UNITED STATES ENVIRONMENTAL PROTECT I ON AGENCY WASH I NGTON, D

. C

. 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION 

### MEMORANDUM DATE: SUBJECT:

TO :

FROM:

THROUGH: January 28, 20 1 5 Response to Public Comments on Registration Review Problem Formulation f or the Ecological Risk Assessment and Drinking Water Exposure Assessment to be Conducted for Etoxazole
. (PC Code No. 107091; DP Barcode 424309) Julia Stokes, Chemical Review Manager Jill Bloom, Team Leader Linda Arrington , Chief Risk Management and Implementation Bra nch V Pesticide Re-evaluation D ivision (7508W) '

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# o/ jl <0 / /

# ~ Justin Housenger, Biologist 

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Environmental Risk Branch V Environmental Fate and Effects Division (7507C) 

# ·**oi/2~/I!J** Mah T. Shamim, Ph.D
. , Ch ief**~** Environmental Risk Branch V Environmental Fate and Effects Divi sion (7507C)

In response to the" 

### Registration Review- Preliminary Problem Formulation for Ecological Risk Assessment and Drinking Water Exposure Assessment to be Conducted for Etoxazole " (Document ID EPA-HQ-OPP-2014

-0133 in www . regulations.gov) (DP Barcode: 0418231 , dated July 1 , 2014), Valen t U.S.A Corporation (hereafter referred to as Valent) provided comments during the p ublic comment period. Valent is the sole U.S. regis trant ofrecord for etoxazole. The purpose of this memorandum is to address those comments. The Environmenta l Fate and Effects Division (EFED) used an outline

-type of format to address the comments. The comments were often written verbatim while other times they were summarized, as required
. EFED's purpose of the document is to respond to technical/science

-related questions and comments.

11. Valent Comment: On the anticipated data need of an Avian Acute Oral Toxicity Test (with passerine species, OCSPP 850.2100): The comprehensive and state-of-the-art data analyses by the Crop Life America (Poster presentation at SETAC North America 35th Annual Meeting is atta ched in Appendix 1) indicate that passerine species have similar sensitivity to mallard duck and bobwhite quail. Considering the low acute toxicity of etoxazole to both mallard duck and bobwhite quail (acute oral LDso 

### > 2000 mg/kg bw with NOEL 

## = 2000 mg/kg bw for mallard duck, acute dietary LCs o > 5200 ppm with NOEC 

### = 5200 ppm for both mallard duck and bobwhite quail), low toxicity to passerines is also expected. Thus, Valent proposes that the Agency remove the acute oral toxicity study with passerine species from the anticipated data needs. EFED Response: EFED acknowledges the findings of the SETAC p o ster. The issue in the case of etoxazole, as indicated by the Problem Formulation is that currently only one acute avian oral toxicity study is available. The Federal standard for outdoor registrations (40 CFR Part 158) is two studies with two different species (as is the case with the subacute dietary studies). This is to provide any information on the differential toxicity of avian species across the acute oral route of exposure. As Valent may be aware, in 2007, the 40 CFR included the passerine acute oral study as the new standard in addition to a study with the mallard duck 

### or northern bobwhite quail. In the case of etoxazole, the case for no impact on risk assessment cannot 

### be made based on the following: First, as indicated in the PF, the sole passerine acute oral study available for this class of chemicals (red winged blackbird study for diflubenzuron) shows increased toxicity over both northern bobwhite quail and mallard duck. While this is only one study, this data suggests that passerine species may be more sensitive to this class of chemicals including etoxazole. Second, as also indicated in the PF , based on current use rates, a passerine study would only have to show a two-fold greater sensitivity to the currently available study for mallard duck to trigger listed species concerns, twelve-fold greater to trigger non-listed species concerns. As indicated by the SET AC poster provided by Valent, for the studies that were completed, a passerine endpoint being lower (i.e. more toxic) than the mallard duck occurred 33% of the time (16/48), certainly within the realm of plausibility and further evidenced by the above mentioned study within the same chemical class as etoxazole. Based on the rationale provided above and reiterating the fact that only one acute oral toxicity study for etoxazole is currently available, EFED recommends retaining the avian acute oral toxicity study with a passerine study as part of its anticipated data needs for etoxazole. 2. Valent Comment: On the anticipated data needs of a Seedling Emergence Study and Vegetative Vigor Study OCSPP 850.4100 and OCSPP 850.4150): Valent does not consider additional studies are necessary. As mentioned in EFED's Preliminary Problem Formulation document, there are currently Tier I Seedling emergence and

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### Tier 1 Vegetative vigor studies available for etoxazole which are both classified as acceptable. The NOECs for each study were 0.06lbs a.i/acre. The maximum single application rate for etoxazole is 0.18 lbs a.i./acre. Valent has conducted a screening level risk assessment using EPA TerrPlant (ver. 1.2.2- attached Appendix 2). There are no LOC exceedances in this screening level assessment, and therefore low risk to non-listed and li sted (endangered) terrestrial plants i s expected from the use patterns of etoxazole. Thus, Valent proposes that the Agency removes these s tudie s from the anticipated data needs. 

### EFED Response: As indicated in Valent's own analysis provided in their response, an increase of application rate to the current maximum application rate would yield RQs roughly two fold lower than a level of concern exceedance. Thi s analysis however assumed that increasing the application rate by three fold would not alter the toxicity already determined from previous studies. There are uncertainties in that statement however as Valent's analysis assumed the EC2s was the application rate when in fact it was estimated this value was above. As stated in the 40 CFR Part 158 and the current terrestrial plant guidelines listed above, testing is preferred on the typical end use product (TEP) rather than technical grade active ingredient (TGAI) which the available studies for etoxazole used. This is for several reasons but primarily because the TEP is more akin to the actual product that will be used in the field and EFED would be interested in non-target plant e ffects from that formulation. Furthermore, TEP formulat ions often have inert ingredients in the formulation that may increase the toxicity to terrestrial plants above the level that TGAI does. 

### It is due to this uncertainty as well as the maximum application rate increasing t hree fo ld over the rate that available studies were previously conducted that EFED recommends retaining the seedling emergence and vegetative vigor s tud ies as an ticipated data needs. EFED reminds Valent these st udies should be conducted with TEP. 

### 3 . Valent Comment: On the anticipated data needs pollinator data requests (Field Testing for Pollinators, honey bee 21-d chronic larval toxicity test, 10-day adult chronic oral toxicity, and residues in pollen and nectar studie s): Etoxazole is also undergoing reregi strat ion under the EU Annex I renewal process according to EU regulation EC 1 1 07/2009. Valent's parent company, Sumitomo Chemical Corporation Company, Limited has conducted s tudie s to evaluate the safety to honey bees. Valent will s ubmit the available s tudies and a safety assessment for the use of etoxazole. All data to date indicate that etoxazole is of low toxicity to honey bees in both laborator y and semi-field tests. 

### EFED Response: EFED looks forward to the submission and receipt of these studies. It 

### is not explicitly stated in Valent's response as to which studies of those that were listed as anticipated data needs would be part of the reference coming submission. It is worth reiterating the fact that EFED is interested particularly in studies that characterize the toxicity of etoxazole to honey bee brood as etoxazole is classified as a chitin bio synthesis inhibitor.



### 4. Valent Comment:

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### Section 6. b: Receptors- Effects to Terrestrial Organisms Valent disagrees with the chronic endpoints for bobwhite quail given in Table 8, Page 20 

### in the Preliminary Problem Formulation (2014). (NOAEC: 286 ppm, LOAEC: 958 ppm). An analysis is presented as to ho w the reviewer's conclusions was based on numerical values per hen accompanying a statistical difference but these numbers should be divided by numbers of eggs set due to those eggs removed to determine eggshell thickness. Valent concludes by stating that both OCSPP 850.2300 and OECD 206 both recommend analyzing recent viable embryos or hatchlings of eggs set , _ EFED Response: EFED acknowledges receipt of the rationale provided by Valent and if it is determined that a new statistical analysis for this s tudy is needed, it will be completed ahead of the time of the Preliminary Risk Assessment as well as any potential changes to the endpoint used for risk estimation.

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