UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

	OFFICE OF CHEMICAL SAFETY 

	& POLUTTION PREVENTION

	

  SEQ CHAPTER \h \r 1 MEMORANDUM

Date:  09/12/2012 

SUBJECT:	Quinclorac on Rhubarb and Low Growing Berries (except
Strawberry).   Summary of Analytical Chemistry and Residue Data.  

		Residue Chemistry Considerations for Registration Review of Quinclorac
and Quinclorac Dimethyl Amine.		

  

PC Codes:  028974, 128974	DP Barcode:  D397719, 404569, 404912

Decision No.: 459055 and 468877	Registration No.: 42750-169

Petition No.:  1E7957	Regulatory Action:  Section 3 Registration and
Registration Review

Risk Assessment Type:  NA	Case No.:  7222

TXR No.:  NA	CAS No.:    SEQ CHAPTER \h \r 1 84087-01-4, 84087-48-9

MRID No.:  48697501, 48697502	40 CFR:  180.463

		              									

From:	        	Susan V. Hummel, Chemist

		Gary Otakie, Chemist

                    	Risk Assessment Branch 4, Health Effects Division
(7509P)

Through:     	Thurston G .Morton, Chemist

                    	Risk Assessment Branch 4, Health Effects Division
(7509P)

To:	        	Sidney Jackson and Barbara Madden, PM#5

	        	RIMUERB, Registration Division (7505P)

	        	Erik Kraft and Kable Davis, PM#25

	        	Herbicide Branch, Registration Division (7505P)

		Wilhelmina Livingston, RM#60

		Pesticide Reevaluation Division (7508P)

Executive Summary

Quinclorac [3,7-Dichloro-8-quinolinecarboxylic acid] is a selective
post-emergent herbicide used for the control of various annual grasses
and broadleaf weeds in barley, wheat, rice, sorghum and grasses grown
for seed.  Permanent tolerances have been established for residues of
quinclorac per se in/on barley, rice, sorghum and wheat at levels
ranging from 0.1 ppm in wheat straw to 1200 ppm in aspirated grain
fractions [40 CFR §180.463(a)].  Permanent tolerances have also been
established for residues of quinclorac, per se, in/on livestock
commodities at levels ranging from 0.05 to 1.5 ppm.  In addition, there
is a tolerance for residues quinclorac on cranberry in §180.463(b), as
a result of a Section 18 emergency exemption at 15 ppm.

The Inter Regional Project No. 4 (IR-4) has submitted a request for
tolerances and registration of quinclorac on low growing berries, except
strawberries, subgroup 13-07H, and rhubarb.  Tolerances were proposed
for residues of quinclorac in low growing berries, except strawberries,
subgroup 13-07H, at 1.1 ppm, and rhubarb at 0.4 ppm.

A new physical form of quinclorac (EPA Reg. No. 7969-272) has recently
been registered: Drive XLR-8 (Reg. No 7969-272), Paramount L Herbicide
(Reg. No. 7969-315), Facet L Herbicide (EPA Reg. No. 7969-316), and
Quinclorac 1.5 DMA (Reg. No 42750-224).  These products are DMA
(dimethylamine) salt forms of quinclorac.  These products were not
proposed for the new uses of quinclorac, proposed in the current
petition, but are registered for use on rice and ornamental turf.  

The qualitative nature of quinclorac residues in plants was considered
adequately understood for the currently registered crops, based upon the
metabolism studies on rice, sorghum, and wheat.  Additional metabolism
data are needed on a fruit commodity to support use on berries.  Further
metabolism data may be needed if uses are further expanded.  The
qualitative nature of quinclorac residues in livestock is also
understood based upon the adequate goat and poultry metabolism studies. 
The Agency had concluded that parent is the only residue of concern in
both plant and livestock commodities for purposes of the tolerance
expression and risk assessment.  However, the official enforcement
method includes a methylation step, so the methyl ester of quinclorac is
implicitly included as a residue of concern.

An adequate enforcement method is available for enforcing quinclorac
tolerances on plants and livestock, a GC/ECD method that uses
methylation with diazomethane.  There are available FDA   SEQ CHAPTER \h
\r 1 multi-residue method (MRM) testing data that indicate that
quinclorac is completely recovered using Protocol B.  

Adequate analytical methods are available for determining residues of
quinclorac, per se,  in/on plant parts, an LC/MS/MS method (BASF Method
A9708/1).  The validated LOQ for quinclorac is 0.05 ppm.  However, this
method would not determine the methyl ester of quinclorac, which is
implicitly included in the residue of concern.

Adequate cattle and poultry feeding studies are available and support
the use of of quinclorac.

Adequate rotational crop studies are available and support the use of
quinclorac.

 

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

860.1200 Directions for Use.   

Cranberry is an aquatic crop, and as such, a label restriction is needed
regarding the use of treated rice and cranberry fields for aquaculture. 
Alternatively, the petitioner may determine residues in catfish and
crayfish raised in treated fields and propose tolerances for these
commodities, if necessary.  The label provided for Quinclorac/QuinStar
4-L does not contain any restriction against aquaculture.

For Registration Review, the PM must ensure that all labels for
quinclorac on rice and cranberry contain a label restriction restricting
the use of treated rice and cranberry fields for aquaculture.

860.1300 Nature of the Residue in Plants

  While the metabolism of quinclorac is adequately understood with
regard to the currently registered uses, there are no plant metabolism
data for quinclorac on commodities similar to cranberry.  

These data are not being required at this time.  However, any further
expansion of the use of quinclorac to other commodities grown on larger
acreages than rhubarb and cranberry, will trigger a requirement of
additional metabolism data.

860.1400 Water, Fish, and Irrigated Crops

Data on catfish and crayfish are required, or the label must prohibit
use of treated water from rice and cranberry fields for aquaculture.

For registration review, the PM must ensure that all quinclorac labels
with uses on rice and cranberry contain such a restriction.

860.1480 Meat, Milk, Poultry, and Eggs

Tolerances in livestock commodities are not pertinent to the current
petition.  However, tolerances in livestock commodities will be changed
in connection with Registration Review.

860.1500 Crop Field Trials

Field trial data are adequate to determine quinclorac, per se.  IR-4
should note the current guidance for differentiating field trial sites.

Field trial data are adequate to support the existing uses of quinclorac
on rice, grain sorghum, barley (imported), and pasture and range
grasses.

The established tolerance on aspirated grain fractions should be revoked
as it is not needed.  The tolerance on rice straw may be revoked, as
rice straw is no longer considered a significant livestock feedstuff.

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

 Albaugh must supply the Pesticide Repository with analytical standards
for quinclorac and the quinclorac methyl ester.

An analytical standard for the quinclorac DMA salt must be submitted to
the EPA National Pesticide Standards Repository.

860.1550 Proposed Tolerances

A tolerance for residues of quinclorac on rhubarb may be set at 0.5 ppm.
 A  tolerance for residues of quinclorac on low growing berries, except
strawberries, subgroup 13-07H, may be set at 1.5 ppm.  At the time of
publication of this tolerance, the tolerance for residues quinclorac on
cranberry in § 180.463(b) should be revoked, since the tolerance being
set will cover the Section 18 use.

In addition, IR-4 should be reminded to use the OECD tolerance
calculation procedures.

Revisions to current tolerances for registration review are documented
in Table 7.

Background

Quinclorac is a herbicide for the selective post-emergent control of
various annual grasses and broadleaf weeds.  Quinclorac is adsorbed via
the root system and partially through the foliage and acts as an
inhibitor of cell wall synthesis.  The nomenclature of quinclorac and
quinclorac DMA salt are summarized in Table 1, and the physicochemical
properties of are summarized in Table 2. 

 



Common name	Quinclorac, DMA salt

Company experimental name	BAS 514 51H  

IUPAC name	3,7-dichloroquinoline-8-carboxylic acid, DMA salt

CAS name	3,7-dichloro-8-quinolinecarboxylic acid, DMA salt

CAS registry number	84087-48-9

Molecular weight	287.2

End-use product (EP)	Drive®XLR8 Herbicide, EPA Reg. No. 7969-272;
Paramount® L Herbicide, EPA Reg. No. 7969-GRA; Facet L Herbicide, EPA
Reg. No. 7969-GRL



Note:  Physicochemical properties of the technical grade quinclorac are
reported below.  

Only several physicochemical properties of the DMA salt of quinclorac
are available.

Table 2.		Physicochemical Properties of the Technical Grade Quinclorac.

Parameter	Value	Reference

Melting point/range	~269°C	D342446, M. Doherty, 9/11/07

pH	3.4-3.5	RCB 3283 S. Hummel, 2/26/88

Density	~560 g/L	D342446, M. Doherty, 9/11/07

Water solubility (20°C)	0.0064 g/100 mL

	Solvent solubility (g/100 mL at 20°C to 25°C)	ethanol	0.2 	toluene
<0.1

Lutrol®	<0.1	acetone	0.2

olive oil	<0.1	n-octanol	<0.1

acetonitrile	<0.1	1,2-propandiol	<0.1

ethyl acetate	0.1	dichloromethane	<0.1

ethyl ether	0.1	n-hexane	<0.1

	Vapor pressure (20°C)	<1.0×10-7 mbar (<0.75×10-7 Torr)

	Dissociation constant, pKa	4.34 at 20°C

4.35 at 25°C

	Octanol/water partition coefficient, log POW (20°C)	1.76 at pH 4

-0.74 at pH 7

 3.74 at pH 10

	UV/visible absorption spectrum	314 nm, 300 nm, 278 nm (95% ethanol)
MRID 48051092



Table 2.		Physicochemical Properties of the Quinclorac, DMA Salt.

Parameter	Value	Reference

Melting point/range	NA

	pH	NA

	Density	NA

	Water solubility (20°C)	NA

	Solvent solubility (g/100 mL at 20°C to 25°C)	NA

	Vapor pressure (20°C)	NA

	Dissociation constant, pKa	4.33 ± 0.15  (Temperature not reported)
MRID 48051092

Octanol/water partition coefficient, log POW (20°C)	NA

	UV/visible absorption spectrum	314 nm, 300 nm, 278 nm (95% ethanol)
MRID 48051092



In addition, the registrant has submitted a comparative study of the
dissociation behavior of quinclorac and its dimethylamine salt (MRID
48051902, “Comparative study of the Dissociation Behavior of
Quinclorac Acid and its Dimethylamine Salt”).  The UV/Vis spectra of
quinclorac TGAI and the UV/Vis spectra and dissociation constant of
quinclorac DMA were presented.  The results of the study show that in
aqueous solutions, the chemical form of the quinclorac dimethylamine
salt is the same as that of the quinclorac acid form.  

860.1200 Directions for Use

There are currently five quinclorac EPs registered to BASF in the U.S.
for use on food/feed crops, three of which contain only quinclorac and
two that are multiple active ingredient (MAI) formulations.  The single
active ingredient formulations include a 50% WP and a 75% DF for use on
rice (EPA Reg. Nos. 7969-93 and 7969-313) and a 75% DF for use on wheat,
sorghum, and grasses grown for seed (EPA Reg. No. 7969-113).  The two
MAI formulations are both 75% DF formulations; one contains 15%
quinclorac and 60% 2,4-D and is registered for use on wheat and sorghum
(EPA Reg. No. 7969-152), and the other contains 62% quinclorac and 13%
imazethapyr and is registered for use on rice.  

Proposed new uses.  IR-4 is proposing use of the Quinclorac 4-L AG (Reg.
No. 42750-169), registered to Albaugh, Inc., containing 3.8 lb
quinclorac/gallon, in connection with the current petition.  

Table 3.	Summary of Proposed Directions for Use Quinclorac 4-L AG



Formulation

[EPA Reg. No.],

a.i. 	Applic. Timing, Type, and Equip. 1	Applic. Rate

(lb ai/A)	Max. Seasonal Applic. Rate

(lb ai/A)	PHI

(days)	Use Directions and Limitations 2

Rhubarb

Quinclorac 4-L

42750-169, 

3.8 lb/gal DF, Quinclorac	Foliar ground application in 10 gal water,
timing not specified.  A second application at least 30 days after the
first application	0.37	0.75	30	Crop oil concentrate permitted.

Low Growing Berries, except Strawberry, subgroup 13-07H

Quinclorac 4-L

42750-169, 

3.8 lb/gal DF, Quinclorac	Foliar ground application in 10 gal water,
timing not specified.  A second application at least 30 days after the
first application	0.50	1.0	60	Adjuvants not mentioned.



Conclusions.  Cranberry is an aquatic crop, and as such, a label
restriction is needed regarding the use of treated rice and cranberry
fields for aquaculture.  Alternatively, the petitioner can determine
residues in catfish and crayfish raised in treated fields and propose
tolerances for these commodities, if necessary.  The label provided for
Quinclorac/QuinStar 4-L does not contain any restriction against
aquaculture.

Existing Uses.  Existing uses of quinclorac include use on rice, grain
sorghum, wheat, pasture and rangeland grasses, and use on barley in
Canada for import into the US.  The dimethylamine salt of quinclorac has
recently been registered for use on rice, grain sorghum, and wheat.

The current uses are as described under 860.1500 Field Trials.

860.1300 Nature of the Residue - Plants

D241204, J. Stokes, 11/6/1998

The qualitative nature of quinclorac residues in plants was considered
adequately understood for the currently registered uses, based upon the
metabolism studies on rice, grain sorghum, and wheat.  In each of these
studies, the major 14C-residue in/on various matrices was identified as
parent compound.  Based on the metabolite profiles observed in these
studies, quinclorac undergoes hydroxylation of the quinoline ring of the
parent, followed by conjugation with glucose and other biologically
available compounds at the hydroxlated site.   Some radioactive residues
are incorporated into the high molecular weight natural products.  Based
on the above studies, HED concluded that parent is the only residue of
concern in plant commodities for purposes of the tolerance expression
and risk assessment.  However, all three metabolism studies are on grain
commodities.  A 4th metabolism study, on canola, is available but has
not been reviewed.

Metabolism in Rice.  (MRID 41063534).  The metabolism of 14C-ring
labeled quinclorac in rice plants was studied under growth chamber and
field conditions.  Growth chamber plants were treated at 1.4 lb.ai/A
14C-BAS 514H, an exaggerated dosage rate, at the four leaf stage of
plant development. Growth-chamber rice plant samples were harvested for
analysis at PHI=97 days. Field plants were treated at 0.75 lb/A 14C-BAS
514H, at the 3-5 leaf stage. The treatment level of field plants
simulates the expected herbicide use rate. Field rice plants were
harvested at PHI= 28 and 118 days.  Greater than 84% of the TRR in rice
grain or straw was identified as the parent compound, quinclorac. 

Metabolism in Sorghum:  (MRID #44322211).  Preemergence and post
emergence applications of radiolabeled quinclorac were made to a
confined sorghum plot.  The soil was a loamy sand soil with low organic
matter.  Treatment levels were 0.47 lb ai/A preemergence (0 DAT) and
0.45 lb a.i./A postemergence (25 DAT) for a total of 0.92 lb ai/A.  Crop
samples were collected and analyzed at various stages of maturity,
including forage samples collected at twenty-five days after the
postemergence treatment, and mature stover and grain collected at the
final harvest (120 DAT).  

TABLE 4.  Distribution and Identification of Residues from Sorghum RACs
Treated at 0.92 lb a.i./A. 

RAC	Radioactive Residues



Identified 	Unidentified	Residuum



quinclorac	quinclorac methyl ester	Soluble polars	Organosoluble



ppm	%TRR	ppm	%TRR	ppm	%TRR	ppm	%TTR	ppm	%TRR	ppm

forage	4.01	73.4	2.94	3.6	0.145	18.7	0.750	4.7	0.188	<1	<0.01

fodder	0.87	21.5	0.186	5.9	0.051	52.4	0.455	19.4	0.169	<1	<0.01

grain	0.83	73.5	0.610	1.7	0.014	5.5	0.044	6.6	0.055	<1	<0.01



The radioactive residues of quinclorac found in sorghum following
typical agricultural practices consist predominantly of parent compound.
 A minor metabolite, the methyl ester of quinclorac, is found in all
tissues, but always at less than 10% TRR.   A lower percentage of the
residue in sorghum fodder was found to be quinclorac, but the majority
of the residue was soluble polar compounds.  The current analytical
methodology (BASF Method No. A8902) employs a similar acetone extraction
step as used in the above extractions.  Therefore, the accountability of
the residues is high.   

 

Metabolism in Wheat:   (MRID #44322207).   The test substance used in
this study was quinclorac (labeled at the 3 position) at two application
rates (0.112 lb ai/A (0.45X the proposed  rate) and 0.446 lb ai/A (1.8X
the proposed rate)).  Only the higher application rate is presented in
the table below.  Plants were grown in greenhouse conditions and sprayed
22 days after planting, when they were in the 3 to 5 leaf stage.  Forage
samples were collected at a 37-day PHI, straw and grain at a PHI of 92
days.    

TABLE 5.  Distribution and Identification of Residues from Wheat RACs
Treated at 0.446 lb ai/A Quinclorac. 

RAC	Radioactive Residues

	

ppm	Identified	Unidentified	Unextracted Marc



quinclorac	quinclorac methyl ester	aqueous acetone soluble	hydrolyzable
non-hydrolyzable



%TRR	ppm	%TRR	ppm	%TRR	ppm	%TRR	ppm	%TRR	ppm

forage	13.1	45.1	5.9	6.4	0.84	38.4	5.1	10.3	0.34	1.9	0.06

straw	8.2	22.4	1.8	12.6	1.0	45.1	3.7	12.4	0.23	3.3	0.06

grain	3.9	68	2.7	3.7	0.15	17.2	0.68	3.3	0.04	0.3	<0.01



The primary path by which plants metabolize quinclorac is through the
hydroxylation of the quinoline ring of the parent, followed by the
conjugation of glucose and other biologically available compounds at the
hydroxlated site.  Ultimately, some radioactive residues are
incorporated into the high molecular weight natural products. 

The petitioner, IR-4, requests a waiver from the requirement of another
metabolism study based on the following.  In the studies to date it has
been shown that in plants the primary path by which quinclorac is
metabolized is through hydroxylation of the quinolone ring of the
parent, followed by the conjugation of glucose and other biologically
available compounds at the hydroxylated site.    These results were
similar for all quinclorac metabolism studies submitted to date.

Rhubarb and cranberry are very low acreage crops.  Cranberry is
commercially grown on just over 40,000 acres, and Rhubarb is
commercially grown on approximately 2,000 acres in the US (based on 2002
census of Agriculture).

In addition, other related quinoline compounds, such as quinoxyfen have
shown similar metabolism results in that the parent is the primary
residue component (D276835, 3/26/2003, G. Kramer) when conducted on a
wide variety of plant matrices (cucumber, grape, sugarbeet, and tomato).
 In these studies, quinoxyfen was the primary residue component and
other remaining compounds were incorporated into natural plant
constituents.  In cucumber and tomato, unchanged quinoxyfen remained
largely on the surface of treated plants.  The presence of multiple
unidentified polar residues suggests that metabolism of quinoxyfen does
occur to some extent to form more polar soluble components with the
incorporation into insoluble material.  

 



Conclusions.  While the metabolism of quinclorac is adequately
understood with regard to the currently registered uses, there are no
plant metabolism data for quinclorac on commodities similar to
cranberry.  These data are not being required at this time.  However,
any further expansion of the use of quinclorac to other commodities
grown on larger acreages than rhubarb and cranberry, will trigger a
requirement of additional metabolism data.

The methyl ester of quinclorac was reported in some grain commodities at
<15% of the TRR.  The methyl ester is measured by the enforcement
method, which includes a methylation step.

 860.1300 Nature of the Residue - Livestock

D241204, J. Stokes, 11/6/1998

D325790, M. Doherty, 9/13/2007

  SEQ CHAPTER \h \r 1 The qualitative nature of quinclorac residues in
livestock is understood based upon the adequate goat and poultry
metabolism studies (MRIDs 41076104 and 41063535, respectively).  In both
studies, quinclorac was the principal residue identified in each
commodity.  HED concluded that parent is the only residue of concern for
risk assessment and tolerance expression for livestock.  However, the
enforcement method includes a methylation step and determines the methyl
ester of quinclorac. 

In a rat metabolism study (MRID 41063533), quinclorac was the primary
metabolite reported.  Elimination was primarily in the urine (91-98%)
with small amounts in the feces (1-4%) eliminated by day 5 after dosing.

Conclusions.  No further livestock metabolism data are required at the
present time.

860.1340 Residue Analytical Methods

D241204, J. Stokes, 11/6/1998

DEB 5554, J. Garbus, PP#9F3755/9H5583, 8/7/90

Adequate analytical methods (GC/ECD) are available to enforcing
quinclorac tolerances on plant (BASF Method A8902; MRID# 41063537) and
livestock (BASF Method 268/1; MRID# 41063536) commodities.  Both methods
have undergone successful agency method validation trials and have been
submitted to FDA for publication in PAM II as the tolerance enforcement
methods.  The LOQ of both methods is 0.05 ppm for all matrices.  

In BASF Method 268/1, used for both plant and animal matrices, samples
are soaked in 0.1 N NaOH for 1 hour and then extracted with acetone, pH
adjusted with sodium bicarbonate, and then the extract is extracted
several times with dichloromethane.  Organic extracts are combined,
redissolved in ether and methanol, treated with diazomethane, and taken
to dryness.  (No suitable substitute was found for the diazomethane.) 
The methylated residue is dissolved in 75% dichloromethane/hexane and
cleaned up with silica gel. The eluant fraction containing the
methylated quinclorac is evaporated to dryness and redissolved in
acetone/hexane. An aliquot is subjected to GC chromatography using a
DB-5 column and electron capture detection.  Methylated standard is used
for quantitation.  The LOD was reportedly 0.05 ppm, but this was also
the lowest level validated.

In the current field trials, residues of quinclorac in/on rice, wheat,
and sorghum plant parts were determined using a LC/MS/MS method (BASF
Method A9708/1).  This method was adequately validated in conjunction
with the analysis of field trial samples.

nal standards.  The 240→196 m/z ion transition was used to detect and
quantify residues.  The validated LOQ for quinclorac is 0.05 ppm in both
matrices, and the LOD was not reported.  With only one ion transition
monitored, the LC/MS/MS method cannot be considered suitable for
enforcement, but it is suitable for data collection.

Conclusions.  An adequate GC/ECD method is available for enforcing the
proposed tolerances, and the field trial data were collected using an
LC/MS/MS method adequate for determining quinclorac, per se.  If
LC/MS/MS is tobe used, a method is needed for the methyl ester of
quinclorac and any other metabolites found in the required metabolism
study.

860.1360 Multiresidue Methods

PP#9F3755,  J. Garbus, 08/07/90

Adequate data are available evaluating quinclorac through the FDA
Multi-Residue Methods Test guidelines, and quinclorac is detected by
Protocol B.  Quinclorac is not detected by the other FDA MRM protocols.

860.1380 Storage Stability

D241204, J. Stokes, 11/6/1998

PP#9F3755,  J. Garbus, 08/07/90

Adequate data are available indicating that quinclorac (and the methyl
ester) is stable under frozen storage conditions for up to 37-40 months
in rice grain and straw, corn grain, forage, silage, and fodder, soybean
grain and fodder, sugar beet roots and tops, alfalfa hay, sorghum
forage, hay, silage, and fodder.  

Storage stability of quinclorac residues in livestock tissues was
assessed by reanalyzing tissue samples after a period of time equal to
their storage prior to the initial analysis.  Stability in animal and
plant tissues has been demonstrated in accountability studies where
plant and animal tissues were stored for 3 years between radiochemcial
and chromatography analyses (See J. Garbus, 08/02/90).

In addition, IR-4 provided concurrent storage stability data for rhubarb
and cranberry, demonstrating stability for the time and conditions the
samples were stored.

Conclusions.  The available storage stability data are adequate and
support the storage conditions and durations incurred in the existing
field trials, for currently registered uses.  The IR-4 concurrent
storage stability data for rhubarb and cranberry are adequate for
residues of quinclorac, demonstrating stability for the time and
conditions the samples were stored.  Storage stability data are needed
for residues of the methyl ester of quinclorac and other residues of
concern found in any future metabolism study.

860.1400 Water, Fish, and Irrigated Crops

For existing use on rice and the proposed use on cranberry, a label
restriction is needed regarding the use of treated rice and cranberry
fields for aquaculture.  Alternatively, the petitioner can determine
residues in catfish and crayfish raised in treated fields and propose
tolerances for these commodities if necessary.  The label provided for
Quinclorac/QuinStar 4-L does not contain any restriction against
aquaculture.

Conclusions.  Data on catfish and crayfish are required, or the label
must prohibit use of treated water from rice and cranberry fields for
aquaculture.

For registration review, the PM must ensure that all quinclorac labels
with uses on rice and cranberry contain such a restriction.

860.1460 Food Handling

This guideline topic is not relevant to the proposed use.

860.1480 Meat, Milk, Poultry, and Eggs

DP# D241204, J. Stokes, 11/6/1998 

DP# D358151, G. Oatkie, 04/30/2009

Adequate cattle and poultry feeding studies are available. The uses
proposed in this petition do not involve livestock feeds, and will not
affect the existing tolerances on meat, milk, poultry and eggs. 

For registration review, we are recommending that the tolerance on
Grain, aspirated fractions be revoked, since data have been received
demonstrating that the tolerance is not needed, as residues on aspirated
grain fractions (AGF) are no higher than the tolerances on the grains.
AGF were the highest contributor to the livestock dietary burden, but
tolerances have since been established for grass commodities, which is
now the highest contributor to the livestock dietary burden.

Dietary burdens for livestock were recalculated in connection with the
petition for residues of quinclorac on pasture and rangeland grasses.
(D358151, 04/30/2009, G. Otakie, MRID 45066302).  In the review of that
petition we concluded:

As the use on grasses does not substantially alter the calculated MDB
for cattle (275 vs 290 ppm), no changes are necessary in the existing
tolerances for milk and meat, fat and meat byproducts of cattle, goats,
horses and sheep.  However, the recalculated MDBs for poultry and swine
indicate that the existing tolerances for poultry and hog commodities
should be reassessed.

These data support the current 0.05 ppm tolerances (LOQ) for eggs and
poultry fat and meat, and indicate that the current 0.1 ppm tolerance
for poultry meat byproducts should be lowered to 0.05 ppm.  HED notes
that lowering the tolerance for poultry meat byproducts to 0.05 ppm will
also harmonize this tolerance with the existing Canadian MRL for poultry
meat byproducts.

These data support the current 0.05 ppm tolerance (LOQ) for hog meat,
and indicate that the current tolerances for hog fat (0.7 ppm) and hog
meat byproducts (1.5 ppm) should also be lowered to 0.05 ppm.  Lowering
the tolerances for these commodities will also harmonize the U.S.
tolerances with the existing Canadian MRLs for hog fat and meat
byproducts.

Conclusions. Tolerances in livestock commodities will be changed in
connection with Registration Review. 

860.1500 Crop Field Trials

48697501.der.doc Rhubarb

48697502.der.doc Cranberry

Cranberry (for Low Growing Berries except strawberry, subgroup 13-07. 
Five cranberry field trials were conducted in the United States during
the 2009 growing season, in North American Free Trade Agreement (NAFTA)
Growing Zones 1 (MA; 2 trials), 5 (WI; 2 trial), and 12 (OR; 1 trial). 
The two MA trials (MA01 and MA03) and the two WI trials (WI01 and WI02)
were each conducted using the same Field Research Director (FRD).  
Careful examination of the field trial records indicates that the only
difference between each pair of trials was the use of different
varieties of cranberry, and distance between MA trials of > 20 miles,
and different soil characterics for the MA trials.  HED has concluded
that there are insufficient distinguishing characteristics to classify
the WI pair as separate trials; however, the trials were conducted prior
to development of the guidance on field trial differentiation.

Following two foliar broadcast applications of the 3.8 lb ai/gal SC
formulation of quinclorac at 0.484-0.528 lb ai/A, residues of quinclorac
(and per trial averages) in/on cranberry harvested at a 57- to 62-day
PHI were 0.15-0.68 (0.16-0.67) ppm.  Applications were made at a 28- to
32-day retreatment interval (RTI) using ground equipment in spray
volumes of 29.7-35.3 gal/A.  A crop oil concentrate (COC) was added to
the spray mixture for each of the applications at 2 pints/A.  

Rhubarb.  Four field trials were conducted in the United States during
the 2009 growing season in the North American Free Trade Agreement
(NAFTA) Growing Zones 5 (MI; 1 trial) and 12 (OR; 3 trials).  The two
rhubarb trials in Canby, OR (OR11 and OR12) and the trial in Hillsboro,
OR (OR10) were conducted by the same Field Research Director (FRD). 
Careful examination of the field trial records indicates there are
sufficient distinguishing characteristics to classify the Hillsboro, OR
trial as a separate trial from the Canby, OR trials, based on location
(>20 miles apart) and spray volume (>25% higher at the Hillsboro site). 
There are insufficient distinguishing characteristics to classify the
two Canby, OR trials as separate trials; therefore, the Canby, OR trials
constitute a single trial with replicate samples for purposes of
860.1500 data requirements.  The adjustment in trial numbers results in
a total of three field trials, with one trial in Zone 5 and two trials
in Zone 12.

Following two foliar broadcast applications of the 3.8 lb ai/gal SC
formulation of quinclorac at 0.736-0.798 lb ai/A, residues (and per
trial averages) of quinclorac in/on rhubarb harvested at a 29- to 33-day
PHI were 0.05-0.231 (0.082-0.205) ppm.  The method LOQ was 0.05 ppm. 
Applications were made at a 28- to 31-day retreatment interval (RTI)
using ground equipment in spray volumes of 19.9-36.7 gal/A.  A crop oil
concentrate (COC) was added to the spray mixture for each of the
applications at a rate of 1-2 pints/A.  

Conclusions.  Field trial data are adequate to determine residues of
quinclorac, per se.  

IR-4 should note the current guidance for differentiating field trial
sites.

Existing Uses of Remaining Crops

Existing uses of Quiclorac include use on rice, wheat, soybeans, barley
(import), grass forage and hay.  Each is discussed below, followed by a
summary of available data for the dimethylamine salt of quinclorac
(quinclorac DMA).

Rice.  (D241198, 10/01/98, J. Stokes, MRID 44323101)  Field trial data
were submitted from fifteen sites in five states [(MS (3), AR (4), LA
(5), MO (1), and TX (2)].  Data from CA were not included since the DF
formulation is not registered in CA.  Rice was treated at 0.5 lb a.i./A
with the DF formulation, with a 40-day PHI (time before flooding the
field).  Residue decline samples from a plots in MS and AR at -6, -3,
+3, and +6 before and after the targeted growth stage harvest per RAC.  
The residues of quinclorac on rice grain ranged from 0.346 ppm to 4.35
ppm, and averaged 0.987 ppm.  The residues of quinclorac on rice straw
ranged from 0.120 ppm to 2.74 ppm, and averaged 1.07 ppm. The
established 5.0 ppm and 12.0 ppm tolerances are adequate to cover
residues of quinclorac in harvested rice grain and straw, respectively,
with a 40-day PHI.   

Grain sorghum and wheat D241204; D248880; D248881, 11/06/98; PP#9F3755,
J. Stokes

Grain Sorghum (MRID#’s 44322212, 44583102).

MRID#44322212: Four grain sorghum field trials with quinclorac 75% DF
were conducted in KS, NE, OK, and TX.  A single postemergence broadcast
spray application was made with  FACET 75 DF Herbicide (EPA Reg. No.
7969-113, 75% a.i. quinclorac) at a rate of 0.25 lb a.i./A at the six
leaf stage.  Samples were collected at two stages of crop maturity,
i.e., at the late dough stage for forage (54 to 83 DAT), and at
grain/stover harvest (81 to 108 DAT).  Residues of quinclorac ranged
from <0.05 ppm to 0.15 ppm in sorghum forage, <0.05 ppm to 0.26 ppm in
sorghum grain, and all samples were <0.05 ppm in sorghum stover.  At the
KS plot additional samples were collected for a residue decline study;
samples were collected at -10, -5, +5, and +10 days in addition to the
target stage samples. All of the samples of sorghum grain and
forage/stover had residues <0.05 ppm.

MRID#44583102:   Twelve field trials trials with quinclorac 75% DF were
conducted in nine states.  Grain sorghum was treated with one
preemergence and one post emergence application of FACET DF at the  rate
of 0.5 lb a.i./A per application.  (0.84X maximum seasonal application
rate (preergemence + postemergence: 0.25 lb a.i./A + 0.38 lb a.i./A =
0.63 lb a.i./A)).   The maximum seasonal rate is 0.75 lb a.i./A.  The
preemergence application was timed prior to planting and the
postemergence allocation was 60 to 65 days before harvest of grain and
stover.  Plants were harvested for forage and hay immediately after
flowering or 30 days after the last treatment.  Silage was targeted to
be harvested at the soft dough stage of the plant growth.   Maximum
residues were reported as 3.67, 6.68, 4.50, 3.13, and 1.08 ppm in grain
sorghum forage, grain, hay, silage, and stover, respectively. 
Tolerances for residues on quinclorac were set at 6.0 ppm for sorghum
grain, 3.0 for sorghum forage, and 1.0 for sorghum fodder. 

Wheat MRID#44322208:  Twelve winter wheat field trials were conducted in
12 states.  A single broadcast preplant application of FACET 75DF was
made at a rate of 0.25 lb a.i./A.  Three additional plots in KS, OK, and
TX received a single broadcast application at  twice the label maximum
rate, i.e., 0.5 lb a.i./A..   Samples were harvested according to normal
crop maturity as follows: forage, 46 to 224 DAT, dried hay, 162 to 268
DAT, and grain and straw, 194 to 324 DAT.   Maximum residues in wheat
commodities from the 0.25 lb ai/A rate were reported as 0.88, 0.32,
0.24, and 0.08 ppm quinclorac in forage, hay, grain, and straw,
respectively; and 1.55, 0.54, 0.56, and 0.12 ppm quinclorac in forage,
hay, grain, and straw, respectively, from the 0.50 lb ai/A rate. 
Tolerances for residues of quinclorac were set on wheat forage (1.0
ppm), hay (0.5 ppm), grain (0.5 ppm), and straw (0.1 ppm).

Barley (imported).  Data for residues of quinclorac DF formulation were
reviewed by PMRA.  Twelve field trials with spring barley, grown in the
prairie provinces, were conducted.  The barley was treated with one
ground application of Facet 75 DF at a target rate of 0.200 kg a.i./ha
[0.18 lbs a.i./A] (2x rate or Canadian GAP).  A surfactant was added to
the tank mix. Forage samples were harvested 16-30 days following
application, while grain and straw were harvested 63-97 days following
application.  Residues in forage ranged from <0.05-2.01 ppm.  The
highest average field trial residue (HAFT) found in forage was 1.78 ppm.
 In the grain, individual residues ranged from <0.05-1.25 ppm.  The HAFT
in the grain was 1.165 ppm.  In the straw, the residues ranged from
<0.05-0.484 ppm, with the HAFT being 0.299 ppm.  A tolerance of 2 ppm
was established for residues of quinclorac on barley grain.

Aspirated Grain Fractions(AGF): Data for quinclorac aspirated grain
fractions were not submitted for the original grain petitions.  The
needed tolerance for AGF was estimated at 200X the 6.0 ppm tolerance for
sorghum grain (200 X 6.0 = 1200 ppm).  Data were later provided.

(D344496, 09/25/08; GOtakie: Quinclorac.  Magnitude of the Residue in
Wheat and Sorghum Aspirated Grain Fractions.  MRIDs 45598703 and
45598704.)

Two field trials were conducted for quinclorac (BAS 514 H) on wheat
aspirated grain fractions and sorghum aspirated grain fractions.  The
studies were conducted in the United States in Zone 5 (York County,
Nebraska) during the 1999 growing season.  Residues of quinclorac were
quantitated at 0.453 and 0.516 ppm in/on wheat AGFs following two
applications of BAS 514 H at 0.25 lb ai/A/application (0.50 lb
ai/A/season).  Residues of quinclorac were quantitated at 0.147 and
0.145 ppm in/on sorghum AGFs following two applications of BAS 514 H at
0.25 and 0.50 lb ai/A/application (0.75 lb ai/A/season). Ash content was
between 12.0 and 17.5% in all wheat AGF samples and between 5.5 and 9.0%
in all sorghum AGF samples.

Tolerances for quinclorac established under 40 CFR 180.463 are 0.5 ppm
and 6.0 ppm on wheat and sorghum grain, respectively.  Average residues
at the maximum application rate in aspirated grain fractions were 0.48
and 0.15 ppm, in wheat and sorghum respectively. Accordingly, separate
tolerances on aspirated grain fractions are not required, pending
submission of detailed weather data, throughout the residue trial
period.  The existing tolerance for residues of quinclorac on AGF should
be revoked.

Pasture and Rangeland Grasses.  (D358151, 04/23/2009, G. Otakie, MRID
45066302).  Thirteen field trials conducted in the United States in
Zones 2, 4, 5, 6, 7, 8, 9, 10, and 11 during 1999, quinclorac (75% DF)
was applied to representative grass species as a single broadcast foliar
application during vegetative development at rates of 0.746-0.780 lb
ai/A (1x rate).  All applications were made using ground equipment in
volumes of 9-41 gal/A, and include both MSO (0.5-3.3% v/v) and aqueous
UAN (0.7-5.6% v/v) as adjuvants.

Following a single foliar application of quinclorac (DF) to grasses at
~1x the proposed rate, residues were 36.3-105.9 ppm in/on 26 samples of
forage harvested at 0 DAT and 3.6-70.1 ppm in/on 26 samples of hay
harvested at 7-8 DAT.  Average quinclorac residues were 68.3 ppm for
forage and 24.3 ppm for hay, and the HAFT residues were 105.7 ppm for
forage and 58.5 ppm for hay.  The residue decline data indicate that
residues in/on forage declined steadily from an average of 43.1 ppm at 0
DAT to 7.1 ppm by 15 DAT.  For hay, residues initially increased from 70
ppm at 0 DAT to 83.5 ppm at 3 DAT, but then declined steadily to 24.3
ppm by 15 DAT.  Tolerances for residues of quinclorac were set at 150
ppm for grass forage and 130 ppm for grass hay based on these data.

Comparison of Quinclorac with Quinclorac DMA in rice, wheat, and
sorghum.  Six field trials, each consisting of side-by-side trials
comparing the dry flowable (DF) and the soluble liquid (SL) formulations
of the dimethylamine salt (DMA) of active ingredient, were conducted in
geographically diverse locations.

The results from these trials indicated that there was no discernable
difference between the residues SL DMA salt in rice, wheat, and grain
sorghum obtained using the dry flowable (DF) or soluble liquid (SL DMA)
formulations of quinclorac.

Conclusions.  Field trial data are adequate to support the existing uses
of quinclorac on rice, grain sorghum, barley (imported), and pasture and
range grasses.  In decline studies on grains, when detectable residues
were initially reported, residues generally degraded substantially
within 14 days.

The established tolerance on aspirated grain fractions should be revoked
as it is not needed.  The tolerance on rice straw may be revoked, as
rice straw is no longer considered a livestock feedstuff.

860.1520 Processed Food and Feed

There are no processed commodities in connection with the current
petition.

For registration review, processing studies submitted to support
existing tolerances are adequate.   Processing studies were submitted
for Rice (MRID 41063543), Sorghum (MRID 44322213), and Wheat (MRID
44322209).

Table 6.  Average Processing Factors for Sorghum

Commodity						Processing Factor (x)

Rice, hulls	1.1

Rice, bran	3.5

Rice, milled	0.76

Grain sorghum flour (dry milling)	0.90

Grain sorghum starch (wet milling)	0.04

Wheat, bran	1.8

Wheat, middlings	0.79

Wheat, shorts	1.24

Wheat, flour	0.66

Wheat, germ	2.8



Tolerances for residue of quinclorac of 1.0 ppm, 1.5 ppm, and 0.75 ppm,
were set for wheat bran, wheat germ, and wheat shorts, respectively.

Conclusions.  Available processing data are adequate to support the
currently registered uses of quinclorac. Residues concentrate on hulls
and some milling fractions.

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

Analytical standards for quinclorac and the quinclorac methyl ester are
available from BASF, but not from Albaugh, Inc. The methyl ester of
quinclorac is used as an analytical standard for the quinclorac
enforcement method.  Albaugh must supply the Pesticide Repository with
analytical standards for quinclorac and the quinclorac methyl ester.

An analytical standard for the quinclorac DMA salt must be submitted to
the EPA National Pesticide Standards Repository.

860.1850/1900 Confined and Field Accumulation in Rotational Crops

DP# D241204, J.Stokes, 11/6/1998 

Adequate rotational crop studies are available to support the use of
quinclorac.  (MRID 42294108, 42294109 – confined rotational crop; MRID
41781428 – field rotational crop)

The confined rotational crop studies are summarized in the tables below.
 No quantifiable residues (<0.05 ppm for the current enforcement method)
were reported in chard, or beet tops or roots 10 months (309 days) after
treatment at the 1x application rate of 0.5 lb ai/A.  Detectable
residues were reported in chard 1 months after a 2x application rate of
1.0 lb ai/A.

Field rotational crop (MRID 41781428). Rotational crop studies were
conducted in LA and MS following the application o f 0.5 1b ai/A of
quinclorac to rice that was harvested in the fall of 1987.  No residues
greater than the limit of detection of 0.05 ppm quinclorac were found in
mustard leaves and turnip leaves and roots when planted 4 months or 9
months (20 and/or 270 days)  after a quinclorac application to rice. 
(The analytical method was validated down to 0.05 ppm, so 0.05 ppm may
be called the limit of quantitation (LOQ) or the lower limit of method
validation (LLMV).

860.1550 Proposed Tolerances

The current tolerance expression for quinclorac is: 

“Tolerances are established for residues of the herbicide quinclorac,
including its metabolites and degradates, in or on the commodities in
the table in this paragraph. Compliance with the tolerance levels
specified in this paragraph is to be determined by measuring only
quinclorac, 3,7-dichloro-8-quinolinecarboxylic acid, in or on the
commodity.”

The tolerance expression is in accord with our current guidance on
tolerance expressions.

Permanent tolerances have been established for residues of quinclorac
in/on small cereal grain commodities at levels ranging from 0.1 ppm in
wheat straw to 15 ppm in rice bran [40 CFR §180.463(a)], and for grass
forage at 150 ppm and grass hay at 130 ppm.  There is also a 1200 ppm
tolerance for AGF; however, recently reviewed data indicate that a
tolerance on AGF is not necessary (DP# 344496, G. Otakie, 9/25/08). 
Permanent tolerances have also been established for residues of
quinclorac per se in/on livestock commodities at levels ranging from
0.05 to 1.5 ppm.  The tolerances being proposed by IR-4 for the current
petition are listed in Table 7, along the HED’s recommended
tolerances.

An adequate number of field trials at ~1x the proposed use rate are
available for rhubarb and cranberry to support permanent tolerances. 
The Agency’s SOP “Guidelines for Setting Pesticide Tolerances Based
on Field Trial Data” were utilized for determining the appropriate
tolerance level for each commodity (Appendix II).  The recommended
tolerance for rhubarb is 0.5 ppm, and the recommended tolerance for Low
growing berries, except strawberries, subgroup 13-07H is 1.5 ppm.

Based on the recalculated dietary burdens for livestock and the data
from the available cattle and poultry feeding studies, the current
tolerances for livestock commodities are adequate, with the exceptions
of the tolerances on poultry meat byproducts and hog fat and meat
byproducts.  Based on the recalculated MDBs for swine (6.0 ppm) and
poultry (5.4 ppm) and the data from the poultry and cattle feeding
studies, the existing tolerances for poultry meat byproducts and hog fat
and meat byproducts are too high as quinclorac residues in these
commodities are expected to be <0.05 ppm at 1x the MDB.  Therefore, the
tolerances for these livestock commodities should be lowered to 0.05
ppm.  Lowering the tolerances on these commodities will also harmonize
the U.S. tolerances with the existing Canadian MRLs for poultry meat
byproducts and hog fat and meat byproducts.

In addition, HED notes that the Agency no longer considers rice straw to
be a significant livestock feedstuff (OPPTS 860.1000, Table I, ChemSAC
memo 6/30/08).  Therefore, the current tolerance for residues of
quinclorac on rice straw may be revoked.

CODEX  has not established any established maximum residue limits (MRLs)
for quinclorac.  Canada has established maximum residue limits (MRLs)
for quinclorac on selected agricultural commodities.  An International
Residue Limit Status Sheet is attached in Appendix I.

The use of the DMA salt of quinclorac will not affect the established
tolerances for quinclorac on rice, grain sorghum, and wheat.

Table 7. 	Tolerance Summary for Quinclorac.  § 180.463

Commodity	Current/Proposed Tolerance (ppm)	Recommended Tolerance (ppm)
Comments; Correct Commodity Definition

Low growing berries, except strawberries, subgroup 13-07H	1.1	1.5
Revised level based on OECD tolerance calculation procedures.  At the
time of publication of this tolerance, the tolerance for residues
quinclorac on cranberry in § 180.463(b) should be revoked.

Rhubarb	0.4	0.5	Revised level based on OECD tolerance calculation
procedures. 

Currently Established Tolerances Reevaluated for Registration Review

Barley, grain	2.0	2.0	The tolerance needs a footnote to indicate that
there are no U. S. Registrations.

Cattle, fat	0.7	0.7

	Cattle, meat byproducts	1.5	1.5

	Cattle, meat	0.05	0.05

	Egg	0.05	0.05

	Goat, fat	0.7	0.7

	Goat, meat byproducts	1.5	1.5

	Goat, meat	0.05	0.05

	Grain, aspirated fractions	1200	revoke	Data submitted demonstrate that
the tolerance is not needed.  Current tolerance was based on a
theoretical calculation.

Grass, forage	150	150

	Grass, hay	130	130

	Hog, fat	0.7	0.05	Based on the residue data from the cattle feeding and
the calculated MDB of 6.0 ppm for swine, the tolerances can be lowered
to the method LOQ (0.05 ppm).  This level is harmonized with Canada. 

Hog, meat byproducts	1.5	0.05	Based on the residue data from the cattle
feeding and the calculated MDB of 6.0 ppm for swine, the tolerances can
be lowered to the method LOQ (0.05 ppm).  This level is harmonized with
Canada. 

Hog, meat	0.05	0.05

	Horse, fat	0.7	0.7

	Horse, meat byproducts	1.5	1.5

	Horse, meat	0.05	0.05

	Milk	0.05	0.05

	Poultry, fat	0.05	0.05

	Poultry, meat byproducts	0.1	0.05	Based on the residue data from the
poultry feeding and the calculated MDB of 5.4 ppm for poultry, the
tolerance can be lowered to the method LOQ (0.05 ppm).   This level is
harmonized with Canada.

Poultry, meat	0.05	0.05

	Rice, bran	15.0	15.0

	Rice, grain	5.0	5.0

	Rice, straw	12.0	Revoke	Rice straw is no longer a regulated livestock
feedstuff.

Sheep, fat	0.7	0.7

	Sheep, meat byproducts	1.5	1.5

	Sheep, meat	0.05	0.05

	Sorghum, grain, forage	3.0	3.0

	Sorghum, grain, grain	6.0	6.0

	Sorghum, grain, stover	1.0	1.0

	Wheat, forage	1.0	1.0

	Wheat, germ	0.75	0.75

	Wheat, grain	0.5	0.5

	Wheat, hay	0.5	0.5

	Wheat, straw	0.1	0.1

	

References

DP Barcode:	None.  CB 6228, 6229, 6230

Subject:		PP#9G3797, FAP#0H5594, EUP# 7969-EUP-25. Quinclorac (New
Chemical on Rice with Temporary Tolerances).

From:		A. Aikins

To:		R. Taylor/V. Walters

Dated:		7/26/1990

MRID(s):	41063501 through -03, 41063534 through -46, 41076101 and
41076104

DP Barcode:	None.  CB 5554

Subject:		New Chemical Review: PP#9F3755/9H5583: Quinclorac (FACET) in
or on Rice Grain and Straw. Evaluation of Analytical Method and Residue
Data.

From:		J. Garbus

To:		R. Taylor/J. Miller

Dated:		8/7/1990

MRID(s):	41063501 through -03, 41063534 through -46, 41076101 and
41076104

DP Barcode:	None.  EFED DER

Subject:		DER for Paulick, R.C. January 1991. Magnitude of the residues
of quinclorac (BAS 514H) in rotational crops (mustard and turnips)
following rice culture in Louisiana (RCN 87096) and Mississippi (RCN
87098). BASF Report No. A9104.  BASF Registration Document No. 91/5022.

From:		RJ. Mahler

To:		R. Taylor/V. Walters

Dated:		11/5/1991

MRID(s):	41781428

DP Barcode:	None.  EFED DER

Subject:		DER for Nelson, DM. 1992. Accumulation study of 14C-BAS 514H
in fall planted confined rotational crops. BASF Protocol No. M8909. BASF
Report No. M9125. BASF Registration Document No. 92/5044. Unpublished
study performed and submitted by BASF Corp. Agricultural Products,
Research Triangle Park, NC. 107 pp

From:		RJ. Mahler

To:		R. Taylor/V. Walters

Dated:		9/15/1992

MRID(s):	42294109

DP Barcode:	None.  EFED DER

Subject:		DER for Uinkler, V and JM Nelson. 1991. Accumulation of
14C-BAS 514H in annual confined rotational crops. BASF Protocol No.
M8910. BASF Report No. M9123. BASF Registration Document No. 91/5170.
Unpublished study performed and submitted by BASF Corp. Agricultural
Products, Research Triangle Park, NC. 104 pp.

From:		RJ. Mahler

To:		R. Taylor/V. Walters

Dated:		9/17/1992

MRID(s):	42294108

DP Barcode:	D241198

Subject:		Quinclorac. ID#007969-00113. Revised Section B. Reduction In
PHI For Use On Rice.

From:		JStokes

To:		MJ Nelson

Dated:		10/01/98 

MRID(s):	44323101

DP Barcode:	D241204; D248880; D248881

Subject:		PP#7F4870. Quinclorac. In/On Grain Sorghum and Wheat.
Evaluation of Analytical Method and Residue Data.

From:		JStokes

To:		MJ Nelson

Dated:		 11/06/98

MRID(s):	 44322206, 44322207, 44322208, 44322209, 44322211, 44322212,
44322213, 44322214, 44322216, 44583101, 44583102, and 44583103

DP Barcode:	D342446

Subject:		Quinclorac – Request for Establishment of Tolerances on
Barley Grain without a U.S. Registration.  Summary of Analytical
Chemistry and Residue Data. Petition Number 0E6114.

From:		M. Doherty

To:		H. Johnson/J. Tompkins

Dated:		9/11/2007

MRID(s):	44817507, 45088301

DP Barcode:	D344496

Subject:		Quinclorac. Magnitude of the Residue in Wheat and Sorghum
Aspirated Grain Fractions.

From:		G. Otakie

To:		J Schnackenbeck

Dated:		9/25/2008

MRID(s):	45598703 & 45598704

.

DP Barcode:	D358151

Subject:		Quinclorac; Petition for Tolerances and Use on Pasture and
Rangeland Grasses.  Summary of Analytical Chemistry and Residue Data.

From:		G. Otakie

To:		James Tompkins

Dated:		04/30/2009

MRID(s):	45066302

F.	DOCUMENT TRACKING

RDI: S. Hummel 08/11/12;RAB4chemists

Petition Number:  1E7957

DP#: D397719 and 

PC Code:  128974, 028974



Attachment 1. Residue Chemistry Data Requirements

Residue Chemistry Data Requirements for Quinclorac

GLN Data Requirements	Current Tolerances (ppm) [§180.463]	Additional
Data Needed?	MRID Nos.

860.1200: Directions for Use	NA



860.1300: Nature of the Residue - Plants	

NA	

No	41063534, 44322207, 44322211, 44817502

860.1300: Nature of the Residue - Livestock	NA	No	41076104, 41063535

860.1340: Residue Analytical Method  

Plant and Livestock Commodities	NA	No	41063537, 44583103

41063536

860.1360: Multiresidue Method

	41063541

860.1380: Storage Stability Data

Plant Commodities	NA	No	41063544, 44322214

Livestock Commodities	NA	No

	860.1400: Magnitude of the Residue - Water, Fish and Irrigated Crops	NA
NA	None

860.1460: Magnitude of the Residue - Food Handling	NA	NA	None

860.1480: Magnitude of the Residue - Meat, Milk, Poultry, Eggs 

 Cattle fat, meat, and meat byproducts	0.7/1.5/0.05	No	41063545

Hog fat, meat and meat byproducts	0.7/1.5/0.05	No	None

Milk	0.05	No	41063545

Eggs and the Fat, Meat and Meat Byproducts of Poultry	0.05/0.05/0.1/0.05
No	41063546

860.1500: Crop Field Trials

Rhubarb	0.5 proposed	No	48697501

Cranberry	1.5 proposed	No	48697502

Grains



	Barley grain (imported)

No	44817507, 45088301

Rice grain, straw	5.0/12.0	No	41063542, 44323101

Sorghum forage, grain, stover	3.0/6.0/1.0	No	44322212

Wheat forage, grain, hay, straw	1.0/0.5/0.5/0.1	No	44322208, 44322209,
45066301

Grain, aspirated fractions

No	45598703, 45598704

Pasture/rangeland grasses

No	45066302

Comparison of DF formulation of quinclorac to quinclorac DMA salt in
rice, sorghum, wheat

No	48051901

860.1520: Processed Food/Feed

Barley

No

	Rice

No	41063543

Sorghum

No	44322213, 44583102, 44583104

Wheat

No	 44322210, 44817501, 

860.1650: Submittal of Analytical Reference Standards	NA	No	None

860.1850: Confined Accumulation in Rotational Crops	NA	No	42294108,
42294109

860.1900: Field Accumulation in Rotational Crops	NA	No	41781428

Attachment 2

Additional information on metabolism from EFED reviews

From 3/8//99 review by R. Mahler and E. Odenkirchen, Quinclorac
Herbicide, Environmental Fate and Effects Assessment and
Characterization for a Section 3 Use on Wheat and Sorghum

Hvdrolysis (161 - 1)

.

Fifty ppm [3-14C] quinclorac was hydrolytically stable in aqueous
buffered pH 5, 7, and 9

solutions. After 737 hours, quinclorac comprised >98% of the applied in
the three buffer

solutions and was the only [14C]compound detected. This study is
acceptable. (MRID

40320816)

P&Q degradation in Water (161-2)

[3-'4C]Quinclorac (radio chemical purity 99.6%), at 5.4 ppm, degraded
slightly (-40% of

the applied) in a sterile aqueous pH 7 buffer solution that was
irradiated for 697 hours

using a xenon arc lamp at 25 C. After 697 hours of irradiation,
quinclorac comprised 92%

Iof the recovered radioactivity, an unidentified degradate comprised
1.6%, and 2.7%

remained near the origin of the TLC plate. The extrapolated half-life
was 100 days (note

extrapolations beyond the study duration are uncertain). The sensitized
half-life using

acetone was 52 days. This study is acceptable. (MRID 41063560)

Conversely, the photolytic half-lives of non-radiolabled quinclorac in
non-sterile natural

river water and solutions containing activated sewage sludge were,
respectively, 5 and 10

days (not corrected for dark control results, which suggest that between
8- 12% of

degradation would be accounted for processes other than photolysis over
a 47-day

incubation). The authors concluded that photolysis was the main route of
degradation in

these two studies; however, they did not identify any degradates.
Furthermore, the length

of exposure was only 6 hours/day.  Had a longer daily sunlight exposure
regime been

used, the half-lives, as determined, may have differed from that
reported and may have

been less by at least one-half, based on a typical 12-hour daylight
exposure period. This

study is supplemental. (MRID 41063564)

From Y Donovan, “Quinclorac: Section 3 Registrations for New Use on
Pasture/ Rangeland: Drinking Water Exposure Assessment, D362085, June 3,
2009.

For persistence, laboratory data indicate that quinclorac is stable to
hydrolysis, photolysis in sterile water, as well as aerobic and
anaerobic metabolism in soil.  Conversely, quinclorac undergoes rapid
photolysis in non-sterile rice paddy, natural river waters, and
solutions containing activated sewage sludge (half-lives of 5-10 days). 
Photolysis on soil surface is also a route of dissipation with a mean
half life of 141 days.   Field studies reviewed to date indicate that
quinclorac is moderately persistent (18-176 days half-lives) in
terrestrial environment. 

According to the aerobic soil metabolism and field dissipation studies
and the research cited in the literature reviews, the fate of quinclorac
can be described as such:

Quinclorac is initially metabolized to the primary degradate,
3-chloro-8-quinoline carboxylic acid (BH 514-1).  This degradate
undergoes further degradation to 5-chloro-2-hydroxy-nicotinic acid,
which in turn is metabolized to 5-chloro-2,6-dihydroxy-nicotinic acid, 2
hydroxy-3-chloro-8-quinoline carboxylic acid (BH 514 2-OH),
7-chloro-8-quinoline carboxylic acid, 8-quinoline carboxylic acid, and
other small fragments.  These compounds can then bind with or become
incorporated into the soil or humic material of the soil as a part of
natural soil components (i.e., carbon pool of the soil), and/or can
degrade to CO2, a major terminal product. 

The only volatile compound detected in the aerobic soil metabolism study
(MRID 44084503) was CO2 at a maximum concentration of 7.1% TRR.  Other
than parent, residues identified at maximum concentrations were: BH 514
2-OH (14.9% TRR), BH 514-Me ester (7.8% TRR).  Parent was found at
maximum concentrations of 58.1% TRR.

BH 541-1 was also reported in the aerobic aquatic metabolism (MRID
42294102), at maximum of 55.7% of the initial radioactivity after 6
months and 30.8% after 12 months.  Adsorption/desorption studies
determine that this degradate is less mobile than its parent, with
Kd’s ranging from 1.56 in sand soil, 1.97 in sandy loam soil, 11.4 in
loam soil, 13.3 in clay loam soil, and 30.2 in silty clay soil.  This
degradate was not reported in any of the terrestrial field dissipation
studies, at any soil depth. 

For mobility in aquatic environment, aquatic field dissipations studies
with rice indicate that the compound is less stable than predicted by
the laboratory and is probably not mobile under normal use conditions.

For volatility, both vapor pressure (7.5 x 10-8 mm Hg at 20o C) and
Henry's Law Constant (1.22 to 24.3 x 10-15 atm.m3 mol-1 ) indicate a low
possibility of volatilization from soil and water.  Bioaccumulation in
fish is not expected according to the acceptable fish accumulation
study, which showed that after 28 days of exposure, quinclorac did not
accumulate in channel catfish.  No BCF value was reported (MRID 40320819
and 41063559).  Furthermore, the octanol/water partition coefficient
(KOW) of 0.266 also suggests that quinclorac has low potential to
bioaccumulate. 

A detailed assessment of the environmental fate of Quinclorac could be
found in the “Environmental Fate and Ecological Effects Assessment and
Characterization for a Section 3 for Use on Wheat and Sorghum” report
dated March 05, 1999 (DP Barcodes: 250179, 248882, 248884, 192866,
231399, and 238400).  The chemical structures of quinclorac and its 2
major metabolites (BH 514-1 and BH 514 2-OH) are shown in Table III.

Table III - Chemical Structures of quinclorac and its major metabolites

Appendix I: International Residue Limits 

Quinclorac (PC Code 128974; Date of Request 7/26/12)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US	Canada	Mexico1	Codex 

40 CFR 180.463

Plant/Livestock: quinclorac, 3,7-dichloro-8-quinolinecarboxylic acid
3,7-dichloro-8-quinolinecarboxylic acid

None

Commodity	Tolerance (ppm) /Maximum Residue Limit (mg/kg)

	US	Canada	Mexico1	Codex 

Barley, grain	2.0	2.0



Cattle, fat	0.7	0.05



Cattle, meat byproducts	1.5	0.05



Cattle, meat	0.05	0.05



Egg	0.05	0.05



Goat, fat	0.7	0.05



Goat, meat byproducts	1.5	0.05



Goat, meat	0.05	0.05



Grass, forage	150



	Grass, hay	130



	Hog, fat	0.7	0.05



Hog, meat byproducts	0.05	0.05



Hog, meat	0.05	0.05



Horse, fat	0.05	0.05



Horse, meat byproducts	1.5	0.05



Horse, meat	0.05	0.05



Milk	0.05	0.05



Poultry, fat	0.05	0.05



Poultry, meat byproducts	0.05	0.05



Poultry, meat	0.05	0.05



Rice, bran	15.0



	Rice, grain	5.0	5.0



Sheep, fat	0.7	0.05



Sheep, meat byproducts	1.5	0.05



Sheep, meat	0.05	0.05



Sorghum, grain, forage	3.0



	Sorghum, grain, grain	6.0



	Sorghum, grain, stover	1.0



	Wheat, forage	1.0



	Wheat, germ	0.75



	Wheat, grain	0.5	0.5



Wheat, hay	0.5



	Wheat, straw	0.1



	Proposed MRLs 

Low growing berries, except strawberries, subgroup 13-07H	1.5



	Rhubarb	0.5









	MRLs With No US Equivalent

Barley, bran

3.5















Completed by: M. Negussie; 07/31/2012

1 Mexico adopts US tolerances and/or Codex MRLs for its export purposes.

(b) Section 18 emergency exemptions . Time-limited tolerances are
established for residues of the herbicide quinclorac, including its
metabolites and degradates, in or on the commodity in the table in this
paragraph. Compliance with the tolerance level specified in this
paragraph is to be determined by measuring only quinclorac,
3,7-dichloro-8-quinolinecarboxylic acid, in or on the commodity. The
tolerance expires and is revoked on the date specified in the table in
this paragraph.

Commodity	Parts per million	Expiration/revocation date

Cranberry	15.0	12/31/12



Appendix II

OECD MRL CALCULATOR 

Quinclorac 

Cranberry 

US 

2 x 0.25 lb ai, 60 PHI 

Quinclorac 

Residues (mg/kg) 	Cranberry 

0.550 	US 

0.180 	2 x 0.25 lb ai, 60 PHI 

0.165 

0.155 	Total number of data (n) 	5 

0.670 	Percentage of censored data 	0% 

Number of non-censored data 	5 

Lowest residue 	0.155 

Highest residue 	0.670 

Median residue 	0.180 

Mean 	0.344 

Standard deviation (SD) 	0.247 

Correction factor for censoring (CF) 	1.000 

Proposed MRL estimate 

- Highest residue 	0.670 

- Mean + 4 SD 	1.331 

- CF x 3 Mean 	1.032 

Unrounded MRL 	1.331 

Rounded MRL 	1.5 

High uncertainty of MRL estimate. 

[Small dataset] 

OECD MRL CALCULATOR 

Quinclorac

Rhubarb 

US 

2 X 0.375 lb ai 

Quinclorac 

Residues (mg/kg) 

Rhubarb 

0.205 

US 

0.173 

2 X 0.375 lb ai 

0.108 

0.067 

Total number of data (n) 

4 

Percentage of censored data 

0% 

Number of non-censored data 

4 

Lowest residue 

0.067 

Highest residue 

0.205 

Median residue 

0.141 

Mean 

0.138 

Standard deviation (SD) 

0.062 

Correction factor for censoring (CF) 

1.000 

Proposed MRL estimate 

- Highest residue 

0.205 

- Mean + 4 SD 

0.388 

- CF x 3 Mean 

0.415 

Unrounded MRL 

0.415 

Rounded MRL 

0.5 

High uncertainty of MRL estimate. 

摧珮!

h p



 

-

8

F

V

`

o

w

‹

Œ

£

¦

Ô

ç

é

ð



&

X

Y

Ԁ8

`

w

Æ

Ç

ñ

@

@

.

X

Y

k

l

฀ꂄㄅĤ葝֠摧ḶlሀY

j

k

l

z

{

¦

¾

Õ

ß

ഀ׆Ā褐㄀Ĥ摧ᇫE

 h|

 h|

 h|

☊଀݆㄀Ĥ摧又

␆༁㢄㄄Ĥ葞и摧ṱÖ

萏ː葞ː摧៍Æ

jÛ

攃昀Ĵ؀

Æ

hÊM

␆ഁ׆Āᨄ㄀Ĥ摧䷊

  h›=

h›=

h›=

h›=

$

$

$

$

愀Ĥ摧㶛

yt›=

愀Ĥ摧㶛

摧㶛

yt›=

 h|

  h›=

h›=

h›=

h›=

h›=

愀Ĥ摧㶛

摧㶛

ﰃ昀Ĵ瑹㶛

$

$

yt›=

hm

hp

hp

h¬

h¬

hp

h|

hni

h¬

 h|

h|

 h|

h|

 hì

hì

$

将

\

  hì

hì

hì

 hì

hì

将

将

将

ytì

将

ytì

gdì

gdì

将

将

将

ytì

将

ytì

gdì

gdì

将

将

将

ytì

将

ytì

$

a$gdì

$

$

a$gdì

将

将

将

ytì

将

ytì

gdì

gdì

将

将

将

ytì

将

ytì

$

a$gdì

$

$

a$gdì

将

将

将

ytì

将

ytì

$

a$gdì

$

a$gdì

将

将

将

ytì

将

ytì

gdì

gdì

将

将

将

ytì

将

ytì

gdì

gdì

将

  hm

hm

hm

hm

  hì

hì

hì

将

将

ytì

  hm

$

$

$

$

`„`úgdm

$

萏֠萑褐葞֠葠褐摧㟖Ý

 h

 h

  hm

hm

h¤@

h¤@

h¤@

h¤@

h¤@

h¤@

h¤@

 h

 h

 h

  h

 h

 h

  h

”ÿô

”ÿô

”ÿô

ì

ì

ì

ì

[Small dataset] 





Quinclorac 128974     	Summary of Analytical Chemistry and Residue Data
DP#: D397719

Page   PAGE  1  of   NUMPAGES   32 

