UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WAS HIN GTO N , D

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August 28, 2014 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

PC Codes: 019201, 019202

MEMORANDUM DP Barcode : 420783

SUBJECT:

FROM : EPA Response to Comments Related to the Preliminary Problem F ormulation for Ecological Risk and Environmental Fate, Endangered Species, and Drinking Water Assessments for MCPB and Its Salt

Hannah Yingling, Biologist

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THROUG H : Mah Shamim, Branch Chief, Ph.D. E nvironmental Risk Branch V E nvironmental Fate and E ffects Division (7507P)

TO: Khue Nguyen RM 51 Pesticide Re-Evaluation Division (7508P)

In response to the posting in the public docket of the "Registration Review :.. Preliminary Problem F ormulation for E cological Risk and E nvironmental Fate

, Endangered Species, and Drinking Water assessments for MCPB" (Document ID E PA-HQ-OPP-2014-0181 in www.regulations.gov)

, Center for Biological Diversity and MC P B T ask F orce provided
comments during the public comments period. The purpose of this memorandum is to address these comments. Listed below are the comments and E PA's responses.Section A. Common Comments from Center for Biological Diversity

1. Comment: EPA has an independent duty under the Endangered Species Act to c onsult with the U.S. Fish and Wildlife Service and National Marine Fisheries Service on the Reregistration of MCPB.

2. Comment: The EPA must make defensible “Not Likely to Adversely Affect” and “Likely to Adversely Affect” determinations as a prerequisite fo r defensible “Jeopardy” and “No Jeopardy” determinations.

3. Comment: EPA and the Services must assess the Adverse Impacts of MCPB in Critical Habitat.

4. Comment: EPA has an independent duty under the Endangered Species Act to consult with the U.S. Fish and Wildlife Service and National Marine Fisheries Service on the Approval of all MCPB end

- use products.

EFED Response: Regarding CBD’s request for EPA to begin informal consultation with the Services immedia tely after the workplan for MCPB is finalized, EPA plans to follow the March 2013 stakeholder engagement paper (“Enhancing Stakeholder Input in the Pesticide Registration Review and ESA Consultation Processes and Development of Economically and Technologically Feasible Reasonable and Prudent Alternatives” ) to identify the appropriate time for initiation of consultation, either formal or informal, with the Services. The stakeholder engagement paper, jointly developed by the EPA, USDA, and the Services and available at http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPP

- 2012

- 0442

- 0038 , allows for early interaction with the Services under informal consultation. EPA and the Services acknowledge that early interac tion as part of informal consultation may result in refinements to EPA’s effects determinations that can improve the efficiency of the ESA compliance
process. For example, EPA may involve the Services at the earliest stages of registration review. In gen eral, EPA plans to initiate formal ESA consultation, if necessary, at the final decision stage in the registration review process. Consulting later in the process allows the EPA to develop more refined ecological risk assessments and to engage stakeholder s in discussions that should result in more focused consultation packages that may include risk mitigation for listed species.

Section B. Common Comments from MCPB Task Force

1. Comment: MCPB Task Force indicated that they will likely accept ass umed stability for soil photolysis and anaerobic aquatic metabolism

.
EFED Response: Since the submitted soil photolysis study (MRID 43829901) was determined unacceptable and no anaerobic aquatic study has been submitted , in order to fully assess the fate of MCPB and its degradates in the environment, the registrant must submit soil photolysis and anaerobic aquatic metabolism studies.2. Comment: For modeling purposes, MCPB Task Force recommended to use four half

lives from four soils in two aerobic soil met abolism studies (MRIDs 43247601 and 47787801).

EFED Response: The Agency agrees with this approach.

3. Comment: MCPB Task Force pointed out that a “

- OH” group is missing in the chemical structure for a degradate (4

- (4

- hydroxy

- 0tolyloxy)butyric acid.

EFE D Response: The Agency will make the correction.

4. Comment: MCPB Task Force pointed out a typographical error on the release date of PRZM 3.12.2

EFED Response: The Agency acknowledges this typographic error. The correct release date of PRZM 3.12.2 is May 12, 2005.

5

. Comment: MCPB Task Force claimed that the formulations for two labels (71368

- 5 and 15440

- 38) are all SC liquids, not EC.

EFED Response: Th ese two labels did not specify the type of formulations. The registrant must add the claimed fo rmulations on these two labels.

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. Comment: MCPB Task Force recommended that the request for dioxins/furans impurity data for MCPB be included in the executive summary and subsequent DCI. The Task Force indicated that previous dioxins/furans studies have focused on the technical active ingredients because formulations are prepared under mild conditions that are not expected to generate dioxins/furans.

EFED Response: EFED noticed an impurity study that was submitted to PMRA and asked the registrant to su bmit th e same study to OPP. In response, t he registrant submitted this study in an informal way. Since th is study used much lower LOQs than those in the currently available impurity studies in analyzing 17 dioxin and furan congeners in technical MCPB, EF ED has determined that this study contains sufficient information to assess the impact of dioxin and furan congeners in the environment. Therefore, the registrant only needs to submit this study formally to OPP. No additional data are needed.

“ Schoisswo hl, D. (2011) Analysis for Tetra

- to Octa

- Chlorinated Dioxins and Furans in Seven Batches of Technical MCPA. Study Number: NUFARM/0711b. Unpublished study prepared by synlab Umweltinstitut Synlab GmbH. ”

Though the MCPB Task Force did not submit comments in pollinator requirements, EFED would like to acknowledge a recent update in the policy on pollinator protection (Guidance for Assessing Pesticide Risks to Bees, 06.23.2014; signed by Donald Brady, Director, EFED 1 ). In

1order to better address potential r isks to bees that are likely to be exposed to pesticides, the

following studies will be requested: :

 Acute oral toxicity to adult honey bees

 Acute oral toxicity to larval honey bees

 Chronic oral toxicity to adult honey bees

 Chronic oral toxicity to lar val honey bees

The Guidance also states that the need for higher tier studies will be determined based on the results of the Tier 1 studies listed above and risk management considerations including potential mitigation options.

Although the adult chroni c oral toxicity study was not specified in the PF, this additional study should be conducted for the MCPB risk assessment. While the PF did indicate that an acute larval toxicity study (following OECD TG237) would be necessary, the release of the new guid ance also requires a multiple

- dose (chronic) larval toxicity study be submitted. The OECD has a draft guideline for this study that may be utilized. It may be possible to conduct the repeat

dose study in such a way as to derive both an LD 50 (acute endpoi nt of interest) and a NOAEC (chronic endpoint of interest) from a single study , thereby negating the need for separate acute and chronic larval toxicity studies

. Furthermore, t he Agency would be receptive to a rationale for bridging bee toxicity data betw een MCPA and MCPB.

http://www.epa.gov/pesticides/science/efed/policy_guidance/team_authors/te rrestrial_biology_tech_team/Guidance AssessingPesticideRisk2Bees.pdf