2

REGISTRATION REVIEW

PROBLEM FORMULATION

Noviflumuron

CAS Number 121451-02-3

US EPA PC CODE 118204

Prepared by:

Ed Odenkirchen, Ph.D., Senior Science Advisor

Christopher M. Koper, M.S., Chemist

Environmental Risk Branch 1

Reviewed by:

Meghan Radtke, Ph.D., Acting RAPL

Stephen Wente, Ph.D., Biologist

Environmental Risk Branch 1

U.S. Environmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch I

1200 Pennsylvania Ave., NW

Mail Code 7507P

Washington, DC 20460
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1 Executive Summary

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem 

formulation for the ecological risk, environmental fate, endangered species, and drinking water 

assessments to be conducted as part of the registration review of noviflumuron. The problem 

formulation describes the methods planned to be used during the completion of drinking water and 

ecological risk assessments in support of Registration Review and provides an overview of the 

environmental fate, ecological effects, and potential risks associated with the use of noviflumuron 

as well as uncertainties unique to risk assessment of noviflumuron. This document also identifies 

additional studies that would be beneficial to the conduct of an ecological risk assessment. 

Major findings include the following data needs described below:

 Acute oral toxicity in a passerine bird: The exposure concept for this risk assessment 

places insectivorous birds as a non-target receptor via consumption of termites feeding on 

bait. The most likely insectivorous birds to be exposed would be passerines. 

 Avian reproduction studies for an upland game bird and a waterfowl species. These 

data are essential for evaluating the potential for noviflumuron to affect the fitness of avian 

species through impacts to reproduction. The use of noviflumuron in bait boxes will likely 

involve long-term placement of treated baits. This is likely to result in residues being 

incorporated into insect biomass (termites) over considerable periods of time. This 

Problem Formulation has established that termites, contaminated with noviflumuron 

constitute a complete exposure pathway to ground feeding insectivorous terrestrial 

vertebrates. Without these data, the risk assessment will consider reproduction data in other 

insect growth regulator compounds (e.g., data from hexaflumuron (D405911) with a 

similar use pattern returned chronic risk quotients threefold higher than the Agency 

established chronic risk level of concern), or more structurally and mechanistically distant 

compounds.

A major uncertainty is that many of the current labels for noviflumuron products do not specify 

the amount of product present in each bait station. In addition, labels do not specify the maximum 

number of bait stations that can be present on a designated area of land. Therefore, as the labels 

are now, application rates of noviflumuron applied to a unit area (i.e., lbs a.i./A) cannot be 

determined. In addition, holes can be drilled for gel use (via applicator syringe) to locations of 

active galleries but there is no mention of how many holes can be drilled per unit area and mass 

per area cannot be determined. Assumptions and limitations are provided in Section 14.

2 Introduction

Noviflumuron is a benzoylphenylurea insecticide/termiticide. Benzoylphenylurea molecules

inhibit chitin synthesis, but the precise target enzyme for noviflumuron is not known for certain.

The mechanism of toxicity is tied closely with a specific life stage of an insect – physical molting

– thus, its speed of action is relatively slow compared to other insecticides. However, it is this slow 
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activity that provides a favorable response to control social insects that tend to exhibit avoidance 

behaviors when exposed to sick or dead members of the population, such as termites.

Noviflumuron was originally registered for use in the United States in September 1990, as a 

conventional pesticide. It is used in conjunction with a monitoring system to control outbreaks of 

termites, subterranean termites, and cockroaches after a problem has been identified. 

3 Use Characterization

Currently, noviflumuron is registered for use in above- and below-ground termite bait systems. 

There are 7 active end-use products containing noviflumuron. 

Noviflumuron is present at 0.5% (i.e., 0.5 grams in 100 grams of bait product) in a bait matrix 

housed in a rigid plastic structural housing with small access windows opened by the user to allow 

for termite access. Bait stations are mounted to solid surfaces such as trees, decks, fences, building 

surfaces, and crawl spaces in locations where termites are actively foraging. These bait stations 

are not designed to attract termites and do not contain an attractant. Many of the current labels for 

noviflumuron products do not specify the amount of product present in each bait station. In 

addition, labels do not specify the maximum number of bait stations that can be present on a 

designated area of land. Therefore, as the labels are now, application rates of noviflumuron applied 

to a unit area (i.e., lbs a.i./A) cannot be determined. 

Noviflumuron is applied as a gel (via applicator syringe) to locations of active galleries or mud 

tubes on buildings by injecting the material into cracks or by drilling small holes into areas of 

active galleries. These holes are then sealed after application. 0.5 to 2 grams of gel bait (0.0025 to 

0.01g ai) are applied per treatment site. Noviflumuron may be reapplied as needed to gain localized 

control or to treat new active sites.

4 Conclusions from Previous Risk Assessments

4.1 Ecological Risk Assessments

The Agency conducted two previous ecological risk assessments for noviflumuron:

 Section 3 request for use of noviflumuron in a gel bait formulation to control cockroaches 

and foraging subterranean termites (2005; DP Barcode: D307981)

 Section 3 request for use of noviflumuron in a bait formulation to control termites (2003; 

DP Barcodes: D285883, D288937)

The conclusions shared by these assessments were:

 Environmental exposures are expected to be low when used as directed on the proposed 

label.

 The greatest concern for potential risks is associated with environmental exposures to

mammals feeding on exposed bait.

 Potential risks to birds and representative taxa is less than that of mammals; however, these 

risks may be underestimated because the contribution to a bird’s diet from the ingestion of 

contaminated prey was not included in the risk estimation.
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4.2 Drinking Water Exposure Assessments

Noviflumuron is applied in above- and below-ground bait stations. Given this application method, 

it has historically been viewed as a “closed system” with minimal likelihood of environmental 

exposure. Therefore, there is no previous drinking water exposure assessment for this chemical.

Drinking water exposures are likely to be low and would not likely exceed the known water 

solubility of 194 μg/L. In addition, based on the high affinity of this compound to sorb to sediments 

and organic materials, removal in physical drinking water treatment processes 

(flocculation/coagulation followed by sedimentation and/or filtration) is likely, but not 

quantifiable. Groundwater concentrations are expected to be low, including in areas of high sand 

content based on high sorption coefficients.

4.3 Clean Water Act Programs

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

under section 303(d) of the Clean Water Act. No Total Maximum Daily Load (TMDL) criteria 

have been developed for noviflumuron. Any data submitted or otherwise located as part of the 

Registration Review process may be used to update aquatic life benchmarks, if applicable. 

5 Environmental Fate and Transport

In soil, the primary route of dissipation for noviflumuron is aerobic metabolism. Noviflumuron is 

stable to hydrolysis at neutral to acidic pHs, but degrades with a half-life of 19 days in alkaline 

pHs. Given the methods of application (e.g., above- and below-ground bait stations), the material 

will not be subject to photodegradation when used as proposed. Since there was a poor correlation 

between Kd and percent organic carbon, Kd values were utilized to describe mobility of 

noviflumuron. Kd values ranging from 859-7,828 in four U.S. soils and 1,475-3,425 in four U.K. 

soils indicate that noviflumuron is immobile. Noviflumuron's low solubility in water, high 

octanol-water partition coefficient, and immobility in soil indicate that it will not dissolve in any 

moisture that may enter the bait stations. In the event that some noviflumuron was leached from 

the bait stations, it should bind readily to the soil. Additionally, current labels carry the 

environmental hazard statement “This product is highly toxic to aquatic invertebrates and possibly 

to fish. Do not allow the bait or its noviflumuron contents to be washed into a body of water 

containing aquatic life, such as a pond or stream” which should reduce, if not eliminate, the 

chances for noviflumuron to migrate to surface and ground water. Considering noviflumuron’s 

properties and registered uses, aquatic exposure is not expected. 

Although the mobility of noviflumuron’s degradates has not been adequately determined, it 

appears that degradates, which are produced under environmental conditions, are not highly 

mobile. Due to the lack of anaerobic fate data, noviflumuron’s persistence in anaerobic 

environments has not adequately been determined. In addition, noviflumuron’s low vapor pressure 

and application methods suggest that volatilization of the active ingredient should not occur. 
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A selection of environmental fate and transport properties of noviflumuron is summarized in Table 

5-1.

Table 5-1. Chemical Properties and Environmental Fate Parameters of Noviflumuron

Parameter Value Source/MRID #

Common name Noviflumuron

Product Chemistry

CAS number 121451-02-3

Chemical name (RS)-1-[3,5-Dichloro-2-fluoro-4-(1,1,2,3,3,3 

hexafluoropropoxy)phenyl]-3-(2,6-difluorobenzoyl)urea

Chemical Class/Category Benoylphenylurea Insecticide

Empirical formula C17H7Cl2F9N2O3

Structure

Molecular Mass 529.15 g/mole

Water Solubility 0.194 mg/L at 25C

Vapor pressure (25C) 5.39 x 10-12 mm Hg

Henry’s Law Constant 1.9 x 10-11 atm m3/mol Calculated1

Octanol/water partition 

coefficient (Kow)

87,096 (log Kow = 4.94) Product Chemistry

Dissociation Constant (pKa)

--

Molecule does not 

contain reversibly 

ionizable functional 

groups

Hydrolysis (t1/2 at 25C)

pH 5 = stable

pH 7 = stable

pH 9 = 19 days

45232421 (A)

Aerobic Soil Metabolism 

(t1/2)

 231 days (silt loam – benzoyl label) 

 251 days (loam – benzoyl label )

 263 days (silty clay loam – benzoyl label) 

 344 days (silt loam – aniline label) 

 202 days loam – aniline label)

 399 days (silty clay loam – aniline label) 

45516708 (A)

Soil Partition Coefficient (Kd) 

(mL/g)

Kd values

1,614 – 1,994 (IN loam)

859 – 1,437 (IN sand)

4,013 – 7,828 (ND loam)

3,008 – 3,755 (ND clay)

1,475 – 3,115 (UK silt loam)

3,151 – 2,897 (UK silty clay loam)

2,137 – 3,275 (UK sand)

2,545 – 3,425 (UK sandy clay loam)

45516709 (A)

1 = Henry’s Law (atm-m3

/mole) = (VAPR/760)/(SOL/MWT), where VAPR is vapor pressure in torr, MWT is 

molecular weight in g/mol, and SOL is the solubility in water in mg/L.

A = Acceptable data
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5.1 Transformation Products

Two major organic degradates of noviflumuron (XDE-007) formed under relevant environmental 

conditions: the urea and amine related forms of noviflumuron, described as XDE-007 urea (45.8% 

formed during hydrolysis; MRID 45232421) and XDE-007 amine (11.8% formed during 

hydrolysis; MRID 45232421 and 13.9% formed during aerobic soil metabolism; MRID 

45515708). Two other major degradates, XDE-007 amide (28%) and XDE-007 DFBA (59%),

formed during a noviflumuron hydrolysis study conducted at 50oC. Although this temperature is 

outside of typical environmental conditions, their formation was significant and they are common 

degradates of a similar chemical, hexaflumuron (PC 118202), so they were added as additional 

information. Significant mineralization occurred during an aerobic soil metabolism study (45.7% 

CO2 evolution; MRID 45515708). In addition, maximum unextracted residues were detected at 

26.9% by study termination (365 days) during an aerobic soil metabolism study (MRID 

45515708). Table 5-2 summarizes the transformation products of noviflumuron and their 

maximum amounts formed.

No environmental fate studies conducted with noviflumuron degradates have been submitted. 

Therefore, the behavior of these degradates is not well understood. Vapor pressures, Henry’s 

Law constants, octanol-water partition coefficients, water solubility, and Koc values were 

estimated using EPISuite (see Table 5.3) for comparison to the parent noviflumuron. Degradates 

XDE-007 amide and XDE-007 DFBA l appear to be more water soluble and mobile than the 

parent compound whereas XDE-007 urea and XDE-007 amine show similar properties (low 

water solubility, high Kow and Koc values) to the parent. In addition, the degradate structures 

show that they retain the majority of the parent structure.
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Table 5-2.Noviflumuron and Its Major Environmental Degradates 

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type MRID Maximum Formation(% Applied)

Noviflumuron

(XDE-007)

CAS Name: 

(RS)-1-[3,5-Dichloro-2-fluoro-4-

(1,1,2,3,3,3 

hexafluoropropoxy)phenyl]-3-(2,6-

difluorobenzoyl)urea

Molecular Weight: 529.15 g/mol 

Chemical Formula:

C17H7Cl2F9N2O3

SMILES: 

Clc1c(c(c([H])c(c1OC([C@]([H])(C

(F)(F)F)F)(F)F)Cl)N([H])C(N([H])C

(c2c(c([H])c([H])c([H])c2F)F)=O)=

O)F

Parent structure shown for reference

XDE-007

Urea Molecular Weight: 389.06 g/mol 

Chemical Formula:

C10H5Cl2F7N2O2

SMILES: 

Clc1c(c(c([H])c(c1OC([C@]([H])(C

(F)(F)F)F)(F)F)Cl)N([H])C(N)=O)F

Hydrolysis pH 9 at 25oC, 33 days 45232421 45.8 (33 days)

Hydrolysis pH 9 at 50oC, 1 day 45232421

30.8 (1 day; 50oC)

XDE-007

Amine Molecular Weight: 346.03 g/mol 

Chemical Formula:

C9H4Cl2F7NO

SMILES: 

Clc1c(c(c([H])c(c1OC([C@]([H])(C

(F)(F)F)F)(F)F)Cl)N)F

Hydrolysis pH 9 at 25oC, 33 days 45232421 11.8 (28 days)

Aerobic Soil Metabolism 45515708 13.9 (365 days)
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Code Name/ 

Synonym Chemical Name Chemical Structure Study Type MRID Maximum Formation(% Applied)

XDE-007

Amide Molecular Weight: 157 g/mol 

Chemical Formula:

C7H5F2NO

SMILES: NC(=O)c1c(F)cccc1F

Hydrolysis pH 9 at 50oC, 1 day 45232421

28.0 (1 day; 50oC)

XDE-007

2,6-

difluorobenzoic 

acid (DFBA)

Molecular Weight: 158.11 g/mol 

Chemical Formula:

C7H4F2O2

SMILES: OC(=O)c1c(F)cccc1F

Hydrolysis pH 9 at 50oC, 1 day 45232421 59.3 (1 day; 50oC)

CO2 Carbon Dioxide O=C=O Aerobic Soil Metabolism 45515708 45.7 (365 days)

Unextractable

Residues Aerobic Soil Metabolism 45515708 26.9 (365 days)

Note: The amide and DFBA degradates formed only in a hydrolysis study conducted at 50oC for 1 day. Their formation was significant and they are common degradates of 

hexaflumuron (PC 118202) so they were added for additional information. The values were italicized for clarity. 
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Table 5-3. Fate Parameters for Noviflumuron Degradates, Estimated Using EPISuite v. 4.10

Chemical/Fate 

parameter

Noviflumuron

(XDE-007) XDE-007

Urea

XDE-007

Amine

XDE-007

Amide

2,6-Difluorobenzoic acid 

(DFBA)

Molecular 

Weight (g/mol) 529 389 346 157 158

Vapor Pressure (torr)

5.39 x 10-12 6.71 x 10-6 2.36 x 10-3 2.86 x 10-4 1.76 x 10-3

Octanol-water Partition 

Coefficient (Log KOW)

4.94 4.57 4.94 0.25 1.59

Water Solubility 

(mg/L; at 25 °C) 0.194 .450 .398 43,140 3,063

Henry's Law Constant 

(atm-m3 mol-1)

1.9 x 10-11 7.63 x 10-6 2.70 x 10-3 1.37 x 10-9 1.20 x 10-7

Leaching/Mobility

Koc (L/kg) 30,670-43,560* 2999-5597* 4919-10,600* 7 – 46* 11 – 44*

*Range of 2 values, EpiSuite estimates
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6 Receptors

The contents in above ground portions of noviflumuron bait boxes are considered to be 

inaccessible to wildlife save for one exposure pathway. The exposure pathway considered to be

complete for terrestrial invertebrate and vertebrate predators of termites feeding on noviflumuron

materials within enclosed bait boxes, thus, this problem formulation only presents effects 

information relative to these taxonomic groups. While data submissions for fish, aquatic 

invertebrates, and aquatic and terrestrial plants have been made for noviflumuron, these taxonomic

groups are not expected to be exposed to the chemical and so will not receive quantitative 

assessment of risk. Table 6-1 provides a summary of toxicity endpoints used to characterize the 

potential acute and chronic ecological effects of noviflumuron to taxonomic groups to be 

considered in the risk assessment. 
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Table 6-1. Summary of the Endpoints from Terrestrial Toxicity Studies for Noviflumuron

Taxon Study Type

TGAI/TEP

(% a.i.)

Species Toxicity Value, Effects, &

Acute Toxicity Classification (If Applicable)

Source & Study 

Classification

Birds 

(surrogate for 

reptiles and 

terrestrialphase 

amphibians)

Acute oral: single dose, 

14-day observation

TGAI (98.6)

Bobwhite quail

(Colinus virginianus)

LD50 > 2000 mg a.i./kg-bw (nom)

NOAEL: 2000 mg a.i./kg-bw (nom)

(no signs of toxicity)

Practically non-toxic

MRID 45232406

Acceptable 

Acute oral Passerine species No data NA

Sub-acute dietary: 5-day 

exposure; 3-day postexposure observation

TGAI (91.5)

Bobwhite quail

(Colinus virginianus)

LC50 4100 mg a.i./kg-diet (nom) 95% C.I.: 3200-5000 mg 

a.i./kg-diet

NOAEC = 320 mg a.i./kg-diet (nom)

LOAEC = 580 mg a.i./kg-diet (nom)

(NOAEC based on reduction in body weight gain)

Practically non-toxic

MRID 45516722

Acceptable

Sub-acute dietary: 5-day 

exposure; 3-day postexposure observation

TGAI (98.4)

Mallard duck

(Anas platyrhynchos)

LC50 >5300 mg a.i./kg-diet (nom)

NOAEC = <320 mg a.i./kg-diet (nom)

LOAEC = 320 mg a.i./kg-diet (nom)

(no mortality; NOAEC based on reduction in body weight gain)

Practically non-toxic

MRID 45516721

Acceptable

Reproduction

(chronic)

Bobwhite quail

(Colinus virginianus)

No data NA

Reproduction

(chronic)

Mallard duck

(Anas platyrhynchos)

No data NA

Mammals Acute oral TGAI 95.6% Rat LD50>5000 mg a.i./kg-bw (nom)

NOEC 5000 mg a.i./kg-bw (nom)

MRID 45232409 

Acceptable

1-Gen Reproduction 

TGAI 95.6%

Rat NOAEC>1000 mg a.i.,/kg-bw 9nom) MRID 45232419 

Acceptable

Terrestrial 

invertebrates

Acute contact: single 

dose, 48-hour observation

Honey bee 

(Apis mellifera)

No data NA
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Taxon Study Type

TGAI/TEP

(% a.i.)

Species Toxicity Value, Effects, &

Acute Toxicity Classification (If Applicable)

Source & Study 

Classification

Acute dietary (oral) Honey bee 

(Apis mellifera)

No data NA

Larval honey bee

(Apis mellifera)

No data NA

NA = not applicable ; nom = nominal
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6.1 Ecological Incidents

A preliminary review on June 12, 2014, of the Ecological Incident Information System (EIIS, 

version 2.1), the IDS aggregated incident database, which are maintained by the Agency’s Office 

of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is 

maintained by the American Bird Conservancy, indicates no reported ecological incidents 

associated with the use of noviflumuron.

7 Exposure Pathways of Concern

Considering the fate parameters for noviflumuron and the method of application (i.e., bait 

stations), the only perceived means of noviflumuron moving into the environment (e.g., soil and 

surface water) would be via termites eating the bait and then transporting it away from the bait

station. Once in the termite, noviflumuron could be transferred to termite predators. 

Termite colonies provide a concentrated and protein-rich food source and are a viable prey item 

(Wood and Sands, 1978). These attributes are consistent with foraging theory (Carroll and 

Janzen, 1973; Oster and Wilson, 1978) that utilization of termites as a food source would 

minimize foraging costs, optimize yield, and result in a net gain in predator energy. Termite 

colonies are relatively sessile (confined within the bounds of the nest substrate) and stable 

through time. A stable food source can be efficiently exploited by reducing travel distances and 

travel time (Hçlldobler and Lumsden, 1980; McIver, 1991; Davidson, 1997). Termite colonies 

are also highly clumped, thus allowing efficient prey discovery and retrieval (Traniello, 1983; 

Pasteels et al., 1987). 

There are likely three scenarios for termite predatory behavior. The first is consumption of 

termites while concentrated in the nest area itself, which may be reserved for only a few larger 

vertebrate species that are able to excavate such areas. The second is consumption of foraging 

worker termites incidentally while ground foraging, which may be an exposure route for a 

variety of ground foraging birds, reptiles, amphibians, and small mammals. The third scenario is 

predation on the alates (mating cast of termites that are capable of flight) by a variety of 

terrestrial vertebrate predators feeding on ground and aerial swarms of alates. However, for 

noviflumuron, with its mode of action focusing on disruption of metamorphosis, it is unlikely 

that alates will be present.

Based on the Kow and Koa of this chemical, it has the potential to bioaccumulate in termite 

predators. Therefore, future ecological risk assessments of noviflumuron will involve assessing 

exposures of terrestrial animals to noviflumuron through consumption of contaminated termites. 

This can be accomplished by estimating the mass of noviflumuron per termite and deriving dietarybased and dose-based exposure concentrations for terrestrial animals through consumption of 

contaminated termites. 

Empirical data may also be used to represent the mass of noviflumuron per termite. For example, 

an available study for the chemical hexaflumuron measuring the uptake rate of 0.5% 14C labeled 

hexaflumuron in termites reported a steady state concentration of 320 ng (radioactive 
15

material)/termite (MRID 45516725). In this study, steady state was reached after 9-12 days. A 

representative termite body weight, such as 3 mg (Zhou et al. 2008), can be used to translate the 

measured pesticide mass per termite to a concentration basis of 107 mg hexaflumuron/kg termite. 

This value can then be used to derive dose-based EECs for terrestrial animals potentially 

consuming termites using allometric equations intended to estimate food intake rates for mammals 

and birds (USEPA 1993). 

8 Analysis Plan

8.1 Stressors of Concern

8.1.1 Ecological Risk Assessment

The risk assessment will address noviflumuron parent. While degradates are apparent in 

environmental fate testing, the conditions they represent (pesticide in water, pesticide mixed in 

soil, pesticide exposed to direct sunlight) are not expected to be encountered for a pesticide placed 

in bait boxes. Consequently degradates are not expected to be present at points of non-target 

organism exposure. 

8.1.2 Drinking Water Exposure Assessment

Based on the application methods (e.g., above- and below-ground bait and gel stations) and the 

fate properties (e.g., log Kow = 4.94, Kd range 859 to 7,828 mL/g) of noviflumuron, the potential 

for noviflumuron to migrate to the soil and to further migrate to surface water and/or ground water 

sources is considered minimal.

8.2 Measures of Exposure

EFED will not use standard available models to evaluate potential exposures to aquatic and 

terrestrial organisms as described at http://www.epa.gov/pesticides/science/models_db.htm. As 

described earlier, bait box placements preclude a concern for aquatic organism exposure and the 

exposure pathway of potential concern is one in which exposed termites constitute a vector 

between bait box-placed pesticide and vertebrate and invertebrate predators of termites. The risk 

assessment will estimate exposure by allocating bait box pesticide content to termites and 

then treat termite residues as a diet-available residue to predators of the termites.

8.2.1 Available Monitoring Data

The Agency is aware of monitoring conducted by federal and state agencies, and this route of 

exposure will be considered in the assessment to the extent that data on noviflumuron are available.

8.3 Measures of Effect

Toxicity data presented in Section 6 of this problem formulation will be used to calculate risk 

quotients. Any additional information submitted by the registrant or found in the open literature 
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prior to conducting the risk assessment will also be considered. The open literature studies are

identified using EPA’s ECOTOXicology database (ECOTOX)1, which employs a literature search 

engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The 

evaluation of both sources of data can also provide insight into the direct and indirect effects of 

pesticides on biotic communities from loss of species that are sensitive to the chemicals and from 

changes in structure and functional characteristics of the affected communities.

9 Endangered Species Assessments

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

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

uses of pesticides in registration review. The process for evaluating potential risks to listed species 

is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm.

10 Endocrine Disruptors Screening Program

Noviflumuron was not included in the chemicals issued an order to conduct Tier 1 EDSP testing. 

For additional information the EDSP program, visit http://www.epa.gov/endo/. 

11 Preliminary Identification of Data Gaps

11.1 Environmental Fate

Table 11-1 identifies environmental fate studies by MRID that offer data for each guideline 

requirement, study classifications, and whether or not further data are needed to support the risk 

assessment.

Table 11-1. Submitted Environmental Fate Data for Noviflumuron

Guideline Description MRID Classification Data Gap? Comments

835.2120 Hydrolysis 45232421 Acceptable No --

835.2240 Aqueous Photolysis NA Not applicable No A

835.4100 Aerobic soil metabolism 45516708 Acceptable No --

835.4200 Anaerobic soil metabolism NA Not applicable No B

835.4300 Aerobic Aquatic Metabolism NA Not applicable No A

835.4400 Anaerobic Aquatic Metabolism NA Not applicable No A

835.1230

835.1240

Leaching and adsorption/

desorption

45516709 Acceptable No

--

835.6100 Terrestrial Field Dissipation NA Not applicable No C

850.1730 Bioaccumulation in Fish NA Not applicable No D

 

1 http://cfpub.epa.gov/
17

Guideline Description MRID Classification Data Gap? Comments

A = When used as proposed, the material is contained inside a bait or gel station and should not be exposed to aqueous 

environments. B = Although anaerobic soil metabolism data would help characterize degradation in anaerobic soil 

environments (as this chemical can be used in underground bait stations), the data are not used as a modeling input parameter 

and value added is limited. C = No Field Applications (bait stations only). D = Although the log Kow of noviflumuron (4.94) 

is greater than 3, this is not considered a data gap, as the potential exposure to fish is negligible. 

11.2 Ecological Effects

Table 11-2 identifies ecological effects studies by MRID that offer data for each guideline 

requirement, study classifications, and whether or not further data are needed to support the risk 

assessment for noviflumuron as labeled for use. It should be noted that this list only includes 

data gaps relative to the conduct of a risk assessment that quantitatively addresses risks only for 

the complete exposure pathways that involve terrestrial organisms.

Data gaps of note include:

 Acute oral toxicity in a passerine bird: The exposure concept for this risk assessment 

places insectivorous birds as a non-target receptor via consumption of termites feeding on 

bait. The most likely insectivorous birds to be exposed would be passerines. 

 Avian reproduction studies for an upland game bird and a waterfowl species. These 

data are essential for evaluating the potential for noviflumuron to affect the fitness of 

avian species through impacts to reproduction. The use of noviflumuron in bait boxes 

will likely involve long-term placement of treated baits. This is likely to result in 

residues being incorporated into insect biomass (termites) over considerable periods of 

time. Without these data, the risk assessment will consider reproduction data in other 

insect growth regulator compounds. Avian reproduction data are available for 

hexaflumuron, an insect growth regulator that is almost identical in structure to 

noviflumuron. Risk quotients generated using these data would exceed the chronic level 

of concern.

Data Gaps Relative to Listed Species

Listed terrestrial vertebrate predator risks from exposure to noviflumuron through consumption 

of termites has resulted in the recommendation for avian reproduction data to fill an important 

gap in the effects data set. In addition, there are no available effects data to address 

noviflumuron risk to listed invertebrate predators that may exploit termites as a food source. 

However, the following would suggest that such exposure pathways are not reasonably expected 

to occur.

The list of terrestrial invertebrates extracted (Appendix A) from US Fish and Wildlife listings of

threatened and endangered species reveals many species that are subterranean cave dwellers 

and/or non-predators. These species can be eliminated from concern as they are not reasonably

expected to have a complete exposure pathway to noviflumuron via the consumption of termites. 

Similarly, there are a variety of emergent aquatic invertebrate predators (e.g. damsel and 

dragonfly species) whose main food source as adults is flying insects. These organisms are not 
18

reasonably expected to be exposed to noviflumuron in worker termites because they are ground 

dwelling. Consumption of noviflumuron tainted flying termite alates also is not expected because 

noviflumuron would have prevented the metamorphosis of immature alates to the adult stage in 

noviflumuron treated termite nests. 

The process to this point leaves a list of five predatory beetles and one spider, which, if 

noviflumuron treated termites were present in their habitat, could be potentially at risk from 

exposure via termite worker predation. A consideration of habitat requirements for these species 

was made referencing US Fish and Wildlife documents:

Ohlone tiger beetle Cicindela ohlone; The habitat of the Ohlone tiger beetle includes 

coastal terraces with remnant stands of open native grassland. Soils at these level or 

nearly level sites are shallow, poorly drained, pale clay or sandy clay soils over bedrock 

of Santa Cruz mudstone. http://ecos.fws.gov/docs/recovery_plan/980928a.pdf

Delta green ground beetle Elaphrus viridis: The habitat is wetland areas. 

http://ecos.fws.gov/docs/five_year_review/doc2384.pdf

Northeastern beach tiger beetle Cicindela dorsalis dorsalis: The habitat is beach areas.

http://ecos.fws.gov/docs/recovery_plan/940929b.pdf

Puritan tiger beetle Cicindela puritana: The habitat is beaches and corresponding bluff

faces, and the riparian areas of rivers. 

http://ecos.fws.gov/docs/recovery_plan/930929a.pdf

Salt Creek tiger beetle Cicindela nevadica lincolniana: The habitat is very specific and 

occurs in saline wetlands on exposed saline mud flats or along mud banks of streams and 

seeps that contain salt deposits and are sparsely vegetated.

http://ecos.fws.gov/docs/recovery_plan/Salt%20Creek%20Tiger%20Beetle%20recovery

%20outline_02-20-2009.pdf

Spruce-fir moss spider Microhexura montivaga: The habitat is associated with 

moderately thick and humid, but well-drained, moss and liverwort mats growing in 

sheltered spots on surfaces of rock outcrops and boulders in mature high-elevation forests 

dominated by Fraser fir (Abies fraseri) http://www.gpo.gov/fdsys/pkg/FR-2000-10-

06/pdf/00-25671.pdf#page=1

The habitat requirements for each of the five beetle species are not consistent with the expected 

areas immediate to the periphery of buildings where soil conditions supporting active termite 

colonies would necessitate noviflumuron bait placement. Therefore, it is not reasonable to expect 

a complete noviflumuron exposure pathway via consumption of treated termites.

In conclusion data requirement for avian reproduction will be important for evaluating risks to 

listed birds and herps but the requirements for honeybees are not necessary for evaluating effects 

to listed terrestrial invertebrates.
19

Table 11-2. Submitted Terrestrial Ecological Effects Data for Noviflumuron

OCSPP 

Guideline

Data 

Requirement

Source

MRID

Classification Data gap? Are Data Needed 

to Conduct the 

Risk 

Assessment?

Justification and Assumptions 

EPA Will Make in the Absence 

of Data 

850.2100 Avian oral 

toxicity

45232406

(upland game)

Acceptable No No --

No data

(passerine)

NA Yes Yes Acute oral toxicity data for a 

passerine species are required 

under the new 40 CFR Part 158. 

A study has not been submitted for 

this data requirement. 

A guideline-compliant passerine 

acute oral toxicity test is needed. 

Acute oral toxicity data are only 

available for one avian species 

(i.e., bobwhite quail). Passerine 

birds may utilize metabolic 

pathways that are different from 

larger birds and therefore be more 

sensitive to noviflumuron. 

Furthermore, passerines exhibit 

behavioral responses to pesticide 

dosing that are potential indicators 

of reduced fitness in the field (e.g., 

regurgitation of contaminated diet) 

even when direct biochemicallymediated lethal toxicity is not 

apparent. 

In the absence of these data, 

passerine toxicity data for 

surrogate pesticides – starting with 

data for closely related insect 

growth regulators pesticides and 

proceeding to data for less related 

pesticides – may be used to 

characterize the acute toxicity of 

noviflumuron to passerine species.

850.2200 Avian dietary

toxicity 

45516722

(upland game)

Acceptable No No --

435516721

(waterfowl)

Acceptable

850.2300 Avian 

reproduction

42495601

(upland game)

NA Yes Yes Avian Reproduction toxicity data 

are required under the new 40 

CFR Part 158. A study has not 

been submitted for this data 

requirement. In the absence of 

these data, reproduction data for 

surrogate pesticides (e.g, 

42661001 

(waterfowl)

NA
20

OCSPP 

Guideline

Data 

Requirement

Source

MRID

Classification Data gap? Are Data Needed 

to Conduct the 

Risk 

Assessment?

Justification and Assumptions 

EPA Will Make in the Absence 

of Data 

hexaflumuron) – starting with data 

for closely related insect growth 

regulators pesticides and 

proceeding to data for less related 

pesticides – may be used to 

characterize the reproduction 

toxicity of noviflumuron to avian 

species

850.3020 Honey bee 

adult acute 

contact 

toxicity

No data NA Yes No Acute contact with this pesticide is 

not expected for insect predators 

of termites.

NonguidelineHoney bee 

adult acute 

oral toxicity

No data NA Yes No Honeybees per se are not expected 

to be exposed. An analysis of the 

Federally listed threatened and 

endangered terrestrial invertebrates 

indicates that there is no 

reasonable complete exposure 

pathway to these organisms as 

well.

NonguidelineHoney bee 

adult chronic 

oral toxicity

No data NA Yes No

NonguidelineLarval honey 

bee acute oral 

toxicity

No data NA Yes No

NA = not applicable
21

12 References

Carroll C.R. and Janzen D.H. 1973. Ecology of foraging by ants. Annu.Rev. Entomol. 4: 231 –

257

Davidson D.W. 1997. Foraging ecology and community organization in desert seed-eating ants. 

Ecology 58: 725 – 737

Hçlldobler B. and Lumsden C.J. 1980. Territorial strategies in ants. Science 210: 732 – 739

McIver J.D. 1991. Dispersed central place foraging in Australian meat ants. Insect. Soc. 38: 129 

– 137

Oster G.F. and Wilson E.O. 1978. Caste and Ecology in the Social Insects. Princeton University 

Press, Princeton, New Jersey. 252 pp

Pasteels J.M., Deneubourg J.-L. and Goss S. 1987. Self-organization mechanisms in ant 

societies. (I) Trail recruitment to newly discovered food sources. In: From Individual to 

Collective Behavior in Social Insects (J.M. Pasteels and J.-L. Deneubourg, Eds). Birkh_user, 

Basel, pp 43–61

Traniello J.F.A. 1983. Social organization and foraging success in Lasius neoniger

(Hymenoptera: Formicidae): Behavioral and ecologicalaspects of recruitment communication. 

Oecologia 59: 94 – 100

USEPA 2003. Section 3 Request for Use of Noviflumuron (PC Code: 118204) in a Bait 

Formulation to Control Termites. Data Package Barcode: 285883, 288937. Environmental Fate 

and Effects Division, Office of Pesticide Programs, United States Environmental Protection 

Agency.

USEPA. 1993. Wildlife Exposure factors handbook. EPA/600/R-93/187. Office of Research and 

Development. United States Environmental Protection Agency.

USEPA. 2005. Section 3 New Use Request for Use of Noviflumuron in a Gel Bait Formulation 

to Control Cockroaches and Foraging Subterranean Termites. Data Package Barcode: 307981. 

Environmental Fate and Effects Division, Office of Pesticide Programs, United States 

Environmental Protection Agency.

Wood T.G. and Sands W.A. 1978. The role of termites in ecosystems. In: Production Ecology of 

Ants and Termites (M.V. Brian, Ed), Cambridge University Press, U.K., pp 245 – 292

Zhou, X., Wheeler, M.M. Wheeler, F.M. Oi, and M.E. Scharf. 2008. RNA interference in the 

termite Reticulitermes flavipes through ingestion of double-stranded RNA. Insect Biochemistry 

and Molecular Biology, 38 (8): 805-815.
22

13 Bibliography:

Environmental Fate Studies 

45232421 Cook, W. (1999) Hydrolysis of XDE-007 at pH 5, 7, and 9 at 25 (degrees 

centigrade) and 50 (degrees centigrade): Lab Project Number: 990050. 

Unpublished study prepared by The Dow Chemical Company. 53 p. 

45516708 Byrne, S. (2001) Aerobic Soil Degradation of 14C-XDE-007: Lab Project 

Number: 990042. Unpublished study prepared by Dow AgroSciences LLC. 66 p

45232422 Balcer, S. (1999) Probe Aerobic Soil Metabolism Study XR-007: Lab Project 

Number: GH-C 4897. Unpublished study prepared by Dow AgroSciences LLC. 

38 p. 

45516709 Byrne, S. (2001) Batch Equilibrium Adsorption and Desorption of 14C-XDE-007 

in Eight Soils: Lab Project Number: 000418. Unpublished study prepared by Dow 

AgroSciences LLC. 88 p.

Ecological Effects Studies

45232406 Kaczor, M.; Miller, V. (2000) XDE-007: 14-Day Avian Acute Oral Toxicity Test 

with Northern Bobwhite (Colinus virginianus): Lab Project Number: 030008: 

000028. Unpublished study prepared by EBA, Inc. 40 p.

45516721 Miller, V. (2001) XDE-007--Dietary Toxicity Test with the Mallard Duck (Anas 

platyrhynchos): Lab Project Number: 12550.4103: 010009. Unpublished study 

prepared by Springborn Laboratories, Inc. 96 p. 

45516722 Miller, V. (2001) XDE-007--Dietary Toxicity Test with the Northern Bobwhite 

Quail (Colinus virginianus): Lab Project Number: 010010: 12550.4102. 

Unpublished study prepared by Springborn Laboratories, Inc. 102 p.
23

14 Labels Summary Table

Use Product Name Reg. No. Method of 

Application

Maximum 

Application Rate 

(ai g/application 

site or bait tube) 

Termites subgroup; 

subterranean 

termites

Recruit IV 62719-453

Bait tube (inground, above 

ground, in 

existing structure)

2 tubes / site 

Termites subgroup; 

subterranean 

termites

Recruit IV AG 62719-454

Bait tube (inground, above 

ground, in 

existing structure)

2 tubes/ site 

Termites subgroup; 

subterranean 

termites

Recruit HD 

AG 62719-652

Bait tube (inground, above 

ground, in 

existing structure)

2 tubes/ site 

Termites subgroup; 

subterranean 

termites

Recruit HD 62719-608

Bait tube (inground, above 

ground, in 

existing structure)

2 tubes/ site 

Termites subgroup; 

subterranean 

termites

Recruit HD2 62719-608

Bait tube (inground, above 

ground, in 

existing structure)

2 tubes / site 

Termites subgroup; 

subterranean 

termites

GF-1252 62719-520 Crack and crevice 

gel applicator 1 app at 0.01g/ site 

Cockroaches GF-1252 62719-520 Crack and crevice 

gel applicator 1 app at 0.025g/ site

Cockroaches GF-1252 62719-520 Gel applicator in 

bait tube 1 app 0.025g/ station 

Insecticide Noviflumuron 

Technical 62719-452 N/A N/A(Technical Use)

Insect growth 

regulator

XDE-007 50% 

Concentrate 62719-478 N/A N/A(Manufacturing Use)
24

Assumptions/Limitations:

i) All end use formulations based on an “as needed” use basis. Applications during initial discovery of 

infestation may be more frequent than the monitoring recommended, and are re-applied as necessary when 

bait is depleted by animals. Min application interval not specified.

ii) Rate not specified on GF-1252 (EPA Reg. No. 62719-520) label for crack and crevice gel applicator on 

cockroaches, rate assumed based on amount for bait station.

iii) Tubes are placed around affected area not to exceed 20 feet apart. Minimum distance between bait tubes 

not stated for Recruit IV, Recruit IV AG, Recruit HD AG, Recruit HD, and Recruit HD2 labels.

iv) Application rates in grams of active ingredient per bait tube not clear for Recruit IV, Recruit IV AG, 

Recruit HD AG, Recruit HD, and Recruit HD2 labels.

N/A: Not Applicable.
25

Appendix A

Federally Listed Terrestrial Invertebrate Species Evaluated

Inverted 

Common Name

Scientific Name Listing Status Potential for 

complete 

exposure 

pathway

Rationale

Harvestman, Bee 

Creek Cave

Texella reddelli E No Subterranean

Harvestman, 

Bone Cave

Texella reyesi E No Subterranean

Pseudoscorpion, 

Tooth Cave

Tartarocreagris 

texana

E No Subterranean

Spider, Tooth 

Cave

Leptoneta 

myopica

E No Subterranean

Beetle, Coffin 

Cave mold

Batrisodes

texanus

E No Subterranean

Beetle, 

Kretschmarr 

Cave mold

Texamaurops 

reddelli

E No Subterranean

Beetle, Tooth 

Cave ground

Rhadine 

persephone

E No Subterranean

Beetle, Comal 

Springs dryopid

Stygoparnus 

comalensis

E No Aquatic

Beetle, Comal 

Springs riffle

Heterelmis 

comalensis

E No Aquatic

Harvestman, 

Cokendolpher 

Cave

Texella 

cokendolpheri

E No Subterranean

Meshweaver, 

Braken Bat Cave

Cicurina venii E No Subterranean

Meshweaver, 

Government 

Canyon Bat 

Cave

Cicurina vespera E No Subterranean

Meshweaver, 

Madla's Cave

Cicurina madla E No Subterranean

Meshweaver, 

Robber Baron 

Cave

Cicurina baronia E No Subterranean

Spider, 

Government 

Canyon Bat 

Cave

Neoleptoneta 

microps

E No Subterranean

Beetle, Helotes 

mold

Batrisodes 

venyivi

E No Subterranean

Ground beetle, Rhadine exilis E No Subterranean
26

[unnamed]

Ground beetle, 

[unnamed]

Rhadine infernalisE No Subterranean

Butterfly, 

mission blue

Icaricia icarioides 

missionensis

E No Herbivore

Butterfly, San 

Bruno elfin

Callophrys mossii 

bayensis

E No Herbivore

Butterfly, Schaus 

swallowtail

Heraclides 

aristodemus 

ponceanus

E No Herbivore

Damselfly, 

blackline 

Hawaiian

Megalagrion 

nigrohamatum 

nigrolineatum

E No Aerial feeder

Damselfly, 

crimson 

Hawaiian

Megalagrion 

leptodemas

ENo Aerial feeder

Damselfly, 

oceanic 

Hawaiian

Megalagrion 

oceanicum

E No Aerial feeder

Damselfly, 

flying earwig 

Hawaiian

Megalagrion 

nesiotes

E No Aerial feeder

Damselfly, 

Pacific Hawaiian

Megalagrion 

pacificum

E No Aerial feeder

Pomace fly, 

[unnamed]

Drosophila aglaiaE No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

differens

E No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

hemipeza

E No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

heteroneura

E No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

montgomeryi

E No Herbivore

Pomace fly, 

[unnamed]

Drosophila mulliT No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

musaphilia

E No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

neoclavisetae

E No Herbivore

Pomace fly, 

[unnamed]

Drosophila obataiE No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

ochrobasis

E No Herbivore

Pomace fly, 

[unnamed]

Drosophila 

substenoptera

E No Herbivore
27

Pomace fly, 

[unnamed]

Drosophila 

tarphytrichia

E No Herbivore

Grasshopper, 

Zayante band-

winged

Trimerotropis 

infantilis

E No Herbivore

Tiger beetle, 

Ohlone

Cicindela ohloneE No Habitat not 

consistent with 

use site

Spider, Kauai 

cave wolf or pe'e 

pe'e maka 'ole

Adelocosa anopsE No Subterranean

Spider, spruce-

fir moss

Microhexura 

montivaga

E No Habitat not 

consistent with 

use site

Beetle, 

American 

burying

Nicrophorus 

americanus

E No Carrion feeder

Beetle, delta 

green ground

Elaphrus viridisT No Habitat not 

consistent with 

use site

Beetle, 

Hungerford's 

crawling water

Brychius 

hungerfordi

E No Aquatic

Beetle, valley 

elderberry 

longhorn

Desmocerus 

californicus 

dimorphus

T No Herbivore

Butterfly, bay 

checkerspot

Euphydryas 

editha bayensis

T No Herbivore

Butterfly, 

Behren's 

silverspot

Speyeria zerene 

behrensii

E No Herbivore

Butterfly, 

callippe 

silverspot

Speyeria callippe 

callippe

E No Herbivore

Butterfly, El 

Segundo blue

Euphilotes 

battoides allyni

E No Herbivore

Butterfly, 

Fender's blue

Icaricia icarioides 

fenderi

E No Herbivore

Butterfly, Karner 

blue

Lycaeides melissa 

samuelis

E No Herbivore

Butterfly, 

Lange's 

metalmark

Apodemia mormo 

langei

E No Herbivore

Butterfly, lotis 

blue

Lycaeides 

argyrognomon 

lotis

E No Herbivore
28

Butterfly, Miami 

Blue

Cyclargus 

(=Hemiargus) 

thomasi 

bethunebakeri

E No Herbivore

Butterfly, 

Mitchell's satyr

Neonympha 

mitchellii 

mitchellii

E No Herbivore

Butterfly, Mount 

Charleston blue

Plebejus shasta 

charlestonensis

E No Herbivore

Butterfly, 

Myrtle's 

silverspot

Speyeria zerene 

myrtleae

E No Herbivore

Butterfly, 

Oregon 

silverspot

Speyeria zerene 

hippolyta

T No Herbivore

Butterfly, Palos 

Verdes blue

Glaucopsyche 

lygdamus 

palosverdesensis

E No Herbivore

Butterfly, Quino 

checkerspot

Euphydryas 

editha quino (=E. 

e. wrighti)

E No Herbivore

Butterfly, Saint 

Francis' satyr

Neonympha 

mitchellii 

francisci

E No Herbivore

Butterfly, 

Smith's blue

Euphilotes 

enoptes smithi

E No Herbivore

Butterfly, 

Uncompahgre 

fritillary

Boloria 

acrocnema

E No Herbivore

Checkerspot, 

Taylor's 

(=whulge)

Euphydryas 

editha taylori

E No Herbivore

Dragonfly, 

Hine's emerald

Somatochlora 

hineana

E No Aerial feeder

Fly, Delhi Sands 

flower-loving

Rhaphiomidas 

terminatus 

abdominalis

E No Herbivore

Fly, Hawaiian 

picture-wing

Drosophila 

digressa

E No Herbivore

Fly, Hawaiian 

picture-wing

Drosophila sharpiE No Herbivore

June Beetle, 

Caseys

Dinacoma caseyiE No Herbivore

Moth, 

Blackburn's 

sphinx

Manduca 

blackburni

E No Herbivore
29

Moth, Kern 

primrose sphinx

Euproserpinus 

euterpe

T No Herbivore

Naucorid, Ash 

Meadows

Ambrysus 

amargosus

T No Herbivore

Skipper, Carson 

wandering

Pseudocopaeodes 

eunus obscurus

E No Herbivore

Skipper, Laguna 

Mountains

Pyrgus ruralis 

lagunae

E No Herbivore

Skipper, Pawnee 

montane

Hesperia 

leonardus 

montana

T No Herbivore

Tiger beetle, 

Northeastern 

beach

Cicindela dorsalis 

dorsalis

T No Habitat not 

consistent with 

use site

Tiger beetle, 

Puritan

Cicindela puritana T No Habitat not 

consistent with 

use site

Tiger beetle, Salt 

Creek

Cicindela 

nevadica 

lincolniana

E No Habitat not 

consistent with 

use site

June Beetle, 

Caseys

Dinacoma caseyi E No Herbivore

Butterfly, cassius 

blue

Leptotes cassius

theonus

SAT No Herbivore

Butterfly, 

ceraunus blue

Hemiargus 

ceraunus 

antibubastus

SAT No Herbivore

Butterfly, 

nickerbean blue

Cyclargus ammon SAT No Herbivore