1 OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON

, D.C. 20460

September 8, 2014

PC Code: 046679

MEMORANDUM DP Barcode: 422679

SUBJECT: Addendum to the EFED Registratio n Review Problem Formulation for Fenamidone Regarding Tier I Honey Bee Toxicity Testing

TO: Christina Scheltema, Chemical Reviewer Manager Avivah Jakob, Team Leader Patricia Parrott, Branch Chief Risk Management and Implementation Branch III

Pesticide Re-Evalua tion Division (7508P)

THROUGH: Dana Spatz, Branch Chief

Environmental Risk Branch 3

Environmental Fate a nd Effects Division (7507P)

FROM: Katherine Stebbins, Biologist Rosanna Louie-Juzwiak, Risk Assessment Process Leader

Environmental Risk Branch 3

Environmental Fate and Effects Division (7507P)

This addendum addresses changes to the data needs identified in the preliminary problem formulation (USEPA, 2014b) and Preliminary Wo rk Plan (USEPA, 2014a) prepared in support of the Registration Review of fenamidone. Specifi cally, this document identifies additional data needs for fenamidone with respect to toxicity tests on honey bees ( Apis mellifera ).

Since the preliminary problem formulation was published, the Agency has issued guidance for assessing the potential risks of pesticides to bees and the data needed to support such assessments (USEPA et al. , 2014). The guidance document indicates that if exposure of bees to a pesticide is expected, a Tier I screening-level risk assessm ent is conducted. The Tier I

assessment is intended to be su fficiently conservative that chemicals that pass the screen are considered to represent a relatively low risk for pot ential adverse effects to bees. Tier I toxicitydata that are needed to complete screening-level risk assessments include a suite of laboratorybased studies of individual bees and include the following tests: acute contact toxicity data to adult honey bees (honey bees serving as a surrogate for all bee species), acute and chronic oral toxicity to adult honey bees, a nd acute and chronic oral toxici ty to honey bee larvae. If risk2 concerns are identified in the screening-level assessment, the assessment may be refined using data that further define exposure or through additional toxi city data from Tier II semi-field or

Tier III full-field studies c onducted with whole colonies.

Fenamidone uses include seed treatments, and foliar applications made by ground, chemigation, and aerial equipment to multiple agricultural crops, where residues in pollen and nectar can occur in both on the target field, as well as fr om spray drift that may land on blooming non-target plants. While fenamidone degrades somewhat rapi dly in the environment (to degradates that appear to be less toxic), fenamidone has partial systemic activity with some movement in the plant, so it is uncertain how persistent fena midone may remain within the plant. As such, residues may be present in pollen and nectar through transport from previous fenamidone applications. Residues can in turn be brought back to bee coloni es by adult forager bees where in-hive bees including young adult and developing brood ( i.e. , eggs, larvae and pupae) may be exposed. Therefore, exposure at all b ee life stages would be expected.

Since exposure of bees to fenamidone residues is expected, Tier I honey b ee laboratory toxicity data are needed to conduct the screening-level ri sk assessment. Acute contact and oral toxicity

data are available that indicat e fenamidone residues are practica lly non-toxic to adult honey bees on an acute contact and oral exposure basis. However, no data are available to evaluate fenamidone’s toxicity from the oral exposure route to larval bees on an ac ute or chronic basis or

to adult bees on a chronic basis.

Therefore, the Environmental Fate and Effects Division (EFED) recommends requesting Tier I laboratory toxicity data on the technical grade active ingredient (TGAI) for acute and chronic oral toxicity for larval honey b ees and for chronic oral toxicity for adult honey bees in order to complete the risk assessment for bees, as is further detailed in the attached data rationale tables. Should the screening level risk assessment identify that there are risk concerns to bees, more refined studies under semi-field or full-field conditions ( e.g. OCSPP guideline 850.3040) that reduce uncertainty by characterizing fenamidone’s effects at the whole-colony level may be

needed.

References

USEPA, 2014a. Fenamidone Preliminary Work Pla n. Registration Review: Initial Docket, Case

Number 7033. Pesticide Re-evaluation Divisi on, Office of Pesticide Programs, USEPA, Washington D.C. March 6, 2014.

USEPA, 2014b. Registration Review - Preliminar y Problem Formulation for the Ecological Risk Assessment and Drinking Water Exposure Assessment to be conducted for Fenamidone.

Environmental Fate and Effect s Division, Office of Pesticide Programs, USEPA, Washington D.C. February 6, 2014. DP Barcode 417865.

USEPA, PMRA, and CDPR, 2014. Guidance for A ssessing Pesticide Risks to Bees. Office of Pesticide Programs, USEPA, Washington D.C. Health Canada Pest Management Regulatory Agency, Ottawa, ON, Canada. California Departme nt of Pesticide Regula tion, Sacramento, CA. June 23, 2014.3 Guideline Number: Non-Guideline Study Title: Adult Honey Bee Chronic Oral Toxicity

Rationale for Requiring the Data

This study is needed to evaluate the potential eff ects of technical grade active ingredient (TGAI) on young adult honey bees from repeat exposure. Fenamidone u ses include seed treatments, and foliar applications made by ground, chemigation, and aerial equipmen t to multiple agricultural crops, where residues in pollen and nectar can occur in both on the target field, as well as from spray drift that may land on blooming non-target plants. While fenamidone degr ades somewhat rapidly in the environment (to degradates that appear to be less toxic), fenamidone h as partial systemic activity with some movement in the plant, so it is uncertain how persistent fenamidone may remain within the plant. As such, residues may be present in pollen and nectar either through tran sport from previous fenamidone applications. Residues can in turn be brought back to bee colonies by adult forager bees where in-hive bees including young adult and developing brood ( i.e. , eggs, larvae and pupae) may be exposed. Therefore, exposure at all bee life stages would be expected.

Since the preliminary Problem Formulation and Prelim inary Work Plan for fenamidone were signed, the Agency finalized its guidance for assessing the risk of pesticides to bees (USEPA et al. , 2014). EPA now requires this study for all use sites where potential exposure to pollinators may occur. Although EPA has not developed a guideline for this study and OECD has yet to finalize test guidance for chronic studies, efforts are currently underway to develop standa rdized guidelines for assessing effects from chronic (10- day) exposures to adult bees in the laboratory. Un til a guideline is finalized, a protocol should be submitted to the Agency for review before study initia tion. Fenamidone technical grade active ingredient (TGAI) should be used in this study.

Practical Utility of the Data

How will the data be used and how could the data impact the Agency’s future decision-making?

The 10-day toxicity study with young adult bees provides data that will be used in estimating chronic risk

to individual adult bees. Risk estimates based on these data will be considered along with other lines of evidence to determine whether higher-tier studi es are needed at the whole colony level.

These data are needed for risk asse ssments written in support of Registration Review as well as for future endangered species assessments. These data would allo w the Agency better characterize the potential for risk to insects (including beneficial pollinators) from the use of fenamidone and other imidazole-class chemicals. These data may help the Agency dete rmine whether any mitigation is needed. If the Registration Review and any future endangered sp ecies risk assessments are performed without these data, the Agency would have to assume that fe namidone "may affect" insects, including bees and beneficial pollinators, directly (and threatened or e ndangered species from other taxa indirectly), and uses of fenamidone might need to be restricted in areas where pollinators could be exposed.4 Guideline Number: Non-Guideline Study Title: Larval Honey Bee Acute and Chronic Oral Toxicity

Rationale for Requiring the Data

These studies are needed to evaluate the potential e ffects of technical grade active ingredient (TGAI) on honey bee larvae from repeat exposure. Fenamidone uses include seed treatments, and foliar applications made by ground, chemigation, and aerial equipmen t to multiple agricultural crops, where residues in pollen and nectar can occur in both on the target field, as well as from spray drift that may land on blooming non-target plants. While fenamidone degr ades somewhat rapidly in the environment (to degradates that appear to be less toxic), fenamidone h as partial systemic activity with some movement in the plant, so it is uncertain how persistent fenamidone may remain within the plant. As such, residues may be present in pollen and nectar either through tran sport from previous fenamidone applications. Residues can in turn be brought back to bee colonies by adult forager bees where in-hive bees including young adult and developing brood ( i.e. , eggs, larvae and pupae) may be exposed. Therefore, exposure at all bee life stages would be expected.

Since the preliminary Problem Formulation and Prelim inary Work Plan for fenamidone were signed, the Agency finalized its guidance for assessing the risk of pesticides to bees (USEPA et al. , 2014). EPA now requires these studies for all use sites where potentia l exposure to pollinators may occur. Although EPA has not developed a guideline for this study, the 21-da y larval toxicity study currently under development by OECD provides a draft guidance protocol for pote ntially assessing both the acute and chronic toxicity to developing brood (larvae and pupae) from repeat exposure to pesticides. Until a guideline is finalized, protocols should be submitted to the Agency for revi ew before study initiation. Registrants may choose to submit a separate acute (single dose) larval toxicity study following OECD TG 237 as well as the 21-day repeat dose chronic toxicity study. Fenamidone tec hnical grade active ingredient (TGAI) should be used in this study.

Practical Utility of the Data

How will the data be used and how could the data impact the Agency’s future decision-making?

The 21-day toxicity study provides data on the effects of technical grade active ingredient (TGAI) on developing bees from acute (short-term) and chr onic (longer term) exposure and will be used for estimating risk to individual (solitary) bees as well as bee colonies (social bees). Risk estimates based on these data will be considered along with other lines of evidence to determine whether higher-tier studies are needed at the whole colony level.

These data are needed for risk asse ssments written in support of Registration Review as well as for future endangered species assessments. These data would allo w the Agency better characterize the potential for risk to insects (including beneficial pollinators) from the use of fenamidone and other imidazole-class chemicals. These data may help the Agency dete rmine whether any mitigations are needed. If the Registration Review and any future endangered sp ecies risk assessments are performed without these data, the Agency would have to assume that fe namidone "may affect" insects, including bees and beneficial pollinators, directly (and threatened or e ndangered species from other taxa indirectly), and uses of fenamidone might need to be restricted in areas where pollinators could be exposed.