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

WASHINGTON, D.C. 20460

PC Code: 103901 DP Barcode: 4 26367 Date: April 17 , 2015

MEMORANDUM

SUBJECT: Response to Public Comments on the EFED ’s Preliminary Risk Assessment on

the Registration Review of Sodium Bentazon

FROM: He Zhong, Ph.D., Biologist

Stephen Wente, Ph.D., Biologist Environmental Risk Branch 1 Environmental Fate and Effects Division ( 7507P)

THROUGH: Sujatha Sankula, Ph.D., Branch Chief

Environmental Risk Branch 1 Environmental Fate and Effects Division (7507P)

TO: Moana Appleyard, Chemical Review Manager

L inda Arrington, Branch Chief Risk Management and Implementation Branch V Pesticide Re

- Evaluation Division (7508P)

In response to the preliminary “ Registration Review Ecological Risk Assessment and Effects Determination for Sodium Bentazon ” (DP 417314), BASF provided informal comments after the public comment period

. Additionally, the North Dakota Department of Agriculture provided Bentazon water quality monitoring data. The Agency appreciates receiving these data and
comments. The purpose of t h e remainder of this memorandum is to address comments that are applicable to the ecological risk a ssessment and effects determination by Environmental Fate and Effects Division (EFED) for the herbicide sodium bentazon.

BASF Comments: Page 3, 3rd para graph : The following two sentences seem at odds

. "Bentazon is hydrolytically stable in pH 5, 7
, and 9 buffered solutions and is also stable in sandy loam soil and clay soil under anaerobic or aerobic conditions. Bentazon degrades (t 1/2 = 4

. 3 to 68 days) in aerobic mineral soils

. " As it reads the first sentence indicates bentazon is stable in so il and the next sentence indicates it is not stable in soil by citing short half

- lives

. The first sentence refers to the aerob i c and anaerob i c aquatic studies where soils from rice growing areas were flooded with2

wate r and i ncubated

. The second sentence refers to the aerob ic (unf looded) soil studies. Therefo r e, BASF suggests the first sentence i s changed as follows "

...... is also stable in fl ooded sandy loam and clay soil under anaerobic or aerobic conditions ." • Page 8
, top of page : T he following i s stated " Bentazon degradates were also not analyzed in any of the terrestrial f

i eld stud i es

. " Based on the titles for the TFD studies cited in Table 3

. 1 ( see table on page 13 and refs on pages 51

- 53 ), the metabol i te AIBA was in c l uded i n a ll except MRID 00044401

. • Page 72

, Appendix C
, bottom line i n Tab l e C

- 1 carrying over to next page : The structure for AIBA is corrupted and needs to be replaced

. • Page 73
, Appendix C
, bottom line in Table C

- 1 carrying over to next page : The structure for Photoproduct 12 is corrupted and needs to be replaced.

EFED Response : EFED agrees with these comments. However on page 72, the structure that appears to be corrupted is O

- nitro

- N

- isopropyl benzamide , rather than AIBA. The corrupted chemical structures from Appendix C are presented in Figure 1.

O

- nitro

- N

- isopropyl benzamide Photoproduct 12

Figure 1 .Chemical structures of Sodium Bentazon Degradates that were corrupted in the Registration Review Ecological Risk Assessment and Effects Determination for Sodium Bentazon

.

BASF Comment : • Page 8

, 2nd bullet from top of page: "The potential for endocrine disruptor

- related effects was observed in mammalian and avian reproduction toxicity studies using bentazon

. There is also a potential for endocr i ne disruptor

- related effects due to the toxicity of the degradates of bentazon." BASF disputes this statement , as there were no avian reproduction effects in either submitted study

, and no mention nor evidence of endocrine disruption effects in the HED
assessment " Sodium Bentazon

- Preliminary Human Health Risk Asses s ment for Registration Review

. " BASF respectfully requests that this bullet point be removed from the document.

EFED Response : The sentences are a recap from the previous risk assessment findings (pages 3 and 17 USEPA 2005, DP 314025). The Agency is unabl e to remove the previous conclusion without new evidence. Currently, bentazon is not subject to the endocrine screening part of the Agency’s Endocrine Disruptor Screening Program (EDSP)

.3

As the ecological risk assessment stated (USEPA 2014, DP 417314) “ Bentazon is not on the first or second li st chemicals for which EPA intends to issue test orders/data call

- ins in the near future. For further information on the status of the EDSP, the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit the website

, http://www.epa.gov/endo/ ”.

References

USEPA. 2005. Ecological Risk Assessment for the IR

- 4 Use of the Herbicide, Bentazon. DP Barco de 314025. 128pp

.
USEPA. 2014

. Registration Review Ecological Risk Assessment and Effects Determination for Sodium Bentazon. DP Barcode 417314. 140pp