Electronic Communication for Docket EPA-HQ-OPP-2013-0411.

From: Smith, Charles 
Sent: Thursday, February 20, 2014 2:49 PM
To: Madden, Barbara; Kumar, Rita; Laws, Meredith
Cc: Perron, Monique; Tyler, Jennifer-R
Subject: Spirodiclofen

RD,

This email is to inform you of the progress regarding the spirodiclofen immunotoxicity and inhalation toxicity study requirements as referenced in the 2011 spirodiclofen risk assessment (J. Tyler; D386201; 11/11/11).

Since the completion of that assessment, HED has reviewed the immunotoxicity study (MRID 49072601) submitted by the registrants.  This study was classified as acceptable/guideline and satisfies the guideline requirement for an immunotoxicity study in rodents (M. Perron; TXR 0056898; 2/19/14).  No treatment related systemic or immunotoxicity related effects were seen at the highest dose tested (1,216 mg/kg/day).  As a result, the immunotoxicity study does not materially impact the results of the 2011 risk assessment.

On February 20, 2014 the Hazard and Science Policy Council (HASPOC) met to discuss the need for an inhalation study in rats to support the registered and future proposed uses of spirodiclofen.  The HASPOC, based on a WOE approach, concludes that a subchronic inhalation toxicity study is not required for spirodiclofen at this time.  This approach considered all of the available hazard and exposure information for spirodiclofen, including: (1) all relevant hazard and exposure information, including its low acute inhalation toxicity; (2) the lowest short- and intermediate-term MOEs calculated using an oral POD are 6,200 and 1,000, respectively; and (3) its physical/chemical properties, including its low volatility.  

Since both of the toxicity data requirements discussed in the 2011 risk assessment have been fulfilled, there are no longer any outstanding toxicity data requirements for spirodiclofen.

Thanks.

Charles (Billy) Smith
Branch Chief, Risk Assessment Branch 1
Health Effects Division/Office of Pesticide Programs
Environmental Protection Agency
703-305-0291


