United States Prevention, Pesticides EPA 738-R-06-004
Environmental Protection And Toxic Substances June 2006
Agency (7508C)
Re registration Eligibility
Decision for Pyrethrins
ListB
Case No. 2580
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Reregistration Eligibility Decision (RED) Document
for
Pyrethrins
Approved by: /S/
Debra Edwards, Ph. D.
Director
Special Review and Reregistration
Division
Date: June 7, 2006
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TABLE OF CONTENTS
Executive Summary 7
I. Introduction 11
II. Chemical Overview 12
A. Regulatory History 12
B. Chemical Identification 13
C. Use Profile 16
1. Pyrethrins Use Profile 16
III. Summary of Pyrethrins Risk Assessments 17
A. Human Health Risk Assessment 18
1. Toxicity Profile 18
2. FQPA Safety and Uncertainty Factors 21
3. Endocrine disruption 22
4. Drinking Water 22
5. Dietary Risk (Food + Water) 23
6. Residential Exposure and Risk 25
7. Aggregate Risk 30
8. Cumulative Risk Assessment 31
9. Occupational Risk 32
B. Environmental Risk Assessment 34
1. Environmental Fate and Transport 35
2. Ecological Risk 35
4. Ecological Incidents 45
IV. Risk Management, Reregistration, and Tolerance Reassessment Decision 46
A. Determination of Reregistration Eligibility and Tolerance Reassessment 46
B. Regulatory Position 46
1. Food Quality Protection Act Findings 47
2. Endocrine Disrupter Effects 48
3. Cumulative Risks 48
C. Tolerance Reassessment Summary 49
D. Regulatory Rationale 60
1. Human Health Risk 60
2. Non-Target Organism (Ecological) Risk Management 68
V. What Registrants Need to Do 75
A. Manufacturing Use Products 75
1. Additional Generic Data Requirements 75
2. Labeling Requirements 77
3. Spray Drift Management 77
4. Endangered Species 77
B. End-Use Products 78
1. Additional Product-Specific Data Requirements 78
2. Labeling for End-Use Products 78
Appendix: Technical Support Documents 107
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Pyrethrins Reregistration Eligibility Decision Team
Office of Pesticide Programs:
Environmental Fate and Effects Risk Assessment
Jose Melendez
Mike Rexrode
Health Effects Risk Assessment
Christine Olinger (Risk Assessor)
Joseph Deluzio
Timothy Dole
Matthew Lloyd
Linda Taylor
Biological and Economic Analysis Division
Alan Halvorson
Nikhil Mallampalli
Registration
Richard Gebken
Mark Suarez
Kevin Sweeney
Risk Management
Tom Myers
Cathryn O'Connell
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Glossary of Terms and Abbreviations
AGDCI
ai
aPAD
AR
BCF
CFR
cPAD
CSF
CSFII
DCI
DEEM
DFR
DWLOC
EC
EDWC
EEC
EPA
EXAMS
EUP
FCID
FDA
FIFRA
FFDCA
FQPA
FOB
G
GENEEC
GLN
HAFT
IR
LC50
LD50
LOC
LOD
LOAEL
ug/L
mg/kg/day
mg/L
MOE
MRID
MUP
NA
NAWQA
NPDES
NR
NOAEL
Agricultural Data Call-In
Active Ingredient
Acute Population Adjusted Dose
Anticipated Residue
Bioconcentration Factor
Code of Federal Regulations
Chronic Population Adjusted Dose
Confidential Statement of Formula
USDA Continuing Surveys for Food Intake by Individuals
Data Call-In
Dietary Exposure Evaluation Model
Dislodgeable Foliar Residue
Drinking Water Level of Comparison.
Emulsifiable Concentrate Formulation
Estimated Drinking Water Concentration
Estimated Environmental Concentration
Environmental Protection Agency
Exposure Analysis Modeling System
End-Use Product
Food Commodity Intake Database
Food and Drug Administration
Federal Insecticide, Fungicide, and Rodenticide Act
Federal Food, Drug, and Cosmetic Act
Food Quality Protection Act
Functional Observation Battery
Granular Formulation
Tier I Surface Water Computer Model
Guideline Number
Highest Average Field Trial
Index Reservoir
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.
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.
Level of Concern
Limit of Detection
Lowest Observed Adverse Effect Level
Micrograms Per Gram
Micrograms Per Liter
Milligram Per Kilogram Per Day
Milligrams Per Liter
Margin of Exposure
Master Record Identification (number). EPA's system of recording and tracking studies
submitted.
Manufacturing-Use Product
Not Applicable
USGS National Water Quality Assessment
National Pollutant Discharge Elimination System
Not Required
No Observed Adverse Effect Level
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OP
OPP
OPPTS
PAD
PCA
PDF
PHED
PHI
ppb
PPE
ppm
PRZM/EXAMS
Qi*
RAC
RED
REI
RfD
RQ
SCI-GROW
SAP
SF
SLC
SLN
TGAI
TRR
USDA
USGS
UF
UV
WPS
Organophosphate
EPA Office of Pesticide Programs
EPA Office of Prevention, Pesticides and Toxic Substances
Population Adjusted Dose
Percent Crop Area
USDA Pesticide Data Program
Pesticide Handler's Exposure Data
Preharvest Interval
Parts Per Billion
Personal Protective Equipment
Parts Per Million
Tier II Surface Water Computer Model
The Carcinogenic Potential of a Compound, Quantified by the EP A's Cancer Risk Model
Raw Agriculture Commodity
Reregistration Eligibility Decision
Restricted Entry Interval
Reference Dose
Risk Quotient
Tier I Ground Water Computer Model
Science Advisory Panel
Safety Factor
Single Layer Clothing
Special Local Need (Registrations Under Section 24(c) of FIFRA)
Technical Grade Active Ingredient
Total Radioactive Residue
United States Department of Agriculture
United States Geological Survey
Uncertainty Factor
Ultraviolet
Worker Protection Standard
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Executive Summary
EPA has completed its review of public comments on the human health and environmental risk
assessments and is issuing its reregistration eligibility and tolerance reassessment decisions for
pyrethrins. There are currently 70 tolerances being reassessed for pyrethrins. EPA will accept public
comments on these decisions and the supporting documents for 60 days. The revised risk
assessments and response documents are based on comments submitted, information from the
Pyrethrin Joint Venture (PJV), and other information provided to EPA. After considering the risks
identified in the revised risk assessments, comments and mitigation suggestions, EPA developed its
risk management decision for uses of pyrethrins that posed risks of concern. As a result, the Agency
has determined pyrethrins-containing products are eligible for reregistration provided that risk
mitigation measures are adopted, and labels are amended accordingly.
Pyrethrins were first registered as an insecticide in the 1950's and are used to target many
different types of flying and crawling insects and arthropods. Pyrethrins are registered for use in
agricultural, residential, commercial, industrial, and public health sites. Approximately 200,000
pounds are sold every year, with about 90% being used in non-agricultural sites.
Overall Risk Summary
Dietary Risk (Food + Drinking Water)
Acute dietary (food and drinking water) risk does not exceed the Agency's level of concern
for the general U.S. population at 54% of the aPAD. The most highly exposed subpopulation,
children 1-2, is at the Agency's level of concern at 100% of the aPAD calculated. Three
commodities, pineapple, banana, and dried-oat baby food, were expected to contribute 71% of
total exposure to children 1-2. 100% crop treated values were used with all three of these
commodities; therefore, with any refinement in the percent crop treatment values or residue
levels, the estimated risk for all population subgroups including children 1-2 is expected to
decrease.
The chronic dietary (food and drinking water) risk is below the Agency's level of concern;
risk estimates are 11% cPAD for the general U.S. population, and 32% of the cPAD for children
1-2 years old, the most exposed subpopulation.
Residential
In the residential handler exposure assessment a number of scenarios were assessed to
estimate the exposure to homeowners handling products containing pyrethrins. From the results
of the residential handler assessment, there are no residential risks of concern when pyrethrins
are mixed, loaded, applied, or handled by homeowners.
A number of post-application residential scenarios were identified for adults and children
exposed to pyrethrins indirectly after application. Of these, three were potentially of concern: 1)
broadcast dust applications to carpets; 2) indoor metered release devices; and 3) outdoor
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residential misting systems. To address the potential risks associated with these post-application
scenarios, the PJV has agreed to limit dust application to carpets by allowing spot treatments
only and add label language and use restrictions to address potential by-stander risks from
products used in both metered release devices and outdoor residential misting systems. The PJV
has agreed to prohibit the use of metered release devices in residential indoor areas. Further, the
Agency will require confirmatory exposure and efficacy data for the outdoor misting systems.
FQPA
An FQPA safety factor of 3X for the lack of a developmental neurotoxicity study has been
retained for the acute dietary and the short-term incidental oral dietary and residential
assessments.
Aggregate Risks
Only short-term aggregate risk was calculated for pyrethrins because the oral and inhalation
endpoints were similar (neurotoxicity). Intermediate- and long-term studies show different
effects for oral and inhalation exposures, so an aggregate assessment is not appropriate.
Since the target MOEs for oral and inhalation exposures differ, the Agency uses an
aggregate risk index (ART) method to combine exposures. An ARI above 1 is not of concern.
The aggregate exposures for most sub-populations were well above the target Aggregate ARI
(ARIagg). The ARIagg for children of 0.96 is slightly below the target; however, it is considered
to be a high-end estimate because the calculated exposure values for food and water were high-
end estimates. For example, percent crop treated data were not available for all commodities,
and high-end field trial data were generally used. Thus, the actual risk is likely to be much
lower.
Cumulative
Pyrethrins are botanical insecticides that come from the pyrethrum flower,
Chrysanthemum cinerariaefolium. Pyrethrins have limitations because of the cost of production
and instability in sunlight; therefore, many synthetic pyrethrins-like compounds were developed
to be more stable in sunlight and cost effective. These compounds are referred to as synthetic
pyrethroids. Although all pyrethrins and pyrethroids alter nerve function by modifying the
normal biochemistry and physiology of nerve membrane sodium channels, EPA is not currently
following a cumulative risk approach based on a common mechanism of toxicity for these
chemicals. Although all pyrethroids interact with sodium channels, there are multiple types of
sodium channels and it is currently unknown whether the pyrethrins and pyrethroids have similar
effects on all channels. EPA does not have a clear understanding of effects on key downstream
neuronal function e.g., nerve excitability, nor does EPA understand how these key events interact
to produce their compound specific patterns of neurotoxicity. There is ongoing research by the
EPA's Office of Research and Development and the pyrethroid registrants to evaluate the
differential biochemical and physiological actions of pyrethroids in mammals. This research is
expected to be completed by 2007. When available, the Agency will consider this research and
make a determination of common mechanism as a basis for assessing cumulative risk.
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Occupational Risks
Of the scenarios assessed for handlers mixing, loading, and applying pyrethrins, three
scenarios were potentially of concern including: 1) mixing and loading wettable powders for
agricultural handlers and PCOs; 2) applying pyrethrins with handheld foggers indoors; and 3)
applying dusts through power duster equipment. To address these potential risks, the PJV has
agreed to repackage all wettable powder formulations into water soluble packages and require all
applicators fogging with handheld equipment indoors to wear a dust-mist (PF5) respirator.
Application of dust formulations with power dusters will be prohibited, due to the high potential
for exposure with this formulation and type of equipment.
There were potential post-application risks estimated for products used in metered release
devices which are commonly used in dairy barns and other sites. EPA believes that the potential
post-application risks are lower for people working in these settings than for residential settings
due to the fact that the occupational areas generally have a greater ventilation capacity. While it
is possible workers could be exposed to pyrethrins from these metered release devices, it is not
likely a worker would be exposed to the full daily amount for 30 or more days, as was assumed
in this assessment. The PJV has agreed to submit data to confirm the assumptions in the risk
assessment.
Ecological Risks
Aquatic Organisms
Risk to aquatic organisms can occur through exposure from agriculture, wide area
mosquito abatement, down-the-drain applications (such as pet shampoos), and other non-
agricultural (urban) use. Risks to aquatic organisms from agricultural applications appear to be
reduced if typical application rates, frequency and numbers of applications are considered.
There are possible risks from mosquito abatement applications to invertebrates and fish, which
can be addressed by establishing release heights, droplets size, and application rates on all
pyrethrins mosquito abatement product labels in accordance with PR Notice 2005-1. There are
no risks of concern predicted from down-the-drain use. Non-agricultural (urban) use was not
quantified in this assessment, but there is an on-going effort to develop a model and work with a
number of stakeholders in order to address this source of pesticide exposure in the near future.
Terrestrial Organisms
The Agency did not find acute or chronic risk for listed or non-listed mammals and birds.
There are risk concerns for honeybees that suggest there may also be non-target insect concerns.
Summary of Mitigation Measures
EPA has determined that the currently registered uses of pyrethrins are eligible for
reregi strati on provided the mitigation measures outlined in this document are implemented
through label amendments. Mitigation measures include:
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Residential
• Restrict carpet dust applications to spot treatments only.
• Prohibit use of products in metered release devices in residential areas and remove day-care
centers, nursing homes, schools and hospitals from product labels.
• Restrict use of outdoor residential misting systems by establishing a maximum use rate and
precautionary label statements.
Occupational
• Require all wettable powders to be repackaged in water soluble packages.
• Require all applicators using hand held foggers indoors to wear a dust-mist (PF5) respirator.
• Prohibit power dusters as an application method.
Ecological
• All agricultural product labels must be updated to specify the following application
information:
o No more than 10 applications per season.
o Do not reapply within 3 days, except under extreme pest pressure.
o In case of extreme pest pressure, do not reapply within 24 hours.
• All wide area mosquito abatement labels will be updated according to PR Notice 2005-1.
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I. Introduction
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was amended in 1988
to accelerate the reregistration of products with active ingredients registered prior to November
1, 1984. The amended Act calls for the development and submission of data to support the
reregistration of an active ingredient, as well as EPA review of all submitted data. 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 risks arising from the currently
registered uses of the pesticide, to determine the need for additional data on health and
environmental effects, and to determine whether or not the pesticide meets the "no unreasonable
adverse effects" criteria of FIFRA.
On August 3, 1996, the Food Quality Protection Act of 1996 (FQPA) was signed into
law. This Act amends FIFRA to require reassessment of all tolerances in effect on the day
before it was enacted. 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 among infants and children, and the cumulative effects of pesticides that
have a common mechanism of toxicity. When the Agency determines that aggregate risks are
not of concern and concludes that there is a reasonable certainty of no harm from aggregate
exposure, the tolerances are considered reassessed. EPA decided that, for those chemicals that
have tolerances and are undergoing reregistration, tolerance reassessment will be accomplished
through the reregistration process.
Pyrethrins are botanical insecticides that come from the pyrethrum flower,
Chrysanthemum cinerariaefolium. Pyrethrins have limitations because of the cost of production
and instability in sunlight; therefore, many synthetic pyrethrins-like compounds were developed
to be more stable in sunlight and cost effective. These compounds are referred to as synthetic
pyrethroids. Although all pyrethrins and pyrethroids alter nerve function by modifying the
normal biochemistry and physiology of nerve membrane sodium channels, EPA is not currently
following a cumulative risk approach based on a common mechanism of toxicity for these
chemicals. Although all pyrethroids interact with sodium channels, there are multiple types of
sodium channels and it is currently unknown whether the pyrethrins and pyrethroids have similar
effects on all channels. Nor do we have a clear understanding of effects on key downstream
neuronal function, e.g., nerve excitability, nor do we understand how these key events interact to
produce their compound specific patterns of neurotoxicity. There is ongoing research by EPA's
Office of Research and Development and the pyrethroid registrants to evaluate the differential
biochemical and physiological actions of pyrethroids in mammals. This research is expected to
be completed by 2007. When available, the Agency will consider this research and make a
determination of common mechanism as a basis for assessing cumulative risk. For information
regarding EPA's procedures for cumulating effects from substances found to have a common
mechanism on EPA's website at http://www.epa.gov/pesticides/cumulative/.
This document addresses the tolerance reassessment and reregistration eligibility
decisions for all the currently registered use of pyrethrins. The Agency also considers potential
modification of the toxicity of a chemical due to the presence of other chemicals when
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information is available which suggests that this could be of concern, as with the pyrethrins.
pyrethrins are often formulated with synergists to extend the insecticidal effects. EPA
considered the possibility for increased toxicity due to the presence of synergists, such as MGK-
264 and piperonyl butoxide, in pyrethrins formulations. In order for synergistic effects to be
observed in humans, the synergist must be absorbed at levels sufficient to affect mixed function
oxidase enzymes. It is unlikely that these levels would occur based on the registered uses of
pyrethrins. Therefore, risk quantification related to pyrethrins toxicity considered only
pyrethrins. Separate risk assessments were completed that considered the specific toxic effects
of the synergists piperonyl butoxide and MGK-264.
The Agency made its reregi strati on eligibility determination based on the required data,
the current guidelines for conducting acceptable studies to generate such data, and published
scientific literature. The Agency has found that currently registered uses of pyrethrins, except
dust applications with power dusters, are eligible for reregi strati on provided the mitigation and
labeling outlined in the RED are implemented. The document consists of six sections: Section I,
the introduction, contains the regulatory framework for reregi strati on/tolerance reassessment;
Section II provides an overview of the chemical, including a profile of its use and usage; Section
III gives an overview of the human health and environmental effects risk assessments; Section
IV presents the Agency's reregi strati on eligibility, tolerance reassessment, and risk management
decisions; Section V summarizes label changes necessary to implement the risk mitigation
measures outlined in Section IV; and Section VI includes the appendices, related supporting
documents and Data Call-In (DCI) information. The revised risk assessment documents and
related addenda are not included in this document, but are available on the Agency's web page
http://www.epa.gov/pesticides, and in the Public Docket under docket number EPA-HQ-OPP-
2005-0043.
II. Chemical Overview
A. Regulatory History
Pyrethrins were first registered in the United States for use as an insecticide in the 1950s.
Currently there are approximately 1,350 end-use products containing pyrethrins for use on
agricultural, commercial, residential, and public health areas. There are 70 tolerances for
pyrethrins listed in the Code of Federal Regulations. The reregi strati on of the pyrethrins is being
supported by the Pyrethrin Joint Venture whose members include: Botanical Resources
Australia, S.C. Johnson & Sons, Inc., McLaughlin Gormely King Co., Prentiss Incorporated,
Pyrethrin Board of Kenya, Societe du Pyrethre au Rwanda, Tanzania Pyrethrum Processing and
Marketing Co., and Valent BioSciences Corporation.
A Phase IV Data Call-In was issued for the pyrethrins in May of 1991. This DCI
required environmental fate and residue chemistry data. An agricultural reentry DCI was issued
in October of 1995.
Pyrethrins are in reregi strati on case 2580. This reregi stration case contains three active
ingredients as described in Table 1 below. The last products for pyrethrum powder other than
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pyrethrins and pyrethrin coils were cancelled in 1991; therefore, this RED does not consider
potential risks associated with those two active ingredients.
Table 1: Ingredients in the Pyrethrin and Derivatives Chemical Case (2580)
PC Code
069001
069002
069004
Chemical Name
Pyrethrins
Pyrethrum powder other than
pyrethrins
Pyrethrin coils
CAS Number
8003-34-7
8003-34-7
Not assigned
Status
Agricultural, commercial, residential,
and public health uses being
reregistered in this document.
Last product cancelled in 1991.
Last product cancelled in 1991.
This Reregi strati on Eligibility Decision document evaluates risks from all currently
registered uses of pyrethrins.
B.
Chemical Identification
Throughout this document the term "pyrethrins" refers to all six isomers found in
pyrethrum, extracts which are obtained from the dried and ground flowers of the pyrethrum
plant, Chrysanthemum cinerariaefolium. The CAS Registry No. for the mixture is 8003-34-7.
The individual isomers are referred to by the common names of the acid followed by an Arabic
number 1 or 2 (i.e., pyrethrin 1, pyrethrin 2, cinerin 1, cinerin 2, jasmolin 1, jasmolin 2). If the
term pyrethrins is followed by a roman numerical designation, than it refers to all of the isomers
of that number in the pyrethrum extract (e.g., pyrethrins I includes pyrethrin 1, cinerin 1, and
jasmolin 1). See Table 2 for a summary of terms.
Table 2: Pyrethrins Terms
Pyrethrum
Pyrethrins
Pyrethrins I
Plant extract from Chrysanthemum cinerarieaefolium,
containing all 6 isomers
pyrethrin 1, pyrethrin 2, cinerin 1, cinerin 2, jasmolin 1,
jasmolin 2
pyrethrin 1, cinerin 1, and jasmolin 1
Currently, food/feed uses are only registered for products under PC code 069001, mixed
esters of (+)-trans-chrysanthemic acid and (+)-pyrethroic acid. The nomenclature of the
individual pyrethrins active ingredients is presented below in Table 3. The physicochemical
properties of the refined pyrethrin extracts (TGAI) are listed in Table 4.
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Table 3: Pyrethrins Nomenclature
Chemical Structure
0
il R2 Pyrethrin I: Rl = CH 3; R2 = CH 2CH=CHCH=CH2
R Pi f If Pyrethrin II: Rl = COOCH 3; R2 = CH 2CH=CHCH=CH2
3 \ r^«««« T. D i mj • DO nu mj mj
H3C-"\~/ ° CH3 Cinerin II: Rl = COOCH 3; R2 = CH 2CH=CH3
V 3 Jasmolinl: Rl = CH 3; R2 = CH 2CH=CHCHCH3
1 Jasmolin II: Rl = COOCH 3; R2 = CH 2CH=CHCHCH3
HsC^x^
Rl
Common name
Molecular Formula
Molecular Weight
IUPAC name
CAS name
CAS#
Common name
Molecular Formula
Molecular Weight
IUPAC name
CAS name
CAS#
Common name
Molecular Formula
Molecular Weight
IUPAC name
CAS name
CAS#
Common name
Molecular Formula
Molecular Weight
IUPAC name
pyrethrin 1
C21H2803
328.4
(Z)-(S)-2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2-enyl(lR,3R)-2,2-
dimethyl-3-(2-methylprop-l-enyl)cyclopropanecarboxylate
(lS)-2-methy l-4-oxo-3 -(2Z)-2,4-pentadieny Icy clopenten-l-yl( lR,3R)-2,2-
dimethyl-3 -(2 -methyl- 1 -propenyl)cyclopropanecarboxylate
121-21-1
pyrethrin 2
C22H2805
372.4
(Z)-(S)-2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2-enyl(E)-(lR,3R)-3-(2-
methoxycarbonylprop- 1 -enyl)-2,2-dimethy Icy clopropane-carboxy late
(lS)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienyl-2-cyclopenten-l-yl(lR,3R)-3-[(lE)-
3-methoxy-2-methyl-3 -oxo- 1 -propenyl] -2,2-dimethy Icy clo-propanecarboxy late
121-29-9
cinerin 1
C20H2803
316.4
(Z)-(S)-3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl(lR,3R)-2,2-dimethyl-3-
(2-methy Iprop- 1 -eny l)cy clopropanecarboxy late
(lS)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-l-yl(lR,3R)-2,2-dimethyl-
3 -(2 -methyl- 1 -propenyl)cy clopropanecarboxy late
25402-06-6
cinerin 2
C21H2805
360.4
(Z)-(S)-3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl(E)-(lR,3R)-3-(2-
methoxycarbonylprop- 1 -eny 1) -2,2-dimethy Icy clopropanecarboxy late
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Table 3: Pyrethrins Nomenclature
CAS name
CAS#
Common name
Molecular Formula
Molecular Weight
IUPAC name
CAS name
CAS#
Common name
Molecular Formula
Molecular Weight
IUPAC name
CAS name
CAS#
(lS)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-l-yl(lR,3R)-3-[(lE)-3-
methoxy-2-methyl-3-oxo-l-propenyl]-2,2-dimethylcyclopropanecarboxylate
121-20-0
jasmolin 1
C2lH3oO3
328.4
(Z)-(S)-2-methyl-4-oxo-3-(pent-2-enyl)cyclopent-2-enyl(lR,3R)-2,2-dimethyl-3-
(2-methy Iprop- 1 -eny l)cy clopropanecarboxy late
(lS)-2-methy l-4-oxo-3 -(2Z)-2-penteny 1-2 -cyclopenten-1 -yl( lR,3R)-2,2-dimethyl-
3 -(2 -methyl- 1 -propenyl)cy clopropanecarboxy late
4466-14-2
jasmolin 2
C22H3o05
374.4
(Z)-(S)-2-methyl-4-oxo-3-(pent-2-enyl)cyclopent-2-enyl(E)-(lR,3R)-3-(2-
methoxycarbonylprop- 1 -eny l)-2,2-dimethy Icy clopropanecarboxy late
(lS)-2-methy l-4-oxo-3 -(2Z)-2-penteny 1-2-cyclopenten- l-yl( !R,3R)-3-[(lE)-3 -
methoxy-2-methyl-3-oxo-l-propenyl]-2,2-dimethylcyclopropanecarboxylate
1172-63-0
Table 4: Physicochemical Properties of Refined Pyrethrins (TGAI)
Parameter
Boiling point
pH
Density, bulk density, or
specific gravity
Water solubility
Solvent solubility
Vapor pressure
Dissociation constant, pKa
Octanol/water partition
coefficient
Value
pyrethrin 1 = 146-148 EC at 2 x 10'3 Torr
pyrethrin 2 = 196-198 EC at 7 x 10"3 Torr
cinerin 1 = 136-138 EC at 8 x 10"3 Torr
cinerin 2 = 182-184 EC at 1 x 10"3 Torr
Not applicable because the TGAI is practically insoluble in water.
0.982 g/mL at 20 EC
pyrethrin 1 = 1.5242 g/mL
pyrethrin 2 = 1.5355 g/mL
<10 ppm
pyrethrin 1 = 0.00002 g/100 mL at 20 EC
pyrethrin 2 = 0.00090 g/100 mL at 20 EC
Completely soluble in nonpolar organic solvents; <0.1% in ethylene glycol
Soluble in alcohol, petroleum ether, and methylene chloride
pyrethrin 1 = 2 x 10"5 mm Hg at 25 EC
pyrethrin 2 = 4 x 10"7 mm Hg at 25 EC
Not applicable because pyrethrins do not dissociate
pyrethrin 1 = 5.90 pKow at 25 EC
pyrethrin 2 = 4.30 pKow at 25 EC
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c.
Use Profile
Pyrethrins are botanical insecticides that come in many chemical forms and are found in
numerous end-use products intended for a wide range of use patterns. Pyrethrins are an
ingredient in approximately 1,350 agricultural, commercial, residential, and public health use
products, as a sole active ingredient and in conjunction with other active ingredients. A Master
Label includes a list of all uses supported by the Pyrethrin Joint Venture. A copy of the Master
Label is available at http://www.epa.gov/oppsrrdl/reregistration/pvrethrins/ucm.pdf. The following is
information on the currently registered uses including an overview of use sites and application
methods. A detailed table of the uses of pyrethrins eligible for reregi strati on is contained in the
Pyrethrins Residue Chemistry Chapter (Deluzio, J. and Olinger, C., September 8, 2005) and
shows there are at least 19 crop groups and several miscellaneous commodities being supported
for reregi strati on.
1. Pyrethrins Use Profile
Type of Pesticide:
Summary of Use:
Target Organisms:
Mode of Action:
Tolerances:
Insecticide
Pyrethrins are botanical insecticides. The six individual pyrethrins are
pyrethrin 1, pyrethrin 2, cinerin 1, cinerin 2, jasmolin 1, and jasmolin 2.
Pyrethrins are used in these four general ways: (i) pre-harvest and post-
harvest uses on many agricultural crops; (ii) direct and indirect treatments
of livestock animals and premises; (iii) treatments of commercial and
industrial facilities and storage areas where raw and processed food/feed
commodities are stored or processed; and (iv) wide area mosquito
abatement use in areas which include aquatic areas.
Pyrethrins are used to kill many different types of flying and crawling
insects and arthropods including various types of ants, worms, beetles,
mites, flies, gnats, spiders, weevils, caterpillars, grubs, moths, ticks, lice,
wasps, aphids, midges, and others.
Pyrethrins target the central and peripheral nervous systems in vertebrates
and invertebrates where they disrupt the signal transmission along the
nerve axon. Pyrethrins bind to the sodium channel causing it to remain
open, whereby the nerve continues to be stimulated uncontrollably causing
tremors. This condition results in rapid knock down and muscular
paralysis in target organism resulting in death. Pyrethrins enter the target
organism via ingestion and physical contact.
There are 70 tolerances (40 CFR §180.128 and §180.905) being assessed
for pyrethrins in/on: (i) plant commodities resulting from post-harvest
uses; (ii) animal commodities; and (iii) food/feed items while in storage
areas.
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Use Classification: General Use
Formulation Types: Aerosol, liquid, ready-to-use solution, dust, wettable powder,
microencapsulate, impregnated material, pressurized gas, pressurized
liquid, pressurized spray, combustible coil, micro-emulsion, dilutable
concentrate, shampoo, towelette, pour-on (spot-on), and water-based
concentrate. Pyrethrins are usually formulated with synergists, such as
piperonyl butoxide and MGK-264, which lack pesticidal effects of their
own, but enhance the pesticidal properties of other chemicals.
Application Methods: Aerosol can, mist blower, metered release devices, total release aerosol,
fixed wing aircraft, helicopter, truck-mounted ultra low volume (ULV)
equipment, cold aerosol generator, hand held sprayers (high or low
pressure handwands), thermal/cold/ULV fogging equipment, conventional
dusting equipment (e.g., power duster, bulb duster, shaker can), outdoor
misting systems, and irrigation systems.
Application Rates: Pyrethrum extracts, used for formulating the final product, contains 20-
25% total pyrethrins, the main active constituents being pyrethrin 1 and
pyrethrin 2, plus smaller amounts of the related cinerins and jasmolins.
Formulated products generally contain 0.25 - 0.50 % active ingredient.
Usage of Pyrethrins: Approximately 200,000 Ibs of pyrethrins are sold every year.
Approximately 9% of the total amount of pyrethrins applied is used on
agricultural commodities. Other sites where pyrethrins are applied
include: 40% on indoor food areas (e.g. farm premises, food processing,
dairies), 35% on indoor residential settings (e.g. pets, household domestic
dwellings), 10% on indoor non-food areas (e.g. commercial, institutional
industrial premises), and 6% on terrestrial non-food areas (e.g. show
animals, turf, recreational areas).
III. Summary of Pyrethrins Risk Assessments
The following is a summary of EPA's human health and ecological risk findings and
conclusions for pyrethrins, as presented fully in the Health Effects Division document,
Pyrethrins: Revised Human Health Risk Assessment for the Reregistration Eligibility Decision.,
(Olinger, March 16, 2006), and the Environmental Fate and Effects Division document, Revised
Pyrethrins RED Chapter After Additional 60-Day Comment Period, Phase 5, (Rexrode, February
16, 2006).
The purpose of this section is to summarize the key features and findings of the risk
assessment in order to help the reader better understand the risk management decisions reached
by the Agency. While the risk assessments and related addenda are not included in this
document, they are available in the public docket EPA-HQ-OPP-2005-0043, that can be accessed
through the website, www.regulations.gov.
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A.
Human Health Risk Assessment
The Agency has conducted a human health risk assessment for pyrethrins for the
purposes of making a reregi strati on eligibility decision. The Agency evaluated the toxicology,
product and residue chemistry, and occupational/residential exposure studies submitted and
determined that the data are adequate to support a reregi strati on decision. Details of the risk
assessments and separate supporting disciplinary documents are available in the electronic
docket. A summary of the human health risk assessment findings and conclusions is provided
below.
Although toxicity studies on degradates were not provided, an evaluation of the structures
indicate that they are the result of the rupture of the ester bridge of the parent, resulting in a
carboxylic acid (chrysanthemic acid), and an alcohol (that subsequently is degraded to an acid as
well). The resulting molecules do not have neurotoxic activity; therefore, they were not
considered in the human health assessment.
1. Toxicity Profile
The toxicological database is adequate to support the reregi strati on of pyrethrins. Data
are sufficient for all exposure scenarios and for FQPA evaluation. A developmental
neurotoxicity study and a comparative thyroid study are required to further characterize effects
observed in the pyrethrins toxicity database.
Acute Toxicity Profile
Pyrethrins have low to moderate acute toxicity via the oral, dermal, and inhalation routes
(Category III and IV). They are a moderate eye irritant (Category III), a mild dermal irritant
(Category IV), and not a skin sensitizer. See Table 5 below.
Table 5: Acute Toxicity Profile - Pyrethrins
Guideline
No.
870.1100
870.1200
870.1300
870.2400
Study Type
Acute oral [rat]
Acute dermal [rabbit]
Acute inhalation [rat]
Acute eye irritation
[rabbit]
MRID
42008101
41964801
42008002
41964802
Results
LD50=1.40g/kg
LD50 = 2.14g/kg(males)
LD50 = 0.70 g/kg (females)
LD50 >2000 mg/kg
LC50 = 3.4mg/L
LC50 = 3.9mg/L(males)
LC50 = 2.5 mg/L (females) tremors
Produced conjunctional irritation in treated
eyes of all 6 exposed rabbits; no
conjunctional irritation observed in any eye
by 72 -hour reading.
No corneal opacity or inflammation of the
iris.
Toxicity Category
III
III
IV
III
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Table 5: Acute Toxicity Profile - Pyrethrins
Guideline
No.
870.2500
870.2600
Study Type
Acute dermal irritation
Dermal sensitization
MRID
41964803
41964804
Results
Mild or slight skin irritant over 72 hours
Not a dermal sensitizer
Toxicity Category
IV
negative
Toxic Effects
The critical toxicological effects of pyrethrins are (1) neurobehavioral effects (tremors,
labored breathing, hyperactivity, secretory signs, matted coats), following acute, short-term, and
chronic exposure, with nervous system lesions observed in the rat and mouse following acute
exposure; (2) thyroid effects, following chronic exposure in the rat and dog; and (3) liver effects,
following short- and long-term exposure in the rat, dog, and mouse. Following inhalation
exposure, neurobehavioral effects were observed initially, and respiratory tract lesions were
observed at all dose levels. The neurobehavioral effects and the mode of action on the sodium
channel are considered relevant to humans because the effects are observed in both the rat and
mouse, and the mode of action affects a basic function of the nervous system that is common to
all animals.
Toxic Mixtures Effects
EPA considered the possibility for increased toxicity due to the presence of synergists
such as MGK-264 and piperonyl butoxide in pyrethrins formulations. In order for synergistic
effects to be observed in humans, absorbed doses high enough to significantly affect the mixed
function oxidase enzymes would be required. It is unlikely that these levels would occur based
on the registered uses of pyrethrins. Therefore, risk quantification considered only the toxicity of
the predominant ingredient in the pyrethrins product. Separate risk assessments were completed
that considered the specific toxic effects of the synergists, piperonyl butoxide and MGK-264,
that are different from those of the pyrethrins.
Neurotoxicity
There is a concern for neurotoxicity resulting from exposure to pyrethrins, based on (1)
tremors in female rats, decreased motor activity in male rats, and neuropathology in both sexes in
a rat acute neurotoxicity study; (2) clinical signs (excessive salivation and head arched
backward) in a female rabbit following exposure during gestation; and (3) tremors in female rats
in a subchronic inhalation study. In the range-finding developmental toxicity studies in rats and
rabbits, tremors/convulsions were observed in those that died during the study. In the mouse 90-
day range-finding study, tremors and increased/decreased activity were observed at dose levels
that also resulted in mortality. As stated previously, pyrethrins are axonic poisons.
Cancer
Pyrethrins are classified as "Suggestive Evidence of Carcinogenicity, but Not Sufficient
to Assess Human Carcinogenic Potential," based on the weight-of-the-evidence including (i) the
occurrence of benign liver tumors in female rats, (ii) no treatment-related increase in liver tumors
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in male rats, (iii) no treatment-related increase in tumors in either sex of mice, and (iv) no
concern for mutagenicity. Therefore, no quantification of cancer risk is required.
Toxicity Endpoints
The toxicological endpoints used in the human health risk assessment for pyrethrins are
listed in Table 6. The uncertainty and safety factors used to account for interspecies
extrapolation, intraspecies variability, and for completeness of the data with respect to exposure
and toxicity to infants and children (FQPA Safety Factor) are also described in the table below.
Table 6: Toxicological Endpoints and Doses Used in the Pyrethrins Risk Assessments
Exposure
Scenario
Doses, Uncertainty
Factors (UFs), and Safety
Factors (SF)
Level of Concern:
Population Adjusted Dose (PAD)
or Target Margin of Exposure
(MOE)
Study and Toxicological Effects
Acute Dietary
(General population
including infants and
children)
NOAEL = 20 mg/kg/day
UF = 100
FQPA SF = 3X (based on
database uncertainties)
Total UF = 300
aPAD = 0.07 mg/kg/day
Rat acute neurotoxicity study
LOAEL = 63 mg/kg/day based on tremors in
females
(MRID: 42925801)
Chronic Dietary
(All populations)
NOAEL= 4.37 mg/kg/day
UF=100
FQPA SF = IX
Total UF = 100
cPAD = 0.044 mg/kg/day
Rat chronic toxicity study
LOAEL = 42.9 mg/kg/day based on increased
incidence of thyroid follicular cell hyperplasia
in males
(MRID: 41559501)
Short-Term
Incidental Oral (1-30
days)
NOAEL= 20 mg/kg/day
UF=100
FQPA SF = 3X (based on
database uncertainties)
Total UF = 300
Residential LOG for MOE =300
Occupational = NA
Rat acute neurotoxicity study
LOAEL = 63 mg/kg/day based on tremors in
females
(MRID: 42925801)
Intermediate-Term
Incidental Oral (1-6
months)
NOAEL = 6.4 mg/kg/day
UF=100
FQPA SF = IX
Total UF = 100
Residential LOG for MOE = 100
Occupational = NA
2-generation rat reproduction study
LOAEL = 65 mg/kg/day based on decreased
Fib pup body weight/body-weight gain
during lactation
(MRID: 41327501)
Short-Term Inhalation
(1 to 30 days)
NOAEL= 0.03 mL/kg/day
(7.67 mg/kg/day)
UF=100
FQPA SF = IX
Total UF = 100
Residential LOG for MOE = 100
Occupational LOG for MOE = 100
Rat subchronic inhalation toxicity study
LOAEL = 25.56 mg/kg/day based on tremors,
labored breathing, hyperactivity, secretory
signs, matted coat, decreased body
weight/body-weight gain
(MRID: 42478201)
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Table 6: Toxicological Endpoints and Doses Used in the Pyrethrins Risk Assessments
Exposure
Scenario
Intermediate-Term
Inhalation (1 to 6
months);
Long-Term Inhalation
(>6 months)
Dermal Exposure
Cancer (oral, dermal,
inhalation)
Doses, Uncertainty
Factors (UFs), and Safety
Factors (SF)
LOAEL = 0.01 mL/kg/day
(2.56mg/kg/day)
LTF=100
FQPA SF = IX
LackofNOAEL = 10X
Total LTF = 1000
Level of Concern:
Population Adjusted Dose (PAD)
or Target Margin of Exposure
(MOE)
Residential LOC for MOE = 1000
Occupational LOC for MOE = 1000
Study and Toxicological Effects
Rat subchronic inhalation toxicity
LOAEL = 2.56 mg/kg/day based on
respiratory tract lesions
(MRID: 42478201)
Dermal risk assessments are not required since no endpoint was identified following repeated [21 days] dermal
exposure to rabbits at the limit dose of 1000 mg/kg/day. (MRID: 42212601)
Classification: "Suggestive Evidence of Carcinogenicity , but Not Sufficient to Assess Human Carcinogenic
Potential"
NOAEL = no observed adverse effect level, LOAEL = lowest observed adverse effect level, PAD = population
adjusted dose (a = acute, c = chronic), RfD = reference dose, MOE = margin of exposure, LOC = level of concern,
NA = Not Applicable
2. FQPA Safety and Uncertainty Factors
The Food Quality Protection Act (FQPA) directs the Agency, in setting pesticide
tolerances, to use an additional tenfold (10X) margin of safety to take into account potential pre-
and postnatal toxicity and completeness of the data with respect to exposure and toxicity to
infants and children. FQPA authorizes EPA to modify this tenfold safety factor only if reliable
data demonstrate that the resulting level of exposure will be safe for infants and children.
No evidence of increased susceptibility of rats or rabbits to pyrethrins was seen in
developmental toxicity studies. Although there was evidence of increased quantitative
susceptibility following in utero and/or pre-/postnatal exposure in the 2-generation reproduction
study in rats, the reproductive/offspring toxicity NOAELs and LOAELs were well characterized
and were used as endpoints for risk assessment for the appropriate population subgroups. There
were no residual uncertainties in the existing data for pyrethrins that indicate the need for a
special FQPA safety factor (SF). However, because the pyrethrins database does not include a
developmental neurotoxicity study (DNT), and there is a concern for neurotoxicity resulting
from exposure to pyrethrins, EPA has retained a 3X FQPA factor for certain scenarios. The
magnitude of 3 is based on a comparison of the lowest dose in the reproduction study to the
doses selected for risk assessment.
A dose analysis was conducted in order to determine the need for and size of an
uncertainty factor in the absence of a DNT for pyrethrins. Based on the dose analysis, the
NOAEL determined in the DNT could be up to 3X lower than the NOAEL that EPA has selected
to assess acute dietary and short-term incidental oral risks. However, it is unlikely that the
NOAEL determined in the DNT would be lower than the doses EPA has selected to assess
chronic dietary, incidental oral, and inhalation risks. Therefore, EPA has retained a 3X FQPA
SF to account for database uncertainties for acute dietary risk and short-term incidental oral risk
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assessment, but has reduced the FQPA SF to IX for the other scenarios. Note that because a
NOAEL was not determined in the study EPA has used for intermediate- and long-term
inhalation risk assessment, EPA has applied a 10X factor to those assessments to account for the
lack of a NOAEL.
3. Endocrine disruption
There is evidence that pyrethrins are associated with endocrine disruption. Direct
measurements of serum thyroid hormones [T3, T4, and TSH], as well as histopathological
alterations in the thyroid indicate there is concern regarding the potential for endocrine
disruption. However, the FQPA SF of 3X due to lack of a DNT study is considered adequately
protective for thyroid effects in the young because thyroid finding in the adult animal occur at
high dose levels. Therefore, the pyrethrins risk assessments are adequately protective of
potential thyroid effects in young and adult populations.
EPA is required under the FFDCA, as amended by FQPA, to develop a screening
program to determine whether certain substances (including all pesticide active and other
ingredients) "may have an effect in humans that is similar to an effect produced by a naturally
occurring estrogen, or other such endocrine effects as the Administrator may designate."
Following recommendations of its Endocrine Disrupter and Testing Advisory Committee
(EDSTAC), EPA determined that there was a 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 additional appropriate screening and/or testing protocols
being considered under the Agency's EDSP have been developed, pyrethrins may be subjected to
further screening and/or testing to better characterize effects related to endocrine disruption.
4. Drinking Water
For more detail on the drinking water assessment, see the Tier 1 Estimated Drinking Water
Concentrations of Pyrethrins and Derivatives for use in Human Health Risk Assessment, (Dutta,
August 19, 2004).
Drinking water exposure to pesticides can occur through ground and surface water
contamination. EPA considers both acute (one-day) and chronic (lifetime) drinking water risks
and uses either modeling or actual monitoring data, if available, to estimate those risks. The
drinking water exposure assessment was performed using the environmental fate characteristics
of a representative chemical, pyrethrin 1, for which the environmental fate database was
developed. All other pyrethrins are expected to have similar environmental fate characteristics;
therefore, the Estimated Drinking Water Concentrations (EDWCs) are considered suitable
representative values for all the pyrethrins. The EDWC values generally represent upper-bound
estimates of the concentrations that might be found in surface water and groundwater due to the
use of pyrethrins on multiple crops. The mosquito adulticide uses of the pyrethrins were not
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considered in this drinking water assessment because the agricultural use, which was simulated
in the model, had higher application rates and will result in more conservative EDWCs.
Surface Water - Tier 1 EDWCs in surface water were modeled using the FIFRA Index Reservoir
Screening Tool (FIRST). The Agency estimated an acute surface water concentration of 4.08
ppb and a chronic surface water concentration of 0.21 ppb based on 10 applications at the
agricultural use rate from the Pyrethrins Master Label of 0.05 Ib a.i./acre for all growing crops
and assumed a re-application interval of 1 day, since none was specified.
Ground Water - Tier I EDWCs for ground water were modeled using the Screening
Concentration In Ground Water (SCI-GROW) model. The Agency estimated a concentration of
0.003 ppb in ground water, based on a maximum seasonal application rate of 0.5 Ibs a.i./acre per
year, a mean soil half-life of 3.2 days and a Koc of 12,400 mL/g pyrethrins.
5. Dietary Risk (Food + Water)
Dietary risk assessment incorporates both exposure to and toxicity of a given pesticide.
Dietary risk is expressed as a percentage of a level of concern. The level of concern is the dose
predicted to result in no unreasonable adverse health effects to any human population subgroup,
including sensitive members of such population subgroups. This level of concern is referred to
as the population adjusted dose (PAD), which reflects the reference dose (RfD), either acute or
chronic, adjusted to account for the FQPA safety factor. Estimated risks that are less than 100%
of the PAD are below EPA's level of concern.
Both acute and chronic dietary (food + water) risk assessments were conducted using the
Dietary Exposure Evaluation Model software with the Food Commodity Intake Database
(DEEM-FCID™, Version 2.03), which uses food consumption data from the USDA's
Continuing Surveys of Food Intakes by Individuals (CSFII) from 1994-1996 and 1998. For
residue in food, the acute and chronic dietary exposure and risk analysis was conducted using
current tolerance values, Codex Maximum Residue Limits (MRLs), field trial data, and data
translated from other crops. DEEM 7.81 processing factors were used in this assessment. An
upper bound estimate for the drinking water concentration was used in the dietary exposure
assessment since no monitoring data were available.
Acute
The acute dietary assessment incorporates both exposure to and toxicity of pyrethrins
considering what is consumed in one day and maximum or high-end residue values in food and
water. The acute Population Adjusted Dose (aPAD) is the dose an individual could be exposed
to in one day and no adverse health effects would be expected.
The aPAD was based on tremors in female rats, as seen at the lowest observed adverse
effect level (LOAEL) of 63 mg/kg/day in an acute neurotoxicity study in rats. The no observed
adverse effect level (NOAEL) was 20 mg/kg/day. An uncertainty factor of 300 (10X for inter-
species extrapolation, 10X for intra-species variation, and 3X FQPA database uncertainty due to
lack of a DNT) was applied to the NOAEL.
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The aPAD was calculated as 20 mg/kg/day + 300 = 0.07 mg/kg/day. Risk is expressed as
a percentage of the aPAD. A risk estimate less than 100% of the aPAD does not exceed the
Agency's level of concern
Dietary risk estimates were calculated for the general U.S. population and various
population subgroups. Pyrethrins acute dietary risk estimates (food + water) for the U.S.
population (54% of the aPAD) and for the most highly exposed population subgroup, children 1-
2 years of age (100% of the aPAD), were at or below the Agency's level of concern as shown in
Table 7. The highest contributors to estimated exposures were pineapple, dried-oat baby food,
and banana (71% of total exposure). EPA assumed 100 percent crop treated in the assessment
for each of these commodities. The acute dietary assessment could be further refined with
additional residue data reflecting pre-harvest uses and additional percent crop treated
information.
Chronic
A somewhat refined assessment was conducted to assess the chronic dietary exposure to
pyrethrins. Current tolerances, field trial data, translated data, default processing factors, percent
crop treated (%CT), and an upper bound point estimate for the chronic drinking water
concentration were used. The HAFT (highest average field trial) of 0.23 ppm from a spray food
handling study was used for all food-handling establishment uses of pyrethrins. The chronic
Population Adjusted Dose (cPAD) is the dose at which an individual could be exposed over the
course of a lifetime and no adverse health effects would be expected
The cPAD was based on increase thyroid follicular cell hyperplasia in male rats as seen at
the lowest observed adverse effect level (LOAEL) of 42.9 mg/kg/day from a rat chronic toxicity
study. The no observed adverse effect level (NOAEL) was 4.37 mg/kg/day. An uncertainty
factor of 100 (1 OX for inter-species extrapolation, 10X for intra-species variation, and IX
FQPA) was applied to the NOAEL.
The cPAD was calculated as 4.37 mg/kg/day + 100 = 0.044 mg/kg/day. Risk is
expressed as a percentage of the cPAD. A risk estimate less than 100% of the cPAD does not
exceed the Agency's level of concern.
Chronic dietary risk estimates were calculated for the general U.S. population and various
population subgroups. Pyrethrins chronic dietary risk estimates (food + water) for the U.S.
population (11% of the cPAD) and for the most highly exposed population subgroup, children 1-
2 years of age (32% of the cPAD), are below the Agency's level of concern.
Table 7: Summary of Dietary Exposure and Risk for Pyrethrins
Population Subgroup
General U.S. Population
Acute Dietary
(99.9th Percentile)
aPAD,
mg/kg/day
0.07
Exposure,
mg/kg/day
0.038
% aPAD
54
Chronic Dietary
cPAD,
mg/kg/day
0.04
Exposure,
mg/kg/day
0.0044
% cPAD
11
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Table 7: Summary of Dietary Exposure and Risk for Pyrethrins
Population Subgroup
All Infants (< 1 yr)
Children 1-2 yrs
Children 3 -5 yrs
Children 6-12 yrs
Youth 13-19 yrs
Adults 20-49 yrs
Adults 50+ yrs
Females 13-49 yrs
Acute Dietary
(99.9th Percentile)
aPAD,
mg/kg/day
0.07
0.07
0.07
0.07
0.07
0.07
0.07
0.07
Exposure,
mg/kg/day
0.068
0.070
0.051
0.034
0.025
0.031
0.019
0.027
% aPAD
97
100
73
49
35
43
27
38
Chronic Dietary
cPAD,
mg/kg/day
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
Exposure,
mg/kg/day
0.0088
0.013
0.011
0.0068
0.0036
0.0035
0.0031
0.0031
% cPAD
22
32
27
17
9
9
8
8
The values for the population with the highest risk for the acute and chronic assessments are bolded.
In the dietary assessment, previously established tolerances were used for many of the
food commodities that were lacking residue data. For all other commodities in the assessment,
data were translated from either residue data or other tolerances values. No monitoring data
were available. Default processing factors were used because there were limited processing data
available. 100% crop treated was used as a default on more than half of crops due to lack of
data. Both, the presence of processing factors and percent crop treated could impact the
assessment greatly.
Estimated drinking water concentrations, which were included in the dietary assessment,
represents the upper-bound estimated concentrations that might be found in surface water and
groundwater due to the use of pyrethrins on multiple crops. This use of upper-bound estimates
for drinking water is a conservative approach. When combining high-end food and water
estimates, modeling results are higher than what is expected under actual conditions.
6. Residential Exposure and Risk
For more detail on the residential exposure and risk assessment, see the Pyrethrins: 2nd Revised
Occupational and Residential Exposure Assessment and Recommendations for the
Reregistration Eligibility Decision, (Dole, September 7, 2005), and for more detail on the
residential outdoor misting system assessment, see the Occupational and Residential Exposure
Assessment for the Use ofPyrethrin in Residential Mosquito Mister Systems., (Dole, September 7,
2005).
Based on the Pyrethrins' Master Label, ten residential exposure scenarios have been
assessed for this RED. Only inhalation and incidental oral ingestion exposure assessments have
been conducted for the residential scenarios. Dermal exposures were not assessed because no
dose or endpoints were identified for dermal risk; therefore, toxicity from dermal exposure is not
expected. Short term inhalation exposures are assessed for all handler and post-application
exposure scenarios.
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Non-cancer risk estimates are expressed as a margin of exposure (MOE) which is a ratio
of the dose from a toxicological study selected for risk assessment, typically a NOAEL, to the
predicted exposure. Estimated MOEs are compared to a level of concern which reflects the dose
selected for risk assessment and uncertainty factors (UFs) applied to that dose. The standard UF
is 100X which includes 10X for interspecies extrapolation (to account for differences between
laboratory animals and humans) and 10X for intraspecies variation (to account for differences
between humans). Additional uncertainty or safety factors may also be applied. A summary of
the residential levels of concern, or target MOEs, is listed in Table 8. For pyrethrins, MOEs
greater than 300 for incidental exposure, 100 for short-term inhalation exposure, and 1000 for
intermediate- and long-term inhalation exposure do not exceed the Agency's level of concern.
Table 8: Residential (non-dietary) Level of Concern Summary (MOEs)
Route of Exposure
Incidental Oral
Dermal
Inhalation
Duration of Exposure
Short-Term
(1-30 Days)
300
NR
100
Intermediate-Term
(1-6 Months)
N/A
NR
1000
Long-Term
(> 6 Months)
N/A
NR
1000
NR = Not Required - No endpoints were identified for dermal exposure because no systemic effects were
observed at the limit dose.
N/A = Not Applicable - Incidental oral exposures are not expected for intermediate- or long-term
scenarios.
a. Toxicity
The toxicological endpoints used in the residential human health risk assessment for
pyrethrins are listed in Table 9.
Table 9: Toxicological Endpoints and Doses Used in the Residential Risk Assessment
Exposure
Scenario
Doses, Uncertainty
Factors (UFs), and Safety
Factors (SF)
Target Level of Concern:
Margin of Exposure (MOE)
Study and Toxicological Effects
Short-Term
Incidental Oral (1-30
days)
NOAEL= 20 mg/kg/day
UF=100
FQPA SF = 3X (based on
database uncertainties)
Total UF = 300
Residential LOG for MOE
=300
Acute neurotoxicity study in rats
LOAEL = 63 mg/kg/day based on tremors in
females
(MRID: 42925801)
Intermediate-Term
Incidental Oral (1-6
months)
NOAEL = 6.4 mg/kg/day
UF=100
FQPA SF = IX
Total UF = 100
Residential LOG for MOE :
100
2-generation rat reproduction study
LOAEL = 65 mg/kg/day based on decreased
Fib pup body weight/body-weight gain
during lactation
(MRID: 41327501)
Short-Term Inhalation
(1 to 30 days)
NOAEL= 0.03 mL/kg/day
(7.67 mg/kg/day)
UF=100
FQPA SF = IX
Total UF = 100
Residential LOG for MOE :
100
Rat subchronic inhalation toxicity study
LOAEL = 25.56 mg/kg/day based on
tremors, labored breathing, hyperactivity,
secretory signs, matted coat, decreased body
weight/body-weight gain
(MRID: 42478201)
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Table 9: Toxicological Endpoints and Doses Used in the Residential Risk Assessment
Exposure
Scenario
Intermediate-Term
Inhalation (1 to 6
months);
Long-Term Inhalation
(>6 months)
Dermal Exposure
Doses, Uncertainty
Factors (UFs), and Safety
Factors (SF)
LOAEL = 0.01 mL/kg/day
(2.56mg/kg/day)
LTF=100
FQPA SF = IX
Lack of LOAEL = 10X
Total LTF = 1000
Target Level of Concern:
Margin of Exposure (MOE)
Residential LOG for MOE =
1000
Study and Toxicological Effects
Rat subchronic inhalation toxicity
LOAEL = 2.56 mg/kg/day based on
respiratory tract lesions
(MRID: 42478201)
Dermal risk assessments are not required since no endpoint was identified following repeated [21 days]
dermal exposure to rabbits at the limit dose of 1000 mg/kg/day.
NOAEL = no observed adverse effect level, LOAEL = lowest observed adverse effect level, MOE = margin of
exposure, LOG = level of concern
b. Residential Exposure Scenarios
Application rates for most of the exposure scenarios assessed are based on information
provided in the Pyrethrins Master Label, which lists all of the uses that the Pyrethrins Joint
Venture members are supporting. However, the application rate for the compact metered release
scenario was based upon the Purge II label (EPA Reg No. 9441-161), which is a representative
product that is used in the compact aerosol dispenser units. The use information on outdoor
residential mosquito misting systems was provided in a discussion paper by the Consumer
Specialty Products Association (CSPA), and the dilution rates are based on the Riptide ULV
label (EPA Reg. No. 1021-1785).
The residential exposure assessment includes both handler and post-application exposure
scenarios. The term "handler" applies to individuals, including homeowners, who mix, load, and
apply the pesticide product. The term "post-application" describes exposure to individuals who
enter areas previously treated with pesticides. Only short-term exposures were assessed for most
scenarios because the pyrethrins are used on an intermittent basis and the residues disperse
quickly. Intermediate-term exposures were assessed for indoor metered release scenarios and
outdoor residential mister systems.
i. Residential Handler Scenarios
The quantitative residential handler exposure/risk assessment is based on these scenarios:
1) Aerosol can application - indoor surface spray
2) Load/apply dusts - indoor surface treatment and home gardens
3) Mix/load/apply liquids with low pressure (LP) handwand - indoor surface spray and
crack and crevice application
3) Mix/load/apply liquids with trigger sprayer - indoor surface spray and crack and crevice
application
4) Mix/load/apply liquids with hose-end sprayer - lawns
5) Load outdoor residential mister tanks
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ii. Residential Post Application Scenarios
The quantitative residential post application exposure/risk assessment is based on these
scenarios:
1) Inhalation exposure from aerial application of mosquito adulticide
2) Inhalation exposure from truck mounted ULV application of mosquito adulticide
3) Toddler incidental oral ingestion of residue from treated turf (ground application)
4) Toddler incidental oral ingestion of residues deposited on carpet
5) Toddler incidental oral ingestion of residues deposited on vinyl flooring
6) Toddler incidental oral ingestion of residues on pets
7) Inhalation exposure to aerosol spray during and after space spray application
8) Inhalation exposure from compact metered release systems
9) Inhalation exposure from outdoor mosquito mister systems
10) Toddler incidental oral ingestion of residue from treated turf (mister application)
Due to lack of data, risk calculations from broadcast dust applications to carpet were not
calculated. Qualitative descriptions of the possible risk concerns are included in Section IV.
c. Exposure Data and Assumptions
Handler Exposure Data
Data from the Pesticide Handler Exposure Database (PHED) and Occupational
Residential Exposure Task Force (ORETF) database were used to assess residential handler
exposures. Default application assumptions regarding areas treated or amounts applied for
residential handler scenarios are documented in the HED Science Advisory Committee on
Exposure SOP 12: Recommended Revisions to the Standard Operating Procedures for
Residential Exposure Assessment (February 22, 2001). Other residential exposure standard
operating procedures (SOPs) may be viewed at the following website:
http://www.epa.gov/oscpmont/sap/1997/september/sopindex.htm.
Post Application Exposure Data
The Agency used default factors from the Exposure Science Advisory Committee SOP
12, Non-Dietary Exposure Task Force (NDETF) data, and Spray Drift Task Force exposure data
throughout the post-application risk assessment. Refer to the Occupational and Residential
Exposure Assessment for further data information.
Exposure Parameters
The parameters and assumptions used in estimating risks from residential exposure to
pyrethrins can be found in Section 7.2 of the Occupational and Residential Exposure Assessment
(September 7, 2005). The information listed was used to assess all scenarios including mosquito
abatement, incidental oral, aerosol space sprays, and outdoor residential misting systems.
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d. Residential Risk Estimates
Most residential handler and post application scenarios were assessed as short-term
exposures because pyrethrins are used only on an intermittent basis and the residues disperse or
degrade rapidly. However, the compact metered release sprays are packaged to release product
regularly for a 30-day period and may be immediately replaced, resulting in intermediate-term
exposures. Products used in metered release devices are usually formulated in ready to use
aerosol cans with a special nozzle that fits into the device. A battery-operated timer system
allows a spray of pyrethrins to dispense regularly throughout a day. These systems are registered
for use to control flying insects in food handling establishments, animal premises, and other
areas.
All of the residential short-term scenarios have MOEs that are greater than the target
MOE; therefore the risks are below EPA's level of concern. Most intermediate-term post-
application inhalation risks associated with metered release devices and outdoor residential
misting systems are above EPA's level of concern (i.e., MOEs are less than 1000). Exposure and
risk estimates for residential scenarios potentially of concern are summarized in Table 10 below.
The indoor metered release device scenario was based on the Multi-Chamber
Concentration and Exposure Model (MCCEM) single chamber model to predict the air
concentrations that could result from metered release device applications to an entire house, or
applications to kitchen areas only. The risk estimates for the metered release scenarios are
conservative because it was assumed that the aerosol particles would remain airborne until they
were removed by ventilation and the effect of aerosol particle settling was not considered.
Aerosol particle settling could be a major factor depending upon the aerosol particle size and rate
of evaporation.
Table 10: Summary of Residential Risks of Concern - Inhalation
Scenario
Exposed
Population
Short Term
MOEa
Intermediate Term
MOEb
Post Application Exposure Following Metered Release
Single Chamber MCCEM Modeling of Whole House Metered
Release at 0. 18 air changes per hour (ACH)
Single Chamber MCCEM Modeling of Whole House Metered
Release at 0.45 ACH
Two Zone MCCEM Modeling of Kitchen Only Metered
Release at 0.18 ACH
Two Zone MCCEM Modeling of Kitchen Only Metered
Release at 0.45 ACH
Children
Adult
Children
Adult
Children
Adult
Children
Adult
120
370
290
890
310
940
740
2,200
40
130
100
310
100
310
240
740
Post Application Exposure - Outdoor Residential Misting Systems
Outdoor Mister
Children
Adult
1,800
3,500
600
1200
a Target short term MOEs are 100 for inhalation exposures.
b The target intermediate term MOE is 1000 for inhalation exposures.
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7. Aggregate Risk
In accordance with the FQPA, the Agency must consider pesticide exposures and risks
from all potential sources. These usually include food, drinking water, and residential exposures.
In an aggregate assessment, exposures from relevant sources are added together and compared to
quantitative estimates of hazard (e.g., a NOAEL), or the risks themselves can be aggregated.
When aggregating exposures and risks from various sources, the Agency considers both the route
(oral, dermal, and inhalation) and duration (short-, intermediate-, or long-term) of exposure.
Endpoints related to neurotoxicity were selected for short-term (1-30 days) via the oral and
inhalation routes, so they may be aggregated. The endpoints selected for intermediate- and long-
term exposures have different effects for the oral and inhalation routes, so an aggregate
assessment for these exposure intervals is not appropriate.
Acute (one-day) Aggregate Risk (Food + Water)
Only food and water are generally aggregated for acute (one-day) exposures to pesticides
and those risk assessment calculations are presented above in the Acute Dietary Risk section of
this document. All acute aggregate risks are at or below EPA's level of concern.
Short-Term (1-30 days) Aggregate Risk (Food + Water + Residential Exposures)
There were different levels of concern for oral (MOE = 300) and inhalation (MOE = 100)
exposure, so an aggregate risk index (ARI) method was used to estimate the short-term risk. An
aggregate ARI above 1 is not of concern for the Agency. The highest oral exposure estimated
was from incidental exposure to residues on vinyl floors after a fogging application (0.0029
mg/kg/day). The highest inhalation exposure was from space spray applications (0.012
mg/kg/day). These two exposure scenarios were included in the aggregate assessment to
represent the highest oral and inhalation values anticipated over a short term duration.
Since there were multiple sources of oral exposure, they were added together for the
short-term aggregate. The chronic dietary exposure (0.011 mg/kg/day) was added to the
incidental oral exposure to residues on vinyl floors after fogging (0.0029 mg/kg/day) to calculate
the total oral exposure expected (0.0139 mg/kg/day). This results in an MOE of 1440 (20
mg/kg/day / 0.0139 mg/kg/day = 1440) for all sources of oral exposure. Only one source of
inhalation exposure was added to the aggregate, the space spray scenario noted above (0.012
mg/kg/day).
The ARI method was then used to compare the oral exposures (target MOE = 300) to the
inhalation exposures (target MOE = 100). See Section 7.2 of the Human Health Assessment for
an explanation of ARI calculations and Table 11 below for a summary of the calculation results
for pyrethrins. The aggregate results for most sub-populations were well above the target
Aggregate ARI (ARIagg) of 1 and are below EPA's level of concern. Although the ARIagg for
children does not reach the target (ARIagg= 0.96) it is considered to be a high-end estimate.
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In the dietary assessment, high-end field trial data and 100 percent crop treated values
were used. The incidental oral and inhalation values from the residential risk assessment both
represent the highest anticipated contribution from these individual routes of exposure. It is
unlikely a child would be exposed to both the highest possible incidental oral exposure from a
fogging application and to the highest possible inhalation exposure from a space spray
application at the same time. The actual short-term aggregate risk is likely to be much lower.
Table 11: Short-Term Aggregate Risk
Population
Adult Male
Adult Female
Child (ages 1-6)
Non-hispanic/non-whilte/non-black
(Highest Exposed Adult Subpop)
MOEFood +
Water +
Incidental
Oral
5405
5850
1440
2900
ARI Food +
Water +
Incidental
Oral1
18
20
4.8
9.7
MOE
Inhalation
370
370
120
370
ARI
Inhalation '
3.7
3.7
1.2
3.7
Aggregate
ARI2
(Target
ARI>1)
3.1
3.1
0.96
2.7
ARI - [MOECALCULATED (; e _ FOOD, WATER, INHALATION, ORAL) ' MOEACCEPTABLE]
2Aggregate ARI = 1
1
1
ARI
-FOOD +WATER+ORAL
ARI
INHALATION
Intermediate-Term (30 days - 6 months) Aggregate Risk
There are no aggregate risk estimates for the intermediate- or long-term durations
because the oral and inhalation endpoints that were selected are based on different toxicological
effects. No incidental oral exposures, were expected for intermediate- or long-term durations.
8. Cumulative Risk Assessment
Pyrethrins are botanical insecticides that come from the pyrethrum flower,
Chrysanthemum cinerariaefolium. Pyrethrins have limitations because of the cost of production
and instability in sunlight; therefore, many synthetic pyrethrins-like compounds were developed
to be more stable in sunlight and cost effective. These compounds are referred to as synthetic
pyrethroids. Although all pyrethrins and pyrethroids alter nerve function by modifying the
normal biochemistry and physiology of nerve membrane sodium channels, EPA is not currently
following a cumulative risk approach based on a common mechanism of toxicity for these
chemicals. Although all pyrethroids interact with sodium channels, there are multiple types of
sodium channels and it is currently unknown whether the pyrethrins and pyrethroids have similar
effects on all channels. EPA does not have a clear understanding of effects on key downstream
neuronal function e.g., nerve excitability, nor does EPA understand how these key events interact
to produce their compound specific patterns of neurotoxicity. There is ongoing research by the
EPA's Office of Research and Development and the pyrethroid registrants to evaluate the
differential biochemical and physiological actions of pyrethroids in mammals. This research is
expected to be completed by 2007. When available, the Agency will consider this research and
make a determination of common mechanism as a basis for assessing cumulative risk. For
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information regarding EPA's procedures for cumulating effects from substances found to have a
common mechanism on EPA's website at http://www.epa.gov/pesticides/cumulative/.
9. Occupational Risk
For more detail on the occupational assessment, see the Pyrethrins: 2nd Revised Occupational
and Residential Exposure Assessment and Recommendations for The Reregistration Eligibility
Decision (RED), (Dole, September 7, 2005).
a. Occupational Toxicity
Table 12 provides a listing of the toxicological endpoints used in the pyrethrins occupational
risk assessment. No dermal endpoint was identified; therefore, no dermal assessment was warranted.
Table 12: Endpoints and Doses Used in the Occupational Risk Assessment
Exposure
Scenario
Doses, Uncertainty
Factors (UFs), and
Safety Factors (SF)
Target Level of Concern:
Margin of Exposure (MOE)
Study and Toxicological Effects
Short-Term Inhalation
(1 to 30 days)
NOAEL= 0.03
mL/kg/day (7.67
mg/kg/day)
LTF=100
Occupational LOG for MOE = 100
Rat subchronic inhalation toxicity study
LOAEL = 25.56 mg/kg/day based on tremors,
labored breathing, hyperactivity, secretory signs,
matted coat, decreased body weight/body-weight
gain
(MRID: 42478201)
Intermediate-Term
Inhalation (1 to 6
months);
Long-Term Inhalation
(>6 months)
LOAEL = 0.01
mL/kg/day (2.56
mg/kg/day)
LTF=100
LackofNOAEL = 10X
Total LTF = 1000
Occupational LOG for MOE :
1000
Subchronic inhalation toxicity - rat
LOAEL = 2.56 mg/kg/day based on respiratory
tract lesions
(MRID: 42478201)
UF = uncertainty factor, NOAEL = no observed adverse effect level, LOAEL = lowest observed adverse effect
level, MOE = margin of exposure, LOG = level of concern
b. Occupational Handler Exposure
Workers can be exposed to a pesticide through mixing, loading, or applying the pesticide
and through reentering a treated site. Worker risk is measured by a Margin of Exposure (MOE)
which determines how close the occupational exposure comes to the NOAEL taken from animal
studies. A summary of the occupational levels of concern is listed in Table 13. In the case of
pyrethrins MOEs that are greater than 100 for short term exposure and 1000 for intermediate-
and long-term exposure do not exceed the Agency's level of concern.
Table 13: Occupational Level of Concern Summary
Route of Exposure
Duration of Exposure
Short-Term
(1-30 Days)
Intermediate-Term
(1-6 Months)
Long-Term
(> 6 Months)
Occupational Exposure
Dermal
Inhalation
NR
100
NR
1000
NR
1000
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NR = Not Required - No endpoints were selected for dermal exposure because no systemic effects were
observed at the limit dose.
c. Occupational Handler Risk Summary
Thirty occupational exposure scenarios have been assessed for pyrethrins. Only
inhalation exposures have been assessed for each of the occupational scenarios because no
toxicological endpoints were seen in dermal exposure studies. Due to lack of data, application of
dust with bulb duster and power duster were not assessed. Also, handlers applying with
handheld foggers could not be assessed due to lack of use and application information. All of the
short term MOEs are greater than 100; therefore short-term risks to handlers are below EPA's
level of concern.
The following 4 intermediate term exposure scenarios with wettable powder formulations
do not reach the target MOE of 1000 with baseline PPE and are potentially of concern:
• Mix/Load wettable powders for aerial application or chemigation to field crops
with an application rate of 0.05 Ib ai/acre. The MOE is 69 for high acreage crops
(1200 acres) and 240 for typical acreage crops (350 acres).
• Mix/Load/Apply wettable powders with low pressure handwand to greenhouses
with an application rate of 0.15 Ib ai/acre. The MOE is 240.
• Mix/Load/Apply wettable powders with low pressure handwand for surface
treatments with an application rate of 0.056 Ib ai/1000 ft2. The MOE is 260
assuming 11,200 square feet (7 buildings) treated per day.
• Mix/Load/Apply wettable powders with low pressure handwand for crack and
crevice treatment at an application rate of 0.22 Ib ai/1000 ft2. The MOE is 66
assuming 11,200 square feet (7 buildings) treated per day and 460 assuming 1600
square feet (one building) treated per day.
d. Occupational Post-application Risk Summary
Occupational post application inhalation exposures are expected from metered release
applications. According to the Master Label, pyrethrins are used as space sprays in a wide
variety of indoor areas such as barns, greenhouses, food storage areas, food processing areas,
restaurants and residences. A scenario that involves a metered release into a dairy barn was
evaluated to assess these exposures because pyrethrins are commonly used in dairy barns and
because the ventilation characteristics of dairy barns are relatively well defined. The MOE for
intermediate term exposure is 400, which does not reach the target MOE of 1000 as shown in
Table 14.
The indoor metered release device scenario used the same model, the MCCEM single
chamber model, as the residential metered release device scenario, except the occupational
assessment assumed a ventilation rate of six air changes per hour, while the residential scenario
assumed less than half an air change per hour. The risk estimates for the metered release
scenarios are conservative because it was assumed that the aerosol particles would remain
airborne until they were removed by ventilation and the effect of aerosol particle settling was not
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considered. Aerosol particle settling could be a major factor depending upon the aerosol particle
size and rate of evaporation. Data will be required to better characterize this exposure.
Table 14: Pyrethrins Occupational Post-Application Estimated Risks Following Metered Release
Exposure Scenario
Metered Release Space
Spray
Location
Dairy Barns
Short Term MOE
(Target MOE = 100)
1,200
Intermediate Term MOE
(Target MOE = 1000)
400
The restricted entry interval (REI) for pyrethrins will remain at 12 hours for all post-
application scenarios that fall under the Worker Protection Standard. In addition, under the
Worker Protection Standard for Agricultural Pesticides -WPS (40 CFR 170) greenhouses must
be appropriately ventilated following pesticide applications so that post-application inhalation
exposures are minimal.
7. Human Incident Data
In evaluating incidents to humans, the Agency reviewed reports from the OPP Incident Data
System (IDS), Poison Control Centers, California Department of Pesticide Regulation, the
National Pesticide Telecommunications Network (NPTN), and the National Institute of
Occupational Safety and Health's Sentinel Event Notification System for Occupational Risks
(NIOSH SENSOR).
Because pyrethrins are often used with a synergist such as piperonyl butoxide (PBO), it
was difficult to determine if the symptoms reported were due to pyrethrins alone. In the
Incident Data System, only one case involving pyrethrum alone was reported. This incident
involved 8 employees in Washington State who developed unspecified symptoms after repacking
pyrethrum powder into smaller containers. Poison Control Center Data (1993-2001) indicated
that there were nearly 10,000 reported pyrethrins exposures resulting in eye, respiratory, and
dermal effects; however, most of these exposures were from pyrethrins in head lice shampoos.
Some of the respiratory symptoms reported including dyspnea or breathing difficulty,
bronchospasm, and cough/choke, could indicate that pyrethrins may pose risks for persons with a
history of respiratory illness, allergy, or asthma. During 1993-1998, 48% of these exposures
involved head lice shampoos and during 1999-2001, 99% of the reported exposures involved
head lice shampoos. Shampoos used on people are regulated by the Food and Drug
Administration (FDA). FDA has required warning language such as: "Ask a doctor before use if
you are allergic to ragweed. May cause breathing difficulty or an asthmatic attack." (FR vol. 68,
No. 250, 12/31/2003, 75414) EPA is considering the need for and feasibility of similar language.
See a further discussion of this topic in Section IV.
B. Environmental Risk Assessment
For more detail on the environmental risk assessment, see the Revised Pyrethrins RED Chapter
After Additional 60-Day Comment Period, Phase 5, (Rexrode, February 16, 2006). A summary
of the Agency's environmental risk assessment for pyrethrins is presented below.
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1. Environmental Fate and Transport
The environmental fate database is adequate to characterize the environmental fate,
drinking water, and ecological exposure of the pyrethrins. However, EPA does intend to issue a
DCI as part of this RED to require submission of additional data for the pyrethrins to address
areas of uncertainty.
Since all six pyrethrins are structurally very similar, they are expected to have similar
environmental fate properties. Pyrethrin 1 was selected as a surrogate for all the pyrethrins to
generate the environmental fate data, because it is difficult to evaluate the environmental fate
properties of a mixture. Based on structure analysis, degradates of pyrethrins are expected to
lose their toxicological activity and are not considered in this risk assessment. The major routes
of dissipation for pyrethrins in the environment are photolysis (both in water and soil, with half
lives of less than one day in both cases) and to a lesser degree, aerobic soil metabolism.
Hydrolysis under alkaline conditions is an important route of dissipation for pyrethrins in water
(half-life at pH 9 is 14-17 hours); however, this reaction appears to be relatively slow under
neutral or acidic conditions, which are more likely to occur in the environment.
Pyrethrins are more persistent to anaerobic microbial metabolism (ti^= 86.1 days) than
aerobic microbial metabolism (t^= 10.5 days). They adsorb strongly to soil surfaces and are
generally considered immobile in soils (Koc range 12,400 to 37,840); therefore, the potential to
leach into groundwater is considered low. Pyrethrins could reach surface water via spray drift or
runoff events accompanied by erosion where they quickly adsorb to suspended solids in the
water column, and partition into the sediment. Non-degraded pyrethrins are likely to bind to
sediment since they appear to persist under anaerobic conditions.
2. Ecological Risk
The Agency's ecological risk assessment compares toxicity endpoints from ecological
toxicity studies to estimated environmental concentrations (EECs) based on environmental fate
characteristics and pesticide use data. To evaluate the potential risk to non-target organisms
from the use of pyrethrins, the Agency calculates a Risk Quotient (RQ), which is the ratio of the
EEC to the most sensitive toxicity endpoint values, such as the median lethal dose (LD50) or the
median lethal concentration (LCso). These RQ values are then compared to the Agency's levels
of concern (LOCs), which are listed below in Table 15 and indicate whether a pesticide, when
used as directed, has the potential to cause adverse effects to non-target organisms. When the
RQ exceeds the LOG for a particular category, the Agency presumes a risk of concern. These
risks of concern may be addressed by further refinements of the risk assessment or mitigation
measures. Use, toxicity, fate, and exposure are considered when characterizing the risk, as well
as the levels of certainty and uncertainty in the assessment. EPA further characterizes ecological
risk based on any reported incidents to non-target terrestrial or aquatic organisms in the field
(e.g., fish or bird kills).
The ecological risk assessment for pyrethrins focuses on maximum and typical
application rates for agricultural and mosquito abatement uses. Consideration was also given for
pharmacological uses in a "Down-the-Drain" scenario. Limited information was available to
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compare the effects from technical grade pyrethrins to product formulated with the synergist
piperonyl butoxide, and this comparison is summarized in the discussion below.
Table 15: EPA's Levels of Concern and Associated Risk Presumptions
Risk Presumption
Acute Risk - there is potential for acute risk
Acute Endangered Species - endangered species may be
adversely affected
Chronic Risk - there is potential for chronic risk
LOC
Terrestrial
Animals
0.5
0.1
1
LOC
Aquatic
Animals
0.5
0.05
1
LOC Plants
1
1
Not
Applicable
a. Risk to Aquatic Organisms
i. Fish and Invertebrate Toxicity and Exposure
1. Toxicity
Aquatic Toxicity
Toxicity testing was conducted with both pyrethrum extract or technical grade active
ingredient (TGAI), FEK-99 (57.5% a.i.), as well as with a formulated end-use product, typically
a Pyreonone crop spray (6.02% a.i.). A comparison of the toxicity results with both the TGAI
and typical end-use product are shown in Table 17. Only toxicity data with the TGAI are
summarized here.
The results of the toxicity testing with the TGAI suggest that pyrethrins are very highly
toxic to freshwater fish (LCso = 5.1 ug/L) and invertebrates (ECso = 11.6 ug/L), as well as to
estuarine/marine fish (LCso = 16.0 ug/L) and invertebrates (LCso/ECso =1.4 ug/L) on an acute
basis.
Chronic toxicity studies were conducted with the TGAI only. Studies show that
pyrethrins impair growth (length and weight) of freshwater fish (LOAEC of 3.0 ug/L) and
reproduction of freshwater invertebrates (LOAEC of 2.0 ug/L). The chronic no observed
adverse effect concentrations (NOAECs) for freshwater fish and invertebrates were reported as
1.9 and 0.86 ug/L, respectively. No data were submitted to evaluate the chronic risk to
estuarine/marine fish or invertebrates. However, as shown in Table 16, based on the acute-to-
chronic ratio method described in Section IV of the EFED Risk Assessment, estimated NOAECs
for the sheepshead minnow and mysid shrimp were used to assess chronic risks.
Since pyrethrins tend to bind to sediment, data regarding the toxicity of pyrethrins to
sediment-dwelling benthic organisms are needed. For this risk assessment the Agency did not
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have sediment monitoring or toxicity data to adequately evaluate the potential risk to benthic
organisms; therefore, the toxicity to benthic organisms was estimated using the equilibrium
partitioning approach, using the pore water concentrations obtained from PRZM/ EXAMS, and
the toxicity reference value of the most sensitive invertebrate species. See Table 10 in the
Environmental Fate and Effects Division's Revised Pyrethrins RED Chapter (Rexrode, January
15, 2006) for more information on this calculation.
Table 16: Toxicity reference values for aquatic organisms exposed to the Pyrethrins 57.5% technical grade
active ingredient (TGAI).
Exposure scenario
Species
Exposure duration
Toxicity
reference value
Freshwater Fish
Acute
Chronic
Rainbow trout
(Oncorhynchus mykiss)
Fathead minnow
(Pimephales promelas)
96 hours
early life stage
LC50 = 5.1 ug/L
NOAEC =1.9
ug/L
Freshwater Invertebrates
Acute
Chronic
Waterflea
(Daphnia magna)
Waterflea
(Daphnia magna)
48 hours
reproduction
EC50=1 1.6 ug/L
NOAEC = 0.86
ug/L
Esutarine/Marine Fish
Acute
Chronic a
Sheepshead minnow
(Cyprinodon
variegatus)
Sheepshead minnow
(Cyprinodon variegatus
96 hours
acute-to-chronic
ratio method
LC50 = 16.0 ug/L
NOAEC = 5.9
ug/L a (estimate)
aThe NOAEC estimated for the sheepshead minnow is based on the acute-to-chronic ratio method, determined by the
following mathematical relationship: Freshwater fish LC50 (5.1) / Freshwater fish NOAEC (1.9) = Estuarine/marine
fish LC50 (16.0 ppb)/ X (estimated value for estuarine/marine NOAEC).
Estuarine/Marine Invertebrates
Acute
Chronic b
Py TGAI 57.5% a.i.
product
Mysid shrimp
(Mysidopsis bahia)
Mysid shrimp
(Mysidopsis bahia)
96 hours
acute-to-chronic
ratio method
LC50= 1.4 ug/L
NOAEC = 0.10
ug/Lb (estimated)
bThe NOAEC estimated for the Mysid shrimp is based on the acute-to-chronic ratio method, determined by the
following mathematical relationship: Freshwater invertebrate LC50 (1 1.6 ppb)/ Freshwater invertebrate NOAEC (0.86
ppb) = Estuarine/marine invertebrate LC50 (1.4 ppb)/ X (estimated value for estuarine/marine NOAEC).
Aquatic Plants
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Table 16: Toxicity reference values for aquatic organisms exposed to the Pyrethrins 57.5% technical grade
active ingredient (TGAI).
Exposure scenario
Acute
Species Exposure
duration Toxicity
reference value
Since toxicity data were unavailable for non-target plants, risks were
not calculated.
LD50 = Lethal dose to 50% of the test population.
NOAEC = No-observed-adverse-effect concentration.
LOAEC = Lowest-observed-adverse-effect concentration.
LC50 = Lethal concentration to 50% of the test population.
EC50/EC25 = Effect concentration to 50/25% of the test population.
Mixtures Toxicity
Toxicity tests on the formulated product (60.25% piperonyl butoxide (PBO), and 6.02%
pyrethrins) showed a relative increase in toxicity for the same species when compared to tests on
pyrethrins alone. Table 17 gives an indication as to the synergistic effects of PBO that help to
increase the effectiveness of the active ingredient. The results indicate that the formulated
product was more acutely toxic to aquatic organisms than pyrethrins alone. Across all aquatic
species tested, the formulated product was more toxic to fish and invertebrates on an acute basis
than the TGAI. The greatest difference in toxicity was seen with the estuarine/marine
invertebrates (e.g., shrimp). There was up to a 90% difference between LC50 values, when
comparing the TGAI to the formulated product.
Table 17: Comparison of acute toxicity of Pyrethrins extract/ technical grade active ingredient (FEK-99)
to the formulated product (Pyrenone crop spray, 6.02% Pyrethrins and PBO).
Test Species
Exposure
duration
LC50 (jig/L)
TGAI
57.5%PyTGAIa.i.
product
Formulation
6.02% Py a.i.
product with PBO
Percent Difference in
Toxicity
Freshwater Fish
Acute
Rainbow
trout
(Oncorhynch
us mykiss)
96 hours
5.1
3.2
37%
Freshwater Invertebrates
Acute
Waterflea
(Daphnia
magnd)
48 hours
11.6
6.7
42%
Esutarine/Marine Fish
Acute
Sheepshead
minnow
(Cyprinodon
variegatus)
96 hours
16.0
3.8
76%
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Table 17: Comparison of acute toxicity of Pyrethrins extract/ technical grade active ingredient (FEK-99)
to the formulated product (Pyrenone crop spray, 6.02% Pyrethrins and PBO).
Test Species
Exposure
duration
LC50 (jig/L)
TGAI
57.5%PyTGAIa.i.
product
Formulation
6.02% Py a.i.
product with PBO
Percent Difference in
Toxicity
Estuarine/Marine Invertebrates
Acute
Mysid shrimp
(Mysidopsis
bahia)
96 hours
1.4
0.14
90%
Aquatic Plants
No aquatic vascular or non-vascular plant data were required for pyrethrins. It is unlikely
that pyrethrins pose a phytotoxic concern based on the toxic mode of action on the sodium
channels in insects. Plants lack these sodium channels and this mode of action would not cause
phytotoxicity in plants.
2. Exposure
Agricultural Exposure-Fish and Invertebrates
For exposure to fish and aquatic invertebrates, EPA considers surface water only, since
most aquatic organisms are not found in ground water. The aquatic exposure assessment for
pyrethrins relied on Tier II aquatic models. The Pesticide Root Zone Model (PRZM version
3.12) simulates fate and transport on the agricultural field, while the water body is simulated
with Exposure Analysis Modeling System (EXAMS version 2.98). Simulations are run for
multiple (usually 30) years and the reported EECs represent the values that are expected once
every ten years based on the thirty years of daily values generated during the simulation.
PRZM/EXAMS modeling of pyrethrins was completed for thirteen crop scenarios based
on 10 applications at the agricultural use rate of 0.05 Ib a.i./acre for all growing crops from the
Pyrethrins Master Label and assumed a re-application interval of 1 day, since none was
specified. The range of peak daily EECs using the maximum application rate and assuming
pyrethrins were reapplied after 1 day for all thirteen scenarios was 0.35-2.77 ug/L. Based on
EPA use data, typical application rates, ranging from 0.01-0.02 Ibs a.i./acre, were modeled for
four crop scenarios. When typical application rates, ranging from 0.007 Ibs a.i./acre to 0.024 Ibs
a.i./acre, were modeled the range of peak daily EECs was 0.002 - 0.056 ug/L. Of the 3 crop
scenarios, Illinois corn, Idaho potato, and California onion, chosen to represent "typical"
applications, the highest EEC is Illinois corn at 2.4 ppb. A complete listing of EECs, including
those used for pyrethrins RQ calculations can be found in Table 6 in the EFED risk assessment
(Melendez, February 16, 2006).
Agriculture Exposure - Sediment Organisms
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The pyrethrins adsorb readily to particulate matter and sediments, thus possibly limiting
exposure to aquatic life in the water column but increasing toxic exposure in the sediment. For
exposure to sediment organisms, the Agency evaluated maximum and typical application rates of
pyrethrins relative to expected sediment residues. The maximum application rate of 0.05 Ibs
a.i./acre produced EEC estimates for benthic pore water from PRZM/EXAMS that range from
0.029-0.209 ug/L, while the typical application rate resulted in lower EEC values of 0.002 -
0.010 ug/L (peak daily concentrations). The range of EECs follows the pattern exhibited by the
surface water EECs with the highest EECs estimated for the IL Corn standard scenario and the
lowest EECs for the CA Grape standard scenario. One of the key parameters in the
PRZM/EXAMS model is weather, especially the rainfall pattern. The amount and frequency of
rain for scenarios representing MN potato, IL corn, and PA tomato uses created conditions for
greater runoff of pyrethrins from the field and into the adjacent pond compared to the warmer,
dryer climates of the CA grape, FL citrus, and GA peaches standard scenarios.
Mosquito Abatement Exposure
The mosquito adulticides are applied as mists (very small droplet sizes) that do not deposit
rapidly and may drift substantially. The deposition and drift of pyrethrins to adjacent bodies of
water was estimated using the AGDISP (AGricultural DISPersal) computer model version 8.07
followed by the tier 2 aquatic model EXAMS, which follows degradation and partitioning
between the water column and sediment, to predict EECs for both surface water and pore water
with the Florida turf scenario. Simulations are run for multiple (usually 30) years and the
reported EECs represent the values that are expected once every ten years based on the thirty
years of daily values generated during the simulation.
The following assumptions were made for mosquito abatement uses: application rate of
0.008 Ibs a.i./acre, 26 applications, and a 4-day interval. Factors such as release height,
application rate, and droplet size all affect the predicted EECs. In general, the higher the release
height, the lower the application rate, and the smaller the droplet size, the lower the predicted
EECs. A range of EECs were predicted for pyrethrins depending on the manipulation of these
three variables and a summary of these EECs is provided in the "Aquatic Exposure Modeling for
Mosquito Abatement" Section of the EFED chapter.
Release Height:
The release height has a significant effect on the level of exposure observed in the pond.
Peak EECs were calculated using the same application rate (0.008 Ib a.i./A), droplet size (50
um), but different release heights. A release height of 75 feet resulted in EECs of 0.81-0.95 ppb
and a release height of 150 feet resulted in EECs of 0.05-0.06 ppb. A higher release height
causes more dispersion of the ULV aerosol, and a smaller amount of it reaches the soil and the
water.
Application Rate:
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The peak EECs were 0.11-0.13 ppb at the maximum application rate of 0.008 Ib a.i./A
and 0.036-0.041 ppb at the typical application rate of 0.0025 Ib a.i./A. The boom height and
droplet size were held constant at 75 feet and 50 um respectively.
Droplet Size:
The peak EECs observed for the runs performed with a droplet size of 40 microns (Dvo.s
~ 40 um) were 0.51-0.59 ppb and 0.81-0.95 ppb with a droplet size of around 50 microns (Dv0.5 ~
50 um). The boom height and application rate were held constant at 75 feet and 0.008 Ib
a. i./acre.
Wide Area Mosquito Adulticide Monitoring Data
In a Sacramento County monitoring study for pyrethrins and piperonyl butoxide (PBO),
water samples were collected after mosquito adulticide applications in the Sacramento
metropolitan area. In samples collected up to 10 hours after application there were detections of
pyrethrins and PBO in the ppb range, that were similar to modeling predictions in the pyrethrins
and the PBO mosquito adulticide assessment. Samples were also collected the day after
application and measured lower or no concentrations for both active ingredients. This indicates
both chemicals appear to dissipate fairly rapidly in the water column. The co-occurrence of
pyrethrins and PBO in some of these first samples is an indication of direct transport to water
from pesticide application and not transport by runoff.
Aquatic Exposure - "Down-the-Drain " Assessment
In order to address the issue of pyrethrins release to domestic wastewater treatment, the
Agency relied on the Office of Pollution Prevention and Toxics (OPPT) consumer exposure
model, Exposure and Fate Assessment Screening Tool (E-FAST) (USEPA, 1999). In particular
the screening level module is specifically designed to address all sources of pollution, such as
pyrethrins that could potentially contribute to domestic wastewater contamination from pesticide
disposal down a drain. The model uses input parameters that include annual production volume
of the pesticide, and takes into account the fraction of the chemical removed during wastewater
treatment. The model assumes that in a given year, the total amount of pyrethrins produced
annually is parceled out on a daily per capita basis to the U.S. population and converted to a
mass release per capita (e.g., grams/person/day). This mass is diluted into the average daily
volume of wastewater released per person per day to arrive at an estimated concentration of
target chemical in wastewater prior to entering a treatment facility. The pyrethrins concentration
in untreated wastewater is then reduced by the fraction removed during wastewater treatment
process before release into a river or stream. The remaining chemical is discharged into surface
water, where it is assumed that it is instantaneously diluted, with no further removal. The
resulting estimated environmental concentration (EEC) values, listed in Table 18, are then used
to calculate ecological risk. This method is a screening level assessment conducted with
conservative assumptions that overestimate the contribution of pyrethrins from down-the-drain
disposal.
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Table 18: Surface Water Concentrations Modeled By E-FAST for "Down-the-Drain" Assessment
Wastewater Treatment Removal
Concentration (WWT)*
92.7%
Acute
0.00242 ppb
Chronic
0.000186 ppb
* Fraction of pyrethrins removed during wastewater treatment.
ii. Fish and Invertebrates Risk
Agricultural Uses
For freshwater and estuarine/marine fish and aquatic invertebrates, including sediment
dwelling organisms, levels of concern (LOCs) were exceeded for acute risk, and endangered
species with RQs ranging from 0.54-1.98 when maximum rates and minimum reapplication
intervals are modeled. The greatest risk among aquatic organisms evaluated was for freshwater
and estuarine/marine invertebrates. Although the estuarine/marine endangered invertebrate level
was triggered, at this time there are no listed species in this category.
Chronic RQs from modeled agricultural exposure scenarios exceeded chronic LOCs for
estuarine/marine invertebrates, while chronic RQs for risk to freshwater and estuarine/marine
fish and freshwater invertebrates did not.
The risk quotients did not change substantially when the reapplication interval of 3 days
was used instead of the high reapplication interval of 1 day. Since pyrethrins are used on a wide
variety of crops, the typical application parameters can vary greatly depending on the
commodity.
Typical application rates and number of applications appear to have the potential to
reduce predicted risk to aquatic systems. Evaluation of four crop scenarios suggests that LOCs
for freshwater and estuarine/marine fish and invertebrates would not be exceeded if the typical
application rates are used.
Mixtures Risk
The Agency also assessed the maximum and typical rates for a product formulated with
both pyrethrins and PBO, but only evaluated acute exposure to aquatic organisms. The
calculated RQs show that acute risk from the highest application rate on the formulated product
label appeared to be higher than risk calculated from the TGAI. This evaluation showed that
acute risk from the formulation was about 2-7 times greater for freshwater and estuarine/marine
fish and about 10 times greater for estuarine/marine invertebrates. However, the typical
formulated product rate appears to reduce the risk (freshwater and estuarine/marine fish and
freshwater invertebrates), but this reduction in exposure still presents the potential for acute, and
chronic risk to estuarine/marine invertebrates species.
Mosquito Abatement
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RQs calculated using the maximum rate of 0.008 Ibs a.i./acre, did not result in acute risk
to freshwater fish and invertebrates or estuarine/marine fish. RQs did exceed the acute LOG for
estuarine/marine invertebrates (RQs range from 0.05 - 0.95). However, the risk to
estuarine/marine invertebrates appears to be eliminated if the boom height is set at 150 ft and the
droplet size at 40 microns (Dv0.5 ~ 40 um).
The Agency also evaluated the typical rate of 0.0025 Ibs a.i./acre, and found that potential
acute risk to estuarine/marine invertebrates could be eliminated with a boom height of 75ft and a
50 microns (Dv0.5 ~ 50 um) droplet size.
Down-the-Drain
The Agency evaluated the risks of pyrethrins found in domestic wastewater using a
Down-the-Drain model and found that aquatic LOCs were not exceeded for freshwater or
estuarine/marine organisms.
iii. Other Non-Agricultural Uses
The other non-agricultural applications of pyrethrins that include perimeter treatments in and
around buildings, lawn care, outdoor surfaces, etc., may result in exposure to aquatic organisms in
adj acent water bodies because of irrigation that can result in runoff and/or erosion. The Agency
recognizes the potential of aquatic toxicity from non-agricultural uses, but did not assess the risks
associated with these uses due to lack of available data at this time. The Agency's plan to consider
aquatic exposure from non-agricultural uses of pyrethrins is further discussed in Section IV.
b. Risk to Terrestrial Organisms
i. Birds and Mammals Toxicity and Exposure
1. Toxicity
See Table 19 below for a summary of toxicity data for mammals and birds.
Birds
Pyrethrins were practically non-toxic to avian species on an acute oral and dietary basis
(oral LD50 >2,000 mg/kg bw; dietary LC50 >5,620 mg/kg diet). Reproductive toxicity data
were not required, so chronic avian risk could not be evaluated.
Mammals
Mammalian toxicity data suggest that pyrethrins are slightly toxic to small mammals on
an acute oral basis (LD50 = 700 mg/kg body weight). In the two generation rat reproduction
study, parental male systemic and reproductive toxicity were detected at 1000 ppm (65 mg/kg
body weight per day) and parental female systemic toxicity was detected at 3000 ppm (196
mg/kg body weight per day). The NOAEL for parental systemic (male) and reproductive
toxicity was 100 ppm (6.4 mg/kg body weight-day).
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Non-target beneficial insects
Honey bee studies suggest that pyrethrins are highly toxic to non-target beneficial insects.
Terrestrial Plants
No vascular or non-vascular terrestrial plant data were submitted for pyrethrins.
However, it is unlikely that pyrethrins pose a phytotoxic concern based on the toxic mode of
action on the sodium channels in insects. Plants lack these sodium channels and this mode of
action would not cause phytotoxicity in plants.
Table 19: Toxicity reference values for mammals and birds exposed to Pyrethrins.
Exposure
Scenario
Test
Chemical a
Species
Exposure
Duration
Toxicity
Reference Value
Mammals
Acute
Chronic
57.6 % a.i
57.6% a.i.
Rat
(Rattus norvegicus)
Rat
(Rattus norvegicus)
Single dose
2-generation
reproduction
LD50 = 700 mg/kg bwb
NOAEL = 6.4 mg/kg-
day
Birds
Acute
Acute
57.6% a.i.
57.6% a.i.
Bobwhite quail (Colinus
virginianus)
Mallard duck
(Anas platyrhynchos)
5 daysc
5 daysc
LC50 >5,620 mg/kg diet
LC50 >5,620 mg/kg diet
Chronic: No data. However, chronic data from permethrin have been used as surrogate information because of
similar mode of action NOAEC = 500 ppm.
"Test material reported as FEK-99, 57.467% to 57.6% a.i. pyrethrins, which is considered to be representative of
technical grade active ingredient (TGAI).
bFemale rats only; LD50 for males in the same study was 2,140 mg/kg bw.
'Referred to as a "subacute study"; 5-day dietary exposure followed by additional 3-day observation period.
2. Exposure
Birds and mammals could be exposed shortly after application through dietary exposure
to vegetative plant material or insects when foraging in the treated fields for nesting material or
food. The EFED terrestrial exposure model (T-REX, Version 1.4), was used to estimate
exposures and risks to avian and mammalian species. Input values on avian and mammalian
toxicity as well as chemical application and foliar half-life data were required to run the model.
The model provides estimates of both exposure concentrations and risk quotients (RQs).
Specifically, the model provides estimates of concentrations (maximum and average) of
chemical residues in different types of foliage that could be sources of dietary exposure to avian,
mammalian, reptilian, or terrestrial-phase amphibian receptors. By comparing these estimated
concentrations to acute and chronic toxicity reference values, acute and chronic RQs were
calculated.
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T-REX was run for a single crop use scenario that is considered generally representative
of the maximum use rate of pyrethrins, with an application rate of 0.05 Ibs a.i./acre, for all
agricultural crops. EPA use information indicates typical rates for four representative crop
scenarios (ID potato, PA tomato, CA onion, and OR snap beans) range from 0.01 - 0.02 Ibs
a.i./acre.
ii. Birds and Mammals Risk
In this screening-level risk assessment, the Agency did not find acute or chronic risks to
listed or non-listed mammalian and avian species. All RQs were below the Agency's LOG.
iii. Terrestrial Plant
RQs were not calculated for terrestrial plants because no data were required for
pyrethrins. However, it is unlikely that pyrethrins pose a phytotoxic concern base on the toxic
mode of action on the sodium channels in insects. Plants lack these sodium channels and this
mode of action would not cause phytotoxicity in plants.
iv. Non-Target Insects Risks
Currently, the Agency does not estimate RQs for terrestrial non-target insects. However,
acute toxicity studies on honeybees suggest that pyrethrins are toxic to non-target beneficial
insects, as well as listed insect species.
4. Ecological Incidents
Most of the ecological incidents reported involving pyrethrins were classified as
"unlikely," except one involving plant damage, which was classified as "possible." Of the 11
reports in the Ecological Incident Information System (EIIS) database, all but one incident
involved pyrethrins causing damage to non-target terrestrial plants. One report associates
pyrethrins use with effects in aquatic organisms after fish from a small pond died after possible
contamination from a dog treated with pyrethrins flea powder, but this report was also classified
as "unlikely." Most of these incidents involved formulated products containing a very low
concentration of pyrethrins and a high percentage of "inert" ingredients. The Agency does not
consider pyrethrins, or the synergist PBO, to have phytotoxic properties and assumes that the
reported toxicity to terrestrial plants after application of a formulation may be the result of inerts
or other circumstances associated with the application.
5. Endangered Species Concerns
The Agency's screening level assessment results in the determination that pyrethrins will
have no direct acute effects on threatened and endangered mammals or birds. The preliminary
risk assessment for endangered species indicates that RQs exceed endangered species LOCs for
freshwater fish and invertebrates, and estuarine/marine fish and invertebrates. Further, potential
indirect effects to any species dependent upon a species that experiences effects from use of
pyrethrins can not be precluded based on the screening level ecological risk assessment. These
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findings are based solely on EPA's screening level assessment and do not constitute "may affect"
findings under the Endangered Species Act.
IV. Risk Management, Reregistration, and Tolerance Reassessment Decision
A. Determination of Reregistration Eligibility and Tolerance Reassessment
Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submission of
relevant data concerning an active ingredient, whether or not products containing the active
ingredient are eligible for reregi strati on. The Agency has previously identified and required the
submission of the generic data to support reregi strati on of products containing pyrethrins. The
Agency has completed its review of these generic data, and has determined that the data are
sufficient to support reregi strati on of all products containing pyrethrins.
The Agency has completed its assessment of the dietary, occupational, residential, and
ecological risk associated with the use of pesticide products containing the active ingredient
pyrethrins. Based on a review of these data and on public comments on the Agency's
assessments for the active ingredient pyrethrins, the Agency has sufficient information on the
human health and ecological effects to make decisions as part of the tolerance reassessment
process under FFDCA and reregi strati on process under FIFRA, as amended by FQPA. The
Agency has determined that products containing pyrethrins are eligible for reregi strati on
provided that: (i) the risk mitigation measures outlined in this document are adopted and (ii)
label amendments are made to reflect these measures. Label changes are described in Section V.
Appendix A summarizes the uses of pyrethrins that are eligible for reregi strati on. Appendix B
identifies the generic data requirements that the Agency reviewed as part of its determination of
reregi strati on eligibility of pyrethrins, and lists the submitted studies that the Agency found
acceptable. Data gaps are identified as generic data requirements that have not been satisfied
with acceptable data.
Based on its evaluation of pyrethrins, the Agency has determined that pyrethrins
products, unless labeled and used as specified in this document, would present risks inconsistent
with FIFRA and FQPA. Accordingly, should a registrant fail to implement any of the
reregi strati on requirements identified in this document, the Agency may take regulatory action to
address the risk concerns from the use of pyrethrins. If all changes outlined in this document are
incorporated into the product labels, then all current risks for pyrethrins will be adequately
mitigated for the purposes of this determination. Once an Endangered Species assessment is
completed, further changes to these registrations may be necessary as explained under
"Endangered Species Concerns" below.
B. Regulatory Position
Through the Agency's public participation process, EPA worked with stakeholders and
the public to refine the risk assessments and reach regulatory decisions for pyrethrins. EPA
released its pyrethrins preliminary risk assessments for public comment on April 27, 2005, for a
60-day public comment period (Phase 3 of the 6 Phase public participation process). Where
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appropriate, the pyrethrins risk assessments were revised in response to the comments received,
and the assessments were released for an additional 60-day public comment period on September
21, 2005 (Phase 5 of the 6-phase public participation process). During both public comment
periods, the Agency received comments from the Pyrethrin Joint Venture, stakeholder groups
such as the American Mosquito Control Association (AMCA), state and local government
entities in California, the State of New York, California Water Boards, publicly owned treatment
works (POTWs), Mosquito and Vector Control Districts, and several private citizens.
The registrant's comments focused on various aspects of the risk assessments including
toxicological issues, human incidents, mosquito abatement modeling parameters, and agricultural
modeling parameters. Others comments were received from the AMCA, local governments, and
mosquito abatement applicators describing mosquito abatement activities and commenting on the
ecological risk assessment. The State of New York pointed out areas of inconsistency in the risk
assessments. All of the comments have been considered and the changes are reflected in this
document where appropriate. Formal responses to these comments have been completed and are
available separate from this RED document. All of the preliminary and revised pyrethrins risk
assessments, public comments, responses to comments, and this RED document are available in
the EPA public docket (OPP-2005-0043) and in the EPA's electronic docket at
www.regulations.gov.
1. Food Quality Protection Act Findings
a. "Risk Cup" Determination
As part of the FQPA tolerance reassessment process, EPA assessed the risks associated
with pyrethrins. EPA has determined that risk from dietary (food + water) exposure is within its
own "risk cup." An aggregate assessment was conducted for pyrethrins for exposures through
dietary and residential exposures. The Agency has determined that the human health risks from
these combined exposures are within acceptable levels. In other words, EPA has concluded that
the tolerances for pyrethrins meet FQPA safety standards. In reaching this determination, EPA
has considered the available information on the special sensitivity of infants and children, as well
as aggregate exposure from food and residential sources.
b. Determination of Safety to U.S. Population
The Agency has determined that the 70 established tolerances for pyrethrins, with
amendments and changes as specified in this document, meet the safety standards under the
FQPA amendments to Section 408(b)(2)(D) of the FFDCA, as amended by FQPA, and that there
is a reasonable certainty no harm will result to the general population or any subgroup from the
use of pyrethrins. In reaching this conclusion, the Agency has considered all available
information on the toxicity, use practices, and the environmental behavior of pyrethrins. The
acute, chronic, short-term, intermediate-term, and long-term risks from food, drinking water, and
residential exposures do not exceed the Agency's levels of concern, with the risk mitigation
specified in this document.
c. Determination of Safety to Infants and Children
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EPA has determined that the established tolerances for pyrethrins, with amendments and
changes as specified in this document, meet the safety standards under the FQPA amendments to
Section 408(b)(2)(C) of the FFDCA. These safety standards require that there is a reasonable
certainty of no harm for infants and children. The safety determination for infants and children
factors in the toxicity, use practices and environmental behavior noted above for the general
population, but also takes into account the possibility of increased dietary exposure due to the
specific consumption patterns of infants and children, as well as the possibility of increased
susceptibility to the toxic effects of pyrethrins residues in this population subgroup.
In determining whether or not infants and children are particularly susceptible to toxic
effects from exposure to residues of pyrethrins, the Agency considered the completeness of the
hazard database for developmental and reproductive effects, the nature of the effects observed,
and other information. An FQPA safety factor of 3X has been retained for the acute dietary and
short-term residential incidental oral assessments for lack of a developmental neurotoxicity
study; there are no other residual uncertainties for pre- and/or post-natal toxicity, exposure is not
underestimated, and there is no evidence of increased susceptibility.
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 endocrine effects as the Administrator may designate." Following
recommendations of its Endocrine Disrupter Screening and Testing Advisory Committee
(EDSTAC), EPA determined that there was a scientific basis for including, the androgen and
thyroid hormone systems as part of the program, in addition to the estrogen hormone system.
EPA also adopted EDSTAC's recommendation that EPA include evaluations of potential effects
in wildlife. For pesticides, EPA will use FIFRA and, to the extent that effects in wildlife may
help determine whether a substance may have an effect in humans, FFDCA authority to require
the wildlife evaluations. As the science develops and resources allow, screening of additional
hormone systems may be added to the Endocrine Disrupter Screening Program (EDSP).
There is evidence that pyrethrins are associated with endocrine disruption. Direct
measurements of serum thyroid hormones [T3, T4, and TSH], as well as histopathological
alterations in the thyroid (i.e. follicular cell hypertrophy, follicular cell hyperplasia, follicular cell
adenomas and/or carcinomas) indicate there is concern regarding the potential for endocrine
disruption. When the appropriate screening and/or testing protocols being considered under the
EDSP have been developed, pyrethrins may be subject to additional screening and/or testing.
3. Cumulative Risks
Pyrethrins are botanical insecticides that come from the pyrethrum flower,
Chrysanthemum cinerariaefolium. Pyrethrins have limitations because of the cost of production
and instability in sunlight; therefore, many synthetic pyrethrins-like compounds were developed
to be more stable in sunlight and cost effective. These compounds are referred to as synthetic
pyrethroids. Although all pyrethrins and pyrethroids alter nerve function by modifying the
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normal biochemistry and physiology of nerve membrane sodium channels, EPA is not currently
following a cumulative risk approach based on a common mechanism of toxicity for these
chemicals. Although all pyrethroids interact with sodium channels, there are multiple types of
sodium channels and it is currently unknown whether the pyrethrins and pyrethroids have similar
effects on all channels. EPA does not have a clear understanding of effects on key downstream
neuronal function, e.g., nerve excitability, nor does EPA understand how these key events
interact to produce their compound specific patterns of neurotoxicity. There is ongoing research
by the EPA's Office of Research and Development and the pyrethroid registrants to evaluate the
differential biochemical and physiological actions of pyrethroids in mammals. This research is
expected to be completed by 2007. When available, the Agency will consider this research and
make a determination of common mechanism as a basis for assessing cumulative risk. For
information regarding EPA's procedures for cumulating effects from substances found to have a
common mechanism on EPA's website at http://www.epa.gov/pesticides/cumulative/.
C. Tolerance Reassessment Summary
Table 20, 21, 22, and 23 provide a summary of the pyrethrins tolerance reassessment
decision. Further tolerance explanation is provided after the table.
All references that indicate use in combination with another active ingredient, such as
piperonyl butoxide or n-octyl bicycloheptene dicarboximide (MGK-264), are removed, or
decoupled from the tolerance expressions for pyrethrins. All tolerances established for use on
bags are being revoked as the last active product supporting this use was cancelled on October
10, 1989, and there are no data to support this use. The 40 CFR should be updated to reflect all
of these changes as summarized in Table 20 below.
Table 20: 40 CFR Changes for Pyrethrins
Current 40 CFR Citation
§ 180. 128(a)(2)(i) all parts
§ 180. 128(a)(2)(ii) all parts
§180.128(a)(2)(iii)(A)
§180.128(a)(2)(iii)(B)
§180.128(a)(2)(iii)(C)
§180.128(a)(2)(iii)(D)
§180.128(a)(2)(iii)(E)
Action
Remove
Remove
Retain
Remove
Retain
Remove
Remove
Comment
This section refers to pyrethrins being used in conjunction
with PBO. All references to use with multiple chemicals
is being removed from the CFR.
This section refers to pyrethrins being used in conjunction
with PBO and MGK-264. All references to use with
multiple chemicals is being removed from the CFR.
This tolerance for cereal grain will be kept as indicated in
Table 21 below.
Recodify under §180.128 (a)(2)
This is a tolerance for use on bags. The last registration
for this use was cancelled in 1989 and there are no data to
support this use.
This citation refers to another part of the CFR for MGK-
264 that is being revised. In order to clarify the statement
it will be stated in its entirety here. The exact statement
and section number are indicated in Table 21 below.
Recodify under §180.128 (a)(3)
This is a tolerance for use on bags. The last registration
for this use was cancelled in 1989 and there are no data to
support this use.
This refers to other sections that are being removed, so
Page 49 of 108
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§180.128(a)(2)(iv)
§180.128(a)(2)(v)
§ 180. 128(a)(3) all parts
Remove
Retain
Remove
this section is not relevant once the other parts are revised.
Old language not used in the CFR currently.
Recodify under §180.128 (a)(4)
This is a tolerance for use on bags. The last registration
for this use was cancelled in 1989 and there are no data to
support this use.
Table 21: Tolerance Reassessment Summary for Pyrethrins (PC 069001)
Commodity
Current
Tolerance
(ppm)
Tolerance
Reassessment
(ppm)
Comment/
[Correct Commodity
Definition]
Tolerances Listed Under 40 CFR §180.128 (a)(l)
Almond, postharvest
Apple, postharvest
Barley, postharvest
Bean, postharvest
Birdseed, mixtures, postharvest
Blackberry, postharvest
Blueberry (huckleberry), postharvest
Boysenberry, postharvest
Buckwheat, grain, postharvest
Cattle, fat
Cattle, meat byproducts
Cattle, meat
Cherry, postharvest
Cocoa bean, postharvest
Coconut, copra, postharvest
Corn (including popcorn), postharvest
Cottonseed, postharvest
Crabapple, postharvest
Currant, postharvest
Dewberry, postharvest
Egg
Fig, postharvest
Flaxseed, postharvest
Goat, fat
Goat, meat byproducts
Goat, meat
1
1
3
1
3
1
1
1
3
0.1
0.1
0.1
1
1
1
3
1
1
1
1
0.1
1
1
0.1
0.1
0.1
TBD1
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
1
0.05
0.05
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
Revoke
TBD
TBD
1
0.05
0.05
[Barley, grain, postharvest}
[Bean, succulent, postharvest}
[Blueberry, postharvest}
[Cocoa bean, dried bean,
postharvest}
[Corn, field and pop, grain,
postharvest}
[Cotton, undelinted seed,
postharvest}
Based on exaggerated feed and
premise treatment studies, there
are no reasonable expectations
of finite residue in poultry
products.
[Flax, seed, postharvest}
Page 50 of 108
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Table 21: Tolerance Reassessment Summary for Pyrethrins (PC 069001)
Commodity
Gooseberry, postharvest
Grape, postharvest
Guava, postharvest
Hog, fat
Hog, meat byproducts
Hog, meat
Horse, fat
Horse, meat byproducts
Horse, meat
Loganberry, postharvest
Mango, postharvest
Milk fat (reflecting negligible residues in milk)
Muskmelon, postharvest
Oat, postharvest
Oranges, postharvest
Peach, postharvest
Peanut (with shell removed), postharvest
Pear, postharvest
Pea, postharvest
Pineapple, postharvest
Plum, prune, fresh, postharvest
Potato, postharvest
Poultry, fat
Poultry, meat byproducts
Poultry, meat
Raspberry, postharvest
Rice, postharvest
Rye, postharvest
Current
Tolerance
(ppm)
1
1
1
0.1
0.1
0.1
0.1
0.1
0.1
1
1
0.5
1
1
1
1
1
1
1
1
1
0.05
0.2
0.2
0.2
1
3
3
Tolerance
Reassessment
(ppm)
TBD
TBD
TBD
1
0.05
0.05
1
0.05
0.05
TBD
TBD
0.05
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
0.05
Revoke
Revoke
Revoke
TBD
TBD
TBD
Comment/
[Correct Commodity
Definition]
[Oat, grain, postharvest}
[Orange, sweet, postharvest]
[Peanut, nutmeat, postharvest}
[Pea, dry, seed, postharvest}
The reassessed tolerance is
based on data reflecting
residues of pyrethrins.
Based on exaggerated feed and
premise treatment studies, there
are no reasonable expectations
of finite residue in poultry
products.
Based on exaggerated feed and
premise treatment studies, there
are no reasonable expectations
of finite residue in poultry
products.
Based on exaggerated feed and
premise treatment studies, there
are no reasonable expectations
of finite residue in poultry
products.
[Rice, grain, postharvest}
[Rye, grain, postharvest}
Page 51 of 108
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Table 21: Tolerance Reassessment Summary for Pyrethrins (PC 069001)
Commodity
Sheep, fat
Sheep, meat byproducts
Sheep, meat
Sorghum, grain, postharvest
Sweet potato, postharvest
Tomato, postharvest
Walnut, postharvest
Wheat, postharvest
Current
Tolerance
(ppm)
0.1
0.1
0.1
1
0.05
1
1
3
Tolerance
Reassessment
(ppm)
1
0.05
0.05
TBD
0.05
TBD
TBD
TBD
Comment/
[Correct Commodity
Definition]
The postharvest use on stored
raw sweet potatoes are
supported by residue data
translated from potatoes.
[Wheat, grain, postharvest}
Tolerance Listed Under 40 CFR §180.128(a)(2)(iii)(A)
Grains, Cereal, Milled Fractions
1
1
Tolerance Listed Under 40 CFR §180.128(a)(2)(iii)(B)
Stored Dried Food (Multiwall paper bags (50
Ibs +))
1
Revoke
This is a tolerance for use on
bags. The last registration for
this use was cancelled in 1989
and there are no data to support
this use.
Tolerance Listed Under 40 CFR §180.128(a)(2)(iii)(C)
Processed Food (food handling establishments)
1
1
Decouple pyrethrins tolerance
from MGK-264 and PBO.
The new tolerance should be
stated as:
"A tolerance of 1.0 ppm is
established for residues of the
insecticide pyrethrins in or on
all food items in food handling
establishments where food and
food products are held,
processed, prepared and/or
served. Food must be removed
or covered prior to use."
Tolerance Listed Under 40 CFR §180.128(a)(2)(iii)(D)
Processed Food (Cotton bags (50 Ibs +) with
waxed paper liners containing Stored Dried
Food (4% fat or less))
1
Revoke
This is a tolerance for use on
bags. The last registration for
this use was cancelled in 1989
and there are no data to support
this use.
Tolerance Listed Under 40 CFR §180.128(a)(3)(iii)(A)
Processed Food (Stored Feed (Dried Feed from
use on outer ply of multiwall paper bags 50 Ibs
or more))
1
Revoke
This is a tolerance for use on
bags. The last registration for
this use was cancelled in 1989
and there are no data to support
this use.
Page 52 of 108
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Table 21: Tolerance Reassessment Summary for Pyrethrins (PC 069001)
Commodity
Current
Tolerance
(ppm)
Tolerance
Reassessment
(ppm)
Comment/
[Correct Commodity
Definition]
Tolerance Listed Under 40 CFR §180.128(a)(3)(iii)(B)
Stored Feed (Dried Feed (containing 4% fat or
less) from use on cotton bags with waxed paper
liners 50 Ibs or more)
1
Revoke
This is a tolerance for use on
bags. The last registration for
this use was cancelled in 1989
and there are no data to support
this use.
Tolerances Listed Under 40 CFR §180.905(a)(6)
Raw Agricultural Commodities
Exemption
Revoke
Formerly established under
180.1001 (b).
The Agency will not revoke this
tolerance immediately, but will
issue a DCI for the data. When
the data have been reviewed
and approved by the Agency,
the appropriate crop group
tolerances will be established
concomitant with revocation of
the exemption.
1 TBD = To be determined. EPA notes that while additional data are needed to support certain tolerances,
conservative assumptions have been used in the risk assessment and no dietary risks have been identified. Thus,
EPA considers the tolerances reassessed.
Table 22: Tolerance Reassessment Summary for Pyrethrum Powder Other than Pyrethins (PC 069002)
Commodity
Current
Tolerance
(ppm)
Tolerance
Reassessment
(ppm)
Comment/
[Correct Commodity
Definition]
Tolerances Listed Under 40 CFR §180.905 (a)(6)
Raw Agricultural Commodities
Exemption
Revoke
Previously established under
180.1001 (b)
The last active product with this
active ingredient was cancelled
in 1991.
Table 23: Pyrethrins Tolerances to be Established Under Section 40 CFR §180.128
Commodity
Current
Tolerance
(ppm)
Proposed
Tolerance
(ppm)
Comment/
[Correct Commodity
Definition]
Tolerances to be Established Under CFR §180.128(a)
Aspirated grain fractions
Atemoya
Avocado
Banana
Carob bean
Cherimoya
None
None
None
None
None
None
TBD1
TBD
TBD
TBD
TBD
TBD
Page 53 of 108
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Coffee, green bean
Cranberry
Date
Durian
Jojoba
Lychee
Okra
Papaya
Persimmon
Pomegranate
Safflower, seed
Strawberry
Sugarcane
Sunflower, seed
Tea, leaves
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
1 TBD = To be determined. EPA notes that while additional data are needed to support certain tolerances,
conservative assumptions have been used in the risk assessment and no dietary risks have been identified.
Tolerance exemption under CFR §180.905(a)(6)
Pyrethrum and pyrethrins are currently exempt from the requirements of tolerances when
applied to growing crops in accordance with good agricultural practices [40 CFR
§180.905(a)(6)]; the tolerance exemption was previously established under 40 CFR
§180.1001 (b). Based on the results of limited field trials reflecting pre-harvest uses, the Agency
recommends for the revocation of this tolerance exemption. The results of pre-harvest trials
show detectable and variable residues of Pyrethrins I components in/on many raw agricultural
commodities following applications of one formulation class (EC) at the maximum seasonal rate
the PJV wishes to support for pre-harvest uses. Additional residue data reflecting pre-harvest
uses are required to confirm and refine the dietary risk assessment. When the requested data
have been evaluated, the Agency will recommend for the revocation of the tolerance exemption
in 40 CFR §180.905(a)(6) concomitant with the establishments of crop group tolerances, if
appropriate, in 40 CFR §180.128 to support all uses.
Tolerances Established Under CFR §180.128
Tolerances are currently established in 40 CFR §180.128 for residues of pyrethrins,
insecticidally active principles of Chrysanthemum cineroriaefolium in/on: (i) plant commodities
resulting from post-harvest uses; (ii) animal commodities; and (iii) food/feed items while in
storage areas. Since residues of pyrethrins are identified by a marker compounds, the tolerance
in the CFR will be updated to read as follows: "Tolerances for residues of pyrethrins 1 ((lS)-2-
methyl-4-oxo-3-(2Z)-2,4-pentadienylcyclopenten-l-yl(lR,3R)-2,2-dimethyl-3-(2-methyl-l-
propenyl)cyclopropanecarboxylate), cinerin 1 ((lS)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-
cyclopenten-1-yl (lR,3R)-2,2-dimethyl-3-(2-methyl-l-propenyl)cyclopropanecarboxylate), and
jasmolin 1 ((lS)-2-methyl-4-oxo-3-(2Z)-2-pentenyl-2-cyclopenten-l-yl (lR,3R)-2,2-dimethyl-3-
(2-methyl-l-propenyl)cyclopropanecarboxylate), which serve as a marker for residues of the
Page 54 of 108
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insecticide pyrethrins (insecticidally active principles of Chrysanthemum cmerariaefolium\ are
established in or on the following food commodities:". A list of tolerances established for
Pyrethrins I along with EPA's recommendations of changes to correct commodity definitions are
presented in Tables 20, 21, and 22.
The qualitative nature of the residue in plants is understood based on acceptable
metabolism studies conducted on three dissimilar crops: leaf lettuce, potatoes, and tomatoes.
The qualitative nature of the residue in ruminants and poultry is also adequately understood
based on acceptable metabolism studies reflecting both dermal and oral treatments. The results
of the above plant as well as animal metabolism studies will be presented to the Agency for a
determination of terminal residues of concern (i.e., residues that need to be regulated or included
in the tolerance expression). If the Agency determines that additional metabolites of
toxicological concern should be regulated (i.e., included in the tolerance expression), then
additional data concerning residue analytical methods, storage stability, and magnitude of the
residue (in plants, processed commodities, animals, and food/feed items in storage areas) may be
required in the future.
The pyrethrins tolerances for plant commodities, resulting from postharvest uses [40 CFR
§180.128(a)(l)], range from 0.05 ppm (potato and sweet potato) to 3 ppm (most cereal grains).
The available data are inadequate to support many of the established tolerances resulting from
postharvest uses (except those uses for potato and sweet potato), and additional data are required
for tolerance reassessment.
Assuming there is a linear relationship between feeding levels and tissue concentrations
and provided that the residues of concern in animals are the components of pyrethrins I, the
established tolerances of negligible residues for milk and 0.1 ppm for the fat, meat, and meat
byproducts of cattle, goat, hogs, horses, and sheep need to be revised. A tolerance of 0.05 ppm
would be appropriate for milk, meat, and meat byproducts of cattle, goats, hogs, horses, and
sheep; a tolerance of 1.0 ppm would be appropriate for fat of cattle, goats, hogs, horses, and
sheep.
The remainder of tolerances and tolerance exemptions established in CFR §180.128
pertain to uses of pyrethrins in food/feed storage areas.
- According to 40 CFR §180.128(a)(2)(i), pyrethrins may be safely used in combination
with piperonyl butoxide (PBO) for control of insects when used according to conditions
specified in the same 40 CFR section.
- According to 40 CFR §180.128(a)(2)(ii), pyrethrins may be safely used in combination
with PBO and N-octylbicycloheptene dicarboximide for insect control in accordance with
40CFR180.367(a)(2).
- According to 40 CFR §180.128(a)(2)(iii), a tolerance of 1 ppm is established for
residues of pyrethrins per se in/on:
(A) milled fractions derived from cereal grains when present therein as a result of its use
in cereal grain mills and in storage areas for milled cereal grain products;
Page 55 of 108
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(B) dried foods when present as a result of migration from its use on the outer ply of
multiwall paper bags of 50 pounds or more capacity;
(C) foods treated in accordance with 40 CFR 180.367(a)(2);
(D) dried foods that contain 4 % fat, or less, when present as a result of migration from its
use on the cloth of cotton bags of 50 pounds or more capacity constructed with waxed
paper liners; and
(E) foods from treated food processing and storage areas provided the food is removed or
covered prior to such use.
- According to 40 CFR §180.128(a)(2)(iv), to assure safe use of the pesticide, its label
and labeling shall conform to that registered with the U.S. Environmental Protection
Agency, and it shall be used in accordance with such label and labeling.
- According to 40 CFR §180.127(a)(2)(v), where tolerances are established on both raw
agricultural commodities and processed foods made from the total residues of pyrethrins
in/on the processed food shall not be greater than that permitted by the larger of the two
tolerances.
- According to 40 CFR §180.128(a)(3), pyrethrins may be safely used in accordance with
the following prescribed conditions:
(i) It is used or intended for use in combination with PBO for control of insects:
(A) On the outer ply of multiwall paper bags of 50 pounds or more capacity in amounts
not exceeding 6 milligrams per square foot; or
(B) On cotton bags of 50 pounds or more capacity in amounts not exceeding 5.5
milligrams per square foot of cloth. Such treated bags are constructed with waxed paper
liners and are to be used only for dried feeds that contain 4 percent fat or less; or
(ii) It is used in combination with PBO, whereby the amount of pyrethrins is equal to 10
percent of the amount of PBO in the formulation. Such treated bags are to be used only
for dried feeds.
The tolerance regulations establish that pyrethrins may be safely used in combination
with piperonyl butoxide [40 CFR §180.128(a)(2)(i)] and piperonyl butoxide and N-
octylbicycloheptene dicarboximide [40 CFR §180.128(a)(2)(ii)], for control of insects in
food/feed processing areas and food/feed storage areas provided that the food/feed is removed or
covered prior to use of the products. The Agency concludes that for pyrethrins no additional
data are required to maintain the above tolerance regulations. This determination does not apply
to PBO and n-octylbicycloheptene dicarboximide because the labels for these pesticide
chemicals were not examined in this decision, but are considered in separate Reregi strati on
Eligibility Decisions documents.
Adequate data depicting the magnitude of residues of pyrethrins in food-handling
establishments and food storage areas are available. These data indicate that the established
tolerance of 1 ppm will not be exceeded in representative food commodities and surfaces that
had been covered during space, contact, and intermittent spray aerosol treatments using
representative soluble concentrate/liquid and pressurized liquid formulations. The submitted
pyrethrins Master Label provides adequate instructions that need to be included on end use
Page 56 of 108
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labels, which specify that food should be removed or covered during treatment, and that all food
processing surfaces should be covered during treatment, or thoroughly cleaned before use.
No data are available to support uses of pyrethrins on foods stored in multi-walled paper
or cloth bags. The last active product with this use was cancelled in October 15, 1989.
Therefore, the stored dried food tolerance in section 180.128(a)(2)(iii)(B), the two processed
food tolerances in sections 180.128(a)(2)(iii)(D) and 180.128(a)(3)(iii)(A), and the stored feed
tolerance in section 180.128(a)(3)(iii)(B) should be revoked.
Maximum Contaminant Level
No maximum contaminant level (MCL) for pyrethrins in potable water has been
established. Pyrethrins can be directly applied to water in flooded rice fields. Data from field
trials conducted in aquatic environments simulating use of the pesticide in flooded rice fields
detected residues of pyrethrins 10 days after application. A 10-day water holding interval must
be established for the kill of adult mosquitoes in flooded rice fields. The 10-day water hold
requirement addresses the concerns of pyrethrins contamination in potable water, so an MCL for
pyrethrins does not need to be established.
Tolerances to be Established Under 40 CFR §180.128
The data requirements to support preharvest uses, which are recommended in the
Pyrethrins Residue Chemistry Chapter (dated 9/8/2005), are designed to support the
establishments of crop group tolerances. Therefore, several crop group tolerances, if appropriate,
will need to be proposed by the registrants when the requested data have been reviewed. In
addition, tolerances for the following miscellaneous commodities need to be proposed upon
receipt of the requested residue data: asparagus, aspirated grain fraction, atemoya, avocado,
banana, carob bean, cherimoya, coffee green bean, cranberry, date, durian, jojoba, kiwifruit,
lychee, okra, papaya, persimmon, pomegranate, safflower seed, strawberry, sugarcane, sunflower
seed, and tea leaves.
Codex/International Harmonization
The Codex Alimentarius Commission has established several maximum residue limits
(MRLs) for residues of pyrethrins. The Codex MRLs are expressed in terms of total pyrethrins,
calculated as the sum of pyrethrins 1 and 2, cinerins 1 and 2, and jasmolins 1 and 2, determined
after calibration with the World Standard pyrethrum extract, which is identical to the current
U.S. tolerance expression. Canadian MRLs have been established for residues of pyrethrins [4-
hydroxy-3-methyl-2-(2,4-pentadienyl)-2-cyclopenten-l-one 2,2-dimethyl-3-(2-methyl-propenyl)
cyclopropanecarboxylate and 4-hydroxy-3-methyl-2-(2,4-pentadienyl)2-cyclopenten-l-one 1-
methyl-3-carboxy-%,2,2-triethylcyclo-propaneacrylate ester]. The Pyrethrins Revised Residue
Chemistry Chapter (Deluzio, September 8, 2005) incorrectly included MRLs from Mexico.
There are no Mexican MRLs established for pyrethrins. A numerical comparison of the Codex
MRLs and the corresponding current U.S. tolerances for pyrethrins is presented in Table 24.
Page 57 of 108
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Table 24: Codex MRLs and Applicable U.S. Tolerances for Pyrethrins
Codex
Commodity, As Defined
Cereal grains
Citrus fruits
Dried fruits
Fruiting veg, cucurbits
Pea hay or fodder
Pea vines (green)
Peanut
Peppers
Pulses
Root and tuber veg
Tomato
Tree nuts
MRL (mg/kg)
0.3 (Po ')
0.05
0.2 (Po)
0.05
1
10
0.5 (Po)
0.05
0.1
0.05
0.05
l(Po)
Limits for Canada
Commodity, As Defined
Raw cereals
Almonds
Apples
Beans
Blackberries
Blueberries
Boysenberries
Cherries
Copra
Crabapples
Cocoa beans
Currants
Dewberries
Figs
Gooseberries
Grapes
Guavas
MRL (mg/kg)
3
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Current U.S.
Tolerance, ppm
1 ppm for oat and sorghum resulting from
postharvest uses; 3 ppm for barley, buckwheat,
com, (including popcorn), rice, rye, and wheat
resulting from postharvest uses
1 ppm for oranges resulting from postharvest uses
1 ppm for muskmelon and tomato resulting from
postharvest uses
1 ppm for pea resulting from postharvest uses
1 ppm for peanut (with shell removed) resulting
from postharvest uses
0.05 ppm for potato and sweet potato resulting
from postharvest uses
1 ppm for tomato resulting from postharvest uses
1 ppm for almond and walnut resulting from
postharvest uses
Current U.S.
Tolerance, ppm
1 ppm for almond resulting from postharvest uses
1 ppm for apple resulting from postharvest uses
1 ppm for bean resulting from postharvest uses
1 ppm for blackberry resulting from postharvest
uses
1 ppm for blueberry (huckleberry) resulting from
postharvest uses
1 ppm for boysenberry resulting from postharvest
uses
1 ppm for cherry resulting from postharvest uses
1 ppm for coconut, copra resulting from
postharvest uses
1 ppm for crabapple resulting from postharvest
uses
1 ppm for cocoa bean resulting from postharvest
uses
1 ppm for currant resulting from postharvest uses
1 ppm for dewberry resulting from postharvest
uses
1 ppm for fig resulting from postharvest uses
1 ppm for gooseberry resulting from postharvest
uses
1 ppm for grape resulting from postharvest uses
1 ppm for guava resulting from postharvest uses
Page 58 of 108
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Table 24: Codex MRLs and Applicable U.S. Tolerances for Pyrethrins
Codex
Commodity, As Defined
Huckleberries
Loganberries
Mangoes
Muskmelons
Oranges
Peaches
Nectarines
Peanuts
Pears
Peas
Pineapple
Plums
Raspberries
Tomatoes
Walnuts
MRL (mg/kg)
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Current U.S.
Tolerance, ppm
1 ppm for blueberry (huckleberry) resulting from
postharvest uses
1 ppm for loganberry resulting from postharvest
uses
1 ppm for mango resulting from postharvest uses
1 ppm for muskmelon resulting from postharvest
uses
1 ppm for oranges resulting from postharvest uses
1 ppm for peach resulting from postharvest uses
1 ppm for peach resulting from postharvest uses
1 ppm for peanut (with shell removed) resulting
from postharvest uses
1 ppm for pear resulting from postharvest uses
1 ppm for pea resulting from postharvest uses
1 ppm for pineapple resulting from postharvest
uses
1 ppm for plum (fresh prune) resulting from
postharvest uses
1 ppm for raspberry resulting from postharvest
uses
1 ppm for tomato resulting from postharvest uses
1 ppm for walnut resulting from postharvest uses
1 Po = Postharvest
Updated 40 CFR
The 40 CFR should be updated to incorporate all the changes specified above. Once
these changes are made the CFR should be in the format listed below.
§180.128 Pyrethrins; tolerances for residues
(a)General.
(1) Tolerances for residues of the pyrethrins 1 ((lS)-2-methyl-4-oxo-3-(2Z)-2,4-
pentadienylcyclopenten-1 -yl (lR,3R)-2,2-dimethyl-3 -(2-methyl-1 -
propenyl)cyclopropanecarboxylate), cinerin 1 ((lS)-3-(2Z)-2-butenyl-2-methyl-
4-oxo-2-cyclopenten-l-yl(lR,3R)-2,2-dimethyl-3-(2-methyl-l-
propenyl)cyclopropanecarboxylate), andjasmolin 1 ((lS)-2-methyl-4-oxo-3-
(2Z)-2-pentenyl-2-cyclopenten-1 -yl (lR,3R)-2,2-dimethyl-3 -(2-methyl-1 -
propenyl)cyclopropanecarboxylate), which serve as a marker for residues of the
insecticide pyrethrins (insecticidally active principles of Chrysanthemum
cinerariaefolium), are established in or on the following food commodities:
[Insert list as specified in the tables above after all data to support these
tolerances have been submitted and reviewed.]
(2) A tolerance of 1.0 ppm is established for residues of the insecticide
pyrethrins in or on milled fractions derived from Grain, cereal when present as a
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result of its use in cereal grain mills and in storage areas for milled cereal grain
products.
(3) A tolerance of 1.0 ppm is established for residues of the insecticide
pyrethrins in or on all food items in food handling establishments where food
and food products are held, processed, prepared and/or served. Food must be
removed or covered prior to use.
(4) Where tolerances are established on both the raw agricultural commodities
and processed foods made there-from, the total residues of pyrethrins in or on
the processed food shall not be greater then that permitted by the larger of the
two tolerances.
(b) Section 18 emergency exemptions.
[Reserved]
(c) Tolerances with regional registrations.
[Reserved]
(d) Indirect or inadvertent residues.
[Reserved]
D. Regulatory Rationale
The Agency has determined that the pyrethrins are eligible for reregi strati on provided
that the risk mitigation measures and label amendments specified in this RED are implemented.
The following is a summary of the rationale for managing risks associated with the use of
pyrethrins.
1. Human Health Risk
a. Dietary (Food and Drinking Water) Risk Mitigation
Acute Risk
Acute dietary (food and drinking water) risk does not exceed the Agency's level of
concern; acute dietary risk estimates are 54% of the aPAD for the general U.S. population, and
100% for children 1-2 years old, the most highly exposed subgroup. The dietary risk assessment
overestimates acute risk because the acute dietary assessment was not refined for all
commodities. EPA calculated that 71 % of the total dietary exposure was attributed to pineapple,
dried-oat baby food, and banana, all of which included the conservative assumption of 100% of
the crop treated with pyrethrins.
In this dietary assessment, previously established tolerances were used for many of the
food commodities that were lacking residue data. For all other commodities in the assessment,
data were translated from either residue data or other tolerances values. No monitoring data
were available. Default processing factors were used because there were limited processing data
available. 100% crop treated was used as a default on more than half of crops due to lack of
data. Both, the presence of processing factors and percent crop treated impact the assessment
greatly.
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Estimated drinking water concentrations, which were included in the dietary assessment,
represents the upper-bound estimated concentrations that might be found in surface water and
groundwater due to the use of pyrethrins on multiple crops. This use of upper-bound estimates
for drinking water is a conservative approach. When combining high-end food and water
estimates, modeling results are higher than what is expected under actual use conditions.
The aPAD for children 1-2 is at the Agency's level of concern at 100%, with any
refinement in the percent crop treatment values or residue levels, the estimated risk for children
1-2 is expected to decrease and therefore, no mitigation is necessary for this scenario.
Chronic Risk
The chronic dietary (food and drinking water) risk is below the Agency's level of
concern; risk estimates are at 11% of the cPAD for the general U.S. population, and 32% of the
cPAD for children 1-2 years old, the most highly exposed population subgroup. Therefore, no
mitigation is necessary for this scenario.
b. Residential Risk Mitigation
Application rates for most of the exposure scenarios assessed were based on information
provided in the Pyrethrins Master Label, which lists all of the uses that the PJV members were
supporting. The label table provided in Section V includes updated label language that reflect
the supported uses, maximum application rates, and use restrictions that are required as a result
of the pyrethrins risk assessments and have been agreed upon by the PJV. All labels must be
revised to reflect these changes.
i. Handler
In the residential handler exposure assessment a number of scenarios were assessed to
estimate the exposure to homeowners handling products containing pyrethrins. From the results
of the residential handler assessment, there are no residential risks of concern when pyrethrins
are mixed, loaded, applied, or handled by homeowners. Therefore, no mitigation is warranted
based on the risk assessment.
ii. Post-Application
A number of post-application residential scenarios were assessed for adults and children
exposed to pyrethrins indirectly after application. Of these scenarios, three post-application
residential scenarios assessed were of concern to the Agency including: 1) broadcast dust
applications to carpets, 2) indoor metered release devices, and 3) outdoor residential misting
systems. To address the potential risks associated with these post-application scenarios, the
following mitigation measures are to be implemented.
Dusts - Broadcast Applications to Carpets
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Applying dusts to carpets over a wide area can lead to exposure to children through
incidental oral exposures. Most of the labels containing this type of application indicate the
dust needs to be vacuumed after application. Since there is no information to determine how
much pyrethrins are removed from the carpet while vacuuming, there is an unknown amount of
dust available for exposure to children. The Agency has concerns form the potential incidental
oral exposure children could have from this type of broadcast application to large carpeted
areas. To reduce exposure to children from broadcast dust applications to carpets, the PJV has
agreed to restrict carpet applications to spot treatments no greater than 3 feet by 3 feet in area.
Pyrethrins are also used on turf, and so an incidental oral assessment was conducted for
use on turf which is considered a conservative risk estimate including 3 separate incidental oral
exposure activities and assumes the exposures occur simultaneously. The turf scenario
methodology, which has been peer reviewed and is better understood than the carpet dust
scenario, includes incidental oral exposure to pesticide on turf from (1) hand to mouth
activities, (2) object to mouth activities, and (3) ingesting soil particles. The aggregate of all
three of these incidental oral turf exposures is above the Agency's target MOE of 300 with an
MOE of 11,000. Given the conservative nature of the turf exposure scenario, it is unlikely that
the magnitude and frequency of exposure to small spot treatments (3 sq ft) of dust formulations
of PBO would result in exposure estimates equal or greater than estimated for the residential
lawns. Since there are no incidental oral risks of concern from the turf scenario, and the PJV
has agreed to reduce the amount of potential exposure to children by restricting applications to
spots only, the Agency is not requiring and additional data at this time.
Indoor Metered Release Devices - Residential
There are potential risk concerns for post-application intermediate-term exposures
following indoor applications with metered release devices. The MOEs range from 40 to 780 and
are less than the target MOE of 1000. The risk calculations for the metered release scenarios are
conservative because it was assumed that the aerosol spray would remain airborne until removed
by ventilation and the effect of aerosol spray settling was not considered. Aerosol spray settling
could be a major factor depending upon the aerosol droplet size and the rate of evaporation.
Information regarding the aerosol droplet size and evaporation rate could be used to refine the
risks, particularly for the residential scenarios where the ventilation removal rate is probably
slower than the settling rate.
Therefore, to reduce the risks to sensitive bystander populations, the Pyrethrin Joint
Venture has agreed to remove the following use sites from their metered release device product
labels: day care centers, nursing homes, schools, and hospitals. In addition, EPA is requiring air
concentration and particle size data for indoor metered release devices and will prohibit metered
release device use in residential areas unless data are submitted in a timely fashion. Once these
data are submitted and reviewed, the Agency will make a determination regarding the use in
residential areas.
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Outdoor Residential Misting Systems
Outdoor residential misting systems are fairly new to the pesticide market, and vary in
their system design. Based on available information including outreach to the pyrethrins
registrants and other stakeholders, and review of labels currently registered for use in these
systems, the Agency used the following assumptions in the pyrethrins risk assessment:
• The spray droplets would be inhaled over a period of 5 hours for adults or 3 hours for
toddlers, based on information from the Exposure Factors Handbook (EPA 1997) on how
much time individuals spend outside.
• The initial concentration is based on instantaneous release and mixing into a fixed space with
a height of 8 feet.
• The exposure is assumed to encompass 2 spray events that occur in the morning or evening.
Based on these assumptions, the Agency has identified a potential risk of concern for
toddlers over the intermediate-term exposure duration. The target intermediate-term inhalation
MOE is 1000, and the toddler bystander assessment calculated an MOE of 400.
The inhalation exposure durations used for the mosquito mister scenarios (5 hours/day for
adults, 3 hours/day for toddlers) represent the 95th percentile values for time spent outdoors at a
restaurant/picnic area (USEPA, 1997). During this exposure period the individual is assumed to
be exposed to 2 spray events each lasting a period of 1 minute. Although this spray duration is
appropriate for risk assessment purposes, shorter spray durations (i.e., 20- or 30-second
durations) may be more representative of actual system rates, particularly for intermediate
exposure durations. If products used in misting systems had standardized label language for use
rates a more refined risk assessment would be possible. Currently, the labels do not specify the
maximum daily application rates.
The Consumer Specialty Products Association (CSPA) submitted a discussion paper
outlining some use information associated with these outdoor residential misting systems.
Mosquito mister risks were calculated based on automatic applications of 2 sprays per day. It
was noted in the CSPA discussion paper that the systems could be manually activated by the
homeowner to apply additional sprays. Although re-filling and maintenance costs would likely
limit homeowner use, label language indicating appropriate daily spray cycles and maximum
daily application rates is also needed to address current concerns over excessive use.
Therefore, to mitigate the risks for toddler bystander exposure from intermediate-term
outdoor residential misting systems, the PJV has agreed to restrict the maximum allowable daily
rate to 0.00011 Ib Py/1000 cubic feet/day, which is the rate where risks to children are not a
concern to the Agency. Further, the PJV has agreed to submit data to allow the Agency to better
understand these systems and refine the risk assessment. Information on use and usage of
outdoor residential misting systems, as well as air concentration and droplet size data will be
submitted. The PJV has also agreed to add the label statements listed in the label table in Section
V of this document. These label statements will restrict the maximum allowable daily rate that
can be applied, specify how the systems should be installed to reduce off-site drift, and specify
measures to make the system reservoirs less accessible to children or other individuals.
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Future Steps for Outdoor Residential Misting Systems
The distribution or sale, and use of pesticides in outdoor residential misting systems are
subject to several statutory requirements. At this time, pyrethrins, piperonyl butoxide (PBO),
and permethrin appear to be the only chemicals known to be used in outdoor residential misting
systems; however, it is possible that other pesticide registered for residential outdoor use might
also be used in similar systems. Section 2(ee)(3) of FIFRA permits the use of any application
methods that are not prohibited by the pesticide's labeling; however, the application must only
be to sites specified by the labeling and at no more than the maximum dosage rates specified by
the labeling. Since most pesticide labels do not explicitly prohibit use in outdoor residential
misting systems, other chemicals that target similar pests could be used in these misting systems.
The Agency is not aware of other pesticides being used in outdoor residential misting systems,
and therefore, has not assessed the potential risks to homeowners associated with use of
pesticides other than pyrethrins, PBO, and permethrin.
All pyrethrins, PBO, and permethrin registrants that do not support outdoor residential
misting systems use for their products will be expected to amend their Manufacturing Use
Product label to state the following, "This product must not be formulated into an end use
product for use in outdoor misting systems." Additionally, all registrants of pyrethrins end-use
products must either include a statement prohibiting use in an outdoor residential misting system,
for example, "This product must not be used in an outdoor residential misting system," or
include separate and specific instructions for use in outdoor residential misting systems,
including the maximum application rate per day, use directions, and restrictions specified in
Section V, Table 26. Although this action will only address pyrethrins, PBO, and permethrin
products, the Agency plans to issue broader guidance pertaining to use of outdoor misting
systems and the pesticides which can be used in these systems as part of its on-going effort to
standardize the way in which these systems are used.
By definition in FIFRA Section 2(e)(l) and (gg), leaving unapplied pesticide at a use site
constitutes the distribution or sale of a pesticide. In order to be in compliance with FIFRA,
companies which sell, install, and service outdoor residential misting systems must ensure that
one of the following transactions occur when providing these services:
• The unopened registered pesticide is distributed or sold to the use-site owner prior to
mixing and loading into the equipment; or
• The diluted registered pesticide is distributed or sold as a custom blend in accordance
with EPA's custom blending policies at FIFRA Compliance Program Policies Nos. 3.4
and 7.1 of the FIFRA Compliance Program Policy Compendium; or
• The diluted pesticide is registered and is distributed or sold to the use-site owner prior to
loading into the equipment.
Several issues, in addition to those discussed above, have been raised to EPA Regions
through State FIFRA Issues Research and Evaluation Group (SFIREG) issue papers, stakeholder
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forums and comments, and other sources regarding the use of these systems. These issues
include, but are not limited to, the potential for inadvertent exposure and risks to residents,
misuse of the systems and pesticide products, offsite drift and potential exposure to non-target
organisms, and pest resistance issues. The Agency is aware of a cooperative effort lead by the
National Pest Management Association involving state and industry stakeholders, and pest
management professionals to standardize these systems and address the issues raised above, and
intends to continue to address these on-going issues through continued involvement and
discussions with the States, industry and stakeholder groups.
The Agency will have a 60-day comment period after the publication of the RED to
solicit feedback on the label language in Section V, Table 26, and the issues discussed above.
i. Human Incidents
EPA has identified potential concern for people using pyrethrins-containing products in
residential settings based on the Agency's analysis of exposure incident reports. This analysis
suggested a possible connection between allergic and respiratory reactions in susceptible
individuals and use of these products. A large number of reported incidents are related to use of
the pediculicide (lice killing) shampoo products. These products are regulated by FDA and
already contain language advising susceptible individuals to contact their physicians before use.
In its incident analysis EPA recommended similar language for all pyrethrins products.
The Pyrethrin Joint Venture, an industry task force representing registrants, submitted a
response to EPA summarizing 61 literature references on pyrethrum botany, chemistry, refining
process, allergic reactions and contact dermatitis. The industry paper concludes that based on
current chemistry and the current level of diagnostic standards, allergic contact dermatitis does
not occur in response to use of pyrethrins products at a significant incidence in ragweed sensitive
individuals as compared to the general population, although EPA's review of the submission
found the basis for that conclusion to be unclear (R. Allen, Review of Mosby, and Registrant
Submissions, DP 326085). The PJV is preparing a similar report focusing on respiratory
incidents.
In order to clarify the issue of possible correlation between use and incidents, the PJV has
committed to a product stewardship program that would involve outreach to physicians and
Poison Control Centers with better guidance and diagnostic standards, as well as prospective in-
depth follow-up of reported cases. In order to track the progress and information gathered from
this program, annual reports that include information the program has collected, as well as
progress of the program will be required as a data requirement in the Data Call-In. These annual
reports will be required for at least 5 years, with a possible extension based on the information
collected.
EPA will continue its research and discussion with the PJV and other interested
stakeholders on whether or not precautionary labeling is warranted for some or all products and
if so, what statements would be most useful to consumers. In the interim, all product labeling
will be revised to include common-sense precautions for all consumers, including required
ventilation statements as noted in Table 26. EPA's analyses and the PJV responses are available
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in the docket (OPP-2005-0043). The protocol for the product stewardship program will also be
posted when it is finalized.
c. Aggregate Risk Mitigation
Only short-term aggregate risk was calculated for pyrethrins because the oral and
inhalation endpoints that were selected demonstrated different effects for the intermediate-term
duration.
i. Short-Term Aggregate
An aggregate ARIagg above 1 is not of risk concern for the Agency. The aggregate results
for most sub-populations were well above the target Aggregate ARI of 1 and are not a concern.
However, the ARIagg (ARIagg = 0.96) for children does not reach the target. It is considered to be
a high-end estimate because the calculated exposure values for food and water were high-end
estimates. Percent crop treated data were not available for all commodities. High-end field trial
data were generally used, because sufficient data were not available for all commodities. The
results from the dietary assessment are discussed in further detail under the "Dietary Mitigation"
section above. Since high end values were used in the dietary assessment, and the incidental oral
and inhalation values both represent the highest anticipated contribution from these sources, the
actual short-term aggregate risk is likely to be much lower. Therefore, the Agency is not
requiring specific mitigation to address the short-term aggregate assessment.
d. Occupational Risk Mitigation
Occupational exposure assessments are completed by the Agency considering the use of
baseline PPE and, if warranted, for handlers, increasing levels of PPE and engineering controls
in order to estimate the potential impact on exposure and risk. The target MOEs for pyrethrins
are 100 for short-term inhalation exposures, and 1000 for intermediate- and long-term inhalation
exposures.
i. Handler Risk Mitigation
Wettable Powders - Agricultural and Pest Control Operator (PCO)
There are inhalation risk concerns for agricultural and PCO mixers and loaders of
wettable powder pyrethrins products at baseline attire. Therefore, to mitigate the risks to mixers
and loaders of wettable powders in agricultural and professional applicator settings, the Pyrethrin
Joint Venture has agreed to package wettable powders only in water soluble bags. When
wettable powder products are packaged in water soluble bags, there are no risks of concern for
mixers and loaders in agricultural settings or for PCOs. Therefore, to be eligible for
reregi strati on, all wettable powders must be in water soluble bags. At this time, the Agency is
not aware of any wettable powder products being actively marketed in the US. If wettable
powders are sold in the future all products must comply with the water soluble bag and other
requirements established in this decision document.
Indoor Handheld Equipment (including thermal, cold, and ULV foggers)
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Handheld fogging equipment was not included in the Phase 5 pyrethrins risk assessment,
but risk has subsequently been estimated based on both conservative application assumptions and
data from a fogging study for the chemical prallethrin (MRID: 45869301). There are potential
risks of concern for professional applicators with this scenario that can be mitigated with
additional PPE of a protection factor 5 (PF5) dust mist respirator for applicators. The application
rate assessed was 0.00042 Ibs ai/1000 cubic feet which is representative of pyrethrins products.
Therefore, to mitigate the risks to applicators using handheld fogging equipment, the Pyrethrin
Joint Venture has agreed to require a PF 5 dust mist respirator for indoor applications, and will
submit information on general fogging practices. There is no risk of concern with applicators
using a PF 5 dust mist respirator while fogging.
Dusts Applied through Power Dusters
The Agency was not able to assess scenarios involving dust applications with power
dusters because there are no exposure data to represent this application method. Power dusters
could potentially pose inhalation risk. Due to a lack of data on this exposure scenario and no
interest in supporting this application method from the Pyrethrin Joint Venture, EPA has
determined that this application scenario is not eligible for reregi strati on. If data are submitted to
support this application method, EPA will reconsider this decision in the future. Dust product
labels must prohibit use of power dusters.
Dusts Applied through Bulb Dusters
The Agency was not able to assess scenarios involving dust applications with bulb
dusters because of a lack of data. Bulb dusters are only used for crack and crevice treatments,
which reduces the possible exposure to an applicator. Due to small amounts of dust used in this
application method, the exposure is expected to be negligible. Therefore, no mitigation or data
are required for this scenario.
ii. Post-Application Worker Risk Mitigation
Metered Release Devices - Dairy Barns
The Agency has similar concerns for post-application intermediate-term exposures from
these systems as described in the occupational post-application section of this chapter.
According to the Master Label, pyrethrins are used as space sprays in a wide variety of indoor
areas such as barns, greenhouses, food storage areas, food processing areas, restaurants and
residences. A scenario that involves a metered release into a dairy barn was evaluated to assess
these exposures because pyrethrins are commonly used in dairy barns and because the ventilation
characteristics of dairy barns are relatively well defined.
There are no risk concerns over the short-term exposure duration (MOE is 1200 and the
target is 100). Risks are lower for these occupational scenarios than for residential settings due
to the fact that the occupational areas generally have a greater ventilation capacity and the risk
assessment assumes a higher number of air changes per hour in these settings. The MOEs for
metered release devices in occupational areas like dairy barns were calculated to be 400 with a
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target of 1000 for intermediate-term exposure. While it is possible workers could be exposed to
pyrethrins from these metered release devices, it is not likely a worker would be exposed to the
full daily amount for more than 30 consecutive days.
Therefore, to confirm the Agency's exposure assumptions that intermediate-term
exposures are not likely to occur from metered release devices in occupational settings, the
Agency is requesting additional usage information about the metered release device products, as
well as requiring the label changes included in Section V. Some products labeled for use in
occupational areas are also labeled for use in residential settings and areas where children may
be present. Therefore, as mentioned in the residential metered release device section above, the
Pyrethrin Joint Venture has agreed to remove the following use sites from metered release device
product labels: day-care centers, nursing homes, schools, and hospitals.
2. Non-Target Organism (Ecological) Risk Management
a. Aquatic Organisms
i. Agricultural Use
For freshwater and estuarine/marine fish and aquatic invertebrates, including sediment
dwelling organisms, acute risk and endangered species RQs exceed LOCs with RQs ranging
from 0.54-1.98 when maximum rates and minimum reapplication intervals are modeled.
Chronic RQs from modeled agricultural exposure scenarios also exceed LOCs for
estuarine/marine invertebrates.
The risk estimates did not change substantially when the "typical" reapplication interval
of 3 days was used instead of the shortest reapplication interval of 1 day. Since pyrethrins are
used on a wide variety of crops, the typical application parameters can vary greatly depending on
the commodity. However, the typical application rates and number of applications represented
in this assessment appear to have the potential to reduce risk to aquatic systems. Evaluation of
four crop scenarios suggests that all LOCs for freshwater and estuarine/marine fish and
invertebrates would not be exceeded if the typical application rate is used.
Currently there are label restrictions on some, but not all product labels indicating the
maximum application frequency and rate. All product labels will be revised to include the
following information:
• No more than 10 applications per season.
• Do not reapply within 3 days except under extreme pest pressure.
• In case of extreme pest pressure, do not reapply within 24 hours.
ii. Mixtures Risk
The Agency assessed the maximum and typical rates for a pyrethrins product formulated
with a synergist, piperonyl butoxide, but only evaluated acute exposure to aquatic organisms
based on the toxicity data available. The calculated EECs show that acute risk from the
maximum formulation rate appeared to be higher than risk calculated only from the TGAI.
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Toxicity data showed that acute risk from the formulation was about 2-7 times greater for
freshwater and estuarine/marine fish and about 10 times greater for estuarine/marine
invertebrates. However, the typical formulated product rate appears to reduce the risk
(freshwater and estuarine/marine fish and freshwater invertebrates), but this reduction in
exposure still presents the potential for acute and chronic risk to estuarine/marine invertebrate
species.
Because the limited information available indicates the toxicity to certain non-target
organisms, specifically aquatic invertebrates, fish, and non-target insects, increases significantly
(2-7 times) in the presence of a synergist, additional product specific data will be required to
better characterize these risks.
iii. Down-the-Drain
There were no risks of concern identified in this assessment attributed to the contribution
of pyrethrins to domestic wastewaters. Therefore, no mitigation is needed.
iv. Wide Area Mosquito Abatement
The estimated exposure for mosquito adulticide applications of pyrethrins were compared
to the toxicity values for both freshwater and estuarine/marine fish and invertebrates. All of the
fish and the freshwater invertebrate risk calculations did not exceed the Agency's acute levels of
concern for acute or endangered species levels.
The only organism for which RQs exceed the Agency's level of concern for acute and
endangered species was the estuarine/marine invertebrate. There are currently no Federally
listed threatened or endangered ("listed") estuarine/marine invertebrates. Even so, different
application parameters were modified in the risk assessment to determine which parameter had
the biggest effect on risk to aquatic organisms from mosquito adulticide applications.
By changing the application rate, droplet size, and release height parameters a range of
RQs were calculated, as shown in Table 25 below. Droplet sizes ranged from 40 um to 50 um,
but only decreased the RQs minimally. Other wide area mosquito adulticide pesticides require a
droplet size of 60 um, and since this parameter does not affect the risk assessment significantly
pyrethrins will conform with this droplet size. Similarly the maximum application rate of 0.008
Ib ai/acre did not significantly affect predicted RQs by rate reduction alone. The parameter to
affect the risk calculation the greatest was the release height. Release heights of 75 feet and 150
were modeled. At a release height of 150 feet and either a smaller droplet size or a typical
application rate, the estimated risk for estuarine/marine invertebrates reaches a level below the
level of concern for endangered species.
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Table 25: Estuarine/marine invertebrate RQs
Rate
(0.0080 or 0.0025 Ib
ai/A)
0.0080
0.0080
0.0025
0.0080
0.0080
0.0025
Droplet
(50 or 40 um)
50
40
50
50
40
50
Boom release height
(75 or 150 ft)
75
75
75
150
150
150
Estuarine/Marine Invertebrate
RQ 6" water
0.81a
o.sr
0.25C
0.05
0.02
0.02
Bolded values do not meet the acute LOG for either acute3 (LOG = 0.5) or acute endangered species ° (0.05) risk.
Therefore, to mitigate the risks from wide area mosquito adulticide applications, the
Pyrethrin Joint Venture agreed to the following restrictions:
• Droplet size for aerial applications: DvO.5 < 60 um and DvO.9 < 80 um
• Droplet size for ground applications: DvO.5 < 30 um and DvO.9 < 50 um
• Release height: 100 ft. airplane, 75 for helicopter
• Yearly application rate: 0.2 Ibs ai/acre/year
• Wind Speed: Apply when the wind speed is greater than or equal to 1 mph.
v.
Other Non-Agricultural Uses
Office of Pesticide Programs (OPP) generally tries to estimate pesticide exposure through
all significant routes of exposure from both agricultural and non-crop uses. However, the
ecological risk assessments for pyrethrins and pyrethroid insecticides focus predominantly on the
agricultural uses for these insecticides, because pesticide transport models are available to
estimate potential aquatic exposure. Based on laboratory toxicity tests with terrestrial and
aquatic animals, aquatic exposure would be more likely to cause adverse effects in the
environment.
However, sales data indicate that non-crop uses of the pyrethrins and pyrethroids
comprise a much larger fraction of total use than agricultural uses. The use of pyrethrins and
pyrethroids in urban and suburban settings has increased since the phase-out of these uses of the
organophosphate insecticides diazinon and chlorpyrifos. Outdoor non-crop uses of pyrethrins
include landscape maintenance and homeowner lawn and garden use. Indoor uses include insect
control, and treatment of pets and clothing.
The Agency uses a "Down-the-Drain" model to perform a screening aquatic risk
assessment for indoor uses of pesticides. In these simulations, waste water containing pesticide
residue from pet shampoos or treated clothing flows into a building drain and passes through a
sanitary sewer and publicly owned treatment works (POTW) before being discharged to surface
water. However, no analogous exposure model has been developed to allow a similar screening
assessment for pesticides applied in an outdoor urban setting. As a result, the Agency has had to
take a qualitative approach to characterize the potential aquatic risk from urban and suburban use
of pyrethrins and pyrethroids.
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For outdoor urban uses it is assumed that runoff water from rain and/or lawn watering
may remove pesticide to storm sewers and then directly to surface water. Conceptually, a greater
contribution to contamination of surface water bodies would be expected from application to
impervious surfaces such as walkways, driveways or the sides of buildings than to lawns or bare
ground, because of the pyrethrins and pyrethroids' strong affinity to bind to organic carbon in
soils. However, the Agency has not identified a model which can simulate the different
application methods for urban use and the physical representation of the urban landscape, storm
sewer and receiving water configuration.
There are models available that can be calibrated to simulate sites and pesticides for
which extensive flow and pollutant data have been collected in advance. The HSPF/NPSM
model, for instance, which is included in the Office of Water's BASINS shell, has been used to
calibrate stream flow and copper pesticide use data to simulate loading of these pesticides
consistent with concentrations measured in surface water monitoring. Risk assessors with the
California Department of Environmental Protection confirmed in conversations with the Agency
that they also have used watershed models calibrated to previously collected flow and pesticide
monitoring data, but that they did not know of any models capable of predicting concentrations
of pyrethrins and pyrethroids that might occur because of outdoor urban uses.
Development of a screening model which could simulate the fate and transport of
pesticides applied in an urban setting would require a large body of data which is currently
unavailable. For instance, an urban landscape cannot be simulated as easily as an agricultural
field. The PRZM model simulates runoff from an agricultural field using readily available data
describing surface soil characteristics and laboratory data detailing the persistence and mobility
of pesticides in these soils. The agricultural field simulated is homogenously planted to a single
crop, and soil and water are transported from the field to a receiving water body with dimensions
consistent with USDA farm-pond construction guidelines.
By contrast, an urban landscape or suburban housing development consists of impervious
surfaces such as streets and sidewalks, and permeable surfaces such as lawns and parkland. One
could expect much greater mobility for pesticides applied to impervious surfaces, but laboratory
soil metabolism studies may not provide an accurate measure of the persistence of pesticides on
these surfaces. The path runoff water and eroded sediment might take is less obvious for an
urban setting than an agricultural field. First, an urban landscape cannot be considered
homogeneous, as the proportion of impervious and pervious surfaces varies for different
locations. In addition, the flow path of runoff water and sediment is not necessarily a direct path
over land, but can pass below ground through storm sewer networks, or be directed or slowed by
pumping stations or temporary holding ponds.
The timing and magnitude of urban uses is less well defined than agricultural uses.
While agricultural uses would occur within a predictable window during the growing season, the
need for urban uses could occur at different times each year, and might occur at different times
within the same watershed. In addition, since records of how and to what extent pyrethrins and
pyrethroids are applied by homeowners are less well defined than for professional applications, it
is harder to estimate the total load to model.
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Monitoring Data
The Agency considers surface water monitoring data in addition to modeling results
when they are available. However, surface water monitoring for pyrethrins has been limited. In a
Sacramento County monitoring study targeting pyrethrins and PBO, water samples were
collected after mosquito adulticide applications in the Sacramento metropolitan area. In samples
collected up to 10 hours after application there were detects of pyrethrins and PBO from in the
ppb range, similar to modeling predictions in the pyrethrins and the PBO mosquito adulticide
assessment. Samples were also collected the day after application and measured lower or no
concentrations for both active ingredients. This indicates both chemicals appear to dissipate
fairly rapidly in the water column. The co-occurrence of pyrethrins and PBO in some of these
first samples is an indication of direct application to water and not transport by runoff.
There has been limited monitoring for the pyrethroids, but recently researchers from the
University of California- Berkeley have published studies which reported transport of
pyrethroids to stream bed sediment as a result of urban uses. In 2004, Weston, et al. collected
sediment from creeks draining a residential area in Rosedale, California. The sediments were
analyzed for 7 pyrethroids (including two currently in the reregi strati on process), as well as for
other insecticides. All of the pyrethroids were detected in the bed sediment from at least one
sampling location. The researchers exposed the aquatic amphipod Hyalella azteca to the 21
sediment samples they collected; pesticide concentrations in 9 of these samples were sufficient to
cause 90% mortality in the amphipods after a 10-day exposure. The concentrations of
pyrethroids detected in the sediments were above the level expected to cause 50% mortality in H.
azteca, suggesting that the pyrethroids were responsible for the observed toxicity.
In a subsequent study, Weston, et al. collected samples from 15 urban creeks in
California and 12 in Tennessee. Toxicity to H. azteca was observed at least once with sediments
taken from 12 of the 15 California sampling sites. In most cases, the toxicity could be accounted
for by the concentrations of pyrethroids detected in the sediment. Pyrethroids were rarely
detected in the Tennessee sediment samples, and exposure to the Tennessee sediments did not
prove to be toxic to H. azteca. The Weston studies did not sample for pyrethrins.
The Weston, et al. studies indicate that urban uses of pesticides can lead to surface-water
contamination, including contamination by pesticide that would bind almost completely to soil in
an agricultural setting. The pyrethrins are similar to pyrethroid in that respect, but are less
persistent and somewhat less toxic to aquatic organism; therefore, while pyrethrins may pose risk
to aquatic organisms in their own right, comments from California water boards have suggested
pyrethrins are a possible alternative to pyrethroids in urban settings. Nevertheless, efforts taken
to better understand use practices and environmental conditions which may lead to transport of
pyrethroids to surface water in urban settings would help improve the exposure assessment for
pyrethrins.
The results of the Weston, et al. studies have led a number of organizations, such as the
California State Water Resources Control Board (SWRCB) to submit comments to the Agency
calling for mitigation measures to prevent pyrethrins and pyrethroid surface-water
contamination. However, the lack of data and information to develop an urban pesticide
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transport model also makes it difficult to identify whether risks may exceed some LOCs, and
appropriate mitigation at this time. The Agency is committed to develop mitigation options
during the reregi strati on process, and to identify steps which can be taken to allow a greater
understanding of potential ecological risk from urban pyrethrins and pyrethroid uses.
One reason that broad mitigation measures cannot be adopted during reregi strati on is that
only three pyrethroid insecticides are being reregistered. If use restrictions were placed on one of
these three pesticides, one of the other pyrethroids would likely replace it for that use. It would
be useful, as some commenters have suggested, to perform a risk assessment for all of the
pyrethroids at the same time. The Weston papers indicated that the sediments which proved
toxic to the tested aquatic invertebrate were contaminated not only with the pyrethroids
undergoing reregi strati on, but also other pyrethroids such as bifenthrin and lambda-cyhalothrin.
The next opportunity to assess the pyrethroids as a group will occur during the
Registration Review program, for which the Agency issued a proposed rule in July 2005 and
plans to issue the final rule and begin implementing the program in 2006. The purpose of
Registration Review is to ensure the periodic review of all pesticides to make sure they continue
to meet current scientific and regulatory requirements, with the goal of reviewing each pesticide
every fifteen years. The pyrethroids are tentatively scheduled for re-evaluation under the
proposed Registration Review program in 2010. Efforts to improve the exposure assessment for
urban uses of pyrethroids should improve the Agency's ability to evaluate these uses for
pyrethrins as well.
A number of steps are planned for the intervening years which should improve the
Agency's ability to assess the level of aquatic exposure to pesticides such as pyrethrins and
pyrethroids from urban use. One step is to better identify what conditions in an urban setting
might lead to greater vulnerability to transport to urban water bodies. Although the Weston paper
reported sediment toxicity from samples from California but not Tennessee, the authors could
only speculate what differences in use or geography made an area more vulnerable to exposure
than the other.
Further investigation into the dominant urban uses and application practices of pyrethrins
around the country would also help provide a clearer picture of relative vulnerability. The
California SWRCB commented that structural pest control is likely a major source of pyrethroids
in urban runoff, and suggested best management practices (BMP). The Pyrethroid Working
Group (PWG) indicated that irrigation of lawns in areas of California with little rainfall during
the application season could be a major contributor, and has contacted organizations such as
Responsible Industry for a Sound Environment (RISE) and the Coalition for Urban/Residential
Environmental Stewardship (CURES) to develop BMPs as part of their product stewardship
plan. As further sediment monitoring studies are published reflecting various parts of the
country with different weather and pest pressures, more detailed usage data will make it easier to
correlate the causes of pyrethrins and pyrethroid contamination of surface water with use
practices.
The Agency will also continue in its efforts to develop a screening model for urban
pesticide uses. Advances in the resolution of GIS databases may allow better representation of
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the impervious and pervious portions of a typical urban landscape. As it becomes clearer which
uses are most likely to lead to transport of pyrethrins and pyrethroids to surface water, the
conceptual model of how urban transport should be simulated will be more focused.
The Agency will evaluate available published literature and call-in data to resolve data
gaps to ensure a robust comparison of the potential ecological risk of all the pyrethrins and
pyrethroids during Registration Review. Toxicity data cited by several commenters from
published literature are included in the Agency's ECOTOX database. The Agency will evaluate
the quality of studies to identify those to be included in the risk assessments during Registration
Review.
Stewardship Language
While the Agency cannot currently assess the potential risks to aquatic organisms from
non-agricultural uses of pyrethrins, the Agency is still seeking to reduce the potential drift and
run-off of pyrethrins into aquatic habits through explicit directions for use on both professional
and consumer use products for use in residential settings. These use directions include best
management and stewardship practices which are formulation specific, and will serve to reduce
the potential run-off and drift that can occur from applications of these products. Label
statements implementing these measures are listed in the "direction for use" section of the label
table (Table 26) in Section V of this RED document.
b. Terrestrial Organisms
Birds and Mammals
No acute and chronic risk for listed or non-listed mammalian and avian species exceed
EPA's level of concern; therefore, no mitigation is needed.
Terrestrial Plants
Risks were not calculated for non-target plants because the sodium channel mechanism of
action for pyrethrins does not indicate that pyrethrins would be toxic to plants. Therefore, no
mitigation is needed.
Non-Target Insects
There are risk concerns for honeybees that suggest there are non-target beneficial insect
concerns as well. Therefore, to mitigate concerns for honeybees and other non-target insects, an
environmental hazard statement for honeybees will be added to all Environmental Hazard
statements on product labels.
b. Endangered Species
The Agency's screening level assessment results in the determination that pyrethrins will
have no direct acute effects on threatened and endangered mammals or birds. The preliminary
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risk assessment for endangered species indicates that RQs exceed endangered species LOCs for
freshwater fish and invertebrates, and estuarine/marine fish and invertebrates. Further, potential
indirect effects to any species dependent upon a species that experiences effects from use of
pyrethrins can not be precluded based on the screening level ecological risk assessment. These
findings are based solely on EPA's screening level assessment and do not constitute "may affect"
findings under the Endangered Species Act.
V. What Registrants Need to Do
The Agency has determined that pyrethrins are eligible for reregi strati on provided that
the mitigation measures and label changes identified in this RED are implemented. Registrants
will need to amend their product labeling to incorporate the label statements set forth in the
Label Changes Summary Table 26. The Agency intends to issue Data Call-Ins (DCIs) requiring
generic and product specific data. Generally, the registrant will have 90 days from receipt of a
DCI to complete and submit response forms or request time extensions and/or waivers with a full
written justification. For product-specific data, the registrant will have eight months to submit
data and amended labels.
A. Manufacturing Use Products
1. Additional Generic Data Requirements
The generic data base supporting the reregi strati on of pyrethrins for currently registered
uses has been reviewed and determined to be substantially complete. However, the data listed
below are necessary to confirm the reregi strati on eligibility decision documented in this RED.
Human Health Data Requirements
The following toxicology and residue chemistry data are being required to support the
registration of pyrethrins:
Toxicology
• Developmental neurotoxicity study.
• Comparative thyroid study.
Residue Chemistry
• An independent lab validation (ILV) for the proposed single analyte regulatory method
(as opposed to multiresidue methods) is required for the determination of pyrethrins
residues of concern in/on plant commodities.
• Storage stability data for representative commodities of oilseeds, non-oily grains, and
root crops.
• Storage stability data for the processed commodities of representative oilseeds
(cottonseed or peanut) and grains (preferably field corn or wheat). In addition, storage
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stability data on dried fruits (preferably raisins or prunes) to confirm whether residues of
pyrethrins 1 decline on other dried processed fruits.
• Magnitude of Residue Studies to support uses of pyrethrins on foods stored in multi-
walled paper or cloth bags.
• Magnitude of the residue studies reflecting preharvest uses on representative
commodities of all crop groups and miscellaneous commodities which are being
supported for reregi strati on.
• Magnitude of the residue studies reflecting postharvest uses for all crops (except potato
and sweet potato) which are being supported for reregi strati on.
• Magnitude of Residue Study to support the use on tobacco.
• Processing studies on apple, barley, cacao bean, coconut, coffee, corn (field), cotton, fig,
flax, oat, peanut, pineapple, plum, rice, rye, safflower, sorghum, soybean, sugarcane,
sunflower, tea, and wheat.
• A confined rotational crop study.
Occupational and Residential Exposure
• Metered release devices: use and usage information, as well as air concentration and
particle size data.
• Outdoor residential misting systems: use and usage information, as well as air
concentration and droplet size data.
• Applicators using handheld fogging equipment: use and usage data on application
practices.
Incident
• In order to clarify the issue of possible correlation between use and incidents, the PJV has
committed to a product stewardship program that would involve outreach to physicians
and Poison Control Centers with better guidance and diagnostic standards, as well as
prospective in-depth follow-up of reported cases. In order to track the progress and
information gathered from this program, annual reports that include information the
program has collected, as well as progress of the program will be required for at least 5
years, with a possible extension based on the information collected.
Environmental Fate and Effects Data Requirements
The fate and ecological effects data bases are adequate to conduct a Tier I risk
assessment. The following ecological effects data are needed because of the phytotoxic effects
pyrethrins have on plants and potential risk to benthic organisms:
• A life-cycle study (Guideline 850.1300 and 850.1350) with an estuarine/ marine
invertebrate (e.g., Mysid shrimp) and fish early life-stage study with an estuarine/marine
fish (e.g., Sheepshead Minnow).
• Tier I plant studies [Guideline 850.4225 Seedling Emergence and Guideline 850.4150
Vegetative Vigor] and aquatic plant growth studies with algae (Guideline 850.5400) and
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duckweed (Guideline 850.4400) be submitted to the Agency to fully evaluate the
potential risk to plants.
• A whole sediment acute test with the freshwater organism, Chironomus ripiriam
(Guideline number 850.1735) and the marine water organism, Leptocheirusplumulosus
(Guideline number 850.1740) are needed to fully evaluate potential risk to benthic
organisms.
• Pyrethrins urban use data, to better identify what conditions in an urban setting might
lead to greater vulnerability to transport to urban water bodies.
In addition to the ecological and fate data requirements listed above for pyrethrins, the
limited information available indicates end-use products formulated with a synergist, like
piperonyl butoxide, to certain non-target organisms, specifically aquatic invertebrates, fish, and
non-target insects, increases the toxicity of the active ingredient significantly. To better inform
these potential risk concerns, additional data for typical end-use products formulated with
piperonyl butoxide, including products containing pyrethrins, will be required in the piperonyl
butoxide RED and Data Call-In.
2. Labeling Requirements
To ensure compliance with FIFRA, manufacturing use product (MUP) labeling should be
revised to comply with all current EPA regulations, PR Notices, and applicable policies. The
MUP labeling must bear the labeling contained in Table 26 to be eligible for reregi strati on.
3. Spray Drift Management
The Agency has been working closely with stakeholders to develop improved approaches
for mitigating risks to human health and the environment from pesticide spray and dust drift. As
part of the reregistration process, the EPA will continue to work with all interested parties on this
important issue.
Specific spray drift language for pyrethrins is outlined in the "spray drift management"
section of the label table.
4. Endangered Species
The Agency has developed the Endangered Species Protection Program to identify
pesticides whose use may cause adverse impacts on endangered and threatened species, and to
implement mitigation measures that address these impacts. The Endangered Species Act (ESA)
requires federal agencies to ensure that their actions are not likely to jeopardize listed species or
adversely modify designated critical habitat. To analyze the potential of registered pesticide uses
that may affect any particular species, EPA uses basic toxicity and exposure data developed for
this RED and considers it in relation to individual species and their locations by evaluating
important ecological parameters, pesticide use information, geographic relationship between
specific pesticide uses and species locations, and biological requirements and behavioral aspects
of the particular species, as part of a refined species-specific analysis. When conducted, this
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species-specific analysis will take into consideration any regulatory changes recommended in
this RED that are being implemented at that time.
Following this future species-specific analysis, a determination that there is a likelihood
of potential impact to a listed species or its critical habitat may result in: limitations on the use of
pyrethrins, other measures to mitigate any potential impact, or consultations with the Fish and
Wildlife Service or the National Marine Fisheries Service as necessary. If the Agency determines
use of pyrethrins "may affect" listed species or their designated critical habitat, EPA will employ
the provisions in the Services regulations (50 CFR Part 402). Until that species-specific analysis
is completed, the risk mitigation measures being implemented through this RED will reduce the
likelihood that endangered and threatened species may be exposed to pyrethrins at levels of
concern. EPA is not requiring specific pyrethrins label language at the present time relative to
threatened and endangered species. If, in the future, specific measures are necessary for the
protection of listed species, the Agency will implement them through the Endangered Species
Protection Program.
B. End-Use Products
1. Additional Product-Specific Data Requirements
Section 4(g)(2)(B) of FIFRA calls for the Agency to obtain any needed product-specific
data regarding the pesticide after a determination of eligibility has been made. The Registrant
must review previous data submissions to ensure that they meet current EPA acceptance criteria
and if not, commit to conduct new studies. If a registrant believes that previously submitted data
meet current testing standards, then the study MRID numbers should be cited according to the
instructions in the Requirement Status and Registrants Response Form provided for each
product. The Agency intends to issue a separate product-specific Data Call-In (PDCI), outlining
specific data requirements. For any questions regarding the PDCI, please contact Karen Jones at
(703) 308-8047.
In addition, efficacy data for all applications that target public health pests must be
submitted, including data for outdoor residential misting systems. Additional information on the
efficacy data can be found in the Series 810 Product Performance Test Guidelines on the
Agency's website.
(http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/810_Product_Performance_Test_Guidelines/index.
html)
2. Labeling for End-Use Products
To be eligible for reregi strati on, labeling changes are necessary to implement measures
outlined in Section IV above. Specific language to incorporate these changes is specified in
Table 26. Generally, conditions for the distribution and sale of products bearing old
labels/labeling will be established when the label changes are approved. However, specific
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.
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Labeling Changes Summary Table 26
In order to be eligible for reregi strati on, all product labels must be amended to incorporate the risk mitigation measures outlined in
Section IV. The following table describes how language on the labels should be amended.
Description
Pyrethrins Required Labeling Language
Placement on Label
Manufacturing-Use Products
Required on all MUPs
"Only for formulation into an insecticide for the following use(s) [fill blank only with those uses
that are being supported by MP registrants]."
"Not for formulation into wettable powder end use products (EUP), unless the EUP is packaged in
water soluble bags."
"Not for formulation into granular End Use Products."
»Delete any reference to tolerance exemptions on labels.
If Registrants are not supporting outdoor residential misting systems use for their products, the
following statement must appear on the MUP label of all liquid or wettable powder products:
"Not for formulation into an end use product for use in outdoor residential misting systems."
Direct Application to Non-domestic Animals/Livestock
Formulated products eligible for reregistration may not contain a percentage of a.i. that
exceeds the following:
Dusts for application to livestock only- 1.0% ai
Liquids for application to livestock only - 0.035 Ib ai/gallon
Towelettes for application to livestock only - 0.2% ai
Spot-on applications - 1.0% ai
Liquids for applications to poultry only - 0.01% ai
Pet Care
Directions for Use
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Description
Pyrethrins Required Labeling Language
Placement on Label
Formulated products eligible for reregistration may not contain a percentage of a.i. that
exceeds the following:
Shampoos - 0.3% ai
Sprays-0.01% ai
Spot-on or Pour-on - 1.0% ai
Dust-1.0%ai
Towelettes-0.2% ai
One of these statements
may be added to a label to
allow reformulation of the
product for a specific use or
all additional uses
supported by a formulator
or user group.
"This product may be used to formulate products for specific use(s) not listed on the MP label if the
formulator, user group, or grower has complied with U.S. EPA submission requirements regarding
support of such use(s)."
"This product may be used to formulate products for any additional use(s) not listed on the MP label
if the formulator, user group, or grower has complied with U.S. EPA submission requirements
regarding support of such use(s)."
Directions for Use
Environmental Hazards
Statements Required by the
RED and Agency Label
Policies
"This product is toxic to aquatic organisms, including fish and invertebrates. Do not discharge
effluent containing this product into lakes, streams, ponds, estuaries, oceans or other waters unless
in accordance with the requirements of a National Pollutant Discharge Elimination System
(NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not
discharge effluent containing this product to sewer systems without previously notifying the local
sewage treatment plant authority. For guidance contact your State Water Board or Regional Office
of the EPA. Do not contaminate water when disposing of equipment wash-waters."
Directions for Use
End-Use Products Intended for Occupational Use (WPS and non-WPS)
And Wide Area Mosquito Adulticide Applications
Handler PPE Requirements
for Wettable Powders
Formulations1 packaged in
water soluble packaging
[Note: Wettable Powders
must be packaged in water
soluble bags to be eligible
for reregistration.]
"Personal Protective Equipment (PPE)"
"Mixers, loaders, applicators, and other handlers must wear:
- long-sleeve shirt,
- long pants, and
- shoes and socks."
"In addition to the above PPE, applicators using hand held foggers in an enclosed area must wear a
half-face, full-face, or hood-style NIOSH-approved respirator with:
— a dust/mist filtering cartridge (MSHA/NIOSH approval number prefix TC-21C), or
Precautionary
Statements: Hazards to
Humans and Domestic
Animals
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Description
Pyrethrins Required Labeling Language
Placement on Label
Note: If the use of
handheld foggers in
enclosed areas is not
permitted or not feasible for
the end-use product, the
statement requiring
respirators for those uses
may be omitted.
~ a canister approved for pesticides (MSHA/NIOSH approval number prefix TC-14G), or
~ a cartridge or canister with any N,R,P or HE filter."
"See engineering controls for additional requirements."
Instruction to Registrant:
Drop the "N" type prefilter from the respirator statement, if the pesticide product contains, or is
used with, oil.
Handler PPE Requirements
for Liquid Formulations1
[including: liquid
concentrates, total release
foggers, microencapsulated
concentrates, foams,
aerosols, gels, pastes, and
pressurized liquids]
Note: The statement may
be omitted if the end-use
product is labeled only for
use on pets.
Note If aerial application is
not permitted or not feasible
for the end-use product, the
reference to engineering
control statements may be
omitted.
Note: If the use of
handheld foggers in
"Personal Protective Equipment (PPE)"
"Mixers, loaders, applicators, and other handlers must wear the following:
- long-sleeve shirt,
- long pants,
- shoes and socks."
"In addition to the above PPE, applicators using hand held foggers in an enclosed area must wear a
half-face, full-face, or hood-style NIOSH-approved respirator with:
~ a dust/mist filtering cartridge (MSHA/NIOSH approval number prefix TC-21C), or
~ a canister approved for pesticides (MSHA/NIOSH approval number prefix TC-14G), or
~ a cartridge or canister with any N,R,P or HE filter."
"See engineering controls for additional requirements."
Instruction to Registrant:
Drop the "N" type filter from the respirator statement, if the pesticide product contains, or is used
with, oil.
Precautionary
Statements: Hazards to
Humans and Domestic
Animals
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Description
Pyrethrins Required Labeling Language
Placement on Label
enclosed areas is not
permitted or not feasible for
the end-use product, the
statement requiring
respirators for those uses
may be omitted.
Handler PPE Requirements
for Dusts l
''Personal Protective Equipment (PPE)"
•'Mixers, loaders, applicators, and other handlers must wear the following:
- long-sleeve shirt,
- long pants,
- shoes and socks."
Precautionary
Statements: Hazards to
Humans and Domestic
Animals
User Safety Requirements
"Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for
washables exist, use detergent and hot water. Keep and wash PPE separately from other laundry."
"Discard clothing and other absorbent material that have been drenched or heavily contaminated
with the product's concentrate. Do not reuse them."
Precautionary
Statements: Hazards to
Humans and Domestic
Animals immediately
following the PPE
requirements
Engineering Controls:
Wettable Powders packaged
in Water-Soluble Bags
[Note: Wettable Powders
must be packaged in water
soluble packages to be
eligible for reregistration.]
"Engineering Controls:"
"Water-soluble packets when used correctly qualify as a closed mixing/loading system under the
Worker Protection Standard for Agricultural Pesticides [40 CFR 170.240(d)(4)]. Mixers and
loaders using water-soluble packets must:
~ wear the personal protective equipment required in the PPE section of this labeling for mixers and
loaders, and
~ be provided and must have immediately available for use in an emergency, such as a broken
package, spill, or equipment breakdown a half-face, full-face, or hood-style NIOSH-approved
respirator with:
~ a dust/mist filtering cartridge (MSHA/NIOSH approval number prefix TC-21C), or
~ a canister approved for pesticides (MSHA/NIOSH approval number prefix TC-14G), or
- a cartridge or canister with any N,R,P or HE filter."
Precautionary
Statements: Hazards to
Humans and Domestic
Animals (Immediately
following PPE and
User Safety
Requirements.)
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Description
Pyrethrins Required Labeling Language
Placement on Label
"Pilots must use an enclosed cockpit that meets the requirements listed in the Worker Protection
Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(6)]."
"Human flagging is prohibited. Flagging to support aerial application is limited to use of the Global
Positioning System (GPS) or mechanical flaggers."
Instructions to Registrant:
Drop the "N" type prefilter from the respirator statement, if the pesticide product contains, or is
used with, oil.
Engineering Controls for all
liquid formulations.
Note if aerial application is
not permitted or not feasible
for the end-use product, the
engineering control
statements referring to
pilots or human flaggers
may be omitted.
"Engineering Controls:"
"Pilots must use an enclosed cockpit that meets the requirements listed in the Worker Protection
Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(6)]."
"Human flagging is prohibited. Flagging to support aerial application is limited to use of the Global
Positioning System (GPS) or mechanical flaggers."
Precautionary
Statements: Hazards to
Humans and Domestic
Animals (Immediately
following PPE and
User Safety
Requirements.)
User Safety
Recommendations
"USER SAFETY RECOMMENDATIONS"
"Users should wash hands before eating, drinking, chewing gum, using tobacco, or using the toilet."
"Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly
and put on clean clothing."
"Users should remove PPE immediately after handling this product. Wash the outside of gloves
before removing. As soon as possible, wash thoroughly and change into clean clothing."
Precautionary
Statements under:
Hazards to Humans and
Domestic Animals
immediately following
Engineering Controls
(Must be placed in a
box.)
Environmental
Hazards Statements for
"ENVIRONMENTAL HAZARDS"
Precautionary
Statements under
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Description
Pyrethrins Required Labeling Language
Placement on Label
products labeled for outdoor
uses other than as a wide
area mosquito adulticide:
(PR Notice 2005-1
recommends separating
labels intended for wide
area mosquito adulticide
applications.)
"This product is toxic to aquatic organisms, including fish and invertebrates. Drift and runoff may
be hazardous to aquatic organisms in water adjacent to treated areas. This product may contaminate
water through runoff. This product has a potential for runoff for several weeks after application.
Poorly draining soils and soils with shallow water tables are more prone to produce runoff that
contains this product."
"This product is highly toxic to bees exposed to direct treatment on blooming crops or weeds. Do
not apply this product or allow it to drift to blooming crops or weeds while bees are actively visiting
the treatment area."
"Do not apply directly to water, to areas where surface water is present or to intertidal areas below
the mean high water mark. Do not contaminate water when disposing of equipment wash-waters or
rinsate."
Environmental Hazards
Environmental
Hazards Statements for
products labeled solely for
use as a wide area mosquito
adulticide:
(PR Notice 2005-1
recommends separating
labels intended for wide
area mosquito adulticide
applications.)
"ENVIRONMENTAL HAZARDS"
"This pesticide is toxic to aquatic organisms, including fish and invertebrates. Runoff from treated
areas or deposition of spray droplets into a body of water may be hazardous to fish and aquatic
invertebrates."
"This product is highly toxic to bees exposed to direct treatment on blooming crops or weeds. Do
not apply this product or allow it to drift to blooming crops or weeds while bees are actively visiting
the treatment area."
"Before making the first application in a season, it is advisable to consult with the state or tribal
agency with primary responsibility for pesticide regulation to determine if other regulatory
requirements exist."
"Do not apply over bodies of water (lakes, rivers, permanent streams, natural ponds, commercial
fish ponds, swamps, marshes or estuaries), except when necessary to target areas where adult
mosquitoes are present, and weather conditions will facilitate movement of applied material away
from the water in order to minimize incidental deposition into the water body. Do not contaminate
bodies of water when disposing of equipment rinsate or washwaters."
Precautionary
Statements under
Environmental Hazards
Environmental
"ENVIRONMENTAL HAZARDS for TERRESTRIAL APPLICATIONS"
Precautionary
Page 84 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
Hazards Statements for
products labeled as a wide
area mosquito adulticide
and is labeled for other
outdoor uses as well:
(PR Notice 2005-1
recommends separating
labels intended for wide
area mosquito adulticide
applications.)
"This product is toxic to aquatic organisms, including fish and invertebrates. Drift and runoff may
be hazardous to aquatic organisms in water adjacent to treated areas. This product may contaminate
water through runoff. This product has a potential for runoff for several weeks after application.
Poorly draining soils and soils with shallow water tables are more prone to produce runoff that
contains this product."
"This product is highly toxic to bees exposed to direct treatment on blooming crops or weeds. Do
not apply this product or allow it to drift to blooming crops or weeds while bees are actively visiting
the treatment area."
"Except as specified in the directions for use, do not apply directly to water, to areas where surface
water is present or to intertidal areas below the mean high water mark. Do not contaminate water
when disposing of equipment wash-waters or rinsate."
"ENVIRONMENTAL HAZARDS for WIDE AREA MOSQUITO ADULTICIDE
APPLICATIONS"
"This pesticide is toxic to aquatic organisms, including fish and invertebrates. Runoff from treated
areas or deposition of spray droplets into a body of water may be hazardous to fish and aquatic
invertebrates."
"When applying as a wide area mosquito adulticide, before making the first application in a season,
it is advisable to consult with the state or tribal agency with primary responsibility for pesticide
regulation to determine if other regulatory requirements exist."
"This product is highly toxic to bees exposed to direct treatment on blooming crops or weeds. Do
not apply when bees are visiting the treatment area, except when applications are made to prevent or
control a threat to public and/or animal health determined by a state, tribal, or local health or vector
control agency on the bases of documented evidence of disease causing agents in vector mosquitoes
or the occurrence of mosquito-borne disease in animal or human populations, or if specifically
approved by the state or tribe during a natural disaster recovery effort."
"When applying as a wide area mosquito adulticide, do not apply over bodies of water (lakes,
Statements under
Environmental Hazards
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Description
Pyrethrins Required Labeling Language
Placement on Label
rivers, permanent streams, natural ponds, commercial fish ponds, swamps, marshes or estuaries),
except when necessary to target areas where adult mosquitoes are present, and weather conditions
will facilitate movement of applied material away from the water in order to minimize incidental
deposition into the water body.
Environmental Hazards for
Products labeled only for
Indoor Use EXCEPT ready
to use impregnated
materials (e.g. flea collars,
ear tags, coils, mats)
(Note: Products used on
domestic animals like flea
collars and ear tags,
generally do not require an
Environmental Hazards
statement.
In addition, products
containing the statement:
"For indoor use only," may
also omit the environmental
hazards statement.)
"ENVIRONMENTAL HAZARDS"
"This product is toxic to aquatic organisms, including fish and invertebrates. Do not contaminate
water when disposing of equipment, washwater, or rinsate. See Directions for Use for additional
precautions and requirements."
For indoor products packaged in containers equal to or greater than 5 gallons or 50 Ibs add
the following statement:
"Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or
other waters unless in accordance with the requirements of a National Pollution Discharge
Elimination System (NPDES) permit and the permitting authority has been notified in writing prior
to discharge. Do not discharge effluent containing this product to sewer systems without previously
notifying the local sewage treatment plant authority. For guidance contact your State Water Board
or Regional Office of the EPA."
Precautionary
Statements under
Environmental Hazards
Restricted-Entry Interval
for products with WPS uses
"Do not enter or allow worker entry into treated areas during the restricted entry interval (REI) of
12 hours."
Directions for Use,
Agricultural Use
Requirements Box
Early Entry Personal
Protective Equipment for
products with WPS uses
"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 soil or water, is:
- coveralls,
- chemical-resistant gloves made of any waterproof material, and
- shoes plus socks."
Directions for Use,
Agricultural Use
Requirements Box
Entry Restrictions
for products with non-WPS
uses on the label
Note: This excludes
Entry Restriction for products applied as a spray (does not apply to products applied directly
to domestic animals):
"Do not enter or allow others to enter until sprays have dried."
If no WPS uses on the
product label, place the
appropriate statement
in the Directions for
Use Under General
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Description
Pyrethrins Required Labeling Language
Placement on Label
products labeled for use
when people are permitted
to be present (e.g. wide-area
mosquito adulticide
applications, metered
release devices, and pet
applications)
Entry Restriction for products applied dry:
"Do not enter or allow others to enter until dusts have settled."
Entry Restriction for products applied as a space spray or as a fog:
"Do not enter or allow others to enter until vapors, mists, and aerosols have dispersed, and the
treated area has been thoroughly ventilated."
Precautions and
Restrictions. If the
product also contains
WPS uses, then create a
Non-Agricultural Use
Requirements box as
directed in PR Notice
93-7 and place the
appropriate statement
inside that box.
Entry Restrictions for
products labeled solely for
use when people are present
(e.g. wide-area mosquito
adulticide applications,
metered release devices,
and applications to pets)
Note to Registrants: No entry restrictions are required. See below under Use Restrictions for
further requirements.
Entry Restrictions for
products labeled for use
when people are present
(e.g. wide-area mosquito
adulticide applications,
metered release devices,
and applications to pets)
and for use on other sites as
a directed or space spray.
Products labeled for use as a directed spray (does not apply to products applied directly to
domestic animals):
"Except when (insert application method or site that allows people to be present), do not enter or
allow others to enter until sprays have dried."
Products labeled for use as a space spray:
"Except when (insert application method or site that allows people to be present), do not enter or
allow others to enter until vapors, mists, and aerosols have dispersed, and the treated area has been
thoroughly ventilated."
Note to Registrant: An example is as follows: Except when applying in a metered release system,
do not enter or allow others to enter until sprays have dried.
If no WPS uses on the
product label, place the
appropriate statement
in the Directions for
Use Under General
Precautions and
Restrictions. If the
product also contains
WPS uses, then create a
Non-Agricultural Use
Requirements box as
directed in PR Notice
93-7 and place the
appropriate statement
inside that box.
General Application
Restrictions for products
"Do not apply this product in a way that will contact workers or other persons, either directly or
through drift."
Place in the Direction
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Description
Pyrethrins Required Labeling Language
Placement on Label
with WPS or non-WPS uses
on the label
Note: This excludes
products that contain any
directions for uses when
people are permitted to be
present in the treated area
(e.g. . wide-area mosquito
adulticide applications,
metered release devices,
and applications to pets)
for Use.
'Only protected handlers may be in the area during application."
General Application
Restrictions for products
with WPS and non-WPS
uses on the label AND
contain directions for uses
when people are permitted
to be present in the treated
area (e.g. . wide-area
mosquito adulticide
applications, metered
release devices, and
applications to pets)
"Except when" (insert application method or site that allows people to be present) "do not apply this
product in a way that will contact workers or other persons, either directly or through drift."
"Except when" (insert application method or site that allows people to be present) "only protected
handlers may be in the area during application."
Place in the Direction
for Use.
General Application
Restrictions for products
labeled for use solely when
people are permitted to be
present in the treated area
(e.g. wide-area mosquito
adulticide applications,
metered-release devices,
and applications to pets)
Note to Registrants: No entry restrictions are required. See below under Use Restrictions for
further requirements.
Place in the Direction
for Use.
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Description
Pyrethrins Required Labeling Language
Placement on Label
Other Application
Restrictions
Note to Registrants: Delete any reference to tolerance exemptions on labels.
In addition add the following restrictions depending on the registered product uses and formulation:
Wettable powder formulations:
"Do not apply this product as a dust."
"Do not apply in forestry areas."
Dust formulations:
"Aerial applications are prohibited."
"Applications with power duster equipment are prohibited."
Products labeled for use as a space spray:
"Do not remain in treated area. Exit area immediately and remain outside the treated area until
aerosols, vapors, and/or mists have dispersed."
Products labeled for spray applications to plants:
"Do not wet plants to point of runoff or drip."
Products labeled for spray applications to articles:
"Do not wet articles to point of runoff or drip."
"Do not use treated article until spray has dried."
Products labeled for applications to clothing articles:
"Dry clean treated clothes before wearing."
Products labeled for dip applications:
"Do not use treated article before it is dry."
Products labeled for crack and crevice, surface or space spray, fogging or dust applications
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
Page 89 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
indoors:
"Remove or cover exposed food and drinking water before application."
"Remove or cover dishes, utensils, food processing equipment, and food preparation surfaces, or
wash them before use."
Products labeled for applications to non-residential indoor sites:
"Do not use in aircraft cabins except in compliance with PR Notice 96-3."
"When used in dairy barns or facilities: Close milk bulk tank lids to prevent contamination from
spray and from dead or falling insects. Remove or cover milking utensils before application. Wash
teats of animals before milking."
Products labeled for use in food handling and processing facilities:
"Do not make space spray applications when facility is in operation."
"During space spray applications, cover or remove food."
"During space spray applications, cover food processing surfaces or clean after treatment with a
suitable detergent and rinse with potable water before use."
Use-Specific Application
Restrictions
(Note: The maximum
allowable application rate
and maximum allowable
seasonal rate must be listed
as pounds or gallons of
formulated product per acre,
not just as pounds active
ingredient per acre.
All rates must be expressed
in terms the applicator can
use in order to arrive at the
maximum application rate.
For example, for sprays
Food Crops Grown Outdoors or in Greenhouses in Agricultural Settings
Maximum application rates:
Field and orchard- 0.05 Ibs ai/acre or 0.0012 Ib ai /1000 square feet
Hydroponically grown crops -0.10 ppm ai in water
Greenhouse space sprays - 0.00014 Ibs ai/1000 cubic feet
Greenhouse surface spray - 0.0012 Ibs per 1000 square feet or 0.05 Ibs ai per acre
Use restrictions:
"Do not apply more than 10 times per season."
"Do not reapply within 3 days except under extreme pest pressure."
"In case of extreme pest pressure, do not reapply within 24 hours."
"Do not harvest until spray has dried."
"Do not apply to cotton within 14 days of seed harvest." (For labels with cotton only)
Rice Fields
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
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Description
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Placement on Label
rates must specify the
duration of spray to a
specific area, i.e., spray for
X seconds to a space Y feet
by Z feet.)
"A 10 day water hold is required for all applications when rice fields are flooded."
Greenhouse Grown Ornamental, Flowering and Foliage Plants:
Maximum application rates:
Surface applications - 0.0036 Ibs ai/1000 square feet (or 0.15 Ib ai/acre)
Space sprays (including space, total release, and fogger applications) - 0.00042 Ibs ai/1000
cubic feet
Use restrictions:
"Do not apply more than 1 time per day."
Post-harvest Application to Vegetables (Potato, Tomato, Pea, Sweet Potato), Fruits (Apple,
Blackberry, Blueberry, Boysenberry, Cherry, Crabapple, Currant, Dewberry, Fig,
Gooseberry, Grape, Guava, Loganberry, Mango, Muskmelon, Orange, Peach, Pear,
Pineapple, Plum, Raspberry) Nuts (Almonds, Walnuts) and Other Commodities (Copra and
Peanut)
Maximum application rates:
Surface applications - 0.010 Ib ai/1000 square feet
Surface application to fruits or tomatoes in baskets or hampers - 1.6 x 10-7 Ibs ai/ Ib of fruit
(or0.16ppm)
Space spray to fruits, vegetables, copra - 0.0001 Ibs ai/1000 cubic feet
Dip or spray - 0.0004 Ibs ai/ gallon
Use restrictions:
"Do not reapply within 7 days."
"Do not apply more than 10 times to sweet potatoes."
Post-harvest Applications to Stored Grain and Seed (Barley, Beans, Lima Beans, Birdseed,
Buckwheat, Cocoa beans, Corn, Cottonseed, Flax, Grain sorghum, Oats, Field Peas, Rice,
Rye, Wheat)
Maximum application rates:
Surface applications - 0.050 Ibs ai/1000 square feet
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Placement on Label
Direct application to bulk grain and seed - 0.10 Ib ai/1000 bushels grain
Maximum application rates:
Barley - 0.0033 oz ai per cwt
Beans - 0.0027 oz ai per cwt
Lima beans - 0.0029 oz ai per cwt
Birdseed - 0.0032 oz ai per cwt
Buckwheat - 0.0033 oz ai per cwt
Cocoa beans - 0.0037 oz ai per cwt
Corn - 0.0029 oz ai per cwt
Cottonseed - 0.0057 oz ai per cwt
Flax - 0.0029 oz ai per cwt
Grain sorghum - 0.0029 oz ai per cwt
Oats - 0.0050 oz ai per cwt
Field peas - 0.0027 oz ai per cwt
Rice - 0.0036 oz ai per cwt
Rye - 0.0029 oz ai per cwt
Wheat (club, common, durham) - 0.0027 oz ai per cwt
Wheat (emmer, spelt) - 0.0040 oz ai per cwt)
Use restrictions:
"Do not reapply within 30 days."
Food Stored in Bags
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Space sprays may be made to the surfaces of bags of stored food products at the rate of 0.0033
Ibs ai/1000 cubic foot.
Use restrictions:
"Direct application to food contact surfaces is prohibited."
Direct Application to Non-domestic Animals/Livestock
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Pyrethrins Required Labeling Language
Placement on Label
Use restrictions:
"Do not apply more than 1 time per day."
"Do not apply microencapsulated product to lactating or food animals."
Indoor Agricultural Premises and Commercial Animal Housing and Equipment
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.056 Ibs ai/1000 square feet
Crack/crevice or spot surface - 0.056 Ibs ai/1000 square feet
Space sprays when non-domestic animals are absent- 0.0033 Ibs ai/1000 cubic feet
Space sprays when non-domestic animals are present - 0.0008 Ib ai/1000 cubic feet
Metered release device space sprays - 0.005 Ibs ai/1000 cubic feet/day
Use Restrictions:
"Do not apply more than 1 time per day."
Indoor Food Handling/Processing Facilities
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.056 Ibs ai/1000 square feet
Crack/crevice or spot surface -0.22 Ibs ai/1000 square feet
Space sprays- 0.00033 Ibs ai/1000 cubic feet
Metered release device space sprays - 0.000476 Ibs ai/1000 cubic feet/day
Use Restrictions:
"Do not apply more than 1 time per day."
In addition, these label statements should be deleted from all products registered for food
handling and processing facilities:
"Except in Federally inspected meat and poultry plants, food processing operations may
continue when the product is applied as a general surface spray with care and in accordance
Page 93 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
with the directions and precautions on the label, at a maximum rate of 0.11 pounds of
pyrethrins per 1000 square feet."
"Except in Federally inspected meat and poultry plants, food processing operations may
continue when the product is applied as a crack and crevice treatment with care and in
accordance with the directions and precautions on the label, at a maximum rate of 0.56 pounds
of pyrethrins per 1000 square feet."
Residential Dwellings and Commercial, Institutional Indoor Sites
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.056 Ibs ai/1000 square feet
Crack/crevice or spot surface - 0.22 Ibs ai/1000 square feet
Space sprays- 0.00033 Ibs ai/1000 cubic feet
Metered release device space sprays - 0.000476 Ibs ai/1000 cubic feet/day
Outdoor Agriculture Premises
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.0075 Ibs ai/1000 square feet
Crack/crevice or spot surface (including applications for fire ant applications or turf diagnostic
aid) - 0.22 Ibs ai/1000 square feet
User Restrictions:
"Do not apply more than 1 time per day."
General Outdoor Sites (including Non-Agricultural rights-of-way,
Commercial/Institutional/Industrial Premises and Outdoor Eating Establishments)
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.0075 Ibs ai/1000 square feet
Crack/crevice or spot surface - 0.22 Ibs ai/1000 square feet
Page 94 of 108
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Description
Application Restrictions for
products used in Metered
Release Devices
Pyrethrins Required Labeling
User Restrictions:
"Do not apply more than 1 time per day."
Outdoor Ornamental and Lawns
Maximum application rates:
Surface applications - 0.0075 Ibs ai/1000 square feet
Language
Crack/crevice or spot surface (including applications for fire ant applications or turf diagnostic
aid) - 0.002 Ibs ai/1000 square feet
User Restrictions:
"Do not apply more than 1 time per day."
Pet Care
Use restrictions:
"Do not apply to pets less than 12 weeks old."
"Consult a veterinarian before applying this product on
or nursing animals."
medicated, debilitated, aged, pregnant,
"Sensitivities may occur after using any pesticide product for pets. If signs of sensitivity occur
bathe your pet with mild soap and rinse with large amounts of water. If signs continue,
consult a veterinarian immediately."
Pet Premise Treatment
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface - 0.056 Ib per 1000 square feet
Crack and crevice - 0.22 Ibs per 1000 square feet
Space spray - 0.0033 Ibs per 1000 square feet
Note to Registrants: Delete nurseries, day care centers, schools, hospitals, and nursing homes as
registered use sites on all product labels for this use pattern.
Placement on Label
Directions for Use
under General
Precautions and
Page 95 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
Add the following statements:
"Not for use in Residential areas."
"Do not use in nurseries or rooms where infants, ill, or aged persons are confined."
"Do not place metering device directly over or within 8 feet of exposed food, dishes, utensils, food
processing equipment, and food handling or preparation."
"Do not install within 3 feet of air vents."
"Carefully follow directions for the dispenser unit when installing the dispenser and replacing cans
or conducting maintenance."
Restrictions and/or
Application
Instructions
Use-Specific Application
Restrictions for all liquid
and wettable powder labels
(Outdoor residential misting
system requirement)
(Note: The maximum
allowable application rate
and maximum allowable
seasonal rate must be listed
as pounds or gallons of
formulated product per acre,
not just as pounds active
ingredient per acre.)
Outdoor Residential Misting Systems
Products not intended for use in outdoor residential misting systems must contain the
following statement:
"Not for use in outdoor residential misting systems."
Products intended for use in outdoor residential misting systems must contain the following
statements:
"Directions for use in outdoor residential misting systems:"
"When using this product installers and service technicians must comply with the license,
certification, or registration requirements of the state(s), tribe(s), or local authority(ies) where they
are installed."
"If the system works on an automatic timer, set the timing for application when people, pets, and
food are unlikely to be present."
"If the system works when a person operates a remote activation device, then application of this
pesticide when people, pets, and food are present is prohibited."
"Do not use in an evaporative cooling system."
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
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Description
Pyrethrins Required Labeling Language
Placement on Label
"Direct nozzles to spray towards the target area and away from swimming pools, water bodies, or
eating and cooking areas."
"If used in a system with a reservoir tank for the end use dilution, the system reservoir tank must be
locked. Securely attach the end use pesticide label and a dilution statement to the system reservoir
tank in a weather protected area or plastic sleeve. The dilution statement must be phrased as
follows: this container holds parts \product name] to parts water"
"If used in a direct injection system, the pesticide container must be locked. Securely attach the end
use label to the pesticide container in a weather protected area or plastic sleeve." (These
instructions not applicable to wettable powder products).
"This product must only be used in systems that have been calibrated to apply no more than the
maximum application rate of [insert product application rate that is equal to 0.00011 Ibs pyrethrins
per 1000 cubic feet per day].
Note to registrant: Also express this application rate as pounds or gallons of end-use product
formulation.
Use-Specific Application
Restrictions for products
labels for
Mosquito Adulticide
Application by ground or
air.
(Note: The maximum
allowable application rate
and maximum allowable
seasonal rate must be listed
as pounds or gallons of
formulated product per acre,
not just as pounds active
ingredient per acre.)
"For use by federal, state, tribal, or local government officials responsible for public health or
vector control, or by persons certified in the appropriate category or otherwise authorized by the
state or tribal lead pesticide regulatory agency to perform adult mosquito control applications, or by
persons under their direct supervision."
The maximum application rate for wide area mosquito adulticide applications is 0.0025 Ibs ai/acre.
When targeting Aedes Taeirorhynchus and other difficult species applications may be made up to
0.008 Ibs ai/acre/day.
"Do not apply more than 0.2 Ibs ai/acre/year in any treated area More frequent treatments may be
made to prevent or control a threat to public and/or animal health determined by a state, tribal, or
local health or vector control agency on the basis of documented evidence of disease causing agents
in vector mosquitoes or the occurrence of mosquito-borne disease in animal or human populations,
or if specifically approved by the state or tribe during a natural disaster recovery effort."
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
Spray Drift Label Language
"SPRAY DRIFT MANAGEMENT for AGRICULTURE CROPS"
Directions for Use
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Description
for all products labeled for
outdoor applications to
agricultural use sites
Spray Drift Label Language
for ALL Products Intended
for ULV Mosquito
Pyrethrins Required Labeling Language
"Avoiding spray drift at the application site is the responsibility of the applicator and the grower.
The interactions of many equipment and weather-related factors determine the potential for spray
drift. The applicator and the grower are responsible for considering all these factors when making
decisions."
"Do not apply at wind speeds greater than 10 mph at the application site."
"Do not make any type of application into temperature inversions."
"Apply as a medium or coarser spray (ASABE standard 572)."
"Additional requirements for aerial applications:"
"Do not release spray at a height greater than 10 feet above the ground or crop canopy."
"The boom length must not exceed 75% of the wingspan or 90% of the rotor blade diameter."
"Aerial applicators must consider flight speed and nozzle orientation in determining droplet size."
"When applications are made with a cross-wind, the swath will be displaced downwind. The
applicator must compensate for this displacement at the downwind edge of the application area by
adjusting the path of the aircraft upwind."
"Additional requirements for ground applications:"
"Do not release spray at a height greater than 4 feet above the ground or crop canopy."
"Additional requirements for airblast applications:"
"Direct sprays into the canopy."
"Turn off outward pointing nozzles at row ends and when spraying outer rows."
"SPRAY DRIFT MANAGEMENT for WIDE AREA MOSQUITO ABATEMENT"
"A variety of factors including weather conditions (e.g., wind direction, wind speed, temperature,
Placement on Label
under General
Precautions and
Restrictions
Directions for Use
under General
Precautions and
Page 98 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
Abatement Programs
relative humidity) and method of application (e.g., ground, aerial, airblast, chemigation) can
influence pesticide drift. The applicator must evaluate all factors and make appropriate adjustments
when applying this product."
WIND SPEED:
"Apply only when wind speed is greater than or equal to 1 mph."
Restrictions
Spray Drift Label Language
For End-Use Products
Applied with Ground-Based
Mechanical Application
Equipment for ULV
Mosquito Abatement
Programs
"Ground-based wide area mosquito abatement application:
Spray equipment must be adjusted so that the volume median diameter is less than 30 microns (Dv
0.5 < 30 um) and that 90% of the spray is contained in droplets smaller than 50 microns (Dv 0.9 <
50 um). Directions from the equipment manufacturer or vendor, pesticide registrant or a test
facility using a laxer-based measurement instrument must be used to adjust equipment to produce
acceptable droplet size spectra. Application equipment must be tested at least annually to confirm
that pressure at the nozzle and nozzle flow rate(s) are properly calibrated."
Directions for Use
under General
Precautions and
Restrictions
Spray Drift Label Language
for Products Applied as an
Aerial Spray for ULV
Mosquito Abatement
Programs
"Aerial wide area mosquito abatement application:
Spray equipment must be adjusted so that the volume median diameter produced is less than 60
microns (Dv 0.5 < 60 um) and that 90% of the spray is contained in droplets smaller than 80
microns (Dv 0.9 < 80 um). The effects of flight speed, and for non-rotary nozzles, nozzle angle on
the droplet size spectrum must be considered. Directions from the equipment manufacturer or
vendor, pesticide registrant or a test facility using a wind tunnel and laser-based measurement
instrument must be used to adjust equipment to produce acceptable droplet size spectra.
Application equipment must be tested at least annually to confirm that pressure at the nozzle and
nozzle flow rate(s) are properly calibrated."
RELEASE HEIGHT:
"Fixed wing:"
"Apply using a nozzle height of no less than 100 feet above the ground or canopy."
"Rotary wing:"
"Apply using a nozzle height of no less than 75 feet above the ground or canopy."
Directions for Use
under General
Precautions and
Restrictions
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Placement on Label
Products Primarily Used by Consumers/Homeowners
Entry Restrictions
for products except those
products that contain any
directions for uses when
people are permitted to be
present in the treated area
(e.g.. applications to pets)
Entry Restriction for products applied as a spray except for sprays applied directly to
domestic animals:
"Do not allow adults, children, or pets to enter the treated area until sprays have dried."
Entry Restriction for products applied dry:
"Do not allow adults, children, or pets to enter the treated area until dusts have settled."
Entry Restriction for products applied as a space spray or as a fog:
"Do not allow adults, children, or pets to enter until vapors, mists, and aerosols have dispersed, and
the treated area has been thoroughly ventilated."
Directions for use
under General
Precautions and
Restrictions
Entry Restrictions for
products products that only
contain directions for uses
when people are permitted
to be present (e.g. pet
applications)
Note to Registrants: No entry restrictions are required. See below under Use Restrictions for
further requirements.
Directions for use
under General
Precautions and
Restrictions
Entry Restrictions for
products that contain
directions for uses when
people are permitted to be
present in the treated area
(e.g. applications to pets)
AND for use on other sites
as a surface spray.
Products labeled for use as a surface spray (does not apply to products applied directly to
domestic animals):
"Except when applying directly to pets, do not allow adults, children, or pets to enter until sprays
have dried."
Directions for use
under General
Precautions and
Restrictions
General Application
Restrictions for all products
except those that contain
"Do not apply this product in a way that will contact adults, children, or pets, either directly or
through drift."
Place in the Direction
for Use
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Description
Pyrethrins Required Labeling Language
Placement on Label
any directions for uses
when people are permitted
to be present in the treated
area (e.g., applications to
pets)
"Remove pets, birds, and cover fish aquariums before spraying."
General Application
Restrictions for products
that only contain directions
for uses when people are
permitted to be present (e.g.
pet applications)
Note to Registrants: No entry restrictions are required. See below under Use Restrictions for
further requirements.
Place in the Direction
for Use
General Application
Restrictions for products
that contain directions for
uses when people are
permitted to be present in
the treated area (e.g.
applications to pets) AND
for use on other sites as a
surface spray.
"Except when applying directly to pets, do not apply this product in a way that will contact adults,
children, or pets, either directly or through drift."
"Remove pets, birds, and cover fish aquariums before spraying."
Place in the Direction
for Use
Environmental Hazards for
Residential Products
(Note: Products used on
domestic animals like flea
collars and ear tags,
generally do not require an
Environmental Hazards
statement.
In addition, products
containing the statement:
"For indoor use only," may
also omit the environmental
hazards statement.)
"ENVIRONMENTAL HAZARDS"
"This product is toxic to aquatic organisms, including fish and invertebrates. Do not contaminate
water when disposing of equipment, washwater, or rinsate. See Directions for Use for additional
precautions and requirements."
Note to Registrants: For products with outdoor uses include the following statement.
"Do not apply directly to or near water. Drift and run-off may be hazardous to fish in water
adjacent to treated areas."
Precautionary
Statements under
Environmental Hazards
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Description
Pyrethrins Required Labeling Language
Placement on Label
Homeowner User Safety
Recommendations
Statements
"User Safety Recommendations
Users should wash hands with plenty of soap and water before eating, drinking, chewing gum, using
tobacco, or using the toilet.
Users should remove clothing immediately if pesticide gets inside. Then wash thoroughly and put
on clean clothing."
Precautionary
Statements under:
Hazards to Humans and
Domestic Animals
immediately following
Engineering Controls
(Must be placed in a
box.)
Other Application
Restrictions
This was copied from
above. Delete what is
inappropriate.
Note to Registrants: Delete any reference to tolerance exemptions on labels.
In addition add the following restrictions depending on the registered product uses and formulation:
Wettable powder formulations:
"Do not apply this product as a dust."
Dust formulations:
"Aerial applications are prohibited."
Products labeled for use as a space spray:
"Do not remain in treated area. Exit area immediately and remain outside the treated area until
aerosols, vapors, and/or mists have dispersed."
Products labeled for spray applications to plants:
"Do not wet plants to point of runoff or drip."
Products labeled for spray applications to articles:
"Do not wet articles to point of runoff or drip."
"Do not use treated article until spray has dried."
Products labeled for applications to clothing articles:
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
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Description
Pyrethrins Required Labeling Language
Placement on Label
"Dry clean treated clothes before wearing."
Products labeled for dip applications:
"Do not use treated article before it is dry."
Products labeled for crack and crevice, surface or space spray, fogging or dust applications
indoors:
"Remove or cover exposed food and drinking water before application."
"Remove or cover dishes, utensils, food processing equipment, and food preparation surfaces, or
wash them before use."
Use-Specific Application
Restrictions
For products with directions
for residential uses
Requirement for Liquid Formulations (except for Ready to Use) with outdoor uses:
"Do not apply directly to or near water, storm drains, or drainage ditches. Do not apply when
windy. To prevent product run-off, do not over water the treated area(s) or apply when heavy rain
is expected. Rinse applicator over lawn or garden area only."
Requirement for Ready to Use Liquid or Dust Formulations with outdoor uses:
"Do not apply directly to or near water, storm drains, or drainage ditches. Do not apply when
windy. To prevent product run-off, do not over water the treated area(s) or apply prior to heavy
rainfall."
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
Residential Use Restriction
(Note: The maximum
allowable application rate
and maximum allowable
seasonal rate must be listed
as pounds or gallons of
formulated product per acre
or per square feet or per
Home Garden or Home Greenhouse Applications
Maximum application rates:
Garden and orchard- 0.05 Ibs ai/acre or 0.012 Ib ai 71000 square feet
Hydroponically grown crops -0.10 ppm ai in water
Greenhouse space sprays - 0.00014 Ibs ai/1000 cubic feet
Greenhouse surface spray - 0.0012 Ibs per 1000 square feet or 0.05 Ibs ai per acre
Use restrictions:
"Do not apply more than 10 times per season."
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
Page 103 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
cubic feet, not just as
pounds active ingredient per
unit area.)
"Do not reapply within 3 days except under extreme pest pressure."
"In case of extreme pest pressure do not reapply within 24 hours."
Residential Dwellings - Indoors
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.056 Ibs ai/1000 square feet
Crack/crevice or spot surface - 0.056 Ibs ai/1000 square feet
Space sprays- 0.0025 Ibs ai/1000 cubic feeta
General Outdoor Sites
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.0075 Ibs ai/1000 square feet
Crack/crevice or spot surface - 0.056 Ibs ai/1000 square feet
User Restrictions:
"Do not apply more than 1 time per day."
Outdoor Ornamental and Lawns
Products must be formulated to deliver no more than this maximum rate when used according
to directions:
Surface applications - 0.0020 Ibs ai/1000 square feet (or 0.10 Ibs ai/acre)
Spot treatment (including applications for fire ant applications or turf aid) - 0.056 Ibs ai/1000
square feet
User Restrictions:
"Do not apply more than 1 time per day."
Pet Care
Use restrictions:
Page 104 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
"Do not apply to pets less than 12 weeks old."
"Consult a veterinarian before using this product on medicated, debilitated, aged, pregnant, or
nursing animals."
"Sensitivities may occur after using any pesticide product for pets. If signs of sensitivity occur
bathe your pet with mild soap and rinse with large amounts of water. If signs continue,
consult a veterinarian immediately."
Dusts
Use Restrictions:
"Only apply as a spot treatment to areas no greater than 3 feet by 3 feet per room."
Use-Specific Application
Restrictions for all liquid
and wettable powder labels
(Outdoor residential misting
system requirement)
(Note: The maximum
allowable application rate
and maximum allowable
seasonal rate must be listed
as pounds or gallons of
formulated product per acre,
not just as pounds active
ingredient per acre.)
Outdoor Residential Misting Systems
Products not intended for use in outdoor residential misting systems must contain the
following statement:
"Not for use in outdoor residential misting systems."
Products intended for use in outdoor residential misting systems must contain the following
statements:
"Directions for use in outdoor residential misting systems:"
"When using this product installers and service technicians must comply with the license,
certification, or registration requirements of the state(s), tribe(s), or local authority(ies) where they
are installed."
"If the system works on an automatic timer, set the timing for application when people, pets, and
food are unlikely to be present."
"If the system works when a person operates a remote activation device, then application of this
pesticide when people, pets, and food are present is prohibited."
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
Page 105 of 108
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Description
Pyrethrins Required Labeling Language
Placement on Label
"Do not use in an evaporative cooling system."
"Direct nozzles to spray towards the target area and away from swimming pools, water bodies, or
eating and cooking areas."
"If used in a system with a reservoir tank for the end use dilution, the system reservoir tank must be
locked. Securely attach the end use pesticide label and a dilution statement to the system reservoir
tank in a weather protected area or plastic sleeve. The dilution statement must be phrased as
follows: this container holds parts \product name] to parts water"
"If used in a direct injection system, the pesticide container must be locked. Securely attach the end
use label to the pesticide container in a weather protected area or plastic sleeve." (These
instructions not applicable to wettable powder products).
"This product must only be used in systems that have been calibrated to apply no more than the
maximum application rate of [insert product application rate that is equal to 0.00011 Ibs pyrethrins
per 1000 cubic feet per day].
Note to registrant: Also express this application rate as pounds or gallons of end-use product
formulation.
PPE that is established on the basis of Acute Toxicity of the end-use product must be compared to the active ingredient PPE in this document. In the case of multiple
active ingredients, the more protective PPE must be placed on the product labeling. For guidance on which PPE is considered more protective, see PR Notice 93-7.
Page 106 of 108
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Appendix: Technical Support Documents
Additional documentation in support of this RED is maintained in the OPP
docket, located in room S-4400, One Potomac Yard (South Building), 2777 S. Crystal
Drive, Arlington, VA 22202. It is open Monday through Friday, excluding legal holidays,
from 8:30 am to 4 pm.
All documents, in hard copy form, may be viewed in the OPP docket room or
downloaded or viewed via the Internet at the following site: http://www.regulations.gov
These documents include:
HED Documents:
Pyrethrins: Revised Human Health Risk Assessment for the Reregi strati on Eligibility
Decision. Olinger, C.; D326648; March 16, 2006.
Pyrethrins: Responses to Public Comments on HED Risk Assessment and Supporting
Documents; Olinger, C., et al.; D 324662; January 31, 2006.
Review of Pyrethrins Incident Reports - Second Revision. Blondell, J.; D320300; August
16, 2005.
Three Pyrethrin Health Effects Reviews: Mosby and Registrant Submissions. Allen,
Ruth; D326085; July 2006.
Pyrethrins. Revised Residue Chemistry Considerations for Reregi strati on Eligibility
Decision. Deluzio, J. and Olinger, C.; D 318633; September 8, 2005.
Pyrethrins RED - Reregi strati on Eligibility Decision. Product Chemistry Considerations.
Deluzio, Joseph; D309022; March 21, 2005.
Pyrethrins: Report of the Cancer Assessment Review Committee (Third Evaluation).
Kidwell, Jessica; TXRNo.0052631, June 22, 2004.
Pyrethrins. Acute and Chronic Dietary Exposure Assessment for the Reassessment
Eligibility Decision (RED) Document. Deluzio, Joseph; D295748; December 20, 2004.
PYRETHRINS Reregi strati on Branch I/Health Effects Division Response to Comments
on Draft Risk Assessment. Taylor, Linda; D320383; TXR# 0053661, August 17, 2005.
Pyrethrins: 2nd Revised Occupational and Residential Exposure Assessment and
Recommendations for the Reregi strati on Eligibility Decision (RED). Dole, T. and Lloyd,
M.; D318630; September 7, 2005.
Occupational and Residential Exposure Assessment for the Use of Pyrethrin in
Residential Mosquito Mister Systems. Dole, Timothy; D315335; September 7, 2005.
Page 107 of 108
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Piperonyl Butoxide (PBO), Pyrethrins and MGK-264: Health Effects Division's
response to the Registrant's concerns for using metaplasia seen in the larynx in
subchronic inhalation studies as an endpoint for inhalation risk assessment. Ramasamy,
S., et al.; D319913, D319914, andD320298; September 8, 2005.
Pyrethrins: Occupational Exposure Assessment for Indoor Fogging Applications. Dole,
T.;D330441; July 5,2006.
Revised Occupational and Residential Exposure Assessment for the Use of Pyrethrins in
Residential Mosquito Mister Systems. Dole, T.; D330442; July 5, 2006.
EFED Documents:
Revised Pyrethrins RED Chapter After Additional 60-Day Comment Period, Phase 5.
Rexrode, M. and Melendez, J.; D324663; January 25, 2006.
Response to Comments of Phase 5 Period About Water Quality, and Other Issues on the
Revised Draft EFED RED Chapters for Pyrethrins, PBO and MGK-264. Davy, M., et al.;
D324663, D324664, D324667, D324662, D324671, and D324673; January 30, 2006.
Tier 1 Estimated Drinking Water Concentrations of Pyrethrin and Derivatives for use in
Human Health Risk Assessment. Dutta, Subijoy; D295750; August 19, 2004.
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