Docket Number EPA-HQ-OPP-2008-0850
www.regulations.gov
ft A A
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Chlorpyrifos
Proposed Interim Registration Review Decision
Case Number 0100
December 2020
Approved by:
Elissa Reaves, Ph.D.
Acting Director
Pesticide Re-evaluation Division
Date:
12-03-2020
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Table of Contents
I. INTRODUCTION 4
A. Summary of Chlorpyrifos Registration Review 6
B. Endangered Species Consultation 8
C. Other Chlorpyrifos Actions 9
D. Approach for Presenting Risk Estimates and Uncertainty Factors 10
II. USE AND US AGE 11
III. SCIENTIFIC ASSESSMENTS 12
A. Human Health Risks 12
1. Hazard Characterization 12
2. Risk Summary and Characterization 13
3. Human Incidents 29
4. Tolerances 31
5. Human Health Data Needs 35
B. Ecol ogi cal Ri sks 35
1. Risk Summary and Characterization 35
2. Ecological Incidents 38
3. Ecological and Environmental Fate Data Needs 38
C. Benefits Assessment 39
IV. PROPOSED INTERIM REGISTRATION REVIEW DECISION 40
A. Proposed and Considered Risk Mitigation and Regulatory Rationale 40
1. Use Cancellations 40
2. PPE 42
3. Use Prohibitions, Application Method Restrictions, and Rate Reductions 55
4. Re-Entry Interval 59
5. Pesticide Resistance Management 59
6. Spray Drift Management 60
7. Updated Water-Soluble Packaging Language for Chlorpyrifos 61
B. Tolerance Actions 61
C. Proposed Interim Registration Review Decision 62
D. Data Requirements 62
V. NEXT STEPS AND TIMELINE 62
A. Proposed Interim Registration Review Decision 62
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B. Implementation of Mitigation Measures 62
Appendix A: Summary of Proposed and Considered Actions for Chlorpyrifos 64
Appendix B: Endangered Species Assessment 81
Appendix C: Endocrine Disruptor Screening Program 83
Appendix Dl: Occupational Post-Application Risks of Concern1 85
Appendix D2: Considered Mitigation for Occupational Post-Application Risks of Concern1... 97
Table of Tables
Table 1: Uncertainty Factor Summary 13
Table 2: DWLOC Values for Chlorpyrifos-Oxon for Infants 15
Table 3: Surface Water Sourced Estimated Drinking Water Concentrations Resulting from
Different Refinements for a Subset of 11 High-Benefit Chlorpyrifos Uses (Assuming Upper
Bound Application Parameters) 16
Table 4: Occupational Risks of Concern from Seed Treatment at the 10X UFdb1 21
Table 5: Groundboom Risk Estimates with MOEs < 100 with Engineering Controls 23
Table 6: Risk Estimates for Backpack Sprayer Applications1 26
Table 7: Summary of Tolerance Revisions for Chlorpyrifos (40 CFR § 180.342(a)).1 32
Table 8: Tolerance Revisions for Chlorpyrifos (40 CFR § 180.342(c))1'2 34
Table 9: Potential Pollinator Data Requirements 37
Table 10: Agricultural Uses Proposed for Retention in Chlorpyrifos Labels with an FQPA Safety
Factor of 10X 40
Table 11: Regional Restrictions for Corn, Tart Cherries, Citrus, Pecan, and Peach with an FQPA
Safety Factor of IX 41
Table 12: Considered engineering controls and PPE for risks of concern from airblast
applications 43
Table 13: Considered PPE for Mixing and Loading Groundboom applications: L/SC/EC 44
Table 14: Considered PPE or Engineering Controls for Groundboom Applicators 45
Table 15: Considered Mitigation for Backpack Sprayer Applications 47
Table 16: Considered mitigation for tractor-drawn applications 48
Table 17: Considered Mitigation for Applications by Rotary Spreader or Hand Dispersal 49
Table 18: Considered Mitigation for Mixing and Loading for Aerial and Chemigation
Applications at the IX FQPA Safety Factor 50
Table 19: Seed Treatment Activities and PPE 58
Table 20: Buffer Distances 61
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I. INTRODUCTION
This document is the Environmental Protection Agency's (the EPA or the agency) Proposed
Interim Registration Review Decision (PID) for chlorpyrifos (PC Code 059101, case 0100), and
is being issued pursuant to 40 CFR §155.56 and §155.58. A registration review decision is the
agency's determination whether a pesticide continues to meet, or does not meet, the standard for
registration in the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The agency may
issue, when it determines it to be appropriate, an interim registration review decision before
completing a registration review. Among other things, the interim registration review decision
may determine that new risk mitigation measures are necessary, lay out interim risk mitigation
measures, identify data or information required to complete the review, and include schedules for
submitting the required data, conducting the new risk assessment and completing the registration
review. Additional information on chlorpyrifos, can be found in the EPA's public docket (EPA-
HQ-OPP-2008-0850) at www .regulations, gov.
FIFRA, as amended by the Food Quality Protection Act (FQPA) of 1996, mandates the
continuous review of existing pesticides. All pesticides distributed or sold in the United States
must be registered by the EPA based on scientific data showing that they will not cause
unreasonable risks to human health or to the environment when used as directed on product
labeling. The registration review program is intended to make sure that, as the ability to assess
and reduce risk evolves and as policies and practices change, all registered pesticides continue to
meet the statutory standard of no unreasonable adverse effects. Changes in science, public
policy, and pesticide use practices will occur over time. Through the registration review
program, the agency periodically re-evaluates pesticides to make sure that as these changes
occur, products in the marketplace can continue to be used safely. Information on this program is
provided at http://www.epa.gov/pesticide-reevaluation. In 2006, the agency implemented the
registration review program pursuant to FIFRA § 3(g) and will review each registered pesticide
every 15 years to determine whether it continues to meet the FIFRA standard for registration.
The EPA is issuing a PID for chlorpyrifos so that it can (1) move forward with aspects of the
registration review that are complete and (2) implement interim risk mitigation (see Appendix
A). EPA is currently working with the National Marine Fisheries Service (NMFS) under a
reinitiated Endangered Species Act (ESA) consultation, and NMFS plans to issue a revised
biological opinion for chlorpyrifos in June 2022. The U.S. Fish and Wildlife Service (FWS) has
not yet completed a biological opinion for chlorpyrifos. EPA will complete any necessary
consultation with NMFS and FWS for chlorpyrifos prior to completing the chlorpyrifos
registration review. See section I. B. and Appendix B for more information. See Appendix C for
additional information on the endocrine screening for the chlorpyrifos registration review.
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Chlorpyrifos (0,0-diethyl 0-(3,5,6-trichloro-2-pyridyl) phosphorothioate) is a broad-spectrum,
chlorinated organophosphate insecticide used to control a variety of foliar and soil-borne insects.
Pesticide products containing chlorpyrifos are registered for use on many agricultural crops, with
the highest uses on corn, soybeans, alfalfa, oranges, wheat, and walnuts in terms of pounds of
chlorpyrifos applied per year. Additionally, chlorpyrifos products are registered for use on non-
food sites such as ornamental plants in nurseries, golf course turf, as wood treatment, and as an
ear tag for cattle. There are also public health uses including aerial and ground-based mosquito
adulticide fogger treatments, use as fire ant control in nursery stock grown in USDA-designated
quarantine areas, and for some tick species that may transmit diseases such as Lyme disease.
The Reregi strati on Eligibility Document for chlorpyrifos was issued July 31, 2006.1 In 1996, the
Food Quality Protection Act set a more stringent safety standard to be especially protective of
infants and children. After finalizing the chlorpyrifos risk assessments for reregi strati on, EPA
identified the need to modify certain chlorpyrifos uses to meet the revised standard of safety, and
to address health and environmental risks from chlorpyrifos exposure. In 1997, the registrant,
Dow AgroSciences (now known as Corteva), voluntarily agreed to cancel chlorpyrifos
registrations for indoor broadcast use and direct pet treatments, except pet collars. In December
2001, the majority of the remaining chlorpyrifos residential products were subject to voluntary
phase out/cancellation. Further changes included label revisions such as buffer zones to ensure
environmental and worker safety in 2002. Additional spray drift mitigation and reduced
application rates were added in 2012 to be protective of bystanders in sensitive areas including
schools and recreational areas. Current chlorpyrifos residential uses are limited to granular ant
mound use (commercial applicator only) and roach bait in child-resistant packaging (for
homeowner use). Chlorpyrifos can be applied as a seed treatment, by chemigation, airblast, and
other ground applications (e.g., groundboom, tractor-drawn spreader), aerial applications,
handheld applications (e.g., handwand, handgun, backpack sprayer, rotary spreader), and as an
impregnated ear tag for some types of cattle. Products containing chlorpyrifos have almost every
type of formulation including wettable powder, emulsifiable concentrate, flowable concentrate,
water-soluble packets (WSP), and granules. There are currently four technical registrants. The
first product containing chlorpyrifos was registered in 1965 and the Tolerance Reassessment and
Risk Management Decision (TRED) was published in 2002. Reregi strati on was completed with
the 2006 update to the Organophosphate Cumulative Risk Assessment.
This document is organized in five sections: thq Introduction, which includes this summary; Use
and Usage, which describes how and why chlorpyrifos is used and summarizes data on its use;
Scientific Assessments, which summarizes the EPA's risk and benefits assessments, updates or
revisions to previous risk assessments, and provides broader context with a discussion of risk
characterization; the Proposed Interim Registration Review Decision, which describes the
mitigation measures proposed to address risks of concern and the regulatory rationale for the
EPA's PID; and, lastly, the Next Steps and Timeline for completion of this registration review.
js://www3.epa.gov/pesticides/chem search/reg actions/re registration/red PC-059.1.0.1. l~M~06.i
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A. Summary of Chlorpyrifos Registration Review
Pursuant to 40 CFR § 155.50, the EPA formally initiated registration review for chlorpyrifos
with the opening of the registration review docket for the case. The following summary
highlights the docket opening and other significant milestones that have occurred thus far during
the registration review of chlorpyrifos.
• March 2009 - The Chlorpyrifos. Human Health Assessment Scoping Document in
Support of Registration Review and Chlorpyrifos Summary Document were posted to the
docket for a 60-day public comment period.
• May 2009 - The Preliminary Problem Formulation for the Ecological Risk and
Environmental Fate, Endangered Species, and Drinking Water Assessments for
Chlorpyrifos was posted to the docket.
• October 2009 - The Chlorpyrifos Final Work Plan (FWP) was issued. The agency
received nine comments on the Chlorpyrifos Summary Document. The comments
received did not change the data and risk assessment needs or schedule for the
chlorpyrifos registration review. The agency also published:
o Response to Comments on Preliminary Problem Formulation for Ecological Risk
and Environmental Fate, Endangered Species and Drinking Water Assessments
for Chlorpyrifos
o Chlorpyrifos. Health Effects Division Response to Comments on the Registration
Review Preliminary Work Plan
o BEAD Response to Comments on Chlorpyrifos Preliminary Work Plan
• September 2010 - The Chlorpyrifos Generic Data Call (GDCI-059101-967) was issued.
There are no studies outstanding from the DCI that are needed to complete the
registration review of chlorpyrifos.
• July 6, 2011 - The agency published the Chlorpyrifos Preliminary Human Health
Assessment for Registration Review, as well as the following supporting materials, to the
public docket for a 90-day comment period:
o Chlorpyrifos: Occupational and Residential Exposure Assessment
o Revised Chlorpyrifos Acute and Chronic Dietary Exposure and Risk Assessments
o Revised Chlorpyrifos Preliminary Registration Review Drinking Water
Assessment
o Chlorpyrifos. Registration Review Action for Chlorpyrifos. Summary of Analytical
Chemistry and Residue Data,
o Chlorpyrifos Carcinogenicity: Review of Evidence from the U.S. Agricultural
Health Study (AHS) Epidemiologic Evaluations 2003-2009
o Reader's Guide to the Preliminary Human Health Risk Assessment for
Chlorpyrifos
o Chlorpyrifos: Tier II Incident Report
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• July 15, 2011 - The agency published the Revised Chlorpyrifos Preliminary Registration
Review Drinking Water Assessment - Appendix D - Typical Use Data for Chlorpyrifos
and Spray Drift Mitigation Decision for Chlorpyrifos and Occupational and Residential
Appendices A through H.
• July 2012 - The agency published Chlorpyrifos - Evaluation of the Potential Risks from
Spray Drift and the Impact of Potential Risk Reduction Measures, Spray Drift Mitigation
Decision for Chlorpyrifos, Appendices E, F, and G of the Evaluation of the Potential
Risks from Spray Drift and the Impact of Potential Risk Reduction Measures, and the
Evaluation of Columbia University Epidemiology Study Claims Related to Brain
Abnormalities andPre-NatalExposures to Chlorpyrifos.
• February 2013 - The Chlorpyrifos Preliminary Evaluation of the Potential Risks from
Volatilization was published for a 30-day public comment period.
• July 2014 - The agency published the Chlorpyrifos: Reevaluation of the Potential Risks
from Volatilization in Consideration of Chlorpyrifos Parent and Oxon Vapor Inhalation
Toxicity Studies.
• December 2014 - The agency published the Chlorpyrifos: Revised Human Health Risk
Assessment for Registration Review and the following:
o Chlorpyrifos: Updated Drinking Water Assessment for Registration Review
o Chlorpyrifos UpdatedDWA Attachment 12/23/2014
o Chlorpyrifos Acute and Steady State Dietary (Food Only) Exposure Analysis to
Support Registration Review
o Chlorpyrifos: Updated Occupational and Residential Exposure Assessment for
Registration Review
• June 2015 - The agency published the Chlorpyrifos: Quality Assurance Assessment of the
Chlorpyrifos Physiologically Based Pharmacokinetic/Pharmacodynamic Model for
Human Health Risk Assessment Applications.
• April 2016 - The Draft Biological Evaluations for Chlorpyrifos, Diazinon, and
Malathion were published for a 60-day comment period.2
• November 2016 - EPA i ssued the Chlorpyrifos: Revised Human Health Assessment for
Registration Review along with the Chlorpyrifos Refined Drinking Water Assessment for
Registration Review.
• January 2017 - The agency announced the availability of the following:
o Endangered Species Act Section 7 Formal Consultation Letter for Chlorpyrifos,
Diazinon, and Malathion
o Response to Comments on the Draft Biological Evaluations for Chlorpyrifos,
Diazinon, and Malathion
2 https://www3.eDa.gov/pesticides/nas/cMorpvrifos/draft-cMorpvrifos.pdf
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o Final Biological Evaluations for Chlorpyrifos, Diazinon, and Malathion3
• September 2020 - The agency issued the Chlorpyrifos: Draft Ecological Risk Assessment
for Registration Review and Chlorpyrifos: Third Revised Human Health Risk Assessment
for Registration Review in addition to the following:
o Updated Chlorpyrifos Refined Drinking Water Assessment for Registration
Review
o Evaluating the Impact of Removal of the 10X FQPA Safety Factor on
Chlorpyrifos Drinking Water Concentrations
o Usage of chlorpyrifos (PC# 059101) on alfalfa grown for alfalfa hay and seed,
cotton, soybeans, sugar beets, spring and winter wheat, Michigan asparagus,
Florida and Texas citrus, and Oregon strawberries by hydrologic region (two-
digit HUC)
• December 2020 - The agency is completing the PID for chlorpyrifos, in preparation for
publication in the docket for a 60-day public comment period. The agency is also taking
comments on the Chlorpyrifos: Draft Ecological Risk Assessment for Registration
Review and Chlorpyrifos: Third Revised Human Health Risk Assessment for Registration
Review issued September 21, 2020. In addition, the agency is also issuing:
o Benefits of Agricultural Uses of Chlorpyrifos (PC# 059101)
o Chlorpyrifos (PC# 059101) Usage and Benefits Assessment for Non-crop Uses
o Average and maximum application rates and average number of applications of
chlorpyrifos (PC# 059101) used in cherries, corn, peaches, pecans, and peppers by
hydrologic region (two-digit HUC)
o Chlorpyrifos (059101) National and State Summary Use and Usage Summary
Matrix
B. Endangered Species Consultation
Chlorpyrifos was one of the first three pilot chemicals that EPA conducted a nationwide ESA
consultation. EPA completed a biological evaluation and initiated consultation with the FWS and
NMFS in January 2017. 4 Pursuant to a consent decree, at the end of December 2017, NMFS
issued its Biological Opinion (BiOp) on chlorpyrifos, diazinon, and malathion.5 In July 2019,
EPA re-initiated formal consultation with NMFS on the December 2017 BiOp.6 EPA re-initiated
consultation because new information on how the pesticides were actually being used may show
that the extent of the effects of the actions may be different than what was previously considered.
As part of this re-initiation, EPA provided additional usage data it believes may be relevant to
the consultation. In its transmittal of this information to NMFS, EPA also referenced usage data
and information that had been recently submitted by the registrants of pesticide products
containing chlorpyrifos, malathion, and diazinon. After reviewing information EPA provided to
NMFS on the 2017 BiOp, NMFS determined that it was appropriate to revise the chlorpyrifos,
llttDS
//www.eDa.gov/endangered-SDecies/biological-evahiation-chaDters-chlorDvrifos-esa-assessment
llttDS
//www.eDa.eov/endaneered-SDecies/bioloeical-evaluation-chaDters-chlorDvrifos-esa-assessment
llttDS
//www.fishe ries.noaa.gov/resoiirce/dociiinent/biological-ODin.ion-Desticides-chlorDvrifos-diazinon-and-
malathion
6 https://www.re gulations.gov/document?D=EPA-HO-OPP-2Q.1.8-0.1.4.1.-0.1.36
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malathion, and diazinon BiOp. NMFS plans to issue a revised final BiOp for chlorpyrifos,
diazinon, and malathion by June 2022. FWS has not yet issued a BiOp on chlorpyrifos. EPA
plans to address risks to listed species and critical habitats from use of chlorpyrifos as part of the
final registration review decision, pending completion of the nationwide consultation process.
C. Other Chlorpyrifos Actions
In September 2007, the Pesticide Action Network North America (PANNA) and Natural
Resources Defense Council (NRDC) filed a Petition requesting that the EPA revoke all
tolerances for chlorpyrifos under section 408(d) of the Federal Food, Drug and Cosmetic Act
(FFDCA) and cancel all chlorpyrifos registrations under FIFRA. Public dockets were opened for
the transmittal of public documents pertaining to this petition in EPA-HQ-OPP-2007-1005 and
EPA-HQ-OPP-2015-0653.
The registration review of chlorpyrifos and the organophosphates (OPs) has presented EPA with
numerous novel scientific issues that the agency has taken to multiple FIFRA Scientific
Advisory Panel (SAP) meetings.7 Many of these complex scientific issues formed the basis of
the 2007 petition filed by PANNA and NRDC and EPA therefore decided to address the Petition
on a similar timeframe to EPA's registration review schedule.
Throughout the development and revisions to the human health draft risk assessment, and after
seeking the expertise of the SAP in 2016, the EPA issued the order to deny the petition in March
2017. The agency concluded that the science addressing neurodevelopmental effects remained
unresolved and further evaluation of the science during the remaining time for completion of
registration review was warranted. The agency specified it would continue to review the science
addressing pre- and postnatal neurodevelopmental effects of chlorpyrifos, and those actions are
described in further detail in this P1D.
Petitioners and other parties filed objections to directly challenge the denial order. In July 2019,
the EPA issued a final order denying objections to EPA's March 2017 order denying PANNA
and NRDC's 2007 Petition to revoke all tolerances and cancel all registrations for chlorpyrifos.8
That 2019 order has been challenged by the Petitioners in the Ninth Circuit, which heard oral
arguments in that case in July 2020. LULAC v. Wheeler, No. 19-71979 (9th Cir.). To date, the
Court had not yet issued a decision on the agency's decision to deny the petition to revoke
chlorpyrifos tolerances.
Documents pertaining to the chlorpyrifos Petition to revoke all tolerances and cancel all
registrations for chlorpyrifos (docket EPA-HQ-OPP-2007-1005) and chlorpyrifos tolerance
rulemaking (docket EPA-HQ-OPP-2015-0653) may be found at www.regulations.gov.9
7 https://www.epa.gov/sap/fifra-scientific-advisorv-Danel-meetings
8 https://www.reguiations.gov/document?D=EPA-HO-OPP-2007-1005-0527
9 https://www.regulations.gov/docket?D=EPA-HO-OPP-2007-10Q5 and
https://www.regulations.gov/docket?D=EPA-HO-OPP-2Q15-0653. respectively
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D. Approach for Presenting Risk Estimates and Uncertainty Factors
As noted in the previous section, the registration review of chlorpyrifos and the OPs has
presented EPA with numerous novel scientific issues, notably the potential for
neurodevelopmental effects on the young (pre-natal, infants and children), that the agency has
taken to multiple FIFRA SAP meetings since the completion of reregi strati on.10 The agency
completed a weight-of-the-evidence (WOE) analysis for neurodevelopmental effects using the
"Framework for Incorporating Human Epidemiologic & Incident Data in Health Risk
Assessment."11 The WOE analysis integrated quantitative and qualitative findings from
experimental toxicology studies, epidemiology studies, and physiologically-based
pharmacokinetic-pharmacodynamic (PBPK-PD) modeling.12 EPA has also considered the
emerging new information from laboratory animal and mechanistic studies in addition to
epidemiology studies that identified potential concern for increased sensitivity and susceptibility
for the young from neurodevelopmental effects in the development of this PID. Despite several
years of study, the science addressing neurodevelopmental effects remains unresolved. Due to
this uncertainty, EPA has retained the FQPA 10X safety factor in its human health risk
assessment in order "to take into account potential pre- and post-natal toxicity and completeness
of the data with respect to exposure and toxicity to infants and children." FFDCA §
408(b)(2)(C). For consistency, EPA has also applied an additional 10X database uncertainty
factor (UFdb) in its assessment of occupational risks.
Notwithstanding, EPA recognizes that the science is evolving on this topic, and that there may be
new information available prior to the completion of registration review that may impact the
agency's conclusions about these effects. Most recently, EPA held a FIFRA SAP meeting from
September 15 to September 18, 2020 to assess new approach methodologies that might be used
to evaluate developmental neurotoxicity in EPA's assessment of risks to human health. EPA will
consider the input and recommendations from the September 2020 FIFRA SAP once the SAP
report is released in December 2020. In order to provide a fuller picture of the potential risk
estimates and the evolving understanding of the potential for neurodevelopmental effects, EPA
has also assessed the potential risks assuming a reduction to IX of the FQPA SF and the UFdb.
This PID presents the risk estimates as reflected in the 2020 human health risk assessment. EPA
is proposing mitigation measures to mitigate risks estimated based on the retention of the 10X
FQPA SF and UFdb. EPA is also presenting measures to mitigate risks assuming a reduction to
IX. Depending on the recommendations of the SAP, EPA's conclusions about risk, and thus
proposed mitigation measures, may be revised.
10 https://www.epa.gov/sap/fifra-scientific-advisorv-panel-meetings
11 U.S. Environmental Protection Agency. 2016. Framework for Incorporating Human Epidemiologic and Incident
Data in Health Risk Assessment, December 28, 2016. Available at https://www3.epa.gov/pesticides/EPA-HO-OPP-
2008-0316-DRAFT-0075.pdf.
12 The PBPK-PD model was used to derive toxicological points of departure (PoDs) and to determine the
appropriate intra-species and inter-species uncertainty factors. https://www.regulations.gov/document?D=EPA-HQ-
OPP-2008-0850-0941.
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II. USE AND USAGE
Chlorpyrifos is a broad-spectrum insecticide and miticide registered for use for control of
numerous insect pests and some mite pests. Products containing chlorpyrifos are registered for
over 50 agricultural uses including fruit and vegetable crops, tree nuts, sorghum, wheat, and
other food uses. Chlorpyrifos is also used to treat non-food uses such as cotton, nursery and
landscape ornamentals, Christmas trees, golf course turf, greenhouse plants, as well as non-
structural wood treatments such as utility poles and fence posts, cockroach bait stations, and as a
mosquito adulticide. Many commercially-applied pesticide products containing chlorpyrifos are
classified as restricted use products (RUPs), which can only be applied by certified applicators or
those under their supervision. There is only one product currently registered for homeowner use
which is formulated as a child-resistant bait station for cockroach control (EPA Reg. No. 9688-
67). There are over 60 FIFRA Section 3 registrations, including eight technical registrations, and
over 30 FIFRA Section 24(c) Special Local Need registrations for products containing
chlorpyrifos, which include co-formulated products (i.e., those with multiple active ingredients
in addition to chlorpyrifos). Overall usage has declined in the past decade but increased for some
specific uses, such as sorghum, sweet corn, sunflowers, tobacco and pears. Since 2019, several
states, including California, Hawaii, New York, Maryland, and Oregon, have initiated state-level
actions to phase out all or most uses of chlorpyrifos.
Chlorpyrifos products are available in a variety of formulations, including wettable powders,
granules, emulsifiable concentrates, WSPs, cattle ear tags, and bait stations. Chlorpyrifos
products may be applied via groundboom sprayer, aircraft, tractor-drawn spreader, hand-wand,
backpack sprayer, mechanically-pressurized handgun, and belly grinder. Application may take
place throughout the agricultural season or throughout the year for non-agricultural applications.
Approximately 5.1 million pounds of chlorpyrifos were used each year for agricultural purposes
in the United States between 2014 and 2018. Soybeans, alfalfa and corn make up nearly 50% of
the total volume of chlorpyrifos used in the United States each year, with soybeans alone
accounting for nearly 25% of total pounds applied. Less than 6% of each crop (i.e., soybeans,
alfalfa and corn), however, is treated with chlorpyrifos. In addition to soybeans, alfalfa, and corn,
crops with relatively high usage of chlorpyrifos (i.e., those with 100,000 lbs applied per year or
more) include almonds, apples, grapes (wine, table, and raisins combined), oranges, peanuts,
pecans, sugar beets, walnuts, spring wheat, and winter wheat. At least 40%, of the total acreage
planted with apples, grapefruit, and asparagus is treated with chlorpyrifos. There has been a
general trend of decreased usage in terms of pounds applied per year from 1998-2018, although
acres treated has remained relatively stable (Kynetec, 2019.)13
Chlorpyrifos is registered for a number of non-crop uses including turf and ornamentals, tree
farms and forest trees, cattle ear tags, livestock housing, rights of way, building perimeters, wood
protection treatments, general outdoor treatments for ants and other pests, and wide area
mosquito adulticide treatments. The majority of chlorpyrifos products registered for residential
treatments were voluntarily cancelled or phased out by the registrants between 1997 and 2001.
While usage data is not available for all non-agricultural use sites, available data indicate that the
13 Kynetec USA, Inc. 2019. "The AgroTrak® Study from Kynetec USA, Inc." Database Subset: 1998-2018.
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majority of non-agricultural chlorpyrifos usage in terms of pounds of active ingredient were
applied to ornamental lawns and turf. Within this market segment, turf farms account for the
majority of usage, with 70,000 pounds of chlorpyrifos applied to approximately 64,000 acres.
Nursery and greenhouse use on ornamentals are a close second, with 50,000 pounds applied to
approximately 67,000 acres (Kline, 2012).14 Far fewer pounds of chlorpyrifos were applied for
wide area mosquito treatment, with only 10,000 pounds applied annually. However, due to very
low application rates typically used for mosquito adulticides, treatments for mosquitos account
for the vast majority of non-crop acres treated with chlorpyrifos, with over 1,000,000 acres
reported to be treated for this purpose (Kline, 2017).15 Chlorpyrifos is also registered for use on
the following additional surveyed non-crop sites: wide area/general outdoor treatment (for ants
and other miscellaneous pests), buildings/premises, rights of way/utilities, and trees. However,
while Kline and Company does survey these sites, the surveys did not report any usage for these
sites, indicating that chlorpyrifos is not widely used in these sectors (Kline, 201616 and Kline,
2017). Chlorpyrifos is also registered for use on livestock areas and animal quarters, but usage
data on pounds applied are unavailable for these sites.
III. SCIENTIFIC ASSESSMENTS
A. Human Health Risks
A summary of the agency's human health risk assessment is presented below. The agency used
the most current science policies and risk assessment methodologies to prepare a risk assessment
in support of the registration review of chlorpyrifos. For additional details on the human health
assessment for chlorpyrifos, see the Chlorpyrifos: Third Revised Human Health Risk Assessment
for Registration Review, which is available in the public docket.
1. Hazard Characterization
Chlorpyrifos is known to form chlorpyrifos-oxon, 3,5,6-trichloro-2-pyridinol (TCP), and 3,5,6-
trichloro-2-methoxypyridine (TMP). Chlorpyrifos undergoes desulfuration, reacting in
bioactivation to degrade to the more toxic and potent acetylcholinesterase (AChE) inhibitor,
chlorpyrifos oxon. Due to rapid deactivation through hydrolytic cleavage by a process called
diarylation, the oxon is highly unstable and breaks down to release TCP, which is not a U.S
residue of concern.
The hazard characterization for chlorpyrifos and its oxon degradate is based on adverse health
effects in animals and humans related to AChE inhibition, and potential for neurodevelopmental
effects. Guideline animal toxicity studies have historically been used in support of the 10% red
14 Kline and Company. 2012. Professional Turf and Ornamental Markets for Pesticides and Fertilizers 2012: U.S.
Market Analysis and Opportunities. [Accessed April 2020.]
15 Kline and Company. 2017. Professional Pest Management Markets for Pesticides 2016: United States Market
Analysis and Opportunities 2016. [Accessed April 2020.]
16 Kline and Company. 2016. Mosquito Control Markets 2015: U.S. Market Analysis and Opportunities. [Accessed
April 2020.]
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blood cell (RBC) AChE inhibition point of departure (POD) for chloipynfos ui EPA risk
assessments.
Since the agency lias used the PBPK-PD model for chlorpyrifos to simulate huinan RBC AChE
inhibition, the default 10X inter-species uncertainty factor (to account for uncertainty in relying
on animal toxicity data to estimate a human toxicity endpoint) is not warranted and is reduced to
IX, The PBPK-PD mode! also incoipoiate-. inter-individual variation in lespon^e to chlorpyrifos
to estimate a distribution of administered doses that could have resulted in 10% RBC AChE
inhibition in humans, meaning a data derived extrapolation factor (DDEF) can be applied in lieu
of the default intra species uncertainty factor. The agency lias selected the 99* percentile of the
distribution to account for variation of sensitivity. The infra-species DDEF is 4X for
chlorpyrifos and 5X for the oxon for all groups except females of reproductive age for whom the
10X intra-species factor was retained.
The 2020 revised human health risk assessment presents potential risks with the 10X FQPA
Safety Factoi iSFK reflecting the uncertainties around doses, that may cause pre- and postnatal
neurodevelopmental effects, as well as IX to demonstrate the range of potential risk estimates.
The uncertainty factors and total level of concern (LOG) for each subpopulation is as follows:
I iihli' t: I ni.ertnin(\ Factor Stiintmirv
t m el nine.
l-OIW I»\
i or \ i\
\ii sillitT Siilip'iniil.ilinii^
l-'l'IIClli'S
\!1 nthrr sjil'impul.Uinn-
1- 1 rlll;ilc-.
fund • I>:11 i-llt)
DiinLiiiu
\\ :)fi r liivMi i
1 'mid ¦; i
DfinUinu
W :lU-r (n\iilli
llllrlMHi'ir-.
lotrxspecies
10
4
5
10
4
5
FQPA
10
10
to
1
1
1
Total LOC
ti®
4®
50
10
4
5
2. Risk Summary and Characterization
Steady State
As with other OPs, ehlorpyrifos exhibits a phenomenon known as steady state AChE inhibition.
Following repeated exposure at the same level, the degree of inhibition reaches equilibrium with
production of new, uninhibited enzyme and the amount of AChE inhibition in a given dose
remains consistent across exposure duration. After reaching steady state, the amount of AChE.
inhibition at a select dose remains constant across exposure duration. It generally takes
approximately 2 to 3 weeks for this class of chemicals to reach steady state (U.S. EPA, 2002);
however, this timeframe can vary with select chemicals. As such, the agency evaluated potential
risks from steady state exposure in lieu of chronic exposure.
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Dietary (Food + Water) Risks
FOOD
Both the acute and steady state dietary (food only) exposure analyses for chlorpyrifos were
highly refined and incorporated monitoring data for almost all foods. Most of the food residues
used were based upon USDA's Pesticide Data Program (PDP) monitoring data except in a few
instances where no appropriate PDP data were available. Chlorpyrifos is routinely included in
PDP monitoring.
The only residue of concern for the dietary (food only) assessment is chlorpyrifos. Food
exposures do not incorporate potential exposure from food handling establishment (FHE) uses
since the agency did not identify any registered FHE uses. Therefore, food exposures are based
only upon field use of chlorpyrifos. At the 99.9th percentile of exposure the subgroup with the
highest acute exposure was females (13-49 years old) at 3.2 % acute population adjusted dose for
food (aPADfood) with the 10X FQPA safety factor retained. For the steady state dietary (food
only) exposure analyses, the population subgroup with the highest exposure was children (1 to
<2 years old) at 9.7% of the ssPADfood at the 99.9th percentile of exposure. No potential risks of
concern were identified from exposure to chlorpyrifos in food only. With the FQPA SF reduced
to IX, acute and steady state dietary risk estimates are <1% of the aPADf00dand ssPADfood for all
populations.
WATER
Drinking Water Assessment and Refinements
The Updated Chlorpyrifos Refined Drinking Water Assessment for Registration Review builds
upon refinements from the 2014 and 2016 assessments at the Tier 3 assessment level, which
included a screening-level approach at the national, regional, and watershed level as well as
monitoring data and effects from water treatment systems. Based on regional screening, the
incidence of high exposures is expected to be highly localized. However, assessing exposure on a
local scale is difficult without regional-specific data and considering several local characteristics
including soil type(s) and weather conditions. To further account for exposure on a local scale,
EPA examined the potential geospatial concentration differences between two Hydrological Unit
Code (HUC 2) Regions. This method was developed to identify use patterns that may result in
estimated drinking water concentrations (EDWCs) that exceed the Drinking Water Level of
Comparison (DWLOC) on a regional basis.
Moreover, the 2020 assessment incorporates the following additional refinements:
• New surface water model scenarios (i.e., soil, weather, and crop data);
• Use of community water system percent cropped area (PCA) adjustment factors and state
level percent crop treated (PCT) data; and
• Quantitative use of surface water monitoring data.
Quantitative use of surface water monitoring data underwent external review in November 2019
from the FIFRA SAP and the remaining refinements were open to public comment and external
14
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Docket Number EPA-HQ-OPP-2OO8-O850
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peer review. Utilization of tlie aforementioned factors and data elevates the drinking water
assessment to a Tier 4 assessment level, the most highly refined assessment tier.17 The
Framework for Conducting Pesticide Drinking Water Assessments for Surface Water (DWrA
Framework) (USEPA. 2020) includes a description of how these methods fit into the overall
tiered drinking w.ttet assessment process.
Drinking Water Level of Comparison (DWLOC) Approach
Given the potential drinking water risks of concern previously identified during the registration
review of chlorpyrifos. the Updated Cidorpxrifos Refined Drinking Water Assessment (DWA) for
Registration Review focuses on a subset of high-benefit18 19 and or critical uses in defined areas
of the country:
• Alfalfa •
• Apple •
• Asparagus •
• Cherry •
• Citrus •
• Cotton
Peach
Soybean
Sugar beet
Strawberry
Wheat (Spring and Winter)
For a drinking water assessment which utilizes a DWLOC, the calculated DWLOC is compared
to the EDWC. When the EDWC is greater than the DWLOC, there may be a risk concern for
exposures to ehloipyrifos and/or ehloipyrifos oxon. Conversely, when the EDWC is less than the
DWLOC. there are no risks of concern.
Both ehloipyrifos and the chlorpyrifos oxon are residues of concern in drinking water. With the
10X FQPA safety factor, the lowest acute DWLOC and steady state DWLOC calculated were 23
ppb and 4 ppb. respectively, for the most sensitive population, infants (' 1 year old). The
DWLOC s are 230 ppb and 43 ppb. Respectively, without letemion of the 1UX FQPA safety
factor. Drinking water concentrations of chlorpyrifos oxon above the DWLOC' indicate a
potential risk concern.
1 able 2: !)\\ I.(>( \ allies tor < hiorp\ rif«i*-( >\\\ I PC (|>|>i>) for infants
Chlori
pyrifos
C hiorpyrifos-oxon
S:llVt\ factor
10X
IX
10X
IX
1?
ISO
4
43
AciUc
100
1000
23
230
17 https://www.epa.aov/sap/meeting-aifonnatioa-november-19-22-2019~seientlfic~acfvisory-paiiei
A high benefit indicates that there are no alternative pesticides for a pest on a specific crop or alternatives
products are expensive or less efficacious. Target pesK in these crops include alfalfa weevil, Jygtis bugs, scale, and
two spotted spider mites. Additional details are provided in Section III.C of this document.
19 hltps^/twywj'eailaficms.goivdociiriie-aii' .m *¦
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As noted earlier, several refinements were considered in the Updated Chlorpyrifos Refined
Drinking Water Assessment (DWA), including usage data, percent cropped area aggregation, and
percent cropped area-percent crop treated aggregation. These refinements are reflected in the
below EDWCs and discussed in detail in the Updated Chlorpyrifos Refined Drinking Water
Assessment (DWA).
Table 3: Surface Water Sourced Estimated Drinking Water Concentrations Resulting from
Different Refinements for a Subset of 11 High-Benefit Chlorpyrifos Uses (Assuming Upper
Bound Application Parameters)
2-digit HUC
Name
Overlapping
States1
2 digit HUC
Uses
Maximum 1 in 10 Year Estimated Chlorpyrifos-oxon
Concentrations in Source Surface Water (ng/L)
Maximum 2-digit HUC
Use Site-Specific
Percent Cropped Area2
Percent
Cropped Area
Aggregation3
Percent Cropped
Area-Percent
Crop Treated
Aggregation4
1-dav
Average
21 day
Average
21-day Average
21-day Average
Mid-Atlantic
VT, MY, PA, NJ,
MD. DE, WV,
DC. VA
HUC-02
Apple and Peach
1.0
0.8
-
-
South Atlantic-
Gulf
VA. NC, SC.
GA. FL. TN. MS
HUC-03
Cotton. Citnis.
Peach, and
Soybean
3.1
1.8
-
-
Great Lakes
WI. MN. MI, IL,
IN. OH. PA, NY
HUC-04
Alfalfa. Sugar
beet. Apple,
Cherry. Peach.
Soybean, and
Asparagus
22.8
19.6
3.4
-
Ohio
IL. IN. OH. PA.
WV, VA. KY,
TN
HUC-05
Apple and
Soybean
5.3
4.0
-
-
Tennessee
VA. KY. TN,
NC. GA. AL.
MS
HUC-06
Apple
0.4
0.2
-
-
Upper
Mississippi
MN. WI. SD. LA
IL, MO. IN
HUC-07
Alfalfa. Sugar
beet, and
Soybean
9.9
7.2
5.4
3.2
Souris-Red-
Rainv
ND. MN. SD
HUC-09
Alfalfa. Sugar
beet. Soybean.
Spring Wheat,
8.3
5.6
5.24
3.3
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and Winter
Wheat
Missouri
MT, ND. WY,
SD. MN. NE.
IA. CO, IA, KS.
MO
HUC-10
Alfalfa. Soybean.
Spring Wheat,
and Winter
Wheat
5.7
3.6
-
-
Arkansas-
Wliite-Red
CO. KS. MO.
NM. TX. OK.
AR LA
HUC-11
Alfalfa. Soybean,
and Winter
Wheat
3.9
3.9
-
-
Texas-Gulf
NM. TX. LA
HUC-12
Citrus. Peach,
and Winter
Wheat
1.1
0.7
-
-
Pacific
Northwest
WA. ID. MT.
OR. WY, UT.
NV
HUC-17
Alfalfa. Sugar
beet. Apple, and
Strawbeny
8.5
6.1
2.5
-
Green shading indicates concentrations are below the 10X DWLOC (1-day = 43 (ig/L and 21-day = 4 Hg/L) while red shading
indicates concentrations are above the 10X DWLOC.
- indicates values are not calculated because the concentrations in the prior step were below the 1 Ox DWLOC.
1 Sites are listed that include any overlap with the HUC-2 region.
2 Use site-snecific PCA refers to the use of a percent cropped area adjustment factor to adiust EDWCs to account onlv for the
potential use sites (e.g.. for example for HUC-03 the PCA is the summation of individual percent cropped area for orchard, cotton,
and soybean) within each individual community water system where chlorpyrifos is being considered (see column "2-digit HUC
Uses").
3 PCA aggregation refers to the use of individual percent cropped area adjustment factors to proportionally allocate pesticide
residue contribution in the development of EDWCs based on potential chlorpyrifos use sites (i.e.. land use data) for individual
watersheds. This analysis was done using the model output l-in-10 year values and does not account for temporal residue
contributions.
4 PCA-PCT aggr egation refers to the use of individual percent cropped area adjustment factors to proportionally allocate pesticide
residue contribution in the development of EDWCs based on known chlorpyrifos use for individual watersheds. This analysis was
done using the model output l-in-10 year values and does not account for temporal residue contributions.
5 The use pattern specific PCA is higher (i.e., >1) than all-ag PCA (0.95). Therefore, the use pattern specific PCA is capped at all-
ag value and the use pattern PCA should not exceed the all-agricultural PCA. However, when aggregating the individual use
residue contributions results, this capping cannot be completed.
Based on the most refined EDWCs, concentrations of chlorpyrifos and cklorpyrifos-oxon in
drinking water are not likely to exceed the drinking water level of comparison (DWLOC) for the
subset of 11 uses considered with the retention of the 10X FQPA safety factor. The consideration
of additional crops would likely result in exceedances of the DWLOC if the 10X FQPA SF is
retained. Dietary risks of concern fr om public health uses, such as mosquito adulticide treatment,
are not expected at either the IX or 10X.
EDWCs from the 2016 drinking water assessment for agricultural uses were compared to the
DWLOCs to assess currently labels uses at the IX FQPA safety factor. With a IX FQPA safety
factor, most of the current labeled uses result in drinking water concentrations below the
DWLOC. Uses with drinking water concentrations above the DWLOC include, peppers, trash
storage bins, and wood treatment, in all areas of the country. Additionally, uses with l-in-10 year
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21-day average drinking water concentrations above the 21-day average DWLOC in certain
HUCs include corn, tart cherries, citrus, pecan, and peach. For additional information on the
chlorpyrifos EDWCs at the IX, please see Evaluating the Impact of Removal of the 10XFQPA
Safety Factor on Chlorpyrifos Drinking Water Concentrations.20
Cancer
Chlorpyrifos has also been evaluated for cancer and is classified as "not likely to be carcinogenic
to humans." Guideline carcinogenicity studies and epidemiological data are available from the
Agricultural Health Study (AHS). Preliminary associations with breast, lung, colorectal, and
prostate cancer warrant monitoring follow-up and additional research. There is no compelling
evidence of an association with other cancer sites (C. Christensen, 6/16/11, D388167). The AHS
chlorpyrifos carcinogenicity studies have been summarized in the memorandum, Chlorpyrifos
Carcinogenicity: Review of Evidence from the U.S. Agricultural Health Study (AHS)
Epidemiologic Evaluations 2003-2009 (Christensen, D388167, 6/16/2011).
Residential Exposure Risks
Currently, chlorpyrifos products registered for residential use are limited to roach bait products
(EPA Reg. No. 9688-67) or ant mound treatments which may only be applied by commercial
applicators. The active ingredient is contained within a bait station which eliminates the potential
for human contact; therefore, residential exposure to chlorpyrifos via these products is
considered negligible. The majority of products registered for residential treatment were
voluntarily cancelled or phased out by the registrants between 1997 and 2001.
There is a potential for exposure to the general population from use on golf courses following
treatment with chlorpyrifos products or from exposures which occur following aerial or ground-
based ultra-low volume (ULV) mosquito applications made directly in residential areas. Risk
estimates for dermal and inhalation exposure were combined since the toxicological endpoint,
RBC AChE inhibition, is the same for each of these exposure routes. With retention of the 10X
FQPA SF, the residential post-application LOC for children is 40 and the adult residential post-
application LOC is 100. Regardless of whether the FQPA SF is retained at 10X or reduced to
IX, there are no residential post-application risk estimates of concern for the registered uses of
chlorpyrifos. The assessment of steady state golfer post-application exposures (dermal only) to
chlorpyrifos treated turf resulted in no risks of concern to children/youth 6 to <16 years old
(Margin of Exposure (MOEs) = 1,200 to 9,900) or adults (MOE = 1,000 to 5,400). With
minimum MOEs of 400, there were no combined risks of concern identified for children 1 to <2
years old (dermal, inhalation, and incidental) or adults (dermal and inhalation) from post-
application exposures following public health mosquito applications.
Aggregate Risk Assessment
A DWLOC approach was used to calculate the amount of exposure that could occur without
exceeding the level of concern for acute and steady state aggregate assessments. This was to
20 https://www.regulations.gov/doeument?D=EPA-HO-OPP-2008-0850-0942
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account for the available space in the "total aggregate risk cup" for exposures to chlorpyrifos
oxon in drinking water after accounting for exposures to parent chlorpyrifos from food and
residential uses. The calculated DWLOCs were then compared to the EDWCs of chlorpyrifos
and chlorpyrifos oxon modeled under a variety of conditions.
With residential exposures considered negligible, the acute aggregate assessment includes only
food and drinking water. The steady state aggregate assessment includes exposures from food,
drinking water, and residential uses (golf courses). As previously mentioned, the drinking water
assessment is highly refined incorporating multiple screening exercises and comparing modeling
results to monitoring data.
When considering all currently registered agricultural and non-agricultural uses of chlorpyrifos,
aggregate exposures are of concern. If considering only the uses that result in DWLOCs below
the EDWCs, aggregate exposures are not of concern.
Non-Occupational Spray Drift Risks
Spray drift from ground or aerial applications can be a potential source of non-occupational
exposure to chlorpyrifos. The potential risks from spray drift exposure and the impact of
potential risk reduction measures were assessed in a July 2012 memorandum.21 To increase
protection for children and other bystanders, chlorpyrifos technical registrants voluntarily agreed
to spray drift mitigation measures including lower application rates, increased droplet sizes, and
buffer zones.
There are no risk estimates of concern incorporating the agreed-upon buffer distances and
droplet sizes/nozzle types by the EPA and the technical registrants in 2012 with or without the
10X FQPA SF for aerial or groundboom applications. There were no combined (dermal +
incidental oral) risks for children 1 to < 2 years old at the field edge from indirect spray drift
exposure to chlorpyrifos and there were no dermal risk estimates of concern at the field edge for
adults (females 13-49 years old). Aerial applications are not permitted at rates higher than 2.0 lb
a.i./ except for treatment of Asian Citrus Psyllid (citrus use) at application rates up to 2.3 lbs
a.i./A. For aerial applications at this highest rate, MOEs of concern were identified within 10 feet
from the edge of the field. However, current buffer distances required on the label mitigate these
potential risks of concern.
The EPA assessed post-application exposures to residential bystanders from spray drift and
volatilization. This assessment focuses primarily on individuals who live on, work in, or frequent
areas adjacent to chlorpyrifos-treated agricultural fields. In June 2014, a re-evaluation of the
2013 preliminary volatilization assessment was conducted to present the results of two new
vapor studies and their impact (MRIDs 49119501 and 49210101). These studies demonstrated
that no toxicity occurred even at the saturation concentration, which is the highest physically
achievable concentration. As such, there are no anticipated risks of concern from exposure to the
volatilization of either chlorpyrifos or chlorpyrifos oxon with or without retention of the 10X
FQPA SF.
21 https://www.re gulations.gov/document?D=EPA-HO-OPP-2008-085Q-0.1.03
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Cumulative Risks
Chlorpyrifos is a member of the OP class of pesticides. EPA considers OPs to express toxicity
through a common biochemical interaction with cholinesterase which may lead to several
potential cholinergic effects and, consequently, the OPs should be considered as a group when
performing cumulative risk assessments. The agency first completed a cumulative risk
assessment for the OPs in 2001, a revised cumulative risk assessment for the OPs was completed
in 200222, and an updated OP cumulative risk assessment was completed in 2006.23 The
cumulative effects of exposure to multiple OPs, including chlorpyrifos, are evaluated in those
documents. Prior to the completion of registration review, the agency will update the OP
cumulative risk assessment to incorporate any toxicity and exposure information available since
2006.
Occupational Handler Risks
Occupational handlers mixing, loading, and/or applying pesticide products containing
chlorpyrifos may be exposed to chlorpyrifos dermally or by inhalation. PBPK-PD model-derived
PODs (dermal and inhalation), which were specifically set up for occupational exposure
scenarios, were used to estimate handler risks. The steady state approach accounts for short-term
exposure duration, as well as for workers that are exposed over longer periods of time (i.e.,
intermediate-term exposures). The dermal and inhalation risk estimates were combined since the
toxicological endpoint, RBC AChE inhibition, is the same for each of these exposure routes.
The human health risk assessment presents estimates assuming both that the database uncertainty
factor (UFdb) has been retained at 10X and has been reduced to IX. If the database uncertainty
factor is retained, the total LOC for occupational exposure assessment is 100X for adults
(represented by females 13-49). If the database uncertainty SF is reduced to IX, the total LOC
for occupational exposure assessment is 10X for adults (represented by females 13-49).
Two hundred eighty-eight steady state occupational handler scenarios were assessed for non-
seed treatments. Assuming a 10X database uncertainty factor is retained (LOC = 100), 119
scenarios are of concern with label-specified personal protective equipment (PPE; baseline attire,
chemical resistant gloves, coveralls, and a protection factor (PF) 10 respirator) (MOEs < 100).
Risks of concern for 45 additional exposure scenarios could potentially be mitigated if
engineering controls are used. Without retention of the 10X database uncertainty factor (UFdb)
(LOC = 10), 19 non-seed treatment scenarios are of concern with baseline attire, chemical
resistant gloves, coveralls, and an elastomeric half mask (PF 10) respirator (MOEs < 10). If
22 US EPA, 2002.
https://nepis.epa.gov/Exe/ZyNET.exe/9100BFLL.TXT7Zy ActionD=ZyDocument&Client=EPA&Index=2000+Thru
±2005&Docs=&QiieBi=^^^
iMdYeaE&QFIeldMoiittE&QFieMPjiB^
%5CIiidex%20Data%5C00thiii05%5CTxt%5C00000023%5C9.1..00BFLL.txt&Uset~ANONYM'OUS&Password=a.n
o irv mous&So rtMethod=h%7 C-
&MaximumDocuments=l&FuzzyDegree=0&ImageOuality=r75g8/r75g8/xl50yl50gl6/i425&Display=hpfr&DefSe
ekPage=x&SearchBaek=ZvActionL&Back=ZvActionS&BackDesc=Results%20Dage&MaximumPages=l&ZvEntr
y=1 & SeekPa ge=x&ZvPURL
23 US EPA, 2006. https://www regulations.gov/document?D=EPA-HQ-OPP-2006-Q6.1.8-0002
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engineering controls are used, risks of concern for 15 additional scenarios could potentially be
mitigated. The changes to the inputs are not expected to result in significant changes to the risk
estimates and have not been updated at this time.24
A total of commercial seed ireafsiiens scenario* were assessed foi chlorpyrifos. The revised
toman health risk assessment identified 22 seed-treatment scenarios of concern with the
assumption that the 10X UFbb is retained. Seed treatment uses include com, cotton (delmted),
cucumber, pumpkin, sorghum grain, triticale (wheat), and a variety of beans. Mo potential risks
of concern were identified with scenarios assessed for cucumber, pumpkin, sorghum grain and
triticale or for planl ing seeds previously treated with ehloqwnfos. If the 10X UFdb is reduced to
IX, there are no seed-treatment scenarios of concern for chlorpyrifos. Potential risks of concern
were found for the following with retention of the 10X UFbb:
1 able 4: Occupationa! Risks off niuirn from Ved I rcatuu-nt at the IU\ I l"i>i*.1
l oi mulalion and PPL
l oader \pp!kator:
Sewer
Bailee!
Multiple
Activities
Worker
Liquid (with double
Com = 67-95
Cotton =
Com - 96 -
Beans - 61 - 86
iaver PPE (coveralls.),
50-71
140
doves, and an
Cotton 33 - 46
Com 50 - 71
elastomeric half mask
Cotton - 46 -
respirator (PF 10)
65
Cotton = 24 - 34
Liquid
Beans only: 59 - 83
Beans
Beans only: 84
Beans only: 44 -
(microencapsulated)
only: 91 -
130
- 120
62
Wettable Powder via
Beans - 75 110
Com = 96 -
Com ~ 89 -
Beans 57 - 79
WSP
Com - 62 - 88
140
130
Com = 47 - 66
1 LOC with 10X = 100
2 Maximum MOEs with listed PPE
NON-SEED TREATMENT
Aerial and/or Chemigation applications
Several chlorpyrifos fonuulations may be applied by aerial or chemigation application. These
include liquids, wettable powders, granule formulations, and water dispersable granules. The
maximum application rate for aerial application is 2.3 lbs al./A for use on citrus.
Even with the use of engineering controls (closed systems), mixing and loading resulted in risks
of concern to workers at the IX UFdb for four uses: com (pre-plant), peanut, sweet potato, and
sunflower. These risks of concern were limited to granular formulations for these uses. The MOE
for aerial application of granular fonuulations of cMorpyrifos on peanuts is 5. MOFs f, >r other
24 Some occupational handler exposure inputs have changed since the previous ORE assessments were completed in
201 i (W. Britten. DJ8SI65. 06:27/2011). 2014 (W. Britton. D4244S4. 12/29/2014). and 2016 (W. Britton.
D436317,11/03,2016) (e.g., amount of seed treated per day. seed planted per day).
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aerial granular applications are 9.4 (sweet potato), 9.5 (sunflower, tobacco), and 9.6 (corn).
Without the 10X UFdb, MOEs for mixing and loading for aerial applications ranges from 0.61 to
6.7 for uses with risks of concern with baseline PPE (long-sleeved shirt, long pants, socks and
shoes). Use of the highest 2 tiers of refinement (double layer (coveralls), gloves, and an
elastomeric half mask respirator or engineering controls result in MOEs of 4.7 to 66 for mixing
and loading granular formulations.
For mixing/loading liquids and wettable powders (WP), nearly all scenarios resulted in MOEs
below the LOC of 100 (with retention of the 10X UFdb). With the exception of ornamental shade
trees and herbaceous plants (MOE = 130 with engineering controls), the risk estimates for mixers
and loaders for all remaining formulations were below the LOC of 100 with a range of 9.6 to 71
for citrus, tree nuts (almonds, filberts, hazelnuts), tree fruit (apple, cherries), cole crops (excludes
Brussels sprouts and cauliflower), Christmas tree plantations, and nursery stock (pre-plant).
Potential risks to aerial or chemigation applicators were found for all starting formulations of
spray applications and granules for the following uses with MOEs from 5 to 94: peanut, sweet
potato, sunflower, tobacco, sod farms (turf), corn (pre-plant and post-emergence), alfalfa, cotton
(except Mississippi), soybean, wheat, sorghum, and Christmas tree plantations. All remaining
aerial applications were above the LOC of 100 and, therefore, not of concern.
Airblast applications
Chlorpyrifos may be applied by airblast application at rates from 1.0 to 6.0 lbs a.i./acre to citrus,
tree nuts, tree fruits, grapes, asparagus, and to shade trees, herbaceous plants, Christmas tree
plantations, and ornamental woody shrubs and vines. Formulations that may be applied by
airblast include liquid/soluble/emulsifiable concentrate (L/SC/EC), WP in WSP, and dry
flowable/water dispersable granule (DF/WSG) in WSP. Risk estimates for mixing, loading, and
applying airblast applications were mostly above the LOC of 100 with the use of engineering
controls. At a rate of 6.0 lbs a.i./acre (California and Arizona citrus), MOEs ranged from 64 to 67
for mixing and loading WSP formulations. MOEs for mixing, loading, and applying citrus
outside of California and Arizona were 98. Mixing, loading, and applying all formulations for
tree nuts (pecans) ranged from 89 to 91. MOEs for remaining uses ranged from 98 to 390 with
engineering controls. All airblast application scenarios without engineering controls, even those
with use of chemical resistant headgear, resulted in potential risks of concern with MOEs from
0.55 to 4.2, which is below the LOC with or without retention of the 10X UFdb.
There were no risks of concern for occupational handlers mixing and loading WSP formulations
except and as mentioned above for citrus and tree nuts (pecans). However, with the use of double
layer (coveralls), gloves, and an elastomeric half mask respirator, only the following uses
resulted in MOEs above the agency's LOC of 100 for all other formulations (L/SC/EC):
• Cherries, tree fruits (pear, plum/prune (dormant, delayed dormant), tree nuts (almonds,
filberts, hazelnuts, pecans, walnuts); MOE =110
• Ornamental and/or shade trees, ornamental woody shrubs and vines, herbaceous plants,
Christmas tree plantations, grapes; MOEs = 220
Risk estimates for all levels of PPE for the remaining uses were from 4.6 to 71 for mixers and
loaders and were, therefore, of concern with retention of the 10X UFdb.
22
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Docket Number EPA-IIQ-OPP-200S-0X-0
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Groundboom applications
Groiuidboom application is one of the most widely used application methods for cMoipyrifos.
Nearly every use resulted in potential risks of concern from mixing, loading, or applying without
the use of PPE above baseline levels (long-sleeved slurt. long pants, socks and shoes ) for mixers,
loader*. and applicator with retention of the 10X < 'i r»>. Risk estimaie* of concern were slill
identified for groundboom applicators \\ ith enuineei iuii control* on coju {pre-j»lant. MOE ¦¦ 67}
and cotton (except in Mississippi. MOE -=¦ sKh and mixers and loaders for the following use*.
1 abU 5. < Jnismdlxsom Risk Estimates w iih MOKs 1incei n»« ( oiurois
i rop i :ir<>vl
< utr2i>r\
\IOi. ith
l>;ls(.-[ifK-
Pi'i
\I<>i.s with
double
layer
(coveralls).
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Docket Number EPA-HQ-OPP-2OO8-O850
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spearmint), peanut,
sunflower
Vpniiiutiir RKk l.stimal«> wiih M()|\ iDii with ! nuiruerin^ Controls or Maximum PI'I!
Spray sail starting
formulations)
Com (pre-plant),
cotton (except
Mississippi)
4.8 - 7.2
31 -47
67-99
Corn {post-
emergencei. tree
nut orchard floors
(pecans, almonds,
walnuts),
ornamental lawns
and turf, sod farms
(turf)
8.3 - 9.8
54 - 62
110-130
Radish, alfalfa,
cotton, .soighum
grain, soybean,
wheat,
12-15
78 - 94
170-210
Rutabaga
15
94
210
Use of engineering controls resulted in mixer loader risk estimates above the LOC of 100 for
mixing and loading for the following uses (MOEs - 120 - 190):
• At a rate of 4.0 lbs a.i.-acre: nursery stock (pre-plan!)
• At a rate of 2.0 to 2.4 lbs a.i./acre: Brussels sprouts (at plant and post-emergence),
cauliflower, cole crops, figs (only in California"*, grapes (foliar, dormant, delayed
dormantj. mini, peanut, pineapple, rutabaga, strawberries (pie-plant i. -amflower (pre-
plan!) sweet potato (pre-plant and soil broadcast), and tobacco (preplant).
• At a rate of 1 0 lb-, a.i. acre: beet-? (table, sugar, at plant), clover (grown, for seed, foliar),
hybrid cottonwood and polar plantations
• At a rate of 1.5 lbs a.i./acre: cranberry
• At a rate of 1.0 lbs aiiacre: alfalfa, cotton, sorghum grain, soybean, and wheat
Mixer and loader risk estimates for these crops with double layer (coveralls), gloves, and an
elastomeric half mask respirator range from 42 to 71. Applicator risks estimates with this level of
PPE ranged from 31 to 470 with risks of concern identified for use on com (pre-plant and post-
emergence) and cotton (except MS), rutabaga. alfalfa, soybean, sorghum grain, wheat, radish
(preplant), tree nut orchard floors i pecan-,, almonds, walnuts) and ornamental lawns and turf with
MOEs rip to 94,
With the exception of microencapsulated formulations for ornamental non-flowering plants and
wettable powder for citrus orchard floors and cole crops (excluding Brussels sprouts and
cauliflower), all remaining uses present potential risks of concern to mixers, loaders, and
applicators with baseline PPE (long-sleeved shirt, long pants, socks, and shoes). MOEs for
mixers and loaders range tip to 27 and up to 72 for applicators. Use of double layer (coveralls),
gloves, and an elastomeric half mask respirator results in risk estimates up to 220 for mixers and
loaders and 470 for applicators and are not of concern.
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Docket Number EPA-HQ-OPP-2008-0850
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Flaggers
Although the use of global positioning systems (GPS) has vastly replaced the use of flaggers to
guide aerial applications, the agency continues to assess exposure as use of flaggers is not
explicitly prohibited on pesticide products containing chlorpyrifos. At the IX UFdb, all risk
estimates were above the LOC of 10 and, therefore, are not of concern. Nearly all applications of
chlorpyrifos products results in potential risks of concern for flaggers with the maximum amount
of PPE (double layer (coveralls), gloves, and PF10 respirator) at the 10X UFdb; risk estimates of
concern ranged from 15 to 88 with the maximum PPE (where the LOC with the 10X UFdb is
100). No risks of concern were identified for flaggers with granule application to turf nor for
applications to sweet potato, corn (pre-plant), sunflower, and tobacco with the maximum amount
of PPE.
Handheld application methods—
Assessment of handheld application methods typically assumes mixer, loader, and applicator
exposure to the same occupational handler.
Manually-pressurized handwand and handgun
Manually-pressurized handwand application is limited to mostly non-food uses such as
ornamental plants, nursery stock, poultry litter, and industrial and commercial areas. Food uses
include select tree nuts and tree fruits. With the use of single layer (long-sleeved shirt and long
pants) and gloves, most uses are above the EPA's LOC of 10 at the IX UFdb (MOEs = 3.9 -
9,000) No risks of concern were identified at the IX UFdb from spot treatment applications
(0.023 lbs a.i./Acre). Without gloves, MOEs ranged from 2.6 - 110 with risks of concern for use
on applications that were not considered spot treatments (i.e., applications of 40 gallons or to
1,000 square feet). MOEs were below the LOC of 100 at the 10X UFdb for the following
handwand applications with maximum PPE (double layer (coveralls)) gloves, and an elastomeric
half mask respirator:
• Wood protection treatment (MOE = 82)
• Nursery, pine seedlings (MOE = 90)
• Indoor commercial, institutional, industrial premises, food processing plant premises
(MOE = 16)
Risks of concerns were found for nearly all scenarios with manually-pressurized handgun
applications and formulations with the exception of:
• WSP application to ornamental woody shrubs and vines (MOEs = 440 to 2100); and
• All formulations registered for use on seed orchard tree (MOEs = 1800 - 8300).
Remaining risk estimates with use of double layer (coveralls), gloves, and an elastomeric half
mask respirator ranged from 11 to 83. An MOE of 83 was determined for ornamental and/or
shade trees, herbaceous plants, and grapes (WSP formulation only).
25 Assessment assumes mixing, loading, and application are conducted by some the same individual and does not
include use of engineering controls.
25
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Docket Number EPA-HQ-OPP-2OO8-O850
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Tractor-drawn spreader
At the I OX UFdb, no occupational handler risks of concern were identified with use of tractor-
drawn spreaders. Nor were risks of concern found with use of a SmartBox®. SmartBox®
v\ stems are closed application system-. that are considered to he protective as engineering
cotmok. Retention of the I OX IHFdb resulted in risks of concern wirli use of only baseline PPE,
MOEs range up lo "1 except for use of.uolfcom.se turf, right > of way. and road medians where
the MOE is 120. Application to most uses are above the LOC of 100 with u&e of gloves,
respirator, and coveralls or engineering controls. Even with engineering controls (excluding
SmartBox systems), risk estimates are below 100 for application to soybean, com, and
ornamental woody shrubs and vines for mixers, loaders, and applicators (MOEs = 53 - 89).
Backpack Sprayers
Risks of concern from backpack sprayers without retention of the 10X UFdb were limited to use
on ornamental and/shade trees, herbaceous plants, ornamental woody shrubs and vines, wide-
area general outdoor treatment, and outdoor commercial 'institutional/industrial premises, non-
agricultural outdoor buildings and struct uiea.
MOEs for liquid concentrate application by backpack sprayer ranged from 1.5 - 76 and exceeded
the agency's LOC of 100 for all levels of PPE except as follows:
1 ;il)lc 6: Risk Estimates for Backpack Npr:i>cr Application^
formulation
Application
i> pi-
( lop 1 ;it«cU'd I M'
pit:
MOE
Dry flowable water-
dispei sable granule in
W'SP
Broadcast
(foliar)
Grapes (pre-bloom)
Double
layer
(coveralls),
gloves, and
an
elastotneric
halt mask
respirator
94
Trunk
spray Drench
Tree fruits (apple)
100
Drench Soil-
Ground-
directed
Grapes (pre-bloom)
130
Liquid/soluble
concentrate/emulsifiable
concentrate
Broadcast
(foliar)
Golf course turf
94
Spot
treatment
applications
(0.025 A
treated t
Ornamental and/or Shade
Trees, herbaceous plants
Baseline
320
Ornamental lawns and turf, sod
farms (turf)
350
Outdoor
c o n m l e rcial/insti futional'indust
rial premises, non-agricultural
buildings and structures, golf
course turf
1300
Microenc apsulated
formula
Broadcast
(foliar)
Ornamental woody shrubs and
vines
Double
layer
94
26
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Docket Number EPA-HQ-OPP-2008-0850
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Ornamental non-flowering
plants
(coveralls),
gloves, and
an
elastomeric
half mask
respirator
130
Directed
broadcast
Outdoor
commercial/institutional/indust
rial premises
Baseline
230
Broadcast
Agricultural farm premises
Baseline
400
Broadcast
Poultry litter
Baseline
1100
WSP
Spot
Ornamental woody shrubs and
vines (pre-transplant)
Baseline
330
Spot
Outdoor lawns and turf, Sod
Farms (turf)
Baseline
350
Broadcast
Ornamental woody shrubs and
vines
Baseline
930
Select uses with risk estimates below the LOC of 100 were included if chlorpyrifos was considered a high benefit.
Granule formulations
Application of chlorpyrifos granule formulations by hand is limited to non-agricultural uses.
Applications by spoon resulted is risk estimates from 1400 to 5700 and were not of concern.
Regardless of PPE, all applications with a belly grinder with retention of the 10X UFdb resulted
in potential risks of concern with a maximum MOE of 43. Hand dispersal resulted in potential
risks on concern with or without retention of the 10X UFdb and regardless of PPE for treatment
of commercial/institutional/industrial premises and utilities with MOEs from 0.49 to 1.4.
Treatment of golf courses and sod farms by the same method were of concern with baseline PPE
(MOE = 90; long-sleeved shirt, long pants, no gloves and no respirator). Hand dispersal and
rotary spreader application resulted in MOEs below the LOC of 100 with retention of the 10X
UFdb for ornamental woody shrubs and vines regardless of PPE with MOEs up to 53. With
baseline PPE, MOEs for all other remaining uses treated by rotary spreader were 63 to 70. Use of
maximum PPE (double-layer (coveralls), gloves, and an elastomeric half mask respirator) results
in MOEs of 290 to 320.
Non-Food and Other Application Methods:
Application of cattle eartags, bait stations, and total release foggers (greenhouses) are considered
to have negligible exposure; therefore, there were no risks of concern identified to occupational
handlers for these treatment methods. However, potential risks of concern were identified for all
levels of personal protective equipment using paint brushes and rollers for wood protection
treatment. Regardless of PPE, all applications with a brush roller resulted in potential risks of
concern with retention of the 10X UFdb with a maximum MOE of 45.
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Wide-area Mosquito Abatement
With label required single layer (long-sleeved shirt and long pants) and gloves, MOEs for mixing
and loading wide area mosquito applications were below the agency's LOC of 100 for aerial
applications and above the LOC for ground applications. Aerial applications were assessed
assuming only engineering control and were not of concern. With the retention of the 10X UFdb,
ground applications were only above the LOC of 100 with the use of engineering controls.
Without engineering controls, ground applicator MOEs were of concern. Ultra-low volume
(ULV) wide-area applications by airblast were below the LOC of 10 without retention of the
10X UFdb with MOEs ranging from 4.4 to 5.6.
Occupational Post-Application Risks
Most crops and activities require a restricted entry interval (REI) of 24 hours on current
chlorpyrifos labels. However, in some cases such as citrus fruits, REIs are up to 5 days after
application. Occupational post-application risks have been updated to incorporate PBPK-derived
steady state PODs based on 10% RBC AChE inhibition. Assuming the UFdb is reduced to IX,
most post-application risk estimates are not of concern 1 day after application. Likewise, the
majority of the post-applications scenarios are not of concern 1 day after application (REI = 24
hours) assuming the UFdb of 10X is retained. However, for some activities result in risks of
concern up to as many as 10 days following application for the non-microencapsulated
formulations and >35 days for the microencapsulated formulation.
The residue of concern for occupational post-application exposures is the chlorpyrifos parent
compound, although it may be possible that the formation of chlorpyrifos oxon is greater and its
degradation slower in greenhouses when compared to the outdoor environment. Dermal exposure
to the oxon on foliar surfaces from reentry into an outdoor environment previously treated with
chlorpyrifos is not anticipated and, therefore, has not been assessed.
The agency has numerous dislodgeable foliar residue (DFR) studies for several chlorpyrifos
registered uses. Specifically, the DFR studies examined the use of 1) granular formulations on
turf and sweet corn; 2) emulsifiable concentrate formulations on citrus, sugar beets, sweet corn,
pecans, cotton, and turf; 3) a microencapsulated liquid formulation on ornamentals; 4) a total
release aerosol formulation on ornamentals; and 5) wettable powder formulations on pecans,
almonds, apples, tomato, cauliflower, and turf. These studies varied in location and calculations
using each of these studies yield different risk estimates. The agency is presenting the full range
of post-application risk estimates in Appendix D1 of this PID.
Dermal exposure assessment on outdoor foliar surfaces was limited to chlorpyrifos exposure
only. Exposure to chlorpyrifos oxon on foliar surfaces from reentry into an outdoor environment
(e.g., field crops and orchards) previously treated with chlorpyrifos is not anticipated and,
therefore, was not assessed. Occupational post-application assessments were performed for: 1)
exposures to the parent compound chlorpyrifos in outdoor environments (all uses), 2) exposures
to the parent chlorpyrifos indoors (e.g., greenhouses) and 3) exposures to both the parent and
chlorpyrifos oxon in greenhouses. Occupational dermal post-application exposures were assessed
in greenhouses using conservative assumptions of oxon formation.
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A quantitative occupational post-application inhalation risk assessment is not required for
chlorpyrifos or chlorpyrifos oxon due to the lack of toxicity from the vapor phase of these
chemicals, even at the saturation concentration. Post-application exposure from seed treatment is
not expected.
The agency's LOC for occupational post-application risks is 100 at the 10X UFdb and 10 at the
IX UFdb. Post-application exposure to agricultural workers from commercial seed treatment is
not expected. The agency has identified potential risks of concern for the following uses and
activities. The comprehensive list of REIs by crop, post-application activity, and study location
yielding those risk estimates are presented in Appendix Dl.
Greenhouse
Chlorpyrifos may be applied to food and non-food uses in greenhouses. Chlorpyrifos
formulations used in greenhouses include emulsifiable concentrate, microencapsulated liquid,
wettable powder in WSP, and total release foggers. The chlorpyrifos parent compound is the
residue of concern for occupational post-application dermal exposures; however, available
exposure data indicate chlorpyrifos oxon may form in indoor environments.26 It is uncertain if
the formation of the oxon is greater and its deactivation slower in greenhouses when compared to
the outdoor environment. Workers reentering indoor environments (i.e., greenhouses) previously
treated with chlorpyrifos could potentially be exposed to the more toxic oxon as chlorpyrifos
degrades. Risks for reentry into treated greenhouses for the parent chlorpyrifos plus chlorpyrifos
oxon were estimated using a total toxic residue approach for all four formulations used in
greenhouses.27 A conservative assumption of 5% (0.05) of the total chlorpyrifos was estimated
as present as DFR in greenhouses and available for contact during post-application activities.
Five percent is the high-end value for the percent of parent that metabolized during the course of
the residue studies. Risk estimates after treatment for total release fogger and liquid concentrate
formulations were not of concern 0 to 6 days. For the microencapsulated formulation, MOEs are
not of concern 3 to > 35 days after treatment (the completion of the monitoring period),
depending on the exposure activity considered.
3. Human Incidents
Chlorpyrifos incidents were previously reviewed in 2011.28 The human incident databases that
were reviewed are:
• Office of Pesticide Programs Incident Data System (OPP IDS);
• National Pesticide Information Center (NPIC);
• NIOSH's Sentinel Event Notification System for Occupational Risks (SENSOR);
• California Pesticide Illness Surveillance Program Incident Data (CA PISP).
Incident information from each of these databases follows.
26 J.L. Martinez Vidal, et al. 1998. Diminution of Chlorpyrifos and Chlorpyrifos Oxon in Tomatoes and Green
Beans Grown in Greenhouses. J. of Agric. and Food Chem. 46 (4), 1440-1444.
27 Total DFR (|ig/cm2) = [Chlorpyrifos DFR (|ig/cm2) * TAF] + [Chlorpyrifos DFR (|ig/cm2)|
28 Chlorpyrifos: Tier II Incident Report https://www.regiilations.gov/document?D=EPA-HO-OPP-2008-0850-0Q32
29
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IDS
The IDS consists of the Aggregate IDS and Main IDS. In Aggregate IDS, queried from January
1, 2002 to May 27, 2010, there are 745 incidents involving chlorpyrifos. Prior to 2011, there are
247 cases reported that involve the active ingredient chlorpyrifos for the Main IDS. Of these
cases, 141 cases are reported for the single chemical chlorpyrifos in the database. Most of these
incidents were categorized as Human Moderates (HCs); 12 were categorized as Human Majors
(HBs); and one was categorized as fatality (HA). Fifteen of these incidents were reported as
affecting children 6 years old or under (2 HBs and 13 HCs). These latter incidents appear to be
due to accidental ingestion and post application exposure to cancelled products. Main IDS-
reported chlorpyrifos incidents appear to have decreased substantially in this period from 43
incidents in 2002, to 2 incidents in 2010. The initial large reductions generally coincide with the
dates for which regulatory actions were taken.
NPIC
Similar to Poison Control Centers, NPIC's primary purpose is to provide information on a
variety of pesticide topics and direct callers for pesticide incident investigation and emergency
treatment. While NPIC does collect information about incidents, it generally receives fewer
reports than IDS. From 2002 to 2010, 178 cases were reported for chlorpyrifos in the NPIC
database. Of these cases, 88 were reviewed because, in these cases, chlorpyrifos was used as a
single chemical and had a certainty classification of probable, possible, or unclassified. Eight of
the chlorpyrifos cases were associated with children six years old or younger.
NIOSH SENSOR
The NIOSH SENSOR database is not national in scope and is limited to participation of 13
states.2930 For the 2011 human incident report, the agency analyzed NIOSH SENSOR data from
1998-2007. SENSOR focuses on occupational pesticide incidents, although both occupational
and non-occupational incidents are included in the database. For NIOSH SENSOR from 1998 to
2007, there were 635 cases reported for chlorpyrifos in the database. Of these cases, 348
involved chlorpyrifos use as a single chemical only and had a certainty classification of definite,
probable, or possible. There was one death due to suicide. Eight cases were classified as high
severity; 60 cases, as moderate severity; and 279 cases, as low severity. Of the 348 chlorpyrifos-
only cases, 18 cases involved children six years old or younger. These latter incidents were
mostly due to accidental ingestions, misapplications around the home, and drift from nearby
properties. Generally, chlorpyrifos incidents involved workers in agricultural or professional
application occupations, homeowners and individuals at work but their job was not related to
pesticide application, and to individuals exposed through drift.
California PISP
One hundred and sixty-four cases are attributable to chlorpyrifos-only exposures were reported
to the California PISP between 1999 and 2008. Of these cases, 87 were occupational incidents
and 77 were non-occupational incidents. A number of these incidents appear to be due to
accidents and misuse. Drift of chlorpyrifos from adjacent fields appears to be the cause of the
29 https://www.ccic. gov/nlosfa/topies/pestieides/overview html
30 Only twelve states had participated between 1998- 2007.
30
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Docket Number EPA-HQ-OPP-2008-0850
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most incidents in PISP accounting for 56% of the cases reported to PISP from 1999 to 2008. In
the NIOSH SENSOR database, chlorpyrifos application appears to lead to the most incidents,
being responsible for 46% reported to NIOSH SENSOR from 1998 to 2007. The chlorpyrifos
incidents reported have declined substantially (95%) among residential users from 2002 to May
27, 2010; however, the rate of occupational incidents reported remained the same during this
reporting period.
Overall, the incident data suggest that incidents associated with chlorpyrifos are declining over
time. IDS incident reports decreased by 95% from 2002 to 2010, and NPIC incident reports have
decreased by 92% from 2002 to 2010. The decrease in the number of chlorpyrifos incidents can
be temporally associated with the phase out/cancellation of most residential chlorpyrifos
products.
Health effects reported include neurological (e.g., tremors, headaches, dizziness, seizures),
gastrointestinal (e.g., nausea, abdominal pain), respiratory (e.g., choking, coughing, shortness of
breath), ocular (e.g., pain, itchiness), dermal (e.g., rash, lesions), and cardiovascular symptoms.
Patients could exhibit multiple symptoms. The incidents reported have been reviewed and the
agency will continue to monitor these incidents and remain alert for any changes in trend or
patterns.
4. Tolerances
The 2020 revised chlorpyrifos human health risk assessment recommended changes to various
tolerance levels to conform with the agency's rounding practice {i.e., adding a trailing zero) at
that time. Since the 2020 risk assessment was issued, the agency has decided to follow the
Organization for Economic Coordination and Development (OECD) rounding class practice,
which does not recommend adding a trailing zero. The EPA notes that the tolerance expression
for chlorpyrifos in the 40 CFR§ 180.342 will be updated to comply with the S. Knizner 5/27/09
memo as follows:
Tolerances are established for residues of chlorpyrifos, including its metabolites and
degradates, in or on the commodities in the table below. Compliance with the tolerance
levels specified below is to be determined by measuring only chlorpyrifos {0,0 -diethyl
O -(3,5,6-trichloro-2-pyridyl) phosphorothioate.
Based on data indicating that residues of chlorpyrifos may be present, EPA is recommending that
tolerances be established for chlorpyrifos on the following: cotton, gin byproducts (15 ppm);
grain, aspirated fractions (30 ppm); corn, field, milled byproducts (0.1 ppm); and wheat, milled
byproducts (1.5 ppm). These recommendations, along with recommendations for revisions to
current tolerances based on the (OECD rounding class practice, commodity definition revisions,
crop group conversions/revisions, and harmonization with Codex, are presented in Tables 7 and
8.
31
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l alde simim;ir\ of 1 oh! aiue ReCi%i>>ns ior < hl>up\rifos i 4'! ( f'R ijl Rounding Class Practice.
Grain, aspirated
fractions
—
Recommended tolerance based on
submitted residue data.
Beet, sugar, dried
pulp
5.0
5
Corrected values to be eousisTent with
OECD Roundina Class Piactice.
Beet, sugar, roots
1.0
1
Corrected values to be consistent with
OECD Rounding Class Practice.
Beet, sugar,
leaves
—
8
Commodity definition revision.
C o tree fed values to be consistent with
OliCI.) Rounding Class Piactice.
Beet, sugar,
tops
8.0
remove
Brassica. leafy
greens, subgroup
4-161
1
Crop group conversion revision.14
Cherry, sweet
1.0
1
Collected values to be consistent with
OECD Rounding Class Practice.
C herry, tart
1.0
1
Collected values to be consistent with
OECD Rouiicline Class Practice.
Fruit, citrus,
group 10-10.
dried pulp
~
5
Crop group conversion revision.
Conected values to be consistent with
OECD Rouiidinu Class Practice.
( 'ttrus. dried
pulp
5.0
remove
Fruit, citrus,
group 10-10, oil
—
:o
Crop group conversion revision.
Citnis. oil
20
remove
Corn, field,
forage
8.0
O
Conected values to be consistent with
OEC D Rounding Class Practice.
Corn. field,
stover
8.0
8
Corrected values to be consistent with
OECD Rounding Class Practice.
( orn. milled
byproducts
—
0.1
Recommended tolerance based on
submitted residue data.
Corn, sweet,
forage
8.0
8
Conected values to be consistent with
OECD Rounding Class Practice.
( orn, sweet,
stover
8.0
8
Conected values to be consistent with
OECD Rouinljna Class Piactice.
Cotton. gin
—
15
Recommended tolerance based on
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Docket Number EPA-HQ-OPP-2008-0850
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byproducts
submitted residue data.
Cotton,
undelinted seed
0.2
0.3
Harmonization with Codex.
Cranberry
1.0
1
Corrected values to be consistent with
OECD Rounding Class Practice.
Fruit, citrus,
group 10-10
—
1
Crop group conversion/revision.
Corrected values to be consistent with
OECD Rounding Class Practice.
Fruit, citrus,
group 10
1.0
remove
Kohlrabi
—
1
Crop group conversion/revision.3'4
Kiwifruit, fuzzy
—
2
Commodity definition revision.
Corrected values to be consistent with
OECD Rounding Class Practice.
Kiwifruit
2.0
remove
Milk
—
0.01
Commodity definition revision.
Corrected values to be consistent with
OECD Rounding Class Practice.
Milk, fat
—
0.3
Milk, fat
(Reflecting 0.01
ppm in whole
milk)
0.25
remove
Pepper, bell
—
1
Commodity definition revision.
Corrected values to be consistent with
OECD Rounding Class Practice.
Pepper, nonbell
—
1
Pepper
1.0
remove
Peppermint,
fresh leaves
—
0.8
Commodity definition revision.
Peppermint,
tops
0.8
remove
Peppermint, oil
8.0
8
Corrected values to be consistent with
OECD Rounding Class Practice.
Radish, roots
—
2
Commodity definition revision.
Corrected values to be consistent with
OECD Rounding Class Practice
Radish
2.0
remove
Rutabaga, roots
—
0.5
Commodity definition revision.
Rutabaga
0.5
remove
Spearmint, fresh
leaves
—
0.8
Commodity definition revision.
Spearmint, tops
0.8
remove
Spearmint, oil
8.0
8
Corrected values to be consistent with
OECD Rounding Class Practice.
Sorghum, grain,
stover
2.0
2
Corrected values to be consistent with
OECD Rounding Class Practice.
Strawberry
0.2
0.3
Harmonization with Codex.
Sweet potato,
tuber
—
0.05
Commodity definition revision.
Sweet potato,
roots
0.05
remove
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Turnip, roots
1.0
1
Corrected values to be consistent with
OECD Rounding Class Practice.
Turnip, leaves
0.3
Conmioditv definition revision.
Tmnip. tops
0.3
lemove
Vegetable,
brassica, head
and stem, group
5-16
—
1
Crop group conversion revision.5
Conected values to be consistent with
OECD Rounding Class Practice.
Vegetable.
brasMca. leafy.
group 5
1.0
remove
Wheat, forage
3.0
3
Collected values to be consistent with
< >!.< 1) Roundmn Cla.ss Practice.
Wheat, milled
byproducts
-
1.5
Recommended tolerance based oil
submitted residue data.
W heat, straw
6.0
6
Conected values to be consistent with
OECD Rotmdmii Class Practice.
5 This table only includes recommended revisions to established tolerances and recommended establishment of new tolerances.
For a complete list of all established tolerances see the International Residue Level Snntmary (IRLS)iu Appendix 4.
- Sugar beet leaves'tops are no longer considered a significant livestock feed item. Commodity."tolerance may be removed
5 The recommended conversion of existing tolerance in'on Vegetable, brassica. leafy, group 5 is to the following: Vegetable,
brassica. brad ami stem. group 5 16: Brassica. l*afj grwns. subgroup 4 1<»B: :ui«l Kohlrabi ("Ci-if C-i vup Coir.crsion ?:.ui
for Existing Tolerances as a Result of Creation of New Crop Groups under Phase IV (4-16. 5-16. and 22}" dated 11/3'2015).
4 BED is recommending for individual tolerances of 1 pprn for Kohlrabi based on the currently established tolerance for this
commodity as part of crop group 5 (Vegetable, brassica. leafy). Kohlrabi is displaced by the crop group conversion noted in the
footnote 3 above.
i able S: I ok-rani'i- Re* isions lor < hloi p\ rii'us i4(i < j R 1 S(».3-I2(c"ii!¦:
i omm<>dit\
( unci! ( 'U!!inodii\ ihTniilion
I sUtblislu1
d
I
( omiiunis
Asparagus
5.0
5
Conected values to be
consistent with OECD
Rounding Class Practice.
1 This tabic only includes recommended revisions to established tolerances. For a complete list of all established tolerances see
the IRJ.S in Appendix 4.
- Regional registrations.
The agency intends to undertake liie^e tolerance actions pursuant to its- Federal Food. Drue
Cosmetic Act (FFIX'A) authority. I ke agency will considei the input and tecommendatioiis
irom the September 2020 F1FRA Scientific Advisory Panel (SAP) on new approach
methodologies- lor nemodcveiopmental toxicity once (lie SAP icport is released. After receiving
the SAP's conclusions, EPA will examine the need for further tolerance actions.
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5. Human Health Data Needs
The following residue chemistry data deficiencies were identified for chlorpyrifos. These data
are not required to support this PID.
• 860.1500:
o Separate magnitude of the residue studies for lemons are needed after application
of Lorsban 4E and 75% WDG formulations in order to reevaluate the existing
tolerance for chlorpyrifos for the citrus fruit crop group.
o Magnitude of the residue studies are needed to establish a tolerance for residues
of chlorpyrifos on wheat hay.
• 860.1520:
o Processing studies are needed for soybean meal, hulls and refined oil.
B. Ecological Risks
A summary of the agency's ecological risk assessment is presented below. As stated earlier in
this document, as part of the EPA's responsibility under the ES A, the agency completed a
nationwide biological evaluation for chlorpyrifos initiated consultation with the NMFS in
January 2017. In July 2019, EPA re-initiated formal consultation. NMFS is planning to issue a
revised final BiOp for chlorpyrifos, diazinon, and malathion by June 2022. FWS has not yet
issued a BiOp on chlorpyrifos.
Because the EPA's assessment of listed species is contained in its biological evaluation
mentioned above, only the potential risks for non-listed species are described below.
The agency used the most current science policies and risk assessment methodologies to prepare
a risk assessment in support of the registration review of chlorpyrifos. The agency has compiled
an evaluation of risks to non-listed species for registration review in the document Chlorpyrifos
Draft Ecological Risk Assessment for Registration Review. That document is based in part on
the agency's biological evaluation for chlorpyrifos.31 For additional details on the ecological
assessment for chlorpyrifos, see the Chlorpyrifos Draft Ecological Risk Assessment for
Registration Review (September 15, 2020), which is available in the public docket.
1. Risk Summary and Characterization
Chlorpyrifos prevents the natural breakdown of various cholines by inhibiting cholinesterase
activity and ultimately causing the neuromuscular system to seize. Chlorpyrifos will initially
enter the environment via direct application and may move off-site via runoff, spray drift, or
volatilization. As it degrades, chlorpyrifos forms chlorpyrifos-oxon, TCP, and TMP. Further
discussion on the consideration of residues of concern, the fate of chlorpyrifos, and study
31 https://www.epa.gov/endangered-species/biological-evalnation-chapters-chlorpyrifos-esa-assessment
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information may be found in the biological evaluation32 and the previously issued drinking water
'i-j 'i a
assessments.
Terrestrial Risks
Mammals
The streamlined ecological risk assessment identified acute and chronic risks of concern from
most uses for chlorpyrifos. Acute risk estimates for mammals from chlorpyrifos exposure ranged
from 0.01 to 10. Half of the uses assessed resulted in acute RQs of 5 or greater (LOC = 0.5).
Chronic risks in animals based on reproductive effects, a 30% loss of pups, ranged from 0.66 to
625. All chronic RQs based on a 4 to 5% decrease in body weight resulted in potential
exceedances to the agency's LOC of 1 with a range of 2.01 to 1900. Fifty percent of uses
resulted in RQs greater than 148 based on a reproductive endpoint and over 450 based on body
weight loss.
Birds. Reptiles, and Terrestrial-Phase Amphibians
Acute RQs ranged from 0.07 to 380 with over half of all uses resulting in RQs greater than 93
(LOC = 0.5). Risk estimates for birds were based on significant reproductive effects, an 83%
reduction in eggs laid. More than half of uses assessed resulted in chronic RQs above 14 with a
total range of 0.60 to 58 (LOC = 1). As a result, there may be adverse effects to birds, as well as
to terrestrial-phase amphibians and reptiles for which birds serve as surrogates.
Terrestrial Invertebrates (honeybees)
Consistent with its use as an insecticide, chlorpyrifos is highly toxic to adult honeybees on an
acute exposure basis. The 2017 biological evaluation did not include the review of one acute
larval honeybee study from Corteva. MRID 49960301 was submitted on the effects of
chlorpyrifos to honeybee larvae after acute in vitro exposure. This study resulted in an LD50 of
0.0165 |ig a.i./larva. This represented the most sensitive endpoint available for effects to
honeybee larvae and was used as the endpoint for risk estimation. Acute RQs range from 820 to
4900 with exceedances for all uses (LOC = 0.4). Chronic toxicity data is not available for
chlorpyrifos; therefore, the risk picture for terrestrial invertebrates is incomplete.
After EPA issued the problem formulation and registration review DCI for chlorpyrifos, EPA
released its June 2014 Guidance for Assessing Pesticide Risks to Bees35. This 2014 guidance lists
additional pollinator studies that were not included in the chlorpyrifos registration review DCI.
Due to the timing of the chlorpyrifos DCI being issued before the guidance came out, EPA is not
requiring any additional studies for assessing pollinators as part of registration review, although
EPA continues to consider whether additional pollinator data are needed for chlorpyrifos. If the
33 https://www.re gulations.gov/document?D=EPA-HO-OPP-2008-085Q-0.1.98
34 https://www.re gulations.gov/document?D=EPA-HO-OPP-2Q .1.5-0653-0437
Available at https://www.epa.gov/sites/produetion/files/20.1.4-
06/documents/poHinator risk assessment guidance 06 .1.9 14.pdf
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agency determines that additional pollinator exposure and effects data are necessary for
chlorpvrifos, then tie EPA will issue a DO to obtain these data. The pollinator studies that could
be required are listed in Table 9 below.
1 able 4): Potential Poilinutor Data Ki-quii cnu nt-,
sMnh
Tier 1
850.3020
Acute contact toxicity studv with adult honey bees
850.3030
Honey bee toxicity of residues on foliage
Non-Guideline (OECD 213)
Honey bee adult acute oral toxicity
Non-Guideline (OECD 237)
Honey bee larvae acute oral toxicity
Non-Guideline
Honey bee adult chronic oral toxicity
Non-Guideline
Honey bee larvae chronic oral toxicity
Tier 2'
Non-Guideline
Field trial of residues in pollen and nectar
Non-Guideline (OECD 75)
Semi-Held testing for pollinators
Tier 3'
8503040
Full-Field testing for pollinators
f The need for higher tier tests for pollinators will be determined based upon the results of lower tiered tests and/or
other lines of evidence and the need for a refined pollinator risk assessment.
Terrestrial and Aquatic Plants
Risk quotients for aquatic vascular, lion-vascular, and terrestrial plants did not exceed EPA's
LOC of 1 with a total range of < 0.01 to 0.42. In addition, there were no vegetative vigor effects
seen for either monocots or dicots and no seedling emergence effects were observ ed for
monocots. There are some incidents involving plants from chloipyrifos exposure, but potential
risks to terrestrial or aquatic plants from chlorpvrifos exposure is considered limited.
Aquatic Risks
Fish and Aquatic-Pha.se Amphibians
The acute and chronic effects of chlorpyrifos exposure have been studied extensively in aquatic
organisms. The acute LCjo for estuarine marine and freshwater fish were 0.37 and 1.7 fig ai./L,
lespeeuvely. The chronic NOAFC was 0.28 ug a.i. T. for esHianne fish but was not determined
for A eshuaiei fish which had a I.OAF.C of 0.251 ug a.i.. I.. Endpoints lor fish were based on a
52% in fecundity for freshwater fish with a LOAEC of 0.251 pg a,i/L, lower than that of 0.48
pg a.i/L, for estuarine fish with 32% reduction in fecundity.
As with mammals, the majority of acute and all chronic RQs exceeded EPA's LOC of 0.5 for
acute risks and 1 for chionic n4:s. O ver 50% of uses assessed resulted in acute RQs above 33
with a range of .42 to 160. Chronic RQs reached a maximum of 135. Given the many use
patterns affiliated with chlorpyrifos use, potential risks to fish and aquatic-phase amphibians
from chloipyrifos exposure can be expected.
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Aquatic Invertebrates
All RQs for aquatic invertebrates were well above the agency's LOC of 0.5 for acute risks and 1
for chronic risks. Maximum acute and chronic RQs were 4300 and 8600, respectively, with 50%
of all uses having RQs over 880 and 1540, respectively. Since chlorpyrifos is registered for a
number of uses patterns across the United States, there exists the potential for risks to aquatic
invertebrates.
2. Ecological Incidents
Numerous notable ecological incidents (e.g., significant fish kills, bee kills, large number of bird
deaths) have been reported for all taxa for chlorpyrifos, including plants. These incidents
summarized herein are based on the incidents reported for the chlorpyrifos Biological Evaluation
and were reported with a high certainty level that chlorpyrifos was the associated causative
agent. The biological evaluation on chlorpyrifos provided an extensive analysis of reported
incidents broken down by individual taxa. Chlorpyrifos was reported as the 'possible,'
'probable,' or 'highly probable' causative agent for 110 adverse aquatic incidents (e.g., fish
kills), 64 incidents involving birds, and 43 terrestrial plant incident reports. Some of the
terrestrial plant incident reports were associated with spray drift, but most involved damage to
the crop treated.
Additionally, 36 bee incidents were classified with a certainty index of 'possible', 'probable' or
'highly probable'. All of the terrestrial invertebrate incident reports involve honeybees, with bees
being exposed via foraging on treated plants or by spray drift.
On August 14, 2020, an updated incident report was generated from the Incident Data System
(IDS) for the time period from approximately January 1, 2015 to August 14, 2020. There were
20 unique incidents reported associated with nontarget organism in IDS. All of these incidents
were associated with bee kills, except for one where the organism impacted was not specified.
Two aggregate incidents, one presumed to involve bees, and one involving non-specified
wildlife, were additionally reported.
EPA will continue to monitor ecological incident information as it is reported to the agency.
Detailed analyses of these incidents are conducted if reported information indicates concerns for
risk to non-target organisms.
3. Ecological and Environmental Fate Data Needs
No additional ecological or environmental fate data are required to support this registration
review decision. EPA will consider requiring submission of pollinator data as a separate action.
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C. Benefits Assessment
Based on a recent analysis36 conducted by the agency for agricultural uses of chlorpyrifos, the
total annual economic benefit of chlorpyrifos to crop production is estimated to be $19 - $130
million. These estimates are based on the additional costs of alternative pest control strategies
likely to be used in the absence of chlorpyrifos or reduced revenue for some crops that do not
have effective alternatives to chlorpyrifos for some pests. In some cases, effective alternatives
could not be found; for those crops, the benefit of chlorpyrifos was estimated by yield or quality
losses if chlorpyrifos were no longer available for use.
The high benefits are reflected in the wide use of chlorpyrifos on many different crops. However,
despite this widespread usage, the majority of the benefits are concentrated in specific crops and
regions that rely on chlorpyrifos without available effective alternatives to control pests. In
particular, there are potentially high total benefits of chlorpyrifos usage in the production of
sugar beets in Minnesota and North Dakota, oranges in California, peaches in the Southeastern
U.S., and soybeans and apples throughout the U.S. The high-end total benefit for each of these
crops is estimated to be in excess of $7 million per year. High total benefits are driven by high
per-acre cost of production without chlorpyrifos in the case of sugar beets, orange, apple, and
peach, and by the extent of acres treated in the case of large field crops like soybean despite
relatively low benefits per acre.
For most non-crop uses, the agency's assessment37 concluded that, chlorpyrifos is no longer
recommended or heavily used for critically important insect pests. However, there a few
exceptions to this overall conclusion. For pests of public health concern, such as mosquitoes and
certain ticks, chlorpyrifos is one of a limited set of effective options available for wide area or
broadcast use in specific use settings, such as government agency mosquito control districts
(when suppressing adult mosquitoes), and golf courses (for ticks). For mosquitoes, chlorpyrifos
also has value as one of a few insecticides that can be used against pyrethroid-resistant
populations or to delay the onset of such resistance. While effective alternatives are available,
due to the consequences to public health posed by the serious diseases transmitted by these pests,
chlorpyrifos provides an important resistance management tool to sustain the effectiveness of
non-organophosphate alternatives.
Similarly, for the protection of certain types of cattle livestock from horn flies, chlorpyrifos
confers a benefit to control fly populations that have developed tolerance to pyrethroids, a widely
used class of insecticides. In addition, for horn fly populations that have not yet developed
pyrethroid resistance, chlorpyrifos is an active ingredient that, when used in rotation with
pyrethroids, could mitigate, delay or even avoid insecticide resistance. Finally, for producers of
outdoor-grown nursery plant stock, chlorpyrifos is one of a very limited set of insecticide options
that qualify producers' products for pest-free certification in southeastern U.S. states that are
currently under a USD A quarantine intended to prevent the spread of imported fire ants.
36 Mallampalli, N., Waterworth, R., and Berwald, D. 2020. Benefits of Agricultural Uses of Chlorpyrifos (PC#
059101). Biological and Economic Analysis Division memorandum to the Pesticide Re-Evaluation Division.
Official record available through the chlorpyrifos docket at www.regulations.gov.
37 Mallampalli, N. and C. Paisley-Jones. 2020. Chlorpyrifos Benefits Assessment for Non-crop Uses. Biological and
Economic Analysis Division memorandum to the Pesticide Re-Evaluation Division. Official record available
through the chlorpyrifos docket at www.regiilations.gov.
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IV. PROPOSED INTERIM REGISTRATION REVIEW DECISION
A. Proposed and Considered Risk Mitigation and Regulatory Rationale
CMoipyrifos poses potential dietary and aggregate risks, associated with drinking wafer exposure
for cunenily labelled uses with and without the 10X FQPA safety factor, and mitigation is being
proposed to reflect the range of potential risks. With the exception of seed-treatment uses, both
occupational handler and post-application risks of concern were identified with and without the
10X ITdb. PPE. use restrictions. and REI extensions are being considered to address these
potential risks. The agency is also proposing spray drift management label language, pesticide
resistance management label language, and other labeling updates consistent with those which
are being required for other pesticides in registration review.
The agency will consider the input and recommendations from the September 2020 FIFRA
Scientific Advisory Panel (SAP) on new approach methodologies for neurodevelopmental
toxicity once the SAP report h released. After receiving the SAP's conclusions, EPA may further
revise the human health risk assessment and proposed/considered mitigation. The agency is
currently in discussions with the registrants regarding the proposed/considered mitigation
measures.
1. Use Cancellations
To nntmale potential dietary exposure to cMoipyrifos. the aeency is proposing to limit
application to select uses in certain regions of the U.S. where the EDWCs for those uses are
lower than the DWJLOCs. Table 10 provides a list of the high-benefit agricultural uses that the
agency has determined will not pose potential risks of concerns with an FQPA safety factor of
10X and may be considered foi intention. In addition to the agricultural uses listed below, the
agency may also retain use on public health pests such as mosquitos. ticks, and fire ants. The
agency will consider registrant and stakeholder input on the subset of crops and regions from the
public comment period and may conduct further analysis to determine if any other limited uses
may be retained.
lahU Hi: \«.:ri
Factor of 1 OX
I si" Site
cultural I. ses Proposed lor Retention in < hlorp\ rit'os Labels uilli :tn FQPA Salelv
State lor retention at the IHV
Alfalfa
AZ, CO, !A, ID, II,, KS, MI, MM, MO, MT, NIX ME, NM. NV, OK, OR, SD, TX,
UT, WA, WI, WY
Apple
AL, DC, DE, GA, ID, IN, KY, MD, MI, NJ, NY, OH, OR, PA, TN, VA, VT, WA,
WV
Asparagus
MI
Cherry (tart)
MI
Citrus
AL. FL, GA, NC. SC, TX
Cotton
AL.. FL. GA, NC, SC, VA
Peach
AL. DC. DF. FL. Ci.A MD, MI, NC, NJ, NY, OH, PA, SC, TX, VA, VT, WV
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Soybean
AL, CO. PL. GA, IA, IL, IN. KS. KY, MN, MO, MT, NC, ND, NE, NM, OH, OK,
PA, SC. SD. I N. TX, VA. WI. WY, WY
Strawberry
OR
Suear beet
IA, ID, IL, MI, MN, NI). OR. WA, WI
Wheat
{spring)
CO, KS, MO, MT, ND, NE, SD, WY
Wheat
i winter)
CO, LA, KS, MN, MO, MT. ND, NE, OK, SD, TX, WY
'Only specific uses in specific 2-digit HUCs were assessed as described in the 20.20 drinking water
assessment. These specific uses are based on usage data and may not reflect maximum label rates on
current labels.
With a IX FQPA safety factor, the majority of labeled cMorpyrifos uses result in drinking water
concentrations below the DWLOC. Uses with drinking water concentrations above the DWLOC
include. 1) peppers, 2) trash storage bins, and 3) wood treatment. In addition, six uses as noted in
Table i i below, can only be retained in certain states. Otherwise, all labeled chlorpynfos uses
can be retained nationwide.
1 able 1!: Regional Restrictions lor ( orn. 1 ni t (lurries. ( itrus. Pecan. and Pencil w iih an
1 OPA SalVtv Factor of I\
I so Site
State for retention at the 1 V
Com
AL, AR, FL, GA, IA, IL. IN, KS, KY, LA, MN, MO, MS, MT, NC, ND, NE, NY,
OH, OK, PA, SC, SD, VA, VA, WI, WV, 'WY
Cherries (tart)
3 lb ai./A
WA, OR. ID. MT (Deer Lodge, Flathead, Granite, Lake, Lincoln, Mineral,
Missoula, Powell, Ravalli, Sanders, and Silver Bow counties)
Cherries (tart)
2 lb a.i. A
MI. WA. OR. II). MT (Deer Lodge. Flathead. Granite. Lake. Lincoln, Mineral,
Missoula. Powell. Ravalli, Sanders, and Silver Bow counties)
Citrus
AL, FL, GA, NC. SC. TX
Pecan
AL. FL. GA, NC, NM. OK, SC, TX
Peach
AL, DC, DE, FL, GA, MI), MI, NC, NJ, NY, OH, PA, SC, 'IX, VA, VI , WV
'Only specific mes in specific slates listed above were assessed as described in the 2020
supplemental document. These specific uses weie assessed based on actual application rates from
reported usage data and nta\ no! reflect maximum label iate- on current labels. If usage data weie not
available no additional refinement was possible, therefore, the state would not be listed.
Stakeholders and registrants identified to EPA pellicular crops they considered to be important
chloipyrifos uses.38 EPA estimated the benefits of chlorpynfos in these, and many other crops
38 bttps://v^rft'w.regnIatio>Ti$JjLOv/.dQg»ioa]tt.?D=EPA-HO-OPF
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with chlorpyrifos use.39 Uses that were identified by stakeholders and registrants as important
were alfalfa, citrus, cotton, soybean, sugar beet, and wheat. The estimated per acre benefits for
alfalfa were low, at around $1 per acre, but over 1 million acres are treated annually, so total
benefits were over $1 million. For citrus, there are potential high benefits for California lemons
in some cases, with benefits of $290 per acre. The high-end benefit estimate for California
oranges was similar. However, chlorpyrifos use is already restricted in California, with almost
all uses banned after 2020.40 Estimated benefits of chlorpyrifos in cotton are up to $14 per acre,
with total benefits of up to $6.1 million annually. The benefit of chlorpyrifos in soybean is up to
$4 per acre, and with over 3 million acres treated annually, the total benefit could be about $12
million. Sugar beets had potentially very high per acre benefits of almost $500 per acre in parts
of Minnesota and North Dakota, leading to high-end estimated benefits over $30 million overall.
Per acre benefits in wheat are estimated to be low, about $1 per acre in both spring and winter
wheat, with a total benefit for both crops of about $1.3 million. In addition to these crops, EPA
estimated high per-acre economic benefits to growers.
Crops that EPA concluded have potentially high benefits per-acre were: apples (nationwide),
where alternatives for some pests could cost up to $51 per acre more than chlorpyrifos;
asparagus, where the lack of alternatives in Michigan specifically could lead to yield losses of up
to $450 per-acre; tart cherries in Michigan, where uncontrolled pest pressure could lead to yield
losses of up to $201 per-acre; peaches in the southeastern U.S., where uncontrolled pest pressure
could lead to yield losses of up to $430 per acre in Georgia and South Carolina; strawberries in
Oregon, where uncontrolled soil pests (garden symphylans) could lead to abandonment of
strawberry acreage, with a loss that corresponds to over $7,800 per acre.
2. PPE
The agency is providing the details for all currently labelled uses that would require additional
PPE should those uses be retained. Given the current proposal in Section IV. A. 1., should
cancellation of uses be pursued, only the subset of remaining uses will be identified as requiring
the additional PPE described below.
As specified in Section III. A.2., of the 288 steady state occupational handler scenarios assessed
for non-seed treatments, 119 scenarios are of concern with label-specified personal protective
equipment (PPE; baseline attire, chemical resistant gloves, coveralls, and an elastomeric half
mask respirator) assuming the 10X UFdb (MOEs < 100). Risks of concern for 45 additional
exposure scenarios could potentially be mitigated if engineering controls are used.
If the 10X database uncertainty factor is reduced to IX (LOC = 10), 19 scenarios are of concern
with label-specified PPE (MOEs < 10). Risks of concern for 15 additional scenarios could
potentially be mitigated if engineering controls are used.
39 Mallampalli, N., Waterworth, R., and Berwald, D. 2020. Benefits of Agricultural Uses of Chlorpyrifos (PC#
059101). Biological and Economic Analysis Division memorandum to the Pesticide Re-Evaluation Division.
Official record available through the chlorpyrifos docket at www.regulations.gov.
40 https://www.ccipr.ca.gOv/ciocs/chiorpvri:fos/pclf/chiorpvrifos action plan.pdf
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a. PPE Requirements - potential risks with the 1 OX UFdb
AirMast applications
Willi ilie exception of alius and tree nuts (pecans s. risk estimates for mixing and loading
formulations in \YSP were above the LOC of 100. Hie agency is considering reducing the rate of
citrus from 6,0 lbs a.i Acre to 4.0 lbs a.i./Acre due to occupational risks identified to airblast
applicators. Although the MOEs for tree nuts (pecans) and citrus at the lower rate do not meet
the LOC of 100, chlorpyrifos is regarded as a high benefit to these uses.
For the remaining formulations (L/SC/EC), risk estimates for mixers and loaders are below the
LOC with the following PPF:
1 able !2. < uii-iidiiid enuirucfirm controls and PPF. for risks of'concern from airblast
applications
( rop I si
PPF F.n«iitU'crinu controls
MOE
Citrus. Non-bearing Fruit and Nut
Trees (Nursery )
Engineering controls
140
Tree Fruits (Nectarine, Peach -
Dormant. Delayed Dormant)
190
Cherries, 'tree finite (pear, plum prune
(dormant, delayed dormant), tree mils
(almonds, filberts, hazelnuts, pecans,
walnuts)
Double layer (coveralls),
gloves, and either a particulate
filtering facepiece (PF5)
110
Ornamental and-'or shade trees,
ornamental woody shrubs and vines,
herbaceous plants, Christmas tree
plantations, grapes
Single layer (long pants and
long sleeve shirt), gloves
150
To address potential risks of concerns from mixing and loading L/SC/EC formulations for
airblast application, the agency is coiisidetiiig engineering controls or PPE as listed for the uses
in Table 12.
M< >Fs foi mixing and loading ahblast applications for citrus at an application rate of 6.0 lbs
a.i acie \CA and A/> are
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Docket Number EPA-HQ-OPP-2OO8-O850
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Groundboom applications
With the retention of the 10X UFdb, EPA is considering requiring engineering controls (closed
systems\ to address potential risks of concerns to occupational handlers mixing and loading
I. SC L'.(' chlorpynfos ton nidations for groundboom applications for the following uses:
• Nuisery stock (pie-plant)
• Brus^eK sprouts (at plant and post-emergence), cauliflower, cole crops, grapes (foliar,
dormant, delayed dormant), mint (peppermint, spearmint), peanut, pineapple, rutabaga,
strawberries (pre-plant), sunflower (pre-plant) sweet potato (pre-plant and soil broadcast),
and tobacco (pre-plant).
• Beets | table, sugar, at plant), clover (grown for seed, foliar), hybrid cottonwood and polar
plantations
• Cranberry
• Alfalfa, cotton, sorghum pain, soybean, and wheat
• Radishes (pre-plant).
Addition of engineering controls (closed systems) for mixing and loading 1. SC EC formulations
for radishes is 96 and below the LOC of 100. Chlorpyrifos, however, is considered a high benefit
for tln.s use.
For the remaining groundboom applications that may be mitigated with additional PPE, EPA is
considering the following measures for mixers and loaders in Table 13 and measures for
applicators in Table 14:
I able 13: Considered 1*1*1". fur Mi\in«i and ! nailing (.nuimihoom applications: I. s( 1 (
( n>p ( M-
Proposed I'IM.
MOl.!
Carrots
Double layer (coverall*).
gloves, and a particulate
filtering facepiece (PF 5)
110
Carrots
92
Ornamental and/or shade trees,
herbaceous plants, ornamental
woody shrubs and vines
Double layer (covet alb i.
and gloves
91
Asparagus, beets (table, sugar: at
plant), citrus orchard floors, foicst
plantings (reforestation, plantation,
tree farm), grass
(forage fodder/hay), legume
vegetables, nonagricultural outdoor
buildings and structures, onions
91
Conifers and deciduous trees, seed
orchard trees
96
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Golf course (fairwavs. fees, greens)
Single layer (long-sleeved
shirt and long pants) and
aloves
'MOE < LOC; however, ehlorpyrilbs is considered to be a high benefit to this use.
lui'k' 14: ( ojisidercd IM'I\ or i
nuiiu'ti ifiii < onirols lor »toimdboom Applicators
< oiiMdiTtd IT!" i>r
( fO|) 1 >!.'
tonsi
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Docket Number EPA-HQ-OPP-2008-0850
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Asparagus, beets (table, sugar;
at plant), citrus orchard floors,
cole crops (excludes Brussels
sprouts and cauliflower),
cotton, forest plantings
(reforestation, plantation, tree
farm), grapes (dormant,
delayed dormant), grass
(forage/fodder/hay), legume
vegetables, nonagricultural
outdoor buildings and
structures, onions, peppers, and
strawberries
Single layer (long-sleeved shirt
and long pants) and gloves
120
Ornamental and/or shade trees,
herbaceous plants, ornamental
120
woody shrubs and vines
Carrots
130
Conifers and deciduous trees,
170
seed orchard trees
Forest trees (softwoods and
conifers)
200
Golf course (fairways, tees,
greens)
250
1MOE < LOC; however, chlorpyrifos is considered to be a high benefit to this use.
Handheld and Tractor-drawn Spreader applications
The agency is considering requiring the use of double layer PPE (coveralls), gloves, and an
elastomeric half mask respirator, for mixers, loaders, and applicators applying chlorpyrifos liquid
concentrate formulations via manually-pressurized handwand for wood protection treatment and
to pine seedlings in a nursery. Although the MOEs are 82 and 90, respectively, and therefore are
of concern at the 10X UFdb, the agency considers chlorpyrifos to be of high benefit for these
uses.
To increase MOEs to the LOC of 100, the agency is considering requiring additional PPE for
manually-pressurized handwand application on the following uses:
• Single layer (long-sleeved shirt, long pants, socks, and shoes), gloves, and a particulate
filtering facepiece for wide area/general outdoor treatment
• Single layer (long-sleeved shirt, long pants, socks, and shoes) and gloves for: Christmas
tree plantations, conifers and deciduous trees; plantation nurseries, grapes, seed orchard
trees, forest trees (softwoods, conifers), golf course turf, mounds/nests, non-agricultural
outdoor buildings and structures, ornamental woody shrubs and vines, ornamental non-
flowering plants, outdoor commercial/institutional/industrial premises (see master label
description), agricultural farm premises, poultry litter, tree fruits (cherries, nectarines,
peaches, plum/prunes), tree nuts (almonds) - pre-plant, tree nuts (apple) - pre-plant, and
fruits and nuts (non-bearing, see master label description).
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Regardie^ of PPE. mk estimates lor application uirli mechanically pressurized handgun were
below EPA's LOC of 100 for all uses except ornamental woody shrubs and vines and seed
orehaid lives (MOE* ~ 440 tc S.300). MOE* of concern ranged liom 2.1 to S3 foi all other use-,
and were (hereto.] e of concern.
For the following backpack sprayer applications and formulations, the PPE listed below is being
proposed in Table 15:
1 aide ! 5: ( nnsi
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FX >cke1 N umber LP A -I-IQ-OPP- 2< )0S-0$50
www. regulations, gov
Broadcast
(foliar)
Ornamental woody shrubs
and vines
Baseline
930
'Baseline PPE includes long-sleeved shirt. Ions pants, shoes, no gloves, and no respirator.
2 Although additional PPE does not result in MOEs above the LOC of 100 with the retention of the 10X UFdb-
chlorpyrifos is considered a high benefit for these uses.
The above-mentioned uses are the only uses which meet the agency's LOC of 100 with retention
of the 10X L- Fdb- All remaining uses ticated by backpack sprayer applications arc considered
below in ->ec?ion TY.A.3 for possible application method prohibition*.
Traaor-drmrn spreader applications
To address risks of concern to occupational handlers applying ehlorpynfos by tractor-drawn
spreader, EPA is considering use of additional PPE. Most MGEs for mixers, loaders, and
applicators are above the LOC of 100 with use of a Smart Box which is considered an
engineering control. Tlie EPA is considering additional PPE as follows for the uses in Table 16:
I able if>: < misidiivd miiiuation |i>r U;Ki
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Dockd Number r:P.A-lIQ-(')PP-2()0K-O850
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Rutabaga
Single layer (long-sleeved shirt
and long pants), gloves, and a
particulate filtering facepiece
97
Alfalfa
92
Cauliflower (post-plant).
Turnip
Single layer (long-sleeved slnrt
and Ions pants) and a
particulate filtering facepiece
86
Brussels Sprouts tpost-planu
86
Sweet potato
92
Cole crops (except
cauliflower), ginseng, sugar
beets, sunflower, tobacco
98
Aspaiaans
130
Nursery stock
Single layer (long-sleeved shirt
and long pants), gloves
98
Citrus orchaid floor.-,, onions
ornamental lawns ami turf, sod
farms (turf)
Double layei icoveralls'i.
gloves
87
1 Although additional PPE does not result in MOEs above the LOC of 100 with the retention of the 10X UFdb-
ehlorpyrifos is considered a high benefit for these uses.
Hand dispersal application
At baseline PPE, MGEs tor the following uses are below the EPA's LOC of 100 when treated by
rotary spreader or hand dispersal application. Therefore, the agency is considering requiring the
following PPE;
1 utile P' ( unsiiitTod Mitigation tin
Applications l>\ Kohuy Spi cadcr io[K-r<.:il
Crop hdiici
CnU'iNm
Application
Ktjiiipmi'ni
\pplkniion I'vp*.-
pit:
MO! s
Doable layer
Nursery stock
(coveralls)
and gloves
110
Golf course
turf, ornamental
and oi shade
trees.
Rotary spreader
Broadcast
herbaceous
plants,
ornamental
Single layer
(long sleeved
shut, long
100
lawns and turf.
pants) and
sod farms
gloves
(flirts)
Golf course
(turf) sod farms
Hand dispersal
Spot
130
( turf)
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Docket Number EPA-HQ-OPP-2OO8-O850
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Risk estimates for all other uses (ornamental woody shrubs and vines,
commercial institutional industrial premises, utilities (pad)) fail below the LOC of 100 with
maximum PPE (double layer (coveralls), gloves, and an elastomeric half mask respirator) and
with retention of the 10X UFdb. Therefore, the remaining iibes are considered for possible
application method prohibitions as addressed below in section IV.A.3.
Wide Area Mosquito Abatement
Risk estimates of concern were found for occupational handlers mixing, loading, and applying
for wide-area mosquito treatment. Chlorpyrifos is not the primary pesticide used for the majority
of wide-area mosquito treatment programs. However, given the public health concern for
mosquito as vectors for a number of pathogens, there are high benefits for maintaining
chlorpyrifos to treat adult inosquitos. particularly in areas with high pest pressure.
Without engineering controls, MOEs for applying wide area treatments of mosquito adulficide
by ground are of concern. Thus, EPA is considering requiring engineering controls (enclosed
cab) for airblast and aerial application of wide area mosquito treatment and double layer
(coveralls), gloves, and an elastonieric half mask respirator for mixing and loading airblast and
aerial applications.
b. PPE Requirements - potential risks without the 10X UFdb
Aerial and Chemigation Application
Due to potential risks of concern to mixers and loaders for aerial application even without
retention of the 10X UFdb, EPA is considering requiring the following;
1 al>U- IS: ( un-adacd Mitigation lur Mi\i»u and I.ondin^ fur Urial and < lu-miuation
Vnulicationi. :it tile 1\ 1 ()P ^ Safctv f';ulor
Crop 1
( aU"ijur>
formula
( nnsidored
I.n^ineerinu
( oiitrols of IMM
moi:
Aerial, < hciuinatioii
Citrus
L/SC/EC
Double layer
(coveralUl. gloves,
and either a
particulate filtering
facepiece or an
elastomeric half mask
respirator
11
Non-bearing fruit and
nut trees (nursery),
radish (jpre-plant),
turhii:KS (sod or
seed)
12
Cherries, hybrid
cotton wood/poplar
plantations, mint
i peppermint and
spearmint), peanut,
rutabaga, strawberries
12
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Docket Number EPA-3 IQ-GPP-200S-0850
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(pre-plant), sunflower
(pre-plant), sweet
potato, tobacco, tree
fruits (apple,),
nectarine. peach,
pear, plum, prune),
free nuts (almonds,
filberts, hazelnuts,
pecans. walnuts),
turfgrass (ornamental
and sod farms)
Clover (grown for
seed), cranberry,
sunflower (post-
emereeuee foliar)
13
Asparagus. Brussels
sprouts, cauliflower,
cole crops,
strawberries, sugar
beets, radish
L/SC'TEC
Single layer (long-
sleeved shirt and long
pants), gloves, and a
paniculate filtering
lacepiece
1
Com (post-
emergence)
L'SC/EC
Engineering Controls
13
Com (pre-plant)
Granule
Double layer
(coveralls), gloves,
and either a
particulate filtering
facepiece or an
elastomeric half mask
respirator
13
Alfalfa, corn (pre-
plan!). cotton (except
Mississippi),
sorghum, soybean,
wheat
L'SO'EC"
Single layer (long-
sleeved shirt and long
pants), gloves, and a
particulate filtering
facepiece
J
Cluistmas tree
plantations
18
Carrots
19
Peanut
Granule
10
Sweet potato
20
Clumigation
Application
Tree nuts, orchard
floors, (pecans)
L/SC/EC
Engineering controls
15
Tree nut orchard
floors (almonds,
walnuts)
17
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Corn (pre-plant)
22
Corn (post-
emergence)
Single layer (long-
sleeved shirt and long
pants), gloves, and a
particulate filtering
facepiece
13
Alfalfa, corn (pre-
plant), cotton (except
Mississippi),
sorghum, soybean,
wheat
18
Groundboom Application
Mixing and loading all formulations in WSP resulted in MOEs above 10 and are not of concern
at the UFdb of IX. Mixing and loading most L/SC/EC formulations with single layer (long-
sleeved shirt, long pants) and a particulate filtering facepiece results in risks of concern for most
uses. MOEs ranged from 1.9 to 28 with risks of concerns for the following uses: Corn (pre-plant
and post-emergence), radish (pre-plant), rutabaga, Brussels sprouts (at-plant, post-plant), grapes
(foliar, dormant, delayed dormant), sweet potato (pre-plant, soil broadcast), cotton (except
Mississippi), cole crops, cauliflower, mint (peppermint, spearmint), peanut, pineapple,
strawberries (pre-plant), sunflower (pre-plant), tobacco (pre-plant), cranberry, alfalfa, cotton,
sorghum grain, soybean, wheat, beets (table, sugar; at plant), clover (grown for seed; foliar),
hybrid cottonwood/poplar plantations, tree nut orchard floors (pecans, almonds, walnuts),
nursery stock (pre-plant), ornamental lawns and turf, and sod farms.
With the addition of gloves for these uses, the range of MOEs increases to 11 - 56 and are no
longer of concern at the UFdb of IX.
Groundboom application risks of concern were identified for corn (pre-plant), tree nut orchard
floors (pecans, almonds, walnuts), and cotton (except Mississippi) (MOEs = 5.3 - 9.9). With the
use of single layer (long-sleeved shirt, long pants) and gloves, all risk estimates for groundboom
applicators are greater than 10 are not of concern at the UFdb of IX.
Airblast and Handheld Applications
For mixing and loading L/SC/EC for airblast applications, EPA is considering single layer (long-
sleeved shirt and long pants) and gloves for the following uses:
• Citrus (CA and AZ); MOE = 24
• Citrus, Non-bearing Fruit and Nut Trees (Nursery); MOE = 36
• Tree Fruits (Nectarine, Peach - Dormant, Delayed Dormant); MOE = 48
EPA is also considering requiring double layer (coveralls) and gloves for backpack application
on wide-area general outdoor treatment, and outdoor commercial/institutional/industrial
premises, non-agricultural outdoor buildings and structures. The MOEs with this additional PPE
range from 12 to 19.
For handheld applications, EPA is considering requiring single layer (long-sleeved and long
pants) and gloves for:
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• Brush roller application to wood protection treatment (MOE =16) and structural (e.g.,
warehouses, food handling establishments, and home bathrooms (MOE = 33)).
• Manually-pressurized handwand application to: Wood protection treatment, nursery (pine
seedlings), wide area/ general outdoor treatment, Christmas tree plantations, conifers and
deciduous trees; plantation nurseries, grapes, seed orchard trees, forest trees (softwoods,
conifers), golf course turf, mounds/nests, non-agricultural outdoor buildings and
structures, indoor commercial/institutional/industrial premises (see master label
description), food processing plant premises, ornamental woody shrubs and vines,
ornamental non-flowering plants, tree fruits (cherries, nectarines, peaches, plum/prunes),
tree nuts (almonds) - pre-plant, and tree nuts (apple) - pre-plant.
c. Additional PPE Labeling Updates and Requirements
PPE Label Consistency Updates
In addition, the agency is considering updating the glove and respirator statements currently on
labels. The proposed new glove and respirator language does not fundamentally change the PPE
that workers need to use, and therefore should impose no impacts on users.
For gloves in particular, all statements that refer to the chemical resistance category selection
chart are proposed to be removed from chlorpyrifos labels, as they might cause confusion for
users. These statements are proposed to be replaced with specific chemical-resistant glove types,
consistent with the Label Review Manual.41
Respirator Requirement for Chlorpyrifos Handlers
To mitigate potential inhalation risk to occupational handlers, the agency is considering requiring
a respirator and, for pesticides covered by the Worker Protection Standard42 (WPS), the
associated fit test, training, and medical evaluation for the aforementioned formulations and uses.
The EPA has recently required fit testing, training, and medical evaluations43 for all handlers
who are required to wear respirators and whose work falls within the scope of the WPS.44 If a
chlorpyrifos handler currently does not have a respirator, an additional cost will be incurred by
the handler or the handler's employer, which includes the cost of the respirator plus, for WPS-
covered products, the cost for a respirator fit test, training, and medical exam.
41 https://www.epa.gov/pesticide-regisfrafii3n/label-review-mannal
42 40 CFR 170
43 Fit testing, training, and medical evaluations must be conducted according to OSHA regulations 29 CFR §
1910.134, 29 CFR § 1910.134(k)(l)(i) through(vi), and 29 CFR § 1910.134, respectively.
44 40 CFR 170 (see also Appendix A of Chapter 10 of the Label Review Manual, available at
https://www.epa.gov/pesticide-registration/label-review-mannan.45 Economic Analysis of the Agricultural Worker
Protection Standard Revisions. Biological and Economic Analysis Division, Office of Pesticide Programs, U.S.
EPA. 2015. p. 205. Available at www regulations.gov. docket number EPA-HQ-OPP-2011-0184-2522.
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Respirator costs are extremely variable depending upon the protection level desired,
disposability, comfort, and the kinds of vapors and particulates being filtered. Based on available
information that the EPA has, the cost of the respirators (whether disposable or reusable) is
relatively minor in comparison to the fit-test requirement under the Worker Protection Standard.
The agency expects that the average cost of a particulate filtering facepiece respirator is lower
than the average cost of an elastomeric half mask respirator. The estimated cost of a respirator fit
test, training and medical exam is about $180 annually.45 The impact of the proposed respirator
requirement is likely to be substantially lower for a chlorpyrifos handler who is already using a
respirator because the handler or handler's employer uses other chemicals requiring a respirator
in the production system or as part of the business (i.e., the handler or employer will only incur
the cost of purchasing filters for the respirator on a more frequent basis). Respirator fit tests are
currently required by the Occupational Safety and Health Administration (OSHA) for other
occupational settings to ensure proper protection.46
The EPA acknowledges that requiring a respirator and the associated fit testing, training, and
medical evaluation places a burden on handlers or employers. However, the proper fit and use of
respirators is essential to accomplish the protections respirators are intended to provide. In
estimating the inhalation risks, and the risk reduction associated with different respirators, the
EPA's human health risk assessments assume National Institute for Occupational Safety and
Health (NIOSH) protection factors (i.e., respirators are used according to OSHA's standards). If
the respirator does not fit properly, use of chlorpyrifos may cause unreasonable adverse effects
on the pesticide handler.
Engineering Requirement for Handlers
EPA is considering requiring that a closed pesticide delivery system be used for mixing and
loading chlorpyrifos for applications to several uses as described above. Professional applicators
likely have closed pesticide delivery systems because they handle multiple chemicals, some of
which likely already require closed pesticide delivery systems. Thus, the impacts of this
restriction would likely be small for situations where hired applicators are used. Individual or
independent growers are much less likely to have closed pesticide delivery systems than
commercial firms, so these restrictions could impede their ability to use chlorpyrifos. Users who
do not already have the appropriate equipment would have to hire a commercial firm to make
chlorpyrifos applications, probably at an increase in cost, or use an alternative insecticide, which
(as described above) could be more expensive and (in some cases) less efficacious. Users could
also invest in a closed pesticide delivery system. The cost of a closed pesticide delivery system
varies and depends on the complexity of the system. Based on available information, the cost of
the equipment may have been around $300.47 It seems unlikely, however, that a grower would
incur such an expense if chlorpyrifos is the only chemical applied to the field that requires a
closed pesticide delivery system.
45 Economic Analysis of the Agricultural Worker Protection Standard Revisions. Biological and Economic Analysis
Division, Office of Pesticide Programs, U.S. EPA. 2015. p. 205. Available at www.regulations.gov, docket number
EPA-HQ-OPP-2011-0184-2522.
46 29 CFR § 1910.134
47 Giles K., & Billing, R. 2013. Designs and Improvements in Closed Systems. Report to: Ken Everett, Pesticide
Enforcement Branch, California Department of Pesticide Regulation.
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EPA is also considering the requirement of an enclosed cab for airblast applications of
chlorpyrifos. Users that do not currently own a tractor with an enclosed cab could hire
commercial applicators to apply chlorpyrifos, at an increased cost, or switch to alternative
insecticides. As described above, users face increased costs using the available alternatives for
some uses, and for some crops (i.e., California oranges, apples, and Southeastern peaches)
effective alternatives are not available and yield and quality losses are possible. The
characteristics of some orchards do not lend themselves well to enclosed cabs. In these
situations, this requirement will most likely result in growers using alternatives insecticides.
3. Use Prohibitions, Application Method Restrictions, and Rate Reductions
For the following application methods, potential risk estimates of concern could not be resolved
with additional PPE or engineering controls. For that reason, the EPA is considering additional
options for mitigating these risks, including application method prohibitions, restricting use of
particular application methods to select use sites, and/or application rate reductions.
The subset of uses that are ultimately retained to address potential dietary risk (discussed in
section IV. A. 1) will impact the mitigation approach taken to address potential occupational risk.
At this time, the EPA is presenting use prohibitions and application restrictions for risk estimates
that were below the LOC. Once the EPA considers the SAP's conclusions, the EPA may further
revise the human health risk assessment and proposed/considered mitigation. This includes
consideration of additional refinements to the occupational risk estimates where possible. The
EPA will also consider the benefits of the crops that are ultimately retained, as well as public
comments, prior to finalizing any use prohibitions and/or application restrictions.
The impacts of the prohibitions and restrictions on uses will depend on the use site. As described
in Section III.C, there are alternatives available to chlorpyrifos for most use sites, at an increased
cost to users in many cases. There are exceptions, and some chlorpyrifos users could see
reductions in pest control using the alternatives, resulting in reduced yield or quality of some
crops.
a. Use Prohibitions and Application Restrictions - with the 1 OX UFdb
Aerial and chemigation applications
Even with engineering controls, risks of concern were identified for most uses from mixing and
loading for aerial and chemigation applications. Most MOEs for mixers and loaders with
engineering controls ranged from 9.6 to 71. Exceptions include mixing and loading for
ornamental and/or shade trees, herbaceous plants (WP in WSP), ornamental non-flowering plants
(microencapsulated formula) and mosquito/vector control (L/SC/EC). Therefore, EPA is
considering limiting application to select uses or prohibit aerial and chemigation application of
chlorpyrifos to all uses except chemigation application of microencapsulated formula on
ornamental non-flowering plants and mosquito/vector control. See Appendix A for a complete
list of considered prohibited uses.
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Although the use of global positioning systems (GPS) has vastly replaced the use of flaggers to
guide aerial applications, the agency continues to assess exposure as use of flaggers is not
explicitly prohibited on pesticide products containing chlorpyrifos. All liquid applications of
chlorpyrifos products results in potential risks of concern for flaggers with the maximum amount
of PPE (double layer (coveralls), gloves, and an elastomeric half mask respirator). Potential risks
of concern were identified for flaggers with granule application for treatment of peanuts
regardless of PPE. Use of chlorpyrifos granule products also resulted in risks of concern without
use of a respirator for application on sweet potato, corn (pre-plant), sunflower, and tobacco. No
risks of concern were identified for flaggers with granule application to sod farms (turf).
Therefore, the agency is considering prohibiting use of flagger for all applications except granule
application to sod farms (turf).
Groundboom application
Risk estimates with engineering controls were still below EPA's LOC of 100 for mixing and
loading the following formulations and respective uses (MOEs = 39 - 98):
• Liquid/Soluble Concentrate: Corn (pre-plant and post-emergence), cotton (except MS),
tree nut orchard floors (pecans, almonds, walnuts), ornamental lawns and turf, and sod
farms
• Wettable powder in WSP: Ornamental lawns and turf, sod farms (turf), ornamental
woody shrubs and vines (pre-transplant)
• Dry flowable (DF) /water-soluble granule (WSG) in WSP: Tree nut orchard floors
(pecans, almonds, walnuts), corn, sorghum grain, soybean, rutabaga, and turnip
Consequently, EPA is considering prohibiting chlorpyrifos application to the above uses and
formulations by groundboom application. This would also address risks of concern to
groundboom applicators for corn (pre-plant), cotton (except Mississippi).
WSP formulations are assessed having the protection factor of engineering controls. The
DF/WSG in WSP formulations do not fully meet the LOC of 100 for sweet potato (pre-plant, soil
broadcast), cole crops (excludes Brussels sprout and cauliflower), mint (peppermint and
spearmint), peanut, sunflower, and tobacco with MOEs ranging from 92 to 98. Chlorpyrifos is
regarded as a high benefit for these uses.
Airblast application
Risk estimates for mixing and loading with engineering controls for citrus (CA and AZ at a rate
of 6.0 lbs a.i./Acre) resulted in MOEs of 96 (L/SC/EC) and 67 (wettable powder in WSP and
DF/WDG in WSP). The MOE for airblast application to citrus at the highest rate was 64 with
engineering controls. Given recent chlorpyrifos restrictions in the state of California, use in
California is expected to be negligible after 2020. EPA is considering reducing the application
rate applied to citrus in Arizona to 4.0 lbs a.i./acre. MOEs for this reduced rate are 98 and still
below the EPA's LOC of 100. However, citrus is recognized as a high-benefit use for
chlorpyrifos. Reducing this rate will also address potential post-application risks of concern for
citrus (assuming retention the 10X UFdb).
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Tractor-drawn spreader
Use of double layer (coveralls), gloves, and a half face respirator results in the highest MOEs for
mixing, loading, or applying chlorpyrifos by tractor-drawn spreader. MOEs for mixing and
loading soybean and corn were 74 and 79, respectively. Engineering controls, excluding
applications by SmartBox®, results in slightly lower risk estimates. Consequently, EPA is
considering prohibiting tractor drawn spreader application on these uses.
Handheld application methods
Regardless of PPE, risk estimates for application with mechanically pressurized handgun were
below EPA's level of concern for all uses except ornamental woody shrubs and vines and seed
orchard trees (MOEs = 440 to 8300); MOEs of concern ranged from 2.1 to 83 for all other uses.
As a result, EPA is considering limiting mechanically-pressurized handgun application only to
ornamental woody shrubs and vines and seed orchard trees.
The agency is considering prohibiting manually pressurized handwand application to indoor
commercial/institutional/industrial premises and food processing plant premises. The risk
estimate for these uses is 16 with maximum PPE.
To address risks of concern to occupational handlers using backpack sprayers, the agency is
considering prohibiting all uses with the retention of the 10X UFdb except for the formulations,
uses, and conditions listed in Section IV.A.2.
The highest MOEs with maximum PPE (double-layer (coveralls), gloves, and an elastomeric half
mask respirator) for application of chlorpyrifos by belly grinder or brush roller are 43 and 45,
respectively. Given the limited uses for this application method, none of which are food uses, the
agency is considering prohibiting application of chlorpyrifos by these handheld methods.
EPA is also considering prohibiting application of granular formulation by hand dispersal to
commercial/institutional/industrial premises and utilities (pad) and by belly grinder to
ornamental wood shrubs and vine. Prohibiting application to sewer manholes by brush roller may
also be considered. MOEs for these applications with double layer (coveralls), gloves, and an
elastomeric half mask respirator ranged from 1.4 to 7.1.
Microencapsulatedformulations on ornamentals in nurseries and in greenhouses (post-
application)
Occupational post-application risks of concern from microencapsulated formulations extend up
to >35 days for ornamentals in nurseries and greenhouses. Extending REIs beyond a week, even
on the basis on select activities, is not considered practical. Other uses which have risk estimates
below the agency's LOC of 100 at the FQPA safety factor of 10X include grape and cole crops.
For these uses, EPA is in the process of determining the most appropriate DFR study to
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characterize risks for mitigation. Given the alternative formulations of clilorpyrifos available
with significantly shorter RE Is. EPA is considering prohibiting microencapsulated formulations
for use on ornamentals in nurseries and greenhouses.
Seed Treatment
Occupational handlers applying clilorpyrifos for seed treatment may potentially conduct multiple
tasks, such as sewing, bagging, loading, and applying. Additional activities increase the amount
of potential exposure to these workers. These activities were assessed with the maximum amount
of PPE available:
1 able I4): V-t'd f iiutnunt Acli\ilie> and P1M
Activity
Maximum 1*1*1. as^issed
Sewing seeds after seed treatment
Single layer (long sleeved shirt and long
pants), no gloves and no respirator
Bagging seeds after seed treatment
Loading,/Applying liquid for seed treatment
Double layer (coveralls), gloves and PF10
respirator
Multiple activities for seed-treatment
As a result, the agency is considering prohibiting use of clilorpyrifos as a seed treatment for the
following formulations and ciops based on risks to multiple activities workeis or occupational
handlers that conduct multiple activities for seed tieatment (.e.g.. applying and bagging):
• Liquid formulation on beans, com, cotton
• Microencapsulated formulation on beans
• Wettable powder in WSP on beans and com
b. Use Prohibitions and Application Restrictions — without the 1 OX UFm
MOEs for aerial application of granular formulations of chloipyrifos on peanuts is 5 with
engineering controls. MOEs for other aerial granular applications range are 9.4 (sweet potato)
and 9.5 (sunflower, tobaccos also with engineering controls. Therefore. FPA is considering
prohibiting this application method on peanuts. Although the risk estimates are still below a LOC
of 10 for sweet potato, stmilowei, and tobacco, these uses aie proposed to be retained given the
benefits associated with the use of chloipyrifos on these crops.
The agency is also considering prohibiting backpack sprayer application to ornamental and shade
trees, herbaceous plants, ornamental woody shrubs and vines. MOb's for application to these
non-food sites are 3.8 with maximum PPE (double layer (coveralls), gloves, and an elastomeric
half mask respirator) and therefore are of concern.
For handheld applications. HPA is considering prohibiting brush roller application for sewer
manholes and hand dispersal to commercial institutional industrial premises and utilities (pad).
With double layer (coveralls), gloves, and an elastomeric half mask lespuator. the MOE is 1.4
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for broadcast hand dispersal application to commercial/institutional/industrial premises and
utilities (pad) and, therefore, is below the LOC. The agency is also considering prohibiting
application with belly grinders on ornamental woody shrubs and vines. With maximum PPE, the
MOE is 7.1 and below the LOC of 10 for these uses.
4. Re-Entry Interval
With retention of the 10X UFdb, risk estimates exceed the LOC of 100 for over 30
activities/uses. These include: berries, field and row crops, tree fruit (deciduous, evergreen),
forestry, tree nuts (almonds), ornamental nurseries (non-bearing fruit trees), fruiting vegetables,
brassica vegetables, leafy vegetables, and grapes. As multiple DFR studies were submitted for
many uses, the MOEs for chlorpyrifos on these crops may vary depending on activity and study
location. EPA is in the process of determining the most appropriate DFR study to characterize
risks for mitigation. Proposed REIs for uses with identified risks of concern may extend over one
week. At the IX UFdb, the MOEs exceed the LOC for approximately 10 crop groups with
proposed REIs extending from 2 to 5 days. See Appendix D2 for the mitigation being considered
to address occupational post-application risks of concern. Mitigation measures for other risks of
concern may impact the selection of uses that are maintained and, thus, how EPA addresses these
post-application risks of concern.
5. Pesticide Resistance Management
Pesticide resistance occurs when genetic or behavioral changes enable a portion of a pest
population to tolerate or survive what would otherwise be lethal doses of a given pesticide. The
development of such resistance is influenced by a number of factors. One important factor is the
repeated use of pesticides with the same mode (or mechanism) of action. This practice kills
sensitive pest individuals but allows less susceptible ones in the targeted population to survive
and reproduce, thus increasing in numbers. These individuals will eventually be unaffected by
the repeated pesticide applications and may become a substantial portion of the pest population.
An alternative approach, recommended by resistance management experts as part of integrated
pest management (IPM) programs, is to use pesticides with different chemical modes (or
mechanisms) of action against the same target pest population. This approach may delay and/or
prevent the development of resistance to a particular mode (or mechanism) of action without
resorting to increased rates and frequency of application, possibly prolonging the useful life of
pesticides.
The EPA is proposing to include resistance-management labeling for insecticides/acaricides from
PRN 2017-1, for products containing chlorpyrifos, in order to provide pesticide users with easy
access to important information to help maintain the effectiveness of useful pesticides.48
Resistance management label language for insecticides may be found at:
https://www.epa.gov/pesticide-reeistration/pesticide-reeistration-notices-vear.
48 https://www.epa.gov/pestjcide-regisfrafii3n/pesficide-regisfration-nofices-vear
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Additional information on the EPA's guidance for resistance management can be found at the
following website: https://www.epa.gov/pesticide~registration/prn~2Q17~l~guidance~pestieide~
registrants-pesticide-resistance-management.
6. Spray Drift Management
EPA is proposing label changes to reduce off-target spray drift and establish a baseline level of
protection against spray drift that is consistent across all chlorpyrifos products. Reducing spray
drift is expected to reduce the extent of environmental exposure and risk to non-target plants and
animals, including listed species whose range and/or critical habitat co-occur with the use of
chlorpyrifos. These spray drift reduction measures, once finalized in the Interim Decision, will
be considered in forthcoming consultation with the Services, as appropriate.
EPA is proposing the following spray drift mitigation language to be included on all chlorpyrifos
product labels for products applied by liquid spray application. The proposed spray drift
language includes mandatory, enforceable statements and supersede any existing language
already on product labels (either advisory or mandatory) covering the same topics. EPA is also
providing recommendations that allow chlorpyrifos registrants to standardize all advisory
language on chlorpyrifos product labels. Registrants must ensure that any existing advisory
language left on labels does not contradict or modify the new mandatory spray drift statements
proposed in this PID, once effective.
• Applicators must not spray during temperature inversions.
• For aerial applications,
o Do not apply when wind speeds exceed 10 mph at the application site,
o The boom length must be 65% or less of the wingspan for fixed wing aircraft and
75% or less of the rotor diameter for helicopters. Applicators must use '/2 swath
displacement upwind at the downwind edge of the field,
o The release height must be no higher than 10 feet from the top of the crop canopy or
ground, unless a greater application height is required for pilot safety.
• For groundboom applications,
o Do not apply when wind speeds exceed 10 mph at the application site,
o Apply with a release height no more than 3 feet above the ground or crop canopy.
• Airblast applications:
o Sprays must be directed into the canopy.
o Do not apply when wind speeds exceed 10 miles per hour at the application site,
o User must turn off outward pointing nozzles at row ends and when spraying outer row.
Buffers were required to mitigate potential spray drift risk to bystanders in the July 2012 Spray
Drift Mitigation Decision for Chlorpyrifos. Buffer distances implemented as a result of that
decision are not superseded by this PID, and are included below for reference:
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1 able 2U: BuflVr Distances
\pplit ation rate (lb ai Ai
Nozzle Droplet l>pe
lii-uuiiiii M'lbaik (P.iiHer /.oium fleeti
Aei i.ii
Ail hlasi
( r! Olllltl
>0.5 -1
coarse or very coarse
10
10
10
>0.5 - 1
medium
25
10
10
>1-2
coarse or very coarse
50
10
10
>1 - 2
medium
80
10
10
>2-3
coarse or very coarse
SO1
10
10
>2-3
medium
1001
10
10
>3-4
medium or coarse
NA2
25
10
>4
medium or coarse
NA
50
10
'Aerial application of greater than 2 lb ai/'A is only permitted for Asian Citrus PsylM control, up to 23 lb ai/A,
•^NA is not allowed.
Spray drift mitigation for chloipyiifos has the potential to decrease an applicator's flexibility to
make timely applications for both ground and aerial applications (e.g.. windspeed and
temperature inversions). Applicators may see a decrease in flexibility of application timing and
an increase m managerial effort fei scheduling production activities, ultimately increasing costs
for the user if chlorpyrifos applications are not made in a timely manner. Some useis may be
forced to use alternative insecticides, which may be more costly and/or less effective than
chloipyiifos. Fixed-wing aircraft will have reduction ill usable boom length, which may
necessitate more passes to complete an application, potentially increasing application costs. EPA
has determined the changes in release height and swath displacement will have minimal impact
on aerial applications. The agency anticipates little impact with residential buffers and considers
that this size buffer corresponds to good application practices when applying near residential
areas.
7. Updated Water-Soluble Packaging Language tor Chlorpyrifos
EPA is proposing updated directions for use language be added to chlorpyrifos labels that are
packaged in WSP, consistent with the language being proposed across WSP products in
registration review. The improved clarity is expected to ensure proper use of these products and
to minimize exposure to occupational handlers.
B. Tolerance Actions
The chlorpyrifos tolerance expressions established 40 CFR § 180.342 will be updated to
incorporate newly revised crop group definitions, OECD rounding class practice, commodity
definition revisions, crop group conversions revisions, and harmonization with Codex. The
agency will consider the input and lecommendations from the September 2020 i ll R A Scientific
Advisory Pane! (SAP) on new approach methodologies for neurodevelopmenlal toxicity once the
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SAP report is released. After receiving the SAP's conclusions which are anticipated in December
2020, EPA will examine the need for further tolerance actions. The agency will use its FFDCA
rulemaking authority to make the needed changes to the tolerances. Refer to Section III. A.4 for
details.
C. Proposed Interim Registration Review Decision
In accordance with 40 CFR § 155.56 and § 155.58, the agency is issuing this PID. The agency
has made the following PID: (1) no additional data from registrants are required at this time and
(2) changes to the affected registrations and their labeling are needed at this time, as described in
Section IV. A and Appendix A.
The agency has concluded that there is no evidence demonstrating that chlorpyrifos potentially
interacts with estrogen, androgen, or thyroid pathways. Therefore, EDSP Tier 2 testing is not
recommended. For more information, see the EDSP Weight of Evidence Conclusions on the Tier
1 Screen Assays for the List 1 Chemicals49 and Appendix C. The proposed mitigation described
in this document is expected to reduce the extent of environmental exposure and may reduce risk
to listed species whose range and/or critical habitat co-occur with the use of chlorpyrifos.
D. Data Requirements
The agency does not anticipate calling-in additional data for registration review of chlorpyrifos
at this time. The EPA will consider requiring submission of pollinator and residue chemistry data
as a separate action.
V. NEXT STEPS AND TIMELINE
A. Proposed Interim Registration Review Decision
A Federal Register Notice will announce the availability of this PID for chlorpyrifos and will
allow a 60-day comment period. If there are no significant comments or additional information
submitted to the docket during the comment period that leads the agency to change its PID, the
EPA may issue an interim registration review decision for chlorpyrifos. However, a final
decision for chlorpyrifos may be issued without the agency having previously issued an interim
decision. A final decision on the chlorpyrifos registration review case will occur after: (1) an
endangered species determination under the ESA and any needed § 7 consultation with the
Services, and (2) the agency completes a revised cumulative risk assessment for OPs.
B. Implementation of Mitigation Measures
49 https://www.regulations.gov/doeument?D=EPA-HO-OPP-2008-0850-0849
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Once the Interim Registration Review Decision is issued, the chlorpyrifos registrants must
submit amended labels that include the label changes described in Appendix A. The agency will
issue a label table after considering the input and recommendations from the September 2020
FIFRA Scientific Advisory Panel (SAP) on new approach methodologies for
neurodevelopmental toxicity. The revised labels and requests for amendment of registrations
must be submitted to the agency for review within 60 days following issuance of the Interim
Registration Review Decision in the docket.
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Appendix A: Summary of Proposed and Considered Actions for Chlorpyrifos
NOTE: The proposed and considered actions below reflect the suite of mitigation measures being considered for each of the currently labeled chlorpyrifos
uses. If the agency moves forward with the use restrictions being proposed to reduce dietary exposure from drinking water, select occupational and post-
application actions proposed below may not be needed. The agency will reexamine the proposed and considered mitigation after considering public input
during the comment period and conclusions from the 2020 SAP.
Registration Review Case#: 0100
PC Code: 059101
Chemical Type: Insecticide
Chemical Family: Organophosphate
Mode of Action: Acetylcho
inesterase inhibition
Affected Population(s)
Source of
Route of
Duration of
Potential Risk(s)
Proposed Actions with 10X
Proposed Actions with the IX
Exposure
Exposure
Exposure
of Concern
FQPA SF
FQPA SF
Infants and children
Dietary (drinking
Ingestion
Acute
Neurotoxicity
To reduce potential dietary
To reduce potential dietary
water)
Steady state
exposure to chlorpyrifos, the
exposure to chlorpyrifos, the agency
Females 13-49 years of age
Dietary (drinking
water)
Ingestion
Acute
Steady state
Neurotoxicity
agency is considering label
amendments to limit use of
chlorpyrifos to the 11 high-
benefit and/or critical uses
(alfalfa, apple, cherries (tart),
asparagus, citrus, cotton,
peach, soybean, strawberry,
sugar beet, wheat (spring),
and wheat (winter)) in select
regions, as well as public
health uses, as identified in
Section IV.A.l. of this PID.
is considering label amendments to
prohibit the following uses:
Peppers, trash storage bins, and
wood treatment; and restrict the
following uses to certain regions:
corn, cherries (tart), citrus, pecans
and peach; and reduce the
application rate for cherries (tart) by
region, as identified in Section
IV.A.l. of this PID.
Considerec
mitigation for Occupational Risks of Concern
Affected Population(s)
Source of
Route of
Duration of
Potential Risk(s)
Mitigation Actions
Mitigation Actions Considered
Exposure
Exposure
Exposure
of Concern
Considered with 10X UFdb
with the IX UFdb
Occupational handler risks
Air
Dermal
Acute
Neurotoxicity
Consider prohibiting aerial
Consider prohibiting application of
from mixing and loading
most aerial and chemigation
Residues
absorption
Inhalation
Steady state
and chemigation application
of chlorpyrifos to all uses
granules on peanuts.
applications: Liquid/Soluble
except for aerial use on
Consider use of double layer
Concentrate/Emulsifiable
ornamental non-flowering
(coveralls), gloves, and an
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Concentrate (L/SC/EC) and
granule
plants and as a wide area
mosquito adulticide (L/SC/EC).
Consider requiring double
layer (coveralls), gloves, and
an elastomeric half mask
respirator for mixing and
loading aerial mosquito
adulticide applications.
elastomeric half mask respirator,
for: Citrus, non-bearing fruit and
nut trees (nursery), radish (pre-
plant), turfgrass (sod or seed),
cherries, hybrid cottonwood/poplar
plantations, mint (peppermint and
spearmint), peanut, rutabaga,
strawberries (pre-plant), sunflower
(pre-plant), sweet potato, tobacco,
tree fruits (apple, nectarine, peach,
pear, plum/prune), tree nuts
(almonds, filberts, hazelnuts,
pecans, walnuts), turfgrass
(ornamental and sod farms), clover
(grown for seed), cranberry,
sunflower (post-emergence/foliar).
Consider single layer (long-sleeved
shirt and long pants), gloves and a
particulate filtering facepiece for:
Asparagus, Brussels sprouts,
cauliflower, cole crops,
strawberries, sugar beets, and
radish.
Occupational handler risks
from mixing and loading
aerial application only:
L/SC/EC and granule
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting all aerial
application of chlorpyrifos on
ornamental non-flowering
plants and as a wide area
mosquito adulticide (L/SC/EC).
Consider requiring double
layer (coveralls), gloves, and
an elastomeric half mask
respirator for mixing and
loading aerial mosquito
adulticide applications.
L/SC/EC:
• Consider requiring
engineering controls for
mixing and loading corn
(post-emergence).
• Consider requiring single
layer (long-sleeved shirt
and long pants), gloves,
and a particulate filtering
facepiece for: Alfalfa,
cotton (except Mississippi),
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sorghum, wheat, Christmas
tree plantations, and
carrots.
Granule:
• Consider double layer
(coveralls), gloves, and
either a particulate filtering
facepiece or an elastomeric
half mask respirator for
corn (pre-plant).
• Consider requiring single
layer (long-sleeved shirt
and long pants), gloves,
and a particulate filtering
facepiece for peanut and
sweet potato.
Occupational handler risks
from mixing and loading
chemigation only
applications: L/SC/EC
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting all
chemigation application of
chlorpyrifos.
Consider requiring engineering
controls for mixing and loading for
use on: Tree nuts, orchard floors
(pecans, almonds, walnuts), corn
(pre-plant).
Consider single layer (long-sleeved
shirt and long pants), gloves, and a
particulate filtering facepiece for
mixing a loading for: Alfalfa, cotton
(except Mississippi), sorghum,
soybean, and wheat.
Occupational handler risks
from mixing and loading
most aerial and chemigation
applications: Dry
flowable/water-dispersable
granules (DF/WDG) in WSP
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting all aerial
and chemigation application
of chlorpyrifos DF/WDG in
WSP formulations.
N/A
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Occupational handler risks
from mixing and loading
most aerial and chemigation
applications: Wettable
Powder (WP), and Spray (all
starting formulations
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application of WP to all uses
except ornamental and/or
shade trees, herbaceous
plants.
N/A
Consider prohibiting
application of spray (all
starting formulations) to the
following uses: Citrus, carrots,
corn (post-emergence),
alfalfa, corn (pre-plant),
Christmas tree plantations,
cole crops, cotton (except
Mississippi), sorghum,
soybean, wheat, asparagus,
Brussels sprouts, cauliflower,
cole crops, strawberries, sugar
beets, radish, clover (grown
for seed; foliar), corn (post-
emergence), cranberry, hybrid
cottonwood/ poplar
plantations grown for pulp,
sunflower (post-emergence/
foliar), non-bearing fruit and
nut trees (nursery), radish
(pre-plant), sweet potato (pre-
plant), cherries, mint
(peppermint and spearmint),
peanut, rutabaga,
strawberries (pre-plant),
sunflower (pre-plant),
tobacco, tree fruits (apple, fig
(CA only), nectarine, peach,
pear, plum/prune),
ornamental and/or shade
trees, herbaceous plants, tree
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nuts (almonds,
filberts/hazelnuts, pecans,
walnuts), and turfgrass
(ornamental and sod farms).
Occupational handler risks
from mixing and loading
groundboom applications
for: L/SC/EC
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application of L/SC/EC
formulations by groundboom
to: Corn (pre-plant, post-
emergence), cotton (except
Mississippi), tree nut orchard
floors (pecans, almonds,
walnuts), ornamentals lawns
and turf, sod farms.
Consider requiring
engineering controls for
mixing and loading L/SC/EC
formulations for: Radish (pre-
plant), alfalfa, cotton,
sorghum grain, soybean,
wheat, rutabaga, Brussels
sprouts (at plant, post-plant),
grapes (foliar, dormant,
delayed dormant), sweet
potato (pre-plant, soil
broadcast), nursery stock
(preplant), cole crops,
cauliflower, mint
(peppermint, spearmint),
peanut, pineapple,
strawberries (pre-plant),
sunflower (pre-plant), tobacco
(pre-plant), beets (table,
sugar, at plant), clover (grown
for seed; foliar), hybrid
cottonwood/poplar
plantations, and cranberry.
Consider requiring single layer
(long-sleeved shirt, long pants),
gloves, and a particulate filtering
facepiece for: Corn (pre-plant and
post-emergence), radish (pre-plant),
rutabaga, Brussels sprouts (at-plant,
post-plant), grapes (foliar, dormant,
delayed dormant), sweet potato
(pre-plant, soil broadcast), cotton
(except Mississippi), cole crops,
cauliflower, mint (peppermint,
spearmint), peanut, pineapple,
strawberries (pre-plant), sunflower
(pre-plant), tobacco (pre-plant),
cranberry, alfalfa, cotton, sorghum
grain, soybean, wheat, beets (table,
sugar; at plant), clover (grown for
seed; foliar), hybrid
cottonwood/poplar plantations,
tree nut orchard floors (pecans,
almonds, walnuts), nursery stock
(pre-plant), ornamental lawns and
turf, and sod farms.
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Consider requiring double
layer (coveralls), gloves and
particulate filtering facepiece
for carrots.
Consider requiring double
layer (coveralls) and gloves
for: Asparagus, beets (tables,
sugar, at plant), citrus orchard
floors, forest plantings
(reforestation, plantation,
tree farm), grass
(forage/fodder/hay), legume,
vegetables, nonagricultural
outdoor buildings and
structures, and onions.
Consider requiring single layer
(long-sleeved shirt and long
pants) and gloves for: Conifers
and deciduous trees, seed
orchard trees, ornamental
and/or shade trees,
herbaceous plants,
ornamental woody shrubs and
vines, and golf course
(fairways, tees, greens).
Occupational handler risks
from mixing and loading
groundboom applications
for: DF/WDG in WSP
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application of DF/WDG in
WSP to: Tree nut orchard
floors (pecans, walnuts,
almonds), corn, sorghum
grain, soybean, rutabaga, and
turnip.
N/A
Occupational handler risks
from mixing and loading
Air
Residues
Dermal
absorption
Acute
Steady state
Neurotoxicity
Consider prohibiting
application of WP (in WSP) to
N/A
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groundboom applications
for: WP (in WSP)
Inhalation
ornamental lawns and turf,
sod farms (turf), and
ornamental woody shrubs and
vines (pre-transplant).
Occupational handler risks
from applying groundboom
applications for: Spray (all
starting formulations)
considered for prohibition or
engineering controls
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application of spray (in all
starting formulations) to corn
(pre-plant).
Consider engineering controls
for application on: Alfalfa,
cotton, sorghum grain, wheat,
radish, turnip, ornamental
lawns and turf and sod farms
(turf).
N/A
Occupational handler risks
from applying groundboom
applications for: Spray (all
starting formulations)
considered for additional PPE
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider double layer
(coveralls), gloves, and an
elastomeric half mask
respirator for: Alfalfa,
sorghum grain, soybean, and
wheat.
Consider double layer
(coveralls), gloves, and
particulate filtering facepiece
for: Brussels sprouts (at plant,
post-plant, and post-
emergence), cauliflower, cole
crops,, grapes (foliar,
dormant, delayed dormant),
mint (peppermint, spearmint),
peanut, pineapple, rutabaga,
strawberries (pre-plant),
sunflower (pre-plant) sweet
potato (pre-plant and soil
broadcast), tobacco (pre-
plant), nursery stock (pre-
Consider requiring single layer
(long-sleeved shirt, long pants) and
gloves for application to corn (pre-
plant), tree nut orchard floors
(pecans, almonds, walnuts), and
cotton (except Mississippi).
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plant), rutabaga, clover
(grown for seed, foliar), hybrid
cottonwood and poplar
plantations and potentially
alfalfa, sorghum grain,
soybean, and wheat.
Consider single layer (long-
sleeved shirt and long pants),
gloves, and an elastomeric
half mask respirator for:
sweet potato (pre-plant and
soil broadcast).
Consider single layer, gloves,
and particulate filtering
facepiece for: Cranberry,
beets (table, sugar; at plant),
clover (grown for seed), and
hybrid cottonwood and poplar
plantations.
Consider single layer and
gloves for the following:
Carrots, asparagus, beets
(table, sugar, at plant), citrus
orchard floors, cole crops
(excludes Brussels sprouts
and cauliflower), cotton,
forest plantings
(reforestation, plantation,
tree farm), grapes (dormant,
delayed dormant), grass
(forage/fodder/hay), legume
vegetables, nonagricultural
outdoor buildings and
structures, onions, peppers,
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strawberries, ornamentals
and/or shade trees,
herbaceous plants,
ornamental woody shrubs and
vines, conifers and deciduous
trees, seed orchard trees,
forest trees (softwoods and
conifers), and golf course
(fairways, tees, and greens).
Occupational handler risks
from airblast applications:
Mixing and loading L/SC/EC
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider requiring
engineering controls for:
Citrus, non-bearing fruit and
nut trees (nursery), and tree
fruits (nectarine, peach -
dormant, delayed dormant).
Consider requiring double-
layer (coveralls), gloves, and
an elastomeric half mask
respirator (PF10) for:
Cherries, tree fruits (pear,
plum/prune (dormant,
delayed dormant), and tree
nuts (almond, filberts,
hazelnuts, pecans, walnuts).
Consider requiring single layer
(long pants and long-sleeved
shirt) and glove for:
Ornamental and/or shade
trees, ornamental woody
shrubs and vines, herbaceous
plants, Christmas tree
plantations, and grapes.
Consider requiring single layer
(long-sleeved shirt and long pants)
and gloves for: Citrus, non-bearing
fruit and nut trees (nursery), tree
fruits (nectarine, peach - dormant,
delayed dormant).
Occupational handler risks
from airblast applications:
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider reducing application
rate from 6.0 lbs a.i./Acre to
4.0 lbs a.i./Acre in Arizona.
N/A
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Mixing and loading DF/WDG
in WSPand WP(inWSP)
Occupational handler risks
from airblast applications:
Applying spray (all starting
formulations)
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider reducing application
rate from 6.0 lbs a.i./Acre to
4.0 lbs a.i./Acre in Arizona.
Consider requiring
engineering controls for all
uses.
N/A
Occupational handler: Seed
treatment for liquid,
microencapsulated, and
wettable powder via WSP to
multiple activities workers
when applied on beans, corn,
and cotton.
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting seed-
treatment for the following
uses and formulations:
• Liquid formulation on
beans, corn, cotton
• Microencapsulated
formulation on beans
• Wettable powder in
WSP on beans and
corn
N/A
Occupational handler: Mixing
and loading, and applying by
tractor-drawn spreader
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application on corn, soybean.
Consider single layer (long-
sleeved shirt and long pants)
and an elastomeric half mask
respirator for alfalfa.
Consider single layer (long-
sleeved shirt and long pants),
gloves, and a particulate
filtering facepiece for:
Rutabaga and sweet potato.
N/A
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Consider single layer (long-
sleeved shirt and long pants),
and a particulate filtering
facepiece for: Asparagus, cole
crops, (excludes Brussels
sprouts and cauliflower),
ginseng, sugar beets,
sunflower, citrus orchard
floors, onions, tobacco,
ornamental lawns and turf,
sod farms (turf), and nursery
stock.
Occupational handler:
Application by tractor-drawn
spreader
Consider requiring double
layer (coveralls), gloves, and
an elastomeric half mask
respirator for: Peanut and
sorghum grain.
Consider requiring double
layer (coveralls) and gloves
for: Citrus orchard floors,
onions, ornamental lawns and
turf, and sod farms (turfs).
Consider requiring single layer
(long-sleeved shirt and long
pants), gloves, and a
particulate facepiece for:
Radish, rutabaga, and alfalfa.
Consider requiring single layer
(long-sleeved shirt and long
pants) and a particulate
facepiece for: Cauliflower
(post-plant), turnip, Brussels
sprouts (post-plant), sweet
potato, cole crops (except
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cauliflower) ginseng, sugar
beets, sunflower, and
tobacco.
Occupational handler: Wide
area mosquito adulticide
applications from mixing,
loading, and applying ground
(airblast surrogate) and aerial
applications.
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider requiring double
layer (coveralls), gloves, and
an elastomeric half mask
respirator for mixers and
loaders.
Consider requiring
engineering controls for
applicators.
Consider requiring gloves and
chemical resistant headgear for
ground (airblast surrogate)
applicators
Consider requiring engineering
controls for aerial applicators.
Occupational handler:
Mechanically-pressurized
handgun applications
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application by mechanically-
pressurized handgun for all
uses except on ornamental
woody shrubs and vines and
seed orchard trees.
Consider requiring double layer
(coveralls), gloves, and a particulate
filtering facepiece respirator
Occupational handler:
Manually-pressurized
handwand
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application to Indoor
commercial, institutional,
industrial premises, food
processing plant premises.
Consider requiring double
layer PPE (coveralls), gloves,
and an elastomeric half mask
respirator (PF10) for wood
treatment and nursery (pine
seedlings).
Consider requiring single layer
(long-sleeved shirt and long
pants), gloves, and a
particulate filtering facepiece
for wide area/general outdoor
treatment.
Consider single layer (long-sleeved
shirt and long pants) and gloves for
Wood protection treatment,
nursery (pine seedlings), wide area/
general outdoor treatment,
Christmas tree plantations, conifers
and deciduous trees; plantation
nurseries, grapes, seed orchard
trees, forest trees (softwoods,
conifers), golf course turf,
mounds/nests, non-agricultural
outdoor buildings and structures,
indoor
commercial/institutional/industrial
premises (see master label
description), food processing plant
premises, ornamental woody shrubs
and vines, ornamental non-
flowering plants, tree fruits
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Consider single layer (long-
sleeved shirt and long pants)
and gloves for: Christmas tree
plantations, conifers and
deciduous trees; plantation
nurseries, grapes, seed
orchard trees, forest trees
(softwoods, conifers), golf
course turf, mounds/nests,
non-agricultural outdoor
buildings and structures,
ornamental woody shrubs and
vines, ornamental non-
flowering plants, outdoor
commercial/institutional/indu
strial premises (see master
label description), agricultural
farm premises, poultry litter,
tree fruits (cherries,
nectarines, peaches,
plum/prunes), tree nuts
(almonds) - pre-plant, tree
nuts (apple) - pre-plant, and
fruits and nuts (non-bearing,
see master label description).
(cherries, nectarines, peaches,
plum/prunes), tree nuts (almonds) -
pre-plant, and tree nuts (apple) -
pre-plant.
Occupational handler:
application by
• Belly grinder
• Brush roller
• Rotary spreader
• Hand dispersal
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application by brush roller and
belly grinder.
Consider prohibiting
application to ornamental
woody shrubs and vines by
rotary spreader.
Consider requiring single layer
(long-sleeved shirt and long
Consider prohibiting brush roller
application for sewer manholes.
Consider requiring single layer
(long-sleeved shirt and long pants)
and gloves for brush roller
application to wood protection
treatment and structural (e.g.,
warehouses, food handling
establishments, home bathrooms)
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pants) and gloves for rotary
spreader application to
nursery stock, golf course turf,
ornamental and/or shade
trees, herbaceous plants,
ornamental lawns and turf,
sod farms (turf).
Consider prohibiting hand
dispersal to commercial/
institutional/industrial/premis
es, utilities (pad).
Consider requiring single layer
(long-sleeved shirt and long
pants) and gloves for hand
dispersal (spo.t treatment) to
golf course (turf), sod farm
(turf).
Consider prohibiting belly grinder
application for ornamental woody
shrubs and vines
Consider prohibiting hand dispersal
to
commercial/institutional/industrial
premises and utilities (Pad)
Occupational handler risks
from backpack sprayer
applications: L/SC/EC
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
application by broadcast (soil
and foliar) and drench/soil-
/ground-directed to:
ornamental and/or shade
trees, herbaceous plants,
outdoor
commercial/institutional/indu
strial premises, non-
agricultural outdoor buildings
and structures, wide area/
general outdoor treatment,
wood protection treatment,
Christmas tree plantations,
tree fruit (cherries), seed
orchard trees, grapes, and
forest trees (softwoods,
conifers)
Consider prohibiting broadcast
(foliar) application with backpack
sprayer of L/SC/EC on ornamental
and/or shade trees, herbaceous
plants.
Consider double layer (coveralls)
and glove for outdoor
commercial/institutional/industrial
premises, non-agricultural outdoor
buildings and structures, and wide
area/ general outdoor treatment.
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Consider limiting broadcast
(foliar) application to golf
course turf with double layer
(coveralls), gloves, and an
elastomeric half mask
respirator.
Consider limiting use on the
following for only spot
treatment with baseline PPE:
ornamental and/or shade
trees, herbaceous plants,
ornamental lawns and turf,
sod farms (turf), outdoor
commercial/institutional/indu
strial premises, non-
agricultural outdoor buildings
and structures, and golf
course turf.
Occupational handler risks
from backpack sprayer
applications: DF/WDG in
WSP
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
broadcast (foliar) or
drench/soil/ground-directed
application to: ornamental
woody shrubs and vines,
Christmas tree plantations,
tree fruits (cherries), tree nuts
(almond), tree fruit
(nectarine, peach,
plum/prune), fruit and nut
(non-bearing, nursery), tree
fruits (apple).
Consider requiring double
layer (coveralls), gloves, and
an elastomeric half mask
respirator for broadcast
Consider prohibiting backpack
sprayer of dry flowable/water-
dispersible granules in WSP for
broadcast (foliar) on ornamental
woody shrubs and vines.
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(foliar) application to grapes
(pre-bloom), trunk
spray/drench to tree fruits
(apple) and drench/soil-
ground directed grapes (pre-
bloom).
Occupational handler risks
from backpack sprayer
applications: WSP
Ait
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting
broadcast use on ornamental
and/or shade trees,
herbaceous plants.
Consider prohibiting backpack
sprayer broadcast application of
WSP on ornamental and/or shade
trees, herbaceous plants
Occupational handler risks
from backpack sprayer
applications: ME
Consider requiring double
layer (coveralls), gloves, and
an elastomeric half mask
respirator for ornamental
non-flowering plants and
ornamental woody shrubs and
vines.
N/A
Occupational handler:
Flagging
Air
Residues
Dermal
absorption
Inhalation
Acute
Steady state
Neurotoxicity
Consider prohibiting flagging
and require use of GPS or
mechanical flagging systems
with the exception of granule
application to sod farms (turf).
N/A
Occupational post-
application risks of concern
Residues
Detmal
absorption
Acute
Steady state
Neuiotoxicity
Consider prohibiting use of
microencapsulated
formulations on ornamentals
in nurseries and greenhouses.
Considering extending REts for
select uses and activities. See
Appendix 01 for potential REI
extensions.
Considering extending REIs for
select uses and activities. See
Appendix D1 for potential REI
extensions.
Proposed Ecological Mitigation
(Wian
Residues on
treated site
Ingestion
Acute
Chronic
Developmental
Reproductive
Application method restrictions are expected to reduce risks to
Mammals
Residues on
treated site
Ingestion
Acute
Chronic
Developmental
Reproductive
liun-idigei uigcmftm*.
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Terrestrial Invertebrates
Residues on
treated site
Dermal
absorption
Ingestion
Acute
Chronic
Acute toxicity
Proposing label changes to reduce off-target spray drift and
establish a baseline level of protection against spray drift that is
consistent across all chlorpyrifos products.
Fish
Water
Dermal
absorption
Ingestion
Acute
Chronic
Acute toxicity
Aquatic Invertebrates
Water
Dermal
absorption
Ingestion
Acute
Chronic
Acute toxicity
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Appendix B: Endangered Species Assessment
This Appendix provides general background about the agency's assessment of risks from
pesticides to endangered and threatened (listed) species under the Endangered Species Act
(ESA). Additional background specific to chlorpyrifos appears at the conclusion of this
Appendix.
In 2013, the EPA, along with the Fish and Wildlife Service (FWS), the National Marine
Fisheries Service (NMFS), and the United States Department of Agriculture (USDA) released a
summary of their joint Interim Approaches for assessing risks to endangered and threatened
(listed) species from pesticides. These Interim Approaches were developed jointly by the
agencies in response to the National Academy of Sciences' (NAS) recommendations that
discussed specific scientific and technical issues related to the development of pesticide risk
assessments conducted on federally threatened and endangered species.
Since that time, EPA has conducted biological evaluations (BEs) on three pilot chemicals
representing the first nationwide pesticide consultations (final pilot BEs for chlorpyrifos,
malathion, and diazinon were completed in January 2017). These initial pilot consultations were
envisioned to be the start of an iterative process. The agencies are continuing to work to improve
the consultation process. For example, after receiving input from the Services and USDA on
proposed revisions to the pilot interim method and after consideration of public comments
received, EPA released an updated Revised Method for National Level Listed Species Biological
Evaluations of Conventional Pesticides (i.e.. Revised Method) in March 2020.50 During the
same timeframe, EPA also released draft BEs for carbaryl and methomyl, which were the first to
be conducted using the Revised Method.
Also, a provision in the December 2018 Farm Bill included the establishment of a FIFRA
Interagency Working Group to provide recommendations for improving the consultation process
required under section 7 of the Endangered Species Act for pesticide registration and
Registration Review and to increase opportunities for stakeholder input. This group includes
representation from EPA, NMFS, FWS, USDA, and the Council on Environmental Quality
(CEQ). Given this new law and that the first nationwide pesticide consultations were envisioned
as pilots, the agencies are continuing to work collaboratively as consistent with the congressional
intent of this new statutory provision. EPA has been tasked with a lead role in this group, and
EPA hosted the first Principals Working Group meeting on June 6, 2019.
Chlorpyrifos was one of the first three pilot chemicals that EPA conducted a nationwide ESA
consultation. EPA completed a biological evaluation and initiated consultation with the FWS and
NMFS in January 2017.51 Pursuant to a consent decree, at the end of December 2017, NMFS
issued its Biological Opinion (BiOp) on chlorpyrifos, diazinon, and malathion.52 In July 2019,
50 https://www.epa.gOY/endangered-species/revised-method-national-level-listed-species-biological-evaliiations-
conventional
51 MMs^wwwjagigg^
52Iltf6Sl//wwwJMieriejjitMi^ov/resffi^^
malathion
81
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EPA re-initiated formal consultation with NMFS on the December 2017 BiOp.53 EPA re-
initiated consultation because new information on how the pesticides were actually being used
may show that the extent of the effects of the actions may be different than what was previously
considered. As part of this re-initiation, EPA provided additional usage data it believes may be
relevant to the consultation. In its transmittal of this information to NMFS, EPA also referenced
usage data and information that had been recently submitted by the registrants of pesticide
products containing chlorpyrifos, malathion, and diazinon. After reviewing information EPA
provided to NMFS on the 2017 BiOp, NMFS determined that it was appropriate to revise the
chlorpyrifos, malathion, and diazinon BiOp. NMFS plans to issue a revised final BiOp for
chlorpyrifos, diazinon, and malathion by June 2022. FWS has not yet issued a BiOp on
chlorpyrifos. EPA plans to address risks to listed species and critical habitats from use of
chlorpyrifos as part of the final registration review decision, pending completion of the
nationwide consultation process.
3s://www.regiilations.gov/docnment?D=EPA-HO-OPP-2Q.1.8-0.1.4.1.-0.1.36
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Appendix C: Endocrine Disruptor Screening Program
As required by FIFRA and FFDCA, the EPA reviews numerous studies to assess potential
adverse outcomes from exposure to chemicals. Collectively, these studies include acute, sub-
chronic and chronic toxicity, including assessments of carcinogenicity, neurotoxicity,
developmental, reproductive, and general or systemic toxicity. These studies include endpoints
which may be susceptible to endocrine influence, including effects on endocrine target organ
histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates,
reproductive loss, and sex ratios in offspring. For ecological hazard assessments, the EPA
evaluates acute tests and chronic studies that assess growth, developmental and reproductive
effects in different taxonomic groups. As part of its most recent registration decision for
chlorpyrifos, the EPA reviewed these data and selected the most sensitive endpoints for relevant
risk assessment scenarios from the existing hazard database. However, as required by FFDCA §
408(p), chlorpyrifos is subject to the endocrine screening part of the Endocrine Disruptor
Screening Program (EDSP).
The EPA has developed the EDSP to determine whether certain substances (including pesticide
active and other ingredients) may have an effect in humans or wildlife similar to an effect
produced by a "naturally occurring estrogen, or other such endocrine effects as the Administrator
may designate." The EDSP employs a two-tiered approach to making the statutorily required
determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a
chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal
systems. Chemicals that go through Tier 1 screening and are found to have the potential to
interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where the
EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data.
Tier 2 testing is designed to identify any adverse endocrine-related effects caused by the
substance, and establish a dose-response relationship between the dose and the E, A, or T effect.
Under FFDCA § 408(p), the agency must screen all pesticide chemicals. Between October 2009
and February 2010, the EPA issued test orders/data call-ins for the first group of 67 chemicals,
which contains 58 pesticide active ingredients and 9 inert ingredients. The agency has reviewed
all of the assay data received for the List 1 chemicals and the conclusions of those reviews are
available in the chemical-specific public dockets. Chlorpyrifos is on List 1 and the review
conclusions are available in the chlorpyrifos public docket EPA-HQ-OPP-2008-0850.54 A
second list of chemicals identified for EDSP screening was published on June 14, 2013,55 and
includes some pesticides scheduled for Registration Review and chemicals found in water.
Neither of these lists should be construed as a list of known or likely endocrine disruptors. For
further information on the status of the EDSP, the policies and procedures, the lists of chemicals,
future lists, the test guidelines and the Tier 1 screening battery, please visit the EPA website.56
54 EDSP Weight of Evidence Conclusions on the Tier 1 Screening for the List 1 Chemicals
https://www. regulations. gov/document?D=EPA~HO~OPP~2008~0850~0849
55 See http://www. regulations. gov/#!documentDetail:D=EP A-HQ-QPPT-2009-0477-0074 for the final second list of
chemicals.
56 https://www.epa. gov/endocrine-dismption
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In this PID, the EPA is making no human health or environmental safety findings associated with
the EDSP screening of chlorpyrifos. Before completing this registration review, the agency will
make an EDSP FFDCA § 408(p) determination.
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Appendix DI: Occupational Post-Application Risks of C oncern1
< !¦¦[!
I'll l!l!ll:i(il-ll.
At i:\ i!> -
\|.p.
Knii1
: 11--
.ii Ai
MOf s
!);i\ !>'
l) f k
M 11:
i 'if.11i¦ >:t
MOf ;
1 siim.in-il KJ !
I'm 1.< >< i'S
\ii M : I'Milli.tlrd
HI 1 K:ll!Lif
Id: t < X I iiif
LC. WP
Hand
Harvesting
1.0
40
AZ
40 at Day 0
48 at Day 1
~S at Day 2
8S at Day 3
120 at Day 4
Berry; Low
Cranberry
LC. WDG
Hand
Harvesting.
Scouting
1.5
26
AZ
26 at Day 0
32 at Day 1
52 at Day 2
58 at Day 3
53 at Day 4
100 at Day 5
Peppermint'
Spearmint
10
CA
10 at Day 0
86 at Day 1
120 at Day 2
Mint
2.0
11
OR
11 at Day 0
110 at Day 1
LC. TOG
Irrigation
3.5
MX
110 at Day 1
110 at Day 1
Grapes. LC
Hand weeding,
scouting
CA
92 at Day 0
390 at Day 1
Grapes. LC
Hand weeding,
scouting
il
CA
11 at Day 0
46 at Day 1
100 at Day 2
Grapes
C ri 3^} e 3.
Hand
harvotina. leaf
pulling.
tying; training
(wine grape)
2.0
6
CA
25 at Day 1
55 at Day 2
63 at Day 3
73 at Day 4
S5 at Day 5
98 at Day 6
110 at Day 7
Grape. LC
Turning (table
grape only*
3
13 at Day 1
29 at Day 2
33 at Day 3
38 at Day 4
44 at Day 5
51 at Day 6
59 at Day ?
69 at Day 8
79 at Day 9
92 at Day 10
110 at Dav 11
85
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Docket Number EPA-HQ-OPP-200S-0850
mvw.regnlatioiis.gov
< i"J!
(>i .mi'
!-•'! >Utll:lf i"ll.
\( iiv in -
K.iii-
dh,
:li VS
MO! s :(!
H:|\ ll"
!>! K
smili
i
MOI :
I\I !
It:«IILit- 1 m ;
!.<>( ii!
MOE; Estimated
RF.I Kiiiijir (days)"
for LOC > 100
Corn: Sweet;
Com: Field.
Including
Grown for Seed
0.8
IL
26 at Day 1
68 at Day 2
1 SO at Day 3
WDG
1.5
1.0
MN
30 at Day 1
66 at Day 2
140 at Day 3
Field and
Row Crop>:
Tall
Detailing,
hand
harvesting}
1.4
OR
54 at Day I
200 at Day 3
Com: Sweet:
Com: Field.
Including
Grown for Seed
WDG
Detassling.
hand harvesting
1.0
1.2
40 at Day 1
ItiO at Day 3
1.5
MN
48 at Day 1
99 at Day 3
220 at Day 4
2.1
OR
81 at Day I
310 at Day 3
Apples,
Cherries.
Peaches. Pear*.
Plums. Primes.
Nectarines
(Dormant and
Delayed
Dormant)
30
CA
4S0 at Day 1
480 at Day 1
15
WA
63 at Day 2
ISO at Day 3
LC for all.
WDG for all.
and WP for
apples only
NY
50 at Day 2
110 at Day 3
Tree Fruit:
Deciduous
Scouting,
pruning.
training
Apples.
Cherries.
Peaches. Pears,
Plums. Prunes,
Nectarine*.
(Dormant and
Delayed
Dormant >
13
CA
200 at Day i
200 at Day 1
2,0
6
WA
26 at Day 2
76 at Day 3
130 af Day 4
LC for all.
WDG for all.
and WP for
apples only
9
NY
21 at Day 2
45 at Da}' 3
96 af Day 4
ISO at Day5
86
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Docket Number EPA-HQ-OPP-200S-0850
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< i"J!
(>i .mi'
i"t >Utll:lf i"ll.
\( iiiii>"
¦M'P-
K.iii-
<11..
:li \»
MO! s :*!
|»:H ll'
H!K
Mijlh
i IK
\5< >1';
K-Uiinid! KI f
K:tiiU<- i i!:i\ -1'
l':.I l.'.M H!
MOE; Estimated
REI Range (d;n -A
for LOC > 100
Hand
harvesting
Apples,.
Cherries.
Peaches. Pears.
Plums. Primes,,
Nectarines
(Dormant and
5
CA
"8 at Day 1
110 at Day 2
Delayed
Dormant)
LC for all,
2
WA
10 at Day 1
30 at Day 2
50 at Day 3
83 at Day 4
140 at Day 5
WDG for ail.
and WP for
apples only
3
NY
8 at Day 1
IS at Day 2
3? at Day 3
69 at Day 4
130 at Day 5
Thinning fruit
Nectarine
(WDG and
eiimlsifiable
51
CA
51 at Day 0
S10 at Day 1
concentrate
(EC)) &
Peaclies (EC)
WA
110 at Day I
110 at Day 1
3.0
(Dormant and
Delayed
Dormant)
NY
35 at Day 1
S4 at Day 1
ISO ar Day 2
Transplanting
Nectarine
(WDG and
emtikifiafale
COiXCeiltl'
-------
Docket Number EPA-HQ-GPP-200S-0S50
www je.®ulatious.sov
[.
(¦ i'i :niii:>(in!i.
,\> 111 ii> "
¦V|*p-
1 lils
;li \)
MOI - ;it
Day « '
IM'K
Mini'.
! "i .tiiiifi
MOI":
I\i- f
li.-lllic iiiiiA \|'
ii> 1 i i )( (if
MOE: Estimated
1\!¦ i 1 i!ii>
for LO< "> 100
(F-C'i Oc
Bench*-< EC)
(Dormant and
Delayed
Dormant)
6
NY
14 at I>ay I
33 tit Day 2
"3 at Day 3
160 at Day 4
Hand
harvestina
Nectarine
{WIXj aud
enmkifiable
3.3
CA
r": .-.r rviv i
71 at Day 3
9"1 at Day 4
130 at Dav 5
concentrate
(EC)) &
Peaches (EC i
3.0
2
WA
~ at Day 1
20 at Day 2
33 at Day 3
56 at Day 4
93 at Day 5
160 at Day 6
(Dormant and
Delayed
Dormant!
Thuuiiuc Suit
2
NY
5 at Day 1
12 at Day 2
25 at Day 3
46 a» Day 4
S5 at Day 5
160 at Day 6
Cherries (Sour)
Transplanting
3S
CA
38 at Day 0
610 at Dav 1
19
WA
19 at Day 0
80 at Day 1
230 at Day 2
26
NY
26 ai Day 0
140 at Day 2
Cherries (Sour)
15
CA
15 at Day 0
240 at Day!
Scouting.
7.5
WA
32 ar Day 1
92 at Day 3
150 at Dav 4
pruning.
training
10
XV
10 at Day 0
25 at Day 2
55 at Day 3
120 at Day 4
6,3
CA
100 at Dav i
100 at Dav 1
Cherries (Sow)
4,0
3.1
WA
13 at Day 1
38 at Day 2
64 at Day 3
110 at Day 5
Hand
harvesting
4.3
NY
10 at Day 1
23 at Day 2
48 at Day 3
89 at Day 4
160 at Day 5
Chenies (Sour)
CA
39 at Day 1
53 at Day 2
7 3 at Day 3
99 at Day 4
140 at Day 5
TMimiug limit
WA
5.1 at Day 1
15 at Day 2
25 at Day 3
42 at Day 4
70 at Day 5
120 at Day 6
88
-------
Docket Number EPA-HQ-OPP-200S-0850
mvw.regnlatioiis.gov
< i"J!
(>i .mi'
< n>|t.
i"l >Utll:lf i"ll.
\( iiv in -
K.iii-
dh,
:li \ !
MO! s :(!
H:|\ ll'
H!K
Mijlh
MOl ;
!\I f
KitllUc '. i!:i\ - i'
l':.I l.'.M H!
MOE; Estimated
Ri i !i:lIliii- si"
for LOC > 100
I."
NY
4 at Day 1
8.8 at Day 2
19 at Day 3
35 at Day 4
64 at Day 5
120 at Day 6
Cimis
LC. WDG
Hand
harvesting
4.0
21:
CA
21 at Day 0
89 at Day 1
200 at Day 2
Citiiii
LC. TOG
86
CA
86 at Day 0
360 at Day 1
Tree Fruit:
Evergreen
Transplanting
Citrus.
LC. VDG
Scouting. Hand
pmniita
6.0
(CA and
' AZi
34
CA
34 at Day 0
140 at Day 1
Citrus
LC. WDG
Hand
harvestins
14
C'A
14 at Day 0
60 at Day 1
130 at Day 2
Hybrid
Cottonwood
Poplar
Plantations
(Dormant and
ISO
CA
ISO at Daj 0
180 at Day 1
S~
WA
ST at Day 0
3 TO at Day 1
Delayed
Dormant)
LC
2.0
NY
21 at Day 0
50 at Day 1
110 at Day 2
Forestry
Scoutine
Hybrid
Cottonwood
Poplar
Plantations
(Dormant and
30
CA
30 af Day 0
480 at Day 1
15
WA
15 at Day 0
63 at Day 1
ISO at Day 2
Delayed
Dormant)
LC
6.3
NY
15 at Day 1
33 at Day 2
7 1 at Day 3
130 at Day 4
Irrigation
89
-------
Docket Number EPA-HQ-OPP-2O08-O85O
www .regulations .gov
< iilj'
< >j'ulfj>
s t"->| J.
\i ii\is\ :
K:\U-
(lis-,
•li \>
\!.n it'
l>i'K
i m
\?OI :
It:«IILit- 1 1:
!.(>( (O
\l< »f : !
Kf i Kall-.ii- ' il;>\ s
for LOC > 100
Hybrid
Cottonwood/
Poplar
Plantations
(Dormant and
Delayed
Dormant)
LC
9
CA
150 at Day 1
150 at Day 1
2,0
4,6
WA
19 at Day i
56 at Day 2
94 at Day 3
160 at Day 4
Irrigation
Almonds
( Dormant and
>7
CA
3 7 at Day 0
76 af Day 1
210 at Dav2
Delayed
45
CA
4 5 af Day 0
730 at Day 1
Dormant)
4.0
1"00
TX
HOG at Day 0
1700 at Day 0
Harvesting
Mechanical
(Shaking)
280
LA
2S0 at Day 0
280 at Day 0
160
GA
160 at Day 0
160 at Day 0
Almonds
tDormant and
Delayed
31
CA
31 at Day 0
63 at Day 1
1 SO at Dav 2
4.0
CA
38 at Day 0
27.000 at Day 1
Tree Nuts2
Dormant1)
14UU
TX
1400 at Day 0
1400 at Day 0
Transplanting
*">'2 A
LA
230 af Day 0
230 af Day 0
150
GA
130 at Dav 0
130 at Day 0
Almonds
('Dormant and
12
CA
12 at Day 0
2 5 af Da}' 1
70 at Day 2
120 at Dav 3
Delayed
4.0
13
CA
15 at Dav 0
240 af Dav 1
Dormant)
560
TX
560 at Dav 0
560 at Day 0
Scouting
92
LA
92 at Day 0
at Day 0
1300 at Dav 1
55
GA
53 at Dav 0
480 at Day 1
Non-bearing
Fruit Trees
(Peach.
Nectarine)
Container
moving, hand
pruning,
tying/training
51
CA
51 at Day 0
810 at Day t
Ornamental
25
WA
25 at Day 0
110 at Day 1
s,- Nurseries
(Outdoor
Only)
3.0
35
NY
35 at Day 0
84 at Day 1
180 at Day 2
Alfalfa (LC.
WDGL
26
CA
26 at Day 0
82 at Day 1
280 at Day 2
Field and
Sovbsan (LC.
1.0
j o
TX
12 at Day 0
340 at Dav 1
Row Crops
WDG j
10
MS
10 at Dav 0
1500 at Dav 1
29
CA
29 at Day 0
380 at Dav i
Scouting
12
TX
12 at Day 0
340 at Dav I
90
-------
Docket Number EPA-HQ-GPP-200S-0S50
www je.®ulatious.sov
[.
{¦ i>!
\> 111 ii> "
A|.|i.
l\:!!c
1 lils
;li
MOI - ;it
Day « '
IM'K
Mini'.
! "i .tiiiifi
MOI":
I\i- f
li.-lllic iiiiiA \|'
ii> 1 i i )( (if
MOE: Estimated
K!¦ i 1 i!ii>
for LOt "> 100
38
AZ
38 ar Day 0
210 at Day 1
Alfalfa
15
CA
15 at Day 0
47 at Day 1
160 at Day 2
6.9
TX
6.9 at Day 0
200 at Dav 1
LC. WDG
6
MS
6 ar Dav 0
890 at Day 1
17
CA
1 ar Dav 0
220 at D.w 1
Irrigation
1
IX
370 at Day t
3?0 at Day I
.42
22 at Day 0
120 at Dav 1
Pepper
WDG
26
CA
26 at Day 0
82 at Day 1
280 at Day 2
12
IX
12 at Day 0
340 at Day 1
Hand
harvesting,
tying
10
MS
10 at Day 0
1500 at Day 1
29
CA
29 at Day 0
380 at Day I
Vegetable:
I U
| 7
TX
12 at DavO
840 at Day 1
Fraitiiig
38
A/.
3S at Day 0
210 at Dav 1
Pepper
IS
CA
15 at Day 0
4? at Day 1
160 at Dav 2
TOG
6.9
IX
200 at Day 1
200 at Dav 1
5.6
MS
890 at Day 1
890 at Dav 1
Inigatioii
17
CA
17 at Dav 1
220 at Day I
7
TX
370 at Day 1
370 at Dav 1
Broccoli (WP.
WDG).
Brussels sprouts
(LC. WP.
WDG). cabbage
(WP. WDG)"
cauliflower
fWP. WIX,>
40
40 at Day 0
-IS at Day 1
78 at Day 2
SS at Day 3
120 at Day 4
Hand Weeding
Vegetable:
Head and
Steal
Brassica
Broccoli (WP.
WDG).
Brussels sprouts
(LC. WP.
WDG), cabbage
(WP. WDG).
cauliflower
iWP. WDG)
Inigatioii
1.0
23
A/.
23 at Day 0
2S at Day 1
45 at Day 2
51 at Day 3
72 ai Day 4
89 at Day 5
110 at Day 6
Broccoli i WP.
WDG).
Brussels sprouts
(LC. WP.
WDG). cabbage
(WP. WDG).
10
AZ
10 at Day 0
13 at Day 1
20 at Day 2
23 at Day 3
33 at Day 4
40 at Day 5
49 at Day 6
61 at Day 7
91
-------
Docket Number EPA-HQ-GPP-200S-0850
www je.®ulatious.sov
< ! nil
< >i
[.
f-.'i
\i in ii\ ¦
Apii.
K:i(o
1 lit";
;li V:
MOl s :tl
i).n i!
m k
^iinu
MOI :
1 Mim.m >1 KI 1
i\:l llm1 ! i i :s> >¦>1
i..! i.or id
\|Of : | si>iii:iicil
Kf I Kunv;!- 'il:i\s
forLOC • ! 'id
cauliflower
(WP. WDG)
Scouting, hand
harvesting;
75 at Day 8
92 at Day °
110 at Day 10
Collards (WP.
WDG). Bok
Clioy t WP),
Kale (WP.
WDG).
Kohlrabi (WP.
WDG)
40
\Z
40 at Day 0
4S at Day 1
~8 at Da y2
SS at Day 3
120 at Day 4
Vegetable:
Leafy
Hand
harvesting
1.0
Collards (WP.
WDG). Bok
Clioy (WP).
Kale ("WP.
WDG").
Kohlrabi (WP.
WDG)
Irrigation
AZ
23 at Day 0
28 at Day 1
45 at Day 2
51 at Day 3
"2 at Day 4
89 at Day 5
110 at Day 6
Cole Crops:
Including
Brussels sprouts
(LC> and
cauliflower
CEO
AZ
16 at Day 0
48 at Day 1
78 at Day 2
88 at Day 3
120 at Day 4
Hand weeding
Vegetable,
leafy
Cole Crops:
Including
Brussels sprouts
(LC) and
cauliflower
(EC)
Irrigation
2,0
II
AZ
11 at Day 0
28 at Day 1
45 at Day 2
51 at Day 3
72 at Day 4
89 at Day 5
110 at Day 6
Cote Crops:
Including
Brussels sprouts
(LC) and
cauliflower
(EC)
Hand weeding,
topping
5
AZ
13 at Day 1
20 at Day 2
23 at Day 3
33 at Day 4
40 at Day 5
49 at Da}' 6
61 at Day ~
75 at Day S
92 at Day 9
110 at Day 10
Cotton
Cotton
1.0
31
CA
31 at Dav 0
100 at Dav 1
92
-------
Docket Number EPA-HQ-OPP-200S-0S50
www j-eanlations .gov
< iilj'
< >j'ulfj>
s t"->| J.
! ¦..'! Dmhii'ij.u
\i ti\is\ :
K:\U-
(lis-,
.li \>
MOEs at
Day Cr
!>i K
\?OI :
I\I !
It:«IILit- 1 1:
S'..! !.(>( i (¦
MOE; Estimated
RE I Range (days)"
for LOC > 100
LC. WPG
15
TX
15 at Day 0
420 at Dav i
12
MS
12 at Day 0
1900 at Day 1
Module builder
36
CA
36 at Dav 0
470 at Day 1
operator
14
TX
3 4 at Dav 0
780 at Dav 1
4 f
AZ
4" at Dav 0
260 at Day 1
Cotton
12
CA
12 at Day 0
38 at Day 1
130 at Dav 2
6
TX
160 at Day 1
160 at Dav 1
LC. WDG
4
MS
"10 at Day 1
710 at Day !
14
CA
14 at Day 0
180 at Day 1
Picker operator.
5
TX
290 at Day 1
290 at Dav I
raker
IS
AZ
1S at Day 0
98 at Day 1
420 at Day 2
Cotton
6
CA
18 at Day 1
6 i at Day 2
91 at Day 3
140 at Dav 4
LC. WDG
3
TX
"75 at Day 1
190 at Day 2
2
MS
340 at Day 1
340 at Dav 1
Tramper
6
CA
84 at Dav 1
130 at Dav 2
3
TX
140 at Dav 1
140 at Dav 1
8
AZ
48 at Day 1
200 at Dav 2
CA (Very
high
exposure
activities)
40 at Day 0
130 at Day 1
Turf giow n for
sod or seed
56
IN (Very
high
exposure
activities)
56 al Day 0
300 at Dav 1
Turf grass
LC. WP
Maintenance
harvesting slab,
iransplanfing.-pl
anting
3.76
34
MS (High
exposure
activities)
34 at Day 0
560 at Day 1
21
CA (High
exposure
activities)
21 at Day 0
130 at Day t
8
IN (High
exposure
activities)
30 at Day 1
100 at Day 2
14
MS (High
expos ore
activities)
1.4 at Day I
130 ai Day 1
Micr<»«'iH i)i)suliii(*(l F'oi tnuiiHion Application
Nursery
(Microenca
P.
Om;uneiital> —
Nurseries and
Greenhouses
1.4
"74
Ornament
als-
suiooth
74 at Day 0
120 at Day 0.33
40 at Day 1
29 at Day 2
260 at Day 3
93
-------
Docket Number EP A-HQ-GPP-2008-08 50
www j-e.aulatious.sov
< ! nil
< >i
t-.'!
\l in iiV:
1\ .!?¦--
i liiN
;li \)
MO! s :ii
1 >-!> 0"
IM U
! <>-. .Ui'Ul
MOI :
! I-!! !
iii'.iw'
l"'.| !.(>< 3 if
MOI*.: Estimated
RE I RjuijiP (days)"
for LOC > 100
Formulation
Container
moving, hand
pruning,
pinching.
50
Ornament
ak- hairy
50 at Day 0
140 at Day 1
tvinii/'trmnuia
Ornamentals -
Ornament
5 at Day 1
Nurseries and
Greenhouses
9.0
als-
smooth
4 at Day 2
32 at Day 3
Over 35 days: MOE =
30 or less at Day 35
Omameii!
ais- liairy
Irrigation
6
1? at Day i
Ornamentals -
Nurseries and
Greenhouses
Hand harvest,
cut flower
3.6
Oiuament
al»-
smooth
2 at Day 1
1 at Day 2
12 al Day 3
Over 35 days: MOE -
12 or less, at Day 35
i
Ornament
ak- hairy
~ at Day i
~ at Day 2
Sat Day 3
13 at Dav 4
Grvcnhotue
Ornamentals -
Liquid
Concentrates
10
CA
I Oat Day 0
86 at Day 1
120 at Day 2
Commercial
Ornamentals.
11
OR
11 at Day 0
110 at Day I
Greenhouse
Production:
Beddins Plants..
Cut Flowers.
Flow ei ma
Hanging
Baskets. Potted
Greenhouse
Flowers.
(Total
Ornamentals.
3.5
MN
110 at Day 1
110 at Day 1
Release
Trees sad
Fogaer and.
Shrubs - Total
Liquid
Release
Concentrate
Faggeis
Formulation
<»)
Irrigation
handset
Oniamentals -
48 at Day 2
Liquid
Concentrates
3 7
CA
34 at Day 1
69 at Day 3
98 at Dav 4
Commercial
140 at Day 5
Ornamentals.
Greenhouse
4.3
OR
42 at Day 1
350 at Day 2
Production:
Bedding Plants.
Cut Flowers.
Flowering
1.4
MN
44 at Day 1
68 at Day 2
100 at Day 3
Hanging
94
-------
Docket Number EPA-HQ-OPP-200S-0850
mvw.regnlatioiis.gov
< i"J!
(>i .mi'
i"l lUtllaf i"ll.
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K.su-
iii-
MOl s a!
Day 03
H!K
Mijlh
MOl ;
!!-!ininsi-i5 KI f
KailUc '. i!:i\ - i'
MOE; Estimated
REI Range (d;«vs)?
for LOC > 100
\( iiv in -
:lj \t
\ m
l':.I l.'.M 10
Baskets. Ported
Flowers,
Ornamentals.
Trees and
Shrubs — Total
Release
Foggers
Hand
harvesting
flowers
Ornamentals -
Liquid
Concentrates
Commercial
Ornamentals.
Greenhouse
Production.
Bedding Plants.
Cut Flowers.
Flowering
Hanging
Baskets. Potted
0.29
18
Omameiit
als- hairy
IS at Day 0
44 at Day 1
140 at Day 2
Flowers.
Ornamentak
Trees and
Shrubs
Total release
aerosol foeeer-,
Haiid harvest
cut flowers
< >1 i '.'lilmu-
^
Greenhouse
nursery
5.0
CA
45 at Bay 1
64 at Day 2
91 at Day3
130 at Dav 4
Irrigation
handsel
5.7
OR
56 at Dav 1
460 at Day 2
1.9
MN
59 at Day 1
90 at Day 2
140 at Day 3
Greenhouse
nursery
2.0
•*) A
CA
1S at Day 1
25 at Day 2
36 at Day 3
51 at Day 4
Greenhouse
73 at Day 5
nursery
100 at Dav 6
Hand harvest
2.2
OR
22 at Day 1
ISO at Day 2
36 at Day 2
0.7
MN
23 at Day 1
55 at Day 3
84 at Day 4
95
-------
Docket Number EPA-HQ-OPP-200S-0S50
www .regulations.gov
< !m|i
'. lo|l.
{>>( lilMUiii'll.
\i. Ii\ iiy;
App.
Rats'
(IliS
af/A)
MOt s :•!
!>:l' ir
Mi 1\
MO! :
>1 K1 !
K.-lllUi' !'I;A *l'
i'=>l i i H in
MOE: Estimated
Kf i ftnniii- ul.i\ -.r
for LOC > 100
130 at Day 5
'Range of MOEs is dependent on study used. See Appendix 11 for Ml range of occupational post-application risk
estimates. -
- Formulations: EC = eimikifiable concentrate. L€ = liquid concentrate. WDG = water dispersed pndv, WP =
wettable powder
3 Dermal l.OC = 10
4 Dermal LOC = 100
96
-------
Docket Number HP A-HQ-GPP-200S-0S50
www.regulations. gov
Appendix 1)2: Considered Mitigation for Occupational Post-Application
Risks ot ( oncern'
{ ( lip
< il'lillp
Crop.
E'ot
Activity1
Viij). K:iii'
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Ml :il
0:i\ i'
i>! K
Siijih
( 11; 11!
i\ i1 1 i il:ii s 1
i'i.i UK <,i'
10'
< mi\iil» i ¦.'(!
Kill d;j* ^ i lot'
[.( X i'i' lilt'""
Strawberry.
LC, WP
Hand Harvesting
1.0
40
N/A
Day 5: SS
Day 4: 120
Bern': Low
Cranberry
AZ
LC, WDG
Hand Harvesting
(raking); scouting
1.5
26
X A
Day 4: S3
Day 5-100
Peppermint; Speann
int
10
CA
N.-A
Day 1: 56
Day 2:120
Mint
2.0
11
OR
N'A
N-A
LC. WDG
Irrigation
3.5
MN
N*A
N.-A
Grapes. LC
Hand weeding.
scouting
11
CA
n;a
Day 2: 106
Grapes
Grapes. LC
Hatid harvesting,
leaf putting,
tying, training (wine
grape)
2.0
6
N.'A
Day 4: 73
Day 5: 85
Day 6: 98
Day"1: 110
Grape. LC
Tun ting (table
.grape onlyi
3
CA
N/A
Day 9: ?9
Day 10: 92
Day 11: 110
Com: Sweet; Com:
Field. Including
Grown for Seed
0,8
IL
N'A
Day 3: 180
Field and
Sweet and Field
Com (including
grown for seed)
(LC).
Sunflower,
sorghum (LC.
WDG)
1.0
MM
N'A
Day 3:140
Row Crops:
Tail
1.5
1 4
uR
N-A
Day 2: 200
-------
Dockei Numhei FPA-IIQ-()PP-2(i0S-08-0
www.regulations, gov
t 1 :iji
< . if i! IJ >
' i'Mt.
i ill 'Hi 1l!:i 1 i! Hi.
Vi-sh if ¦- ¦
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\lur- ;»r
!>:l> H
!>! K
i
Hi 1
I'.M i < K
1(>'
( Olltillt'l i't .if ion"
Detassiing, hand
harvesting (corn
onhr)
Cora: Sweet, Corn:
Field. Including
Grown for Seed
Sweet and Field
Com (including
grown for seed)
t L.C L
Sunflower,
sorghum (LC,
WDG)
Detassiing. hand
harvesting (com
only)
I
II.
N A
Day 2. 100
1.0
1,5
MN
N A
Day 2: 99
Day 3: 220
N'A
Day 1: 81
Day 2:310
Apples, Cherries.
Peaches. Pears.
Plums, Prunes.
30
CA
N/A
N'A
Nectarines
(Dormant and
Delayed Dormant)
LC for all, TOG
2,0
1
WA
NA
Day 1: 63
Day 2: ISO
lor all. and WP for
apples only
Scouting, pinning,
training
21
NY
N'A
Day 2:110
Tree Fruit:
Deciduous
Apples, Cherries.
Peaches, Pears.
Plums. Prunes,
Nectarines
(Dormant and
Delayed Dormant )
13
CA
N/A
N.'A
2 0
6
WA
N/A
Day 2: "6
Day 3:130
LC for all WDG
for all and WP for
apples only
9
NY
N'A
Day 3: 96
Day 4: ISO
Hand luuvestnu
Apples. Cherries.
Peaches, Pe.us,
Plums, Praties,
Nectarines
(Dormant and
Delayed Dormant)
2.0
5
CA
N'A
Day 2: 110
98
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Docker Nuinbei EP A-JtQ-OPP-2008-0850
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LC for all, WDG
2
WA
N/A
Day 4: 83
Day 5: 140
for all, and WP for
apples only
3
XY
Day 1:S
Day 2; 18
Day 5: 130
Thinning: fruit
Nectarine (WDG
and EC) & Peach
(EC I
51
CA
X A
X A
(Dormant and
Delayed Dormant)
Transplanting
3.0
25
WA
N'A
X A
35
NY
N. A
Day I: 84
Day 2: ISO
Nectarine (WDG
and enmlsifiable
concentrate (ECl)
& Peaches (ECl
20
CA
N, A
Day 1: 320
10
WA
N:A
Day 2: 120
(Dormant and
Delayed Dormant!
3.0
NY
N;'A
Day 2: "3
Day 3: 160
Scooting, pruning,
training
Nectarine (WDG
and eomlsiliable
concentrate (ECl)
& Peaches (EO
(Dormant and
Delayed Dormant i
8.4
CA
N A
N A
4
WA
N; A
Day 3. S5
Dav 4: 140
3.0
6
NY
N/A
Day 3: 64
Day 4: 120
Hand harvesting
Nectarine (WDG
and eauikifiable
3.3
CA
N/A
Day 3; 97
Dav 4: 130
concentrate (EC)J
& Peaches (EC)
WA
Day 1: 7
Day 2; 20
Day 5: 93
Day 6- 160
(Dormant and
Delayed Dormant)
3.0
2
NY
Day 2; 1.2
Day 5: 85
Day 6: 160
'Dunning truir
Cherries (Sour)
Transplanting
38
CA
N'A
N/A
19
WA
N'A
Day 1: SO
Day 2: 230
4.0
26
NY
N'A
Dav 2; 140
Cherries (Sow)
C A
N/A
N'A
99
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Activity3
Apj). i\;li;¦
¦>
!>!'!<
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i% i 1 ..J:lW
t'ol 1 < X ..i'
10?
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K i ! i • -1 t"ni
l .f i»f \on"
22
AZ
N/A
NA
Pepper
CA
N/A
Day i: 82
Day 2- 280
WDG
12
TX
N/A
NA
Field and
10
MS
N/A
NA
Row Crops:
Hand harvesting,
lying
29
CA
NA
NA
Low to
1.0
I"*
TX
NA
N A
Medium
38
AZ
N A
N-A
(Outdoor
Only i
Pepper
15
CA
N'A
Dav 2: 160
6.9
TX
NA
NA
WDG
5.6
MS
V A
NA
r
CA
X A
NA
Irrigation
*7
TX
N'A
N A
Pepper
26
CA
NA
n,i> i >2
!>»-¦ 2' 2N"
WDG
12
TX
NA
N A
10
MS
N/A
N A
Hand harvesting,
tying
29
CA
N'A
N A
Vegetable:
1.0
12
TX
NA
N A
Fnuring
38
AZ
NA
Ni-A
Pepper
15
CA
NA
Day 2: 160
6.9
TX
N A
N A
WDG
5.6
MS
N A
N/A
1-
CA
N'A
N'A
Irrigation
**
IX
NA
N A
Broccoli (WP,
WDG). Brunei*
sprouts (LC. WP.
WDG). cabbage
{WP. WDGV
cauliflower (WP.
WDG)
AZ
NA
Day 2: "S
Day 3: SS
Day 4: 120
Hand Wecdtua
Vegetable:
Head and
Stem
Brassica
Broccoli (WP.
WDG). Brussels
sprouts (LC. WP.
WDG), cabbage
iwp. wdgl
cauliflower f \YP.
WDG)
Irrigation
1.0
AZ
\ \
Day 4: "2
Day 5: 89
Day 6: 110
Broccoli (WP.
WDG). Brussels
sprouts (LC. WP,
WDG). cabbage
(WP. WDG).
10
A/
NA
Day S: 75
Day 9: 92
Day 10: 110
102
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Picker operator,
raker
18
i\Z.
N'A
Day 1: 9Ł
Dav 2:420
6
CA
NrA
Day 3: 91
Day 4: 140
Cotton
3
TX
NA
Day i: 75
Day 2: 190
LC. WDG
2
MS
N-'A
K'A
Tramper
6
CA
N-'A
Day 1: 84
Dav 2: 130
3
TX
N/A
N.'A
8
AZ
N/A
Day 2: 200
Fot intihiliou Application
Ornamentals -
Nurseries and
Greenhouses
Ornament
als-
smooth
N-'A
Day 0.33: 120
Day 1: 40
Day 2: 29
Dav 3: 260
Container moving,
kind pruning,
pinching.
tyiag'traiiiing
Ornament
a Is- hairy
N-'A
N'A
Nurserv
Ornamentals -
9.0
Ornament
als-
smootli
Day 1:5
Day 2; 4
Dav 3: 32
Proposed
cancelling use
of
(Microeuca
p.
Formulation
si
Nurseries aud
Greenhouses
Irrigation
1.4
6
Ornament
a Is- haky
Day 1: 17
inkroeneapsulaf
ed tomml.ttions
in nurseries
MOE = 30 or
less at Dav 35
Ornamentals -
Nurseries and
Greenhouses
Hand harvest, cut
flower
3.6
Ornament
als-
SlHOOfll
Day 1: 2
Day 2: 1
Day 3:12
Proposed
cancelling use
of
2
Ornament
als- hairy
Day 1: 7
Day 2: 7
Day 3: S
Day 5: 13
microencapsulat
ed formulations
in irai-,series
MOF. = 12 or
less at Day 35
Greenhouse
Greenhouse
(Total
Ornamentals -
Liquid
Concentrates
10
CA
N/A
Day 1: 86
Day 2: 120
Release
Fogger and,
Liquid
Concentrate
Formulation
s>
Commercial
Ornamentals.
Greenhouse
2
It
OR
N-'A
N A
Production:
Bedding Plants.
Cut Flowers.
Flowering Manama
3.5
MN
N< A
\*,A
104
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Dockei Numhei FPA-IIQ-()PP-2(i0S-08-0
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A|'|j i-i.'ir:¦
{lbs si/A)
MO.Es at
Day 0
!>! K
'Miuti
i in
Hi 1 nlnw
l'..l i « K
( Olltillt'l i'1 .if l"n
Baskets, Potted
Flowers,
Ornamentals. Trees
and Shrubs - Total
Release Foggers
Irrigation handset
Ornamentals -
Liquid
Concentrates
Commercial
Ornamentals,
Greenhouse
Production:
Bedding Plants,
Cut Flowers,
Flowering Hanging
Baskets. Potted
Flowers.
Ornamentals. Trees
and Shrubs - Total
Release Foggers
Hand harvesting
flowers
3.7
CA
N/A
Day 4r 98
Day 5: 140
4.3
OR
N-'A
Day 2:350
1.4
MN
N/A
Day 3; 100
Ornamentals. -
Liquid
Concentrates
Commercial
Ornamentals.
Greenhouse
Production;
Bedding Plants.
Cut Flowers,
Flowering Hanging
Baskets. Potted
Flowers.
Ornamentals. Trees
and Shrubs
Total release
aerosol loggers.
Hand harvesting
(flowers)
0.29
18
Ornament
als- hair}'
N/A
Day 2: 140
( ¦! i OvhI!
Greenhouse
nursery
Greenhouse
aiirsery
> fx
5.0
IA
N A
Day 3: 91
Pay 4: 130
105
-------
Docket Number EPA-HQ-GPP-2008-0S50
mvw .regulations, cov
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Crop.
In! Ill!i!;!i.
Acrivitv'
ii'li- iii \i
MOEs ;»f
Day 0
i>! R
Muili
! i"
Ri i
iiM 1 <)i ill'
I"'
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Kill i«:i\ "0 !"i
1 t>t t.f nui"'
5,7
OR
MA
Dav 2;460
Irrigation handset
19
MN
N/A
Day 2- 90
Day 3: 140
Greenhouse
2.0
CA
N'A
Day 51 73
Day 6: 100
nursery
1 "s
OR
V A
Day 2: 180
Hand harvest
0."
MN
N'A
Day 4. 84
Dav 5: 130
'Risk estimate-, may be fooucli J,*.! •..' 1_- 1" iT."
- Formulation1-; EC = emiiMtlable concentrate. LC = liquid concentiate. WDG = water dispersed gramilai WP =
wettable powder
3N, A = RE I of 24 hours is protective of risks of concern,
106
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