Document ID: EPA-HQ-OPP-2007-1135-0003
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-12-19T05:00Z

Quinclorac Summary Document

Registration Review: Initial Docket

December 2007

Case # 7222



Quinclorac Summary Document

Registration Review: Initial Docket

December 2007

								

Approved By:

								

___________________

								Steven Bradbury, Ph.D.

								Director, Special Review and

		       Reregistration DivisionTABLE OF CONTENTS

											Page #

Preliminary Work Plan (PWP)						4

Fact Sheet									9

Glossary of Terms and Abbreviations					14

Ecological Risk Assessment Problem Formulation			16

Human Health Effects Scoping Document				56

I. Preliminary Work Plan - Quinclorac

Introduction:

The Food Quality Protection Act of 1996 mandated a new program:
registration review.  All pesticides distributed or sold in the United
States generally must be registered by the U.S. Environmental Protection
Agency (USEPA; EPA; The Agency), based on scientific data showing that
they will not cause unreasonable risks to human health, workers, or the
environment when used as directed on product labeling.  The new
registration review program is intended to make sure that, as the
ability to assess risk evolves and as policies and practices change, all
registered pesticides continue to meet the statutory standard of no
unreasonable adverse effects.  Changes in science, public policy, and
pesticide use practices will occur over time.  Through the new
registration review program, the Agency periodically reevaluates
pesticides to make sure that as change occurs, products in the
marketplace can be used safely.  Information on this program is provided
at: http://www.epa.gov/oppsrrd1/registration_review/. 

The Agency has begun to implement the new registration review program,
and will review each registered pesticide every 15 years to determine
whether it continues to meet the FIFRA standard for registration.  The
public phase of registration review begins when the initial docket is
opened for each case.  The docket is the Agency’s opportunity to state
what it knows about the pesticide and what additional risk analyses and
data or information it believes are needed to make a registration review
decision.  After reviewing and responding to comments and data received
in the docket during this initial comment period, the Agency will
develop and commit to a final work plan and schedule for the
registration review of quinclorac.

Quinclorac is a systemic pre- and post- emergent herbicide to control
broadleaf and grass weeds.  It is registered for use on agricultural
crops as well as on turf in residential and commercial areas.

Anticipated Risk Assessment and Data Needs:

The Agency will conduct a comprehensive ecological risk assessment,
including an endangered species assessment for quinclorac.  The Agency
will also perform an occupational risk assessment, a drinking water
assessment, a residential handler assessment, and an aggregate
assessment.   

Ecological Risk:

The most recent comprehensive ecological risk assessment for registered
uses was conducted on wheat and sorghum in 1999.  The Agency has not
conducted a risk assessment that supports a complete endangered species
determination.  Please refer to Section IV, Ecological Risk Assessment
Problem Formulation, for a detailed discussion of the anticipated risk
assessment needs.

The Agency anticipates needing the following data in order to conduct a
complete ecological risk assessment, including an endangered species
assessment, for all uses:

(GLN 850.1010) Aquatic invertebrate acute toxicity test, freshwater
daphnids

(GLN 850.1300) Daphnid chronic toxicity test

(GLN 835.7100) Ground water monitoring

The planned ecological risk assessment will allow the Agency to
determine if quinclorac’s use has "no effect" on federally listed
threatened or endangered species (listed species) or their designated
critical habitat. If the screening level assessment indicates that
quinclorac "may affect" a listed species or its designated critical
habitat, the assessment will be refined. The refined assessment will
allow the Agency to determine whether use of quinclorac is “likely to
adversely affect” the species or critical habitat or "not likely to
adversely affect" the species or critical habitat. When an assessment
concludes that a pesticide's use "may affect" a listed species or its
designated critical habitat, the Agency will consult with the U.S. Fish
and Wildlife Service and/or National Marine Fisheries Service
(Services), as appropriate.

Human Health Risk:

The toxicological endpoint selections are adequate; however, the
toxicology database for quinclorac is incomplete at this time.  A 90-day
inhalation toxicity study in the rat is required to assess inhalation
exposure from spray uses (GLN 870.3465).

The residue chemistry database is complete.  However, newly submitted
aspirated grain fraction studies on wheat and sorghum will have to be
reviewed, and livestock tolerances may need to be revised based on this
review.

The dietary (food alone) assessment is adequate.  However, a new
drinking water assessment will be conducted; therefore, an aggregate
assessment will be needed. 

The residential post application exposure assessment is adequate,
therefore no residential post application assessment is needed. 
However, no residential handler risks were assessed; therefore, a new
residential handler assessment is needed.   

No occupational risk assessments have been conducted. Occupational risk
assessments will be needed for all scenarios.

Please refer to Section V of this document, Human Health Effects Scoping
Document, for a detailed discussion of the anticipated risk assessment
needs for human health.

  

Timeline:

EPA has created the following estimated timeline for the completion of
the quinclorac registration review.  The Agency may conduct the
occupational assessment much earlier in the process, allowing mitigation
(if necessary) to occur well before completion of the final decision.

Registration Review for quinclorac –

Projected Registration Review Timeline

Activities 	Estimated Month/Year

Phase 1: Opening the docket

Open Public Comment Period for Quinclorac Docket  	2007 – Dec.

Close Public Comment Period 	2008 – Mar.

Phase 2:  Case Development

Develop Final Work Plan (FWP)	2008 – Apr.- Jun.

Issue DCI 	2009 – Jan - Mar.

Data Submission	2013 – Jan - Mar.

Open Public Comment Period for Preliminary Risk Assessments 	2014 –
Jul. – Sept.

Close Public Comment Period	2014 - Oct. – Dec. 

Phase 3: Registration Review Decision

Open Public Comment Period for Proposed Reg. Review Decision 	2015 –
Jan. – Mar.

Close Public Comment Period 	2015 – Apr. – Jun.

Final Decision and Begin Post-Decision Follow-up	2015 – Jul. Sept.

Total (years)	8

Guidance for Commenters:

The public is invited to comment on EPA’s preliminary registration
review work plan and rationale.  The Agency will carefully consider all
comments as well as any additional information or data provided prior to
issuing a final work plan for the quinclorac case.

Through the registration review process, the Agency intends to solicit
information on trade irritants and, to the extent feasible, take steps
toward facilitating irritant resolution.  Growers and other stakeholders
are asked to comment on any trade irritant issues resulting from lack of
Maximum Residue Limits (MRLs) or disparities between U.S. tolerances and
MRLs in key export markets, providing as much specificity as possible
regarding the nature of the concern.  Please see section V of this
document, Quinclorac, Human Risk Problem Formulation Document in Support
of Registration Review, for a listing of the differences among the U.S.,
Canada, Codex, and Mexico tolerances.

Quinclorac is not identified as a cause of impairment for any water
bodies listed as impaired under section 303(d) of the Clean Water Act,
based on information provided at
http://oaspub.epa.gov/tmdl/waters_list.impairments?p_impid=3.  The
Agency invites submission of water quality data for this pesticide.  To
the extent possible, data should conform to the quality standards in
Appendix A of the “OPP Standard Operating Procedure: Inclusion of
Impaired Water Body and Other Water Quality Data in OPP’s Registration
Review Risk Assessment and Management Process” (see:   HYPERLINK
"http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1-sop.pdf" 
http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1-sop.pdf ),
in order to ensure they can be used quantitatively or qualitatively in
pesticide risk assessments. 

EPA seeks to achieve environmental justice, the fair treatment and
meaningful

involvement of all people, regardless of race, color, national origin,
or income, in

the development, implementation, and enforcement of environmental laws,

regulations, and policies. To help address potential environmental
justice issues,

the Agency seeks information on any groups or segments of the population
who,

as a result of their location, cultural practices, or other factors, may
have atypical,

unusually high exposure to quinclorac compared to the general
population.

Please comment if you are aware of any sub-populations that may have
atypical,

unusually high exposure compared to the general population.

Stakeholders are also specifically asked to provide information and data
in the following areas.

There is specific information that will assist the Agency in refining
the ecological risk assessment, including any species-specific effects
determinations.  The Agency is interested in obtaining the following
information regarding the use of quinclorac:

confirmation on the following label information

sites of application

formulations

application methods and equipment

maximum application rates

frequency of application, application intervals, and maximum number of
applications per season

geographic limitations on use

use or potential use distribution (e.g., acreage and geographical
distribution of relevant crops)

use history

median and 90th percentile reported use rates (lbs ai/acre) from usage
data – national, state, and county

application timing (date of first application and application intervals)
by crop – national, state, and county

sub-county crop location data

usage/use information for non-agricultural uses (e.g., forestry,
residential, rights-of-way)

directly acquired county-level usage data (not derived from state level
data)

maximum reported use rate (lbs ai/acre) from usage data – county

percent crop treated – county

median and 90th percentile number of applications – county

total pounds per year – county

the year the pesticide was last used in the county/sub-county area

the years in which the pesticide was applied in the county/sub-county
area

typical interval (days)

state or local use restrictions

ecological incidents (non-target plant damage and avian, fish,
reptilian, amphibian and mammalian mortalities) not already reported to
the Agency

monitoring data

Next Steps:

After the comment period closes, the Agency will prepare a Final Work
Plan for this pesticide.

II. FACT SHEET

 

Background Information:

Quinclorac Registration Review case number: 7222 

Quinclorac is a systemic pre- and post- emergent herbicide to control
broadleaf and grass weeds on rice, sorghum, wheat, residential lawns,
ornamentals and turf grass.  

Quinclorac PC code: 128974;		CAS #: 84087-01-4

Technical Registrant:  Albaugh Inc.    

First approved for use in 1992, therefore not subject to reregistration.

Tolerance Reassessment was released on March 26, 1999 through
publication in the Federal Register (64 FR 14626).  

Special Review and Reregistration Division (SRRD), Chemical Review
Manager (CRM): Joy Schnackenbeck: schnackenbeck.joy@epa.gov

Registration Division (RD) Contacts: 

Jim Tompkins: tompkins.jim@epa.gov; Hope Johnson: johnson.hope@epa.gov

34 total active products are registered; 1 technical product, 3
manufacturing use products, 26 end use products, and 4 special local
needs permits (SLN; 24c). 

Quinclorac is sold in several different formulations including water
dispersible granules, emulsifiable concentrate and wettable powder.

Quinclorac can be applied through aerial equipment, tank spray, boom
sprayer, hand held sprayer, and backpack sprayer.

Use & Usage Information:  (For additional details, please refer to the
BEAD Appendix A document in the quinclorac docket.)

Quinclorac is a quinoline carboxylic acid, whose mechanism of herbicidal
action is generally mimicry of the plant growth hormone, auxin.

Quinclorac is used on less than 2.5 % of the total crop treated for
corn, summer fallow, sorghum and wheat.  On average, it is used on 30%
of the total crop treated for rice.

Approximately 313,000 pounds of quinclorac are used annually.

Recent Actions:

A Rule for quinclorac was issued on 10/28/2007 (72 FR 55068) which
established tolerances for residues in or on imported barley grain. 
BASF Corporation requested this tolerance under the Federal Food, Drug,
and Cosmetic Act (FFDCA).

A Rule for quinclorac was issued on 3/26/1999 (64 FR 14626), which
established FQPA tolerances for residues on wheat and sorghum.  This
Rule also included the tolerance reassessment for rice, sorghum, wheat,
residential lawns, ornamentals and turf grass. 

Ecological Risk Assessment Status:

Please refer to Section IV of this document, Ecological Risk Assessment
Problem Formulation for quinclorac registration review, for a detailed
discussion of the anticipated ecological risk assessment needs. Below is
a summary of the findings:

The Agency will need to conduct new assessments for all registered uses
because some uses and application type scenarios were not assessed for
ecological risk and did not include current terrestrial and aquatic
models.

The Agency has some freshwater invertebrate data which indicates low
risk for aquatic animals, however there are some unusual results with
these studies, which were completed with a formulated product. 
Therefore, the Agency is requiring freshwater invertebrate tests with
the technical, and will use these tests to estimate risks to estuarine
animals.

No acute or chronic risk exceedences of the Agency’s level of concern
are anticipated for aquatic fish or invertebrates.  However, uncertainty
exists for acute and chronic risks to estuarine marine invertebrates
until further data is submitted.  Chronic risks to estuarine marine fish
will be estimated from acute to chronic ratios.

Before the risk assessments are developed for public comment, the Agency
will

ensure that all currently registered uses of quinclorac have an
endangered species

assessment completed. The ecological risk assessment will allow the
Agency to

determine whether quinclorac use has "no effect" or "may affect"
federally listed

threatened or endangered species (listed species) or their designated
critical

habitat. If the assessment concludes that a pesticide's use "may affect"
a listed

species or its designated critical habitat, the Agency will consult with
the U.S.

Fish and Wildlife Service and/or National Marine Fisheries Service
(Services), as

appropriate.

Human Health Risk Assessment Status:

Please refer to Section V of this document, Human Health Effects Scoping
Document, for a detailed discussion of the anticipated risk assessment
needs for human health.  A summary follows:

Dietary (Food and Water):

The residue chemistry database is complete with the newly submitted
aspirated grain fraction (AGF) studies.  A review of the AGF studies are
needed, and livestock tolerances may need to be revised based on this
review.  

The dietary exposure assessment is up-to-date, and no further dietary
assessments are needed.  There are no risks of concern even with a very
conservative assessment. 

A drinking water assessment is needed.

Residential: 

The post application exposure assessments are adequate.

No residential handler assessment has been conducted; therefore, a
residential handler assessment is needed for the registration review of
quinclorac.

Occupational:

No occupational assessments have been conducted for quinclorac.  A new
occupational assessment is required for the registration review once the
inhalation endpoint is selected.

Aggregate:

Once the drinking water assessment is completed, the Agency will conduct
an aggregate assessment.

Incident Reports:

The search of the National Poison Control Center System (NPCS) showed
only a

total of five incidents related to quinclorac in the 13-year span of
data collected and only

two cases were reported in OPP’s Incident Data System (IDS) from 1999
to the

present. In addition, there were no cases reported in the National
Institute of

Occupational Safety and Health Sentinel Event Notification System for

Occupational Risks (NIOSH/SENSOR) database involving quinclorac. A more

detailed summary is provided in a separate document in this docket.

Tolerances: 

US tolerances are listed under 40 CFR 180.463.  A table listing the
differences between current US tolerances as compared to Codex, Canada,
and Mexico appears in section V of this document, Human Health Effects
Scoping Document.

Data Call-In Status:

There are no current data call-ins.

Labels: 

A list of registration numbers may be found in the quinclorac docket and
the labels can then be obtained from the Pesticide Product Label System
(PPLS) website: http://oaspub.epa.gov/pestlabl/ppls.home. 

Registration #	Product Name	Company Name	Percent Active Ingredient

228-423	DQD SELECTIVE HERBICIDE	NUFARM AMERICAS INC.	7.91

228-531	NUP 12D02 HERBICIDE	NUFARM AMERICAS INC.	8.25

239-2689	LAWN CRABGRASS AND WEED KILLER	THE ORTHO BUSINESS GROUP	0.1

538-296	TURF BUILDER WITH WEED CONTROL III	SCOTTS COMPANY, THE	0.52

1381-209	QUINCLORAC 75 DF	WINFIELD SOLUTIONS, LLC	75

2217-885	EH-1426 HERBICIDE	PBI/GORDON CORP	3.49

2217-886	EH-1427 HERBICIDE	PBI/GORDON CORP	5.69

2217-887	EH-1428 HERBICIDE	PBI/GORDON CORP	0.121

2217-888	EH-1425 HERBICIDE	PBI/GORDON CORP	8.38

2217-894	EH-1432 HERBICIDE	PBI/GORDON CORP	1.61

2217-896	EH-1437 HERBICIDE	PBI/GORDON CORP	2.13

2217-901	EH-1434 HERBICIDE	PBI/GORDON CORP	5.65

2217-906	EH-1449 HERBICIDE	PBI/GORDON CORP	0.104

7969-93	FACET 50 WP	BASF CORPORATION	50

7969-109	QUINCLORAC MANUFACTURING USE PRODUCT	BASF CORPORATION	98

7969-113	FACET 75 DF HERBICIDE	BASF CORPORATION	75

7969-130	DRIVE 75 DF HERBICIDE	BASF CORPORATION	75

7969-152	PARAMOUNT BW HERBICIDE	BASF CORPORATION	15

7969-158	FACET GR HERBICIDE 46	BASF CORPORATION	1.5

7969-172	DRIVE 75 MANUFACTURERS CONCENTRATE	BASF CORPORATION	75

7969-222	CLEARPATH HERBICIDE	BASF CORPORATION	61.98

34704-920	QUINCLORAC 75DF HERBICIDE	LOVELAND PRODUCTS, INC.	75

42750-85	QUINCLORAC TECHNICAL	ALBAUGH INC	99

42750-88	QUINCLORAC 75DF AG	ALBAUGH INC	75

42750-90	QUINCLORAC 75DF SP	ALBAUGH INC	75

42750-131	QUINCLORAC 75 SWF	ALBAUGH INC	75

71085-26	RICEPRO	RICECO LLC	2

73220-15	QUALI-PRO QUINCLORAC 75	FARMSAVER.COM, LLC	75

79676-22	QUINCLORAC G-PRO 75 DF	GRO-PRO, LLC	75

81927-21	ALLIGARE QUINCLORAC 75 WDG	ALLIGARE, LLC	75

AR070006	RICEPRO	RICECO LLC	2

UT990003	FACET 75 DF HERBICIDE	BASF CORPORATION	75

98ND20	 	ND Dept. of Agriculture	 

98NE07	 	NE Department of Agriculture	 

 III. GLOSSARY of TERMS and ABBREVIATIONS

ai		Active Ingredient

AR		Anticipated Residue

CFR		Code of Federal Regulations

cPAD		Chronic Population Adjusted Dose

CSF		Confidential Statement of Formula

CSFII		USDA Continuing Surveys for Food Intake by Individuals

DCI		Data Call-In

DEEM		Dietary Exposure Evaluation Model

DFR		Dislodgeable Foliar Residue

DNT		Developmental Neurotoxicity

DWLOC		Drinking Water Level of Comparison

EC		Emulsifiable Concentrate Formulation

EDWC		Estimated Drinking Water Concentration

EEC		Estimated Environmental Concentration

EPA			Environmental Protection Agency

EUP		End-Use Product

FDA		Food and Drug Administration

FIFRA		Federal Insecticide, Fungicide, and Rodenticide Act

FFDCA		Federal Food, Drug, and Cosmetic Act

FQPA		Food Quality Protection Act

FOB		Functional Observation Battery

GENEEC		Tier I Surface Water Computer Model

IR		Index Reservoir

LC50	Median Lethal Concentration.  A statistically derived concentration
of a substance that can be expected to cause death in 50% of test
animals.  It is usually expressed as the weight of substance per weight
or volume of water, air or feed, e.g., mg/l, mg/kg or ppm.

LD50	Median Lethal Dose.  A statistically derived single dose that can
be expected to cause death in 50% of the test animals when administered
by the route indicated (oral, dermal, inhalation).  It is expressed as a
weight of substance per unit weight of animal, e.g., mg/kg.

LOC		Level of Concern

LOAEL		Lowest Observed Adverse Effect Level

µg/g		Micrograms Per Gram

µg/L		Micrograms Per Liter

mg/kg/day		Milligram Per Kilogram Per Day

mg/L		Milligrams Per Liter

MOE		Margin of Exposure 

MRID	Master Record Identification (number).  EPA's system of recording
and tracking submitted studies.

MUP		Manufacturing-Use Product

NA		Not Applicable

NAWQA		USGS National Ambient Water Quality Assessment

NPDES		National Pollutant Discharge Elimination System

NR		Not Required

NOAEL		No Observed Adverse Effect Level

OPP		EPA Office of Pesticide Programs

OPPTS		EPA Office of Prevention, Pesticides and Toxic Substances

PAD		Population Adjusted Dose

PCA		Percent Crop Area

PDP		USDA Pesticide Data Program

PHED		Pesticide Handler's Exposure Data

PHI			Preharvest Interval

ppb		Parts Per Billion

PPE		Personal Protective Equipment

ppm		Parts Per Million

PRZM/EXAMS		Tier II Surface Water Computer Model  

Q1*	The Carcinogenic Potential of a Compound, Quantified by the EPA's
Cancer Risk Model

RAC		Raw Agriculture Commodity

RED		Reregistration Eligibility Decision

REI		Restricted Entry Interval

RfD		Reference Dose

RQ		Risk Quotient

SCI-GROW		Tier I Ground Water Computer Model

SAP		Science Advisory Panel

SF		Safety Factor

SLN		Special Local Need  (Registrations Under Section 24©) of FIFRA)

TGAI		Technical Grade Active Ingredient

USDA		United States Department of Agriculture

UF		Uncertainty Factor

WPS		Worker Protection StandardIV. Ecological Risk Assessment Problem
Formulation

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

Washington, D.C. 20460	

									             OFFICE OF 

	PREVENTION, PESTICIDES

	AND TOXIC SUBSTANCES 

								

Date: November 27, 2007

MEMORANDUM 					

Subject:	EFED Problem Formulation for Quinclorac Registration Review 

                         PC: Code: 128974   D344485

To:		Joy Schnackenbeck, Chemical Review Manager 

Special Review and Reregistration Division (7508P)

From:	Marie Janson, Environmental Scientist, ERBI

	Thuy Nguyen, RAPL, ERBI

Nancy Andrews Ph.D., Branch Chief, ERBI

Environmental Fate and Effects Division (7507P)

Attached is the EFED’s problem formulation document in support of the
Quinclorac registration review docket opening.  This memorandum outlines
(1) the methods that will likely be used in the ecological risk
assessment of Quinclorac (2) data gaps, and (3) additional data needs. 

EXECUTIVE  SUMMARY

 Quinclorac is systemic pre- and post-emergent herbicide to control
broadleaf and grass weeds on residential/commercial turf grasses and on
other turf grasses (picnic grounds, athletic field, golf, and sod
farms), agricultural fallow/ idleland, agricultural rights of way/ fence
rows/ hedge rows, grasses grown for seed, rice, sorghum and wheat. In
addition to the above registered uses, Emergency Use Permits (EUPs) on
impounded waters were also issued. 

The most recent comprehensive risk assessment for registered uses was
conducted on wheat and sorghum (Feb 17, 1999). The most recent EUP was
conducted on aquatic weed control to non-flowing water bodies (May
17,2007). The drinking water assessment was conducted on turf grass
application (September 13, 2007). 

Based on the results of the above risk assessments the following risk
concerns were noted from registered uses:             

 risks to listed and non-listed terrestrial plants wheat and sorghum
applications

(listed and non-listed) acute risk to birds from wheat and sorghum
applications*

Based on the results of the above EUP for aquatic weed control the
following risk concerns were noted:

risks to listed and non-listed terrestrial plants (spray drift
exceedences only)

risks to non listed* and listed unicellular and vascular plants

(listed and non-listed) acute and chronic risk to mammals*

(listed and non-listed) acute and chronic risk to birds*

There is insufficient evidence to completely refute these exceedences,
however there is sufficient evidence to refine the concerns.

Based on available laboratory studies, EFED has identified two major (BH
514-1 and BH 514 2-OH; >10% applied)) and one minor (BH 514-HMe-ester;
<10% applied) quinclorac metabolites.  In most of the acceptable
terrestrial field dissipation studies (1988/1989, 1989/1990, and
1996/1997 studies), leaching from these degradates.  An acceptable
guideline adsorption/desorption study for BH-514-1 indicates that this
metabolite is mobile to very mobile in sand, sandy loam, loam, clay
loam, and silty clay soils. Two guideline leaching and
adsorption/desorption studies (MRID 45598701 and 45598702) for BH 514
2-OH and BH 514-HMe-ester were submitted to the Agency, in 2002, however
not yet reviewed.  These studies will undergo reviews and until they are
deemed acceptable by the Agency, the above mentioned metabolites are
considered potential contaminants of groundwater resources, based on the
“Acceptable” field studies.  EFED believes that since quinclorac is
persistent and mobile and its metabolites have the ability to leach
through soil profiles, the potential for groundwater impacts to
non-target crops via contaminated groundwater is likely.  Therefore, a
small scale prospective groundwater contamination study for quinclorac
(and possibly its metabolites) under the expected conditions of use of
all currently registered crops is requested.  

EFED anticipates revisions to the risk assessments based on new
application scenarios and additional toxicity data requested.  Previous
assessments were based on lower application scenarios or higher
intervals between applications.  

 

PROBLEM FORMULATION	

				

Problem formulation is used to establish the direction and scope of an
ecological risk assessment.  According to the Guidelines for Ecological
Risk Assessment (USEPA, 1998), problem formulation consists of defining
the problem and purpose for the assessment, and developing a plan for
analyzing and characterizing risk.  The critical components of the
problem formulation are selection of the assessment endpoints,
formulation of risk hypotheses and the conceptual model, and development
of an analysis plan.  The analysis plan and supporting rationale are
aimed at determining whether the uses of  Quinclorac on
residential/commercial turf grasses and on other turf grasses (picnic
grounds, athletic field, golf, and sod farms), agricultural fallow/
idleland, agricultural rights of way/ fence rows/ hedge rows, grasses
grown for seed, rice, sorghum and wheat could result in exposures that
cause unreasonable adverse effects (risk) to non-target organisms
including those federally listed as threatened or endangered (hereafter
referred to as “listed”).   Emergency Use Permits also will also be
characterized in the assessment on aquatic weed control on impounded
waters.

1.	INTEGRATION OF AVAILABLE INFORMATION

The risk assessments available in the docket, and which serve as the
basis for this problem formulation, include the following:

Feb 17, 1999, Quinclorac Herbicide Environmental Fate and Ecological
Effects

      Assessment and Characterization for a Section 3 for Use on Wheat
and Sorghum

May 17, 2007, Ecological Risk Assessment for Experimental Use Permit for
Quinclorac

             for  Aquatic Weed Control for the application of quinclorac
to non- flowing water bodies

             such as retention ponds and lakes to evaluate the control
and selectivity of submerged

             and emergent aquatic weed species DPBarcode: D334717.

September 13, 2007,  Estimated Drinking Water Assessment for Quinclorac
(3,7-dichloro-8-quinolinecarboxylic acid,  CAS# 84087-01-4) Use on
Turfgrasses  DPBarcode: 341487

Based on the results of the above risk assessments the following risk
concerns were noted from registered uses:        

 risks to listed and non-listed terrestrial plants from wheat and
sorghum applications

(listed and non-listed) acute risk to birds from wheat and sorghum
applications*

Based on the results of the above EUP for aquatic weed control the
following risk concerns were noted:

risks to listed and non-listed terrestrial plants (spray drift
exceedences only)

risks to non listed* and listed unicellular and vascular plants

(listed and non-listed) acute and chronic risk to mammals*

(listed and non-listed) acute and chronic risk to birds*

There is insufficient evidence to completely refute these exceedences,
however there is sufficient evidence to refine the concerns.

The following maximum use rates were used in previous assessments: 

Feb 17, 1999, Section 3 Assessment for Use in Wheat and Sorghum:  The
maximum annual application rate is 0.75 lb a.i./acre at 0.125 - 0.245 lb
ai/acre for ground and aerial applications.

 

September 13, 2007, Estimated Drinking Water Assessment for Quinclorac
Use on Turfgrasses:   The maximum annual application rate is 1.5 lb
a.i./acre at 0.25 – 0.75 lb ai/A/ appl at 21-day interval for ground
spray or spot spray application.

May 17, 2007, Ecological Risk Assessment for Experimental Use Permit for
Quinclorac

for  Aquatic Weed Control:  For submerged vegetation control quinclorac
is applied in sufficient quanity to reach a water concentration of 0.5
mg/L with up to 2 applications per year.

All assessments did not provide the highest labeled application rates (2
applications @0.75 lb ai/A) and current minimum intervals (14 days).  In
addition, current labels have ground, aerial and granular applications
which were not incorporated in all assessments.   Therefore, a new
drinking water assessment and ecological risk assessment is required
with the above maximum application rates, minimum intervals and
application scenarios. 

There are two reported incidents for quinclorac.  Both incidents ref#
I012162-001 and ref# I015496-001 indicated plant damage to tomatoes in
Arkansas from drift exposure. There are additional data that suggest the
effects of primary drift may occur at considerable distances downwind
from the target site and effect commercial yields of sensitive crops.
Additional information is summarized in the 1999 EFED risk assessment in
the Risk Characterization Section on Non-Target Plant Effects (Drift
Implications for Risks to Non-Target Crops and Wild Plants). tc \l3
"Non-Target Plant Effects (Drift Implications for Risks to Non-Target
Crops and Wild Plants) 

DATA GAPS AND ANTICIPATED DATA NEED

 

Acute and chronic freshwater invertebrate toxicity tests- The acute
freshwater invertebrate toxicity test was based on a formulated product
(quinclorac with surfactant BAS 864 01 S).

 tc \l3 "Freshwater Invertebrate Toxicity from Chronic Exposure The
Daphnia magna 21-day NOAEC of 110 mg/L is used as the freshwater
invertebrate toxicity endpoint for chronic exposure.  It should be noted
that the 21-day NOAEC unexpectedly exceeds the 48-hour EC50 for the same
species.  This observation is likely the result of differences in test
water conditions, or as the result of surfactant use in the acute
toxicity test.  As quinclorac is an acid subject to dissociation in
water, differences in water hardness may influence the toxicity of the
compound.  The available data suggest that quinclorac is more toxic to
freshwater invertebrates in soft water (48-hour LC50= 28.9 mg/l in water
40-48 mg CaCO3/L) compared to harder water (21-day NOAEC 110 mg/l in
water >150 mg CaCO3/L).  An alternative explanation for the disparate
toxicity results may be the presence of surfactant in the acute test,
whereas no surfactant is evident for the chronic test.  The use of the
available 21-day chronic data as the toxicity endpoint for all
freshwater systems represents an uncertainty.

Decision:   Acute and chronic freshwater invertebrate studies conducted
on TGAI and current guideline requirements are requested. This data will
then be used to estimate values for estuarine marine invertebrate
chronic toxicity.

 

Estuarine marine fish and estuarine marine invertebrate Early Life-Stage
toxicity tests- No early life-stage or full life-cycle studies were
submitted for estuarine marine fish or invertebrates. 

Decision:    Early life-stage chronic estuarine marine fish and
invertebrate toxicity tests for  quinclorac are not requested. Estimated
values derived from ACRs will be sufficient pending acute and chronic
freshwater invertebrate study based on TGAI.

Ground water contamination study for quinclorac (and possibly its
metabolites):

Based on available laboratory studies, EFED has identified two major (BH
514-1 and BH 514 2-OH; >10% applied)) and one minor (BH514-HMe-ester;
<10 % applied) quinclorac metabolites.  In the field (1988/1989,
1989/1990, and 1996/1997 studies), leaching from these degradates  into
the soil profiles were observed.  An acceptable guideline
adsorption/desorption study for BH-514-1 indicated that this metabolite
is mobile to very mobile in sand, sandy loam, loam, clay loam, and silty
clay soils. Two guideline leaching and adsorption/desorption studies
(MRID 45598701 and 45598702) for BH 514 2-OH and BH 514-HMe-ester were
submitted to the Agency, in 2002, however not yet reviewed.  These
studies will undergo reviews and until they are deemed acceptable by the
Agency, the above mentioned metabolites are considered potential
contaminants of groundwater resources, as suggested by data from the
“Acceptable” terrestrial field dissipation studies.  

Decision:  Based on the environmental persistence of quinclorac, its
potential to enter groundwater (as modeled by SCI-GROW and indicated in
terrestrial field studies), and the potential for groundwater impacts to
non-target crops via contaminated groundwater, a small scale prospective
groundwater contamination study for quinclorac (and possibly its
metabolites) under the expected conditions of use of all currently
registered crops is requested.  Specifically, since both parent
quinclorac and BH 514-1 are carboxylic acids, they are  expected to be
anions under the normal environmental pH range (5.5 – 8.5), therefore
possess high potential to be mobile in mineral soils. 

 

3.	  TC \l3 "		Overview of Pesticide Usage  PESTICIDE TYPE, CLASS, AND
MODE OF ACTION

Quinclorac is a quinoline carboxylic acid.  The mechanism of herbicidal
action is generally similar to the mechanism for the phenoxy herbicides
(i.e., mimicry of the plant growth hormone auxin). The risk assessment
only assesses parent quinclorac risks.  For most fate processes the
parent compound is stable.  While quinclorac may be relatively rapidly
photo-labile in natural waters, the available studies of this fate
process have not chemically identified degradates or their rate of
production.  There is therefore insufficient information to assess
degradate risks with any useful degree of confidence and no information
is available to suggest that any degradates could be biologically
active.

4.            STRESSOR SOURCE AND DISTRIBUTION

 

The stressor of this assessment is identified by the chemical name
3,7-dichloro-8-quinolinecarboxylic acid.  The trade name for this
compound is quinclorac, the CAS number is 84087-01-4, and the PC code is
128974. Currently, quinclorac is applied as  ground spray, aerial spray,
aerial granular, ground granular applications.

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. 

The adsorption coefficients Kd of less than 1 suggest that leaching
could be a route of dissipation.  In the field, some leaching was
observed, as quinclorac was detected below the 12 inch soil depth in the
several of the terrestrial field dissipation studies (1988/1989
studies): detections of residues of quinclorac and its degradates in the
soil down to 42-48 inches (quinclorac), 12-18 inches (BH 514-2-OH) and
6-12 inches (BH 514-ME) were noted in terrestrial field studies
performed in KS, CA, MO, and NJ.  

Runoff under normal field situations to near surface water is also
expected, since Kd is low (<1.0) and the chemical can be applied near
the soil surface (pre emergence).  

 5.	OVERVIEW OF PESTICIDE USAGE

Quinclorac is a pre- and post-emergent herbicide to control broadleaf
and grass weeds on residential/commercial turf grasses and on other turf
grasses (picnic grounds, athletic field, golf, and sod farms),
agricultural fallow/ idleland, agricultural rights of way/ fence rows/
hedge rows, grasses grown for seed, rice, sorghum and wheat.  In
addition, quinclorac controls submerged and emergent aquatic weed
species in impounded waters for EUPs.  

The highest annual application rate among all registered and proposed
uses is via Drive 75 DF and Quinclorac G-Pro 75 DF labels, which allows
2 to 3 ground broadcast or spray spot applications of 0.25, 0.50, or
0.75 lb ai/A per application, not exceeding 1.5 lb ai/A/year.  
Sequential applications should be timed 14 days apart.  Additional
maximum rate application scenarios are provided in Table 1 for aerial,
ground and granular applications based on BEAD 2007 information. Table
30 provides all current registrations and EUPs based on BEAD 2007
information.

 

Table 1  Maximum  Quinclorac Aerial, Ground and Granular application
rate scenarios derived from BEAD 2007 to be used in future risk
assessments*

Type of application	Label	Maximum application rate	Maximum # apps
Maximum application per season

aerial spray and aerial granular applications	7969-158 Facet GR(aerial),
 42750-88 Quinclorac 75 DF AG,7969-93 Facet 50 WP	0.5 lb ai/A	1	0.5 lb
ai/A

aerial spray application	42750-131 Quinclorac SWF	0.375 lb ai/A	2	0.75lb
ai/A

ground granular application	583-296 Scotts turf builder	0.75 Lb ai/A	2
Not  specified (assume 2@ 0.75) 60 day interval 

ground spray application	7969-130 Drive 75 DF and 79676-00022 Quinclorac
G-Pro 75 DF	0.75lb ai/A	2	1.5 lb ai/A

*assume 14 day interval unless indicated

 The application rate for emergent vegetation control is indicated on
the proposed label for the EUP to be a maximum of 3 lbs a.i. per year,
with up to two applications in a calendar year.  Applications can be
made to drawn down water bodies to expose vegetation.  In such cases
re-flooding may occur 14 days after application. The application rate
for submerged vegetation is quinclorac applied in sufficient quantity to
reach a water concentration of 0.5 mg/L.  Up to two application of
quinclorac per year can be made. 

6.	ENVIRONMENTAL FATE SUMMARY

ENVIRONMENTAL FATE

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. 

For mobility in terrestrial environment, the adsorption coefficients Kd
of less than 1 suggest that leaching could be a route of dissipation. 
In the field, some leaching was observed, as quinclorac was detected
below the 12 inch soil depth in the several of the terrestrial field
dissipation studies (1988/1989 studies): detections of residues of
quinclorac and its degradates in the soil down to 42-48 inches
(quinclorac), 12-18 inches (BH 514-2-OH) and 6-12 inches (BH 514-Me
ester) were noted in terrestrial field studies performed in KS, CA, MO,
and NJ.  It is not clear from these studies whether or not the
metabolite BH 514-1 was analyzed for at the time the studies were
conducted. However, as referenced in the April 25, 1996 letter to Mr
Robert Taylor, RD, EPA, the registrant claimed a reanalysis (no analysis
date was specified) of the soil samples from the 1988/1999 studies did
not detect presence of this carboxylic acid metabolite.  Additional
studies performed between 1989 and 1990 in FL, WI, and NY only showed
movement of parent quinclorac to a maximum depth of 24 inches, while the
degradate BH-514-1 was not found at any sampling interval and/or
sampling depths.  These studies and the details of the reanalyses of BH
514-1 have not yet been received nor reviewed by EFED.  Two guideline
leaching and adsorption/desorption studies (MRID 45598701 and 45598702)
for BH 514 2-OH and BH 514-HMe-ester were submitted to the Agency, in
2002, however not yet reviewed.  EFED SCI-GROW model predicts an upper
bound ground water exposure concentration of 29 µg/L for parent
quinclorac.

In summary, based on all “Acceptable” guideline studies, EFED
concludes that quinclorac has has the potential to leach and runoff in
the soil environment and into groundwater.  Furthermore, BH 514-1, the
primary degradate of quinclorac, also has the potential to leach to the
groundwater in soil containing low amount of clay or organic matter. 
EFED notes that quinclorac and BH-514-1 are both carboxylic acids;
therefore, they are expected to be anions under the normal environmental
pH range (5.5-8.5).  This suggests that these two chemicals have great
potential to be mobile in mineral soils.

Runoff under normal field situations to near surface water is also
expected, since Kd is low (<1.0) and the chemical can be applied near
the soil surface (pre emergence).  For 1 in 10 year annual peak (acute)
surface water residue, EFED PRZM/EXAMS estimates a value of 22.9 µg/L;
for 1 in 10 year annual mean (chronic), 14.5 µg/L; and for 30 year
annual mean (cancer), 10.3 µg/L.  Note that all values were based on
post emergence non residential turf uses ,such as picnic grounds,
athletic fields, sod farms, etc, … The acute value was estimated from
the FL Turf scenario, and the chronic and cancer from the PA Turf
scenario.

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 29.

 

7.	  TC \l2 "

	Receptors ECOLOGICAL EFFECTS SUMMARY  TC \l3 "		Ecological Effects 

Table 2 provides taxonomic groups and test species used to indicate the
potential for ecological effects in this screening-level risk
assessment.  Within each of these very broad taxonomic groups, an acute
and/or chronic endpoint is selected from the available test data.

Table 2.  Taxonomic Groups and Most Sensitive Test Species Evaluated 
for Ecological Effects of Quinclorac *  TC \f 1 "Table 2.2  Taxonomic
Groups and Most Sensitive Test Species Evaluated for 

Ecological Effects of Triflumizole. 

Taxonomic group	Example(s) of representative species	Endpoint Used

Birdsa	Bobwhite quail (Colinus virginianus)

Mallard duck (Anas platyrhynchos)

Bobwhite quail (Colinus virginianus)

	Acute LC50 5000 mg/kg-diet

Acute LD50  >1900 mg/kg-bw

Chronic, NOAEC 500 mg/kg-diet

Mammals	Laboratory rat (Wistar)	Acute LD50  2190 mg/kg-bw

NOAEC 160 mg/kg-bw/day

Terrestrial insects	Honeybees (Apis mellifera)	Acute Contact  LD50>181
ug/bee

Freshwater fishb	Bluegill sunfish (Lepomis macrochirus)

Fathead minnow (Pimephales promelas)	Acute LC50 31.6 mg/L

Chronic NOAEC 16 mg/L

Freshwater invertebrates	Water flea (Daphnia magna)

 	Acute EC50 29.8 mg/L

NOAEC  110 mg/L

Estuarine/marine fish	Sheepshead minnow (Cyprinodon variegatus)	Acute
LC50 >94.4 mg/L

NOAEC no studies submitted or values determined. However, estimated
values   derived from acute to chronic ratios will be used in future
risk assessments. 

Estuarine/marine invertebrates	Mysid shrimp (Mysidopsis bahia) 

 	Acute EC50 69.4 mg/L NOAEC no studies submitted or values determined.
However, estimated values   derived from acute to chronic ratios will be
used in future risk assessments. 

Terrestrial plants*	Dicots – carrot

Dicots- tomato	Seedling Emergence  EC25 0.004 lb a.i./acre, NOAEC <0.004
lb a.i./acre

Vegetative Vigor EC25  

EC25 0.007 lb a.i./acre, NOAEC 0.5 lb a.i./acre

Vascular aquatic plants 	Duckweed (Lemna gibba) Tier1	Acute   EC50 >0.5
mg/L

NOAEC 0.5 mg/L

 Non-vascular aquatic plants	Green algae (Selanastrum capricornutum )

Freshwater diatom (Navicula pelliculosa)

Marine diatom (Skeletonema costatum)

Bluegreen alga (Anabaena flos-aquae)	Acute  EC50 >0.5 mg/L

NOAEC 0.5 mg/L

 

aBirds are used as surrogates for terrestrial phase amphibians and
reptiles (US EPA, 2004).

bFreshwater fish are used as surrogates for aquatic phase amphibians (US
EPA, 2004).

* Dicots were the most sensitive terrestrial plant species tested,
however the most sensitive monocots for seedling emergence is onion
(EC25 0.118 lb, NOAEC<0.118 lb ai/A)  and for vegetative vigor is corn 
( EC25  1.09 lb a.i./acre, NOAEC 0.5 lb ai/A)

8.	ECOSYSTEMS AT RISK  TC \l3 "		Ecosystems at Risk 

The ecosystems that could be potentially at risk due to agricultural and
ornamental turf use of  quinclorac include terrestrial and aquatic
(lakes, ponds, streams and estuarine marine water bodies)  habitats in
proximity to  quinclorac use areas.  These habitats may be at risk from
drift and/or runoff of quinclorac from use areas.  

Organisms of concern include birds, mammals, reptiles, fish, and
terrestrial and aquatic invertebrates, plants, and amphibians.  The
assessment endpoints are intended to reflect population sustainability
and community structure within ecosystems and hence relate back to
ecosystems at risk.  If risks are expected for given species/taxa based
on the screening-level assessment, then risks might be expected to
translate to higher levels of biological organization.

Identifying specific ecosystems at risk in a screening-level assessment
is beyond the scope of the effort.  

Receptors

 The aquatic receptors likely to be exposed to quinclorac from turf and
rice applications include fish, invertebrates, aquatic stages of
amphibians and plants living in waterways adjacent to or downstream from
treated areas.  

Terrestrial receptors likely to be exposed to quinclorac include birds,
mammals, reptiles, and terrestrial stages of amphibians that may occur
in treated fields and terrestrial plants adjacent to, or down slope from
treated areas. The above taxonomic groups exposed to quinclorac are
simular for impounded waters as well.

8.2.	Assessment Endpoints  TC \l2 "	Assessment Endpoints 

Assessment endpoints are defined as “explicit expressions of the
actual environmental value that is to be protected.”  Operationally,
the environmental value is represented by an ecological entity and
associated attributes or characteristics.  The assessment endpoints for
this ecological risk assessment will be survival, growth, and
reproduction of terrestrial and aquatic animals and plants. 
Specifically, this assessment will address birds, mammals, reptiles,
amphibians, terrestrial and aquatic invertebrates, terrestrial and
aquatic plants, and fish.  These endpoints, in turn, are meant to
reflect population sustainability and community diversity within
ecosystems.

Assessment endpoints and toxicity data used to evaluate the assessment
endpoints are identified in Table 2.

CONCEPTUAL MODEL

Figure 1.  No conceptual model was provided in previous assessments,
however this new conceptual model  of the fate/transport and effects of
Quinclorac applied to the terrestrial environment will be applied in
future assesssments. In addition, granular applications will be assessed
in future risk assessments.

*The vapor pressure of quinclorac, reported to be 1 x 10-7 mbar (0.76 x
10-7 mm Hg) at 20o C, and Henry's Law Constant both indicate a low
possibility of volatilization.

For direct application to the aquatic environment, the conceptual model
of the fate/transport and effects of Quinclorac will be used from the
May 17, 2007 Ecological Risk Assessment for Experimental Use Permit for
Quinclorac for Aquatic Weed Control DP Barcode: D334717.

10.       RISK HYPOTHESES  TC \l3 "		Risk Hypotheses 

Used in accordance with proposed or existing labels quinclorac may: 

 

adversely affect growth, survival, or fecundity of birds and/or small
mammals (and terrestrial amphibians and reptiles) ingesting the
incidentally contaminated vegetation, seeds, fruits, or invertebrates
associated with direct application to terrestrial plants, soil surface,
drained impounded water bodies or the intentionally  treated bait or
seed stock,

adversely affect growth, survival, and or reproduction of aquatic
invertebrates, fish, amphibians in both freshwater and estuarine marine
environments,

adversely affect the emergence or growth of terrestrial plants receiving
exposure either by drift from treated areas under conditions of ground
or aerial spray.

      

11.	ANALYSIS PLAN  TC \l2 "	Analysis Plan 

The analysis plan is the final step in problem formulation.	During this
step measures of exposure and measures of effect are used to evaluate
the risk hypotheses and are listed in Tables 2 and 3 for a specific
assessment endpoint.  The RQ is obtained by dividing the measures of
exposure for a particular assessment endpoint by the measures of effect
for that endpoint.

11.1.	Measures of Exposure  TC \l4 "			Measures of Exposure 

		

Measures of exposure for quinclorac that will be used in this assessment
are obtained from modeling efforts only, since national-scale monitoring
data were not identified.  Exposure models used for this assessment
include the suite of standard exposure models commonly used in pesticide
risk assessments (EPA, 2004).  Generally, aquatic exposure estimates are
generated from EFED models and incorporate maximum proposed use rates
and empirically-derived fate properties.  Aquatic exposure will be
estimated using the Tier 1 GENEEC model and will consist of aquatic EECs
derived using a water body that is vulnerable and representative of
static ponds and first order waterways.

Measures of exposure for terrestrial mammals, birds, reptiles, and
amphibians similarly incorporate maximum proposed use rates but rely
less on fate properties.  Instead, terrestrial exposure estimates are
derived directly from empirically determined observations of pesticide
residues on various terrestrial food items.  For numerous applications
for a given use, the exposure model incorporates a first-order decay
rate dependent on the soil half-life of the chemical.  In place of
unavailable foliar dissipation data, the default foliar dissipation
half-life of 35 days will be used.  The currently used terrestrial
exposure model is TREX v.1.3.1.

Exposure to terrestrial plants will be estimated using the TerrPlant
model that assumes  quinclorac drifts or moves with runoff to adjacent
areas. 

             Listed Species Assessment

Based on preliminary EECs from terrestrial application scenarios and the
assumptions discussed above, acute risks at the highest labeled
application rate are expected for listed birds based on the
non-definitive LD50 of >1900 mg/kg-bw (1.5 lbs a.i./A per season)  Risks
are expected as well for listed species of terrestrial plants (monocots
and dicots) inhabiting semi-aquatic and dry areas based on exposures of
quinclorac originating from the maximum application rate.  

  

Based on preliminary EECs from direct application to a water body and
the assumptions discussed above, acute risks at the highest labeled
application rate are expected for listed birds, mammals, terrestrial
plants (monocots and dicots) and aquatic non-vascular plants.    

Because of the potential risk from direct effects to the listed and
non-listed taxa described above, should exposure occur, listed species
in all taxa may potentially be affected indirectly due to alterations in
their habitat (e.g., food sources, shelter, and areas to reproduce).  An
evaluation of risk conclusions based on direct and indirect effects for
each taxonomic group will be summarized in the future assessment for all
proposed labels.

If the planned ecological risk assessment continues to indicate that
quinclorac may potentially impact, either directly or indirectly, listed
species or critical habitat, and therefore does not support a “not
likely to adversely affect” determination, further refinements will be
made.  This will involve determining whether use of quinclorac “may
affect” a particular listed species, and if so, whether it is
“likely to adversely affect” the species, or in the case of
designated critical habitat, whether use of the pesticide may destroy or
adversely modify any principle constituent elements for the critical
habitat, and if so, whether the expected impacts are “likely to
adversely affect” the critical habitat.  The first step in the process
is to improve the exposure estimates based on refining the geographic
proximity of quinclorac use and the listed species and/or critical
habitat.  If there is no geographic proximity, this information would
support a determination that quinclorac use will have no effect on the
species or critical habitat.  If after conducting the first step of this
analysis the Agency determines that geographic proximity exists, both
potential direct effects and any potential indirect effects of the
pesticide use will be examined.  This process is consistent with the
Agency's Overview Document.  The Agency will consult as necessary with
the U.S. Fish and Wildlife Service and National Marine Fisheries Service
(collectively ‘the Services’), consistent with the Services'
regulations.

If the screening level risk assessment identifies potential concerns for
indirect effects on listed species, the next step for EPA and the
Services would be to identify which listed species and critical habitat
are potentially implicated.  Analytically, the identification of such
species and critical habitat can occur in either of two ways.  First,
the agencies could determine whether the action area overlaps critical
habitat or the occupied range of any listed species.  If so, EPA would
examine whether quinclorac potential impacts on non-endangered species
would affect the listed species indirectly or directly affect a
constituent element of the critical habitat.  Alternatively, the
agencies could determine which listed species depend on biological
resources, or have constituent elements that fall into, the taxa that
may be directly or indirectly impacted by quinclorac.  Then EPA would
determine whether the use of quinclorac overlaps the critical habitat or
the occupied range of those listed species.

11.2.	Measures of Effect	  tc \l3 "	Field result goes here	Aquatic
Effects Characterization	  tc \l4 "		Field result goes here	Aquatic
Animals 

                    EFFECTS ASSESSMENT

The Effects assessment for this risk assessment has been based on
previous risk assessment data evaluations conducted in 1999.  There has
been no update of the toxicological review of the compound in the
intervening years.  These risk assessments DO NOT include a search and
evaluation of the ECOTOX database.

                       Toxicity to Terrestrial Animals tc \l2 "Toxicity
to Terrestrial Animals 

Acute and Subacute Avian Toxicity tc \l3 "Acute and Subacute Avian
Toxicity 

The results of available avian acute toxicity tests are listed in Table
3.  The most sensitive species is the mallard duck (LD50 >1900 mg/kg,
LD50 value expressed on a bodyweight-based dose), which serve as the
toxicological endpoint in avian single oral dose exposure risk
calculations.

Table 3  Avian Acute Oral Toxicity Data tc \l1 "Table 6. Avian Acute
Oral Toxicity Data 

Species	

% Active Ingredient	

LD50 

(confidence limits) 

(mg/kg-bw)	

MRID No.	

Classification

Northern bobwhite quail Colinus virginianus	

98	

>2000

(no mortality at 2000)	

41063547	

acceptable

Mallard duck

Anas platyrhynchos	

98	

>1900

(no mortality at 970, 20% mortality and convulsions at 1900)	

40320810	

supplemental*

LD50: Lethal dose to 50% of test population

NOAEL: No observed adverse effect level

* listed as supplemental due to questionable husbandry practices (e.g.,
the necks of ducks bound with bands to prevent regurgitation)

 The results of available avian sub-acute dietary testing are summarized
in Table 4.  The LC50 of >5000 mg/kg-diet exhibited for both northern
bobwhite quail and the mallard duck serve as the basis of the
toxicological endpoint for sub-acute dietary exposure risk calculations.

Table 4  Avian Subacute Dietary Toxicity Data tc \l1 "Table 7. Avian
Subacute Dietary Toxicity Data 

Species	

% Active Ingredient	

LC50 

(confidence limits) (mg/kg-diet)	

MRID No.	

Classification

Northern bobwhite quail Colinus virginianus	

96	

>5000

(no mortality to 2500)	

40320812	

acceptable

Mallard duck Anas platyrhynchos	

96	

>5000 

(no mortality to 5000)

	

40320811	

acceptable

LC50: Lethal dietary concentration to 50% of test population

NOAEC: No observed adverse effect concentration	

Chronic Avian Exposure Effects tc \l3 "Chronic Avian Exposure Effects 

The results of avian reproduction testing are listed in Table 5.  The
northern bobwhite reproduction NOAEL of 500 mg/kg-diet serves as the
reproduction toxicity endpoint for avian reproduction risk calculations.
 This NOAEL is established with respect to the most sensitive toxicity
endpoint observed for the study, reduced survival of 14-day old
hatchlings from eggs set.

Table 5   Avian Reproduction Toxicity Data tc \l1 "Table 8. Avian
Reproduction Toxicity Data 

Species	

% Active Ingredient	

LOAEC

 (mg/kg-diet)	

NOAEC (mg/kg-diet)	

MRID No.	

Classification

Northern bobwhite quail Colinus virginianus	

99.19	

1000 (reduced 14 day survivors of egg set)	

500	

44129201	

acceptable

Mallard duck Anas platyrhynchos	

99.19	

>1000	

1000	

44084501	

acceptable 

LOAEC: Lowest observed adverse effect concentration

NOAEC: No observed adverse effect concentration	

Acute and Chronic Mammalian Toxicity tc \l3 "Acute and Chronic Mammalian
Toxicity 

Acute mammalian toxicity data are summarized in Table 6.  The most
sensitive acute endpoint is for the laboratory rat (Wistar strain), with
a minimum LD50 of 2190 mg/kg bodyweight.  

Table 6   Mammal Acute Toxicity Data tc \l1 "Table 9. Mammal Acute
Toxicity Data 

Species	

% Active Ingredient	

LD50

 (mg/kg)	

MRID No.	

Classification

Rat (Wistar)	

technical	

male: 3060

female: 2190	

41063506	

acceptable

Mouse (B6C3F1)	

technical	

>2000	

41063507	

acceptable

LD50: Lethal dose to 50% of test population

NOAEL: No observed adverse effect level

The following table summarizes the reproduction, and developmental
toxicity data for laboratory mammals chronically exposed to quinclorac. 
For the purposes of this risk assessment, the rat 2-generation
reproduction study NOAEL of 160 mg/kg-bw/day for reduced pup viability
was selected as the threshold for mammals chronically exposed to
quinclorac.  This value is quite similar to the threshold for rabbit
developmental data, in which the NOAEL for increased fetal resorptions
was 200 mg/kg-bw/day.

Table 7   Mammal Chronic, Reproduction, and Developmental Toxicity Data
tc \l1 "Table 10. Mammal Chronic, Reproduction, and Developmental
Toxicity Data 

Species	

% Active 	

Duration/

Study Type	

LOAEL

 (mg/kg-diet) or   

(mg/kg-bw/day)	

NOAEL 

(mg/kg-diet) or 

(mg/kg-bw/day)	

MRID No.	

Classification

Rat (Wistar)	

96.5	

3 month feeding	

12000 mg/kg-diet

slight nephritis	

4000 mg/kg-diet	

41063516	

supplemental

Rat (Wistar)	

96.5	

Developmental	

	

>438 

mg/kg-bw/day	

41063524	

minimum

Rabbit 	

98.3	

Developmental	

600 

mg/kg-bw/day 

increased fetal resorptions	

200 

mg/kg-bw/day	

41063525	

minimum

Rat (Wistar)	

97.40-

98.3	

2 generation reproduction	

480 

mg/kg-bw/day

reduced pup viability	

160 mg/kg-bw/day	

41063526

41910001	

minimum

LOAEL: Lowest observed adverse effect level

NOAEL: No observed adverse effect level

Beneficial Insect Toxicity tc \l3 "Beneficial Insect Toxicity 

The available studies of quinclorac effects on honeybees (Table 8)
indicate that technical quinclorac and the 50% formulation are
relatively non-toxic to bees on an acute contact basis

Table 8   Beneficial Insect Toxicity Data tc \l1 "Table 11. Beneficial
Insect Toxicity Data 

Species	

% Active Ingredient	

LD50

 (µg/bee)	

NOAEL (µg/bee)	

MRID No.	

Classification

Honeybee 

Apis mellifera	

98	

>357	

238	

41063575	

acceptable

Honeybee 

Apis mellifera	

50	

>181	

<60.4 (lowest dose tested)	

41063576	

acceptable

LD50: Lethal dose to 50% of test population

NOAEL: No observed adverse effect level

Terrestrial Plant Toxicity tc \l3 "Terrestrial Plant Toxicity 

 

Table 9   summarizes the available data for the effects of quinclorac on
terrestrial plants.  The toxicological threshold for seedling emergence
used in the risk assessment is based on the carrot EC25 of 0.004 lb
a.i./acre.  The toxicological threshold for vegetative vigor used in the
risk assessment is based on the tomato EC25 of 0.007 lb a.i./acre.

  

Table 9   Terrestrial Plant Toxicity Data tc \l1 "Table 17.  Terrestrial
Plant Toxicity Data 

Species	

% Active Ingredient	

Test Type	

EC25 

(lb a.i./acre)	

NOAEC

(lb a.i./acre)	

MRID No.	

Classification for all

Soybean

Glycine max	

96	

SE	

0.047	

<0.047	

41403501	

acceptable

	

96	

VV	

0.203	

0.125	

41403503

	

Lettuce

Lactuca sativa	

96	

SE	

0.013	

<0.01	

41403501

96	

VV	

0.01	

<0.01	

41403503

	

Carrot

Daucus carota	

96	

SE	

0.004	

<0.004	

41403501

96	

VV	

0.027	

0.02	

41403503

	

Tomato 

Lycopersion esculentum	

96	

SE	

0.026	

0.02	

41403501

96	

VV	

0.007	

0.005	

41403503

	

Cucumber

Cucumis sativus	

96	

SE	

0.012	

<0.012	

41403501

96	

VV	

0.028	

0.012	

41403503

	

Cabbage

Brassica oleracea	

96	

SE	

0.162	

0.125	

41403501

96	

VV	

26.0	

2.0	

41403503

	

Oat

Avena sativa	

96	

SE	

0.771	

<0.77	

41403501

96	

VV	

68.3	

2.0	

41403503

	

Ryegrass

Lolium perenne	

96	

SE	

0.271	

<0.27	

41403501

96	

VV	

>2.0	

2.0	

41403503

	

Corn

Zea mays	

96	

SE	

0.211	

<0.211	

41403501

96	

VV	

1.09	

0.5	

41403503

	

Onion

Allium cepa	

96	

SE	

0.118	

<0.118	

41403501

96	

VV	

12.33	

2.0	

41403503

	SE: seedling emergence

VV: vegetative vigor

EC25: Effective concentration for 25% reduction in emergence or growth
measures

NOAEL: no observed adverse effect level

Toxicity to Aquatic Animals tc \l2 "Toxicity to Aquatic Animals 

Freshwater Fish Acute Toxicity tc \l3 "Freshwater Fish Acute Toxicity 

The results for available acute toxicity testing with freshwater fish
(Table 10) indicate that quinclorac is slightly toxic to fish on an
acute basis.  The guideline requirement (72-1) is fulfilled.  The
bluegill sunfish LC50 of 31.6 mg/L is used as the acute freshwater
toxicity endpoint for the risk assessment.

Table 10   Freshwater Fish Acute Toxicity Data tc \l1 "Table 12.
Freshwater Fish Acute Toxicity Data 

Species	

% Active Ingredient	

LC50

(confidence limit)

 (mg/L)	

MRID No.	

Classification

Bluegill sunfish  

Lepomis macrochirus	

96	

31.6 (26.7-39.6)	

41063555	

acceptable

Rainbow trout 

Oncorhynchus mykiss	

96	

>83.5

(no mortality at highest dose tested)	

41063548	

acceptable

LC50: Lethal concentration to 50% of test population

NOAEC: No observed adverse effect concentration

Freshwater Fish Toxicity from Chronic Exposure tc \l3 "Freshwater Fish
Toxicity from Chronic Exposure 

The following table summarizes the available freshwater fish toxicity
data from chronic exposure.

Table 11   Freshwater Fish Chronic Toxicity Data (Early Life Stage
Study) tc \l1 "Table 13. Freshwater Fish Chronic Toxicity Data (Early
Life Stage Study) 

Species	

% Active Ingredient	

LOAEC

 (mg/L)	

NOAEC (mg/L)	

MRID No.	

Classification

Fathead minnow

Pimephales promelas	

technical	

31 (larval growth)	

16	

44084502	

acceptable

LOAEC: Lowest observed adverse effect concentration

NOAEC: No observed adverse effect concentration

Freshwater Invertebrate Acute Toxicity tc \l3 "Freshwater Invertebrate
Acute Toxicity 

Results of invertebrate toxicity testing are listed in Table 12.  The
results indicate that quinclorac is slightly toxic to aquatic
invertebrates on an acute basis.   The Daphnia magna EC50 of 29.8 mg/L
serves as the freshwater invertebrate toxicity endpoint for risk
assessment. A freshwater aquatic invertebrate toxicity test using the
technical grade of the active ingredient is required to assess the
toxicity of a pesticide to freshwater invertebrates.  Results of
invertebrate toxicity testing are listed in the table below.  The
results indicate that quinclorac is slightly toxic to aquatic
invertebrates on an acute basis.  The guideline requirement (72-2) is
fulfilled. 

Quinclorac was conducted on a formulated product (quinclorac plus
surfactant) instead of TGAI.  Therefore, use of the available acute data
as the toxicity endpoint for all freshwater systems represents an
uncertainty.

Table 12   Freshwater Invertebrate Acute Toxicity Data tc \l1 "Table 14.
Freshwater Invertebrate Acute Toxicity Data 

Species	

% Active Ingredient	

EC50

(confidence limit)

 (mg/L)	

MRID No.	

Classification

Daphnia magna	

96	

29.8 (23.8-42.4)	

41063556	

acceptable

EC50: Effective concentration to 50% of test population

NOAEC: No observed adverse effect concentration

Freshwater Invertebrate Toxicity from Chronic Exposure

 tc \l3 "Freshwater Invertebrate Toxicity from Chronic Exposure  

Data for freshwater invertebrate chronic toxicity are listed in Table
13.  The guideline requirement (72-4) is fulfilled.

The Daphnia magna 21-day NOAEC of 110 mg/L is used as the freshwater
invertebrate toxicity endpoint for chronic exposure.  It should be noted
that the 21-day NOAEC unexpectedly exceeds the 48-hour EC50 for the same
species.  This observation is likely the result of differences in test
water conditions, or as the result of surfactant use in the acute
toxicity test.  As quinclorac is an acid subject to dissociation in
water, differences in water hardness may influence the toxicity of the
compound.  The available data suggest that quinclorac is more toxic to
freshwater invertebrates in soft water (48-hour LC50= 28.9 mg/l in water
40-48 mg CaCO3/L) compared to harder water (21-day NOAEC 110 mg/l in
water >150 mg CaCO3/L).  An alternative explanation for the disparate
toxicity results may be the presence of surfactant in the acute test,
whereas no surfactant is evident for the chronic test.  The use of the
available 21-day chronic data as the toxicity endpoint for all
freshwater systems represents an uncertainty.

Table 13   Freshwater Invertebrate Chronic Toxicity Data (21-day life
cycle test) tc \l1 "Table 15. Freshwater Invertebrate Chronic Toxicity
Data (21-day life cycle test) 

Species	

% Active Ingredient	

LOAEC

 (mg/L)	

NOAEC (mg/L)	

MRID No.	

Classification

Daphnia magna	

technical	

>110	

110	

44129202	

acceptable

LOAEC: Lowest observed adverse effect concentration

NOAEC: No observed adverse effect concentration

Estuarine and Marine Animal Acute Toxicity tc \l3 "Estuarine and Marine
Animal Acute Toxicity 

Table 14 summarizes the data available for quinclorac effects on
estuarine and marine animals.  For the purposes of this risk assessment,
the sheepshead minnow LC50 of > 94.4 mg/L will be used as the acute
toxicity threshold for estuarine/marine fish and the mysid EC50 of 69.4
will serve as the threshold for estuarine/marine invertebrates.

Table 14   Estuarine and Marine Animal Acute Toxicity Data tc \l1 "Table
16. Estuarine and Marine Animal Acute Toxicity Data 

Species	

% Active Ingredient	

EC50/LC50

(confidence limit) (mg/L)	

MRID No.	

Classification

Sheepshead minnow

Cyprinodon variegatus	

96	

>94.4

(no mortality at highest dose)	

41063549	

core

Quahog clam

Mercenaria mercenaria	

96	

>96.1

(26% reduction in number of normal larvae at highest dose)	

41063552	

core

Mysid

Mysidopsis bahia	

96	

69.4 (50.4-118)	

41063553	

core

Blue crab

Callinectes sapidus 	

96	

>94.4

(no mortality at highest dose)	

41063551	

supplemental*

LC50: Lethal concentration to 50% of test population

EC50: Effective concentration to 50% of test population

NOAEC: No observed adverse effect concentration

*not listed acceptable test species

Estuarine and Marine Animal Toxicity from Chronic Exposure tc \l3
"Estuarine and Marine Animal Toxicity from Chronic Exposure 

No data are available for the toxicity of quinclorac to estuarine and
marine animals following chronic exposures.  

Aquatic Plant Toxicity tc \l3 "Aquatic Plant Toxicity 

Table 15 summarizes the available aquatic plant toxicity data for
quinclorac

Table 15   Aquatic Plant Toxicity Data tc \l1 "Table 18. Aquatic Plant
Toxicity Data 

Species	

% Active Ingredient	

EC50

 (mg/L)	

NOAEC (mg/L)	

MRID No.	

Classification

Freshwater diatom

Navicula pelliculosa	

96	

>0.5	

0.5	

41063574	

acceptable

Green alga

Selenastrum capricornutum	

96	

>0.5	

0.5	

41063574

	

Marine diatom

Skeletonema costatum	

96	

>0.5	

0.5	

41063574

	

Duckweed

Lemna gibba	

96	

>0.5	

0.5	

41063574

	

Bluegreen alga

Anabaena flos-aquae 	

96	

>0.5	

0.5	

41063574

	EC50: Effective concentration for 50% inhibition

NOAEC: No observed adverse effect concentration

11.3.	Preliminary Identification of Data Gaps for Fate and Ecological
Assessment

Table 16 identifies fate and ecological studies which are missing or are
not acceptable, and may be requested to assess risk to the environment:

  TC \l3 "		Preliminary Identification of Data Gaps and Methods 

Table 16   Preliminary Identification of Data Gaps for Fate and
Ecological Assessment

Fate and Ecological Taxa studies	Description of study	Projected status
of data gap	Basis for decision

Chronic freshwater invertebrate	Chronic freshwater invertebrate NOAEC
value was greater than the acute LD50 value for freshwater aquatic
invertebrates	Study requested	A new study is requested due to
uncertainties with the NOAEC value which is greater than the acute LD50
value for freshwater aquatic invertebrates. 

 In addition, this study will be used to estimate chronic estuarine
marine invertebrate toxicity 

Acute freshwater invertebrate	Acute  freshwater invertebrate study used
a surfactant which it is uncertain that this surfactant effected the
results of the  toxicity  test	Study  requested	 A new study is
requested due to uncertainties with the LD 50 value which is less than
the chronic NOAEC value for freshwater aquatic invertebrates. In
addition, this study was based on a formulated product (quinclorac and
surfactant). 

This study will be used to estimate chronic estuarine marine
invertebrate toxicity

Estuarine/marine fish	Chronic study for estuarine/marine fish  was not
submitted	Study not requested 	Acute to chronic ratios will be
sufficient to not request study 

 

Estuarine/marine invertebrate	Chronic study for estuarine/marine
invertebrate  was not submitted	Study not requested 	Acute to chronic
ratios will be sufficient to not request study pending a chronic
freshwater invertebrate daphnia magna study based on TGAI . 

 

 Data on  the degradates (BH514-1 and BH 514 2-OH; >10% applied)) and
one minor (BH514-HMe-ester; 8% applied)   to determine risks to
groundwater

	The registrant claimed that studies performed later between 1989 and
1990 in FL, WI, and NY showed no movement of quinclorac degradates below
surface levels	Studies requested	The degradates  (BH514-1 and BH 514
2-OH; >10% applied)) and one minor (BH514-HMe-ester; 8% applied) studies
have not yet been received nor reviewed by EFED.  Until these studies
which were performed 1989-1990 are submitted, reviewed, and deemed
acceptable by the Agency, the above mentioned metabolites are considered
potential contaminants of groundwater resources.  

Foliar dissipation residue data	Foliar dissipation data studies or
related data  were not available	  Study not requested	Acute and chronic
mammal exceedences did not occur with LD50 and NOAEC values. Acute avian
LOCs occurred with the non-definitive LD50 of  >1900 mg/kg-bw. Fate
studies indicate that half-lives may be greater than one year. 

 Therefore,A default foliar dissipation rate of 35 days will be used in
the modeling in place of the data if study is not submitted.   

Small scale prospective groundwater contamination study	Small scale
prospective groundwater contamination study for the quinclorac under the
expected conditions of  the currently registered crops.	Study requested
Based on the environmental persistence of quinclorac, its potential to
enter groundwater as modeled by SCI-GROW and indicated in terrestrial
field studies, the potential for groundwater impacts to non-target crops
via contaminated groundwater a small scale prospective groundwater a
contamination study for the compound under the expected conditions of
use in wheat and sorghum is requested

.   

	

	12.	OPEN LITERATURE

Previous assessments did not include open literature data as identified
by ORD, MED ECOTOX literature search program.

13.	NEW ASSESSMENT DECISION

EFED needs additional data (or will apply alternate effects assumptions)
and would need to conduct new assessments for all registered outdoor
uses.  The new assessments are needed because of the following:

(a)  Some uses and application type scenarios were not assessed for
ecological risk or

      did not include current terrestrial or aquatic models.  

 

(b)	Open literature data, as identified by ORD, MED ECOTOX literature
search program, were not included in previous assessments.

 

            (dc)   A new drinking water assessment needs to be completed
based on a 14 day interval 

                    and aerial applications. 

SUMMARY OF RISK

Summary of risks identified from previous assessments and anticipated
risks for maximum use rate application scenarios. 

Estimated LOC exceedences for are summarized in Table 17 below.  The
risk conclusions are based on previously conducted risk assessments and
anticipated exceedences for maximum use rates. The most recent
comprehensive risk assessment was conducted on wheat and sorghum (1999).
The most recent EUP was conducted on aquatic weed control in impounded
waters (2007). The label maximum single application rates for
quinclorac: (1) wheat and sorghum with a maximum seasonal rate of 0.75
lb ai /acre (2 applications @ 0.375lb ai/A, intervals were not included
in terrestrial RQ calculations); (2) aquatic weed control with a maximum
seasonal rate of 3.0 lb ai /acre.  Acute dose based for avian exposure
to quinclorac exceeded the LOCs with RQs ranging from 0.12- 0.83 for the
both of the above application scenarios. Terrestrial plant RQs exceeded
the LOCs for the wheat, sorghum and aquatic weed control application
scenarios with RQs ranging 1 to 40. 

Nonvascular and vascular plants exceeded the LOCs for the aquatic weed
control scenario with RQs exceedences of 1.0.  LOCs were exceeded for
acute mammalian exposure with the maximum RQ of 0.14 for aquatic weed
control scenarios. Chronic LOCs were exceeded for mammals and birds for
the aquatic weed control scenario with a maximum RQs of 1.95 (mammals)
and 1.4 (birds).

 Anticipated LOCs are based on the maximum use and application rate for
quinclorac for turf at 1.50 lb ai/A (2 applications@ 0.75 lb ai/A and 14
day intervals). Anticipated LOC exceedences from the above maximum use
rate are for acute birds (RQs 0.16- 0.37) and acute terrestrial plants
(RQs 2.33- 95.63) for monocots and dicots. The acute avian LOC
exceedence was based on the non-definitive LD50 value of >1900 mg/kg-bw.
 It is necessary that these exceedences derived from the non-definitive
LD50 value of >1900 will be characterized with additional data in future
assessments.  No chronic avian LOC exceedences occurred with higher
application rates. 

Aquatic EECs for the maximum application rates for labeled crops and
additional GENEEC scenarios need to be determined. However, no acute or
chronic exceedences are anticipated for aquatic fish or invertebrates.
Uncertainty exists for chronic risks to estuarine marine invertebrates
until further data is submitted. Chronic risks to estuarine marine fish
will be estimated from acute to chronic ratios.  LOC exceedences for
aquatic plants based on direct application to impounded waters result in
RQs of 1.0.  

Table 17  LOC Exceedences from Use on Wheat, Sorghum, Turf and Aquatic
weed control. 

Use	Endpoint	Birds	Mammals	Terr.

Plants	Insects	FW fish	SW Fish	FW

Inverts	SW

Inverts	Aquatic

Plants

Turf 

1.50 lb ai/A

per season

2applications @0.75 per app, 14 day interval)	Acute 	( based on
non-definitive value

  ((listed and nonlisted)

	Reproductive

 

	Wheat and sorghum

0.75lb ai/A

per season1	Acute 	( based on non-definitive value

((listed and nonlisted)

	Reproductive

	Aquatic weed control

3 lbs a.i./season1,2	Acute 	( based on non-definitive value	(	 ((listed
and nonlisted)

(  (listed)

	Reproductive	(	(

	1All risk conclusions are based on previously conducted risk
assessments  Degradate toxicity was not      

   included. 

2This EUP  was based on aquatic weed control applied at 3lbs ai/season
to reach a water concentration of 0.5mg/L                       

(       Risk is anticipated to be > any of the Agency’s LOC

           Blank cells indicate no LOC exceedences

         

Aquatic Organisms

Based on the (GENEEC) modeling, the 1999 risk assessment on turf showed
no acute LOC exceedence for aquatic organisms.   The highest modeled
application rate scenario for the above crops was turf, which was based
on 2 ground applications at a single rate of 0.375 lb ai/acre. 

The peak EEC is selected to represent exposures for acute effect risks. 
The 56-day and 21-day average EECs serve as the exposures for chronic
effects to fish and invertebrates, respectively.

 Tables 18 to 22 summarizes the quinclorac RQs, EECs ((peak), (21-day),
(56-day)) and the toxicity data used in the 1999 assessment on turf with
ground and aerial applications.   No acute or chronic LOCs were exceeded
for the exposure scenarios assessed.  There are no estuarine/marine
organism toxicity data from chronic exposures available for use in
calculating chronic risk quotients for these organisms.  However, the
similar acute sensitivities of these organisms to freshwater fish and
invertebrates, coupled with the very low chronic risk quotients
calculated for freshwater organisms; suggests that chronic risk concerns
for estuarine and marine fish and invertebrates are likely to be
minimal.

Table 18   Acute and Chronic Risk Quotients for Freshwater Fish tc \l1
"Table 28.  Acute and Chronic Risk Quotients for Freshwater Fish 

Product1/ Application Method	

Peak EEC (µg/L)	

LC50 (µg/L)	

Acute RQ

(Peak EEC/LC50)	

56-day EEC (µg/L)	

NOAEC (µg/L)	

Chronic RQ

(56-d EEC/NOAEC)

ParamountTM/Aerial

90 and 14-day intervals	

40.28	

31,600	

0.0013	

40.17	

16,000	

0.0025

	

40.28	

31,600	

0.0013	

40.17	

16,000	

0.0025

ParamountTM/

Ground Spray 

90 and 14-day intervals	

40.20	

31,600	

0.0013	

40.10	

16,000	

0.0025

	

40.20	

31,600	

0.0013	

40.10	

16,000	

0.0025

ParamountTM BW/

Aerial 1 application	

13.16	

31,600	

0.0004	

13.11	

16,000	

0.0008

ParamountTM BW/

Ground Spray 1 application	

13.13	

31,600	

0.0004	

12.10	

16,000	

0.0008

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

2,4-D component of this product.

Table 19   Acute and Chronic Risk Quotients for Freshwater Invertebrates
tc \l1 "Table 29.  Acute and Chronic Risk Quotients for Freshwater
Invertebrates 

Product1/ Application Method	

Peak EEC (µg/L)	

LC50 (µg/L)	

Acute RQ

(Peak EEC/LC50)	

21-day EEC (µg/L)	

NOAEC (µg/L)	

Chronic RQ

(21-d EEC/NOAEC)

ParamountTM/Aerial

90 and 14-day intevals	

40.28	

29,800	

0.0014	

40.23	

110,000	

0.0004

	

40.28	

29,800	

0.0014	

40.23	

110,000	

0.0004

ParamountTM/

Ground Spray

90 and 14 day intervals	

40.20	

29,800	

0.0013	

40.16	

110,000	

0.0004

	

40.20	

29,800	

0.0013	

40.16	

110,000	

0.0004

ParamountTM BW/

Aerial	

13.16	

29,800	

0.0004	

13.14	

110,000	

0.0001

ParamountTM BW/

Ground Spray	

13.13	

29,800	

0.0004	

13.12	

110,000	

0.0001

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

2,4-D component of this product.

Table 20   Acute and Chronic Risk Quotients for Estuarine/Marine Fish tc
\l1 "Table 30.  Acute and Chronic Risk Quotients for Estuarine/Marine
Fish 

Product1/ Application Method	

Peak EEC (µg/L)	

LC50 (µg/L)	

Acute RQ

(Peak EEC/LC50)	

56-day EEC (µg/L)	

NOAEC (µg/L)	

Chronic RQ

(56-d EEC/NOAEC)2

ParamountTM/Aerial

90 and 14-day intervals	

40.28	

>94,400	

<0.0004	

40.17	

no data	

--

	

40.28	

>94,400	

<0.0004	

40.17	

no data	

--

ParamountTM/

Ground Spray

90 and 14-day intervals	

40.20	

>94,400	

<0.0004	

40.10	

no data	

--

	

40.20	

>94,400	

<0.0004	

40.10	

no data	

--

ParamountTM BW/

Aerial	

13.16	

>94,400	

<0.0001	

13.11	

no data	

--

ParamountTM BW/

Ground Spray	

13.13	

>94,400	

<0.0001	

12.10	

no data	

--

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

  2,4-D component of this product.

2 -- lack of toxicity data precludes calculation of quotient

Table 21   Acute and Chronic Risk Quotients for Estuarine/Marine
Invertebrates tc \l1 "Table 31.  Acute and Chronic Risk Quotients for
Estuarine/Marine Invertebrates 

Product1/ Application Method	

Peak EEC (µg/L)	

LC50 (µg/L)	

Acute RQ

(Peak EEC/LC50)	

21-day EEC (µg/L)	

NOAEC (µg/L)	

Chronic RQ

(21-d

EEC/NOAEC)2

ParamountTM/Aerial

90 and 14-day intervals	

40.28	

69,400	

0.0006	

40.23	

no data	

--

	

40.28	

69,400	

0.0006	

40.23	

no data	

--

ParamountTM/

Ground Spray

90 and 14-day intervals	

40.20	

69,400	

0.0006	

40.16	

no data	

--

	

40.20	

69,400	

0.0006	

40.16	

no data	

--

ParamountTM BW/

Aerial	

13.16	

69,400	

0.0002	

13.14	

no data	

--

ParamountTM BW/

Ground Spray	

13.13	

69,400	

0.0002	

13.12	

no data	

--

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

  2,4-D component of this product.

2 -- lack of toxicity data precludes calculation of quotient

Table 22   Aquatic Plant Risk Quotients tc \l1 "Table 34.  Aquatic Plant
Risk Quotients 

Product1/ Application Method	

Peak EEC (µg/L)	

Alga EC50 (µg/L)	

Lemna gibba 

EC50 (µg/L)	

Lemna gibba NOAEC (µg/L)	

Algal RQ2

 	

Acute

Aquatic Vascular Plant RQ3 	

Endangered Aquatic Plant RQ4

ParamountTM/Aerial

90 and 14-day intervals	

40.28	

>500	

>500	

500	

<0.081	

<0.081	

0.0806

	

40.28	

>500	

>500	

500	

<0.081	

<0.081	

0.0806

ParamountTM/

Ground Spray

90 and 14-day intervals	

40.20	

>500	

>500	

500	

<0.080	

<0.080	

0.0804

	

40.20	

>500	

>500	

500	

<0.080	

<0.080	

0.0804

ParamountTM BW/

Aerial	

13.16	

>500	

>500	

500	

<0.026	

<0.026	

0.0263

ParamountTM BW/

Ground Spray	

13.13	

>500	

>500	

500	

<0.026	

<0.026	

0.0263

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

  2,4-D component of this product.

2 EEC/alga EC50

3 EEC/Lemna gibba EC50

4 EEC/Lemna gibba NOAEC

Terrestrial Organisms

Risk Assessment for Nontarget Terrestrial Animals

 tc \l2 "Risk Assessment for Nontarget Terrestrial Animals 

Avian Acute and Chronic Risks tc \l3 "Avian Acute and Chronic Risks 

The acute and chronic risk quotients for broadcast applications of
quinclorac formulations are listed in Tables 23 and 24 based on the 1999
risk assessment for a single seasonal application rate of 0.25 lb ai/A
and 0.75 lb ai/A .   No levels of concern (LOCs) are exceeded under the
exposure scenarios assessed. 



Table 23  Avian Acute Risk Quotients for Single Application of
Quinclorac Products (Aerial and Ground Spray) Based on a Northern
Bobwhite Quail LC50 of >5000 mg/kg-diet tc \l1 "Table 24.  Avian Acute
Risk Quotients for Single Application of Quinclorac Products (Aerial and
Ground Spray) Based on a Northern Bobwhite Quail LC50 of >5000
mg/kg-diet  

Product1 	

Application

Rate 

(lbs ai/A)	

Food Items	

Maximum EEC (mg/kg-diet)	

LC50 (mg/kg-diet)	

Acute RQ

(EEC/LC50)

ParamountTM	

0.75

per season	

Short

grass	

180	

>5000

	

<0.036

Tall

grass	

82.5	

>5000	

<0.017

Broadleaf

plants/Insects	

101.3	

>5000	

<0.020

Seeds	

11.3	

>5000	

<0.002

ParamountTMDW	

0.25

 per season	

Short

grass	

60.0	

>5000

	

<0.012

Tall

grass	

27.5	

>5000	

<0.006

Broadleaf

plants/Insects	

33.8	

>5000	

<0.007

Seeds	

3.8	

>5000	

<0.001

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

2,4-D component of this product.



Table 24  Avian Chronic Risk Quotients for Single Application of
Quinclorac Products (Aerial and Ground Spray Based on a Northern
Bobwhite Quail NOAEC of 500 mg/kg-diet) tc \l1 "Table 25.  Avian Chronic
Risk Quotients for Single Application of Quinclorac Products (Aerial and
Ground Spray Based on a Northern Bobwhite Quail NOAEC of 500 mg/kg-diet)

Product1	

Application

Rate 

(lbs ai/A)	

Food Items	

Maximum EEC

 (mg/kg-diet)	

NOAEC (mg/kg-diet)	

Chronic RQ

(EEC/NOAEC)

ParamountTM	

0.75 per season	

Short

grass	

180	

500

	

0.36

Tall

grass	

82.5	

500	

0.17

Broadleaf

plants/Insects	

101.3	

500	

0.20

Seeds	

11.3	

500	

0.02

ParamountTMBW	

0.25 per season	

Short

grass	

60.0	

500

	

0.12

Tall

grass	

27.5	

500	

0.06

Broadleaf

plants/Insects	

33.8	

500	

0.07

Seeds	

3.8	

500	

0.01

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

2,4-D component of this product.

Mammalian Acute and Chronic Risks tc \l3 "Mammalian Acute and Chronic
Risks 

Mammalian acute risk quotients were calculated using the daily oral dose
estimates for a 15 g mammal consuming 95% of its bodyweight as diet and
the LD50 for laboratory rats.  The results of these calculations are
expressed in terms of LD50s per day.   Table 25 summarizes the results
of these risk quotient calculations.  None of the acute risk quotient
results exceed EFED levels of concern.

 Mammalian chronic risk quotients were calculated using the daily oral
estimates for the same 15 g mammal and the daily oral dose corresponding
to the NOAEL for reproduction effects in laboratory rats.  Table 26
summarizes the results of these risk quotients calculations based on the
1999 assessment.  In all cases, except for consumption of short grass
(RQ = 1.07), the EFED level of concern was not exceeded.

 



Table 25  Mammalian Acute Risk Quotients for Application of Quinclorac
Products (Aerial and Ground Spray Based on a Laboratory Rat LD50 of 2190
mg/kg-bw tc \l1 "Table 26.  Mammalian Acute Risk Quotients for
Application of Quinclorac Products (Aerial and Ground Spray Based on a
Laboratory Rat LD50 of 2190 mg/kg-bw  

Product1	

Application

Rate 

(lbs ai/A)	

Food Items	

Daily Oral Dose 

(mg/kg-bw/day)	

LD50 

(mg/kg-bw)	

Acute RQ

(LD50/day or

Dose/LD50)

ParamountTM	

0.75 per season	

Short

grass	

171.6	

2190

	

0.08

Tall

grass	

78.7	

2190	

0.04

Broadleaf

plants/Insects	

96.5	

2190	

0.04

Seeds	

10.7	

2190	

0.005

ParamountTMDW	

0.25 per season	

Short

grass	

57.2	

2190

	

0.03

Tall

grass	

26.2	

2190	

0.01

Broadleaf

plants/Insects	

32.2	

2190	

0.01

Seeds	

3.6	

2190	

0.002

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

2,4-D component of this product.

Table 26   Mammalian Chronic (Reproduction) Risk Quotients for
Application of Quinclorac Products (Aerial and Ground Spray Based on a
Laboratory Rat NOAEL of 160 mg/kg-bw/day tc \l1 "Table 27.  Mammalian
Chronic (Reproduction) Risk Quotients for Application of Quinclorac
Products (Aerial and Ground Spray Based on a Laboratory Rat NOAEL of 160
mg/kg-bw/day 

Product1	

Application

Rate 

(lbs ai/A)	

Food Items	

Daily Oral Dose 

(mg/kg-bw/day)	

NOAEL

(mg/kg-bw/day)	

RQ

(Dose/NOAEL)

ParamountTM	

0.75 per season	

Short

grass	

171.6	

160

	

1.07

Tall

grass	

78.7	

160	

0.49

Broadleaf

plants/Insects	

96.5	

160	

0.60

Seeds	

10.7	

160	

0.067

ParamountTMBW	

0.25 per season	

Short

grass	

57.2	

160

	

0.36

Tall

grass	

26.2	

160	

0.16

Broadleaf

plants/Insects	

32.2	

160	

0.20

Seeds	

3.6	

160	

0.023

1 Risks for ParamountTMBW are for the quinclorac component alone, no
assessment has been performed for the 

2,4-D component of this product.

Risks to Beneficial Insects tc \l2 "Risks to Beneficial Insects 

Currently, EFED has no procedure for assessing risk to nontarget
insects.  However, the results of acceptable toxicity studies are used
for recommending appropriate label precautions.  The relatively
non-toxic nature of quinclorac with respect to honeybees suggests no
concern that quinclorac will directly impact beneficial insects. 

15.	RESIDUES OF  QUINCLORAC  IN WATER AND THE TERRESTRIAL ENVIRONMENT

 drinking water residue profile  TC "5.2.  drinking water residue
profile" \f C \l "2"  

The Agency does not have monitoring data available to perform a
quantitative drinking water risk assessment for quinclorac at this time 

A Tier II screening-level drinking water assessment for quinclorac
(3,7-dichloro-8-quinolinecarboxylic acid , BAS 514-H was  provided in
support of the new proposed uses of this herbicide to control broadleaf
and grass weeds on residential/commercial turf grasses and on other turf
grasses (picnic grounds, athletic field, and sod farms) (see September
13, 2007,  Estimated Drinking Water Assessment for Quinclorac
(3,7-dichloro-8-quinolinecarboxylic acid,  CAS# 84087-01-4) Use on
Turfgrasses  DPBarcode: 341487) 

EFED believes that quinclorac has the potential for movement into ground
water.  Furthermore, since quinclorac is not tightly bound to soils, it
could be available to run off in surface water as well as by erosion to
surface waters.  Tables 27 and 28 list the EDWCs of quinclorac residues
in surface and ground water, respectively, as reported in the
aforementioned drinking water assessment. These concentrations are based
on the current environmental fate data for quinclorac, the maximum use
rate from registered and proposed uses (Drive 75DF Herbicide label turf
use, 2 to 3 applications of 0.25 – 0.75 lb ai/A/ appl at 21-day
interval, not to exceed 1.5 lb ai/A per year) and EFED aquatic models
(PRZM/EXAMS for surface water and SCI-GROW for ground water. 

Quinclorac major degradation products such as BH 514-1 and BH 514 2-OH
were not considered in this assessment.  Although these degradates were
detected in the laboratory studies, they seem to be intermediate
degradates (see Environmental Fate section), and were not found in the
terrestrial field dissipation studies at any significant levels (>10% of
total applied). Furthermore, since quinclorac is persistent and mobile,
it is expected to be the predominant residue in ground and surface
waters.

Table 27 – Surface Water DWECs for Quinclorac use on Turfgrasses,
ground application

Scenario	Surface Water EWDCs (µg/L)

	1 in 10 year annual peak

(acute)	1 in 10 year annual mean

(chronic)	30 year annual mean

(cancer)

PCA / CAF 	1.00*	0.82**	1.00	0.82	1.00	0.82

0.5 lb ai/A, 3 appl, 21 days apart

PA Turf – pre emergence

PA Turf – post emergence

FL Turf – pre-emergence

FL Turf – post emergence

0.75 lb ai/A, 2 appl, 21 days apart 

PA Turf – post emergence

FL Turf – post emergence

	

17.5

21.2

17.9

22.9

22.5

21.4	

14.3

17.4

14.7

18.8

18.5

17.5

    	

12.3

14.5

10.7

12.7

14.2

11.6	

10.1

11.9

8.8

10.4

11.6

9.5	

8.7

10.3

6.3

7.1

9.9

6.9	

7.1

8.4

5.2

5.8

8.1

5.7

*Results with PCA of 1 can be used for other turf use, such as picnic
grounds, athletic fields, sod farms, … 

**Results adjusted with CAF of 0.82 represents the maximum percent
treated on turf, residential and commercial use.  This assumes four
houses of 2000ft2 each per acre and does not take into account driveway,
sidewalk, or porches, …

Note that the EDWCs were estimated for both pre and post emergence uses
for the 0.5 lb ai/A applications.  The differences between the two sets
of data result from the method of application (soil applied vs. foliar
applied) and the application dates.  Only post emergence uses are
allowed for the 0.75 lb ai/A applications. 

Table 28 - Ground Water EDWCs for Quinclorac use on Turfgrasses (3
applications of 0.5 lb ai/A/application)

Ground Water EDWCs (µg/L) (3 appl of 0.5 lb ai/A/appl) 

Ground Water EDWCs (µg/L) (2 appl of 0.75 lb ai/A/appl) 

	

29.0

28.9

The groundwater concentrations generated by SCI-GROW are based on the
largest 90-day average recorded during the sampling period.  Since there
is relatively little temporal variation in groundwater concentrations
compared to surface water, the concentration of 29µg/L can be
considered as both the acute and chronic values.

Although current uses also include aerial applications with an assumed
shorter re-application interval (14 days) on certain crops (sorghum,
wheat, non agricultural rights of way/ fence row/ hedgerows,
agricultural fallowland/idleland, grasses grown for seed), it is not
expected that the EDWCs from these crops will exceed those reported from
turf use as listed in above Tables 28 and 29.  Granular applications do
not need to be incorporated in the drinking water assessment because the
application rates are less than ground and aerial spray applications.  

Chemical structures for quinclorac are summarized in Table 29.

  Table 29  Chemical name and structure of  quinclorac and its
degradates BH514-1 and 

 

 

 

Table 30 list all the current registrations and EUPs based on BEAD
information 2007.

Table 30   Current Registrations and EUPs  for Quinclorac based on BEAD
information (2007)

  HYPERLINK "javascript:sortUpdate(document.sort,'8')"  Registration # 
Name	Status	  HYPERLINK "javascript:sortUpdate(document.sort,'5')" 
Company Name 	  HYPERLINK "javascript:sortUpdate(document.sort,'6')" 
Percent Active Ingredient 

228-423	DQD SELECTIVE HERBICIDE	Conditionally Registered (06-Apr-2005)
NUFARM AMERICAS INC.	7.91

228-531	NUP 12D02 HERBICIDE	Conditionally Registered (24-Aug-2007)
NUFARM AMERICAS INC.	8.25

239-2689	LAWN CRABGRASS AND WEED KILLER	Conditionally Registered
(03-Sep-2004)	THE ORTHO BUSINESS GROUP	0.1

538-296	TURF BUILDER WITH WEED CONTROL III	Conditionally Registered
(09-Dec-2002)	SCOTTS COMPANY, THE	0.52

1381-209	QUINCLORAC 75 DF	Registered (11-Oct-2006)	WINFIELD SOLUTIONS,
LLC	75

2217-885	EH-1426 HERBICIDE	Conditionally Registered (18-Jan-2006)
PBI/GORDON CORP	3.49

2217-886	EH-1427 HERBICIDE	Conditionally Registered (18-Jan-2006)
PBI/GORDON CORP	5.69

2217-887	EH-1428 HERBICIDE	Conditionally Registered (18-Jan-2006)
PBI/GORDON CORP	0.121

2217-888	EH-1425 HERBICIDE	Conditionally Registered (18-Jan-2006)
PBI/GORDON CORP	8.38

2217-894	EH-1432 HERBICIDE	Conditionally Registered (21-Apr-2006)
PBI/GORDON CORP	1.61

2217-896	EH-1437 HERBICIDE	Conditionally Registered (25-Aug-2006)
PBI/GORDON CORP	2.13

2217-901	EH-1434 HERBICIDE	Conditionally Registered (30-Jan-2007)
PBI/GORDON CORP	5.65

2217-906	EH-1449 HERBICIDE	Conditionally Registered (27-Aug-2007)
PBI/GORDON CORP	0.104

7969-93	FACET 50 WP	Conditionally Registered (13-Oct-1992)	BASF
CORPORATION	50

7969-109	QUINCLORAC MANUFACTURING USE PRODUCT	Conditionally Registered
(28-Oct-1992)	BASF CORPORATION	98

7969-113	FACET 75 DF HERBICIDE	Registered (09-Nov-1994)	BASF CORPORATION
75

7969-130	DRIVE 75 DF HERBICIDE	Conditionally Registered (09-Nov-1998)
BASF CORPORATION	75

7969-152	PARAMOUNT BW HERBICIDE	Conditionally Registered (04-Jun-1999)
BASF CORPORATION	15

7969-158	FACET GR HERBICIDE 46	Conditionally Registered (27-Apr-1998)
BASF CORPORATION	1.5

7969-172	DRIVE 75 MANUFACTURERS CONCENTRATE	Conditionally Registered
(10-Dec-1998)	BASF CORPORATION	75

7969-222	CLEARPATH HERBICIDE	Registered (12-Jul-2004)	BASF CORPORATION
61.98

34704-920	QUINCLORAC 75DF HERBICIDE	Conditionally Registered
(03-Mar-2006)	LOVELAND PRODUCTS, INC.	75

42750-85	QUINCLORAC TECHNICAL	Conditionally Registered (10-Oct-2005)
ALBAUGH INC	99

42750-88	QUINCLORAC 75DF AG	Conditionally Registered (10-Oct-2005)
ALBAUGH INC	75

42750-90	QUINCLORAC 75DF SP	Conditionally Registered (10-Oct-2005)
ALBAUGH INC	75

42750-131	QUINCLORAC 75 SWF	Conditionally Registered (06-Feb-2006)
ALBAUGH INC	75

71085-26	RICEPRO	Registered (13-Mar-2007)	RICECO LLC	2

73220-15	QUALI-PRO QUINCLORAC 75	Registered (02-Oct-2007)	FARMSAVER.COM,
LLC	75

79676-22	QUINCLORAC G-PRO 75 DF	Conditionally Registered (14-Dec-2005)
GRO-PRO, LLC	75

81927-21	ALLIGARE QUINCLORAC 75 WDG	Registered (18-Oct-2007)	ALLIGARE,
LLC	75

AR070006	RICEPRO	Under Review (07-May-2007)	RICECO LLC	2

UT990003	FACET 75 DF HERBICIDE	Registered (20-Sep-1999)	BASF CORPORATION
75

7969-EUP-25	 	Issued (20-Mar-1991)	BASF CORPORATION	100

7969-EUP-27	 	Issued (14-Jan-1991)	BASF CORPORATION	50

7969-EUP-29	 	Issued (22-May-1991)	BASF CORPORATION	50

7969-EUP-40	 	Issued (23-May-2007)	BASF CORPORATION	75

98ND20	 	Issued (19-Sep-1998)	ND Dept. of Agriculture	 

98NE07	 	Issued (25-Jun-1998)	NE Department of Agriculture	 

V. Human Health Effects Scoping Document

 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

MEMORANDUM

Date: September 26, 2007

SUBJECT:	Quinclorac (PC code 128974).  Human Health Risk Problem
Formulation Document in Support of Registration Review.  DP Barcode
344486.

FROM:	Yan Donovan, Risk Assessor

		Health Effects Division (7509P)

		Office of Pesticide Programs

THRU:	Ray Kent, Branch Chief

		Susan Hummel, Senor Scientist

		Reregistration Action Branch 4

		Health Effects Division (7509P)

		Office of Pesticide Programs

TO:	Sherrie Kinard

		Chemical Review Manager

		Special Review and Reregistration Division (7508P)

		Office of Pesticide Programs

Executive Summary

Attached is Health Effects Division’s (HED) human health risk
assessment status update for quinclorac as part of the Registration
Review process.  Quinclorac is a systemic herbicide currently registered
for use on rice, sorghum, and wheat.  It is also registered for use on
residential lawns, ornamentals, and turf grass.  The most recent
comprehensive risk assessment for quinclorac was conducted in
association with the establishment of import tolerance on barley
(September, 2007).  The toxic effects being regulated are developmental
effects such as increased resorptions and post-implantation loss,
decreased number of live fetuses, and reduced fetal body weight. 
Chronic effects include decreased body weights.  Based on the 2005
Guidelines for Carcinogen Risk Assessment, quinclorac was tentatively
classified as "Not likely to be carcinogenic to humans" since only
benign tumors were seen in only one sex and in one species.  Aggregate
risk assessments included dietary exposure (food + water) and
residential post-application exposure from use on grass.  Risk estimates
were based on conservative, health-protective assumptions and the
resulting aggregate risk estimates are not of concern.  Neither
residential handler nor occupational risks were assessed.   

HED’s problem formulation conclusions are: 1) The toxicology endpoint
selections are adequate.  However, the toxicology database for
quinclorac is incomplete at this time.  A 90-day inhalation toxicity
study in the rat is required to assess inhalation exposure from spray
uses.  2)  The dietary exposure database is complete. However, the newly
submitted aspirated grain fraction (AGF) studies on wheat and sorghum
have not been reviewed.  A full review of these AGF studies is needed. 
AGF and livestock tolerances may need to be revised based on the review
of the AGF studies. The drinking water assessment is adequate.  The
dietary exposure assessment (included food and water) is adequate.  3)
The residential post application exposure assessment is adequate. 
However, no residential handler risks were assessed; therefore, a new
residential handler assessment is needed for the Registration Review of
quinclorac.  4) Aggregate risk assessment is adequate.  5) No
occupational risk assessments have been conducted before.  A new
occupational assessment is required for Registration Review.



Introduction

HED has evaluated the existing human health risk assessments for
quinclorac to determine whether sufficient data are available and
whether a new human health risk assessment is needed to support
Registration Review.  HED has considered the most recent risk
assessments for quinclorac (HED memo of 9/13/2007, M. Doherty, D325790,
and HED memo of 12/15/98, M. Nelson, D238399), updates to its toxicity,
exposure and usage databases, information available through HED and
OPPIN database, literature search, and current Agency science policies
and risk assessment methods.  Quinclorac is a persistent and mobile,
systemic herbicide currently registered for use on weed control in rice,
sorghum, and wheat.  It is also registered for use on residential lawns,
ornamentals, and turf grass.  The mechanism of action of herbicidal
effects is not completely understood.  Permanent tolerances are
currently established for parent quinclorac per se in/on rice, sorghum,
wheat, and livestock commodities [40 CFR 180.463].  Some quinclorac
products also contain other active ingredients such as
2,4-dichlorophenoxyacetic acid [2,4-D]. The problem formulation
conducted in this review is for quinclorac only.

Chemical Identity

 

Common name	Quinclorac

Empirical formula	C10H5Cl2NO2

Molecular weight	242.1

PC Code	128974

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

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

CAS registry number	84087-01-4

	

Hazard Identification/Toxicology

Quinclorac (technical grade material) has a low order of acute toxicity
as demonstrated by classification into Toxicity Category III by the
oral, dermal, and inhalation routes. The chemical is a mild eye
irritant, is not a skin irritant, but was positive for dermal
sensitization. Subchronic toxicity includes decreased body weight gains,
increased water intake, increased liver enzymes and focal chronic
interstitial nephritis.  Chronic toxic effects include body weight
decrement, increase in kidney and liver weights, and hydropic
degeneration of the kidneys.  At high doses, chronic toxicity also
includes increased incidences of pancreatic acinar cell hyperplasia and
adenomas.  Developmental toxicities include increased resorptions,
post-implantation loss, decreased number of live fetuses, and reduced
fetal body weight.  These effects occurred at much higher dose than the
maternal effects which demonstrated by increased mortality, decrease in
food consumption and increase in water consumption, decreased body
weight gain, clinical signs of reduced defecation, diarrhea, apathy, and
poor general state.  Because there is no evidence of neurotoxic effects,
no acute, subchronic, or developmental neurotoxicity studies are
required.  Evaluated under the 2005 Guidelines for Carcinogen Risk
Assessment, quinclorac was tentatively classified as "Not likely to be
carcinogenic to humans" since only benign tumors were seen in only one
sex and in one species.  The chronic RfD would adequately account for
all chronic effects, including the observed adenomas, likely to result
from exposure to quinclorac. The acute dietary endpoint was based on
developmental toxicity, while the chronic dietary endpoint was based on
decreased body weight in the 18-month carcinogenicity study.  No data
were available on the inhalation toxicity of quinclorac.  Inhalation
endpoint was based maternal toxicity from the rabbit developmental study
and assuming inhalation absorption of 100%.

The FQPA Safety Factor was reduced from 10X to 1X for infants and
children based upon the fact that the toxicology database for quinclorac
is complete and there is no indication of increased susceptibility of
rat or rabbit fetuses to in utero and/or postnatal exposure in the
developmental and reproductive toxicity data.  A summary of the
toxicological endpoint decisions from the most recent human health risk
assessment of quinclorac is given in Appendix A. 

Conclusions:  The HED Registration Review problem formulation team has
re-evaluated the above toxicity endpoints and dose response according to
the current policies.  HED concluded that the endpoint selections in the
most recent risk assessment are adequate.  A 28-day subchronic
inhalation study is recommended.

Dietary Exposures

The residue of concern in food and water was determined to be quinclorac
per se. The estimated drinking water concentration (EDWC) from
groundwater (29 µg/L) was used in the dietary assessment as these are
greater than the surface water values.  Since there is relatively little
temporal variation in groundwater concentrations compared to surface
water, the concentration (29 ug/L) was used for both acute and chronic
exposure assessment.  Acute and chronic aggregate dietary (food +
drinking water) exposure were conducted using the Dietary Exposure
Evaluation Model DEEM-FCID™, Version 2.03 which use food consumption
data from the U.S. Department of Agriculture’s Continuing Surveys of
Food Intakes by Individuals (CSFII) from 1994-1996 and 1998.  Both the
acute and chronic dietary assessment are based on tolerance-level
residues for all agricultural commodities, assume 100% crop treated, use
DEEM 7.81 default processing factors, and directly incorporate modeled
quinclorac EDWCs.  

The acute assessment provides a risk estimate of < 1% of the acute
population-adjusted dose (aPAD) at the 95th percentile of exposure for
females 13-49 years of age.  Risk estimates for the chronic assessment
vary by population group and range from < 1% of the chronic PAD (cPAD)
to 2% of the cPAD.  

Conclusions: The residue chemistry database is complete with the newly
submitted AGF studies. These new studies have not been reviewed.  A
review of these studies is needed.  Existing AGF tolerance was
previously determined by applying the maximum theoretical concentration
factor (200X) to the proposed tolerance (6 ppm) on grain sorghum grain
which is 1200 ppm.  The new AGF tolerance will likely be a lot lower
based on the new AGF studies and as a result, the animal dietary burden
will likely be lower, hence the residues in meat and meat byproducts
will likely be lower as well. Revisions to the existing AGF and
livestock tolerances may be needed.  The drinking water assessment is
adequate.  The dietary exposure assessment is also adequate.  No new
dietary assessment is needed.

Residential Exposure

Based on the registered use pattern, there are residential handler and
residential post application exposure scenarios.  Post-application
incidental oral (hand-to-mouth, object-to-mouth, and soil ingestion)
exposures were evaluated using the maximum application rates (0.0172 lb
ai per 1000 sq ft).  The combined MOE (5,000) is greater than 100 and,
therefore, is not of concern to HED.  

Conclusions: The post-application exposure assessments are adequate. 
However, no residential handler assessment was conducted.  A new
residential handler assessment is needed for the Registration Review of
quinclorac.

Aggregate 

Aggregate risk assessments were conducted for acute, chronic, and
short-term.  There is no risk for concern.

Conclusions:  HED problem formulation team concluded that the most
recent aggregate risk assessment is adequate.  No new aggregate risk
assessment is needed for the Registration Review of quinclorac.

Occupational Exposure 

There are occupational exposure scenarios based on the use patterns. 
However, no occupational risk assessments have been conducted before.  A
new occupational assessment is required for the Registration Review once
the inhalation endpoint is selected.

Incident Report

No incident report has been generated for quinclorac.  A new incident
report is needed with the Registration Review.

Cumulative

Quinclorac has not been identified as a member of common mechanism
group; therefore, accumulative assessment has not been conducted for
quinclorac.

Human Studies

No human studies were used in either hazard or exposure assessment.

Codex MRLs

No Codex or Mexico MRLs are reported.  The U.S. tolerances on livestock
fat and meat byproducts are not harmonized with Canada MRLs (see
Appendix B for details).  Future work is needed to harmonize these
tolerances. 

Conclusions/Future Actions Needed

Below are the detailed actions needed in the future Registration Review
for quinclorac:

Exposure

The 1998 risk assessment indicated the need for data on aspirated grain
fractions as a data gap in the residue chemistry database, and
submission of such data should be made a condition of registration. 
Since then, residue data on wheat and sorghum aspirated grain fractions
have been submitted but not been reviewed.  They are:

45598703   	Haughey, D.; Abdel-Baky, S.; Daussin, S. (2000) Magnitude of
BAS 514 H Residues in Wheat Aspirated Grain Fraction: Lab Project
Number: 2000/5187: 59553. Unpublished study prepared by BASF Corp. 61 p.
{OPPTS 860.1500}.

45598704 	Haughey, D.; Daussin, S. (2000) Magnitude of BAS 514 H
Residues in Sorghum Aspirated Grain Fraction: Lab Project Number: 59552:
2000/5186. Unpublished study prepared by BASF Corp. 61 p. {OPPTS
860.1500}. 

Tolerances on AGF and livestock commodities may need to be revised based
on the review of the above studies.  

A residential handler assessment is needed.

Occupational Exposure and Risk

A new occupational assessment is needed.

Incident Report

A new incident report is needed.

Data Requirements

A 28-day subchronic inhalation study is recommended.

References

HED memo of 9/13/07, M. Doherty, D325790;

HED memo of 12/15/98, M. Nelson, D238399;

Bibliography for Quinclorac (OPPIN database).

Appendix A

Summary of Toxicological Doses and Endpoints from the Most Recent Risk
Assessment.

Exposure/

Scenario	Point of Departure	Uncertainty/FQPA Safety Factors	RfD, PAD,
Level of Concern for Risk Assessment	Study and Toxicological Effects

Acute Dietary (General Population, including Infants and Children)	Not
applicable.  An endpoint for acute dietary exposure to the general
population was not selected because there was no available endpoint that
was appropriate for this scenario (effects observed in the available
studies are presumed to require more than one exposure).

Acute Dietary

(Females 13-49 years of age)	NOAEL (developmental) = 200 mg/kg/day	UFA=
10x

UFH=10x

FQPA SF= 1x

	Acute NOAEL =  200 mg/kg/day

aPAD = 2.0 mg/kg/day	Developmental toxicity study in rabbits
Developmental toxicity LOAEL =  600 mg/kg/day based on increased early
resorptions and postimplantation loss, decreased live fetuses, decreased
fetal weight.  These fetal effects are presumed to occur after a single
dose.

Chronic Dietary (All Populations)	NOAEL= 37.5 mg/kg/day	UFA= 10x

UFH=10x

FQPA SF= 1x

	Chronic NOAEL = 37.5

mg/kg/day

cPAD =  0.38 mg/kg/day	Dietary carcinogenicity study in mice

LOAEL = 150 mg/kg/day based on decreased body weight.

Incidental Oral Short-Term (1-30 days) and Intermediate-Term (1-6
months)	NOAEL= 70 mg/kg/day	UFA= 10x

UFH=10x

FQPA SF= 1x	Residential LOC for MOE = 100	Developmental toxicity study
in rabbits.

Maternal toxicity LOAEL = 200 mg/kg/day based on decreased maternal body
weight gain and food consumption (and increased water consumption).

Dermal (all durations)	Not applicable.  A dermal endpoint was not
selected because an appropriate endpoint was not available (no dermal
toxicity at limit dose of 1000 mg/kg/day in a 21-day dermal toxicity
study).

Inhalation Short-Term (1-30 days) and Intermediate-Term (1-6 months)
NOAEL= 70 mg/kg/day

[Inhalation absorption rate = 100% relative to oral absorption]	UFA= 10x

UFH= 10x

FQPA SF= 1x	Residential LOC for MOE = 100	Developmental toxicity study
in rabbits.

Maternal toxicity LOAEL = 200 mg/kg/day based on decreased maternal body
weight gain and food consumption (and increased water consumption).

(Supported by subchronic and chronic dietary data on mice).

Inhalation Long-Term (>6 months)	Not applicable.  Long-term inhalation
exposure is not anticipated under current use scenarios.

Cancer (oral, dermal, inhalation)	Available carcinogenicity studies
indicate that there was equivocal evidence of an increase in the
incidence of pancreatic acinar cell adenomas in the male rat, but no
treatment-associated increases in tumors were observed in female rats or
in mice.  A quantification of cancer risk is not warranted because the
chronic RfD of 0.4 mg/kg/day is approximately 1200-fold lower than the
dose (487 mg/kg/day) that induced the benign pancreatic tumors.  Thus,
the chronic RfD will adequately account for all chronic effects,
including the observed adenomas, likely to result from exposure to
quinclorac.   If quinclorac is evaluated under the current 2005
Guidelines for Carcinogen Risk Assessment, quinclorac will be classified
as "Not Likely to be Carcinogenic to Humans" since only benign tumors
were seen in only one sex and in one species.

Point of Departure (POD) = A data point or an estimated point that is
derived from observed dose-response data and  used to mark the beginning
of extrapolation to determine risk associated with lower environmentally
relevant human exposures.  NOAEL = no observed adverse effect level. 
LOAEL = lowest observed adverse effect level.  UF = uncertainty factor. 
UFA = extrapolation from animal to human (interspecies).  UFH =
potential variation in sensitivity among members of the human population
(intraspecies).  UFL = use of a LOAEL to extrapolate a NOAEL.  UFS = use
of a short-term study for long-term risk assessment.  UFDB = to account
for the absence of key date (i.e., lack of a critical study).  FQPA SF =
FQPA Safety Factor.  PAD = population adjusted dose (a = acute, c =
chronic).  RfD = reference dose.  MOE = margin of exposure.  LOC = level
of concern.  N/A = not applicable.

Appendix B

Quinclorac

US	Canada	Mexico	Codex

Residue Definition:

Quinclorac (3,7-dichloro-8-quinoline carboxylic acid)

40CFR180.463

	3,7-dichloroquinolin-8-

carboxylic acid	none	none

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

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

Grain, aspirated fractions	1200	-

Hog, fat	0.7	0.05

Hog, meat byproducts	1.5	0.05

Hog, meat	0.05	0.05

Horse, fat	0.7	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	0.1	0.05

Poultry, meat	0.05	0.05

Rice, bran	15.0	-

Rice, grain	5.0	5

Rice, straw	12.0	-

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	-

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