Docket Number EPA-HQ-OPP-20 15-0400 

www.regulations.gov 

Amicarbazone Final Work Plan 

Registration Review 

Case Number 7269 

February 2016 

Approved by: 

Date: 
INTRODUCTION 

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

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

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

registration review docket (EPA-HQ-OPP-20 15-0400). Amicarbazone, 4-amino-N-( 1, 1-

dimethylethyl)-4,5-dihydro-3-(1-methylethyl)-5-oxo-1 H-1 ,2,4-triazole-1-carboxamide, is a 

selective herbicide that acts through the inhibition of photosynthesis. It is registered for use as a 

preplant, preemergence, or postemergence application to field com for selective control of 

broad leaf weeds. It is also used for control of broad leaf weeds on turf, Christmas tree farms, 

conifers in nurseries, and non-crop areas. Tolerances are established in 40CFR § 180.615 for 

residues in or on field com, livestock commodities, and rotational crops. 

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.' 

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 amicarbazone. Lastly, there is a discussion of next steps. 

UPDATES SINCE THE PWP WAS ISSUED 

There are no additional updates on amicarbazone since the PWP (September 2015). 

SUMMARY OF COMMENTS AND AGENCY RESPONSES 

During the 60-day public comment period on the amicarbazone PWP, which opened 

on October 2, 20 15 and closed on December 2, 2015, the Agency received a public comment 

from one stakeholder. The comment was submitted by the Center for Biological Diversity. The 

comment does not address the timeline described in the PWP or the planned human health risk 

assessments and data requirements. It does address the planned ecological risk assessment. 

Consideration of this comment did not result in any changes to the data the Agency anticipates 

requiring for the amicarbazone registration review or the planned risk 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 infonnation were received on those issues. 

1 http://www2.cpa.gov/pcslicidc-rcevalualion 

2 
Summarized below is the sole public comment received on the amicarbazone PWP. The 

comment in its entirety is located in the docket. 

Comment submitted by the Center for Biological Diversity (CBD) in EPA-HQ-OPP-2015-

0400-0007. 

Comment: The CBD focuses on the EPA 's duty under the Endangered Species Act (ESA) to 

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

Services) on the registration review of amicarbazone. 

Response: EPA 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 April 20 13 National Academy of Sciences (NAS) report, 

available at http://vvww.nap.edu/catalog.php?record _id= 18344. EPA will address 

concerns specific to amicarbazone in connection with the development of its registration 

review decision for amicarbazone. 

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 connection with their obligations under the ESA and FIFRA. At this time, 

EPA has not fu lly 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 of the National 

Academy of Sciences April 20 13 Report," available at 

http://www.epa.gov/espp/2013/nas.html). The Interim Approaches were developed 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 j oint 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 and State-FIFRA Issues 

Research and Evaluation Group meetings, allowing additional opportunities for 

stakeholders to comment. As part of a phased, iterative process for further development 

of the Interim Approaches, the Agencies will also consider public comments on the 

Interim Approaches in the context of upcoming registration review decisions. 

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PLANNED DATA NEEDS 

Table l below summari zes the planned data needs [or amicarbazone based on the Amicarbazone 

Problem Formulation for Registration Review and Amicarbazone Scoping Document and Draft 

Human Health Risk Assessment for Registration Review. The planned data needs have not 

changed from what was included in the PWP. 

Table 1: Planned Data Needs for the Amicarbazonc Registration Review 

Guideline Study Title Test Number 

Material1 

Planned Data Needs for Amicarbazone 

835.4200 Anaerobic soil metabolism 

835.4300 Aerobic aquatic metabolism 

835.4400 Anaerobic aquatic metabolism 

850.2100 A vi an oral toxicity (passerine 

species) 

Special Study2 

Honey bee larvae acute oral toxicity (Tier I) 

Special Study Honey bee adult chronic oral toxicity (Tier 1) 

Special Study Honey bee larvae clu·onic oral 

(Tier I) toxicity 

Special Study Field trial of residues in pollen and 

(Tier 2) nectar 

Special Study3 Semi-field testing for pollinators 

(Tier 2) (tunnel or colony feeding studies) 

850.3040 Field testing for pollinators (Tier 3) 

860.19004 Field rotational crops 

1 TGAI = tcchn1cal grade acuve 1ngrcd1cnt; TEP = typ1cal end-usc product 2 I Ioney bee acute larval toxicity test protocol available through OECD TG 237 3 Semi-field tunnel study protocol available through OECD Guidance 75 

TGAI 

TGAI 

TGAI 

TGAI 

TGAI 

TGAI 

TGAI 

TEP 

TEP 

TEP 

TEP 

Estimated 

Timeframe 

(Months 

from receipt 

ofDCI) 

24 

24 

24 

12 

12 

12 

12 

12 

24 

24 

36 

4 lfthe registrant wishes to retain root and tuber vegetables as rotational crops, additional tlcld rotational crop data are needcd. 

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RISK ASSESSMENTS FOR REGISTRATION REVIEW 

The most recent dietary (food and drinking water) exposure and risk assessment for 

amicarbazone was completed in June 2015. The most recent ecological and environmental fate 

risk assessment was conducted in April 2005. Findings and conclusions from these risk 

assessments are summarized in Amicarbazone. Scoping Document and Draji Human Health Risk 

Assessment for Registration Review and Amicarbazone Problem Formulation for Registration 

Revie'vv. 

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

including an endangered species assessment, for all uses of amicarbazone. The Agency intends 

to consider the need for bystander drift and volatilization human health risk assessments. In 

addition, if toxicological endpoints or points of departure are revised based on the data that are 

required for registration review, they will be considered in the new assessments, as will any 

changes to the standard operating procedures or default exposure assumptions. 

Table 2 below summarizes the planned registration review risk assessments. The planned 

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

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Table 2: Planned Risk Assessments for the Amicarbazone Registration Review 

Type of Risk Assessment Conduct? Notes 

Ecolo2ical and Environmental Fate 

Comprehensive ecological y The Agency will conduct a comprehensive ecological 

(species to be assessed risk assessment for the parent amicarbazone, 

include terrestrial and aquatic including an endangered species assessment. 

organisms), including 

endangered species 

Incidents Will check for For a discussion of rep011ed ecological incidents for 

updates amicarbazone, see page 19 of the Problem 

Formulation. 

Human Health ' 

... -· 

Dietary 

Food N A new dietary (food) risk assessment is not 

anticipated to be needed during registration review. 

Drinking water N A new drinking water risk assessment is not 

anticipated to be needed during registration review 

unless there are significant increases to the drinking 

water exposure estimates. 

Occupational 

Handlers (mixers, loaders, N A new occupational handler risk assessment is not 

applicators) anticipated to be needed during registration review. 

Post-application N A new occupational post-application exposure is not 

anticipated to be needed during registration review. 

Residential 

Handlers N A new residential handler exposure assessment is not 

anticipated to be needed duri ng registration review. 

Post-appli cation y During registration review, the Agency will determine 

if data (e.g., .flux studies) or fUJ1her analysis is 

required for a bystander risk assessment. 

Other 

Aggregate N A new aggregate assessment is not anticipated to be 

needed unless there are changes in endpoints, PODs, 

or other components of aggregate risk. 

Cumulative N EPA has not made a common mechanism oftoxicity 

finding for amicarbazone and any other substances; 

and amicarbazone does not appear to produce a toxic 

metabolite produced by other substances. 

Tolerances y If the registrant chooses to support the root and tuber 

vegetable plant-back timeframes through data 

submission, the Agency will review those data and 

propose any necessary changes to the tolerances for 

such crops. 

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Incidents Will check for There have been no reported human incidents for 

updates amicarbazone; see page 35 of the Scoping 

Document/Draft Risk Assessment and Amicarbazone: 

Tier 1 (Scoping) Review of Human Incidents. 

TIM ELINE 

EPA has created the following estimated timel ine for the completion of the amicarbazone 

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

Table 3: Registration Review for Amicarbazonc - Projected Registration Review 

Timelinc 

Activities Estimated Date 

Opening the Docket 

Open Docket and 60-day Public Comment Period September 20 15 -

Completed 

Close Public Comment November 20 I 5 -

Completed 

Case Development 

Final Work Plan February 2016 

Issue DCI April- June 2016 

Data Submission April- June 2019 

60-day Public Comment Period for Draft Risk Assessments2 October - December 

2020 

Registration Review Decision 

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

Decision 2021 

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

Total (years) 6 

NEXT ST EPS 

As noted previously, the Agency plans to require several environmental fate, ecological effects, 

and residue studies for amicarbazone through a Data Call-In Notice, expected to be issued in 

April - June 2016. 

1 The regulmions governing Rcgistrntion Review generally require the Agency to provide a public comment period of at least 30 calendar days 

lor dmli risk assessments; sec 40 CFR Pan 155.53(c). For conventional pesticides, the Agency plnns 10 provide a 60 calendar day public 

cornn1c1H period gcncrnlly for draft risk assessments. 

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