1 **Chlorsulfuron Focus**  **Meeting Summary** 

**December 6 , 2012**  **1 1:00am** 
**- 12:30pm** 
**A ttendees**  **E.I. DuPont de Nemours and Company ( DuPont** **) :**  Aldos Barefoot, Dave W. Saunders, Craig M. Alford, Cecilia Much Hirata, Richard J. Ambrose **Environmental Protection Agency (EP A or Agency)**  **:** Kaitlin Keller (PRD), Patricia Parrott (PRD), Monica Hawkins (HED) , Sheila Piper (HED, Christine Olinger (HED), Mary Clock

- Rust (EFED), Ed Scollon (EFED), Katrina White (EFED), Cy nthia Doucoure (BEAD), Stephen Smearman (BEAD) **Objective** The purpose of the meeting was for members of the EPA ’s Pesticide Re

- evaluation Division (PRD) , Environmental F ate and Effects Division (EFED) , Biological and Economic Anal ys is Division (BEAD), and Health Effects Division (HED) to meet with DuPont , a technical registrant for chlorsulfuron , for the following reasons: 1) discuss European Union studies on chlorsulfuron degradates that EPA requested be submitted for review ; 2) discuss annual us age information needed for the reg istration review human health and eco logical risk assessment s ; 3 ) discuss use of chlorsulfuron on uncultivated areas and intermittently flooded areas as well as potential label clarifications for these use s ; 4 ) discuss label language to reduce spray drift.
**Discussion** Degradate and Metabolite Information On October 25, 2012, EPA provided DuPont with a list of degradate studies submitted to the European Union (EU) to support European registrations of chlorsulfuron and requested that DuPont submit these studies for review. On November 29, 20 12 , DuPont submitted six EU studies on chlorsulfuron degradates as requested for the registration review of chlorsulfuron. DuPont provided an overview of the findings in these studies in the meeting as well as an overview of the environmental fate and phy sical chemistry properties of chlorsulfuron. EPA indicated it would be useful to have the foreign soil classifications on studies submitted that were conducted on foreign soils using the guidance available at: http://www.epa.gov/oppfead1/international/naf tatwg/projects/regulatory /soil

- crosswalks.pdf. Use/Usage Information DuPont provided a list of active registrations for the EPA to cross - check with those EPA believes are active registrations. DuPont also provided usage information in terms of amounts us ed in pounds per ye ar nationally and regionall y by product and use category (in terms of cereal products, range and pasture products, and vegetation management) , noting that this information can be broken down b y state and will b e submitted to the Agency

. EPA agreed that a breakdown of the data b y state would be helpful. DuPont also indicated that they are working toward standardizing placement of application use information on all DuPont chlorsulfuron labels and will provide EPA with a master spreadsheet that tabulates all chlorsulfuron use information, such as use sites, application timing, application methods, single maximum and seasonal maximum uses rates and minimum retreatment intervals.2

Label Clarifications DuPont provided an overview of chlorsul furon products used and the intended us e definition for uncultivated areas. EPA and DuPont agreed that DuPont products are not intended for use in residential settings. EPA explained that unless products specificall y prohibit residential use, EPA would c on duct a residential assessment because certain chlorsulfuron uses, such as ornamentals and various uncultivated area sites, could be used by residential homeowners. DuPont agreed to work with EPA to develop appropriate language for labels that would prohibit residential use prior to the risk assessment phase of registration review. Additionally , DuPont further clarified the intermittently flooded areas use of chlorsulfuron. DuPont stated that the intended use is primaril y in the Western United States as a spot treatment in areas that would flood during spring snow melt and runoff. Moisture in these areas makes them prone to noxious weeded which landowners are required b y state regulators to control. Based on the intended use for flooded areas, EPA an d DuPont agreed that label language could be better defined. EPA also explained that more descriptive use sites could help reduce conservative assumptions in ecological risk asse ssments. Additionally, EPA requested more information on the size of the spo t treated for intermittently flooded areas. DuPont agreed to work with the Agency

to develop label language that more accurately defines this use and to provide information on the size of a spot treatment for this use. Spray Drift DuPont reviewed spray drift requirements and recommendations required by the 2005 Reregistration Eligibility

Decision (RED) and indicated that most products do have all appropriate spray

drift mitigation on the labels. Two products are missing the requirement for a maximum bo om height of 10 feet above target vegetation for aerial applications. However, DuPont noted that this is the default height in practice. DuPont committed to ensuring that the two product labels without this language are updated prior to the registration review risk assessment phase.
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 DuPont will provide the foreign soil classification for studies submitted that were conducted on foreign soils.

 DuPont will provide EPA with overall annual chlorsulfuron usage b y product broken down by state and E PA Region.

 DuPont will provide EPA with a master spreadsheet of all DuPont chlorsulfuron product use information.

 DuPont will provide EPA with the size of a ty pical spot application of chlorsulfuron on intermittently

flooded areas.

 DuPont will ensure that spray drift label language is updated on the two DuPont products currentl y missing the 10 ft. aerial application maximum boom height restriction.

 EPA will work with DuPont to develop revised label language to clearl y prohibit residential use of chlorsulfuron and better define intermittently flooded areas.