OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

Problem Formulation for the

Environmental Fate, Ecological Risk, and Endangered 

Species in Support of the Registration Review of 

Buprofezin

PC Code 275100

CAS Number 69327-76-0

C1=CC=CC(=C1)N2C(N(C(SC2)=NC(C)(C)C)C(C)C)=O

Prepared by:

Ronald Parker, Ph.D., Senior Environmental 

Engineer

Nicholas Mastrota, Wildlife Biologist

Reviewed by:

Melissa Panger, Ph.D. Senior Biologist

Rosanna Louie-Juzwiak, RAPL

Approved by:

Dana Spatz, Branch Chief

May 21, 2012
2

TABLE OF CONTENTS

1.0 Description of Regulatory Action ...................................................................................... 3

2.0 Stressor Source and Distribution....................................................................................... 3

2.1 Nature of Stressor...............................................................................................................3

2.2 Mode of Action ..................................................................................................................3

2.3 Conclusions from Previous Risk Assessments ..................................................................3

2.4 Use Characterization ..........................................................................................................5

3.0 Environmental Fate Summary .......................................................................................... 8

4.0 Ecological Effects Summary ............................................................................................ 12

4.1 Aquatic Effects.................................................................................................................12

4.2 Terrestrial Effects.............................................................................................................16

4.3 Ecological Incidents.........................................................................................................18

5.0 Ecosystems Potentially at Risk......................................................................................... 18

6.0 Assessment Endpoints....................................................................................................... 19

7.0 Conceptual Model ............................................................................................................. 20

7.1 Risk Hypothesis................................................................................................................20

7.2 Conceptual Diagram.........................................................................................................21

8.0 Analysis Plan ..................................................................................................................... 22

8.1 Stressors of Concern.........................................................................................................22

8.2 Measures of Exposure ......................................................................................................23

8.3 Measures of Effect ...........................................................................................................26

8.4 Integration of Exposure and Effects.................................................................................27

8.5 Endangered Species Assessment......................................................................................27

8.6 Drinking Water Assessment.............................................................................................28

9.0 Clean Water Act................................................................................................................ 29

10.0 Anticipated Data Needs.................................................................................................... 30

10.1 Environmental Fate.......................................................................................................30

10.2 Ecological Effects.........................................................................................................30

11.0 References.......................................................................................................................... 40
3

1.0 Description of Regulatory Action

This document serves as a problem formulation for the upcoming ecological risk and drinking 

water exposure assessments that the EPA will conduct for buprofezin during the Registration 

Review process. The problem formulation provides a framework on the purpose and objectives 

of the risk assessment, evaluates the nature of the problem, and provides a plan for analyzing the 

data and characterizing the risk (USEPA, 1998). 

2.0 Stressor Source and Distribution

2.1 Nature of Stressor

Buprofezin (CAS Number 69327-76-0) is an insect growth regulator that is used as an active 

ingredient in insecticidal products. It is classified as a chitin biosynthesis inhibitor (Group 16) by 

the Insecticide Resistance Action Committee (IRAC). It is available in multiple products that are 

used to control insects on the stems and foliage of agricultural crops and ornamental plants. 

Insect pests that are controlled by buprofezin include whiteflies, mealybugs, scale, leafhoppers, 

and planthoppers. Products containing buprofezin are formulated either with buprofezin as the 

sole active ingredient or in combination with flubendiamide. (BEAD Chemical Profile for 

Registration Review: Buprofezin, 15 December 2011). 

2.2 Mode of Action

Buprofezin controls insects by interrupting the growth and development of the larval stages by 

inhibiting chitin biosynthesis. It also suppresses oviposition of adult insects and reduces the 

viability of insect eggs.

2.3 Conclusions from Previous Risk Assessments

Previous risk assessments include an ecological assessment in support of the 2001 Reregistration 

Eligibility Decision (RED, D271561) and numerous new use assessments, which are summarized 

in Table 1. All recent assessments have identified a risk of chronic effects to mammals above 

EPA’s level of concern (LOC). Chronic risk was also concluded for birds for uses with higher 

application rates, including on most fruit trees (except apple), almonds, and coffee. Acute risk to 

small mammals exceeded the LOC for endangered species for most uses, and the LOC for nonendangered species for some uses with high use rates (some fruit trees and coffee). Risk to birds 

exceeded the acute endangered species LOC for the use on stone fruit and tropical fruit. For 

terrestrial insects, while an acute contact toxicity test with adult honey bees showed low toxicity, 

because buprofezin is an insecticide, some risk to terrestrial insects has been presumed.

Previous assessments generally concluded low acute and chronic risk to fish and aquatic 

invertebrates, except for endangered aquatic invertebrates from use on coffee. Also, recent 

assessments from 2008 concluded that adverse effects to endangered aquatic invertebrates were 

possible, based on sublethal effects observed in an acute toxicity study with the waterflea. 

Previous assessments did not identify any risk to fish exceeding the LOC. All of the previous

assessments concluded low risk to terrestrial and aquatic plants.
4

A summary of previous human health drinking water exposure assessments is included in section 

8.6 below. 

Table 1. Summary of Previous Ecological Risk Assessments on Buprofezin

Assessment ID 

(Year) Use

Max. 

Application 

Rate (lbs 

ai/A)

Max. 

Seasonal or 

Yearly Rate 

(lbs ai/A)

Risk Identified as Exceeding 

the EPA Level of Concern

D271561

(2001)

Almonds 2.0 2.0 Chronic risk to birds, acute risk to 

endangered small mammals

Citrus Fruit 2.0 4.0 Chronic risk to birds, acute risk to 

endangered small mammals

Grape 0.50 1.0 Acute risk to endangered small 

mammals

Cotton 0.35 0.70 None

Bananas 0.31 1.24 Acute risk to endangered small 

mammals

D293231, D292582, 

D292035

(2004)

Pear 1.58 3.16 Chronic risk to birds and 

mammals, acute risk to small 

mammals

Tropical Fruit 1.58 3.16 Chronic risk to birds and 

mammals, acute risk to 

endangered birds

Apple 1.5 1.5 Chronic risk to mammals, acute 

risk to small mammals

D323242, D323244, 

D323245 (2007)

Stone Fruit 1.5 3.0 Chronic risk to birds and 

mammals, acute risk to small 

mammals, acute risk to 

endangered birds

D340340, D340342

(2008)

Olive 2.0 4.0 Chronic risk to birds and 

mammals, acute risk to 

endangered small mammals, 

possible risk to nontarget insects, 

possible acute risk to endangered 

aquatic invertebrates

Berries 0.38 0.76 Chronic risk to mammals, 

possible risk to nontarget insects, 

possible acute risk to endangered 

aquatic invertebrates

Leafy Vegetable 0.38 0.76 Chronic risk to mammals, 

possible risk to nontarget insects, 

possible acute risk to endangered 

aquatic invertebrates

D343066

(2008)

Fruiting 

Vegetables

0.38 0.76 Chronic risk to mammals, 

possible risk to nontarget insects, 

possible acute risk to endangered 

aquatic invertebrates

D354845, D354848,

D354881, D354893

Coffee 2.0 4.0 Chronic risk to birds and 

mammals, acute risk to 
5

Assessment ID 

(Year) Use

Max. 

Application 

Rate (lbs 

ai/A)

Max. 

Seasonal or 

Yearly Rate 

(lbs ai/A)

Risk Identified as Exceeding 

the EPA Level of Concern

(2009) endangered mammals, acute risk 

to endangered aquatic 

invertebrates

Pomegranate 2.0 3.0 Chronic risk to birds and

mammals, acute risk to 

endangered small mammals

Brassica 

vegetables

0.38 1.5 Chronic risk to mammals

2.4 Use Characterization

Buprofezin is formulated as an emulsifiable concentrate, soluble concentrate, dry flowable, and 

wettable powder products. Acting as a contact insecticide, buprofezin products are applied as a 

spray to the foliage of plants to control insect pests. The products are used on a variety of 

agricultural food crops, including leafy and stem vegetables, herbs, fruiting vegetables, melons, 

fruit trees, grapes, berries, tree nuts, and coffee. Of the fruit tree uses, oranges and pears are crops 

with the largest uses of buprofezin, but it may also be used on various other citrus, stone, pome, 

and tropical fruit trees. Use on grapes includes table grapes, raisin grapes, and wine grapes. A 

major non-food agricultural use of buprofezin is on cotton. Buprofezin is also used on 

ornamental plants, including herbaceous plants, shrubs, vines, and trees. Ornamental use is 

limited to agricultural sites such as nurseries and greenhouses. A national map with 2006-2010

usage data for buprofezin is presented in Figure 1. 
6

 

Figure 1. Buprofezin Usage by Crop Reporting District (2006-2010). (USEPA, 2012).

For all crops, buprofezin products are registered for foliar application using either ground 

equipment or aircraft. Buprofezin is registered for ultra low volume (ULV) application on tomato 

and ornamental plants. Application of buprofezin through irrigation systems (i.e., chemigation) is 

prohibited. Labels of buprofezin products contain no restrictions that would prevent application 

to the crops during bloom. The label for NNI-0871 SC (Vetica Insecticide, EPA Reg. No. 71711-

32), which contains flubendiamide as well as buprofezin, requires that a 15-ft buffer zone be 

maintained between the treated field and any aquatic habitat. Products containing buprofezin 

alone do not have buffer zone requirements. Table 2 below, summarizes the currently registered 

uses of buprofezin and application information for each crop or use site.

Table 2. Use Site and Application Information for Buprofezin

Site Description Products1

AI Single 

Maximum 

Applicatio

n Rate

(lb/A)

AI 

Maximum 

Seasonal 

Rate2(lb/A)

Max. 

Apps/ 

Crop 

Cycle3

MRI4

(days)

Application 

Methods Restrictions

Almond and Pistachio Applaud, 

Buprofezin 2.01 2.01 1 NA

Ground, 

Airblast, 

Aircraft
7

Bean, Succulent Applaud, 

Buprofezin 0.38 0.692 NS 14 Ground, Aircraft

NNI 0.31 0.692 NS 14 Ground, 

Aircraft

No aerial 

application in 

NY

Berries (blueberries, 

cranberries, 

strawberries)

Buprofezin, 

NNI 0.34 0.674

2 10 Ground, 

Aircraft

NNI 0.34 0.6742 10 Ground, 

Aircraft

No aerial 

application in 

NY

Coffee Applaud 1.01 3.98 NS 14 Ground, 

Aircraft

Cotton Applaud, 

Buprofezin 0.35 (0.70)

2 28 Ground, 

Aircraft

NNI 0.66 0.661 28 Ground, 

Aircraft

No aerial 

application in 

NY

Chrysanthemum

NNI 0.31 0.69 NS7

Ground, 

Aircraft

No aerial 

application in 

NY

Fruit, Citrus Applaud 2.01 4.02

2 60 Ground, 

Aircraft

Fruit, Pome (except 

pears) Applaud, 

Buprofezin 1.15 1.15

1 NA

Ground, 

Airblast, 

Aircraft

NNI 0.31 0.84 NS7

Ground, 

Airblast, 

Aircraft

Fruit, Pome, Pears Applaud, 

Buprofezin 2.01 3.02 NS

7

Ground, 

Aircraft

NNI 0.31 0.84 NS7

Ground, 

Airblast 

Aircraft

Fruit, Stone (peach, 

plum, nectarine, 

apricot, cherry) and 

Pomegranate

Applaud, 

Buprofezin 2.01 3.02 NS 14 Ground, Aircraft

NNI 0.26 0.67 NS 14

Ground, 

Airblast, 

Aircraft

Fruit, Tropical 

(includes avocado, 

guava, and minor 

crops, excludes 

banana, mango, 

papaya)

Applaud 1.51 3.022 14 Ground, 

Aircraft

FL, HI, and 

PR only

Fruit, Tropical, Banana Applaud 0.31 (1.23)

4 14 Ground, 

Aircraft

Fruit, Tropical, Mango 

and Papaya Applaud 0.53 1.97 NS 14 Ground, Aircraft

FL, HI, and 

PR only

Fruit, Minor Crops, 

Except Mayhaw 

(cantistel, longan, 

lychee, pulasan, 

rambutan, and Spanish 

lime)

Applaud 1.51 3.022 14 Ground, 

Aircraft

Fruit, Minor Crops, 

Mayhaw

Applaud, 

Buprofezin 1.51 1.51

1 NA Ground
8

NNI 0.31 0.83 NS 7

Ground, 

Airblast

Grape Applaud 1.05 1.05 NS NA Ground, 

Aircraft CA, AZ only

Applaud 0.53 1.05 2 14 Ground, 

Aircraft

NNI 0.26 0.68 NS 14 Ground, 

Airblast

Ornamental Plants 

(trees, Christmas trees, 

nonbearing fruit and 

nut trees, shrubs, 

vines, ground cover, 

and herbaceous plants)

Applaud, 

Buprofezin 0.613 1.23 2 NS

Ground, 

ULV Spray, 

Aircraft

Vegetables, 

Brassicaceae 

(broccoli, cabbage, 

cauliflower, celery, 

cauliflower, etc)

Buprofezin 0.38 0.77 2 7

Ground, 

Aircraft

NNI 0.36 0.73 2 7

Ground, 

Aircraft

No aerial 

application in 

NY

Vegetable, 

Cucurbitaceae 

(cucumbers, gourds, 

melons, pumpkin)

Applaud, 

Buprofezin 0.38 (0.76) 2 (4/yr) 7

Ground, 

Aircraft

Vegetables, Fruiting 

(tomato, pepper, 

eggplant, etc)

Applaud, 

Buprofezin 0.38 (0.76) 2 5 (28) Ground, Aircraft

NNI 0.31 0.69 NS 5

Ground, 

Aircraft

No aerial 

application in 

NY

Tallus 0.38 (0.69) 2 28 Greenhouse 

sprayers

For use in 

greenhouses 

only; CA, CO, 

PA, and VA 

only

Courier 0.38 (0.69) 2 28 Ground, 

Aircraft CA only

Vegetables, Leafy, 

Excluding Brassicacea 

(lettuce, spinach, etc) 

and Herbs (chervil, 

fennel, parsley)

Buprofezin 0.38 0.77 2 (4/yr) 7

Ground, 

Aircraft

NNI 0.31 0.69 NS 7

Ground, 

Aircraft

No aerial 

application in 

NY

1 Applaud: Applaud 70DF Insect Growth Regulator (71711-21) and Applaud 70WP Insect Growth Regulator 

(71711-15); Buprofezin: Buprofezin 40SC (71711-20); NNI: NNI-0772 SC (Tourismo Insecticide, 71711-33) and 

NNI-0871 SC (Vetica Insecticide, 71711-32); Courier: Courier 40SC Insect Growth Regulator (CA050008 and 

FL040012); Talus: Talus 40SC Insect Growth Regulator (CA070010, CO070005, PA070004. VA07001)

2 Values in parenthesis are not stated on the label but were assumed to be the product of the single application rate 

and the maximum number of applications.

3 NS = Not stated

4 MRI = minimum retreatment interval

3.0 Environmental Fate Summary

The environmental fate database for buprofezin is considered essentially complete. A summary of 

buprofezin’s chemical and physical properties, and environmental fate, including degradation 
9

half-lives and BCF values, is provided below. The limitations and assumptions presented in 

previous assessments also are included in this problem formulation. 

Terrestrial Environments: In terrestrial environments, buprofezin may persist for weeks to 

months, with biodegradation in soil as the primary route of dissipation. Aerobic soil metabolism 

half-lives were measured at 37 and 101 days for a sandy loam and sandy clay loam soil, 

respectively, and buprofezin was found to be stable to photolysis on soil. Field dissipation studies 

indicate that buprofezin dissipated at relatively consistent rates, with half-lives of 38 days in a 

sandy loam (Fresno, CA) and in a loamy sand (Pikeville, NC) when applied four times to bare 

ground at an application rate of 0.38 lb a.i./A/app. Buprofezin is not expected to volatilize from 

soil (vapor pressure: 6.4 x e-6 mm Hg). No major degradates other than carbon dioxide were

found in soil metabolism studies.

Laboratory results suggest that buprofezin has moderate to low mobility in soil with measured Kd

values ranging from 11 mL/g to 277 mL/g. The fraction of organic matter in the soil was not 

found to explain the variability in sorption and so binding to organic matter may not play as large 

a role as binding to the mineral fraction of soil. 

Given its sorption characteristics, buprofezin also has a low potential to leach or move with 

surface water runoff as a dissolved fraction. Consistent with these results, there is no evidence of 

buprofezin leaching in the terrestrial field dissipation studies; neither buprofezin nor its

degradates were detected below 7.5 cm. (See Buprofezin Degradates section below.) Therefore, 

buprofezin is expected to be persistent in terrestrial soils, with only slow dissipation by transport 

in surface and ground water.

Aqueous Environments: As described above, buprofezin binds moderately to soil and therefore is 

expected to reach surface water primarily by way of spray drift or bound soil particles eroded 

during runoff events.

Once in an aquatic system, buprofezin is stable to hydrolysis in neutral and alkaline conditions 

but it does hydrolyze slowly in acidic conditions (half-life of 58 days). In clear, shallow water 

bodies, photolysis may contribute to degradation of buprofezin (half-life = 38 days). 

Volatility studies were not submitted, but some volatilization was observed when buprofezin was 

applied to a thin, moist soil layer, irradiated, and continuously purged with air (soil photolysis 

study: MRID 44435902). However, under the conditions of the aerobic soil metabolism study, 

volatilization was not detected. EFED believes that buprofezin physical properties (molecular 

weight of 305, melting point of 105 C and Henry’s Law Constant of 6.73 x 10-6atm - m

3

/mole)

support the aerobic soil metabolism study findings and volatilization from soil is insignificant 

under field conditions. For volatility in water, based on Henry's Law constant (6.73 x 10-6atm -

m

3

/mole), buprofezin is classified as a semi-volatile compound. Therefore volatilization of 

buprofezin may be expected from water bodies. See Table 3, for a summary of buprofezin’s 

chemical, physical, and environmental fate properties.
10

Table 3. Chemical, Physical and Environmental Fate Properties of Buprofezin

PARAMETER Value Study

Summary of Chemical and Physical Properties

Chemical name(s)

2-tert-butylimino-3-isopropyl5phenylperhydro-1,3,5-

thiadiazin-4-one

Chemical Abstract Service number 69327-76-0

PC Code 275100

Empirical Formula C16H23N3OS

Physical State Solid 428738-04

Odor Odorless 428738-04

Color White 428738-04

Melting Point 104.2 - 105.5 C 428738-04

Molecular weight (gr/moles) 305.4 Calculated

Aqueous solubility (at 25 C) 0.382 mg/L 428738-04

Henry’s Law Constant 6.73 x 10-6

atm - m

3

/mole Calculated

Vapor pressure (at 20 C) 6.4 x e-6 mm Hg 428738-04

Log Kow (at 20o C) 4.31 428738-04

Summary of Environmental Fate Properties MRID

Hydrolysis half life (pH 5) (days)

(pH 7)

(pH 9)

51 days

stable

stable

44394041

Aqueous photolysis half life (days) 38 days 44463102

Soil photolysis half life (days) 39 days 44453902

Aerobic soil metabolism half-lives (days)

-Sandy loam soil

-Sandy clay loam soil

36.5 days

101 days

44394042

Anaerobic aquatic metabolism half-lives stable 44394043

Soil-water partition coefficient (Kd)

Kads values of 11 mL/g in sand 

soil; 85 in clay loam soil; 69, 87, 

and 90 in three sandy loam soils; 

70 in loamy sand soil; and 277 in 

silty clay loam soil.

Kdes values were 7.7 mL/g in 

sand soil; 173 in clay loam soil; 

65, 85, and 118 in sandy loam 

soils; 71 in loamy sand soil; and 

330 in silty clay loam soil.

44990601

No data are available for biodegradation of buprofezin in aerobic aquatic environments, but in 

anaerobic aquatic environments, buprofezin was found to be stable to metabolism. 
11

Given the soil sorption coefficients observed in laboratory studies, buprofezin is likely to partition 

to sediment or suspended particles. Along with its relative persistence in aquatic environments, 

buprofezin can be expected to accumulate in sediments. An aerobic aquatic metabolism study 

would help to inform this prediction.

Buprofezin Degradates

Three major degradates were observed in the laboratory aqueous studies: BF-12 and BF-251

(formed through hydrolysis at pH 5), and BF-21 (formed through aquatic photolysis). No major 

degradate (except for CO2) was detected in the laboratory soil studies; however BF-12 was seen 

as a minor degradate under both aerobic and anaerobic conditions. This suggests that it is unlikely 

that any buprofezin degradates found in the laboratory studies will form or accumulate in 

significant quantities in the field. When analyzed for in the terrestrial field samples, BF-12 was 

detected at maximum, less than 10% of parent and only in the top soil layer (0-12 inches). 

Therefore, as with the parent, buprofezin degradates do not appear to have the potential to leach 

into ground water. Table 4 lists all degradates/metabolites (minor (x) and major (X)) identified in 

both laboratory and field studies. Proposed degradation pathways for buprofezin in soil, water, 

and light are presented in Appendix B. Names, chemical structures of buprofezin, and major 

transformation products are presented in Appendix C, at the end of this report.

Table 4. Degradates (Minor(x) and Major(X)) Identified in Laboratory and Field Studies

Degradates / 

Metabolites

Hydrolysis Photolysis 

(water)

Photolysis 

(soil)

Aerobic Soil Anaerobic 

Water

Terrestrial 

Field

BF-2 x

BF-9 x x

BF-10 x x x

BF-11 x (pH 5) x x

BF-12 X (pH 5) x x x x (top layer)

BF-16 x

BF-19 x x

BF-21 X

BF-22 x

BF-25 X (pH 5) x

Unknown C 14x

CO2 X x

 

1 BF-12: N-(l-methylethy1)-N’-phenylurea

BF-25: N-[[(1, l-dimethylethyl)amino]thioxomethyl]-N-(1-methyleyl)-N’-phenylea; thiobiuret

BF-21: N-phenylformamide
12

BF-2 = 2-[(1,1-dimethylethyl)imino]tetrahydro-5-(4-hydroxyphenyl)-3-(1-methylethyl)-4H-1,3,5-thiadiazin-4-one

BF-9 = dihydro-3-(1-methylethyl)-5-phenyl-2H-1,3,5-thiadiazine-2,4(3H)-dione

BF-10 = 2-[(1,1-dimethylethyl)imino]tetrahydro-3-(1-methylethyl)-5-phenyl-4H-1,3,5-thiadiazin-4-one 1-oxide

BF-11 = N-(1,1-dimethylethyl)-2-(1-methylethyl)-N’-phenylimidodicarbonic diamide

BF-12 = N-(1-methylethyl)-N’-phenylurea

BF-13 = N-(4-hydroxyphenyl)-N-isopropylurea

BF-16 = phenylurea

BF-19 = 6-[(1,1-dimethylethyl)amino]-2,3-dihydro-3-phenyl-4H-1,3,5-thiadiazin-4-one

BF-21 = N-phenylformamide

BF-22 = 4-aminophenol

BF-25 = N-[[(1,1-dimethylethyl)amino]thioxomethyl]-N-(1-methylethyl)-N’-phenylurea; thiobiuret

The environmental fate database for buprofezin’s major degradates (BF-12, BF-21, and BF-25) is 

incomplete and does not allow a quantitative assessment of their impact on water resources. 

However, based on the available data, the proposed use rates, and the estimated EECs of 

buprofezin, it is not expected that these degradates will form or accumulate in significant 

quantities in the field, or reach ground and surface water at any appreciable concentration. 

Furthermore, the HED/MARC meeting concluded that buprofezin (parent) was the only residue of 

concern in drinking water (D264546, T. Bloem, 20 April 2000). Additional environmental fate 

data for buprofezin degradates are therefore not needed.

Buprofezin has a low to moderate propensity to bioaccumulate in aquatic organisms. The log of 

the octanol water partitioning coefficient (log Kow) is 4.31, indicating that it may accumulate in 

fatty tissue. However, a bioaccumulation study with the bluegill sunfish (44394047) found 

limited bioconcentration, with measured bioconcentration factors of 86 in fillet, 846 in viscera, 

and 537 in whole fish. Depuration was rapid, with depuration of 92%, 99% and 98% of the [14C] 

accumulated residues from the edible, non-edible and whole fish tissue samples, respectively, 

within 7 days. The rapid depuration appears to limit the bioconcentration of the compound in 

fish.

4.0 Ecological Effects Summary

4.1 Aquatic Effects

Table 5 presents the data on the acute toxicity of buprofezin to aquatic animals and plants. 

Freshwater fish also serve as a surrogate to assess risk to aquatic-phase amphibians. Acute 

toxicity testing demonstrates that buprofezin is not acutely toxic to fish and aquatic invertebrates 

at the solubility limit. This has been shown in both freshwater and saltwater species. Kikuchi et 

al. (2000), in a test of the acute toxicity of buprofezin with Daphnia magna, found that the acute 

48-hr EC50 was greater than 320 μg/L. Because the limited solubility of buprofezin in water 

prevented determination of definitive acute endpoints, the acute toxicity cannot be categorized. 

However, because buprofezin concentrations in natural waters are not expected to exceed the 

solubility limit, results of acute toxicity testing are adequate for concluding that exposure to 

buprofezin will not result in significant acute toxicity to fish and aquatic invertebrates.

Except for the oyster shell deposition study, the study reports for all of the acute aquatic toxicity 

studies did not give any indication that the test solutions were filtered or centrifuged prior to 
13

chemical analysis. Because of concern that the measurements of unfiltered samples 

overestimated concentrations of dissolved buprofezin, the classification of all of the acute toxicity 

studies, except for the shell deposition study, was downgraded from acceptable to supplemental

in the EFED risk assessment which was conducted to support new uses on citrus, almonds, 

grapes, cotton and bananas (5/2001).

Table 5. Acute Toxicity of Buprofezin to Aquatic Species

Taxonomic 

Group, Study 

Type

Surrogate Species Toxicity 

(Expressed as AI)

Citation

MRID

Study 

Classification

Fish

Freshwater fish,

Acute

Bluegill Sunfish

(Lepomis macrochirus)

LC50 > 330 μg/L

(No mortality or adverse 

effects were observed; highest 

test level was close to the 

solubility limit)

44394015 Supplemental1

Rainbow Trout 

(Oncorhynchus mykiss)

LC50 > 330 μg/L

(No mortality or adverse 

effects were observed; highest 

test level was close to the 

solubility limit)

44394016 Supplemental1

Saltwater fish,

Acute

Sheepshead minnow

(Cyprinodon variegatus)

LC50 > 500 μg/L

(No mortality or adverse 

effects were observed; highest 

test level was close to the 

solubility limit)

44394018 Supplemental1

Aquatic Invertebrates

Freshwater 

invertebrates,

Acute

Water flea

(Daphnia magna)

48-hr EC50 > 420 μg/L 42873833 Supplemental1

Saltwater mollusc, 

shell deposition

Eastern oyster

(Crassostrea virginica)

96-hr IC50 > 187 μg/L 44394019 Acceptable

Saltwater 

invertebrate, Acute

Grass shrimp

(Palaemonetes pugio) 96-hr LC50 > 560 μg/L 44394020 Supplemental1

Aquatic Plants

Algae

Green algae

(Pseudokrichneriella 

subcapitata)

72-hr IC50 > 382 μg/L 

(solubility limit),

10% growth inhibition at 

solubility limit.

44394039 Supplemental1

Vascular Aquatic 

Plants

Duckweed

(Lemna gibba)

14-day IC50 > 400 μg/L,

No inhibition at the solubility 

limit.

44394038 Supplemental1

1 The study was classified as supplemental because the measured test concentration were based on unfiltered 

samples and thus may have included undissolved test material. The study nevertheless provides adequate information 

on acute toxicity for ecological risk assessments.

Table 6 presents data on the chronic toxicity of buprofezin to fish and aquatic invertebrates. The

assessment of chronic effects is uncertain and incomplete because of problems with several of the 

submitted chronic toxicity studies. For fish, the only acceptable study was a fish early life-stage 

study (MRID 44394021), which found that chronic exposure of buprofezin inhibits the growth of 

rainbow trout at concentrations as low as 76 μg/L with a NOAEC established at 52 μg/L. A 

recent supplemental life-cycle study with the fathead minnow (MRID 48083904) found 
14

significant decreases in the number of eggs produced and percent spawning frequency at all test 

concentrations, including at the lowest test concentration (8.4 μg ai/L). Because significant 

effects were observed at all test concentrations, the study failed to establish an NOAEC. These 

reproductive results are uncertain, because they were confounded by very high variability in 

reproductive success among replicates, even in the controls. This study also found a significant 

reduction of growth at 15 μg ai/L. This result is also uncertain because no significant growth 

effect was observed at the higher concentration of 28 μg ai/L. The study gave clear evidence that 

chronic exposure to buprofezin adversely affects growth at concentrations of 55 μg ai/L and 

above, which is consistent with the results of the fish early life-stage study. 

Along with the fish life-cycle study, the registrant provided an additional fecundity study on the 

adult fathead minnow to better characterize the potential effects of buprofezin on reproduction. 

This fecundity study yielded a NOAEC of 56 μg ai/L, and a LOAEC of 116 μg ai/L, based on 

significant effects on egg production. It should be noted, however, that the fecundity study was 

initiated with breeding groups of adult minnow. Thus, the results may not be as sensitive as those 

obtained during a full life-cycle toxicity test, which is initiated with embryos. Furthermore, the 

fecundity study involves only 21 days of exposure, which is a much shorter duration than in the 

full life-cycle study (281 days). Results on reproductive endpoints from the original study, while 

uncertain, indicate that reproduction may be significantly more impaired during the full life-cycle 

exposure. Therefore, to address these uncertainties in the chronic toxicity of buprofezin to fish, 

the EPA is requesting the registrant to submit a new fish life-cycle study.

Table 6. Chronic Toxicity of Buprofezin to Aquatic Species

Taxonomic 

Group, Study 

Type

Surrogate Species Toxicity 

(Expressed as AI)

Citation

MRID

Study 

Classification

Fish1

Freshwater fish, 

Early Life-Stage

Rainbow Trout 

(Oncorhynchus mykiss)

NOAEC = 52 μg/L

LOAEC = 76 μg/L

(Reduced growth of young)

44394021 Acceptable

Freshwater fish, 

Life Cycle

Fathead Minnow

(Pimephales promelas)

NOAEC = 78 μg/L

LOAEC = 170 μg/L

(Reduced hatching success and 

reduced survival of young)

42873834 Supplemental

Freshwater fish, 

Life Cycle

Fathead Minnow

(Pimephales promelas)

Survival:

NOAEC = 55 μg/L

LOAEC > 55 μg/L

Growth:

NOAEC = 8.4 μg/L

LOAEC = 15 μg/L

Reproduction:

NOAEC < 8.4 μg/L

LOAEC = 8.4 μg/L

48083904 Supplemental

Aquatic Invertebrates

Freshwater 

invertebrates,

Chronic

Water flea

(Daphnia magna)

Survival:

NOAEC = 360 μg/L

LOAEC > 360 μg/L

Reproduction:

NOAEC = 80 μg/L

LOAEC = 120 μg/L

Growth: 

44435901 Acceptable
15

Taxonomic 

Group, Study 

Type

Surrogate Species Toxicity 

(Expressed as AI)

Citation

MRID

Study 

Classification

NOAEC = 120 μg/L

LOAEC = 200 μg/L

Saltwater 

Invertebrate LifeCycle

Mysid 

(Americamysis bahia)

Survival:

NOAEC = 22.5 μg/L

LOAEC = 45.2 μg/L

47676702 Supplemental

Freshwater 

Benthic 

Invertebrate with 

Spiked Sediment,

Subchronic

(OECD 218)

Midge

(Chironomous riparius)

Sediment Concentrations

Survival:

 10-d EC50 >5.54 mg/kg

 10-d NOAEC: 5.54 mg /kg

 10-d LOAEC: >5.54 mg /kg

Emergence:

 28-d EC50: >5.54 mg/kg

 28-d NOAEC: 5.54 mg/kg

 28-d LOAEC: >5.54 mg/kg

Development Rate:

 28-d EC50: >5.54 mg/kg

 28-d NOAEC: 2.72 mg/kg

 28-d LOAEC: 5.54 mg/kg

Growth: Not measured

47676703 Supplemental2

Freshwater 

Benthic 

Invertebrate with 

Spiked Water,

subchronic

(OECD 219)

Midge

(Chironomous riparius)

Emergence and Development 

Rate, Pore Water Conc.:

 28-d NOAEC = 15 μg/L

 28-d LOAEC > 15 μg/L

 28-d EC50 > 15 μg/L

Emergence and Development 

Rate, Overlying Water Conc.:

 28-d NOAEC = 35 μg/L

 28-d LOAEC > 35 μg/L

 28-d EC50 > 35 μg/L

Growth: Not measured

46597901 Supplemental

1

Fish serve as surrogate species for aquatic phase amphibians.

2 This study was conducted according to OECD Guideline 218 which measures 28-day emergence of the midge with 

spiked sediment exposure. While the test design does not match any OPPTS test guideline, the study does provide 

information on acute toxicity that is similar to that provided by Guideline 850.1735.

The life-cycle study conducted with Daphnia magna (MRID 44435901) provides acceptable 

information on the chronic toxicity of buprofezin to freshwater crustaceans. Based on the 

observation of significant adverse effects on reproduction at 120 μg ai/L, this study established the 

chronic NOAEC at 80 μg ai/L. The life-cycle study conducted with the mysid (Americamysis

bahia) (MRID 47676702) was classified as supplemental and provides limited information on the 

chronic toxicity of buprofezin to marine and estuarine crustaceans. Based on the observed 

reduction of survival at 31 days, this study established the chronic NOAEC and LOAEC of 22.5 

μg ai/L and 45.2 μg ai/L, respectively. These studies indicate that the mysid is more sensitive to 

chronic exposures of buprofezin than Daphnia magna.

For chronic effects of buprofezin to sediment-dwelling invertebrates, currently, only data from 

supplemental studies are available. Two studies with Chironomous riparius were submitted and 

evaluated: one conducted with spiked sediment according to OECD guideline 218 (MRID 

47676703), and a second conducted with spiked water according to OECD guideline 219 (MRID 

46597901). Neither study provides adequate information to fully assess the chronic risk of 
16

buprofezin to sediment-dwelling invertebrates. The studies were conducted for a shorter duration 

than recommended in the OCSPP test guideline for chronic chironomid testing (850.1760), and 

also were lacking required measurements on growth (length and dry weight). New acceptable 

studies are needed to fully assess risk from buprofezin. 

4.2 Terrestrial Effects

Table 7 presents the toxicity data that the EPA plans to use to assess the risk of buprofezin to 

terrestrial animals and plants. Birds act as surrogates for reptiles and terrestrial-phase amphibians

when data on those species are not available. Overall the toxicity data indicate that buprofezin has 

low acute toxicity to terrestrial vertebrates. Acute toxicity studies show that buprofezin is 

practically nontoxic to birds and slightly toxic to mammals. Studies on dermal and inhalation 

toxicity in mammals found no mortality at the doses tested, indicating low acute toxicity through 

these exposure routes. These studies categorized the toxicity category for mammalian dermal and 

inhalation toxicity as IV for the tested formulated product (40% ai), and categories III-IV for the 

technical product. Toxicity studies have shown that buprofezin can cause chronic toxic effects to 

both birds and mammals. An avian reproductive test with the northern bobwhite found significant 

eggshell thinning and reduction of 14-day-old chick weights at a dietary exposure of 2000 mg 

ai/kg diet, establishing an NOAEC at 500 mg ai/kg diet. A 2-generation reproduction test with 

mammals found reduced pup weight in rats exposed at 1000 mg ai/kg diet, and established the 

chronic NOAEL at 100 mg ai/kg diet.

Table 7. Acute and Chronic Toxicity of Buprofezin to Terrestrial Species.

Taxonomic 

Group,

Study Type

Surrogate Species Toxicity 

(expressed as AI)

Citation

MRID

Study

Classification

Birds1

Birds, Acute 

Oral

Mallard 

(Anas platyrhynchos)

LD50 > 2000 mg/kg bw 42873827 Acceptable

Northern Bobwhite

(Colinus viginianus)

LD50 > 2000 mg/kg bw 42873828 Acceptable

Birds, Subacute 

Dietary

Mallard 

(Anas platyrhynchos)

LC50 > 5090 mg/kg diet 42873829 Acceptable

Northern Bobwhite

(Colinus viginianus)

LC50 > 5243 mg/kg diet 42873830 Acceptable

Birds, Chronic

Mallard 

(Anas platyrhynchos)

NOAEC= 2000 mg/kg diet

LOAEC > 2000 mg/kg diet 44394014 Acceptable

Northern Bobwhite

(Colinus viginianus)

NOAEC= 500 mg/kg diet

LOAEC = 2000 mg/kg diet

(decreased eggshell 

thickness, decreased growth 

of chicks)

44394013 Acceptable

Mammals

Mammals, 

Acute Oral

Laboratory rat

(Rattus norvegicus)

LD50 = 1635 mg/kg bw 

(males) 42873806 Acceptable

Mammals, 

Acute Dermal

Laboratory rat

(Rattus norvegicus)

LD50 > 2000 mg/kg bw242873822 Acceptable

Mammals, Laboratory rat LC50 > 0.832 mg/L345699101 Acceptable
17

Taxonomic 

Group,

Study Type

Surrogate Species Toxicity 

(expressed as AI)

Citation

MRID

Study

Classification

Acute Inhalation (Rattus norvegicus)

Mammals,

Chronic

(2-generation 

reproduction)

Laboratory rat

(Rattus norvegicus)

NOAEC = 100 mg/kg diet

LOAEC = 1000 mg/kg diet

(reduced pup weight)

42873814 Acceptable

Terrestrial Insects

Insects Honey bee (adult)

(Apis mellifera L.)

LD50 (contact) > 200 μg/bee 44394040 Acceptable

Terrestrial Plants

Terrestrial 

Plants, Seedling 

Emergence

Cabbage, cucumber, 

lettuce, radish, soybean, 

tomato, corn, oat, onion, 

wheat

Inhibition 0-12% at 4.0 lbs 

ai/A 44394036 Acceptable

Terrestrial 

Plants, 

Vegetative 

Vigor

Cabbage, cucumber, 

lettuce, radish, soybean, 

tomato, corn, oat, onion, 

wheat

0-16% inhibition

at 4.0 lbs ai/A 44394037 Acceptable

1. Birds represent surrogates for terrestrial-phase amphibians and reptiles.

2. This study was conducted with the formulated product Liquid Applaud 40 SC (40% buprofezin). The 

toxicity endpoint was converted to represent toxicity of the active ingredient.

3. This study was conducted with the formulated product Buprofezin 40 SC (40% buprofezin). The toxicity 

endpoint was converted to represent toxicity of the active ingredient.

Passerine Toxicity Testing

Toxicity data with the mallard and northern bobwhite has shown that buprofezin is practically 

nontoxic to birds. No mortality was observed in tests with either species when they were 

administered a dose of 2000 mg ai/kg bw, or given a dietary concentration of over 5000 mg/kg 

(Table 7). No frank sublethal effects were observed in these studies. Furthermore, since 

buprofezin is an insect growth regulator and has a mode of action that is not relevant to terrestrial 

vertebrates (chitin biosynthesis inhibition), acute toxicity to birds is expected to be minimal. 

Therefore, an acute oral toxicity test (850.2100) with a passerine bird would not likely show any

toxic effects and would not likely change the conclusion of low acute toxicity to birds which have 

been made in previous assessments. Therefore, the EPA does not anticipate needing this study for 

assessing ecological risk.

Insect Pollinator Testing

An acute contact test with adult honey bees determined the LD50 to be greater than 200 μg/bee, 

classifying it as practically nontoxic. However, being that buprofezin is an insect growth regulator 

that inhibits chitin biosynthesis, toxicity is likely to be much greater to eggs and larval stages of 

bees and other insect pollinators than to the adult bees. Therefore, a laboratory bee larvae toxicity 

study would help to better assess the potential effects of buprofezin on insect pollinators.

Toxicity studies by Mommaerts et al. (2006) with the bumblebee (Bombus terrestris) provide 

some information on the hazard of buprofezin to bees from reproductive and developmental 

toxicity. While the study found no evidence of acute toxicity of buprofezin to adult bees, adverse 

effects on reproduction and survival of larval stages were observed. In one set of tests, worker 
18

bumblebees were exposed to a concentration of 75 mg ai/L, the maximum field recommended 

concentration (MFRC) for Applaud® Insecticide. Bees were exposed either dermally through 

topical application, orally through treated sugar water, or orally through treated pollen. Dermal 

exposure did not result in any significant adverse effects. Exposure through water caused 

significant adverse effects to reproduction (decreased number of males produced and decreased 

egg hatching). Exposure through pollen caused significant adverse effect to reproduction 

(decreased number of males produced) and larval development (increased number of dead 1st and 

2

nd instar larvae). In a second set of tests using multiple treatment levels at logarithmic serial 

dilutions, exposure of buprofezin through pollen caused significant adverse effects to 

reproduction, with NOAEC and LOAEC values established at 1/100 the MFRC (0.75 mg ai/L) 

and 1/10 the MFRC (7.5 mg ai/L) and respectively. Measurements of the number of males 

produced per nest with five workers yielded EC50 values of 69 mg ai/L with exposure through 

sugar water and 79 mg ai/L with exposure through pollen. The authors of this paper noted, 

however, that the adverse effects they observed in tests with buprofezin were relatively weak 

compared to those they observed in identical tests with two other chitin synthesis inhibiting 

insecticides, diflubenzuron and teflubenzuron.

Terrestrial Plant Testing

Tier 1 phytotoxicity tests with ten crop species show that buprofezin caused no more than minor 

inhibition (<25%) of emergence and growth of terrestrial plants when tested at the rate of 4.0 lbs 

ai/A. Since this application rate equals the highest maximum seasonal application rate (4.0 lbs 

ai/A for citrus trees and coffee), these data are adequate for demonstrating that buprofezin would 

pose minimal risk to terrestrial plants.

4.3 Ecological Incidents

A preliminary review of the Ecological Incident Information System (EIIS, version 2.1) in 

January 2012 did not identify any reported ecological incident of adverse field effects to nontarget 

plants or animals attributed to the use of buprofezin. Also, review of the Avian Incident 

Monitoring System (AIMS), which is maintained by the American Bird Conservancy, did not 

identify any ecological incident associated with the use of buprofezin. 

In addition to the incidents recorded in EIIS and AIMS, the EPA maintains a database that stores 

counts of minor incidents that pesticide registrants record in quarterly aggregated incident reports. 

Ecological incidents recorded in these aggregated reports include those categorized as ‘minor fish 

and wildlife’ (W-B), ‘minor plant’ (P-B), and ‘other non-target’ (ONT) incidents. ‘Other nontarget’ incidents include reports of adverse effects to insects and other terrestrial invertebrates. A 

review of this database in January 2012 did not identify any minor fish, wildlife, plant, or other 

non-target incident associated with use of buprofezin.

5.0 Ecosystems Potentially at Risk

Terrestrial habitats near treated agricultural sites may be exposed through spray drift and other 

off-site movement of the applied pesticide. Furthermore, terrestrial animals that use treated 

fields, orchards, and vineyards may be exposed from direct application of spray and from feeding 
19

on contaminated food items. As the toxicity of buprofezin is specific to early life-stages of 

invertebrates, risk to terrestrial habitats is expected to be limited mainly to adverse direct effects 

on terrestrial arthropods, and indirect effects that may occur to animals that depend on terrestrial 

arthropods.

Aquatic habitats near and downstream of treated fields and orchards may be at risk. These 

habitats may be exposed from contaminated runoff from the treated use sites, as well as by spray 

drift and movement of contaminated soil particles. Because applications of buprofezin can occur 

in coastal areas, exposure may occur to saltwater as well as freshwater ecosystems. Exposure of 

aquatic habitats with buprofezin is expected to pose little risk to adult organisms, but toxicity data 

indicate chronic exposure may pose risk to aquatic animals as the result of adverse effects on 

reproduction and development of early life-stages. Because buprofezin binds to sediment and is 

relatively persistent, buprofezin may accumulate in sediment, potentially resulting in risk to 

ecosystems associated with benthic freshwater and estuarine habitats.

Use of buprofezin occurs in all regions of the United States, including Hawaii and Puerto Rico. 

Habitats in regions with high concentrations of fruit, nut, and vegetable production are expected 

to be at greatest potential risk. Buprofezin is not registered for use on forests, pastures, 

rangelands, or grain crops. Therefore, ecological risk in regions dominated by these land uses is 

expected to be minimal. Also, since buprofezin is not registered for residential use, risk to 

regions dominated by urban and suburban areas is also expected to be minimal.

6.0 Assessment Endpoints

A summary of the assessment and measurement endpoints selected to characterize potential 

ecological risks associated with exposure to buprofezin are summarized in Table 8. The 

ecological relevance of selecting these assessment endpoints is as follows: 1) complete exposure 

pathways exist for these receptors, 2) the receptors may be potentially sensitive to pesticides in 

affected media and residues in aquatic organisms, and 3) the receptors could potentially inhabit 

water bodies receiving pesticides from treated use sites.

The planned risk assessment is not intended to represent a site or time-specific analysis, but is 

intended to represent high-end exposures at a national level. Likewise, the most sensitive toxicity 

endpoints are used from surrogate test species to estimate treatment-related direct effects on acute 

mortality and chronic reproductive, growth and survival assessment endpoints. Toxicity tests are 

intended to determine effects of pesticide exposure on birds, mammals, fish, terrestrial and 

aquatic invertebrates, and plants. These tests include short-term acute, subacute, and reproduction 

studies and are typically arranged in a hierarchical or tiered system that progresses from basic 

laboratory tests to applied field studies. The toxicity studies are used to evaluate the potential of a 

pesticide to cause adverse effects, to determine whether further testing is required, and to 

determine the need for precautionary label statements to minimize the potential adverse effects to 

non-target animals and plants (40 CFR §158.202, 2002).

In order to protect threatened and endangered species, all assessment endpoints are measured at 

the individual level. Measuring endpoints at the individual level also provides insight about risks 

at higher levels of biological organization (e.g. population and communities). For example, 
20

pesticide effects on individual survivorship have important implications for both population 

growth increase and habitat carrying capacity.

Table 8. Summary of Assessment Endpoints and Measures of Ecological Effects

Assessment Endpoint Surrogate Species and Measures of 

Ecological Effect1 Measures of Exposure

Birds2

Survival

Bobwhite quail acute oral LD50

Bobwhite quail and mallard duck 

subacute dietary LC50

Predicted peak residues 

in wildlife food items

Reproduction 

and growth

Bobwhite quail and mallard duck 

reproduction NOAEC

Mammals

Reproduction 

and growth

Laboratory rat reproduction 

NOAEC and NOAEL

Survival Laboratory rat acute oral LD50

Freshwater fish3

Survival Rainbow trout and bluegill sunfish 

acute LC50

Peak EEC4

Reproduction 

and growth Freshwater fish reproduction NOAEC 60-day average EEC4

Freshwater

invertebrates

Survival Water flea acute EC50 Peak EEC4

Reproduction 

and growth Water flea reproduction NOAEC 21-day average EEC4

Estuarine/marine fish Survival Sheepshead minnow acute LC50 Peak EEC4

Estuarine/marine 

invertebrates Survival Eastern oyster acute EC50 and mysid 

acute LC50 

Peak EEC4

Benthic invertebrates

Survival Amphipod acute LC50 and midge 

acute LC50 

Peak EEC4

Reproduction 

and growth Midge NOAEC 21-day average EEC4

Aquatic plants and 

algae

Survival and 

growth

Algal (green algae) and vascular plant 

(duckweed) EC50 and NOAEC values 

for growth rate and biomass 

measurements 

Peak EEC4

1 If species listed in this table represent most commonly encountered species from submitted studies, risk assessment 

guidance indicates most sensitive species tested within taxonomic group are to be used for baseline risk assessments.

2 Birds represent surrogates for amphibians (terrestrial phase) and reptiles.

3 Freshwater fish may be surrogates for amphibians (aquatic phase).

4 Based on standard pond estimates of aquatic EECs.

5 Four species of two families of monocots - one is corn, six species of at least four dicot families, of which one is 

soybeans. 

7.0 Conceptual Model

7.1 Risk Hypothesis

The EPA will employ the following risk hypothesis when assessing ecological risks of the use of 

buprofezin:
21

Buprofezin, when used in accordance with current labels, may result in contamination of 

ecosystems and adverse effects upon the survival, growth, and reproduction of non-target 

terrestrial and aquatic organisms, including organisms that are Federally-listed as 

threatened and endangered species.

7.2 Conceptual Diagram

The potential exposure pathways and effects of buprofezin are depicted for aquatic environments 

in Figure 2 and for terrestrial environments in Figure 3. 

Figure 2. Conceptual model depicting stressors, exposure pathways, and potential effects to 

aquatic animals and plants from the use of buprofezin. Dotted lines depict exposure routes that 

are expected to be insignificant.
22

Figure 3. Conceptual model depicting stressors, exposure pathways, and potential effects to 

terrestrial animals and plants from the use of buprofezin. Dotted lines depict exposure routes that 

are expected to be insignificant.

8.0 Analysis Plan 

In registration review, pesticide ecological risk assessments will follow the EPA’s Guidelines for 

Ecological Risk Assessment, will be in compliance with the paper titled “Overview of the 

Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental 

Protection Agency” (“Overview Document”) (January 2004), and will be done in accordance with 

Section 7 of the Endangered Species Act (US EPA, 2004).

8.1 Stressors of Concern

The EPA does not routinely include, in its risk assessments, an evaluation of mixtures of active 

ingredients, either those mixtures of multiple active ingredients in product formulations or those 

in the applicator’s tank. In the case of the product formulations of multiple active ingredients (that 

is, a registered product containing more than one active ingredient), each active ingredient is 

subject to an individual risk assessment for regulatory decision regarding the active ingredient on 

a particular use site. If effects data are available for a formulated product containing more than 

one active ingredient, they may be used qualitatively or quantitatively in accordance with the 
23

EPA’s Overview Document and the Services’ Evaluation Memorandum (U.S., EPA 2004; 

USFWS/NMFS 2004). 

Eleven degradation products of buprofezin have been identified. Neither environmental fate nor 

ecological effects data for the degradation products have been submitted. However, OPP’s Health 

Effects Division (HED) concluded that the only residue of concern is parent buprofezin. 

Therefore, ecological risk and drinking water assessments conducted in registration review will 

focus only on the parent compound. 

8.2 Measures of Exposure

In order to estimate risks of buprofezin exposures in aquatic and terrestrial environments, all 

exposure modeling and resulting risk conclusions will be based on registered labels including 

maximum application rates and methods cited earlier for each use of buprofezin. Measures of 

exposure are based on aquatic and terrestrial models that predict estimated environmental 

concentrations (EECs) of buprofezin. 

The model used to predict terrestrial EECs on food items is T-REX. Three models are used to to 

derive EECs relevant to terrestrial and wetland plants. TerrPlant is used to estimate exposure to 

terrestrial plants from runoff from treated sites, whereas AgDrift and AgDisp are used to estimate 

exposure to terrestrial plants from spray drift. See the following web site for further information 

on these models: http://www.epa.gov/oppefed1/models/terrestrial/index.htm.

8.2.1 Aquatic Exposure and Modeling Input Parameters

The appropriate input parameters are selected from the environmental fate data and in accordance 

with USEPA-OPP-EFED water model parameter selection guidelines. Potential aquatic exposures 

will be estimated using the Tier II models Pesticide Root Zone Model (PRZM v3.12.2, May 12, 

2005) and Exposure Analysis Modeling System (EXAMS v2.98.04.06, April 25, 2005) coupled 

with the input shell pe5.pl (Nov. 16, 2006). PRZM simulates fate and transport of pesticides on 

the agricultural field and EXAMS simulates the fate and resulting daily concentrations of 

pesticides that reach an adjacent water body through runoff, erosion, and spray drift. Simulations 

are based on crop-specific scenarios developed to represent environmental conditions at sites at 

high runoff-vulnerability for pesticide transport to surface waters from a particular crop. Exposure 

is estimated using a standard pond scenario based on a10-ha field bordering a 1-ha water body, 2-

m deep (20,000 m3) with no outlet. Using appropriate scenarios linked with local meteorological 

data, the model is run for 30 years with the reported EECs representing the values that are 

expected once every ten years, based on the thirty years of daily values generated during the 

simulation. Additional information about model assumptions and uncertainties, input guidance, 

and scenario metadata are available at the EPA’s water modeling website, 

http://www.epa.gov/oppefed1/models/water/.

The environmental fate values to be used for modeling are summarized in Table 9. Pesticide 

specific inputs used are the estimated 90 percent upper bound value of the first-order kinetics 

aerobic soil metabolism half-lives (T1/2 = 168 days; the 90%upper-bound on mean), a maximum 
24

aquatic photolysis half-life (T1/2 = 38 days), the lowest non-sand Kd value of 69 mL/g, and 16%

spray drift (aerial application). Because the aerobic aquatic metabolism rates are not known it is 

estimated (as 336 days) using EFED guidance (taking the upper 90 percent half-life for aerobic 

soil metabolism and multiplying it by 2).

Table 9. Summary of model input parameters used for assessing aquatic exposure

Fate Property Value Model used

Molecular Weight 305.4 EXAMS

Henry’s constant 6.73 x 10-6atm - m

3

/mole EXAMS

Vapor Pressure 6.4 x 10-6 mm Hg at 25C EXAMS

Solubility in Water 0.382 mg/L at 25 C EXAMS

Photolysis in Water 38 days EXAMS

Aerobic Soil Metabolism Half-life 168 days (90% upper bound on mean)

68.75 days (mean)

PRZM

SCI-GROW1

Anaerobic Soil Metabolism Half-life No data EXAMS

Hydrolysis stable @ pH = 7 EXAMS

Aerobic Aquatic Metabolism 336 ( 2 * 168) EXAMS

Anaerobic Aquatic Metabolism Stable EXAMS

Kads 69 PRZM/ EXAMS

Koc 2791 SCI-GROW1

Spray Drift 0.16 – aerial; 0.064 ground EFED guidance

Application Efficiency 0.95; -aerial 0.99 – ground EFED guidance

1

http://www.epa.gov/oppefed1/models/water/scigrow_description.htm

8.2.2 Monitoring Data for Surface Water

No surface or ground water monitoring data were found for buprofezin. Sources checked include 

the U.S Geological Service National Water Quality Assessment database (NAWQA, 2007), the 

USGS/EPA Reservoir Monitoring Program (Blomquist et al., 2001), the California Department of 

Pesticide Regulation Surface Water Database (DPR, 2006), the National Stream Quality 

Accounting Network database (NASQAN, 2006), the USDA Pesticide Data Program (PDP) 

surface water monitoring program, and the USEPA STORET database of water quality 

parameters. 

8.2.3 Terrestrial Exposure

Exposure to terrestrial animals and plants will be assessed for general crop groups to represent all 

uses of buprofezin. For each crop group, exposure will be quantitatively assessed based on 
25

restrictions on the product labels for the maximum application rate, maximum seasonal use rate, 

maximum number of applications allowed per season, and minimum reapplication interval, as 

given in Figure 1. Buprofezin Usage by Crop Reporting District (2006-2010). (USEPA, 2012).

For all crops, buprofezin products are registered for foliar application using either ground 

equipment or aircraft. Buprofezin is registered for ultra low volume (ULV) application on tomato 

and ornamental plants. Application of buprofezin through irrigation systems (i.e., chemigation) is 

prohibited. Labels of buprofezin products contain no restrictions that would prevent application 

to the crops during bloom. The label for NNI-0871 SC (Vetica Insecticide, EPA Reg. No. 71711-

32), which contains flubendiamide as well as buprofezin, requires that a 15-ft buffer zone be 

maintained between the treated field and any aquatic habitat. Products containing buprofezin 

alone do not have buffer zone requirements. Table 2 below, summarizes the currently registered 

uses of buprofezin and application information for each crop or use site.

Table 2. Since all buprofezin products are applied only as foliar spray, EPA will use its standard 

methodology for assessing terrestrial exposure based on consumptions of contaminated food 

items on sprayed use sites. The current version of the Terrestrial Residue Exposure Model (TRex) will be used to estimate maximum concentrations of buprofezin active ingredients on 

various types of on wildlife food items, including short grass, broadleaf plants, fruit, seeds, and 

insects. For uses involving a single application, the maximum concentration will be the initial 

concentration immediately following spraying, and for uses with multiple applications allowed, 

the maximum concentration will be the predicted peak application of accumulated residues, 

taking into account dissipation. The peak concentrations from multiple applications will be 

modeled assuming a reasonably conservative (slow) rate of dissipation based on data available 

from submitted studies on magnitude of residue, reduction of residue, and foliar dissipation for 

registered uses on appropriate commodities, such as leafy vegetable crops. If these studies do not 

provide adequate data to estimate the foliar dissipation half-life for buprofezin, then the division’s 

default value of 35 days will be assumed. 

The T-Rex model assesses risk to birds and mammals based on dietary exposure. Dietary 

exposure then will be assessed for animals which are assumed to consume each of the various 

terrestrial food types, assuming that 100% of their diet consists of contaminated food of a single 

type. EPA has used the Screening Tool for Inhalation Risk (STIR, Version 1.0) and the Screening 

Imbibition Program (SIP, version 1.0) to screen for the potential for registered uses of buprofezin 

to result in significant exposure through inhalation and drinking water. Because of the low 

volatility and solubility of buprofezin, relative to its toxicity, these models have found that 

exposure through drinking water and inhalation will not significantly contribute to the exposure or 

risk to terrestrial birds and mammals. Therefore, these routes of exposure will not be included in 

the assessment of risk to terrestrial wildlife. While the terrestrial risk assessment will be 

conducted for risk to birds and mammals, the risk conclusions will be presumed to be protective 

of reptiles and terrestrial phases of amphibians as well. 

The T-Rex model does not predict exposure to terrestrial insects. Because buprofezin is highly 

toxic to immature developing insects, exposure to larvae and pupae stages of bees and other insect 

pollinators is a concern. Exposure to immature stages of insect may occur when adult insects 

forage on treated fields and carry nectar and/or pollen back to feed developing young. Therefore, 

to assess exposure to terrestrial insect pollinator, EPA will seek information in the open literature 

on residues buprofezin in the nectar, pollen, honey, and bee bread. If such information is not 
26

available, EPA may request additional data to measure exposure and effects to bees from use of 

buprofezin.

EECs for terrestrial plants inhabiting upland and wetland areas will be derived using TerrPlant. 

This model uses estimates of pesticides in runoff and in spray drift to calculate EECs. EECs are 

based upon solubility, application rate and minimum incorporation depth in addition to type of 

formulation and method of application. Two spray drift models, AGDisp and AgDRIFT, are used 

to assess exposures of terrestrial plants to buprofezin deposited in terrestrial habitats by spray 

drift. 

Exposure will also be assessed for piscivorous (fish-eating) terrestrial wildlife which feed on 

aquatic organisms, such as the bald eagle. Exposure and risk to piscivorous wildlife feeding on 

aquatic organisms will be assessed using the current version of the KABAM model 

(http://www.epa.gov/oppefed1/models/water/#kabam). Guidance for this model recommends 

using the model for non-ionic organic compounds for which the log of the octanol-water partition 

coefficient (log Kow) is between 4 and 8. The log Kow for buprofezin at 20oC is 4.31.

8.3 Measures of Effect

Ecological effects data are used as measures of direct and indirect effects to biological receptors. 

Measures of effects to animals with acute exposure are the LD50 and LC50, or for aquatic 

invertebrates, an EC50 based on immobility. Measures of effects to animals from chronic 

exposure are the NOAEL or NOAEC for based on observable lethal and sublethal effects. 

Toxicity endpoints used to measure effects to terrestrial plants are the IC25 for nonlisted species 

and either the NOAEL or IC05 for listed species. 

Data are obtained from registrant-submitted studies and/or from literature studies identified by 

ECOTOX. The ECOTOX database provides more ecological effects data in an attempt to bridge 

existing data gaps. ECOTOX is a source for locating single chemical toxicity data and potential 

chemical mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX was 

created and is maintained by EPA, Office of Research and Development, and the National Health 

and Environmental Effects Research Laboratory's Mid-Continent Ecology Division.

Information on the potential effects of buprofezin on non-target animals is also collected from the 

Ecological Incident Information System (EIIS; USEPA, 2007c). The EIIS is a database 

containing adverse effect (typically mortality) reports on non-target organisms where such effects 

have been associated with the use of pesticides. Incidents reported in the aggregate incident 

reports and the Avian Incident Monitoring System (AIMS) will also be searched. AIMS is a 

database administered by the American Bird Conservancy (partially funded by EPA). It contains 

publicly available data on reported avian incidents involving pesticides 

(http://www.abcbirds.org/abcprograms/policy/pesticides/aims/aims/index.cfm). Finally, the 

Incident Data System (IDS), a component of the PRISM database maintained by ITRMD, is also 

a source of incident information.

Where available, sub-lethal effects observed in both registrant-submitted and open literature 

studies will be evaluated qualitatively. Such effects may include behavioral changes (e.g., 
27

lethargy and changes in coloration). Quantitative assessments of risks, though, are limited to 

those endpoints that can be directly linked to the EPA’s assessment endpoints of impaired 

survival, growth and reproduction.

The assessment of risk for direct effects to non-target organisms makes the assumption that 

toxicity of buprofezin to birds is similar to terrestrial-phase amphibians and reptiles. The same 

assumption is made for fish and aquatic-phase amphibians. 

8.4 Integration of Exposure and Effects

Risk characterization is the integration of exposure and ecological effects characterization to 

determine the potential ecological risk from the use of buprofezin and the likelihood of direct and 

indirect effects to non-target organisms in aquatic and terrestrial habitats. The exposure and 

toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects on 

non-target species. For the assessment of buprofezin risks, the risk quotient (RQ) method is used 

to compare exposure and measured toxicity values. EECs are divided by acute and chronic 

toxicity values. The resulting RQs are then compared to the EPA’s Levels of Concern (LOC) 

(USEPA, 2004). These criteria are used to indicate when buprofezin’s use, as directed on the 

labels, has the potential to cause adverse direct or indirect effects to non-target organisms. In 

addition, incident data from EIIS, incident data system reports, and AIMS will be considered as 

part of the risk characterization. 

When calculating risk quotients (RQ’s) for aquatic invertebrates, EFED typically compares acute 

toxicity endpoints with the peak predicted water concentration of the pesticide, whereas chronic 

invertebrate life-cycle toxicity endpoints are typically compared with a predicted water 

concentration averaged over 21 days. The 21-day average EEC is typically used to match the 

duration of exposure encountered in the laboratory effects testing. However, the inhibition of 

chitin synthesis during specific stages of larval development is considered an acute event that 

requires only a short-term exposure during the specific stage of development (Touart and Rao, 

1987; MRID 44460702 ). Risk assessment for other chitin-synthesis inhibitors, such as 

diflubenzuron, have therefore calculated chronic RQs using the acute peak EEC rather than the 

21-day average EEC (e.g. Section 3 Registration Request for Uses of Diflubenzuron on Pears, 

Stone Fruits, Tree Nuts, Peppers, and Pasture Grass (Chemical # 108201, DP Barcode D279732, 

D279735, D278770). EPA plans on using this approach in calculating chronic RQs for the effects 

of buprofezin on aquatic invertebrates.

8.5 Endangered Species Assessment

Consistent with the EPA’s responsibility under the Endangered Species Act (ESA), the EPA will 

evaluate risks to Federally-listed threatened and/or endangered (listed) species from registered 

uses of buprofezin. Risk assessments will be conducted in accordance with the Overview 

Document (USEPA, 2004), provisions of the ESA, and the Services’ Endangered Species 

Consultation Handbook (USFWS/NMFS, 1998).
28

8.6 Drinking Water Assessment

OPP/EFED has recently finalized a new human health drinking water exposure assessment 

(DWA) for buprofezin on for the proposed uses of buprofezin, requested by IR-4, on leafy 

brassica vegetables, turnip greens, and persimmon and expanding use to the full crop subgroup 

for fruiting vegetables, except non-bell pepper (Group 8-10); citrus fruit (Group 10-10), pome 

fruit (Group 11-10), and succulent bean. (See 275100 D395217 and D393932 New Uses DWA, 

issued April 5, 2012). This new DWA reconfirms the EDWC values calculated previously (See 

275100 D360583 Amended DWA, issued January 12, 2009). Using the PRZM/EXAMS2 model 

to estimate potential concentrations in water, the highest, peak, surface water concentration value

is 58.2 μg/L, and the 1-in-10 year average (chronic) EDWC is 18.6 μg/L, based on the Puerto 

Rico coffee scenario. For citrus, the highest, peak, surface water concentration value is 57.1 μg/L, 

and the 1-in-10 year average EDWC is 12.4 μg/L, based on the Florida citrus scenario. Using 

SCI-GROW1 model to estimate potential residues in groundwater, the concentration value for 

both citrus and coffee is 0.09 μg/L. Therefore, this assessment reconfirms that the estimated 

drinking water concentrations (EDWC) previously calculated for the reduced application rate on 

coffee continue to produce the highest EDWC. 

Two Tier II screening level Drinking Water Assessments had been previously conducted for 

buprofezin uses at the maximum rate (DP Barcode D339828 dated January 7, 2008 and D343066 

dated April 23, 2008). Surface water EDWCs for all modeled uses are listed below in Table 8. 

EDWCs ranged from 4.5 to 58.2 ppb for acute exposure in surface water and from 1.5 to 18.6 ppb 

for chronic exposure. Groundwater EDWCs do not reflect site-specific environments or 

agricultural practices other than application rates, so all uses with the maximum application rate 

share the highest values. The proposed use on olives, as well as currently registered uses on citrus, 

peaches, and pears, all lead to acute and chronic groundwater EDWCs of 0.09 ppb.

`Table 8. Summary of Previous Human Health Drinking Water EDWCs for Buprofezin

Table 8. Tier II EDWCs in surface water drinking water sources resulting from application of buprofezin.

Use PRZM Scenario 1-in-10 year acute 

(ppb)

1-in-10 year chronic 

(ppb)

30- year average 

(ppb)

Strawberry

CA strawberry 11.0 3.0 2.1

FL strawberry 11.2 3.8 2.9

Low-growing 

berries

OR berry 4.5 1.5 1.3

GA peach 6.5 1.7 1.3

MI cherry 11.6 4.2 3.1

CA wine grape 13.1 3.6 2.6

Olive CA olive 7.0 3.5 2.6

Leafy vegetables

CA row crop 9.6 2.6 2.0

FL pepper 16.1 4.3 3.1

CA lettuce 19.1 6.4 4.5

 

2

For additional information on the PRZM/EXAMs and SCI-GROW models, refer to 

http://www.epa.gov/pesticides/science/models_pg.htm#aquatic.
29

FL tomato 20.4 5.0 3.7

Cranberries a N/A 47.9 N/A N/A

Coffee PR coffee 58.2 18.6 13.6

Citrus FL citrus 57.4 12.5 9.1

a Modeled using Tier I Rice Model v. 1.0.

8.7 Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different taxonomic 

groups. As part of its reregistration decision, EPA reviewed these data and selected the most 

sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. 

However, as required by FFDCA section 408(p), buprofezin is subject to the endocrine screening 

part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including pesticide active 

and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a 

“naturally occurring estrogen, or other such endocrine effects as the Administrator may 

designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the EPA must screen all pesticide chemicals. Between October 

2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, 

which contains 58 pesticide active ingredients and 9 inert ingredients. Buprofezin is not among 

the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. 

Accordingly, as part of registration review, EPA will issue future EDSP orders/data call-ins, 

requiring the submission of EDSP screening assays for buprofezin. For further information on the 

status of the EDSP, the policies and procedures, the list of 67 chemicals, future lists, the test 

guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/.

9.0 Clean Water Act
30

Buprofezin is not identified as a cause of impairment for any water bodies listed as impaired 

under section 303(d) of the Clean Water Act3. In addition, no Total Maximum Daily Loads 

(TMDL) have been developed for buprofezin4. More information on impaired water bodies and 

TMDLs can be found at the EPA’s website5. The EPA 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 

Process6in order to ensure they can be used quantitatively or qualitatively in pesticide risk 

assessments.

10.0 Anticipated Data Needs

The EPA does foresee requiring additional fate and ecological effects studies prior to 

conducting the planned assessments. Data gaps, uncertainties and potential paths forward for the 

assessment of buprofezin are described below.

10.1 Environmental Fate

The following information is needed in order to conduct the planned assessments. According to 

EPA records, these studies have never been submitted for review:

835.4300 Aerobic Aquatic Metabolism 

835.6100 Environmental Chemistry Method and Independent Laboratory Validation- soil

835.6200 Environmental Chemistry Method and Independent Laboratory Validation-water

Additional data are requested to upgrade the storage stability data of the Terrestrial Field 

Dissipation study (MRID 44394044, Guideline 835.6100) from "Upgradable" to "Acceptable" in 

accordance to the Subdivision N Guidelines.

10.2 Ecological Effects 

EPA anticipates that the following additional ecological effects studies are needed to characterize 

risk for buprofezin in the upcoming risk assessment for Registration Review. See Appendix A for 

a complete listing of the current status of data requirements.

850.1350 Chronic Toxicity with the Mysid

The methodology used in the mysid life-cycle toxicity test (47676702) deviated significantly from 

the methodology recommended by the 850 test guidelines. Significant deficiencies of the study 

include no measurement of time to first brood and measurements of length which were not 

recorded by gender. In addition, measurements of test concentrations over time showed high 

variability in all treatment levels (CV of 26-38%). While uncertain, the results of this study do 

 

3

http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

4

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_group_name=PESTICIDES

5

http://www.epa.gov/owow/tmdl/

6

http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm
31

indicate greater toxicity than does earlier invertebrate life-cycle testing with a freshwater 

waterflea (Daphnia magna), and thus may change the previous conclusions of low chronic risk to 

aquatic invertebrates. Furthermore, the chronic toxicity of buprofezin to the mysid cannot be 

estimated with available data using the acute-to-chronic ratio method because the acute toxicity 

endpoints for the mysid and the waterflea are nondefinitve. Therefore, a new life-cycle test with 

the mysid is needed.

Chronic Sediment Toxicity with Freshwater Benthic Invertebrates

Because buprofezin is persistent, binds to sediment, may reach aquatic habitats, and exhibits 

toxicity to aquatic invertebrates, obtaining good information on the toxicity of buprofezin to 

sediment-dwelling invertebrates is important for characterizing ecological risk. The chemical 

meets all of the EPA criteria for requesting chronic sediment toxicity testing. The chemical has 

been shown to have half-lives greater than 10 days in both the terrestrial environment (aerobic 

soil half-lives 36.5-101 days, MRID 44394042) and the aquatic environment (stable under 

anaerobic aquatic metabolism conditions, MRID 44394043). The chemical also meets all of the 

physical chemistry triggers for chronic sediment toxicity testing (Kd>50, log Kow>3, and 

Koc>1000). Chronic testing may be requested when any one of these physical chemistry triggers 

are met.

The registrants have submitted two 28-day subchronic studies on the effects of buprofezin on the 

emergence of the midge, Chironomus riparius, one with spiked water (MRID 46597901) and one 

with spiked sediment (MRID 47676703). However, these studies were done according to the 

OECD guidelines (OECD guidelines 218 and 219), which differs substantially from the OCSPP 

test guidelines for acute and chronic sediment toxicity testing. Differences include the test 

species, the duration of exposure, and the toxicity endpoints measured. Because of these 

substantial differences, the submitted study is not acceptable for fulfilling any test requirements 

for testing toxicity of buprofezin to benthic organisms. Nevertheless, the study was adequate to 

demonstrate that buprofezin has relatively low toxicity to Chironomus sp. with short-term 

exposure. MRID47676703 provided evidence that the 10-day LC50 of developing midges 

exposed to spiked water exceeds 5.54 mg ai/L. As this provides adequate data for assessing acute 

toxicity to sediment-dwelling invertebrates, additional 10-day sediment toxicity tests with a 

freshwater species (Guideline 850.1735) and a saltwater species (Guideline 850.1740) will not 

needed.

The observation of relatively low acute toxicity to benthic invertebrates agrees with studies with 

other aquatic crustaceans that show buprofezin is much more toxic on a chronic basis than on an 

acute basis. An acute test with the waterflea found the 48-hr EC50 to be greater than 420 μg ai/L 

(MRID 42873833), whereas a chronic test with the same species established an NOAEC at 80 μg 

ai/L (MRID 44435901). Similarly, an acute test with the grass shrimp found the 96-hr LC50 to be 

greater than 560 μg ai/L (MRID 44394020), whereas a life-cycle study with the mysid (another 

saltwater crustacean) established an NOAEC at 22.5 μg ai/L (MRID 47676702). The life-cycle 

studies with the water flea (MRID 44435901), as well as supplemental life-cycle studies with the 

fathead minnow (MRID 42873834 and 48083904), found that the most sensitive endpoints were 

reproductive measures such as percent egg hatching and number of young produced. The much 

greater toxicity observed in chronic studies relative to acute studies is also consistent with the 

mode of action of buprofezin, the inhibition of chitin synthesis. Chronic testing with the 
32

sediment-dwelling invertebrates (OCSPP in prep. Guidelines 850.1760, 850.1770, and 850.1780) 

are therefore needed as these are the only sediment toxicity guideline which measures 

reproductive endpoints. 

Maximum concentrations expected in pore water were compared to results of the supplemental 

28-day Chironomus toxicity study to determine if expected environmental concentrations are 

toxicologically relevant. Modeling with PRZM and EXAMS, based on the scenario for use of 

buprofezin on citrus in Florida, determined that the maximum EEC for pore water to be 14.4 μg. 

In the 28-day Chironomus toxicity study with spiked sediment (MRID476767-03), the measured 

pore water concentration associated with the NOAEC (at the test level with an overlying water 

concentration of 2.8 mg/L) was 21 μg/L. Since this EEC is greater than 1/10 the NOAEC of the 

28-day study, expected environmental concentrations are at toxicologically relevant levels where 

significant chronic effects may occur.

Chronic sediment testing with three benthic invertebrates is recommended to ensure protection of 

all benthic invertebrate species which may be exposed to buprofezin. The three test species the 

EPA recommends for chronic sediment toxicity testing are a freshwater midge (Chironomus 

dilutes or C. tentans), the freshwater amphipod Hyaella azteca, and the saltwater amphipod 

Leptocheirus plumulosus. Testing of the freshwater midge is needed because it is an egg-laying 

insect, and thus likely would have similar sensitivity to buprofezin as target species. Furthermore, 

as stated above, 28-day testing with Chironomous riparius indicates that expected environmental 

concentrations are at toxicologically relevant for Chironomous species. Testing with a freshwater 

and a saltwater amphipod are also desired to determine the sensitivity of these divergent 

taxonomic groups to chronic toxicity of buprofezin. However, chronic tests with freshwater and 

saltwater amphipods would not be needed if data could be provided which demonstrates that these

groups of organisms are no more sensitive to buprofezin than the freshwater midge, or that the 

chronic risk assessment for aquatic crustaceans inhabiting overlying water, based on chronic 

toxicity data for the waterflea (Daphnia magna) and the mysid (Americamysis bahia), would be 

protective of sediment-dwelling crustaceans.

850.1500 Fish Life-Cycle Toxicity, Freshwater or Saltwater Species

The methodology of the fish life-cycle study with a fathead minnow (MRID 48083904) had 

relatively minor deviations from the test guideline, but the study failed to establish an NOAEC for 

reproductive effects, and the reproductive results were confounded by very inconsistent 

reproductive performance among the replicate test vessels. At lower concentrations, some 

replicates showed very poor reproduction while others showed reproduction similar to that 

observed in the control. One replicate in the control also showed very poor reproduction. 

Because of this, the study author concluded that the reproductive results were “inconclusive.” 

However, the statistically significant reduction in egg production and percent spawning observed 

at all treatment levels cannot be discounted. A high-quality fish life-cycle study is critical for risk 

assessment because life-cycle testing with the waterflea and the mysid indicate that reproductive 

toxicity is the most sensitive endpoint. Furthermore, comparison of the results of the supplemental 

fish life-cycle study with those of the fish early life-stage study (MRID 44394021) suggest that 

life-cycle test is a more sensitive for detecting chronic effects of buprofezin. Therefore, a new 

fish life-cycle study is needed to establish the fish chronic NOAEC. This study may be conducted 

with either a freshwater or a saltwater fish species.
33

Special Study: Honey Bee Larvae Feeding Study

In an attempt to address protection of pollinators, EPA is anticipating needing data to assess the 

potential hazard to insect pollinators from exposure to buprofezin. In this assessment, the 

honeybee (Apis mellifera) will likely be used as a surrogate for all insect pollinators. In moving 

forward with addressing potential risk to these organisms, EPA will consider the 

recommendations of the Society of Environmental Toxicology and Chemistry (SETAC) 

Workshop on Pesticide Risk Assessment for Pollinators and the FIFRA Science Advisory Panel, 

and will be working with its federal and state partners, industry, and academia to determine 

appropriate assessment methodology. For compounds such as buprofezin, which is (1) known to 

be toxic to insects and (2) known to have exposure routes to bees, the EPA is requesting toxicity 

and exposure studies to allow for evaluation of risks to pollinators. The study of Mommaerts et 

al. (2006) provide evidence that buprofezin is toxic to reproduction and development of the 

honeybee, although the exact level of exposure of the bees in this study is uncertain (see Section 

4.2). The potential for exposure of bees and other insect pollinators to buprofezin is believed to 

be significant because it is used on many flowering crops which are attractive to pollinators, 

including fruit trees, berries, grapes, fruiting vegetables, and ornamental plants. Furthermore, the 

product labels do not prohibit application during times when the crops are in bloom.

At this time, the most important gap in the understanding of the potential risk of buprofezin to 

insect pollinators is the toxicity of the compound to larval stages. Therefore, EPA anticipates the 

need for a bee larvae study with buprofezin. As there is not currently an OCSPP guideline for 

conducting a bee larvae test, the registrant is requested to consult with the EPA on the proposed 

protocol to be used prior to conducting the study. The published method of Aupinel et al. (2007) 

is recommended as an example of a protocol for this type of study.

The EPA will evaluate the need for higher tier toxicity testing of buprofezin after reviewing 

results of the bee larvae toxicity study and other available data, such as residues of buprofezin in 

plant parts. Higher-tiered testing may include field or semi-field honey bee studies and studies 

that measure residues in nectar and pollen of treated crops. EPA will consider the 

recommendations of the SETAC workshop on Pesticide Risk Assessment for Pollinators and the

FIFRA Scientific Advisory Panel in deciding on the type of testing needed and the test protocols 

which should be used. At this time, however, the need for higher-tier toxicity testing with insect 

pollinators is not anticipated for buprofezin because it is not a systemic insecticide and evidence 

does exist not indicate that its use poses a serious hazard to pollinators.

Data call-in justification tables are provided for the special studies which are needed. See 

Appendix A for a complete listing of the current status of data requirements for ecological effects.
34

Data Call-In Justification Tables

Guideline Number: 835.4300 (Aerobic Aquatic Metabolism)

Rationale for Requiring the Data

Buprofezin has a moderate capacity for sorption (binding) to soils and therefore can 

enter shallow or deep surface waters by such routes as direct application, spray drift, 

run-off, and/or through attachment to eroding soil. The conditions in natural aquatic 

sediment systems are often aerobic in the upper water phase. The surface layer of 

sediment can be either aerobic or anaerobic, whereas the deeper sediment is usually 

anaerobic. An aerobic aquatic test simulates an aerobic water column over an aerobic 

sediment layer that is underlain with an anaerobic gradient. This study is used for 

chemicals which are directly applied to water or which are likely to reach the aqueous 

environment by the routes described above. This study is also required for uses such as

aquatic food crop, aquatic nonfood outdoor, aquatic nonfood industrial, aquatic nonfood 

residential and forestry. 

Practical Utility of the Data

How will the data be used?

Aerobic aquatic metabolism data is used to estimate the rate by which the pesticide will 

disappear from aquatic environmental through the route of metabolism by microbiota in the 

water.

How could the data change the Agency’s decision, or impact the Agency’s future decisionmaking? 

Aerobic aquatic metabolism data is required as an input to EFED environmental fate and 

transport surface water and groundwater models. Having this data will eliminate the need to use 

conservative default values in the modeling.

Guideline Number: 835.6100 (Environmental Chemistry Method and Independent 

Laboratory Validation Only) – Soil

Guideline Number: 835.6200 (Environmental Chemistry Method and Independent 

Laboratory Validation Only) - Water

Rationale for Requiring the Data

Independently validated analytical methods for residues in soil, water, sediment, and plant 

material (environmental chemistry methods) submitted by the registrant are used to evaluate 

analyses described in submitted environmental fate and ecological effects studies. Submitted 

analytical methods are also used by various federal, state, tribal, and local agencies to detect and 

monitor residues that are or are suspected to be in environmental compartments due to outdoor 

uses and accidental releases. Independent laboratory validations for submitted analytical 

methods are necessary to confirm that the methods are functional and to confirm the levels of 

detection and quantitation reported in registrant-prepared validations.

Use of buprofezin may impact terrestrial or aquatic environments due to residues of concern 
35

during the application process. Therefore, outside agencies may request analytical methods 

with which to monitor for buprofezin residues of concern in soil and water.

An independently validated environmental chemistry method for buprofezin residues in soil and 

one for water have not been submitted by the registrant. Validated environmental chemistry 

methods and independent laboratory validations of the methods are required to support 

monitoring for buprofezin residues and to evaluate newly submitted environmental fate and 

ecological effects data.

Practical Utility of the Data

How will the data be used?

In the absence of independently validated environmental chemistry methods, submitted 

environmental fate and ecological effects data may not be reviewable and entities outside the 

EPA may lack chemical-specific methods for analyses in environmental compartments. 

Independently validated environmental chemistry methods will be used to evaluate newly 

submitted environmental fate and ecological effects data and will be made available for 

enforcement and monitoring purposes at the federal, state, and local levels.

How could the data change the Agency’s decision, or impact the Agency’s future decisionmaking? 

Risk assessment conclusions could be altered if they are not supported by either study data or 

environmental monitoring detections that are based on independently validated environmental 

chemistry methods. Furthermore, while not directly related to EPA decision-making, 

independently validated environmental chemistry methods are necessary to ensure the safety of 

those in proximity to releases of buprofezin residues in the environment.

No chronic whole sediment toxicity data for freshwater or saltwater invertebrates are available. 40 CFR 

158 conditionally requires whole sediment chronic toxicity data for freshwater and estuarine/marine 

invertebrates. Buprofezin meets conditions for requiring these data based on high persistence (aerobic soil 

and aquatic metabolism half-lives > 10 days) and based on physical-chemical properties associated with 

high binding to sediment (Kd>50, log Kow>3, and Koc>1000). Furthermore, a life-cycle study with the 

water flea, as well as supplemental life-cycle studies with the fathead minnow, found that the most 

sensitive endpoints were reproductive measures such as percent egg hatching and number of young 

produced. Chronic tests with the sediment-dwelling invertebrates are therefore needed as these are the 

only sediment toxicity tests which measures reproductive endpoints. 

Current EFED recommendations for freshwater sediment testing follow Agency-wide guidance stated in 

Test Method 100.4: 

“Hyalella azteca 42-d Test for Measuring the Effects of Sediment Associated Contaminants on 

Survival, Growth, and Reproduction” contained in USEPA 2000 Methods for Measuring the 

Guideline Number: Non-guideline study (OCSPP 850.1770, in prep.), use test method 100.4 (citation 

included in text).

Study Title: Whole Sediment: Chronic Toxicity to Freshwater Invertebrate - Examining Survival, 

Growth, and Reproduction for Hyaella azteca.

Rationale for Requiring the Data
36

Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater 

Invertebrates EPA 600/R-99/064 (OCSPP 850.1770). 

A protocol should be submitted for approval prior to testing. Based on test variability for the endpoints of 

concern and the need to establish a NOAEC/LOAEC the following number of replicates and test animals 

are recommended for the freshwater amphipod H. azteca: 

12 replicates per treatment (4 for 28-d survival and growth and 8 for the remainder of the test) 

with 10 neonates per replicate.

In the absence of data, toxicity will be estimated using the lowest chronic toxicity endpoint for freshwater 

invertebrates and the estimated pore water concentrations in sediment. This does not consider possible 

exposure via ingestion or contact with contaminated sediment, and therefore would be uncertain.

The requested data would allow EPA to estimate chronic risks to benthic invertebrates, including defining 

an effect area for endangered species. Risk mitigation strategies, such as determining the maximum 

application rate at which the RQ would not exceed the LOC, cannot be evaluated without these data.

Practical Utility of the Data

How will the data be used? 

The data would allow the EPA to determine chronic risk to benthic freshwater invertebrates from 

buprofezin in water and sediment. The effects data would be used to determine the likelihood that the 

chronic risks can potentially impact aquatic communities, either by direct effects or by indirect effects on 

other organisms by reducing their food sources. 

How could the data impact the Agency’s future decision-making? 

Risk assessment and mitigation strategies, such as determining the maximum application rate that results 

in RQs that do not exceed the LOC, cannot be evaluated without these data. If future endangered species 

risk assessments are performed without these data, the EPA would have to assume that buprofezin “may 

affect” endangered freshwater benthic invertebrates directly (and endangered species from other taxa 

indirectly), and use of buprofezin might need to be restricted in areas where endangered species could be 

exposed. The lack of these data will limit the flexibility the EPA and registrants have in coming into 

compliance with the Endangered Species Act and could result in use restrictions for buprofezin which are 

unnecessarily severe.

No chronic whole sediment toxicity data for freshwater or saltwater invertebrates are available. 40 CFR 

158 conditionally requires whole sediment chronic toxicity data for freshwater and estuarine/marine 

invertebrates. Buprofezin meets conditions for requiring these data based on high persistence (aerobic soil 

and aquatic metabolism half-lives > 10 days) and based on physical-chemical properties associated with 

high binding to sediment (Kd>50, log Kow>3, and Koc>1000). Furthermore, a life-cycle study with the 

water flea, as well as supplemental life-cycle studies with the fathead minnow, found that the most 

sensitive endpoints were reproductive measures such as percent egg hatching and number of young 

produced. Chronic tests with the sediment-dwelling invertebrates are therefore needed as these are the 

only sediment toxicity tests which measures reproductive endpoints. 

Current EFED recommendations for freshwater sediment testing follow Agency-wide guidance stated in 

Guideline Number: Non-guideline study (OCSPP 850.1760, in prep.), use test method 100.5 (citation 

included in text).

Study Title: Whole Sediment: Chronic Toxicity to Freshwater Invertebrates - Examining Survival, 

Growth, and Reproduction for Chironomus dilutus or C. tentans.

Rationale for Requiring the Data
37

Test Method 100.5: 

“Life-cycle Test for Measuring the Effects of Sediment-associated Contaminants on Chironomus 

dilutus or C. tentans” contained in USEPA 2000 Methods for Measuring the Toxicity and 

Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates EPA 600/R99/064 (OCSPP 850.1760). 

A protocol should be submitted for approval prior to testing. Based on test variability for the endpoints of 

concern and the need to establish a NOAEC/LOAEC the following number of replicates and test animals 

are recommended for the midge test with C. dilutus or C. tentans: 

16 replicates per treatment containing 12 test organisms each (12 replicates at test initiation; 4 

added at 10 days for auxiliary males).

In the absence of data, toxicity will be estimated using the lowest chronic toxicity endpoint for freshwater 

invertebrates and the estimated pore water concentrations in sediment. This does not consider possible 

exposure via ingestion or contact with contaminated sediment, and therefore would be uncertain.

The requested data would allow EPA to estimate chronic risks to benthic invertebrates, including defining 

an effect area for endangered species. Risk mitigation strategies, such as determining the maximum 

application rate at which the RQ would not exceed the LOC, cannot be evaluated without these data.

Practical Utility of the Data

How will the data be used? 

The data would allow the EPA to determine chronic risk to benthic freshwater invertebrates from 

buprofezin in water and sediment. The effects data would be used to determine the likelihood that the 

chronic risks can potentially impact aquatic communities, either by direct effects or by indirect effects on 

other organisms by reducing their food sources. 

How could the data impact the Agency’s future decision-making? 

Risk assessment and mitigation strategies, such as determining the maximum application rate that results 

in RQs that do not exceed the LOC, cannot be evaluated without these data. If future endangered species 

risk assessments are performed without these data, the EPA would have to assume that buprofezin “may 

affect” endangered freshwater benthic invertebrates directly (and endangered species from other taxa 

indirectly), and use of buprofezin might need to be restricted in areas where endangered species could be 

exposed. The lack of these data will limit the flexibility the EPA and registrants have in coming into 

compliance with the Endangered Species Act and could result in use restrictions for buprofezin which are 

unnecessarily severe.

No chronic whole sediment toxicity data for freshwater or saltwater invertebrates are available. 40 CFR 

158 conditionally requires whole sediment chronic toxicity data for freshwater and estuarine/marine 

invertebrates. Buprofezin meets conditions for requiring these data based on high persistence (aerobic soil 

and aquatic metabolism half-lives > 10 days) and based on physical-chemical properties associated with 

high binding to sediment (Kd>50, log Kow>3, and Koc>1000). Furthermore, a life-cycle study with the 

water flea, as well as supplemental life-cycle studies with the fathead minnow, found that the most

sensitive endpoints were reproductive measures such as percent egg hatching and number of young 

produced. Chronic tests with the sediment-dwelling invertebrates is therefore needed as these are the only 

Guideline Number: Non-guideline study (OCSPP 850.1780, in prep.), use citation included in text.

Study Title: Whole Sediment: Chronic Toxicity to Saltwater Invertebrates - Examining Survival, 

Growth, and Reproduction for Leptocheirus plumulosus.

Rationale for Requiring the Data
38

sediment toxicity tests which measures reproductive endpoints. 

Current EFED recommendations for freshwater sediment testing follow Agency-wide guidance stated in:

“Method for Assessing the Chronic Toxicity of Marine and Estuarine Sediment-associated 

Contaminants with the Amphipod Leptocheirus plumulosus EPA 600/R-01/020 (OCSPP 

850.1780). 

A protocol should be submitted for approval prior to testing. In the absence of data, toxicity will be 

estimated using the lowest chronic toxicity endpoint for saltwater invertebrates and the estimated pore

water concentrations in sediment. This does not consider possible exposure via ingestion and could 

underestimate risk for some invertebrates where ingestion is an important exposure pathway; therefore, 

there will be considerable uncertainty in risk conclusions.

In the absence of data, toxicity will be estimated using the lowest chronic toxicity endpoint for freshwater 

invertebrates and the estimated pore water concentrations in sediment. This does not consider possible 

exposure via ingestion or contact with contaminated sediment, and therefore would be uncertain.

The requested data would allow EPA to estimate chronic risks to benthic invertebrates, including defining 

an effect area for endangered species. Risk mitigation strategies, such as determining the maximum 

application rate at which the RQ would not exceed the LOC, cannot be evaluated without these data.

Practical Utility of the Data

How will the data be used? 

The data would allow the EPA to determine chronic risk to benthic saltwater invertebrates from buprofezin 

in water and sediment. The effects data would be used to determine the likelihood that the chronic risks 

can potentially impact aquatic communities, either by direct effects or by indirect effects on other 

organisms by reducing their food sources. 

How could the data impact the Agency’s future decision-making? 

Risk assessment and mitigation strategies, such as determining the maximum application rate that results 

in RQs that do not exceed the LOC, cannot be evaluated without these data. If future endangered species 

risk assessments are performed without these data, the EPA would have to assume that buprofezin “may 

affect” endangered saltwater benthic invertebrates directly (and endangered species from other taxa 

indirectly), and use of buprofezin might need to be restricted in areas where endangered species could be 

exposed. The lack of these data will limit the flexibility the EPA and registrants have in coming into 

compliance with the Endangered Species Act and could result in use restrictions for buprofezin which are 

unnecessarily severe.
39

Study Title: Acute Honey Bee Larvae Feeding Study

Guideline Number: Non-guideline

Rationale for Requiring the Data

While buprofezin has low toxicity to adult bees, the mode of action (chitin biosynthesis 

inhibitor) suggests that it is likely much more toxic to larval stages. A published study 

demonstrated toxic effects of buprofezin to developing bumblebees (Bombus terrestris) 

(Mommaerts et al. 2006). Buprofezin is sprayed to the foliage of many flowering crops which 

are attractive to bees, and thus foraging bees are expected to collect contaminated food (pollen 

and nectar) from treated plants and carry residues back to the hive, where developing larval 

stages could be exposed. Furthermore, environmental fate properties indicate that residues of 

buprofezin will persist in the terrestrial environment for weeks to months. Because of the 

potential for pollen and nectar to be contaminated with buprofezin, it is important to determine 

the toxicity of this compound to pollinator larvae. The registrant should consult the EPA on the 

design of the protocol prior to the initiation of the study.

Practical Utility of the Data

How will the data be used?

This study would allow EPA to refine the screening level risk assessment for beneficial 

terrestrial arthropods, including insect pollinators. The effects data will be used to determine the 

potential for hazard to insect pollinators through direct effects on the larvae. The toxicity levels 

measured in this study would be compared to residue levels expected in nectar and pollen from 

treated crops to assess risk. 

How could the data change the Agency’s decision or impact the Agency’s future decision-making? 

Toxicity testing with adult bees indicate that buprofezin is not a hazard to adult insect 

pollinators; however, since buprofezin is more toxic to developing larval stages than to the 

adults, an assessment based on toxicity to bee larvae may reveal a risk to nontarget beneficial 

insects, and this risk could warrant imposing label warnings or other risk mitigation measures. 

In addition, bee larvae toxicity data could impact EPA’s decisions on whether or not use of 

buprofezin is likely to jeopardize the continued existence of endangered or threatened species of 

terrestrial arthropods.
40

11.0 References

Aupinel, P., D. Fortini, B. Michaud, F. Marolleau, J-N Tasei and J-F Odoux. 2007. Toxicity of 

dimethoate and fenoxycarb to honey bee brood (Apis mellifera), using a new in vitro 

standardized feeding method. Pest Management Science 63: 1090 – 1094.

Blomquist, J.D. and J.M. Denis, J.L. Cowles, J.A. Hetrick, R.D. Jones, N.B. Birchfield. 2001. 

Pesticides in Selected Water-Supply Reservoirs and Finished Drinking Water, 1999-2000: 

Summary of Results from a Pilot Monitoring Program. USGS Open File Report 01-456. 

Sacramento, CA

Burns, L. A. 2002. EXAMS (Exposure Analysis Modeling System) Version 2.98.04. (Compiled 

07/18/04). Environmental Research Laboratory., U. S. Environmental Protection Agency. 

Athens, GA.

Carsel, R. F., J. C. Imhoff, P. R. Hummel, J.M. Cheplick, and A.S. Donigian, Jr. 1998. PRZM-3, 

Version 3.12 beta (Compiled (05/24/01). A Model for Predicting Pesticide and Nitrogen 

Fate in the Crop Root and Unsaturated Soil Zones: Users Manual for Release 3.0. United 

State Environmental Protection Agency. Athens, GA.

DPR. 2007. Surface Water Database. California Environmental Protection Agency, Department 

of Pesticide Regulation, Surface Water Protection Program. Available at: 

http://pestreg.cdpr.ca.gov/docs/sw/surfdata.htm. Accessed December, 2007.

Environmental Fate and Effects Division. 2002. Guidance for Selecting Input Parameters in 

Modeling the Environmental Fate and Transport of Pesticides, Version II. U. S. 

Environmental Protection Agency. Washington, D.C. 

http://www.epa.gov/oppefed1/models/water/input_guidance2_28_02.htm/

IRAC. 2011. IRAC MoA Classification buprofezin. Version 7.1. IRAC International MoA 

Working Group. 23 pp. Available online at:

http://www.irac-online.org/wp-content/uploads/2009/09/MoA_Classification.pdf

Jones, R.D. et al., 2000. Guidance for use of the Index Reservoir and Percent Crop Area Factor in 

Drinking Water Assessments (March 21, 2000). Office of Pesticide Programs, 

Environmental Fate and Effects Division, U.S. Environmental Protection Agency. 

Arlington, VA.

Kikuchi, M., Y. Sasaki, and M. Wakabayashi. 2000. Screening of organophosphate pollution in 

water by using Daphnia magna. Ecotoxicology and Environmental Safety. 47:239-245.

Lyman WJ, Reehl WF, Rosenblatt DH. 1990. Handbook of Chemical Property Estimation 

Methods: Environmental Behavior of Organic Compounds. American Chemical Society, 

Washington, DC, USA.

Mommaets, V., G. Sterk, and G. Smagghe. 2006. Hazard and uptake of chitin synthesis 

inhibitors in bumblebees Bombus terrestris. Pest Management Science. 62:752-758.
41

NASQAN. 2007. National Stream Quality Accounting Network. United States Geological 

Survey. Available at: http://water.usgs.gov/nasqan/. Accessed December, 2007.

NAWQA. 2007. USGS National Water Quality Assessment Data Warehouse. United States 

Geological Survey. Available at: 

http://infotrek.er.usgs.gov/traverse/f?p=NAWQA:HOME:3765519528892019. Accessed 

December, 2007.

Office of Pesticide Programs. 2000. Drinking Water Screening Level Assessments. 

http://www.epa.gov/oppfead1/trac/science/reservoir.pdf.

USEPA. 1999. Guidance for Use of the Index Reservoir in Drinking Water Exposure 

Assessments. Arlington, VA.

USEPA. 2000. Drinking Water Screening Level Assessment. Part A: Applying a Percent Crop 

Area Adjustment to Tier II Surface Water Model Estimates for Pesticide Drinking Water 

Exposure Assessments. FQPA Science Policy Document .Public Comment Draft 

September 1, 2000. Federal Register: October 11, 2000 (volume 65, number 197). 

Electronic copy available at http://www.epa.gov/pesticides/trac/science/ .

USEPA. 2002a. Guidance for Selecting Input Parameters in Modeling the Environmental Fate 

and Transport of Pesticides, Version II (February 28, 2002). Office of Pesticide 

Programs, Environmental Fate and Effects Division, U.S. Environmental Protection 

Agency. Arlington, VA.

U.S. EPA. 2002b. Pesticide Root Zone Model (PRZM) Field and Orchard Crop Scenarios: 

Standard Procedures for Conducting Quality Control and Quality Assurance. Office of 

Pesticide Programs, Environmental Fate and Effects Division, U.S. Environmental 

Protection Agency. Arlington, VA. 

USEPA. 2002b. Pesticide Root Zone Model (PRZM) Field and Orchard Crop Scenarios: Standard 

Procedures for Conducting Quality Control and Quality Assurance. Office of Pesticide 

Programs, Environmental Fate and Effects Division, U.S. Environmental Protection 

Agency. Arlington, VA.

U.S. EPA. 2003b. Use of Regional Percent Crop Area Factors in Refined Drinking Water 

Assessments. US EPA Office of Pesticide Programs (OPP), Environmental Fate and 

Effects Division (EFED), Water Quality Technical Team (WQTT). Arlington, VA

USEPA. 2003c. SCI-GROW 2.3: Windows Version of SCI-GROW. September 30, 2003. Office 

of Pesticide Programs, Environmental Fate and Effects Division, U.S. Environmental 

Protection Agency. Arlington, VA. 

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide 

Programs. United States Environmental Protection Agency (USEPA). Environmental 
42

Fate and Effects Division. Office of Pesticide Programs. Available at 

http://www.epa.gov/espp/consultation/ecorisk-overview.pdf.

USEPA. 2012. Buprofezin Usage Map by Crop Reporting District (PC Code: 275100). 

Memorandum from Biological and Economical Analysis Division to the Environmental 

Fate and Effects Division. April 26, 2012.
43

APPENDIX A

DATA REQUIREMENTS FOR

Buprofezin

PC Code: 129032

Data Requirement Use

Pattern1

Does EPA Have

Data To Satisfy

This Requirement?

(Yes, No, or Partially)

Bibliographic

Citation 

Must Additional

Data Be Submitted

Under FIFRA 

3(c)(2)(B)?

§158.630 WILDLIFE AND AQUATIC ORGANISMS

850.2100/71-1(a) Acute Avian Oral, Quail/Duck 1,2,3 Yes 42872827

42873828

No

850.2100 Acute Avian Oral, Passerine 1,2,3 No No2

850.2200/71-2(a) Avian Dietary, Quail 1,2,3 Yes 42873830 No

850.2200/71-2(b) Acute Dietary, Duck 1,2,3 Yes 42873829 No

850.2300/71-4(a) Avian Reproduction, Quail 1,2,3 Yes 44394013 No

850.2300/71-4(b) Avian Reproduction, Duck 1,2,3 Yes 44394014 No

850.1075/72-1(a) Acute Freshwater Fish, Bluegill 1,2,3 No

44394015,

42873831

No3

850.1075/72-1(c) Acute Freshwater Fish, Trout 1,2,3 No

44394016

42873832

No3

850.1010/72-2(a) Acute Freshwater Invertebrate 1,2,3 Yes 42873833 No3

850.1075/72-3(a) Acute Estuarine/Marine, Fish 1,2,3 Yes 44394018 No3

850.1025/72-3(b) Acute Estuarine/Marine, Bivalve

850.1055 1,2,3 Yes 44394019 No

850.1035/72-3(c) Acute Estuarine/Marine, Crustacean

850.1045 1,2,3 Yes 44394020 No3

850.1400/72-4(a) Fish Early-Life Stage Fish 1,2,3 Yes 44394021 No

850.1300/72-4(b) Freshwater Invertebrate Life Cycle 1,2,3 Yes 44435901

42873835 No

850.1350/72-4(b) Saltwater Invertebrate Life Cycle 1,2,3 No 47676702 Yes4

850.1500/72-5 Fish Life Cycle 1,2,3 No 48083904

42873834 Yes4

850.1710/165-4 Fish BCF 1,2,3 Yes 44394047 No

850.1735 Whole Sediment Acute Invertebrate, 

Freshwater 1,2,3 No 47676703

46597901 No5

850.1740 Whole Sediment Acute Invertebrate, Marine 1,2,3 No No5

850.160 (in prep) Whole Sediment Chronic Freshwater 

Invertebrate, Chironomus dilutes 1,2,3 No Yes
44

Data Requirement Use

Pattern1

Does EPA Have

Data To Satisfy

This Requirement?

(Yes, No, or Partially)

Bibliographic

Citation 

Must Additional

Data Be Submitted

Under FIFRA 

3(c)(2)(B)?

850.170 (in prep) Whole Sediment Chronic Freshwater 

Invertebrate, Hyalella azteca 1,2,3 No Yes6

850.180 (in prep) Whole Sediment Chronic 

Marine/Estuarine Invertebrate, Leptocheirus plumulosus 1,2,3 No Yes6

§158.660 PLANT PROTECTION

850.4100/122-1(a) Seedling Emergence, Tier 1 1,2,3 Yes 44394036 No

850.4150/122-1(b) Vegetative Vigor, Tier 1 1,2,3 Yes 44394037 No

850.4100/123-1(a) Seedling Emergence, Tier 2 No

850.4150/123-1(b) Vegetative Vigor, Tier 2 No

850.4400/122-2 Aquatic Plant Growth, Vascular Plant,

 Tier 1 1,2,3 No 44394038 No3

850.5400/122-2 Aquatic Plant Growth, Algae, Tier 1 1,2,3 No 44394039 No3

850.4400/123-2 Aquatic Plant Growth, Vascular Plant,

 Tier 2 No

850.5400/123-2 Aquatic Plant Growth, Algae, Tier 2 No

§158.630 NONTARGET INSECT TESTING

850.3020/141-1 Honeybee Acute Contact 1,2,3 Yes 44394040 No

850.3030/141-2 Honeybee, Residues on Foliage No

850.3040/141-5 Field Test for Pollinators No

Special Study: Honey Bee Larvae Toxicity 1,2,3 No Yes7

§158.1300 ENVIRONMENTAL FATE

Degradation Studies—Lab

835.2120/161-1 Hydrolysis 1,2,3 Yes 44394041 No

835.2240/161-2 Photodegradation In Water 1,2,3 Yes 44463102 No

835.2410/161-3 Photodegradation On Soil 1,2,3 Yes 44453903 No

Metabolism Studies—Lab

835.4100/162-1 Aerobic Soil 1,2,3 Yes 44394042 No

835.4200/162-2 Anaerobic Soil No

835.4300/162-3 Anaerobic Aquatic 1,2,3 Yes 44394043 No

835.4400/162-4 Aerobic Aquatic 1,2,3 No No data were

submitted Yes

Mobility Studies

835.1230/163.1 Leaching- Adsorption/Desorption

835.1240 1,2,3 Yes 42990601 No
45

Data Requirement Use

Pattern1

Does EPA Have

Data To Satisfy

This Requirement?

(Yes, No, or Partially)

Bibliographic

Citation 

Must Additional

Data Be Submitted

Under FIFRA 

3(c)(2)(B)?

835.1410/163-2 Volatility (Lab) Yes No

Dissipation Studies—Field

835.6100/164-1 Terrestrial 1,2,3 Yes 44394044 No

835.6200/164-2 Aquatic (Sediment) No

FOOTNOTES:

1. 1=Terrestrial Food; 2=Terrestrial Feed; 3=Terrestrial Non-Food; 4=Aquatic Food; 5=Aquatic Non-Food(Outdoor);6=Aquatic Non-Food (Industrial);7=Aquatic NonFood (Residential);8=Greenhouse Food; 9=Greenhouse Non-Food;10= Forestry; 11=Residential Outdoor; 12=Indoor Food; 13=Indoor Non-Food; 14=Indoor 

Medicinal;15=Indoor Residential.

2. Acute toxicity testing with a passerine species is not needed because existing acute toxicity data, as well as the mode of action of buprofezin, indicate that the acute 

toxicity of buprofezin to vertebrates is low.

3. All acute aquatic toxicity studies, except for the oyster shell deposition study, were classified as supplemental because the study reports did not indicate that the 

analysis conducted to measure test concentrations were filtered prior to analysis to remove suspended solids, making the concentration dissolved test material 

uncertain. Nevertheless, the studies were sufficient to show that no mortality occurs at the solubility limit of buprofezin. Therefore, no additional acute aquatic toxicity 

testing is required.

4. The study(studies) submitted for this guideline is (are) classified as supplemental and does not provide adequate information to characterize the chronic toxicity. A 

new study for this guideline is needed.

5. The two supplemental studies provided do not fulfill the test guideline but are sufficient to characterize the acute toxicity of buprofezin to sediment-dwelling 

invertebrates.

6. These studies may not be needed if data are provided which demonstrates that these test organisms are no more sensitive to buprofezin than the freshwater midge, or 

that the chronic risk assessment for aquatic crustaceans inhabiting overlying water, based on chronic toxicity data for the waterflea (Daphnia magna) and the mysid 

(Americamysis bahia), would be protective of sediment-dwelling crustaceans.

7. Although this guideline has been fulfilled, a special study is needed to provide data on the toxicity of buprofezin to honeybee larvae.

8. A laboratory study on volatility is not required because existing data on the vapor pressure and Henry’s Law Constant of buprofezin indicate that it has low 

volatility.
46

Appendix B. Proposed Degradation Pathways for Buprofezin in Soil(s), Water (w) and Light (l).
47

Appendix C. Names and Chemical Structures of Buprofezin and

Major Transformation Products

PARENT COMPOUND

N

S

N

O

N

Buprofezin

2-tert-butylimino-3-isopropyl-5-phenyl-1,3,5-thiadiazin-4-one

MAJOR DEGRADATES (≥10%)

N

H

O

N

H

CH(CH3)

2

BF-12 

N-(l-methylethy1)-N’-phenylurea

N

H

CH

O

BF-21

N-phenylformamide

N

H

O

N

CH(CH3)

2

S

C(CH3)

3

BF-25 

N-[[(1, l-dimethylethyl)amino]thioxomethyl]-N-(1-methyleyl)-N’-phenylea; thiobiuret