Docket Number EPA-HQ-OPP-2009-0624 www.regulations.gov



## Sulfentrazone Final Workplan Registration Review

March 2010

1Approved by:



### Date: 

## Sulfentrazone Final Work Plan Registration Review

March 2010

Case Number 7231

2Introduction

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP) for the registration review of sulfentrazone. This FWP includes the expected registration review timeline. This work plan also addre sses public comments received concerning the Preliminary

Work Plan in the Summary Document , which was posted in the sulfentrazone registration review docket (EPA-HQ-OPP-2009-0624), and a ny other comments concerning the initial docket postings. The sulfentrazone Summary Document provided information on what EPA knows about the pesticide and what additional risk analysis data or information the Agency

believes are needed to make a registration review decision.

The Agency is implementing the registration revi ew program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), a nd will review each registered pesticide every 15 years to determine whether it continues to meet th e FIFRA standard for registration. Changes in science, public policy, and pesticide use practices occur over time. The registration review program is intended to ensure 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 wh en the initial docket is opened for each case. The docket is the Agency’s opportunity to stat e what it knows about the pesticide and what additional risk analyses and data or information it believes ar e needed to make a registration review decision. After reviewing and responding to comments and data received in the docket during this initial comment period, the Agency will develop and commit to a final work plan and schedule for the registration review of sulfentrazone.

Sulfentrazone is an aryl triazoli none herbicide registered for use to control a variety of broadleaf weeds, and is a member of the light-dependent peroxidizing herbicide (LDPH) class of weed control chemicals. It was first registered with the Agency in February 1997 and, therefore, was not subject to the reregistration requirements of FIFRA. Sulfentrazone is registered for use on several agricultural crops, ornamental turf/plant products, residential lawns, and recreational areas, such as golf courses. Several new uses have been proposed for sulfentrazone and are currently under Agency review, they are: Brassica, head and stem, Subgroup 5A; Brassica, Leafy greens, Subgroup 5B; Melon, Subgroup 9A; Fruiting Vegetable, Group 89 and Okra; Pea, Succulent; Flax; Strawberry; and Tuberous and corm Vegetable, Subgroup 1C.

Updates Since the Summary Document:

Endocrine Disruptor Screening Program

As required under FFDCA section 408(p), EP A has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substances (inc luding pesticide active and other ingredients) may have an effect in humans or wildlife si milar 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 ap proach to making the statutorily required

determinations. Tier 1 consists of a battery of 11 scr eening assays to identify the potential of a chemical substance to interact with the estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to

3interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine related eff ects caused by the substance, and establish a quantitative relationship betw een the dose and the E, A, or T effect.

Between October 2009 and February 2010, EPA issued test orders / data call-ins for the first group of 67 chemicals, which contains 58 pesticid e active ingredients and 9 inert ingredients.

This list of chemicals was selected based on th e potential for human exposure through pathways such as food and drinking water, residential activity, and certain post- application agricultural

scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Sulfentrazone is not among the gr oup of 58 pesticide activ e 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 issuin g future EDSP orders / data call-ins for all registration review cases, in cluding those for which EPA ha s already opened a registration review docket for a pesticide active ingredient.

For further information on the status of the ED SP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery, pleas e visit EPA’s website: http://www.epa.gov/endo/

.

Agricultural Health Study

Sulfentrazone is among several agricultural chem icals included in the Agricultural Health Study (AHS). The AHS began in 1993 and is a collaboration of the National Institute of Environmental Health Sciences (NIEHS), the Nati onal Cancer Institute (NCI), the EPA, and the National Institute for Occupational Safety and H ealth (NIOSH). Designed as a large long-term epidemiological study, the AHS collects and analyzes data on the health and work practices of nearly 90,000 farmers and their families in Iowa and North Carolina who enrolled in the study before any disease developed. The study focu ses particularly on fa rmers' exposure to 50 chemicals including many of the most widely used pesticides. Sulfentrazone is not one of the 50 chemicals explicitly referenced in the AHS Phase 1 questionnaire. However, it was included in a set of chemicals that were not explicitly re ferenced, but which "were used by 300 or more respondents (approximately 1% of respondent applicators).” Exposur e to these chemicals is also

considered in the AHS.

As data are collected over a period of years, sc ientists can compare overa ll health outcomes for people who differ in whether they have had ex posure to various chemicals. While these comparisons cannot conclusively demonstrate how exposure affects health, they can show some

statistical associations . More information on the AHS can be found at: http://aghealth.nci.nih.gov . EPA is monitoring the results of the AHS and will consider this study in the registration review of sulfentrazone as appropriate.

Data Call In Status

In January 2006, EPA issued a data call-in (DC I) to a group of registra nts who hold technical registrations for the LDPHs requiring submi ssion of Guideline number 850.1400, fish early life4stage toxicity test, to measure how different wavelengths of light affect the toxicity of the LDPHs on aquatic organisms. FMC Corporation, the technical registra nt for sulfentrazone, requested a waiver for this data requirement, which the Agency denied in December 2009. In January 2010, FMC joined the LDPH industry 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 submissi on of the data expected in late 2010.

Comments Received on Preliminary Work Plan

The sulfentrazone docket received three comm ents during the 60-day public comment period. Two of these comments, from the FIFRA Enda ngered Species Task Force (FESTF) and FMC Corporation, are relevant to sulfentrazone. The other comment, from G. Whitten, was about a different pesticide chemical, Rhozol, which is not related to sulfentr azone. Therefore, the comment from G Whitten has been moved to the appropriate docket.

The Agency believes that the comments received do not in any way change the data and risk assessment needs or the timeline provided in the Sulfentrazone Preliminary Workplan. Therefore, this document finalizes the work pl an for the sulfentrazone registration review process. An overview of the comments and EPA’s response are presented in the Summary of

Comments section of this document.

Risk Assessment and Data Needs

The Agency will be updating and revising the ecological risk assessment for sulfentrazone (including an endangered species risk assessmen t) and updating and revising the occupational, residential, and aggregate portions of the human h ealth risk assessment. Additional data that the Agency needs to complete these assessments are specified below.

Ecological Risk:

• The most recent ecological risk assessment was conducted in July of 2008. Ecological fate and effects data have been submitted to support sulfentrazone registrations.

• The environmental fate database for sulfentrazone is largely complete; however, data gaps have been identified. The following envi ronmental fate data requirements have not been fulfilled: anaerobic soil metabolism and aerobic aquatic metabolism. In addition, the Agency does not have Environmental Chemistry Methods (ECM) and Independent Laboratory Validation (ILV) studies to suppor t sulfentrazone. The Agency will require these studies for registration review.

• Four ground water monitoring studies have been submitted, and the Agency is in the process of reviewing these studies.

• The ecological effects database is largely complete and adequate for risk assessment purposes. Because sulfentrazone is a light-dependent peroxidizing herbicide (LDPH), the Agency has required a phototoxicity study to determine if animals exposed to LDPHs and

5intense light (similar to sunlight ) show increased toxicity rela tive to controls exposed to sulfentrazone and low intensity light vi a a group data call in for LDPH (GDCI-129081- 26293). The Agency has not received this study for sulfentrazone.

• The Agency has not conducted a risk asse ssment that supports a complete endangered species determination. The ecological risk assessment planned during registration review will allow the Agency to determine whether sulfentrazone use has “no effect” or “may affect” federally listed threatened or e ndangered species (listed species) or their designated critical habitats. When an asse ssment concludes that a pesticide’s use “may affect” a listed species or its designated critic al habitat, the Agency will consult with the

U.S. Fish and Wildlife Service and/or Nationa l Marine Fisheries Service (the Services), as appropriate.

• EPA will issue a data call in (DCI) requiring the following ad ditional guideline studies in order to conduct a complete ecological risk assessment for the registration review of

sulfentrazone:

o GDLN 835.4200 – Anaerobic soil metabolism

o GDLN 835.4300 – Aerobic aquatic metabolism

o GDLN 835.6100 1 – Environmental Chemistry Analytical Methods – Soil

o GDLN 835.6200 2 – Environmental Chemistry Analytical Methods – Water

• Please refer to the September 9, 2009 document “ EFED Problem Formulation for Sulfentrazone Registration Review” in the registration review docket (EPA-HQ-OPP2009-0624) for a detailed discussion of th e anticipated risk assessment needs.

Human Health Risk:

• The most recent human health risk assessmen t on sulfentrazone was conducted in May of 2003 in order to support the regi stration of sulfentrazone use on several agricultural crops, ornamental turf/plant products, reside ntial lawns, and non-crop land areas. In addition, a human health risk assessment is currently underway for the recently proposed new agricultural uses of sulfentrazone.

• The toxicity database for sulfentrazone is largely complete, with the exception of an immunotoxicity study (870.7800), which is required as a part of new data requirements in

the 40 CFR Part 158 for conven tional pesticide registration

. This study will be included in the upcoming DCI.

As part of the ongoing risk assessment for the propos ed new uses of sulfentrazone, . the Agency is considering revision of the h azard assessment to include change s to the point of departure and uncertainty factors, based on the Agency’s revi ew of a published developmental neurotoxicity study (DNT) study.

1 EPA will require only the analytical method portion of OPPTS GDLN 835.610 0, terrestrial field dissipation.

2 EPA will require only the analytical method portion of OPPTS GDLN 835.6200, aquatic field dissipation.

6• The dietary exposure database is adequate to support existing registration. The Agency does not anticipate requiring any additional dietary exposure data during registration

review.

• The most recent acute and chronic dietary exposure (food and drinking water) assessment, conducted in May 2003, identified no risks of concern. As part of the ongoing risk assessment for the proposed uses of sulfentrazone, however, a revised acute and chronic dietary assessment is underway. The Agency does not anticipate revising the drinking water assessment for this current dietary assessment. However, the Agency will reconsider the need for a new drinking wate r and dietary assessment based on the results of the four groundwater studies currently under review and other outstanding data requirements.

• No residential handler scenarios have pr eviously been assessed by the Agency. Although the May 2003 risk assessment includes turf use on lawns and gof courses, the products registered for this use were labeled for use only by Professional Lawn Care Operators. Therefore, handler exposure to homeowners was not expected. A recent review of sulfentrazone labels, however, id entified labels that allow for homeowner application of these products to residential areas. Therefore, the Agency determined that residential handlers are likely to be exposed to sulfentr azone residues via dermal and inhalation routes during mixing, loading, a nd applying activities. The Agency will

conduct a residential handler assessment.

• A residential post-applicati on risk assessment was conducte d in May 2003; however, the assessment only considered liquid applica tions of sulfentrazone at a maximum application rate of 0.03 lb ai/A. There are other formulations available, such as dry flowables and granular, and higher registered application rates for residential turf use (0.375 lb ai/A). The Agency intends to update the risk assessment to account for these

additional formulations and the higher application rate.

• The most recent aggregate exposure assessment was conducted in May 2003. The aggregate assessment is being revised as pa rt of the ongoing risk assessment for proposed new uses, and will consider the possible changes to the hazard assessment and the residential handler and post -application assessments.

• The most recent occupational handler and pos t-application exposure assessments were conducted in May 2003. Since the last assessmen t, additional formulations, such as dry flowables and granulars, have been registered. Based on these new scenarios, as well as the changes being considered for the h azard assessment, some handler and postapplication scenarios may n eed to be reassessed.

• In summary, EPA will issue a DCI re quiring the following guideline study:

o GDLN 870.7800 – Immunotoxicity Study

• Please refer to the September 9, 2009 “ Sulfentrazone. Human Health Assessment Scoping Document in Support of Registration Review” in the registration review docket

7(EPA-HQ-OPP-2009-0624) for a detailed discussi on of the anticipated risk assessment

needs.

Other Data Needs

• 830.7050 UV/Visible Light Absorption – this st udy is a new data requirement under 40 CFR part 158 (Product Chemistry Data Require ments) for registration of a pesticide (food and non-food uses). The Agency will be requiring this study to obtain basic information about the compound’s identity/com position and the wavelengths at which the compound may be susceptible to photochemical degradation.

Timeline:

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

Registration Review for Sulfentrazone – Projected Registration Review Timeline

Activities Estimated

Month/Year Phase 1: Opening the docket Open Docket and Public Comment Period Sept. 2009

Close Public Comment Nov. 2009 Phase 2: Case Development Develop Final Work Plan (FWP) March 2010

Issue Data Call-In Oct – Dec. 2010

Data Submission Oct – Dec. 2012 Open Public Comment Period for Preliminary Risk Assessments April – June 2014

Close Public Comment Period July – Sept. 2014 Phase 3: Registration Review Decision Proposed Registration Review Decision Oct. – Dec. 2014

Close Public Comment Period Jan. – March 2015 Final Registration Review Decision and Begin Post-Decision Follow-up 2015 Total (years) 6

Summary of Comments

(1) FIFRA Endangered Species Task Force (FESTF)

Comment: FMC corporation is a member of FEST F and is entitled to rely on the FESTF information management system (IMS) and Natu reServe data to fulfill the requirements of Pesticide Registration Notice 2000-2.

Response: The Agency thanks FESTF for its comment and will consider this information as it conducts the registration review and ma kes its registration review decisions.

8(2) FMC Corporation

FMC Corporation, the sulfentrazone registrant, su bmitted several comments to the sulfentrazone registration review docket on a variety of topics. A summary of these comments and EPA’s responses is provided below. None of these co mments change the Agency’s proposed workplan or anticipated data needs for sulfentrazone.

Comment: FMC disagrees with anticipated environmen tal fate data requirements, and cites the Code of Federal Regulations (CFR, 40 CFR ).

Response: FMC cited the CFR section pertaining to antimicrobial pesticides, not conventional pesticides such as sulfentrazone. Therefore, EP A does not intend to change the anticipated data requirements for sulfentrazone.

Comment: FMC cites several environmental fate and groundwater studies submitted to the Agency. FMC believes that these studies will inform the ecological risk assessment for

sulfentrazone.

Response: EPA will review these studies and consider them when conducting the ecological risk

assessment for sulfentrazone.

Comment: FMC cites a fish early life stage for another chemical th at it believes satisfies the outstanding data requirement for phototoxicity from the LDPH group DCI.

Response: EPA has re-evaluated the cited study and determined that it will not satisfy the data requirement. FMC has since agreed to join an in dustry work group which is sharing the cost of developing phototoxicity data.

Comment: FMC disagrees with the Agency’s interp retation of a developmental neurotoxicity study from the published literature and the proposed use of this study in human health risk assessment for sulfentrazone. FMC submits an expert opinion containing a cri tical review of this study as an addendum to its comments.

Response: EPA is reviewing the expert opinion and will consider it in the human health risk

assessment for sulfentrazone.

Comment: FMC requests clarification on a residue ch emistry data gap identified for flax and tomato processing studies.

Response: EPA considers this a data gap because of deficiencies in the submitted studies.

Comment: FMC disputes the maximum single and seas onal application rate of 2.25 lbs ai/A cited by EPA in the Summary Document.

9Response: EPA has verified that FMC is correct and that the maximum app lication rate is 0.375

lb ai/A.

Next Steps

The Agency plans to develop and issue a Data Ca ll-In Notice (DCI) for the studies identified in this document by December 31, 2010.

10