  SEQ CHAPTER \h \r 1 U. S. ENVIRONMENTAL PROTECTION AGENCY

Washington, D.C. 20460	

									     OFFICE OF

PREVENTION, PESTICIDES

	AND TOXIC SUBSTANCES 

Date: June 07, 2007

Chemical: Mefluidide, Mefluidide -DEA and Mefluidide-K

PC Code: 114001,114002, 114003

DP Barcode: D340048

MEMORANDUM

SUBJECT:    Error Corrections First Phase for Reregistration of  

                      Mefluidide acid, Mefluidide -DEA and Mefluidide-K

                       Mefluidide acid (CAS Reg. No.53780-34-0)

                       Mefluidide-DEA (CAS Reg. No.53780-36-2)

                       Mefluidide-K (CAS Reg. No. 83601-83-6)

TO:		Wilhelmena Livingston	

		Special Review and Re-Registration Division (7508P)

											

FROM:	Marie Janson, Environmental Scientist

		James Hetrick, Ph.D., Senior Scientist Advisor

		Nancy Andrews, Ph.D., Branch Chief

		Environmental Risk Branch I

		Environmental Fate and Effects Division (7507P)

	

             	

	 

	

Attached please find the Environmental Fate and Effects Division’s
(EFED) revised environmental risk assessment, which is for the phase of
error corrections only.  

 

 In this Phase I of the public process, only comments considered as
errors were corrected. Mefluidide-DEA application rates and modeled
scenarios were also corrected from 1.2 to 1.0 lb ae/A.  The registrant
offered other comments on the draft risk assessment which dealt with
substantive questions on interpretation.  Such comments will not be
addressed in this phase, but will be addressed in Phase III, the
response to public comment.

All errors comments were responded as identified by the task force in
the error correction document.

#1 Registrant comments: 

Page 4, Disclaimer:  “Based on the maximum application rate of 1.2 lb
ae/A” is an incorrect statement.  The 1.2 lb ae/A rate is taken from
the 2217-788 label which is an RTU label and the product treats less
than 1000 ft2.  As HED concluded this label rate should not be used as
the maximum use rate.  The maximum use rate is 1 lb ae/A for both
Mefluidide-K and Mefluidide-DEA as a liquid.  The maximum use rate for a
granular product is 0.5 lb ae/A from registration 538-181. 

Page 15, paragraph 2 (continued):  “The maximum application rates for
mefluidide applied as ground sprays are 0.89 lb ae/A for mefluidide-K
and 1.5 lb ae/A for mefluidide-DEA.  The maximum application rates for
mefluidide, as a granular formulation, is 0.05 lb ae/A.”  These rates
are incorrect, they should be 1.0 lbs ae/A for both mefluidide-K and
mefluidide-DEA liquid.  The mefluidide granular rate should be 0.5 lb
ae/A.  Similar language should also be corrected on page 23.

Page 25, Section 3.2.2.1, Aquatic Exposure Modeling:  “Table 3.4
contains a summary of the various labled application rates which
suggests that the maximum rate is that of mefluidide-DEA.”  This
statement is incorrect, both mefluidide-K and Mefluidide-DEA have
equivalent maximum rates of 1 lb ae/A.

Page 26, Table 3.1:  Application rate input values are all three
incorrect and should be changed to acid - 0.56 kg ae/ha, DEA salt –
1.12 kg ae/ha, K Salt – 1.12 kg ae/ha.

#1 EFED response:

The application rate and modeled scenarios for mefluidide-DEA were
changed from 1.2 lb ae/A to 1 lb ae/A in the risk assessment to address
comments for pages 4, 15, 25 and 26. Application rate input values for
mefluidide-DEA salt was changed to 1.12 kg ae/ha. Only DEA was changed 
with new application rate of 1.0 lb ae/A.

#2 Registrant comment: 

Page 5, Executive Summary:  “1.1 Nature of Stressor”  

The word stressor should be replaced by compound here and globally in
the document.

#2 EFED response: 

The word “Stressor” in the executive summary will remain the same.

#3 Registrant comment: 

 “No mortality occurred at the single dose treatment level (1500 mg
ae/L)”, should this be “1500 mg ae/A”

#3EFED response: 

1500 mg ae/L was changed to 1500 mg/kg-bw for acute bird single dose
treatment, 1500 mg ae/A is incorrect.

#4 Registrant comment: 

Page 5, paragraph 1:  “Although the registrant did not submit
dissociation data for the Mefluidide-K and Mefluidide-DEA” This is an
incorrect statement.  PBI-Gordon submitted dissociation studies for both
forms.  MRID 42282001-2  mefluidide-K dissociation, MRID 42283301-2
mefluidide-DEA dissociation.  Mefluidide-K completely dissociated in 7
min.  Mefluidide-DEA completely dissociated in 3 min.

#4 EFED response:

Page 5, paragraph 1 and throughout the assessment:  the above statement
was replaced with the following: “ Based on the ionic nature of
mefluidide-K and mefluidide-DEA and two unreviewed dissociation studies,
mefluidide-K and mefluidide-DEA will dissociate rapidly and completely
to form mefluidide acid.  The two unreviewed dissociation studies (MRIDs
422833-01 and 42282001) indicated mefluidide-K completely dissociated in
7 minutes and mefluidide-DEA completely dissociated in 3 minutes”. 

 #5 Registrant comment: 

Page 15, Use Characterization, paragraph 2:  “Annual use of mefluidide
in the United States is generally less than 10,000 lbs ae.”  This
sentence should be removed.  PBI-Gordon currently has the only sales of
either mefluidide-K or Mefluidide-DEA products and this would reveal
market intelligence to potential competitors.  Similar sentences should
be removed if present in other locations (e.g. page 23).

#5  EFED response:

EFED removed the following sentence from the assessment: “Annual use
of mefluidide in the United States is generally less than 10,000 lbs
ae.”  

 

#6 Registrant comment: 

Pages 40, 41, 42 and in Table E6, Appendix E:  Studies 41602101,
41602102, 41602103, 41601901, 41601902, and 41601903 are listed as
supplemental.  However in Appendix A all are listed acceptable.

#6 EFED response:

Appendix A studies with MRIDs 41602101, 41602102 and 41602103 were
changed from acceptable to Supplemental.

#7 Registrant comment: 

Page 62, paragraph 4:  Acute RQs were calculated for birds based on the
non-definitive LD50 value of >1500 mg ae/A. PBI-Gordon considers this an
error since data from the following MRID No.s were not used:  00073632,
00073633, and 00073634.  MRID No. 00073632 was a mefluidide acid acute
LD50 oral study that concluded a purity corrected LD50 > 4315 mg ae/kg. 
Coupling this LD50 value with the correct 1.0 lb ae/A maximum rate
should correct any RQ exceedances for birds.

#7 EFED response:

The above comment will be addressed in Phase 2 comment period. However,
the following statements were inserted in Appendix E:

Appendix  table E-5: Avian  acute oral studies were submitted for 
114001-Mefluidide and are in review MRIDs 7362 with LD50 4640 mg/kg bw.

Appendix table E-6: Avian  acute dietary studies were submitted for 
114001-Mefluidide and are in review MRIDs, 7633 and 7634 with LC50s of
>10,000 mg/kg diet.

 

#8 Registrant comment: 

Appendix E, Table 1 :  No freshwater fish studies were submitted for
114001-Mefluidide and 114003-Mefluidide potassium salt.  This statement
is incorrect, MRID No.s 41602101, 41602102, & 41602103 were conducted
with Mefluidide acid.

#8 EFED response:

Appendix  table E-1: The following sentences replaced the above
sentence: Freshwater fish studies were submitted for 114001-Mefluidide
and are in review MRIDs 73635, 80027, 80028 , 87475, 41893801 and
41893802 with LC50s ranging from > 96.4 mg/L to 1720 mg/L  

No freshwater fish studies were submitted for 114003 -Mefluidide
potassium salt

#9 Registrant comment: 

Appendix E, Table 2:  No freshwater invertebrate studies were submitted
for 114001-Mefluidide and 114003-Mefluidide potassium salt.  This
statement is incorrect, MRID No. 41893803 was conducted with Mefluidide
acid.

#9 EFED response: 

Appendix table  E-2 The following sentences replaced the above sentence:

Freshwater invertebrate study was submitted for 114001-Mefluidide and is
in review, MRID 41893803 with an EC50 of >111.

No freshwater invertebrate studies were submitted for114003 -Mefluidide
potassium salt

 

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