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INTRODUCTION

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP) for 

the registration review of propazine. This work plan addresses public comments received 

concerning the Preliminary Work Plan (PWP), which was posted in the propazine registration 

review docket (EPA-HQ-OPP-2013-0250). Propazine is a triazine herbicide registered for use to 

control broadleaf and grass weeds. It is registered for use on grain sorghum and containerized 

ornamental plants grown in greenhouses. Propazine is a triazine herbicide and part of the 

triazine common mechanism group based on a common toxicity end-point and known 

mechanism of toxicity. The other members of the triazine common mechanism group are 

atrazine, simazine, and the three major chloro metabolites: desethyl-s-atrazine (DEA), 

desisopropyl-s-atrazine (DIA), and diaminochlorotriazine (DACT).1 

The Agency is implementing the registration review program pursuant to Section 3(g) of the 

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and will review each registered 

pesticide every 15 years to determine whether it continues to meet the FIFRA standard for 

registration. Changes in science, public policy, and pesticide use practices occur over time. The 

registration review program is intended to make sure that, as the ability to assess risk evolves and 

as policies and practices change, all registered pesticides continue to meet the statutory standard. 

The public phase of registration review begins when the initial docket is opened for each case. 

Information on this program is provided on the Agency’s website.2

The FWP begins with any updates since the PWP was issued. Next is a summary of comments 

received during the public comment period for the PWP, and a summary of the Agency’s 

responses to those comments. This section is followed by registration review planned data 

needs, risk assessments expected to be conducted, and the projected registration review timeline 

for propazine. Lastly, there is a discussion of next steps. 

UPDATES SINCE THE PWP WAS ISSUED

The case number for propazine was inaccurately listed as # 7278 in the PWP. The FWP reflects 

the correct case number for propazine, which is # 230. 

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the Propazine Preliminary Work Plan which 

opened on June 26, 2013 and closed on August 26, 2013, the Agency received two sets of public 

comments. The comments were submitted by the technical registrant for propazine, Albaugh, 

Inc., and the FIFRA Endangered Species Task Force (FESTF). They do not address the timeline 

or planned registration review risk assessments, but did include one comment on the data 

requirements identified in the PWP. The comments were not substantive in nature and did not 

result in a change to the planned data requirements, registration review timeline, or planned risk 

 

1

 There are other triazine pesticides, such as ametryn, prometryn, and prometon, but they are excluded from the 

triazine common mechanism group because they do not share the same toxicity profile. For additional 

information, see the triazine cumulative risk assessment at http://www.regulations.gov/#!docketDetail;D=EPAHQ-OPP-2005-0481. 2

 http://www.epa.gov/oppsrrd1/registration_review/ 
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assessments. In the PWP, EPA also solicited comments on the specific topics of environmental 

justice, water quality concerns, and trade irritants, but no comments or information were received 

on those issues. 

This section summarizes and addresses all public comments received. 

Comments submitted by FESTF in EPA-HQ-OPP-2013-0250-0009. 

Comment: The technical registrant, as identified on the fact sheet included in the PWP, is 

Albaugh, Inc., which is a FESTF member and is entitled to rely on FESTF data. 

Response: EPA thanks FESTF for the comment and will consider these data during registration 

review. 

Comments submitted by Morris Gaskin, Registration Manager, Albaugh Inc. in EPA-HQOPP-2013-0250-0010. 

Comment: The Agency listed Guideline 850.2300 for Avian Reproduction as a data gap because 

a study submitted in 2009 under MRID # 48036201 is deficient and classified as supplemental. 

Because Albaugh did not receive the Agency's data evaluation record (DER) for that study until 

August 22, 2013, there was not sufficient time to evaluate the deficiencies noted in the DER. 

Albaugh will consult with performing laboratory to determine if the original study can be 

amended to upgrade the supplemental status.

Response: At this time, Guideline 850.2300 (Avian Reproduction) is required in support of 

registration review. EPA will review the proposed submission when it is received; if this study 

is upgraded, the guideline will be fulfilled. 

Comment: The ornamental plants grown in greenhouses use noted in the PWP was a 

placeholder use registered by Griffin Corp. in the 1990's while they pursued the Section 3 

registration for sorghum. There is no actual use of propazine on ornamentals grown in 

greenhouses. Albaugh intends to amend its technical and end use labels to delete the use. 

Response: EPA will review the label amendment request when submitted. The registrant should 

also submit a written request to voluntarily cancel this use, which EPA will publish in the 

Federal Register for comment before finalizing. If the use on ornamental plants grown in 

greenhouses is cancelled prior to development of the human health and ecological risk 

assessments for propazine, it will not be included in the risk assessments. 

Comment: Propazine 4L (EPA Reg. No. 42750-148) is a restricted use pesticide (RUP). 

Response: The PWP incorrectly indicated in Table 3, Propazine Use and Usage Information, 

that propazine is not a restricted use pesticide. Propazine’s one registered end use product (EPA 

Reg. No. 42750-148) is restricted use due to ground and surface water concerns. 
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PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for propazine based on the Registration 

Review: Problem Formulation for Environmental Fate and Ecological Risk, Endangered 

Species, and Drinking Water Assessments for Propazine and Atrazine, Propazine, and Simazine. 

Human Health Risk Scoping Document in Support of Registration Review. The planned data 

needs have not changed from what was included in the PWP. 

Table 1: Planned Data Needs for the Propazine Registration Review 

Guideline 

Number1 Study Title Test Material 

Estimated 

Timeframe 

(Months from 

receipt of DCI) 

850.2100 Acute avian toxicity (passerine species) TGAI 12 

850.2300 Avian reproduction TGAI 24 

TGAI = technical grade active ingredient 

1

 On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850 – Ecological Effects Tests 

– including renumbering and other designations or changes for some guideline studies. See “Final Test Guidelines; 

OCSPP 850 Series; Notice of Availability” 77 FR 38282, June 27, 2012. 

http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0154-0028

RISK ASSESSMENTS FOR REGISTRATION REVIEW

During registration review, the Agency will conduct a comprehensive ecological risk assessment, 

including an endangered species assessment, for all uses of propazine. For human health, EPA 

will conduct revised dietary, residential, and occupational, and cumulative risk assessments 

during registration review. If toxicological endpoints or points of departure are revised based on 

the results of literature reviewed during registration review, they will be considered in the new 

assessments, as well as any changes to the standard operating procedures or default exposure 

assumptions. 

Table 2 below summarizes the planned registration review risk assessments based on the EFED 

Problem Formulation and HED Scoping Document, and the planned assessments have not 

changed from what was included in the PWP. 

Table 2: Planned Risk Assessments for the Propazine Registration Review 

Type of Risk Assessment Conduct? Notes 

Ecological and Environmental Fate 

Comprehensive ecological 

(species to be assessed 

include terrestrial and 

aquatic organisms), 

including endangered 

species 

Y The parent propazine will be considered the stressor 

of concern because it is expected to be protective for 

any non-target organisms that may be exposed to the 

parent and any of its degradates. 
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Table 2: Planned Risk Assessments for the Propazine Registration Review

Type of Risk Assessment Conduct? Notes 

Ecological and Environmental Fate

Incidents Will check for 

updates 

For a discussion of reported ecological incidents for 

propazine, see page 15 of the Problem Formulation. 

Human Health

Dietary 

Food Y During registration review, an updated dietary 

assessment will be conducted to include any updates 

to toxicological endpoints, dietary exposure estimates, 

and changes to assessment SOPs. 

Drinking water Y EPA plans to update the drinking water assessment 

for propazine during registration review. 

Occupational 

Handlers (mixers, loaders, 

applicators) 

Y In registration review, an up-to-date quantitative 

occupational risk assessment will be conducted to 

account for current registered application rates, unit 

exposures, transfer coefficients (TCs), and toxicity 

endpoints and safety factors. 

Post-application Y 

Residential 

Handlers N There are no registered residential uses of propazine. 

Post-application N 

Other 

Aggregate Y Evaluates the combined risk from dietary and 

residential exposures. Since there are no registered 

residential uses of propazine, its aggregate assessment 

consists of the dietary exposure assessment only. 

Cumulative Y An assessment of the triazine cumulative group is 

planned as part of registration review. 

Tolerances Y Tolerances are established under 40 CFR §180.243 

for residues of propazine in/on sorghum commodities. 

EPA plans to update the residue definition for the 

tolerance expression for propazine to be in accordance 

with current policy on tolerance definitions. 

Incidents Will check for 

updates 

For a discussion of reported human incidents for 

propazine, see page 12 of the Scoping Document and 

the Atrazine, Propazine, and Propazine: Review of 

Human Incident Reports.

TIMELINE

EPA has created the following estimated timeline for the completion of the propazine 

registration review in Table 3 below. The projected timeline has not changed since the PWP. 
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Table 3: Registration Review for Propazine – Projected Registration Review Timeline

Activities Estimated Date

Opening the Docket 

Open Docket and 60-day Public Comment Period 2013 – June 

Table 3: Registration Review for Propazine – Projected Registration Review Timeline

Activities Estimated Date

Close Public Comment 2013 – August 

Case Development 

Final Work Plan 2013 – December 

Issue DCI 2014 July - September 

Data Submission 2016 July - September 

60-day Public Comment Period for Draft Risk 

Assessments1

2018 January – March 

Registration Review Decision 

60-day Public Comment Period for Proposed 

Registration Review Decision 

2018 October – December 

Registration Review Decision and Begin Post-Decision 

Follow-up 

2019 

Total (years) 6 1

 The regulations governing Registration Review require the Agency to provide a public comment period of at least 

30 calendar days for draft risk assessments; see 40 CFR Part 155.53(c). The Agency plans to provide a 60 calendar 

day public comment period for draft risk assessments as a general standard of practice. 

NEXT STEPS

As noted previously, the Agency plans to require two ecological effects studies for propazine 

through a Data Call-In Notice, expected to be issued by September 2014.