2,4‐DP‐p Registration Review Focus Meeting Minutes

October 24, 2013; 10 am – 12 pm

EPA Potomac Yards South, Room 9100

EPA Invitees

Environmental Fate and Effects Division – Meghan Radtke, Faruque Khan, Sujatha Sankula

Health Effects Division – Seyed Tadayon, Ideliz Encarnacion, Ronnie Bever, Mike Metzger

Biological and Economic Analysis Division – Sepehr Haddad, Bill Phillips, Derek Berwald, Tim Kiely, Skee

Jones

Registration Division – Kathryn Montague

Pesticide Reevaluation Division – Kaitlin Keller, Tracy Perry, Patricia Parrott, Michael Goodis

USDA Invitees

USDA / Office of Pest Management Policy –  Harold Coble, Sheryl Kunickis, (phone)

2,4‐DP‐p Task Force Invitees

Nufarm UK Ltd – Andrew Bond Regulatory Affairs Mgr,

Nufarm Americas, Inc. – Nathan Ehresman, Director, Regulatory Affairs

2,4‐DP‐p Task Force –William M. Mahlburg, Debra Miller, Charles M. Schofield (Chairman EPA Liaison),

Edward Sharkey  (Executive Director)

Objective

The purpose of this meeting was for members of the EPA’s 2,4‐DP‐p registration review team  to meet  

with the 2,4‐DP‐p Task Force for the following reasons:  1) discuss usage information needed for the  

registration review ecological risk assessments, 2) discuss anticipated human health, ecotoxicity and  

environmental fate data requirements, and 3)discuss  the creation of a 2,4‐DP‐p master label.

Discussion Topics

 Introductions

 EPA provided an overview of registration review process for 2,4‐DP‐p. The Preliminary Work

Plan (PWP) for 2,4‐DP‐p will be completed in December 2013 with a 60‐day public comment

period.  The Final Work Place (FWP) will be completed in May 2014, and the Data Call‐In will be

issued in mid‐2014.   

 EPA and the 2‐4DP‐p Task Force discussed the list of 2,4‐DP‐p non‐agricultural use sites, which

includes rights‐of‐way, commercial and residential turf, and along pipelines, ditch banks, fence

rows, and tank farms, among other spot treatments.  EPA requested clarification of a pasture

use site that was outlined in BEAD’s findings based on consumer usage.  It was confirmed that

two 2, 4‐D dimethylamine salt products with pasture and rangeland uses are incorrectly listed in
OPP’s database as 2,4‐DP‐p dimethylamine salt products.  However, the Task Force indicated

that some growers use 2,4‐DP‐p along fencerows and may report this use as a pasture use.  The

Task Force confirmed that there are no supported broad spectrum pasture uses for 2,4‐DP‐p

end use products.   EPA will review the BEAD data to see if any clarification can be made on how

the use questions were posed to growers.

 EPA and the Task Force also discussed the chemistries of the eight PC codes listed in the

registration review 2,4‐DP‐p case.  The Task Force indicated that active products should only be

listed for PC codes 031402 (acid), 031403 (salt), and 031465 (ester).  They believe that two

products listed as active registrations for PC Code 031419 are also mislabeled in the EPA

database.  The Task Force will provide EPA with a list of their supported PC Codes, CAS Numbers,

and chemical names, and EPA will ensure that products incorrectly listed as 2,4‐DP‐p

registrations will be reassigned to the 2,4‐D registration review case.   The degradate 2,4‐DCP, a

common phenoxy herbicide degradate, was also discussed. The attendees agreed that EPA will

coordinate with the 2,4‐D registration review team on potential data needs and data review.  

 EPA and the Task Force also discussed a 2,4‐Dp‐p Master Label.  The Task Force agreed to

provide a matrix that includes the following information for all registration numbers:

formulation type, use site, application methods, application timing, maximum single application

rate, maximum number of applications per year, maximum yearly application rate, minimum

application intervals, pre‐harvest intervals, use site specific restrictions, and geographic

restrictions.  Additional information, such as more detailed descriptions of non‐agricultural use

sites, that may provide clarification for the risk assessments will also be provided.  The Task

Force indicated that they are also hoping to develop more geographic specific information and

provide additional clarifications on application methods and target pests.  

 The Task Force stated that most end use formulations are co‐formulated with other herbicides,

which allows for lower use rates.  2,4‐DP‐p only formulations have higher use rates.  As such,

they suggested this difference be taken into consideration in the risk assessment phase of

registration review.  EFED indicated that any available plant data on co‐formulation products

would be helpful for comparative toxicity purposes.  EPA also provided an overview of the

anticipated data needs, primarily for the ecological risk assessments.

 EPA and the Task Force discussed the EPA information requests provided on the agenda.  In

addition to the contents of the Master Label, EPA requested usage and sales data at a county or

regional level, clarification on the size, makeup, and concentration of active ingredient of

granular formulations, and the definition of a spot treatment.  EPA explained that the

information on granules will be used to calculate bird and mammal ingestion, as well as

incidental oral exposure to children for the residential turf use scenario.  The Task Force

indicated that they will provide summaries of non‐guideline avian ingestion studies that may

also be useful for risk assessment purposes.  Regarding the size of a spot treatment, the Task

Force representatives stated that the 2007 2,4‐DP‐p Reregistration Eligibility Decision

(RED)required a spot treatment be listed as a maximum 1,000 ft2

.  While this is not currently on

all labels, any labels without this restriction will be updated prior to the timing of the risk

assessments.  The Task Force will also provide an approximate quantification for the ”spray until

wet” use direction.
Follow‐up

 EPA will confirm that the four end use products listed under PC codes 031416 and 031419

belong in the 2,4‐D registration review case and ensure they are recoded in EPA databases as

such.

 The 2,4‐DP‐p Task Force will send EPA a list of supported PC codes with the corresponding CAS

numbers and chemical names.  

 The 2,4‐DP‐p Task Force will submit non‐guideline avian study summaries, relevant plant toxicity

data, and the 2,4‐DP‐p Master Label as soon as possible, ideally around the timing of the PWP

publication in December 2013.