UNITED ST ATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, DC 20460 

January 29, 2016 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

DECISION MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

EPA Recommendation to Cancel All Currently Registered Flubendiamide Products (BEL TTM SC 

Insecticide (EPA Reg. No. 264-1025); SYNAPSETM WG Insecticide (EPA Reg. No. 264-1026); 

FLUBENDIAMIDE Technical (EPA Reg. No. 71711-26); VmCA® Insecticide (EPA Reg. No. 

71711-32); and TOURISMO® Insecticide (EPA Reg. No. 71711-33)) 

Susan 

Registration 

T. Lewis, 

Division (7505P) 

Director ~l/V'\ c:J\. ~ 

Jack E. Housenger, Director 

Office of Pesticide Programs (7501P) 

1. Regulatory Background 

On August 1, 2008, the EPA granted a time-limited (5-year) conditional registration under section 3(c)(7) of 

FIFRA for flubendiamide to Bayer CropScience LP as agent for Nichino America, Inc., hereafter jointly 

identified as BCS/NAI. EPA issued a time-limited/conditional registration due to the Agency's initial concerns 

regarding flubendiamide's mobility, stability/persistence, accumulation in soils, water columns and 

sediments, and the extremely toxic nature of the primary degradate NNI-001-des-iodo ( des-iodo) to aquatic 

invertebrates. Flubendiamide currently has foliar (ground & aerial) uses on over 200+ use sites with some 

crops having as many as 6 applications per year. Flubendiamide acts against the larvae of the target pests 

(Lepidoptera spp.) via oral ingestion of toxic residues on plants. 

As a condition of registration, as established in the preliminary acceptance letter (PAL) for flubendiamide 

(copy attached), if the Agency makes a determination that further registration of the flubendiamide 

technical and end-use products will result in unreasonable adverse effects on the environment, within (1) 

week of this finding, BCS/NAI must submit a voluntary cancellation of the flubendiamide technical and all 

end use products. BCS/NAI's original release for shipment of the flubendiamide products constituted 

acceptance of the conditions of registration as outlined in the PAL. As stated in the notices of registration for 

each flubendiamide product, if the conditions of registration are not complied with, the registration for all 

flubendiamide products would be subject to cancellation in accordance with section 6(e) of FIFRA. 

In addition, as part of these conditions of registration, BCS/NAI agreed to generate and submit a vegetative 

filter strip (VFS) study and, if the VFS proved to be ineffective in reducing the contamination, to conduct a 

farm pond water monitoring program. The VFS study was required to assess the efficacy of the BCS/NAIproposed 15-foot VFS in field conditions. The VFS study was submitted to the Agency on August 3, 2010. 

Prior to the Agency's completion of the VFS study review, BCS/NAI submitted a waiver request for the farm 

pond water monitoring program study. This waiver request was denied by the Agency via a letter dated 

November 8, 2010 because the Agency had identified a major modeling error in BCS/NAI's VFS study and 

believed that even if the error was corrected, a VFS "would be insufficient to preclude ecological risk 

concerns". As a result, the second data-related condition of registration, the farm pond water monitoring 

program was triggered. The farm pond water monitoring program was comprised of 3 years of water 

monitoring from 2 VFS-protected farm ponds in Georgia and North Carolina (submitted December 22, 

2014). The Agency review, provided to BCS/NAI on February 20, 2015, indicated that both flubendiamide 
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and des-iodo were accumulating in all of the farm ponds' overlying water, sediment, and pore water; 

therefore, the VFSs were ineffective at preventing flubendiamide and des-iodo from accumulating in aquatic 

systems downstream of the fields to which flubendiamide had been applied. 

2. Time-Limited/Conditional Registration Expiration Date Extensions 

The original time-limited/conditional registration expiration date for flubendiamide was July 31, 2013; 

however, BCS/NAI has requested several extensions to the time-limited/conditional registration expiration 

date, with the latest extension out to January 29, 2016. The latest extension allowed EPA to host a technical 

discussion between its scientists and BCS/NAI scientists on January 6, 2016, which allowed them to engage 

in dialogue related to the conditional data and the EPA's conclusions related to flubendiamide. This 

extension also allowed additional time for EPA to review 2 newly submitted data volumes (an aqueous 

photolysis study and a spiked sediment study) and to consider the most recent label proposal submitted by 

BCS/NAI on January 8, 2016. 

3. Human Health Risk Assessment: 

No human health concerns have been identified with the use of flubendiamide. The human health 

assessment for flubendiamide has not changed since the initial risk assessment in 2008. Flubendiamide has 

a low acute oral (LDso >2,000 mg/kg body weight/day (mg/kg/day)); dermal (LDso >2,000 mg/kg/day); and 

inhalation toxicity (LCso >68.5 mg/m3 air). Though it is a slight irritant to the eye, flubendiamide is not a 

skin irritant and it is not a skin sensitizer. The primary target organ is liver with thyroid and kidney effects 

being secondary. Ocular effects were observed in multiple studies and used for acute dietary risk 

assessment. Flubendiamide is considered "Not Likely to be Carcinogenic to Humans," and was not 

mutagenic. There is no residual uncertainty for pre- and post-natal toxicity, and flubendiamide is not 

neurotoxic. The FQPA safety factor was reduced to lX. Aggregate exposure (refined food and updated 

estimated drinking water concentrations) are below the Agency's level of concern. EPA has not found 

flubendiamide to share a common mechanism of toxicity with any other substances, and flubendiamide does 

not appear to produce a toxic metabolite produced by other substances. 

4. Ecological Fate and Effects Risk Assessments 

Flubendiamide has been subject to three (3) ecological fate and effects risk assessments. The initial 

assessment, dated June 23, 2008, was followed by two (2) subsequent separate assessments (May 17, 

2010 and December 16, 2010, respectively) to add new crops/uses in 2010. The most recent document: 

"Flubendiamide: Ecological Risk Assessment Addendum Summarizing All Submissions and Discussions to 

Date," dated January 28, 2016, is an addendum/compilation of all of the ecological fate and effects 

submissions and technical discussions with BCS/NAI to date. 

The June 23, 2008 risk assessment addressed BCS/NAI's initial registration proposals for one (1) technical 

product and two (2) flubendiamide end-use product formulations. The 480 SC product was proposed for 

corn, cotton, tobacco, grapes, pome fruit, stone fruit, and tree nut crops. A second formulation, 24 WG, was 

proposed for use on cucurbit vegetables, fruiting vegetables, leafy vegetables, and brassica (cole) leafy 

vegetables. 

The June 23, 2008 risk assessment's evaluation of the physical and chemical properties of flubendiamide 

indicated that flubendiamide is stable to hydrolysis, aerobic and anaerobic soil metabolism, and aerobic 

aquatic metabolism. Photolysis and anaerobic aquatic metabolism were reported to be the main routes of 

degradation for flubendiamide. Flubendiamide degrades to des-iodo under anaerobic aquatic conditions (t1h 

= 364 days) and direct aqueous photolysis (tl/2 = 11.6 days), but rather slowly by soil photolysis (t1h = 

70.5 days). Submitted fate data indicate flubendiamide slowly converts to its des-iodo degradate, which 
Page 3 of 11 

does not further breakdown. Flubendiamide and des-iodo were reported to have the potential for 

groundwater contamination in vulnerable soils with low organic carbon content after a very heavy rainfall 

and/or in the presence of shallow groundwater. 

The June 23, 2008 risk assessment also noted that the overall stability/persistence profiles for flubendiamide 

and the des-iodo degradate were suggestive of accumulation in soils, water column, and sediments with 

each successive application. Analysis of available ecological effects data resulted in the conclusion that both 

flubendiamide and its des-iodo degradate were of toxicological concern. EFED modeling predicted that 

flubendiamide and des-iodo would accumulate in aquatic systems eventually exceeding Agency LOCs, and 

concluded that there is a potential for risk to benthic invertebrates1 exposed to flubendiamide and its desiodo degradate, and that the formulated products 480 SC and 24 WG do result in direct acute and chronic 

risk to freshwater invertebrates. The acute risk issue is relatively minor and refers to enhanced toxicity of 

the formulations compared to the technical grade active ingredient (applicable only to direct application to 

aquatic environments through spray drift), while the chronic risk to freshwater invertebrates is the major 

risk concern. Because of these chronic aquatic risk concerns, two (2) data-related conditions of registration 

were imposed and conveyed to BCS/NAI by the PAL: 

• Vegetative Filter Strip Study - a run-off study to determine the magnitude of the parent, flubendiamide, 

retained in buffer strips of various widths; and 

• Farm Pond Water Monitoring Program - if a risk assessment, based on the results from the small-scale 

run-off/vegetative filter strip study and additional available data, indicates that there are still risk 

concerns, monitoring of selected receiving waters will be required within watersheds where 

flubendiamide will be used. 

According to the flubendiamide PAL, the "Agency believed that the efficacy of vegetative buffers for 

flubendiamide use is uncertain." Since 2008, BCS/NAI has argued that: (1) VFSs would prevent 

accumulation from exceeding Agency LOCs (flubendiamide labels require a 15-foot VFS around aquatic 

areas); and (2) the Agency overestimates aquatic exposure because the EFED modeling cannot account for 

the effect of VFSs. During the Agency's cursory review of the VFS study protocol, a major modeling error 

was identified. The Agency requested the study be corrected and re-submitted; however, BCS/NAI never resubmitted a corrected study. Therefore, the second data-related conditional registration requirement, the 

'farm pond' water monitoring program, was triggered. 

The May 17, 2010 environmental risk assessment addressed additional registration proposals for 480 SC 

formulation use on Christmas trees and legume vegetables including soybeans, and the 24 WG formulation 

for rotational plant-back interval use for legume vegetables. The conclusions of the May 17, 2010 risk 

assessment were not markedly different from the 2008 risk assessment's characterization of the 

environmental fate, stressors of concern, nor the risk conclusions: (1) concern for long-term accumulation of 

the parent flubendiamide and the des-iodo degradate; (2) flubendiamide and the des-iodo degradate as 

stressors of concern and; (3) risk concerns for benthic invertebrates from both flubendiamide and the desiodo degradate as well as surface water concerns for the formulations to freshwater invertebrates. However, 

the risk assessment also addressed the potential for distance buffers between application sites and surface 

waters as a risk mitigation option. The May 17, 2010 risk assessment concluded that buffers, from a spray 

drift perspective, would have little impact on the risks of concern. 

1 Some species of aquatic invertebrates inhabit the overlying water (water above the sediment in a water body), while others inhabit 

the benthic zone (in or on the sediment in a water body). Because exposure and effects endpoints can vary between overlying and 

benthic (or pore) water, it is sometimes necessary to specify overlying or benthic if referring to only one portion of the water body or 

one of these groups of aquatic invertebrates. 
Page 4 of 11 

The December 16, 2010 risk assessment addressed proposed new uses of flubendiamide on alfalfa, globe 

artichoke, low growing berries (except cranberry), peanut, pistachio, small fruit vine climbing (except fuzzy 

kiwifruit), sorghum, sugarcane, sunflower, safflower, turnip greens, and a proposed increased application 

rate on brassica leafy vegetables. The proposed new uses and increased rate included the water dispersible 

granule formulation SYNAPSETM WG (39% flubendiamide) and BELTTM SC (24% flubendiamide), a 

suspension concentrate formulation. Flubendiamide was proposed for ground application, aerial application 

(restricted for pistachio, and small fruit vine climbing group), and chemigation. Again, as in the previous risk 

assessments, flubendiamide and the des-iodo degradate were identified as the stressors of concern. 

Environmental fate and transport data indicated that flubendiamide is stable to hydrolysis, aerobic and 

anaerobic soil metabolism, and aerobic aquatic metabolism. Photolysis and anaerobic aquatic metabolism 

appeared to be the main routes of degradation for flubendiamide. 

Flubendiamide degrades to des-iod6 under anaerobic aquatic conditions (t1/2 = 364 days), direct aqueous 

photolysis (t1

/z = 11.6 days), and by soil photolysis (t1/2 = 35.3 days). Flubendiamide was expected to be 

slightly to hardly mobile in the environment. The des-iodo degradate was concluded to be persistent (stable 

in an aerobic soil environment) and expected to be moderately mobile. As in the previous risk assessments, 

concern was indicated for chronic risk to benthic invertebrates from exposures in the water column and pore 

water from the total residues of flubendiamide and des-iodo. The December 16, 2010 risk assessment 

mentions that a field study of the efficacy of vegetative filter strips to reduce pesticide loading to surface 

waters was under review at the time of writing. However, the results of that study were not incorporated 

into the December 16, 2010 risk assessment. 

5. Label Proposal, Additional Data and Interactions with BCS/NAI 

The 3-year report on the farm pond water monitoring study of water column, sediments, and pore water in 

3 ponds (2 in Georgia and 1 in North Carolina) was submitted by BCS/NAI in December of 2014. The 

Agency's review has identified several issues with this monitoring data. Despite these issues, EPA believes 

the monitoring data shows clear evidence that both flubendiamide and des-iodo accumulate in the ponds 

monitored. The accumulation measured in the first 3 years of the pond data largely matches the initial 

predictions. Because the Agency's modeling does not account for the effect of VFSs, but still largely matches 

the monitoring data, we believe the effect of VFSs is not large enough to mitigate the ecological risks posed 

by flubendiamide applications. Our conclusion is the original and subsequent ecological risk assessments 

performed by the Agency adequately reflect the risks posed by flubendiamide applications and rejects 

BCS/NAI's argument that the label-required 15-foot VFSs around aquatic areas would prevent accumulation 

from exceeding Agency LOCs. Accumulation was consistent with the Agency's 2008 model predictions for a 

pond without grassed waterways. Since both flubendiamide and des-iodo were found to be accumulating in 

surface water, sediment, and pore water in all three of the VFS-protected ponds monitored, the VFSs were 

deemed ineffective in preventing accumulation of flubendiamide and des-iodo in water bodies. 

In late October 2015 through January 2016, numerous re-review and validation refinements of the 

ecological and fate data evaluation records and new model scenarios occurred in critical documents. 

BCS/NAI also asked the Agency to consider various label mitigation options of reducing crops and 

application rates and frequency, deleting aerial use and considering an increase in the buffer size so that the 

chemical might retain its active registration status. The Agency performed numerous series of "bracketing 

scenarios" of label applications and rates. Also during this time, the water values were reassessed by using 

a time-weighted average (TWA) approach instead of a single measured value. This recalculation of TWA 

values reduces the LOAEC for parent flubendiamide in overlying water by a factor greater than two and pore 

water by a factor slightly greater than one. The TWA values factor in the variability of measured 

concentrations rather than relying on a single measured value at onset of test consistent with current 

guidance in EFED. Recalculation of TWA values for the des-iodo degradate produced no change in the 

NOAEC values for overlying and pore water. These latest proposed label mitigation scenarios exceed Agency 
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LOCs based on TWA endpoints. 

6. Comparison of EPA Use of Flubendiamide and Des-iodo Toxicity Endpoints in Previous Risk 

Assessments 

A comparison of the use of the flubendiamide toxicity endpoints in the previous risk assessments shows that 

TWA concentrations were not reported in the previous risk assessments for the NOAEC in overlying and 

pore waters, and shows that they reported the LOAEC as a single post-application measured dose of 69 

μg/L in overlying water and 3 μg/I in pore water. In addition, a comparison of the use of the des-iodo 

degradate toxicity endpoints in the previous risk assessments shows that TWA concentrations are the same 

as those in previous risk assessments for the NOAEC in overlying and pore waters, and that the previous 

risk assessments did not report a TWA for the LOAEC. A detailed summary of the toxicity endpoints used in 

previous risk assessments for flubendiamide and des-iodo is shown within Tables 3 and 4, on pages 7 to 8, 

of the EFED document entitled "Flubendiamide: Ecological Risk Assessment Addendum Summarizing All 

Submissions and Discussions to Date," dated January 28, 2016. 

7. Final Suite of Available Effects Toxicity Endpoints 

Table 1 lists the final suite of flubendiamide and des-iodo chronic toxicity endpoints for Chironomus riparius 

(an aquatic invertebrate of the benthos) in spiked water and spiked sediment tests. Consistent with other 

studies with this species and sediment, emergence of the organisms proved to be the most sensitive 

endpoint. These endpoints are all based on emergence inhibition. (For example, 80% emergence inhibition 

indicates that 80% of the test organisms were unable to emerge as the adult, reproductive life-stage from 

the sediment where the juveniles reside, while 20% were able to emerge and potentially complete their lifecycle.) 

Table 1. Current Flubendiamide and Des-iodo Toxicity Endpoints for Chironomus riparius in 

s ;p1 "k d e w ater an d s ;p1 "k d d e Se iment Tests. 

Overlying Water TWA (ua/L) Pore Water TWA (1Jg/L) Endpoint Label 

Flubendiamide Endpoints in Chironomus Spiked Water 28-Day (MRID 46817022) 

15.5 1.51 NOAEC Percent emerqence 

29.9 2.50 LOAEC 22% inhibition 

62.0 6.05 100% inhibition 

Flubendiamide Endpoints in Chironomus Spiked Sediment (MRID 49661801) (in review) 

5.23 1.53 NOAEC Percent emerqence 

12.3 4.32 LOAEC Percent emergence 

Des-iodo Endpoints in Chironomus Spiked Water 28-Day (MRID 46817023) 

1.90 0.278 NOAEC Percent emergence 

4.14 0.737 LOAEC 17% inhibition 

8.27 1.47 33% inhibition 

16.0 3.91 80% inhibition 

Des-iodo Endpoints in Chironomus Spiked Sediment (MRID 48175605) 

7.18 19.5 NOAEC (Highest dose tested) 

>7.18 >19.5 LOAEC 

8. Discussion of Ecological Fate and Effects Data Submitted after the Last Risk Assessment 

Dated December 16, 20 10 

Several ecological fate and effects studies have been submitted since the December 16, 2010 risk 

assessment for flubendiamide. In 2015, while the evaluation of all lines of evidence was underway with 

respect to the efficacy of vegetative filter strips, model assumptions, and surface water monitoring, the RD 
Page 6 of 11 

risk managers requested that exposure modelling results be compared to the full suite of effects endpoints 

from the two spiked water prolonged sediment toxicity tests with Chironomus riparius (MRIDs 46817022 

(flubendiamide) and 46817023 (des-iodo degradate)). As a result, EPA scientists issued a memorandum that 

summarized the approach for evaluation of the two studies, and the findings of that effort. A detailed 

summary of the resulting toxicological endpoints for flubendiamide and des-iodo, expressed as TWA, is 

shown within Tables 1 and 2, on page 7, of the EFED document entitled "Flubendiamide: Ecological Risk 

Assessment Addendum Summarizing All Submissions and Discussions to Date," dated January 28, 2016. 

9. Ecological Fate Data 

The flubendiamide fate data interpretation has not changed since the new chemical assessment in 

December 16, 2008. Additional laboratory fate data was requested and submitted for the des-iodo 

degradate after the new chemical assessment. All of this additional des-iodo fate data indicated that the 

des-iodo degradate does not degrade in the environment with the exception of the des-iodo aquatic 

photolysis study that was recently submitted on January 5, 2016. 

10. New Des-iodo Aquatic Photolysis Study (MRID 4966170 1) 

BCS/NAI submitted a 10-day aqueous photolysis study on January 5, 2016, that estimates a 79-day half-life 

for the des-iodo degradate when expressed as an environmentally relevant half-life for June in Phoenix, AZ. 

While this study is in review, the following is a preliminary analysis: 

"At the end of the 10-day aqueous photolysis study, 77% of the des-iodo remained as untransformed desiodo. The other 23% had transformed into 14 degradates and C02. Because so many degradates together 

make up so little mass, no degradate exceeded 6% and only two degradates could be identified. None of 

the degradates have toxicity data, so none can be ruled out as degradates of concern other than C02. 

Assuming that all of the degradates, other than C02, are degradates of concern would produce a total toxic 

residue (TTR) half-life exceeding 1,000 years." 

11. Tree Nut Use Modeling 

At the most recent technical meetings between EPA scientists and BCS/NAI scientists on January 6, 2016, 

BCS/NAI inquired about the possibility of submitting a new label mitigation proposal where BCS/NAI would 

retain only one use - tree nuts on their label, and stated that it would not exceed any of the Agency's LOCs. 

On January 8, 2016, BCS/NAI submitted a new revised label to the Agency that: (1) eliminated aerial 

applications; (2) limited use to tree nuts in California only; and (3) further limited application rates for tree 

nut uses below that on the current label for EPA Reg. No. 264-1025 (BELTTM SC Insecticide). 

Modeling of this proposed remaining use allowed the Agency to perform an assessment of not only the 

reduced application rates, but also allowed EPA to incorporate the 79-day aqueous photolysis half-life data 

for des-iodo into this assessment. Previous analyses were unable to use this half-life estimate since it was 

only just submitted to the Agency on January 5, 2016. Flubendiamide air blast applications to tree nuts were 

modeled using the California almond scenario, based on an application rate of 0.125 pound of active 

ingredient per acre with a 7-day application interval and up to 3 applications per year. The scenario 

modeled assumes that flubendiamide has not previously been used in the fields to which it is to be applied, 

and includes a 30-ft spray drift buffer zone around aquatic areas based on the new proposed label (previous 

modeling had only included a 15-ft spray drift buffer zone which was correct based on the spray drift 

language of the previous labels). 
Page 7 of 11 

To provide an estimate of the ecological effects to be anticipated at different RQ levels, the NOAEC and any 

additional treatment levels that showed a significant effect above the NOAEC were included. Analyzed 

endpoints include both the Agency endpoints based on TWAs and the BCS/NAl-suggested endpoints that 

are not supported by the Agency guidance. 

A detailed summary of the comparison of EFED's most sensitive endpoints based on TWA concentrations 

and BCS/NAl-suggested most sensitive endpoints for flubendiamide and its des-iodo degradate, is shown 

within Table 6, on page 10, of the EFED document entitled "Flubendiamide: Ecological Risk Assessment 

Addendum Summarizing All Submissions and Discussions to Date," dated January 28, 2016. All of the 

existing uses for the time-limited/conditional flubendiamide registrations as well as the latest proposed use 

scenarios exceed the Agency LOCs for aquatic system invertebrates based on the TWA effect endpoints 

from C riparius testing compared with estimated toxicant concentrations for sediment pore- and overlyingwater. 

12. Integration of New Ecological Fate and Effects Information into the Amended EFED Risk 

Assessment 

Results from the Farm Pond Water Monitoring Studv: At the end of three (3) years of water monitoring, 

BCS/NAI submitted the final farm pond water monitoring reports. In its review, EFED identified several 

issues with this monitoring data. Despite these issues, EFED believed the monitoring data showed clear 

evidence that both flubendiamide and des-iodo accumulated in the ponds monitored. The accumulation 

measured in the first 3 years of the pond data least impacted by the identified issues largely matched the 

initial 3 years of concentration predictions of EFED's aquatic exposure modeling. Because EPA's modeling 

does not account for the effect of VFSs, but still largely matched the monitoring data, EPA believes the 

effect of VFSs is not large enough to mitigate the ecological risks posed by flubendiamide applications. EPA 

concluded the original and subsequent ecological risk assessments performed by the Agency adequately 

reflect the risks posed by flubendiamide applications and rejects BCS/NAI's argument that the label-required 

15-foot VFSs would prevent accumulation from exceeding Agency LOCs. 

Analvsis of Results from Four Requlatorv Scenarios for Multiole Crops: The Agency compared four regulatory 

scenarios for multiple crops based on standard EPA aquatic modeling procedures. The crops selected were 

those with the largest number of acres treated according to proprietary pesticide usage data available to the 

Agency. The regulatory scenarios assumed maximum use rates from 2009 (the year after flubendiamide was 

registered) to 2015, and then changed according to the regulatory scenario modeled, which included 'no 

change from current label,' 'change to one ground application forever,' 'change to one ground application, 

then cancel in 2018,' and 'cancel uses after the 2015 application.' When considering the TWA endpoints, all 

four (4) of the regulatory scenarios exceed Agency LOCs for all of the simulated crops. Consistently, the 

greatest exceedances occur for des-iodo in pore water, and many of the scenarios achieve exposure levels 

that resulted in 80% emergence inhibition in the des-iodo chronic laboratory toxicity study, which indicates 

at this exposure level that 80% of the test organisms were unable to emerge as the adult (reproductive lifestage) from the sediment (where the juveniles reside), while 20% were able to emerge and potentially 

complete their life-cycle. 

Flubendiamide and its des-iodo degradate pose a long-term risk long after a regulatory action may take 

place (i.e., there is a time-lag between mitigation and the maximum risk). For example, under the "cancel 

now" regulatory scenario, flubendiamide applications to the watershed above the modeled pond stop after 

2015; however, risk from des-iodo in pore water does not level-off (stop increasing) for more than a decade 

after. This time-lag is due to the time required to transport the flubendiamide from the field to the pond and 

subsequent conversion of flubendiamide in the pond into des-iodo. 

The TWA endpoint exceedances tend to occur quite early in the temporal trends. For example, all of the 
Page 8 of 11 

des-iodo pore water TWA endpoints exceed Agency LOCs within two years. Considering that flubendiamide 

applications could have started in 2009 for these crops, these projected exceedances could have occurred 

as early as five years ago. Even if risk were judged by the less sensitive endpoints suggested by BCS/NAI, 

all but two of the regulatory scenarios exceed Agency LOCs. These two regulatory scenarios are the 

"Change to one ground application then cancel after the studies are submitted" and "Cancel now" scenarios 

for the leafy vegetables (based on the CA lettuce scenario, with ground applications initially in the first time 

period). 

Analvsis Results from High and Low Exposure Analvsis for 13 Crop Uses: BCS/NCI requested the Agency 

also consider another label mitigation option where only 13 crops remained on the labels. This analysis 

provided additional characterization of ecological risk through consideration of a subset of crops proposed as 

posing limited ecological risk to aquatic invertebrates. The crop scenarios were selected based on the 13 

crops (or crop groups; i.e., alfalfa, brassica leafy vegetables, cotton (AZ and CA only), cucurbit vegetables, 

fruiting vegetables, grape, leafy vegetables, legume vegetables, pome fruit, stone fruit, strawberry, tobacco, 

and tree nuts) that BCS/NAI proposed to retain on flubendiamide labels. Only two crop scenarios (high and 

low exposure) were investigated for this second memo to capture the range of flubendiamide risk from the 

BCS/NAI-proposed crops to be retained. This analysis assumed no prior use of flubendiamide and modeled 

different numbers of applications from the maximum allowed on the label down to one at the maximum 

single application rate. Both the high and low exposure/risk crop scenarios exceed Agency LOCs (based on 

the TWA endpoints). There is risk for all application numbers modeled for both high and low scenarios. The 

low exposure scenario exceeds Agency LOCs in: 3 years at six, five, or four applications per year; 4 years at 

three applications per year; 6 years at two applications per year; and 9 years with only one application per 

year. The high exposure scenario applying two applications per year (the most allowed by the BCS/NAI 

proposal) exceeds Agency LOCs in 2 years, while the first exceedance occurs in 3 years with only one 

application per year. 

Although the Agency does not agree with the use of the nominal-based endpoints that were suggested by 

BCS/NAI, the low exposure scenario exceeds Agency LOCs in 11 years at six applications per year, 13 years 

at five applications per year, 16 years at four applications per year, and 21 years at three applications per 

year using the BCS/NAI-suggested endpoints. The low exposure scenario based on either one or two 

applications per year does not exceed LOCs within the 30 years simulated based on the BCS/NAI-suggested 

endpoints. However, both application patterns of either one or two applications per year would be expected 

to eventually exceed if applications continued long enough. The high exposure scenario applying two 

applications per year exceeds LOCs based on the BCS/NAI-suggested endpoints in eight years, while the 

first exceedance occurs in 11 years with only one application per year. Therefore, when considering 

BCS/NAI's less conservative proposed endpoints, use of flubendiamide still results in risk concerns for 

aquatic system invertebrates. 

Tree Nut Assessment Results: The Agency received a new proposed label for flubendiamide on January 8, 

2016 that limits the label only to tree nuts in California, and further limits application rates. Modeling this 

proposed use allowed the Agency to perform an assessment of not only the reduced application rates, but 

also incorporate the 79-day aqueous photolysis half-life for des-iodo into this assessment (previous analyses 

had not used this half-life estimate since it was submitted to the Agency on January 5, 2016). This analysis 

also assumed no prior use of flubendiamide and modeled different numbers of applications from the 

maximum allowed on the label down to one at the maximum single application rate. Based on the TWA 

endpoints, the currently proposed flubendiamide tree nut use results in risk that exceeds Agency LOCs for 

all numbers of applications modeled. The tree nut scenario proposed by the BCS/NAI exceeds Agency LOCs 

in 2 years at three applications per year and 3 years at two or one application(s) per year. Although the 

Agency does not agree with the use of the nominal-based endpoints that were suggested by BCS/NAI, the 

proposed tree nut scenario exceeds Agency LOCs using these endpoints in 10 years at three applications per 

year, 11 years at two applications per year, and 21 years at one application per year. Therefore, when 
Page 9 of 11 

considering BCS/NAI's less conservative proposed endpoints, the continued use of flubendiamide still results 

in risk concerns for aquatic system invertebrates. Based on the California almond scenario presented above, 

as well as the other recent modeling, significant chronic risk effects to aquatic organisms due to the use of 

flubendiamide could potentially occur in as little as 2 years. 

While BCS/NAI has raised many issues as discussed in detail within the amended ecological risk assessment, 

none have persuaded the Agency that the original and subsequent ecological risk assessment conclusions 

were inaccurate nor have they diminished confidence in those conclusions. 

13. USGS Monitoring Information 

Additional information from U.S. Geological Survey (USGS) stream and river monitoring data (2012 to 2014) 

indicate that flubendiamide and des-iodo was detected at 26 sites in 14 states. California, Georgia, North 

Carolina, Mississippi, and Louisiana had multiple sites with frequent detections. These detections were 

filtered water samples only. The Agency fully expects higher concentrations in unfiltered water or sediment 

samples. 

14. Other Persistent Chemicals 

In terms of the Agency's history in mitigating the ecological risks posed by other persistent and toxic 

insecticides, EPA has limited similar insecticide products to greenhouses, perimeter structural treatments, or 

indoor uses. Since flubendiamide only has outdoor above-ground foliar crop uses, this type of mitigation is 

not a regulatory option for the compound. 

15. Mitigation and Labeling Requirements 

A series of meetings between EPA scientists and BCS/NAI scientists has occurred since March 2015, where 

the Agency has continued to engage in dialogue about the referenced conditional data and the 

environmental risk conclusions. After review of all the BCS/NAI data submissions and previous risk 

assessments, EPA's conclusions on the environmental risks posed by flubendiamide and des-iodo today are 

consistent with those identified in 2008. EPA originally concluded that "Flubendiamide and the des-iodo 

degradate's overall stability/persistence suggests that they will accumulate in soils, water column, and 

sediments with each successive application." 

EPA's analysis of BCS/NAI's farm pond water monitoring study concludes that there is: (1) accumulation of 

both flubendiamide and des-iodo in the water column, sediment, and pore water for all ponds monitored; 

and (2) definitive evidence that VFSs do not sufficiently control off-site transport of these chemicals to 

downstream waterbodies. In addition, stream and river monitoring conducted by BCS/NAI and the USGS 

over much of the United States indicates: (1) the failure of VFSs to contain these chemicals is a widespread 

occurrence; and (2) the potential for water quality impacts is also widespread. 

16. Benefits and Alternatives 

EPA evaluated the benefits and alternatives for flubendiamide in a memo dated July 24, 2015 (copy 

attached). The Agency reviewed benefit information submitted by BCS/NAI, which included a combination of 

private pesticide surveys of growers, trade journals, articles, state extension Integrated Pest 

Management websites, Arthropod Management Tests, and expert opinions to support claims of 

benefits. The benefits of flubendiamide are that it plays a role in integrated pest management and 

insecticide resistance management based upon the following characteristics: (1) specificity to Lepidopteran 

larvae; (2) non-systemic but translaminar properties; and (3) no to low impacts on beneficial arthropods. If 

flubendiamide is unavailable, pyrethroids would most likely be the alternative chemistry used by growers. 
Page 10 of 11 

Other alternatives are insect growth regulators (e.g., diflubenzuron, methoxyfenozide), other diamides (e.g., 

chlorantraniliprole, cyantraniliprole), and spinosyns (e.g., spinetoram). Overall, EPA concludes that there are 

efficacious alternatives for flubendiamide. 

17. EPA Risk Management Decision and Regulatory Determination 

The initial environmental risk concerns from 2008 to the present have continued to center around 

flubendiamide being a mobile, persistent, and extremely toxic insecticide and because the parent degrades 

only through aquatic photolysis and anaerobic aquatic metabolism to des-iodo, which does not further 

degrade except slowly through photolysis. EPA has identified chronic concerns for Flubendiamide to aquatic 

system invertebrates for both parent and its des-iodo degradate. These risks concerns are based on 

comparisons of overlying and sediment pore water concentrations of the two compounds to effects 

endpoints established using the emergent aquatic insect C riparius, a commonly tested species with 

juvenile life stages that exist in the benthic sediment and are exposed to both sediment pore- and overlyingwater. However, because des-iodo is 10X more toxic to aquatic invertebrates than the parent flubendiamide, 

it is des-iodo that causes the greatest risk concern. Therefore, with each successive flubendiamide 

application, more flubendiamide is transported to aquatic environments via runoff and spray drift where it 

accumulates and slowly degrades to des-iodo, which in turn accumulates, causing unreasonable adverse 

effects to aquatic environments. 

EPA has assessed the risks and benefits associated with the continued use of flubendiamide as currently 

registered (and the modifications proposed by BCS/NAI), and determined that the risks of allowing the 

continued use of flubendiamide outweigh the benefits, and will result in unreasonable adverse effects to the 

environment. In conclusion, all of the existing uses for the time-limited/conditional flubendiamide 

registrations as well as the latest proposed use scenarios exceed the Agency's LOCs for aquatic system 

invertebrates based on the TWA effect endpoints from C riparius testing compared with estimated toxicant 

concentrations for sediment pore- and overlying- water. The modelling scenarios based on the latest label 

submitted by BCS/NAI and the TWA endpoints exceed Agency LOCs within 2 years. Considering that 

flubendiamide applications most likely started in 2009 (7 years ago), these exceedances could have 

occurred as early as 5 years ago. Such adverse impacts would directly impact aquatic invertebrates in 

ponds, lakes, reservoirs, estuaries, areas of sediment accumulation in flowing waterbodies and any nonflowing waterbodies where des-iodo would accumulate-downstream of lands where flubendiamide is used as 

well as indirect impacts to fish and wildlife for which aquatic invertebrates serve as the basis for their food 

chain. 

Within the parameters of the time limited/conditional registration agreement signed by both the Agency and 

BCS/NAI, the companies (BCS/NAI) agreed to voluntarily cancel all flubendiamide products if the Agency 

makes the determination that there are unreasonable adverse effects to the environment. If the companies 

(BCS/NAI) fail to voluntarily cancel all registrations by the close of business on Friday, February 5, 2016, I 

recommend the Agency move forward with cancellation under section 6(e) of FIFRA. 
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EPA RECOMMENDATION: I recommend that you concur with the cancellation of all flubendiamide 

products in accordance with the BCS/NAI and the Agency's time limited/conditional registration agreement 

that was signed and dated, July 31, 2008. 

DATE 

DO NOT CONCUR DATE