UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460-0001

                                                                        
                                                                        
       OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

DP Barcode: D336709

PC Code: 018101

Date: 04/11/2007

SUBJECT:	Environmental Fate and Ecological Risk Assessment in Support of
the Reregistration Eligibility Decision for Chlormequat Chloride

TO:		Robert McNally, Risk Manager

Tracy Perry, Risk Review Manager

Special Review and Reregistration Division (7508P)

FROM:	Brian D. Kiernan, Biologist

Marietta Echeverria, Environmental Scientist

Environmental Risk Branch IV 

Environmental Fate and Effects Division (7507P)

APPROVED

BY: 	Elizabeth Behl, Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFED) has completed an
environmental fate and ecological risk assessment chapter in support of
the reregistration eligibility decision for chlormequat chloride
(Cycocel®; EPA Reg. No. 241-74).  An environmental risk assessment in
support of a Section 3 registration for use on containerized nursery
crops and bedding plants was completed last year (DP Barcode D333104),
and the only difference is a lower application rate.  Based on current
label uses at maximum rates there are potential risks to birds,
reptiles, terrestrial-phase amphibians, mammals, and both terrestrial
and aquatic plants.  No chronic toxicity data are available for aquatic
vertebrates; therefore, the potential chronic risks to fish and
aquatic-phase amphibians cannot be evaluated and is presumed.  

Table 1 lists the status of the ecological effect dataset.  A major
deficiency is the lack of a no-observed adverse effect concentration
(NOAEC) for avian reproduction.  Table 2 lists the status of the fate
dataset.  Major deficiencies include the lack of hydrolysis, photolysis
and anaerobic soil metabolism data, as well as unidentified
transformation products in the aerobic soil and aerobic aquatic
metabolism studies.

This assessment also assumes that chlormequat chloride will be applied
by low-boom sprayer to bedding plants and by back-pack sprayer to most
containerized ornamentals.  If this assumption is not supported by the
registrant, spray drift and runoff estimates may be affected.

Recommended label language:

"Do not discharge effluent containing this product into lakes, streams,
ponds, estuaries, oceans, or other waters unless in accordance with the
requirements of a National Pollutant Discharge Elimination System
(NPDES) permit and the permitting authority has been notified in writing
prior to discharge.  Do not discharge effluent containing this product
to sewer systems without previously notifying the local sewage treatment
plant authority.  For guidance contact your State Water Board or
Regional Office of the EPA."

“Do not apply directly to water, or to areas where surface water is
present or to intertidal areas below the mean high water mark.  Do not
contaminate water when disposing of equipment washwater or rinsate."

“Drift and runoff may be hazardous to aquatic organisms in water
adjacent to treated areas.”

Endangered Species

	Levels of concern for threatened and endangered species are exceeded
for several types of wildlife, including birds, mammals and both aquatic
and terrestrial plants.  Because potential risk is indicated in their
surrogates, there is potential risk to listed amphibians and reptiles. 
Exceedance of LOCs for plants indicate concern for indirect effects on
listed terrestrial animal species reliant on susceptible plant
communities, or those solely dependent on a sensitive plant for some
portion of their life cycle (obligate relationships).  Due to lack of
data, chronic risk to freshwater fish is presumed.

Table 1.  Status of ecological data requirements for chlormequat
chloride.

DATA REQUIREMENT	Adequate for Ecological Risk Assessment	CITATION:

MRID or ECOTOX

850.2100	71-1A	Avian Acute Oral Toxicity	-	-

Non-guideline	Avian Acute Oral Toxicity	Yes	467152-11; supplemental

850.2200	71-2A	Avian Dietary Toxicity - Quail	Yes	467152-122;
supplemental

850.2200	71-2B	Avian Dietary Toxicity - Duck	Yes	467152-13; acceptable

850.2300	71-4A	Avian Reproduction - Quail	-	-

850.2300	71-4B	Avian Reproduction - Duck	-	-

Non-guideline	Avian Reproduction - Quail	No	467152-14; supplemental

850.1075	72-1A	Fish Acute Toxicity Bluegill	Yes	001232-61; acceptable

850.1075	72-1B	Fish Acute Toxicity Fathead Minnow	Yes	000374-33;
acceptable

850.1075	72-1C	Fish Acute Toxicity Rainbow Trout	-	-

Non-guideline	Fish Acute Toxicity Rainbow Trout	Yes	467152-17;
supplemental

850.1010	72-2A	Invertebrate Acute Daphnid Toxicity 	Yes	001387-19;
supplemental

850.1075	72-3A	Estuarine/Marine Toxicity - Fish	Yes	ECOTOX

850.1025	72-3B	Estuarine/Marine Toxicity - Mollusk	-	-

850.1035	72-3C	Estuarine/Marine Acute Toxicity 	Yes	ECOTOX

850.1300	72-4A	Daphnid Chronic Toxicity (life cycle)	Yes	467152-16;
supplemental

850.1350	72-4B	Estuarine/Marine Invertebrate chronic  (Mysid Shrimp, 
Life Cycle)	-	-

850.1400	72-4C	Freshwater Fish- Early Life Stage	No	Data gap

850.1400	72-4D	Estuarine Fish- Early Life Stage	-	-

850.4100	123-1A	Terrestrial Plant Toxicity, Seedling Emergence	-	-

Non-guideline	Terrestrial Plant Toxicity, Seedling Emergence	Yes
467152-19; supplemental

850.4150	123-1B	Terrestrial Plant Toxicity, Vegetative Vigor	-	-

Non-guideline	Terrestrial Plant Toxicity, Vegetative Vigor	No	467152-20;
supplemental

850.4400	123-2	Aquatic Plant Growth- Lemna	Yes	467152-21; acceptable

850.4500	123-2	Aquatic Plant Growth- Algae	Yes	467152-22; acceptable

850.4550	123-2	Aquatic Plant Growth- Cyanobacteria	Yes	467152-23;
supplemental

850.3020	141-1	Honey Bee Acute Contact	Yes	467152-24; acceptable



Table 2.  Status of environmental fate and transport data requirements
for chlormequat chloride.

Data Requirement and Guideline Reference Number	Adequate for Ecological
Risk Assessment



Degradation - Lab

161-1 Hydrolysis

161-2 Photolysis in Water

161-3 Photolysis in Soil

161-4 Photodegradation in Air

	

No1 

No2 

NA

NA

Metabolism Studies – Lab

162-1 Aerobic Soil Metabolism

162-2 Anaerobic Soil Metabolism

162-3 Anaerobic Aquatic Metabolism

162-4 Aerobic Aquatic Metabolism

	

No3 

No

NA

No4 



Mobility Studies – Lab

163-1 Leaching and Adsoprtion/Desorption

163-2 Volatility from Soil (Lab)

163-3 Volatility from Soil (Field)

	

Yes (MRIDs 46715228, 46715229)

NA

NA

Field Dissipation Studies

164-1 Terrestrial

164-2 Aquatic

164-3 Forestry

164-4 Combination and tank mixes

164-5 Terrestrial (Long-Term)

	

No

NA

NA

NA

NA

Accumulation Studies

165-1 In Confined Rotational Crops

165-2 In Field Rotational Crops

165-3 In Irrigated Crops

165-4 In Fish

165-5 Aquatic Non-Target Organisms	

NA

NA

NA

No

NA



MRID 124063 is classified as unacceptable

MRID 124063 is classified as unacceptable

MRID 46715225 is classified as supplemental because all transformation >
10% may not have been identified.

MRID 46715227 is classified as supplemental because all transformation >
10% may not have been identified.

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