Document ID: EPA-HQ-OPP-2008-0730-0006
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2009-12-18T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

	OFFICE OF PREVENTION, PESTICIDE

	AND TOXIC SUBSTANCES

  SEQ CHAPTER \h \r 1 MEMORANDUM

Date:  22 October 2009

SUBJECT:	Endothall; Petition for Tolerances on Irrigated Crops.  Summary
of Analytical Chemistry and Residue Data. 

PC Codes:  038901, 038904 and 038905	DP Barcode:  356315

Decision No.:  399181	Registration Nos.:  70506-175 and 70506-176

Petition No.:  8E7419	Regulatory Action:  Section 3

Risk Assessment Type:  NA	Case No.:  2245

TXR No.:  NA	CAS Nos.:  145-73-3; 2164-07-0; 66330-88-9

MRID No.:  See MRID Summary Table	40 CFR:  180.293 

		              									Ver.Apr.08

FROM:	David Soderberg, Chemist  SEQ CHAPTER \h \r 1 

		HED, RAB V (7509P)

		

THROUGH:	Jack Arthur, Chief

		HED, RAB V (7509P)

		

TO:		Sidney Jackson, Product Manager  SEQ CHAPTER \h \r 1   SEQ CHAPTER
\h \r 1 

		Barbara Madden, Team Leader 

RD, Risk Integration, Minor Use and Emergency Response Branch,

Minor Use Team (7505P)

MRID Summary Table

MRID No.	Study Type	Comments

47520701	860.1400 Irrigated Crops (Root & Tuber Vegetables)	New DERs,
47520701.de1 (sugar beet, carrot and potato field trials) and 
47520701.de2 (sugar beet processing study)

47520702	860.1400 Irrigated Crops (Bulb Vegetables)	New DERs,
47520702.de1 (onion field trials)

47520703	860.1400 Irrigated Crops (Leafy Vegetables)	New DER,
47520703.der (lettuce field trials)

47520704	860.1400 Irrigated Crops (Brassica Leafy Vegetables)	New DER,
47520704.der (cabbage field trials)

47520705	860.1400 Irrigated Crops (Legume Vegetables)	New DER,
47520705.de1 (pea, bean and soybean field trials) and 47520705.de2
(soybean processing study)

47520706	860.1400 Irrigated Crops (Fruiting Vegetables)	New DERs,
47520706.de1 (tomato field trials) and 47520706.de2 (tomato processing
study)

47520707	860.1400 Irrigated Crops (Cucurbit Vegetables)	New DER,
47520707.der (cucumber field trials)

47520708	860.1400 Irrigated Crops (Citrus Fruits)	New DER, 47520708.de1
(orange field trials) and 47520708.de2 (orange processing study)

47520709	860.1400 Irrigated Crops (Pome Fruit)	New DERs, 47520709.der
(apple field trials) and 47520709.de2 (apple processing study)

47520710	860.1400 Irrigated Crops (Stone Fruit)	New DER, 47520710.der
(peach field trials)

47520711	860.1400 Irrigated Crops (Berry Group)	New DER, 47520711.der
(blueberry and blackberry field trials)

47520712	860.1400 Irrigated Crops (Tree Nut Group)	New DER, 47520712.der
(almond and pecan field trials)

47520713	860.1400 Irrigated Crops (Cereal Grain)	New DER, 47520713.de1
(corn, sorghum and wheat field trials) and 47520713.de2 (corn, sorghum
and wheat processing studies)

47520714	860.1400 Irrigated Crops (Grass)	New DER, 47520714.der (grass
field trials)

47520715	860.1400 Irrigated Crops (Nongrass animal feeds)	New DER,
47520715.der (alfalfa field trials)

47520716	860.1400 Irrigated Crops (Grapes)	New DER, 47520716.de1 (grape
field trials) and 47520716.de2 (grape processing study)

47520717	860.1400 Irrigated Crops (Mint)	New DER, 47520717.de1 (mint
field trials) and 47520707.de2 (mint processing study)

47520718	860.1400 Irrigated Crops (Rice)	New DER, 47520718.de1 (rice
field trials) and 47520718.de2 (rice processing study)

47520719	860.1380 Storage Stability (Various Crops)	New DER,
47520719.der (plant storage stability data)

  SEQ CHAPTER \h \r 1 This document was originally prepared under
contract by Dynamac Corporation (1910 Sedwick Road, Building 100, Suite
B; Durham, NC 27713).  The document has been reviewed by the Health
Effects Division (HED) and revised as needed for clarity, correctness,
and to reflect current Office of Pesticide Programs (OPP) policies.

Executive Summary

  SEQ CHAPTER \h \r 1 Endothall is a selective contact herbicide,
defoliant, desiccant, and aquatic algaecide belonging to the
dicarboxylic acid chemical class.  The free acid of endothall and its
dipotassium and mono-N,N-dimethylalkyl-amine salts (monoalkylamine) are
registered in the United States primarily as aquatic herbicides for the
control of a variety of plants in water bodies.  This includes
irrigation canals, but only with a 7 day holding period.  Endothall is
also registered for desiccation/de-foliation of alfalfa/clover (grown
for seed only), cotton, and potatoes prior to harvest, and for reduction
of sucker branch growth in hops.  Permanent tolerances have been
established for the combined residues of endothall and its monomethyl
ester at 0.1 ppm in/on cotton seeds, fish, dried hops and potatoes, and
at 0.05 ppm in/on rice grain and straw [40 CFR §180.293(a)(1)].  An
interim tolerance of 0.2 ppm has also been established for endothall,
per se, in potable water resulting from the use of the monoalkylamine or
dipotassium salts of endothall for control of aquatic plants in canals,
lakes, ponds and other potential water sources.  An interim tolerance
has also been established for endothall on sugar beet at 0.2 ppm [40 CFR
§180.319].

There are currently three endothall end-use products registered to
United Phosphorus, Inc. (UPI) for control of algae and aquatic weeds in
drainage and irrigation canals, including two monoalkylamine salt
formulations and a dipotassium salt formulation.  The monoalkylamine
salt of endothall is formulated as either a 2 lb ae/gal SC/L formulation
(EPA Reg. No. 70506-175) or an 11% granular (G) formulation (EPA Reg.
No. 70506-174), containing 5% ae.  The dipotassium salt is formulated as
a 4.23 lb ai/gal SC/L (EPA Reg. No. 70506-176), which is equivalent to
3.0 lb ae/gal SC/L.  [In order to avoid the complications of different
molecular weights for different salts, endothall concentrations are
expressed as the free acid equivalents (ae).]  Labels for these products
allow for repeated broadcast applications to irrigation canals at rates
yielding endothall concentrations of up to 5 ppm ae for the
monoalkylamine salt and 3.5 ppm ae for the dipotassium salt.  The labels
do not currently specify a maximum number of applications per season or
a maximum seasonal use rate.  Depending on the concentration in the
treated water, the use directions specify minimum holding times of 7
days (0.3 ppm rate) to 25 days (5 ppm rate) prior to using the treated
water for irrigation of crops.

 

Interregional Research Project No. 4 (IR-4) has proposed amending the
use directions for the 2 lb ae/gal SC/L monoalkylamine salt and the 3 lb
ae/gal dipotassium salt of endothall to remove the holding times after
water is treated with endothall before it can be used to irrigate crops,
which would enable use of endothall on moving water in canals etc, and
would effectively create a zero day PHI.  The amended uses specify
minimum retreatment interval (RTI) of 7 days for irrigation canals and a
maximum seasonal use rate of 30 ppm ae per season (6 applications at up
to 5 ppm ae/application). In conjunction with the proposed amendments,
IR-4 has proposed the following tolerances for indirect or inadvertent
residues of endothall on irrigated crops:

Vegetable, root and tuber, group 1	2 ppm

Vegetable, leaves of root and tuber, group 2	3.5 ppm

Vegetable, bulb, group 3-07	2 ppm

Vegetable, leafy, except Brassica, group 4	3.5 ppm

Vegetable, Brassica, leafy, group 5	0.1 ppm

Vegetable, legume, group 6	3 ppm

Vegetable, fruiting, group 8	0.05 ppm

Vegetable, cucurbit, group 9	1.1 ppm

Fruit, citrus, group 10	0.05 ppm

Fruit, pome, group 11	0.05 ppm

Fruit, stone, group 12	0.25 ppm

Berry and small fruit, group 13-07	0.6 ppm

Nut, tree, group 14	0.05 ppm

Almond, hulls	10 ppm

Grain, cereal, group 15	2.5 ppm

Grain, cereal, forage, fodder and hay, group 16, forage	3.5 ppm

Grain, cereal, forage, fodder and hay, group 16, hay	5 ppm

Grain, cereal, forage, fodder and hay, group 16, stover	11 ppm

Grain, cereal, forage, fodder and hay, group 16, straw	6 ppm

Grain, aspirated fractions	24 ppm

Grass, forage fodder, and hay, group 17, forage	3 ppm

Grass, forage fodder, and hay, group 17, hay	19 ppm

Nongrass animal feed, group 18, forage 	3.5 ppm

Nongrass animal feed, group 18, hay	8 ppm

Grape	0.9 ppm

Peppermint tops	7 ppm

Spearmint tops	7 ppm

Rice, grain	1.7 ppm

Rice, straw	4.5 ppm

The qualitative nature of endothall residues in plants is adequately
understood based upon the metabolism studies on alfalfa, cotton and
sugar beets.  The qualitative nature of endothall residues in livestock
is also understood based upon the adequate goat and poultry metabolism
studies.  The Agency has concluded that endothall and its monomethyl
ester are the residues of concern in both plant and animal commodities
for purposes of the tolerance expression and risk assessment.    SEQ
CHAPTER \h \r 1 The residue of concern in water is only endothall.  

  SEQ CHAPTER \h \r 1 A GC method with microcoulometric nitrogen
detection is listed as Method I in the Pesticide Analytical Manual (PAM,
Volume II) for determining endothall residues in/on crop commodities,
and a confirmatory HPLC/MSD method (Method No. KP218R0) is also
available for determining residues of endothall and its monomethyl ester
in fish and residues of endothall in plant commodities.  For the
irrigated crop field trails and processing studies submitted with the
current petition, endothall residues in/on plant commodities were
determined using an adequate LC/MS/MS method (Method No. KP-242R1).  For
this method, residues are extracted with water and then derivatized with
heptafluoro-p-tolylhydrazine (HFTH) in 50% H3PO4.  The derivatized
residues are cleaned up by solvent partitioning and elution through a
solid phase extraction (SPE) cartridge.  Residues are then analyzed by
LC/MS/MS using external standards for quantitation.  Residues are
expressed in endothall acid equivalents, and the validated limit of
quantitation (LOQ) for endothall is 0.05 ppm for plant commodities.

  SEQ CHAPTER \h \r 1 Adequate storage stability data are available
supporting the sample storage conditions and durations for the irrigated
crop field trials and processing studies.  The newly submitted storage
stability data indicate that endothall is stable for up to 15 months in
frozen tomatoes, lettuce, sugar beet roots, and corn grain and for up to
10 months in soybean seeds and oil.

The submitted field trial data on irrigated crops were conducted
according to the previously submitted protocol.  Two to four field
trials were conducted on each of the following crops in their major
growing regions: potato, carrot, sugar beet, green and bulb onions, leaf
and head lettuce, cabbage, succulent podded peas and beans, dry beans,
soybean, tomato, cucumber, orange, apple, peach, blueberry, blackberry,
grape, pecan, almond, field and sweet corn, sorghum, wheat, rice,
alfalfa, grasses and mint.  These crops were selected to represent the
major crop groups.  In each field trial, the monoalkylamine salt of
endothall (2 lb ae/gal SC/L) was used to treat the irrigation water at a
rate of ~5 ppm ae, and the treated water was then applied via overhead
sprinklers as six broadcast foliar applications at RTIs of 5-10 days. 
[The target application volume in each trial was equivalent to ~1 acre
inch of water (27,154 gal/A).  Based on the concentration of the
endothall in the irrigation water and the amount of water applied, the
application rates for endothall were equivalent to 1.10-1.25 lb
ae/A/application, for totals of 5.64-7.17 lb ae/A/season.]   We note
that each field trial comprised only a single plot that was then sampled
twice to provide two results.

With only a few exceptions, samples of the regulated raw agricultural
commodities (RACs) from each crop were harvested on the day of the sixth
application (0 days after treatment, DAT).  The 0 DAT exceptions
comprise soybean seed harvested from one plot at 1 DAT, wheat grain and
straw (and also the source of the aspirated grain fraction result)
harvested from one plot at 1 DAT, rice grain and straw harvested from
one plot at 1 DAT, some of the grass samples harvested at 1 – 2 DAT. 
(Interestingly, much higher results were found for the single soybean
seed and single wheat grain samples harvested at 1 DAT than for the
other soybean samples and wheat grain samples harvested at 0 DAT.  This
was not true for rice.)   In addition, in the field corn, sorghum and
wheat field trials, samples of forage and hay (wheat only) were
collected at 0 DAT, but following only 2 or 3 applications of endothall
treated water.

Side-by-side tests were also conducted on some of these crops (sugar
beets, lettuce, cucumber, and peaches) comparing application of the
dipotassium salt of endothall (3 lb ae/gal SC/L) with the monoalkylamine
salt.  Although the dipotassium salt was applied to the irrigation water
following the label directions for that salt, the resulting
concentration of endothall in the water was 3.5 ppm ae (0.7x rate). 
[The application rates for the dipotassium salt were equivalent to
0.74-091 lb ae/A/application, for totals of 4.67-5.07 lb ae/A/season.]  

Several deficiencies were noted in the field trials (see below), but the
submitted field trial data can generally be considered adequate for
assessing inadvertent residues of endothall on irrigated crops.  Results
should be very conservative.  

The residues determined in the 0 DAT samples should represent an
over-estimate of residues for many of the crops tested because
irrigation on the day of harvest would be highly unlikely to occur in
commercial harvesting procedures.  Crops and commodities which would be
unlikely to be irrigated just prior to harvest include: sugar beets,
carrots, potatoes, dry bulb onions, dried peas and beans, soybeans, tree
nuts, field corn grain and stover, sorghum grain and stover, wheat grain
and straw, and rice grain and straw.  

Also, all crops were overhead irrigated.  For grapes at least, according
to BEAD, the vines may be overhead irrigated when not in fruit, as in
these trials, but are usually only irrigated by drip irrigation once in
fruit, to reduce the growth of mold on the grape.  In addition, HED
notes that phytotoxicity was reported on a number of the crops tested,
including legume vegetables, cucumbers, apple trees, peach trees, grape
vines, mint and grass.  The phytotoxicity generally appeared beginning
after the second application and consisted of leaf chlorosis and
necrosis, with some crops also having reduced growth and stunting.  The
occurrence of phytotoxicity on a wide range of crops suggests that
repeated irrigation with water containing high levels (5 ppm) endothall
is unlikely to occur undetected under normal agricultural conditions. 
Finally, of course, the application rate used was, appropriately, at the
maximum permitted rate, and the number of applications at the high end
of the number of treatments expected in a season.  As always, it is
expected that the maximum rate and maximum number of treatments will not
be often used.    

Adequate processing studies were submitted for all possible irrigated
crops, with the exception of oil seed crops and processing of grapes to
grape juice.  Although no processing data were submitted for any crops
in the “Oilseeds Crop Group”, the available soybean processing study
can serve that purpose in this case and indicates that endothall
residues are unlikely to concentrate in either oilseed meal or refined
oil.  Because there were problems in study for processing grapes into
grape juice, a maximum theoretical processing factor of 1.2x has been
used in place of the study data.  Grape juice can therefore take the
same tolerance as grapes.  

Based on the highest average field trial (HAFT) residues for the various
irrigated crops and the observed processing factors, separate tolerances
are required for the following processed commodities at the recommended
levels:  apple wet pomace (0.15 ppm), raisins (3 ppm), dried citrus pulp
(0.1 ppm), rice hulls (5 ppm), soybean hulls (0.3 ppm), sugar beet
molasses (1.2 ppm), tomato paste (0.1 ppm), and wheat milled byproducts
(5 ppm).  The wheat grain processing study also indicates that endothall
residues can concentrate in aspirated grain fractions (AGF) by 15x. 
Based on the HAFT residues for wheat grain, which were the highest for
all grains, an appropriate tolerance for AGF would be 30 ppm.

No cattle and poultry feeding studies have been submitted for endothall.
 Considering the exposure of livestock to endothall residues through
both the consumption of feedstuffs from irrigated crops and from the
drinking of endothall treated water treated at 5 ppm endothall ae, the
calculated maximum dietary exposure of livestock to endothall is 27.7
ppm for beef cattle, 35.8 ppm for dairy cattle, 16.8 ppm for poultry,
and 19.7 ppm for swine.

Proposed tolerances in meat tissues have therefore been based upon these
dietary burdens and upon the TRR developed in the meat tissues when
goats and chickens were fed radiolabeled endothall for the metabolism
studies.  Approval will require confirmatory submission of the required
feeding studies.  

The Agency has concluded that the only residues of significance in
rotated crops are endothall and its monomethyl and dimethyl esters. 
Although data from limited field rotational crop trials have been
previously required, the inadvertent exposure of crops to endothall via
the use of treated irrigation water will exceed the potential exposure
of crops from being planted in rotation with endothall treated primary
crops.  Therefore, the establishment of tolerances for
indirect/inadvertent residues of endothall on the proposed irrigated
crops precludes any further need for limited field rotational trial data
or for rotational crop tolerances.

  SEQ CHAPTER \h \r 1 Regulatory Recommendations and Residue Chemistry
Deficiencies

Several deficiencies were noted in the subject petition, but none of
these would preclude establishing permanent tolerances for inadvertent
endothall residues in/on irrigated crop commodities.  Although the
following deficiencies were noted in the irrigate crop field trials, no
action is required to resolve these deficiencies.

	•	The bridging studies comparing the use of the monoalkylamine and
dipotassium salts of endothall were of limited use as the two
formulations were applied at different rates.  In terms of acid
equivalents, the monoalkylamine salt was applied at a concentration of 5
ppm and the dipotassium salt was applied at a concentration of 3.5 ppm,
which is the maximum allowed use rate of the dipotassium salt (0.7x rate
for the monoalkylamine salt).  For each of the crops tested with both
salt formulations, endothall residues were 0.6-0.9x lower for the
dipotassium salt than for the monoalkylamine salt, which is consistent
with the lower use rate for the dipotassium salt.  Although the bridging
studies do not allow for direct comparison of the two salts, the data do
indicate that endothall residues resulting from application of the
dipotassium salt to irrigation canals would generally be expected to be
lower than from the monoalkylamine salt, when both are applied according
to current label directions.  

	•	Spinach should have been used as the representative leafy vegetable
crop, as foliar applications generally result in higher residues on
spinach than on lettuce (leaf and head) or celery. 

	•	Mustard greens should have been used as the representative Brassica
vegetable crop, as foliar applications generally result in higher
residues on mustard greens than on broccoli, cauliflower or cabbage.

	•	Field corn forage, sorghum forage and wheat forage and hay only
received 2-3 applications prior to harvest.  For these crops, separate
plots should have been established for collection of forage and hay
samples so that all six applications could have made prior to harvest of
forage and hay.

	•	No field trials were conducted on an oil seed crop such as, canola,
flax, safflower, or sunflower.

	•	No field trials were conducted on peanuts, which is a major field
crop.

The following additional deficiencies were also noted in the submitted
petition; however, these deficiencies must be resolved as a condition of
registration.

	•	Data are required indicating whether or not the submitted LC/MS/MS
method is capable of extracting and recovering the monomethyl ester of
endothall.

	•	Dairy cattle and laying hen feeding studies are required to support
immediate application of endothall-treated irrigation water to crops.

	•	A revised Section F is required including the recommended
tolerances on RACs and processed commodities from irrigated crops.

HED recommends for establishing permanent tolerances for indirect or
inadvertent residues of endothall on irrigated crops.  The recommended
tolerances for the various crops and crop groups and their associated
processed commodities are listed in Table 10.  The tolerances for
irrigated crops should be established under 40 CFR §180.293(d).   A
human health risk assessment for endothall is forthcoming.

Background

  SEQ CHAPTER \h \r 1 Endothall is a dicarboxylic acid that is a
selective contact herbicide, defoliant, desiccant, and aquatic
algaecide.  The free acid of endothall (PC Code 038901) and its
dipotassium (PC Code 038904) and monoalkylamine (PC Code 038905) salts
are registered primarily as aquatic herbicides for the control of a
variety of plants in water bodies, including irrigation canals. 
However, these uses require a minimum 7 day holding period before the
water can be used on crops.  They are also registered for desiccation/
defoliation of alfalfa/clover (grown for seed only), cotton, and
potatoes prior to harvest, and for reduction of sucker branch growth in
hops.  The Reregistration Eligibility Decision (RED) for endothall was
issued September 2005. 

Permanent tolerances are established for the combined residues of
endothall and its monomethyl ester at 0.1 ppm in/on cotton seeds, dried
hops and potatoes, and at 0.05 ppm in/on rice grain and rice straw [40
CFR §180.293(a)(1)]; and an interim tolerance has also been established
for endothall on sugar beet at 0.2 ppm [40 CFR §180.319].  These
tolerances are intended to cover intended direct use of endothall on
these crops.  Permanent tolerances are also established for fish at 0.1
ppm straw [40 CFR §180.293(a)(1)].  

Residue data supporting irrigation of crops with endothall treated water
were previously submitted using cabbage, celery, grapefruit, peppers and
turnips as representative crops.  However, these studies were deemed
inadequate to support the establishment of crop group tolerances. 
Additional data were required for other representative crop group
commodities and the irrigated crop studies were conducted using
endothall in the water at 3 ppm, which is 0.6x the maximum application
rate of 5 ppm for aquatic sites.  The Endothall RED reiterated the need
for extensive crop field trials to support the use of treated irrigation
water on crops.  The application rate in these tests needed to reflect
the maximum aquatic use rate of endothall (5 ppm) and the maximum
possible number of applications per season.

In response to the above requirements, IR-4 has proposed amendments to
the use directions for endothall on irrigation canals and has submitted
extensive crop field trials to support tolerances on irrigated crops
(PP#8E7419) when endothall is used with a zero day holding period.  The
chemical structure and nomenclature of endothall and its salts are
listed in Table 1.  The physicochemical properties of technical grade
endothall and its salts are listed in Table 2. 

  SEQ CHAPTER \h \r 1 

Table 1.  Structure and Nomenclature of Endothall and its Salts.

Chemical Structure	

Common name	Endothall

Molecular Formula	C8H10O5

Molecular Weight	186.16

IUPAC name	7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid

CAS name	7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid

CAS #	145-73-3

PC Code	038901

Current Food/Feed Site Registration	Cotton, hops, potato, alfalfa grown
for seed

Chemical Structure	

Common name	Endothall, dipotassium salt

Molecular Formula	C8H8K2O5

Molecular Weight	262.33

IUPAC name	Not available

CAS name	Not available

CAS #	2164-07-0

PC Code	038904

Current Food/Feed Site Registration	Cotton, hops, potato, alfalfa grown
for seed, aquatic uses 

Chemical Structure	

Common name	Endothall, mono-N,N-dimethylalkyl amine salt

Molecular Formula	Not available

Molecular Weight	Average:  422 

IUPAC name	7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid, compound
with N,N-dimethylcocoamine

CAS name	Not available

CAS #	66330-88-9

PC Code	038905

Current Food/Feed Site Registration	Cotton, hops, potato, alfalfa grown
for seed, aquatic uses 

Table 2.  Physicochemical Properties of Endothall and its Salts.

Parameter	Value	Reference

Endothall (acid)

Melting point	108-110 ̊C	DP# 304026, D. Soderberg, 6/10/2004

pH	2.7 at 25 ̊C (1% solution)

	Density, bulk density, or specific gravity	0.481 g/cm3 (bulk) at 25 ̊C

	Water solubility at 25 ̊C	109.8 g/L

13.1 g/100 mL in water, pH 5

12.7 g/100 mL in water, pH 7

12.5 g/100 mL in water, pH 9

	Solvent solubility at 25 ̊C	3.4 g/100 mL in acetonitrile

2.4 g/100 mL in n-octanol

16.0 g/100 mL in tetrahydrofuran

	Vapor pressure	3.92 x 10-5 mm Hg at 24.3 ̊C

	Dissociation constant, pKa	4.32 for Step 1 and 6.22 for Step 2 at 20
̊C (0.2% solution in 20% basic ethanol); dissociation rate 1.8-2.3 x
103 µmho within 3-5 minutes at ∼25 ̊C, by conductivity meter

	Octanol/water partition coefficient	Not applicable to endothall acid

	UV/visible absorption spectrum	Not available

	Endothall, dipotassium salt

Melting point	>360 ̊C	DP# 304026, D. Soderberg, 6/10/2004

pH	9.1 at 25 ̊C (1% solution)

	Density, bulk density, or specific gravity	0.766 g/cm3 (bulk) at 25 ̊C

	Water solubility	>65 g/100 mL in water, pH 5, pH 7, and pH 9

	Solvent solubility	<0.001 g/100 mL in acetonitrile, n-octanol, and
tetrahydrofuran

	Vapor pressure	Not applicable.  An organic acid K salt is anticipated
to have an insignificant vapor pressure.

	Dissociation constant, pKa	4.16 for Step 1 and 6.14 for Step 2 at 20
̊C in water; dissociation complete at 5 mins (13.6 x 103 µmho)

	Octanol/water partition coefficient	KOW <0.02 and <0.3 at
concentrations of 9 x 10-3 M and 9 x 10-4 M, respectively, at 25 ̊C

	UV/visible absorption spectrum	Not available

	Endothall, mono-N,N-dimethylalkyl amine salt

Boiling point	Not available	DP# 304026, D. Soderberg, 6/10/2004

pH	5.2 at 25 ̊C (1% solution)

	Density, bulk density, or specific gravity	1.028 g/mL at 25 ̊C

	Water solubility at 25 ̊C	≥49.2 g/100mL in water, pH 5

≥51.6 g/100 mL in water, pH 7

≥49.8 g/100 mL in water, pH 9

	Solvent solubility at 25 ̊C	≥102.5 g/100mL in acetonitrile

≥95.4 g/100 mL in n-octanol

≥104.3 g/100 mL in tetrahydrofuran

	Vapor pressure	2.09 x 10-5 mm Hg at 25 ̊C (calculated; mixed mono- and
dialkylamine (C8-C20))

	Dissociation constant, pKa	4.24 for Step 1 and 6.07 for Step 2 at 20
̊C for mixed mono- and dialkylamine (C8-C20) in acidified
ethanol/water; dissociation complete ∼17 minutes (1.7 x 103 µmho) at
25 ̊C

	Octanol/water partition coefficient	KOW 2.097 at concentrations of 8.9
x 10-3 M and 8.9 x 10-4 M, at 25 ̊C

	UV/visible absorption spectrum	Not available

	

860.1200  Directions for Use

There are currently three endothall end-use products registered to UPI
for control of algae and aquatic weeds in drainage and irrigation
canals, including two monoalkylamine salt formulations and a dipotassium
salt formulation.  The monoalkylamine salt of endothall is formulated as
either a 2 lb ae/gal SC/L formulation (Hydrothol 191; EPA Reg. No.
70506-175) or an 11% G formulation (Hydrothol Granular; EPA Reg. No.
70506-174), which contains 5% acid equivalent of endothall.  The
dipotassium salt is formulated as a 4.23 lb ai/gal SC/L (Aquathol® K;
EPA Reg. No. 70506-176), which is equivalent to 3.0 lb ae/gal SC/L.  

The current labels for these products allow for repeated broadcast
applications to irrigation canals at rates yielding endothall
concentrations of up to 5 ppm ae for the monoalkylamine salts and 3.5
ppm ae for the dipotassium salt.  (HED notes that the label directions
for the dipotassium salt are expressed in lb ai rather than lb ae;
therefore the use rates for the dipotassium salt are ~0.7x the use rates
for the monoalkylamine salt.)  The labels do not currently specify a
maximum number of applications per season or a maximum seasonal use
rate.  Depending on the concentration in the treated water, the use
directions specify minimum holding times of 7 days (0.3 ppm rate) to 25
days (5 ppm rate) prior to using the treated water for irrigation of
crops.

 

IR-4 is supporting an amendment to the use directions for the 2 lb
ae/gal SC/L monoalkylamine salt and the 3 lb ae/gal SC/L dipotassium
salt of endothall to remove the holding time restriction for using
endothall-treated water from irrigation canals for the irrigation of
crops.  The amended uses also specify a minimum RTI of 7 days and a
maximum seasonal use rate of 30 ppm ae per season.  Example labels
containing the proposed use directions were provided and are summarized
below in Table 3.

Table 3.	Summary of Proposed Use Directions for Endothall Salts on
Irrigation and Drainage Canals.

Applic. Timing, Type, and Equip.	Formulation 1

[EPA Reg. No.]	Applic. Rate 2	Maximum Seasonal Rate 2	PHI (days)	Use
Directions and Limitations

Endothall Monoalkylamine Salt (PC Code 038905)

Broadcast surface application to water; ground equipment	2.0 lb ae/gal
SC/L

[70506-175]	5.0 ppm	30 ppm	0 3	A minimum 7-day RTI is specified.

Do not use treated water for domestic purposes or animal consumption
within the following period:  0.3 ppm - 7 DAT; 3.0 ppm - 14 DAT; and
5.0 ppm - 25 DAT.

Endothall dipotassium salt  (PC Code 038904)

Broadcast surface application to water; ground equipment	3.0 lb ae/gal
SC/L

[70506-176]	3.5 ppm	21 ppm	0 3	A minimum 7-day RTI is specified.

Do not use treated water for domestic purposes or animal consumption
within the following period:  0.3 ppm - 7 DAT; 3.0 ppm - 14 DAT; and
5.0 ppm - 25 DAT.

1	The formulations are expressed in lb endothall ae/gal.

2	The maximum single and seasonal application rates are expressed in
concentration of the endothall acid.  The 30 ppm seasonal maximum rate
is equivalent to 6 applications at the maximum single use rate.

3	No holding time is required prior to use of treated water for
irrigation of crops.

NS = not specified.

Conclusions.  The submitted labels are adequate to evaluate the residue
data relative to the proposed use of endothall on irrigation canals.

 860.1300:  Nature of the Residue - Plants

DP# D321179, D. Soderberg, 8/30/2005

The nature of endothall residues in plants is adequately understood
based on the acceptable alfalfa, cotton, and sugar beet metabolism
studies reflecting use of the dipotassium salt of [14C]endothall.  An
adequate cotton metabolism study is also available reflecting use of the
mono-N,N-dimethylalkylamine salt of [14C]endothall.  HED has concluded
that the metabolism studies using the dipotassium salt will also fulfill
metabolism data requirements for the monoalkylamine salt as the two
salts would be expected to behave similarly in plants.  The HED
Metabolism Committee (S. Funk, 11/8/96) has also concluded that the
residues of concern for both risk assessment and tolerance enforcement
in plant commodities include parent endothall and its monomethyl ester. 

860.1300:  Nature of the Residue - Livestock

DP# D321179, D. Soderberg, 8/30/2005

The qualitative nature of the endothall residues in livestock is
adequately understood based on the acceptable poultry and goat
metabolism studies.  The HED Metabolism Committee has concluded that the
residues of concern in animal commodities consist of parent endothall
and its monomethyl ester.

860.1340 Residue Analytical Methods

DP# D321179, D. Soderberg, 8/30/2005

Enforcement Methods

  SEQ CHAPTER \h \r 1 An enforcement method (GC with microcoulometric
nitrogen detection) is listed as Method I in the Pesticide Analytical
Manual (PAM, Volume II) for the determination of endothall in plant
commodities.  Using this method, residues in crop commodities are
extracted using acetone acidified with HCl.  The extract is
concentrated, and the oil and oil-soluble materials are removed by
partitioning solvents.  The endothall containing oil-free fraction is
concentrated by boiling with acetic acid.  Any endothall present is
converted to the N-methoxyimide derivative by reaction with methoxyamine
hydrochloride.  The imide is partitioned into chloroform, concentrated
and analyzed by GC using a nitrogen specific detector.  The method LOQ
is 0.1 ppm. 

A confirmatory HPLC/MSD method (Method No. KP218R0) is also available
for determining residues of endothall and its monomethyl ester in fish
and residues of endothall in plant commodities.  For this method,
residues are extracted with water, acidified and, if necessary, purified
using a C18 SPE column.  Residues are then derivatized with
heptafluoro-p-tolylhydrazine (HFTH) and partitioned into dichloromethane
(DCM).  Derivatized residue are concentrated, redissolved in toluene,
and cleaned up using a silica gel cartridge.  Residues are determined by
HPLC/MSD using the 397 amu ion for detection and quantitation.  The
validated LOQ is 0.05 ppm for fish (endothall and endothall monomethyl
ester), and the LOQs for plant commodities range from 0.01-0.10 ppm,
with the initial C18 SPE cleanup step.  This method has undergone a
successful independent laboratory validation using fish samples.  

Data Collection Methods

m/z 397→166 ion transition was used for quantifying residues. 
Residues are expressed in endothall acid equivalents.  The validated LOQ
is 0.05 ppm for plant commodities.

In conjunction with the irrigated crop field trials, the above method
was adequately validated on all plant matrices tested.

 

Conclusions.  Adequate methods are available for enforcing the proposed
tolerances, and the residue data from the field trials and processing
studies were collected using an adequate LC/MS/MS method.  The
conditions for the derivatization step used in Method No. KP-242R1
should hydrolyze the monomethyl ester to the free acid.  However, no
data were provided as to whether or not the LC/MS/MS method can recover
residues of the methyl ester of endothall, which are also residues of
concern.  

860.1360 Multiresidue Methods

DP# D321179, D. Soderberg, 8/30/2005

Adequate data are available evaluating the recovery of endothall using
the FDA multiresidue methods   SEQ CHAPTER \h \r 1 published in the FDA
Pesticide Analytical Manual, Volume I (PAM Vol. I). The available data
indicate that endothall is not recovered through the FDA multiresidue
methods.

860.1380 Storage Stability

DP# D321179, D. Soderberg, 8/30/2005

47520719.der.doc

Adequate storage stability data are available indicating that endothall
is stable under frozen storage conditions for up to 5.5 years in rice,
broccoli, oranges and tomatoes; 15 months in sugar beet tops and roots;
12 months in potatoes and cottonseed; and 9 months in alfalfa seed.  

≤-8°C.  Stored samples of frozen tomatoes, lettuce, sugar beet roots
and corn grain were analyzed after 0, 1, 10 and 15 months of storage and
the frozen soybean seed and oil samples were analyzed after 0, 1, 5 and
10 months of storage.  Endothall residues were completely stable for up
to 15 months in frozen tomatoes, lettuce, sugar beet roots, and corn
grain and for up to 10 months in soybean seeds and oil.  The tests on
soybean seeds and oil are on-going. 

The storage durations and conditions of samples from the irrigated crop
field trials submitted to support this petition are presented in Table
4.  

Table 4.	Summary of Storage Conditions and Durations of Samples from
Irrigated Crop Field Trial and Processing Studies.  

Matrix 	Storage Temperature  (°C)	Actual Storage Duration (days)
Interval of Demonstrated Storage Stability (days)

Field Trials

Carrot	≤-18	33-272	469

Potato

41-58

	Sugar beet tops and roots

47-64

	Onions, green and bulb	≤-18	63- 143	469

Lettuce	≤-18	34-92	469

Cabbage	≤-18	61-118	469

Lima beans, succulent podded	 ≤-10	93-431	315-469

Dried beans

63-76

	Garden peas, succulent podded

113-127

	Soybean seed

39-385

	Tomatoes	 ≤-11	77-106	~2000

Cucumbers	 ≤-10	478	~2000

Oranges	 ≤-18	105-107	~2000

Apples	 ≤-18	230	~2000

Peaches	 ≤-10	154	~2000

Blueberries and blackberries	≤-18	85-98	~2000

Pecan nutmeat	≤-18	203	315-469

Almond nutmeats and hulls

90-96

	Corn, K+CWHR, forage, grain, and stover	≤-10	42-238	466-469

Sorghum forage, grain and stover	≤-10	51-83	466-469

Wheat forage, grain, hay and straw	≤-10	42-113	466-469

Grass forage and hay	≤-10	404-440	469

Alfalfa Forage and hay	≤-18	66-83	469

Grapes	 ≤-10	88-379	467

Mint tops	≤-18	22-336	469

Rice grain and straw	≤-10	64-99	466-469

Processing Studies

Sugar beet roots, dried pulp, molasses and refined sugar	≤-18	19-64
465

Soybean seed, hulls, meal and refined oil	≤-10	17-78	306-315

Tomato fruit, paste and puree	≤-5	77-80	~2000

Orange fruit, dried pulp, juice and oil	≤-18	109-121	~2000

306 (oil)

Apple fruit, juice and wet pomace	≤-18	231-286	~2000

Sorghum grain and flour	≤-10	26	~2000

Wheat grain, middlings, bran, flour, shouts and germ	≤-10	34-79	~2000

Corn grain, grits, meal, flour, starch, and oil 	≤-10	22-37	~2000

306 (oil)

Grape fruit, juice and raisins	 ≤-10	377-379	~2000

Mint Tops	≤-17	22-336	467

Mint Oil 

241	306

Rice grain, hulls, bran and polished rice	≤-10	39-48	~2000

Conclusions.  The available storage stability data are adequate and
support the sample storage conditions and durations from the irrigated
crop field trials.

  SEQ CHAPTER \h \r 1 860.1400 Water, Fish, and Irrigated Crops

Fish.  

DP# D307060 D. Soderberg 8/23/2004

Residue data were submitted (MRIDs 44820102, 43315801 and 42644001)
showing metabolism of endothall in fish, bioconcentration of endothall
residues in fish, and magnitude of the residue data in fish.  Most of
the endothall radioactive residue was incorporated into natural
components of the fish.  No endothall, per se, or either of its methyl
esters were identified in the metabolism study, but one could infer from
the combination of studies and other correlate information, that the
residues of interest would be endothall and its monomethyl and dimethyl
esters.  

A magnitude of the residue study was performed using bluegill, catfish,
crayfish, and freshwater clams in seven treated fresh water tanks and
one control tank.  Using a method with an LOQ of 0.02 ppm, residues of
endothall, per se, were not detected in catfish, were up to 0.026 ppm in
bluegills, up to 0.23 ppm in crayfish and in freshwater clams were up to
0.96 ppm.  There was no measurable contribution to the residue from
either of the methyl esters, however recovery of the methyl esters was
not good.  

Consistent with the  registrant’s proposal for tolerance, HED agreed
that these data could support tolerances at 0.1 ppm for fish, 1 ppm for
crustaceans, and 4 ppm for mussels - pending submission of either a
revised metabolism study or a radio-validation study more clearly
showing the importance of the methyl esters in the total residue, or
revised residue data using a method showing better recovery of the two
methyl esters.  A tolerance of 0.1 ppm has since been published for
fish.  

Irrigated Crops.  

DP# D321179, D. Soderberg, 8/30/2005

47520701.de1.doc	(Sugar beet, carrot, potato)	47520702.der.doc	(Green
and dry bulb onions)

47520703.der.doc	(Cabbage)	47520704.der.doc	(Leaf and head lettuce)

47520705.de1.doc	(Legume vegetables)	47520706.de1.doc	(Tomato)

47520707.der.doc	(Cucumber)	47520708.de1.doc	(Orange)

47520709.de1.doc	(Apple)	47520710.def.doc	(Peach)

47520711.der.doc	(Blueberry and blackberry)	47520712.der.doc	(Pecan and
Almond)

47520713.de1.doc	(Corn, sorghum and wheat)	47520714.der.doc	(Grass)

47520715.der.doc	(Alfalfa)	47520716.de1.doc	(Grape)

47520717.de1.doc	(Mint)	47520718.de1.doc	(Rice)

Residue data supporting the use of endothall-treated water for
irrigation of crops were previously submitted on cabbage, celery,
grapefruits, peppers, and turnips as representative crops (DP# D321179,
D. Soderberg, 8/30/2005).  In these earlier tests, the SC/L or G
formulations of the monoalkylamine or dipotassium salts for endothall
were applied to the above crops at a concentration of ~3 ppm using
overhead or furrow irrigation, with each crop receiving 5-7
applications.  HED concluded that these data were not adequate because
endothall was not applied at the maximum use rate allowed for irrigation
canals (5 ppm) and because the data were insufficient to cover all
irrigation crops.

In response, IR-4 submitted a protocol for conducting limited field
trials on representative irrigated crops.  This protocol was discussed
with ChemSAC, which provided only minor comments (ChemSAC minutes for
5/12/06 meeting).  Subsequently, IR-4 has submitted limited field trial
data covering a wide variety of crops and crop groups that could be
irrigated with endothall-treated water, including:  carrots, potatoes
and sugar beets (groups 1 and 2); green and dry bulb onions (group 3);
leaf and head lettuce (group 4); cabbage (group 5); dried and succulent
(podded) peas and beans (group 6); tomatoes (group 8), cucumbers (group
9); oranges (group 10), apples (group 11), peaches (group 12),
blueberries and blackberries (group 13); almonds and pecans (group 14);
corn, sorghum, wheat and rice (groups 15 and 16); grass (group 17);
alfalfa (group 18); and mint.  Although the field trials cover a wide
variety of crops, the number of field trials conducted on any given
crops was limited, ranging from 2 to 4 tests per crop.

In each field trial, the monoalkylamine salt of endothall (2 lb ae/gal
SC/L) was used to treat the irrigation water at a rate of ~5 ppm ae
(ae), and the treated water was then applied via overhead sprinklers as
six broadcast foliar applications at RTIs of ~7 days.  The target
application volume in each trial was equivalent to ~1 acre inch of water
(27,154 gal/A).  Based on the concentration of the endothall in the
irrigation water and the amount of water applied, the target application
rate for endothall was equivalent to 1.13 lb ae/A/application, for a
total of 6.79 lb ae/A/season.  Side-by-side tests were also conducted on
selected crop (sugar beets, lettuce, cucumber, and peaches) comparing
application of the dipotassium salt of endothall (3 lb ae/gal SC/L) with
the monoalkylamine salt.  However, although the dipotassium salt was
applied to the irrigation water according to the label directions for
that salt, the resulting concentration of endothall in the water was 3.5
ppm ae.  [Unlike the label directions for the alkylamine salt, the label
directions for the potassium salt assume that it is applied at 5 ppm as
the salt, not as the acid equivalent, that is to say, the potassium salt
labeled instructions describe application at 5 ppm ai, not 5 ppm ae.]

In each field trial, the endothall residues were determined using an
adequate LC/MS/MS method (Method No. KP-242R1), which is described in
the above Residue Analytical Methods Section.  The method was validated
in conjunction with each trial, and the validated LOQ for endothall is
0.05 ppm in each commodity.  The sample storage conditions and durations
for the various crop commodities from each of the field trials are
supported by the available storage stability data.  The details for each
of the submitted field trials are discussed below, and the endothall
residues in the commodities are summarized in Table 5.

TABLE 5.	Summary of Residue Data from Field Trials with Endothall.

Commodity	Formulation type	Total Applic. Rate 1	PHI (days)	Residue
Levels (ppm) 2

n	Min.	Max.	HAFT 3	Median

(STMdR)	Mean

(STMR)	Std. Dev.

Root and Tuber Vegetables

Sugar beet, tops	Monoamine salt (SC/L)	5 ppm

(6.77-6.79)	0	2	1.32	1.36	1.36	1.34	1.34	0.033

	Dipotassium salt (SC/L)	3.5 ppm

(4.80-4.88)	0	2	0.527	1.114	1.114	0.820	0.820	0..415

Sugar beet, roots	Monoamine salt (SC/L)	5 ppm

(6.77-6.79)	0	2	0.165	0.493	0.493	0.330	0.330	0.230

	Dipotassium salt (SC/L)	3.5 ppm

(4.80-4.88)	0	2	0.118	0.330	0.331	0.224	0.224	0.151

Carrot	Monoamine salt (SC/L)	5 ppm

(6.77-6.79)	0	2	0.0685	0.088	0.088	0.078	0.078	0.014

Potato	Monoamine salt (SC/L)	5 ppm

(6.77-6.83)	0	2	0.0725	0.875	0.0875	0.080	0.080	0.011

Bulb Vegetables

Green Onion	5.0 ppm

(6.75)	0	1	0.259	0.259	0.259	0.259	0.259	NA

Dry Bulb onion	5.0

(6.76)	0	1	<0.05	<0.05	<0.05	<0.05	<0.05	NA

Leafy Green Vegetables – Lettuce

Leaf lettuce	Monoamine salt (SC/L)	5 ppm

(6.73-6.76)	0	2	0.436	.9915	0.9915	0.714	0.714	0.393

	Dipotassium salt (SC/L)	3.5 ppm

(4.67-4.81)	0	2	0.248	0.7975	0.7975	0.523	0.523	0.363

Head lettuce	Monoamine salt (SC/L)	5 ppm 

(6.76-7.17)	0	2	0.0865	0.5475	0.5475	0.292	0.317	0.270

	Dipotassium salt (SC/L)	3.5 ppm

(4.81-5.07)	0	2	0.066	0.509	0.509	0.2875	0.2875	0.3132

Brassica - Cabbage 

Cabbage, head with wrapper leaves	5 ppm

(5.64-7.00)	0	2	0.0615	0.0625	0.0625	0.062	0.062	0.0007

Legume Vegetables 

Succulent podded beans	5 ppm

(6.75, 9.02) 4	0	2	0.3075	0.4675	0.4675	0.3875	0.3875	0.113

Succulent podded peas	5 ppm

(6.74)	0	2	0.5295	0.939	0.939	0.734	0.734	0.290

Dried Beans	5 ppm

(6.77)	0	2	0.102	0.116	0.116	0.109	0.109	0.010

Soybean, dried seed	5 ppm

(6.75-6.77)	0-1	4	<0.050	0.07	0.07	0.034	0.034	0.025

Fruiting Vegetables – Tomatoes

Tomato	5 ppm

(6.74-6.77)	0	2	<0.05	<0.05	<0.05	0.05	0.05	N/A

Cucurbits - Cucumbers 

Fruit 	Monoamine salt (SC/L)	5 ppm

(6.75-6.77)	0	2	0.259	0.738	0.738	0.499	0.499	0.339

Fruit	Dipotassium salt (SC/L)	3.5 ppm

(4.80-4.81)	0	2	0.324	0.433	0.433	0.522	0.522	0.389

Citrus - Orange 

Orange	5 ppm

(6.63-6.78)	0	2	0.0215	0.026	0.026	0.024	0.024	0.0032

Pome Fruit – Apple

Apple	5 ppm

(6.64-6.79)	0	2	0.039	0.043	0.043	0.041	0.041	0.0028

Stone Fruits – Peach

Fruit 	Monoamine salt (SC/L)	5 ppm

(6.78-7.08)	0	2	0.044	0.152	0.152	0.098	0.098	0.076

Fruit	Dipotassium salt (SC/L)	3.5 ppm

(4.82-5.05)	0	2	0.045	0.127	0.127	0.086	0.086	0.058

Berries

Blueberry	5.0 ppm

(6.77)	0	1	0.177	0.177	0.177	0.177	0.177	N/A

Blackberry	5.0 ppm

(6.73)	0	1	0.328	0.328	0.328	0.328	0.328	N/A

Tree Nuts

Pecan, nutmeat	5 ppm

(7.01)	0	1	0.24	024	0.024	0.024	0.024	N/A

Almond, nutmeat	5 ppm

(6.80)	0	1	0.037	0.037	<0.037	0.037	0.037	N/A

Almond, hulls

0	1	7.56	7.56	7.56	7.56	7.56	N/A

Cereals, except Rice

Sweet Corn

K+CWHR	5 ppm

(6.75-6.91)

	0	2	0.05	0.17	0.17	0.11	0.11	0.085

Forage w/o ears

0	2	0.585	1.23	1.23	0.908	0.908	0.456

Forage  w/ears

0	2	0.445	0.97	0.97	0.708	0.708	0.371

Stover w/ears

0	2	0.635	4.88	4.88	2.758	2.758	3.002

Field Corn

Forage	5 ppm

(2.26-3.38) 5	0	4	0.285	0.385	0.385	0.334	0.334	0.041

Grain	5 ppm

(6.75-7.10)	0	4	0.04	0.05	0.05	0.05	0.05	0.005

Stover

0	4	1.44	3.19	3.19	2.08	2.08	0.82

Sorghum

Forage	5 ppm

(2.26-3.38) 5	0	3	0.35	2.67	2.67	1.262	1.262	1.237

Grain	5 ppm

(6.77)	0	3	0.645	1.21	1.21	1.00	1.00	0.311

Stover

0	3	0.96	4.90	4.90	2.91	2.91	1.97

Wheat

Forage	5 ppm

(2.19-3.39) 5	0	4	0.685	2.13	2.13	1.15	1.15	0.662

Hay

0	4	1.055	3.09	3.09	1.94	1.94	0.89

Grain	5 ppm

(6.58-6.77)	0-1	4	0.32	1.91	1.91	0.71	0.71	0.800

Straw

0-1	4	1.07	2.74	2.74	1.83	1.83	0.74

AGF

	1	20.3	20.3	20.3	20.3	20.3	N/A

Grasses

Forage	5 ppm

(6.64-7.02)	0-2	6	1.94	2.73	2.73	2.21	2.21	0.32

Hay

0-2	6	5.87	13.65	13.65	8.77	8.77	3.00

Alfalfa

Forage	5 ppm

(5.94-6.58)	0	2	1.77	2.12	2.12	1.95	1.95	0.25

Hay

0	2	4.93	5.20	5.20	5.07	5.07	0.19

Grapes

Grape	5.0 ppm

(6.64-6.76)	0	3	0.405	0.642	0.642	0.522	0.522	0.119

Mint

Mint	5 ppm

(6.64-6.77)	0	2	1.49	2.80	2.80	2.14	2.14	0.923

Rice

Rice grain	5 ppm

(6.75-6.77)	0-1	4	0.756	1.18	1.18	1.05	1.05	0.200

Rice Straw

0-1	4	1.02	2.6	2.6	1.90	1.90	0.66

1	The endothall concentrations are expressed in acid equivalents, and
the values in parentheses are the total application rates in terms of lb
ae/A.

2	Residues are expressed in terms of the free acid.  The LOQ is 0.05
ppm.  The LOQ was used for all values reported as ≤LOQ.

3	HAFT = Highest Average Field Trial.

4	One of the succulent podded bean field trials used 8 applications
rather than 6 applications due to slow plant growth and maturation.

5	Field corn forage, sorghum forage, and wheat forage and hay were
harvested after only two or three applications.

Root and Tuber Vegetables (Group 1).  

Two field trials each were conducted on sugar beets, carrots, and
potatoes in Zones 5, 10 and 11 during 2006-2007.  In each test, the
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  In addition, in
the two sugar beet field trials, side-by-side test were also conducted
using the dipotassium salt of endothall applied to the irrigation water
at a concentration of 3.5 ppm ae.  The treated water was applied during
vegetative development as six broadcast foliar applications using
overhead sprinklers, at RTIs of 6-8 days.  Based on the concentration of
the endothall and the amount of water applied, the application rates for
the monoalkylamine salt of endothall were equivalent to 1.13-1.14 lb
ae/A/application, for a total of 6.77-6.83 lb ae/A/season.  The
application rates for the dipotassium salt were equivalent to 0.80-0.81
lb ae/A/application, for a total of 4.80-4.88 lb ae/A/season.  Single
control and duplicate treated samples of sugar beet roots and tops,
carrot roots and potato tubers were harvested from the respective tests
on the day of the final application (0 DAT).                            
                               

Following six endothall (monoalkylamine salt) applications totaling
6.77-6.83 lb ae/A/season, endothall residues at 0 DAT were 1.11-1.62 ppm
in/on 4 samples of sugar beet tops from 2 plots, 0.136-0.591 ppm in/on 4
samples of sugar beet roots from 2 plots, 0.062-0.088 ppm in/on 4
samples of carrot roots from 2 plots , and 0.067-0.103 ppm in/on 4
samples of potato tubers from 2 plots.  Average endothall residues were
1.34 ppm for sugar beet tops, 0.330 ppm for sugar beet roots, 0.078 ppm
for carrot roots, and 0.080 ppm for potato tubers.  The HAFT residues
were 1.36 ppm for sugar beet tops, 0.493 ppm for sugar beet roots and
0.088 ppm for both carrot roots and potato tubers.  No residue decline
data were provided.  No phytotoxicity was reported in any of the tests.

Following six endothall (dipotassium salt) applications totaling
4.80-4.88 lb ae/A/season, endothall residues at 0 DAT were 0.523-1.28
ppm in/on 4 samples of sugar beet tops from 2 plots and 0.115-0.345 ppm
in/on 4 samples of sugar beet roots from 2 plots.  Average endothall
residues were 0.821 ppm in/on sugar beet tops and 0.224 ppm in/on sugar
beet roots, and HAFT residues in/on sugar beet tops and roots were 1.11
and 0.331 ppm, respectively.  Average endothall residues in/on sugar
beet tops and roots were 0.6x-0.7x lower for the dipotassium salt
formulation than for the monoalkylamine salt formulation.  The lower
level of endothall residues for the dipotassium salt correlated closely
with the lower use rate (0.7x) for the dipotassium salt.

Bulb Vegetables (Group 3). 

In one green onion and one dry bulb onion field trial conducted during
2007 in Zones 6 and 10, respectively, the monoalkylamine salt
formulation of endothall (2 lb ae/gal SC/L) was used to treat the
irrigation water at a rate of 5 ppm ae.  The treated water was applied
to onions during vegetative development as six broadcast foliar
applications using overhead sprinklers, at RTIs of 7-8 days.  Based on
the concentration of the endothall and the amount of water applied, the
application rates for endothall were equivalent to 1.12-1.13 lb
ae/A/application, for a total of 6.75-6.76 lb ae/A/season.  Single
control and duplicate treated samples of green onions and dry bulb
onions were harvested from the respective tests on the day of the final
application (0 DAT).  Endothall residues at 0 DAT were 0.234 and 0.284
ppm in/on 2 samples from one plot of green onions and <0.05 ppm in/on 2
samples from one plot of dry bulb onions.  The average residues were
0.259 ppm for green onions and <0.05 ppm for dry bulb onions.  No
residue decline data was provided, and no phytotoxicity was reported on
the treated onion crops.  

Leafy Vegetables, except Brassica (Group 4).  

Two leaf lettuce field trials and two head lettuce field trials were
conducted in Zones 1 and 10 during 2006-2007.  Side-by-side tests were
conducted in each field trial using irrigation water treated with either
the monoalkylamine salt of endothall (2 lb ae/gal SC/L) at a
concentration of 5 ppm ae, or the dipotassium salt of endothall (3.0 lb
ae/gal SC/L) at a concentration of 3.5 ppm ae.  The treated water was
applied in each test during vegetative development as six broadcast
foliar applications using overhead sprinklers, at RTIs of 6-8 days. 
Based on the endothall concentrations and the amount of water applied,
the application rates for the monoalkylamine salt of endothall were
equivalent to 1.12-1.20 lb ae/A/application, for a total of 6.73-7.17 lb
ae/A/season.  The application rates for the dipotassium salt were
equivalent to 0.78-0.84 lb ae/A/application, for a total of 4.67-5.07 lb
ae/A/season.  Single control and duplicate treated samples of leaf
lettuce and head lettuce (with wrapper leaves) were harvested from the
respective tests on the day of the final application (0 DAT).

Following applications of the monoalkylamine salt at level equivalent to
6.73-7.17 lb ae/A/season, endothall residues at 0 DAT were 0.410-1.24
ppm in/on 4 samples of leaf lettuce from 2 plots and 0.081-0.604 ppm
in/on 4 samples of head lettuce from 2 plots.  Average endothall
residues were 0.714 ppm for leaf lettuce and 0.317 ppm for head lettuce.
 The HAFT residues in/on leaf and head lettuce were 0.992 and 0.548 ppm,
respectively.  No phytotoxicity was reported on the treated lettuce.

Following six applications of the dipotassium salt at levels equivalent
to 4.67-5.07 lb ae/A/season, endothall residues at 0 DAT were 0.241-1.01
ppm in/on 4 samples of leaf lettuce from 2 plots and <0.05-0.582 ppm
in/on 4 samples of head lettuce from 2 plots.  Average endothall
residues were 0.523 ppm in/on leaf lettuce and 0.288 ppm in/on head
lettuce, and HAFT residues in/on leaf and head lettuce were 0.798 and
0.509 ppm, respectively.  Average endothall residues were lower
(0.7x-0.9x) for the dipotassium salt than the monoalkylamine salt, which
is comparable to the lower use rate for the dipotassium salt (0.7x).

Brassica Vegetables (Group 5).

In two cabbage field trials conducted during 2006 in Zone 1, the
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was applied to cabbage during vegetative development as six broadcast
foliar applications using overhead sprinklers, at RTIs of 6-9 days. 
Based on the concentration of the endothall and the actual amount of
water applied, the application rates for endothall were equivalent to
0.94 or 1.17 lb ae/A/application, for a total of 5.64 or 7.00 lb
ae/A/season.  Single control and duplicate treated samples of cabbages
(with wrapper leaves) were harvested from each test on the day of the
final application (0 DAT).  Endothall residues at 0 DAT were <0.05-0.075
ppm in/on 4 samples of cabbage from 2 plots.  The average residues were
0.062 ppm and the HAFT residues were 0.063 ppm.  No residue decline data
were provided, and no phytotoxicity was noted on the treated cabbage.

Legume Vegetables (Group 6).

A total of 10 tests were conducted on legume vegetables in Zones 1, 4,
5, 10 and 12 during 2006-2007, including 2 tests on succulent podded
beans, 2 tests on dry beans, 2 tests on succulent podded peas, and 4
tests on soybeans.  In each test, a monoalkylamine salt formulation of
endothall (2 lb ae/gal SC/L) was used to treat the irrigation water at a
rate of 5 ppm ae.  The treated water was applied during flowering
through pod and seed development as broadcast foliar applications using
overhead sprinklers, at RTIs of 6-9 days.  A total of six applications
were made in each test, except in one of the succulent bean tests, which
used eight applications.  Based on the concentration of the endothall
and the amount of water applied, the application rates for endothall
were equivalent to 1.12-1.13 lb ae/A/application, for a total of
6.74-6.77 lb ae/A for the six applications or 9.02 lb ai/A for the eight
applications.  Single control and duplicate treated samples of legume
pods with seeds were harvested from the succulent bean and pea field
trials and samples of dried seeds were harvested from the dry bean and
soybean field trials.

Endothall residues were 0.291-0.521 ppm in/on 4 samples of succulent
podded beans from 2 plots, 0.522-1.00 ppm in/on 4 samples of succulent
podded peas from 2 plots, 0.070-0.134 ppm in/on 4 samples of dried beans
from 2 plots, and <0.05-0.072 ppm in/on 8 samples of soybeans from 4
plots harvested at 0-1 DAT.  Average endothall residues were 0.388 ppm
for succulent podded beans, 0.734 ppm for succulent podded peas, 0.109
ppm for dry beans, and 0.055 ppm for soybeans.  The HAFT residues were
0.468 ppm for succulent podded beans, 0.939 ppm for succulent podded
peas, 0.116 ppm for dry beans, and 0.070 ppm for soybeans.  No residue
decline data was provided.  Phytotoxicity was reported on plants at two
field site, and consisted of chlorosis and necrosis of leaves.

Fruiting Vegetables, except cucurbits (Group 8).  

In two tomato field trials conducted during 2006 in Zones 3 and 10, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was applied to tomatoes during flowering and fruit development as six
broadcast foliar applications using overhead sprinklers, at RTIs of 6-8
days.  Based on the concentration of the endothall and the amount of
water applied, the application rates for endothall were equivalent to
1.12-1.13 lb ae/A/application, for a total of 6.74-6.77 lb ae/A/season. 
Single control and duplicate treated samples of tomatoes were harvested
from each test on the day of the final application (0 DAT).  Endothall
residues at 0 DAT were <0.05 ppm in/on 4 samples of tomatoes from 2
plots.  No residue decline data were provided, and no phytotoxicity was
reported on the treated tomato crops.

Cucurbit Vegetables (Group 9).

Two cucumber field trials were conducted in Zones 1 and 5 during
2006-2007.  In each trial, side-by-side tests were conducted using
irrigation water treated with either the monoalkylamine salt of
endothall (2 lb ae/gal SC/L) at a concentration of 5 ppm ae, or the
dipotassium salt of endothall (3 lb ae/gal SC/L) at a concentration of
3.5 ppm ae.  The treated water was applied in each test during flowering
and fruit development as six broadcast foliar applications using
overhead sprinklers, at RTIs of 6-8 days.  Based on the endothall
concentration and the amount of water applied, the application rate for
the monoalkylamine salt of endothall was equivalent to 1.13 lb
ae/A/application, for a total of 6.75-6.77 lb ae/A/season.  The
application rate for the dipotassium salt was equivalent to 0.80 lb
ae/A/application, for a total of 4.80-4.81 lb ae/A/season.  Single
control and duplicate treated samples of cucumber were harvested from
each test on the day of the final application (0 DAT).

Endothall residues were 0.234-0.738 ppm in/on 4 cucumber samples from 2
plots harvested at 0 DAT following irrigation applications of the
monoalkylamine salt of endothall at 5 ppm ae, and were 0.310-0.459 ppm
in/on 4 cucumber samples from 2 plots harvested at 0 DAT following six
irrigation applications of the dipotassium salt of endothall at 3.5 ppm.
 Average endothall residues in/on cucumbers were 0.499 and 0.522 ppm for
the monoalkylamine and dipotassium salt formulations, respectively.  The
HAFT residues were 0.738 and 0.433 ppm for the monoalkylamine and
dipotassium salt formulations, respectively.  Average endothall residues
were lower (0.8x) for the dipotassium salt than the monoalkylamine salt,
which was comparable to the lower use rate for the dipotassium salt
(0.7x).

Phytotoxicity was reported in one of the tests, and consisted of the
loss of older leaves, stunting of growing tips, cupping of young leaves,
chlorosis, and cessation of flowering.  However, fruit set and growth
were not effected.  

Citrus Fruits (Group 10).  

In two orange field trials conducted during 2006 in Zones 3 and 10, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was applied to the orange trees during fruit development as six
broadcast foliar applications using overhead sprinklers, at RTIs of 5-8
days.  Based on the concentration of the endothall and the amount of
water applied, the application rates for endothall were equivalent to
1.10-1.13 lb ae/A/application, for a total of 6.63-6.78 lb ae/A/season. 
Single control and duplicate treated samples of oranges were harvested
from each test on the day of the final application (0 DAT).  Endothall
residues were <LLMV in/on 4 orange samples from 2 plots at 0 DAT, with
residues above the LOD on all four samples at 0.021-0.028 ppm.  The
average and HAFT residues were 0.024 ppm and 0.026 ppm, respectively,
in/on oranges.  No phytotoxicity was reported on the treated trees.  

Pome Fruits (Group 11).

In two apple field trials conducted during 2006 in Zones 1 and 11, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was applied to the apple trees during fruit development as six broadcast
foliar applications using overhead sprinklers, at RTIs of 7 days.  Based
on the concentration of the endothall and the amount of water applied,
the application rates for endothall were equivalent to 1.11-1.13 lb
ae/A/application, for a total of 6.64-6.79 lb ae/A/season.  Single
control and duplicate treated samples of apples were harvested from each
test on the day of the final application (0 DAT).  Endothall residues at
0 DAT were <LLMV in/on 4 samples of apples from 2 plots, but were
greater than the LOD, at 0.031-0.047 ppm, in 3 of the 4 samples.  The
average and HAFT residues were 0.041 ppm and 0.043 in/on apples. 
Phytotoxicity was noted on the treated trees (necrotic spots on leaves),
but no damage was noted on the fruits.

Stone Fruits (Group 12).  

Two peach field trials were conducted in Zones 2 and 10 during 2007.  In
each trial, side-by-side tests were conducted using irrigation water
treated with either the monoalkylamine salt of endothall (2 lb ae/gal
SC/L) at a concentration of 5 ppm ae, or the dipotassium salt of
endothall (3 lb ae/gal SC/L) at a concentration of 3.5 ppm ae.  The
treated water was applied in each test during fruit development as six
broadcast foliar applications using overhead sprinklers, at RTIs of 6-8
days.  Based on the endothall concentration and the amount of water
applied, the application rate for the monoalkylamine salt of endothall
was equivalent to 1.13-1.25 lb ae/A/application, for a total of
6.78-7.08 lb ae/A/season.  The application rate for the dipotassium salt
was equivalent to 0.79-0.91 lb ae/A/application, for a total of
4.82-5.05 lb ae/A/season.  Single control and duplicate treated samples
of peaches were harvested from each test on the day of the final
application (0 DAT).

Endothall residues at 0 DAT in/on peaches were <0.05-0.160 ppm in/on 4
samples from 2 plots treated with the monoalkylamine salt and
<0.05-0.136 ppm in/on the 4 samples from 2 plots treated with
dipotassium salt.  Average endothall residues in/on peaches were 0.098
and 0.086 ppm for the monoalkylamine and dipotassium salt formulations,
respectively.  The HAFT residues were 0.152 and 0.127 ppm for the
monoalkylamine and dipotassium salt formulations, respectively.  Average
endothall residues were lower (0.9x) for the dipotassium salt than the
monoalkylamine salt, which is comparable to the lower use rate for the
dipotassium salt (0.7x).  Phytotoxicity was reported on the treated
peach trees.

Berries (Group 13). 

In one blueberry and one blackberry field trial conducted during 2007 in
Zones 5 and 11, respectively, a monoalkylamine salt formulation of
endothall (2 lb ae/gal SC/L) was used to treat the irrigation water at a
rate of 5 ppm ae.  The treated water was applied to the berry crops
during fruit development and maturation as six broadcast foliar
applications using overhead sprinklers, at RTIs of 6-8 days.  Based on
the concentration of the endothall and the amount of water applied, the
application rates for endothall were equivalent to 1.12-1.13 lb
ae/A/application, for a total of 6.73-6.77 lb ae/A/season.  Single
control and duplicate treated samples of blueberries and blackberries
were harvested from the respective tests on the day of the final
application (0 DAT).  Endothall residues at 0 DAT were 0.158 and 0.197
ppm in/on 2 samples of blueberry from 1 plot and 0.311 and 0.346 ppm
in/on 2 samples of blackberry from 1 plot.  The average residues were
0.177 and 0.328 ppm for blueberries and blackberries, respectively.  No
residue decline data was provided, and no phytotoxicity was reported on
the treated crops.  

Grapes. 

In three grape field trials conducted in Zones 1, 10 and 11 during 2006
and 2007, a monoalkylamine salt of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae. The treated water
was then applied using overhead sprinklers to the grapes as six
broadcast foliar applications during fruit development at RTIs of 6-8
days.  Based on the concentration of the endothall and the amount of
water applied, the application rates for endothall were equivalent to
1.11-1.13 lb ae/A/application, for a total of 6.64-6.76 lb ae/A/season. 
Single control and duplicate treated samples of grapes were harvested on
the day of the final application (0 DAT).  Endothall residues in/on
grapes harvested at 0 DAT were 0.376-0.696 ppm.  The average residues
were 0.522 ppm and the HAFT residues were 0.642 ppm.  No residue decline
data was provided.  At two of the three field sites, phytotoxicity was
noted beginning with the second application and increased in severity
with subsequent applications.  The leaves initially showed signs of
chlorosis and browning, with leaf necrosis occurring at later
applications.

Tree Nuts (Group 14). 

In a pecan and almond field trial conducted during 2006-2007 in Zones 2
and 10, respectively, a monoalkylamine salt formulation of endothall (2
lb ae/gal SC/L) was used to treat the irrigation water at a rate of 5
ppm ae.  The treated water was applied to the tree nut crops during nut
development and maturation as six broadcast foliar applications using
overhead sprinklers, at RTIs of 7-8 days.  Based on the concentration of
the endothall and the amount of water applied, the application rates for
endothall were equivalent to 1.13-1.17 lb ae/A/application, for a total
of 6.80-7.01 lb ae/A/season.  Single control and duplicate treated
samples of pecan and almond nutmeats and almond hulls were harvested
from the respective tests on the day of the final application (0 DAT). 
No phytotoxicity was reported on the treated nut crops.  

Endothall residues at 0 DAT were <LOQ in/on two samples each from 1 plot
each of pecan and almond nutmeats.  However, residues were detectable at
0.024 ppm in one of the pecan nutmeat samples and at 0.036 and 0.037 ppm
in the two almond nutmeat samples.  Residues in/on the two almond hull
samples were 6.91 and 8.20 ppm.  Average endothall residues and the HAFT
residues were both 0.05 ppm for nutmeats and 7.56 ppm for almond hulls.

Cereal Grains (Except Rice).

A total of 13 field trials were conducted during 2006 and 2007 in Zones
1, 2, 5, 6, 7, and 11, including two trials on sweet corn, four trials
on field corn, three trials on sorghum, and four trials on wheat (3
winter wheat and 1 spring wheat).  In each test, the monoalkylamine salt
formulation of endothall (2 lb ae/gal SC/L) was used to treat the
irrigation water at a rate of 5 ppm ae.  The treated water was applied
to each crop during seed head formation and development as six broadcast
foliar applications using overhead sprinklers, at RTIs of 6-9 days. 
Based on the concentration of the endothall in the irrigation water and
the amount of water applied, the overall application rates for endothall
were equivalent to 1.10-1.25 lb ae/A/application, for a total of
6.58-7.10 lb ae/A/season.  Because samples of field corn forage, sorghum
forage, and wheat forage and hay were harvested after only 2 or 3
applications, the total application rates for these commodities was
2.19-3.39 lb ae/A. 

Duplicate control and treated samples of each commodity were harvested
from the respective tests.  Samples of field corn forage, sorghum forage
and wheat forage and hay were harvested 0 days after the second or third
application (0 DAT).  Samples of sweet corn forage, kennels plus cob
with husks removed (K+CWHR) and stover, field corn grain and stover,
sorghum grain and stover, and wheat grain and straw were harvested
following the sixth application at 0 DAT (or at 1 DAT in one wheat
test).  

In the sweet corn field trials, endothall residues at 0 DAT were
<0.05-0.17 ppm in/on 4 samples of  K+CWHR, 0.52-1.28 ppm in/on 4 samples
of forage without ears, 0.40-1.06 ppm in/on 4 samples of forage with
ears, and 0.58-5.06 ppm in/on 4 samples of stover with ears.  Average
endothall residues were 0.11 ppm for K+CWHR, 0.91 ppm for forage without
ears, 0.71 ppm for forage with ears, and 2.76 ppm for stover with ears. 
The HAFT residues were 0.17 ppm in/on K+CWHR, 1.23 ppm in/on forage
without ears, 0.97 ppm in/on forage with ears, and 4.88 ppm in/on stover
with ears.

In the field corn field trials, endothall residues at 0 DAT were
0.21-0.42 ppm in/on 8 samples of  forage harvested after only 2 or 3
applications (2.26-3.38 lb ae/A).  Following all six applications
(6.75-7.10 lb ae/A), endothall residues at 0 DAT were <0.05 ppm in/on 8
samples of grain and 1.07-3.48 ppm in/on 8 samples of stover from 4
plots each.  Average endothall residues were 0.33 ppm for forage, <0.05
ppm for grain, and 2.08 ppm for stover.  The HAFT residues were 0.385
ppm in/on forage, <0.05 ppm in/on grain, and 3.19 ppm in/on stover.

In the sorghum field trials, endothall residues at 0 DAT were 0.29-3.05
ppm in/on 6 samples of  forage harvested from 3 plots after only 2 or 3
applications (2.26-3.38 lb ae/A).  Following all six applications (6.77
lb ae/A), endothall residues at 0 DAT were 0.49-1.41 ppm in/on 6 samples
of grain and 0.81-7.19 ppm in/on 6 samples of stover.  Average endothall
residues were 1.26 ppm for forage, 1.00 ppm for grain, and 2.91 ppm for
stover.  The HAFT residues were 2.67 ppm in/on forage, 1.21 ppm in/on
grain, and 4.90 ppm in/on stover.

In the wheat field trials, endothall residues at 0 DAT were 0.63-2.27
ppm in/on 8 samples of  forage and 1.00-3.09 ppm in/on 8 samples of hay
harvested from 4 plots after only 2 or 3 applications (2.19-3.39 lb
ae/A).  Following all six applications (6.58-6.77 lb ae/A), endothall
residues at 0 or 1 DAT were 0.20-2.01 ppm in/on 8 samples of grain and
0.61-2.76 ppm in/on 8 samples of straw from 4 plots each.  Average
endothall residues were 1.15 ppm for forage, 1.94 ppm for hay, 0.71 ppm
for grain, and 1.83 ppm for straw.  The HAFT residues were 2.13 ppm
in/on forage, 3.09 ppm in/on hay, 1.91 ppm in/on grain, and 2.74 ppm
in/on straw.  Residue decline data were not provided in any field
trials, and no phytotoxicity was reported for any of the treated cereal
grain crops.

Rice.

In four rice field trials conducted during 2007 in Zones 4, 6 and 10, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was applied to the rice during grain development and maturation as six
broadcast foliar applications using overhead sprinklers, at RTIs of 6-8
days.  Based on the concentration of the endothall and the amount of
water applied, the application rates for endothall were equivalent to
1.13 lb ae/A/application, for a total of 6.75-6.77 lb ae/A/season. 
Single control and duplicate treated samples of rice grain and straw
were harvested from each test on the day of the final application or one
day later (0-1 DAT).  Endothall residues were 0.69-1.22 ppm in/on 4
samples of rice grain and 0.94-2.61 ppm in/on 4 samples of rice straw
harvested from 2 plots each at 0-1 DAT.  Average endothall residues were
1.01 ppm for grain and 1.90 ppm for straw, and the HAFT residues were
1.18 ppm for grain and 2.60 ppm for straw.  No residue decline data was
provided, and no phytotoxicity was reported on the treated rice.

Grass forage and hay (Group 17).

A total of six grass field trials were conducted in Zones 4, 6, 11 and
12 during 2006 and 2007, including 2 field trials each on bluegrass,
Bermuda grass, and fescue grass.  In each test, the monoalkylamine salt
formulation of endothall (2 lb ae/gal SC/L) was used to treat the
irrigation water at a rate of 5 ppm ae.  The treated water was applied
to the grass during vegetative development as six broadcast foliar
applications using overhead sprinklers, at RTIs of 6-10 days.  Based on
the concentration of the endothall in the irrigation water and the
amount of water applied, the application rates for endothall were
equivalent to 1.11-1.17 lb ae/A/application, for a total of 6.64-7.02 lb
ae/A/season.  Duplicate control and treated samples of grass forage and
hay were harvested on either the day of the final application (0 DAT) in
the fescue tests, at 1 DAT in the Bermuda grass tests, or at 1-2 DAT in
the bluegrass tests.  The forage samples were collected immediately
after harvest, and the hay samples were field-dried for 2-6 days prior
to collection.

 

Endothall residues were 1.70-2.86 ppm in/on 12 forage samples and
5.34-14.2 ppm in/on 12 hay samples harvested from 6 plots each at 0-2
DAT.  Average endothall residues were 2.21 ppm for forage and 8.77 ppm
for hay, and the HAFT residues were 2.73 ppm for forage and 13.65 ppm
for hay.  No residue decline data were provided.  Phytotoxicity was
reported on the treated bluegrass at one field site, and consisted of
stunting and slight chlorosis

Nongrass Animal Feeds (Forage, Fodder and Hay) (Group 18). 

In two alfalfa field trials conducted during 2007 in Zones 5 and 7, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was applied to the alfalfa during vegetative development as six
broadcast foliar applications using overhead sprinklers, at RTIs of 6-8
days.  Based on the concentration of the endothall in the irrigation
water and the amount of water applied, the application rates for
endothall were equivalent to 0.99-1.10 lb ae/A/application, for a total
of 5.94-6.58 lb ae/A/season.  Duplicate control and treated samples of
alfalfa forage and hay were harvested from each test on the day of the
final application (0 DAT), and the hay samples were field-dried for 1-5
days prior to collection.  

Endothall residues were 1.41-2.24 ppm in/on 4 forage samples and
3.09-5.31 ppm in/on 4 hay samples harvested from 2 plots at 0 DAT. 
Average endothall residues were 1.95 ppm for forage and 5.07 ppm for
hay, and the HAFT residues were 2.12 ppm for forage and 5.20 ppm for
hay.  No residue decline data were provided.  No phytotoxicity on the
treated alfalfa was reported at either test site.

Mint.

In two mint field trials conducted during 2006 and 2007 in Zones 5 and
11, a monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L)
was used to treat the irrigation water at a rate of 5 ppm ae.  The
treated water was applied to the mint during vegetative development as
six broadcast foliar applications using overhead sprinklers, at RTIs of
6-7 days.  Based on the concentration of the endothall and the amount of
water applied, the application rates for endothall were equivalent to
1.11-1.13 lb ae/A/application, for a total of 6.64-6.77 lb ae/A/season. 
Single control and duplicate treated samples of mint tops were harvested
from each test on the day of the final application (0 DAT).  Endothall
residues were 1.31-2.89 ppm in/on 4 samples of mint tops harvested from
2 plots at 0 DAT.  Average endothall residues were 2.14 ppm, and the
HAFT residues were 2.80 ppm.  No residue decline data was provided.  At
one of the field sites, the treated mint exhibited signs of
phytotoxicity, which consisted of reduced development and stunting of
the crop. 

 

Conclusions.  Issues pertaining to residues in potable water and fish
have been resolved and are discussed in the Residue Chemistry Chapter of
the Endothall RED (DP# D321179, D. Soderberg, 8/30/2005).

The submitted field trial data on irrigated crops were conducted
according the previously submitted protocol.  Two to four field trials
were conducted for each representative crop in the major growing regions
for the respective crops.  With only a couple of exceptions, sample of
regulated commodities were harvested at 0 DAT from each field trial. 
Samples were analyzed for residues of endothall using an adequate
LC/MS/MS method, and the sample storage durations and conditions are
supported by the available storage stability data.

The submitted data are generally adequate for assessing inadvertent
residues of endothall on irrigated crops.  In addition, the residues
determined in the 0 DAT samples will represent an over-estimate of
residues for many of the crops tested, because, because application is
at the maximum rate, is all applied by overhead irrigation,  and
irrigation on the day of harvest would be highly unlikely to occur due
to commercial harvesting procedures.  Crops and commodities which would
be unlikely to be irrigated prior to harvest include: sugar beets,
carrots, potatoes, dry bulb onions, dried peas and beans, soybeans, tree
nuts, field corn grain and stover, sorghum grain and stover, wheat grain
and straw, and rice grain and straw. 

In addition, HED notes that phytotoxicity was reported on a number of
the crops tested, including legume vegetables, cucumbers, apple trees,
peach trees, grape vines, mint and grass.  The phytotoxicity generally
appeared beginning after the second application and consisted of leaf
chlorosis and necrosis, with some crops also having reduced growth and
stunting.  The occurrence of phytotoxicity on a wide range of crops
suggests that repeated irrigation with water containing high levels (5
ppm) endothall is unlikely to occur under normal agricultural condition.

Although the submitted data are deemed adequate for assessing tolerances
for inadvertent residues on irrigated crops, the following deficiencies
were noted in the submitted field trial data.

	●	The bridging studies comparing the use of the monoalkylamine and
dipotassium salts of endothall were of limited use as the two
formulations were applied at different rates.  In terms of acid
equivalents, the monoalkylamine salt was applied at a concentration of 5
ppm and the dipotassium salt was applied at a concentration of 3.5 ppm,
which is the maximum allowed use rate of the dipotassium salt (0.7x rate
for the monoalkylamine salt).  For each of the crops tested with both
salt formulations, endothall residues were 0.6-0.9x lower for the
dipotassium salt than for the monoalkylamine salt, which is consistent
with the lower use rate for the dipotassium salt.  Although the bridging
studies do not allow for direct comparison of the two salts, the data do
indicate that endothall residues
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	●	Spinach should have been used as the representative leafy vegetable
crop, as foliar applications generally result in higher residues on
spinach than on lettuce (leaf and head) or celery. 

	●	Mustard greens should have been used as the representative Brassica
vegetable crop, as foliar applications generally result in higher
residues on mustard greens than on broccoli, cauliflower or cabbage.

	●	Field corn forage, sorghum forage and wheat forage and hay only
received 2-3 applications prior to harvest.  For these crops, separate
plots should have been established for collection of forage and hay
samples so that all six applications could have made prior to harvest of
forage and hay.

	●	No field trials were conducted on an oil seed crop such as, canola,
flax, safflower, or sunflower.

	●	No field trials were conducted on peanuts, which is a major field
crop.

The levels of inadvertent residues for endothall supported by the
available field trial data are listed in Table 10 and discussed below in
the Proposed Tolerances Section.

860.1460 Food Handling

There are no registered uses that are relevant to this guideline topic.

860.1480 Meat, Milk, Poultry, and Eggs

DP# D321179, D. Soderberg, 8/30/2005

No cattle or poultry feeding studies are currently available for
endothall, and the Endothall RED noted that these studies are required. 
Because IR-4 is proposing tolerances on a wide variety of livestock
feedstuffs, the dietary burdens of livestock for endothall residues were
recalculated for this petition based on the maximum reasonably balanced
diets (MRBD).  Using the proposed and recommended tolerances and the
recent changes in calculating residues in MRBDs (Revisions of Table 1
Feedstuffs, June 2008), the MRBDs for livestock to endothall residues
were calculated to be 8.97 ppm for beef cattle, 7.65 ppm for dairy
cattle, 3.30 ppm for poultry and 3.58 ppm for swine (Table 6) based upon
residues in the feeds.

In addition to the dietary exposure of livestock through the consumption
of feedstuffs, the Endothall RED noted that livestock may also be
exposed to endothall residues through the consumption of
endothall-treated water.  For purposes of setting tolerances it must be
considered that livestock may be exposed to water at the maximum labeled
value of 5 ppm.  The potential contribution of endothall residues in
water to the dietary exposure of livestock was calculated following the
procedures described in PP#1F3991/1F3935 (G. Okatie, 9/4/92), based on
the concentration of endothall in the drinking water, the daily water
consumption, and the daily feed intake.  The estimated values for daily
water consumption and food intake (dry wt. basis) are presented in Table
7, along with the calculated contribution of the treated water to the
dietary burden.  When expressed on the basis of the dry feed intake, the
contribution of endothall-treated water to the dietary burden would be
19.2 ppm for beef cattle, 45.4 ppm for dairy cattle, 13.5 ppm for
poultry, and 16.1 ppm for swine.  When combined with the exposure to
endothall residues in feedstuffs, the total dietary exposure of
livestock to endothall residues would be 27.7 ppm for beef cattle, 35.8
ppm for dairy cattle, 16.8 ppm for poultry, and 19.7 ppm for swine (as
shown in Table 8.

Using the TRR estimated in the relevant livestock tissues after dosing
in the metabolism it is possible to make some estimate of the maximum
residues expected in the livestock tissues.  In this way, residues in
the tissues are estimated as shown in Table 9.  However, given the
levels of dietary exposure of livestock to endothall residues in both
their feedstuffs and drinking water, cattle and poultry feeding studies
are required and registration must be contingent upon submission of
these studies.

Table 6.   Calculation of Dietary Burdens of Endothall Residues in
Livestock.

Feedstuff	Type1	% Dry Matter2	% Diet2	Recommended Tolerance (ppm)
Dietary Contribution (ppm)3

Beef Cattle R: 15%; CC: 80%; PC: 5%

Grass, hay	R	88	15	18	3.07

Grain, aspirated fractions	CC	85	5	35	2.06

Wheat, milled byproducts	CC	88	40	5.0	2.28

Grain, cereal, group 15	CC	88	30	4.0	1.37

Sugar, beet, molasses	CC	75	5	1.5	0.1

Soybean, meal	PC	92	5	0.24	0.01

	TOTAL BURDEN

	100

8.9

Dairy Cattle R: 45%; CC: 45%; PC: 10%

Grass, hay	R	88	20	18	4.09

Almond, hulls	R	90	5	15	0.83

Animal feed, Nongrass, group 18, forage	R	35	20	4.0	2.29

Wheat, milled byproducts	CC	88	30	5.0	1.70

Grain, cereal, group 15	CC	88	10	4.0	0.46

Sugar, beet, molasses	CC	75	5	1.5	0.1

Soybean, meal	PC	92	10	0.24	0.02

	TOTAL BURDEN

	100

9.5

Poultry  CC: 75%; PC:  25%

Grain, cereal, group 15	CC	88	75	4.0	3.0

Alfalfa , meal, (Animal feed, Nongrass, group 18, hay) 	PC	89	5	10.0	0.5

Soybean, meal	PC	92	20	0.24	0.04

	TOTAL BURDEN	--	--	100	--	3.6

Swine  CC: 85 %;  PC:  15%

Grain, cereal, group 15	CC	88	85	4.0	3.4

Alfalfa , meal, (Animal feed, Nongrass, group 18, hay) 	PC	89	5	10.0	0.5

Soybean, meal	PC	92	10	0.24	0.02

	TOTAL BURDEN	--	--	100	--	4.0

1  R:  Roughage; CC:  Carbohydrate concentrate; PC:  Protein
concentrate.

2  OPPTS 860.1000 Table 1 Feedstuffs (June 2008).  

3  Contribution = ([tolerance /% DM] X % diet) for beef and dairy
cattle; contribution = ([tolerance] X % diet) for poultry and swine. 

4 The tolerance for soybean seeds was used for soybean meal.

Table 7.	Calculation of Dietary Burdens of Endothall Residues to
Livestock from Consumption of Treated Water.

Feedstuff	Endothall concentration in water (ppm)	Water  consumption
(kg/day)	Feed consumption (kg dry wt./day) 1	Dietary Contribution from
water (ppm) 2

Beef cattle (feedlot cattle)	5.0	35	9.1	19.2

Dairy cattle (lactating cows)	5.0	218	24	45.4

Poultry (laying hens)	5.0	0.14	0.052	13.5

Swine (finishing hogs)	5.0	10	3.1	16.1

1	Feed consumption from ChemSAC Memo, 6/30/2008.

2	 Contribution = (endothall concentration X water consumption/day) ÷
feed consumption/day. 

Table 8.	Calculation of Total (Feed Plus Water) Dietary Burdens of
Endothall Residues to Livestock 

Feedstuff	Feed	Water	Total

Beef cattle (feedlot cattle)	8.9	19.2	28.1

Dairy cattle (lactating cows)	9.5	45.4	54.9

Poultry (laying hens)	3.6	13.5	17.1

Swine (finishing hogs)	4.0	16.1	20.1

Table 9.  Calculation of estimated Residues in Livestock Tissues Based
upon the TRR in the Metabolism Studies.

Residues of Endothall in Dairy Cattle Tissues Based upon the Goat
Metabolism Study

Tissue	

Total Radioactive Residues (ppm) after Feeding at 12.0 ppm	

Anticipated Residues (ppm) after Feeding at 54.9 ppm  

Milk.	

0.006	0.028

Kidney	

0.046	0.21

Liver	

0.020	0.092

Muscle 	

0.005	0.023

Fat	

0.002	0.009

Residues of Endothall in Beef Cattle Tissues, Sheep, Goats Based upon
the Goat Metabolism Study

Tissue	

Total Radioactive Residues (ppm) after Feeding at 12.0 ppm	

Anticipated Residues (ppm) after Feeding at 28.1 

Kidney	

0.046	0.108

Liver	

0.020	0.047

Muscle 	

0.005	0.012

Fat	

0.002	0.005

Residues of Endothall in Swine Tissues Based upon the Goat Metabolism
Study

Tissue

	

Total Radioactive Residues (ppm) after Feeding at 12.0 ppm	

Anticipated Residues (ppm) after Feeding at 20.1 ppm

Kidney

	

0.046	0.077

Liver	

0.020	0.034

Muscle 

	

0.005	0.008

Fat	

0.002	0.003

Residues of Endothall in Poultry Tissues Based upon the Chicken
Metabolism Study

Tissue	

Total Radioactive Residues (ppm) after feeding at 9.7 ppm	

Anticipated Residues (ppm) after feeding at 17.1 ppm

Eggs	

0.024	0.042

    Yolk	

0.024	0.042

    White	

0.002	0.004

Kidney and Other Meat Byproducts	

0.088	0.16

Liver	

0.021	0.037

Muscle 	

0.008	0.014

Fat	

0.007	0.012

860.1500 Crop Field Trials

No new direct uses on crops are being proposed in the current petition;
therefore, data requirements for crop field trials are not relevant to
this petition.  In addition, because of the high application rates the
current data are expected to yield higher residues than would occur in
crops rotated after a terrestrial use.  Thus, these tolerances preempt
the need for additional rotational crop studies. 

860.1520 Processed Food and Feed

DP# D321179, D. Soderberg, 8/30/2005

47520701.de2.doc	(Sugar beet)	47520705.de2.doc	(Soybean)

47520706.de2.doc	(Tomato)	47520708.de2.doc	(Orange)

47520709.de2.doc	(Apple)	47520713.de2.doc	(Field corn, sorghum and
wheat)

47520716.de2.doc	(Grape)	47520717.de2.doc	(Mint)

47520718.de2.doc	(Rice)

Adequate cotton and potato processing studies are available supporting
the direct use of endothall on these two crops as a defoliate/desiccant
(DP# D321179, D. Soderberg, 8/30/2005).   In the acceptable cotton
processing study, cotton plants were treated with endothall as two
broadcast foliar applications at rates totaling 3.2 lb ae/A (25-32x
rate), with the second application being made 3 days prior to harvest. 
Endothall residues were 1.49 ppm in/on the undelinted cottonseed (RAC),
which was then processed into hulls, meal and crude and refined oils. 
Endothall residues did not concentrate in hulls (0.36x), meal (0.22x),
or refined oil (0.03x).

In the acceptable potato processing study, mature potato plants were
treated with endothall (2 lb ae/gal) as two broadcast foliar
applications at 5.0 lb ae/A, at RTI of 5 days, for a total of 10 lb ae/A
(10x rate).  Mature tubers harvested 7 days after the second application
and processed into flakes, chips and wet peel.  Endothall residues were
0.084 ppm in/on mature tubers, 0.088 ppm in flakes, 0.045 ppm in chips
and 0.024 ppm in wet peel.  These data indicate that endothall residues
concentrated only slightly in flakes (1.04x) and were reduced in chips
(0.54x) and wet peel (0.28x) fractions.

ple, residue values ≥LOD were used to calculated processing factors
whenever possible.

The sample storage conditions and durations for the various RACs and
processed fractions from each of the studies are supported by the
available storage stability data.  The details for each of the submitted
processing studies are discussed below, and the resulting processing
factors from each study are summarized in Table 10.

Table 10.	Summary of Processing Factors for Endothall from Crops
Irrigated with Endothall-treated water.

RAC	Processed Commodity	Application Rate 1	PHI

(days)	Processing Factor

ppm	lb ae/A

Apple 2	Juice	5.0	6.79	0	1.2x

	Wet pomace

2.8x

Field Corn	Grits	5.0	6.77	0	NC 3

	Meal

NC 3

	Flour

NC 3

	Refined oil (dry milling)

NC 3

	Starch

NC 3

	Refined oil (wet milling)

NC 3

Grape	Juice	5.0	6.73	0	1.2x5

	Raisins

4.4x

Mint	Oil	5.0	6.64	0	<0.001x

Orange 2	Dried pulp	5.0	6.63	0	2.2x

	Juice

0.7x

	Oil

<0.2x

Rice	Hulls	5.0	6.75	1	3.9x

	Bran

2.3x

	Polished rice

0.07x

Sorghum	Flour	5.0	6.77	0	0.7x

Soybean 2	Hulls	5.0	6.77	0	3.9x

	Meal

0.8x

	Refined oil

<0.005x

Sugar beet	Dried pulp	5.0	6.79	0	1.1x

	Molasses

2.4x

	Refine sugar

<0.1x

Tomato 2	Puree	5.0	6.77	0	2.1x4

	Paste

3.3x4

Wheat	Aspirated grain fractions (AGF)	5.0	6.71	0	15x

	Germ

2.6x

	Bran

2.3x

	Middlings

0.9x

	Flour

0.6x

	Shorts

1.4x

1	The rate is expressed both in terms of the concentration in the
irrigation water (ppm) and the total amount (lb ae/A) applied.

 but ≥LOD were used for calculating processing factors.

3	Residues were <LLMV and <LOD in/on field corn grain and each processed
fraction.  NC = not calculated.

4	Residues were below the LLMV (<0.05 ppm) in both fruit and puree
samples, but were well above the LOD at 0.002 ppm) 

5  1.2x is the Maximum Theoretical Processing Factor for grape juice

Apple.  In a field trial conducted in NY (Zone 1) during 2006, a
monoalkylamine salt formulation of endothall (2.0 lb ae/gal SC/L) was
used to treat the irrigation water at a rate of 5 ppm ae.  The treated
water was then applied using overhead sprinklers to the apple trees as
six broadcast foliar applications during fruit development at a RTI of 7
days.  A volume equivalent to 1 acre inch of water (~27,154 gal/A) was
applied for each application.  Based on the concentration of the
endothall and the amount of water applied, the application rate for
endothall was equivalent to 1.13 lb ae/A/application, for a total of
6.79 lb ae/A/season.  Single bulk control and treated samples of apples
were harvested at normal crop maturity, immediately following the last
irrigation (0 DAT).  The fruit was processed into juice and wet pomace
using simulated commercial procedures.  

Although endothall residues were <LOQ (<0.05 ppm) in/on whole fruits and
juice, residues in these fractions were still above the estimated LOD
(0.0025 ppm).  Therefore, residue values >LOD were used to calculate the
processing factors.  Residues of endothall averaged 0.033 ppm in/on
whole fruit (<LOQ) and were 0.041 ppm in juice and 0.091 ppm in wet
pomace.  The calculated processing factors were 1.2x for juice and 2.8x
for wet pomace.

Based on HAFT residues of 0.039 ppm for apples, the maximum expected
residues would be 0.047 ppm in juice and 0.109 ppm in wet pomace.  As
the recommended tolerance for pome fruits is 0.05 ppm, a separate
tolerance for apple juice is not required, but a tolerance of 0.15 ppm
is required for wet apple pomace.

Field corn.  In a field trial conducted in IL (Zone 5) during the 2007,
a monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was
used to treat the irrigation water at a rate of 5 ppm ae.  The treated
water was then applied using overhead sprinklers to field corn as six
broadcast foliar applications during grain development and maturation at
RTIs of 6-8 days.  A volume equivalent to 1 acre inch of water (~27,154
gal/A) was applied for each application.  Based on the concentration of
the endothall in the irrigation water and the amount of water applied,
the application rate for endothall was equivalent to 1.12-1.13 lb
ae/A/application, for a total of 6.77 lb ae/A/season.  Single bulk
control and treated samples of mature corn grain was harvested on the
day of the last irrigation (0 DAT), and the corn grain was processed
into grits, meal, flour and oil by dry-milling and into starch and oil
by wet-milling.

Following applications totaling 6.77 lb ae/A, endothall residues were
<0.05 ppm (<LOQ) in/on the corn grain (RAC) and all its processed
fractions.  Although processing factors could not be determined for any
processed corn fractions, there was no indication of endothall residues
concentrating in processed corn commodities.  Therefore, endothall are
unlikely to occur in processed commodities derived from irrigated field
corn.

Grape.  In a field trial conducted in NY (Zones 1) during 2006, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to the grapes as six
broadcast foliar applications during fruit development at RTIs of 7
days.  A total of ~1 acre inch of water (27,154 gal/A) was applied for
each application.  Based on the concentration of the endothall and the
amount of water applied, the application rates for endothall were
equivalent to 1.12 lb ae/A/application, for a total of 6.73 lb
ae/A/season.  Single bulk control and treated samples of grapes were
harvested at normal crop maturity, immediately following the last
irrigation (0 DAT), and the grapes were processed into juice and raisins
using simulated commercial procedures.

Residues of endothall averaged 0.28 ppm in/on whole grapes (RAC) were
1.24 ppm in juice and 1.21 ppm in raisins.  Thus, the processing factors
calculated from these data for juice and raisins were 4.3x and 4.4x,
respectively.  However, the theoretical concentration factors for juice
and raisins are 1.2x and 4.7x, respectively.  Although the processing
factor for raisins was in line with the theoretical value, the
processing factor for juice was impossibly higher than the theoretical
value.  Therefore, the 1.2x factor will be used for assessing the need
for grape juice tolerance (and in the dietary exposure assessment).  

Based on HAFT residues of 0.642 ppm for grapes, the maximum expected
residues would be 0.77 ppm in juice and 2.8 ppm in raisins.  As the
recommended tolerance for grapes is 0.9 ppm, a separate tolerance for
grape juice is not required, but a tolerance of 3.0 ppm is required for
raisins. 

Mint.  In a field trial conducted in WA (Zone 11) during 2006, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to mint as six broadcast
foliar applications during vegetative development at RTIs of 7 days.  A
volume equivalent to 1 acre inch of water (~27,154 gal/A) was applied
for each application.  Based on the concentration of the endothall in
the irrigation water and the amount of water applied, the application
rate for endothall was equivalent to 1.11 lb ae/A/application, for a
total of 6.64 lb ae/A/season.  Single bulk control and treated samples
of mint tops were harvested at normal crop maturity, immediately
following the last irrigation (0 DAT) and were processed into oil using
simulated commercial procedures.  

Following six overhead sprinkler applications of endothall to mint at
rates totaling 6.64 lb ae/A, residues were 3.96 ppm in mint tops (RAC)
and nondetectable (<0.0001 ppm) in mint oil, indicating that the
processing factor of endothall in mint oil is <0.001x.  As residues are
reduced in mint oil, a separate tolerance for mint oil is not required.

Orange.  In a field trial conducted in FL (Zone 3) during 2006, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to the orange trees as six
broadcast foliar applications during fruit development at RTIs of 5-6
days.  A volume equivalent to 1 acre inch of water (~27,154 gal/A) was
applied for each application.  Based on the concentration of the
endothall and the amount of water applied, the application rate for
endothall was equivalent to 1.10 lb ae/A/application, for a total of
6.63 lb ae/A/season.  Single bulk control and treated samples of oranges
were harvested at normal crop maturity, immediately following the last
irrigation (0 DAT).  The fruit was processed into juice, oil and dried
pulp using simulated commercial procedures. 

Although endothall residues were <LOQ (<0.05 ppm) in/on whole orange
fruits and in each processed fraction, residues above the estimated LOD
(0.0025 ppm) were detected in each fraction except oil.  Residues were
detected at 0.019 ppm in/on whole fruit and at 0.014 ppm in juice, 0.041
ppm in dried pulp.  Residues in oil were <LOD.  Based on these residue
values the processing factors were 0.7x for juice, 2.2x for dried pulp,
and <0.2x for oil.  The theoretical processing factors for citrus juice
and oil are 2x and 1000x, respectively.

Based on HAFT residues of 0.026 ppm for oranges, the maximum expected
residues would be 0.057 ppm dried pulp.  As the recommended tolerance
for citrus fruits is 0.05 ppm, a separate tolerance of 0.1 ppm is
required for dried citrus pulp.  Separate tolerances are not required
for citrus juice and oil.

Rice.  In a field trial conducted in TX (Zone 6) during 2007, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to rice as six broadcast
foliar applications during grain development and maturation at RTIs of
6-7 days.  A volume equivalent to 1 acre inch of water (~27,154 gal/A)
was applied for each application.  Based on the concentration of the
endothall in the irrigation water and the amount of water applied, the
application rate for endothall was equivalent to 1.13 lb
ae/A/application, for a total of 6.75 lb ae/A/season.  Single bulk
control and treated samples of rice grain were harvested at normal crop
maturity, one day after the last irrigation (1 DAT), and processed into
hulls, bran and polished rice using simulated commercial procedures. 

Following six sprinkler applications of endothall at rates totaling 6.75
lb ae/A, residues in whole grain (RAC) were 0.872 ppm at 1 DAT, and the
residues in the processed fractions were 0.60 ppm for polished rice,
3.44 ppm for hulls and 2.03 ppm for bran.  The resulting processing
factors were 0.07x for polished rice, 3.9x for hulls and 2.3x for bran. 
The theoretical processing factors for rice are 5x for hulls and 7.7x
for bran.

Based on HAFT residues of 1.18 ppm for rice grain, the maximum expected
residues would be 4.6 ppm for hulls and 1.48 ppm for bran.  As the
recommended tolerance for cereal grains is 3.0 ppm, a separate tolerance
for rice bran is not required, but a tolerance of 5.0 ppm is required
for rice hulls.

Sorghum.  In a field trial conducted in KS (Zone 7) during 2007, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to the sorghum crop as six
broadcast foliar applications during grain development and maturation at
RTIs of 6-8 days.  A volume equivalent to 1 acre inch of water (~27,154
gal/A) was applied for each application.  Based on the concentration of
the endothall in the irrigation water and the amount of water applied,
the application rate for endothall was equivalent to 1.12-1.13 lb
ae/A/application, for a total of 6.77 lb ae/A/season  Single bulk
control and treated samples of mature sorghum grain were harvested on
the day of the last irrigation (0 DAT), and the grain samples processed
into flour using simulated commercial procedures.

 

Endothall residues were 1.49 ppm in/on sorghum grain (RAC) and 1.09 ppm
in sorghum flour, indicating that residues were reduced in flour by
0.7x.  Therefore, separate tolerance is not required for sorghum flour.

Soybean.  In a field trial conducted in IA (Zone 5) during 2007, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to soybeans as six broadcast
foliar applications during seed and pod development at RTIs of 6-8 days.
 A volume equivalent to 1 acre inch of water (~27,154 gal/A) was applied
for each application.  Based on the concentration of the endothall in
the irrigation water and the amount of water applied, the application
rate for endothall was equivalent to 1.13 lb ae/A/application, for a
total of 6.77 lb ae/A/season.  Single bulk control and treated samples
of soybeans were harvested at normal crop maturity, immediately
following the last irrigation (0 DAT).  The soybeans were processed into
hulls, meal and refined oil using simulated commercial procedures. 

Following six overhead sprinkler applications of endothall
(monoalkylamine salt) to soybeans at rates totaling 6.77 lb ae/A,
endothall residues were 0.021 ppm (<LOQ) in/on whole seeds, 0.083 ppm
in/on hulls, 0.017 ppm in meal, and nondetectable (<0.0001 ppm) in
refined oil.  The processing factors were 3.9x for hulls, 0.8x for meal,
and <0.005x for oil.  The theoretical processing factors for soybean
commodities are 11.3x for hulls, 2.2x for meal, and 12x for oil. 

Based on HAFT residues of 0.07 ppm for soybeans, the maximum expected
residues would be 0.273 ppm for hulls.  As the recommended tolerance for
soybean seeds is 0.2 ppm, a separate tolerance of 0.3 ppm is required
for soybean hulls.  

Sugar beet.  In a field trial conducted in CA (Zones 10) during 2007, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to the sugar beets as six
broadcast foliar applications during vegetative development at RTIs of
7-8 days.  A volume equivalent to 1 acre inch of water (~27,154 gal/A)
was applied for each application.  Based on the concentration of the
endothall and the amount of water applied, the application rate for
endothall was equivalent to 1.13 lb ae/A/application, for a total of
6.79 lb ae/A/season.  Single bulk control and treated samples of sugar
beet roots were harvested at normal crop maturity, immediately following
the last irrigation (0 DAT).  The roots were washed and processed into
dried pulp, molasses, and refined sugar using simulated commercial
procedures. 

Residues of endothall averaged 0.493 ppm in/on whole unwashed roots
(RAC) and were 0.554 ppm in dried pulp, 1.203 in molasses, and <0.05 ppm
in refined sugar.  The processing factors were 1.1x for dried pulp, 2.4x
for molasses, and <0.1x for refined sugar.  The theoretical
concentration factor for refined sugar is 12.5x.

Based on HAFT residues of 0.493 ppm for sugar beet roots, the maximum
expected residues would be 0.542 ppm for dried pulp and 1.18 ppm in
molasses.  As the recommended tolerance for root and tuber vegetables is
1.0 ppm, a separate tolerance is not required for dried pulp, but a
tolerance of 1.2 ppm is required for sugar beet molasses.  

Tomato.  In a field trial conducted in FL (Zone 3) during 2006, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to tomatoes as six broadcast
foliar applications during fruit development at RTIs of 8 days.  A
volume equivalent to 1 acre inch of water (~27,154 gal/A) was applied
for each application.  Based on the concentration of the endothall in
the irrigation water and the actual amount of water applied, the
application rate for endothall was equivalent to 1.13 lb
ae/A/application, for a total of 6.77 lb ae/A/season.  Single bulk
control and treated samples of tomatoes were harvested at normal crop
maturity, immediately following the last irrigation (0 DAT).  The
tomatoes were processed into puree and paste using simulated commercial
procedures.

 

Residues of endothall were formally reported to be <0.05 ppm in/on whole
fruits and puree and 0.069 ppm in tomato paste.  However, page 81 of the
report indicated that detectable residues (≥0.002 ppm) were present in
whole fruit at 0.021 ppm, 0.044 ppm in the puree, and 0.069 in the
paste.  Since the residues in the puree seemed no less likely to be
reasonable estimates than those on the raw fruit or in the puree (all
are below the LLMV, but above the LOD. We have used these numbers to
estimate factors of 2.1x for puree and 3.3x for the paste.  These
numbers make reasonable sense when compared to the mass balance
calculations.  EPA’s published theoretical processing factors for
tomato puree and paste are 1.4 and 5.5x, respectively.

Both processing factors lead to values above the recommended tolerance. 
Therefore, a separate tolerance of 0.1 ppm is required for both tomato
puree and tomato paste.  

Wheat.  In a field trial conducted in TX (Zone 6) during 2007, a
monoalkylamine salt formulation of endothall (2 lb ae/gal SC/L) was used
to treat the irrigation water at a rate of 5 ppm ae.  The treated water
was then applied using overhead sprinklers to the wheat crop as six
broadcast foliar applications during grain development and maturation at
RTIs of 6-8 days.  A volume equivalent to 1 acre inch of water (~27,154
gal/A) was applied for each application.  Based on the concentration of
the endothall in the irrigation water and the amount of water applied,
the application rate for endothall was equivalent to 1.12-1.13 lb
ae/A/application, for a total of 6.71 lb ae/A/season.  Single bulk
control and treated samples of mature wheat grain were harvested at
normal maturity, on the day of the last irrigation (0 DAT).  The wheat
grain was initially cleaned to generate AGF and was then milled using
simulated commercial procedures into germ, bran, middlings, shorts and
flour.

Endothall residues were 1.34 ppm in/on the bulk sample of wheat grain
and 20.3 ppm in/on the composited AGF sample, for a concentration factor
of 15x for wheat AGF.  Following processing, endothall residues were
3.44 ppm in germ, 3.10 ppm in bran, 1.14 ppm in middlings, 0.75 ppm in
flour, and 1.81 ppm in shorts.  The resulting processing factors were
2.6x for germ, 2.3x for bran, 0.9x for middlings, 0.6x for flour, and
1.4x for shorts.

Based on HAFT residues of 1.91 ppm for wheat grain, the maximum expected
residues would be 28.7 ppm for AGF, 4.97 ppm for germ, 4.39 ppm for bran
and 2.67 ppm for shorts.  Because residues in shorts are below the
recommended 3 ppm tolerance for cereal grains, a separate tolerance in
not required for shorts.  However, a tolerance of 5.0 ppm in required on
wheat milled byproducts to cover residues in wheat germ and bran.  In
addition, a 30 ppm tolerance is required for grain AGF.

Conclusions.  The submitted processing studies for irrigated crops are
adequate, and cover all the crops requested in the Endothall RED.  The
appropriate processed fractions were generated in each study, and
endothall residues in each RAC and processed commodity were determined
using an adequate LC/MS/MS method.  The sample storage conditions and
durations are also supported by the available storage stability data. 
With the exception of field corn grain, detectable residues of endothall
were found in all RAC samples.  HED notes that although residues were
reported to be <0.05 ppm (<LOQ) in the apple, orange, soybean and tomato
samples used for processing, endothall residues were detectable in each
of these RACs at 0.019-0.033 ppm.  Therefore, these detectable residues
were used for calculating processing factors for these crops.

Endothall residues were shown to concentrate in the following processed
fractions:  apple juice (1.2x) and wet pomace (2.8x), grape raisins
(4.4x), dried citrus pulp (2.2x), rice hulls (3.9x) and bran (2.3x),
soybean hulls (3.9x), sugar beet molasses (2.4x) and dried pulp (1.1x),
tomato paste (3.3x), and wheat germ (2.6x), bran (2.3x) and shorts
(1.4x).  (Although grape juice had an apparent concentration factor of
4.3x, HED used the maximum theoretical processing factor for grape juice
(1.2x) to assess the need for a separate grape juice tolerance.)

Based on the above processing factors and the HAFT residues for the
various RACs, the maximum expected residues in various processed
commodities exceeded the tolerance recommended for the associated RAC. 
Therefore, separate tolerances are required for the following processed
commodities at the recommended levels:  apple wet pomace (0.15 ppm),
raisins (3 ppm), dried citrus pulp (0.1 ppm), rice hulls (5 ppm),
soybean hulls (0.3 ppm), sugar beet molasses (1.2 ppm), tomato paste
(0.1 ppm), and wheat milled byproducts (5 ppm).

Although no processing studies are available for oilseed crops (canola,
flax, safflower, and sunflower), the available soybean processing study
is adequate for assessing the potential for concentration of endothall
in oil seed meal and refined oil for purposes of this petition.  The
soybean processing data indicate that endothall residues are unlikely to
concentrate in meal and oil fractions from other oil seed crops.

In addition, wheat processing study showed that residues concentrated in
AGF by 15x indicating that a separate tolerance will be required for
AGF.  Because endothall residues were higher in wheat grain than in the
other major grains (field corn, soybean and sorghum), the HAFT for wheat
grain (1.91 ppm) was used to calculate the maximum expected residues for
AGF (28.7 ppm).  These data indicate that a tolerance of 30 ppm would be
appropriate for AGF.

  SEQ CHAPTER \h \r 1 860.1650 Submittal of Analytical Reference
Standards

An analytical standard for endothall is currently available in the EPA
National Pesticide Standards Repository (personal communication with
Dallas Wright, ACB, 10/23/08), with an expiration date of 12/28/2012. 
Analytical reference standards must be replenished as requested by the
Repository.  

Analytical standards of the monomethyl and dimethyl esters are required
to be submitted.  The reference standards should be sent to the
Analytical Chemistry Lab, which is located at Fort Meade, to the
attention of either Theresa Cole or Thuy Nguyen at the following
address:

	USEPA

	National Pesticide Standards Repository/Analytical Chemistry Branch/OPP

	701 Mapes Road

	Fort George G. Meade, MD  20755-5350

860.1850/1900 Confined and Field Accumulation in Rotational Crops

DP# D321179, D. Soderberg, 8/30/2005

Although the available confined rotational crop study was deemed
inadequate, HED has concluded that  based upon the results of the plant
metabolism data and of soil and water metabolism data, it is possible to
infer that the only possible residues of significance in rotated crops
are endothall and its mono methyl and dimethyl esters.  Therefore, a new
confined rotational crop study is no longer required so long as limited
field trials are performed that measure all three of endothall, and the
monomethyl- and dimethyl- esters of endothall.   

Although the Endothall RED required data from limited field rotational
crop trials, the inadvertent exposure of crops to endothall via the use
of treated irrigation water will clearly exceed the potential secondary
exposure of crops planted in rotation with endothall treated crops such
as cotton and potatoes.  Therefore, the establishment of tolerances for
indirect/inadvertent residues of endothall on the proposed irrigated
crops supersedes the need for limited field rotational trial data or the
need for rotational crop tolerances.

860.1550 Proposed Tolerances

The residues of concern for endothall for purposes of both risk
assessment and tolerance enforcement in plant and animal commodities
include parent endothall and its monomethyl ester.  Permanent tolerances
are currently established for the combined residues of endothall and its
monomethyl ester at 0.1 ppm in/on cotton seeds, fish, dried hops and
potatoes, and at 0.05 ppm in/on rice grain and straw [40 CFR
§180.293(a)(1)].  An interim tolerance of 0.2 ppm has also been
established for endothall acid in potable water resulting from the use
of the monoalkylamine or dipotassium salts of endothall for control of
aquatic plants in canals, lakes, ponds and other potential water
sources.  An interim tolerance has also been established for endothall
on sugar beet at 0.2 ppm [40 CFR §180.319].

The available field trial data are adequate for purposes of assessing
inadvertent residues of endothall on irrigated crops.  Although the
residue data available on any given crop is limited, the field trials
are likely to represent a very conservative estimate of endothall
residues on irrigated crops.  This is not only because crops are
(properly) treated at the maximum use rate and the maximum number of
times per season, but also because overhead irrigation was used and
because a short PHI (0-DAT) used in each field trial.  The occurrence of
phytotoxicity on a number of the crops tested also make it unlikely that
repeated irrigation with water containing high levels of endothall (5
ppm) will go unrecognized and be allowed to occur under normal
agricultural conditions.

In calculating recommended tolerances for irrigated crops, HED has not
utilized the NAFTA MRL Calculator (or Tolerance Harmonization
Spreadsheet) except for grass commodities, corn grain and soybeans.  The
residues are already expected to be very conservative.  In addition,
only a very limited number of field trials were performed for any
crop/crop group, and there was only one plot for each field trial. 
Thus, in some cases there was only a single plot tested for a crop/crop
group.  Correct use of the NAFTA MRL Calculator given these limited data
would add an unrealistically large additional conservative factor onto
these already conservative results, and results would have less
reliability given the limited number of values use for each
distribution.  In addition, several tolerances are based upon residues
detected below the LOQ of the method, but above the LOD.  These residues
cannot be considered to be non-detectable, but the precision of
determination of residues in this range is larger than normally
attributed to the method, and results are usually biased high due to
undue influence of background contribution to the responses. Given all
of this, given that these tolerances are for inadvertent residues and
therefore in many cases are based upon very broad translations of data,
sometimes even across crop groups, HED has concluded that it makes
better sense to estimate tolerances using a more practical, common sense
approach.  In most cases these tolerances are approximately twice the
highest results from the highest residues/plot tested.  

The proposed tolerances for irrigated crops are listed in Table 10,
along with the Agency’s recommended tolerances.  As the tolerances on
irrigated crops are for inadvertent residues, they should be established
under 40 CFR §180.293(d).  Substantial changes in the proposed
tolerances are noted below.

IR-4 provided residue data on cabbage to support the tolerance on
Brassica leafy vegetables.  However, because mustard greens typically
have higher residues than cabbage, the leaf lettuce field trial data
were used to assess the tolerance on Brassica leafy vegetables.

For legume vegetables, the available field trial data indicated that a
single crop group tolerance is not appropriate.  Therefore, HED is
recommending that separate tolerances be established for the three
legume vegetable subgroups (6A, 6B and 6C), along with a tolerance on
soybean seeds.  In addition, IR-4 did not propose a tolerance for the
foliage of legumes (group 7).  HED is recommending a tolerance for
legume foliage based on the alfalfa field trial data.

Tolerances for okra, pistachios and herbs (subgroup 19A) are being
recommended based on the respective field trial data for tomatoes, tree
nuts and mint.

For cereal grains, IR-4 proposed tolerances for cereal grains (except
rice); however, the available residue data indicate that residues for
rice grain are similar to wheat and sorghum grain, while residues in/on
corn (field and sweet) are substantially lower.  Therefore, HED is
recommending a crop group tolerance for cereal grain, except corn, and
establishing separate tolerances for field and pop corn grain and sweet
corn K+CWHR.

Although IR-4 did not propose tolerances on any processed crop
fractions, the available field trial and processing data indicate that
separate tolerances are required for the following processed commodities
at the recommended levels:  apple wet pomace (0.15 ppm), raisins (3
ppm), dried citrus pulp (0.1 ppm), rice hulls (5 ppm), soybean hulls
(0.3 ppm), sugar beet molasses (1.2 ppm), tomato paste (0.1 ppm), and
wheat milled byproducts (5 ppm).  A separate tolerance is also AGF at 30
ppm.

There are currently no established Codex, Canadian, or Mexican maximum
residue limits (MRLs) for endothall on plant or animal commodities. 
Therefore, there are no issues related to harmonization with
international MRLs.

Table 11. 	Tolerance Summary for Endothall.

Commodity	Proposed Tolerance (ppm)	Recommended Tolerance (ppm)	Comments;

Correct Commodity Definition

40 CFR §180.293(d)

Vegetable, root and tuber, group 1	2	1.0	Based on maximum residues in
sugar beets (0.493 ppm), carrots (0.088 ppm) and potatoes (0.103 ppm)

Beet, sugar, molasses	None	1.5	Maximum expected residues are 1.18 ppm in
molasses based on HAFT residues of 0.493 ppm in sugar beet roots and a
2.4x processing factor. 

Vegetable, leaves of root and tuber, group 2	3.5	3.0	Based on maximum
residues in sugar beet tops (1.62 ppm)

Vegetable, bulb, group 3	2	0.5	Based on maximum residues in green onions
(0.26 ppm) and dry bulb onions (<0.05 ppm)

Vegetable, leafy, except brassica, group 4   	3.5	2.0	Based on maximum
independent plot residues in leaf lettuce (0.99 ppm) and head lettuce
(0.60 ppm)

Vegetable, brassica, group 5	0.1	None	Based upon Cabbage HAFT of 0.063
ppm)

Vegetable, brassica, head and stem subgroup 5A	None	0.1	Based upon
Cabbage HAFT of 0.063 ppm)

Vegetable, brassica, leafy, group 5B	None	2	Based upon maximum residues
in leaf lettuce, which better represents residues on leafy Brassica than
does cabbage.

Vegetable, legume, group 6	3	None	Separate tolerances should be
established for soybeans and the various legume subgroups based on the
maximum residues in succulent beans (0.47 ppm) and succulent peas (0.94
ppm), and those in dried beans (0.12 ppm), and on soybeans (0.07 ppm). 
Soybean seed tolerance (4 trials) is based upon tolerance spreadsheet.

Vegetable, legume, edible podded, subgroup 6A and

Pea and bean, succulent shelled, subgroup 6B

	None

	2.0

	Pea and bean, dried shelled, subgroup 6C	None	0.2

	Soybean seed	None	0.2

	Soybean, hulls 	None	0.5	Maximum expected residues are 0.27 ppm in
hulls based on HAFT residues of 0.07 ppm in soybeans and a 3.9x
processing factor. 

Vegetable, foliage of legume, group 7	None	4	Based on maximum residues
in alfalfa forage

Vegetable, fruiting, group 8	0.05	0.05	Based on maximum residues in
tomatoes (<0.05 ppm).

Okra	None	0.05

	Tomato, paste 

	None	0.1	Maximum expected residues are 0.069 ppm in paste based on HAFT
residues of 0.021 ppm in tomatoes and a 3.3x processing factor for
paste.

Tomato, puree	None	0.1	Maximum expected residues are 0.044 ppm in paste
based on HAFT residues of 0.021 ppm in tomatoes and a 2.1x processing
factor for puree.

Vegetable, cucurbit, group 9	1.1	1.5	Based on maximum residues in
cucumbers (0.74 ppm).

Fruit, citrus, group 10	0.05	0.05	Based on maximum residues in oranges
(<0.05 ppm).

Citrus, dried pulp	None	0.1	Maximum expected residues are 0.057 ppm in
dried pulp based on HAFT residues of 0.026 ppm in oranges and a 2.2x
processing factor. 

Fruit, pome, group 11	0.05	0.05	Based on maximum residues in apples
(<0.05 ppm).

Apple, wet pomace	None	0.15	Maximum expected residues are 0.109 ppm in
wet pomace based on HAFT residues of 0.039 ppm in apples and a 2.8x
processing factor. 

Fruit, stone, group 12	0.25	0.3	Based on maximum residues in peaches
(0.15 ppm).

Canebery subgroup 13-07A

and bushberry subgroup 13-07B 	0.6	0.6	Based on maximum residues in
blueberries (0.18 ppm) and blackberries (0.33 ppm).

Grape	0.9	1.0	Based upon maximum residues on grapes ( 0.64 ppm).

Grape, raisin	None	5.0	Maximum expected residues are 2.8 ppm in raisins
based on HAFT residues of 0.64 ppm in grapes and a 4.4x processing
factor. 

Nut, tree, group 14	0.05	0.05	Based on maximum residues in almond and
pecan nutmeats (<0.05 ppm).

Pistachio	None	0.05

	Almond, hulls	10	15	Based on maximum residues in hulls (8.2 ppm).

Grain, cereal, group 15, except corn	1.9	4	The available data support a
crop group tolerance, except for corn

Corn, sweet, kernel plus cob with husks removed	None	0.3	Tolerance based
on maximum residues in sweet corn K+CWHR (0.17 ppm)

Corn, field, grain	None	0.07	Tolerance based on tolerance spreadsheet
for corn grain

Corn, pop, grain	None	0.07

	Cereal, forage, fodder and straw, group 16, hay 	5.0	None	Combined into
Forage, Hay and Straw

Cereal, forage, fodder and straw, group 16, straw	6	None	Combined into
Forage, Hay and Straw

Cereal, forage, fodder and straw, group 16, forage	3.5	None	Combined
into Forage, Hay and Straw

Cereal, forage, fodder and straw, Group 16, except stover

 	3.5	6	Based on maximum residues on various forages (2.7) and wheat hay
and straw.  Note that field corn, sorghum and wheat forages received
only 2-3 applications prior to harvest (0.3-0.5x rate).

Cereal, forage, fodder and hay, group 16, stover	11	10	Based on adequate
data from field corn and sorghum stover (max 5.0 ppm).

Grain, aspirated fractions	24	35	Maximum expected residues in AGF are 29
ppm based on HAFT residues of 1.9 ppm for wheat grain and a
concentration factor of 15x for AGF.

Grass, forage, fodder, and hay, group 17, forage	3	3.5	Based upon
tolerance spreadsheet (6 trials)

Grass, forage, fodder, and hay, group 17, hay	19	18	Based upon tolerance
spreadsheet (6 trials)

Animal feed, Nongrass, group 18, forage	3.5	4.0	Based on maximum
residues in alfalfa forage (2.1 ppm) and hay (4.9 ppm)

Animal feed, Nongrass, group 18, hay	8	10

	Peppermint, tops	7	5	Based on maximum residues in mint tops (2.8 ppm).

Spearmint, tops	7	5

	Herb and spice, group 19	None	5

	Rice, grain	1.7	None	Separate tolerances are not required for rice
grain and straw as these commodities are covered by the tolerances on
cereal grains and cereal grain straw.

Rice, straw	4.5	None

	Rice, hulls	None	8	Based on HAFT residues of 1.0 ppm for rice grain and
a processing factor of 3.9x for hulls, the maximum expected residues in
rice hulls is 4.0 ppm.

Wheat, milled byproducts	None	5	Based on HAFT residues of 1.9 ppm for
wheat grain and processing factors of 2.6x for germ, and 2.3x for bran,
and 1.4x for shorts, the maximum expected residues in milled byproducts
is 5.0 ppm.

Food commodities	None	5	Inadvertent residues on any food crop/commodity
not included within the assigned crop groups and miscellaneous
tolerances.  Based upon Mint.

Feed commodities	None	10	Inadvertent residues on any feed crop/commodity
not included within the assigned crop groups and miscellaneous
tolerances.  Based upon Cereal Grains.

Cattle, muscle	None	0.03	Based upon calculations for Dairy Cattle using
metabolism data.

Cattle, kidney	None	0.20	Based upon calculations for Dairy Cattle using
metabolism data.

Cattle, liver	None	0.10	Based upon calculations for Dairy Cattle using
metabolism data.

Cattle, fat	None	0.01	Based upon calculations for Dairy Cattle using
metabolism data.

Milk	None	0.03	Based upon calculations for Dairy Cattle using metabolism
data.

Sheep, muscle	None	0.015	Based upon calculations for Beef Cattle using
metabolism data.

Sheep, kidney	None	0.15	Based upon calculations for Beef Cattle using
metabolism data.

Sheep, liver	None	0.05	Based upon calculations for Beef Cattle using
metabolism data.

Sheep, fat	None	0.005	Based upon calculations for Beef Cattle using
metabolism data.

Goat, muscle	None	0.015	Based upon calculations for Beef Cattle using
metabolism data.

Goat, kidney	None	0.15	Based upon calculations for Beef Cattle using
metabolism data.

Goat, liver	None	0.05	Based upon calculations for Beef Cattle using
metabolism data.

Goat, fat	None	0.005	Based upon calculations for Beef Cattle using
metabolism data.

Hog, muscle	None	0.01	Based upon calculations using metabolism data.

Hog, kidney	None	0.10	Based upon calculations using metabolism data.

Hog, liver	None	0.05	Based upon calculations using metabolism data.

Hog, fat	None	0.005	Based upon calculations using metabolism data.

Poultry, muscle	None	0.015	Based upon calculations using metabolism
data.

Poultry, liver	None	0.05	Based upon calculations using metabolism data.

Poultry, fat	None	0.015	Based upon calculations using metabolism data.

Poultry, meat byproducts	None	0.20	Based upon calculations using
metabolism data.

Egg	None	0.05	Based upon calculations using metabolism data.

References

DP Number:	D321179

Subject:	Endothall and its Salts.  Residue Chemistry Considerations for
Reregistration Eligibility Decision.  Revised per Registrant Comments.

From:	D. Soderberg

To:	R. Zendzian

Dated:	8/30/2005

MRID(s):	None

  SEQ CHAPTER \h \r 1 Attachments:  

Attachment 1.  Table of Individual Residue Values Found for Each
Different Commodity Attachment 2:	 Tolerance Spreadsheet analyses for
Commodities with Four or More Field Trials 



Residue Data for Endothall

Trial ID

(City, State; Year)	Zone	Crop; Variety	Matrix	Total Rate4	PHI

(days)	Residues (ppm)5,6

ppm	lb ae/A

TABLE C.3.	Residue Data from Root and Tuber Vegetable Field Trials with
Endothall.

Sugar Beets

Conklin, MI 2007

MI$19	5	Sugar beet; Beta 5451	Tops	5.0	6.77	0	1.256	1.374

3.5	4.80	0	0.523	0.531

	Roots	5.0	6.77	0	0.199	0.136

3.5	4.80	0	0.120	0.115

Arroyo Grande, CA  2007

CA$22	10	Sugar beet; Alpine Medium Quickprime	Tops	5.0	6.79	0	1.618
1.105

3.5	4.88	0	1.279	0.948

	Roots	5.0	6.79	0	0.591	0.395

3.5	4.88	0	0.345	0.316

Carrot

Ravenna, MI  2007

MI$20	5	Carrot; Recoleta	Root	5.0	6.77	0	0.075	0.062

Arroyo Grande, CA 2006

CA$06	10	Carrot; Nantes	Root	5.0	6.79	0	0.088	0.088

Potato

Conklin, MI  2007

MI$21	5	Potato; Dark Red Norland	Tuber	5.0	6.77	0	0.072	0.103

Payette, ID  2007

ID$23	11	Potato; Ranger Russet	Tuber	5.0	6.83	0	0.067	0.078

TABLE C.3.	Residue Data from Onion Field Trials with Endothall (SC/L).

East Bernard, TX 2007

TX$07	6	Green Onion; Evergreen Hardy White	Whole plant without roots	5.0
6.75	0	0.284	0.234

Arroyo Grande, CA  2007

CA$18	10	Dry Bulb Onion; Onion Yellow Granex F1	Dry Bulb	5.0	6.76	0
0.0231	0.0231

TABLE C.3.	Residue Data from Lettuce Field Trials with Endothall Salts
(SC/L).

Leaf Lettuce

Arroyo Grande, CA 2006

CA$04	10	Leaf lettuce; Greenstar	Leaves 	5.0	6.76	0	0.743	1.240

3.5	4.81	0	0.582	1.013

North Rose, NY 2007

NY$28	1	Leaf Lettuce; Green salad bowl	Leaves	5.0	6.73	0	0.462	0.410

3.5	4.67	0	0.255	0.241

Head Lettuce

Arroyo Grande, CA 2006

CA$05	10	Head Lettuce; Snaiper	Heads, 

w/wrapper leaves	5.0	6.76	0	0.092	0.081

3.5	4.81	0	0.0321	0.082

Lyons, NY 2007

NY$31	1	Head Lettuce; Ithaca MTO	Heads, 

w/wrapper leaves	5.0	7.17	0	0.604	0.491

3.5	5.07	0	0.582	0.436

TABLE C.3.	Residue Data from Cabbage Field Trials with Endothall (SC/L).

North Rose, NY 2006

NY$23	1	Matsumo	Head with wrapper leaves	5.0	7.00	0	0.0251	0.075

Baptistown, NJ  2006

NJ$08	1	Blue Lagoon	Head with wrapper leaves	5.0	5.64	0	0.065	0.058

TABLE C.3.	Residue Data from Legume Field Trials with Endothall
Monoamine Salt (SC/L).

Succulent Podded Beans

Arroyo Grande, CA 2007

CA$26	10	Succulent Lima /speckled	Succulent seed w/pod	5.0	9.02	0	0.414
0.521

Baptistown, NJ 2006

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Succulent seed w/pod	5.0	6.75	0	0.291	0.324

Dried Beans

Delavan, WI 2007

WI$13	5	Dry bean/

Pinto	Dried seed	5.0	6.77	0	0.134	0.070

Richland, IA 2007

IA$14	5	Dry bean/

Great Northern	Dried seed	5.0	6.77	0	0.109	0.123

Succulent Podded Peas

Ephrata, WA 2007

WA$17	12	Succulent pea/

Tonic	Succulent seed w/pod	5.0	6.74	0	0.878	1.00

Delavan, WI 2007

WI$12	5	Succulent pea/

Wanto	Succulent seed w/pod	5.0	6.74	0	0.537	0.522

Soybean

Baptistown, NJ 2006

NJ$25	1	Soybean/

93244449	Dried seed	5.0	6.75	1	0.072	0.068

Newport, AR 2007

AR$16	4	Soybean/

BPR 5423 nRR	Dried seed	5.0	6.76	0	0.0171	ND2

Richland, IA 2007

IA$15	5	Soybean/

93M42	Dried seed	5.0	6.77	0	0.0201	0.0171

Sparta, IL 2007

IL$11	5	Soybean/

Asgrow AG 3905	Dried seed	5.0	6.77	0	0.0381	0.0261

TABLE C.3.	Residue Data from Tomato Field Trials with Endothall
Monoamine Salt (SC/L).

Grande Arroyo, CA 20006

CA$28	10	Tomato/ Organic Yaqui	Fruit	5.0	6.74	0	NR3 	NR3 

Oviedo, FL 2006

FL$27	3	Tomato/ Celebrity	Fruit	5.0	6.77	0	0.0271	0.0301

TABLE C.3.	Residue Data from Cucumber Field Trials with Endothall Salts
(SC/L).

Baptistown, NJ 2006

NJ$02	1	Burpless bush	Fruit	5.0	6.75	0	0.738	0.738

3.5	4.80	0	0.406	0.459

Conklin, MI 2007

MI$42	5	Fancipack	Fruit	5.0	6.77	0	0.234	0.284

3.5	4.81	0	0.337	0.310

TABLE C.3.	Residue Data from Orange Field Trials with Endothall
Monoamine Salt (SC/L).

Dinuba, CA 2006

CA$11	10	Rush Thompson Improved	Fruit	5.0	6.78	0	0.0241	0.0281

Oviedo, FL 2006

FL$10	3	Hamlin	Fruit	5.0	6.63	0	0.0221	0.0211

TABLE C.3.	Residue Data from Apple Field Trials with Endothall Monoamine
Salt (SC/L).

North Rose, NY 2006

NY$29	1	Empire	Fruit	5.0	6.79	0	0.0311	0.0471

Ephrata, WA 2006

WA$16	11	Braeburn	Fruit	5.0	6.64	0	ND2	0.0431

TABLE C.3.	Residue Data from Peach Field Trials with Endothall Salts
(SC/L).

Morven, GA 2007

GA$01	2	White	Fruit	5.0	7.08	0	0.0451	0.0431

3.5	5.05	0	0.0431	0.0461

Dinuba, CA 2007

CA$02	10	Snow Princess	Fruit	5.0	6.78	0	0.144	0.160

3.5	4.82	0	0.118	0.136

TABLE C.3.	Residue Data from Crop Field Trials with Endothall Monoamine
Salt (SC/L).

Conklin, MI 2007

MI$32	5	Blueberry: Blue Ray (Highbush)	Fruit	5.0	6.77	0	0.158	0.197

Hillsboro, OR 2007

OR$41	12	Blackberry (Boysen)	Fruit	5.0	6.73	0	0.311	0.346

TABLE C.3.	Residue Data from Tree Nut Field Trials with Endothall
Monoamine Salt (SC/L).

Irwinville, GA 

2006

GA$22	2	Pecan; summer	Nutmeat	5.0	7.01

	0	ND2	0.0241

Coalinga, CA 2007

CA$40	10	Almond; nonpariel	Nutmeat	5.0	6.80	0	0.0361	0.0371

	Hulls 

6.91	8.20

TABLE C.3.	Residue Data from Cereal Crop Field Trials with Endothall.

Sweet Corn

Sodus, NY 2006

NY$17	1	Sweet corn; Speedy Sweet	K+CWHR	5.0	6.75	0	0.05	NR3 

	Forage (w/o ears)

0.52	0.65

	Forage (w/ears)

0.49	0.40

	Stover (w/ears)

0.69	0.58

Campbell. MN 2007

MN$10	5	Sweet corn: Vitality	K+CWHR	5.0	6.91	0	0.17	0.17

	Forage (w/o ears)

1.18	1.28

	Forage (w/ears)

0.88	1.06

	Stover (w/ears)

4.70	5.06

Field Corn

Baptistown, NJ 2006

NJ$18	2	Field corn; 

TA 3892	Forage	5.0	3.38 4	0	0.40	0.28

	Grain

6.75

0.0411	0.0391

	Stover

3.48	2.89

Sparta, IL 2007

IL$09	5	Field Corn DK61-73	Forage	5.0	6.77	0	0.31	0.34

	Grain

NR3	NR3

	Stover

1.56	1.39

Richland, IA 2007

IA$06	5	Field Corn 34A16	Forage	5.0	2.26 3	0	0.35	0.42

	Grain

6.77

NR3	NR3

	Stover

2.07	2.37

Centerville, SD 2007

SD$05	5	Field Corn DKC 54-46	Forage	5.0	2.40 3	0	0.36	0.21

	Grain

7.10

NR3	NR3

	Stover

1.07	1.81

Sorghum

Sparta, IL 2007

IL$08	5	Sorghum Dekalb 44	Forage	5.0	3.38 4	0	3.05	2.29

	Grain

6.77

1.41	0.91

	Stover

2.60	7.19

Richland, IA 2007

IA$07	5	Sorghum 85G01	Forage	5.0	3.38 4	0	0.96	0.57

	Grain

6.77

0.49	0.80

	Stover

1.11	0.81

Larned, KS 2007

KS$03	7	Sorghum Pioneer 87G57	Forage	5.0	2.26 3	0	0.29	0.41

	Grain

6.77

1.23	1.18

	Stover

3.10	2.65

Wheat 

Ephrata, WA 2007

WA$20	11	Winter Wheat; Stevens	Forage	5.0	2.21 3	0	0.74	0.63

	Hay

1.00	1.11

	Grain

6.64

0.20	0.25

	Straw

2.20	1.93

Bernard, TX 2007

TX$19	6	Winter wheat; Fannin	Forage	5.0	2.24 3	0	1.99	2.27

	Hay

3.09	3.09

	Grain

6.71	1	2.01	1.80

	Straw

2.72	2.76

St, Johns, KS 2007

KS$21	5	Winter Wheat; Jagger	Forage	5.0	2.26 3	0	0.84	0.89

	Hay

3.39 4

1.31	1.62

	Grain

6.77

0.32	0.32

	Straw

1.49	1.38

Velva, ND 2007

ND$04	7	Spring Wheat; Glenn	Forage	5.0	2.19 3	0	0.89	0.94

	Hay

3.29 4

2.24	2.09

	Grain

6.58

0.30	0.47

	Straw

1.52	0.61

TABLE C.3.	Residue Data from Grass Feed Crop Field Trials with Endothall
Monoamine Salt (SC/L).

Lecompte, LA 2006

LA$12	4	Bermuda grass;  Russell	Forage	5.0	7.02	1	2.08	2.23

	Hay

9.80	12.40

East Bernard, TX 2006

TX$14	6	Bermuda grass; Coastal	Forage	5.0	6.75	1	1.85	2.03

	Hay

13.1	14.2

Ephrata, WA 2006

WA$15	11	Bluegrass; Kentucky	Forage	5.0	6.64	1	1.82	1.85

	Hay

7.17	8.91

Newport, SR 2007

AR$37	4	Bluegrass; Kentucky	Forage	5.0	6.76	2	2.65	2.81

	Hay

6.51	6.78

Alexandria, LA 2006

LA$13	4	Fescue;

 not available	Forage	5.0	7.00	0	1.70	2.86

	Hay

5.89	5.84

Hillsboro, OR 2007

OR$38	12	Fescue; 

Pure Gold	Forage	5.0	6.73	0	2.65	1.99

	Hay

5.34	9.24

TABLE C.3.	Residue Data from Non Grass Crop Field Trials with Endothall
Monoamine Salt (SC/L).

Velva, ND 2007

ND$20	7	Alfalfa; NK919	Forage	5.0	6.58	0	2.13	1.41

	Hay

4.98	4.87

Tilden, IL 2007

IL$30	5	Alfalfa; cattleman’s	Forage	5.0	5.94	0	2.24	1.99

	Hay

5.31	3.09

TABLE C.3.	Residue Data from Crop Field Trials with Endothall Monoamine
Salt (SC/L).

Velva, ND 2007

ND$20	7	Alfalfa; NK919	Forage	5.0	6.58	0	2.13	1.41

	Hay

4.98	4.87

Tilden, IL 2007

IL$30	5	Alfalfa; cattleman’s	Forage	5.0	5.94	0	2.24	1.99

	Hay

5.31	3.09

TABLE C.3.	Residue Data from Grape Field Trials with Endothall (2 lb
ae/gal SC/L).

North Rose, NY 2006

NY$01	1	Elvira	Fruit	4.98	6.73	0	0.433	0.376

San Luis Obispo, CA 2007

CA$31	10	Pinot 155	Fruit	4.98	6.76	0	0.588	0.449

Ephrata, WA 2006

WA$02	11	Riesling	Fruit	4.97	6.64	0	0.587	0.696

TABLE C.3.	Residue Data from Rice Field Trials with Endothall Monoamine
Salt (SC/L).

East Bernard, TX 2007

TX$24	6	Rice; Cocodrie	Grain	5.0	6.75	1	1.22	1.14

	Straw

1.99	2.24

Cheneyville, LA 2007

LA$25	4	Rice; Clearfield 161	Grain	5.0	6.77	0	1.16	1.19

	Straw

1.09	0.94

Newport, AR 2007

AR$26	4	Rice; Wells	Grain	5.0	6.76	0	0.818 3	0.694 3

	Straw

1.90	1.86

Biggs, CA 2007

CA$27	10	Rice; M-205	Grain	5.0	6.76	0	0.802 3	1.08

	Straw

2.59	2.61

TABLE C.3.	Residue Data from Mint Field Trials with Endothall Monoamine
Salt (SC/L).

Ephrata, WA 2006

WA$09	11	Mint (Todd’s Mitchem)	Tops	5.0	6.64	0	2.89	2.70

Elkhorn, WI 2007

WI$39	5	Mint (Black Mitchem)	Tops	5.0	6.77	0	1.67	1.31

Residues below LLMV, but above LOD.

Non Detect – no residues seen

No Reportable Residues – no residues below the 0.05 ppm LLMV were
reported

The rate is expressed both in terms of the concentration in the
irrigation water (ppm and the total amount (lbs ae/A) applied.

Expressed in acid equivalents.  The LLMV is 0.05 ppm and the LOD is
below 0.001 ppm.

The two results for each field trial represent two samples taken from a
single plot, not two plots.  



Attachment 2. Tolerance Spreadsheet Results for Crops with Four or More
Field Trials – When the Spreadsheet Was Used to Calculate Tolerances 
(Please note that the spreadsheet was not used when less than four field
trials were performed and in those cases where data from multiple crops
were combined into a group tolerance.)

 



 

 

 

Template Version April 2008

 

Endothall	Summary of Analytical Chemistry and Residue Data	DP#:  356315

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