1 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460 

PC Code: 121001 

DP Barcode: 427828 

July 23, 2015 

MEMORANDUM

Subject: EFED Response to Public Comments Regarding the Registration Review Problem 

Formulation for Sethoxydim: Docket ID# EPA-HQ-OPP-2015-0088. 

To: James Parker, Chemical Review Manager 

Neil Anderson, Branch Chief 

Risk Management and Implementation Branch 1 

Pesticide Re-evaluation Division (7508P) 

Office of Pesticide Programs 

From: Christina Wendel, Biologist 

Environmental Risk Branch II 

Environmental Fate and Effects Division (7507P) 

Office of Pesticide Programs 

Reviewed 

By: Melissa Panger, Ph.D., Senior Advisor 

Environmental Risk Branch II 

Environmental Fate and Effects Division (7507P) 

Office of Pesticide Programs 

Through: Elyssa Arnold, Risk Assessment Process Leader (RAPL) 

Brian Anderson, Branch Chief 

Environmental Risk Branch II 

Environmental Fate and Effects Division (7507P) 

Office of Pesticide Programs 

Attached please find the Environmental Fate and Effects Division (EFED)’s response to public 

comments on the problem formulation for Registration Review of Sethoxydim (Docket ID No.: 

EPA-HQ-OPP-2015-0088). Comments on EFED’s problem formulation were received from the 

BASF Corporation. The comments are provided below, along with EFED’s responses.

2015.07.23 13:47:04 

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Response to Public Comments Regarding the Problem Formulation for 

the Registration Review of Sethoxydim 

BASF Corporation 

Comment 1: “BASF disagrees with EPA’s finding that sethoxydim is “moderately toxic” to 

bees. This finding is based on a 1981 study performed at a single dose of 10 micrograms per bee. 

In footnote 8 to Table 7 of the Problem Formulation document, EFED correctly notes that the 

existing study (MRID 41510607) showed no mortality with the technical material, but does not 

mention that the same study showed only 5% mortality with the formulated product. Since this 

study does not conform to current guidelines, BASF intends to repeat the honeybee acute oral 

and contact study to support upcoming registration review, and plans to conduct adult and larval 

chronic studies as well.”

EFED Response: EFED thanks BASF for the comment, and EFED is looking forward to 

reviewing the new honeybee data when it is all submitted. EFED appreciates BASF pointing 

out the additional toxicity data regarding the formulated product. EFED appreciates that new 

data will be collected; however the current study classification of moderately toxic was based 

on the acute honey bee toxicity data available at the time the sethoxydim problem 

formulation was written. Based on the information provided in the currently available honey 

bee study, it is likely that sethoxydim will at most be moderately toxic to adult honeybees on 

an acute contact exposure basis; however until new data are submitted and reviewed, this 

remains an uncertainty. 

Comment 2: “At this time, there is no evidence to indicate that sethoxydim is “moderately 

toxic” to bees. Additionally, there is no evidence to support sethoxydim’s inclusion as an 

Acutely Toxic Pesticide in Appendix A of “EPA’s Proposal to Mitigate Exposure to Bees from 

Acutely Toxic Pesticide Products,” dated May 28, 2015 (Docket EPA-HQ-OPP-2014-0818-

0002). BASF requests that the EPA remove sethoxydim from this document.”

EFED Response: EFED thanks BASF for the comment. As discussed in the previous 

comment, due to the uncertainty associated with the available honeybee toxicity data, there is 

a potential for sethoxydim to be moderately toxic to honeybees. Therefore, until additional 

data becomes available to show otherwise, sethoxydim will likely remain on the list.