Document ID: EPA-HQ-OPP-2005-0266-0020
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-07-27T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

Office of Prevention

Pesticides and

Toxic Substances

								PC Code: 044301, 044303

DP Barcode: 310537

Date: June 15, 2007

MEMORANDUM

SUBJECT:	Review of the Comments on the Reregistration Eligibility
Decision (RED) for Dodine

TO:	Cathryn O’Connell, Chemical Review Manager

	Tom Myers, Risk Manager

	Special Review and Reregistration Division

FROM:	Marietta Echeverria, Environmental Scientist

	Christopher J. Salice, Biologist

	Environmental Risk Branch IV

	Environmental Fate and Effects Division (7507P)

THROUGH:	Elizabeth Behl, Branch Chief

	Environmental Risk Branch IV

	Environmental Fate and Effects Division (7507P)

	The Environmental Fate and Effects Division (EFED) has completed review
of comments received from the California Pear Advisory Board and the
North Central Integrated Management Center in response to the
reregistration eligibility decision (RED) for dodine.  Each of the
submitted comments is addressed below.  

North Central Integrated Pest Management Center: 

“Specify medium to coarse droplet size - The increase to coarser
droplet size is inefficient and isn't logical.  Most of the cherry
growers use an air curtain type sprayer which has the lowest drift
potential of the sprayers available but uses a small droplet.  It
delivers a horizontal distribution for the spray and blows air up above
the pesticide to hold the pesticide spray in the canopy.  If growers had
to go to coarser droplet sizes they would have to switch sprayers and
use higher rates of the product.  The curtain type sprayers are much
more efficient than the non-curtain sprayers."

EFED Response:  The purpose of the proposed label language is to reduce
the potential of off-site transport resulting from spray drift.  The RED
currently limits droplet size to “medium coarser spray (ASAE standard
572)”.  Droplet size, along with release height and wind speed, is one
of the driving variables that can influence off-site transport resulting
from spray drift.  It is possible that certain spray equipment can
reduce spray drift if the spray is directed below horizontal.  The
Agency, however, is unaware of data quantifying the spray drift
potential for these types of air curtain type sprayers that are common
practice for the cherry growers.  If there were data quantifying the
spray drift potential from these types of sprayers, the data could be
used to support spray drift management label language which is specific
to these types of sprayers.      

California Pear Advisory Board:

“We are asking for an increase from two (2) to three (3) applications
in the ‘New Maximum/Rescue Application Rate (lbs. a.i./acre)’ as
outlined on Table 23, page 49 of the RED.  We are not asking for any
increase in the ‘New Yearly Maximum Application Rates’ of 7.8 lbs
a.i./A/yr.”

EFED Response: The ecological risk assessment done in support of the
Reregistration Eligibility Decision  (RED) evaluated the potential
exposure resulting from applications to pears at a maximum rate of 1.95
lbs ai/A for 6 applications made per year with a reapplication interval
of 5 days (annual rate of 11.7 lbs ai/A/yr).  At this annual rate, the
assessment identified potential acute risk to freshwater invertebrates,
risk to aquatic non-vascular plants, and acute and chronic risk to birds
and mammals.   

The proposed RED imposed the risk mitigation measures that resulted in a
reduced maximum typical application rate of 1.3 lbs ai/A with a maximum
of 4 applications per year and a maximum rescue rate of 1.95 lbs ai/A
allowed for 2 applications per year, resulting in a maximum yearly rate
not to exceed 9.1 lbs ai/A/year to pears.  EFED has not quantitatively
evaluated the potential exposures resulting from the mitigated use
patterns as specified in the RED.  However, the ecological risk
assessment did evaluate the potential risk resulting from a yearly
application rate of 7.8 lbs ai/A/year to cherries.  At this lower yearly
rate, the assessment still identified acute risk to freshwater
invertebrates, risk to aquatic non-vascular plants, and acute and
chronic risk to birds and mammals.  

The California Pear Advisory Board is requesting an increase in the
number of applications allowed at the maximum rescue rate from 2 to 3
applications per year without an increase to the maximum allowed yearly
rate of 9.1 lbs ai/A/year.  The request will not result in an increase
in yearly load of dodine into the environment and it is therefore not
expected to result in significant changes in potential chronic
exposures.  The increase in the number of applications at the proposed
rescue rate could result in an increase in acute exposures if the rescue
rates are made consecutively.  The Advisory Board states that the
decision about which rate to use is being made on the expected
meteorological conditions and with the help of real-time spore trapping
data.

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