c. Antimicrobials Division Organizational Structure/Contact List
d. 53 F.R. 15952, Pesticide Registration Procedures; Pesticide Data Requirements
(PDF format)
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e. 40 CFR Part 156, Labeling Requirements for Pesticides and Devices (PDF
format)
f. 40 CFR Part 158, Data Requirements for Registration (PDF format)
g.. 50 F.R. 48833, Disclosure of Reviews of Pesticide Data (November 27,1985)
Before submitting your application for registration, you may wish to consult some additional sources
ofinformatioa These include:
1. The Office of Pesticide Programs' website.
2. The booklet "General Information on Applying for Registration of Pesticides in the United
States", PB92-221811, available through the National Technical Information Service
(NTIS) at the following address:
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield, VA 22161
The telephone number for NTIS is (703) 605-6000.
3. The National Pesticide Information Retrieval System (NPIRS) of Purdue University's
Center for Environmental and Regulatory Information Systems. This service does charge a
fee for subscriptions and custom searches. You can contact NPIRS by telephone at (765)
494-6614 or through their website.
4. The National Pesticide Information Center (NPIC) can provide information on active
ingredients, uses, toxicology, and chemistry of pesticides. You can contact NPIC by
telephone at (800) 858-7378 or through their website: http://npic.orst.edu..
The Agency will return a notice of receipt of an application for registration or amended
registration, experimental use permit, or amendment to a petition if the applicant or
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petitioner encloses with his submission a stamped, self-addressed postcard. The postcard
must contain the following entries to be completed by OPP:
Date of receipt;
EPA identifying number, and
Product Manager assignment.
Other identifying information may be included by the applicant to link the acknowledgment
of receipt to the specific application submitted. EPA will stamp the date of receipt and
provide the EPA identifying file symbol or petition number for the new submission. The
identifying number should be used whenever you contact the Agency concerning an
application for registration, experimental use permit, or tolerance petition.
To assist us in ensuring that all data you have submitted for the chemical are properly
coded and assigned to your company, please include a list of all synonyms, common and
trade names, company experimental codes, and other names which identify the chemical
(including "blind" codes used when a sample was submitted for testing by commercial or
academic facilities). Please provide a chemical abstract system (CAS) number if one has
been assigned.
Documents Associated with this RED
The following documents are part of the Administrative Record for this RED document and may be
included in the EPA's Office of Pesticide Programs Public Docket. Copies of these documents are not
available electronically, but may be obtained by contacting the person listed on the respective Chemical
Status Sheet.
1. Health Effects Division and Environmental Fate and Effects Division Science Chapters,
which include the complete risk assessments and supporting documents.
2. Detailed Label Usage Information System (LUIS) Report.
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