United States Prevention, Pesticides E
Environmental Protection And Toxic Substances DATE August 20(f2
Agency (7508C)
Interim Reregistration
EPA Eligibility Decision (IRED)
738F02008
Methamidophos
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United States
Environmental Protection
Agency
Prevention, Pesticides
and Toxic Substances
(7508C)
EPA 738-F-02-008
August 2002
3rERr\ Methamidophos Facts
EPA has assessed the risks of methamidophos and reached an Interim Reregistration
Eligibility Decision (IRED) for this organophosphate (OP) pesticide. Although current uses may pose
unreasonable adverse effects to human health and the environment, these effects can be mitigated by
the measures identified in the Methamidophos IRED. Provided that these risk mitigation measures
are adopted, methamidophos' individual, aggregate risks will be within acceptable levels, and the
pesticide will be eligible for reregistration once EPA has considered the cumulative risks of the OPs.
Used to control insects on potatoes, cotton,
and tomatoes, methamidophos residues in food do
not pose risk concerns. Screening level modeling
estimates indicate that drinking water from surface
water sources may pose risk concerns. However,
actual drinking water exposures and risks are likely
to be lower than predicted by these estimates. EPA
will require confirmatory surface water monitoring
data to confirm its current interim conclusion that
drinking water risks are not of concern and do not
require mitigation. Methamidophos has no
residential uses, so children and others should not be
significantly exposed to this pesticide around the
home. EPA assumes that methamidophos will fit
into its own "risk cup;" it will not pose significant
dietary or aggregate risk concerns. Methamidophos
poses risks of concern to workers who mix, load, and
apply the pesticide to agricultural sites, and to
workers who re-enter treated agricultural areas.
Birds, mammals, and freshwater invertebrates also
encounter risks of concern. With mitigation
measures, these worker and ecological risks will be
below levels of concern for reregistration.
EPA's next step under the Food Quality
Protection Act (FQPA) is to consider the cumulative
effects of the OP pesticides, which share a common
mechanism of toxicity. The interim decision on methamidophos will not be final until OP cumulative
risks have been considered. The OP cumulative assessment may result in further risk mitigation
measures for methamidophos.
The OP Pilot Public Participation Procss
The organophosphates (OPs) are a group
of related pesticides that affect the functioning of
the nervous system. They are among EPA's
highest priority for review in implementing
provisions of the Food Quality Protection Act
(FQPA) of 1996.
EPA encourages the public to participate
in the review of the OP pesticides. Through a six-
phased pilot public participation process, the
Agency has released for review and comment its
preliminary and revised scientific risk assessments
for individual OPs. (Please contact the OP
Docket, telephone 703-305-5805, or see EPA's
web site, www.epa.gov/pesticides/op.)
EPA is exchanging information with
stakeholders and the public about the OPs, their
uses, and risks through Technical Briefings,
stakeholder meetings, and other fora. USDA is
coordinating input from growers and other OP
pesticide users.
Based on current information from
interested stakeholders and the public, EPA is
making interim risk management decisions for
individual OP pesticides. The Agency will make
final decisions after considering the cumulative
risks of the OPs. (Please see
www.epa.gov/pesticides/cumulative.htm.)
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EPA is reviewing the OP pesticides to determine whether they meet current health and safety
standards. Older OPs require decisions about their eligibility for reregistration under FIFRA. OPs
with food, drinking water, residential, and any other non-occupational exposures must be reassessed to
make sure they meet the new FFDCA safety standard, brought about by FQPA.
The methamidophos interim decision was made through the OP pilot public participation
process, which has increased transparency and maximized stakeholder involvement in EPA's
development of risk assessments and risk management decisions. EPA worked extensively with
affected parties to reach the decisions presented in this interim decision document.
Uses
An insecticide/acaricide, methamidophos is used to control a broad spectrum of insects in
cotton, potato, and tomato crops (the latter for special local needs only). Methamidophos also
is registered for use in California on alfalfa grown for seed, a nonfood use. It is used on
peppers, strawberries, and squash grown in other countries and imported into the U.S. (import
tolerances are established or pending for these uses). Methamidophos has no residential uses.
Approximately 640,000 pounds of the active ingredient methamidophos are used annually.
Use is highest on potatoes (87% of the total pounds applied), followed by tomatoes (8%) and
cotton (5%).
Methamidophos is classified as a Restricted Use Pesticide.
Health Effects
Methamidophos can cause cholinesterase inhibition in humans; that is, it can overstimulate
the nervous system causing nausea, dizziness, confusion, and at very high exposures (e.g.,
accidents or major spills), respiratory paralysis and death.
Methamidophos also is one of the most acutely toxic organophosphate pesticides.
Risks
Methamidophos is a metabolite of the OP pesticide acephate. EPA's food risk assessments,
and to some extent the drinking water assessment, encompass the risk from applications of
methamidophos only and from "all sources," which includes applications of acephate.
EPA's human health risk assessment for methamidophos indicates some risk concerns.
Dietary risk from food sources alone is not of concern. Screening level modeling estimates
indicate that acute and chronic dietary risks from surface water sources of drinking water are
above the Agency's level of concern for all segments of the population. Due to uncertainties
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and limitations of model predictions, however, actual drinking water exposures and risks from
methamidophos are likely to be lower than estimated.
Residential risks are not of concern because methamidophos is not registered for use in
residential settings. Methamidophos is a metabolite of acephate, which had numerous
residential, recreational, and institutional uses that were evaluated and mitigated through the
Acephate IRED. Post-mitigation risks for these uses, associated with the degradation of
acephate to methamidophos, were evaluated in the Acephate IRED and found to be negligible.
Occupational exposure to methamidophos is of concern to the Agency. EPA has risk
concerns for workers who mix, load, and/or apply methamidophos to agricultural sites, and for
workers who re-enter treated agricultural areas.
EPA also has identified acute and chronic risks to birds and mammals, and some risk to
freshwater invertebrates, that are of concern.
Risk Mitigation
The following mitigation measures are required for methamidophos to address drinking water,
worker, and ecological risks of concern.
To mitigate dietary risks:
Because actual drinking water exposures are likely lower than predicted by modeling
estimates, EPA has made an interim determination that no additional mitigation is
necessary at this time. The Agency will require confirmatory surface water
monitoring data for methamidophos to refine the drinking water modeling values
based on actual concentrations in drinking water sources, to confirm this interim
conclusion.
To mitigate residential risks:
Methamidophos has no residential uses, so risk mitigation is not necessary.
To mitigate occupational risks to agricultural handlers:
The cotton use must be cancelled. This use will be phased out over 5 years to allow
ample time for transition to alternatives.
Applicators must be in an enclosed cab tractor or enclosed cockpit.
Flaggers must be in enclosed vehicles, mechanical Saggers must be used, or global
positioning system (GPS) equipment that negates the need for flaggers for aerial
application must be used.
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To mitigate occupational risks to post-application agricultural workers:
For tomatoes, increase Restricted Entry Intervals (REIs) for all activities to 4 days in
all states except California, where the REI will remain at 3 days per the current labels.
For potatoes, increase REIs for all activities to 4 days.
To mitigate ecological risks to terrestrial birds and mammals, and to freshwater and estuarine
invertebrates:
Phase out and cancel the cotton use, and implement the other occupational risk
mitigation measures listed above.
For cotton during the phase-out period, reduce the maximum number of applications
to 2 per season.
For tomatoes, reduce the maximum number of applications to 4 per season.
Next Steps
Numerous opportunities for public comment were offered as this decision was being
developed. The Methamidophos IRED therefore is issued in final, without a formal public
comment period. (Please see www.epa.gov/pesticides/reregistration/status.htm or
www.epa. gov/pesticides/op). The docket remains open, however, and any comments
submitted in the future will be placed in this public docket.
Once EPA has considered the cumulative risks of the OP pesticides, the Agency will issue its
final tolerance reassessment decision for methamidophos and may need to pursue further risk
management measures. The Agency will revoke seven methamidophos tolerances now
because no corresponding uses are registered at present; will modify three tolerances; and
will correct several other commodity definitions. For all OPs, tolerances will not be raised or
established until cumulative risks have been considered.
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S UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
PREVENTION. PESTICIDES
AND TOXIC SUBSTANCES
MEMORANDUM
SUBJECT: Errata Sheet for Changes to the Methamidophos Interim Reregistration Eligibility
Decision.
FROM: Debta
Director
Special Review and Reregistration Divsion
TO: Public Docket for Endosulfan
1) In Section V of the IRED, OPPTS guideline numbers were updated (i.e., Photolysis on Soil,
OPPTS 161-3, was changed to OPPTS 835.2410).
2) The previous contact for methamidophos, Mark Hartman, has been replaced by Craig Doty,
the current Chemical Review Manager.
3) General grammatical errors were corrected.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
PREVENTION, PESTICIDES
AND TOXIC SUBSTANCES
April 7,2002
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
preliminary and revised risk assessments for the organophosphate pesticide methamidophos. The
public comment period on the revised risk assessment phase of the reregistration process is closed.
Based on comments received during the public .comment period and additional data received from the
registrant, the Agency revised the human health and environmental effects risk assessments and made
them available to the public on February 3,2000. Additionally, the Agency held a Technical Briefing
on February 3,2000, where the results of the revised human hearth and environmental effects risk
assessments were presented to the general public. This Technical Briefing concluded Phase 4 of the
OP Public Participation Pilot Process developed by the Tolerance Reassessment Advisory Committee,
and initiated Phase 5 of that process. During Phase 5, all interested parties were invited to participate
and provide comments and suggestions on ways the Agency might mitigate the estimated risks
presented in the revised risk assessments. This public participation and comment period commenced
on February 22,2000, and closed on April 22,2000.
Based on its review, EPA has identified risk mitigation measures that the Agency believes
mitigation measures are necessary to address the human health and environmental risks associated with
the current use of methamidophos. The EPA is now publishing its interim decision on the reregistration
eligibility of and risk management decision for the current uses of methamidophos and its associated
human health and environmental risks. The reregistration eligibility and tolerance reassessment decisions
for methamidophos will be finalized once the cumulative risks for all of the organophosphate pesticides
are considered. The enclosed "Interim Reregistration Eligibility Decision for methamidophos," which
was approved on April 5,2002, contains the Agency's decision on the individual chemical
methamidophos.
A Notice of Availability for this Interim Reregistration Eligibility Decision for methamidophos is
being published in the Federal Register. To obtain a copy of the interim 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 interim
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RED and all supporting documents are available on the Internet See http:www.epa.gov/pesticides/op.
The interim RED is based on the updated technical information found in the methamidophos
public docket The docket not only includes background information and comments on the Agency's
preliminary risk assessments, it also now includes the Agency's revised risk assessments for
methamidophos (Revised Dietary Exposure and Risk Analyses for the HED Revised Human
Health Risk Assessment, July 19, 2000, Methamidophos: Addendum to the Revised Occupational
and Residential Exposure Assessment and Recommendations for the Reregistration Eligibility
Decision Document, September 15, 2000, Recalculated Tier II Drinking Water EECsfor
Methamidophos Incorporating the Index Reservoir and Percent Cropped Area, October 17,
2000.), and a document summarizing the Agency's Response to Comments. The Response to
Comments document addresses corrections to the preliminary risk assessments submitted by chemical
registrants, as well as responds to comments submitted by the general public and stakeholders during
the comment period on the risk assessment The docket will also include comments on the revised risk
assessment, and any risk mitigation proposals submitted during Phase 5. For methamidophos, no
proposal was submitted by Bayer, the technical registrant.
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 these 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 on the organophosphate pesticides and to engage the public in the
reregistration and tolerance reassessment processes for these chemicals. This open process follows the
guidance developed by the Tolerance Reassessment Advisory Committee (TRAC), a large multi-
stakeholder advisory body that advised the Agency on implementing me new provisions of the FQPA.
The reregistration and tolerance reassessment reviews for the organophosphate pesticides are following
this new process.
Please note mat the methamidophos risk assessment and the attached interim RED concern only
this particular organophosphate. This interim RED presents the Agency's conclusions on the dietary
risks posed by exposure to methamidophos alone. The Agency has also concluded its assessment of
the ecological and worker risks associated with the use of methamidophos. Because the FQPA directs
the Agency to consider available information on the basis of cumulative risk from substances sharing a
common mechanism of toxichy, such as the toxiciry expressed by the organophosphates through a
common biochemical interaction with cholinesterase enzyme, the Agency will evaluate the cumulative
risk posed by the entire organophosphate class of chemicals after considering the risks for the individual
organophosphates. The Agency is working towards completion of a methodology to assess cumulative
risk and the individual risk assessments for each organophosphate are likely to be necessary elements
of any cumulative assessment The Agency has decided to move forward with individual assessments
and to identify mitigation measures necessary to address those human health and environmental risks
associated with the current uses of methamidophos. The Agency will issue the final tolerance
reassessment decision for methamidophos and finalize decisions on reregistration eligibility once the
cumulative risks for all of the organophophates are considered.
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This document contains a generic and/or a product-specific Data Call-In(s) (DCI) that outline(s)
further data requirements for this chemical. Note that a complete DCI, with all pertinent instructions, is
being sent to registrants under separate cover. Additionally, for product-specific DCIs, the first set of
required responses to is due 90 days from the receipt of the DCI letter. The second set of required
responses is due eight months from the date of the DCI.
In this interim RED, the Agency has determined that metharnidophos will be eligible for
reregistration provided that all the conditions identified in this document are satisfied, including
implementation of the risk mitigation measures outlined in Section IV of the document. The Agency
believes that current uses of methamidophos may pose unreasonable adverse effects to human health
and the environment, and that such effects can be mitigated with the risk mitigation measures identified
in this interim RED. Accordingly, the Agency recommends that registrants implement these risk
mitigation measures immediately. Sections IV and V of this interim RED describe labeling amendments
for end-use products and data requirements necessary to implement these mitigation measures.
Instructions for registrants on submitting the revised labeling can be found in the set of instructions for
product-specific data that accompanies this interim RED.
Should a registrant fail to implement any of the risk mitigation measures outlined in this document,
the Agency will continue to have concerns about the risks posed by methamidophos. Where the
Agency has identified any unreasonable adverse effect to human health and the environment, the
Agency may at any time initiate appropriate regulatory action to address this concern. At that time, any
affected person(s) may challenge the Agency's action.
If you have questions on this document or the label changes necessary for reregistration, please
contact the Special Review and Reregistration Division representative, Mark A. Hartman, at (703)
308-0734. For questions about product reregistration and/or the Product DCI that accompanies this
document, please contact Bonnie Adler at (703) 308-8523.
Sincerely,
Lois A. Rossi, Director
Special Review and
Reregistration Division
Attachment
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Interim Reregistration Eligibility Decision
for
Methamidophos
Case No. 0043
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TABLE OF CONTENTS
Executive Summary 1
I. Introduction 6
n. Chemical Overview 8
A. Regulatory History 8
B. Chemical Identification 8
C. Use Profile 9
D. Estimated Usage of Pesticide 10
in. Summary of Methamidophos Risk Assessment . 11
A. Human Health Risk Assessment 11
1. Dietary Risk from Food 12
a. Toxicity 12
b. FQPA Safety Factor 13
c. Population Adjusted Dose (PAD) 13
d. Exposure Assumptions 14
e. Food Risk Characterization 14
2. Dietary Risk from Drinking Water 15
a. Surface Water 15
b. Ground Water 17
c. Drinking Water Levels of Comparison (DWLOCs) 18
3. Aggregate Risk 19
4. Occupational and Residential Risk 20
a. Toxicity 20
b. Exposure 21
c. Occupational Handler Risk Summary 22
1) Agricultural Handler Risk 23
2) Post-Application Occupational Risk 24
B. Environmental Risk Assessment 25
1. Environmental Fate and Transport 25
2. Ecological Risk Assessment 26
a. Ecological Hazard Profile 26
b. Risk to Birds and Mammals 28
c. Risk to Aquatic Animals 29
d. Incidents 29
e. Endangered Species 29
C. Benefits 30
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IV. Interim Risk Management and Reregistration Decision 34
A. Determination of Interim Reregistration Eligibility 34
B. Summary of Phase 5 Comments and Responses 35
C Regulatory Position 39
1. FQPA Assessment 39
a. "Risk Cup" Determination 39
b. Tolerance Summary 40
2. Endocrine Disrupter Effects 46
3. Labels 46
a. Agricultural Use Exposure Reduction Measures 46
b. Homeowner Use Exposure Reduction Measures 47
D. Regulatory Rationale 47
1. Human Health Risk Mitigation 47
a. Dietary Mitigation 47
1) Acute Dietary (Food) ....47
2) Chronic Dietary (Food) 48
3) Drinking Water . 48
b. Homeowner Risk Mitigation 50
c. Aggregate Risk Mitigation 50
d. Occupational Risk Mitigation . .51
1) Agricultural Uses 51
2. Environmental Risk Mitigation 56
E. Other Labeling 57
1. Endangered Species Statement 57
2. Spray Drift Management 57
F. Methamidophos Risk Mitigation Summary 59
1. Dietary Risk , 59
2. Occupational Risk 59
3. Ecological Risks 60
V. What Registrants Need to Do 61
A. Data Call-In Responses 61
B. Manufacturing Use Products 62
1. Additional Generic Data Requirements 62
2. Labeling for Manufacturing Use Products 63
C End-Use Products 63
1. Additional Product-Specific Data Requirements 63
2. Labeling for End-Use Products 63
D. Existing Stocks 64
E. Labeling Changes Summary Table 65
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VI. Related Documents and How to Access Them 76
A. Availability at OPP Docket Room 76
B. Availability on the Internet 76
Appendix A. Use Patterns Eligible for Reregistration 79
Appendix B: Data Supporting Guideline Requirements for the Reregistration of
Methamidophos 85
Appendix C: Technical Support Documents 95
Appendix D: Bibliography 97
Appendix E: Generic Data Call In 121
Appendix F: Product Specific Data Call In 129
Appendix G: EPA'S Batching of Methamidophos Products for Meeting Acute Toxicity
Data Requirements for Reregistration 141
Appendix H: List of Registrants Sent DCIs 143
Appendix I:List of Available Related Documents and Electronically
Available Forms 145
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Methamidophos TEAM
Office of Pesticide Programs:
Health Effects Risk Assessment
Felecia Fort
Susan Hanley
Nancy McCarroll
Environmental Fate Risk Assessment
Michael Davy
Ian Kennedy
Stephanie Syslo
Use and Usage Analysis
Timothy Kiety
Angel Chiri
Donald Atwood
Registration Support
Marilyn Mautz
Risk Management
MarkHartman
Elizabeth Vizard-Knee
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GLOSSARY OF TERMS AND ABBREVIATIONS
AE Acid Equivalent
ai. Active Ingredient
AGDCI Agricultural Data Call-In
ai Active Ingredient
aPAD Acute Population Adjusted Dose
AR Anticipated Residue
ARC Anticipated Residue Contribution
BCF Bioconcentration Factor
CAS Chemical Abstracts Service
CI Cation
CNS Central Nervous System
cPAD Chronic Population Adjusted Dose
CSF Confidential Statement of Formula
CFR Code of Federal Regulations
CSFII USDA Continuing Surveys for Food Intake by Individuals
DCI Data Call-In
DEEM Dietary Exposure Evaluation Model
DFR Dislodgeable Foliar Residue
ORES Dietary Risk Evaluation System
DWEL Drinking Water Equivalent Level (DWEL) The DWEL represents a medium specific
(i.e., drinking water) lifetime exposure at which adverse, noncarcinogenic health effects
are not anticipated to occur.
D WLOC Drinking Water Level of Comparison.
EC Emulsifiable Concentrate Formulation
EEC Estimated Environmental Concentration. The estimated pesticide concentration in an
environment, such as a terrestrial ecosystem.
EP End-Use Product
EPA U.S. Environmental Protection Agency
FAO Food and Agriculture Organization
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 Surfece Water Computer Model
GLC Gas Liquid Chromatography
GLN Guideline Number
GM Geometric Mean
GRAS Generally Recognized as Safe as Designated by FDA
HA Health Advisory (HA). The HA values are used as informal guidance to municipalities
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and other organizations when emergency spills or contamination situations occur.
HAFT Highest Average Field Trial
HOT Highest Dose Tested
IR Index Reservoir
LCSO 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.
LDSO 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.
LEL Lowest Effect Level
LOG Level of Concern
LOD Limit of Detection
LOAEL Lowest Observed Adverse Effect Level
MATC Maximum Acceptable Toxicant Concentration
MCLG Maximum Contaminant Level Goal (MCLG) The MCLG is used by the Agency to
regulate contaminants in drinking water under the Safe Drinking Water Act
mg/kg/day Milligram Per Kilogram Per Day
mg/L Milligrams Per Liter
MOE Margin of Exposure
MP Manufacturing-Use Product
MPI Maximum Permissible Intake
MRID Master Record Identification (number). EPA's system of recording and tracking
studies submitted.
N A Not Applicable
N/A Not Applicable
NAWQA USGS National Water Quality Assessment
NOEC No Observable Effect Concentration
NOEL No Observed Effect Level
NOAEL No Observed Adverse Effect Level
NPDES National Pollutant Discharge Elimination System
NR Not Required
OP Organophosphate
OPP EPA Office of Pesticide Programs
OPPTS EPA Office of Prevention, Pesticides and Toxic Substances
Pa pascal, the pressure exerted by a force of one newton acting on an area of one square
meter.
PAD Population Adjusted Dose
PADI Provisional Acceptable Daily Intake
PAG Pesticide Assessment Guideline
PAM Pesticide Analytical Method
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PCA Percent Crop Area
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
PRN Pesticide Registration Notice
PRZM/
EXAMS Tier H Surfece Water Computer Model
Qj* The Carcinogenic Potential of a Compound, Quantified by the EPA's Cancer Risk
Model
RAC Raw Agriculture Commodity
RBC Red Blood Cell
RED Registration Eligibility Decision
REI Restricted Entry Interval
RID Reference Dose
RQ Risk Quotient
RS Registration Standard
RUP Restricted Use Pesticide
SAP Science Advisory Panel
SCI-GROW Tier I Ground Water Computer Model
SF Safety Factor
SLC Single Layer Clothing
SLN Special Local Need (Registrations Under Section 24(c) of FDFRA)
TC Toxic Concentration. The concentration at which a substance produces a toxic effect.
TD Toxic Dose. The dose at which a substance produces a toxic effect.
TEP Typical End-Use Product
TGAI Technical Grade Active Ingredient
TLC Thin Layer Chromatography
TMRC Theoretical Maximum Residue Contribution
torr A unit of pressure needed to support a column of mercury 1 mm high under standard
conditions.
TRR Total Radioactive Residue
UF Uncertainty Factor
ug/g Micrograms Per Gram
ug/L Micrograms Per Liter
USDA United States Department of Agriculture
USGS United States Geological Survey
UV Ultraviolet
WHO World Heahh Organization
WP Wettable Powder
WPS Worker Protection Standard
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Executive Summary
EPA has completed its review of public comments on the revised risk assessments and is
issuing its risk management decisions for methamidophos. The decisions outlined in this document do
not include the final tolerance reassessment decision for methamidophos; however, some tolerance
actions will be undertaken prior to completion of the final tolerance reassessment Seven tolerances will
be revoked now, because there are no currently registered uses; three tolerances will be modified, and
several other commodity definitions will be corrected. The final tolerance reassessment decision for this
chemical will be issued once the cumulative risks for all of the organophosphates are considered. The
Agency may need to pursue further risk management measures for methamidophos once cumulative
risks are considered.
The revised risk assessments are based on review of the required target data base supporting
the use patterns of currently registered products and new information received. The Agency invited
stakeholders to provide proposals, ideas or suggestions on appropriate mitigation measures before the
Agency issued its risk mitigation decision on methamidophos. After considering the revised risks and
comments and mitigation suggestions from the technical registrant, Bayer, and other interested parties
EPA developed its risk management decision for uses of methamidophos that pose risks of concern.
This decision is discussed fully in this document
Methamidophos is an organophosphate insecticide used on a variety of insects, first registered
in 1972 for cotton, potatoes and numerous other crops. Use data from 1999 and 2000 indicate an
average annual domestic use of approximately 640,000 pounds of active ingredient (Ibs ai) of
methamidophos.
The methamidophos risk assessments are different than those for most organophosphate
pesticides because methamidophos is a metabolite of the organophosphate pesticide acephate.
Consequently, the dietary (food) assessments, and to some extent the drinking water assessment,
encompass the risk of methamidophos from applications of methamidophos only, and from "all sources"
which includes applications of acephate. Methamidophos is not registered for use in residential settings.
Previously, acephate had numerous residential, recreational and institutional uses which were evaluated
in the acephate IRED. To mitigate risks of concern, acephate use in these settings have been limited to
indoor use in institutional settings such as schools and hospitals, use on ornamentals in the residential
settings, spot or mound treatments for fire ant control, and use on golf course turf. The risks
associated with the degradation of acephate to methamidophos for these uses were evaluated in the
acephate IRED and were found to be negligible.
Overall Risk Summary
EPA's human health risk assessment for methamidophos indicates some risk concerns. Food
risk, bom acute and chronic, is below the Agency's level of concern Drinking water risk estimates
based on screening models, from surface water for acute and chronic exposures, is of concern for all
1
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populations. Conversely, drinking water risk estimates based on screening models, from ground water
for acute and chronic exposures, is not of concern for all populations. There are concerns for workers
who mix, load, and apply methamidophos to agricultural sites and to workers who re-enter treated
areas. Also, EPA has identified acute and chronic risk to birds and mammals that are of concern, and
some risk to freshwater invertebrates.
To mitigate risks of concern posed by the uses of methamidophos the Agency has decided on a
number of label amendments to address the worker, drinking water and ecological concerns. Results
of the risk assessments, and the necessary label amendments to mitigate those risks, are presented in
mis interim RED.
Dietary Risk rfoodl
Acute and chronic dietary risk assessments for food do not exceed the Agency's level of
concern; therefore, no mitigation is warranted at mis time for dietary (food) exposure to
methamidophos from food.
Dietary (drinking water)
Surface water estimated concentrations were derived from the PRZM-EXAMS model with the
Standard Index Reservoir and percent crop area (PCA) and the GEENEC model (for methamidophos
derived from application of acephate). Ground water estimated concentrations were derived from the
SCI-GROW Model. These are screening level estimates designed to provide high-end estimates of
potential pesticide exposure. Such predictions provide a screen to eliminate those chemicals that are
not likely to cause concerns in drinking water. Exceedances in drinking water risk assessments using
the screening model estimates do not necessarily mean a risk of concern actually exists, but may
indicate the need for better data (e.g., monitoring studies specific to use patterns and drinking water
sources) on which to confirm decisions.
Based on model predictions of currently registered uses, the EECs for methamidophos from the
application of methamidophos in surface water range from 28.6 to 61.8 ppb for acute exposure, and
from 1.5 to 3.8 ppb for chronic exposure. The only surface water EEC calculated for methamidophos
from the application of acephate, using the Tier I GEENEC model is 22 ppb. The acute and chronic
EEC for methamidophos in groundwater is 0.028 ppb. The SCI-GROW model was also used to
estimate ground water concentrations for methamidophos resulting from the application of acephate.
The modeled EEC for methamidophos in ground water from the application of acephate to cotton is
0.005 ppb. Table 3 summarizes the modeled EECs for the respective crop scenarios. The DWLOCs
for methamidophos from all sources are 2.9 for acute exposure and 0.6 for chronic exposure. The
Agency is therefore concerned with possible exposure to methamidophos residues in surface water
sources of drinking water and is requiring confirmatory monitoring data to evaluate actual acute and
chronic concentrations of methamidophos. The Agency does not have risk concerns for exposure to
drinking water from ground water sources.
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Aggregate Risk
The acute aggregate risk assessment for methamidophos from all sources combines exposure
from food and drinking water sources only. Acute dietary (food) risk estimates are below 100% of the
aPAD for the US population and all population subgroups. Infants is the most highly exposed
population subgroup and has an acute drinking water level of comparison (DWLOC) of 2.9 ppb.
Based on screening-level model predictions of the remaining supported uses, the acute (peak) drinking
water estimated concentration in surface water is 61.8 ppb which is of risk concern to the Agency. The
screening-level model predictions of acute concentrations in ground water is 0.033 ppb for
methamidophos, which is less man the DWLOC and not of risk concern to the Agency.
However, due to the uncertainties and limitations of the model predictions, the Agency believes
that actual acute concentration of methamidophos in surface water is likely to be less than the
DWLOC. To demonstrate mis, confirmatory surface water monitoring data is to be generated to
address this risk concern.
Similarly, the chronic aggregate risk assessment for methamidophos combines exposure from
food and drinking water sources only. Chronic dietary (food) risk estimates are well below 100% of
the cPAD for the US population and all population subgroups. Children 1-6 years old is the most highly
exposed population subgroup and result in a chronic DWLOC of 0.9 ppb. Based on screening-level
model predictions of the remaining supported uses, the average (chronic) estimated concentration in
surface water is 3.8 ppb, which is of risk concern to the Agency. Similarly, due to the same
uncertainties and limitations of the model predictions for acute exposure, the Agency also believes that
actual chronic concentrations of methamidophos in surface water is likely to be less than the DWLOC.
To demonstrate this confirmatory surface water monitoring data is to be generated to address the risk
concern.
The screening-level model predictions of acute concentrations in ground water is 0.033 ppb for
methamidophos, which is less than the DWLOC and not of risk concern to the Agency.
Occupational Risk
Occupational exposure to methamidophos is of concern to the Agency, and it has been
determined that a number of mitigation measures are necessary at this time. For the agricultural uses of
methamidophos, several mixer/loader/ applicator risk scenarios currently exceed the Agency's level of
concern (i.e., MOEs are less than 100). EPA believes that most of these risks can be mitigated to an
acceptable level by phasing out use on cotton and with the following label restrictions: use of closed
cabs by applicators; use of enclosed vehicles for flaggers or the use of ground positioning system (GPS)
equipment that negates the need for flaggers for aerial application.; and increased Restricted Entry
Intervals (REIs).
Ecological Risk
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Ecological risks are also of concern to the Agency. The Agency's assessment suggests the
potential for the liquid formulation to cause acute effects to birds for broadcast applications. The avian
acute RQs range from 0.38 to 6.63. The highest avian acute RQ is from nine 1 Ib ai/A ground or aerial
applications to tomatoes. For the same use patterns, mammalian acute RQs range from 0.2 to 20.3.
Regarding chronic risk to birds, the RQs range from 2.49 to 32.87. Again the same use patterns
resulted in chronic RQs for mammals ranging from 0.75 to 9.86. All use patterns are of concern to the
Agency for acute and chronic effects to birds and mammals.
Acute risk to freshwater fish and estuarine fish is not of concern for any use patterns, with RQs
ranging from <0.05 to 0.07. The acute high risk, restricted use risk and endangered species risk is of
concern for freshwater invertebrates at die maximum application rate of 1.0 Ib ai/A with RQs ranging
from 1.1 to 3.0 and may be of concern for estuarine invertebrates. No chronic risk assessment was
conducted since mere are no chronic data for aquatic species.
Because of the toxicity of methamidophos, to help protect terrestrial birds, mammals and
freshwater invertebrates, it is very important to reduce their potential exposure to methamidophos
products that have been applied. In additional to the phase out of the cotton use to mitigate
occupational risks of concern which will also serve to reduce risk to birds and mammals, reductions in
the maximum number of applications allowed per season are needed to reduce risks to birds, mammals
and fresh water invertebrates.
The Agency has determined mat, with the phase-out of the cotton use and the addition of the
label restrictions and amendments detailed in this document, until the outcome of cumulative risks for all
of the organophosphates has been considered, other currently registered uses of methamidophos may
continue.
The Agency is issuing mis Interim Reregistration Eligibility Document (IRED) for
methamidophos, as announced in a Notice of Availability published in the Federal Register. This
interim RED document includes guidance and time frames for complying with any necessary label
changes for products containing methamidophos. Note that there is no comment period for this
document, and that the time frames for compliance with the label changes outlined in this document are
shorter man those given in previous REDs. As part of the process discussed by the TRAC, which
sought to open up the process to interested parties, the Agency's risk assessments for methamidophos
have already been subject to numerous public comment periods, and a further comment period for
methamidophos was deemed unnecessary. Phase 6 of the pilot process did not include a .public
comment period; however, for some chemicals, the Agency may provide for another comment period,
depending on the content of the risk management decision. With regard to complying with the risk
mitigation measures outlined in this document, the Agency has shortened mis time period so that the
risks identified herein are mitigated as quickly as possible. Neither the tolerance reassessment nor the
reregistration eligibility decision for methamidophos can be considered final, however, until the
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cumulative risks for all organophosphate pesticides is considered. The cumulative assessment may
result in further risk mitigation measures for methamidophos.
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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 to 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 the pesticide meets the
"no unreasonable adverse effects" criteria of FIFRA.
On August 3,1996, the Food Quality Protection Act of 1996 (FQPA) was signed into law.
This Act amends FIFRA to require tolerance reassessment of all existing tolerances. The Agency had
decided that, for those chemicals that have tolerances and are undergoing reregistration, the tolerance
reassessment will be initiated through this reregistration process. It also requires that by 2006, EPA
must review all tolerances in effect on the day before the date of the enactment of the FQPA. 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. Methamidophos belongs to a group of pesticides called
organophosphates, which share a common mechanism of toxicity - they all affect the nervous system by
inhibiting cholinesterase. Although FQPA significantly affects the Agency's reregistration process, it
does not amend any of the existing reregistration deadlines. Therefore, the Agency is continuing its
reregistration program while it resolves the remaining issues associated with the implementation of
FQPA.
This document presents the Agency's revised human health and ecological risk assessments; its
progress toward tolerance reassessment; and die interim decision on the reregistration eligibility of
methamidophos. It is intended to be only the first phase in the reregistration process for
methamidophos. The Agency will eventually proceed with its assessment of the cumulative risk of the
OP pesticides and issue a final reregistration eligibility decision for methamidophos.
The implementation of FQPA has required the Agency to revisit some of its existing policies
relating to the determination and regulation of dietary risk, and has also raised a number of new issues
for which policies need to be created. These issues were refined and developed through collaboration
between the Agency and the Tolerance Reassessment Advisory Committee (TRAC), which was
composed of representatives from industry, environmental groups, and other interested parties.
In addition to the policy issues that resulted from the TRAC process, the Agency issued, on
Sept. 29,2000, a Pesticide Registration Notice (PR 2000-9) that presents EPA's approach for
managing risks from organophosphate pesticides to occupational users. The Worker Risk Mitigation
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for Organophosphate Pesticides PR Notice describes the Agency's baseline approach to managing
risks to handlers and workers who may be exposed to organophosphate pesticides, and the Agency
expects that other types of chemicals will be handled similarly. Generally, basic protective measures
such as closed mixing and loading systems, enclosed cab equipment, or protective doming, as well as
increased reentry intervals will be necessary for most uses where current risk assessments indicate a
risk and such protective measures are feasible. The policy also states that the Agency will assess each
pesticide individually, and based upon the risk assessment, determine the need for specific measures
tailored to the potential risks of the chemical. The measures included in this interim RED are consistent
with the Worker Risk PR Notice.
This document consists of six sections. Section I contains the regulatory framework for
reregistration/tolerance reassessment. Section n provides a profile of the use and usage of the
chemical. Section IE gives an overview of the revised human health and environmental effects risk
assessments resulting from public comments and other information. Section IV presents the Agency's
interim decision on reregistration eligibility and risk management Section V summarizes the label
changes necessary to implement the risk mitigation measures outlined in Section IV. Section VI
provides information on how to access related documents. Finally, the Appendices lists Data Call-in
(DCI) information. The revised risk assessments and related addenda are not included in mis
document, but are available on the Agency's web page www.epa.gov/pesticides/op, and in the Public
Docket.
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II. Chemical Overview
A. Regulatory History
Methamidophos was first registered in the United States in 1972 under the trade name Monitor.
It was used principally on potatoes, cotton, and cole crops to control a broad spectrum of insects
through contact, and systemic action inhibiting cholinesterase. A Registration Standard, which
describes the terms and conditions for the continued registration of methamidophos, was issued for
methamidophos in 1982.
In 1997, the technical registrant, Bayer Corporation, voluntarily cancelled all uses of
methamidophos except for use on cotton, potatoes, and tomatoes (special local need only). In 1998, a
special local needs registration was issued for use on alfalfa grown for seed in California. By December
1999, the registrant had also voluntarily phased-in closed mixing and loading systems for all remaining
uses to address potential worker exposures.
B. Chemical Identification
Methamidophos:
o
ii
H3C^ ^P^
S ' NH,
Common Name: Methamidophos
Chemical Name: O,S-dimethylphosphoramidothioate
Chemical family: Organophosphate
Case number: 0043
CAS registry number: 10265-92-6
OPP chemical code: 101201
Empirical formula: C2HgNO2PS
Molecular weight: 141.1
Trade and other names: Monitor
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Basic manufacturer: Bayer Corporation, Valent U.S A
Methamidophos is a colorless to white crystalline solid with a strong mercaptan-like odor, and
a melting point of 46.1°C. It is readily soluble (>200 g/L) in water, acetone, dimethylfomamide,
dichloromethane, and 2-propanol, and is soluble in n-octanol at 50-100 g/L, toluene at 2-5 g/L, and n-
hexane at <1 g/L. The vapor pressure of methamidophos is approximately 1.725 x lO"5 mm Hg.
C. Use Profile
The following information is based on the currently registered uses of methamidophos:
Type of Pesticide: Insecticide/acaricide.
Summary of Use Sites:
Food/Feed Crop: Cotton, potato, and tomato.
Other Agricultural Sites: None.
Residential: None.
Public Health None.
Nonfood Crop: Alfalfa grown for seed
Target Pests: Broad spectrum of insects including: aphid, Colorado potato
beetle, green peach aphid, leafhopper, leafininer, lygus bug,
stink bug, tomato pinworm, and whitefry.
Formulation Types Registered:
Technical Grade/Manufacturer-Use Product (MUF): liquid 60-72% ai.
End-Use Product: emulsifiable concentrate (EC) 40% ai.
Method and Rates of Application:
Equipment Aircraft, ground sprayer, and sprinkler irrigation.
Method and Rate: Chemigation (potatoes only), high volume spray (dilute), and low
volume spray (concentrate). Maximum use rate for all crops is 1.0 Ib
ai/A. The label allows four applications per season on cotton and
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potatoes, and up to nine applications per season on tomatoes.
Timing: Methamidophos end-use products are applied at various times including at-
plant, and foliar timings.
Use Classification: Restricted Use
D. Estimated Usage of Pesticide
Table 1 summarizes the best available estimates for me pesticide uses of methamidophos. These
estimates are derived from a variety of published and proprietary sources available to the Agency for
1999 and 2000. A full listing of all uses of methamidophos, with the corresponding use and usage data
for each site, has been completed and is in the "Quantitative Use Assessment," dated 5-9-2000 and the
"Use and Usage Analysis for Methamidophos," dated November 20,2001, which are available in the
public docket. Approximately 640,000 pounds of active ingredient (Ibs ai) of methamidophos are used
annually, according to Agency estimates. Methamidophos use is highest on potatoes (87% of total
methamidophos pounds applied), followed by tomato (8% of total methamidophos pounds applied),
and cotton (5% of total methamidophos pounds applied).
Table 1. Methamidophos Usage Summary in the United States1
Crop
Alfalfa for Seed
(CA only)
Cotton
Potatoes
Tomatoes (Fresh)
Tomatoes
(Processed)
Percent Crop
Treated
50%
2%
29%
15%
3%
Base Acres
Treated (1000
acres)2
33*
288*
322*
18*
9*
Average Number
of Applications
Per Year
1.0
1.0
1.7
2.5
1.0
Average
Application Rate
(Ibs ai/A)
0.8
0.3
0.9
0.6
0.9
Pounds Active
Ingredient
Applied
(1000 Ibs.)
36
84
520
28
8
'Source: USDA 1999 and 2000 Agricultural Chemical Use (May, 2000, May 2001, July, 2001) and California
Department of Pesticide Regulation, Pesticide Use Report (2000)..
2Base acres treated derived from estimate of acres grown in USDA 1999 and 2000 Agricultural Chemical Use (May
2000, May 2001, July, 2001).
*Base acres treated for California derived from harvested acreage; other states based on USDA 2000 Agricultural
Chemical Use.
10
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IE. Summary of Methamidophos Risk Assessment
Hie purpose of this summary is to assist the reader by identifying the key features and findings
of these risk assessments, and to better understand the conclusions reached in the assessments.
Following is a list of EPA's revised human health and ecological risk assessments and supporting
information that were used to formulate the findings and conclusions for the organophosphate pesticide
methamidophos. The listed documents may also be found on the Agency's web page at
www.epa.gov/pesticides/op and in the public docket.
These risk assessments for methamidophos were presented at a February 3,2000 technical
briefing, which was followed by an opportunity for public comment on risk management for this
pesticide. The risk assessments presented here form the basis of the Agency's risk management
decision for methamidophos only; the Agency must consider a cumulative assessment of the risks of all
the OP pesticides before any final decisions can be made.
Human Health Risks
Human Health Risk Assessment-Methamidophos Revised Risk Assessment, February 3,
2000.
Revised Dietary Exposure and Risk Analyses for the HED Revised Human Health Risk
Assessment, July 19,2000.
Methamidophos: Addendum to the Revised Occupational and Residential Exposure
Assessment and Recommendations for the Reregistration Eligibility Decision Document,
September 15,2000.
Recalculated Tier II Drinking Water EECsfor Methamidophos Incorporating the Index
Reservoir and Percent Cropped Area, October 17,2000.
Environmental Fate and Ecological Effects
Amended EFED Methamidophos RED Chapter, September 15,1999.
A. Human Health Risk Assessment
The methamidophos risk assessments are different than those for most organophosphate
pesticides because methamidophos is a metabolite of the organophosphate pesticide acephate.
Consequently, the assessments encompass the risk of methamidophos from applications of
methamidophos only, and from "all sources" which includes applications of acephate. Acute
probabilistic and chronic dietary (food) risk assessments were conducted as well as a qualitative
assessment of the potential exposure to all methamidophos sources through drinking water. EPA
issued its preliminary risk assessments for methamidophos on October 30,1998 (Phase 3 of the TRAC
process). In response to comments and studies submitted during Phase 3 and Phase 5, the risk
11
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assessments were updated and refined. Major revisions to the human health risk assessment are listed
below:
Refinement of the acute dietary (food) risk assessment to use probabilistic (Monte
Carlo) techniques;
Incorporation of data from USDA's Pesticide Data Program (POP) into the dietary
(food) risk assessment;
Adjustment to percent crop treated estimates;
Incorporating washing and cooking factors into the dietary (food) assessment;
Revised anticipated residues were calculated for use in the dietary risk assessment;
Use of residue data from a potato processing study was incorporated into the dietary
risk assessment;
Information concerning a submitted import tolerance petition for peppers, squash, and
strawberries was incorporated.
1999 PDP monitoring data on canned tomatoes was incorporated in the dietary
assessment
Use of new toxicological endpoints for dermal risk assessment. These data affect the
lowest observed effect level, and no observed effect level in the dermal risk
assessments.
Use of three dislodgeable foliar residue studies submitted by Bayer to assess post-
application exposure to agricultural workers, and set restricted entry intervals.
Recalculated Tier n drinking water EECs incorporating the Index Reservoir and
Percent Cropped Area.
1. Dietary Risk from Food
a. Toxicity
The Agency has reviewed all toxicity studies submitted and has determined that the toxicity
database is complete, and mat it supports an interim RED for all currently registered uses. Further
details on the toxicity of methamidophos can be found in the February 3,2000 "Human Health Risk
12
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Assessment" and subsequent addenda. A brief overview of the studies and safety factors used for the
dietary (food) risk assessment is outlined in Table 2 in this document
b. FQPA Safety Factor
The FQPA Safety Factor (SF) was reduced from lOx to 3x. A weight-of-the-evidence
approach indicated neuropathology in hens and humans reported in the open scientific literature. This
led the Agency to conclude that an FQPA safety factor is appropriate. In studies from the open
scientific literature, ingestion of methamidophos has been shown to result in delayed peripheral
neuropathy in humans. Similarly, adult hens developed poly neuropathy. The Agency determined that
the 1 Ox factor can be reduced to 3x primarily because: 1) there was no increased susceptibility of the
offspring of rats or rabbits to pre- and/or post-natal exposure 2) a two-generation reproductive toxicity
study in rats showed no increased sensitivity in pups when compared to adults 3) die toxicology
database is complete; and 4) the dietary food exposure assessment does not underestimate the potential
exposure for infants and children from residues in food. However, based on this evidence, the
requirement of a developmental neurofoxicfty study has been triggered. This study will in turn provide
additional data (e.g., potential increased susceptibility, and effects on the development of the fetal
nervous system, etc.). More information can be found in the document 'TQPA Safety Factor
Recommendations for the Organophosphates," dated August 6,1998.
c. Population Adjusted Dose (PAD)
The PAD is a term that characterizes the dietary risk of a chemical, and reflects the reference
dose, either acute or chronic, mat has been adjusted to account for the FQPA safety factor (i.e.,
RfD/FQPA safety factor). The RfD is calculated by taking the no observed adverse effect level
(NOAEL) from an appropriate study and dividing it by an uncertainty factor (i.e., NOAEL/UF). A risk
estimate that is less than 100% of the acute PAD (aPAD) or chronic PAD (cPAD) does not exceed
the Agency's risk concern. In the case of methamidophos, the FQPA safety factor is 3x; therefore the
acute and chronic PADs are equivalent to the acute and chronic RfDs divided by 3, respectively. The
aPAD for methamidophos is 0.001 mg/kg/day. The cPAD for methamidophos is 0.0001 mg/kg/day.
The basis for the aPAD and the cPAD are summarized in Table 2 below.
Table 2. Summary of Toxicological End
Exposure
Scenario
Acute dietary
Dose
NOAEL = 0.3
mg/kg/day
LOAEL = 0.7
mg/kg/day
Endpoint
Plasma,
erythrocyte and
tnain
cholinesterase
inhibition.
points Used in the Dietary Risk Assessment
Toxicology Study
Acute neurotoxicity study in
rats
(MRIDs 43025001,
43345801)
UF
100
FQPA
Safety
Factor
3
PAD
(mg/kg/day)
0.001
13
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Chronic dietary
NOAEL = 0.03
mg/kg/day
LOAEL = 0.06
mg/kg/day
Brain
cholinesterase
inhibition.
8- week subchronic oral
toxicity cholinesterase study
in rat (MRID 41867201)
100
3
0.0001
d. Exposure Assumptions
The Agency conducts dietary (food) risk assessments using the dietary exposure evaluation
model (DEEM), which incorporates consumption data generated in USDA's continuing survey of
food intakes by individuals, 1989-1992. For the assessment of dietary (food) exposure to residues of
methamidophos resulting from the use of methamidophos, monitoring data generated through the
USDA Pesticide Data Program (PDF) for potatoes and tomatoes, and through the Food and Drug
Administration (FDA) Surveillance Monitoring Program for peppers, squash, and strawberries were
used. Anticipated residue values from crop residue field trial studies, and percent crop-treated data
were used for cotton. For the assessment of dietary (food) exposure to residues of methamidophos
resulting from the use of acephate, PDF or FDA monitoring data were used for succulent beans,
cauliflower, celery, lettuce and peppers. Anticipated residue values from crop residue field trial studies,
and percent crop-treated data were used for dry beans, Brussels sprouts, cotton, cranberries,
macadamia nuts, mint, peanuts and soybeans.
For acute probabilistic dietary risk assessments, the entire distribution of single-day food
consumption events is combined with a distribution of residues to obtain a distribution of exposure in
mg/kg/day. Chronic dietary (food) risk assessments use the three-day average of consumption for each
subpopulation combined with residues in commodities to determine average exposure in mg/kg/day.
For probabilistic assessments, the Agency regulates at the 99.9th percentile of exposure. Both
assessments included the dietary (food) risk from methamidophos exposure from use of
methamidophos and from the use of acephate.
Valent U.S A. Corporation has submitted an import tolerance petition in support of uses of
methamidophos on squash, strawberries and peppers. There is an existing tolerance for
methamidophos on peppers, but none has been established for the latter two commodities. The dietary
risk assessment includes these proposed uses. Otherwise, these proposed tolerances are not
addressed in this RED.
e.
Food Risk Characterization
Generally, a dietary (food) risk estimate that is less than 100% of the acute or chronic
Population Adjusted Dose does not exceed EPA's risk concerns. Acute dietary (food) exposure to
methamidophos from applications of methamidophos alone, and from "all sources" (applications of
methamidophos and acephate) result in risk estimates that are below the Agency's level of
concernthat is, less than 100% of the acute PAD is used. For example, for exposure resulting from
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applications of methamidophos alone, for the most exposed subpopulation, children 7-12 years old, the
percent acute PAD value is 33% at the 99.9th percentile of exposure from consumption of food alone.
For exposure resulting from applications of memamidophos from "all sources", for the most exposed
subpopulation, all infants, the percent acute PAD value is 76% at the 99.9th percentile of exposure
from consumption of food alone.
Chronic dietary (food) exposure estimates are also below the Agency's level of concern for all
subpopulations. For the most highly exposed subpopulation, children 1-6 years old, the percent
chronic PAD values are 15% for methamidophos alone and 37% when including methamidophos
residues from the application of acephate, from consumption of food alone.
2. Dietary Risk from Drinking Water
Drinking water exposure to pesticides can occur through ground water and surface water
contamination. EPA considers both acute (one day) and chronic (lifetime) drinking water risks and
uses either modeling or actual monitoring data, if available, to estimate those risks. Modeling is
considered to be an unrefined assessment and provides a high-end estimate of risk. Very limited
monitoring data is available for memamidophos therefore, modeling was used to estimate drinking water
risks from these sources.
The GENEEC and PRZM-EXAMS models were used to estimate surface water
concentrations, and SCI-GROW was used to estimate groundwater concentrations. All of these are
considered to be screening models, with the PRZM-EXAMS model being somewhat more refined than
the other two.
As in the dietary risk assessment for food, separate drinking water risk assessments were
conducted for both exposure to methamidophos as a result of the application of memamidophos and
exposure to methamidophos from all sources including the application of acephate.
Although the environmental fate data base for memamidophos is not complete, supplemental
information from ungradable laboratory studies indicate that methamidophos is not persistent in aerobic
environments but may be persistent in anaerobic aquatic environments where it will be associated with
the aqueous phase. No acceptable data are available on the behavior of methamidophos under field
conditions, but information from acceptable terrestrial field dissipation studies for acephate indicated
that methamidophos is not persistent
a. Surface Water
The Tier n PRZM-EXAMS screening model is used to estimate upper-bound environmental
concentrations (EECs) in drinking water derived from surface water. This model, in general, is based
on more refined, less conservative assumptions man the Tier I GENEEC screening model. Acute
modeled EECs for methamidophos in surface water from the application of methamidophos alone range
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from 29 ppb to 48 ppb, depending on the crop site. Chronic modeled EECs for methamidophos in
surface water from the application of methamidophos alone range from 3.9 ppb to 6.9 ppb, depending
on the crop site.
The Agency also used the recently implemented Index Reservoir (IR) and Percent Crop Area
(PCA) modifications to the Tier n PRZM-EXAMS model to calculate upper-bound EECs for
methamidophos in drinking water derived from surface water. Applying the IR and PCA modifications,
acute modeled EECs for methamidophos in surface water from the application of methamidophos alone
range from 28.6 ppb to 61.8 ppb depending on the crop site. Chronic modeled EECs for
methamidophos in surface water from the application of methamidophos alone range from 1.5 ppb to
3.8 ppb, depending on the crop site.
The surface water model assumes methamidophos applications are made at the maximum rate
for each crop on the current label, using the labeled methods of application. The model results are also
based on four applications per season with a seven day retreatment interval. The lack of acceptable
aerobic aquatic metabolism data increase the uncertainty of the chronic estimated environmental
concentrations (EECs).
To estimate the potential exposure to methamidophos from the application of acephate, the
Agency relied upon the Tier IGENEEC screening model. A higher-tiered model was not used in this
case due to the high level of uncertainty surrounding any estimate of the decay rate for acephate and the
transformation rate of acephate to methamidophos which are needed to use the PRZM-EXAMS
model. The acute modeled EEC for methamidophos in surface water from die application of acephate
to cotton is 22 ppb. The chronic modeled EEC for methamidophos in surface water from the
application of acephate to cotton is 12 ppb. This analysis assumes a 25% conversion efficiency from
acephate to methamidophos at time of application resulting in the equivalent of six applications at 025
Ib methamidophos/aiyA on cotton. EECs for other crops were not developed.
For die purposes of assessing drinking water risks from exposure to methamidophos from all
sources (i.e. including both methamidophos and acephate applications) die Agency will rely upon die
model estimates generated using die PRZM-EXAMS model widi die Index Reservoir (IR) and Percent
Crop Area (PCA) modifications described above which are based upon die application of
methamidophos alone. The Agency believes tiiat the conservative default PCA used for die scenario
with die highest EEC (potatoes in ME) would most likely account for methamidophos residues from
both methamidophos and acephate applications in a given watershed. For this scenario, die default
PCA value of 0.87 was used to calculate die EEC. This assumes tiiat 87% of die watershed being
evaluated is cropped in potatoes and/or other crops that methamidophos can be applied to. In diis
particular case, it is estimated that 65,000 acres of potatoes are grown in die state of Maine each year.
Cotton is not grown in Maine and there is not a SLN for tomatoes diere so all methamidophos use in
that state would be on potatoes. If h was assumed diat all that acreage fell into any one of die nine
watersheds in Maine as a worst-case scenario, die range of PCA values would likely be 0.04 to 0.16
or 4% to 16%, significantly lower tiian die 87% assumption. The effect of die PCA value on EECs has
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a linear relationship. Consequently, using these values would reduce EECs by a factor of 5 to 20.
Further, the main crop uses of acephate (beans, cotton, lettuce and tobacco) are either not grown in
Maine or are not likely to have significant acreage. Therefore, additional contribution of
methamidophos residue from the application of acephate in this scenario is very unlikely. Even though
this analysis has not been deemed to be sufficient to change die PCA quantitatively, it does support the
belief that this EEC likely provides a sufficiently protective estimate of exposure to methamidophos
from all sources in drinking water. Further, the information is not currently available to enable die
Agency to use a Tier n model to estimate concentrations of methamidophos from the application of
acephate, as described above, and it is not considered appropriate to combine the results of a Tier II
assessment (methamidophos applications) with the results of a Tier I assessment (acephate
applications).
Monitoring for methamidophos in surface water is limited. No residues were detected in the
available samples (328 samples primarily from Florida and Mississippi) but the limits of detection for
this sampling are uncertain and it is unclear if these samples were taken in areas where methamidophos
was being used. Given these limitations, die existing surface water monitoring database cannot be used
to estimate concentrations of methamidophos in surface water. The U.S. Geological Survey (USGS) in
its National Water Quality Assessment (NAWQA) program is not currently analyzing for
methamidophos.
b. Ground Water
The Tier I screening model, SCI-GROW, was used to estimate drinking water concentrations
derived from groundwater. The acute and chronic EEC for methamidophos in groundwater is 0.028
ppb. The ground water modeling assumes die maximum yearly total application of methamidophos
(nine applications at 1.0 lb/ai7A on tomatoes in Florida) per the current labels. Methamidophos is not
expected to leach significantly to groundwater given that it is not persistent under aerobic conditions.
This expectation is reflected in die results of die model. Further, a majority of use areas will have
ground water that is less vulnerable to contamination than that in areas used to derive die SCI-GROW
estimate. Very limited ground water monitoring data for methamidophos is available. Four detections
were recorded in diese data which were collected between 1984 and 1993.
The SCI-GROW model was also used to estimate ground water concentrations for
methamidophos resulting from die application of acephate. The modeled EEC for methamidophos in
ground water from die application of acephate to cotton is 0.005 ppb. This analysis assumes a 25%
conversion efficiency from acephate to methamidophos at time of application resulting in die equivalent
of six applications at 0.25 Ib methamidophos/ai./A on cotton. EECs for otiier crops were not
developed.
Since die same model was used to develop bodi die EECs from methamidophos applications
and methamidophos resulting from applications of acephate, die Agency has decided to combine die
estimates for die purposes of assessing drinking water risks from exposure to methamidophos from all
17
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sources.
c. Drinking Water Levels of Comparison (DWLOCs)
To determine the maximum allowable contribution of water containing pesticide residues
permitted in the diet, EPA first looks at how much of the overall allowable risk is contributed by food
(and if appropriate, residential uses) then determines a "drinking water level of comparison"(DWLOC)
to determine whether modeled or monitoring levels exceed this level. The Agency uses the DWLOC
as a surrogate to capture risk associated with exposure from pesticides in drinking water. The
DWLOC is the maximum concentration in drinking water which, when considered together with dietary
(food) exposure, does not exceed a level of concern.
The results of the Agency's drinking water analysis are summarized here. Details of this
analysis, which used screening models, are found in the HED Human Health Risk Assessment dated
February 3,1999, me EFED Environmental Risk Assessment dated September 15,1999, and the
Recalculated Tier n Drinking Water EECs for Methamidophos Incorporating the Index Reservoir and
Percent Cropped Area, October 17,2000.
For acute risk, surface water EECs exceed the acute DWLOCs for all subpopulations (Table
3). Even if it is assumed that there are no food exposures to methamidophos, drinking water alone,
based on model estimates, would result in exceedences of the risk cup, particularly for infants and
children. Ground water EECs do not exceed the acute DWLOCs for any subpopulations. Therefore,
the Agency does not have a risk concern for ground water sources of dietary exposure for the general
U.S. population or the most highly exposed subpopulation. The table below presents the calculations
for the acute drinking water assessment
Table 3. Summary of DWLOC Calculations for Acute Risk
Population
Subgroup
PAD
(mg/kg/day)
Food Exposure
(mg/kg/day)
Available
Water
Exposure
(mg/kg/day)
DWLOC
(ppb)
Maximum
Surface Water
EECs
(PP*>)
Maximum
Groundwater
EECs
(PI*)
Methamidophos
U.S. Population
Children 7-12
years old
0.001
0.001
0.000269
0.000334
0.000731
0.000684
25.6
6.8
61.8
61.8
0.028
0.028
Methamidophos from all Sources
U.S. Population
All Infants
0.001
0.001
0.000429
0.000762
0.000571
0.000238
20
2.4
61.8
61.8
0.033
0.033
For chronic risk, surface water EECs slightly exceed the chronic DWLOCs for all
18
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subpopulations (Table 4). Ground water EECs do not exceed the chronic DWLOCs for any
subpopulations. Therefore, the Agency does not have a risk concern for ground water sources of
dietary exposure for die general U.S. population or the most highly exposed subpopulation. The table
below presents the calculations for the chronic drinking water assessment.
Table 4. Summary of DWLOC Calculations for Chronic Risk
Population
Subgroup
cPAD
(mg/kg/day)
Food Exposure
(mg/kg/day)
Available Water
Exposure
(mg/kg/day)
DWLOC
(ppb)
Maximum
Surface Water
EECs
(ppb)
Maximum
Groundwater
EECs
(ppb)
Methamidophos
U.S. Population
Children 1-6
yean old
0.0001
0.0001
0.000007
0.000015
0.000093
0.000085
3.3
0.9
3.8
3.8
0.028
0.028
Methamidophos from all Sources
U.S. Population
Children 1-6
years old
0.0001
0.0001
0.000023
0.000037
0.000077
0.000063
3
0.6
3.8
3.8
0.033
0.033
The acute and chronic dietary risks from drinking water exposure are above the Agency's level
of concern for most subpopulations.
3. Aggregate Risk
An aggregate risk assessment looks at the combined risk from dietary exposure (food and
drinking water routes) and any non-occupational exposures (residential use). Acute and chronic
aggregate risk assessments were conducted for methamidophos. Methamidophos is not registered for
use in residential settings. Previously, acephate had numerous residential, recreational and institutional
uses which were evaluated in the acephate IRED. To mitigate risks of concern, acephate use in these
settings have been limited to indoor use in institutional settings such as schools and hospitals, use on
ornamentals in the residential settings, spot or mound treatments for fire ant control, and use on golf
course turf. The risks associated with the degradation of acephate to methamidophos for these uses
were evaluated in the acephate IRED and were found to be negligible. Therefore, aggregate short-term
exposures were not estimated. Results of the aggregate risk assessment are summarized here, and are
discussed in the methamidophos human health risk assessment
The Agency was only able to quantify food sources of dietary exposure to methamidophos
because dietary exposures through drinking water have only been estimated using models. Neither
adequate groundwater or surface water monitoring data were available to estimate potential drinking
water exposures to methamidophos.
Acute Aggregate Risk Assessment: Potential acute dietary risks from food sources alone do not
exceed the Agency's level of concern. The most exposed subpopulation, all infants, consume 76% of
19
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the acute PAD at the 99.9th percentile of exposure, based on highly refined exposure estimates.
Further, potential drinking water risks from exposure to water from ground water sources does not
exceed the acute DWLOCs and, therefore, do not exceed the Agency's level of concern. However,
when drinking water exposure concentrations, derived from surface water models, are added to the
acute dietary risk assessment, the potential exists for acute dietary exposures through drinking water
that exceed the acute DWLOCs, resulting in acute aggregate risks of concern.
Chronic Aggregate Risk Assessment: In the case of the food component of the chronic
aggregate risk assessment, risks are well below the Agency's level of concern. No more than 37% of
chronic PAD is consumed for children 1-6. Further, potential drinking water risks from exposure to
water from ground water sources does not exceed the chronic DWLOCs and, therefore, do not
exceed the Agency's level of concern. However, based on modeled estimates of methamidophos
concentrations in surface water, the potential exists for chronic dietary exposures through drinking
water that exceed the chronic DWLOCs, resulting in chronic aggregate risks of concern.
4. Occupational and Residential Risk
Occupational workers can be exposed to a pesticide through mixing, loading, and/or applying a
pesticide, or re-entering treated sites. Methamidophos is a restricted use pesticide and has no uses in
residential areas. However, methamidophos is a degradant of die pesticide acephate which does have
residential uses. Methamidophos residential exposure risk resulting from acephate applications in
residential areas was evaluated in the Interim Reregistration Eligibility Decision for Acephate dated
September 30,2001. Occupational handlers of methamidophos include: individual farmers or growers
who mix, load, and/or apply pesticides, professional or custom agricultural applicators. Risk for all of
these potentially exposed populations is measured by a Margin of Exposure (MOE) which determines
how close the occupational or residential exposure comes to a No Observed Adverse Effect Level
(NOAEL). Generally, MOEs greater than 100 do not exceed the Agency's risk concern.
a. Toxicity
The toxicity of methamidophos is integral to assessing Has occupational risk. All risk
calculations are based on the most current toxicity information available for methamidophos, including a
21-day dermal toxicity study. The toxicological endpoints, and other factors used in the occupational
and residential risk assessments for methamidophos are listed below. Due to the use patterns of
methamidophos, long-term exposure is considered highly unlikely.
Table 5. Summary of Toxicological Endpoints and Other Factors Used in the Human
Occupational Risk Assessments for Methamidophos
Route and Duration
of Exposure
Toxicological Endpoint and Dose
Study
Absorption
Factor
20
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Short-Term Dermal
Intermediate-Term
Dermal
Short-Term
Inhalation
Intermediate-Term
Inhalation
NOAEL = 0.745 mg/kg/day,
LOAEL = 1 1 .2, mg/kg/day, based on plasma, red
blood cell, and brain cholinesterase inhibition
NOAEL = 0.745 mg/kg/day,
LOAEL = 1 1 .2, mg/kg/day, based on plasma, red
blood cell, and brain cholinesterase inhibition
NOAEL = 0.001 mg/1,
LOAEL = 0.005 mg/1, based on plasma, red blood
cell, and brain cholinesterase inhibition
NOAEL = 0.001 mg/1,
LOAEL = 0.005 mg/1, based on plasma, red blood
cell, and brain cholinesterase inhibition
21 -day dermal
toxicity in rats
21 -day dermal
toxicity in rats
90-day inhalation
toxicity study-rats
90-day inhalation
toxicity study-rats
NA
NA
NA
NA
Methamidophos is acutely toxic, causing death to laboratory animals shortly after exposure to
relatively low oral, dermal, or inhalation doses. Methamidophos is only moderately irritating to the eyes
and mildly irritating to the skin. Death and other signs of systemic toxicity occurred shortly after dermal
or ocular application. These findings suggest that methamidophos is rapidly absorbed via these routes.
Table 6. Acute Toxicity Profile for Occupational Exposure for Methamidophos
Study Type (MRID)
Acute Oral-Rat (00014044)
Acute Dermal-Rabbit (00014049)
Acute Inhalation-Rat (00148449)
Primary Eye Irritation-Rabbit (00014221)
Primary skin irritation-Rabbit (00014220)
Dermal Sensitization-Guinea Pig (00147929)
Results
LD 50=15.6 mg/kg
-------
sources of data currently available to the Agency for completing these kinds of assessments. The
application rates are derived directly from methamidophos labels. The exposure factors (e.g., body
weight, amount treated per day, protection factors, etc.) are all standard values that have been used by
the Agency over several years, and the PHED unit exposure values are the best available estimates of
exposure. Some PHED unit exposure values are high quality while others represent low quality, but are
the best available data. The quality of the data used for each scenario assessed is discussed in the
Human Health Assessment document for methamidophos, which is available in the public docket
Anticipated use patterns and application methods, range of application rates, and daily amount
treated were derived from current labeling. Application rates specified on methamidophos labels range
to a maximum of 1.0 pounds of active ingredient per acre in agricultural settings. The Agency typically
uses acres treated per day values that are thought to represent eight hours of application work for
specific types of application equipment
Occupational handler exposure assessments are conducted by the Agency using different levels
of personal protection. The Agency typically evaluates all exposures with minimal protection and then
adds additional protective measures using a tiered approach to obtain an appropriate MOE (i.e., going
from minimal to maximum levels of protection). The lowest suite of personal protective equipment
(PPE) is baseline PPE. If required (i.e., MOEs are less than 100), increasing levels of risk mitigation
PPE are applied. If MOEs are still less than 100, engineering controls (EC) are applied. The levels of
protection that formed the basis for calculations of exposure from methamidophos activities include:
Baseline: Long-sleeved shirt and long pants, shoes and socks.
Minimum PPE: Baseline + chemical resistant gloves and a respirator if risk is driven by
inhalation.
Maximum PPE: Coveralls over long-sleeved shirt and long pants, chemical resistant
gloves, chemical footwear plus socks, chemical resistant headgear for
overhead exposures, and a respirator if risk is driven by inhalation.
Engineering controls: Engineering controls such as a closed cab tractor for application
scenarios, or a closed mixing/loading system such as a closed
mechanical transfer system for liquids. Some engineering controls are
not applicable for certain scenarios (e.g., for handheld application
methods there are no known devices that can be used to routinely
lower the exposures).
For methamidophos, since the same toxicological endpoint and uncertainty factors are being
used for both short-term and intermediate-term (1-30 days to several months) exposure durations, both
risk estimates are identical. Although information is not available to determine what percentage of
applicators apply methamidophos continuously for more than 30 days, it is believed to be a very small
segment of commercial applicators.
c. Occupational Handler Risk Summary
Inhalation and dermal exposure to methamidophos can result from occupational use. The
22
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Agency assessed dermal and inhalation risks (MOEs) for each crop currently registered for
methamidophos. Since the toxicological endpoints used for dermal and inhalation exposures are the
same; plasma, red blood cell, and brain cholinesterase inhibition, the MOEs for each route of exposure
were combined to create a single MOE for each scenario. For methamidophos, occupational MOEs
greater than 100 are not of risk concern to the Agency.
1) Agricultural Handler Risk
EPA has determined that there are potential exposures to mixers, loaders, applicators, or other
handlers during typical use-patterns associated with methamidophos. All the MOEs in the tables below
are based on combined dermal and inhalation MOEs. The scenario numbers correspond to the
scenario numbers detailed and discussed in Appendix A of the Occupational and Residential Exposure
Chapter. The current labels require use of a dry-coupling mixing/loading system. Based on the use
patterns, five major exposure scenarios (each assessed at the same maximum application rate of 1.0 Ib
ai/A) were identified for methamidophos:
(la) mixing/loading of liquid formulation for aerial application and chemigation (potato
only);
(Ib) mixing/loading of liquid formulation for groundboom application;
(2) applying sprays with an aircraft;
(3) applying sprays with groundboom equipment; and
(4) flagging aerial spray applications.
As summarized in Table 7, occupational risks are of concern (i.e., MOEs < 100) for most
scenarios, even when maximum PPE are utilized. Handler risks are also of concern for many scenarios
with engineering controls. Engineering controls are considered to be the maximum feasible mitigation.
It is notable that dermal exposures are driving the Agency's risk concern for the occupational scenarios
in question rather than inhalation exposures especially in the case of applicators and flaggers. For
example, the MOE of 51 for groundboom applicators for cotton using enclosed cabs is composed of
an MOE of 53 for the dermal component and an MOE of 2198 for the inhalation component
Table 7. Agricultural Uses: Remaining Risk Concerns
(combined dermal & inhalation MOEs)
Exposure Scenario
Crop
Area Treated
(A/day)
Total MOEs for Short- and
Intermediate-Term Risks
Baseline
Min.
PPE
Max.
PPE
Engineering
Controls
Mixer/Loader
[la) Mixing/loading liquid formulation for
aerial application or chemigation
[Ib) Mixing/loading liquid formulation for
Troundboom appication
Cotton/Alfalfa
Potato/Tomato
Cotton/Alfalfa
Potato/Tomato
1200
350
200
80
0.015
0.052
0.090
0.23
1.8
6.3
11
28
2.5
8.7
15
38
5
17
30
74
Applicator
23
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(2) Applying sprays with an aircraft
(3) Applying sprays with groundboom
equipment
Cotton/Alfalfa
Potato/Tomato
Cotton/Alfalfa
Potato/Tomato
1200
350
200
80
NA
NA
16
41
NA
NA
18
46
NA
NA
23
59
8.4
29
51
128
Flagger
(4) Flagging aerial spray applications
Cotton/Alfalfa
Potato/Tomato
1200
350
3.7
13
3.6
12
3.9
14
183
626
2) Post-Application Occupational Risk
The Agency also assessed post-application risks to workers who may be exposed to
methamidophos when they enter previously treated fields, because their skin may contact treated
surfaces. Exposures are directly related to the kind of tasks performed. EPA examines the amount of
pesticide residue found on the workers over time from various studies. The Agency evaluates this
information to determine the number of days following application that must elapse before the pesticide
residues dissipate to a level where worker MOEs equal or exceed 100 while wearing baseline attire.
Baseline attire is defined as long-sleeved shirt, long pants, coveralls, shoes and socks. Based on the
results of the post-application worker assessment, the Agency establishes restricted entry intervals
(REIs) before workers may enter treated areas. At present, the Worker Protection Standard
designates the REI to be 48 hours, or 72 hours in regions where the annual rainfall is less than 25
inches.
The Agency completed a post-application exposure assessment for methamidophos for the
following scenarios: irrigating, scouting, thinning, and weeding immature plants for cotton, potatoes and
tomatoes; irrigating, scouting, and weeding mature plants for potatoes and tomatoes; and pruning,
staking, tying and hand harvesting for tomatoes. The dermal NOAEL of 0.745 mg/kg/day based on a
21-day dermal toxicity study in rats (Table 5) was used to assess potential dermal exposure to workers
re-entering treated fields. The post-application assessment is also based on 8 hours of worker daily
exposure and the default transfer coefficients (Tcs) shown in Table 8. Also, three chemical-specific
dislodgeable foliar residue (DFR) studies were conducted for methamidophos which were used to
determine the Dm values used in conducting the post-application risk assessment
For post-application risks to methamidophos, an MOE of 100 or greater is not of concern to
the Agency. Table 8 summarizes the occupational post-application risks following foliar applications of
methamidophos. In summary, except for methamidophos use on cotton, which resulted in a MOE
>100 within one day after being treated, all crops are of post-application risk concern with REIs as
high as 18 days after being treated, such as foliar use of methamidophos on tomatoes in Florida.
Table 8. Occupational Post-application Risks from Foliar Applications of Methamidophos
Crop
Task
Transfer Coefficient
(cm2/hr)
DAT* where MOE >
100
24
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Cotton
Potato
Tomato
Irrigating, scouting, thinning, and weeding immature plants
Irrigating, scouting, thinning, and weeding immature plants
Irrigating and scouting mature plants
Irrigating, scouting, thinning, and weeding immature plants
Irrigating and scouting mature plants
Hand harvesting, pruning, staking, tying
100
300
1500
500
700
1000
DATO
DAT 4 (KA)
DAT 1 (MO)
DAT 2 (WA)
DAT11(KA)
DAT 4 (MO)
DAT 7 (WA)
DAT12(FL)
DAT 4 (CA)
DAT 6 (GA)
DAT 15 (FL)
DAT 5 (CA)
DAT 8 (GA)
DAT 18 (FL)
DAT 7 (CA)
DAT 9 (GA)
* DAT = Day after treatment
B. Environmental Risk Assessment
A summary of the Agency's environmental risk assessment is presented below. For detailed
discussions of all aspects of the environmental risk assessment, see Amended EFED Methamidophos
RED Chapter, September IS, 1999, available in the public docket The only revision to this publicly
available document is a revised drinking water assessment discussed in the dietary risk section above.
1. Environmental Fate and Transport
Although tiie environmental fete database for methamidophos is not complete, supplemental
information from upgradable laboratory studies indicate mat metnamidophos is not persistent in aerobic
environments but may be persistent in anaerobic aquatic environments where it will be associated with
the aqueous phase. No acceptable data are available on the behavior of methamidophos under field
conditions, but information from acceptable terrestrial field dissipation studies for acephate indicate that
methamidophos is not persistent
Aerobic soil metabolism is the main degradative process for methamidophos. Methamidophos
degraded with a calculated half-life of 14 hours in a sandy loam soil at exaggerated applications rates.
Its major degradates also rapidly degrade in soil (half-life < four days). Methamidophos
photodegrades rapidly on soil (half-life of 63 hours) but photodegrades very slowly in sterile aqueous
solutions (half-life of > 200 days) and is stable against hydrolysis under acidic conditions..
Laboratory studies show that methamidophos is very soluble and very mobile. The
methamidophos degradate DMPT is also expected to be very mobile. Because methamidophos and its
degradate are not persistent under aerobic conditions, little methamidophos residue could be expected
to leach to groundwater. Volatilization from soil water is not expected to be a major route of
25
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dissipation for methamidophos because of its rapid metabolism in soil and its calculated Henry's
constant of 1.6 x 10"11 mole/m3.
2. Ecological Risk Assessment
The Agency's ecological risk assessment compares toxicity endpoints from ecological studies
to estimated environmental concentrations (EECs) based on environmental fete characteristics and
pesticide use data. To evaluate die potential risk to nontarget organisms from the use of
methamidophos products, the Agency calculates a Risk Quotient (RQ), which is the ratio of the EEC to
the toxicity endpoint values, such as the median lethal dose (LDSO) or the median lethal concentration
(LC50). These RQ values are then compared to the Agency's levels of concern (LOCs) which
indicates whether a chemical, when used as directed, has the potential to cause undesirable effects on
nontarget organisms. In general, the higher the RQ the greater the concern. When the RQ exceeds the
LOG for a particular category (e.g. endangered species), the Agency presumes a risk of concern to
that category. The LOCs and the corresponding risk presumptions are presented in Table 9.
Table 9. LOCs and Associated Risk Presumptions
IF... " ITHEN the Agency presumes...
Mammals and Birds
The acute RQ > LOC of 0.5,
The acute RQ >LOC of 0.2,
The acute RQ > LOC of 0.1,
The chronic RQ > LOC of 1
Acute risk
Risk that may be mitigated through restricted use
Acute effects may occur in Endangered species
Chronic risk and
Chronic effects may occur in Endangered species
Fish and Aquatic Invertebrates
The acute RQ > LOC of 0.5
The acute RQ > LOC of 0.1
The acute RQ >LOC of 0.05
The chronic RQ > LOC of 1
Acute risk
Risk that may be mitigated through restricted use
Acute effects may occur in Endangered species
Chronic risk and
Chronic effects may occur in Endangered species
Plants
The RQ > LOC of 1
The RQ > LOC of 1
Acute risk
Acute risk and endangeed plants may be affected
a. Ecological Hazard Profile
Avaian/Mammaliam
Based on a review of the available toxicity database, data for birds showed methamidophos to
be highly to very highly toxic for acute oral exposure and slightly to very highly toxic for subacute
dietary exposure. Table 10 summarizes selected acute toxicity information for birds.
26
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Table 10. Acute Oral Toxicity to Birds
Species
Acute Oral (Singh
Mallard Duck
Northern Bobwhite Quail
Common Crackle
Dark eyed Junco
LDH (mg/kg) JToxicity Category
t dose by gavage)
8.48
8
6.7
8
Very highly toxic
Very highly toxic
Very highly toxic
Very highly toxic
Subacute dietary1 (five days of treated feed)
Mallard Duck
Northern Bobwhite Quail
847.7
42
Moderately toxic
Very highly toxic
The effects in avion reproduction testing included reduced egg thickness. Table 11 summarizes
the results of the chronic toxicity tests for avion species.
Table 11. Avian Reproductive Toxicity
Species/
Study Duration
Northern bobwhite
Mallard duck
NOEC (ppm ai)
3
>15
LOEC (ppm ai)
5
>15
LOEC Endpoints
Egg thickness
No Effect
Wild mammal testing is not required for methamidophos. Rat toxicity values obtained from the
Agency's Health Effects Division (HED) substitute for wild mammal testing. Acute and chronic rat
toxicity data relevant to ecological effects show that methamidophos is highly toxic to small mammals on
an acute oral and dermal basis and is considered highly toxic to bees.
Aquatic
Data, for freshwater fish showed methamidophos to be slightly toxic for acute exposure. For
freshwater aquatic invertebrates, data indicated mat methamidophos is very highly toxic for acute
exposure. Data for estuarine and marine fish showed methamidophos to be moderately toxic for acute
exposure. For estuarine and marine aquatic invertebrates, data indicated mat methamidophos is slightly
to very highly toxic for acute exposure. Data was either not required (fish) or unavailable
(invertebrates) to assess the chronic effects of methamidophos. Table 12 summarizes invertebrate
toxicity.
Table 12. Acute Toxicity to Aquatic Invertebrates
Species,
Study Type
ECH(ppmai)
48-hr
96-hr
Toxicity Category
Freshwater
27
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Table 12. Acute Toxicity to Aquatic Invertebrates
Waterflea
0.026
-
Very highly toxic
Estuarine/Marine
Oyster
Blue Shrimp
Mysid Shrimp
-
-
-
36
0.00016
1.05
Slightly toxic
Very highly toxic
Moderately toxic
b.
Risk to Birds and Mammals
EPA uses models to estimate exposure of nontarget plants and animals to methamidophos. For
terrestrial birds and mammals, the Agency first estimates initial levels of pesticide residues on various
wildlife food hems. Acute and chronic risks to birds and mammals were predicted for the liquid
formulations of methamidophos.
The Agency's assessment suggests the potential for the liquid formulation to cause acute effects
to birds for broadcast applications. The avian acute RQs range from 0.38 to 6.63. The highest avian
acute RQ is from nine 1 Ib ai/A ground or aerial applications to tomatoes. Regarding chronic risk to
birds, the RQs range from 2.49 to 32.87. Table 13 summarizes the risk quotients for birds.
Table 13. Avian Acute and Chronic Risk Quotients Based on Bobwhite Quail
Number of Applications
Tomatoes at 5 app at 1.0 Ib ai
Tomatoes at 9 app at 1 .0 Ib ai
Potatoes/Cotton at 4 app at 1 .0 Ib
ai
Diet
Short grass
Tall grass
Broad Leaf
Seed Fruit
Short grass
Tall grass
Broad Leaf
Seed Fruit
Short grass
Tall grass
Broad Leaf
Seed Fruit
EEC (ppm)
Max.
256
117
144
16
278
128
157
17
256
117
144
16
Mean
91
38
48
7
99
42
52
8
91
38
48
7
Risk Quotient
Acute
6.10
2.79
3.43
0.38
6.63
3.04
3.73
0.41
6.10
2.79
3.43
0.38
Chronic
30.22
12.80
16.00
2.49
32.87
13.92
17.40
2.71
30.22
12.80
16.00
2.49
For the same use patterns, mammalian acute RQs range from 02 to 20.3 and in chronic RQs
for mammals ranging from 0.75 to 9.86. All use patterns are of concern to the Agency for acute and
28
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chronic effects to birds and mammals.
c. Risk to Aquatic Animals
To assess potential risk to aquatic animals, the Agency uses a computer model to generate
EECs of methamidophos in surface water. However, unlike the drinking water assessment described in
the human health risk assessment section of this document, the ecological water resource assessment
does not include the index reservoir and percent crop area factor. These refinements are solely used to
assess pesticide exposure to humans from drinking water sources. Hence, the EECs used to assess
exposure to aquatic animals are not the same as the EEC values used to assess human dietary exposure
from drinking water sources.
Acute risk to freshwater fish and estuarine fish is not of concern for any use patterns, with RQs
ranging from <0.05 to 0.07. The acute high risk, restricted use risk and endangered species risk is of
concern for freshwater invertebrates at the maximum application rate of 1.0 Ib ai/A with RQs ranging
from 1.1 to 3.0. Risk may be of concern for some estuarine invertebrates based on supplemental data
on blue shrimp. No chronic risk assessment was conducted since there are no chronic data for aquatic
species.
d. Incidents
Approximately six wildlife mortality incidents likely not to be associated with misuse have been
reported to the Agency since 1980. Four of these incidents involved crops which are no longer
registered. Three of these incidents involved adverse impacts on bee colonies including two from use
on potatoes.
e. Endangered Species
Endangered species LOCs are exceeded for acute and chronic risks to birds and mammals and
acute risks to freshwater invertebrates for all currently registered uses of methamidophos.
The Agency is currently engaged in a Proactive Conservation Review with FWS and the
National Marine Fisheries Service under section 7(aXl) 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 methamidophos use to federally listed threatened and endangered species. At that time the
Agency will also consider any regulatory changes recommended in the IRED mat 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
IRED which address methamidophos, will serve as interim protection measures to reduce the likelihood
that endangered and threatened species may be exposed to methamidophos at levels of concern.
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C. Benefits
The Agency has assessed the benefits of all registered uses of methamidophos. A summary of
the Agency's benefits findings is presented below; for more information, see the following documents:
Use and Usage Analysis for Methamidophos, dated November 20, 2001, and Methamidophos Use
on Cotton, Tomatoes and Potatoes, dated December 6,2001. All of these documents are available
in the public docket and on the internet
Alfalfa for Seed
In 2000, more than 50% of the alfalfa seed acreage in California was treated with
methamidophos. The primary target pest of methamidophos applications is h/gus bug, which is a key
pest in alfalfa seed. Lygus bug can cause significant economic damage to alfalfa grown for seed
throughout the growing season. Methamidophos is an important element of a resistance management
program for this pest early in the season, before introducing pollinators into the fields. It is the most
effective chemical for lygus bug control at this time of the season. The alternatives to methamidophos
include methidafhion, which is less effective; and synthetic pyrethroids, which have limited use due to
problems with resistance. Methamidophos is applied once per season at an average rate of one pound
per acre.
Cotton
In 2000, an estimated 2% of the U.S. cotton acreage was treated with methamidophos.
Arkansas and Louisiana reported 4% of state cotton acreage treated in that year, while California
reported 2%. The average number of applications made to cotton per year is one at an average
application rate of 0.3 pounds of active ingredient per acre. In California, methamidophos use is
targeted primarily for the control of lygus bugs. State cotton specialists have indicated that
methamidophos is an important part of their IPM programs in California and also noted that lygus bugs
are developing resistance to some alternatives to methamidophos. The alternatives to methamidophos
for lygus bug control include acephate, aldicarb, bifenthrin, cyfiuthrin, cypermethrin, dimethoate,
oxamyL, and zetamethrin.
In Louisiana and Arkansas methamidophos applications are targeted primarily for control of
whiteflies and thrips. State experts in Louisiana have indicated that a shifting thrip species population in
that state has increased the importance of methamidophos use there. For thrip control, the alternatives
to methamidophos include acephate, aldicarb, dicrotophos, imidacloprid and phorate. For the control
of whiteflies the alternatives include acephate, buprofezin, chlorpyrifos, fenpropathrin, profenofos, and
pyriproxifen.
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Potatoes
In 2000, an estimated 29% of the U.S. potato acreage was treated with methamidophos.
Washington reported 80% of state acreage treated in that year, while Idaho, Oregon and Pennsylvania
all reported greater than 28% of state acreage treated. The average number of applications made to
potatoes per year ranged from 1 to 3.2 at an average application rate of between 0.6 and 1.0 pound of
active ingredient per acre. Methamidophos application in potatoes is generally a 7 -10 day
preventative program and cannot be applied within 14 days of harvest
The three primary target pests for use of methamidophos on potatoes are green peach aphid,
Colorado potato beetle and leafhoppers. Pre- and post-emergence control of the green peach aphid, a
vector for the potato leafroll virus, is the critical methamidophos use in most areas of the country.
Alternatives for pre-emergence control include aldicarb, imidacloprid and phorate. Only imidacloprid is
a potential alternative for post-emergence control but it is significantly more costly and does not have
the period of residual effectiveness that methamidophos has that is necessary in some potato growing
regions. There is also concern for potential resistance in some regions for imidacloprid. Aldicarb's use
for pre-emergence control is limited due to a ISO day pre-harvest interval (PHI). These circumstances
make methamidophos critical to potato production, especially in the production of potatoes for seed,
where there is zero tolerance for aphids or the viruses they carry.
For Colorado potato beetle control, alternatives to methamidophos include carboruran,
esfenvalerate, endosulfan, imidacloprid and phosmet The effectiveness of the alternatives vary by
region. In the major production areas, carbofuran and methamidophos are the most efficacious
pesticides for controlling this pest. For the control of leamoppers in potatoes, there are a number of
registered alternatives to methamidophos, however, only carbaryl may provide acceptable efficacy.
Tomato (Fresh)
In 2000, an estimated 15% of the U.S. fresh market tomato acreage was treated with
methamidophos. This is down from an estimated 60% of the U.S. fresh tomato crop treated with
methamidophos in 1994. In Florida, which accounts for more than 40% of U.S. fresh market tomato
production, 14% of the fresh tomato acreage was treated with methamidophos in 2000. In California,
which accounts for 30% of U.S. fresh market tomato production, 8% of the fresh tomato acreage was
treated with methamidophos in 2000. In Georgia, North Carolina, South Carolina and Tennessee,
which account for a combined 10% of U.S. fresh market tomato production, 86%, 58%, 46% and
22% of the tomato acreage in each state was treated with methamidophos in 2000, respectively. The
average number of applications made with methamidophos to fresh market tomatoes per year ranged
from 12 to 3.3, with average application rates ranging from 0.5 and 1.0 pound of active ingredient per
acre.
Methamidophos is used primarily to control Western flower thrips in fresh tomatoes in the
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Southeastern U.S. This pest a primary vector of Tomato Spotted Wilt Virus, which can reduce the
marketable yields on fresh tomatoes by up to 50%. Methamidophos applications are critical for the
control of this pest because growers target as many as 5-6 insecticide applications per season for this
pest, and the only effective alternative to methamidophos, spinosad, is limited to two applications per
season. Without methamidophos, growers would not achieve sufficient control of the pest, and would
likely face significant yield losses from the virus.
Methamidophos is also used to control silverleaf whitefly in the Southeastern U.S. This is a
difficult pest to manage and it transmits Tomato Mottle Virus and Tomato Yellow Leaf Curl Virus,
which can cause significant tomato damage. Methamidophos is considered to be important as a cost-
effective synergist mixed with a synthetic pyrethroid insecticide to control this pest The alternatives to
methamidophos to control silverleaf whitefly include endosulfan, esfenvalerate, fenpropamrin,
imidacloprid, permethrin, pymetrozine, pyriproxifen and thiamethoxam.
In California, the primary target pest for methamidophos on fresh tomatoes is stink bug.
Methamidophos is the only effective insecticide available for controlling this economically important
pest The primary alternatives to methamidophos for the control of this pest are limited in their
effectiveness. Imidacloprid is only effective against low populations, dimethoate is a severe hazard to
bees, and endosulfan has waterway restrictions which limit its use. Without methamidophos, growers
would not achieve sufficient control of the pest, and would likely face significant yield losses.
, Methamidophos is applied to fresh tomatoes late in the growing season in California
Therefore, many cultural activities such as weeding, pruning, staking and lying are completed well in
advance of application of this material. By contrast, in the Southeastern U.S., methamidophos is
applied throughout the season, resulting in applications before or soon after these activities occur in the
field. Current labels require a 7 day PHI.
Tomato (Processed}
California accounts for more than 95% of the U.S. production of processed tomatoes. In
2000, an estimated 3% of the California processed tomato acreage was treated with methamidophos.
Methamidophos usage on processed tomatoes has seen a steady decline since the mid-1990's. An
average of one application is made with methamidophos to California processed tomatoes per year,
and slightly less than one pound of active ingredient is applied on average per acre per application.
As in the case of fresh tomatoes in California, the primary target pest of methamidophos
application to processing tomatoes is stink bug. The limitations mentioned earlier on the primary
alternatives to methamidophos for control of this pest, make methamidophos an important tool in
processed tomato production.
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Methamidophos is applied to processed tomatoes late in the growing season in CA. Therefore,
many cultural activities such as weeding, pruning, staking and tying are completed well in advance of
application of this material. Current labels require a 14 day PHI in CA.
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IV. Interim Risk Management and Reregistration Decision
A. Determination of Interim Reregistration Eligibility
Section 4(gX2XA) of FIFRA calls for the Agency to determine, after submissions of relevant
data concerning an active ingredient, whether products containing the active ingredient are eligible for
reregistration. The Agency has previously identified and required the submission of the generic (i.e., an
active ingredient specific) data required to support reregistration of products containing methamidophos
active ingredient
The Agency has completed its assessment of the occupational and ecological risks associated
with the use of pesticides containing the active ingredient methamidophos, as well as a
methamidophos-specific dietary risk assessment that has not considered the cumulative effects of
organophosphates as a class. Based on a review of these data and public comments on the Agency's
assessments for the active ingredient methamidophos, EPA has sufficient information on the human
health and ecological effects of methamidophos to make an interim decision as part of the tolerance
reassessment process under FFDCA and reregistration under FIFRA, as amended by FQPA. The
Agency has determined that methamidophos products are eligible for reregistration provided that: (i)
current data gaps and additional data needs are addressed; (ii) the risk mitigation measures outlined in
this document are adopted including the phase out of the cotton use, and label amendments are made to
reflect these measures; and (iii) cumulative risks considered for the organophosphates support a final
reregistration eligibility decision.
As part of the Agency's ongoing process to review and take the necessary risk reduction
measures as required by FQPA, on December 4,2001, EPA released the preliminary cumulative risk
assessment for organophosphate pesticides for public comment. That assessment is based on
evaluation of the potential exposure of 31 total organophosphate pesticides from eating food, drinking
water, and residential sources. The assessment also takes into account EPA's past regulatory actions
on various pesticides, such as eliminating uses. Continuing the effort to ensure transparency of decision
processes, EPA conducted a technical briefing and presented the assessment to the Scientific Advisory
Panel for peer review and comment The Agency intends to release a revised cumulative risk
assessment during summer 2002.
Although the Agency has not yet considered its final cumulative risk assessment for the
organophosphates, the Agency is issuing this interim assessment now in order to identify risk reduction
measures that are necessary to support the continued use of methamidophos. Based on its current
evaluation of methamidophos alone, the Agency has determined that methamidophos products, unless
labeled and used as specified in this document, would present risks inconsistent with FIFRA.
Accordingly, should a registrant fail to implement any of the risk mitigation measures identified in this
document, the Agency may take regulatory action to address the risk concerns from use of
methamidophos.
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At the time that the cumulative assessment is finalized, the Agency will address any outstanding
risk concerns. For methamidophos, if all changes outlined in this document are incorporated into the
labels, then all currently recognized risks will be adequately managed. But, because mis is an interim
RED, the Agency may take further actions, if warranted, to finalize the reregistration eligibility decision
for methamidophos after assessing the cumulative risk of the organophosphate class. Such an
incremental approach to the reregistration process is consistent with the Agency's goal of improving the
transparency of the reregistration and tolerance reassessment processes. By evaluating each
organophosphate in turn and identifying appropriate risk mitigation measures, the Agency is addressing
the risks from the organophosphates in as timely a manner as possible.
Because the Agency has not yet concluded its cumulative risk assessment for the
organophosphates, this interim reregistration eligibility decision does not fully satisfy the reassessment of
the existing methamidophos food residue tolerances as called for by the Food Quality Protection Act
(FQPA). When the Agency has concluded its cumulative risk assessment, methamidophos tolerances
will be reassessed in that light At that time, the Agency will reassess methamidophos along with the
other organophosphate pesticides to complete the FQPA requirements and make a final reregistration
determination. By publishing this interim decision on reregistration eligibility and requesting mitigation
now for the individual chemical methamidophos, the Agency is not deferring or postponing FQPA
requirements; rather, EPA is taking steps to assure that uses which exceed FIFRA's unreasonable risk
standard do not remain on the label indefinitely, pending completion of assessment required under the
FQPA. This decision does not preclude the Agency from making further FQPA determinations and
tolerance-related rulemakings that may be required on this pesticide or any other in the future.
If the Agency determines, before finalization of the RED, that any of the determinations
described in this interim RED are no longer appropriate, the Agency will pursue appropriate action,
including but not limited to, reconsideration of any portion of this interim RED.
Label changes for methamidophos are described in Section IV. Appendix B identifies the
generic data requirements that the Agency reviewed as part of its interim determination of reregistration
eligibility of methamidophos, and lists the submitted studies mat the Agency found acceptable. ,
B. Summary of Phase 5 Comments and Responses
When making its interim reregistration decision, the Agency took into account all comments
received during Phase 5 of the OP Public Participation Process. These comments in their entirety are
available in the docket The Agency received comments from the technical registrant Bayer
Corporation. Comments were also received from the National Potato Council, the California Tomato
Research Institute, the National Agricultural Aviation Association, Florida Fruit and Vegetable
Association, Washington State University, California Tomato Commission and Environmental Focus.
The Agency also received approximately 10 comments from various agri-business companies and
associations, commodity groups, farm bureaus, universities, extension, and state agencies, as well as
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private citizens, supporting the use of methamidophos. A brief summary of the comments and the
Agency response is noted here.
Registrant Comments
Comment: Bayer noted differences between dietary assessment conducted by EPA versus the
Bayer assessment. The three main differences noted were (1) processing factors used,
particularly in tomato residue assessment, (2) percent crop treated data used and (3)
imputation of composite residue data appears to be inappropriate and exaggerates
high-end predictions for residues.
Response: The dietary assessment was conducted with the best available data and in accordance
with Agency policy. The most recent dietary assessment reflects some of the concerns
noted by the registrant These include changes to the % crop treated and the use of
processed tomato data.
Comment: Some assumptions used by the Agency in the assessment appear not to be reflective of
assumptions supported by data the Agency has on hand. The risk assessment uses
transfer coefficients ranging from 2500 to 10000 whereas recent studies have shown
that more realistic values range from 100 to 650 for activities such as scouting and
harvesting.
Response: The risk assessment has been revised to incorporate updated TC's which were
generated as a result of the ARTF data. The range of TC's used is 300 to 1500
depending on the crop involved and die activity being evaluated.
Comment: The assessment also appears to have inadequately considered the personal protective
equipment requirements specified on the product label. The revised assessment failed
to use NIOSH exposure reduction factors for the label specified respiratory protection.
The revised assessment also used dermal exposure reduction factors that are not
consistent with exposure reduction factors used by other regulatory agencies or with
exposure reduction factors derived from PHED data.
Response: Where possible, the labeled PPE was accounted for in the various PPE scenarios
evaluated in the risk assessment There are some PPE, such as chemical-resistant
aprons, that the Agency views as qualitative measures because there are no recognized
protection factors (PF) to assess their effectiveness. The Agency has no protection
factors to assess headgear. Face and neck wipe monitoring data constitutes dermal
head exposure values. All occupational handlers were assessed as wearing footwear
(socks plus shoes or boots), foot exposure is not traditionally monitored, and therefore,
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a 100 percent protection factor is implied. Finally, inhalation exposures were not the
most significant risk factor, (if protection factors were increased, little change in
combined MOEs would result).
Comment: The uncertainty attributed to interspecies variability for the selected endpoint is not
supported by available human and animal data. Therefore Bayer believes that an MOE
of 10 provides an adequate margin of safety for the product and should be used for the
methamidophos occupational exposure and risk assessment.
Response. Consistent with the Agency's policy announced on December 14,2001, this
assessment does not consider or rely on any third-party studies which intentionally dose
human subjects with toxicants to identify or quantify their effects. Therefore, the
Agency continues to employ the uncertainty of 100.
Washington State University
Comment: Comments that EPA rejected a human exposure study and indicated that if these results
were used, the 100-fold uncertainty factor applied to the chronic RfD could be
confidently reduced.
Response: Consistent with the Agency's policy announced on December 14,2001, this
assessment does not consider or rely on any third-party studies which intentionally dose
human subjects with toxicants to identify or quantify their effects. Therefore, the
Agency continues to employ the 100-fold uncertainty factor.
Comment: The potato processing study, although submitted by the manufacturer, has some serious
methodological flaws as pointed out by the Agency. Consequently, the 10X
concentration factor for potato chips is completely unrealistic. The DEEM analysis for
tomato puree has an ambiguous entry. The stated processing factor for tomato puree is
0.7, yet the acute DEEM analysis shows that there are several puree types with factors
of 3.3.
Response: Although some irregularities were noted in the potato processing study, the Agency
concluded that these actions did not likely affect the overall conclusions of the study.
Unless additional information is provided, the 10X concentration factor will continue to
be used in the dietary assessment With respect to tomatoes, a revised dietary
assessment has been conducted which incorporates monitoring data for processed
tomatoes. Since actual processed commodity data was used, a processing factor was
not applied. Consequently, the concerns about the tomato processing factor is no
longer applicable.
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Comment: The post application exposure scenario included hand harvesting of potatoes. This is a
situation that is a remote exception rather than the rule. Further, a question was raised
as to the use of different transfer coefficients for different compounds having the same
post occupational activity.
Response: The current policy on transfer coefficients lists potatoes under Vegetables, "root".
Within the root vegetable category, mechanical potato harvesting exposure was
assigned a value of 0. Hand harvesting was listed as out of scope of the transfer
coefficient table. Therefore, hand harvesting is no longer a scenario for which risk
estimates are developed.
California Tomato Research
Comment: The commentor states that the PDF data are not representative of California's 95%
portion of the US processed crop and mat using the PDF data coupled with a
processing factor does not deliver a relevant or accurate processed methamidophos
exposure. Use information and residue data collected by California Department of
Pesticide Regulation was provided.
Response: As discussed earlier, a revised dietary assessment which includes USDA monitoring
data for processed tomatoes and percent crop treated information which separates
processed and fresh tomato has been conducted.
Environmental Focus
Comment: Environmental Focus has concerns pertaining to assigning a 1 5% default value for drift
when applying methamidophos next to surface water. The AgDRIFT model does not
specify a drift default value associated with aerial application.
Response: The 15% value is the result of the adoption of the AgDRIFT model, which when used
with default values for droplet size, pond size and wind speed gives that result The
modeling conducted by the Agency is intended to be a conservative screening
assessment The assumptions made are not considered unreasonable and fall within the
range of allowed use of the chemical.
Comment: Environmental Focus has concerns that the Agency uses a scenario in its assessment
that assumes an aerial applicator will apply next to a drinking water supply when wind
speed is 10 mph.
Response: The models are used as a screening tool and, as such, are intended to simulate
situations mat could occur in the field. The modeling is done according to the label, and
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in conditions that are not intended to be typical but are realistic.
National Agricultural Aviation Association
Comment: NAAA is concerned mat the data the EPA uses to determine the occupational risk
associated with the aerial application are outdated and overly conservative.
Specifically, PHED does not include data on worker exposure subsequent to 1992-
which is before the Worker Protection Standards went into effect at a time when many
techniques and equipment to protect workers became commonplace. NAAA
believes that if more current data that takes into account technological advancements
that enhance worker protection, any exposure assessment would demonstrate an
adequate margin of safety for those involved aerial application including new
technological advances.
Response: The Agency considered this comment during the risk mitigation process. The Agency
would consider any data that the NAAA would submit
Comment: NAAA has concerns pertaining to assigning a 15% default value for drift when applying
methamidophos next to surface water. The AgDRIFT model does not specify a drift
default value associated with aerial application.
Response: See earlier response to similar question.
C Regulatory Position
1. FQPA Assessment
a. "Risk Cup" Determination
As part of the FQPA tolerance reassessment process, EPA assessed the risks associated with
this organophosphate. The assessment is for this individual organophosphate, and does not attempt to
fully reassess these tolerances as required under FQPA. FQPA requires the Agency to evaluate food
tolerances on the basis of cumulative risk from substances sharing a common mechanism of toxichy,
such as the toxichy expressed by the organophosphates through a common biochemical interaction with
the cholinesterase enzyme. The Agency will evaluate the cumulative risk posed by the entire class of
organophosphates once the methodology is fully developed and the policy concerning cumulative
assessments is resolved.
EPA has determined that risk from exposure to methamidophos is within its own "risk cup." In
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other words, if methamidophos did not share a common mechanism of toxicity with other chemicals,
EPA would be able to conclude today that the tolerances for methamidophos meet the FQPA safety
standards, provided the risk mitigation measures outlined in this document are implemented and
additional data needs are addressed In reaching this determination EPA has considered the available
information on the special sensitivity of infants and children, as well as the chronic and acute food
exposure. An aggregate assessment was conducted for exposures through food, residential uses, and
drinking water. Results of this aggregate assessment indicate that the human health risks from these
combined exposures are considered to be within acceptable levels. While the combined risks from all
exposures to methamidophos "fill" the aggregate risk cup, the water exposures are based on screening-
level modeling estimates. Hie Agency has determined that actual drinking water exposures are likely to
be lower than predicted by these models and has made a regulatory determination that combined risks
from all exposures to methamidophos "fit" within the individual risk cup. Except for those tolerances
that are to be lowered or revoked, the current methamidophos tolerances remain in effect and
unchanged until a full reassessment of the cumulative risk from all organophosphates is considered later
this year.
b. Tolerance Summary
Tolerances for residues of methamidophos in/on plant commodities [40 CFR §180.315 (a) and
(b)] are currently expressed in terms of residues of methamidophos/jer se.
The available plant and animal metabolism studies indicate that the residue of concern is the
parent methamidophos. Methamidophos is also a metabolite of acephate. It is recommended that
residues of methamidophos resulting from the metabolism of acephate be included under the tolerance
regulations for methamidophos as a pesticide [40 CFR §180.315(c)]. This change is needed to
achieve compatibility with the MRLs of the Codex Alimentarius Commission, if only in terms of residue
definition. Such a change in the residue definition requires deletion of paragraph (d) (8) of 40 CFR
§180.3 which states mat methamidophos residues may not exceed the higher of the two tolerances
established for the use of acephate or methamidophos as a pesticide.
The listing of methamidophos tolerances under 40 CFR §180.315 should be subdivided into
parts (a), (b), and (c). Part (a) should be reserved for permanent tolerances, part (b) for tolerances
with regional registration, and part (c) for tolerances reflecting use of acephate formulations alone (i.e.,
no methamidophos formulations are registered for use on these commodities).
The Agency will commence proceedings to revoke and modify existing tolerances, and correct
commodity definitions. The establishment of a new tolerance or raising tolerances will be deferred,
pending consideration of cumulative risk for the organophosphates. "Reassessed" does not imply that
all of the tolerances have been reassessed as required by FQPA, since these tolerances may only be
reassessed once the cumulative risk assessment of all organophosphate pesticides is considered, as
required by the statute. Rather, this IRED provides reassessed tolerances for methamidophos in/on
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various commodities, supported by all the submitted residue data, only for the single organophosphate
chemical methamidophos. EPA will finalize these tolerances after considering the cumulative risks for
all organophosphate pesticides. The Agency's tolerance summary is provided in Table 14. This table
lists several tolerances associated with uses that are no longer registered, as announced in FIFRA
6(fXl) Notices of Receipt of Requests from the registrant for cancellation and/or use deletion, which
EPA approved. Therefore, the associated tolerances should be revoked.
Table 14. Tolerance Summary for Methamidophos
Commodity
Tolerance Listed
Under 40 CFR
§180315
Reassessed
Tolerance
Tolerance Listed
Under 40 CFR
§180.108
Comment
[Correct Commodity Definition]
Tolerances Listed Under 40 CFR §180.315 ()
Beets, sugar, roots
Beets, sugar, tops
Broccoli
Brussels sprouts
Cabbage
Cauliflower
Cottonseed
Cucumbers
Eggplant
Lettuce, head
Melons
Peppers
Potatoes
Tomatoes
0.02
0.50
1.0
1.0
1.0
1.0
0.1 (N)
1.0
1.0
1.0
0.5
1.0
0.1(N)
1.0
Revoke
Revoke
Revoke
1.0
Revoke
0.5
0.2
Revoke
Revoke
1.0
Revoke
1.0
0.1
2.0
-
-
-
0.5
--
0.5
-
-
1
- '
1
The registrants are not supporting
there are no registered acephateuses.
The registrants are not supporting
methamidophos use on broccoli and there
are no registered acephate uses.
This tolerance must be moved to
§180.315(c).
The registrants are not supporting
methamidophos use on cabbage and there
are no registered acephate uses.
This tolerance must be moved to
§180.315(c).
[Cotton, undelinted seed\
The registrants are not supporting
methamidophos use on cucumbers and
there are no registered acephateuses.
The registrants are not supporting
methamidophos use on eggplant and there
are no registered acephate uses.
This tolerance must be moved to
§180.315(c).
The registrants are not supporting
methamidophos use on melons and there
are no registered acephate uses.
This tolerance must be moved to
§180.315(c). [Pepper, bell and non-bell]
Tolerance To Be Proposed Under 40 CFR §180315 (a)
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Commodity
Cotton, gin
byproducts
Tolerance Listed
Under 40 CFR
§180315
-
Reassessed
Tolerance
10
Tolerance Listed
Under 40 CFR
§180.108
-
Comment
/Correct Commodity Definition/
Tolerance Listed Under 40 CFR §180315 (b)
Celery
1
1.0
1
This tolerance must be moved to
§180315(c).
Tolerances to be Listed Under 40 CFR §180315(c)
Beans (succulent
and dry form)
Brussels sprouts
Cauliflower
Celery
Cranberries
Lettuce
Mint hay
Peppers
Soybeans
-
1.0
1.0
1
~
1.0
-
1.0
-
1.0
1.0
1.0
1.0
0.1
1.0
2
1.0
-
1
0.5
0.5
1
0.1
1
1
1
1
Beans, dry and succulent]
Lettuce, head]
Mint, tops (leaves and stem)]
Teppers, bell and non-bell]
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Tolerances Listed Under 40 CFR §180.315 (a)
Pending label amendments for some crops, adequate field trial data are available to reassess the
established tolerances for cottonseed, potatoes, and tomatoes. The available data suggest that the
tolerance levels for cottonseed and tomato should be raised to 0.2 ppm and 2.0 ppm, respectively.
The use of methamidophos on Brussels sprouts, cauliflower, lettuce, and peppers was cancelled in
1997. Because there are registered acephate uses on these crops, methamidophos tolerances for these
crops should be moved to 40 CFR § 180.315(c).
The following tolerances should be revoked as the registrants are not supporting methamidophos
uses and there are no registered acephate uses on these commodities: beets, sugar, roots; beets, sugar,
tops; broccoli; cabbage; cucumbers; eggplant; and melons.
Tolerance to be Proposed Under 40 CFR §180315 (a)
A tolerance for residues of methamidophos in/on cotton gin byproducts must be proposed. The
available data support a tolerance level of 10 ppm.
Tolerance Listed Under 40 CFR §180315 (b)
The use of methamidophos on celery was cancelled in 1997. Because there are registered acephate
uses on this crop, the methamidophos tolerance for this crop should be moved to 40 CFR
§180.315(c).
Tolerances to be Listed Under 40 CFR §180 J15(c)
The basic producer of acephate (Valent U.SA. Corporation) intends to support use of acephate on
the following food/feed crops: beans (snap, dry, and lima); Brussels sprouts; cauliflower; celery;
cotton; cranberries; lettuce, head; peanut; pepper, non-bell; pepper, bell; peppermint/spearmint;
soybean; and tobacco. Therefore, tolerances for residues of methamidophos in/on these commodities
(except tobacco) resulting from use of acephate should be established under 40 CFR §180.315(c).
The tolerance expression in mis section should read: 'Tolerances are established for residues of
methamidophos in or on the following raw agricultural commodities as a result of the application of
acephate:".
Tolerances for combined residues of acephate and methamidophos in cottonseed meal and hulls
have been established (40 CFR §180.108). However, based on a cottonseed processing study
submitted to satisfy methamidophos reregistration requirements, methamidophos residues do not
concentrate in cottonseed processed commodities. Therefore, tolerances for methamidophos residues
in cottonseed processed commodities are not required under 40 CFR §180.315(c).
43
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A tolerance for the combined residues of acephate and methamidophos in soybean meal has been
established (40 CFR §180.108). Data for soybean processed commodities were reviewed in the
Acephate Reregistration Standard Update (dated 1/29/92). In one study conducted in 1978, soybeans
were treated with three applications of a 75% SC/S formulation at 1 or 2 Ib ai/A/application (2x or 4x
the maximum seasonal rate Valent wishes to support). Methamidophos residues were found to
concentrate slightly in soybean meal (average concentration of 12x) and hulls (average concentration of
1.9x) but not in crude oil. In a second study conducted in 1987, soybeans were treated with 11
applications of a 75% SC/S formulation at 2 Ib ai/A/application (~ 15x the maximum seasonal rate
Valent wishes to support). Methamidophos residues were 0.01-0.02 ppm in/on soybeans, 0.02 ppm in
meal, 0.02 ppm in hulls and O.01 ppm in refined oil. Based on the exaggerated application rates used
in the studies and the resulting residues in processed commodities, the Agency concludes that no
tolerances are required for methamidophos residues in soybean processed commodities.
For mint hay, data submitted by the registrant since die tolerance was set support an increase in the
tolerance.
Tolerances Listed Under 40 CFR §180315(a) and (b)
Tolerances have been established for residues of methamidophos in/on various raw agricultural
commodities [40 CFR §180.315(a) and (b)]. In addition, tolerances have been established for
combined residues of acephate and its metabolite methamidophos in/on various plant and animal
commodities [40 CFR §180.108(a) and (b)]. Tolerances established for acephate in/on several
commodities (beans, Brussels sprouts, cauliflower, celery, cranberries, lettuce, mint hay, and peppers)
include limits on residues of methamidophos.
Residue Analytical Methods
Adequate methods are available for data collection and tolerance enforcement for plant
commodities. For tolerance enforcement, the Pesticide Analytical Manual (PAM) Vol. n lists a GLC
method (designated as Method 1) with thermionic detection tor the determination of methamidophos
(LOD = 0.01 ppm) residues in/on plant commodities. PAM Vol. H also lists a TLC method
(designated as Method A) as a confirmatory method. Adequate radiovalidation data for the
enforcement method using samples from the plant metabolism studies have been submitted and
evaluated.
Because no tolerances are required for animal commodities, no enforcement method for animal
commodities is required.
CODEX Harmonization
The Codex Alimentarius Commission has established several maximum residue limits (MRLs) for
residues of methamidophos in/on various plant and animal commodities. The Codex MRLs are
expressed in terms of methamidophos per se. The expression of residues for Codex MRLs and U.S.
tolerances is harmonized. A numerical comparison of the Codex MRLs and the corresponding
44
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reassessed U.S. tolerances is presented in Table 15. Further harmonization of U.S. tolerances and
Codex MRLs are not feasible at this time because of differences in agricultural practices.
Table 15. Codex MRLs and Applicable U.S. Tolerances for Methamidophos.
Codex
Commodity, As Defined
Alfalfa forage (green)
Brussels sprouts
Cabbages, Head
Cattle fat
Cattle meat
Cauliflower
Celery
Cottonseed
Cucumber
Goat fat
Goat meat
Hops, dry
Lettuce, Head
Melons, except Watermelon
Milks
Peach
Peppers, Chili
Peppers, Sweet
Pome fruits
Potato
Rape seed
Sheep fat
Sheep meat
Soya bean (dry)
Sugar beet
Sugar beet leaves or tops
Tomato
Tree tomato
Watermelon
MRL
(rag/kg)
21
1
0.5 2
0.01 (*)'
0.01 (*)
0.5 2
1
O.I4
1
0.01 (*)
0.01 (*)
5
1
0.5
0.01 (*)
I2
2
1
0.5
0.05 4
0.1
0.01 (*)
0.01 (*)
0.05'
0.05
1
I2
0.01 (*) '
0.5
Reassessed U.S.
Tolerance, ppm
-
1.0
-
-
-
0.5
1.0
0.2
-
-
-
-
1.0
-
-
-
1.0
1.0
-
0.1
-
-
~
0.01
~
-
2
-
.
Recommendation And Comments
No U.S. registrations.
U.S. registrants not supporting use.
U.S. registrants not supporting use.
No U.S. registrations.
U.S. registrants not supporting use.
No U.S. registrations.
No U.S. registrations
No U.S. registrations
U.S. registrants not supporting use.
U.S. registrants not supporting use.
No U.S. registrations.
U.S. registrants not supporting use.
Based on treatment with acephate.
45
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2 The MRL is based on residues from the use of methamidophos, not acephate (1996 JMPR).
3 (*) = At or about the limit of detection.
4 Including residues resulting from the use of acephate.
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 the recommendations of its
Endocrine Disrupter Screening and Testing Advisory Committee (EDSTAQ, EPA determined that
there were scientific bases 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 the Program include evaluations of potential effects in wildlife. For pesticide chemicals, 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 Disrupter
Screening Program (EDSP).
When the appropriate screening and/or testing protocols being considered under the Agency's
EDSP have been developed, methamidophos may be subjected to additional screening and/or testing
to better characterize effects related to endocrine disruption.
3. Labels
A number of label amendments, in addition to die existing label requirements, are
necessary in order for methamidophos products to be eligible for reregistration. The Agency has
determined that these measures, in addition to the existing label requirements, will adequately reduce
risks to handlers.
Provided the following risk management measures are incorporated in their entirety into labels for
methamidophos-containing products, the Agency finds that all currently registered uses of
methamidophos are eligible for interim reregistration, pending consideration of cumulative risks of the
organophosphates. While all uses are eligible at this time, the cotton use will be phased out over five
years. The regulatory rationale for each of the risk management measures outlined below is discussed
immediately after this list of required risk management measures.
a. Agricultural Use Exposure Reduction Measures
For agricultural use, the following measures are required, in addition to the existing labeling
requirements to address drinking water, occupational handler and ecological risks of concern. The
registrant has not yet agreed to these measures.
Require all labels be amended to indicate that applications must be made using enclosed cab
tractors or enclosed cockpits.
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Require all labels be amended to indicate that flaggers must be in enclosed vehicles or mechanical
flaggers be used; or the use of ground positioning system (GPS) equipment mat negates the need
for flaggers for aerial application.
Require all labels to reduce maximum # of applications to 2 per season during phase out period
for cotton.
Require all labels to reduce maximum # of applications to 4 or less per season for tomatoes
(current SLNs mat have maximum # of applications less than 3 would retain that number of
applications).
Require all labels to increase REIs for all activities to 4 days for potatoes.
Require Section 24(c) labels to increase REIs for all activities to 4 days for tomatoes except in
CA where the REI will remain at 3 days.
b. Homeowner Use Exposure Reduction Measures
There are no residential uses for methamidophos.
D. Regulatory Rationale
The following is a summary of the rationale for managing risks associated with the use of
methamidophos. Where labeling revisions are imposed, specific language is set forth in the summary
tables of Section V of this document
1. Human Health Risk Mitigation
a. Dietary Mitigation
Dietary risk from food sources alone are not of concern. Screening level modeling estimates
indicate that aggregate methamidophos exposure from food and drinking water may fill the risk cup:
however, the Agency has determined that drinking water exposures are likely lower than predicted.
Therefore, the Agency has made an interim determination that no additional mitigation is necessary at
this time. EPA will require additional data to refine the drinking water modeling values and confirm this
interim conclusion.
1) Acute Dietary (Food)
Acute dietary (food) exposure to methamidophos from applications of methamidophos alone,
and from "all sources" (applications of methamidophos and acephate) result in risk estimates that are
below the Agency's level of concernmat is, less than 100% of the acute PAD is used. For example,
for exposure resulting from applications of methamidophos alone, for the most exposed subpopulation,
children 7-12 years old, the percent acute PAD value is 33% at the 99.9th percentile of exposure from
consumption of food alone.. For exposure resulting from applications of methamidophos alone and
methamidophos residues from the application of acephate, for the most exposed subpopulation, all
infants, the percent acute PAD value is 76% at the 99.9th percentile of exposure from consumption of
food alone. No mitigation measures are necessary at this time to address acute dietary risk from food.
47
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2) Chronic Dietary (Food)
Chronic dietary (food) exposure estimates are below the Agency's level of concern for all
subpopulations. For die most highly exposed subpopulation, children 1-6 years old, the percent
chronic PAD values are 15% for methamidophos alone and 37% when including methamidophos
residues from the application of acephate, from consumption of food alone. No mitigation measures are
necessary at this time to address chronic dietary risk from food.
3) Drinking Water
Surface water drinking water estimated concentrations were derived from the PRZM-EXAMS
model with the Standard Index Reservoir and percent crop area (PCA) and the GEENEC model (for
methamidophos derived from application of acephate). Ground water estimated concentrations were
derived from the SCI-GROW Model. These are screening level estimates designed to provide high-
end estimates of potential pesticide exposure. Such predictions provide a screen to eliminate those
chemicals that are not likely to cause concerns in drinking water, Exceedances in drinking water risk
assessments using the screening model estimates do not necessarily mean a risk of concern actually
exists, but may indicate the need for better data (e.g., monitoring studies specific to use patterns and
drinking water sources) on which to confirm decisions.
Based on model predictions of currently registered uses, the EECs for methamidophos from the
application of methamidophos in surface water range from 28.6 to 61.8 ppb for acute exposure, and
from 1.5 to 3.8 ppb for chronic exposure. The only surface water EEC calculated for methamidophos
from the application of acephate, using the Tier I GEENEC model is 22 ppb. The acute and chronic
EEC for methamidophos from all sources in groundwater is 0.033 ppb. Table 3 summarizes the
modeled EECs for the respective crop scenarios.
The acute and chronic dietary risks from drinking water exposure from ground water sources are
not of concern because the groundwater EECs are well below the DWLOCs. The acute and chronic
dietary risks from drinking water exposure from surface water sources are above the Agency's level of
concern for all subpopulations. However, there are uncertainties which lead the Agency to expect mat
actual exposure from drinking water is unlikely to be as high as the levels used in the development of the
risk assessment which are based on screening models. Based on these uncertainties and the anticipated
reduction in water contamination implementing the risk reduction measures contained in this document,
the Agency believes that the risks from drinking water are not of concern.
The drinking water risk assessments are based on screening level models that are conservative in
their estimates of drinking water exposure. Actual exposure is expected to be lower than the EEC's
reported in the IRED. An example of the type of assumptions used in the model that can contribute to
conservative estimates involves rainfall levels. To determine what rainfall level to use in the model, the
Agency identifies a peak rainfall level for each of 36 years of daily rainfall data. The model men
assumes that rainfall will equal the 90th percentile of these 36 annual peak values when estimating
concentrations, a conservative assumption. Also, the percent cropped area (PCA) assumption for
potatoes used in the model is 0.87, the default assumption. This means the model assumes that 87% of
a watershed is planted with one of these crops and mat 100% of this crop is treated with
48
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methamidophos, which appears unlikely to occur especially considering that the PCA calculated for
major crops like com and cotton using data submitted to the Agency are 0.46 and 0.20 respectively.
For example, with respect to the scenario with the highest calculated EEC, potatoes in Maine, it is
estimated that 65,000 acres of potatoes are grown in the state of Maine each year. If it was assumed
that all that acreage fell into any one of the nine watersheds in Maine as a worst-case scenario, the
range of PCA values would likely be 0.04 to 0.16 or 4% to 16%, significantly lower than the 87%
assumption. Hie effect of die PCA value on EECs has a linear relationship. Consequently, using these
values would reduce EECs by a factor of 5 to 20. Even though this analysis has not been deemed to be
sufficient to change the PCA quantitatively, it does provide a sense of the potential uncertainty of the
modeled water concentrations in this case.
With regard to die potential risks associated with acephate application, the model used to
estimate water concentrations is a tier I model and, as such, is not as refined as the tier IIPRZM-
EXAMS model. A higher-tiered model was not used in this case due to the high level of uncertainty
surrounding any estimate of the decay rate for acephate and the transformation rate of acephate to
methamidophos which are needed to use the PRZM-EXAMS model. This increases the level of
uncertainty associated with these estimates. For the purposes of assessing drinking water risks from
exposure to methamidophos from all sources (i.e. including bom methamidophos and acephate
applications) the Agency will rely upon the model estimates generated using the PRZM-EXAMS model
with the Index Reservoir (IR) and Percent Crop Area (PCA) modifications described above which are
based upon the application of methamidophos alone. The Agency believes mat the conservative default
PCA used for the scenario with the highest EEC (potatoes in ME) discussed above would most likely
account for methamidophos residues from both methamidophos and acephate applications in a given
watershed. As mentioned above, these estimates may be as much as a factor of 5 to 20 times greater
than actual water concentrations. Further, the main crop uses of acephate (beans, cotton, lettuce and
tobacco) are either not grown in Maine or are not likely to have significant acreage. Therefore,
additional contribution of methamidophos residue from the application of acephate in this scenario is
very unlikely. These considerations support the belief that this modeled EEC likely provides a
sufficiently protective estimate of exposure to methamidophos from all sources in drinking water.
Further, the information is not currently available to enable the Agency to use a Tier n model to
estimate concentrations of methamidophos from the application of acephate, as described above, and it
is not considered appropriate to combine the results of a Tier n assessment (methamidophos
applications) with the results of a Tier I assessment (acephate applications).
The risk reduction measures contained in this IRED, including a phase out of the cotton use and
the reduction in the maximum number of applications allowed per season for all crops, are expected to
reduce the amount of methamidophos available to reach surface waters. This supports the Agency's
belief that drinking water risks will be reduced to a level at which the risk cup is not exceeded.
Furthermore, for many chemicals where there are uncertainties in the modeling estimates, the
Agency also relies on actual monitoring data to confirm resultant expectations. Thus, for
methamidophos, the Agency is also requiring confirmatory surface water monitoring data to evaluate
actual acute and chronic concentrations of methamidophos in the drinking water sources. This
monitoring data is to be generated from a multi-year sampling program involving community water
systems from surface water sources in multiple locations in different regions of the country to represent
different use sites, crops, soil types, and rainfall regimes. Water samples are to be analyzed to
49
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determine the concentrations of methamidophos. Also, prior to initiating this sampling program, the
registrant is required to submit a study protocol to the Agency to ensure that the sampling locations and
procedures are adequate to address the drinking water risk concerns.
b. Homeowner Risk Mitigation
Methamidophos is not registered for use in residential settings. Previously, acephate had
numerous residential, recreational and institutional uses which were evaluated in the acephate RED.
To mitigate risks of concern, acephate use in these settings have been limited to indoor use in non-
residential institutional settings such as schools and hospitals, use on ornamentals in the residential
settings, spot or mound treatments for fire ant and harvester ant control, and use on golf course turf.
The risks associated with the degradation of acephate to methamidophos for these uses were evaluated
in the acephate RED and were found to be negligible. Therefore, no further risk mitigation is needed
with respect to the residential uses of acephate to address risks associated with methamidophos
exposure.
c. Aggregate Risk Mitigation
The Agency's aggregate risk assessment for methamidophos is based on exposure estimates for
food and residential uses, and uses a screening-level assessment of modeled estimates for drinking
water contamination. Dietary (food) risk estimates are based on a refined assessment that incorporates
percent crop treated data, monitoring data, and processing data.
Acute Exposure
The acute aggregate risk assessment for methamidophos from all sources combines exposure
from food and drinking water sources only. Acute dietary (food) exposure estimates are below 100%
of the aPAD for the US population and all population subgroups. Infants are the most highly exposed
population subgroup and result in an acute drinking water level of comparison (DWLOC) of 2.9 ppb.
Based on screening-level model predictions of the remaining supported uses, the acute (peak) drinking
water estimated concentration in surface water is 61.8 ppb which is of risk concern to the Agency. The
screening-level model predictions of acute concentrations in ground water is 0.033 ppb for
methamidophos, which is less than the DWLOC and not of risk concern to the Agency.
However, due to the uncertainties and limitations of the model predictions, the Agency believes
that actual acute concentration of methamidophos in surface water is likely to be less man the
DWLOC. To demonstrate this, confirmatory surface water monitoring data is to be generated to
address this risk concern.
Short-Term Exposure
As mentioned above, methamidophos is not registered for use in residential settings. Previously,
acephate had numerous residential, recreational and institutional uses which were evaluated in the
acephate RED. To mitigate risks of concern, acephate use in these settings have been limited to
indoor use in institutional settings such as schools and hospitals, use on ornamentals in die residential
settings, spot or mound treatments for fire ant control, and use on golf course turf. The risks
50
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associated with the degradation of acephate to methamidophos for these uses were evaluated in the
acephate IRED and were found to be negligible. Therefore, no further risk mitigation is needed with
respect to the residential uses of acephate to address risks associated with methamidophos exposure.
Chronic Exposure
Similarly, the chronic aggregate risk assessment for methamidophos combines exposure from
food and drinking water sources only. Chronic dietary (food) risk estimates are well below 100% of
the cPAD for the US population and all population subgroups. Children 1-6 years old is the most highly
exposed population subgroup and result in a chronic DWLOC of 0.9 ppb. Based on screening-level
model predictions of the remaining supported uses, die average (chronic) estimated concentration in
surface water is 3.8 ppb, which is of risk concern to the Agency. Similarly, due to the same
uncertainties and limitations of the model predictions for acute exposure, the Agency also believes mat
actual chronic concentrations of methamidophos in surface is likely to be less than the DWLOC. To
demonstrate this confirmatory surface water monitoring data is to be generated to address the risk
concern.
The screening-level model predictions of acute concentrations in ground water is 0.033 ppb for
methamidophos, which is less than die DWLOC and not of risk concern to the Agency.
d. Occupational Risk Mitigation
1) Agricultural Uses
As described in PR Notice 2000-9, Worker Risk Mitigation for Organophosphate Pesticides,
it is the Agency's policy to mitigate occupational risks to the greatest extent necessary and feasible with
personal protective equipment and engineering controls. In managing risk, EPA must take into account
the economic, social, and environmental costs and benefits of the pesticide's use. A wide range of
factors are considered in making risk management decisions for worker risks. These factors include, in
addition to die calculated MOEs, incident data, die nature and severity of adverse effects, uncertainties
in die risk assessment, die cost, availability and relative risk of alternatives, importance of die chemical
in integrated pest management (IPM) programs, and other similar factors.
Handlers
As summarized in Table 7, occupational risks are of concern (i.e., MOEs < 100) for all
scenarios, even when maximum PPE (i.e, double layer clothing, gloves, and a respirator) are utilized.
Handler risks are also of concern for many scenarios with engineering controls (closed mixing/loading,
enclosed cabs). Engineering controls are considered to be the maximum feasible mitigation. For
workers wearing me maximum PPE described above, MOEs range from 2.5 to 38 for mixer/loaders
and from 3.9 to 59 for applicators and flaggers. For workers using die engineering controls described
above, MOEs range from 5 to 74 for mixer/loaders and from 8.4 to 626 for applicators/flaggers.
Current labels require closed mixing/loading systems to be used. To mitigate occupational risks
associated with die use of methamidophos, die following measures are to be implemented for die alfalfa,
cotton, tomato and potato uses to be eligible for reregistration.
51
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Applicators must be in an enclosed cab or cockpit.
Flaggers must be in enclosed vehicles or mechanical flaggers; or the use of global positioning
system (GPS) equipment that negates the need for flaggers for aerial application must be used.
The cotton use must be cancelled.
Even with maximum engineering controls (closed mixing/loading system and enclosed cabs) the
MOEs for all mixer/loader scenarios, the groundboom applicator for cotton scenario and all aerial
application scenarios remain less than the Agency's target of 100. For cotton scenarios, the Agency
has determined mat the benefits of this use do not offset the risks. However, the benefits discussed
above are significant enough mat a 5-year phase out rather than immediate cancellation of mis use is
justified to allow ample time for transition to alternatives.
For the alfalfa seed use of methamidophos, the Agency has determined that significant benefits
exist to support reregistration for this use. Methamidophos is critical for the control of lygus bug in
California alfalfa seed fields. It is an important element of California's lygus bug resistance management
program, and is the most effective control of lygus pest early in the season, prior to introducing
pollinators into the fields.
For the potato uses, the Agency has determined mat significant benefits exist to support
reregistration for this use. As mentioned earlier, post-emergence control of the green peach aphid, a
vector for the potato leafroll virus, is the critical use in most areas of the country. Only imidacloprid is a
potential alternative for post-emergence control but it is significantly more costly and does not have the
period of residual effectiveness mat methamidophos has mat is necessary in some potato growing
regions. There is also concern for potential resistance in some regions for imidacloprid. These
circumstances make methamidophos critical to potato production, especially in the production of
potatoes for seed where mere is zero tolerance for aphids or the viruses they carry.
For the tomato uses of methamidophos, the Agency has determined that significant benefits exist
to support reregistration for this use. In the Southeastern U.S., methamidophos is one of only two
chemicals available for the control of the Western flower thrip, which is a vector for Tomato Spotted
Wilt Virus, which can cause significant economic damage to a tomato crop. For fresh and processed
tomatoes in California, methamidophos is the only effective insecticide available for controlling the
economically important stink bug. The limitations mentioned earlier on endosulfan, dimethoate and
imidacloprid make methamidophos an important tool in fresh and processed tomato production in
California
In addition to the benefits outlined above, mere is some uncertainty associated with the Agency's
risk estimates for methamidophos. This uncertainty is explained in the following section on post
application risk.
Post-Application Risk
EPA develops exposure assessments on post-application workers for various crops and
activities at intervals following the application until risk falls below a target level. For methamidophos,
52
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the target level for risk concerns is an MOE of 100.
In order to determine the REI for a crop, EPA calculates the number of days that must elapse
after pesticide application until residues dissipate and risk to a worker fells below the target MOE.
Occupational risks are regulated under the FIFRA section 3(c)(5) standard - "without unreasonable
adverse effects on the environment" - which means that both risks and benefits must be considered in
making a risk management decision, lliis standard may be met at a level below the target MOE when
there are significant benefits associated with a specific activity. As the worker exposure database has
improved, risk assessments are now conducted for a variety of post-application activities based on the
level of exposure for each worker activity. For a specific crop/pesticide combination, the duration
required to achieve the target MOE can vary depending on the activity assessed.
In general, EPA prefers to set a single REI for all activities related to a crop or crop group
without additional activity-based labeling. This approach is favored because handlers and workers are
more likely to understand and comply with simpler labels. Also, permitting entry for some activities
during the REI could cause confusion and compromise the effectiveness of the Worker Protection
Standard (WPS). However, when the consideration of risks and benefits indicate mat a single REI is
unworkable, EPA may consider either setting an REI with early entry exceptions for one or more
critical tasks or establishing an entry prohibition for a specific task after the REI has expired. For
methamidophos, no critical activities have been identified to warrant the use of an activity-based
exception or prohibition.
In weighing worker risks and benefits, the Agency considered the timing of field activities mat are
critical to crop production. For many of the methamidophos uses discussed below, scouting and
irrigation are critical activities in crop production, and these activities routinely need to be performed
soon after application. In evaluating the restricted entry intervals, the Agency considered the exceptions
to the WPS that could inform the decision. EPA's proposed REIs take into account the flexibility
already provided by these exceptions. Scouting is a handler activity under the WPS, so anyone
performing this activity may legally enter the treated field during the REI provided they use the handler
personal protective equipment (PPE) specified on the label. In addition, if the scout is a certified crop
advisor as defined in the WPS (40 CFR 170.204(b)), the individual can determine the appropriate PPE
to be used. For many of these crops, irrigation equipment is not routinely moved by hand. For these
methods, the primary activity involves entering the field to turn the watering equipment on and off. This
activity is allowed during me REI under the no contact exception to WPS (40 CFR 170.112(b)).
Should irrigation equipment need unexpected repairs during the REI, WPS allows workers to enter a
treated field provided early entry PPE is used (40 CFR 170.112(c)).
To mitigate post-application occupational risks associated with the use of methamidophos, the
following measures are to be implemented for the tomato and potato uses to be eligible for
reregistration.
Increase REIs for all activities for tomatoes to 4 days in all states except California where
the REI would remain at 3 days per the current labels.
Increase REIs for all activities for potatoes to 4 days.
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For tomatoes in California, hand harvesting re-entry risks are adequately addressed by the 7-day
and 14-day PHIs currently on labels. Methamidophos is applied late season to tomatoes in California
therefore pruning, staking, tying and activities associated with immature plants are not a re-entry issue
mere. An REI of 3 days would result in an MOE of 70 for irrigation and scouting of mature plants
which are the key activities of concern.
For tomatoes in Florida, an REI of 4 days would result in an MOE of 31 for irrigation and
scouting of mature plants and an MOE of 22 for hand harvesting lying, pruning and staking which are
the key activities of concern. Re-entry risks for hand harvesters are not adequately addressed by the
7-day Pffl currently on labels (MOE = 30).
For tomatoes in other areas of the country, an REI of 4 days would result in an MOE of 45 for
irrigation and scouting of mature plants and an MOE of 32 for hand harvesting, tying, pruning and
staking which are the key activities of concern. Re-entry risks for hand harvesters are not adequately
addressed by the 7-day Pffl currently on labels (MOE = 66).
For potatoes, an REI of 4 days would result in an MOE of 44 for irrigation and scouting of
mature plants which are the key activities of concern.
While the MOEs mat result from these mitigation steps do not fully address the risks of concern
(i.e. MOEs are not greater than 100), the following information was taken into consideration in making
these risk management decisions. These considerations are in addition to the benefits that have been
discussed previously in this document
In the case of tomatoes, as mentioned earlier, the Agency evaluated reentry risk based on data
available from CA, FL and GA. More specifically, the dak from FL was developed in the southern
part of the state while die GA data was collected in the southern part of that state. The test area in GA
is significantly closer to the areas in FL where methamidophos use is critical, which are predominantly in
the northern areas of the state, than the test fields where the data were developed in southern FL.
Therefore, it is likely mat the GA data and the associated REIs would be more appropriate when
considering the re-entry risks in the major methamidophos use areas in FL resulting in significantly
increased MOEs for the FL scenario.
Further, mere is some uncertainty associated with the Agency's worker risk estimates from the
endpoint selected for methamidophos. MOEs are calculated by dividing the hazard endpoint by the
estimated exposure. At present time, the Agency selects endpoints based on NOAELs and LOAELs
from available toxicology studies. By definition, NOAELs and LOAELs are actual dose levels tested in
these studies. The value of the NOAEL or LOAEL is determined solely by the dose selection in the
toxicity study. NOAELs and LOAELs may be numerically close (e.g., 5 mg/kg/day vs. 6.5 mg/kg/day);
or they may also be orders of magnitude apart (e.g., 5 mg/kg/day vs. 500 mg/kg/day). The use of
NOAELs and LOAELs as toxicological endpoints is an established and scientifically accepted method
of performing risk assessments and will continue to be used in risk assessments performed by the
Agency. However, the Agency is considering the use of benchmark dose modeling techniques for
determining toxicological endpoints for use in risk assessment Benchmark dose modeling involves the
use of statistical and mathematical curve fitting procedures to refine the endpoints used in risk
assessment
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In the case of methamidophos, a short-term dermal endpoint of 0.75 mg/kg/day was selected for
use in occupational exposure assessments. As mentioned earlier, this endpoint is based on the
NOAEL from a 21-day dermal toxicity study. The LOAEL from this study is 11.2 mg/kg/day based
on brain, plasma and RBC cholinesterase inhibition. For this dermal toxicity study, the value of the
NOAEL is approximately 15-fold smaller than the LOAEL.
Methamidophos was selected as the index chemical in the Preliminary Cumulative Risk
Assessment (PCRA) for the OPs. This selection was based on the availability of high quality dose-
response data for brain, plasma, and RBC cholinesterase inhibition and also the availability of data for
all of the exposure routes of interest (oral, dermal, and inhalation). Due to the complexity of issues
surrounding the estimation of cumulative risk of a large group of chemicals, it was determined that
benchmark dose modeling was preferred over using NOAELs/LOAELs for determining endpoints for
use in cumulative risk extrapolations. In the PCRA the BMD10, or the estimated dose to cause a 10%
reduction brain cholinesterase activity, was selected as an appropriate endpoint. Because
methamidophos is being used as the index chemical in the cumulative risk assessment of OPs, BMD!0s
and also the respective BMDLs (the lower 95% confidence limit on the BMD10) have been calculated
from the methamidophos 21-day dermal toxicity study mentioned above for male and female rat brain
cholinesterase. These BMD10s and BMDLs for male and female rat brain cholinesterase activity are
shown in the table below.
Table 16. BMDIOs and BMDLs from the methamidophos 21-day dermal study for brain
cholinesterase activity measured in female and male rats
Route of
Administration
Dermal
Sex
F
M
BMD.o
(mg/kg/day)
2.12
1.88
BMDL
(mg/kg/day)
1.77
1.41
NOAEL
(mg/kg/day)
0.75
It is notable mat the BMDLs are very close to the BMD10s indicating very narrow confidence
limits. Although the BMD10 s and BMDLs have not been calculated for plasma and RBC
cholinesterase inhibition, based on the results of other toxicity studies in methamidophos, the Agency
does not expect the benchmark dose calculations for the BMD10s or the BMDLs from the blood
compartments to be significantly different from the results shown in Table 16.
The Agency's draft guidance on use of benchmark dose specifies that the BMDL, and not the
BMD10, should be used as the endpoint for risk extrapolation. As the Agency expands its use of
benchmark dose modeling techniques in its single chemical risk assessments, the BMDLs, not BMD10s,
are likely to be used.
The BMDL for male brain cholinesterase inhibition (1.44 mg/kg/day) is approximately 1.9 times
larger than the NOAEL of 0.75 mg/kg/day being used to estimate short-term dermal occupational risk.
In order to better characterize the potential risks to persons entering treated fields and being exposed to
methamidophos residues, the Agency looked at the effect of using the BMDL instead of the NOAEL as
is customary in deriving MOEs. For example, using the NOAEL of 0.75, the resulting MOE for short-
55
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term post application risk for potatoes at day 4 after treatment is 44. If the more refined endpoint (i.e.,
the BMDL of 1.44 mg/kg/day) were used instead the resulting MOE would be approximately 84.
Based on this comparison, the Agency believes that the short-term dermal occupational risk would not
exceed 44 but may be as high as 84.
In summary, when deciding whether the benefits of use provided by methamidophos outweigh
the risk the Agency takes into consideration all available information. This includes the effects of the
use of the BMDL versus the NOAEL on MOEs, dislodgeable foliar residue data specific to those
regions of the country where methamidophos is most likely to be used, and the need for growers to
enter treated fields at a particular time to perform specific activities and the consequences of not being
able to complete those activities. Therefore, the Agency believes that the REIs set forth as mitigation in
this IRED are appropriate.
2. Environmental Risk Mitigation
The Agency has ecological risk concerns regarding the acute risks of methamidophos to
terrestrial birds and mammals, and to freshwater and estuarine invertebrates; and chronic risk concerns
to birds and mammals and freshwater and estuarine invertebrates. The ecological risk assessments
exhibit RQ values which exceed the various target levels of concern (LOCs).
Birds and Mammals
The Agency's assessment suggests the potential for the liquid formulation to cause acute effects
to birds for broadcast applications. The avian acute RQs range from 0.38 to 6.63. The highest avion
acute RQ is from nine 1 Ib ai/A ground or aerial applications to tomatoes. For the same use patterns,
mammalian acute RQs range from 02 to 20.3. Regarding chronic risk to birds, the RQs range from
2.49 to 32.87. Again the same use patterns resulted in chronic RQs for mammals ranging from 0.75 to
9.86. All use patterns are of concern to the Agency for acute and chronic effects to birds and
mammals.
Because of the toxicity of methamidophos, to help protect terrestrial birds and mammals, it is
very important to reduce their potential exposure to methamidophos products that have been applied.
In additional to me phase out of the cotton use previously described in mis document to mitigate
occupational risks of concern which will also serve to reduce risk to birds and mammals, several
additional mitigation measures are needed to reduce risks to birds and mammals. These are:
Require all labels to reduce maximum # of applications to 2 per season during phase out period
for cotton.
Require all labels to reduce maximum # of applications to 4 per season for tomatoes.
It should also be noted that significant benefits exist for both the tomato and potato uses as
described earlier.
Aquatic Organisms
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Acute risk to freshwater fish and estuarine fish is not of concern for any use patterns, with RQs
ranging from <0.05 to 0.07. Hie acute high risk, restricted use risk and endangered species risk is of
concern for freshwater invertebrates at the maximum application rate of 1.0 Ib ai/A with RQs ranging
from 1.1 to 3.0. No chronic risk assessment was conducted since mere are no chronic data for aquatic
species.
Many of the measures previously described in this document to reduce occupational and
terrestrial risks will also serve to reduce aquatic risks of concern. It should also be noted that significant
benefits exist for both the tomato and potato uses as described earlier.
£. Other Labeling
In order to remain eligible for reregistration, other use and safety information need to be placed
on the labeling of all end-use products containing methamidophos. For the specific labeling statements,
refer to Section V of this document
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 toxichy 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 mere 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 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, will soon be proposed for public
comment in the Federal Register.
2. Spray Drift Management
The Agency has been working with the Spray Drift Task Force, EPA Regional Offices, State
Lead Agencies for pesticide regulation, and other parties to develop the best spray drift management
practices. The Agency has completed its evaluation of the new database submitted by the Spray Drift
Task Force and is developing policy on how to appropriately apply the data and the AgDRDFT
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computer model to its risk assessments for pesticides applied by air, orchard airblast, or ground
hydraulic spray. After the policy is in place, the Agency may impose further refinements in spray drift
management practices to reduce off-target drift and risks associated with aerial application or other
application methods associated with drift, where appropriate.
Based on these analyses, the Agency is in the process of developing more appropriate label
statements for spray, and dust drift control to ensure that public health, and the environment are
protected from unreasonable adverse effects. In August 2001, EPA published draft guidance for label
statements in a pesticide registration (PR) notice ("Draft PR Notice 2001-X" http://www.epa.gov/
PR_Notices/#2001). A Federal Register notice was published on August 22,2001
(http://www.epa.gov/fedrgstr) announcing the availability of this draft guidance for a 90-day public
comment period. After review of the comments, the Agency will publish final guidance in a PR notice
for registrants to use when labeling their products.
In the interim, registrants may choose to use the proposed statements. Registrants should read
and refer to the draft PR notice to obtain a full understanding of the proposed guidance and its intended
applicability, exemptions for certain products, and the Agency's willingness to consider other versions
of the statements.
Registrants may elect to adopt the appropriate sections of the proposed language below, or a
version that is equally protective, for their end-use product labeling for the purpose of complying with
the deadlines for label submission outlined in this document The proposed label language is as follows:
For products applied outdoors as liquids:
"Do not allow spray to drift from the application site and contact people, structures
people occupy at any time and the associated property, parks and recreation areas, nontarget
crops, aquatic and wetland areas, woodlands, pastures* rangelands, or animals."
"For ground boom applications, apply with nozzle height no more than 4 feet above the ground
or crop canopy, and when wind speed is 10 mph or less at the application site as measured by
an anemometer. Use (registrant to fill in blank whh spray quality, e.g. fine or medium) or
coarser spray according to ASAE 572 definition for standard nozzles or VMD for spinning
atomizer nozzles."
'Tor aerial applications, the boom width must not exceed 75% of the wingspan or 90% of the
rotary blade. Use upwind swam displacement, and apply only when wind speed is 3 - 10 mph
as measured by an anemometer. Use (registrant to fill in blank with spray quality, e.g. fine
or medium) or coarser spray according to ASAE 572 definition for standard nozzles or VMD for
spinning atomizer nozzles. If application includes a no-spray zone, do not release spray at a
height greater than 10 feet above the ground or the crop canopy."
For overhead chemigation:
"Apply only when wind speed is 10 mph or less."
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On all product labels:
"The applicator also must use all other measures necessary to control drift."
"For ground rig applications, apply product no more than 4 feet above the ground
or the crop canopy, and only when wind speed is 10 mph or less at the application
site as measured by an anemometer."
"For aerial applications, use upwind swath displacement, and apply only when wind speed is 3 -
10 mph as measured by an anemometer. If application includes a no-spray zone, do not release
dust at a height greater than 10 feet above the ground or the crop canopy."
Or
"The applicator also must use all other measures necessary to control drift."
Alternatively, registrants may elect to use the following language, which is the current Agency
policy on drift labeling:
For products that are applied outdoors in liquid sprays (except mosquito adulticides). regardless
of application method, the following must be added to Ihe labels:
"Do not allow mis product to drift."
The Agency recognizes that the above option does not address other application types.
Registrants may therefore wish to adapt some variation of the old, and proposed new language for their
particular products, depending on their application methods.
F. Methamidophos Risk Mitigation Summary
Based on the rationale for the interim decisions associated with the use of methamidophos, the
following risk mitigation measures are also necessary to be incorporated in their entirely into labels for
methamidophos-containing products in order for methamidophos to be eligible for reregistration.
Registrants may propose, and EPA will consider, alternative mitigation measures that provide
appropriate mitigation of the identified risks. Specific language of these revisions is set forth in the
summary tables of Section V of this document Likewise, the data required to be provided to the
Agency to confirm these regulatory decisions are also listed in Section V.
1. Dietary Risk
No label changes necessary, however certain confirmatory data listed in Section V is required.
2. Occupational Risk
The fbllowine measures are necessary to mitigate handler risk:
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Applications must be made using enclosed cab tractors or enclosed cockpit aircraft.
Mechanical flaggers for aerial application; or the use of global positioning system (GPS)
equipment that negates the need for flaggers.
The following measures are necessary to mitigate risk to post-application workers:
For foliar application of the liquid formulation, a 4 day REI is necessary for tomatoes in all states
except CA
For foliar application of the liquid formulation, a 4 day REI is necessary for potatoes.
The following additional measures are necessary to mitigate risks of concern for specific crops:
Cotton: Implement a 5-year phase out of the use on cotton.
3. Ecological Risks
EPA has determined that remaining uses are eligible for reregistration provided that
The maximum # of applications on all labels be reduced to 2 per season during phase out period
for cotton.
The maximum # of applications on all labels be reduced to 4 per season for tomatoes.
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V. What Registrants Need to Do
In order to be eligible for reregistration, registrants need to implement the risk mitigation
measures outlined in Section IV, which include submission of the following:
A. Data Call-In Responses
For methamidophos technical grade active ingredient products, registrants need
to submit the following hems.
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:
(1) cite any existing generic data which address data requirements or submit
new generic data responding to the DCI.
Please contact Mark Hartman at (703) 308-0734 with questions regarding reregistration and/or
the DCI. All materials submitted in response to the generic DCI should be addressed:
Ry^ IS mail: By express or courier service:
Document Processing Desk (DCI/SRRD) Document Processing Desk (DCI/SRRD)
Mark A. Hartman Mark A. Hartman
US EPA (7508C) Office of Pesticide Programs (7508C)
1200 Pennsylvania Ave., NW Room 266A, Crystal Mall 2
Washington, DC 20460 1921 Jefferson Davis Highway
Arlington, VA 22202
B. For product? containing the active ingredient methamidophos. 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) completed 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.
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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 17 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.
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: By express or courier service only:
Document Processing Desk (PDCI/PRB) Document Processing Desk (PDCI/PRB)
Bonnie Adler Bonnie Adler
US EPA (7508C) Office of Pesticide Programs (7508C)
1200 Pennsylvania Ave., NW Room 266A, Crystal Mall 2
Washington, DC 20460 1921 Jefferson Davis Highway
Arlington, VA 22202
B. Manufacturing Use Products
1. Additional Generic Data Requirements
The generic data base supporting the reregistration of methamidophos for the above eligible
uses has been reviewed and determined to be substantially complete. The following data gaps remain:
1. Drinking water monitoring data for surface water sources for methamidophos in potato and
tomato growing regions. This data is requested in order to confirm that the level of
methamidophos is lower than predicted in the Agency's water models (OPPTS 167-1-SS)
2. Chronic Estuarine Invertebrate Study using Mysid shrimp (OPPTS 850.1350)
3. Photolysis on Soil (OPPTS 835.2410)
4. Anaerobic Aquatic Metabolism (OPPTS 835.4400)
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5. Terrestrial Field Dissipation (OPPTS 835.6100)
6. Daphnid Chronic Toxicity Study (OPPTS 850.1300)
7. Terrestrial Plant Toxicity, Seedling Emergence (OPPTS 850.4100)
8. Terrestrial Plant Toxicity, Vegetative Vigor (OPPTS 850.4150)
9. Dermal Passive Dosimetry Exposure (OPPTS 8752400)
10. Mixer/Loader exposure data for dry coupling closed mixing/loading system (OPPTS 875.1100
and 875.1300)
11. Confined Accumulation in Rotational Crops (OPPTS 860.1850)
12. Product chemistry data requirements for all technical and manufacturing use products have not
been fulfilled. (830 series\60 series)
Also, a Data Call-In Notice (DCI) was recently sent to registrants of organophosphate
pesticides currently registered under FIFRA (August 6,1999 64FR42945-42947, August 18
64FR44922-44923). DCI requirements included acute, subchronic, and developmental neurotoxicity
studies; the developmental neurotoxicity study is currently in review. Acceptable acute and subchronic
studies have been received and reviewed by the Agency.
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 Table 17 at the end of this section.
C. End-Use Products
1. Additional Product-Specific Data Requirements
Section 4(g)(2)(B) 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 MRED numbers should be cited according to the instructions in the
Requirement Status and Registrants Response Form provided for each product.
A product-specific data call-in, outlining specific data requirements, accompanies this interim RED.
2. Labeling for End-Use Products
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Labeling changes are necessary to implement the mitigation measures outlined in Section FV
above. Specific language to incorporate these changes is specified in the Table 17 at the end of mis
section.
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 interim RED. Persons other than the registrant may generally
distribute or sell such products for 50 months from the date of the issuance of this interim RED.
However, existing stocks time frames will be established case-by-case, depending on the number of
products involved, the number of label changes, and other factors. Refer to "Existing Stocks of
Pesticide Products; Statement of Policy"; Federal Register, Volume 56, No. 123, June 26, 1991.
The Agency has determined mat registrant may distribute and sell methamidophos products
bearing old labels/labeling for 26 months from the date of issuance of mis interim RED. Persons other
than the registrant may distribute or sell such products for 50 months from the date of the issuance of
this interim RED. Registrants and persons other than the registrant remain obligated to meet pre-
existing label requirements and existing stocks requirements applicable to products they sell or
distribute.
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E. Labeling Changes Summary Table
hi 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 17: Summary of Labeling Changes for methamidophos
Description
Amended Labeling Language
Placement on Label
Manufacturing Use Products
Formulation Instructions
required on all MUPs
"Only for formulation into an insecticide for the following use(s): alfalfa grown for seed, cotton,
tomatoes and potatoes."
Directions for Use
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
"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)."
Directions for Use
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Description
Environmental Hazards
Statements Required by
Agency Label Policies
Amended Labeling Language
"Environmental Hazards"
"This chemical is extremely toxic to birds, mammals, and aquatic invertebrates. 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 Pollutant 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."
Placement on Label
Precautionary Statements
under Environmental
Hazards
End Use Products Intended for Occupational Use (WPS)
Restricted Use Pesticide
"RESTRICTED USE PESTICIDE"
Due to Acute Toxicity. "For retail sale to and use only by certified applicators or persons under their
direct supervision, and only for those uses covered by the certified applicator's certification."
Top of Front Panel
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Description
Amended Labeling Language
Placement on Label
Handler PPE requirements
"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 flaggers using engineering controls must wear:
Long-sleeved shirt and long pants
Shoes plus socks
In addition, mixers and loaders must wear chemical-resistant gloves and a chemical resistant aproa "
"See engineering controls for additional requirements.
"Handlers engaged in those activities for which use of an engineering control is not possible, such as
cleaning up a spill or leak and cleaning or repairing contaminated equipment, must wear:
Coveralls over long-sleeved shirt and long pants,
Chemical-resistant gloves,
Chemical resistant footwear plus socks,
Chemical-resistant headgear if overhead exposure,
In addition, handlers exposed to the concentrate must wear:
A respirator with an organic-vapor removing cartridge with a prefilter approved for pesticides
(MSHA/NIOSH approval number prefix TC-23C), or a canister approved for pesticides (MSHA/NIOSH
approval number prefix TC-14G), or a NIOSH-approved respirator with an organic vapor (OV) cartridge
or canister with any N, R or P or He prefilter;
Chemical-resistant apron"
Immediately
following/below
Precautionary Statements:
Hazards to Humans and
Domestic Animals
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Description
Amended Labeling Language
Placement on Label
User Safety Requirements
"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."
"Discard clothing or other absorbent materials that have been drenched or heavily contaminated with
this product's concentrate. Do not reuse them."
Precautionary Statements:
Hazards to Humans and
Domestic Animals
immediately following the
PPE requirements
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Description
Amended Labeling Language
Placement on Label
Engineering Controls
"Engineering Controls
"Mixers and loaders must use a closed system that provides dermal and inhalation protection and must use and
maintain this system in a manner that meets the requirements specified in the Worker Protection
Standard for Agricultural Pesticides [40 CFR 170.240(d)(4)]. The system must be capable of removing the
pesticide from the shipping container and transferring it into mixing tanks and/or application equipment At any
disconnect point, the system must be equipped with a dry disconnect or dry couple shut-off device that is warranted b;
the manufacturer to minimize drippage to not more than 2 mL. per disconnect point." Mixers and loaders must
also:
-wear the personal protective equipment required above for mixers/loaders using engineering
controls,
- wear protective eyewear if the system operates under pressure, and
- be provided and have immediately available for use in an emergency, such as a broken
package, spill, or equipment breakdown the PPE specified above for handlers engaged in those
activities for which use of an engineering control is not possible."
"Applicators using motorized ground equipment and flaggers supporting aerial applications must use an
enclosed cab that meets the definition in the Worker Protection Standard for Agricultural Pesticides [40
CFR 170.240(d)(5)] for dermal protection. In addition, such applicators and flaggers must:
wear the personal protective equipment required above for applicators using engineering
controls,
be provided and must have immediately available for use in an emergency when they must
exit the cab in the PPE specified above for handlers engaged in those activities for which use of
an engineering control is not possible.
- take off any extra PPE that was put on and worn in the treated area before reentering the cab,
and
store all such PPE in a chemical-resistant container, such as a plastic bag, to prevent
contamination of the inside of the cab."
"Pilots must use an enclosed cockpit in a manner that meets the requirements listed in the Worker
protection Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(6)];"
Precautionary Statements:
Hazards to Humans and
Domestic Animals
(Immediately following
PPE and User Safety
Requirements.)
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Description
Amended Labeling Language
Placement on Label
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.)
Environmental Hazards
"This pesticide is extremely toxic to birds, mammals, and aquatic invertebrates. Do not apply directly
to water, or to areas where surface water is present or to intertidal areas below the mean high-water mark.
Drift and runoff may be hazardous to aquatic organisms in neighboring areas. Do not contaminate water
when disposing of equipment washwater or rinsate."
"This product may contaminate water through drift of spray in wind. This product has a high potential
for runoff. Poorly draining soils and soils with shallow watertables are more prone to produce runoff
that contains this product."
"This pesticide is toxic to bees. Application should be timed to coincide with periods of minimum bee
activity, usually between late evening and early morning."
Precautionary Statements
immediately following the
User Safety
Recommendations
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Description
Restricted-Entry Interval
(all products except those
listed below)
Special Local Needs
Registrations in California
(CA78016300;
CA79009600)
Amended Labeling Language
"Do not enter or allow workers to enter into treated areas during the restricted entry interval (REI).
The REI for cotton and alfalfa is is 48 hours. The REI for cotton and alfalfa is 72 hours in areas where
average rainfall is less than 25 inches a year.
The REI for potatoes is 4 days.
The REI for tomatoes is 3 days.
Placement on Label
Directions for Use,
Agricultural Use
Requirements Box
71
-------
Description
Amended Labeling Language
Placement on Label
Special Local Needs
Registrations in states other
than California
(AL89000800;
AR97000400;
DE91000200; DE92000200;
FL80004600; FL89000700;
FL89004100; FL90000300;
FL92000400; GA86000400;
GA90000100; IN79000100;
IN93000300; LA91000800,
LA99001100;
MD91000900;
MI78001600; MI93000300;
NC89000700; NJ96001000;
OH79000800;
OH79001000; PR92000100;
SC78001600; TN89000700;
TN93000300; TN96000600;
TX91001200; TX91001600;
VA91000500;
VA93000200)
The RE1 for tomatoes is 4 days.
72
-------
Description
Amended Labeling Language
Placement on Label
Early Re-entry Personal
Protective Equipment
established by the IRED.
Early Entry PPE (WPS)
"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 worn over long-sleeve shirt and long pants,
* chemical-resistant gloves made of any waterproof material,
* chemical-resistant footwear plus socks, and
* chemical-resistant headgear (if overhead exposure)
* protective eyewear"
*'"Notify workers of the application by warning them orally and by posting warning signs at entrances
to treated area."
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.
Other Application
Restrictions
Crop-Specific Application Restrictions (labels must be amended to reflect the requirements specified
below)
All Crops: An advisory that application of methamidophos products after applications of acephate may
result in illegal residues.
Tomatoes: The different use directions for tomatoes destined to be processed is not considered to be
practical and must be removed from die label.
Cotton: The cotton grazing/feeding restrictions are not considered practical and must be removed.
Cotton: Maximum number of applications per season is two.
Directions for Use
73
-------
Description
Amended Labeling Language
Placement on Label
Other Application
Restrictions (SLNs)
Tomatoes: Maximum number of applications per season is four.
Other Application
Restrictions (SLNs currently
w/ < 3 apps)
Tomatoes: Maximum number of applications per season is two.
Spray Drift Restrictions
for Outdoor Products
Applied as a Liquid
"Do not allow spray to drift from the application site and contact people, structures people occupy at
any time and the associated property, parks and recreation areas, nontarget crops, aquatic and wetland
areas, woodlands, pastures, rangelands, or animals."
Directions for Use in
General Precautions and
Restrictions
Spray Drift language
"Aerial Spray Drift Management"
" For aerial applications, the boom width must not exceed 75% of the wingspan or 90% of the rotary
blade. Use upwind swath displacement and apply only when wind speed is 3-10 mph at the application
site as measured by an anemometer. Use (registrant to fill in blank with spray quality, e.g. fine or
medium) or coarser spray according to ASAE 572 definition for standard nozzles or VMD for spinning
atomizer nozzles. If application includes a no-spray zone, do not spray at a height greater than 10 feet
above the ground or the crop canopy."
"For overhead chemigation, apply only when wind speed is 10 mph or less."
"For ground boom applications, apply with nozzle height no more than four feet above the ground or
crop canopy and when wind speed is 10 mph or less at the application site as measured by an
anemometer. Use (registrant to fill in blank with spray quality, e.g. fine or medium) or coarser
spray according to ASAE 572 definition for standard nozzles or VMD for spinning atomizer nozzles.
"The applicator also must use all other measures necessary to control drift."
Directions for Use in
General Precautions and
Restrictions
74
-------
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.
75
-------
VI. Related Documents and How to Access Them
This interim Reregistration Eligibility Document is supported by documents that are presently
maintained in the OPP docket. The following sections indicate the means to view or obtain copies of paper
or electronic versions of these documents and lists titles of documents that are now in the docket files.
A. Availability at OPP Docket Room
The OPP docket is 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 p.m.
The docket initially contained preliminary risk assessments and related documents as of 1999.
Sixty days later the first public comment period closed. The EPA men considered comments, revised the
risk assessment, and added the formal "Response to Comments" document and the revised risk assessment
to the docket on February 22,2000.
B. Availability on the Internet
Many of the supporting documents may be viewed or downloaded from the Internet The web site
is as follows: http://www.epa.gov/oDDSiTdl/OD/.
76
-------
VII. Appendices
77
-------
78
-------
Appendix A. Use Patterns Eligible for Reregistration
Site
Application Type
Application Timing
Application Equipment
Formulation
[EPA Reg. No.]
Maximum Single
Applkation Rate (ai)
Maximum
Number of
Applications Per
Season
Maximum Seasonal
Rate (ai)
Preharvest
Interval,
(Days)
Use Directions and Limitations
Alfalfa
Foliar
Ground or aerial
41b/galEC
[CA980013]
1.0 Ib/A
1
l.Olb/A
N/A
Applications may be made in a
minimum of 25 gal/A by ground,
3 gal/A by air. Do not teed refuse
to livestock. Alfalfa seed from
treated fields may not be used for
growing sprouts for human or
animal consumption. Do not
apply through any type of
irrigation system.
Cotton
Foliar (Before boils open)
Ground or aerial
41b/galEC
[3125-280]
[AR870007]
[MS8 10014]
4 to/gal EC
[59639-56]
1.0 Ib/A
1.0 Ib/A
2
2
2.0 Ib/A
2.01b/A
50
50
Applications may be made in a
minimum of 25 gal/A by ground,
3 gal/A by air, or by irrigation
systems. The feeding of gin trash
to livestock or grazing of
animals on treated fields is
prohibited.
Applications may be made in a
minimum of 25 gal/A by ground
or 3 gal/A by air. The feeding of
gin trash to livestock or grazing
of animals on treated fields is
prohibited.
79
-------
Site
Application Type
Application Timing
Application Equipment
Foliar
Ground or aerial
Formulation
[EPA Reg. No.]
41b/galEC
[AR810044]
[AR890005]
[CA780189]
[CA790188]
[LA830018]
[MS8 10055]
[MS830013]
[TN880004]
Maximum Single
Application Rate (ai)
1.0 Ib/A
Maximum
Number of
Applications Per
Season
2
Maximum Seasonal
Rate (ai)
2.0 Ib/A
Preharvest
Interval,
(Days)
NS
Use Directions and Limitations
Use limited to AR, CA, LA, MS,
andTN. Applications after 65%
of the bolls are open are
prohibited. Applications may be
made in a minimum of 25 gal/A
by ground or 1 gal/ A by air
(MS810055 only). The feeding of
gin trash to livestock or grazing
of animals on treated fields is
prohibited.
Potato
Foliar
Ground or aerial
41b/galEC
[3125-280]
[59639-56]
1.0 Ib/A
4
4.0 Ib/A
14
Applications may be made in a
minimum of 25 gal/A by ground,
3 gal/A by air, or by sprinkler
irrigation systems with a
retreatment interval of 7- to 10-
days as a preventative program or
as needed.
Tomato
Foliar
Ground
41rVgalEC
[FL890041]
l.Olb/A
4
4.0 Ib/A
7
Tank mix use limited to FL.
80
-------
Site
Application Type
Application Timing
Application Equipment
Formulation
[EPA Reg. No.]
4tb/galEC
[FL920004]
41b/galEC
PN790001]
[IN930003]
[MI780016]
[MI930003]
[OH790008]
[OH790010]
41b/galEC
[SC780016]
41b/galEC
[AL890008]
Maximum Single
Application Rate (ai)
1.0 Ib/A
1.0 Ib/A
l.Olb/A
0.75 Ib/A
Maximum
Number of
Applications Per
Season
4
3
4
4
Maximum Seasonal
Rate(ai)
4.01b/A
3.0 Ib/A
4.0 Ib/A
3.0 Ib/A
Preharvest
Interval,
(Days)
7
7
14
7
Use Directions and Limitations
Use limited to FL. Applications
may be made in a minimum of 25
gal/A by ground with a
retreatment interval of 5- to 7-
days.
Use limited to IN, MI, and OH.
Applications may be made in a
minimum of 25 gal/A by ground
with a retreatment interval of 7-
to 10-days.
Use limited to SC. Applications
may be made in a minimum of 50
gal/ A by ground with a
retreatment interval of 7- to 10-
days.
Use limited to AL and GA.
Applications may be made in a
minimum of 25 gal/A by ground
with a retreatment interval of 5-
to 7-days.
81
-------
Site
Application Type
Application Timing
Application Equipment
Foliar
Ground or aerial
Formulation
[EPA Reg. No.]
4lb/galEC
[PR920001]
41h/galEC
[TX910016]
41b/galEC
[FL800046]
[FL890007]
[LA910016]
[TX910012]
Maximum Single
Application Rate (ai)
0.75 Ib/A
l.Olb/A
l.Olb/A
Maximum
Number of
Applications Per
Season
4
4
4
Maximum Seasonal
Rate (ai)
3.0 Ib/A
4.01WA
4.0 Ib/A
Preharvest
Interval,
(Days)
7
14
7
%
Use Directions and Limitations
Use limited to PR. Applications
may be made in a minimum of 25
gal/A by ground with a
retreatment interval of 7- to 10-
days.
Use limited to TX. Applications
may be made alone or as a tank
mix with a pyrethroid.
Applications may be made in a
minimum of 25 gal/A by ground
or 5 gal/A by air with a
retreatment interval of 7- to 10-
days.
Use limited to FL, LA, and TX.
Applications may be made in a
minimum of 25 gal/A by ground
or 3 gal/A by air with a
retreatment interval of 7- to 10-
day s.
82
-------
Site
Application Type
Application Timing
Application Equipment
-
Formulation
[EPA Reg. No.]
41b/galEC
[AR970004]
[CA780163]
[CA790096]
[DE910002]
IDE920002]
[LA910008]
[MD910009]
[NC890007]
[NJ900006]
[NJ960010]
[TN890007]
[TN930003]
[TN960006]
[VA910005]
([VA930002]
Foliar
Ground or aerial
Elb/galEC
:A780163]
Maximum Single
Application Rate (ai)
1.0 Ib/A
1.0 Ib/A
Maximum
Number of
Applications Per
Season
4
4
Maximum Seasonal
Rate(ai)
4.0 Ib/A
*
4.0 Ib/A
Preharvest
Interval,
(Days)
7
14
Use Directions and Limitations
Use limited to AR, CA, DE, LA,
MD,NC,NJ,TN,andVA.
Applications may be made in a
minimum of 25 gal/A by ground
or 5 gal/A by air with a
retreatment interval of 7- to 10-
days.
Use limited to CA for processing
tomatoes. Applications may be
made in a minimum of 25 gal/A
by ground or 5 gal/A by air with
a retreatment interval of 7- to 10-
days.
83
-------
84
-------
Appendix B: Data Supporting Guideline Requirements for the Reregistration of Methamidophos
REQUIREMENT
USE PATTERN
CITATION(S)
PRODUCT CHEMISTRY
New Guideline Old Guideline
Number
830.1550
830.1600
830.1620
830.1650
830.1670
830.1700
830.1750
830.1800
830.6302
830.6303
830.6304
830.6313
Number
61-1
158-160
61-2A
158-165
61-2B
62-1
62-2
62-3
63-2
63-3
63-4
63-13
Product Identity and
Composition
Description of Materials Used
to Produce Product
Start. Mat. & Mnfg. Process
Description of Formulation
Process
Formation of Impurities
Preliminary Analysis
Certification of limits
Analytical Method
Color
Physical State
Odor
Stability
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
00014037, 43661001, Data Gap
Data Gap
00014024, 43661001, Data Gap
Data Gap
00014024, 43661001, Data Gap
00014024, 43661002, Data Gap
00014024, 43661002, Data Gap
00014023, 00014025-00014030, 00014032,
00014033, 43661001, Data Gap
00014021, 43661001, 43661003, Data Gap
00014021, 43661001, 43661003, Data Gap
00014021, 43661001, 43661003, Data Gap
000 14021, Data Gap
85
-------
REQUIREMENT
USE PATTERN CITATION(S)
830.6314 63-14
830.6315 63-15
830.6316 63-16
830.6317 63-17
830.6319 63-19
830.6320 63-20
830.6321 158-165
830.7000 63-12
830.7050 None
830.7100 63-18
830.7200 63-5
830.7220 63-6
830.7300 63-7
830.7370 63-10
830.7550 63-11
830.7840 63-8
830.7860
Oxidizing/Reducing Action
Flammability
Explodability
Storage Stability
Miscibility
Corrosion Characteristics
Dielectric Breakdown Voltage
pH
UV/Visible Absorption
Viscosity
Melting Point
Boiling Point
Density
Dissociation Constant
Octanol/Water Partition
Coefficient
Solubility
A, B Data Gap
A, B Data Gap
A, B Data Gap
A, B Data Gap
A, B Data Gap
A,B 00014021, Data Gap
A, B Data Gap
A, B Data Gap
A, B Data Gap
A, B Data Gap
A, B 43661001,43661003, Data Gap
A, B 43661001,43661003
A, B 00014021,43661001, 43661003, Data Gap
A,B 43661003, Data Gap
A,B 43661003, Data Gap
A,B 00014021,43661001,43661003
86
-------
REQUIREMENT
USE PATTERN CITATION(S)
830.7950 63-9 Vapor Pressure
ECOLOGICAL EFFECTS
850.1010 72-2A Invertebrate Toxicity
850.1075 72-1A Fish Toxicity Bluegill
850.1075 72-1C Fish Toxicity Rainbow Trout
850.2100 71-1 Avian Acute Oral Toxicity
850.2200 71-2A
850.2200 71-2B
850.2300
850.2300
None
850.1025
71-4A
71-4B
72-3A
72-3B
850.1035 72-3C
850.1300 72-4A
Avian Dietary Toxicity - Quail
Avian Dietary Toxicity - Duck
Avian Reproduction - Quail
Avian Reproduction - Duck
Estuarine/Marine Toxicity -
Fish
Estuarine/Marine Toxicity -
Mollusk
Estuarine/Marine Toxicity -
Shrimp
Daphnid Chronic Toxicity
A,B
00014021, 4361001, 43661003
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
00041311, 00014110, 00014305
00041312, 00144432, 44484402, 00014063
00041312, 00144429, 00144432, 00014063
00014094, 00014095, 00041313, 00093914,
00109717, 00109718, 00144428
00093904, 00014304, 00145655, 00130823,
00014064, 44484404
00041658, 00130823, 00014304, 00145655,
44484403
00014114
00014113
00144431
40088601
00144430
Data Gap
87
-------
REQUIREMENT
850.1350
850.4100
850.4150
850.3020
72-4B
122-1
122-1
141-1
Estuarine/Marine Invertebrate
Life Cycle
Terrestrial Plant Toxicity
(Seedling Emergence)
Terrestrial Plant Toxicity
(Vegetative Vigor)
Honey Bee Acute Contact
USE PATTERN
A,B
A,B
A,B
A,B
CITATIONS)
Data Gap
Data Gap
Data Gap
00036935
TOXICOLOGY
870.1100
870.1200
870.1300
870.2400
870.2500
870.2600
870.3100
870.3150
870.3200
870.3700
81-1
81-2
81-3
81-4
81-5
81-6
82-1A
82-1B
82-2
83-3A
Acute Oral Toxicity-Rat
Acute Dermal Toxicity-
Rabbit/Rat
Acute Inhalation Toxicity-Rat
Primary Eye Irritation-Rabbit
Primary Skin Irritation
Dermal Sensitization
90-Day Feeding - Rodent
90-Day Feeding - Non-rodent
21-Day Dermal - Rabbit/Rat
Developmental Toxicity - Rat
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
00014044, Data Gap
000 14049, Data Gap
00148449, Data Gap
00014221, Data Gap
00014220, Data Gap
00147929, Data Gap
00014155
00014153
44525301 -,
00148454, 43906901
-------
REQUIREMENT
870.3700
870.3800
870.3465
870.4100
870.4300
870.4200
870.6100
870.6200
None
83-3B
83-4
82-4
83-1B
83-1A/
83-2A
83-2B
81-7
81-8
82-1SS
Developmental Toxicity -
Rabbit
2-Generation Reproduction -
Rat
90-Day Inhalation-Rat
Chronic Feeding Toxicity -
Non-Rodent
Combined Chronic Toxicit/
Carcinogenicity - Rodent
Oncogenicity - Mouse
Acute Delayed Neurotoxicity -
Hen
Acute Neurotoxicity Screen
8-Week Subchronic Oral
USE PATTERN
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
CITATION(S)
00041315,44040601
00148455, 41234301, 44466001, 44815401,
44815402
41402401
00147938, 41234304
00148952, 43248102
00145579, 00147937, 43248101
00041317
43025001,43345801
41867201
None
82-5A
None 82-5B
870.5140 84-2
Toxicity Cholinesterase Study -
Rodent
90-Day Delayed Neurotoxicity
-Hens
90-Day Neurotoxicity - Rat
Gene Mutation (Ames Test)
A,B
40985202
A,B 43197901
A, B 00098457
89
-------
REQUIREMENT
870.5375
870.5300
870.5900
870.6200
870.6200
870.7485
84-2
84-2
84-2
82-7
82-7
85-1
Structural Chromosomal
Aberration
Gene Mutation - Mammalian
Cells
Other Mutagenic Mechanisms
- in vitro
Subchronic Neurotoxicity
Screening Study - Rodent
Subchronic Oral Delayed
Neurotoxicity - Hen
General Metabolism
USE PATTERN
A,B
A,B
A,B
A,B
A,B
A,B
OTATION(S)
41234306, 41461401
42854701
41234305
43197901
40985202
00015224
OCCUPATIONAL/RESroENTIAL
EXPOSURE
875.2100
875.2200
875.2400
875.2500
875.1100
132-1A
132-1B
133-3
133-4
231
Foliar Residue Dissipation
Soil Residue Dissipation
Dermal Passive Dosimetry
Exposure
Inhalation Passive Dosimetry
Exposure
Estimation of Dermal
A,B
A,B
A,B
A,B
A,B
40985203, 44685501, 44685502, 44685503
Waived
Data Gap
Waived
Data Gap
Exposure at Outdoor Sites
90
-------
REQUIREMENT
875.1300
232
ENVIRONMENTAL
835.1240
860.1850
835.2120
835.2240
835.2410
835.4100
835.4200
835.4300
835.4400
835.6100
None
None
163-1
165-1
161-1
161-2
161-3
162-1
162-2
162-4
162-3
163-2
164-1
165-4
167-1-SS
Estimation of Inhalation
Exposure at Outdoor Sites
FATE
Leaching/Adsorption/Desorpti
on
Confined Rotational Crop
Hydrolysis
Photodegradation - Water
Photodegradation - Soil
Aerobic Soil Metabolism
Anaerobic Soil Metabolism
Aerobic Aquatic Metabolism
Anaerobic Aquatic
Metabolism
Volatility
Terrestrial Field Dissipation
Bioaccumnlation in Fish
Drinking Water Monitoring
USE PATTERN
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
CITATION(S)
Data Gap
40504811
42758701, Data Gap
00150609
00150610
00 1506 11, Data Gap
41372201
43541202
Data Gap (can be fulfilled by 835.4400)
43541202, Data Gap
40985206
40985206, 43541201, Data Gap
00014015
Data Gap
RESIDUE CHEMISTRY
91
-------
REQUIREMENT
USE PATTERN CITATION(S)
860.1300 171-4A Nature of Residue-Plants
860.1300 171-46 Nature of Residue - Livestock
860.1340 171-4C
860.1340 171-4D
860.1380 171-4E
860.1480 171-4J
Residue Analytical Method -
Plants
Residue Analytical Method -
Animals
Storage Stability
Magnitude of Residues -
Meat/Milk/Poultry
/Egg (Milk and the Fat, Meat,
and Meat Byproducts of
Cattle, Goats, Hogs, Horses,
and Sheep)
860.1500 171-4K Crop Field Trials-Root and
Tuber Vegetables Group
(Beets, sugar, roots)
860.1500 171-4K Crop Field Trials-Root and
Tuber Vegetables Group
(Potatoes)
A,B
A,B
A,B
A,B
A,B
A,B
A,B
A,B
00014077, 00014081,44209701, 44209702
00014555, 00014995, 00015222, 4429703,
44209704
00014085, 44209705, 44209706
44209707,44209708
44514302
00015183,00015225
00013677, 00014266,00014269
00014075,40747301,44512201
92
-------
REQUIREMENT
USE PATTERN CTTATIONfS)
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
Crop Field Trials-Leaves of A, B
Root and Tuber Vegetables
Group (Beets, sugar, tops)
Crop Field Trials-Leafy A, B
Vegetables (except Brassica)
Vegetables Group (Lettuce)
Crop Field Trials-Brassica A, B
(Cole) Vegetables Group
(Broccoli)
Crop Field Trials-Brassica
(Cole) Vegetables Group
(Brussels sprouts)
Crop Field Trials-Brassica
(Cole) Vegetables Group
(Cabbage)
Crop Field Trials-Brassica A, B
(Cole) Vegetables Group
(Cauliflower)
Crop Field Trials-Fruiting A, B
Vegetables (Except Cucurbits)
Group (Eggplant)
00013677, 00014266, 00014269
00014073
00014069
A, B 00014070
A, B 00014071
00014072
00014119, 00014120, 00014130, 00014131
93
-------
REQUIREMENT
USE PATTERN CITATION(S)
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
860.1500 171-4K
860.1520 171-4L
860.1520 171-4L
860.1520 171-4L
Crop Field Trials-Fruiting
Vegetables (Except Cucurbits)
Group (Pepper)
Crop Field Trials-Fruiting
Vegetables (Except Cucurbits)
Group (Tomato)
Crop Field Trials-Cucurbits
Vegetables Group (Cucumber)
Crop Field Trials-Cucurbits
Vegetables Group (Melon)
Miscellaneous Commodities-
Cotton, Seed and Gin
Byproducts
Processed Food/Feed (Cotton,
seed)
Processed Food/Feed (Potato)
Processed Food/Feed (Tomato)
A, B 00014121, 00014122, 00014123, 00014140
A, B 00014124-00014129,40007401,44514301
A, B 00014132, 00014133, 00014138, 00014139
A,B , 00014134,00014135
A, B 00014074,44558801
A, B 41966302
A,B 44815406
A, B 40007401
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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 January 8,
1999. Sixty days later the first public comment period closed. The EPA men considered comments,
revised the risk assessment, and added the formal "Response to Comments" document and the revised risk
assessment to the docket on February 3,2000.
All documents, in hard copy form, may be viewed in the OPP docket room or downloaded or viewed
via the Internet at the following she:
www.epa.gov/pesticides/op
These documents include:
Methamidophos: Revision of EFED Risk Assessment for the Reregistration Eligibility
Decision (RED) Document to Include Registrant's Comments.
EFED Response to Comments Submitted to the Methamidophos Docket During the 60-
day Comment Period on the EFED Methamidophos RED Chapter.
Methamidophos: HED Risk Assessment and Disciplinary Chapters for the Reregistration
Eligibility Decision (RED) Document List A Reregistration Case 0043. ChemcalNo.
101201. DP Barcode: D250644. October 30, 1998
Human Health Risk Assessment: Methamidophos. February 3,2000
Methamidophos Summary. December 2, 1999
Overview of the Revised Methamidophos Risk Assessment. January 13,2000
Acephate and Methamidophos: Technical Briefing. February 3,2000
Methamidophos: Revised Toxicology Chapter for RED. February 3,2000
Final Usage Analysis for Methamidophos RED.
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Methamidophos. List A Case No. 0043. Chemical No. 101201. Revised Dietary
Exposure and Risk Analyses for the HED Revised Human Health Risk Assessment and
HED Review of the Bayer Corporation Probabilistic (Monte Carlo) Acute Dietary
Exposure Assessment. DP Barcodes D256039, D256042. MRIDNo. 448154-10.
October 4,1999
Methamidophos: Revised Occupational and Residential Exposure Assessment and
Recommendations for the Reregistration Eligibility Decision Document PC Code 101201;
DP Barcode: D258447. August 9,1999
Review of Methamidophos Incident Reports. DP Barcode D258608, Chemical # 101201.
October 5,1999
Methamidophos List B Reregistration Case No. 0043/Chemical ID No. 101201.
Response to Comments to the Draft Methamidophos Reregistration Eligibility Decision
(RED) Document. DP Barcode D254708. August 18,1999
Response to Public Comments on the Preliminary Risk Assessments for me
Organophosphate Methamidophos. February 16,2000
Methamidophos: Review of 21-day Dermal Toxicity in Rats (MRID No. 44525301 and
Addendum to MRID No. 44525301)/Short- and Intermediate- Term Dermal Risk
assessments. May 18,1999
Methamidophos: Review of Two Generation Reproduction Toxicity Study in Rats (MRID
No. 4466001 and Addenda MRID No. 44815402)/Impact on Dietary and Non-dietary
Risk Assessments. June 16,1999
Methamidophos: Review of Potato Processing Study; Chemical ID No. 101201;
Reregistration Case No. 0043; MRID No. 44815406; DP Barcode D256034.
August 11,1999
Methamidophos. Chemical ID No. 101201. Sensitivity Analysis. November 29,
1999
96
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Appendix D: Bibliography
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 die 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, mis 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 mem, treating them as a single study.
3. IDENTIFICATION OF ENTRIES. The entries in mis 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 identify volumes of submitted studies (see paragraph 4(dX4) 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.
b. Document date. The date of the study is taken directly from the document. When the date is
followed by a question mark, me 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
97
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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.
98
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MRIP Citation
00013677 Morse Laboratories, Incorporated (1976) Chemagro Agricultural
DivisionMobay Chemical Corporation Residue Experiment: 462-5746-75D:
Report No. 49920. (Unpublished study including report nos. 49921,50844 and
50845, received Aug 24,1978 under 3125-280; submitted by Mobay Chemical
Corp., Agricultural Div., Kansas City, Mo.; CDL:097318-H)
00014015 Baychem Corporation (1972) Chemagro, Division of Baychem Corporation,
Residue Experiment: Report No. 31933. (Unpublished study received on
unknown date under OF0956; submitted by Chevron Chemical Co., Richmond,
Calif.; CDL:093266-G)
00014021 Chevron Chemical Company (1970) Monitor Insecticide Residue Tolerance
Petition: Physical and Chemical Properties. (Unpublished study received Mar 5,
1970 under OF0956; CDL:093266-M)
00014023 Hayman, E.L. (1969) Monitor by Gas Chromatography. Method dated
Oct 16,1969. (Unpublished study received Mar 5,1970 under
OF0956; submitted by Chevron Chemical Co., Richmond, Calif.;
CDL:093266-Q)
00014024 Chevron Chemical Company (19??) Monitor Insecticide Residue Tolerance
Petition: Manufacturing Process. (Unpublished study received Mar 5,1970
under OF0956; CDL:093266-R)
00014025 Leary, J.B. (1969) Determination of Monitor Insecticide and the Thiono Isomer
Impurity in Technical Monitor Insecticide. Method dated Apr 23,1969.
(Unpublished study received Mar 5,1970 under OF0956; submitted by Chevron
Chemical Co., Richmond, Calif.; CDL:093266-S)
00014026 Leary, J.B. (1968) Determination of N,O,S-Trimethyl phosphoramidothioate in
Monitor Insecticide. Method dated Jun 13,1968. (Unpublished study received
Mar 5,1970 under OF0956; submitted by Chevron Chemical Co., Richmond,
Calif.; CDL: 093266-T)
00014027 Leary, J.B. (1968) Determination of N,O,O-Trimethyl phosphoramidothioate in
Monitor Insecticide. Method dated Jun 13,1968. (Unpublished study received
Mar 5,1970 under OF0956;! submitted by Chevron Chemical Co., Richmond,
Calif.; CDL:093266-U)
00014028 Leary, J.B. (1969) Determination of O,~S-Dimethyl phosphorothioate in Monitor
99
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00014029
Insecticide. Method dated Dec 12,1969. (Unpublished study received Mar 5,
1970 under OF09S6; submitted by Chevron Chemical Co., Richmond, Calif.;
CDL:093266-V)
Leary, J.B. (1968) Determination of Dimethyl sulfate in Monitor Insecticide.
Method dated Jun 13,1968. (Unpublished study received Mar 5,1970 under
OF0956; submitted by Chevron Chemical Co., Richmond, Calif.; CDL:093266-W)
00014030 Leary, J.B. (1970) Determination of Methyl sulfuric acid in Monitor Insecticide.
Method dated Jan 21,1970. (Unpublished study received Mar 5,1970 under
OF0956; submitted by Chevron Chemical Co., Richmond, Calif.; CDL:093266-X)
00014032 Leary, J.B. (1968) Determination of N, N, O, S -Tetramethyl
phosphoramidothioate in Monitor Insecticide. Method dated Jun 13,1968.
(Unpublished study received Mar 5,1970 under OF0956; submitted by Chevron
Chemical Co., Richmond, Calif.; CDL:093266-Z)
00014033 Leary, J.B. (1968) Determination of N, N, O, O-Tetramethyl
phosphoramidothioate in Monitor Insecticide. Method dated Jun 13,1968.
(Unpublished study received Mar 5,1970 under OF0956; submitted by Chevron
Chemical Co., Richmond, Calif.; CDL:093266-AA)
00014037 Chevron Chemical Company (19??) Monitor Insecticide Residue Tolerance
Petition: Name and Chemical Identity. (Unpublished study received Mar 5,1970
under OF0956; CDL:093266-AF)
00014044 Cavalli, R.D.; Hallesy, D.W. (1968) Acute Oral Toxicity of RE 9006 (95%) in
Rats: SOCO 14/1:87. (Unpublished study received Mar 5,1970 under OF0956;
submitted by Chevron Chemical Co., Richmond, Calif.; CDL:093265-B)
00014049 Cavalli, RJX; Hallesy, D.W. (1968) Acute Dermal Toxicity of Monitor
Technical: SOCO 30/1:121-8. (Unpublished study received Mar 5,1970 under
OF0956; submitted by Chevron Chemical Co., Richmond, Calif.; CDL:093265-G)
00014063 Schoenig, G. (1968) Report to Chevron Chemical Company, Ortho Division:
Four-Day Fish Toxicity Study on Monitor (RE-9006) 75% Technical SX-171:
IBT No. A6482. (Unpublished study received Mar 5,1970 under OF0956;
prepared by Industrial Bio-Test Laboratories, Inc., submitted by Chevron
Chemical Co., Richmond, Calif.; CDL:093265-W)
00014064 Jackson, G.L. (1968) Report to Chevron Chemical Company, Ortho Division:
Quail Toxicity of Monitor (RE 9006): IBT No. J6483. (Unpublished study
100
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00014069
received Mar 5,1970 under OF0956; prepared by Industrial Bio-Test
Laboratories, Inc., submitted by Chevron Chemical Co., Richmond, Calif.;
CDL:093265-X)
Mayberry, T.W.; Sakamoto, S.S.; Leary, J.B.; et al. (1969) Residue Data Sheet:
Broccoli. (Unpublished study received Mar 5,1970 under OF0956; submitted by
Chevron Chemical Co., Richmond, Calif.; CDL:093264-B)
00014070 Cinereski, J.E.; Leary, J.B.; Sakamoto, S.S.; et al. (1969) Residue Data Sheet:
Brussels Sprouts. (Unpublished study received Mar 5,1970 under OF0956;
submitted by Chevron Chemical Co.* Richmond, Calif.; CDL:0932644)
00014071 Cinereski, J.E.; Leary, J.B.; Mayberry, T.W.; et aL (1969) Residue Data Sheet:
Cabbage. (Unpublished study received Mar 5,1970 under OF0956; submitted by
Chevron Chemical Co., Richmond, Calif.; CDL:093264-L)
00014072 Mayberry, T.W.; Sakamoto, S.S.; Leary, J.B.; et al. (1970) Residue Data Sheet:
Cauliflower. (Unpublished study received Mar 5,1970 under OF0956; submitted
by Chevron Chemical Co., Richmond, Calif.; CDL:093264-R)
00014073 Sakamoto, S.S.; Leary, J.B.; Klaich, M.; et al. (1969) Residue Data Sheet:
Lettuce. (Unpublished study received Mar 5,1970 under OF0956; submitted by
Chevron Chemical Co., Richmond, Calif.; CDL:093264-W)
00014074 Sakamoto, S.S.; Kalens, K.J.; Witherspoon, B. (1969) Residue Data Sheet:
Cotton. (Unpublished study received Mar 5,1970 under OF0956; submitted by
Chevron Chemical Co., Richmond, Calif.; CDL:093264-AQ
00014075 Gerber, C.E.; Leary, J.B.; Sakamoto, S.S. (1970) Residue Data Sheet: Potatoes.
(Unpublished study received Mar 5,1970 under OF0956; submitted by Chevron
Chemical Co., Richmond, Calif.; CDL:093264-AG)
00014077 Chevron Chemical Company (1968) Metabolism of Monitor Insecticide
by Plants. (Unpublished study received Mar 5,1970 under OF0956;
CDL:093264-AO)
00014081 Tutass, H.O. (1968) Uptake and Translocation of Monitor Insecticide
by Tomato, Cabbage and Bean Plants. (Unpublished study received Mar 5,1970
under OF0956; submitted by Chevron Chemical Co., Richmond, Calif.;
CDL:093264-AU)
00014085 Chevron Chemical Company (1968) Monitor Residue Analysis by Thermionic
101
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Gas Chromatography. Method RM-10 dated May 31,1968. (Unpublished study
including letter dated Oct 17,1969 from D.E. Pack to Kenneth J. Kalens,
received Mar 5,1970 under OF0956;CDL:093264-AY)
00014094 Fletcher, D. (1971) Report to Chevron Chemical Company, Ortho Division:
Acute Oral Toxicity Study with Monitor Technical in Bobwhite Quail: ffiT No.
J261. (Unpublished study received Mar 22,1972 under OF0956; prepared by
Industrial Bio-Test Laboratories, Inc., submitted by Chevron Chemical Co.,
Richmond, Calif.; CDL: 092118-Q
00014095 Fletcher, D. (1971) Report to Chevron Chemical Company, Ortho Division:
Acute Oral Toxicity Study with Monitor Technical in Mallard Ducks: IBT No.
J262. (Unpublished study received Mar 22,1972 under OF0956; prepared by
Industrial Bio-Test Laboratories, Inc., submitted by Chevron Chemical Co.,
Richmond, Calif.; CDL: 092118-D)
00014110 Wheeler, RE. (1978) 48 Hour Acute Static Toxicity of Monitor
(SX887) to 1st Stage Nymph Water Fleas (Daphnia magna Straus).
(Unpublished study received Sep 15,1978 under 239-2404; submit-
ted by Chevron Chemical Co., Richmond, Calif.; CDL:235153-A)
00014113 Fink, R (1977) Final Report: One-Generation Reproduction Study- Mallard
Duck: Project No. 149-104; Report No. 54030. (Unpublished study received Apr
9,1979 under 239-2404; prepared by Wildlife International, Ltd. in cooperation
with Glencoe Mills, Inc. and Washington College for Mobay Chemical Corp.,
submitted by Chevron Chemical Co., Richmond, Calif.; CDL:238015-B)
00014114 Beavers, J.B.; Fink, R (1978) One-Generation Reproduction Study- Bobwhite
Quail-Technical Monitor: Final Reports: Report No. 66155. (Unpublished study
received Apr 9,1979 under 239- 2404; prepared by Wildlife International, Ltd. in
cooperation with Glencoe Mills, Inc. and Washington College for Mobay
Chemical Corp., submitted by Chevron Chemical Co., Richmond, Calif.;
CDL:238015-Q
00014119 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Cnliacan 2: Report No. 37305. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-D)
00014120 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Culiacan 1: Report No. 37306. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-E)
102
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00014121 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Culiacan 1: Report No. 37307. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-F)
00014122 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 1: Report No. 37308. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-G)
00014123 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 2: Report No. 37309. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-H)
00014124 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Culiacan 1: Report No. 37310. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-I)
00014125 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Culiacan 2: Report No. 37311. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-J)
00014126 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 1: Report No. 37312. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-K)
00014127 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 2: Report No. 37313. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-L)
00014128 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 1: Report No. 37314. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-M)
00014129 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 2: Report No. 37315. Rev. (Unpublished
103
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study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-N)
00014130 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 1: Report No. 37316. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-O)
00014131 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 2: Report No. 37317. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-P)
00014132 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 2: Report No. 37318. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-Q)
00014133 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 2: Report No. 37319. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-R)
00014134 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 1: Report No. 37320. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL-.093798-S)
00014135 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Los Mochis 2: Report No. 37321. Rev. (Unpublished
study received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Ma; CDL:093798-T)
00014138 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Culiacan 2: Report No. 37389. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Ma; CDL:093798-W)
00014139 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Culiacan-1: Report No. 37390. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:093798-X)
104
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00014140 Baychem Corporation (1973) Chemagro Division of Baychem Corporation
Residue Experiment: Culiacan 2: Report No. 37391. Rev. (Unpublished study
received Jul 20,1973 under 4F1424; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL-.093798-Y)
00014153 Loser, E. (1970) Subchronic lexicological Studies on Dogs: (Three-Month
Feeding Experiment): Report Nos. 2164; 27986. (Unpublished study received
Nov 18,1974 under 5F1571; prepared by Farbenfabriken Bayer, A.G., submitted
by Chevron Chemical Co., Richmond, Calif.; CDL:095175-F)
00014155 Loser, E. (1970) Subchronic Toxicological Studies on Rats: (Three-Month
Feeding Experiment): Report Nos. 2165; 28043. (Unpublished study received
Nov 18,1974 under 5F1571; prepared by Farbenfabriken Bayer, A.G., submitted
by Chevron Chemical Co., Richmond, Calif.; CDL:095175-I)
00014220 Levy, J.E. (1979) The Skin Irritation Potential of Monitor Technical: Socal
1445/39:24. (Unpublished study received Sep 11,1979 under 239-2452;
submitted by Chevron Chemical Co., Richmond, Calif.; CDL:241023-A)
00014221 Rittenhouse, J.R. (1977) The Eye Irritation Potential of Monitor Technical: Socal
1108/30:110. (Unpublished study received Jun 22,1978 under 239-2452;
submitted by Chevron Chemical Co., Richmond, Calif.; CDL:234801-A)
00014266 Chemonics Industries, Incorporated (1977) Chemagro Agricultural
Division-Mobay Chemical Corporation Residue Experiment: 263-5736-76H:
Report No. 53030. (Unpublished study received Aug 24,1978 under 3125-280;
submitted by Mobay Chemical Corp., Agricultural Div., Kansas City, Mo.;
CDL:097317-D)
00014269 Analytical Biochemistry Laboratories (1975) Chemagro Agricultural
Division-Mobay Chemical Corporation Residue Experiment: 461-5725B-74D:
Report No. 43802. (Unpublished study including report no. 43875, received Aug
24,1978 under 3125-280; submitted by Mobay Chemical Corp., Agricultural Div.,
Kansas City, Mo.; CDL:097318-D)
00014304 Lamb, D.W.; Burke, M.A. (1977) Dietary Toxicity of MonitorV^(R>i Technical to
Bobwhite Quail and Mallard Ducks: Report No. 51596. (Unpublished study
received Mar 27,1978 under 3125-280; submitted by Mobay Chemical Corp.,
Agricultural Div., Kansas City, Mo.; CDL:238096-B)
00014305 Nelson, D.L.; Burke, M.A. (1977) Acute Toxicity of %(R) Monitor
Technical to Daphnia magna: Report No. 54045. (Unpublished
105
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study received Mar 27,1978 under 3125-280; submitted by Mobay
Chemical Corp., Agricultural Div., Kansas City, Mo.; CDL:
238096-C)
00014555 Tucker, B.V. (1974) Characterization of 14C in Tissues and Milk from Goats Fed
S-Methyl-14C-Orthene or S-Methyl-14C-Ortho 9006. (Unpublished study
including test no. T-3201, received Nov 10,1976 under 239-2418; submitted by
Chevron Chemical Co., Richmond, Calif.; CDL:095572-K)
00014995 Crossley, J.; Lee, H. (1971) The Fate of Orthene in Lactating Ruminants
(Goats). (Unpublished study including letter dated Oct 18,1971 from R. Barth to
John Crossley, received Feb 23,1972 under 2G1248; submitted by Chevron
Chemical Co., Richmond,Calif.; CDL:091774-AD)
00015222 Crossley, J.; Lee, H. (1972) The Fate of Orthene in Lactating Ruminants
(Goats)-FinaI Report (Unpublished study including letter dated Oct 18,1971
from R. Barth to John Crossley, received Mar 27,1973 under 239-EX-60;
submitted by Chevron Chemical Co., Richmond, Calif.; CDL:223489-D)
00015224 Crossley, J.; Tutass, H.O. (1969) Metabolism of Monitor Insecticide by Rats.
(Unpublished study received Mar 27,1973 under 239-EX-60; submitted by
Chevron Chemical Co., Richmond, Calif.; CDL:223489-F)
00015183 Ladd, R. (1972) Report to Chevron Chemical Company, Ortho Division, Meat
and Milk Residue Study with Orthene-Ortho 9006 (SX-434) in Dairy Cattle: ffiT
No. J2042. (Unpublished study received Mar 27,1973 under 3F1375; prepared
by Industrial Bio-Test Laboratories, Inc., submitted by Chevron Chemical Co.,
Richmond, Calif.; CDL:093669-H)
00015225 Tucker, B.V. (1973) Meat and Milk Residue Study with Orthene and Ortho 9006
in Dairy Cattle. (Unpublished study received Mar 27,1973 under 239-EX-60;
submitted by Chevron Chemical Co., Richmond, Calif.; CDL:223489-G)
00036935 Atkins, EX.; Greywood, E.A.; Macdonald, R.L. (1975) Toxicity of Pesticides and
Other Agricultural Chemicals to Honey Bees: Laboratory Studies. By University
of California, Dept. of Entomology: UC, Cooperative Extension. (Leaflet 2287;
published study.)
00041311 Nelson, D.L.; Roney, D.J. (1979) Acute Toxicity of Monitor%(R>i
Technical to Daphnia magna: Report No. 67732. (Unpublished
study received Mar 19,1980 under 3125-280; submitted by Mobay
Chemical Corp., Kansas City, Mo.; CDL:242410-B)
106
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00041312 Nelson, D.L.; Roney, D.J. (1979) Acute Toxicity of Monitor%(R) Technical to
Bluegill and Rainbow Trout: Report No. 67739. (Unpublished study received
Mar 19,1980 under 3125-280; submitted by Mobay Chemical Corp., Kansas
City, Mo.; CDL:242410-C)
00041313 Nelson, D.L.; Burke, M.A.; Burnett, R.M. (1979) Acute Oral Toxicity of
Monitor%(R)n Technical to Bobwhite Quail: Report No. 67993. (Unpublished
study received Mar 19,1980 under 3125-280; submitted by Mobay Chemical
Corp., Kansas City, Ma; CDL:242410-E)
00041315 Machemer, L.; Lorke, D. (1979) SRA 5172 (Methamidophos): Studies of
Embryotoxic and Teratogenic Effects on Rabbits following Oral Administration:
Report No. 8410; Report No. 67990. (Unpublished study received Mar 19,1980
under 3125-280; prepared by Bayer, AG, submitted by Mobay Chemical Corp.,
Kansas City, Mo.; CDL: 242411-B)
00041317 Kruckenberg, SJVL; Fenwick, B.W.; Brown, S.M.; et aL (1979) Acute Delayed
Neurotoxicity Study on Monitor Technical: Study No. 79 ANHO1; Report No.
68037. (Unpublished study including published data, received Mar 19,1980
under 3125-280; prepared by Kansas State Univ., Dept. of Pathology, submitted
by Mobay Chemical Corp., Kansas City, Mo.; CDL:242411-D)
00041658 Nelson, D.L.; Burke, M.A.; Burnett, R.M. (1979) Acute Dietary LCjiSO'/i of
Monitor%(R>i Technical to Ducks: Report No. 67844. (Unpublished study
received Mar 19,1980 under 3125-280; submitted by Mobay Chemical Corp.,
Kansas City, Mo.; CDL:242410-D)
00093904 Fink, R; Beavers, J.B.; Brown, R.; et al. (1979) Final Report: Eight-day Dietary
LC50-Bobwhite Quail: Technical Monitor: Project No. 149-111. (Unpublished
study received Jan 26,1982 under 239-2404; prepared by Wildlife International,
Ltd. and Washington College, submitted by Chevron Chemical Co., Richmond,
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00093914 Zinkl, J.G.; Roberts, R.B.; Shea, P.J.; et al. (1981) Toxicity of acephate and
methamidophos to dark-eyed junkos. Archives of Environmental Contamination
and Toxicology 10:185-192. (Also in unpublished submission received Jan 26,
1982 under 239-2471; submitted by Chevron Chemical Co., Richmond, Calif.;
CDL: 246657-L)
00098457 Machado, M.L. (1982) Salmonella Mammalian Microsome Mutagenicity Test
(Ames Test) with Monitor Technical: Socal 1711. (Unpublished study received
Apr 6,1982 under 239-2404; submitted by Chevron Chemical Co., Richmond,
107
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Calif.; CDL:247222-A)
00109717 Fletcher, D. (1971) Report to Chevron Chemical Company, Ortho Division:
Acute Oral Toxicity Study with Monitor Technical in Bobwhite Quail: IBT No.
J261. (Unpublished study received Mar 22,1972 under 239-2326; prepared by
Industrial Bio-Test Laboratories, Inc., submitted by Chevron Chemical Co.,
Richmond, CA; CDL:001565-Q
00109718 Fletcher, D. (1971) Report to Chevron Chemical Company, Ortho Division:
Acute Oral Toxicity Study with Monitor Technical in Mallard Ducks: IBT No.
J262. (Unpublished study received Mar 22,1972 under 239-2326; prepared by
Industrial Bio-Test Laboratories, Inc., submitted by Chevron Chemical Co.,
Richmond, CA; CDL:001565-D)
00130823 Lamb, D.; Burke, M. (1977) Dietary Toxicity of Monitor Technical to Bobwhite
Quail and Mallard Ducks: 51596. (Unpublished study received Sep 13,1983
under 239-2452; prepared by Mobay Chemical Co., submitted by Chevron
Chemical Co., Richmond, CA; CDL: 251220-C)
00144428 Lamb, D.; Roney, D. (1972) Acute Oral Toxicity of Monitor to the Common
Crackle: Report No. 31952. Unpublished study prepared by Chemagro Div. of
Baychem Corp. 4 p.
00144429 Hermann (1980) Fish Toxicity to Methamidophos: Report No. FF106.
Unpublished Mobay report no. 88500 prepared by Bayer AG. 4 p.
00144431 Larkin, J. (1983) The Acute Toxicity of Methamidophos (Technical) to
Sheepshead Minnow (Cyprinodon variegatus): Project No. 83-E-402S.
Unpublished Mobay study No. 86640 prepared by Biospherics Inc. 16 p.
00144432 Lamb, D.; Roney, D. (1972) Acute Toxicity of Monitor 4 to Fish: Report No.
32312. Unpublished study prepared by Chemagro Div. of Baychem Corp. 4 p.
00145579 Hayes, R. (1984) Oncogenicity Study of Methamidophos Technical (Monitor) on
Mice: Study No. 80-332-01. Unpublished study prepared by Mobay Chemical
Corp. 667 p.
00145655 Lamb, D.; Burke, M. (1977) Dietary Toxicity of Monitor Technical to Bobwhite
Quail and Mallard Ducks: Report No. 51596; Reference 74-103. Unpublished
study prepared by Mobay Chemical Corp. 2 p.
00147929 Korenaga, G. (1984) Modified Buehler Test for the Skin Sensitization Potential
108
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of Methamidophos Technical (SX-1490): SOCAL 2135. Unpublished study
prepared by Standard Oil Company of California, Environmental Health &
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00147937 Hayes, R (1984) Oncogenicity Study of Methamidophos Technical (Monitor) on
Mice: Study No. 80-332-01: Mobay Report No. 87479. Unpublished study
prepared by Mobay Chemical Corp. 664 p.
00147938 Hayes, R (1984) One-year Feeding Study of Methamidophos (Monitor) in Dogs:
Study No. 81-174-01: Mobay Report No. 87474. Unpublished study prepared by
Mobay Chemical Corp. 413 p.
00148449 Sangha, G. (1984) Acute Inhalation Toxicity Study with Technical
Methamidophos (Monitor) in Rats: Study No. 84-041-02: Toxicology Report No.
519. Unpublished study prepared by Mobay Chemical Corp. 19 p.
00148454 Hixson, E. (1984) Embryotoxic and Teratogenic Effects of Methamidophos
(Monitor) in Rats: Study No. 82-611-01: Toxicology Report No. 542.
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00148455 Hixson, E. (1984) Effect of Methamidophos (Monitor) on Reproduction in Rats:
Study No. 82-671-01: Toxicology Report No. 553. Unpublished study prepared by
Mobay Chemical Corp. 174 p.
00148952 Reagan, E. (1985) Primary Eye Irritation Study of Saf-Sol Brand Sanitizer Lot
#5414501 in New Zealand White Rabbits: Study No. 8422B: Test Article ID
85-0028. Unpublished study prepared by Food & Drug Research Laboratories,
Inc. 27 p.
00150609 Chopade, H. (1985) Hydrolysis of Carbon-14 Methamidophos in
Sterile Aqueous Buffers: Report No. 88829. Unpublished study
prepared by Stanley Research Center, Mobay Chemical Corp. 18 p.
00150610 Chopade, H. (1985) Photodecomposition of Carbon-14 Methamidophos
in Aqueous Solution: Report No. 88830. Unpublished study prepared by Stanley
Research Center of Mobay Chemical Corp. 17 p.
00150611 Chopade, H.; Freeseman, P. (1985) Photodecomposition of Carbon-14
Methamidophos on Soil: Report No. 88831. Unpublished study prepared by
Stanley Research Center of Mobay Chemical Corp. 20 p.
109
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40007400 Fujie, G. (1986) Monitor (Methamidophos) Residue on Tomatoes: Laboratory
Project ID: 8613652. Unpublished study prepared by Chevron Chemical Co. 175
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40088601 Surprenant, D. (1987) Acute Toxicity of Monitor to Eastern Oysters
(Crassostrea virginica): Report #BW-86-12-2248: Study #274-0486-6108-504.
Unpublished Mobay report 94221 prepared by Springborn Bionomics, Inc. 25 p.
40504811 Pack, D.; Verrips, I. (1988) Freundlich Soil Adsorption/Desorption Coefficients of
Acephate and Soil Metabolites: Proj. ID 8800031. Unpublished study prepared
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40747301 Koch, D. (1988) Monitor - Magnitude of the Residue on Potatoes: Final Rept.
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40985202 Sachase, K. (1987) 3-Month Subchronic Delayed Neurotoxicity Study with SRA
5172 (C.N. Methamidophos): Laboratory Project ID 94213/064293. Unpublished
study prepared by KFM Kleintierfarm Madoerin AG in cooperation with RCC
Research and Consulting Co. AG. 116 p.
40985203 Fujie, G. (1985) Dissipation of Dislodgeable Methamidophos Residues
from Cotton Leaves: Laboratory Project ID 741.il/MONTrOR.
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40985206 Panthani, A. (1988) Laboratory Soil Volatility Study of Methamidophos:
Laboratory Project ID MEF-0087. Unpublished study prepared by Chevron
Chemical Co. 59 p.
41234301 Hixon, H. (1984) Effect of Methamidophos (Monitor) on Reproduction in Rats:
Project ID 88686-1. Unpublished study prepared by Mobay Corp. 43 p.
41234304 Hayes, R (1984) One-Year Feeding Study of Methamidophos (Monitor) in Dogs:
Project ID 87474-1. Unpublished study prepared by Mobay Corp. 9 p.
41234305 Curren, R (1988) Unscheduled DNA Synthesis in Rat Primary Hepatocytes:
Monitor Technical: Project ID T5844380. Unpublished study prepared by
Microbiological Associates, Inc. 33 p.
41234306 Esber, H. (1983) In Vivo Cytogenetics Study in Mice Methamidophos Technical:
Project ID MRI-176-CCC-82-56. Unpublished study prepared by EG &
G/Mason Research Institute. 79 p.
110
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4137220 Panthani, A. (1989) Methamidophos Aerobic Soil Metabolism: Laboratory
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58 p.
41402401 Pauluhn, J. (1988) SRA 5172: Study of the Subchronic Inhalation Toxicity to Rats
in Accordance with OECD Guideline No. 413: Lab Project Number: 98370:
16578: T9022366. Unpublished study prepared by Bayer AG. 1040 p.
41461401 Murli, H. (1990) Mutagenicity Test on SRA 5172 in an in vitro Cytogenetic
Assay Measuring Chromosomal Aberration hi Chinese Hamster Ovary (CHO)
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Laboratories America, Inc. 34 p.
41867201 Christenson, W. (1991) Technical Grade Methamidophos (Monitor): An
Eight-Week Subchronic Cholinesterase Study in Fischer 344 Rats:
Lab Project Number: 89/972/CV. Unpublished study prepared by
Mobay Corp. 155 p.
41966302 Cole, R. (1991) Magnitude of the Residue on Cotton Seed Processed Parts:
Methamidophos: Lab Project Number: 99786. Unpublished study prepared by
Morse Laboratories, Inc. 107 p.
42758701 Mattern, G.; Parker, G.; Wendt, S. (1992) Confined Accumulation
of (S-Methyl-(carbon 14)) Methamidophos Residues in Rotational Crops: Lab
Project Number: MN051601: 91.028: P309W.1 Unpublished study prepared by
Miles Inc., Plant Sciences, Inc. and PTRL West, Inc. 127 p.
42854701 Bigger, A.; Sigler, C. (1993) CHO/HGPRT Mutation Assay: Monitor Technical:
Lab Project Number: TC865J32: 93-C500-SO: 105076. Unpublished study
prepared by Microbiological Associates, Inc. 33 p.
43025001 Sheets, L.; Hamilton, B. (1993) An Acute Oral Neurotoxicity Screening Study
with Technical Grade Methamidophos (MONITOR) in Rats: Lab Project
Number: 92-412-QL: 105053: E-200.1 Unpublished study prepared by Miles, Inc.
496 p.
43197901 Hamilton, B. (1994) A Subchronic Dietary Neurotoxicity Screening Study with
Technical Grade Methamidophos (MONITOR) in Fischer 344 Rats: Lab Project
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43248101 Hayes, R. (1994) Oncogenicity Study of Methamidophos Technical (MONITOR)
on Mice: (Report Addendum): Lab Project Number: 80/332/01: 87479/2.
Ill
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43248102 Hayes, R. (1994) Chronic Feeding/Oncogenicity Study of Technical
Methamidophos (MONITOR) to Rats: (Report Addendum): Lab Project
Number: 81/271/01: 88687/2. Unpublished study prepared by Miles Agricultural
Division Toxicology. 262 p.
43345801 Sheets, L. (1994) An Acute Oral Neurotoxicity Screening Study with Technical
Grade Methamidophos (MONITOR) in Rats: Supplemental: Lab Project
Number: 92-412-QL: 94-412-YW: 105053-1. Unpublished study prepared by
Miles, Inc. 246 p.
43541201 Grace, T.; Cain, K (1990) Dissipation of Methamidophos in
California Soils: Lab Project Numbers: 100166: MN830089R01:89.027.
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and NET Atlantic, Inc. 1775 p.
43541202 Schmidt, J. (1993) Anaerobic Aquatic Metabolism of (Carbon
14)-Methamidophos: Lab Project Number: 106211: MN042401:39665.
Unpublished study prepared by ABC Labs, Inc. 81 p.
43661001 Fontaine, L. (1995) Product Chemistry of Monitor Technical: LabProject
Number: PEN0366: ANR-00195: BR1890. Unpublished study prepared by
Bayer Corp. 80 p.
43661002 Fontaine, L. (1995) Product Chemistry of Monitor Technical: Lab Project
Number: 106538:106724: BR 1891. Unpublished study prepared by Bayer
Corp. 127 p.
43661003 Fontaine, L. (1995) Product Chemistry of Monitor Technical: Lab Project
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43740301 Temple, D. And D. Palmer, 1995. An Evaluation of the Effects of Monitor 4
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Cabbage Fields in East-Central Wisconsin.
43906901 Astroff, A. (1996) A Developmental Toxicity Study with Monitor Technical in the
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44040601 Hoberman, A. (1996) Oral (Stomach Tube) Developmental Toxicity Study of
112
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44209700
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Lai, J. (1997) Validation of the Extraction Efficiency of RM-12A-9 to Remove
Methamidophos Residues from Egg Yolk and Liver: Lab Project Number:
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44209701 Jalal, M.; Maurer, J. (1997) Nature of the Residues: Metabolism of (S-(carbon
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44209702 Jalal, M.; Maurer, J. (1997) Nature of the Residues: Metabolism of (S-(carbon
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95503. Unpublished study prepared by Valent Technical Center. 184 p.
44209703 Baker, F.; Bautista, A. (1997) The Metabolism of (carbon 14)Methamidophos in
the Lactating Goat: Lab Project Number: 969E/565W: 9700121: 969.
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44209704 Hatton, C.; McKemie, D.; Baker, F. (1997) The Metabolism of (carbon
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290 p.
44209705 Lai, J. (1997) Validation of the Extraction Efficiency of RM-12A-9 to Remove
Methamidophos Residues from Potatoes: Lab Project Number: VP-11307:
9700058: V-96-11307. Unpublished study prepared by Valent Technical Center.
45 p.
44209706 Lai, J. (1997) Validation of the Extraction Efficiency of RM-12A-9 to Remove
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9700123: V-96-11306. Unpublished study prepared by Valent Technical Center.
44 p.
44209707 Lai, J. (1997) Validation of the Extraction Efficiency of RM-12A-9 to Remove
Methamidophos Residues from Milk and Goat Tissue: Lab Project Number:
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44466001 Eigenberg, D.; Freshwater, K.; Lake, S. (1998) A Two-Generation Dietary
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44484402 United States Environmental Protection Agency (1977) Biological Report of
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44484403 Product Safety Labs (1981) LC50 Tests with Mallard Ducks on Sodium Arsenite,
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44514302 Williams, B. (1994) Methamidophos-Freezer Storage Stability Study in Potato
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44525301 Sheets, L.; Gastner, M.; Hamilton, B. (1997) Repeated-Dose 21-Day Dermal
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44558801 Russo, L. (1998) Monitor 4-Magnitude of the Residue in Cotton: Lab Project
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44600501 Fontaine, L. (1998) Supplement to MRIDs 43661001 and 43661002: Product
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114
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830.1550, 830.1620, 830.1750, 830.1800}
44685501 Ellisor, G. (1998) Evaluation of Foliar Dislodgeable Residues
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44685502 Ellisor, G. (1998) Evaluation of Dislodgeable Foliar Residues
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44685503 Willard, T. (1998) Dissipation of Dislodgeable Foliar
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44815401 Astroff, A.; Eigenberg, D. (1998) A Two-Generation Dietary Reproduction Study
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299 p.
44815402 Moore, K. (1999) A Two-Generation Dietary Reproduction Study in Rats with
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44815406 Lenz, C. (1994) Monitor 4-Magnitude of the Residues on Potato Processed
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119
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Appendix £: Generic Data Call In
121
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DRAFT COPY
Page 1 of 1
United States Environmental Protection
Agency Washington, D.C. 20460
DATA CALL-IN 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
2. Case # and Name
0043 Methamidophos
Chemical # and Name 101201
Methamidophos
3. Date and Type of DCI and Number
DD-MMM-YYYY
GENERIC
ID# GDCI-101201-NNNNN
4. EPA
Product
Registration
5. I wish to
cancel this
product regis-
tration volun-
tarily
6. Generic Data
6a. I am claiming a Generic
Data Exemption because I
obtain the active ingredient
from the source EPA regis-
tration number listed below.
6b. I 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
I agree to satisfy the MUP
requirements on the attached
form entitled "Requirements
Status and Registrant's
Response."
7b. My product is an EUP and
I agree to satisfy the EUP
requirements on the attached
form entitled "Requirements
Status and Registrant's
Response."
NNNNNN-NNNNN
8. Certification I certify that the statements made on this form and all attachments are true, accurate, and complete. I acknowledge that any
knowingly false or misleading statement may be punishable by fine, imprisonment or both under applicable law.
Signature and Title of Company's Authorized Representative
9. Date
-------
United States Environmental Protection
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
UMb Approval MIU-VWI
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
2. Case # and Name
0043 Methamidophos
Chemical # and Name 101201
Methamidophos
3. Date and Type of DCI and Number
DD-MMM-YYYY
GENERIC
ID# GDCI-101201-NNNNN
4. Guideline
Requirement
Number
5. Study Title
Progress
Reports
6. Use
Pattern
7. Test
Substance
8. Time
Frame
(Months)
9. Registrant
Response
875.1100
875.1300
835.2410
835.4400
835.6100
850.4100
850.4150
875.2400
Applicator Exposure Data Requirements (Conventional
Chemical)
Dermal exposure-outdoor
Inhalation exposure-outdoor
(10,11 ,12
,13)
Environmental Fate Data Requirements (Conventional
Chemical)
Photodegradation of parent and degradates in soil (6)
Anaerobic aquatic metabolism
Terrestrial field dissipation (7 ,8)
Nontarqet Plant Protection Data Requirements (Conventional
Chemical)
Terrestrial plant toxicity, Tier 1 (seeding emergence)
Terrestrial plant toxicity, Tier 1 (vegetative vigor)
Post-Application Exposure Data Requirements (Conventional
Chemical)
Dermal exposure
(14,15,16
,17,18)
A,B
A.B
A,B
A. B
A.B
A.B
A, B
A,B
TEP
TEP
TGAI or PAIRA
TGAI
TEP
TGAI
TGAI
TEP
12
12
12
24
24
12
12
24
10. Certification I certify that the statements made on this form and all attachments are true, accurate, and complete. I acknowledge that any
knowingly false or misleading statement may be punishable by fine, imprisonment or both under applicable law
Signature and Title of Company's Authorized Representative
11. Date
12. Name of Company
13. Phone Number
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DRAFT COPY
Page 2 of 3
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 2. Case # and Name 3. Date and Type of DCI and Number
SAMPLE COMPANY 0043 Methamidophos DD-MMM-YYYY
NO STREET ADDRESS Chemical # and Name 101201 GENERIC
NO CITY, XX 00000 Methamidophos ,D# GDCI-101201-NNNNN
4. Guideline
Requirement
Number
830.6313
830.7050
830.7200
830.7370
830.7550
860.1850
850.1300
850.1350
5. Study Title
Product Chemistry Data Reauirements (Conventional
Chemical)
Stability to sunlight, normal and elevated
temperatures, metals, and metal ions
UV/Visible absorption
Melting point/melting range (1 ,2)
Dissociation constant in water (3 ,4)
Partition coefficient (n-octanol/water), shake flask (5)
method
Residue Chemistry Data Reauirements for Food Uses
(Conventional Chemical)
Confined accumulation in rotational crops (9)
Terrestrial and Aauatic Nontaraet Oraanisms Data
Reauirements (Conventional Chemical)
Daphnid chronic toxicity test
Mysid chronic toxicity test
p
R
0
T
0
C
L
Progress
Reports
1
2
3
6. Use
Pattern
A, B
A,B
A, B
A, B
A, B
A, B
A,B
A, B
Initial to indicate certification as to information on this nane
7. Test
Substance
TGAI
TGAI/PAI
TGAI or PAI
TGAI or PAI
TGAI or PAI
PAIRA
TGAI
TGAI
8. Time
Frame
(Months)
9
8
9
9
9
24
12
12
9. Registrant
Response
~.,-
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unuea oiaies tinvironmeniai rroiecuon
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
UMB Approval zuvu-uiu/
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 2. Case # and Name
SAMPLE COMPANY 0043 Methamidophos
NO STREET ADDRESS Chemical # and Name 1 01 201
NO CITY, XX 00000 Methamidophos
4. Guideline
Requirement
Number
167-1-SS
5. Study Title
Drinking Water Monitoring (19)
P
R
O
T
O
C
L
Progress
Reports
1
2
3
6. Use
Pattern
A,B
3. Date and Type of DCI and Number
DD-MMM-YYYY
GENERIC
ID# GDCI-101201-NNNNN
initial to indicate certification as to information on this page
'ii text of certification is on page one).
7. Test
Substance
TEP
8. Time
Frame
(Months)
24
9. Registrant
Response
Date
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DRAFT COPY Page 1 of2
United States Environmental Protection
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 0043 Methamidophos
DCI Number: GDCI-101201 -NNNNN
Key: PAIRA = PAI Radio Labeled [PAIRA]; TEP = Typical End Use Product [TEP]; TGAI = Technical Grade Active Ingredient FJGAI]; TGAI or PAI = Technical Grade of the Active Ingredient or Pure
Active Ingredient; TGAI or PAIRA = Technical Grade of the Active Ingredient or Active Ingredient, Radio-Labelled; TGAI/PAI = Technical Grade Active Ingredient, Pure Active Ingredient
Use Categories Key:
A - Terrestrial food crop
B - Terrestrial feed crop
Footnotes: [The following notes are referenced In column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE form.]
1 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).
2 Required when the TGAI is solid at room temperature.
3 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).
4 Required when the test substance contains an acid or base functionality (organic or inorganic) or an alcoholic functionality (organic).
5 Required if the TGAI or PAI is organic and non-polar.
6 Not required when the chemical is to be applied only by soil injection or is incorporated in the soil.
7 Required for aquatic food and nonfood crop uses for aquatic sites that are intermittently dry. Such sites include, but are not limited to cranberry bogs and rice paddies.
8 Environmental chemistry methods used to generate data associated with this study must include results of a successful confirmatory method trial by an independent laboratory. The
environmental chemistry methods must include a statement of no data confidentiality claims, i.e., non-CBI. Test standards and procedures for independent laboratory validation are available
as addenda to the guideline for this test requirement.
9 Required when it is reasonably foreseeable that a food or feed crop could be subsequently planted on the site of the pesticide application.
10 Biological monitoring data may be submitted in addition to, or in lieu of, dermal and inhalation exposure data, provided the human pharmocokinetics of the pesticide and/or metabolite/analog
compounds (i.e., whichever method is selected as an indicator of body burden or internal dose) allow for the back calculation to actual dose.
11 Protocols must be submitted for approval prior to the initiation of the study. Details for developing protocols are available from the Agency.
12 Data are required for outdoor occupational site if the product is applied outdoors.
13 Data are required for residential use sites if the product is applied outdoors.
14 Protocols must be submitted for approval prior to the initiation of the study. Details for developing protocols are available from the Agency.
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UltltVk) 1_/11 V 1J.VS*U1..LV'.11.1«-VI Ji
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUKEMENTS
Case # and Name: 0043 Methamidophos
DCI Number: GDCI-101201-NNNNN
Key: PAIRA = PAI Radio Labeled [PAIRA]; TEP = Typical End Use Product [TEP]; TGAI = Technical Grade Active Ingredient [TGAI]; TGAI or PAI = Technical Grade of the Active Ingredient or Pure
Active Ingredient; TGAI or PAIRA = Technical Grade of the Active Ingredient or Active Ingredient, Radio-Labelled; TGAI/PAI = Technical Grade Active Ingredient, Pure Active Ingredient
Use Categories Key:
A - Terrestrial food crop
B - Terrestrial feed crop
Footnotes: [The following notes are referenced in column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE form.]
15 Bridging applicable residue dissipation data to dermal exposure is required.
16 Biological monitoring data may be submitted in addition to, or in lieu of, dermal and inhalation exposure data provided the human pharmocokinetics of the pesticide and/or metabolite/analog
compounds (i.e., whichever method is selected as an indicator of body burden or internal dose) allow for a back-calculation to the total internal dose.
17 Data are required for residential sites if post-application exposures are likely.
1 s Data are required for occupational sites if the human activity data indicate that workers are likely to have post-application exposures while participating in typical activities.
19 Monitoring program of community drinking water systems from surface water sources in areas where methamidophos is used.
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128
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Appendix F: Product Specific Data Call In
129
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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 0043 Methamidophos DD-MMM-YYYY
NO STREET ADDRESS Chemical # and Name 101201 PRODUCT SPECIFIC
NO CITY. XX 00000 Methamidophos |Q# pDCM01201.NNNN
4. EPA
Product
Registration
NNNNNN-NNNNN
5. I wish to
cancel this
product regis-
tration volun-
tarily
6. Generic Data
6a. I am claiming a Generic
Data Exemption because I
obtain the active ingredient
from the source EPA regis-
tration number listed below.
6b. I 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
I agree to satisfy the MUP
requirements on the attached
form entitled "Requirements
Status and Registrant's
Response."
7b. My product is an EUP and
I 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
-------
united states Environmental rroiecuon
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
UMB Approval zu/u-uiu/
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
830.1550
830.1600
830.1620
830.1650
830.1670
830.1700
830.1750
830.1800
830.6302
830.6303
830.6304
5. Study Title
2. Case # and Name
0043 Methamidophos
EPA Reg. No. NNNNNN-NNNNN
Product Chemistry Data Requirements (Conventional
Chemical)
Product Identity and composition
(1)
Description of materials used to produce the product (2)
Description of production process
Description of formulation process
Discussion of formation of impurities
Preliminary analysis
Certified limits
Enforcement analytical method
Color
Physical state
Odor
(3)
(4)
(5)
(6 ,7 ,8)
(9 ,10)
(11)
(12)
(13)
(14)
P
R
0
T
0
C
L
Progress
Reports
1
2
3
6. Use
Pattern
A.B
A.B
A, B
A, B
A,B
A.B
A.B
A, B
A, B
A, B
A, B
3. Date and Type of DCI and Number
DD-MMM-YYYY
PRODUCT SPECIFIC
ID# PDCI-101201-NNNN
7. Test
Substance
TGAI/MP/EP
TGAI/MP/EP
TGAI
MP/EP
TGAI/MP/EP
TGAI
TGAI/MP/EP
TGAI/MP/EP
TGAI/MP/EP
TGAI/MP/EP
TGAI/MP/EP
10. Certification 1 certify that the statements made on this form and all attachments are true, accurate, and complete. 1 acknowledge that any
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
8. Time
Frame
(Months)
8
8
8
8
8
8
8
8
8
8
8
9. Registrant
Response
11. Date
13. Phone Number
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DRAFT COPY
Page 2 of 4
United States Environmental Protection
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
. OMB Approval 2070-0 1 07
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
830.6313
830.6314
830.6315
830.6316
830.6317
830.6319
830.6320
830.6321
830.7000
830.7050
830.7100
830.7200 .
5. Study Title
2. Case # and Name
0043 Methamidophos
EPA Reg. No. NNNNNN-NNNNN
Stability to sunlight, normal and elevated (15,16)
temperatures, metals, and metal ions
Oxidizing or reducing action
Flammability
Explodability
Storage stability of product
Miscibility
Corrosion characteristics
Dielectric breakdown voltage
pH of water solutions or suspensions
UV/Visible absorption
Viscosity
Melting point/melting range
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24 ,25)
(26)
(27 ,28)
P
R
0
T
0
C
0
L
Progress
Reports
1
2
3
6. Use
Pattern
A, B
A, B
A, B
A,B
A,B
A,B
A,B
A, B
A,B
A, B
A,B
A, B
3. Date and Type of DCI and Number
DD-MMM-YYYY
PRODUCT SPECIFIC
ID# PDCI-101201-NNNN
7. Test
Substance
TGAI
MP/EP
MP/EP
MP/EP
MP/EP
MP/EP
MP/EP
MP/EP
TGAI/MP/EP
TGAI/PAI
MP/EP
TGAI
8. Time
Frame
(Months)
8
8
8
8
8
8
8
8
8
8
8
8
9. Registrant
Response
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united states environmental rroiecuon
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
utviD rtppiuvai £\j/v-\Ji\ji
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
830.7220
830.7300
830,7370
830.7550
830.7570
830.7840
830.7860
830.7950
870.1100
870.1200
870.1300
5. Study Title
Boiling point/boiling range
Density/relative density
Dissociation constant in water
2. Case # and Name 3. Date and Type of DCI and Number
0043 Methamidophos DD-MMM-YYYY
PRODUCT SPECIFIC
ID# PDCI-101201-NNNN
EPA Reg. No. NNNNNN-NNNNN
(29 ,30)
(31 ,32)
(33 ,34)
Partition coefficient (n-octanol/water), shake flask (35)
method
Partition coefficient (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)
Toxicoloov Data Reauirements (Conventional Chemical)
Acute Oral Toxicity
Acute dermal toxicity
Acute inhalation toxicity
(41 ,42)
(43 ,44 ,45)
(46)
P
R
0
T
O
C
L
Progress
Reports
1
2
3
6. Use
Pattern
A.B
A,B
A, B
A.B
A, B
A,B
A, B
A,B
A,B
A, B
A.B
Initial to indicate certification as to information on this page
(full text of certification is on page one).
7. Test
Substance
TGAI
TGAI/MP/EP
TGAI or PAI
TGAI/PAI
TGAI/PAI
TGAI or PAI
TGAI or PAI
TGAI or PAI
TGAI/MP/EP
TGAI/MP/EP
TGAI/MP/EP
8. Time
Frame
(Months)
8
8
8
8
8
8
8
8
8
8
8
9. Registrant
Response
Date
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DRAFT COPY
Page 4 of4
United States Environmental Protection
Agency Washington, D.C. 20460
REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE
OMB Approval 2070-0 107
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
870.2600
5. Study Title
Acute eye irritation
Acute dermal irritation
Skin sensitization
2. Case # and Name
0043 Methamidophos
EPA Reg. No. NNNNNN-NNNNN
(47)
(48 ,49)
(50 ,51)
P
R
O
T
0
C
0
L
Progress
Reports
1
2
3
6. Use
Pattern
A, B
A, B
A,B
3. Date and Type of DCI and Number
DD-MMM-YYYY
PRODUCT SPECIFIC
ID# PDCI-101201-NNNN
Initial tft inrlirata f*or+ifi^a*inn oe *« informa+iAn «r» Hi!*. M^MA
7. Test
Substance
TGAI/MP/EP
TGAI/MP/EP
TGAI/MP/EP
8. Time
Frame
(Months)
8
8
8
9. Registrant
Response
~_._
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v_nmcu
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 0043 Methamidophos
DCI Number: PDCI-101201-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/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
Footnotes: [The following notes are referenced in column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANT'S RESPONSE form.]
1 Data must be provided in accordance with the "Product Composition" Section.(158.155)
2 Data must be provided in accordance with the "Description of Materials used to Produce the Product" Section.(158.160)
3 Data must be provided in accordance with the "Description of Production Process" Section.(158.162)
4 Data must be provided in accordance with the "Description of Formulation Process" Section.(158.165)
5 Data must be provided in accordance with the "Description of Formation of Impurities" Section(158.167)
6 Data must be provided in accordance with the "Preliminary Analysis" Section.(158.170)
7 Required for TGAIs and products produced by an integrated system.
8 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).
9 Data must be provided in accordance with the "Certified Limits" Section(158.175)
1 o 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).
11 Data must be provided in accordance with the "Enforcement Analytical Method" Section.(158.180)
12 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).
13 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).
14 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).
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DRAFT COPY Page2of4
United States Environmental Protection
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 0043 Methamidophos
DCI Number: PDCI-101201 -NNNN
Key: MP/EP = Manufacturing-Use Product, Pure Active Ingredient; TGAI = Technical Grade Active Ingredient fJGAI]; TGAI or PAI = Technical Grade of the Active Ingredient or Pure Active Ingredient;
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
Footnotes: [The following notes are referenced In column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANTS 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
18 Required when the product contains combustible liquids.
19 Required when the product is potentially explosive.
20 Please see attached "Additional Information and Requirements Pertaining to Storage Stability (OPPTS 830.6317) and Corrosion Characteristics (OPPTS 830.6320) Data Requirements of the
Product Specific Data Call-ins issued under the Reregistration Eligibility Decision (RED)/lnterim Registration Eligibility Decision (IRED) Documents."
21 Required if the product is an emulsifiable liquid and is to be diluted with petroleum solvents.
22 Please see attached "Additional Information and Requirements Pertaining to Storage Stability (OPPTS 830.6317) and Corrosion Characteristics (OPPTS 830.6320) Data Requirements of the
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.
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UJ.J.1LVVI
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 0043 Methamidophos
DCI Number: PDCI-101201 -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/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
Footnotes: FJhe following notes are referenced In column two (5. Study File) of the REQUIREMENTS STATUS AND REGISTRANT'S 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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Page 4 of 4
United States Environmental Protection
Agency Washington, D.C. 20460
FOOTNOTES AND KEY DEFINITIONS FOR GUIDELINE REQUIREMENTS
Case # and Name: 0043 Methamidophos
DCI Number: PDCI-101201-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/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
Footnotes: [The following notes are referenced In column two (5. 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
rvtneiHaratirin unrlAr CA/*4inn 4 £4 "7/a\M\
44
45
46
47
48
49
50
51
consideration under Section 154.7(a)(1).
Not required if test material is a gas or a highly volatile liquid.
Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
Required if the product consists of, or under conditions of use will result in, a respirable material (e.g., gas, vapor, aerosol, or particulate).
Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
Not required if test material is a gas or a highly volatile liquid.
Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
Not required if test material is corrosive to skin or has a pH of less than 2 or greater than 11.5.
Required if repeated dermal exposure is likely to occur under conditions of use.
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Appendix G: EPA'S Batching of Methamidophos Products for Meeting Acute Toxicity Data
Requirements for Reregistration
In an effort to reduce Ifae time, resources and number of animals needed to fulfill the acute toxicity
data requirements for reregistration of products containing Methamidophos as 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 lexicological 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 lexicological
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 die 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 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)
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those studies.
Five products were found which contain Methamidophos as the active ingredient These products
have been placed into one batch and a No Batch in accordance with the active and inert ingredients
and type of formulation.
Batch 1
EPA Reg. No.
3125-280
59639-56
Percent active ingredient
40.58
40.58
Formulation Type
Solid
Solid
No Batch
EPA Reg. No.
3125-341
3125-348
59639-68
Percent active ingredient
74.6
60.0
72.0
Formulation Type
Solid
Liquid
Solid
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Appendix H: List of Registrants Sent DCIs
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United States Environmental Protection
Agency Washington, D.C. 20460
LIST OF ALL REGISTRANTS SENT THIS DATA CALL-IN NOTICE
Case # and Name: 0043,Methamidophos
Co. Nr.
Company Name
Agent For
Address
City & State
Zip
264
3125
59639
BAYER CROPSCIENCE LP
BAYER CORP
VALENT U.S.A. CORPORATION
2 T.W. ALEXANDER DRIVE
RESEARCH
TRIANGLE PARK
KANSAS CITY
PO Box 4913 8400 HAWTHORN RD
PO Box 8025 1600 RIVIERA AVENUE, SUITE 200 WALNUT CREEK
NC 27709
MO 641200013
CA 94596
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Appendix I: List of Available Related Documents and Electronically Available Forms
Pesticide Registration Forms are available at the following EPA internet site:
http://www.epa.gov/opprd001/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 williamsjiicole@epa.gov.
The following Agency Pesticide Registration Forms are currently available via the internet
at the following locations:
8570-
1
8570-
4
8570-
5
8570-
17
8570-
25
8570-
27
Application for Pesticide
Registration/Amendment
Confidential Statement of Formula
Notice of Supplemental Registration of
Distribution of a Registered Pesticide
Product
.
Application tor an .experimental Use
Permit
Application for/Notification of State
Registration of a Pesticide To Meet a
Special Local Need
Formulator's Exemption Statement
http://www.epa.gov/opprd001/forms/8570-l.pdf
http://www.epa.gov/opprd001/forms/8570-4.pdf
http://www.epa.gov/opprd001/forms/8570-5.pdf
http://www.epa.gov/opprdOO 1 /forms/8570- 1 7.pdf
http://www.epa.gov/opprd001/forms/8570-25.pdf
http://www.epa.gov/opprd001/forms/8570-27.pdf
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8570-
28
8570-
30
8570-
32
8570-
34
8570-
35
8570-
36
8570-
37
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/8570-28.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
htto://www.eoa.gov/ODDDmsdl/PR Notices/or98-
l.pdf
http://www.epa.gov/opppmsd 1 /PR Notices/pr98-
l.pdf
Pesticide Registration Kit
Dear Registrant:
www.eDa.gov/pesticides/registrationkit/
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):
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) of 1996.
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
£ 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
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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)
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 of
information. 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 (NITS) 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.
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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 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 mat 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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