Document ID: EPA-HQ-OPP-2013-0661-0035
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2019-07-31T04:00Z

Meeting Summary:  5/16/19 EPA Teleconference with 2,4-DB Task Force
The following is a list of the EPA 2,4-DB team members that participated:
Samantha Thomas  -  Chemical Review Manager, Pesticide Re-Evaluation Division,  
Khue Nguyen  -  Team Leader, Pesticide Re-Evaluation Division
Cathryn Britton  -  Branch Chief, Pesticide Re-Evaluation Division
Sunil Ratnayake  -  Biologist, Biological and Economic Analysis Division
William Chism  -  Senior Biologist, Biological and Economic Analysis Division
Derek Berwald -- Senior Economist, Biological and Economic Analysis Division 

The following is a list of the 2,4-DB Task Force representatives that participated:
Mike Schofield, Technical Chair, 2,4-DB Task Force
Fred Trudwig, Aceto
Morris Gaskins, Albaugh
Nathan Ehresman, Nufarm
Bill Mahlburg, Consultant to the Task Force
Andrew Bond, Consultant to the Task Force
Ed Sharkey, Executive Director, 2,4-DB Task Force
Alice Otten, Data Group Management
Debra Miller, Data Group Management
Discussion:
EPA sought feedback from the 2,4-DB Task Force on potential risk mitigation for the 2,4-DB Proposed Interim Registration Review Decision. EPA discussed tolerance adjustments, corrections to the restricted entry interval on one label, potential spray drift management language, potential label advisory statements, and other potential label clean-up measures. The registrants agreed to the outlined potential risk mitigation without revisions or comments. 
The potential risk mitigation was previously emailed to the 2,4-DB Task Force on 5/6/2019, but consist of the following deliberative measures:
 Removal/modification of some tolerances  -  indicated on page 7 of Human Health Assessment.
 Update all labels with REI (Restricted Entry Interval) of 48 hours -- most labels have this information already, except EPA Reg. No. 34704-906, which lists an REI of 12 hrs.
 Spray drift management language (most of this is already indicated on newer 2,4-DB labels):
 Aerial Application 
 Do not release spray at a height greater than 10 ft above the ground or vegetative canopy, unless a greater application height is necessary for pilot safety.
 Applicators must use (1/2) swath displacement upwind at the downwind edge of the field.
 Do not apply when wind speeds exceed 15 mph at the application site. If the windspeed is greater than 10 mph, the boom length must be 65% or less of the wingspan for fixed wing aircraft and 75% or less of the rotor diameter for helicopters. Otherwise, the boom length must be 75% or less of the wingspan for fixed-wing aircraft and 90% or less of the rotor diameter for helicopters.  
 Ground Application
 User must only apply with the release height recommended by the manufacturer, but no more than 4 feet above the ground or crop canopy.
 For both aerial and ground application
 Applicators are required to use a medium or coarser droplet size (ASABE S572.1).
 Do not apply during temperature inversions.
 Non-target organism advisory statement (applied for all herbicides):
 "This product is toxic to plants and may adversely impact the forage and habitat of non-target organisms, including pollinators, in areas adjacent to the treated site.  Protect the forage and habitat of non-target organisms by following label directions intended to minimize spray drift."
 Revised groundwater advisory statement:
 "2,4-DB is known to leach through soil into groundwater under certain conditions as a result of label use. This chemical may leach into groundwater if used in areas where soils are permeable, particularly where the water table is shallow."
 Additional label clean up: 
 Ensure labels have a maximum yearly rate for each crop.  
 Remove references to VMD (volumetric mean diameter).

The Task Force had a comment about the inhalation data used in the 2,4-DB human health risk assessment, which refers to 2,4-D results instead of 2,4-DB results.  The Task Force is primarily concerned with data compensation issues, as well as the cost burden of the 2,4-DB inhalation studies.  The 2,4-DB HED team was not in attendance at the meeting, but PRD urged the Task Force to submit formal comments outlining these concerns, so they could be addressed.