US Environmental Protection Agency
Office of Pesticide Programs
Reregistration Eligibility Decision
for Trichlorfon
When EPA concluded the organophosphate (OP) cumulative risk assessment in July 2006, all
tolerance reassessment and reregi strati on eligibility decisions for individual OP pesticides were
considered complete. OP Interim Reregistration Eligibility Decisions (IREDs), therefore, are
considered completed REDs. OP tolerance reassessment decisions (TREDs) also are considered
completed.
Combined PDF document consists of the following:
• Finalization of Interim Reregistration Eligibility Decisions (IREDs) and Interim Tolerance
Reassessment and Risk Management Decisions (TREDs) for the Organophosphate Pesticides, and
Completion of the Tolerance Reassessment and Reregistration Eligibility Process for the
Organophosphate Pesticides (July 31, 2006)
• Trichlorfon TRED
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3:
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UJ
C3
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON D.C., 20460
OFFICE OF
PREVENTION, PESTICIDES AND TOXIC
SUBSTANCES
MEMORANDUM
DATE: July 31,2006
SUBJECT: Finalization of Interim Reregi strati on Eligibility Decisions (IREDs) and Interim
Tolerance Reassessment and Risk Management Decisions (TREDs) for the
Organophosphate Pesticides, and Completion of the Tolerance Reassessment and
Reregi strati on Eligibility Process for the Organophosphate Pesticides
FROM: Debra Edwards, Director
Special Review and Reregi strati on Division
Office of Pesticide Programs
TO: Jim Jones, Director
Office of Pesticide Programs
As you know, EPA has completed its assessment of the cumulative risks from the
Organophosphate (OP) class of pesticides as required by the Food Quality Protection Act of
1996. In addition, the individual OPs have also been subject to review through the individual-
chemical review process. The Agency's review of individual OPs has resulted in the issuance of
Interim Reregi strati on Eligibility Decisions (IREDs) for 22 OPs, interim Tolerance
Reassessment and Risk Management Decisions (TREDs) for 8 OPs, and a Reregi strati on
Eligibility Decision (RED) for one OP, malathion.l These 31 OPs are listed in Appendix A.
EPA has concluded, after completing its assessment of the cumulative risks associated
with exposures to all of the OPs, that:
(1) the pesticides covered by the IREDs that were pending the results of the OP
cumulative assessment (listed in Attachment A) are indeed eligible for reregistration; and
Malathion is included in the OP cumulative assessment. However, the Agency has issued a RED for malathion,
rather than an IRED, because the decision was signed on the same day as the completion of the OP cumulative
assessment.
Page 1 of 3
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(2) the pesticide tolerances covered by the IREDs and TREDs that were pending the
results of the OP cumulative assessment (listed in Attachment A) meet the safety standard under
Section 408(b)(2) of the FFDCA.
Thus, with regard to the OPs, EPA has fulfilled its obligations as to FFDCA tolerance
reassessment and FIFRA reregi strati on, other than product-specific reregi strati on.
The Special Review and Reregi strati on Division will be issuing data call-in notices for
confirmatory data on two OPs, methidathion and phorate, for the reasons described in detail in
the OP cumulative assessment. The specific studies that will be required are:
- 28-day repeated-dose toxicity study with methidathion oxon; and
- Drinking water monitoring study for phorate, phorate sulfoxide, and phorate sulfone
in both source water (at the intake) and treated water for five community water
systems in Palm Beach County, Florida and two near Lake Okechobee, Florida.
The cumulative risk assessment and supporting documents are available on the Agency's website
at www.epa.gov/pesticides/cumulative and in the docket (EPA-HQ-OPP-2006-0618).
Page 2 of 3
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Attachment A:
Organophosphates included in the OP Cumulative Assessment
Chemical
Acephate
Azinphos-methyl (AZM)
Bensulide
Cadusafos
Chlorethoxyphos
Chlorpyrifos
Coumaphos
DDVP (Dichlorvos)
Diazinon
Dicrotophos
Dimethoate
Disulfoton
Ethoprop
Fenitrothion
Malathion
Methamidophos
Methidathion
Methyl Parathion
Naled
Oxydemeton-methyl
Phorate
Phosalone
Phosmet
Phostebupirim
Pirimiphos-methyl
Profenofos
Propetamphos
Terbufos
Tetrachlorvinphos
Tribufos
Trichlorfon
Decision Document
IRED
IRED
IRED
TRED
TRED
IRED
TRED
IRED
IRED
IRED
IRED
IRED
IRED
TRED
RED
IRED
IRED
IRED
IRED
IRED
IRED
TRED
IRED
TRED
IRED
IRED
IRED
IRED
TRED
IRED
TRED
Status
IRED completed 9/2001
IRED completed 10/2001
IRED completed 9/2000
TRED completed 9/2000
TRED completed 9/2000
IRED completed 9/2001
TRED completed 2/2000
IRED completed 6/2006
IRED completed 7/2002
IRED completed 4/2002
IRED completed 6/2006
IRED completed 3/2002
IRED completed 9/2001
IRED addendum completed 2/2006
TRED completed 10/2000
RED completed 8/2006
IRED completed 4/2002
IRED completed 4/2002
IRED completed 5/2003
IRED completed 1/2002
IRED completed 8/2002
IRED completed 3/2001
TRED completed 1/2001
IRED completed 10/2001
TRED completed 12/2000
IRED completed 6/2001
IRED completed 9/2000
IRED completed 12/2000
IRED completed 9/2001
TRED completed 12/2002
IRED completed 12/2000
TRED completed 9/2001
Page 3 of 3
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United States Prevention, Pesticides EPA 738-R-01-009
Environmental Protection And Toxic Substances September 2001
Agency (7508C)
Report on FQPA Tolerance
Reassessment Progress and
Interim Risk Management
Decision (TRED) for
Trichlorfon
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, B.C. 20460
.
'3 OFFICE OF PREVENTION, PESTICIDES
*
AND TOXIC SUBSTANCES
CERTIFIED MAIL
Dear Registrant:
This is to inform you that the Environmental Protection Agency (hereafter referred to as the EPA
or the Agency) has completed its review of the available data and public comments received related to the
revised risk assessment for the organophosphate pesticide trichlorfon. The public comment period on the
revised risk assessment phase of the tolerance reassessment process is closed. Comments were received
during the public comment period, and the Agency revised the human health risk assessment and made it
available to the public on April 28, 2000. The attached document summarizes the Agency's assessment
of the dietary risk from trichlorfon, the related food tolerances for this chemical, revised occupational risks,
and provides the Agency's risk management decision.
A Notice of Availability for this "Report on FQPA Tolerance Reassessment Progress and Interim
Risk Management Decision for Trichlorfon" is published in the Federal Register. This document and the
technical documents supporting it are available for viewing in the Office of Pesticide Programs' Public
Docket and can also be found on the Agency's web page, www.epa.gov/pesticides/op.
This document is based on the updated technical information found in the trichlorfon public docket.
The docket not only includes background information and comments on the Agency's preliminary risk
assessments, but also now includes the revised risk assessment and addenda for trichlorfon, and a
document summarizing the Agency's Response to Comments. The Response to Comments document
addresses corrections to the preliminary risk assessment submitted by the chemical manufacturer, Bayer
Corporation, as well as comments submitted by the general public and stakeholders during the comment
period.
The process used to develop this document is the result of a pilot process to facilitate greater public
involvement and participation in the reregistration and/or FQPA tolerance reassessment decisions on
pesticides. As part of the Agency's effort to involve the public in the implementation of the Food Quality
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Protection Act of 1996 (FQPA), and to engage the public in the reregistration and tolerance reassessment
processes for these chemicals, the Agency is maintaining open public dockets on the organophosphate
pesticides. The idea of using such an open process was developed by the Tolerance Reassessment
Advisory Committee (TRAC), a large multi-stakeholder advisory body, which advised the Agency on
implementing the new provisions of the FQPA.
Please note that the trichlorfon risk assessment concerns only this particular organophosphate.
Because the FQPA directs the Agency to consider available information on cumulative risk from
substances sharing a common mechanism of toxicity, such as the toxicity expressed by the
organophosphates through a common biochemical interaction with cholinesterase, the Agency will evaluate
the cumulative risk posed by the entire organophosphate class of chemicals after completing risk
assessments for the individual organophosphates. The Agency is working to complete a methodology to
assess cumulative risk, and individual assessments of 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 where necessary. The Agency will issue the final tolerance
reassessment decision for trichlorfon once the cumulative assessment for all of the organophosphates is
complete.
If you have questions regarding this document, please contact the Chemical Review Manager for
trichlorfon, Kylie Rothwell, at 703-308-8055.
Sincerely,
Lois A. Rossi, Director
Special Review and
Reregistration Division
Attachment
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Report on FQPA Tolerance Reassessment Progress
and Interim Risk Management Decision
for
Trichlorfon
Case 0104
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Table of Contents
Trichlorfon Team i
Glossary Of Terms and Abbreviations iii
I. Introduction 5
II. Chemical Overview 6
A. Regulatory History 6
B. Chemical Identification 7
C. Use Profile 8
D. Estimated Usage of Pesticide 9
III. Summary of Trichlorfon Risk Assessment 9
A. Human Health Risk Assessment 10
1. Dietary Risk from Food 10
a. Toxicity 10
b. FQPA Safety Factor 11
c. Reference Dose and Population Adjusted Dose 11
d. Exposure Assumptions 12
2. Food Risk Characterization 12
a. Acute Dietary (Food) Risk 12
b. Chronic Dietary (Food) Risk 12
3. Dietary Risk from Drinking Water 13
a. Surface Water 13
b. Ground Water 14
c. Drinking Water Levels of Comparison (DWLOCs) 14
i. Acute DWLOCs 14
ii. Chronic DWLOCs 15
4. Residential Handler and Non-Occupational Risk 15
a. Toxicity 16
b. Residential Handler and Lawn Care Operator Risks 16
c. Non-Occupational Post-Application Risk 19
5. Aggregate Risk 21
a. Acute Aggregate Risk 21
b. Short/Intermediate Term Aggregate Risk 21
c. Chronic (Non-Cancer) Aggregate Risk 22
6. Occupational Risk 22
a. Toxicity 23
b. Occupational Risk Assessment 23
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i. Occupational Handler Risk 24
ii. Short/Intermediate-Term Risk 25
7. Post-application Exposure 28
8. Incident Information 30
B. Environmental Risk Assessment 30
IV. FQPA Tolerance Reassessment Progress & Interim Risk Management Decision . . 30
A. Tolerance Reassessment Progress & Interim Risk Management Decision . . 30
B. Phase 5 Comments 31
C. Regulatory Position 31
1. FQPA Assessment 31
a. "Risk Cup" Determination 31
b. Tolerance Summary 32
2. Endocrine Disrupter Effects 33
3. Risk Mitigation 33
a. Ornamental Fish and Bait Pond 35
b. Turf Uses: Occupational and Aggregate 35
c. Ornamentals: Re-entry Worker Risks 35
d. Residential Use 35
e. Summary of Worker Risks and Label Impacts 36
4. Regulatory Rationale 38
5. Codex Harmonization 39
6. Spray Drift Management 39
V. What Manufacturers Must Do 40
A. Additional Data Requirements 40
1. Labeling Requirements for Manufacturing Use Products 40
2. End-Use Products 40
3. Existing Stocks 41
B. Risk Mitigation Requirements 41
C. Labeling Summary Table 41
VI. Related Documents and How To Access Them 48
Appendix A: Trichlorfon (Case 0104): Use Patterns Eligible for Reregistration 49
Appendix B: Data Supporting Guideline Requirements For Reregistration 50
Appendix C: Technical Support Documents 57
Appendix D: Bibliography 59
Appendix E: Generic Data Call-In 67
Appendix F: List Of Registrants Sent this Data Call-In 71
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Trichlorfon Team
Office of Pesticide Programs:
Health Effects Risk Assessment
Ray Kent
Timothy Leighton
Thurston Morton
Abdallah Khasawinah
Environmental Fate
Betsy Behl
Dana Spatz
Use and Usage Analysis
Alan Halverson
Registration Support
Akiva Abramovitch
Risk Management
Kylie Rothwell
Carmelita White
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Glossary Of Terms and Abbreviations
AE Acid Equivalent
a.i. Active Ingredient
AGDCI Agricultural Data Call-In
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.
DWLOC 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 Observational Battery
G Granular Formulation
GENEEC Tier I Surface 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 and other
organizations when emergency spills or contamination situations occur.
HAFT Highest Average Field Trial
HOT Highest Dose Tested
IR Index Reservoir
LC50 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.
Ill
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LD50 Median Lethal Dose. A statistically derived single dose that can be expected to cause death in
50% of the test animals when administered by the route indicated (oral, dermal, inhalation). It is
expressed as a weight of substance per unit weight of animal, e.g., mg/kg.
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.
NA 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
PCA Percent Crop Area
PDF USDA Pesticide Data Program
PLED Pesticide Handler's Exposure Database
PHI Preharvest Interval
ppb Parts Per Billion
PPE Personal Protective Equipment
ppm Parts Per Million
PRN Pesticide Registration Notice
PRZM/EXAMS Tier II Surface Water Computer Model
Q!* The Carcinogenic Potential of a Compound, Quantified by a Cancer Risk Model
RAC Raw Agriculture Commodity
RBC Red Blood Cell
RED Reregistration Eligibility Decision
REI Restricted Entry Interval
RfD Reference Dose
RQ Risk Quotient
RS Registration Standard
RUP Restricted Use Pesticide
SAP Science Advisory Panel
SCI-GROW Tier I Ground Water Computer Model
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SF Safety Factor
SLC Single Layer Clothing
SLN Special Local Need (Registrations Under Section 24(c) of FIFRA)
STORE! Storage Retrieval database
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
Mg/g Micrograms Per Gram
,ag/L Micrograms Per Liter
USDA United States Department of Agriculture
USGS United States Geological Survey
UV Ultraviolet
WHO World Health Organization
WP Wettable Powder
WPS Worker Protection Standard
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VI
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Executive Summary
The Federal Food, Drug, and Cosmetic Act (FFDC A) as amended by the Food Quality Protection
Act (FQPA) of 1996, requires EPA to reassess all tolerances for registered chemicals in effect on or before
the date of the enactment of FQPA. In reassessing these tolerances, the Agency must consider, among
other things, aggregate risks from non-occupational sources of pesticide exposure, whether there is
increased susceptibility to infants and children, and the cumulative effects of pesticides with a common
mechanism of toxicity. The tolerances are considered reassessed once the safety finding has been made
or a revocation occurs.
A reregistration eligibility decision (RED) for trichlorfon was completed in September 1995.
Therefore, the Agency must reconsider tolerances and tolerance exemptions to ensure they meet the safety
standard required by the 1996 amendments.
This FQPA Tolerance Reassessment Progress and Interim Risk Management Decision document
(otherwise known as TRED) is based on a thorough review of required data as well as new information
received by the Agency as a result of the public participation process. After considering the revised risk
assessments; registrant-proposed risk mitigation measures; and stakeholder input; EPA developed its risk
management decisions for uses of trichlorfon that pose risks of concern. These decisions are discussed fully
in this document.
The Agency is also providing preliminary information on the trichlorfon degradate, dichlorvos
(DDVP) in this document. DDVP is a registered organophosphate (OP) pesticide that is currently
undergoing reregistration. Once the DDVP interim RED is complete, the Agency will determine whether
DDVP exposure resulting from trichlorfon use poses risk concerns and if any of the decisions for
trichlorfon require modification.
Since the Agency has not yet completed the cumulative risk assessment for the OPs, this TRED
maybe revised to reflect a cumulative assessment of all OPs as required by the FQPA. When the Agency
completes the cumulative assessment, trichlorfon tolerances will be considered reassessed.
First registered in the United States in 1955, trichlorfon is a systemic insecticide with non-
agricultural uses, such as golf course turf, home lawns, non-food contact areas of food and meat processing
plants, ornamental shrubs and plants, and ornamental fish and bait ponds. Although there are no agricultural
or other registered food uses, trichlorfon is used outside the US as a pour-on treatment for cattle which
requires a tolerance (commonly referred to as an import tolerance when there is no US registration). From
1994 to 1999, average domestic use of trichlorfon was about one million pounds of active ingredient (ai)
per year, most of which was used by lawn care operators (74% of total ai) and on golf courses (18% of
total ai).
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Overall Risk Summary
EPA's human health risk assessment for trichlorfon indicates few risk concerns. Neither acute nor
chronic dietary risks exceed the Agency's level of concern. Drinking water risk estimates, based on
surface and groundwater screening models, do not exceed the Agency's level of concern for any
subpopulation, except for children 1-6 years when the source of drinking water is surface water.
The Agency has determined that occupational risks for most uses are not of concern while certain
residential use is of concern. Of the ten occupational scenarios evaluated, three exceed the Agency's level
of concern. For occupational scenarios that indicated potential risks of concern, the registrant has agreed
to modify the use practices to address these concerns. For the residential scenario that indicated potential
risks of concern, the registrant has agreed to voluntarily cancel this use.
Dietary Risk (Food and Water)
The population adjusted dose (PAD) characterizes the dietary risk of a chemical and reflects the
Reference Dose, either acute or chronic, that has been adjusted to account for the FQPA safety factor (i.e,
RfD/FQPA safety factor). A risk estimate that is less than 100% of the acute population adjusted dose
(aPAD) or chronic population adjusted dose (cPAD) does not exceed the Agency's risk concern.
There is a tolerance for imported beef and beef byproducts that covers cattle treated outside of the
US. This is the only food use of trichlorfon. The revised risk assessment for trichlorfon indicates that both
the acute and chronic dietary (food) risks associated with trichlorfon exposure are less than 100% of the
aPAD (18%) and cPAD (24%) for all population subgroups. Therefore, dietary risks from food for both
acute and chronic exposure are not of concern to the Agency, and no mitigation is warranted at this time
for any dietary (food) exposure to trichlorfon.
Surface and groundwater assessments were conducted using GENEEC and SCI-GROW
computer models. Most trichlorfon use is on turf; however, there is not a surface water model scenario for
turf so a refined Tier n surface water assessment could not be conducted. The GENEEC Tier 1 model
was moderately refined for surface water. Except for children 1-6 years, the GENEEC model predicted
trichlorfon estimated environmental concentrations (EECs) did not exceed the acute dietary drinking water
level of comparison (DWLOC). For children 1-6, the surface water EEC is 179 ppb while the acute
dietary DWLOC is 82 ppb. Similarly, the chronic surface water EEC is 2.7 ppb and the chronic dietary
DWLOC is 1.5 ppb. Conversely, neither acute nor chronic DWLOCs exceed groundwater EECs based
on SCI-GROW modeled estimates. Therefore, neither acute or chronic exposure to trichlorfon from food
and groundwater sources of drinking water are of concern to the Agency.
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Residential and Recreational Risk Summary
Trichlorfon is also used on residential lawns and ornamentals. Residents or homeowners may be
exposed to trichlorfon through mixing, loading, or application, or through entering or performing other
activities on treated areas. Residential handler and lawn care operator (LCO) exposures to trichlorfon via
dermal and inhalation routes were assessed. The Agency used additional data from the Outdoor Re-entry
Task Force (ORETF) to further characterize the potential risks to homeowners and LCOs treating
residential lawns and house perimeters using a push-type broadcast spreader. The risks to residential
handlers and LCOs do not exceed the Agency's level of concern except for the home perimeter and ant
mound treatments by homeowners which the registrant has agreed to voluntarily cancel. No additional risk
mitigation is warranted at this time to address residential risks.
Non-Occupational Post-Application Risk (Golfers. Homeowners and Residents)
There is potential dermal exposure and inadvertent oral exposure to children from incidental
ingestion of trichlorfon-treated lawns and/or granules. Post-application exposure was assessed for adults
and children from entering treated lawns, and for golfers playing on treated courses. The exposure
assessments indicated that post-application dermal risks are low for adults, as are both oral hand-to-mouth
and dermal risk for children, and do not exceed the Agency's level of concern.
Aggregate Risk Summary
An aggregate risk assessment combines risks from dietary exposure (food and water), and
nonoccupational exposure (e.g., residential and/or golfer). Except for children 1-6 years, aggregate risks
for acute and chronic dietary (food and drinking water) exposure, and short/intermediate-term (dermal,
inhalation and incidental oral) exposure do not exceed the Agency's level of concern; therefore, no
mitigation is warranted. Acute aggregate risks for food, water and residential may be of concern for
children 1-6 years when the source of drinking water is surface water. The Agency is implementing
mitigation measures to address this potential risk.
Occupational/Residential Risk Summary
Although trichlorfon is under review for tolerance reassessment only, the Agency received new
ORETF exposure data from a registrant-based task force. These data were used to reassess the potential
occupational and residential/recreational (non-occupational) human health risks. Therefore, this assessment
includes both tolerance reassessment and occupational risk determinations.
Workers can be exposed to a pesticide through mixing, loading, and/or application, or when re-
entering treated sites. With the addition of personal protective equipment, combined dermal and inhalation
risks to handlers that mix/load and apply trichlorfon products to turf are significantly reduced. Occupational
risks from mixing/loading and applying trichlorfon to large ornamental fish and bait ponds exceed the
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Agency's level of concern. However, use of a truck drawn spray rig with the on - off switch located inside
the truck cab is expected to mitigate risks for large ornamental fish or bait pond uses of trichlorfon.
The hand application of trichlorfon to ant mounds and the house perimeter use pose risks that
exceed the Agency's level of concern. In response to risk concerns, the registrant requested voluntarily
cancellation of these uses.
The Agency has also determined that there are post-application dermal risk concerns for workers
re-entering treated areas following foliar treatment of ornamentals. Conversely, potential exposure to golf
course workers while mowing and maintaining the turfgrass on the day of application is not of concern. To
mitigate post-application risk concerns following foliar treatment of ornamentals, the use pattern will be
revised to prohibit foliar application and allow only direct application to soil for ornamental plants.
Environmental Risk Summary
The scope of this review is limited to consideration of human health risks for trichlorfon as required
by FQPA to complete the tolerance reassessment and reassessed the occupational risks based on new
data. Ecological risks are not addressed in the TRED. However, the ecological assessment in the RED,
which was issued in 1995, may be amended if warranted to account for new data or information that the
Agency may receive.
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I. Introduction
This trichlorfon tolerance reassessment of is the result of the pilot process developed through the
Tolerance Reassessment Advisory Committee (TRAC) to facilitate greater public involvement in the
ongoing Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) reregistration, the Federal, Food,
Drug and Cosmetic Act (FFDCA), and the Food Quality Protection Act (FQPA) tolerance reassessment
initiatives on pesticides. Trichlorfon is subject only to the FQPA because it has tolerances associated with
its use outside the U.S. as a pour on treatment for cattle.
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 the 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 health and environmental effects data; and to determine
whether the pesticide meets the "no unreasonable adverse effects" standard of FIFRA. The Reregistration
Eligibility Decision (RED) for trichlorfon was completed in 1995.
On August 3, 1996, FQPA was signed into law. This Act amends the FFDCA to require
reassessment of all tolerances in effect on the day before the date of the enactment of the FQPA. FQPA
also amends the FFDCA to require a safety finding in tolerance assessment based on factors including an
assessment of the cumulative effects of chemicals with a common mechanism of toxicity. Although the
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.
The Agency has determined organophosphate (OP) pesticides exhibit or share a common
mechanism of toxicity, cholinesterase inhibition. The Agency must, therefore, complete a cumulative
assessment of the risks of all OP pesticides before it can complete its reassessment of the trichlorfon
tolerances. While the methodology for completing the cumulative assessment for all OPs is being
developed, individual risk assessments are being conducted, and risk mitigation measures implemented.
The individual dietary assessment will be used in the cumulative assessment of all the OP chemicals.
This Report on FQPA Tolerance Reassessment Progress and Interim Risk Management Decision
for Trichlorfon (otherwise know as TRED) considers acute and chronic dietary risks from food and water
and risk from occupational sources of pesticide exposure. After the Agency released the Revised
Preliminary Human Risk Assessment for Trichlorfon, dated September 19,2000, the risk assessments
were further refined.
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The Agency decided to limit this risk assessment to trichlorfon/>er se, rather than also considering
the risks associated with the degradate dichlorvos (DDVP). Although DDVP is a significant environmental
degradate of trichlorfon, it is undergoing a separate, parallel reregistration review. If the DDVP risk
assessment indicates that the contribution of DDVP from trichlorfon is of concern and additional data are
needed (e.g., water monitoring), the Agency will, at that time, issue a Data Call-in (DCI) for these data as
part of the trichlorfon reregistration process. Similarly, if the results of the DDVP reregistration assessment
indicate that DDVP resulting from the use of trichlorfon could pose significant human health exposure
concerns, the Agency may reconsider any or all requirements in this document. The Agency is providing
available exposure information on the trichlorfon sources of DDVP residues in this TRED for information
purposes only.
In response to biological and environmental fate issues identified in the 1995 RED, the registrant
furnished new data on the environmental effects of trichlorfon. The Agency intends to address
environmental issues in a separate action, since the intention of this document is to provide an FQPA update
and tolerance reassessment.
This document consists of six sections. Section I contains the regulatory framework for
reregistration/tolerance reassessment. Section n provides a profile of the usage of the chemical. Section
m gives an overview of the dietary risk assessment for trichlorfon, including a discussion of any revisions
that were made to the preliminary risk assessment, as well as residential, recreational and occupational
exposure assessments. Section IV presents the Agency's progress towards tolerance reassessment
including its interim reregistration eligibility decision for trichlorfon. Section V discusses what the
manufacturer's obligations are with respect to further actions required, and Section VT provides information
on how to access related documents. The entire revised risk assessment is not included in this document,
but is available on the Agency's web page www.epa.gov/pesticides/op, and in the Public Docket.
II. Chemical Overview
A. Regulatory History
Trichlorfon was originally registered in the United States by the United States Department of
Agriculture in 1955. At that time, trichlorfon was registered for use as an insecticide on a variety of
vegetable, fruit and field crops as well as livestock, ornamental and forestry plants, agricultural premises
and domestic dwellings, and for the control of parasites on fish in designated aquatic environments.
The Agency issued the Registration Standard for trichlorfon inl 984, which included a Data Call-in
(DCI) requiring studies to support the existing use patterns. Additional data were required in 1991 to
complete the database for trichlorfon and to support reregistration. The trichlorfon database is largely
complete. Some of the studies were not acceptable or only partially satisfied the requirement. However,
the Agency was able to use available information to assess the potential risks as part of this TRED.
-------
The 1995 RED for trichlorfon considered all data submitted in response to the 1984 Registration
Standard and the subsequent 1991 DCI. Ornamental and turf uses (excluding sod farm use) were eligible
for reregistration. Since issuance of the RED, three states issued Special Local Need registrations for use
of trichlorfon in commercial bait and ornamental fish ponds.
Bayer Corporation, the manufacturer of the trichlorfon technical product, requested voluntary
cancellation of all food, feed, and field crop uses, poultry packing plants and food areas of food-handling
establishments in 1995, but decided to support a "tolerance with no U.S. registration" for beef and beef
byproducts. Other trichlorfon registrants agreed to remove the unsupported uses from their product labels.
The Agency determined that all tolerances should be revoked except tolerances for beef and beef
byproducts imported into this country. Those tolerances are listed in Title 40 of the US Code of Federal
Regulations Part 180.198. The Agency recommended that tolerances for beef and beef byproducts be
revoked if an adequate nature of the residue study for these commodities was not submitted. Although the
registrant submitted the study, the Agency determined that it was unacceptable; however, the Agency was
able to propose "reassessed tolerances" using some of the information in the metabolism study.
B. Chemical Identification
0
II
.P. .OH
H CO | ^f
H,CO I
CCL
Empirical Formula: C4H8O4C13P
Molecular Weight: 257.6
Vapor Pressure (PAI): 2.8 x 10'6 at 20°C
Octanol/Water Partition
Coefficient (Kow): 3.3
Common Name: Trichlorfon
Chemical Name: Dimethyl (2,2,2-trichloro-l-hydroxyethyl) phosphonate
Chemical Family: Organophosphate
CAS Registry No.: 52-68-6
OPP Chemical Code: 057901
Trade and Other Names: Dylox
-------
Technical Manufacturer: Bayer Corporation
Technical trichlorfon is a white crystalline solid with a melting point of 75 - 84°C. Trichlorfon is
soluble in water, dichloromethane, 2-propanol, and toluene and nearly insoluble in N - hexane. Trichlorfon
is expected to have a half-life of 6.4 days in soil and 1.4 days in aqueous conditions. The Agency believes
that the short half-life of trichlorfon may limit its persistence in the environment.
C.
Use Profile
The trichlorfon use profile has changed dramatically in recent years. The use information provided
here is based on the currently registered uses of trichlorfon. The following section summarizes use patterns,
application methods, and other technical details on the current pesticidal uses of trichlorfon.
Type of Pesticide:
Summary of Use Sites:
Target Pests:
Formulation Types:
Application Rates:
Method of Application:
Systemic insecticide.
Non-agricultural uses such as golf course turf, home lawns, non-
food contact areas of food and meat processing plants,
ornamental shrubs and plants, and ornamental and bait fish ponds.
(Trichlorfonis used overseas as cattle pour-on, which is classified
as a food-use).
Insects such as lepidopteran larvae (caterpillars), white grubs,
mole crickets, cattle lice, sod webworms, leaf miners, stink bugs,
flies, ants, cockroaches, earwigs, crickets, diving beetle, water
scavenger beetle, water boatman, backswimmer, water
scorpions, giant water bugs, and pillbugs.
• Technical product with 98% active ingredient (ai)
• Soluble powder with 80% ai (which may only be applied
by commercial applicators)
• Granular products with 5% and 6.2% ai
• Lawns/recreational turf: 1.1 Ib ai/acre to 8.2 Ib ai/acre;
Ornamentals: 0.01 to 0.015 Ib ai/gallon
• Commercial ponds/aquatic tank: 0.64 to 1.4 Ib ai/acre-
foot of pond water.
Groundboom sprayer, low and high-pressure handwand,
backpack sprayer, handgun sprayer, sprinkling can, push-type
granular spreader, and irrigation systems.
-------
Timing: Product labels do not give specific timing for application of
trichlorfon. For turf and lawns, most labels indicate application
can be made monthly beginning in May or June. Two or three
applications per week may be necessary for trichlorfon treatment
of commercial ponds according to special local need labels.
Use Classification: General use pesticide.
D. Estimated Usage of Pesticide
This section summarizes the best pesticidal usage estimates available for trichlorfon. These
estimates are derived from a variety of published and proprietary sources. The data, which are reported
on an aggregate and site basis, reflect annual fluctuations in use patterns as well as the variability in using
data from different sources.
Based on pesticide usage information mainly for 1994 through 1999, average domestic usage of
trichlorfon is about one million pounds ai per year. In terms of pounds ai, total usage is allocated mainly
to lawn care operators (74%) and golf courses (18%). Other sites with small usage include landscaping,
institutional turf, nursery/greenhouse, and livestock areas. On average less than 2% of all turf sites are
treated with trichlorfon. Application rates per acre on these sites are generally less than 7 Ibs ai/acre.
III. Summary of Trichlorfon Risk Assessment
The following is a summary of EPA's revised human health risk findings and conclusions as
presented in the revised risk assessment document and addenda listed below:
(1) HED 's Revision of the Trichlorfon Residential Exposure/Risk Assessment.
August 09, 2000;
(2) HED's Insert to the Trichlorfon Risk Assessment: Residential Handler's and
Postapplication Ornamental Uses, August 30, 2000;
(3) HED's Review of Determination of Transferable Turf Residues on Turf Treated with
Trichlorfon, September 6, 2000;
(4) HED's Revised Preliminary Human Health Risk Assessment for Trichlorfon,
September 19, 2000;
(5) HED's Reassessment of the Use ofORETF Granular Push-Type Spreader Studies
(LCO and Homeowner) for the Trichlorfon Risk Assessment, November 1, 2000;
(6) Trichlorfon: Refined Tier I Surface Water EECs for Use in the Human Health
Drinking Water Risk Assessment, March 23, 2001; and
(7) HED's Revised Drinking Water Levels of Concern and Aggregate Risk Assessment
-------
for Trichlorfon, April 24, 2001.
These documents are available in the public docket and on the Internet at
www.epa.gov/pesticides/op. During the tolerance reassessment of trichlorfon, the registrant submitted new
exposure studies. These new data had a material effect on the occupational and residential risk assessments
for trichlorfon which are detailed in the documents listed above.
The Agency received public comments from the Golf Course Superintendents Association of
America (GCSAA) and the Natural Resources Defense Council on the trichlorfon risk assessment. These
comments and the Agency response can be seen in their entirety in the public docket and are summarized
later in Chapter IV.
A. Human Health Risk Assessment
The human health risk assessment for trichlorfon looked at acute dietary, chronic dietary (non-
cancer), drinking water, residential, and occupational risks. Since the Agency released its preliminary risk
assessment in April 2000, there have been changes in the use profile and application method to ornamentals
which impacts both the residential and occupational risk assessments. The ant mound treatment and
homeowner building perimeter uses have been voluntarily canceled by the registrant because of Agency
exposure concerns.
1. Dietary Risk from Food
a. Toxicity
The Agency has reviewed all toxicity studies and determined that the toxicity database is largely
complete, and that it supports tolerance reassessment. Table 1 summarizes the lexicological endpoints and
safety and/or uncertainty factors used by EPA for the dietary risk assessments.
Trichlorfon was evaluated for carcinogenicity in mice, rats and monkeys. The Agency's Cancer
Assessment Review Committee classified trichlorfon as "not likely to be carcinogenic to humans at low
doses, but is likely to be carcinogenic at high doses". Therefore, a quantitative carcinogenicity assessment
is not required.
10
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Table 1. Endpoints and Other Factors for Acute and Chronic Dietary Exposure
Exposure
Scenario
Acute
Dietary
Chronic
Dietary
Dose1
10
(NOAEL)
0.2
(NOAEL)
Endpoint
Clinical signs (oral, red nasal,
and urine stains; decreased
motor activity), plasma, RBC
and brain cholinesterase
inhibition
Brain cholinesterase inhibition
in both sexes
Study
Acute
Neurotoxicity- Rat
(MRID 44578001)
Chronic
Toxicity -Monkey
(MRID 40776001)
TJF
100
100
FQPA Safety
Factor
lOx
lOx
RfD1
0.1
0.002
PAD1
0.01
0.0002
UF - Uncertainty Factor
1) Expressed in mg/kg/day
b. FQPA Safety Factor
The Agency determined the 1 Ox FQPA safety factor should be retained for the protection of infants
and children from acute and chronic dietary exposure to trichlorfon based on the occurrence of
neuropathology in animal studies and data gaps. Specifically, neuropathology concerns include: 1)
organophosphate induced delayed Neurotoxicity, 2) neuropathology in hens observed in the acute delayed
neurotoxicity study, and 3) literature studies in which oral administration of trichlorfon resulted in decreased
brain weights in guinea pig fetuses. There are also data gaps for a prenatal developmental toxicity study
and a developmental neurotoxicity study. [The Agency has previously issued a separate DCI to all
registrants of OPs requiring a developmental neurotoxicity study (DNT)]. Methods to assess dietary and
non-occupational exposures are unlikely to underestimate exposure.
c. Reference Dose and Population Adjusted Dose
The acute reference dose (acute RfD) is an estimate of a single oral exposure level for the human
population, including the sensitive subpopulation, that is likely to be without an appreciable risk of
deleterious effects.
The chronic reference dose (chronic RfD) is an estimate of a daily oral exposure level for the human
population, including sensitive subpopulation, that is likely to be without an appreciable risk of deleterious
effects during a lifetime.
The acute and chronic RfDs are calculated by dividing the no observed adverse effect level
(NOAEL) or the lowest observed adverse effect level (LOAEL) by uncertainty factors. Uncertainty
factors are used to account for differences between different humans (intraspecies variability) and for
differences between the test animals and humans (interspecies extrapolation). If the LOAEL is used, an
additional uncertainty factor is used.
11
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RfD= NOAEL orLOAEL
Total UF
The population adjusted dose (PAD) is the acute RED or the chronic RED modified by the FQPA
safety factor. The PAD is calculated by dividing the RfD by the FQPA safety factor.
PAD= Acute or Chronic RfD
FQPA Safety Factor
For trichlorfon, the NOAEL was used and the uncertainty factor is 100; the FQPA safety factor
is lOx. The chronic and acute PADs and RfDs are shown in Table 1 above. A risk estimate that is less
than 100% of the acute or chronic PAD is not a risk of concern.
d. Exposure Assumptions
The revised acute and chronic dietary risk analyses for trichlorfon were conducted with the Dietary
Exposure Evaluation Model (DEEM™). DEEM incorporates consumption data generated in USDA's
Continuing Survey ofFood Intake by Individuals (CSFII), 1989-91. Generally, a dietary risk assessment
that is less than 100% of the acute or chronic Population Adjusted Dose is not of concern.
In the dietary exposure analyses, the Agency used tolerance level residues in addition to the
assumption that 10 % of beef and beef byproducts consumed in the US is imported. The Agency also
assumed that 100% of imported beef is treated with trichlorfon which is a conservative estimate. This is
the only food use and only tolerances established for trichlorfon.
2. Food Risk Characterization
a. Acute Dietary (Food) Risk
The Agency conducted an acute probabilistic/Monte Carlo type dietary exposure analysis for
trichlorfon. The results of this assessment indicate that dietary exposure from food is below the Agency's
level of concern at the 99.9th percentile (<100% aPAD) for all population subgroups. Acute dietary
exposure for the general US population from food was estimated be 11% of the aPAD. For the most
highly exposed subgroup, children 1 -6 years, the dietary exposure was estimated to be 18% of the aPAD.
b. Chronic Dietary (Food) Risk
Use of the assumptions noted above results in chronic dietary exposure that is also below the
Agency's level of concern. Dietary exposure for the general US population was estimated to be 12% of
the cPAD. For the most highly exposed population subgroup, children 1 -6 years, the dietary exposure was
estimated to be 24% of the cPAD.
12
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3. Dietary Risk from Drinking Water
Trichlorfon and its degradate, DDVP, may contaminate surface and ground water. However, this
TRED addresses exposure and risk for trichlorfon only. The risks associated with DDVP as an
environmental degradate of trichlorfon will be assessed in the context of the DDVP interim reregistration
eligibility decision, rather than in this document, once toxicity endpoints and other information necessary
for risk assessment are determined. However, the existing exposure estimates for DDVP derived from
trichlorfon use are provided here for completeness.
Tier 1 surface water and groundwater assessments were completed using GENEEC and SCI-
GROW modeling. A Tier n surface water assessment was not conducted because there is no PRZM-
EXAMS scenario for turf, which is the predominant use.
a. Surface Water
The surface water assessment indicates that trichlorfon has a high potential to reach surface water.
The Agency conducted this assessment using refinements to GENEEC, which is a Tier 1 screening model
that provides a high-end estimate. On its own merits, GENEEC is not an ideal tool for drinking water
exposure assessments. Surface-water-sourced drinking water tends to come from bodies of water
substantially larger than the 1-hectare pond typically used in the model. In addition, GENEEC assumes
that essentially the whole basin receives an application of the chemical. In virtually all actual cases, basins
large enough to support a drinking water facility will contain a substantial fraction of area that does not
receive the chemical. Furthermore, there is always at least some flow (in a river) or turn over (in a reservoir
or lake) of the water so the persistence of the chemical near the drinking water facility is usually
overestimated by GENEEC. Consequently, GENEEC usually provides an upper bound on the
concentration of pesticide that could be found in drinking water and therefore can be appropriately used
only in screening calculations.
The Agency used the standard input parameters which include application rate, application interval,
persistence, solubility and other factors in the GENEEC model. Then the Agency refined the EECs by
incorporating an 87% crop treated area factor (default PC A) and applied an average expectancy that 27%
of the golf course is potentially treated (based on golf course characteristics from the GCSAA database),
rather than assuming 100% of the golf course is treated. Using this approach, the Agency believes the
results are not overly conservative and may be somewhat more representative of the actual concentrations
of trichlorfon. The estimated environmental concentrations (EECs) for surface water are based on this
refined Tier 1, GENEEC estimate and are shown in Table 2. (The Agency has listed the EECs for DDVP
solely as information since it is a degradate of trichlorfon. Drinking water exposure to all sources of DDVP,
including trichlorfon, will be addressed as part of the pending DDVP IRED).
13
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Table 2. Estimated Environmental Concentrations Associated With Use of Trichlorfon on
Turf
Drinking Water Source
(Model)
Surface Water (GENEEC)
Groundwater (SCI-GROW)
Estimated Environmental Concentration (EEC) (ppb)
for 7-day retreatment interval
Peak =179 ppb
Average 56-day (chronic value) =
Peak = 8 1.7 ppb (DDVP)2
Average 56-day (chronic value) =
2.7 ppb1
11. 7 ppb
0.27 ppb
0.006 ppb (DDVP)2
1 Value reported was 8.2 ppb, current Agency policy states that the average 56 day GENEEC (or chronic) value should
be divided by 3 for chronic DWLOC calculation.
2 For informational purposes, DDVP EECs are provided
b. Ground Water
Very limited groundwater monitoring data for trichlorfon are available. There are no detectable
residues reported in the EPA STORET (storage retrieval) database. Consequently, the SCI-GROW
model was used to estimate a Tier I screening value for the groundwater EEC. In the absence of a limit
on maximum applications per year on the current trichlorfon labels, the Agency ran the model assuming the
pesticide was used three (3) times per year with a seven day retreatment intervals a reasonable average
estimate. Modeled acute and chronic groundwater EECs are shown above in Table 2.
c. Drinking Water Levels of Comparison (DWLOCs)
To determine the maximum allowable contribution from water-containing pesticide residues
permitted in the diet, the Agency first looks at how much food (and if appropriate, residential uses)
contributes to the total allowable risk. The Agency then estimates 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 define 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 the Agency's level of concern.
i. Acute DWLOCs
The acute DWLOC represents the maximum peak concentration of trichlorfon that may occur in
water without a risk concern. Acute DWLOCs for trichlorfon were calculated based on the acute dietary
(food) exposure and the Agency default values for body weight and drinking water consumption. The
assumptions and equation for calculating the acute DWLOC can be found in the HED 's Revised
Preliminary Human Health Risk Assessment for Trichlorfon, dated September 19, 2000, and in the
memorandum Trichlorfon: Refined Tier I Surface Water EECs for Use in the Human Health Drinking
Water Risk Assessment, March 23, 2001.
14
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The acute surface water EEC (179 ppb) for trichlorfon, based on the refined GENEEC model, is
greater than the acute DWLOC (82 ppb) for the most highly exposed population subgroup, children 1 -
6 years. This suggests acute exposure to trichlorfon from food and surface water sources of drinking water
could exceed the Agency's level of concern.
The acute EEC for trichlorfon in groundwater (0.27 ppb), which is based on SCI-GROW
modeling, is less than the acute DWLOC (312 ppb) for the general population and the most highly exposed
subpopulation, children 1-6 years (82 ppb). Therefore, acute exposure to trichlorfon from food and
groundwater sources of drinking water is not of concern. These results are presented below in Table 3.
Table 3. Drinking Water Levels of Comparison for Acute Dietary Exposure
Population
Subgroup
US Population
Children 1-6
Acute PAD
(mg/kg/day)
0.01
0.01
Food Exposure
(mg/kg/day)
0.001086
0.001761
Max. Water
Exposure
(mg/kg/day)
0.008914
0.008239
DWLOCacute
(Ppb)
312
82
GENEEC surface
water EEC (ppb)
179
179
SCI-GROW
groundwater
EEC (ppb)
0.27
0.27
11.
Chronic DWLOCs
Chronic DWLOCs were estimated based on the chronic dietary (food) exposure and default body
weights and water consumption. The assumptions and equation for calculating the chronic DWLOC are
detailed in the September 19, 2000, Revised Preliminary Human Health Risk Assessment for
Trichlorfon.
The modeled chronic surface water EEC (2.7 ppb) exceeds the DWLOC (1.5 ppb) for the
subpopulation children 1-6 years. Therefore, chronic exposure risk to trichlorfon from surface water
sources of drinking water appear to exceed the Agency's level of concern. These data are presented in
Table 4 below.
The modeled EEC (0.27 ppb) for groundwater is less than the chronic DWLOC for all population
groups. Therefore, chronic exposure to trichlorfon in food and water from groundwater sources of drinking
water is not of concern for even the most highly exposed subpopulation, children 1-6 years old. These
data are also presented below in Table 4.
Table 4. Drinking Water Levels of Comparison for Chronic Dietary Exposure
Population
Subgroup
US Population
Children 1-6
Chronic PAD
(mg/kg/day)
0.0002
0.0002
Food Exposure
(mg/kg/day)
0.000025
0.000049
Max. Water
Exposure
(mg/kg/day)
0.000175
0.000151
DWLOCchronlc
(ppb)
6.1
1.5
GENEEC
surface water
EEC (ppb)
2.7
2.7
SCI-GROW
groundwater
EEC (ppb)
0.27
0.27
15
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4. Residential Handler and Non-Occupational Risk
This section addresses residential risk associated with the use of trichlorfon. New data and
methodologies are now available to assess these risk scenarios since the RED was completed in 1995.
Residents or homeowners may be exposed to a pesticide through mixing, loading, or applying, or
through entering or performing other activities on treated areas. Residential handlers include homeowner
applicators treating their own lawns. As mentioned above, trichlorfon exposure to adults and children also
occurs from contact with treated lawns or other turf areas. Estimated 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 NOAEL.
a. Toxicity
All risk calculations are based on the most current toxicity information available for trichlorfon. The
lexicological endpoints, and other factors used in the residential risk assessment for trichlorfon are shown
in Table 5.
Table 5. Endpoints for Assessing Residential Risks for Trichlorfon
Endpoint
Short/ Intermediate-Term
Dermal
Long-Term Dermal
Inhalation
Any time period
NOAEL
mg/kg/day
100
Margin of Exposure and
Uncertainty Factor
1,000 (residential)
UF=100
FQPA SF = lOx
Study/Effect
21 -day dermal (rabbit),
RBCChEI
(MRIDs 0040369, 40306901)
A long-term exposure scenario is not expected based on the use patterns of trichlorfon.
3.45
(0.0127 mg/La)
1,000 (residential)
UF=100
FQPA SF = 10X
21 -day inhalation (rats),
RBCChEI
(MRID 00256446)
3.45 mg/kg/day = NOAEL (0.0127 mg/1) x respiration rate of ayoung adult Wistar rat (8.46 L/hr) x study daily exposure
duration (6 hr/day)/body weight of a young adult Wistar rat (0.187 kg).
b. Residential Handler and Lawn Care Operator Risks
Trichlorfon is also used on residential lawns and ornamentals. In determining the residential handler
risks, the Agency assumed that homeowners wear only short sleeved shirts and short pants while applying
trichlorfon to turf. The professional lawn care operator (LCO) treating residential lawns is assessed at
baseline attire, which includes only long sleeved shirt, long pants, shoes and socks (no gloves or respirator).
Residential handler exposure to trichlorfon residues via dermal and inhalation routes can occur during
handling, mixing, loading, and applying activities. The endpoints for the short-term and intermediate term
scenario durations are the same, so the actual time duration of the activity is unimportant in estimating the
risk. The areas treated per day in this risk assessment were assumed to be 0.5 and 5 acres for turf
broadcast applications for homeowners andLCOs, respectively. The resultant MOEs do not exceed the
Agency's level of concern and can be found in Table 6 of this document.
16
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Using the Pesticide Handler Exposure Database (PHED) data and preliminary information from
the Occupational and Residential Exposure Task Force (ORETF), the Agency was able to assess risk to
handlers loading/applying granules to residential lawns using a "push-type" broadcast spreader. The same
assumptions are used to estimate exposures for the LCO and residential handler; therefore, exposure and
combined MOEs for the professional LCO (Scenario 8) and residential handler are both presented in Table
6. For residential exposure and risk estimates, an uncertainty factor of 100 was used to account for inter-
species extrapolation and intra-species variability, because the 1 Ox FQPA safety factor was retained for
the protection of infants and children. The target residential MOE is 1,000 (100 x lOx FQPA safety
factor). Neither MOEs for residential handlers or LCOs exceed the Agency's levels of concern.
17
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Table 6. Residential and LCO Dermal, Inhalation, and Combined MOEs for Trichlorfon Based on ORETF Data
Exposure Scenario
Dermal
Unit
Exposure3
(mg/lb ai)
Inhalation
Unit
Exposure
d^g/lb ai)
Usec
Application Rate d
(Ib ai/acre)
Amount
Handled per
Day6
Dermal f g
Daily Dose f
(mg/kg/day)
MOEg
Inhalation111'
Daily Dose"
(mg/kg/day)
MOE
Combined J
MOE
Loader/ Applicator Risks: Residential Granular Push-Type Spreader (short-sleeved shirt, short pants, no gloves). MOE of 1,000 Needed for Combined Dermal
and Inhalation Exposures.
Loading/ Applying
with a Push Type
Spreader (R2)
0.68
(7.6 max)
0.91
(3.7)
turf
8.2 Ib ai/acre
0.5 acres
0.040
2,500
0.000053
65,000
2,400
Loader/ Applicator Risks: Lawn Care Operator (LCO) Granular Push- Type Spreader (long-sleeved shirt, long pants, no gloves). MOE of 100 Needed for
Combined Dermal and Inhalation Exposures.
Loading/ Applying
with a Push Type
Spreader (8)
0.31
(max 2.1)
7.1
(max 29)
turf
8.2 Ib ai/acre
5 acres
0.18
550
0.0042
830
330
Footnotes:
a,b Dermal and inhalation unit exposure values from the Outdoor Residential Exposure Task Force (ORETF). Residential dermal exposure assumes
short pants, short sleeved shirt, shoes and socks and no gloves. LCO dermal exposures assumes long-sleeved shirt, long pants, shoes and socks, no gloves and
no respirator.
c "Use" - broadcast turf application.
d Application rate is the maximum application rate presented on EPA registered labels. Rate are taken from the 3125-507 label.
e Amount handled per day values are EPA estimates of acreage treated found in the Residential SOPs draft December 1997.
f Dermal daily dose (mg/kg/day) = daily unit exposure (mg/lb ai) x application rate (Ib ai/acre) x amount handled per day (acres) / body weight (70 kg).
g Dermal MOE = dermal NOAEL (100 mg/kg) / daily dose (mg/kg/day). Target MOE of 1,000 for residential uses and 100 for occupational handlers.
h Inhalation daily dose (mg/kg/day) = inhalation unit exposure (//g/lb ai) x application rate (Ib ai/acre) x amount handled per day (acres) x conversion
factor (1 mg/1,000 //g) /body weight (70 kg).
i Inhalation MOE = NOAEL (3.45 mg/kg/day) / daily dose (mg/kg/day). Target MOE of 1,000 for residential uses and 100 for occupational handlers.
j Total MOE = 1 / [(I/dermal MOE) + (1/mhalation MOE)].
18
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c. Non-Occupational Post-Application Risk
In addition to residential handler risk, there is potential dermal exposure and inadvertent oral
exposure to children from incidental ingestion of trichlorfon from trichlorfon-treated lawns. A chemical-
specific turf transferable residue (TTR) study was submitted by the registrant. This study was used by the
Agency to refine post-application exposure concerns for toddlers and adults playing on treated lawns.
Table 7 below presents the DDVP TTR data for informational purposes only. Following the table
is a discussion of the acute, short/intermediate term, and chronic aggregate risk assessments based on
moderate refinements to the GENEEC model.
19
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Table 7. Dermal Post-application Risks to Toddlers and Adults from Granular and Soluble Powder Formulations When
Keenterm
Scenario
Toddler
Adult
Golfer -
Adult
s, Ireated Lawns
Application
Rate
(Ib ai/acre)a
5.4
8.2
5.4
8.2
5.4
8.2
TTR
(fig/cm2)
Trichlorfon"
0.0092
0.0138
0.0092
0.0138
0.0092
0.0138
DDVP"
(1) 0.0028
(2)0.0065
(1) 0.0042
(2)0.0097
(1)0.0028
(2) 0.0065
(1)0.0042
(2)0.0097
(1)0.0028
(2) 0.0065
(1)0.0042
(2)0.0097
Transfer
Coefficient
(cm2/hr)
5,200
5,200
14,500
14,500
500
500
Exposure
Duration
(hours)
2
2
2
2
4
4
Daily Dermal Doseb
(mg/kg/day)
Trichlorfon
0.0064
0.0096
0.0038
0.0057
0.00026
0.00039
DDVP
(1) 0.00021
(2) 0.00050
(1) 0.00032
(2) 0.00074
(1)0.00013
(2) 0.00030
(1)0.00019
(2) 0.00044
(1) 8.8E-6
(2) 2.0E-5
(1) 1.3E-5
(2) 3.0E-5
Dermal MOE0
Trichlorfon
16,000
10,000
26,000
17,000
380,000
250,000
(1) TTRs based on the longest 1A life from the Florida site in the DDVP Turf study (FL is 0.156 days; CA is 0.069 days; Ontario, Canada is 0.022 days) and the longest
1A life of trichlorfon (2.5 days), and
(2) The longest 1A life from the FL site in the DDVP Turf study and the shortest 1A life of trichlorfon (0.93 days).
a The maximum application rate is 8.2 Ibs ai/acre based on the turf transferable (TTR) residue from MRID 450672-01 from the GA site (granular formulation) at 12 hours
after treatment (0.0138 //g/cm2). The Agency also assumed estimated hours exposed as 2 hours for toddlers playing on the lawn and 4-hours for golfers for an 18-hole
round of golf. The low application rate is 5.4 Ibs ai/acre based on an extrapolation of this study and assumptions.
b Daily Dermal Dose (mg/kg/day) = [TTR ((ig/cm ) x Transfer Coefficient (cmVhr) x unit conversion (1 mg/1000 (ig) x Exposure Duration (hrs/day) x absorption f actor]/-
Body Weight (kg). Trichlorfon is assessed using a dermal toxicological endpoint and therefore the dose is not adjusted for absorption. DDVP dermal absorption
is estimated at 11 percent. Inputs and calculations are derived from the SOPs for Residential Exposure Assessments, except for golfers. Golfer transfer coefficient
is an estimate.
c Postapplication Trichlorfon Dermal MOE = (100 mg/kg/day )/Daily Dermal Dose (mg/kg/day). Target MOE is 1,000. All pesticide exposure sources of DDVP will be
considered in the DDVP IRED.
20
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5. Aggregate Risk
An aggregate risk assessment combines risks from dietary (food and drinking water), and non-
occupational exposure (residential exposure: dermal and inhalation for homeowner applicators, and
incidental oral for toddlers; and recreational exposures: dermal post-application to golfers). The results
of the acute, short/intermediate term, and chronic aggregate risk assessments are discussed below.
Trichlorfon residues from food alone are not of concern. Acute exposure (food only) to trichlorfon
was 18 % of the aPAD for the most highly exposed population (children 1-6 years) while chronic exposure
(food only) to trichlorfon residues was 24 % of the cPAD. However, risk estimates suggest acute,
short/intermediate term and chronic aggregate dietary exposure (food and water) to trichlorfon may be a
concern when the source of drinking water is surface water.
a. Acute Aggregate Risk
The acute aggregate risk estimates for trichlorfon address exposure from food and drinking water.
Acute exposure is considered to occur in a one-day time frame via the oral route of exposure. Acute
dietary risks are below the Agency's level of concern if less thanlOO % of the aPAD. The estimated
concentrations of trichlorfon in groundwater are below the Agency's level of concern for all subpopulation
including children 1-6 years. Based on available information, it appears that residues of trichlorfon in
drinking water (when considered along with food) could result in an acute aggregate human health risk of
concern for children 1 -6 years when the source of drinking water is surface water. However, this modeled
EEC is likely overly conservative as will be discussed in chapter 4 of this TRED, and therefore, does not
indicate an aggregate risk concern.
b. Short/Intermediate Term Aggregate Risk
The aggregate short/intermediate-term risk assessment provides risk estimates resulting from
residential exposure combined with average food and water. High end residential and recreational (golfing)
exposure estimates are added to estimates of average food and water exposure. These are compared to
an appropriate NOAEL from a toxicity study. The target MOE, including the FQPA safety factor of 1 Ox,
is 1,000 for combined dermal and inhalation exposure. Each of the following short/intermediate term
residential exposure scenarios equaled or exceeded the target MOE (1000) when aggregated with the
average food and water exposure. They are 1) dermal post-application residential handler exposure for
adults loading/applying with a push type spreader to turf (8.2 Ib ai/acre), 2) toddler post-application dermal,
and 3) combined toddler post-application oral hand-to-mouth and dermal exposures.
A short term DWLOC of 182 ppb was calculated for dermal post-application risks to adults using
a push type spreader, when aggregated with chronic food and water exposure. The GENEEC model
estimated an EEC of 2.7 ppb. The EEC is less than the short/intermediate term DWLOC and therefore
not of concern when aggregated with chronic food and water. Toddler post-application dermal exposure
21
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associated with entering a lawn treated at 8.2 Ib ai/acre (the maximum label rate) was assessed. When
aggregated with chronic food and water exposure, it results in a short/intermediate term DWLOC of 90
ppb which when compared to the EECs of 2.7 ppb does not exceed the Agency's level of concern.
Finally, toddler postapplication dermal exposure combined with hand-to-mouth exposure from entering
trichlorfon lawns treated at the maximum label rate, when aggregated with chronic food and water
exposures, do not exceed the Agency's level of concern. The short term DWLOC is 86 ppb while the
EEC is 2.7 ppb. Further details can be seen in the memorandum dated April 24, 2001, Trichlorfon:
HED 's Revised Drinking Water Levels of Concern and Aggregate Risk Assessment for Trichlorfon.
Although the Agency acknowledges the contribution of trichlorfon residues to aggregate risks from
drinking water from surface water sources for children 1-6 years old could be of concern, based on a
comparison of the three scenarios mentioned above as compared to the chronic GENEEC model EECs,
the Agency believes that the estimated aggregate risks for children 1-6 from surface water contributions
are conservative and when coupled with appropriate mitigation measures will not exceed the Agency's level
of concern.
c. Chronic (Non-Cancer) Aggregate Risk
A chronic aggregate assessment estimates risk from long term exposure to food and water, and also
includes residential exposure if any long term scenarios are identified. No long term chronic residential and
golfing use scenarios for trichlorfon were identified. The chronic DWLOC for Children 1-6 years is 1.5
ppb, while the surface water EEC is 2.7 ppb. The chronic EEC for surface water is only slightly greater
than the chronic DWLOC. However, this modeled EEC is likely overly conservative as will be discussed
in chapter 4 of this TRED, and therefore, does not indicate an aggregate risk concern.
6. Occupational Risk
The Agency usually only assesses the dietary risks when complying with the requirements to report
on tolerance reassessment progress for pesticides reregistered prior to the enactment of FQPA, which
amended FFDCA. For trichlorfon, the Agency received new data and applied revised methodologies and
policies to more completely characterize the risks associated with occupational and residential uses.
Therefore, the Agency has included an updated assessment for workers that can be exposed to a pesticide
through mixing, loading, and/or application, or when reentering treated sites. Occupational handlers of
trichlorfon include applicators who mix, load, and/or apply pesticides, including lawncare and turf
management professionals. Occupational risks for lawncare operators were shown previously in Table 6.
For occupational scenarios, MOEs greater than 100 do not exceed the Agency's level of concern. MOEs
for the remaining nine occupational scenarios assessed by the Agency are presented in Table 10.
22
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a. Toxicity
All risk calculations are based on the most current toxicity information available for trichlorfon. For
occupational exposure and risk estimates, an uncertainty factor of 100 was used to account for inter-
species extrapolation and intra-species variability. The lexicological endpoints, and other factors used in
the occupational risk assessment for trichlorfon are shown in Table 8.
Table 8. Endpoints for Assessing Occupational Risks for Trichlorfon
Endpoint
Short and Intermediate-
Term Dermal
Long-Term Dermal
Inhalation
Any time period
NOAEL
mg/kg/day
100
Margin of Exposure and
Uncertainty Factor
100
UF = 100
Study/Effect
21 -day dermal (rabbit),
RBCChEI
(MRTDs 0040369, 40306901)
A long-term exposure scenario is not expected based on the use patterns of trichlorfon.
0.0127 mg/La
(3.45)
100
UF = 100
21 -day inhalation (rats),
RBCChEI
(MRTD 00256446)
a 3.45 mg/kg/day = NOAEL (0.0127 mg/1) x respiration rate of ayoung adult Wistar rat (8.46 L/hr) x study daily exposure
duration (6 hr/day) /body weight of a young adult Wistar rat (0.187 kg).
Acute toxicity values for trichlorfon in experimental animals and the corresponding Toxicity
Categories are summarized in Table 9. Trichlorfon is relatively toxic given the category n rating for acute
oral toxicity and acute eye irritation.
Table 9. Acute Toxicity Dose levels and Categories of Trichlorfon
Guideline Number and Study
870 1 100 Acute Oral Toxicitv - Rat
870. 1200 Acute Dermal Toxicity - Rabbit
870. 1300 Acute Inhalation Toxicity - Rat 4 hour
870.2400 Acute Eye Irritation - Rabbit
870.2500 Acute Dermal Irritation - Rabbit
870.2600 Skin Sensitization - Guinea Pig
MRID#
00256446
00090786
00256446
44471301
40306901
00257599
Result
LD™=136-173me/ke
LD50 > 2 g/kg
LC50=533 mg/irf
moderately irritating
non irritating
moderate contact allergen
Category
II
III
III
II
IV
NA
b. Occupational Risk Assessment
No chemical-specific handler exposure data were submitted for trichlorfon. Therefore, an exposure
assessment for each scenario was developed, using thePesticide Handlers Exposure Database (PHED)
Version 1.1., ORETF handler data, and standard assumptions about average body weight, work day, daily
areas treated, volume of pesticide used, and other factors to estimate risks. The quality of the data and
exposure factors represent the best sources of data currently available to the Agency for completing these
23
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types of assessments. The PHED unit exposures from handling trichlorfon range from low to high quality.
The scenario assessments are discussed in ^Reassessment of the Use ofORETF Granular push-type
Spreader Studies (LCO and Homeowner—MRID No. 449722-01) for the Trichlorfon RiskAssessment,
November 1, 2000, and the Revised Preliminary Human Health Risk Assessment for Trichlorfon,
September 19, 2000.
Anticipated use patterns and application methods, range of application rates, and daily acres treated
were used in the risk assessment. Application rates specified on trichlorfon labels range from 1.1 Ib a.i./acre
to 8.2 Ib ai/acre. The Agency typically uses acres treated per day values that are thought to represent a
typical work day (e.g., 8 hours) when using specific types of application equipment.
Occupational handler exposure assessments are conducted by the Agency assuming different levels
of personal protection equipment (PPE). The Agency will evaluate all exposures with minimal protection
and then add additional protective measures using a tiered approach to obtain an appropriate MOE (i.e.,
increasing from minimal to maximum levels of PPE) that is not of concern to the Agency. The lowest level
of PPE is baseline PPE. If MOEs are less than 100, increasing levels of PPE are applied. If MOEs are
still less than 100, engineering controls are applied. However, for trichlorfon, the Agency did not consider
this risk mitigation since engineering controls are not practicable for those scenarios with MOEs that exceed
the Agency's level of concern. The current trichlorfon label requires handlers to wear long pants, a long-
sleeved shirt, shoes, socks and chemical-resistant gloves. The levels of PPE that formed the basis for
calculations of exposure from trichlorfon activities in this TRED include:
• Baseline: Long-sleeved shirt and long pants, shoes and socks.
• Minimum PPE: Baseline + chemical resistant gloves and a respirator.
Maximum PPE: Baseline + coveralls, chemical resistant gloves, and a respirator.
i. Occupational Handler Risk
The Agency evaluated ten occupational exposure scenarios for trichlorfon.(see the Revised
Preliminary Risk Assessment, September 19, 2000). They are: (1) mixing/loading soluble powders for
groundboom and chemigation applications; (2) applying with groundboom equipment; (3) mixing/loading/
applying with groundboom equipment for drench application; (4) mixing/loading/applying with high pressure
handwand sprayer; (5) mixing/loading/applying with handgun sprayer; (6) mixing/loading/applying with low-
pressure handwand sprayer; (7) mixing/loading/applying with backpack sprayer; (8) loading/applying with
push-type drop spreader; (9) applying granulars by sprinkler can; and (10) applying granulars by hand
around the house perimeter and to ant mounds. Table 10 shows MOEs for nine of the ten scenarios
because the registrant has requested voluntarily cancellation of the residential house perimeter and ant mound
use (scenario 10).
For both dermal and inhalation exposures, route specific studies were available and provided the
NOAELs used to estimate risks. The same toxic effect or endpoint (i.e., ChEI) was selected to assess
24
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dermal and inhalation risks. Therefore, the Agency combined the dermal and inhalation exposures to assess
risks for various scenarios. The target MOE for occupational worker risks is 100. MOEs below this level
represent a risk of concern.
Based on the occupational and residential exposure (ORE) assessment presented in Table 10, two
scenarios posed potential risks of concern. Scenario 1, mixing/loading soluble powder for groundboom and
chemigation application to golf courses and ornamentals has a total MOE of 51. Combined MOEs for
scenario 6, mixing/loading/applying with a low pressure handwand for large (see ponds sizes and rate
description below) ornamental fish and bait ponds range from 27 to 120 depending on the size of the pond
and the application rate.
ii. Short/Intermediate-Term Risk
The Agency used various assumptions in performing the occupational assessment. The acres treated
or amount of trichlorfon handled per day may vary depending on the target pest and application equipment.
The Agency considered all scenarios to be of short/intermediate term in duration. The following is a list of
the area treated per day assumptions used in the assessments:
• Golf course turfgrass and chemigation treatments: 40 acres;
• Turfgrass broadcast treatments: 5 acres;
• Turfgrass perimeter/spot treatments: 100 sq ft using a sprinkler can, and 1,000 ft2 for hand-applied
treatments;
• Narcissus drench treatment (groundboom): 1,000 gallons;
• Ornamental treatments: 1,000 gallons high-pressure handwand, 40 gallons for low-pressure
handwand and backpack; and
• Pond/aquatic tank treatments: large pond (volume equals 15 acre-feet) and small pond (volume
equals 7.5 acre-feet).
25
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Table 10. Summary of Occupational Handler Short-term/intermediate-term Risks for Trichlorfon at Baseline and PPE
Exposure Scenario (Scenario #)
Use
Short/Intermediate-term MOEs
(Target MOE = 100)
Baseline
Dermal
Inhalation
Total
PPE
Dermal
Inhalation 3
Total
MIXER/LOADER EXPOSURE
Mixing/Loading Soluble Powder for Groundboom
and Chemigation Application (1)
Turf (golf courses, ornamental lawns)
5.8
17
4.3
1301
86a
51b
APPLICATOR EXPOSURES
Applying Spray with a Groundboom Sprayer (2)
Turf (golf courses, ornamental lawns)
1,500
990
600
NA
NA
NA
MIXER/LOADER/APPLICATOR EXPOSURES
Vlixing/Loading/ Applying with a Groundboom as a
Drench (3)
Vlixing/Loading/ Applying with a High Pressure
Handwand Sprayer (4)
Vlixing/Loading/ Apply ing with a Handgun Sprayer
(5)
Vlixing/Loading/ Applying with a Low Pressure
Handwand (soluble powder formulation) (6)
Narcissus
Ornamentals
Turf
Turf (spot treat)
Ornamentals
Livestock areas
Pond - 1 .4 Ib ai/acre ft (5.0 acres surface
area x 3 ft deep)
Pond - 0.64 Ib ai/acre ft (5.0 acres surface
area x 3 ft deep)
Pond - 1 .4 Ib ai/acre ft (2.5 acres surface
area x 3 ft deep)
Pond - 0.64 Ib ai/acre ft (2.5 acres surface
area x 3 ft deep)
1,900
No Data
No Data
No Data
No Data
No Data
No Data
No data
No Data
No data
19,000
130
4,200
1,200
370
55
10
23
21
46
1,700
No
Data
No
Data
No
Data
No
Data
No
Data
No
Data
No
Data
No data
No data
NA
1901
5001
4,300'
1,400'
200'
542
1202
HO2
2402
NA
670'
NA
NA
NA
270
52
110
100
230
NA
150a
450
NA
NA
120
27
58
53
120
26
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Exposure Scenario (Scenario #)
Mixing/Loading/ Applying with a Backpack Sprayer
(7)
Loading/Applying Granular with a Push Type
Spreader (8)
Loading/ Applying with a Sprinkling Can (9)
Use
Turf (spot treat)
Ornamentals
Livestock areas
Turf - maximum rate
Turf (spot treat)
Short/intermediate-term MOEs
(Target MOE = 100)
Baseline
Dermal
No Data
No Data
No Data
550
12,000
Inhalation
42,000
13,000
2,000
830
1.3E+6
Total
No data
No data
No data
330
12,000
PPE
Dermal
15,000'
4,700'
700'
130'
NA
Inhalation 3
NA
NA
NA
NA
NA
Total
11,000
3,500
520
120
NA
NA - indicates acceptable MOEs at baseline.
No data - indicates that there is no data for baseline attire
Footnotes:
a Baseline dermal unit exposure represents long pants, long sleeved shirt, no gloves, open mixing/loading, and open cab tractor.
b The Agency expects this risk to increase two-fold if a more realistic breathing rate is applied.
1 Long pants, long sleeved shirt, chemical resistant gloves.
2 Double layer of clothing; chemical resistant gloves.
3 PPE inhalation unit exposure represents use of dust mist respirator (80% protection factor applied to baseline unit exposure)
27
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7. Post-application Exposure
Exposure to workers can occur upon entering trichlorfon treated sites after application. The Agency
determined there are potential post-application exposures to workers performing tasks in treated golf
courses and hand labor activities associated with treated ornamentals. Golf course activities of concern
include mowing and maintenance of turfgrass. Potential exposure activities for nursery-grown ornamentals
include pruning, harvesting, and thinning flowers.
Current labels for turf and ornamental use specify foliar spray application. The Agency relied on
surrogate post-application exposure data to determine potential risks for these scenarios. The Agency
determined that there is a post-application risk to nursery workers following foliar treatment of ornamentals
up to 23 days after treatment. The registrant has agreed to voluntarily cancel this application method
because of post-application risk concerns, and instead support only a direct soil application. Although the
Agency did not perform a quantitative risk assessment for direct soil application to ornamentals, the Agency
believes discontinuing foliar application and allowing soil application only at the base of the plant, combined
with a 12 hour REI is appropriate to address postapplication exposure concerns. Details of the post-
application exposure and risk assessment for occupational workers are presented in the Revised
Preliminary Human Health Risk Assessment for Trichlorfon., September 19, 2000, and the August 30,
2000 addendum to the Trichlorfon Risk Assessment: Residential Handler's and Post-application
Ornamental Uses ".
The registrant submitted several turf transferable residue (TTR) studies for trichlorfon that the
Agency used to assess the potential post-application exposure and risks to workers that mow and maintain
treated golf courses. Estimated daily dermal post-application exposure to these workers resulted in MOEs
greater than 100 on the day of application. Therefore, the risks are not of concern. Post-application risks
are summarized in Table 11.
Although only trichlorfon residues were analyzed in the submitted study, potential exposure and risks
from trichlorfon's degradate, DDVP, could pose a risk of concern.
Two estimates of DDVP TTR were developed for this risk assessment. Both estimates of DDVP
began with the initial trichlorfon concentration of 0.0829 jig/cm2 detected on the first sampling interval using
the soluble powder formulation. The first DDVP estimate assumes the longest half-life from the FL site in
the DDVP turf study (FL is 0.156 days; CA is 0.069 days; Ontario is 0.022 days) and the longest half-life
of trichlorfon (2.5 days). The second estimate assumed the longest DDVP half-life from the FL site in the
DDVP turf study and the shortest half-life of trichlorfon (0.93 days). The range of modeled residue levels
of DDVP used in the risk assessment is 0.0028 to 0.0097 jig/cm2. The highest value, 0.0097 jig/cm2, is
based on using the shortest half-life of trichlorfon. This value represents the estimate on turf 11 hours after
treatment at the 8.2 Ib ai/acre rate. It represents the highest value based on the trichlorfon TTR results and
may overstate the levels at the time a child may be exposed because it occurs 11 hours after treatment (e.g.,
8:00 am treatment and playing on turf at 7:00 pm). The Agency is including these data for completeness
(only in Table 10) since the scope of this reregistration is limited to trichlorfon.
28
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Table 11. Trichlorfon Occu
Crop
Appl. Rate
national Post-Application Risk
DAT3
DFR
(US/cm2)"
Golf Course
Turf
Ornamentals
Ornamentals
8.2 Ib ai/A
3 Ib ai/A
(foliar)
(0.0151bai/gal
* 200 gal/A)
6 Ib ai/A
(foliar)
(0.0151bai/gal
* 400 gal/A)
0
0
9
13
16
0
16
20
23
6.7
2.6
1.7
1.2
13
2.5
1.6
1.2
TTR ( jig/cm2) c
(DDVP)
0.0138
(1) 0.0042
(2) 0.0097
No data available to
estimate potential
DDVP residues
No data available to
estimate potential
DDVP residues
Golf Course:
Mow/Maintain
Tc=500 cmVhr d e
Dermal Dose
(mg/kg/day)
Trichlorfon
0.00079
-
-
-
-
-
-
MOE
130,00
0
-
-
-
-
-
-
Dermal
Dose
(mg/kg/day)
DDVP
(1) 2.6E-5
(2)6.1E-5
-
-
-
-
-
-
Ornamentals:
Pruning, harvesting,
thinning flowers
Tc = 7,00 0 cmV-hr de
Dermal Dose
(mg/kg/day)
Trichlorfon
5.4
2.1
1.4
1.0
11
2.0
1.3
0.95
MOE
19
48
73
100
9
50
76
110
Footnotes :-
a DAT is "days after treatment."
b DFR=ApplicationratexConversionfactor(lbai/-acre= 11.209/L/g/cm2)xfractionof initial airetainedonfoliage(20%for ornamentals)* (1-daily dissipationrate)t, assuming
a daily dissipation of 10%.
c Turftransferableresidues(TTR)fortrichlorfonfromtheGAsite(granula^
oninitialtrichlorfonresidueofO. 0829 |ig/cm2and(l)the longest !/2lifefromFL site in theDDVPTurf study (FLis0.156days;CAis0.069days;OntisO. 022 days)and
the longest 1/2lifeoftrichlorfon(2.5 days); and(2)the longest !/2lifefromFL site in theDDVPTurf study (FLis0.156days;CAis0.069days;OntisO. 022 days)andthe
shortest Vi life of trichlorfon (0.93 days).
d Daily DermalDose(mg/kg/day)= [TTRorDFR(|ig/cm2)xTransferCoefficient(/hr)xunitconversion(l mg/1000 |ig)xExposureDuration(hrs/day)xabsorptionfactor]/-
BodyWeight(kg).Trichlorfonisassessedusingadermaltoxicologicalendpointand therefore thedoseisnotadjustedforabsorption. DDVP dermal absorptionisestimated
at 11 percent
e MOE = NOAEL (mg/kg/day) / Dermal Dose ( mg/kg/day); where trichlorfon dermal NOAEL is 100 mg/kg/day with a target MOE of 100.
29
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8. Incident Information
Relatively few incidents of illness have been reported due to trichlorfon based on the Incident Data
System, Poison Control Center Data, or the California Pesticide Illness Surveillance Program. Because of
uncertainty surrounding these limited data, those data were not factored into the risk assessment or risk
mitigation decisions.
B. Environmental Risk Assessment
The scope of this review is limited to consideration of human health risks for trichlorfon as required
by FQPA to complete the tolerance reassessment and reassessed the occupational risks based on new data.
Ecological risks are not addressed in the TRED. However, the ecological assessment in the RED, which
was issued in 1995, may be amended if warranted to account for new data or information that the Agency
may receive or become aware of after this document has been issued.
IV. FQPA Tolerance Reassessment Progress & Interim Risk Management Decision
A. Tolerance Reassessment Progress & Interim Risk Management Decision
This document presents the Agency's assessment of the dietary and occupational risks of trichlorfon.
Based on a review of generic data and public comments on the Agency's revised risk assessments for the
active ingredient trichlorfon, the Agency has sufficient information on the human health effects of trichlorfon
to make an interim decision as part of the tolerance reassessment process under FQPA.
Because the Agency has not yet completed its cumulative risk assessment for the OPs, this interim
decision does not fully address tolerance reassessment as required by Section 408(q) of the FQPA;
however, the Agency has completed its assessment of risk from dietary exposure to trichlorfon alone. When
the cumulative assessment is considered, the FQPA tolerance reassessment requirement will be completed.
Nothing in this report precludes the Agency from making further FQPA determinations and tolerance-related
rulemaking that may be required on this pesticide or any other in the future. The Agency has also not
considered risks associated with exposure to DDVP resulting from trichlorfon use. DDVP, although a
trichlorfon degradate, is a registered OP pesticide that is currently undergoing reregistration. Once the
DDVP IRED is complete, the Agency will determine whether the DDVP exposure resulting from trichlorfon
use poses risk concerns. The Agency may determine that further action is necessary after assessing the
cumulative risk of the organophosphate class. At that time, the Agency may also address any other risk
concerns that may arise including risks associated with DDVP exposure.
Such an incremental approach to the tolerance reassessment process is consistent with the Agency's
goal of improving the transparency of the implementation of FQPA. By evaluating each OP in turn and
identifying appropriate risk reduction measures, the Agency is addressing the risks from the OPs in as timely
a manner as possible.
30
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The Agency has determined that aggregate dietary risk from exposure to trichlorfon may exceed the
Agency's level of concern for children 1-6 years when the source of drinking water is surface water.
Therefore, mitigation measures are needed at this time to address this concern.
B. Phase 5 Comments
EPA released its revised risk assessment for trichlorfon to the public on April 25, 2000, and
provided a 60-day comment period for interested parties to submit information, including risk mitigation
suggestions or proposals. The public comment closed June 28, 2000. Chemical-specific comments were
provided by the Golf Course Superintendents Association of America (GCSAA), and general comments
by the Natural Resources Defense Council (NRDC).
GCSAA provided information on the benefits of trichlorfon in controlling pests on golf courses.
Additionally, the GCSAA surveyed nearly 7,500 golf course superintendents to gather data on trichlorfon
use. This information has been instrumental in helping the Agency understand exactly how trichlorfon is used
in the golf course environment and provided a basis for refining use assumptions.
General comments concerning several OPs were received from the NRDC that were similar to those
submitted regarding other OPs. The comments included remarks regarding the use of the FQPA 1 Ox safety
factor, aggregate exposure assessment and cumulative risk. EPA responses to these comments as well as
the full text of the general comments document can be found in the public docket.
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
individual OP. FQPA also requires the Agency to consider available information on cumulative risk from
substances sharing a common mechanism of toxicity, such as the toxicity expressed by the OPs through a
common biochemical interaction with the cholinesterase enzyme. The Agency will evaluate the cumulative
risk posed by the entire class of OPs once the methodology is developed. The tolerances to cover use on
beef products into the U.S. remain in effect and unchanged until a full reassessment of the cumulative risk
from all OPs is considered.
EPA has determined that risk from exposure to trichlorfon is within its own "risk cup." In other
words, if trichlorfon did not share a common mechanism of toxicity with other chemicals, EPA would be able
to conclude today that the import tolerances for trichlorfon on beef and beef byproducts meet the FQPA
safety standards. In reaching this determination, EPA has considered the available information on the special
sensitivity of infants and children, as well as chronic and acute food exposure. An aggregate assessment was
conducted for exposures through food, drinking water, and non-occupational uses (e.g., residential uses).
31
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As noted in Chapter 3 of this TRED, the Agency's modeled acute surface water EEC exceeds the DWLOC
by slightly more than a factor of two for the population subgroup, children 1-6 years old.
The modeled acute surface water EEC for trichlorfon is larger than the DWLOC and therefore
trichlorfon does not appear to fit within its own "risk cup." However, the Agency does not believe the
currently registered uses of trichlorfon actually pose an aggregate risk concern for the general population or
any population subgroup for the following reasons and trichlorfon does fit within its own risk "cup." First,
predicted trichlorfon concentrations for surface water are based on a moderately refined Tier I screening
model. This level of analysis is intended to identify those situations where additional information, such as
monitoring data, might be needed for risk assessment and/or risk mitigation purposes. In the case of
trichlorfon, the Agency believes the assessment is conservative and the EECs sufficiently small, so as not to
trigger monitoring or any other data requirement to address aggregate risks based on the current use pattern.
Second, trichlorfon is not registered for use in the United States on any agricultural or other dietary
commodity. There is a tolerance for beef intended to cover use on cattle outside the US. The Agency's
dietary assessment conservatively assumes one, tolerance level residues for all imported beef, two that all
imported beef has been treated with trichlorfon, and three, that 10% of consumed beef is imported.
However, it is doubtful that the most highly exposed population subgroup, children 1-6 years old, would
consume solely imported beef consistent with the conservative assumptions in the risk assessment.
Additionally, the predicted surface water drinking water concentrations are based on using trichlorfon on
a golf course since the Agency does not have a model scenario to quantitatively predict drinking water
exposure from the residential turf use. Even though the majority of trichlorfon use is on residential turf and
runoff to surface water is likely, trichlorfon's short half-life together with the expectation that not every
neighborhood lawn would be treated with trichlorfon on the same day together with the mitigation measures
that will be implemented in accordance with this TRED are expected to adequately address potential surface
water drinking water risks. Lastly, non-occupational and residential risks alone are not of concern for
trichlorfon. Therefore, based on the conservative trichlorfon tolerance reassessment, the Agency does not
believe aggregate risks are of concern nor is confirmatory data necessary based on the current limited use
patterns.
b. Tolerance Summary
In this individual assessment, tolerances for residues of trichlorfon in/on livestock commodities are
currently expressed in terms of residues of trichlorfon per se [40 CFR § 180.198]. These established
tolerances may be reassessed upon the completion of the cumulative risk assessment of all OPs, and the
additional data required to satisfy the metabolism in livestock guideline. The Agency is proposing the
modifications to the existing tolerances shown in Table 12 but plans to defer modification of these tolerances
pending the outcome of the cumulative assessment.
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Table 12. Tolerance Summary for Trichlorfon
Commodity
Cattle, fat
Cattle, (mybp)
Cattle, meat
Tolerance Listed Under 40
CFR§180.198
0.1 (N)
0.1 (N)
0.1 (N)
Reassessed
Tolerance1
0.5 ppm
0.1 ppm
0.2 ppm
Comment
The "(N)" designation (negligible residues) should be
removed from all entries to conform to current Agency
administrative practice.
1 The term "reassessed" here is not meant to imply that the tolerance has been reassessed as required by FFDCA as
amended by FQPA, since tolerances may be reassessed only upon consideration of the cumulative risk assessment of
all OPs, as required by this law. Rather, it provides a tolerance level for this single chemical.
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 (EDSTAC), EPA determined that there was scientific
basis for including, as part of the program, the androgen and thyroid hormone systems, in addition to the
estrogen hormone system. EPA also adopted EDSTAC's recommendation that 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, trichlorfon may be subjected to additional screening and/or testing to better
characterize effects related to endocrine disruption.
3. Risk Mitigation
Summary
The Agency has determined most exposure scenarios for trichlorfon do not result in risks that are
of concern. The ant mound and house perimeter uses have been voluntarily cancelled by the registrant to
mitigate certain residential risk. Specific label changes are necessary in order for use on golf course turf and
ornamentals and use in ornamental fish and bait ponds to be eligible for reregistration. Additionally workers
will be required to use a dust/mist respirator when mixing and loading the soluble powder formulation to
address inhalation exposure associated with handling large volumes of pesticide for groundboom and
chemigation applications. Therefore, of the ten scenarios originally evaluated for trichlorfon, six did not raise
risk concerns and are eligible for reregistration without any changes to the registration. Two uses have been
voluntarily canceled to mitigate risk, and specific label changes are necessary for use on golf course turf
(scenario 1) and use in ornamental fish and bait ponds (scenario 6) to be eligible for reregistration (see Table
10).
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Ornamental Fish and Bait Pond Uses
Estimated MOEs did not exceed the target MOE of 100 for certain use rates for scenario 6
(mixing/loading/applying with a low pressure handwand for ornamental fish and bait pond uses). The worker
MOEs range from 50 to!20 when trichlorfon is applied by handwand sprayer depending on the application
rate and size of the fish pond. Application of trichlorfon to small ponds at the lowest assessed application
rate resulted in an MOE (120) that did not exceed the Agency's level of concern.
The Agency obtained detailed information from the California Aquaculture Association, the Missouri
Aquaculture Association and the Arkansas Bait and Ornamental Pond Association to better characterize
actual ornamental fish and bait pond use practices. These stakeholders indicated that for large ponds,
trichlorfon is applied, in virtually all cases, by a truck drawn sprayer rig rather than with handheld equipment.
Although the Agency does not have data specific to this use, PHED does contain data for enclosed cabs
versus open cabs which have shown a significant decrease in the exposure and risks to applicators in such
instances. Therefore, the Agency believes dermal and inhalation risks can be mitigated if the
mixer/loader/applicator uses a truck drawn spray rig with a switch that is operated from inside the vehicle.
A pair of chemical resistant gloves must be available in the truck for use in the event of an equipment
problem.
With respect to small ponds, the Agency assessed the combined risks (dermal and inhalation) for a
2.5 acre, 3-foot deep pond with an application rate of 0.64 Ib ai/acre foot assuming workers wear gloves
and a double layer of clothing and using a low pressure handwand sprayer. Based on these assumptions,
the MOE is 120, which is below the Agency's level of concern. Use at the maximum labeled application
rate of 1.4 Ib ai/acre for the same size pond (2.5 acres surface area by 3 feet deep) resulted in a MOE of
53 which exceeds the Agency's level of concern.
As a general rule, the Agency does not believe limitations on "acres treated" represents a preferred
risk mitigation practice. However, given the unique nature of the ornamental fish and bait pond industry
combined with the limited scope of the Section 24(c) labels, and the well defined pond areas, such an
approach in this instance represents a sound, enforceable measure. Therefore, the Agency intends to allow
use of hand-held equipment only for ponds with one acre of surface area and a maximum depth of three feet.
The combined MOE (51) for scenario 1, mixing/loading soluble powder for groundboom and
chemigationto golf course turf and ornamental lawns exceeds the Agency's level of concern. However, the
registrant has agreed to modify the golf course use pattern to address drinking water exposure. As
discussed below, this modification will also result in a significant reduction in the amount of trichlorfon that
can be applied to a golf course. Therefore, mixer/loader risks would not be of concern to the Agency.
To assess surface water vulnerability, the GENEEC model was run using the standard input
parameters which include application rate, application interval, persistence, solubility, mobility, etc. Then,
a series of refinements were applied to the EECs. These refinements included incorporating an 87% crop
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area factor (default PCA) as well as the percentage of the golf course that actually receives pesticide
treatment., bringing the resulting PCA factor down to 17%. It was assumed that tees and greens comprise
2.8% (5 acres) of the acreage of a golf course. When fairways are included, an additional 16.7% (30 acres)
of the golf course is treated. In order to address concerns of runoff to surface water, the registrant has
agreed to limit broadcast/chemigation use on golf courses to tees and greens and allow spot treatment of
fairways only. The registrant has also agreed to establish a 7-day application interval and to limit application
to three times per calendar year. These changes to the trichlorfon label will effectively mitigate occupational
risk for groundboom and chemigation use on golf course turf and address surface water concerns. Below
is a summary of risk mitigation measures for trichlorfon.
a. Ornamental Fish and Bait Pond
S Prohibit use of hand-held equipment for all ponds greater than one acre, three feet
deep.
S Application to any pond equal to or greater than 1 acre, 3 feet deep must be done
using a truck drawn sprayer rig where the spray is activated by a switch in the cab.
A pair of chemical resistant gloves must be available in the truck.
S Handlers mixing/loading/applying to small ponds must wear double layer of clothing,
gloves and a respirator.
b. Turf Uses: Occupational and Aggregate
For the golf course use:
S Limit applications to three per calendar year with 7-day retreatment interval.
Broadcast/chemigation use is limited to tees and greens; use on fairways is limited
to spot treatment.
c. Ornamentals: Re-entry Worker Risks
S Prohibit ornamental foliar use; allow only direct soil application at base of the plant.
d. Residential Use
S Voluntary cancellation of home perimeter and ant mound uses.
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e. Summary of Worker Risks and Label Impacts
This TRED incorporates new information regarding the occupational and residential risks that resulted
in some modifications to the original 1995 RED requirements. Also, the registrant requested voluntarily
cancellation of the ant mound and house perimeter uses. Therefore, the requirements listed in the 1995 RED
for these uses are no longer applicable. Table 13 summarizes changes to the 1995 RED resulting from this
TRED. The list summarizes the original decision and any modifications that resulted from this assessment,
as well as new requirements.
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Table 13. Impact of 2001 TRED Decisions on the 1995 RED
Scenario
TRED Label Amendments
RED Label Amendment Decisions (1995)
Occupational:
1) Formulations:
a) Soluble powder for
groundboom and
chemigation.
b) Granular push-type spreader
Recommends same PPE, but adds
dust/mist respirator.
Long-sleeved shirt and long , shoes and
socks.1
Long-sleeved shirt and long pants, socks and shoes, chemical resistant
gloves.
Coveralls over long-sleeve shirt and long pants, chemical resistant gloves
and chemical resistant footwear.2
Post-Application:
1) Worker Protection Standard.
a)Omamentals
i) Reentry Intervals
ii) Early Entry.
2) Non-Worker Protection
Standards.
a) Golf Courses
i) Early Entry
Prohibit foliar application; only soil
application.
12-hour REI.
Do not allow people or pets to come into
contact with anything that has been
treated.
Foliar application.
24-hour REI.
Coveralls over long-sleeve shirt and long pants, chemical resistant
gloves, shoes plus socks.
Same restrictions as RED.
Liquid- Do not allow people or pets to enter until dry.
Granular - Watering in required. Do not allow people or pets to enter
(except people watering) and surface is dry.
Ornamental Ponds
1) Greater than 1 acre, 3 feet
deep.
2) Less thanl acre, 3 feet deep.
Use truck-drawn spray with operating
switch inside rig.
Chemical resistant gloves available inside
truck.
Not considered. Special Local Need issued after 1995 RED.
Handwand sprayer may be used. Long
sleeve shirt and long pants, gloves, and
shoes and socks.
Not considered. Special Local Need issued after 1995 RED.
}olf Course Treatment
Broadcast treatment permitted on tees and
greens only.
Only spot treatment to fairways is
permitted.
Broadcast treatment allowed for entire golf course.
1 Agency considered new data and assumed 0.5 acre rather than 1.0 acre in original RED based on new information.
2 No push type spreader data is available.
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4. Regulatory Rationale
Trichlorfon has three tolerances on beef and beef byproducts, which were used in the dietary risk
assessment. The assessment for exposure from food alone is not of concern to the Agency. The acute
dietary exposure for the general US population from food was estimated be 11% of the aPAD (17.6% of
the PAD for the most highly exposed subgroup, children 1-6 years) and the chronic dietary exposure for
the same population was estimated to be 12% of the cPAD (25% of the cPAD for children 1-6 years).
Based on analyses of both acute and chronic dietary risk, the dietary risk estimates are below the Agency's
level of concern when the source of drinking water is ground water, therefore, no mitigation measures are
necessary for dietary risk. However, when the source of drinking water is surface water, there appears to
be an aggregate risk concern for acute dietary risk to children 1-6 years.
The Agency believes the modeled estimates for exposure to trichlorfon residues in surface water
sources of drinking water, which exceed the DWLOC by about two-fold, overestimate the dietary risk for
several reasons. One, the exposure model used to generate the EEC values for surface water is a screening
tool and is not well suited for estimating an EEC for a pesticide applied to turf. Two, the environmental fate
properties for trichlorfon indicate that parent trichlorfon residues in surface waters are unlikely to reach
consumers because of the rapid aerobic dissipation in the environment. Three, the GENEEC modeling is
based on golf course use; however, most trichlorfon use is in the residential setting (78%) while only 18%
is used on golf courses. Residential use is likely to be random, varying from residence-to-residence, but
will likely cover less acres in a single day than the golf course use. Lastly, the target MOE is 1000,
providing an additional safety factor for children which when combined with the conservatism in the modeled
surface water and dietary assessments, provides high confidence that aggregate risks are not of concern nor
is confirmatory data required.
The ornamental post-application worker risk is a concern to the Agency for the current application
method. However, on December 20, 2000, the Bayer Corporation informed the Agency that they will
revise the use pattern for its soluble powder products and prohibit foliar application. Only direct application
to soil will be allowed for ornamentals. Prohibiting foliar application significantly impacts previous MOE
estimates and restricted entry intervals (REB S). Although the Agency has not recalculated the MOEs, direct
soil application to ornamentals is expected to effectively mitigate risk concerns. A statement must be placed
on the label prohibiting foliar application and allowing only direct soil application at the base of the plant
enabling the Agency to require a 12 hour REI.
The baseline inhalation MOE is 55 for treating livestock areas which is of concern. An MOE of 270
is attainable when considering the use of PPE (respirator). However, the Agency is in the process of
revising its current inhalation exposure policy to reflect internationally accepted practices which would
include matching the breathing rate to the handler's level of activity. If a breathing rate consistent with this
policy where applied to the livestock use risk assessment, the MOE is expected to increase at least two-
fold. Therefore, the Agency does not believe the risks during treatment of livestock areas will exceed the
Agency's level of concern and risk mitigation is not warranted at this time.
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For mixer/loaders handling soluble powder for groundboom and chemigation application, as
mentioned earlier, the Agency expects the changes to the use practice for golf course turf will mitigate
worker risk concerns. Limiting the broadcast treatment to tees and greens is expected to reduce the amount
of trichlorfon handled. Again mitigation measures presented in this TRED address exposures and risk
associated with use of trichlorfon alone. If it is determined that DDVP resulting from trichlorfon use presents
potential risk concerns, the Agency will reconsider all applicable decisions.
5. Codex Harmonization
There are no Codex Maximum Residue Levels for residues of trichlorfon. Therefore, harmonization
is not an issue at this time.
6. Spray Drift Management
Spray Drift Management
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 is protected from unreasonable adverse effects. In
August 2001, EPA published for public comment draft guidance for label statements ("Draft PR Notice
2001-X" http://www.epa.gov/PR_Notices/#2001) and a Federal Register Notice, August 22,
2001,(http://www.epa.gov/fedrgstr/) announcing the availability of this draft guidance for a 90-day public
comment period. After receipt and review of comments the Agency will publish final guidance (PR Notice)
for registrants to use in labeling their products.
In the interim, until EPA decides upon and publishes the final label guidance for spray/dust drift,
registrants (and applicants) may choose to use the proposed statements. Registrants should refer to and
read 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 specified language in Chapter V or a version that is
equally protective.
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V. What Manufacturers Must Do
This section specifies the data requirements, responses and labeling changes necessary for the
reregistration of trichlorfon manufacturing products. The label table includes requirements based on this
TRED and incorporates amendments to requirements in the 1995 RED as appropriate.
A. Additional Data Requirements
The trichlorfon registrant has committed to conduct a developmental neurotoxicity study in rats in
response to a data call-in notice issued to all registrants of OPs. The Agency is discussing the protocol for
the conduct of the study. The following data gap exists; the Agency is issuing a DCI for this requirement.
Data Requirements:
Product chemistry:
98% T (EPA Reg.# 3125-9) - 830.7050 UV/Visible Absorption
1. Labeling Requirements for Manufacturing Use Products
To remain in compliance with FIFRA, manufacturing use product (MUP) labeling must be revised
to comply with all current EPA regulations, PR Notices and applicable policies.
All registrants must submit applications for amended registration. This application should include
the following items: EPA application form 8570-1 (filled in), five copies of the draft label with all required
label amendments outlined in Table 13 of this document incorporated, and a description on the application,
such as, "Responding to Report on Tolerance Progress and interim Management Decision" document. All
amended labels must be submitted within 90 days of signature of this document. The Registration Division
contact for trichlorfon is Akiva Abramovitch. Flis phone number is (703) 308-8328. Amended labels must
be mailed to the Document Processing Desk, Office of Pesticide Program (7504C), U.S. Environmental
Protection Agency, Ariel Rios Building, 1200 Pennsylvania Avenue, NW, Washington DC 20460-0001,
Attn: Akiva Abramovitch.
2. End-Use Products
Additional Generic 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
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study MRID 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 decision.
3. Existing Stocks
Registrants may generally distribute and sell products bearing old labels/labeling for 12 months from
the date of the issuance of this TRED. Persons other than the registrant may generally distribute or sell such
products for 24 months from the date of the issuance of this TRED. 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.
B. Risk Mitigation Requirements
As discussed in this document, the Agency is concerned about several potential risks and is
recommending risk management measures (see table below). The Agency may need to pursue further risk
management measures for trichlorfon once the cumulative and DDVP assessments are finished.
C. Labeling Summary Table
See Table 13 below for the summary of label changes for trichlorfon.
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Table 13: Summary of Labeling Changes for Trichlorfon
Description
Amended Labeling Language
Placement on Label
Manufacturing Use Products
One of these statements may
3e added to a label to allow
reformulation of the product
for a specific use or all
additional uses supported
3y a formulator or user
group.
:'Only for formulation into an insecticide for the following use(s) [fill blank only with those uses that
are being supported by MP registrant]."
'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)."
Directions for Use
The use on Ant Mounds
and home perimeters is not
Deing supported by the
registrant.
'Not for formulation into products labeled for ant mound and house perimeter use.'
Directions for Use
Environmental Hazards
Statements Required by the
RED and Agency Label
Policies.
"Environmental Hazards" "This chemical is toxic to aquatic species. 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 the 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.
Precautionary Statement
Under Environmental
Hazards.
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Description
Amended Labeling Language
Placement on Label
Occupational Uses (WPS and non-WPS)
PPE Requirements
Established by the tolerance
reassessment progress
report for soluble powder
formulations and based on
the a.i.1
"Personal Protective Equipment" (PPE)
"Some materials that are chemical-resistant to this product are [registrant inserts correct material]. If
you want more options, follow the instructions for category [registrant insert A, B, C, D, E, F, G, or
H] on an EPA chemical-resistant category selection chart."
"Mixers, loaders, applicators, and other handlers must wear:
Long-sleeved shirt and long pants, shoes plus socks."
In addition to the above, all mixers and loaders plus applicators using handheld equipment must
wear chemical-resistant gloves. Applicators using handwand sprayers to treat ornamental fish and
bait ponds must wear a respirator equipped with any N, R, or P series filter.
In additional to the above, all mixers and loaders supporting groundboom and chemigation
applications to golf courses and ornamental lawns must wear a non-powered air purifying respirator
with any N, R, P, or HE filter."
Precautionary Statements:
Immediately following the
Hazards to Humans and
Domestic Animals
The respirator statement that
applies to application to
ornamental fish and bait
ponds must be placed on the
SLN label.
PPE Requirements
Established by the tolerance
reassessment progress
report for granular
formulations and based on
the a.i.1
"Personal Protective Equipment" (PPE)
"Some materials that are chemical-resistant to this product are [registrant inserts correct material]. If
you want more options, follow the instructions for category [registrant insert A, B, C, D, E, F, G, or
H] on an EPA chemical-resistant category selection chart."
Mixers, loaders, applicators, and other handlers must wear:
Long-sleeved shirt and long pants, shoes plus socks
Precautionary Statements:
Immediately following the
Hazards to Humans and
Domestic Animals.
User Safely 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.
Precautionary Statements
immediately following the
PPE.
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Description
Engineering Controls for
Water Soluble Powder
Formulations
Engineering Controls for
24(c) Label for ornamental
fish and bait ponds
User Safety
Recommendations
Environmental Hazards
Restricted-Entry Interval for
sroducts subject to WPS as
required by Supplement
Three PR Notice 93 -7.
Entry Restrictions for Water
Soluble formulations with
Don WPS occupational uses .
Amended Labeling Language
"Engineering Controls"
"When handlers use closed systems or enclosed cabs in a manner that meets the requirements
listed in the Worker Protection Standard (WPS) for agricultural pesticides (40 CFR 170.240(d)(4-6),
the handler PPE requirements may be reduced or modified as specified in the WPS."
Engineering Controls:
Applicators applying to ornamental ponds that are greater than 1 acre must use a truck-drawn spray
rig equipped with an on/off operating switch located inside the truck cab.
"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."
For terrestrial uses, do not apply directly to water. Do not contaminate water by cleaning of
equipment or disposal of waste."
"Do not enter or allow others to enter the treated area until sprays have dried, worker entry into
treated areas during the restricted entry interval (REI) of 12 hours."
"Exception: if the product is applied by direct spray to base of plant, the Worker Protection
Standard, under certain circumstances, allows workers to enter the treated areas without restriction
if there will be no contact with anything that has been treated."
Do not enter or allow others to enter the treated area until sprays have dried.
Placement on Label
Precautionary Statements
immediately following the
User Safety Requirements .
Vlust appear on the SLN
Label
Precautionary Statements
immediately following the
User Safety Requirements
(Must be placed in a box..)
Precautionary Statements
immediately
Directions for Use
Directions for Use
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Description
Entry Restrictions for
Granular Formulations (non
WPS occupational uses).
Early Entry Personal
Protective Equipment for
sroducts subject to WPS as
required by Supplement
Three of PR Notice 93-7.
General Application
Restrictions
Other Application
Restrictions for all
formulations
Other Application
Restrictions for Granular
Formulations Only.
Amended Labeling Language
Do not enter or allow others to enter the treated area (except those persons involved in the
incorporation) until the incorporation is complete. If the incorporation is accomplished by watering-
in, do not enter or allow others to enter the treated area until the surface is dry after the watering-
in."
"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
- chemical resistant gloves made out of any waterproof material
- socks and shoes
"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. "
Got application to ornamental plants, foliar use is prohibited; allow only direct soil application at
base of the plant.
- For applications to turf, limit applications to 3 per calendar year with 7-day retreatment interval.
- Broadcast/chemigation use on turf is limited to tees and greens; use on fairways is limited to spot
treatment.
- Limit applications to 24.51 Ibs ai/A per year for grubs and mole crickets and 16.2 Ibs ai/A per year
for surface feeding insects.
Instructions for incorporation by watering in must be included in the directions for use.
Placement on Label
Directions for Use.
Directions for Use, in the
Agricultural Use Box.
Place in the Direction for Use
directly above the
Agricultural Use Box.
Place in the Direction for Use
in General Precautions and
Restrictions section.
Directions for Use.
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Description
Spray Drift Language
Amended Labeling Language
The following spray drift language, or equivalent language proposed by the registrant must be
placed on the label.
"Do not allow spray (or dust) 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 with sprav quality, e. g. fine or medium) or coarser
spray according to ASAE 572 definition for standard nozzles or VMD for spinning atomizer
nozzles."
"For overhead chemigation, apply only when wind speed is 10 mph or less."
"The applicator also must use all other measures necessary to control drift."
Placement on Label
Directions for Use
End Use Products Intended for Occupational Use (Non-WPS)
Removal of Ant Hill and
louse perimeter Site
All references to use on Ant Hills and house perimeter must be removed from label as these uses are
no longer supported
Directions for Use.
1 PPEthat is established on the basis of the 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.
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VI. Related Documents and How To Access Them
This TRED for Trichorfon is supported by documents that are presently maintained in the OPP public
docket. The OPP docket is located in Room 119, Crystal Mall #2, 1921 Jefferson Davis Highway,
Arlington, VA. It is open Monday through Friday, excluding holidays from 8:30 to 4:00 pm.. All documents
in hard copy form, may be viewed in the OPP docket room or viewed or downloaded or viewed via the
Internet (http://www.epa.gov/opppsrrdl/op/).
The following documents are included in the public docket:
Revised HED Assessment;
Residential Post-application Exposure and Risks;
Revised Residential Handler's and Post-application Ornamental Uses;
Review of Determination of Transferable Turf Residues on Turf Treated with Trichlorfon;
Reassessment of the Use of ORETF Granular Push-Type Spreader Studies (LCO and Homeowner);
Refined Tier I Surface Water EECs;
Revised Drinking Water Levels of Concern and Aggregate Risk Assessment.
47
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48
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Appendix A: Trichlorfon (Case 0104): Use Patterns Eligible for Reregistration
Application Type
Timing
Equipment
Formulation EPA reg
No.
Max Single
App.Rate
(Ibai/A)
Max No of Apps
Restrictions/Comments
Lawns/recreational turf (golf courses)
Foliar
Groundboom and chemigation
soluble powder granular
3125-9,3125-184,3125-
371,3125-449,3125-507
8.2 Ib ai/acre
3 times per
calendar year
Spot treatment for fairways; broadcast treatment only to tees
and greens.
7-day application interval.
Curative treatment for white grubs and mole crickets.
Ornamentals
Handwand sprayer
granular
3125-184; 3125-449
0.015 Ibai/gallon
NS
Apply to base of plant.
12hourREI.
Commercial Ponds/Aquatic tank
Foliar
Handwand sprayer; truck-pulled
spray rig.
AR98-003
CA98-0014
MO99-0005
(3125-184)
1.41b ai/acre
foot
NS
Two or three applications per week may be necessary for
trichlorfon treatment for commercial ponds according to
special needs labels
Residential
Spreader
Ready -to-Use Granules
3125-507
8.2 Ib ai/acre
Apply when
grubs are
present
None
49
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50
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Appendix B: Data Supporting Guideline Requirements For Reregistration
GUIDE TO APPENDIX B
Appendix B contains listing of data requirements which support the reregistration for active ingredients
within case #0104, trichlorfon, covered by this TRED. It contains generic data requirements that apply to
trichlorfon in all products, including data requirements for which a "typical formulation" is the test substance.
The data table is organized in the following formats:
1. Data Requirement (Column 1). The data requirements are listed in the order in which they appear
in 40 CFR part 158. the reference numbers accompanying each test refer to the test protocols set
in the Pesticide Assessment Guidance, which are available from the National technical Information
Service, 5285 Port Royal Road, Springfield, VA 22161 (703) 487-4650.
2. Use Pattern (Column 2). This column indicates the use patterns for which the data
requirements apply. The following letter designations are used for the given use patterns.
A. Terrestrial food
B. Terrestrial feed
C. Terrestrial non-food
D. Aquatic food
E. Aquatic non-food outdoor
F. Aquatic non-food industrial
G. Aquatic non-food residential
H. Greenhouse food
I. Greenhouse non-food
J. Forestry
K. Residential
L. Indoor food
M. Indoor non-food
N. Indoor medical
O. Indoor residential
3. Bibliographic Citation (Column 3). If the Agency has acceptable data in its files, this column list the
identify number of each study. This normally is the Master Record Identification (MIRD) number,
but may be a "GS" number if no MRID number has been assigned. Refer to the Bibliography
appendix for a complete citation of the study.
51
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52
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PRODUCT CHEMISTRY
New Guideline Old Guideline
Number Number
830.1550
830.1600
830.1670
830.1750
830.1800
830.6302
61-1
61-2A
61-2B
62-2
62-3
63-2
830.6303 63-3
830.6304 63-4
830.7300 63-7
830.7370 63-10
830.7000 63-12
830.6314 63-14
830.6316 63-16
830.6317 63-17
830.6320 63-20
Study
Product Identity and Composition
Start. Mat. & Mnfg. Process
Formation of Impurities
Certification of limits
Analytical Method
Color
Physical State
Odor
Density
Dissociation Constant
pH
Oxidizing/Reducing Action
Explodability
Storage Stability
Corrosion characteristics
Use Pattern Citation
All 00158290,42835204
All 42835204
All 42835204
All 00158290,42835205
All 42835205
All 02835206
All 42835206
All 42835206
All 42835206
All 42835206
All 42835206
All 42835206
All 42835206
All 43139501
All 43139501
53
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TOXICOLOGY
870.1100 81-1
870.1200 81-2
870.1300 81-3
870.2400 81-4
870.2500 81-5
870.2600 81-6
870.3150 82-1
870.3200 82-2
870.3465 82-4
870.3700 83-3
870.3700 83-3
870.3800 83-4
870.4100 83-1
870.4200 83-2
870.4300 83-5
870.5300 84-2
Acute Oral Toxicity-Rat All
Acute Dermal Toxicity-Rabbit/Rat All
Acute Inhalation Toxicity-Rat All
Primary Eye Irritation-Rabbit All
Primary Skin Irritation All
Dermal Sensitization All
Subchronic Toxicity-Dog All
21-Day Dermal Toxicity All
90-day Inhalation - Rat All
Prenatal developmental toxicity All
- Rat
Prenatal developmental toxicity All
- Rabbit
2-Generation Reproduction - Rat All
Chronic Toxicity All
Carcinogenicity - Mouse All
Combined Chronic All
toxicity/carcinogenicity - Rat
in vitro cytogenic study in
mammalian cells
All
00152135, 00256446
00090786, 40306901
00256446
41571302, 44471301
40306901
00257599
HED #1668 & 1669
00403069
00256446
40255601
41565201
42228301
00090786
40782401, 40844301
41056201 41973001
00022865
54
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870.5550 84-2
870.5500 84-2
870.5575 84-2
870.5900 84-2
870.6100 81-7
82-5
870.6200 81-8
870.7485 85-1
Residue Chemistry
860.1300 171-4(b)
860.1340 171-4(d)
860.1380 171-4(e)
Salmonella typhimurium gene
mutation
Bacterial DNA damage/repair
Sacharomyces cerevisae gene
mutation
Sister chromatid exchange -
Chinese hamster
Acute and 28-day delayed
neurotoxicity
All
All
All
All
All
Neurotoxicity screening battery All
Metabolism - Rat All
Nature of Residue - livestock All
Residue Analytical Method - All
animals
Storage stability All
00249535, 00256446,
00028625
00256446
00256446
40277201, 00028625
00152136, 00256446,
40351201, 40879301
44578001, 43871701
40438101
44500701, 44500702
44500704
44781401
860.1480 171-4(j)
Magnitude of Residue - Meat,
Eggs, Poultry
Occupational and Residential Exposure
875.2100 132-1 Transferable Turf Residues
All
All
44500703
45067201
55
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56
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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 August 10,
1998. Sixty days later the first public comment period closed. The EPA then considered comments,
revised the risk assessment, and added the formal "Response to Comments" document and the revised
risk assessment to the docket on June 16, 1999.
All documents, in hard copy form, may be viewed in the OPP docket room or downloaded or viewed
via the Internet at the following site:
www.epa.gov/pesticides/op
57
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58
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Appendix D: Bibliography
1. CONTENTS OF BIBLIOGRAPHY. This bibliography contains citations of all studies
considered relevant by EPA in arriving at the positions and conclusions stated elsewhere in the
Reregistration Eligibility Document. Primary sources for studies in this bibliography have been
the body of data submitted to EPA and its predecessor agencies in support of past regulatory
decisions. Selections from other sources including the published literature, in those instances
where they have been considered, are included.
2. UNITS OF ENTRY. The unit of entry in this bibliography is called a "study". In the case of
published materials, this corresponds closely to an article. In the case of unpublished materials
submitted to the Agency, the Agency has sought to identify documents at a level parallel to the
published article from within the typically larger volumes in which they were submitted. The
resulting "studies" generally have a distinct title (or at least a single subject), can stand alone for
purposes of review and can be described with a conventional bibliographic citation. The
Agency has also attempted to unite basic documents and commentaries upon them, treating them
as a single study.
3. IDENTIFICATION OF ENTRIES. The entries in this bibliography are sorted numerically by
Master Record Identifier, or "MRID" number. This number is unique to the citation, and should
be used whenever a specific reference is required. It is not related to the six-digit "Accession
Number" which has been used to identify volumes of submitted studies (see paragraph 4(d)(4)
below for further explanation). In a few cases, entries added to the bibliography late in the
review may be preceded by a nine character temporary identifier. These entries are listed after
all MRID entries. This temporary identifying number is also to be used whenever specific
reference is needed.
4. FORM OF ENTRY. In addition to the Master Record Identifier (MRID), each entry consists
of a citation containing standard elements followed, in the case of material submitted to EPA, by
a description of the earliest known submission. Bibliographic conventions used reflect the
standard of the American National Standards Institute (ANSI), expanded to provide for certain
special needs.
a Author. Whenever the author could confidently be identified, the Agency has chosen to show a
personal author. When no individual was identified, the Agency has shown an identifiable
laboratory or testing facility as the author. When no author or laboratory could be identified, the
Agency has shown the first submitter as the author.
b. Document date. The date of the study is taken directly from the document. When the date is
followed by a question mark, the bibliographer has deduced the date from the evidence
contained in the document. When the date appears as (1999), the Agency was unable to
59
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determine or estimate the date of the document.
c. Title. In some cases, it has been necessary for the Agency bibliographers to create or enhance a
document title. Any such editorial insertions are contained between square brackets.
d. Trailing parentheses. For studies submitted to the Agency in the past, the trailing parentheses
include (in addition to any self-explanatory text) the following elements describing the earliest
known submission:
(1) Submission date. The date of the earliest known submission appears immediately
following the word "received."
(2) Administrative number. The next element immediately following the word "under" is the
registration number, experimental use permit number, petition number, or other
administrative number associated with the earliest known submission.
(3) Submitter. The third element is the submitter. When authorship is defaulted to the
submitter, this element is omitted.
(4) Volume Identification (Accession Numbers). The final element in the trailing parentheses
identifies the EPA accession number of the volume in which the original submission of
the study appears. The six-digit accession number follows the symbol "CDL," which
stands for "Company Data Library." This accession number is in turn followed by an
alphabetic suffix which shows the relative position of the study within the volume.
60
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BIBLIOGRAPHY
MRID
CITATION
00090780 Bukva, N.F.; Fogman, R. W. (1970) Dermal L Dea 50-Test-Rabbits. (Unpublished
study received Novl4, 1972 under 3GG1310; submitted by Sandoz Inc., Homestead,
Fla.; CDL: 092233-B) 00146516 Mihail, F. (1985) L 13/59 (c.n. Trichlorfon, ISO)
Study for Skin sensitizing Effects on Guinea Pigs: T 6018557. Unpublished Translation
of L 13/59, untersuchung auf Hautsensibiliserende Wirkung bei Meerschweinchen.
Mobay report 88978. 21 p (Accession No 00257599)
00256446 Crawford, C.; Anderson, R (1973) the Acute Oral and Intraperitoneal Toxicity
of five Trichlorfon Technical Samples of Rats: Report No. 37204. Unpublished
study prepared by Mobay Chemical Corp. 7 p. (also numbered as 00152135).
00152135 Crawford, C.; Anderson, R (1973) the Acute Oral and Intraperitoneal Toxicity
of five Trichlorfon Technical Samples of Rats: Report No. 37204. Unpublished
study prepared by Mobay Chemical Corp. 7 p. (also numbered as 00256446).
00152136 Kimmerle, G. (1975) L 13/59: Acute Inhalation Toxicity Study on Rats: Report
No. 5581 Unpublished Mobay Report 45153 prepared by Bayer AG. 7 p.
00147436 Krohn, J. (1983) Letter sent to Hagen dated Jul 14, 1983: Partition
coefficient of Trichlorfon and Methamidophos: Registration in Egypt. Translation
of Verteilungskoeffizienten von trichlorfon Methamidophos: Registrierung in
Aegypten prepared by Bayer AG, Mobay report 85931. 1 p.
00148973 Slahck, S. (1985) Composition of Technical Trichlorfon: Report No.88931.
Unpublished study prepared by Mobay Chemical Corporation. 25 p
00152133 Mobay Chemical Corp. (1985) Product Chemistry of Trichlorfon
Technical: Dylox Technical. Unpublished compilation. 22 p
00158290 Talbott, T. (1986) Maximum andMinimum Certified Limits for Dylox
80 Concentrate Formulation: Report No. 90973. Unpublished study
prepared by Mobay Chemical Corp. 13 p.
00162307 Technology Services Group (1986) Product Chemistry Data for Technical
Trichlorfon. Unpublished compilation. 101 p.
61
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BIBLIOGRAPHY
MRID
CITATION
40306901 Heimann, K.; Wood, C (1987) Trichlorfon Technical: Study of Sub-acute Dermal
Toxicity to Rabbits : Lab Project ID: 94790. Unpublished study prepared by
bayer AG. 166 p.
40776001 Griffin, T. (1988) Safety Evaluation and Tumorigenesis of Trichlorfon in Rhesus
Monkeys: A Ten Year Study: Study No. 800108. Unpublished study prepared by
White Sands Research Center.
41056201 Hayes, R (1989) Chronic Toxicity/Oncogenicity Study of Technical Grade
Trichlorfon (Dylox) with Rats Study No. 86-271-02 Unpublished study prepared
by Mobay Corp. 2893 p.
41535301 Sewekow. (1988) Vapor Pressure of Trichlorfon Pure Active Ingregdient: Lab
Project Number: 100 128: 87267. Unpublished study prepared by Mobay Corp. 11
P-
41535302 Weber. (1987) Vapor Pressure of Trichlorfon Pure Active Ingredient: Lab
Project Number: 681 538: 94641. Unpublished study prepared by Corp., and Bayer
Ag. 7 p.
42228301 Eigenberg, D. (1991) A Two-Generation Dietary Reproduction Study in Rats Using
Technical Grade Trichlorfon (Dylox): Lab Project Number: 89-672-EA. Unpublished
study prepared by Mobay Corp. 1075 p.
42682701 Herbold, B. (1992) L 13/59 In vivo Cytogenetic Study of the Spermatogonia in Chinese
Hamster to Evaluate for Induced Clastogenic Effects: Lab Project Number: 103298: T.
42722001 Eigenberg, D. (1993) A Two-Generation Dietary Reproduction Study in Rats Using
Technical Trichlorfon (DYLOX): A Supplemental: Lab Project Nos.: 89-672-EA:
101937-2. Unpublished study prepared by Miles, Inc. 47 p.
42835201 Fontaine, L. (1993) Product Chemistry of Dipterex Technical: Supplemental: Lab
Project number: MCL0006A: MCL0006B: 605161. Unpublished study prepared
by Miles Inc. 30 p.
62
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BIBLIOGRAPHY
MRID
CITATION
42835202 Fontaine, L. (1993) Product Chemistry of Dipterex Technical: Supplemental: Lab
Project Number: 88931: 88935: 93156. Unpublished study prepared by Mies Inc. 75
P-
42835203 Fontaine, L. (1993) Product Chemistry of Dipterex Technical: Supplemental: Lab
Project Number: 90153: 90155: 91700. Unpublished study prepared by Miles Inc.
42835204 Fontaine, L. (1993) Product Chemistry of Dylox 80 Concentrate: Supplemental:
Lab Project Number: 605161: 501968: 501821. Unpublished study prepared by Miles
Inc.
42835205 Fontaine, L. (1993) Product Chemistry of Dylox 80 Concentrate: Supplemental:
Lab Project Number: 88931: 90973: 93156. Unpublished study prepared by
Miles Inc. 61 p.
42835206 Fontaine, L. (1993) Product Chemistry of Dylox 80 Concentrate: Supplemental:
Lab Project Number: 99697: 103879: 105144. Unpublished study prepared by
Miles Inc. 15 p.
42835207 Fontaine, L. (1993) Product Chemistry of Dylox Technical: Supplemental:
Lab Project Number: ANR-00393: BR 1832: MCL0340. Unpublished study
prepared by Miles Inc. 16 p.
42835208 Fontaine, L. (1993) Product Chemistry of Dylox Technical: Supplemental: Lab
Project Number: 105136: 105141: ANR-00493, Unpublished study prepared by
Miles Inc. 55 p.
42835209 Fontaine, L. (1993) Product Chemistry of Dylox Technical: Lab Project Number:
86166: 90153: 90155. Unpublished study prepared by Miles Inc.. 79 p.
43871701 Sheets, L.; Hamilton, B. (1995) A Subchronic Dietary Neurotoxicity Screening Study
with Technical Grade Trichlorfon (Dylox, Dipterex) in Fischer 344 Rats: Lab Project
Number: 92-472-ND: 107153. Unpublished study prepared by Bayer Corp. 455 p.
63
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BIBLIOGRAPHY
MRID
CITATION
44024701 Fontaine, L. (1996) Product Chemistry of Dipterex Technical: (Product Identity
and Composition): Supplement to MRID 42835201: Lab Project Number:
AKR-00496: ANR-00596. Unpublished study prepared by Bayer Corp. 19 p.
44024702 Fontaine, L. (1996) Product Chemistry of Dipterex Technical: (Preliminary
Analysis and Certification of Limits): Supplement to MRID 42835202: Lab
Project Number: 93059: BR 1909. Unpublished study prepared byBayer Corp. p37
44024703 Fontaine, L. (1996) Product Chemistry of Dipterex Technical: (Stability and
Corrosion Characteristics): Lab Project Number: 107211: BR 1910. Unpublished
study prepared by Bayer Corp. 10 p.
44024704 Fontaine, L. (1996) Product Chemistry of Dylox Technical: (Product Identity and
Composition): Supplement to MRID 42835207: Lab Project Number:
ANR-00296: ANR-00396: BR 1911. Unpublished study prepared by
Bayer Corp. 14 p.
44024705 Fontaine, L. (1996) Product Chemistry of Dylox Technical: (Preliminary
Analysis):Supplement to MRID 42835208: Lab Project Number: ANR-00696:
BR 1912. Unpublished study prepared by Bayer Corp. 10 p.
44024706 Fontaine, L. (1996) Product Chemistry of Dylox Technical: (Physical and
Chemical Characteristics): Lab Project Number: 107218: 107236: BR 1913.
Unpublished study prepared by Bayer Corp. 25 p.
44308001 Manley, A. (1997) Metrifonate (MTF)/Dichlorvos (DDVP): Position Document on
Long Term Administration in Humans: Lab Project Number: AM/001. Unpublished
study prepared by Amvac Chemical Corp. 146 p.
44471301 Wakefield, A. (1997) Primary Eye Irritation Study in Rabbits with Dipterex Technical:
Final Report: Lab Project Number: COVANCE 18738-0-820: 97-C335-MM:
108044. Unpublished study prepared by Covance Labs., Inc. 20 p.
64
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BIBLIOGRAPHY
MRID
CITATION
44479406 Sheets, L.; Gastner, M. (1998) Acute Oral Toxicity Study with Dylox Technical in Rats:
Lab Project Number: 108022: 8401: 97-012-OG. Unpublished study prepared by
Bayer Corp. 36 p.
44479407 Sheets, L.; Halliburton, A. (1998) Acute Dermal Toxicity Study with Dylox Technical in
Rats: Lab Project Number: 97-022-OF: 108027: 8404. Unpublished study prepared
by Bayer Corp. 31 p.
44479408 Sturdivant, D. Halliburton, A. (1998) Acute Four-Hour Inhalation Toxicity Study with
Dylox Technical in Rats: Lab Project Number: 97-042-OR: 108037: 8409.
Unpublished study prepared by Bayer Corp. 46 p.
44479409 Sheets, L.; Avila, V. (1998) Acute Oral Toxicity Study with Dipterex Technical in Rats:
Lab Project Number: 97-012-MQ: 108016: 8400. Unpublished study prepared by
Bayer Corp. 42 p.
44479410 Sheets, L.; Gastner, M. (1998) Acute Dermal Toxicity Study with Dipterex Technical in
Rats: Lab Project Number: 108009: 8402: 97-022-MR. Unpublished study prepared
by Bayer Corp. 31 p.
44479411 Sturdivant, D.; Halliburton, A. (1998) Acute Four-Hour Inhalation Toxicity Study with
Dipterex Technical in Rats: Lab Project Number: 97-042-OQ: 108030: 8407.
Unpublished study prepared by Bayer Corp. 47 p.
44500701 Lynch, C.; Speirs, G (1998) (Ethyl-1-(carbon 14)-Trichlorfon: Total Residue
Depletion Study in Cattle After Dermal Application (In-Life Phase): Lab Project
Number: 159648: PNR 632: 116.303. Unpublished study prepared by Inveresk
Research. 46 p. (OPPTS 860.1300}
44500702 Phillips, M.; Johnson, S. (1998) (Ethyl-l-(carbonl4))-Trichlorfon: Investigation
of the Nature of Metabolites in Edible Tissues of Cattle After Dermal Application
(Animals 1 (Male) and 2 (Female)): Lab Project Number: 161395: PNP 632:
111.805. Unpublished study prepared by Inveresk Research. 226 p. {OPPTS
860.1300}
65
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BIBLIOGRAPHY
MRID
CITATION
44500703 Auer, S.; Krebber, R. (1998) Determination of Residues of Trichlorfon and
Dichlorvos in Edible Tissues (Muscle, Fat, Kidney and Liver) 12 Hours to 7 Days after
a Single Spray Treatment on Cattle: Lab Project Number: V 97-002:
111.807: PNR 632. Unpublished study prepared by Bayer AG. 119 p.
(OPPTS 860.1480}
44500704 Krebber, R. (1998) Method for the HPLC/MS/MS Determination of Trichlorfon
and Dichlorvos in Cattle Tissue: Lab Project Number: 74951: 00508: 117.642.
Unpublished study prepared by Bayer Corp. 25 p. {OPPTS 860.1480}
44578001 Sheets, L. (1996) An Acute Oral Neurotoxicity Screening Study with Technical
Grade Trichlorfon(Dylox) in Fischer 344 Rats: Lab Project Number: 95-412-DT.
Unpublished study prepared by Bayer Corporation. 403 p.
44781401 Krebber, R. (1998) Determination of Storage Stability of Trichlorfon and
Dichlorvos in Tissues of Cattle: Lab Project Number: P64375030: 140.077:
NR 632. Unpublished study prepared by Bayer Ag. 61 p. {OPPTS 860.1380}
44709601 Becker, R.; Colliver, 1; Elble, R. et al. (1998) Effects of metrifonate, a long-acting
cholinesterase inhibitor, in Alzheimer disease: report of an open trial. Drug Development
Research 19.
45067201 Hofen, J. (2000) Determination of Transferable Turf Residues on Turf Treated
with Trichlorfon: Lab Project Number: SARS-98-71.
66
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Appendix E: Generic Data Call-In
See attached table for a list of generic data requirements. Note that a complete Data Call-in
(DCI), with all pertinent instructions, is being sent to registrants under separate cover.
67
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Insert Generic Sample DCI Here
68
-------
Insert chemical specific DCI Here
69
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70
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Appendix F: List Of Registrants Sent this Data Call-In
71
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Insert the List of Registrants Sheet Here.
72
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73
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