Docket Number EPA-HQ-OPP-2013-0250
www.regulations.gov

Propazine
Proposed Interim Registration Review Decision
Case Number 0230
December 2019
Approved by:

Elissa Reaves, Ph.D.
Acting Director
Pesticide Re-evaluation Division
Date:
12-18-2019

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Table of Contents
I.	INTRODUCTION	3
A.	Summary of Propazine Registration Review	4
B.	Summary of Public Comments on the Draft Risk Assessments and Agency Responses 5
II.	USE AND US AGE	6
III.	SCIENTIFIC ASSESSMENTS	6
A.	Human Health Risks	6
1.	Risk Summary and Characterization	7
2.	Human Incidents and Epidemiology	9
3.	Tolerances	9
4.	Human Health Data Needs	10
B.	Ecological Risks	10
1.	Risk Summary and Characterization	11
2.	Ecological Incidents	12
3.	Ecological and Environmental Fate Data Needs	13
C.	Benefits Assessment	13
IV.	PROPOSED INTERIM REGISTRATION REVIEW DECISION	14
A.	Proposed Risk Mitigation and Regulatory Rationale	14
2.	Mandatory Spray Drift Reduction	14
3.	Non-target Advisory Statement	15
4.	Herbicide Resistance Management	15
5.	Label Cleanup	16
6.	Expected Impacts of Proposed Mitigation	16
B.	Tolerance Actions	18
C.	Proposed Interim Registration Review Decision	19
D.	Data Requirements	19
V.	NEXT STEPS AND TIMELINE	19
A.	Proposed Interim Registration Review Decision	19
B.	Implementation of Mitigation Measures	20
Appendix A: Summary of Proposed Actions for Propazine	21
Appendix B: Proposed Labeling Changes for Propazine Products	22
Appendix C: Endangered Species Assessment	26
Appendix D: Endocrine Disruptor Screening Program	28
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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 propazine (PC Code 080808, case 0230), 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 require new risk mitigation measures, impose 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 propazine can be found in the EPA's public docket (EPA-HQ-OPP-
2013-0250) 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 propazine so that it can (1) move forward with aspects of the
registration review that are complete and (2) implement interim risk mitigation (see Appendices
A and B). The agency is currently working with the U.S. Fish and Wildlife Service and the
National Marine Fisheries Service (collectively referred to as, "the Services") to develop
methodologies for conducting national threatened and endangered (listed) species assessments
for pesticides in accordance with the Endangered Species Act (ESA)  7. Therefore, although the
EPA has not yet fully evaluated risks to federally-listed species, the agency will complete its
listed species assessment and any necessary consultation with the Services for propazine prior to
completing the propazine registration review. Likewise, the agency will complete endocrine
screening for propazine, pursuant to the Federal Food, Drug, and Cosmetic Act (FFDCA) 
408(p), before completing registration review. See Appendices C and D, respectively, for
additional information on the listed species assessment and the endocrine screening for the
propazine registration review.
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Propazine is an herbicide with products registered for use to control broadleaf and grass weeds. It
is a member of the triazine chemical class, which includes atrazine and simazine and the three
major chloro-metabolites: desethyl-s-atrazine (DEA), desisopropyl-s-atrazine (DIA), and
diaminochlorotriazine (DACT). Of the three major triazine chloro metabolites, only DEA and
DACT are metabolites of propazine. The EPA has determined that the triazines and their
degradates share a common mechanism of toxicity, and as such, human health risks were
assessed together through a triazine cumulative risk assessment. Each of the triazines produces a
hydroxy degradate (i.e. hydroxypropazine) that has a different mode of action from the parent
and major chloro-metabolites. Pesticide products containing propazine are registered for use on
grain sorghum and containerized ornamental plants grown in greenhouses. There are no
registered residential uses of propazine. The first product containing propazine was registered in
1998, and therefore propazine was not subject to reregi strati on which was the process to re-
evaluate pesticides registered prior to November 1, 1984. There is one technical and end-use
registrant for propazine: Albaugh, LLC.
This document is organized in five sections: the Introduction, which includes this summary and a
summary of public comments and the EPA's responses; Use and Usage, which describes how
and why propazine 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 case.
A. Summary of Propazine Registration Review
Pursuant to 40 CFR  155.50, the EPA formally initiated registration review for propazine 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 propazine.
	June 2013 - The Propazine Preliminary Work Plan (PWP) (June 2013); Atrazine,
Propazine, and Simazine. Human Health Risk Scoping Document in Support of
Registration Review (June 2013), and Registration Review: Problem Formulation for
Environmental Fate and Ecological Risk, Endangered Species, and Drinking Water
Assessments for Propazine (May 2013) were posted to the docket for a 60-day public
comment period.
	January 2014 - The Propazine Final Work Plan (FWP) was issued. The agency received
two sets of public comments concerning the PWP from the technical registrant for
propazine, Albaugh, Inc., and the FIFRA Endangered Species Task Force (FESTF). The
comments did not result in a change to the schedule, risk assessment needs, or anticipated
data requirements in the FWP. In the PWP, the EPA also solicited comments about the
specific topics of environmental justice, water quality concerns, and trade irritants, but no
comments or information were received concerning those issues.
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	May 2014 - A Generic Data Call-In (GDCI) for propazine was issued for data needed to
conduct the registration review risk assessments (GDCI-080808-1371). All data were
submitted, and the GDCI is satisfied. A subsequent GDCI was issued on December 2018
requiring multiresidue testing (OSCPP 860.1360) for propazine and its chloro
metabolites: G-30033 (DEA) and G-28273 (DACT). This study was determined to be
acceptable, and the GDCI is satisfied.
	June 2016 and July 2018 - The agency announced the availability of Preliminary
Ecological Risk Assessment for Registration Review of Propazine and Propazine. Draft
Human Health Risk Assessment for Registration Review, respectively for public comment
periods. 1,225 comments specific to propazine were received during the comment
periods. These comments and the agency's responses are summarized below. The
comments did not change the risk assessments or registration review timeline for
propazine.
	December 2019 - The agency has completed the PID for propazine. The EPA will
announce the availability of the PID in the propazine docket and open a 60-day public
comment period. Along with the PID, the following documents will also be posted to the
propazine docket:
o Atrazine, Simazine, Propazine: Response to Public Comments on Registration
Review Human Health Risk Assessments, November 21, 2019
o Propazine - EFED Response to Public Comments Received on the Preliminary
Risk Assessment for Registration Review, November 21, 2019
o Atrazine and Propazine Use on Grain Sorghum and Fallow Areas: Response to
Comments, Usage, Benefits, and Impacts of Potential Mitigation, November 25,
2019
B. Summary of Public Comments on the Draft Risk Assessments and Agency
Responses
During the public comment periods for the Preliminary Ecological Risk Assessment for
Registration Review of Propazine, which opened on June 6, 2016 and closed on October 5, 2016
and for the Propazine. Draft Human Health Risk Assessment for Registration Review, which
opened on July 26, 2018 and closed on November 23, 2018, the agency received comments
specific to propazine from approximately 1,225 sources. Most comments (approximately 1,220)
were submitted as part of a mass mailing campaign in support of propazine use on sorghum. In
addition to the mass mailing campaign, comments were submitted by the propazine technical
registrant (Albaugh, LLC), the U.S. Department of Agriculture (USD A), sorghum and
agricultural farmers, and citizens. Albaugh, LLC provided comments of a technical nature about
the draft risk assessments and the benefits of propazine. The USDA and sorghum/agricultural
farmers provided comments in support of propazine use and information about its use and usage,
and benefits for sorghum. Other public comments submitted to the propazine docket included
comments for or against triazine use (some of which mention propazine; others were specific to
simazine and atrazine only), and generic comments about pesticides not related to the triazines or
propazine.
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Comments of a technical nature concerning the draft propazine risk assessments, use and usage,
or benefits of propazine are summarized and addressed in the Atrazine, Simazine, Propazine:
Response to Public Comments on Registration Review Human Health Risk Assessments,
Propazine - EFED Response to Public Comments Received on the Preliminary Risk Assessment
for Registration Review; and Atrazine and Propazine Use on Grain Sorghum and Fallow
Areas: Response to Comments, Usage, Benefits, and Impacts of Potential Mitigation. For
additional details please refer to these documents which will be posted on the propazine
registration review docket (www.regulations.gov). The agency thanks all commenters for their
comments and has considered them in developing this PID.
II. USE AND USAGE
Propazine is a selective herbicide that is grouped by the Weed Science Society of America with
other triazines in Class 5. Propazine has residual activity and can prevent weeds from emerging
for several weeks. The primary target pests based on pesticide Market Research Data and
extension literature are pigweed species.
Sorghum is the only crop that has recorded propazine use. Based on the available pesticide usage
data, growers apply propazine to 4% of the sorghum crop and treat a total of 308,800 acres. The
average number of applications per year is slightly over one application and the average single
application rate is 0.707 pounds of active ingredient per acre.
Most sorghum growers apply propazine before crop emergence (80% of acres treated). Propazine
can be applied by ground equipment or by air. Propazine was annually applied by air to an
average of 1,200 acres over the years 2013-2017, all in Texas and Kansas. All aerial
applications were done with liquid formulations.
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 propazine. The EPA has made a determination of a
common mechanism of toxicity for propazine, atrazine, and simazine (the triazines) and their
chlorinated metabolites. Therefore, in addition to assessing potential risk from propazine, the
EPA evaluated the potential cumulative risk from combined exposure to the triazines and their
metabolites. For additional details on the human health assessments, see the Propazine Draft
Human Health Risk Assessment for Registration Review and the Chlorotriazines: Cumulative
Risk Assessment: Atrazine, Propazine, and Simazine, which are available in the public docket.
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1. Risk Summary and Characterization
There are no dietary, residential (handler and post-application), non-occupational bystander, or
occupational post-application risk estimates of concern for the registered uses of propazine.
Occupational handler (combined dermal and inhalation exposure) risk estimates of concern with
baseline attire and label-specified PPE (chemical resistant gloves) were identified for some
worker scenarios for the greenhouse ornamental use. See below for details.
Dietary (Food + Water) Risks
There are no anticipated food exposures to propazine. Based on available food consumption
survey data and pesticide field trial residue studies, human exposure to propazine residues from
sorghum use is considered negligible1. With insignificant exposure to propazine in food expected
from the current uses, the total dietary exposure to propazine and its metabolites is through
drinking water. A drinking water level of comparison (DWLOC) approach was used to calculate
potential drinking water exposure and risk to propazine and its major chloro metabolites, as well
as hydroxypropazine residues of concern. No dietary (drinking water) risks of concern were
identified. For propazine and its major chloro metabolites, the acute and 4-day DWLOCs are
greater than estimated drinking water concentrations (EDWCs). For hydroxypropazine, the
chronic DWLOCs are greater than the EDWCs. Therefore, there are no dietary (drinking water)
risks of concern for propazine and its major chloro metabolites or hydroxypropazine.
Residential Handler and Post-Application Risks
There are no registered residential uses of propazine. Consequently, no risk assessment was
performed for these scenarios. Therefore, there are no residential risks of concern.
Non-Occupational Spray Drift Risks
A quantitative non-occupational spray drift assessment was conducted for propazine use on
sorghum (1.2 lb ai/A) to assess potential exposure from off-target movement and deposition of
propazine (i.e., spray drift); spray drift is not expected from the registered use on greenhouse
ornamentals. Adult dermal and children's (1 to < 2 years old) dermal and incidental oral risk
estimates from spray drift exposure to propazine were not of concern at the edge of field
assuming screening-level nozzle types and droplet sizes (MOEs > the level of concern (LOC) of
30).
Aggregate Risks
There are no residential uses of propazine, and exposures from food are not expected. Exposures
are only expected from drinking water, and there are no risks estimates of concern for this
pathway. There are no aggregate risks of concern for propazine.
Cumulative Risks
1 What We Eat in America (WWEIA/NHANES). 2003-2010. USDA and DHHS surveys report no human
consumption for sorghum grain. In addition, field trial studies have demonstrated that residues of propazine and its
metabolites are less than the limit of quantification (LOQ) of the analytical test method in sorghum grain.
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The EPA has determined that propazine shares a common mechanism of toxicity
(neuroendocrine effects in rats that can cause developmental and reproductive toxicity) with the
other triazine herbicides, atrazine and simazine, and their chlorinated metabolites (DEA, DIA,
and DACT). The EPA assessed cumulative risk from the triazines and their chlorinated
metabolites in the July 10, 2018 document titled Chlorotriazines: Cumulative Risk Assessment -
Atrazine, Propazine, and Simazine which is available in the public docket.
There were no risks of concern identified for the chlorotriazine 4-day cumulative dietary (food
only) exposure and risk assessment or for the 4-day dietary cumulative aggregate (food +
drinking water) exposure and risk assessment. There were also no cumulative risks of concern
for the chronic dietary (food only) or screening-level aggregate (food + drinking water)
assessment for the hydroxytriazines.
There were some 4-day cumulative aggregate (food + drinking water + residential) exposures;
however, these risks of concern were driven by residential uses of simazine and atrazine.
Propazine did not contribute to the aforementioned 4-day cumulative aggregate (food + drinking
water + residential) exposures as there are no registered residential uses of propazine. Further
information regarding these cumulative aggregate risks of concern can be found in
Chlorotriazines: Cumulative Risk Assessment - Atrazine, Propazine, and Simazine.
Occupational Handler Risks
Occupational handler dermal and inhalation exposure and risk estimates were calculated for the
registered uses of propazine. The occupational handler exposure and risk estimates indicate that
some of the combined dermal and inhalation risk estimates are not of concern (MOEs > 30) with
baseline attire + label specified PPE (chemical resistant gloves) for greenhouse ornamental use.
Mixing/loading/applying liquids via backpack spray equipment to greenhouse ornamentals is not
of concern with the addition of a double layer of clothing. Mixing/loading/applying liquids with
a mechanically pressurized handgun to greenhouse ornamentals remains of concern when
assuming label-specified PPE, a double layer of clothing, and a particulate-filtering facepiece
respirator (PF10) respirator. Dermal exposures are the highest contributors to the combined
dermal + inhalation risk estimates.
The propazine registrant has requested to voluntarily cancel the greenhouse use which will
nullify these risks.
Occupational Post-Application Risks
Occupational post-application dermal exposure and risk estimates were assessed for registered
uses of propazine (sorghum and greenhouse-grown ornamentals). Although there are no
chemical-specific dislodgeable foliar residue (DFR) data available for propazine, DFR data are
available on field corn treated with liquid and dry flowable formulations of atrazine. Using
atrazine-specific DFR data, the occupational post-application MOEs (range from 120 to 2,500)
are not of concern for the registered uses of propazine on the day of application (LOC = 30).
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2.	Human Incidents and Epidemiology
The agency performed an updated Tier I review of human incidents from 2010-2017 for the
triazine herbicides (atrazine, propazine and simazine) using the following sources: OPP Incident
Data System (IDS); the National Pesticide Information Center (NPIC); the California Pesticide
Illness Surveillance Program (CA PISP); and the Centers for Disease Control and
Prevention/National Institute for Occupational Safety and Health (CDC/NIOSH) Sentinel Event
Notification System for Occupational Risk-Pesticides (SENSOR) databases (S. Recore et. al.,
D444041, 11/01/2017). The Agricultural Health Study (AHS) findings and epidemiological
investigations for the triazines are reviewed in separate documents (A. Aldridge, D447696,
7/09/2018 and A. Aldridge, D447697, 07/09/2018).
No propazine incidents were reported to IDS, NPIC, CA PISP, or SENSOR-Pesticides and there
does not appear to be a concern at this time. The agency will continue to monitor the incident
information and additional analyses will be conducted if ongoing incident monitoring indicates a
concern.
The agency recently conducted an updated epidemiology systematic literature review to
investigate evidence about the human health effects associated with exposure to atrazine,
simazine, and/or propazine. Ninety-three publications from 1990 - 2017 were identified for
inclusion in the epidemiology literature review. Of these 93 publications, 90% reported an
estimate of effect for atrazine and 14% reported an estimate of effect for simazine (not mutually
exclusive). No epidemiology studies were found for propazine. However, since atrazine,
simazine and propazine share a common mechanism of toxicity, refer to the risk assessments for
atrazine (K. Rickard et al., D418316, 07/10/2018) and simazine (K. Rickard et al., D402163,
D428603, 07/10/2018) for additional information regarding the human health effects associated
with certain triazines.
3.	Tolerances
Tolerances are established under 40 CFR 180.243 for residues of propazine in/on sorghum
commodities. In a separate action, the EPA will use its Federal Food, Drug, and Cosmetic Act
(FFDCA) rulemaking authority to propose changes which will have a public comment period.
The agency intends to propose that the residue definition for the tolerance expression for
propazine be modified in accordance with current policy on tolerance definitions, to read:
"Tolerances are established for residues of the herbicide propazine, 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 the sum of propazine, 6-chloro-
N,N'-bis(l-methylethyl)-l,3,5-triazine-2,4-diamine, its desisopropyl metabolite 2-amino-4-
chloro-6-isopropylamino-s-triazine (G-30033) (DEA), and its diamino metabolite 2,4-diamino-6-
chloro-s-triazine (G-28273) (DACT), calculated as the stoichiometric equivalent of propazine, in
or on the commodity. "
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The recommended tolerances are lower than the established tolerances and are based on limit of
quantification (LOQ) considerations. There were no detects in sorghum grain or stover;
therefore, the proposed tolerance is 0.15 ppm (LOQ = 0.05 ppm; 0.05+0.05+0.05=0.15 ppm).
There were no detects in trials with sorghum forage for propazine or G-30033, but a maximum
level of 0.078 ppm was found for DACT, so the EPA intends to propose the tolerance be set at
0.2 ppm.
No Codex or Canada Pest Management Regulatory Agency (PMRA) maximum residue levels
(MRLs) have been established for propazine. There are no harmonization issues at this time.
Table 1: Summary of Proposed Tolerance Revisions for Propazine (40 CFR 180.243)
Commodity/
Correct Commodity
Definition
Established
Tolerance (ppm)
Recommended
Tolerance (ppm)
Comments
Sorghum, grain, forage
0.25
0.2
Sum of LOQs for propazine and DEA plus
maximum level of DACT in forage
Sorghum, grain, grain
0.25
0.15
Sum of LOQs: no detects in grain
Sorghum, grain, stover
0.25
0.15
Sum of LOQs: no detects in stover
4. Human Health Data Needs
The Propazine Draft Human Health Risk Assessment for Registration Review stated that there
were no multiresidue method testing results (OCSPP 860.1360) for the regulated chloro
metabolites of propazine: G-30033 (DEA) and G-28273 (DACT); however, this study (MRID
50917201) was recently submitted to the EPA and found to be acceptable. The agency does not
anticipate any further human health data needs for the propazine registration review.
B. Ecological Risks
A summary of the agency's ecological 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 propazine. For additional details on the ecological
assessment for propazine, see the Preliminary Risk Assessment for Registration Review of
Propazine and Propazine: Addendum to "Preliminary Risk Assessment for Registration Review
of Propazine "for Update on ECOTOX Database Query which are available in the public docket.
The EPA is currently working with its federal partners and other stakeholders to implement an
interim approach for assessing potential risk to listed species and their designated critical
habitats. Once the scientific methods necessary to complete risk assessments for listed species
and their designated critical habitats are finalized, the agency will complete its endangered
species assessment for propazine. See Appendix C for more details. As such, potential risks for
non-listed species only are described below.
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1. Risk Summary and Characterization
The EPA calculated risk estimates associated with propazine use to non-target mammals; birds,
reptiles and terrestrial-phase amphibians; terrestrial invertebrates; terrestrial plants; fish,
amphibians, and aquatic invertebrates; and aquatic vascular and nonvascular plants. Risk
estimates (risk quotients, or RQs) were compared with the EPA's LOC. For ecological risk,
RQ's below the LOC are not of concern to the agency. For all taxa in the terrestrial assessment,
except for plants, the LOC for acute exposure is 0.5, and the LOC for chronic exposure is 1.0.
The LOC for plants is 1.0. In the draft risk assessment, the agency identified potential chronic
risk concerns for mammals, birds, reptiles, and terrestrial-phase amphibians. Risks from spray
drift were identified for terrestrial and aquatic nonvascular plants. In addition, available
information suggests potential risk to terrestrial invertebrates. The draft risk assessment assessed
the maximum label number of applications and maximum application rate (1.2 lb.
a.i./A/application).
Terrestrial Risks
Mammals
Propazine is classified as practically nontoxic to mammals on an acute exposure basis, but
effects from chronic exposure (adult toxicity and reproduction effects) were observed as low as
50 mg ai/kg-body weight/day. The ecological risk assessment did not identify acute risks of
concern for mammals; however, chronic risk estimates exceed the agency's LOC of 1 for most
scenarios modeled for all uses. Chronic RQs range from 0.16 - 25, compared to the LOC of 1.0,
based on on-field exposure estimates.
Birds. Reptiles, and Terrestrial-Phase Amphibians
Propazine is classified as practically nontoxic to terrestrial birds from acute dose-based or
dietary-based exposure. Chronic risk estimates minimally exceed the agency's LOC of 1
(chronic RQ =1.1, LOC = 1). The adverse effect upon which the chronic endpoint is based is
adult female body weight gain.
Terrestrial Invertebrates (honeybees)
Available toxicity data indicate that propazine is practically non-toxic to honeybees on an acute
contact basis.
Given the uncertainty surrounding potential risks to terrestrial invertebrates due to lack of data,
additional data may be necessary to fully evaluate risks to non-target terrestrial invertebrates,
especially pollinators. The EPA is currently determining whether additional pollinator data are
needed for propazine. If the agency determines that additional pollinator exposure and effects
data are necessary to help make a final registration review decision for propazine, then the EPA
will issue a DCI to obtain these data. The pollinator studies that could be required are listed in
Table 2 below and based on the EPA's June 2014 Guidance for Assessing Pesticide Risks to
Bees2
2 Available at https://www.epa.gov/sites/production/files/2014-
06/documents/poHinator risk assessment guidance 06 .1.9 14.pdf
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Table 1: Potential Pollinator Data Requirements
Guideline #
Study
Tier 1
850.3020
Acute contact toxicity study 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-field testing for pollinators (tunnel or colony
feeding study)
Tier 3*
850.3040
Full-Field testing for pollinators
' The need for liigher 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 Plants
There were risks of concern for terrestrial plants. Effects were seen in both seedling emergence
and vegetative vigor studies in both monocots and dicots, more so for dicots. The plants used in
the guideline testing were crop species. The EPA used a 25% inhibition of growth endpoint
focusing on either biomass or emergence. For aerial applications of propazine, monocot RQs
were 2.06 (dry), 5.14 (semi-aquatic), and 1.71 (spray drift) and dicot RQs were 4.50 (dry), 11.25
(semi-aquatic), and 3.75 (spray drift) which all exceeded the LOC of 1. For ground applications
of propazine, monocot RQs were 0.69 (dry), 3.77 (semi-aquatic), and 0.34 (spray drift) and dicot
RQs were 1.50 (dry) and 8.25 (semi-aquatic), and 0.75 (spray drift) with an LOC of 1. RQ
numbers exceeding the LOC indicate a potential for risk to that plant group.
Aquatic Risks
Fish. Amphibians, and Aquatic Invertebrates
There are no risks of concern for fish, amphibians, and aquatic invertebrates.
Aquatic Vascular and Nonvascular Plants
There is no risk of concern for aquatic vascular plants from the propazine use on sorghum (RQ =
0.32 - 0.43; LOC = 1). There is a risk of concern for aquatic nonvascular plants from the
propazine use on sorghum via aerial and ground spray drift with RQs (1.3 - 1.7) exceeding the
LOC of 1.
2. Ecological Incidents
The ecological incident information system (EIIS) is an OPP database that houses ecological
incidents that have been reported to the Agency. When available, EIIS includes data and location
of an incident, type and magnitude of effects observed in various species, use(s) of pesticides
known or suspected of contributing to the incident, and results of any chemical residue analysis
or other analyses conducted during incident investigation. IIS incidents are categorized
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according to the certainty that the incident resulted from pesticide exposure. The Avian
Monitoring System (AIMS) is a database administered by the American Bird Conservancy that
contains publicly available data on reported avian incidents involving pesticides. Many of the
incidents listed in this database are also in the EIIS.
As of October 2019, there are no reported incidents for propazine in the Ecological Incidents
database or in the Aggregate Summaries database.
The absence of reported incidents should not be interpreted as an absence of incidents. Incident
reports for non-target organisms typically provide information only on mortality events and plant
damage. Sublethal effects in organisms such as abnormal behavior, reduced growth and/or
impaired reproduction are rarely reported, except for phytotoxic effects in terrestrial plants.
The agency 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
Except for the potential pollinator data requirements described previously, the ecological and
environmental fate database for propazine is complete.
C. Benefits Assessment
General Benefits of Propazine
Flexible Use Pattern
Propazine can be applied either before or after the crop emerges. Additionally, propazine has
residual activity and can prevent weeds from emerging for several weeks.
Crop Safety
Propazine is one of three herbicides registered for use on sorghum that do not require a seed
safener to prevent injury to the emerging crop. Saflufenacil and atrazine are the other sorghum
use herbicides that do not require a safener. Generally, propazine offers better crop safety against
grain sorghum than atrazine.
Inexpensive
Propazine is a relatively inexpensive herbicide, at approximately $4/acre to apply, on average; as
compared to a commonly used preemergence active ingredient, metolachlor-S, at $10/acre.
Propazine is mostly used before crop emergence when control of weed pests is paramount to
establishing a crop which significantly reduces the probability of incurring some yield and
financial loss.
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IV. PROPOSED INTERIM REGISTRATION REVIEW DECISION
A. Proposed Risk Mitigation and Regulatory Rationale
The agency has reviewed the risks, benefits, and uses of propazine in formulating its proposed
risk mitigation. The EPA has identified potential human health risks of concern for occupational
handlers from dermal and inhalation exposure scenarios, such as mixing/loading/applying using
backpack sprayers and mechanically pressurized handgun application equipment for greenhouse
ornamental use. The EPA also identified cumulative risks for the triazines which stem from
atrazine and simazine, but not propazine. The EPA has also identified potential ecological risks
of concern for mammals, birds, terrestrial plants, and non-vascular aquatic plants. The agency
weighed the benefits against the potential ecological risks and, as a result, is proposing
mandatory spray drift language which will reduce ecological exposure of propazine in the
environment. Besides mandatory spray drift management language, the EPA is proposing to
update the herbicide resistance management language and personal protective equipment
(gloves) on the propazine label. The registrant has agreed to all of the proposed label changes
for propazine.
1.	Cancellation of Greenhouse Use
The registrant has requested cancellation of the greenhouse use. This will nullify the
occupational handler risks of concern for dermal and inhalation exposures that are present for
greenhouse uses. This cancellation will be published in the federal register as a separate action.
2.	Mandatory Spray Drift Reduction
The agency is proposing label changes to reduce off-target spray drift and establish a baseline
level of protection against spray drift that is consistent across propazine products. Reducing
spray drift will minimize the extent of environmental exposure and potential risk to non-target
plants and animals. Although the agency is not making a complete endangered species finding at
this time, these label changes are expected to reduce the extent of exposure and may reduce risk
to listed species whose range and/or critical habitat co-occur with the use of propazine.
The agency is proposing the following spray drift mitigation language to be included on all
propazine product labels for products applied by liquid spray application. The proposed spray
drift language is intended to consist of mandatory, enforceable statements and supersede any
existing language already on product labels (either advisory or mandatory) covering the same
topics. The agency is providing recommendations which allow propazine registrants to
standardize all advisory language on propazine 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, do not apply when wind speeds exceed 15 mph at the application
site. If the windspeed is greater than 10 mph, 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.
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Otherwise, the boom length must be 75% or less of the wingspan for fixed-wing aircraft
and 90% or less of the rotor diameter for helicopters.
	For aerial applications, if the windspeed is 10 miles per hour or less, applicators must use
'/2 swath displacement upwind at the downwind edge of the field. When the windspeed is
between 11-15 miles per hour, applicators must use 3/4 swath displacement upwind at the
downwind edge of the field.
	For aerial applications, 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, do not apply when wind speeds exceed 15 mph at the
application site.
	For ground boom applications, apply with the release height no more than 4 feet above
the ground or crop canopy.
	For ground and/or aerial applications, select nozzle and pressure that deliver medium or
courser droplets as indicated in nozzle manufacturers' catalogues and in accordance with
American Society of Agricultural & Biological Engineers Standard 572.1 (ASABE
S572.1).
3.	Non-target Advisory Statement
The agency is also proposing the addition of a non-target organism advisory statement. The
protection of pollinating organisms is a priority for the agency. Risk to pollinators from the use
of propazine is uncertain. It is possible that pollinators may be exposed to propazine from
residues in pollen or nectar through spray drift. This may negatively impact forage and habitat of
pollinators and other non-target organisms. It is the agency's goal to reduce spray drift whenever
possible and to educate growers on the potential for indirect effects on the forage and habitat of
pollinators and other non-target organisms. Therefore, the EPA is proposing non-target organism
advisory language to be placed on propazine labels to address this potential concern. The
proposed statement is below.
"NON-TARGET ORGANISM ADVISORY STATEMENT: This product is toxic to
plants and may adversely impact the forage and habitat of non-target organisms,
including pollinators, in areas adjacent to the treated site. Protect the forage and habitat
of non-target organisms by following label directions intended to minimize spray drift."
4.	Herbicide Resistance Management
On August 24, 2017, the EPA finalized a Pesticide Registration Notice (PRN) on herbicide
resistance management.3 Consistent with the Notice, the EPA is proposing the implementation of
herbicide resistance measures for existing chemicals during registration review, and for new
chemicals and new uses at the time of registration. In registration review, herbicide resistance
elements will be included in every herbicide PID.
3 PRN 2017-2, "Guidance for Herbicide Resistance Management Labeling, Education, Training, and Stewardship".
Available at https://www.epa.gov/pesficicie-registrafion/pesticide-registration-tiotices-vear
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The development and spread of herbicide resistant weeds in agriculture is a widespread problem
that has the potential to fundamentally change production practices in U.S. agriculture. While
herbicide resistant weeds have been known since the 1950s, the number of species and their
geographical extent, has been increasing rapidly. Currently there are over 250 weed species
worldwide with confirmed herbicide resistance. In the United States, there are over 155 weed
species with confirmed resistance to one or more herbicides.
Management of herbicide resistant weeds, both in mitigating established herbicide resistant
weeds and in slowing or preventing the development of new herbicide resistant weeds, is a
complex problem without a simple solution. Coordinated efforts of growers, agricultural
extension, academic researcher, scientific societies, pesticide registrants, and state and federal
agencies are required to address this problem.
The EPA is requiring measures for the pesticide registrants to provide growers and users with
detailed information and recommendations to slow the development and spread of herbicide
resistant weeds. This is part of a more holistic, proactive approach recommended by crop
consultants, commodity organizations, professional/scientific societies, researchers, and the
registrants themselves.
5.	Label Cleanup
The agency is proposing two items for label cleanup as stated below.
	The agency is proposing to update the glove statement currently on labels to be consistent
with the Label Review Manual4. The proposed new glove language does not
fundamentally change the personal protective equipment that workers need to use, and
therefore should impose no impacts on users.
	The agency is proposing to add the following information on product labels near rate
tables: "Do not apply propazine if atrazine has been or will be applied to the same
acreage in the same growing season."
6.	Expected Impacts of Proposed Mitigation
Spray drift reduction language is being proposed. The impact of each component to sorghum
growers is discussed below.
Impacts of Inversion Restriction
This requirement could reduce the amount of time users have to apply triazines. Users may
switch to other products that only have advisory language for this restriction if they encounter
temperature inversions when needing to treat a field.
4 See https://www.epa.gov/sites/production/files/2016-02/documents/chap-10-feb-2Q16.pdf
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Impacts of the Percent of Usable Boom Length and Wind Speed Restrictions
If this mitigation is adopted, there will be no impact on propazine applications when boom length
is 75% or less for fixed wing aircraft. However, flexibility will be increased by allowing
applications to occur at a reduced percentage of the useable boom length (65% or less) except
when wind speeds are greater than 10 mph and less than 15 mph. Given that applications with
fixed wing aircraft were previously prohibited at wind speeds greater than 10 mph, this change
would increase flexibility.
For rotary aircraft, there would be a 15% increase in boom length when wind speeds are less than
10 mph allowingmore area to be covered in less time. Additionally, there would be no reduction
in boom length for applications made with helicopters when the wind speed is between 10 and 15
mph which would provide greater flexibility for applicators given that aerial applications are not
allowed above 10 mph.
The agency has not assessed the impacts of windspeed restrictions for aerial applications and the
requirement of a V2 swath displacement upwind at the downwind edge of the field.
Impacts of Establishing a Mandatory Maximum Spray Release Height Requirement for Ground
Applications
Spray release height is important to minimize overlap of spray from nozzles while maintaining
proper coverage. The agency has determined that a maximum release height of 4-feet allows
adequate coverage for the majority of nozzles5. Therefore, the EPA does not anticipate any
negative impact to growers.
Impacts of Windspeed Restrictions for Ground Applications
Wind conditions vary across the U.S., and wind speed restrictions could prevent timely
applications of propazine. Survey data indicate that most applicators consider wind speed when
making applications and typically apply at wind speeds of 15 mph or lower6. However, there are
situations when applicators will spray at wind speeds greater than 15 mph (less than 10 percent
of survey respondents). Mandatory wind speed restrictions complicate weed and crop
management by reducing the available time to make applications and make it more likely that a
grower may need to alter weed control plans. Once the window of application passes for either
the crop or weeds, the weeds may be too large to be adequately controlled by propazine which
could accelerate the development of resistance or there may be phytotoxicity issues at the later
crop stage, either of which could reduce yields. Alternatively, a grower may develop another
weed control strategy. However, changing plans could become more costly given that a different,
more expensive herbicide(s) may be used or multiple applications could be needed to achieve the
same level of weed control as propazine. Additionally, growers are likely to incur higher costs if
they hire a custom applicator or purchase additional spray equipment and hire additional
5 Tindall, K. and C. Hanson. 2018. Qualitative Benefits and Usage Assessment of Diflufenzopyr (PC Code 005108)
and Diflufenzopyr-Sodium (PC Code 005107). Available at: https://www.regulafions.gov/document?D=EPA-HO-
OPP-;	)22.
6: Bish, M. and K.W. Bradley. 2017. Survey of Missouri Pesticide Applicator Practices, Knowledge, and
Perceptions. Weed Technology 31:165-177. Available at:
https://weedscience.missouri.edii/Pesticide%20Applieator%20Knowledge 2017.pdf.
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personnel to operate the sprayers to make applications in a timely manner. If applications were
not made in a timely manner, weed control could decline necessitating additional herbicide
applications and/or resulting in yield losses.
Droplet Size
The agency is proposing a restriction on droplet size, because coarser droplets have been
demonstrated to decrease spray drift and therefore reduce potential risks to non-target species.
Because chemical-specific data for the performance of droplet sizes is limited, EPA was not able
to evaluate the effects of medium or coarser droplet sizes (as defined by ASABE S572.1)
specifically for propazine. Therefore, the EPA does not know the effect this requirement will
have on the performance of propazine across various use patterns, especially regarding tank mix
partners that require a finer droplet size. In general, potential negative impacts to growers from
requiring larger droplets could include reductions in efficacy, increased selection pressure for the
evolution of herbicide resistance due to a decrease in lethal dose delivered to target weeds,
increased application rates used by growers, increased costs associated with reduced yield, more
herbicide applications, purchase of alternative products, or an inability to use tank mix or premix
products. The EPA encourages comments on any potential impacts to growers from specifying a
mandatory minimum droplet size on product labels.
In addition to including the spray drift restrictions on propazine labels, all references to
volumetric mean diameter (VMD) information for spray droplets are proposed to be removed
from all propazine labels where such information currently appears. The proposed new language
above, which cites ASABE S572.1, eliminates the need for VMD information.
Impacts of Interaction of Individual Components of Spray Drift Mitigation
The agency acknowledges the impacts of multiple mitigations could be compounded and further
reduce the time in which applicators could apply herbicides. For instance, applicators may deal
with wind restrictions by spraying early in the morning/late evenings when winds are calmer;
however, temperature inversions are more likely to occur several hours before sunset and can
persist until 1-2 hours after sunrise. As the window of application gets smaller, growers will be
forced to switch to products without these restriction on short notice. Therefore, the alternative
may be based on availability and not cost and/or performance which could be costly and reduce
weed control. Additionally, growers may have situations where a tank is loaded and ready to
spray, but they are not able to spray due to prolonged weather conditions that prevent application
due to mandatory multi-layered restrictions. In rare situations, there could be scenarios where
applicators cannot spray what is mixed in the tank for a long period of time and would need to
dispose of a large quantity of mixed herbicides in order to switch to an alternative mixture. There
may be additional concerns (e.g. tank clean-out when products settle out) when a loaded tank sits
hours or possibly days.
B. Tolerance Actions
The EPA intends to propose amendment of the tolerance expression and tolerances for several
commodities. Refer to Section III. A 3 for details. The agency will use its FFDCA rulemaking
authority to propose the needed changes to the tolerances.
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C. Proposed Interim Registration Review Decision
In accordance with 40 CFR  155.56 and 155.58, the agency is issuing this PID. Except for the
Endocrine Disruptor Screening Program (EDSP), the Endangered Species Act (ESA), and
pollinator components of this case, the agency has made the following PID: (1) no additional
data 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 Appendices A and B.
In this PID, the agency is making no human health or environmental safety findings associated
with the EDSP screening of propazine, nor is it making a complete endangered species finding or
a complete assessment of effects to pollinators. Although the agency is not making a complete
endangered species finding at this time, 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 propazine. The agency's final
registration review decision for propazine will be dependent upon the result of the agency's ESA
assessment and any needed  7 consultation with the Services, and an EDSP FFDCA  408(p)
determination.
D. Data Requirements
The propazine registration review generic data call-in issued in 2014 (GDCI-080808-1371) has
been satisfied. The EPA issued a second propazine registration review DCI in 2018 (GDCI-
080808-1776) requiring multiresidue testing (OSCPP 860.1360) for propazine and its chloro
metabolites: G-30033 (DEA) and G-28273 (DACT). These data were found acceptable, and the
data call-in has been satisfied. No additional data are anticipated as being needed at this time for
this registration review. The EPA will consider requiring submission of additional pollinator data
as a separate action.
The analytical reference standard for propazine's chloro metabolite G-28273 (DACT) has
expired and must be submitted to the EPA's National Pesticide Standards Repository (see
https://www.epa.gov/pesticide-analvtical-methods/national-pesticide-standard-repository).
V. NEXT STEPS AND TIMELINE
A. Proposed Interim Registration Review Decision
A Federal Register Notice will announce the availability of this PID for propazine and will allow
a 60-day comment period on the PID. 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 propazine. However, a
final decision for propazine may be issued without the agency having previously issued an
interim decision. A final decision on the propazine registration review case will occur after: (1)
an EDSP FFDCA  408(p) determination, and (2) an endangered species determination under the
ESA and any needed  7 consultation with the Services.
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B. Implementation of Mitigation Measures
Once the Interim Registration Review Decision is issued, the propazine registrants must submit
amended labels that include the label changes described in Appendices A and B. 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 Actions for Propazine
Registration Review Case#: 0230





PC Code: 080808






Chemical Type: herbicide






Chemical Family: triazine






Mechanism of Action: inhi
oiting photosynthesis
in photosystem II (PSII)




Affected Population(s)
Source of Exposure
Route of Exposure
Duration of
Potential Risk(s) of
Proposed Actions
Comment (use



Exposure
Concern

to briefly clarify






or elaborate on






risk or






mitigation)
Occupational handler (for
Dermal and inhalation
Dermal and
Short and
Neurological, reproductive,
Cancel greenhouse
Registrant
greenhouse ornamentals)

inhalation
intermediate
developmental effects
ornamental use and
requests



term

remove use from labels
voluntary use






cancellation
Avian
Dietary and spray drift
Ingestion
Chronic
Growth
Enforceable spray drift
Chronic dietary





management measures
RQ = 1.1 which






marginally






exceeds the LOC






of 1
Mammals
Dietary and spray drift
Ingestion
Chronic
Reproductive and Growth
Enforceable spray drift






management measures

Terrestrial Plants
Spray drift
Direct contact
Acute
Growth
Enforceable spray drift
Aerial spray drift



Chronic

management measures
modeling showed






RQs from 1.71 -






3.75 which






exceed the LOC of
1
Aquatic plants (nonvascular)
Spray drift and runoff
Direct contact
Acute
Growth
Enforceable spray drift
Aerial and ground



Chronic

management measures
spray modeling






showed RQs from






1.3 -1.7 which






exceed the LOC of
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Appendix B: Proposed Labeling Changes for Propazine Products
Description
Proposed Label Language for Propazine Products
Placement on Label

Manufacturing Use Product

Removal of
greenhouse use
pattern and use site
Remove "greenhouse weeds" / "in greenhouses" wording
Title/Directions for Use

End Use Products

Removal of
greenhouse use
Remove wording referring to container grown ornamentals in greenhouses use
Title, Greenhouse
Application Instructions
Mechanism of
Action Group
Number
Note to registrant:
	Include the name of the ACTIVE INGREDIENT in the first column
	Include the word "GROUP" in the second column
	Include the MODE/MECHANISM OF ACTION CODE in the third column (for
herbicides this is the Mechanism of Action, for fungicides this is the FRAC Code, and for
insecticides this is the Primary Site of Action)
	Include the type of pesticide (i.e., HERBICIDE or FUNGICIDE or INSECTICIDE) in
the fourth column.
Front Panel, upper right
quadrant.
All text should be black,
bold face and all caps
on a white background,
except the mode of
action code, which
should be white, bold
face and all caps on a
black background; all
text and columns should
be surrounded by a
black rectangle.
PROPAZINE
GROUP
5
HERBICIDE
Updated Gloves
Statement
Update the glove statements to be consistent with Chapter 10 of the Label Review Manual. The propazine end-use
product contains outdated glove statements. All appropriate glove types must be identified on the label (not named as
examples). Registrants are no longer allowed to reference solvent categories (A-H) or category charts on the product
labels.
In the Personal
Protective Equipment
(PPE) within the
Precautionary
Statements and
Agricultural Use
Requirements, if
applicable
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Description
Proposed Label Language for Propazine Products
Placement on Label
Non-target
Organism Advisory
Statement
"NON-TARGET ORGANISM ADVISORY STATEMENT: This product is toxic to plants and may adversely impact
the forage and habitat of non-target organisms, including pollinators, in areas adjacent to the treated site. Protect the
forage and habitat of non-target organisms by following label directions intended to minimize spray drift."
Enviromnental Hazards
HERBICIDE
RESISTANCE
MANAGEMENT:
Weed Resistance
Management
Include resistance management label language for herbicides fromPRN 2017-1 and PRN 2017-2
(https://www.epa.eov/pesticide-reeistration/pesticide-reeistration-notices-vear)
Directions for Use, prior
to directions for specific
crops under the heading
"WEED
RESISTANCE-
MANAGEMENT"
Additional
Required Labelling
Action
Applies to all
products delivered
via liquid spray
applications
Remove information about volumetric mean diameter from all labels where such information currently appears.
Directions for Use
Spray Drift
Management
Application
Restrictions for all
products delivered
via liquid spray
application and allow
aerial application
SPRAY DRIFT
Aerial Ai)i)lications:
	Do not release spray at a height greater than 10 ft above the ground or vegetative canopy, unless a greater
application height is necessary for pilot safety.
	Applicators are required to use a Medium or coarser droplet size (ASABE S572.1).
	If the windspeed is 10 miles per hour or less, applicators must use Vi swath displacement upwind at the downwind
edge of the field. When the windspeed is between 11-15 miles per hour, applicators must use 3/i swath
displacement upwind at the downwind edge of the field.
	Do not apply when wind speeds exceed 15 mph at the application site. If the windspeed is greater than 10 mph, 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. Otherwise, the boom length must be 75% or less of the wingspan for fixed-wing aircraft and 90% or
less of the rotor diameter for helicopters.
	Do not apply during temperature inversions."
Directions for Use, in a
box titled "Spray Drift"
under the heading
"Aerial Applications"
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Description
Proposed Label Language for Propazine Products
Placement on Label
Spray Drift
Management
Application
Restrictions for
products that are
applied as liquids
and allow ground
boom applications
SPRAY DRIFT
Ground Boom Ai)i)lications:
	User must only apply with the release height recommended by the manufacturer, but no more than 4 feet above the
ground or crop canopy.
	Applicators are required to use a Medium or coarser droplet size (ASABE S572.1).
	Do not apply when wind speeds exceed 15 miles per hour at the application site.
	Do not apply during temperature inversions."
Directions for Use, in a
box titled "Spray Drift"
under the heading
"Ground Boom
Applications"
Advisory Spray
Drift Management
Language for all
products delivered
via liquid spray
application
SPRAY DRIFT ADVISORIES
THE APPLICATOR IS RESPONSIBLE FOR AVOIDING OFF-SITE SPRAY DRIFT.
BE AWARE OF NEARBY NON-TARGET SITES AND ENVIRONMENTAL CONDITIONS.
IMPORTANCE OF DROPLET SIZE
An effective way to reduce spray drift is to apply large droplets. Use the largest droplets that provide target pest
control. While applying larger droplets will reduce spray drift, the potential for drift will be greater if applications are
made improperly or under unfavorable enviromnental conditions.
Controlling Droplet Size - Ground Boom (note to registrants: remove if ground boom is prohibited on product
labels)
	Volume - Increasing the spray volume so that larger droplets are produced will reduce spray drift. Use the highest
practical spray volume for the application. If a greater spray volume is needed, consider using a nozzle with a higher
flow rate.
	Pressure - Use the lowest spray pressure recommended for the nozzle to produce the target spray volume and droplet
size.
	Spray Nozzle - Use a spray nozzle that is designed for the intended application. Consider using nozzles designed to
reduce drift.
Controlling Droplet Size - Aircraft (note to registrants: remove if aerial application is prohibited on product labels)
	Adjust Nozzles - Follow nozzle manufacturers' recommendations for setting up nozzles. Generally, to reduce fine
droplets, nozzles should be oriented parallel with the airflow in flight.
BOOM HEIGHT - Ground Boom (note to registrants: remove if ground boom is prohibited on product labels)
For ground equipment, the boom should remain level with the crop and have minimal bounce.
RELEASE HEIGHT - Aircraft (note to registrants: remove if aerial application is prohibited on product labels)
Directions for Use, just
below the Spray Drift
box, under the heading
"Spray Drift
Advisories"
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Description
Proposed Label Language for Propazine Products
Placement on Label

Higher release heights increase the potential for spray drift.
SHIELDED SPRAYERS
Shielding the boom or individual nozzles can reduce spray drift. Consider using shielded sprayers. Verity that the
shields are not interfering with the uniform deposition of the spray on the target area.
TEMPERATURE AND HUMIDITY
When making applications in hot and dry conditions, use larger droplets to reduce effects of evaporation.
TEMPERATURE INVERSIONS
Drift potential is high during a temperature inversion. Temperature inversions are characterized by increasing
temperature with altitude and are common on nights with limited cloud cover and light to no wind. The presence of an
inversion can be indicated by ground fog or by the movement of smoke from a ground source or an aircraft smoke
generator. Smoke that layers and moves laterally in a concentrated cloud (under low wind conditions) indicates an
inversion, while smoke that moves upward and rapidly dissipates indicates good vertical air mixing. Avoid
applications during temperature inversions.
WIND
Drift potential generally increases with wind speed. AVOID APPLICATIONS DURING GUSTY WIND
CONDITIONS.
Applicators need to be familiar with local wind patterns and terrain that could affect spray drift."

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Appendix C: 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. Additional background specific to propazine 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 pesticides7. 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. These initial consultations were pilots
and were envisioned to be the start of an iterative process. The agencies are continuing to work
to improve the consultation process. For example, advancements to the initial pilot interim
methods have been proposed based on experience conducting the first three pilot BEs. Public
input on those proposed revisions is currently being considered.
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 on this group, and
EPA hosted the first Principals Working Group meeting on June 6, 2019.
Given that the agencies are continuing to develop and work toward implementation of
approaches to assess the potential risks of pesticides to listed species and their designated critical
habitat, the ecological risk assessment supporting this PID for propazine does not contain a
complete ESA analysis that includes effects determinations for specific listed species or
designated critical habitat. Although the EPA has not yet completed effects determinations for
specific species or habitats, for this PID, the EPA's evaluation assumed, for all taxa of non-target
wildlife and plants, that listed species and designated critical habitats may be present in the
vicinity of the application of propazine. This will allow the EPA to focus its future evaluations
on the types of species where the potential for effects exists once the scientific methods being
developed by the agencies have been fully vetted. Once that occurs, these methods will be
applied to subsequent analyses for propazine as part of completing this registration review.
7 https://www.era.gov/endangered-species/draFt-revised-method-iKitioreil-leYel-cndangered-species-risk-assessnKnt-
process
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Docket Number EPA-HQ-OPP-2013-0250
www.regulations.gov
Propazine is one of the chemicals in stipulated partial settlement agreement in the case of Center
for Biological Diversity et. al., v. United States Environmental Protection Agency et al., No. 3:11
cv 0293 (N.D. Cal.). Among other provisions, this agreement sets an August 14, 2021, deadline
for EPA to complete nationwide ESA section 7(a)(2) effects determination for propazine and, as
appropriate, request initiation of any ESA section 7(a)(2) consultations with the Services that
EPA may determine to be necessary as a result of those effects determinations.
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Docket Number EPA-HQ-OPP-2013-0250
www.regulations.gov
Appendix D: 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
propazine, 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), propazine 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. A second list of chemicals identified for EDSP
screening was published on June 14, 2013,8 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. Propazine is not on either list. 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.9
In this PID, the EPA is making no human health or environmental safety findings associated with
the EDSP screening of propazine. Before completing this registration review, the agency will
make an EDSP FFDCA  408(p) determination.
8	See http://www.regulations.gov/#!documentDetail:D=EPA-HO-OPPT-2009-0477-0074 for the final second list of
chemicals.
9	https ://www. epa. eov/e ndoe ri ne-di srupt io m
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