Docket Number EPA-HQ-OPP-2015-0303 

www.regulations.gov 

Penoxsulam Final Work Plan 

Registration Review 

Case Number 7625 

March 2016 

Approved by: ~t~~tt;Va}JtL:::- ~ Director 

Pesticide Re-evaluation Division 

Date: 

INTRODUCTION 

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

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

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

review docket (EPA-HQ-OPP-2015-0303). Penoxsulam is an herbicide belonging to the 

triazolopyrimidine sulfonamide family. It is a systemic herbicide applied as a post-emergence 

treatment for selective control of annual grasses, sedges, and broadleaf weeds in agricultural and 

non-agricultural use sites. It is also used for control of vegetation in lakes, ponds, canals and 

reservoirs. 

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. 1 

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

comments received during the public comment period for the PWP concerning anticipated data 

needs, expected risk assessments, or the estimated timeline identified in 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 penoxsulam. Lastly, there is a discussion of next steps. 

UPDATES SINCE THE PWP WAS ISSUED 

Updates to penoxsulam since the PWP include the registration of the following uses: pome fruit 

group 11-1 0; stone fruit group 12-12, small vine and climbing subgroup 13-07F (except fuzzy 

kiwi), tree nut group 14-12, olive and pomegranate. The petition and label amendment 

application for these additional food uses for penoxsulam were submitted by Interregional 

Research Project No. 4 (IR-4). The docket for this action is EPA-HQ-OPP-2014-0879, which 

includes the Notice of Filing for the Petition and the Notice of Receipt for the Registration 

Action, as well as the Final Rule establishing tolerances, which was published in the Federal 

Register on March 2, 2016. The label was also updated by this action. 

SUMMARY OF COMMENTS AND AGENCY RESPONSES 

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

opened on September 30, 2015 and closed on December 1, 2015, the Agency received 3 public 

comments. Comments were submitted by FIFRA Endangered Species Task Force (FESTF) and 

the Center for Biological Diversity (CBD) and Dow AgroSciences (DAS). DAS comments 

included typographical errors and data interpretation. The comments do not have any 

1 http:/ /www2 .epa.gov /pesticide-reevaluation 

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implications for the anticipated registration review data needs or the registration review timeline 

described in the PWP, but they are of relevance to the planned ecological and human health risk 

assessments. A few public comments are summarized below. Public comments and EPA 

responses in their entirety, including BEAD's Responses to Comments from Dow AgroSciences 

on Use and Usage Information in the US. EPA's Penoxsulam Registration Review Docket, are 

located in docket EPA-HQ-OPP-2015-0303. 

Comments submitted by FESTF in EPA-HQ-OPP-2015-0303-0016. 

1. Comment: In the Preliminary Work Plan for Penoxsulam, the Agency had not completed an 

endangered species determination for whether the uses have "no effect " or "may affect " 

federally listed species or their designated critical habitats. At such time as an endangered 

species evaluation is conducted by EPA, the data developed by FESTF, in response to the 

Agency 's endangered species data requirements, will address species proximity to penoxsulam 

uses. FESTF indicated that the technical registrant, Dow AgroSciences, LLC, is a FESTF 

member and entitled to rely on FESTF data. 

FESTF also indicated that the data they have previously submitted to the Agency are the best 

available data necessary to support the analysis of Penoxsulam use; listed species locations and 

potential exposure. They also fulfill the data requirements indicated in Pesticide Registration 

Notice 2000-2. 

EPA Response: EPA thanks FESTF for its comment and will consider all appropriate 

information as we conduct the registration review assessment and make our registration review 

decision. 

Comments submitted by Center for Biological Diversity in EPA-HQ-OPP-2015-0303-0018. 

2. Comment: The Center for Biological Diversity's (CBD) comments focus on the EPA 's duty to 

consult with the US. Fish and Wildlife Service and the National Marine Fisheries Service (the 

Services) on the registration review of penoxsulam in accordance with the Endangered Species 

Act (ESA). The CBD comments mention various aspects of the risk assessment process, 

including use of the best available data to develop endangered species risk assessments, and 

evaluation of effects on endangered and threatened species and their designated critical habitat. 

CBD also expresses concern regarding the rigor of the Agency's preliminary determinations 

regarding the effects of penoxsulam on endangered and threatened (listed) species and their 

designated critical habitatfor the penoxsulam registration review. 

EPA Response: EPA has reviewed the comments from CBD on the Penoxsulam Preliminary 

Work Plan and plans to address many of the concerns raised by CBD as part of the 

implementation plan for assessing the risks of pesticides to listed species based on the 

recommendations ofthe April2013 National Academy of Sciences (NAS) report. EPA will 

address concerns specific to penoxsulam in connection with the development of its final 

registration review decision for penoxsulam. 

The NAS report outlines recommendations on specific scientific and technical issues related to 

the development of pesticide risk assessments that EPA and the Services must conduct in 

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connection with their obligations under the ESA and FIFRA. At this time, EPA has not fully 

developed its risk assessment process for listed species. In November 2013, the EPA, along with 

the Services and the U.S. Department of Agriculture, released a summary of their joint Interim 

Approaches for assessing risks to listed species from pesticides (see the white paper "Interim 

Approaches for National-Level Pesticide Endangered Species Act Assessments Based on the 

Recommendations ofthe National Academy of Sciences April2013 Report," available at 

http://www.epa.gov/espp/2013/nas.html). The Interim Approaches were developed jointly by 

the agencies in response to the NAS recommendations and reflect a common approach to risk 

assessment shared by the agencies as a way of addressing scientific differences between the EPA 

and the Services. 

The joint Interim Approaches were released prior to a stakeholder workshop held on November 

15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 

Pesticide Program Dialogue Committee (PPDC) and State-FIFRA Issues Research and 

Evaluation Group (SFIREG) meetings. The agencies also held stakeholder workshops in April 

and October 2014, allowing additional opportunities for stakeholders to comment on the Interim 

Approaches. Additional workshops are planned to enhance stakeholder involvement. As part of 

a phased, iterative process for developing the Interim Approaches, the agencies will also 

consider public comments on the Interim Approaches in connection with the development of 

upcoming Registration Review decisions. 

Comments submitted by Dow AgroSciences (DAS) in EPA-HQ-OPP-2015-0303-0015. 

3. Comment: A summary of the screening level estimates of agricultural uses of penoxsulam is 

presented in Table 2 which includes plums/prunes as crops. This entry should be deleted since 

penoxsulam is not currently registered in plums or prunes. 

EPA Response: The Agency thanks DAS for calling our attention to the fact that penoxsulam was 

not previously registered for use on, "bearing" plums/prunes. This use was updated on March 2, 

2016 and the registered use is now on the technical and end use label (Registration No. 62719-612) 

for "nonbearing" fruit trees including plums and fresh prune. 

PLANNED DATA NEEDS 

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

Review Ecological Risk Assessment for Penoxsulam and the Penoxsulam Human Health 

Assessment Scoping Document in Support of Registration Review. The planned data needs have 

not changed from what was included in the PWP. 

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Table 1: Planned Data Needs for the Penoxsulam Registration Review 

Estimated 

Guideline Study Title2 Timeframe 

Number-2 Test Material (Months from 

receipt of DCI) 

Non-guideline Acute oral toxicity to larval honey bees 

TGAI 12 

(OECD 237) 

Non-guide! ine Chronic oral toxicity to adult honey bees3 TGAI 12 

Non-guideline Chronic oral toxicity to larval honey bees3 TGAI 12 

Non-guideline Field trial of residues in pollen and necta · 4 TEP 24 

Non-guide line Semi-field testing for pollinator3A TEP 24 

850.3040 Field testing for pollinators4 TEP 24 

TGAI = techmcal grade acttve mgredtent; TEP = typtcal end-use product 

RISK ASSESSMENTS FOR REGISTRATION REVIEW 

During registration review and after data are received and reviewed, the Agency will update the 

risk assessment only for honey bees for all uses of penoxsulam. The most recent risk assessment 

will not be revised, except for honey bee information. For human health, EPA will conduct 

residential and occupational risk assessments during registration review and possibly a dietary 

risk assessment. If toxicological endpoints or points of departure are revised based on data 

received 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 anticipated registration review risk assessments based on the 

Registration Review Ecological Risk Assessment for Penoxsulam and Penoxsulam Human Health 

Assessment Scoping Document in Support of Registration Review; the planned assessments have 

not changed from what was included in the PWP. 

2 On June 27, 20 12, 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/EPA-HQ-OPPT -2009-0 154-0028 3

Guidance for these studies can be found at: http://www2.epa.gov/pollinator-protection/pollinator-risk-assessmentguidance. 4 Pending review of lower Tier studies. 

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Table 2: Planned Risk Assessments for the Penoxsulam Registration Review 

Type of Risk Assessment Conduct? Notes 

Ecological and Environmental Fate 

Comprehensive ecological y The PRA for ecological risk was posted to the docket 

(species to be assessed along with the PWP. When data required for 

include terrestrial and aquatic registration review are received, the Agency expects 

organisms), including to be able to conduct an assessment for honey bees. 

endangered species 

Incidents Will check for For a discussion of reported ecological incidents for 

updates penoxsulam, see page 19 of the Registration Review 

Ecological Risk Assessment for Penoxsulam. 

Human Health 

Dietary 

Food N The most recent dietary risk assessment is adequate to 

support registration review. However, a dietary 

assessment would be conducted if there were 

unanticipated changes to dietary endpoints/safety 

factors or a new drinking water assessment. 

Drinking water N A new drinking water assessment will not be 

conducted in the registration review process unless 

any new use registration requests submitted to EPA 

warrant it. 

Occupational 

Handlers (mixers, loaders, y Updated occupational handler assessments will be 

applicators) conducted to reflect all the registered uses and current 

occupational exposure policies. 

Post -application y No dermal endpoint has been identified, so no dermal 

occupational post-application assessment is planned. 

If the Agency's volatilization screening tool or data 

from the Agricultural Reentry Task Force indicate 

that analyses of occupational post-application 

inhalation exposures are needed, they will be included 

in the registration review risk assessment for 

penoxsulam. 

Residential 

Handlers y No short-term dermal endpoint has been identified, so 

a quantitative dermal residential handler exposure 

assessment is not planned. Residential inhalation 

handler exposures were previously assessed, and are 

not of concern. The Agency will conduct a residential 

handler assessment for the aquatic use; however, no 

risks of concern are anticipated. 

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Post -application y The Agency previously conducted residential postapplication assessments for the turf and aquatic uses. 

The risk estimates were not of concern. However, 

during registration review, these assessments will be 

updated as needed based on revised inputs, 

assumptions, and SOPs. The Agency also will 

consider the potential for residential post-application 

exposure through spray drift and volatilization. 

Other 

Aggregate y HED will conduct a new aggregate risk assessment 

that will be based on any policy changes and potential 

updates to points of departure. 

Cumulative N Penoxsulam is not a member of a cumulative group 

with a common mechanism of toxicity to humans. 

Therefore no cumulative risk assessment is planned. 

Tolerances N Per the Scoping Document, the Agency expects to 

revise the tolerance expression for penoxsulam at 40 

CFR § 180.605. 

Incidents Will check for For a discussion of reported human incidents for 

updates penoxsulam, see page 11 of Penoxsulam Human 

Health Assessment Scoping Document in Support of 

Registration Review and the Penoxsulam: Tier I 

Review of Human Incidents. 

TIME LINE 

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

registration review in Table 3 below. The projected timeline has not changed since the PWP. 

Table 3: Registration Review for Penoxsulam- Projected Registration Review Timeline 

Activities Estimated Date 

Opening the Docket 

Open Docket and 60-day Public Comment Period September 2015 - Completed 

Close Public Comment December 2015 - Completed 

Case Development 

Final Work Plan March 2016 - Completed 

Issue DCI June 2016 

Data Submission June 2018 

60-day Public Comment Period for Draft Risk Assessments5 December 2019 

Registration Review Decision 

5 The regulations governing Registration Review generally 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). For conventional pesticides, the 

Agency plans to provide a 60 calendar day public comment period generally for draft risk assessments. 

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Table 3: Registration Review for Penoxsulam- Projected Registration Review Timeline 

Activities Estimated Date 

60-day Public Comment Period for Proposed Registration Review September 2020 

Decision 

Registration Review Decision and Begin Post-Decision Follow-up March 2021 

Total (years) 6 

NEXT STEPS 

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

penoxsulam through a Data Call-In Notice, expected to be issued by June 2016. 

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