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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 flumiclorac-pentyl. The FWP includes the expected 

registration review time line. The FWP also addresses public comments received 

concerning initial docket postings, including the Preliminary Work Plan (PWP) in the 

Summary Document. The comments are posted in the flumiclorac-pentyl registration 

review docket (EPA-HQ-OPP-2009-0084). The Summary Document provides 

information on what EPA knows about the pesticide and what additional risk analyses 

and data or information the Agency believes are needed to make a registration review 

decision. 

The Agency is implementing the registration review program and will review each 

registered pesticide every 15 years to determine whether it continues to meet the Federal 

Insecticide, Fungicide, and Rodenticide Act (FIFRA) standard for registration. Changes in 

science, public policy, and pesticide use practices will 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 that statutory 

standard. The public phase of registration review begins when the initial docket is 

opened for each case. Information on this program is provided at: 

http://www.epa.gov/oppsrrd1/registration_review/. 

Flumiclorac-pentyl is a post-emergence light-dependent peroxidizing herbicide (LDPH) 

registered for use on field corn, soybeans, cotton, and a variety of non-cropped areas. 

There are no labeled residential homeowner uses, but there is potential for nonoccupational exposure from use on public recreational areas. 

Since flumiclorac-pentyl was first registered in 1994, it was not subject to a 

Reregistration Eligibility Decision, but a tolerance reassessment was required under the 

1996 Food Quality Protection Act (FQPA). Flumiclorac-pentyl was the subject of an 

August 2005, “Report of the Food Quality Protection Act (FQPA) Tolerance 

Reassessment Progress and Risk Management Decision (TRED),” (available at 

http://www.epa.gov/oppsrrd1/REDs/flumiclorac_tred.pdf). 

Updates Since the Summary Document:

• As required under FFDCA section 408(p), EPA has developed the Endocrine 

Disruptor Screening Program (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) 
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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 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 quantitative relationship between the dose and the E, A, or T effect. 

Between October 2009 and February 2010, EPA is issuing test orders/data call-ins 

for the first group of 67 chemicals, which contains 58 pesticide active ingredients 

and 9 inert ingredients. This list of chemicals was selected based on the potential 

for human exposure through pathways such as food and water, residential activity, 

and certain post-application agricultural scenarios. This list should not be 

construed as a list of known or likely endocrine disruptors. 

Flumiclorac-pentyl is not among the group of 58 pesticide active ingredients on 

the initial list to be screened under the EDSP. Under FFDCA sec. 408(p) the 

Agency must screen all pesticide chemicals. Accordingly, EPA anticipates 

issuing future EDSP orders/data call-ins for all registration review cases, 

including those for which EPA has already opened a registration review docket 

for a pesticide active ingredient. 

For further information on the status of the EDSP, the policies and procedures, the 

list of 67 chemicals, the test guidelines and the Tier 1 screening battery, please 

visit our website: http://www.epa.gov/endo/. 

• In January 2006, a data call-in (DCI) was issued to a group of registrants who 

hold technical registrations for the LDPHs requiring submission of Guideline 

number 850.1400, fish early life-stage toxicity test, to measure how different 

wavelengths of light affect the toxicity of the LDPHs on aquatic organisms. 

Valent USA, the technical registrant for flumiclorac-pentyl, has joined a work 

group which submitted a modified protocol for Guideline 850.1400, as required 

by EPA, to detect phototoxicity in fish in the presence of the LDPHs. The 

protocol has been reviewed and approved by EPA, and pilot testing for the study 

was initiated in November 2009 with submission of the data expected in late 

2010. 

Comments Received on the Preliminary Work Plan:

The Agency received one comment during the 60-day public comment period on the 

initial flumiclorac-pentyl docket, which opened on September 23, 2009, and closed on 

November 23, 2009. A description of the comment and EPA’s response is provided in 

the “Summary of Comments and Agency Response” section of this document. The 

comment did not change the data and risk assessment needs or the timeline detailed in the 

PWP. Therefore, this document finalizes the work plan for the flumiclorac-pentyl 

registration review process. 
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Additionally in the PWP, EPA solicited comments on the specific topics of 

environmental justice, water body impairment, and trade irritants, in addition to questions 

specific to flumiclorac-pentyl concerning use, usage, benefits, and available alternatives. 

No comments or information were received during the comment period concerning these 

issues. 

Risk Assessment and Data Needs:

The Agency will conduct a comprehensive ecological risk assessment for flumicloracpentyl, including an endangered species assessment, using data generated from the newly 

required studies. A revised human health risk assessment will be required if indicated by 

the newly required studies. Below is a summary of the issues relevant to the registration 

review of flumiclorac-pentyl. 

Ecological Risk: 

• The most recent ecological risk assessment was completed in October 2005 to 

support the proposed (and subsequently registered) use of flumiclorac-pentyl on 

cotton. 

• The Agency has not conducted a risk assessment that supports a complete 

endangered species determination. The ecological risk assessment planned during 

registration review will allow the Agency to determine whether flumicloracpentyl’s use has “no effect” or “may affect” federally listed threatened or 

endangered species (listed species) or their designated critical habitats. When an 

assessment concludes that a pesticide’s use “may affect” a listed species or its 

designated critical habitat, the Agency will consult with the U.S. Fish and 

Wildlife Service and/or National Marine Fisheries Service (the Services), as 

appropriate. 

• The Agency will conduct a new drinking water assessment during registration 

review pending the receipt and review of new data. 

• Gaps exist in the environmental fate and environmental toxicity databases for 

flumiclorac-pentyl and its primary degradate of toxicological concern, IMCA. 

EPA will require the following guideline studies in order to conduct a complete 

ecological risk assessment for the registration review of flumiclorac-pentyl. 

Some of the studies are required for the parent flumiclorac-pentyl while others are 

required for IMCA. 

835.4300 – Aerobic aquatic metabolism (parent) 

835.6100 (7) – Environmental chemistry analytical method in soil 

(independent laboratory validation only, parent and IMCA) 

835.6200 (7) – Environmental chemistry analytical method in water 

(parent and IMCA) 

850.1300 – Aquatic invertebrate life-cycle, freshwater (IMCA degradate) 
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850.1350 – Aquatic invertebrate life-cycle, saltwater (IMCA degradate) 

850.2100 – Avian acute oral toxicity (passerine species, parent) 

850.4225 – Seedling emergence, Tier II (IMCA degradate for 10 species 

of terrestrial plants) 

850.5400 – Acute non-vascular aquatic plant growth, Tier II (IMCA 

degradate for three species of non-vascular aquatic plants) 

• Please refer to the July 10, 2009 document “Registration Review – Preliminary 

Problem Formulation for the Ecological Risk Assessment of Flumiclorac-pentyl”

in the registration review docket (EPA-HQ-OPP-2009-0084) for a detailed 

discussion of risk assessment needs. 

Human Health Risk:

• The most recent human health risk assessment was conducted in June 2005 to 

support the TRED and included assessments for the pending (and subsequently 

registered) new use on cotton. 

• Since the previous assessment, the percent of cotton gin byproducts assumed to be 

in the diets of ruminants has been lowered from 25% to 5%. A new dietary 

exposure assessment will be conducted during registration review and would 

reassess the dietary burden to livestock and incorporate any updates to toxicity 

endpoints, safety factors, and residue levels. 

• There are no currently registered residential uses of flumiclorac-pentyl, but 

adults and children could potentially be exposed through its use in public 

recreational areas. A new non-occupational exposure assessment will be 

conducted during registration review to incorporate new data, methods, and 

modeling parameters. Additionally, current maximum application rates, which 

are below those previously modeled, would be used. 

• A new aggregate assessment, combining food, drinking water, and nonoccupational exposures, will be conducted during registration review. 

• A new occupational handler exposure assessment will be conducted during 

registration review to incorporate new data, methods, and modeling parameters 

and would include rights-of-way and low/high pressure handwand equipment 

scenarios. 

• The tolerance expression in 40 CFR §180.477 will be revised during registration 

review to ensure that it appropriately addresses the metabolites and degradates of 

flumiclorac-pentyl. The proposed revisions are to the chemical description rather 

than the individual tolerance levels. 

• The toxicity database for flumiclorac-pentyl is largely complete except for new 

studies required under the revised 40 CFR Part 158. EPA will be requiring the 
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following guideline studies in order to conduct a complete human health risk 

assessment for the registration review of flumiclorac-pentyl: 

870.6200 – Neurotoxicity battery (acute and subchronic studies) 

870.7800 – Immunotoxicity study 

• Please refer to the August 28, 2009 document “Flumiclorac-pentyl. Revised 

Human Health Assessment Scoping Document in Support of Registration Review”

in the registration review docket (EPA-HQ-OPP-2009-0084) for a detailed 

discussion of the risk assessment needs. 

Timeline:

EPA has created the following estimated timeline for the completion of the flumicloracpentyl registration review. 

Registration Review for Flumiclorac-pentyl – Projected Registration Review Timeline

Activities Estimated Date 

Opening the docket 

Open Docket and Public Comment Period 2009 – Sept. 

Close Public Comment 2009 – Nov. 

Case Development 

Final Work Plan 2010 – Jan. 

Issue DCI 2010 – Oct. - Dec. 

Data Submission 2012 – Oct. - Dec. 

Open Public Comment Period for Preliminary Risk Assessments 2014 – April – June 

Close Public Comment Period 2014 – July - Sept. 

Registration Review Decision 

Open Public Comment Period for Proposed Registration Review 

Decision 

 2014 – Oct. - Dec. 

Close Public Comment Period 2015 – Jan. - March 

Final Registration Review Decision and Begin Post-Decision 

Follow-up 

 2015 

Total (years) 6 

Summary of Comments and Agency Responses:

The Agency received one comment during the 60-day public comment period on the 

PWP from the FIFRA Endangered Species Task Force (FESTF). The comment and 

EPA’s response is presented below. 

Comment: FESTF stated that its data on endangered species proximity contained in the 

FESTF Information Management System (FESTF IMS) and NatureServe data 

submissions to the Agency (MRIDs 46325901, 46486301, and 47260101) “fulfill the data 
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requirements... and provide the best available data necessary for the proximity analysis 

of flumiclorac-pentyl use and listed species locations.” FESTF stated that Valent USA 

Corporation is a current member of FESTF, and as such, is entitled to the FESTF data on 

federally-listed threatened and endangered species. 

Response: The Agency is aware of the information and will consider the information 

contained in the FESTF IMS, as may be applicable to flumiclorac-pentyl. However, 

preliminary reviews of the FESTF IMS indicate that these data do not satisfy all of the 

outstanding data gaps regarding the environmental fate and ecological effects of 

flumiclorac-pentyl identified in the Summary Document. The Agency will conduct a 

more thorough review during the development of the risk assessments, which will include 

addressing the status of the outstanding data requirements at that time, and the 

appropriateness of the submitted data to fulfill these requirements.

Next Steps

• The Agency plans to issue a DCI in late 2010 requiring the flumiclorac-pentyl 

studies needed to complete both the ecological and human health risk 

assessments. 

• The Agency will conduct an ecological risk assessment, an endangered species 

assessment, and a human health risk assessment for flumiclorac-pentyl.